diff --git a/.ci/bwcVersions b/.ci/bwcVersions
index 6b86da2c91261..6a5db93053e3b 100644
--- a/.ci/bwcVersions
+++ b/.ci/bwcVersions
@@ -23,4 +23,8 @@ BWC_VERSION:
   - "2.9.0"
   - "2.9.1"
   - "2.10.0"
+  - "2.10.1"
   - "2.11.0"
+  - "2.11.1"
+  - "2.11.2"
+  - "2.12.0"
diff --git a/.gitattributes b/.gitattributes
index 65f909981595f..b74462afb27bd 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,4 +1,5 @@
 * text eol=lf
+*.jar binary
 *.bat binary
 *.zip binary
 *.exe binary
diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
index 4fa118e8486f1..68d02d5f7d544 100644
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -1 +1,27 @@
-*   @reta @anasalkouz @andrross @Bukhtawar @CEHENKLE @dblock @gbbafna @setiah @kartg @kotwanikunal @mch2 @nknize @owaiskazi19 @peternied @Rishikesh1159 @ryanbogan @saratvemulapalli @shwetathareja @dreamer-89 @tlfeng @VachaShah @dbwiddis @sachinpkale @sohami @msfroh
+# CODEOWNERS manages notifications, not PR approvals
+# For PR approvals see /.github/workflows/maintainer-approval.yml 
+
+# Files have a single rule applied, the last match decides the owner
+# If you would like to more specifically apply ownership, include existing owner in new sub fields
+
+# To verify changes of CODEOWNERS file
+# In VSCode
+#   1. Install extension https://marketplace.visualstudio.com/items?itemName=jasonnutter.vscode-codeowners
+#   2. Go to a file
+#   3. Use the command palette to run the CODEOWNERS: Show owners of current file command, which will display all code owners for the current file.
+
+# Default ownership for all repo files
+* @abbashus @adnapibar @anasalkouz @andrross @Bukhtawar @CEHENKLE @dblock @dbwiddis @dreamer-89 @gbbafna @kartg @kotwanikunal @mch2 @msfroh @nknize @owaiskazi19 @reta @Rishikesh1159 @ryanbogan @sachinpkale @saratvemulapalli @setiah @shwetathareja @sohami @tlfeng @VachaShah
+
+/modules/transport-netty4/ @peternied
+
+/plugins/identity-shiro/ @peternied
+
+/server/src/main/java/org/opensearch/extensions/ @peternied
+/server/src/main/java/org/opensearch/identity/ @peternied
+/server/src/main/java/org/opensearch/threadpool/ @peternied
+/server/src/main/java/org/opensearch/transport/ @peternied
+
+/.github/ @peternied
+
+/MAINTAINERS.md @abbashus @adnapibar @anasalkouz @andrross @Bukhtawar @CEHENKLE @dblock @dbwiddis @dreamer-89 @gbbafna @kartg @kotwanikunal @mch2 @msfroh @nknize @owaiskazi19 @peternied @reta @Rishikesh1159 @ryanbogan @sachinpkale @saratvemulapalli @setiah @shwetathareja @sohami @tlfeng @VachaShah
diff --git a/.github/ISSUE_TEMPLATE/bug_template.md b/.github/ISSUE_TEMPLATE/bug_template.md
deleted file mode 100644
index be3ae51b237ee..0000000000000
--- a/.github/ISSUE_TEMPLATE/bug_template.md
+++ /dev/null
@@ -1,33 +0,0 @@
----
-name: 🐛 Bug report
-about: Create a report to help us improve
-title: "[BUG]"
-labels: 'bug, untriaged'
-assignees: ''
----
-
-**Describe the bug**
-A clear and concise description of what the bug is.
-
-**To Reproduce**
-Steps to reproduce the behavior:
-1. Go to '...'
-2. Click on '....'
-3. Scroll down to '....'
-4. See error
-
-**Expected behavior**
-A clear and concise description of what you expected to happen.
-
-**Plugins**
-Please list all plugins currently enabled.
-
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
-
-**Host/Environment (please complete the following information):**
- - OS: [e.g. iOS]
- - Version [e.g. 22]
-
-**Additional context**
-Add any other context about the problem here.
diff --git a/.github/ISSUE_TEMPLATE/bug_template.yml b/.github/ISSUE_TEMPLATE/bug_template.yml
new file mode 100644
index 0000000000000..2cd1ee8a7e688
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/bug_template.yml
@@ -0,0 +1,79 @@
+name: 🐛 Bug report
+description: Create a report to help us improve
+title: "[BUG] <title>"
+labels: ['bug, untriaged']
+body:
+  - type: textarea
+    attributes:
+      label: Describe the bug
+      description: A clear and concise description of what the bug is.
+    validations:
+      required: true
+  - type: dropdown
+    attributes:
+      label: Related component
+      description: Choose a specific OpenSearch component your bug belongs to.  If you are unsure which to select or if the component is not present, select "Other".
+      multiple: false
+      options:
+        - Other
+        - Build
+        - Clients
+        - Cluster Manager
+        - Extensions
+        - Indexing:Performance
+        - Indexing:Replication
+        - Indexing
+        - Libraries
+        - Plugins
+        - Search:Aggregations
+        - Search:Performance
+        - Search:Query Capabilities
+        - Search:Query Insights
+        - Search:Relevance
+        - Search:Remote Search
+        - Search:Resiliency
+        - Search:Searchable Snapshots
+        - Search
+        - Storage:Durability
+        - Storage:Performance
+        - Storage:Remote
+        - Storage:Snapshots
+        - Storage
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: To Reproduce
+      description: Steps to reproduce the behavior.
+      value: |
+        1. Go to '...'
+        2. Click on '....'
+        3. Scroll down to '....'
+        4. See error
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Expected behavior
+      description: A clear and concise description of what you expected to happen.
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Additional Details
+      description: Add any other context about the problem here.
+      value: |
+        **Plugins**
+        Please list all plugins currently enabled.
+
+        **Screenshots**
+        If applicable, add screenshots to help explain your problem.
+
+        **Host/Environment (please complete the following information):**
+         - OS: [e.g. iOS]
+         - Version [e.g. 22]
+
+        **Additional context**
+        Add any other context about the problem here.
+    validations:
+      required: false
diff --git a/.github/ISSUE_TEMPLATE/feature_request.md b/.github/ISSUE_TEMPLATE/feature_request.md
deleted file mode 100644
index 53b3614a34342..0000000000000
--- a/.github/ISSUE_TEMPLATE/feature_request.md
+++ /dev/null
@@ -1,19 +0,0 @@
----
-name: 🎆 Feature request
-about: Suggest an idea for this project
-title: ''
-labels: 'enhancement, untriaged'
-assignees: ''
----
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.
diff --git a/.github/ISSUE_TEMPLATE/feature_request.yml b/.github/ISSUE_TEMPLATE/feature_request.yml
new file mode 100644
index 0000000000000..d93ac8b590706
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/feature_request.yml
@@ -0,0 +1,62 @@
+name: 🎆 Feature request
+description: Suggest an idea for this project
+title: '[Feature Request] <title>'
+labels: ['enhancement, untriaged']
+body:
+  - type: textarea
+    attributes:
+      label: Is your feature request related to a problem? Please describe
+      description: A clear and concise description of what the problem is.
+      placeholder: Ex. I'm always frustrated when [...]
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Describe the solution you'd like
+      description: A clear and concise description of what you want to happen.
+    validations:
+      required: true
+  - type: dropdown
+    attributes:
+      label: Related component
+      description: Choose a specific OpenSearch component your feature request belongs to.  If you are unsure of which component to select or if the component is not present, select "Other".
+      multiple: false
+      options:
+        - Other
+        - Build
+        - Clients
+        - Cluster Manager
+        - Extensions
+        - Indexing:Performance
+        - Indexing:Replication
+        - Indexing
+        - Libraries
+        - Plugins
+        - Search:Aggregations
+        - Search:Performance
+        - Search:Query Capabilities
+        - Search:Query Insights
+        - Search:Relevance
+        - Search:Remote Search
+        - Search:Resiliency
+        - Search:Searchable Snapshots
+        - Search
+        - Storage:Durability
+        - Storage:Performance
+        - Storage:Remote
+        - Storage:Snapshots
+        - Storage
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Describe alternatives you've considered
+      description: A clear and concise description of any alternative solutions or features you've considered.
+    validations:
+      required: false
+  - type: textarea
+    attributes:
+      label: Additional context
+      description: Add any other context or screenshots about the feature request here.
+    validations:
+      required: false
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 0defcaf727771..8c4f4d59ea1fc 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -711,6 +711,14 @@ updates:
     labels:
       - "dependabot"
       - "dependencies"
+  - directory: /modules/crypto/
+    open-pull-requests-limit: 1
+    package-ecosystem: gradle
+    schedule:
+      interval: weekly
+    labels:
+      - "dependabot"
+      - "dependencies"
   - directory: /plugins/
     open-pull-requests-limit: 1
     package-ecosystem: gradle
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
index 69616e533d1ed..908a032bf833e 100644
--- a/.github/pull_request_template.md
+++ b/.github/pull_request_template.md
@@ -17,8 +17,10 @@ Resolves #[Issue number to be closed when this PR is merged]
   - [ ] All tests pass
 - [ ] New functionality has been documented.
   - [ ] New functionality has javadoc added
+- [ ] Failing checks are inspected and point to the corresponding known issue(s) (See: [Troubleshooting Failing Builds](../blob/main/CONTRIBUTING.md#troubleshooting-failing-builds))
 - [ ] Commits are signed per the DCO using --signoff
 - [ ] Commit changes are listed out in CHANGELOG.md file (See: [Changelog](../blob/main/CONTRIBUTING.md#changelog))
+- [ ] Public documentation issue/PR [created](https://github.com/opensearch-project/documentation-website/issues/new/choose)
 
 By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
 For more information on following Developer Certificate of Origin and signing off your commits, please check [here](https://github.com/opensearch-project/OpenSearch/blob/main/CONTRIBUTING.md#developer-certificate-of-origin).
diff --git a/.github/workflows/add-untriaged.yml b/.github/workflows/add-untriaged.yml
deleted file mode 100644
index 11db8b9a61f50..0000000000000
--- a/.github/workflows/add-untriaged.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-name: Apply 'untriaged' label during issue lifecycle
-
-on:
-  issues:
-    types: [opened, reopened, transferred]
-
-jobs:
-  apply-label:
-    if: github.repository == 'opensearch-project/OpenSearch'
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/github-script@v6
-        with:
-          script: |
-            github.rest.issues.addLabels({
-              issue_number: context.issue.number,
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              labels: ['untriaged']
-            })
diff --git a/.github/workflows/assemble.yml b/.github/workflows/assemble.yml
new file mode 100644
index 0000000000000..382105364c048
--- /dev/null
+++ b/.github/workflows/assemble.yml
@@ -0,0 +1,27 @@
+name: Gradle Assemble
+on: [pull_request]
+
+jobs:
+  assemble:
+    if: github.repository == 'opensearch-project/OpenSearch'
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        java: [ 11, 17, 21 ]
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up JDK ${{ matrix.java }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: temurin
+      - name: Setup docker (missing on MacOS)
+        if: runner.os == 'macos'
+        run: |
+          brew install docker
+          colima start
+          sudo ln -sf $HOME/.colima/default/docker.sock /var/run/docker.sock
+      - name: Run Gradle (assemble)
+        run: |
+          ./gradlew assemble --parallel --no-build-cache -PDISABLE_BUILD_CACHE
diff --git a/.github/workflows/auto-release.yml b/.github/workflows/auto-release.yml
index ae41ae00d018d..252cbda1392f8 100644
--- a/.github/workflows/auto-release.yml
+++ b/.github/workflows/auto-release.yml
@@ -14,7 +14,7 @@ jobs:
     steps:
       - name: GitHub App token
         id: github_app_token
-        uses: tibdex/github-app-token@v1.5.0
+        uses: tibdex/github-app-token@v2.1.0
         with:
           app_id: ${{ secrets.APP_ID }}
           private_key: ${{ secrets.APP_PRIVATE_KEY }}
diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
index 607c6de58b7f6..2a95177174e9b 100644
--- a/.github/workflows/backport.yml
+++ b/.github/workflows/backport.yml
@@ -26,7 +26,7 @@ jobs:
     steps:
       - name: GitHub App token
         id: github_app_token
-        uses: tibdex/github-app-token@v1.5.0
+        uses: tibdex/github-app-token@v2.1.0
         with:
           app_id: ${{ secrets.APP_ID }}
           private_key: ${{ secrets.APP_PRIVATE_KEY }}
diff --git a/.github/workflows/check-compatibility.yml b/.github/workflows/check-compatibility.yml
index d93f7e73b91e7..d6c65ddd446cd 100644
--- a/.github/workflows/check-compatibility.yml
+++ b/.github/workflows/check-compatibility.yml
@@ -36,7 +36,7 @@ jobs:
           echo "### Compatible components"   >> "${{ github.workspace }}/results.txt" && grep -e 'Compatible component'   $HOME/gradlew-check.out | sed -e 's/Compatible component: \[\(.*\)\]/- \1/'   >> "${{ github.workspace }}/results.txt"
 
       - name: Upload results
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: results.txt
           path: ${{ github.workspace }}/results.txt
@@ -48,7 +48,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Download results
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: results.txt
 
diff --git a/.github/workflows/copy-linked-issue-labels.yml b/.github/workflows/copy-linked-issue-labels.yml
new file mode 100644
index 0000000000000..33b5e92dc10da
--- /dev/null
+++ b/.github/workflows/copy-linked-issue-labels.yml
@@ -0,0 +1,21 @@
+name: Copy labels from linked issues
+on:
+  pull_request_target:
+    types: [opened, edited, review_requested, synchronize, reopened, ready_for_review]
+
+jobs:
+  copy-issue-labels:
+    if: github.repository == 'opensearch-project/OpenSearch'
+    runs-on: ubuntu-latest
+    permissions:
+      issues: read
+      contents: read
+      pull-requests: write
+    steps:
+      - name: copy-issue-labels
+        uses: michalvankodev/copy-issue-labels@v1.3.0
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          labels-to-exclude: |
+            untriaged
+            triaged
diff --git a/.github/workflows/create-documentation-issue.yml b/.github/workflows/create-documentation-issue.yml
index 373eeb3569a51..df63847f8afca 100644
--- a/.github/workflows/create-documentation-issue.yml
+++ b/.github/workflows/create-documentation-issue.yml
@@ -14,7 +14,7 @@ jobs:
     steps:
       - name: GitHub App token
         id: github_app_token
-        uses: tibdex/github-app-token@v1.5.0
+        uses: tibdex/github-app-token@v2.1.0
         with:
           app_id: ${{ secrets.APP_ID }}
           private_key: ${{ secrets.APP_PRIVATE_KEY }}
diff --git a/.github/workflows/dependabot_pr.yml b/.github/workflows/dependabot_pr.yml
index f03a3d125067d..e6feb3b852ad0 100644
--- a/.github/workflows/dependabot_pr.yml
+++ b/.github/workflows/dependabot_pr.yml
@@ -11,7 +11,7 @@ jobs:
     steps:
       - name: GitHub App token
         id: github_app_token
-        uses: tibdex/github-app-token@v1.5.0
+        uses: tibdex/github-app-token@v2.1.0
         with:
           app_id: ${{ secrets.APP_ID }}
           private_key: ${{ secrets.APP_PRIVATE_KEY }}
@@ -27,7 +27,7 @@ jobs:
           ./gradlew updateSHAs
 
       - name: Commit the changes
-        uses: stefanzweifel/git-auto-commit-action@v4.7.2
+        uses: stefanzweifel/git-auto-commit-action@v5
         with:
           commit_message: Updating SHAs
           branch: ${{ github.head_ref }}
@@ -40,7 +40,7 @@ jobs:
           ./gradlew spotlessApply
 
       - name: Commit the changes
-        uses: stefanzweifel/git-auto-commit-action@v4.7.2
+        uses: stefanzweifel/git-auto-commit-action@v5
         with:
           commit_message: Spotless formatting
           branch: ${{ github.head_ref }}
@@ -54,7 +54,7 @@ jobs:
           version: 'Unreleased 2.x'
 
       - name: Commit the changes
-        uses: stefanzweifel/git-auto-commit-action@v4
+        uses: stefanzweifel/git-auto-commit-action@v5
         with:
           commit_message: "Update changelog"
           branch: ${{ github.head_ref }}
diff --git a/.github/workflows/gradle-check.yml b/.github/workflows/gradle-check.yml
index bda3bbbc1f125..8c33d41c6b2b4 100644
--- a/.github/workflows/gradle-check.yml
+++ b/.github/workflows/gradle-check.yml
@@ -72,7 +72,7 @@ jobs:
 
       - name: Upload Coverage Report
         if: success()
-        uses: codecov/codecov-action@v2
+        uses: codecov/codecov-action@v3
         with:
           files: ./codeCoverage.xml
 
@@ -82,10 +82,7 @@ jobs:
         with:
           issue-number: ${{ env.pr_number }}
           body: |
-            ### Gradle Check (Jenkins) Run Completed with:
-            * **RESULT:** ${{ env.result }} :white_check_mark:
-            * **URL:** ${{ env.workflow_url }}
-            * **CommitID:** ${{ env.pr_from_sha }}
+            :white_check_mark: Gradle check result for ${{ env.pr_from_sha }}: [${{ env.result }}](${{ env.workflow_url }})
 
       - name: Extract Test Failure
         if: ${{ github.event_name == 'pull_request_target' && env.result != 'SUCCESS' }}
@@ -108,10 +105,8 @@ jobs:
         with:
           issue-number: ${{ env.pr_number }}
           body: |
-            ### Gradle Check (Jenkins) Run Completed with:
-            * **RESULT:** ${{ env.result }} :grey_exclamation: ${{ env.test_failures }}
-            * **URL:** ${{ env.workflow_url }}
-            * **CommitID:** ${{ env.pr_from_sha }}
+            :grey_exclamation: Gradle check result for ${{ env.pr_from_sha }}: [${{ env.result }}](${{ env.workflow_url }}) ${{ env.test_failures }}
+
             Please review all [flaky tests](https://github.com/opensearch-project/OpenSearch/blob/main/DEVELOPER_GUIDE.md#flaky-tests) that succeeded after retry and create an issue if one does not already exist to track the flaky failure.
 
       - name: Create Comment Failure
@@ -120,12 +115,9 @@ jobs:
         with:
           issue-number: ${{ env.pr_number }}
           body: |
-            ### Gradle Check (Jenkins) Run Completed with:
-            * **RESULT:** ${{ env.result }} :x: ${{ env.test_failures }}
-            * **URL:** ${{ env.workflow_url }}
-            * **CommitID:** ${{ env.pr_from_sha }}
-            Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green.
-            Is the failure [a flaky test](https://github.com/opensearch-project/OpenSearch/blob/main/DEVELOPER_GUIDE.md#flaky-tests) unrelated to your change?
+            :x: Gradle check result for ${{ env.pr_from_sha }}: [${{ env.result }}](${{ env.workflow_url }})
+
+            Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure [a flaky test](https://github.com/opensearch-project/OpenSearch/blob/main/DEVELOPER_GUIDE.md#flaky-tests) unrelated to your change?
 
       - name: Create Issue On Push Failure
         if: ${{ github.event_name == 'push' && failure() }}
diff --git a/.github/workflows/lucene-snapshots.yml b/.github/workflows/lucene-snapshots.yml
index c2a2cedaaefb4..05ca93e7be2aa 100644
--- a/.github/workflows/lucene-snapshots.yml
+++ b/.github/workflows/lucene-snapshots.yml
@@ -7,7 +7,8 @@ on:
     # Inputs the workflow accepts.
     inputs:
       ref:
-        description:
+        description: 'Lucene ref in github.com/apache/lucene'
+        type: string
         required: false
         default: 'main'
 
@@ -21,40 +22,60 @@ jobs:
       contents: read
 
     steps:
-      - uses: actions/checkout@v4
-      - name: Set up JDK 17
-        uses: actions/setup-java@v3
-        with:
-          java-version: '17'
-          distribution: 'adopt'
-
-      - name: Checkout Lucene
+      - name: Checkout Lucene ref:${{ github.event.inputs.ref }}
         uses: actions/checkout@v4
         with:
           repository: 'apache/lucene'
-          path: lucene
           ref: ${{ github.event.inputs.ref }}
 
-      - name: Set hash
-        working-directory: ./lucene
+      - name: Get Java Min Version and Lucene Revision from Lucene Repository
         run: |
-          echo "::set-output name=REVISION::$(git rev-parse --short HEAD)"
-        id: version
+          java_version=`cat build.gradle | grep minJavaVersion | head -1 | grep -Eo '_[0-9]+$' | tr -d '_'`
+          echo "JAVA_VERSION=$java_version" >> $GITHUB_ENV
+          echo "REVISION=$(git rev-parse --short HEAD)" >> $GITHUB_ENV
+
+      - name: Setup JDK ${{ env.JAVA_VERSION }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ env.JAVA_VERSION }}
+          distribution: 'temurin'
 
       - name: Initialize gradle settings
-        working-directory: ./lucene
         run: ./gradlew localSettings
 
       - name: Publish Lucene to local maven repo.
-        working-directory: ./lucene
-        run: ./gradlew publishJarsPublicationToMavenLocal -Pversion.suffix=snapshot-${{ steps.version.outputs.REVISION }}
+        run: ./gradlew publishJarsPublicationToMavenLocal -Pversion.suffix=snapshot-${{ env.REVISION }}
+
+      - name: Configure AWS credentials
+        uses: aws-actions/configure-aws-credentials@v4
+        with:
+          role-to-assume: ${{ secrets.LUCENE_SNAPSHOTS_SECRET_ROLE }}
+          aws-region: us-east-1
+
+      - name: Get S3 Bucket
+        id: get_s3_bucket
+        run: |
+          lucene_snapshots_bucket=`aws secretsmanager get-secret-value --secret-id jenkins-artifact-bucket-name --query SecretString --output text`
+          echo "::add-mask::$lucene_snapshots_bucket"
+          echo "LUCENE_SNAPSHOTS_BUCKET=$lucene_snapshots_bucket" >> $GITHUB_OUTPUT
+
+      - name: Configure AWS credentials
+        uses: aws-actions/configure-aws-credentials@v4
+        with:
+          role-to-assume: ${{ secrets.LUCENE_SNAPSHOTS_S3_ROLE }}
+          aws-region: us-east-1
+
+      - name: Copy files to S3 with the aws CLI (New)
+        run: |
+          aws s3 cp ~/.m2/repository/org/apache/lucene/ s3://${{ steps.get_s3_bucket.outputs.LUCENE_SNAPSHOTS_BUCKET }}/snapshots/lucene/org/apache/lucene/  --recursive --no-progress
 
       - name: Configure AWS credentials
-        uses: aws-actions/configure-aws-credentials@v2
+        uses: aws-actions/configure-aws-credentials@v4
         with:
           role-to-assume: ${{ secrets.LUCENE_SNAPSHOTS_ROLE }}
           aws-region: us-west-2
 
-      - name: Copy files to S3 with the aws CLI.
+        # We will remove this step once all the lucene snapshots old links are updated with the new one
+      - name: Copy files to S3 with the aws CLI (Old)
         run: |
           aws s3 cp ~/.m2/repository/org/apache/lucene/ s3://${{ secrets.LUCENE_SNAPSHOTS_BUCKET }}/snapshots/lucene/org/apache/lucene/  --recursive --no-progress
diff --git a/.github/workflows/maintainer-approval.yml b/.github/workflows/maintainer-approval.yml
new file mode 100644
index 0000000000000..2f87afd372d90
--- /dev/null
+++ b/.github/workflows/maintainer-approval.yml
@@ -0,0 +1,33 @@
+name: Maintainers approval
+
+on:
+  pull_request_review:
+    types: [submitted]
+
+jobs:
+  maintainer-approved-check:
+    name: Minimum approval count
+    runs-on: ubuntu-latest
+    steps:
+      - id: find-maintainers
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          result-encoding: string
+          script: |
+            // Get the collaborators - filtered to maintainer permissions
+            const maintainersResponse = await github.request('GET /repos/{owner}/{repo}/collaborators', {
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                permission: 'maintain',
+                affiliation: 'all',
+                per_page: 100
+            });
+
+            return maintainersResponse.data.map(item => item.login).join(', ');
+
+      - uses: peternied/required-approval@v1.2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          min-required: 1
+          required-approvers-list: ${{ steps.find-maintainers.outputs.result }}
diff --git a/.github/workflows/precommit.yml b/.github/workflows/precommit.yml
index f562b46d5b124..800aacec98516 100644
--- a/.github/workflows/precommit.yml
+++ b/.github/workflows/precommit.yml
@@ -1,4 +1,4 @@
-name: Gradle Precommit and Asssemble
+name: Gradle Precommit
 on: [pull_request]
 
 jobs:
@@ -7,28 +7,16 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
+        java: [ 11, 17, 21 ]
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 11
-        uses: actions/setup-java@v3
+      - name: Set up JDK ${{ matrix.java }}
+        uses: actions/setup-java@v4
         with:
-          java-version: 11
+          java-version: ${{ matrix.java }}
           distribution: temurin
           cache: gradle
       - name: Run Gradle (precommit)
         run: |
           ./gradlew javadoc precommit --parallel
-      - name: Setup docker (missing on MacOS)
-        if: runner.os == 'macos'
-        run: |
-          # Workaround for https://github.com/actions/runner-images/issues/8104
-          brew remove --ignore-dependencies qemu
-          curl -o ./qemu.rb https://raw.githubusercontent.com/Homebrew/homebrew-core/f88e30b3a23ef3735580f9b05535ce5a0a03c9e3/Formula/qemu.rb
-          brew install ./qemu.rb
-          brew install docker
-          colima start
-          sudo ln -sf $HOME/.colima/default/docker.sock /var/run/docker.sock
-      - name: Run Gradle (assemble)
-        run: |
-          ./gradlew assemble --parallel
diff --git a/.github/workflows/publish-maven-snapshots.yml b/.github/workflows/publish-maven-snapshots.yml
index 8c08df269a999..1b2db22c7c20b 100644
--- a/.github/workflows/publish-maven-snapshots.yml
+++ b/.github/workflows/publish-maven-snapshots.yml
@@ -20,13 +20,13 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Set up JDK 17
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           distribution: adopt
           java-version: 17
 
       - name: Configure AWS credentials
-        uses: aws-actions/configure-aws-credentials@v2
+        uses: aws-actions/configure-aws-credentials@v4
         with:
           role-to-assume: ${{ secrets.PUBLISH_SNAPSHOTS_ROLE }}
           aws-region: us-east-1
diff --git a/.github/workflows/pull-request-checks.yml b/.github/workflows/pull-request-checks.yml
new file mode 100644
index 0000000000000..11998e36c2dbb
--- /dev/null
+++ b/.github/workflows/pull-request-checks.yml
@@ -0,0 +1,28 @@
+name: Pull Request Checks
+
+on:
+  pull_request:
+    types:
+      [
+        opened,
+        edited,
+        review_requested,
+        synchronize,
+        reopened,
+        ready_for_review,
+      ]
+
+jobs:
+  verify-description-checklist:
+    name: Verify Description Checklist
+    runs-on: ubuntu-latest
+    steps:
+      - uses: peternied/check-pull-request-description-checklist@v1
+        with:
+          checklist-items: |
+            New functionality includes testing.
+            All tests pass
+            New functionality has been documented.
+            New functionality has javadoc added
+            Commits are signed per the DCO using --signoff
+            Commit changes are listed out in CHANGELOG.md file (See: [Changelog](../blob/main/CONTRIBUTING.md#changelog))
diff --git a/.github/workflows/stalled.yml b/.github/workflows/stalled.yml
index bc0a98fff511e..d171332b402f1 100644
--- a/.github/workflows/stalled.yml
+++ b/.github/workflows/stalled.yml
@@ -1,4 +1,4 @@
-name: Close Stalled PRs
+name: Label Stalled PRs
 on:
   schedule:
     - cron: '15 15 * * *' # Run every day at 15:15 UTC / 7:15 PST / 8:15 PDT
@@ -11,19 +11,18 @@ jobs:
     steps:
       - name: GitHub App token
         id: github_app_token
-        uses: tibdex/github-app-token@v1.5.0
+        uses: tibdex/github-app-token@v2.1.0
         with:
           app_id: ${{ secrets.APP_ID }}
           private_key: ${{ secrets.APP_PRIVATE_KEY }}
           installation_id: 22958780
       - name: Stale PRs
-        uses: actions/stale@v8
+        uses: actions/stale@v9
         with:
           repo-token: ${{ steps.github_app_token.outputs.token }}
           stale-pr-label: 'stalled'
-          stale-pr-message: 'This PR is stalled because it has been open for 30 days with no activity. Remove stalled label or comment or this will be closed in 7 days.'
-          close-pr-message: 'This PR was closed because it has been stalled for 7 days with no activity.'
+          stale-pr-message: 'This PR is stalled because it has been open for 30 days with no activity.'
           days-before-pr-stale: 30
-          days-before-pr-close: 7
           days-before-issue-stale: -1
+          days-before-pr-close: -1
           days-before-issue-close: -1
diff --git a/.github/workflows/triage.yml b/.github/workflows/triage.yml
new file mode 100644
index 0000000000000..c305818bdb0a9
--- /dev/null
+++ b/.github/workflows/triage.yml
@@ -0,0 +1,34 @@
+name: Auto triage based on the component label in issue
+
+on:
+  issues:
+    types: [opened, reopened, transferred]
+
+jobs:
+  apply-label:
+    if: github.repository == 'opensearch-project/OpenSearch'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v7
+        with:
+          script: |
+            const { issue, repository } = context.payload;
+            const { number, body } = issue;
+            const { owner, name } = repository;
+            const regex = /###\sRelated\scomponent\n\n(\w.*)\n/gm;
+            let match;
+            while ( ( match = regex.exec( body ) ) ) {
+              const [ , component_label ] = match;
+              await github.rest.issues.addLabels( {
+                owner: owner.login,
+                repo: name,
+                issue_number: number,
+                labels: [ `${ component_label }` ],
+              } );
+            }
+            github.rest.issues.addLabels({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              labels: ['untriaged']
+            })
diff --git a/.github/workflows/version.yml b/.github/workflows/version.yml
index 2fe4fb1ac9d48..a20c671c137b2 100644
--- a/.github/workflows/version.yml
+++ b/.github/workflows/version.yml
@@ -13,7 +13,7 @@ jobs:
     steps:
       - name: GitHub App token
         id: github_app_token
-        uses: tibdex/github-app-token@v1.5.0
+        uses: tibdex/github-app-token@v2.1.0
         with:
           app_id: ${{ secrets.APP_ID }}
           private_key: ${{ secrets.APP_PRIVATE_KEY }}
@@ -59,7 +59,7 @@ jobs:
           sed -i "s/CURRENT = $CURRENT_VERSION_UNDERSCORE;/CURRENT = $NEXT_VERSION_UNDERSCORE;/g" libs/core/src/main/java/org/opensearch/Version.java
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v3
+        uses: peter-evans/create-pull-request@v5
         with:
           token: ${{ steps.github_app_token.outputs.token }}
           base: ${{ env.BASE }}
@@ -86,7 +86,7 @@ jobs:
           sed -i "s/public static final Version $CURRENT_VERSION_UNDERSCORE = new Version(\([[:digit:]]\+\)\(.*\));/\0\n    public static final Version $NEXT_VERSION_UNDERSCORE = new Version($NEXT_VERSION_ID\2);/g" libs/core/src/main/java/org/opensearch/Version.java
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v3
+        uses: peter-evans/create-pull-request@v5
         with:
           token: ${{ steps.github_app_token.outputs.token }}
           base: ${{ env.BASE_X }}
@@ -113,7 +113,7 @@ jobs:
           sed -i "s/public static final Version $CURRENT_VERSION_UNDERSCORE = new Version(\([[:digit:]]\+\)\(.*\));/\0\n    public static final Version $NEXT_VERSION_UNDERSCORE = new Version($NEXT_VERSION_ID\2);/g" libs/core/src/main/java/org/opensearch/Version.java
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v3
+        uses: peter-evans/create-pull-request@v5
         with:
           token: ${{ steps.github_app_token.outputs.token }}
           base: main
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d3e6de03709f4..52b89e57c0959 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,7 +10,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Allow mmap to use new JDK-19 preview APIs in Apache Lucene 9.4+ ([#5151](https://github.com/opensearch-project/OpenSearch/pull/5151))
 - Add events correlation engine plugin ([#6854](https://github.com/opensearch-project/OpenSearch/issues/6854))
 - Introduce new dynamic cluster setting to control slice computation for concurrent segment search ([#9107](https://github.com/opensearch-project/OpenSearch/pull/9107))
-- Implement on behalf of token passing for extensions ([#8679](https://github.com/opensearch-project/OpenSearch/pull/8679))
+- Implement on behalf of token passing for extensions ([#8679](https://github.com/opensearch-project/OpenSearch/pull/8679), [#10664](https://github.com/opensearch-project/OpenSearch/pull/10664))
+- Provide service accounts tokens to extensions ([#9618](https://github.com/opensearch-project/OpenSearch/pull/9618))
+- [AdmissionControl] Added changes for AdmissionControl Interceptor and AdmissionControlService for RateLimiting ([#9286](https://github.com/opensearch-project/OpenSearch/pull/9286))
+- GHA to verify checklist items completion in PR descriptions ([#10800](https://github.com/opensearch-project/OpenSearch/pull/10800))
+- Allow to pass the list settings through environment variables (like [], ["a", "b", "c"], ...) ([#10625](https://github.com/opensearch-project/OpenSearch/pull/10625))
+- [Admission Control] Integrate CPU AC with ResourceUsageCollector and add CPU AC stats to nodes/stats ([#10887](https://github.com/opensearch-project/OpenSearch/pull/10887))
+- Maintainer approval check ([#11378](https://github.com/opensearch-project/OpenSearch/pull/11378))
 
 ### Dependencies
 - Bump `log4j-core` from 2.18.0 to 2.19.0
@@ -30,7 +36,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Bump `com.google.code.gson:gson` from 2.10 to 2.10.1
 - Bump `com.maxmind.geoip2:geoip2` from 4.0.0 to 4.0.1
 - Bump `com.avast.gradle:gradle-docker-compose-plugin` from 0.16.11 to 0.16.12
-- Bump `org.apache.commons:commons-compress` from 1.22 to 1.23.0
 - Bump `org.apache.commons:commons-configuration2` from 2.8.0 to 2.9.0
 - Bump `com.netflix.nebula:nebula-publishing-plugin` from 19.2.0 to 20.3.0
 - Bump `io.opencensus:opencensus-api` from 0.18.0 to 0.31.1 ([#7291](https://github.com/opensearch-project/OpenSearch/pull/7291))
@@ -41,6 +46,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Bump `org.bouncycastle:bcmail-jdk15on` to `org.bouncycastle:bcmail-jdk15to18` version 1.75 ([#8247](https://github.com/opensearch-project/OpenSearch/pull/8247))
 - Bump `org.bouncycastle:bcpkix-jdk15on` to `org.bouncycastle:bcpkix-jdk15to18` version 1.75 ([#8247](https://github.com/opensearch-project/OpenSearch/pull/8247))
 - Bump JNA version from 5.5 to 5.13 ([#9963](https://github.com/opensearch-project/OpenSearch/pull/9963))
+- Bumps jetty version to 9.4.52.v20230823 to fix GMS-2023-1857 ([#9822](https://github.com/opensearch-project/OpenSearch/pull/9822))
+- Bump `org.eclipse.jgit` from 6.5.0 to 6.7.0 ([#10147](https://github.com/opensearch-project/OpenSearch/pull/10147))
+- Bump OpenTelemetry from 1.30.1 to 1.31.0 ([#10617](https://github.com/opensearch-project/OpenSearch/pull/10617))
+- Bump OpenTelemetry from 1.31.0 to 1.32.0 and OpenTelemetry Semconv from 1.21.0-alpha to 1.23.1-alpha ([#11305](https://github.com/opensearch-project/OpenSearch/pull/11305))
 
 ### Changed
 - [CCR] Add getHistoryOperationsFromTranslog method to fetch the history snapshot from translogs ([#3948](https://github.com/opensearch-project/OpenSearch/pull/3948))
@@ -49,6 +58,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Change http code on create index API with bad input raising NotXContentException from 500 to 400 ([#4773](https://github.com/opensearch-project/OpenSearch/pull/4773))
 - Improve summary error message for invalid setting updates ([#4792](https://github.com/opensearch-project/OpenSearch/pull/4792))
 - Return 409 Conflict HTTP status instead of 503 on failure to concurrently execute snapshots ([#8986](https://github.com/opensearch-project/OpenSearch/pull/5855))
+- Add task completion count in search backpressure stats API ([#10028](https://github.com/opensearch-project/OpenSearch/pull/10028/))
+- Performance improvement for Datetime field caching ([#4558](https://github.com/opensearch-project/OpenSearch/issues/4558))
+- Deprecate CamelCase `PathHierarchy` tokenizer name in favor to lowercase `path_hierarchy` ([#10894](https://github.com/opensearch-project/OpenSearch/pull/10894))
+
 
 ### Deprecated
 
@@ -71,30 +84,121 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Fixed
 - Fix 'org.apache.hc.core5.http.ParseException: Invalid protocol version' under JDK 16+ ([#4827](https://github.com/opensearch-project/OpenSearch/pull/4827))
 - Fix compression support for h2c protocol ([#4944](https://github.com/opensearch-project/OpenSearch/pull/4944))
+- Don't over-allocate in HeapBufferedAsyncEntityConsumer in order to consume the response ([#9993](https://github.com/opensearch-project/OpenSearch/pull/9993))
+- [BUG] Fix the thread context that is not properly cleared and messes up the traces ([#10873](https://github.com/opensearch-project/OpenSearch/pull/10873))
+- Handle canMatchSearchAfter for frozen context scenario ([#11249](https://github.com/opensearch-project/OpenSearch/pull/11249))
 
 ### Security
 
 ## [Unreleased 2.x]
 ### Added
+- [Admission control] Add Resource usage collector service and resource usage tracker  ([#9890](https://github.com/opensearch-project/OpenSearch/pull/9890))
+- [Admission control] Add enhancements to FS stats to include read/write time, queue size and IO time ([#10541](https://github.com/opensearch-project/OpenSearch/pull/10541))
+- [Remote cluster state] Change file names for remote cluster state ([#10557](https://github.com/opensearch-project/OpenSearch/pull/10557))
+- [Search Pipelines] Add request-scoped state shared between processors (and three new processors) ([#9405](https://github.com/opensearch-project/OpenSearch/pull/9405))
+- Per request phase latency ([#10351](https://github.com/opensearch-project/OpenSearch/issues/10351))
+- [Remote Store] Add repository stats for remote store([#10567](https://github.com/opensearch-project/OpenSearch/pull/10567))
+- [Remote cluster state] Upload global metadata in cluster state to remote store([#10404](https://github.com/opensearch-project/OpenSearch/pull/10404))
+- [Remote cluster state] Download functionality of global metadata from remote store ([#10535](https://github.com/opensearch-project/OpenSearch/pull/10535))
+- [Remote cluster state] Restore global metadata from remote store when local state is lost after quorum loss ([#10404](https://github.com/opensearch-project/OpenSearch/pull/10404))
+- [Remote cluster state] Make index and global metadata upload timeout dynamic cluster settings ([#10814](https://github.com/opensearch-project/OpenSearch/pull/10814))
+- Add search query categorizer ([#10255](https://github.com/opensearch-project/OpenSearch/pull/10255))
+- Per request phase latency ([#10351](https://github.com/opensearch-project/OpenSearch/issues/10351))
+- Add cluster state stats ([#10670](https://github.com/opensearch-project/OpenSearch/pull/10670))
+- [Remote cluster state] Restore cluster state version during remote state auto restore ([#10853](https://github.com/opensearch-project/OpenSearch/pull/10853))
+- Update the indexRandom function to create more segments for concurrent search tests ([10247](https://github.com/opensearch-project/OpenSearch/pull/10247))
+- Add support for query profiler with concurrent aggregation ([#9248](https://github.com/opensearch-project/OpenSearch/pull/9248))
+- Introduce ConcurrentQueryProfiler to profile query using concurrent segment search path and support concurrency during rewrite and create weight ([10352](https://github.com/opensearch-project/OpenSearch/pull/10352))
+- Implement on behalf of token passing for extensions ([#8679](https://github.com/opensearch-project/OpenSearch/pull/8679))
+- Provide service accounts tokens to extensions ([#9618](https://github.com/opensearch-project/OpenSearch/pull/9618))
+- [Streaming Indexing] Introduce new experimental server HTTP transport based on Netty 4 and Project Reactor (Reactor Netty) ([#9672](https://github.com/opensearch-project/OpenSearch/pull/9672))
+- Add back half_float BKD based sort query optimization ([#11024](https://github.com/opensearch-project/OpenSearch/pull/11024))
+- Request level coordinator slow logs ([#10650](https://github.com/opensearch-project/OpenSearch/pull/10650))
+- Add template snippets support for field and target_field in KV ingest processor ([#10040](https://github.com/opensearch-project/OpenSearch/pull/10040))
+- Allowing pipeline processors to access index mapping info by passing ingest service ref as part of the processor factory parameters ([#10307](https://github.com/opensearch-project/OpenSearch/pull/10307))
+- Make number of segment metadata files in remote segment store configurable ([#11329](https://github.com/opensearch-project/OpenSearch/pull/11329))
+- Allow changing number of replicas of searchable snapshot index ([#11317](https://github.com/opensearch-project/OpenSearch/pull/11317))
+- Adding slf4j license header to LoggerMessageFormat.java ([#11069](https://github.com/opensearch-project/OpenSearch/pull/11069))
+- [BWC and API enforcement] Introduce checks for enforcing the API restrictions ([#11175](https://github.com/opensearch-project/OpenSearch/pull/11175))
+- Create separate transport action for render search template action ([#11170](https://github.com/opensearch-project/OpenSearch/pull/11170))
+- Add additional handling in SearchTemplateRequest when simulate is set to true ([#11591](https://github.com/opensearch-project/OpenSearch/pull/11591))
 
 ### Dependencies
-- Bump `peter-evans/create-or-update-comment` from 2 to 3 ([#9575](https://github.com/opensearch-project/OpenSearch/pull/9575))
-- Bump `actions/checkout` from 2 to 4 ([#9968](https://github.com/opensearch-project/OpenSearch/pull/9968))
-- Bump OpenTelemetry from 1.26.0 to 1.30.1 ([#9950](https://github.com/opensearch-project/OpenSearch/pull/9950))
-- Bump `org.apache.commons:commons-compress` from 1.23.0 to 1.24.0 ([#9973](https://github.com/opensearch-project/OpenSearch/pull/9973))
+- Bump Lucene from 9.7.0 to 9.8.0 ([10276](https://github.com/opensearch-project/OpenSearch/pull/10276))
+- Bump `commons-io:commons-io` from 2.13.0 to 2.15.1 ([#10294](https://github.com/opensearch-project/OpenSearch/pull/10294), [#11001](https://github.com/opensearch-project/OpenSearch/pull/11001), [#11002](https://github.com/opensearch-project/OpenSearch/pull/11002), [#11446](https://github.com/opensearch-project/OpenSearch/pull/11446), [#11554](https://github.com/opensearch-project/OpenSearch/pull/11554))
+- Bump `com.google.api.grpc:proto-google-common-protos` from 2.10.0 to 2.25.1 ([#10208](https://github.com/opensearch-project/OpenSearch/pull/10208), [#10298](https://github.com/opensearch-project/OpenSearch/pull/10298))
+- Bump `com.netflix.nebula.ospackage-base` from 11.4.0 to 11.6.0 ([#10295](https://github.com/opensearch-project/OpenSearch/pull/10295), [#11630](https://github.com/opensearch-project/OpenSearch/pull/11630))
+- Bump `org.apache.zookeeper:zookeeper` from 3.9.0 to 3.9.1 ([#10506](https://github.com/opensearch-project/OpenSearch/pull/10506))
+- Bump `de.thetaphi:forbiddenapis` from 3.5.1 to 3.6 ([#10508](https://github.com/opensearch-project/OpenSearch/pull/10508))
+- Bump `org.codehaus.woodstox:stax2-api` from 4.2.1 to 4.2.2 ([#10639](https://github.com/opensearch-project/OpenSearch/pull/10639))
+- Bump `org.bouncycastle:bc-fips` from 1.0.2.3 to 1.0.2.4 ([#10297](https://github.com/opensearch-project/OpenSearch/pull/10297))
+- Bump `com.google.http-client:google-http-client` from 1.43.2 to 1.43.3 ([#10635](https://github.com/opensearch-project/OpenSearch/pull/10635))
+- Bump `com.squareup.okio:okio` from 3.5.0 to 3.7.0 ([#10637](https://github.com/opensearch-project/OpenSearch/pull/10637), [#11632](https://github.com/opensearch-project/OpenSearch/pull/11632))
+- Bump `org.apache.logging.log4j:log4j-core` from 2.20.0 to 2.22.0 ([#10858](https://github.com/opensearch-project/OpenSearch/pull/10858), [#11000](https://github.com/opensearch-project/OpenSearch/pull/11000), [#11270](https://github.com/opensearch-project/OpenSearch/pull/11270))
+- Bump `aws-actions/configure-aws-credentials` from 2 to 4 ([#10504](https://github.com/opensearch-project/OpenSearch/pull/10504))
+- Bump `stefanzweifel/git-auto-commit-action` from 4 to 5 ([#11171](https://github.com/opensearch-project/OpenSearch/pull/11171))
+- Bump `actions/github-script` from 6 to 7 ([#11271](https://github.com/opensearch-project/OpenSearch/pull/11271))
+- Bump `jackson` and `jackson_databind` from 2.15.2 to 2.16.0 ([#11273](https://github.com/opensearch-project/OpenSearch/pull/11273))
+- Bump `netty` from 4.1.100.Final to 4.1.101.Final ([#11294](https://github.com/opensearch-project/OpenSearch/pull/11294))
+- Bump `com.avast.gradle:gradle-docker-compose-plugin` from 0.16.12 to 0.17.5 ([#10163](https://github.com/opensearch-project/OpenSearch/pull/10163))
+- Bump `com.squareup.okhttp3:okhttp` from 4.11.0 to 4.12.0 ([#10861](https://github.com/opensearch-project/OpenSearch/pull/10861))
+- Bump `org.apache.commons:commons-text` from 1.10.0 to 1.11.0 ([#11344](https://github.com/opensearch-project/OpenSearch/pull/11344))
+- Bump `reactor-netty-core` from 1.1.12 to 1.1.13 ([#11350](https://github.com/opensearch-project/OpenSearch/pull/11350))
+- Bump `com.gradle.enterprise` from 3.14.1 to 3.16.1 ([#11339](https://github.com/opensearch-project/OpenSearch/pull/11339), [#11629](https://github.com/opensearch-project/OpenSearch/pull/11629))
+- Bump `actions/setup-java` from 3 to 4 ([#11447](https://github.com/opensearch-project/OpenSearch/pull/11447))
+- Bump `commons-net:commons-net` from 3.9.0 to 3.10.0 ([#11450](https://github.com/opensearch-project/OpenSearch/pull/11450))
+- Bump `org.apache.maven:maven-model` from 3.9.4 to 3.9.6 ([#11445](https://github.com/opensearch-project/OpenSearch/pull/11445))
+- Bump `org.apache.xmlbeans:xmlbeans` from 5.1.1 to 5.2.0 ([#11448](https://github.com/opensearch-project/OpenSearch/pull/11448))
+- Bump `logback-core` and `logback-classic` to 1.2.13 ([#11521](https://github.com/opensearch-project/OpenSearch/pull/11521))
+- Bumps `jetty` version from 9.4.52.v20230823 to 9.4.53.v20231009 ([#11539](https://github.com/opensearch-project/OpenSearch/pull/11539))
+- Bump `org.wiremock:wiremock-standalone` from 3.1.0 to 3.3.1 ([#11555](https://github.com/opensearch-project/OpenSearch/pull/11555))
+- Bump `org.apache.commons:commons-compress` from 1.24.0 to 1.25.0 ([#11556](https://github.com/opensearch-project/OpenSearch/pull/11556))
+- Bump `actions/stale` from 8 to 9 ([#11557](https://github.com/opensearch-project/OpenSearch/pull/11557))
 
 ### Changed
-- Add instrumentation in rest and network layer. ([#9415](https://github.com/opensearch-project/OpenSearch/pull/9415))
-- Allow parameterization of tests with OpenSearchIntegTestCase.SuiteScopeTestCase annotation ([#9916](https://github.com/opensearch-project/OpenSearch/pull/9916))
 - Mute the query profile IT with concurrent execution ([#9840](https://github.com/opensearch-project/OpenSearch/pull/9840))
+- Force merge with `only_expunge_deletes` honors max segment size ([#10036](https://github.com/opensearch-project/OpenSearch/pull/10036))
+- Add the means to extract the contextual properties from HttpChannel, TcpCChannel and TrasportChannel without excessive typecasting ([#10562](https://github.com/opensearch-project/OpenSearch/pull/10562))
+- Search pipelines now support asynchronous request and response processors to avoid blocking on a transport thread ([#10598](https://github.com/opensearch-project/OpenSearch/pull/10598))
+- [Remote Store] Add Remote Store backpressure rejection stats to `_nodes/stats` ([#10524](https://github.com/opensearch-project/OpenSearch/pull/10524))
+- [BUG] Fix java.lang.SecurityException in repository-gcs plugin ([#10642](https://github.com/opensearch-project/OpenSearch/pull/10642))
+- Add telemetry tracer/metric enable flag and integ test. ([#10395](https://github.com/opensearch-project/OpenSearch/pull/10395))
+- Add instrumentation for indexing in transport bulk action and transport shard bulk action. ([#10273](https://github.com/opensearch-project/OpenSearch/pull/10273))
+- Disallow removing some metadata fields by remove ingest processor ([#10895](https://github.com/opensearch-project/OpenSearch/pull/10895))
+- Refactor common parts from the Rounding class into a separate 'round' package ([#11023](https://github.com/opensearch-project/OpenSearch/issues/11023))
+- Performance improvement for MultiTerm Queries on Keyword fields ([#7057](https://github.com/opensearch-project/OpenSearch/issues/7057))
+- Performance improvement for date histogram aggregations without sub-aggregations ([#11083](https://github.com/opensearch-project/OpenSearch/pull/11083))
+- Disable concurrent aggs for Diversified Sampler and Sampler aggs ([#11087](https://github.com/opensearch-project/OpenSearch/issues/11087))
+- Made leader/follower check timeout setting dynamic ([#10528](https://github.com/opensearch-project/OpenSearch/pull/10528))
+- Improve boolean parsing performance ([#11308](https://github.com/opensearch-project/OpenSearch/pull/11308))
+- Interpret byte array as primitive using VarHandles ([#11362](https://github.com/opensearch-project/OpenSearch/pull/11362))
+- Change error message when per shard document limit is breached ([#11312](https://github.com/opensearch-project/OpenSearch/pull/11312))
+- Automatically add scheme to discovery.ec2.endpoint ([#11512](https://github.com/opensearch-project/OpenSearch/pull/11512))
+- Restore support for Java 8 for RestClient ([#11562](https://github.com/opensearch-project/OpenSearch/pull/11562))
 
 ### Deprecated
 
 ### Removed
+- Remove deprecated classes for Rounding ([#10956](https://github.com/opensearch-project/OpenSearch/issues/10956))
 
 ### Fixed
+- Fix failure in dissect ingest processor parsing empty brackets ([#9225](https://github.com/opensearch-project/OpenSearch/pull/9255))
+- Fix class_cast_exception when passing int to _version and other metadata fields in ingest simulate API ([#10101](https://github.com/opensearch-project/OpenSearch/pull/10101))
+- Fix Segment Replication ShardLockObtainFailedException bug during index corruption ([10370](https://github.com/opensearch-project/OpenSearch/pull/10370))
+- Fix some test methods in SimulatePipelineRequestParsingTests never run and fix test failure ([#10496](https://github.com/opensearch-project/OpenSearch/pull/10496))
+- Fix passing wrong parameter when calling newConfigurationException() in DotExpanderProcessor ([#10737](https://github.com/opensearch-project/OpenSearch/pull/10737))
+- Fix SuggestSearch.testSkipDuplicates by forceing refresh when indexing its test documents ([#11068](https://github.com/opensearch-project/OpenSearch/pull/11068))
+- Delegating CachingWeightWrapper#count to internal weight object ([#10543](https://github.com/opensearch-project/OpenSearch/pull/10543))
+- Fix per request latency last phase not tracked ([#10934](https://github.com/opensearch-project/OpenSearch/pull/10934))
+- Fix for stuck update action in a bulk with `retry_on_conflict` property ([#11152](https://github.com/opensearch-project/OpenSearch/issues/11152))
+- Fix the issue with DefaultSpanScope restoring wrong span in the TracerContextStorage upon detach ([#11316](https://github.com/opensearch-project/OpenSearch/issues/11316))
+- Remove shadowJar from `lang-painless` module publication ([#11369](https://github.com/opensearch-project/OpenSearch/issues/11369))
+- Fix remote shards balancer and remove unused variables ([#11167](https://github.com/opensearch-project/OpenSearch/pull/11167))
+- Fix bug where replication lag grows post primary relocation ([#11238](https://github.com/opensearch-project/OpenSearch/pull/11238))
+- Fix template setting override for replication type ([#11417](https://github.com/opensearch-project/OpenSearch/pull/11417))
+- Fix Automatic addition of protocol broken in #11512 ([#11609](https://github.com/opensearch-project/OpenSearch/pull/11609))
 
 ### Security
 
 [Unreleased 3.0]: https://github.com/opensearch-project/OpenSearch/compare/2.x...HEAD
-[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.11...2.x
+[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.12...2.x
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d379d78829318..4a1162cf2558b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -8,6 +8,7 @@
   - [Developer Certificate of Origin](#developer-certificate-of-origin)
   - [Changelog](#changelog)
   - [Review Process](#review-process)
+  - [Troubleshooting Failing Builds](#troubleshooting-failing-builds)
 
 # Contributing to OpenSearch
 
@@ -162,3 +163,14 @@ During the PR process, expect that there will be some back-and-forth. Please try
 If we accept the PR, a [maintainer](MAINTAINERS.md) will merge your change and usually take care of backporting it to appropriate branches ourselves.
 
 If we reject the PR, we will close the pull request with a comment explaining why. This decision isn't always final: if you feel we have misunderstood your intended change or otherwise think that we should reconsider then please continue the conversation with a comment on the PR and we'll do our best to address any further points you raise.
+
+## Troubleshooting Failing Builds
+
+The OpenSearch testing framework offers many capabilities but exhibits significant complexity (it does lot of randomization internally to cover as many edge cases and variations as possible). Unfortunately, this posses a challenge by making it harder to discover important issues/bugs in straightforward way and may lead to so called flaky tests - the tests which flip randomly from success to failure without any code changes. 
+
+If your pull request reports a failing test(s) on one of the checks, please:
+ - look if there is an existing [issue](https://github.com/opensearch-project/OpenSearch/issues) reported for the test in question 
+ - if not, please make sure this is not caused by your changes, run the failing test(s) locally for some time
+ - if you are sure the failure is not related, please open a new [bug](https://github.com/opensearch-project/OpenSearch/issues/new?assignees=&labels=bug%2C+untriaged&projects=&template=bug_template.md&title=%5BBUG%5D) with `flaky-test` label
+ - add a comment referencing the issue(s) or bug report(s) to your pull request explaining the failing build(s)
+ - as a bonus point, try to contribute by fixing the flaky test(s)
diff --git a/benchmarks/build.gradle b/benchmarks/build.gradle
index 02aa9319cc583..6b4634c7e791c 100644
--- a/benchmarks/build.gradle
+++ b/benchmarks/build.gradle
@@ -40,7 +40,7 @@ application {
 }
 
 base {
-  archivesBaseName = 'opensearch-benchmarks'
+  archivesName = 'opensearch-benchmarks'
 }
 
 test.enabled = false
diff --git a/benchmarks/src/main/java/org/opensearch/benchmark/time/RoundingBenchmark.java b/benchmarks/src/main/java/org/opensearch/benchmark/time/RoundingBenchmark.java
deleted file mode 100644
index cdbcbfc163191..0000000000000
--- a/benchmarks/src/main/java/org/opensearch/benchmark/time/RoundingBenchmark.java
+++ /dev/null
@@ -1,180 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.benchmark.time;
-
-import org.opensearch.common.Rounding;
-import org.opensearch.common.rounding.DateTimeUnit;
-import org.opensearch.common.time.DateUtils;
-import org.opensearch.common.unit.TimeValue;
-import org.joda.time.DateTimeZone;
-import org.openjdk.jmh.annotations.Benchmark;
-import org.openjdk.jmh.annotations.BenchmarkMode;
-import org.openjdk.jmh.annotations.Fork;
-import org.openjdk.jmh.annotations.Measurement;
-import org.openjdk.jmh.annotations.Mode;
-import org.openjdk.jmh.annotations.OutputTimeUnit;
-import org.openjdk.jmh.annotations.Scope;
-import org.openjdk.jmh.annotations.State;
-import org.openjdk.jmh.annotations.Warmup;
-
-import java.time.ZoneId;
-import java.time.ZoneOffset;
-import java.util.concurrent.TimeUnit;
-
-import static org.opensearch.common.Rounding.DateTimeUnit.DAY_OF_MONTH;
-import static org.opensearch.common.Rounding.DateTimeUnit.MONTH_OF_YEAR;
-import static org.opensearch.common.Rounding.DateTimeUnit.QUARTER_OF_YEAR;
-import static org.opensearch.common.Rounding.DateTimeUnit.YEAR_OF_CENTURY;
-
-@Fork(3)
-@Warmup(iterations = 10)
-@Measurement(iterations = 10)
-@BenchmarkMode(Mode.AverageTime)
-@OutputTimeUnit(TimeUnit.NANOSECONDS)
-@State(Scope.Benchmark)
-@SuppressWarnings("unused") // invoked by benchmarking framework
-public class RoundingBenchmark {
-
-    private final ZoneId zoneId = ZoneId.of("Europe/Amsterdam");
-    private final DateTimeZone timeZone = DateUtils.zoneIdToDateTimeZone(zoneId);
-
-    private long timestamp = 1548879021354L;
-
-    private final org.opensearch.common.rounding.Rounding jodaRounding = org.opensearch.common.rounding.Rounding.builder(
-        DateTimeUnit.HOUR_OF_DAY
-    ).timeZone(timeZone).build();
-    private final Rounding javaRounding = Rounding.builder(Rounding.DateTimeUnit.HOUR_OF_DAY).timeZone(zoneId).build();
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitJoda() {
-        return jodaRounding.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitJava() {
-        return javaRounding.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding jodaDayOfMonthRounding = org.opensearch.common.rounding.Rounding.builder(
-        DateTimeUnit.DAY_OF_MONTH
-    ).timeZone(timeZone).build();
-    private final Rounding javaDayOfMonthRounding = Rounding.builder(DAY_OF_MONTH).timeZone(zoneId).build();
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitDayOfMonthJoda() {
-        return jodaDayOfMonthRounding.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitDayOfMonthJava() {
-        return javaDayOfMonthRounding.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeIntervalRoundingJoda = org.opensearch.common.rounding.Rounding.builder(
-        TimeValue.timeValueMinutes(60)
-    ).timeZone(timeZone).build();
-    private final Rounding timeIntervalRoundingJava = Rounding.builder(TimeValue.timeValueMinutes(60)).timeZone(zoneId).build();
-
-    @Benchmark
-    public long timeIntervalRoundingJava() {
-        return timeIntervalRoundingJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeIntervalRoundingJoda() {
-        return timeIntervalRoundingJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcDayOfMonthJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.DAY_OF_MONTH)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcDayOfMonthJava = Rounding.builder(DAY_OF_MONTH).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcDayOfMonthJava() {
-        return timeUnitRoundingUtcDayOfMonthJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcDayOfMonthJoda() {
-        return timeUnitRoundingUtcDayOfMonthJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcQuarterOfYearJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.QUARTER)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcQuarterOfYearJava = Rounding.builder(QUARTER_OF_YEAR).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcQuarterOfYearJava() {
-        return timeUnitRoundingUtcQuarterOfYearJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcQuarterOfYearJoda() {
-        return timeUnitRoundingUtcQuarterOfYearJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcMonthOfYearJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.MONTH_OF_YEAR)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcMonthOfYearJava = Rounding.builder(MONTH_OF_YEAR).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcMonthOfYearJava() {
-        return timeUnitRoundingUtcMonthOfYearJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcMonthOfYearJoda() {
-        return timeUnitRoundingUtcMonthOfYearJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcYearOfCenturyJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.YEAR_OF_CENTURY)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcYearOfCenturyJava = Rounding.builder(YEAR_OF_CENTURY).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcYearOfCenturyJava() {
-        return timeUnitRoundingUtcYearOfCenturyJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcYearOfCenturyJoda() {
-        return timeUnitRoundingUtcYearOfCenturyJoda.round(timestamp);
-    }
-}
diff --git a/benchmarks/src/main/java/org/opensearch/common/ArrayRoundingBenchmark.java b/benchmarks/src/main/java/org/opensearch/common/round/RoundableBenchmark.java
similarity index 89%
rename from benchmarks/src/main/java/org/opensearch/common/ArrayRoundingBenchmark.java
rename to benchmarks/src/main/java/org/opensearch/common/round/RoundableBenchmark.java
index 64c0a9e1d7aa6..4e07af452968b 100644
--- a/benchmarks/src/main/java/org/opensearch/common/ArrayRoundingBenchmark.java
+++ b/benchmarks/src/main/java/org/opensearch/common/round/RoundableBenchmark.java
@@ -6,7 +6,7 @@
  * compatible open source license.
  */
 
-package org.opensearch.common;
+package org.opensearch.common.round;
 
 import org.openjdk.jmh.annotations.Benchmark;
 import org.openjdk.jmh.annotations.BenchmarkMode;
@@ -27,13 +27,13 @@
 @Warmup(iterations = 3, time = 1)
 @Measurement(iterations = 1, time = 1)
 @BenchmarkMode(Mode.Throughput)
-public class ArrayRoundingBenchmark {
+public class RoundableBenchmark {
 
     @Benchmark
-    public void round(Blackhole bh, Options opts) {
-        Rounding.Prepared rounding = opts.supplier.get();
+    public void floor(Blackhole bh, Options opts) {
+        Roundable roundable = opts.supplier.get();
         for (long key : opts.queries) {
-            bh.consume(rounding.round(key));
+            bh.consume(roundable.floor(key));
         }
     }
 
@@ -90,7 +90,7 @@ public static class Options {
         public String distribution;
 
         public long[] queries;
-        public Supplier<Rounding.Prepared> supplier;
+        public Supplier<Roundable> supplier;
 
         @Setup
         public void setup() {
@@ -130,10 +130,10 @@ public void setup() {
 
             switch (type) {
                 case "binary":
-                    supplier = () -> new Rounding.BinarySearchArrayRounding(values, size, null);
+                    supplier = () -> new BinarySearcher(values, size);
                     break;
                 case "linear":
-                    supplier = () -> new Rounding.BidirectionalLinearSearchArrayRounding(values, size, null);
+                    supplier = () -> new BidirectionalLinearSearcher(values, size);
                     break;
                 default:
                     throw new IllegalArgumentException("invalid type: " + type);
diff --git a/build.gradle b/build.gradle
index 9d62e942a4431..b1cd1d532bfeb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -375,7 +375,7 @@ allprojects {
         } else {
           // Link to non-shadowed dependant projects
           project.javadoc.dependsOn "${upstreamProject.path}:javadoc"
-          String externalLinkName = upstreamProject.base.archivesBaseName
+          String externalLinkName = upstreamProject.base.archivesName
           String artifactPath = dep.group.replaceAll('\\.', '/') + '/' + externalLinkName.replaceAll('\\.', '/') + '/' + dep.version
           String projectRelativePath = project.relativePath(upstreamProject.buildDir)
           project.javadoc.options.linksOffline artifactsHost + "/javadoc/" + artifactPath, "${projectRelativePath}/docs/javadoc/"
diff --git a/buildSrc/build.gradle b/buildSrc/build.gradle
index 3dc689795151b..0efa170250a7b 100644
--- a/buildSrc/build.gradle
+++ b/buildSrc/build.gradle
@@ -103,32 +103,32 @@ dependencies {
   api localGroovy()
 
   api 'commons-codec:commons-codec:1.16.0'
-  api 'org.apache.commons:commons-compress:1.23.0'
+  api 'org.apache.commons:commons-compress:1.25.0'
   api 'org.apache.ant:ant:1.10.14'
   api 'com.netflix.nebula:gradle-extra-configurations-plugin:10.0.0'
   api 'com.netflix.nebula:nebula-publishing-plugin:20.3.0'
   api 'com.netflix.nebula:gradle-info-plugin:12.1.6'
   api 'org.apache.rat:apache-rat:0.15'
-  api 'commons-io:commons-io:2.13.0'
+  api 'commons-io:commons-io:2.15.1'
   api "net.java.dev.jna:jna:5.13.0"
   api 'com.github.johnrengelman:shadow:8.1.1'
   api 'org.jdom:jdom2:2.0.6.1'
   api "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${props.getProperty('kotlin')}"
-  api 'de.thetaphi:forbiddenapis:3.5.1'
-  api 'com.avast.gradle:gradle-docker-compose-plugin:0.16.12'
+  api 'de.thetaphi:forbiddenapis:3.6'
+  api 'com.avast.gradle:gradle-docker-compose-plugin:0.17.5'
   api "org.yaml:snakeyaml:${props.getProperty('snakeyaml')}"
-  api 'org.apache.maven:maven-model:3.9.4'
+  api 'org.apache.maven:maven-model:3.9.6'
   api 'com.networknt:json-schema-validator:1.0.86'
   api 'org.jruby.jcodings:jcodings:1.0.58'
   api 'org.jruby.joni:joni:2.2.1'
   api "com.fasterxml.jackson.core:jackson-databind:${props.getProperty('jackson_databind')}"
-  api "org.ajoberstar.grgit:grgit-core:5.2.0"
+  api "org.ajoberstar.grgit:grgit-core:5.2.1"
 
   testFixturesApi "junit:junit:${props.getProperty('junit')}"
   testFixturesApi "com.carrotsearch.randomizedtesting:randomizedtesting-runner:${props.getProperty('randomizedrunner')}"
   testFixturesApi gradleApi()
   testFixturesApi gradleTestKit()
-  testImplementation 'com.github.tomakehurst:wiremock-jre8-standalone:2.35.0'
+  testImplementation 'org.wiremock:wiremock-standalone:3.3.1'
   testImplementation "org.mockito:mockito-core:${props.getProperty('mockito')}"
   integTestImplementation('org.spockframework:spock-core:2.3-groovy-3.0') {
     exclude module: "groovy"
diff --git a/buildSrc/reaper/src/main/java/org/opensearch/gradle/reaper/Reaper.java b/buildSrc/reaper/src/main/java/org/opensearch/gradle/reaper/Reaper.java
index c5b4de157c75c..662510fbbf61c 100644
--- a/buildSrc/reaper/src/main/java/org/opensearch/gradle/reaper/Reaper.java
+++ b/buildSrc/reaper/src/main/java/org/opensearch/gradle/reaper/Reaper.java
@@ -45,17 +45,16 @@
 
 /**
  * A standalone process that will reap external services after a build dies.
- *
  * <h2>Input</h2>
  * Since how to reap a given service is platform and service dependent, this tool
  * operates on system commands to execute. It takes a single argument, a directory
  * that will contain files with reaping commands. Each line in each file will be
  * executed with {@link Runtime#exec(String)}.
- *
+ * <p>
  * The main method will wait indefinitely on the parent process (Gradle) by
  * reading from stdin. When Gradle shuts down, whether normally or abruptly, the
  * pipe will be broken and read will return.
- *
+ * <p>
  * The reaper will then iterate over the files in the configured directory,
  * and execute the given commands. If any commands fail, a failure message is
  * written to stderr. Otherwise, the input file will be deleted. If no inputs
diff --git a/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy b/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy
index 556763333d279..13f5f8724c6f2 100644
--- a/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy
+++ b/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy
@@ -89,7 +89,7 @@ class PluginBuildPlugin implements Plugin<Project> {
             String name = extension1.name
 
             BasePluginExtension base = project.getExtensions().findByType(BasePluginExtension.class)
-            base.archivesBaseName = name
+            base.archivesName = name
             project.description = extension1.description
 
             if (extension1.name == null) {
@@ -155,7 +155,7 @@ class PluginBuildPlugin implements Plugin<Project> {
         // Only configure publishing if applied externally
         if (extension.hasClientJar) {
             project.pluginManager.apply('com.netflix.nebula.maven-base-publish')
-            // Only change Jar tasks, we don't want a -client zip so we can't change archivesBaseName
+            // Only change Jar tasks, we don't want a -client zip so we can't change archivesName
             project.tasks.withType(Jar) {
                 archiveBaseName = archiveBaseName.get() +  "-client"
             }
@@ -163,7 +163,7 @@ class PluginBuildPlugin implements Plugin<Project> {
             project.publishing.publications.nebula(MavenPublication).artifactId(extension.name + "-client")
             final BasePluginExtension base = project.getExtensions().findByType(BasePluginExtension.class)
             project.tasks.withType(GenerateMavenPom.class).configureEach { GenerateMavenPom generatePOMTask ->
-                generatePOMTask.destination = "${project.buildDir}/distributions/${base.archivesBaseName}-client-${project.versions.opensearch}.pom"
+                generatePOMTask.destination = "${project.buildDir}/distributions/${base.archivesName}-client-${project.versions.opensearch}.pom"
             }
         } else {
             if (project.plugins.hasPlugin(MavenPublishPlugin)) {
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/BwcVersions.java b/buildSrc/src/main/java/org/opensearch/gradle/BwcVersions.java
index cddd03ccc2019..4d45640b75e3d 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/BwcVersions.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/BwcVersions.java
@@ -52,15 +52,15 @@
 
 /**
  * A container for opensearch supported version information used in BWC testing.
- *
+ * <p>
  * Parse the Java source file containing the versions declarations and use the known rules to figure out which are all
  * the version the current one is wire and index compatible with.
  * On top of this, figure out which of these are unreleased and provide the branch they can be built from.
- *
+ * <p>
  * Note that in this context, currentVersion is the unreleased version this build operates on.
  * At any point in time there will surely be four such unreleased versions being worked on,
  * thus currentVersion will be one of these.
- *
+ * <p>
  * Considering:
  * <dl>
  *     <dt>M, M &gt; 0</dt>
@@ -84,7 +84,7 @@
  * Each build is only concerned with versions before it, as those are the ones that need to be tested
  * for backwards compatibility. We never look forward, and don't add forward facing version number to branches of previous
  * version.
- *
+ * <p>
  * Each branch has a current version, and expected compatible versions are parsed from the server code's Version` class.
  * We can reliably figure out which the unreleased versions are due to the convention of always adding the next unreleased
  * version number to server in all branches when a version is released.
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/LoggingOutputStream.java b/buildSrc/src/main/java/org/opensearch/gradle/LoggingOutputStream.java
index 5ae7ad1595e2f..5259700b3a63d 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/LoggingOutputStream.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/LoggingOutputStream.java
@@ -38,7 +38,7 @@
 
 /**
  * Writes data passed to this stream as log messages.
- *
+ * <p>
  * The stream will be flushed whenever a newline is detected.
  * Allows setting an optional prefix before each line of output.
  */
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java
index 97e923c366598..7ec21bba18c64 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java
@@ -77,7 +77,7 @@ public void apply(Project project) {
     }
 
     private static String getArchivesBaseName(Project project) {
-        return project.getExtensions().getByType(BasePluginExtension.class).getArchivesBaseName();
+        return project.getExtensions().getByType(BasePluginExtension.class).getArchivesName().get();
     }
 
     /**Configuration generation of maven poms. */
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/internal/InternalBwcGitPlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/internal/InternalBwcGitPlugin.java
index 159270d28e3d6..c6e49dc44d6bd 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/internal/InternalBwcGitPlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/internal/InternalBwcGitPlugin.java
@@ -76,7 +76,7 @@ public InternalBwcGitPlugin(ProviderFactory providerFactory, ExecOperations exec
     public void apply(Project project) {
         this.project = project;
         this.gitExtension = project.getExtensions().create("bwcGitConfig", BwcGitExtension.class);
-        Provider<String> remote = providerFactory.systemProperty("bwc.remote").forUseAtConfigurationTime().orElse("opensearch-project");
+        Provider<String> remote = providerFactory.systemProperty("bwc.remote").orElse("opensearch-project");
 
         TaskContainer tasks = project.getTasks();
         TaskProvider<LoggedExec> createCloneTaskProvider = tasks.register("createClone", LoggedExec.class, createClone -> {
@@ -105,7 +105,6 @@ public void apply(Project project) {
             String remoteRepo = remote.get();
             // for testing only we can override the base remote url
             String remoteRepoUrl = providerFactory.systemProperty("testRemoteRepo")
-                .forUseAtConfigurationTime()
                 .getOrElse("https://github.com/" + remoteRepo + "/OpenSearch.git");
             addRemote.setCommandLine(asList("git", "remote", "add", remoteRepo, remoteRepoUrl));
         });
@@ -113,7 +112,6 @@ public void apply(Project project) {
         TaskProvider<LoggedExec> fetchLatestTaskProvider = tasks.register("fetchLatest", LoggedExec.class, fetchLatest -> {
             Provider<Object> gitFetchLatest = project.getProviders()
                 .systemProperty("tests.bwc.git_fetch_latest")
-                .forUseAtConfigurationTime()
                 .orElse("true")
                 .map(fetchProp -> {
                     if ("true".equals(fetchProp)) {
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionRule.java b/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionRule.java
index aa81ef75701fa..db46d2e3edc55 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionRule.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionRule.java
@@ -40,7 +40,7 @@
 
 /**
  * Represent rules for tests enforced by the @{link {@link TestingConventionsTasks}}
- *
+ * <p>
  * Rules are identified by name, tests must have this name as a suffix and implement one of the base classes
  * and be part of all the specified tasks.
  */
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/tar/SymbolicLinkPreservingTar.java b/buildSrc/src/main/java/org/opensearch/gradle/tar/SymbolicLinkPreservingTar.java
index 1423b52c443d9..e82d8ed73ced2 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/tar/SymbolicLinkPreservingTar.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/tar/SymbolicLinkPreservingTar.java
@@ -61,7 +61,7 @@
 
 /**
  * A custom archive task that assembles a tar archive that preserves symbolic links.
- *
+ * <p>
  * This task is necessary because the built-in task {@link org.gradle.api.tasks.bundling.Tar} does not preserve symbolic links.
  */
 public class SymbolicLinkPreservingTar extends Tar {
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java
index a420c8b63b02c..1ad7e056b6ae6 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java
@@ -77,9 +77,9 @@
 import java.util.stream.Stream;
 
 public class DistroTestPlugin implements Plugin<Project> {
-    private static final String SYSTEM_JDK_VERSION = "11.0.20+8";
+    private static final String SYSTEM_JDK_VERSION = "17.0.9+9";
     private static final String SYSTEM_JDK_VENDOR = "adoptium";
-    private static final String GRADLE_JDK_VERSION = "17.0.8+7";
+    private static final String GRADLE_JDK_VERSION = "17.0.9+9";
     private static final String GRADLE_JDK_VENDOR = "adoptium";
 
     // all distributions used by distro tests. this is temporary until tests are per distribution
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/rest/RestResourcesPlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/test/rest/RestResourcesPlugin.java
index 728e36ce98bff..fcadf35593ce6 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/test/rest/RestResourcesPlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/rest/RestResourcesPlugin.java
@@ -65,7 +65,7 @@
  * <strong>Rest YAML tests :</strong> <br>
  * When the {@link RestResourcesPlugin} has been applied the {@link CopyRestTestsTask} will copy the Rest YAML tests if explicitly
  * configured with `includeCore` through the `restResources.restTests` extension.
- *
+ * <p>
  * Additionally you can specify which sourceSetName resources should be copied to. The default is the yamlRestTest source set.
  * @see CopyRestApiTask
  * @see CopyRestTestsTask
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/testfixtures/TestFixturesPlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/testfixtures/TestFixturesPlugin.java
index 3aba941875115..c9e18426966f9 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/testfixtures/TestFixturesPlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/testfixtures/TestFixturesPlugin.java
@@ -170,6 +170,7 @@ public void execute(Task task) {
                 .findFirst();
 
             composeExtension.getExecutable().set(dockerCompose.isPresent() ? dockerCompose.get() : "/usr/bin/docker");
+            composeExtension.getUseDockerComposeV2().set(false);
 
             tasks.named("composeUp").configure(t -> {
                 // Avoid running docker-compose tasks in parallel in CI due to some issues on certain Linux distributions
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantMachine.java b/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantMachine.java
index 2d71b9361963b..7abf9bf5fbef6 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantMachine.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantMachine.java
@@ -53,7 +53,7 @@
 
 /**
  * An helper to manage a vagrant box.
- *
+ * <p>
  * This is created alongside a {@link VagrantExtension} for a project to manage starting and
  * stopping a single vagrant box.
  */
@@ -185,7 +185,7 @@ public void setArgs(String... args) {
 
         /**
          * A function to translate output from the vagrant command execution to the progress line.
-         *
+         * <p>
          * The function takes the current line of output from vagrant, and returns a new
          * progress line, or {@code null} if there is no update.
          */
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantShellTask.java b/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantShellTask.java
index 85d3e340c50e7..ca1b95183505f 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantShellTask.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/vagrant/VagrantShellTask.java
@@ -47,7 +47,7 @@
 
 /**
  * A shell script to run within a vagrant VM.
- *
+ * <p>
  * The script is run as root within the VM.
  */
 public abstract class VagrantShellTask extends DefaultTask {
diff --git a/buildSrc/src/test/java/org/opensearch/gradle/pluginzip/PublishTests.java b/buildSrc/src/test/java/org/opensearch/gradle/pluginzip/PublishTests.java
index c0e7320ba7615..8e246ff9ecd11 100644
--- a/buildSrc/src/test/java/org/opensearch/gradle/pluginzip/PublishTests.java
+++ b/buildSrc/src/test/java/org/opensearch/gradle/pluginzip/PublishTests.java
@@ -58,7 +58,7 @@ public void tearDown() {
      * This test is used to verify that adding the 'opensearch.pluginzip' to the project
      * adds some other transitive plugins and tasks under the hood. This is basically
      * a behavioral test of the {@link Publish#apply(Project)} method.
-     *
+     * <p>
      * This is equivalent of having a build.gradle script with just the following section:
      * <pre>
      *     plugins {
@@ -202,7 +202,7 @@ public void useDefaultValues() throws IOException, URISyntaxException, XmlPullPa
         GradleRunner runner = prepareGradleRunnerFromTemplate("useDefaultValues.gradle", "build", ZIP_PUBLISH_TASK);
         BuildResult result = runner.build();
 
-        /** Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
+        /* Check if build and ZIP_PUBLISH_TASK tasks have run well */
         assertEquals(SUCCESS, result.task(":" + "build").getOutcome());
         assertEquals(SUCCESS, result.task(":" + ZIP_PUBLISH_TASK).getOutcome());
 
@@ -277,7 +277,7 @@ public void allProjectsGroup() throws IOException, URISyntaxException, XmlPullPa
         GradleRunner runner = prepareGradleRunnerFromTemplate("allProjectsGroup.gradle", "build", ZIP_PUBLISH_TASK);
         BuildResult result = runner.build();
 
-        /** Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
+        /* Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
         assertEquals(SUCCESS, result.task(":" + "build").getOutcome());
         assertEquals(SUCCESS, result.task(":" + ZIP_PUBLISH_TASK).getOutcome());
 
@@ -312,7 +312,7 @@ public void groupPriorityLevel() throws IOException, URISyntaxException, XmlPull
         GradleRunner runner = prepareGradleRunnerFromTemplate("groupPriorityLevel.gradle", "build", ZIP_PUBLISH_TASK);
         BuildResult result = runner.build();
 
-        /** Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
+        /* Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
         assertEquals(SUCCESS, result.task(":" + "build").getOutcome());
         assertEquals(SUCCESS, result.task(":" + ZIP_PUBLISH_TASK).getOutcome());
 
@@ -348,7 +348,7 @@ public void missingPOMEntity() throws IOException, URISyntaxException, XmlPullPa
         GradleRunner runner = prepareGradleRunnerFromTemplate("missingPOMEntity.gradle", "build", ZIP_PUBLISH_TASK);
         BuildResult result = runner.build();
 
-        /** Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
+        /* Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
         assertEquals(SUCCESS, result.task(":" + "build").getOutcome());
         assertEquals(SUCCESS, result.task(":" + ZIP_PUBLISH_TASK).getOutcome());
 
@@ -395,7 +395,7 @@ public void customizedGroupValue() throws IOException, URISyntaxException, XmlPu
         GradleRunner runner = prepareGradleRunnerFromTemplate("customizedGroupValue.gradle", "build", ZIP_PUBLISH_TASK);
         BuildResult result = runner.build();
 
-        /** Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
+        /* Check if build and {@value ZIP_PUBLISH_TASK} tasks have run well */
         assertEquals(SUCCESS, result.task(":" + "build").getOutcome());
         assertEquals(SUCCESS, result.task(":" + ZIP_PUBLISH_TASK).getOutcome());
 
diff --git a/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/GradleThreadsFilter.java b/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/GradleThreadsFilter.java
index b64c719440733..def5248c1f255 100644
--- a/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/GradleThreadsFilter.java
+++ b/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/GradleThreadsFilter.java
@@ -36,7 +36,7 @@
 
 /**
  * Filter out threads controlled by gradle that may be created during unit tests.
- *
+ * <p>
  * Currently this includes pooled threads for Exec as well as file system event watcher threads.
  */
 public class GradleThreadsFilter implements ThreadFilter {
diff --git a/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/JUnit3MethodProvider.java b/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/JUnit3MethodProvider.java
index 163a903d31832..1a2e36aa78e9f 100644
--- a/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/JUnit3MethodProvider.java
+++ b/buildSrc/src/testFixtures/java/org/opensearch/gradle/test/JUnit3MethodProvider.java
@@ -43,7 +43,7 @@
 
 /**
  * Backwards compatible test* method provider (public, non-static).
- *
+ * <p>
  * copy of org.apache.lucene.util.LuceneJUnit3MethodProvider to avoid a dependency between build and test fw.
  */
 public final class JUnit3MethodProvider implements TestMethodProvider {
diff --git a/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle b/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle
index cb8050d1718c4..f24b61ef0d165 100644
--- a/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle
+++ b/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle
@@ -15,8 +15,9 @@ plugins {
 repositories {
   mavenCentral()
 }
+
 dependencies {
-  implementation "org.apache.logging.log4j:log4j-core:2.20.0"
+  implementation "org.apache.logging.log4j:log4j-core:2.22.0"
 }
 
 ["0.0.1", "0.0.2"].forEach { v ->
diff --git a/buildSrc/version.properties b/buildSrc/version.properties
index ee666f90f83dd..74d655cfb1045 100644
--- a/buildSrc/version.properties
+++ b/buildSrc/version.properties
@@ -1,22 +1,20 @@
 opensearch        = 3.0.0
-lucene            = 9.8.0-snapshot-4373c3b
+lucene            = 9.8.0
 
 bundled_jdk_vendor = adoptium
-bundled_jdk = 20.0.2+9
-# See please https://github.com/adoptium/temurin-build/issues/3371
-bundled_jdk_linux_ppc64le = 20+36
+bundled_jdk = 21.0.1+12
 
 # optional dependencies
 spatial4j         = 0.7
 jts               = 1.15.0
-jackson           = 2.15.2
-jackson_databind  = 2.15.2
+jackson           = 2.16.0
+jackson_databind  = 2.16.0
 snakeyaml         = 2.1
 icu4j             = 70.1
 supercsv          = 2.4.0
-log4j             = 2.20.0
+log4j             = 2.21.0
 slf4j             = 1.7.36
-asm               = 9.5
+asm               = 9.6
 jettison          = 1.5.4
 woodstox          = 6.4.0
 kotlin            = 1.7.10
@@ -28,9 +26,13 @@ jakarta_annotation = 1.3.5
 # when updating the JNA version, also update the version in buildSrc/build.gradle
 jna               = 5.13.0
 
-netty             = 4.1.97.Final
+netty             = 4.1.101.Final
 joda              = 2.12.2
 
+# project reactor
+reactor_netty     = 1.1.13
+reactor           = 3.5.11
+
 # client dependencies
 httpclient5       = 5.2.1
 httpcore5         = 5.2.2
@@ -48,14 +50,14 @@ reactivestreams   = 1.0.4
 # when updating this version, you need to ensure compatibility with:
 #  - plugins/ingest-attachment (transitive dependency, check the upstream POM)
 #  - distribution/tools/plugin-cli
-bouncycastle=1.75
+bouncycastle=1.76
 # test dependencies
 randomizedrunner  = 2.7.1
 junit             = 4.13.2
 hamcrest          = 2.1
-mockito           = 5.4.0
+mockito           = 5.5.0
 objenesis         = 3.2
-bytebuddy         = 1.14.3
+bytebuddy         = 1.14.7
 
 # benchmark dependencies
 jmh               = 1.35
@@ -68,4 +70,5 @@ jzlib             = 1.1.3
 resteasy          = 6.2.4.Final
 
 # opentelemetry dependencies
-opentelemetry         = 1.30.1
+opentelemetry         = 1.32.0
+opentelemetrysemconv  = 1.23.1-alpha
diff --git a/client/benchmark/build.gradle b/client/benchmark/build.gradle
index 6fd5262f0ab4f..c1af5fa92e35c 100644
--- a/client/benchmark/build.gradle
+++ b/client/benchmark/build.gradle
@@ -33,7 +33,7 @@ apply plugin: 'application'
 
 base {
   group = 'org.opensearch.client'
-  archivesBaseName = 'client-benchmarks'
+  archivesName = 'client-benchmarks'
 }
 
 // Not published so no need to assemble
diff --git a/client/benchmark/src/main/java/org/opensearch/client/benchmark/metrics/SampleRecorder.java b/client/benchmark/src/main/java/org/opensearch/client/benchmark/metrics/SampleRecorder.java
index e53e4f1ad692d..9cd12f5e78bd0 100644
--- a/client/benchmark/src/main/java/org/opensearch/client/benchmark/metrics/SampleRecorder.java
+++ b/client/benchmark/src/main/java/org/opensearch/client/benchmark/metrics/SampleRecorder.java
@@ -37,7 +37,7 @@
 
 /**
  * Stores measurement samples.
- *
+ * <p>
  * This class is NOT threadsafe.
  */
 public final class SampleRecorder {
diff --git a/client/rest-high-level/build.gradle b/client/rest-high-level/build.gradle
index 770cb3f78ca47..fdc93d8037ce6 100644
--- a/client/rest-high-level/build.gradle
+++ b/client/rest-high-level/build.gradle
@@ -39,7 +39,7 @@ apply plugin: 'opensearch.rest-resources'
 
 base {
   group = 'org.opensearch.client'
-  archivesBaseName = 'opensearch-rest-high-level-client'
+  archivesName = 'opensearch-rest-high-level-client'
 }
 
 restResources {
diff --git a/client/rest-high-level/src/main/java/org/opensearch/client/ClusterClient.java b/client/rest-high-level/src/main/java/org/opensearch/client/ClusterClient.java
index 5bd5a5d0e308e..eb0a8b0e8f40a 100644
--- a/client/rest-high-level/src/main/java/org/opensearch/client/ClusterClient.java
+++ b/client/rest-high-level/src/main/java/org/opensearch/client/ClusterClient.java
@@ -170,8 +170,8 @@ public ClusterHealthResponse health(ClusterHealthRequest healthRequest, RequestO
 
     /**
      * Asynchronously get cluster health using the Cluster Health API.
-     *
      * If timeout occurred, {@link ClusterHealthResponse} will have isTimedOut() == true and status() == RestStatus.REQUEST_TIMEOUT
+     *
      * @param healthRequest the request
      * @param options the request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
      * @param listener the listener to be notified upon request completion
diff --git a/client/rest-high-level/src/main/java/org/opensearch/client/RequestConverters.java b/client/rest-high-level/src/main/java/org/opensearch/client/RequestConverters.java
index 61a202d25167f..35d9929a649ff 100644
--- a/client/rest-high-level/src/main/java/org/opensearch/client/RequestConverters.java
+++ b/client/rest-high-level/src/main/java/org/opensearch/client/RequestConverters.java
@@ -451,9 +451,9 @@ static void addSearchRequestParams(Params params, SearchRequest searchRequest) {
             params.withIndicesOptions(searchRequest.indicesOptions());
         }
         params.withSearchType(searchRequest.searchType().name().toLowerCase(Locale.ROOT));
-        /**
-         * Merging search responses as part of CCS flow to reduce roundtrips is not supported for point in time -
-         * refer to org.opensearch.action.search.SearchResponseMerger
+        /*
+          Merging search responses as part of CCS flow to reduce roundtrips is not supported for point in time -
+          refer to org.opensearch.action.search.SearchResponseMerger
          */
         if (searchRequest.pointInTimeBuilder() != null) {
             params.putParam("ccs_minimize_roundtrips", "false");
diff --git a/client/rest-high-level/src/main/java/org/opensearch/client/TimedRequest.java b/client/rest-high-level/src/main/java/org/opensearch/client/TimedRequest.java
index dad5b6a3679ec..d40445b2daa81 100644
--- a/client/rest-high-level/src/main/java/org/opensearch/client/TimedRequest.java
+++ b/client/rest-high-level/src/main/java/org/opensearch/client/TimedRequest.java
@@ -37,7 +37,7 @@
 
 /**
  * A base request for any requests that supply timeouts.
- *
+ * <p>
  * Please note, any requests that use a ackTimeout should set timeout as they
  * represent the same backing field on the server.
  */
diff --git a/client/rest-high-level/src/main/java/org/opensearch/client/indices/CreateIndexRequest.java b/client/rest-high-level/src/main/java/org/opensearch/client/indices/CreateIndexRequest.java
index 7805a7853b003..62c5b54c0e75e 100644
--- a/client/rest-high-level/src/main/java/org/opensearch/client/indices/CreateIndexRequest.java
+++ b/client/rest-high-level/src/main/java/org/opensearch/client/indices/CreateIndexRequest.java
@@ -156,7 +156,7 @@ public MediaType mappingsMediaType() {
 
     /**
      * Adds mapping that will be added when the index gets created.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      *
      * @param source The mapping source
@@ -168,7 +168,7 @@ public CreateIndexRequest mapping(String source, MediaType mediaType) {
 
     /**
      * Adds mapping that will be added when the index gets created.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      *
      * @param source The mapping source
@@ -179,7 +179,7 @@ public CreateIndexRequest mapping(XContentBuilder source) {
 
     /**
      * Adds mapping that will be added when the index gets created.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      *
      * @param source The mapping source
@@ -196,7 +196,7 @@ public CreateIndexRequest mapping(Map<String, ?> source) {
 
     /**
      * Adds mapping that will be added when the index gets created.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      *
      * @param source The mapping source
@@ -282,7 +282,7 @@ public CreateIndexRequest aliases(Collection<Alias> aliases) {
 
     /**
      * Sets the settings and mappings as a single source.
-     *
+     * <p>
      * Note that the mapping definition should *not* be nested under a type name.
      */
     public CreateIndexRequest source(String source, MediaType mediaType) {
@@ -291,7 +291,7 @@ public CreateIndexRequest source(String source, MediaType mediaType) {
 
     /**
      * Sets the settings and mappings as a single source.
-     *
+     * <p>
      * Note that the mapping definition should *not* be nested under a type name.
      */
     public CreateIndexRequest source(XContentBuilder source) {
@@ -300,7 +300,7 @@ public CreateIndexRequest source(XContentBuilder source) {
 
     /**
      * Sets the settings and mappings as a single source.
-     *
+     * <p>
      * Note that the mapping definition should *not* be nested under a type name.
      */
     public CreateIndexRequest source(BytesReference source, MediaType mediaType) {
@@ -311,7 +311,7 @@ public CreateIndexRequest source(BytesReference source, MediaType mediaType) {
 
     /**
      * Sets the settings and mappings as a single source.
-     *
+     * <p>
      * Note that the mapping definition should *not* be nested under a type name.
      */
     @SuppressWarnings("unchecked")
diff --git a/client/rest-high-level/src/main/java/org/opensearch/client/indices/PutMappingRequest.java b/client/rest-high-level/src/main/java/org/opensearch/client/indices/PutMappingRequest.java
index 6d7e95d191ba6..a63393bd2341b 100644
--- a/client/rest-high-level/src/main/java/org/opensearch/client/indices/PutMappingRequest.java
+++ b/client/rest-high-level/src/main/java/org/opensearch/client/indices/PutMappingRequest.java
@@ -105,7 +105,7 @@ public MediaType mediaType() {
 
     /**
      * The mapping source definition.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      */
     public PutMappingRequest source(Map<String, ?> mappingSource) {
@@ -120,7 +120,7 @@ public PutMappingRequest source(Map<String, ?> mappingSource) {
 
     /**
      * The mapping source definition.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      */
     public PutMappingRequest source(String mappingSource, MediaType mediaType) {
@@ -131,7 +131,7 @@ public PutMappingRequest source(String mappingSource, MediaType mediaType) {
 
     /**
      * The mapping source definition.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      */
     public PutMappingRequest source(XContentBuilder builder) {
@@ -142,7 +142,7 @@ public PutMappingRequest source(XContentBuilder builder) {
 
     /**
      * The mapping source definition.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      */
     public PutMappingRequest source(BytesReference source, MediaType mediaType) {
diff --git a/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskGroup.java b/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskGroup.java
index c419884700587..9129de717459f 100644
--- a/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskGroup.java
+++ b/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskGroup.java
@@ -38,7 +38,6 @@
 
 /**
  * Client side counterpart of server side version.
- *
  * {@link org.opensearch.action.admin.cluster.node.tasks.list.TaskGroup}
  */
 public class TaskGroup {
diff --git a/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskInfo.java b/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskInfo.java
index 51ac62830446f..75badc4e3dbf2 100644
--- a/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskInfo.java
+++ b/client/rest-high-level/src/main/java/org/opensearch/client/tasks/TaskInfo.java
@@ -54,6 +54,7 @@ public class TaskInfo {
     private long runningTimeNanos;
     private boolean cancellable;
     private boolean cancelled;
+    private Long cancellationStartTime;
     private TaskId parentTaskId;
     private final Map<String, Object> status = new HashMap<>();
     private final Map<String, String> headers = new HashMap<>();
@@ -127,6 +128,14 @@ void setCancelled(boolean cancelled) {
         this.cancelled = cancelled;
     }
 
+    public Long getCancellationStartTime() {
+        return this.cancellationStartTime;
+    }
+
+    public void setCancellationStartTime(Long cancellationStartTime) {
+        this.cancellationStartTime = cancellationStartTime;
+    }
+
     public TaskId getParentTaskId() {
         return parentTaskId;
     }
@@ -180,6 +189,7 @@ private void noOpParse(Object s) {}
         parser.declareString(TaskInfo::setParentTaskId, new ParseField("parent_task_id"));
         parser.declareObject(TaskInfo::setHeaders, (p, c) -> p.mapStrings(), new ParseField("headers"));
         parser.declareObject(TaskInfo::setResourceStats, (p, c) -> p.map(), new ParseField("resource_stats"));
+        parser.declareLong(TaskInfo::setCancellationStartTime, new ParseField("cancellation_time_millis"));
         PARSER = (XContentParser p, Void v, String name) -> parser.parse(p, new TaskInfo(new TaskId(name)), null);
     }
 
@@ -199,7 +209,8 @@ && isCancelled() == taskInfo.isCancelled()
             && Objects.equals(getParentTaskId(), taskInfo.getParentTaskId())
             && Objects.equals(status, taskInfo.status)
             && Objects.equals(getHeaders(), taskInfo.getHeaders())
-            && Objects.equals(getResourceStats(), taskInfo.getResourceStats());
+            && Objects.equals(getResourceStats(), taskInfo.getResourceStats())
+            && Objects.equals(getCancellationStartTime(), taskInfo.cancellationStartTime);
     }
 
     @Override
@@ -216,7 +227,8 @@ public int hashCode() {
             getParentTaskId(),
             status,
             getHeaders(),
-            getResourceStats()
+            getResourceStats(),
+            getCancellationStartTime()
         );
     }
 
@@ -250,6 +262,8 @@ public String toString() {
             + headers
             + ", resource_stats="
             + resourceStats
+            + ", cancellationStartTime="
+            + cancellationStartTime
             + '}';
     }
 }
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/AbstractRequestTestCase.java b/client/rest-high-level/src/test/java/org/opensearch/client/AbstractRequestTestCase.java
index 49bcb61b2dc3d..c464ee9ece74a 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/AbstractRequestTestCase.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/AbstractRequestTestCase.java
@@ -44,7 +44,7 @@
 
 /**
  * Base class for HLRC request parsing tests.
- *
+ * <p>
  * This case class facilitates generating client side request test instances and
  * verifies that they are correctly parsed into server side request instances.
  *
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/AbstractResponseTestCase.java b/client/rest-high-level/src/test/java/org/opensearch/client/AbstractResponseTestCase.java
index 27704b01560c4..7d2d6b87b85c6 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/AbstractResponseTestCase.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/AbstractResponseTestCase.java
@@ -44,7 +44,7 @@
 
 /**
  * Base class for HLRC response parsing tests.
- *
+ * <p>
  * This case class facilitates generating server side response test instances and
  * verifies that they are correctly parsed into HLRC response instances.
  *
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/BulkProcessorRetryIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/BulkProcessorRetryIT.java
index b7f6328b3c88e..3678cc042ba47 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/BulkProcessorRetryIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/BulkProcessorRetryIT.java
@@ -180,7 +180,7 @@ private static MultiGetRequest indexDocs(BulkProcessor processor, int numDocs) {
     /**
      * Internal helper class to correlate backoff states with bulk responses. This is needed to check whether we maxed out the number
      * of retries but still got rejected (which is perfectly fine and can also happen from time to time under heavy load).
-     *
+     * <p>
      * This implementation relies on an implementation detail in Retry, namely that the bulk listener is notified on the same thread
      * as the last call to the backoff policy's iterator. The advantage is that this is non-invasive to the rest of the production code.
      */
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java
index d5c1888e78b5d..b0990560b08ba 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java
@@ -24,7 +24,6 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
@@ -72,7 +71,7 @@ public void testCreateAndDeletePit() throws IOException {
         assertTrue(deletePitResponse.getDeletePitResults().get(0).getPitId().equals(createPitResponse.getId()));
     }
 
-    public void testDeleteAllAndListAllPits() throws IOException, InterruptedException {
+    public void testDeleteAllAndListAllPits() throws Exception {
         CreatePitRequest pitRequest = new CreatePitRequest(new TimeValue(1, TimeUnit.DAYS), true, "index");
         CreatePitResponse pitResponse = execute(pitRequest, highLevelClient()::createPit, highLevelClient()::createPitAsync);
         CreatePitResponse pitResponse1 = execute(pitRequest, highLevelClient()::createPit, highLevelClient()::createPitAsync);
@@ -91,11 +90,9 @@ public void testDeleteAllAndListAllPits() throws IOException, InterruptedExcepti
         List<String> pits = getAllPitResponse.getPitInfos().stream().map(r -> r.getPitId()).collect(Collectors.toList());
         assertTrue(pits.contains(pitResponse.getId()));
         assertTrue(pits.contains(pitResponse1.getId()));
-        CountDownLatch countDownLatch = new CountDownLatch(1);
         ActionListener<DeletePitResponse> deletePitListener = new ActionListener<>() {
             @Override
             public void onResponse(DeletePitResponse response) {
-                countDownLatch.countDown();
                 for (DeletePitInfo deletePitInfo : response.getDeletePitResults()) {
                     assertTrue(deletePitInfo.isSuccessful());
                 }
@@ -103,19 +100,20 @@ public void onResponse(DeletePitResponse response) {
 
             @Override
             public void onFailure(Exception e) {
-                countDownLatch.countDown();
                 if (!(e instanceof OpenSearchStatusException)) {
                     throw new AssertionError("Delete all failed");
                 }
             }
         };
         final CreatePitResponse pitResponse3 = execute(pitRequest, highLevelClient()::createPit, highLevelClient()::createPitAsync);
-
+        assertTrue(pitResponse3.getId() != null);
         ActionListener<GetAllPitNodesResponse> getPitsListener = new ActionListener<GetAllPitNodesResponse>() {
             @Override
             public void onResponse(GetAllPitNodesResponse response) {
                 List<String> pits = response.getPitInfos().stream().map(r -> r.getPitId()).collect(Collectors.toList());
                 assertTrue(pits.contains(pitResponse3.getId()));
+                // delete all pits
+                highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
             }
 
             @Override
@@ -126,11 +124,12 @@ public void onFailure(Exception e) {
             }
         };
         highLevelClient().getAllPitsAsync(RequestOptions.DEFAULT, getPitsListener);
-        highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
-        assertTrue(countDownLatch.await(10, TimeUnit.SECONDS));
+
         // validate no pits case
-        getAllPitResponse = highLevelClient().getAllPits(RequestOptions.DEFAULT);
-        assertTrue(getAllPitResponse.getPitInfos().size() == 0);
-        highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
+        assertBusy(() -> {
+            GetAllPitNodesResponse getAllPitResponse1 = highLevelClient().getAllPits(RequestOptions.DEFAULT);
+            assertTrue(getAllPitResponse1.getPitInfos().size() == 0);
+            highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
+        });
     }
 }
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IndicesClientDocumentationIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IndicesClientDocumentationIT.java
index abb2d75aea751..ce080b45273b4 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IndicesClientDocumentationIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IndicesClientDocumentationIT.java
@@ -137,15 +137,15 @@
  * You need to wrap your code between two tags like:
  * // tag::example
  * // end::example
- *
+ * <p>
  * Where example is your tag name.
- *
+ * <p>
  * Then in the documentation, you can extract what is between tag and end tags with
  * ["source","java",subs="attributes,callouts,macros"]
  * --------------------------------------------------
  * include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[example]
  * --------------------------------------------------
- *
+ * <p>
  * The column width of the code block is 84. If the code contains a line longer
  * than 84, the line will be cut and a horizontal scroll bar will be displayed.
  * (the code indentation of the tag is not included in the width)
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IngestClientDocumentationIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IngestClientDocumentationIT.java
index d14759065b5eb..28909cf58541a 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IngestClientDocumentationIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/IngestClientDocumentationIT.java
@@ -65,15 +65,15 @@
  * You need to wrap your code between two tags like:
  * // tag::example
  * // end::example
- *
+ * <p>
  * Where example is your tag name.
- *
+ * <p>
  * Then in the documentation, you can extract what is between tag and end tags with
  * ["source","java",subs="attributes,callouts,macros"]
  * --------------------------------------------------
  * include-tagged::{doc-tests}/IngestClientDocumentationIT.java[example]
  * --------------------------------------------------
- *
+ * <p>
  * The column width of the code block is 84. If the code contains a line longer
  * than 84, the line will be cut and a horizontal scroll bar will be displayed.
  * (the code indentation of the tag is not included in the width)
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/SnapshotClientDocumentationIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/SnapshotClientDocumentationIT.java
index 50bcf79642eac..d0015db044843 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/SnapshotClientDocumentationIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/SnapshotClientDocumentationIT.java
@@ -90,15 +90,15 @@
  * You need to wrap your code between two tags like:
  * // tag::example
  * // end::example
- *
+ * <p>
  * Where example is your tag name.
- *
+ * <p>
  * Then in the documentation, you can extract what is between tag and end tags with
  * ["source","java",subs="attributes,callouts,macros"]
  * --------------------------------------------------
  * include-tagged::{doc-tests}/SnapshotClientDocumentationIT.java[example]
  * --------------------------------------------------
- *
+ * <p>
  * The column width of the code block is 84. If the code contains a line longer
  * than 84, the line will be cut and a horizontal scroll bar will be displayed.
  * (the code indentation of the tag is not included in the width)
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/StoredScriptsDocumentationIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/StoredScriptsDocumentationIT.java
index 6916ae11556e2..2e2d15df5392a 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/StoredScriptsDocumentationIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/StoredScriptsDocumentationIT.java
@@ -66,15 +66,15 @@
  * You need to wrap your code between two tags like:
  * // tag::example
  * // end::example
- *
+ * <p>
  * Where example is your tag name.
- *
+ * <p>
  * Then in the documentation, you can extract what is between tag and end tags with
  * ["source","java",subs="attributes,callouts,macros"]
  * --------------------------------------------------
  * include-tagged::{doc-tests}/StoredScriptsDocumentationIT.java[example]
  * --------------------------------------------------
- *
+ * <p>
  * The column width of the code block is 84. If the code contains a line longer
  * than 84, the line will be cut and a horizontal scroll bar will be displayed.
  * (the code indentation of the tag is not included in the width)
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/TasksClientDocumentationIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/TasksClientDocumentationIT.java
index 03e267aafd1b7..cbac0b8c97d9c 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/documentation/TasksClientDocumentationIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/documentation/TasksClientDocumentationIT.java
@@ -66,15 +66,15 @@
  * You need to wrap your code between two tags like:
  * // tag::example
  * // end::example
- *
+ * <p>
  * Where example is your tag name.
- *
+ * <p>
  * Then in the documentation, you can extract what is between tag and end tags with
  * ["source","java",subs="attributes,callouts,macros"]
  * --------------------------------------------------
  * include-tagged::{doc-tests}/{@link TasksClientDocumentationIT}.java[example]
  * --------------------------------------------------
- *
+ * <p>
  * The column width of the code block is 84. If the code contains a line longer
  * than 84, the line will be cut and a horizontal scroll bar will be displayed.
  * (the code indentation of the tag is not included in the width)
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/indices/RandomCreateIndexGenerator.java b/client/rest-high-level/src/test/java/org/opensearch/client/indices/RandomCreateIndexGenerator.java
index 1f747dc139d15..edb4d16c6d992 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/indices/RandomCreateIndexGenerator.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/indices/RandomCreateIndexGenerator.java
@@ -44,7 +44,7 @@ public class RandomCreateIndexGenerator {
 
     /**
      * Returns a random {@link CreateIndexRequest}.
-     *
+     * <p>
      * Randomizes the index name, the aliases, mappings and settings associated with the
      * index. When present, the mappings make no mention of types.
      */
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/tasks/CancelTasksResponseTests.java b/client/rest-high-level/src/test/java/org/opensearch/client/tasks/CancelTasksResponseTests.java
index 835a93b5b09ce..faf5024d0c173 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/tasks/CancelTasksResponseTests.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/tasks/CancelTasksResponseTests.java
@@ -84,6 +84,10 @@ protected CancelTasksResponseTests.ByNodeCancelTasksResponse createServerTestIns
         for (int i = 0; i < 4; i++) {
             boolean cancellable = randomBoolean();
             boolean cancelled = cancellable == true ? randomBoolean() : false;
+            Long cancellationStartTime = null;
+            if (cancelled) {
+                cancellationStartTime = randomNonNegativeLong();
+            }
             tasks.add(
                 new org.opensearch.tasks.TaskInfo(
                     new TaskId(NODE_ID, (long) i),
@@ -97,7 +101,8 @@ protected CancelTasksResponseTests.ByNodeCancelTasksResponse createServerTestIns
                     cancelled,
                     new TaskId("node1", randomLong()),
                     Collections.singletonMap("x-header-of", "some-value"),
-                    null
+                    null,
+                    cancellationStartTime
                 )
             );
         }
@@ -135,6 +140,7 @@ protected void assertInstances(
             assertEquals(ti.isCancelled(), taskInfo.isCancelled());
             assertEquals(ti.getParentTaskId().getNodeId(), taskInfo.getParentTaskId().getNodeId());
             assertEquals(ti.getParentTaskId().getId(), taskInfo.getParentTaskId().getId());
+            assertEquals(ti.getCancellationStartTime(), taskInfo.getCancellationStartTime());
             FakeTaskStatus status = (FakeTaskStatus) ti.getStatus();
             assertEquals(status.code, taskInfo.getStatus().get("code"));
             assertEquals(status.status, taskInfo.getStatus().get("status"));
diff --git a/client/rest/build.gradle b/client/rest/build.gradle
index 2c437c909fb03..f18df65dfddfa 100644
--- a/client/rest/build.gradle
+++ b/client/rest/build.gradle
@@ -34,13 +34,13 @@ apply plugin: 'opensearch.build'
 apply plugin: 'opensearch.publish'
 
 java {
-  targetCompatibility = JavaVersion.VERSION_11
-  sourceCompatibility = JavaVersion.VERSION_11
+  targetCompatibility = JavaVersion.VERSION_1_8
+  sourceCompatibility = JavaVersion.VERSION_1_8
 }
 
 base {
   group = 'org.opensearch.client'
-  archivesBaseName = 'opensearch-rest-client'
+  archivesName = 'opensearch-rest-client'
 }
 
 dependencies {
@@ -109,3 +109,10 @@ thirdPartyAudit.ignoreMissingClasses(
   'javax.servlet.ServletContextEvent',
   'javax.servlet.ServletContextListener'
 )
+
+tasks.withType(JavaCompile) {
+  // Suppressing '[options] target value 8 is obsolete and will be removed in a future release'
+  configure(options) {
+    options.compilerArgs << '-Xlint:-options'
+  }
+}
diff --git a/client/rest/src/main/java/org/opensearch/client/RestClient.java b/client/rest/src/main/java/org/opensearch/client/RestClient.java
index e819fa27a8939..15905add76c4f 100644
--- a/client/rest/src/main/java/org/opensearch/client/RestClient.java
+++ b/client/rest/src/main/java/org/opensearch/client/RestClient.java
@@ -310,7 +310,7 @@ public boolean isRunning() {
      * they will be retried). In case of failures all of the alive nodes (or
      * dead nodes that deserve a retry) are retried until one responds or none
      * of them does, in which case an {@link IOException} will be thrown.
-     *
+     * <p>
      * This method works by performing an asynchronous call and waiting
      * for the result. If the asynchronous call throws an exception we wrap
      * it and rethrow it so that the stack trace attached to the exception
@@ -1116,9 +1116,15 @@ public long getContentLength() {
                 if (chunkedEnabled.get()) {
                     return -1L;
                 } else {
-                    long size;
+                    long size = 0;
+                    final byte[] buf = new byte[8192];
+                    int nread = 0;
+
                     try (InputStream is = getContent()) {
-                        size = is.readAllBytes().length;
+                        // read to EOF which may read more or less than buffer size
+                        while ((nread = is.read(buf)) > 0) {
+                            size += nread;
+                        }
                     } catch (IOException ex) {
                         size = -1L;
                     }
diff --git a/client/rest/src/main/java/org/opensearch/client/nio/HeapBufferedAsyncEntityConsumer.java b/client/rest/src/main/java/org/opensearch/client/nio/HeapBufferedAsyncEntityConsumer.java
index 9bd17d1c24c7e..ae38c1a0308d1 100644
--- a/client/rest/src/main/java/org/opensearch/client/nio/HeapBufferedAsyncEntityConsumer.java
+++ b/client/rest/src/main/java/org/opensearch/client/nio/HeapBufferedAsyncEntityConsumer.java
@@ -86,25 +86,29 @@ protected void data(final ByteBuffer src, final boolean endOfStream) throws IOEx
             return;
         }
 
+        int len = src.limit();
+        if (len < 0) {
+            len = 4096;
+        } else if (len > bufferLimitBytes) {
+            throw new ContentTooLongException(
+                "entity content is too long [" + len + "] for the configured buffer limit [" + bufferLimitBytes + "]"
+            );
+        }
+
         ByteArrayBuffer buffer = bufferRef.get();
         if (buffer == null) {
-            buffer = new ByteArrayBuffer(bufferLimitBytes);
+            buffer = new ByteArrayBuffer(len);
             if (bufferRef.compareAndSet(null, buffer) == false) {
                 buffer = bufferRef.get();
             }
         }
 
-        int len = src.limit();
         if (buffer.length() + len > bufferLimitBytes) {
             throw new ContentTooLongException(
                 "entity content is too long [" + len + "] for the configured buffer limit [" + bufferLimitBytes + "]"
             );
         }
 
-        if (len < 0) {
-            len = 4096;
-        }
-
         if (src.hasArray()) {
             buffer.append(src.array(), src.arrayOffset() + src.position(), src.remaining());
         } else {
@@ -136,4 +140,12 @@ public void releaseResources() {
             buffer = null;
         }
     }
+
+    /**
+     * Gets current byte buffer instance
+     * @return byte buffer instance
+     */
+    ByteArrayBuffer getBuffer() {
+        return bufferRef.get();
+    }
 }
diff --git a/client/rest/src/test/java/org/opensearch/client/documentation/RestClientDocumentation.java b/client/rest/src/test/java/org/opensearch/client/documentation/RestClientDocumentation.java
index b2807d35d230e..42c31864e0578 100644
--- a/client/rest/src/test/java/org/opensearch/client/documentation/RestClientDocumentation.java
+++ b/client/rest/src/test/java/org/opensearch/client/documentation/RestClientDocumentation.java
@@ -89,15 +89,15 @@
  * You need to wrap your code between two tags like:
  * // tag::example[]
  * // end::example[]
- *
+ * <p>
  * Where example is your tag name.
- *
+ * <p>
  * Then in the documentation, you can extract what is between tag and end tags with
  * ["source","java",subs="attributes,callouts,macros"]
  * --------------------------------------------------
  * include-tagged::{doc-tests}/RestClientDocumentation.java[example]
  * --------------------------------------------------
- *
+ * <p>
  * Note that this is not a test class as we are only interested in testing that docs snippets compile. We don't want
  * to send requests to a node and we don't even have the tools to do it.
  */
diff --git a/client/rest/src/test/java/org/opensearch/client/nio/HeapBufferedAsyncEntityConsumerTests.java b/client/rest/src/test/java/org/opensearch/client/nio/HeapBufferedAsyncEntityConsumerTests.java
new file mode 100644
index 0000000000000..fdfe49ca901c9
--- /dev/null
+++ b/client/rest/src/test/java/org/opensearch/client/nio/HeapBufferedAsyncEntityConsumerTests.java
@@ -0,0 +1,71 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.client.nio;
+
+import org.apache.hc.core5.http.ContentTooLongException;
+import org.opensearch.client.RestClientTestCase;
+import org.junit.After;
+import org.junit.Before;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertThrows;
+
+public class HeapBufferedAsyncEntityConsumerTests extends RestClientTestCase {
+    private static final int BUFFER_LIMIT = 100 * 1024 * 1024 /* 100Mb */;
+    private HeapBufferedAsyncEntityConsumer consumer;
+
+    @Before
+    public void setUp() {
+        consumer = new HeapBufferedAsyncEntityConsumer(BUFFER_LIMIT);
+    }
+
+    @After
+    public void tearDown() {
+        consumer.releaseResources();
+    }
+
+    public void testConsumerAllocatesBufferLimit() throws IOException {
+        consumer.consume((ByteBuffer) randomByteBufferOfLength(1000).flip());
+        assertThat(consumer.getBuffer().capacity(), equalTo(1000));
+    }
+
+    public void testConsumerAllocatesEmptyBuffer() throws IOException {
+        consumer.consume((ByteBuffer) ByteBuffer.allocate(0).flip());
+        assertThat(consumer.getBuffer().capacity(), equalTo(0));
+    }
+
+    public void testConsumerExpandsBufferLimits() throws IOException {
+        consumer.consume((ByteBuffer) randomByteBufferOfLength(1000).flip());
+        consumer.consume((ByteBuffer) randomByteBufferOfLength(2000).flip());
+        consumer.consume((ByteBuffer) randomByteBufferOfLength(3000).flip());
+        assertThat(consumer.getBuffer().capacity(), equalTo(6000));
+    }
+
+    public void testConsumerAllocatesLimit() throws IOException {
+        consumer.consume((ByteBuffer) randomByteBufferOfLength(BUFFER_LIMIT).flip());
+        assertThat(consumer.getBuffer().capacity(), equalTo(BUFFER_LIMIT));
+    }
+
+    public void testConsumerFailsToAllocateOverLimit() throws IOException {
+        assertThrows(ContentTooLongException.class, () -> consumer.consume((ByteBuffer) randomByteBufferOfLength(BUFFER_LIMIT + 1).flip()));
+    }
+
+    public void testConsumerFailsToExpandOverLimit() throws IOException {
+        consumer.consume((ByteBuffer) randomByteBufferOfLength(BUFFER_LIMIT).flip());
+        assertThrows(ContentTooLongException.class, () -> consumer.consume((ByteBuffer) randomByteBufferOfLength(1).flip()));
+    }
+
+    private static ByteBuffer randomByteBufferOfLength(int length) {
+        return ByteBuffer.allocate(length).put(randomBytesOfLength(length));
+    }
+}
diff --git a/client/sniffer/build.gradle b/client/sniffer/build.gradle
index f645b2dbbc933..4b50a996d1f9f 100644
--- a/client/sniffer/build.gradle
+++ b/client/sniffer/build.gradle
@@ -37,7 +37,7 @@ java {
 
 base {
   group = 'org.opensearch.client'
-  archivesBaseName = 'opensearch-rest-client-sniffer'
+  archivesName = 'opensearch-rest-client-sniffer'
 }
 
 dependencies {
diff --git a/client/sniffer/licenses/jackson-core-2.15.2.jar.sha1 b/client/sniffer/licenses/jackson-core-2.15.2.jar.sha1
deleted file mode 100644
index ec6781b968eed..0000000000000
--- a/client/sniffer/licenses/jackson-core-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-a6fe1836469a69b3ff66037c324d75fc66ef137c
\ No newline at end of file
diff --git a/client/sniffer/licenses/jackson-core-2.16.0.jar.sha1 b/client/sniffer/licenses/jackson-core-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..c2b70fb4ae202
--- /dev/null
+++ b/client/sniffer/licenses/jackson-core-2.16.0.jar.sha1
@@ -0,0 +1 @@
+899e5cf01be55fbf094ad72b2edb0c5df99111ee
\ No newline at end of file
diff --git a/client/sniffer/src/test/java/org/opensearch/client/sniff/documentation/SnifferDocumentation.java b/client/sniffer/src/test/java/org/opensearch/client/sniff/documentation/SnifferDocumentation.java
index 440e9a2ea5cd1..8a4ca1fb0a136 100644
--- a/client/sniffer/src/test/java/org/opensearch/client/sniff/documentation/SnifferDocumentation.java
+++ b/client/sniffer/src/test/java/org/opensearch/client/sniff/documentation/SnifferDocumentation.java
@@ -49,15 +49,15 @@
  * You need to wrap your code between two tags like:
  * // tag::example[]
  * // end::example[]
- *
+ * <p>
  * Where example is your tag name.
- *
+ * <p>
  * Then in the documentation, you can extract what is between tag and end tags with
  * ["source","java",subs="attributes,callouts,macros"]
  * --------------------------------------------------
  * include-tagged::{doc-tests}/SnifferDocumentation.java[example]
  * --------------------------------------------------
- *
+ * <p>
  * Note that this is not a test class as we are only interested in testing that docs snippets compile. We don't want
  * to send requests to a node and we don't even have the tools to do it.
  */
diff --git a/client/test/build.gradle b/client/test/build.gradle
index f81a009389681..b77865df6decf 100644
--- a/client/test/build.gradle
+++ b/client/test/build.gradle
@@ -30,8 +30,8 @@
 apply plugin: 'opensearch.build'
 
 java {
-  targetCompatibility = JavaVersion.VERSION_11
-  sourceCompatibility = JavaVersion.VERSION_11
+  targetCompatibility = JavaVersion.VERSION_1_8
+  sourceCompatibility = JavaVersion.VERSION_1_8
 }
 
 base {
@@ -69,3 +69,10 @@ dependenciesInfo.enabled = false
 //we aren't releasing this jar
 thirdPartyAudit.enabled = false
 test.enabled = false
+
+tasks.withType(JavaCompile) {
+  // Suppressing '[options] target value 8 is obsolete and will be removed in a future release'
+  configure(options) {
+    options.compilerArgs << '-Xlint:-options'
+  }
+}
diff --git a/distribution/archives/darwin-arm64-tar/build.gradle b/distribution/archives/darwin-arm64-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/darwin-arm64-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/darwin-tar/build.gradle b/distribution/archives/darwin-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/darwin-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/freebsd-tar/build.gradle b/distribution/archives/freebsd-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/freebsd-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/integ-test-zip/build.gradle b/distribution/archives/integ-test-zip/build.gradle
index 9418223b0a44d..ffaea5e8ca771 100644
--- a/distribution/archives/integ-test-zip/build.gradle
+++ b/distribution/archives/integ-test-zip/build.gradle
@@ -38,7 +38,7 @@ apply plugin: 'com.netflix.nebula.maven-publish'
 
 base {
   group = "org.opensearch.distribution.integ-test-zip"
-  archivesBaseName = "opensearch"
+  archivesName = "opensearch"
 }
 
 integTest {
diff --git a/distribution/archives/jre-linux-tar/build.gradle b/distribution/archives/jre-linux-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/jre-linux-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/linux-arm64-tar/build.gradle b/distribution/archives/linux-arm64-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/linux-arm64-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/linux-ppc64le-tar/build.gradle b/distribution/archives/linux-ppc64le-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/linux-ppc64le-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/linux-s390x-tar/build.gradle b/distribution/archives/linux-s390x-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/linux-s390x-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/linux-tar/build.gradle b/distribution/archives/linux-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/linux-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/no-jdk-darwin-arm64-tar/build.gradle b/distribution/archives/no-jdk-darwin-arm64-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/no-jdk-darwin-arm64-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/no-jdk-darwin-tar/build.gradle b/distribution/archives/no-jdk-darwin-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/no-jdk-darwin-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/no-jdk-freebsd-tar/build.gradle b/distribution/archives/no-jdk-freebsd-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/no-jdk-freebsd-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/no-jdk-linux-arm64-tar/build.gradle b/distribution/archives/no-jdk-linux-arm64-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/no-jdk-linux-arm64-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/no-jdk-linux-ppc64le-tar/build.gradle b/distribution/archives/no-jdk-linux-ppc64le-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/no-jdk-linux-ppc64le-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/no-jdk-linux-tar/build.gradle b/distribution/archives/no-jdk-linux-tar/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/no-jdk-linux-tar/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/no-jdk-windows-zip/build.gradle b/distribution/archives/no-jdk-windows-zip/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/no-jdk-windows-zip/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/archives/windows-zip/build.gradle b/distribution/archives/windows-zip/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/archives/windows-zip/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/docker/docker-arm64-build-context/build.gradle b/distribution/docker/docker-arm64-build-context/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/docker/docker-arm64-build-context/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/docker/docker-arm64-export/build.gradle b/distribution/docker/docker-arm64-export/build.gradle
index 3506c4e39c234..62f3dc68b0c8e 100644
--- a/distribution/docker/docker-arm64-export/build.gradle
+++ b/distribution/docker/docker-arm64-export/build.gradle
@@ -11,3 +11,5 @@
 
 // This file is intentionally blank. All configuration of the
 // export is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/docker/docker-export/build.gradle b/distribution/docker/docker-export/build.gradle
index 3506c4e39c234..62f3dc68b0c8e 100644
--- a/distribution/docker/docker-export/build.gradle
+++ b/distribution/docker/docker-export/build.gradle
@@ -11,3 +11,5 @@
 
 // This file is intentionally blank. All configuration of the
 // export is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/docker/docker-ppc64le-export/build.gradle b/distribution/docker/docker-ppc64le-export/build.gradle
index 820a0cdf69dfc..ae7def32c4d6c 100644
--- a/distribution/docker/docker-ppc64le-export/build.gradle
+++ b/distribution/docker/docker-ppc64le-export/build.gradle
@@ -10,3 +10,5 @@
 
 // This file is intentionally blank. All configuration of the
 // export is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/docker/docker-s390x-export/build.gradle b/distribution/docker/docker-s390x-export/build.gradle
index 3506c4e39c234..62f3dc68b0c8e 100644
--- a/distribution/docker/docker-s390x-export/build.gradle
+++ b/distribution/docker/docker-s390x-export/build.gradle
@@ -11,3 +11,5 @@
 
 // This file is intentionally blank. All configuration of the
 // export is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/docker/src/docker/config/log4j2.properties b/distribution/docker/src/docker/config/log4j2.properties
index 761478a9fdc6e..8edd6a7354a16 100644
--- a/distribution/docker/src/docker/config/log4j2.properties
+++ b/distribution/docker/src/docker/config/log4j2.properties
@@ -34,6 +34,16 @@ logger.deprecation.appenderRef.deprecation_rolling.ref = deprecation_rolling
 logger.deprecation.appenderRef.header_warning.ref = header_warning
 logger.deprecation.additivity = false
 
+appender.search_request_slowlog_json_appender.type = Console
+appender.search_request_slowlog_json_appender.name = search_request_slowlog_json_appender
+appender.search_request_slowlog_json_appender.layout.type = OpenSearchJsonLayout
+appender.search_request_slowlog_json_appender.layout.type_name = search_request_slowlog
+
+logger.search_request_slowlog_logger.name = cluster.search.request.slowlog
+logger.search_request_slowlog_logger.level = trace
+logger.search_request_slowlog_logger.appenderRef.search_request_slowlog_json_appender.ref = search_request_slowlog_json_appender
+logger.search_request_slowlog_logger.additivity = false
+
 appender.index_search_slowlog_rolling.type = Console
 appender.index_search_slowlog_rolling.name = index_search_slowlog_rolling
 appender.index_search_slowlog_rolling.layout.type = OpenSearchJsonLayout
diff --git a/distribution/packages/arm64-deb/build.gradle b/distribution/packages/arm64-deb/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/arm64-deb/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/arm64-no-jdk-deb/build.gradle b/distribution/packages/arm64-no-jdk-deb/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/arm64-no-jdk-deb/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/arm64-no-jdk-rpm/build.gradle b/distribution/packages/arm64-no-jdk-rpm/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/arm64-no-jdk-rpm/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/arm64-rpm/build.gradle b/distribution/packages/arm64-rpm/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/arm64-rpm/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/build.gradle b/distribution/packages/build.gradle
index 7914fcc172ef4..ededa7bff34d8 100644
--- a/distribution/packages/build.gradle
+++ b/distribution/packages/build.gradle
@@ -63,7 +63,7 @@ import java.util.regex.Pattern
  */
 
 plugins {
-  id "com.netflix.nebula.ospackage-base" version "11.4.0"
+  id "com.netflix.nebula.ospackage-base" version "11.6.0"
 }
 
 void addProcessFilesTask(String type, boolean jdk) {
@@ -213,7 +213,7 @@ Closure commonPackageConfig(String type, boolean jdk, String architecture) {
     configurationFile '/etc/opensearch/jvm.options'
     configurationFile '/etc/opensearch/log4j2.properties'
     from("${packagingFiles}") {
-      dirMode 02750
+      dirMode 0750
       into('/etc')
       permissionGroup 'opensearch'
       includeEmptyDirs true
@@ -223,7 +223,7 @@ Closure commonPackageConfig(String type, boolean jdk, String architecture) {
     }
     from("${packagingFiles}/etc/opensearch") {
       into('/etc/opensearch')
-      dirMode 02750
+      dirMode 0750
       fileMode 0660
       permissionGroup 'opensearch'
       includeEmptyDirs true
@@ -281,8 +281,8 @@ Closure commonPackageConfig(String type, boolean jdk, String architecture) {
         dirMode mode
       }
     }
-    copyEmptyDir('/var/log/opensearch', 'opensearch', 'opensearch', 02750)
-    copyEmptyDir('/var/lib/opensearch', 'opensearch', 'opensearch', 02750)
+    copyEmptyDir('/var/log/opensearch', 'opensearch', 'opensearch', 0750)
+    copyEmptyDir('/var/lib/opensearch', 'opensearch', 'opensearch', 0750)
     copyEmptyDir('/usr/share/opensearch/plugins', 'root', 'root', 0755)
 
     into '/usr/share/opensearch'
diff --git a/distribution/packages/deb/build.gradle b/distribution/packages/deb/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/deb/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/no-jdk-arm64-deb/build.gradle b/distribution/packages/no-jdk-arm64-deb/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/no-jdk-arm64-deb/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/no-jdk-arm64-rpm/build.gradle b/distribution/packages/no-jdk-arm64-rpm/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/no-jdk-arm64-rpm/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/no-jdk-deb/build.gradle b/distribution/packages/no-jdk-deb/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/no-jdk-deb/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/no-jdk-rpm/build.gradle b/distribution/packages/no-jdk-rpm/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/no-jdk-rpm/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/rpm/build.gradle b/distribution/packages/rpm/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/distribution/packages/rpm/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/distribution/packages/src/deb/lintian/opensearch b/distribution/packages/src/deb/lintian/opensearch
index 854b23131ecbc..e6db8e8c6b322 100644
--- a/distribution/packages/src/deb/lintian/opensearch
+++ b/distribution/packages/src/deb/lintian/opensearch
@@ -15,11 +15,11 @@ missing-dep-on-jarwrapper
 
 # we prefer to not make our config and log files world readable
 non-standard-file-perm etc/default/opensearch 0660 != 0644
-non-standard-dir-perm etc/opensearch/ 2750 != 0755
-non-standard-dir-perm etc/opensearch/jvm.options.d/ 2750 != 0755
+non-standard-dir-perm etc/opensearch/ 0750 != 0755
+non-standard-dir-perm etc/opensearch/jvm.options.d/ 0750 != 0755
 non-standard-file-perm etc/opensearch/*
-non-standard-dir-perm var/lib/opensearch/ 2750 != 0755
-non-standard-dir-perm var/log/opensearch/ 2750 != 0755
+non-standard-dir-perm var/lib/opensearch/ 0750 != 0755
+non-standard-dir-perm var/log/opensearch/ 0750 != 0755
 executable-is-not-world-readable etc/init.d/opensearch 0750
 non-standard-file-permissions-for-etc-init.d-script etc/init.d/opensearch 0750 != 0755
 
diff --git a/distribution/src/config/jvm.options b/distribution/src/config/jvm.options
index 952110c6c0289..1a0abcbaf9c88 100644
--- a/distribution/src/config/jvm.options
+++ b/distribution/src/config/jvm.options
@@ -81,7 +81,7 @@ ${error.file}
 
 # JDK 20+ Incubating Vector Module for SIMD optimizations;
 # disabling may reduce performance on vector optimized lucene
-20:--add-modules=jdk.incubator.vector
+20-:--add-modules=jdk.incubator.vector
 
 # HDFS ForkJoinPool.common() support by SecurityManager
 -Djava.util.concurrent.ForkJoinPool.common.threadFactory=org.opensearch.secure_sm.SecuredForkJoinWorkerThreadFactory
diff --git a/distribution/src/config/log4j2.properties b/distribution/src/config/log4j2.properties
index bb27aaf2e22e6..d040afae82e53 100644
--- a/distribution/src/config/log4j2.properties
+++ b/distribution/src/config/log4j2.properties
@@ -113,6 +113,47 @@ logger.deprecation.appenderRef.deprecation_rolling_old.ref = deprecation_rolling
 logger.deprecation.appenderRef.header_warning.ref = header_warning
 logger.deprecation.additivity = false
 
+######## Search Request Slowlog JSON ####################
+appender.search_request_slowlog_json_appender.type = RollingFile
+appender.search_request_slowlog_json_appender.name = search_request_slowlog_json_appender
+appender.search_request_slowlog_json_appender.fileName = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs\
+  .cluster_name}_index_search_slowlog.json
+appender.search_request_slowlog_json_appender.filePermissions = rw-r-----
+appender.search_request_slowlog_json_appender.layout.type = OpenSearchJsonLayout
+appender.search_request_slowlog_json_appender.layout.type_name = search_request_slowlog
+appender.search_request_slowlog_json_appender.layout.opensearchmessagefields=message,took,took_millis,phase_took,total_hits,search_type,shards,source,id
+
+appender.search_request_slowlog_json_appender.filePattern = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs\
+  .cluster_name}_index_search_slowlog-%i.json.gz
+appender.search_request_slowlog_json_appender.policies.type = Policies
+appender.search_request_slowlog_json_appender.policies.size.type = SizeBasedTriggeringPolicy
+appender.search_request_slowlog_json_appender.policies.size.size = 1GB
+appender.search_request_slowlog_json_appender.strategy.type = DefaultRolloverStrategy
+appender.search_request_slowlog_json_appender.strategy.max = 4
+#################################################
+######## Search Request Slowlog Log File -  old style pattern ####
+appender.search_request_slowlog_log_appender.type = RollingFile
+appender.search_request_slowlog_log_appender.name = search_request_slowlog_log_appender
+appender.search_request_slowlog_log_appender.fileName = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs.cluster_name}\
+  _index_search_slowlog.log
+appender.search_request_slowlog_log_appender.filePermissions = rw-r-----
+appender.search_request_slowlog_log_appender.layout.type = PatternLayout
+appender.search_request_slowlog_log_appender.layout.pattern = [%d{ISO8601}][%-5p][%c{1.}] [%node_name]%marker %m%n
+
+appender.search_request_slowlog_log_appender.filePattern = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs.cluster_name}\
+  _index_search_slowlog-%i.log.gz
+appender.search_request_slowlog_log_appender.policies.type = Policies
+appender.search_request_slowlog_log_appender.policies.size.type = SizeBasedTriggeringPolicy
+appender.search_request_slowlog_log_appender.policies.size.size = 1GB
+appender.search_request_slowlog_log_appender.strategy.type = DefaultRolloverStrategy
+appender.search_request_slowlog_log_appender.strategy.max = 4
+#################################################
+logger.search_request_slowlog_logger.name = cluster.search.request.slowlog
+logger.search_request_slowlog_logger.level = trace
+logger.search_request_slowlog_logger.appenderRef.search_request_slowlog_json_appender.ref = search_request_slowlog_json_appender
+logger.search_request_slowlog_logger.appenderRef.search_request_slowlog_log_appender.ref = search_request_slowlog_log_appender
+logger.search_request_slowlog_logger.additivity = false
+
 ######## Search slowlog JSON ####################
 appender.index_search_slowlog_rolling.type = RollingFile
 appender.index_search_slowlog_rolling.name = index_search_slowlog_rolling
diff --git a/distribution/src/config/opensearch.yml b/distribution/src/config/opensearch.yml
index 1d2cfe7eccae6..b7ab2e1c2309b 100644
--- a/distribution/src/config/opensearch.yml
+++ b/distribution/src/config/opensearch.yml
@@ -121,3 +121,9 @@ ${path.logs}
 # index searcher threadpool.
 #
 #opensearch.experimental.feature.concurrent_segment_search.enabled: false
+#
+#
+# Gates the optimization of datetime formatters caching along with change in default datetime formatter
+# Once there is no observed impact on performance, this feature flag can be removed.
+#
+#opensearch.experimental.optimization.datetime_formatter_caching.enabled: false
diff --git a/distribution/tools/launchers/build.gradle b/distribution/tools/launchers/build.gradle
index e75267f7c4a74..aee205a24dea3 100644
--- a/distribution/tools/launchers/build.gradle
+++ b/distribution/tools/launchers/build.gradle
@@ -39,7 +39,7 @@ dependencies {
 }
 
 base {
-  archivesBaseName = 'opensearch-launchers'
+  archivesName = 'opensearch-launchers'
 }
 
 tasks.withType(CheckForbiddenApis).configureEach {
diff --git a/distribution/tools/launchers/src/main/java/org/opensearch/tools/launchers/SystemJvmOptions.java b/distribution/tools/launchers/src/main/java/org/opensearch/tools/launchers/SystemJvmOptions.java
index aa3dfbe39ee96..726c381db09f6 100644
--- a/distribution/tools/launchers/src/main/java/org/opensearch/tools/launchers/SystemJvmOptions.java
+++ b/distribution/tools/launchers/src/main/java/org/opensearch/tools/launchers/SystemJvmOptions.java
@@ -101,15 +101,15 @@ private static String maybeShowCodeDetailsInExceptionMessages() {
     }
 
     private static String javaLocaleProviders() {
-        /**
-         *  SPI setting is used to allow loading custom CalendarDataProvider
-         *  in jdk8 it has to be loaded from jre/lib/ext,
-         *  in jdk9+ it is already within ES project and on a classpath
-         *
-         *  Due to internationalization enhancements in JDK 9 OpenSearch need to set the provider to COMPAT otherwise time/date
-         *  parsing will break in an incompatible way for some date patterns and locales.
-         *  //TODO COMPAT will be deprecated in at some point, see please https://bugs.openjdk.java.net/browse/JDK-8232906
-         * See also: documentation in <code>server/org.opensearch.common.time.IsoCalendarDataProvider</code>
+        /*
+           SPI setting is used to allow loading custom CalendarDataProvider
+           in jdk8 it has to be loaded from jre/lib/ext,
+           in jdk9+ it is already within ES project and on a classpath
+
+           Due to internationalization enhancements in JDK 9 OpenSearch need to set the provider to COMPAT otherwise time/date
+           parsing will break in an incompatible way for some date patterns and locales.
+           //TODO COMPAT will be deprecated in at some point, see please https://bugs.openjdk.java.net/browse/JDK-8232906
+          See also: documentation in <code>server/org.opensearch.common.time.IsoCalendarDataProvider</code>
          */
         return "-Djava.locale.providers=SPI,COMPAT";
     }
diff --git a/distribution/tools/plugin-cli/build.gradle b/distribution/tools/plugin-cli/build.gradle
index 2db3fef55d02e..f40fb1c4b0a9f 100644
--- a/distribution/tools/plugin-cli/build.gradle
+++ b/distribution/tools/plugin-cli/build.gradle
@@ -31,14 +31,14 @@
 apply plugin: 'opensearch.build'
 
 base {
-  archivesBaseName = 'opensearch-plugin-cli'
+  archivesName = 'opensearch-plugin-cli'
 }
 
 dependencies {
   compileOnly project(":server")
   compileOnly project(":libs:opensearch-cli")
   api "org.bouncycastle:bcpg-fips:1.0.7.1"
-  api "org.bouncycastle:bc-fips:1.0.2.3"
+  api "org.bouncycastle:bc-fips:1.0.2.4"
   testImplementation project(":test:framework")
   testImplementation 'com.google.jimfs:jimfs:1.3.0'
   testRuntimeOnly("com.google.guava:guava:${versions.guava}") {
diff --git a/distribution/tools/plugin-cli/licenses/bc-fips-1.0.2.3.jar.sha1 b/distribution/tools/plugin-cli/licenses/bc-fips-1.0.2.3.jar.sha1
deleted file mode 100644
index c71320050b7de..0000000000000
--- a/distribution/tools/plugin-cli/licenses/bc-fips-1.0.2.3.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-da62b32cb72591f5b4d322e6ab0ce7de3247b534
\ No newline at end of file
diff --git a/distribution/tools/plugin-cli/licenses/bc-fips-1.0.2.4.jar.sha1 b/distribution/tools/plugin-cli/licenses/bc-fips-1.0.2.4.jar.sha1
new file mode 100644
index 0000000000000..da37449f80d7e
--- /dev/null
+++ b/distribution/tools/plugin-cli/licenses/bc-fips-1.0.2.4.jar.sha1
@@ -0,0 +1 @@
+9008d04fc13da6455e6a792935b93b629757335d
\ No newline at end of file
diff --git a/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/InstallPluginCommand.java b/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/InstallPluginCommand.java
index 66f43b1e30d28..838d6e22a37bd 100644
--- a/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/InstallPluginCommand.java
+++ b/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/InstallPluginCommand.java
@@ -107,7 +107,7 @@
 
 /**
  * A command for the plugin cli to install a plugin into opensearch.
- *
+ * <p>
  * The install command takes a plugin id, which may be any of the following:
  * <ul>
  * <li>An official opensearch plugin name</li>
@@ -411,7 +411,7 @@ private String getMavenUrl(Terminal terminal, String[] coordinates, String platf
 
     /**
      * Returns {@code true} if the given url exists, and {@code false} otherwise.
-     *
+     * <p>
      * The given url must be {@code https} and existing means a {@code HEAD} request returns 200.
      */
     // pkg private for tests to manipulate
@@ -698,7 +698,6 @@ InputStream getPublicKey() {
 
     /**
      * Creates a URL and opens a connection.
-     *
      * If the URL returns a 404, {@code null} is returned, otherwise the open URL opject is returned.
      */
     // pkg private for tests
diff --git a/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/ProgressInputStream.java b/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/ProgressInputStream.java
index 579f676631a5a..02be3dbc82a44 100644
--- a/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/ProgressInputStream.java
+++ b/distribution/tools/plugin-cli/src/main/java/org/opensearch/plugins/ProgressInputStream.java
@@ -41,7 +41,7 @@
  * The listener is triggered whenever a full percent is increased
  * The listener is never triggered twice on the same percentage
  * The listener will always return 99 percent, if the expectedTotalSize is exceeded, until it is finished
- *
+ * <p>
  * Only used by the InstallPluginCommand, thus package private here
  */
 abstract class ProgressInputStream extends FilterInputStream {
diff --git a/distribution/tools/upgrade-cli/build.gradle b/distribution/tools/upgrade-cli/build.gradle
index 99824463f14f8..92c043132c021 100644
--- a/distribution/tools/upgrade-cli/build.gradle
+++ b/distribution/tools/upgrade-cli/build.gradle
@@ -10,7 +10,7 @@
 apply plugin: 'opensearch.build'
 
 base {
-  archivesBaseName = 'opensearch-upgrade-cli'
+  archivesName = 'opensearch-upgrade-cli'
 }
 
 dependencies {
diff --git a/distribution/tools/upgrade-cli/licenses/jackson-annotations-2.15.2.jar.sha1 b/distribution/tools/upgrade-cli/licenses/jackson-annotations-2.15.2.jar.sha1
deleted file mode 100644
index f63416ddb8ceb..0000000000000
--- a/distribution/tools/upgrade-cli/licenses/jackson-annotations-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4724a65ac8e8d156a24898d50fd5dbd3642870b8
\ No newline at end of file
diff --git a/distribution/tools/upgrade-cli/licenses/jackson-annotations-2.16.0.jar.sha1 b/distribution/tools/upgrade-cli/licenses/jackson-annotations-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..79ed9e0c63fc8
--- /dev/null
+++ b/distribution/tools/upgrade-cli/licenses/jackson-annotations-2.16.0.jar.sha1
@@ -0,0 +1 @@
+dc30995f7428c0a405eba9b8c619b20d2b3b9905
\ No newline at end of file
diff --git a/distribution/tools/upgrade-cli/licenses/jackson-databind-2.15.2.jar.sha1 b/distribution/tools/upgrade-cli/licenses/jackson-databind-2.15.2.jar.sha1
deleted file mode 100644
index f16d80af8dce6..0000000000000
--- a/distribution/tools/upgrade-cli/licenses/jackson-databind-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9353b021f10c307c00328f52090de2bdb4b6ff9c
\ No newline at end of file
diff --git a/distribution/tools/upgrade-cli/licenses/jackson-databind-2.16.0.jar.sha1 b/distribution/tools/upgrade-cli/licenses/jackson-databind-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..da00d281934b1
--- /dev/null
+++ b/distribution/tools/upgrade-cli/licenses/jackson-databind-2.16.0.jar.sha1
@@ -0,0 +1 @@
+3a6b7f8ff7b30d518bbd65678e9c30cd881f19a7
\ No newline at end of file
diff --git a/distribution/tools/upgrade-cli/src/main/java/org/opensearch/upgrade/UpgradeTask.java b/distribution/tools/upgrade-cli/src/main/java/org/opensearch/upgrade/UpgradeTask.java
index b7dcbd50cf781..708f644bcdeb6 100644
--- a/distribution/tools/upgrade-cli/src/main/java/org/opensearch/upgrade/UpgradeTask.java
+++ b/distribution/tools/upgrade-cli/src/main/java/org/opensearch/upgrade/UpgradeTask.java
@@ -17,7 +17,7 @@
  * An interface for an upgrade task, which in this instance is an unit of
  * operation that is part of the overall upgrade process. This extends the
  * {@link java.util.function.Consumer} interface.
- *
+ * <p>
  * The implementing tasks consume and instance of a tuple of {@link TaskInput}
  * and {@link Terminal} and operate via side effects.
  *
diff --git a/doc-tools/missing-doclet/src/main/java/org/opensearch/missingdoclet/MissingDoclet.java b/doc-tools/missing-doclet/src/main/java/org/opensearch/missingdoclet/MissingDoclet.java
index e6122e7baf91a..e1ad55fe4b60b 100644
--- a/doc-tools/missing-doclet/src/main/java/org/opensearch/missingdoclet/MissingDoclet.java
+++ b/doc-tools/missing-doclet/src/main/java/org/opensearch/missingdoclet/MissingDoclet.java
@@ -45,7 +45,7 @@
  *   It isn't recursive, just ignores exactly the elements you tell it.
  * Has option --missing-method to apply "method" level to selected packages (fix one at a time).
  *   Matches package names exactly: so you'll need to list subpackages separately.
- *
+ * <p>
  * Note: This by default ignores javadoc validation on overridden methods.
  */
 // Original version of this class is ported from MissingDoclet code in Lucene,
diff --git a/docs/build.gradle b/docs/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/docs/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 7f93135c49b76..d64cd4917707c 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index f01f0a84a786a..f1d76d80bbfa3 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -11,7 +11,7 @@
 
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionSha256Sum=bb09982fdf52718e4c7b25023d10df6d35a5fff969860bdf5a5bd27a3ab27a9e
+distributionSha256Sum=c16d517b50dd28b3f5838f0e844b7520b8f1eb610f2f29de7e4e04a1b7c9c79b
diff --git a/gradlew b/gradlew
index 0adc8e1a53214..1aa94a4269074 100755
--- a/gradlew
+++ b/gradlew
@@ -145,7 +145,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
         # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
@@ -153,7 +153,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
       '' | soft) :;; #(
       *)
         # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -202,11 +202,11 @@ fi
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
diff --git a/libs/cli/src/main/java/org/opensearch/cli/Command.java b/libs/cli/src/main/java/org/opensearch/cli/Command.java
index eed5c4ba4ee6f..cc9230bdb2282 100644
--- a/libs/cli/src/main/java/org/opensearch/cli/Command.java
+++ b/libs/cli/src/main/java/org/opensearch/cli/Command.java
@@ -162,7 +162,7 @@ protected static void exit(int status) {
 
     /**
      * Executes this command.
-     *
+     * <p>
      * Any runtime user errors (like an input file that does not exist), should throw a {@link UserException}. */
     protected abstract void execute(Terminal terminal, OptionSet options) throws Exception;
 
diff --git a/libs/cli/src/main/java/org/opensearch/cli/Terminal.java b/libs/cli/src/main/java/org/opensearch/cli/Terminal.java
index be030c18507ad..fb1097178e5a3 100644
--- a/libs/cli/src/main/java/org/opensearch/cli/Terminal.java
+++ b/libs/cli/src/main/java/org/opensearch/cli/Terminal.java
@@ -44,7 +44,7 @@
 
 /**
  * A Terminal wraps access to reading input and writing output for a cli.
- *
+ * <p>
  * The available methods are similar to those of {@link Console}, with the ability
  * to read either normal text or a password, and the ability to print a line
  * of text. Printing is also gated by the {@link Verbosity} of the terminal,
diff --git a/libs/common/build.gradle b/libs/common/build.gradle
index 973fe30d09842..4f89b81636420 100644
--- a/libs/common/build.gradle
+++ b/libs/common/build.gradle
@@ -14,7 +14,7 @@ import org.opensearch.gradle.info.BuildParams
 apply plugin: 'opensearch.publish'
 
 base {
-  archivesBaseName = 'opensearch-common'
+  archivesName = 'opensearch-common'
 }
 
 dependencies {
diff --git a/libs/common/src/main/java/org/opensearch/bootstrap/JarHell.java b/libs/common/src/main/java/org/opensearch/bootstrap/JarHell.java
index c4ba778e7db86..fc5e364241d12 100644
--- a/libs/common/src/main/java/org/opensearch/bootstrap/JarHell.java
+++ b/libs/common/src/main/java/org/opensearch/bootstrap/JarHell.java
@@ -104,7 +104,7 @@ public static void checkJarHell(Consumer<String> output) throws IOException, URI
 
     /**
      * Parses the classpath into an array of URLs
-     * @return array of URLs
+     * @return collection of URLs
      * @throws IllegalStateException if the classpath contains empty elements
      */
     public static Set<URL> parseClassPath() {
@@ -114,7 +114,7 @@ public static Set<URL> parseClassPath() {
     /**
      * Parses the classpath into a set of URLs. For testing.
      * @param classPath classpath to parse (typically the system property {@code java.class.path})
-     * @return array of URLs
+     * @return collection of URLs
      * @throws IllegalStateException if the classpath contains empty elements
      */
     @SuppressForbidden(reason = "resolves against CWD because that is how classpaths work")
diff --git a/libs/common/src/main/java/org/opensearch/common/Booleans.java b/libs/common/src/main/java/org/opensearch/common/Booleans.java
index 2ca061820b2eb..ab7ad37e92612 100644
--- a/libs/common/src/main/java/org/opensearch/common/Booleans.java
+++ b/libs/common/src/main/java/org/opensearch/common/Booleans.java
@@ -45,30 +45,72 @@ private Booleans() {
     /**
      * Parses a char[] representation of a boolean value to <code>boolean</code>.
      *
-     * @return <code>true</code> iff the sequence of chars is "true", <code>false</code> iff the sequence of chars is "false" or the
-     * provided default value iff either text is <code>null</code> or length == 0.
+     * @return <code>true</code> iff the sequence of chars is "true", <code>false</code> iff the sequence of
+     * chars is "false" or the provided default value iff either text is <code>null</code> or length == 0.
      * @throws IllegalArgumentException if the string cannot be parsed to boolean.
      */
     public static boolean parseBoolean(char[] text, int offset, int length, boolean defaultValue) {
-        if (text == null || length == 0) {
+        if (text == null) {
             return defaultValue;
-        } else {
-            return parseBoolean(new String(text, offset, length));
         }
+
+        switch (length) {
+            case 0:
+                return defaultValue;
+            case 1:
+            case 2:
+            case 3:
+            default:
+                break;
+            case 4:
+                if (text[offset] == 't' && text[offset + 1] == 'r' && text[offset + 2] == 'u' && text[offset + 3] == 'e') {
+                    return true;
+                }
+                break;
+            case 5:
+                if (text[offset] == 'f'
+                    && text[offset + 1] == 'a'
+                    && text[offset + 2] == 'l'
+                    && text[offset + 3] == 's'
+                    && text[offset + 4] == 'e') {
+                    return false;
+                }
+                break;
+        }
+
+        throw new IllegalArgumentException(
+            "Failed to parse value [" + new String(text, offset, length) + "] as only [true] or [false] are allowed."
+        );
     }
 
     /**
-     * returns true iff the sequence of chars is one of "true","false".
+     * Returns true iff the sequence of chars is one of "true", "false".
      *
      * @param text   sequence to check
      * @param offset offset to start
      * @param length length to check
      */
     public static boolean isBoolean(char[] text, int offset, int length) {
-        if (text == null || length == 0) {
+        if (text == null) {
             return false;
         }
-        return isBoolean(new String(text, offset, length));
+
+        switch (length) {
+            case 0:
+            case 1:
+            case 2:
+            case 3:
+            default:
+                return false;
+            case 4:
+                return text[offset] == 't' && text[offset + 1] == 'r' && text[offset + 2] == 'u' && text[offset + 3] == 'e';
+            case 5:
+                return text[offset] == 'f'
+                    && text[offset + 1] == 'a'
+                    && text[offset + 2] == 'l'
+                    && text[offset + 3] == 's'
+                    && text[offset + 4] == 'e';
+        }
     }
 
     public static boolean isBoolean(String value) {
@@ -91,63 +133,45 @@ public static boolean parseBoolean(String value) {
         throw new IllegalArgumentException("Failed to parse value [" + value + "] as only [true] or [false] are allowed.");
     }
 
-    private static boolean hasText(CharSequence str) {
-        if (str == null || str.length() == 0) {
-            return false;
-        }
-        int strLen = str.length();
-        for (int i = 0; i < strLen; i++) {
-            if (!Character.isWhitespace(str.charAt(i))) {
-                return true;
-            }
-        }
-        return false;
-    }
-
     /**
+     * Parses a string representation of a boolean value to <code>boolean</code>.
+     * Note the subtle difference between this and {@link #parseBoolean(char[], int, int, boolean)}; this returns the
+     * default value even when the value is non-zero length containing all whitespaces (possibly overlooked, but
+     * preserving this behavior for compatibility reasons). Use {@link #parseBooleanStrict(String, boolean)} instead.
      *
      * @param value text to parse.
-     * @param defaultValue The default value to return if the provided value is <code>null</code>.
+     * @param defaultValue The default value to return if the provided value is <code>null</code> or blank.
      * @return see {@link #parseBoolean(String)}
      */
+    @Deprecated
     public static boolean parseBoolean(String value, boolean defaultValue) {
-        if (hasText(value)) {
-            return parseBoolean(value);
-        }
-        return defaultValue;
-    }
-
-    public static Boolean parseBoolean(String value, Boolean defaultValue) {
-        if (hasText(value)) {
-            return parseBoolean(value);
+        if (value == null || value.isBlank()) {
+            return defaultValue;
         }
-        return defaultValue;
+        return parseBoolean(value);
     }
 
-    /**
-     * Returns {@code false} if text is in "false", "0", "off", "no"; else, {@code true}.
-     *
-     * @deprecated Only kept to provide automatic upgrades for pre 6.0 indices. Use {@link #parseBoolean(String, Boolean)} instead.
-     */
     @Deprecated
-    public static Boolean parseBooleanLenient(String value, Boolean defaultValue) {
-        if (value == null) { // only for the null case we do that here!
+    public static Boolean parseBoolean(String value, Boolean defaultValue) {
+        if (value == null || value.isBlank()) {
             return defaultValue;
         }
-        return parseBooleanLenient(value, false);
+        return parseBoolean(value);
     }
 
     /**
-     * Returns {@code false} if text is in "false", "0", "off", "no"; else, {@code true}.
+     * Parses a string representation of a boolean value to <code>boolean</code>.
+     * Analogous to {@link #parseBoolean(char[], int, int, boolean)}.
      *
-     * @deprecated Only kept to provide automatic upgrades for pre 6.0 indices. Use {@link #parseBoolean(String, boolean)} instead.
+     * @return <code>true</code> iff the sequence of chars is "true", <code>false</code> iff the sequence of
+     * chars is "false", or the provided default value iff either text is <code>null</code> or length == 0.
+     * @throws IllegalArgumentException if the string cannot be parsed to boolean.
      */
-    @Deprecated
-    public static boolean parseBooleanLenient(String value, boolean defaultValue) {
-        if (value == null) {
+    public static boolean parseBooleanStrict(String value, boolean defaultValue) {
+        if (value == null || value.length() == 0) {
             return defaultValue;
         }
-        return !(value.equals("false") || value.equals("0") || value.equals("off") || value.equals("no"));
+        return parseBoolean(value);
     }
 
     /**
@@ -163,71 +187,4 @@ public static boolean isFalse(String value) {
     public static boolean isTrue(String value) {
         return "true".equals(value);
     }
-
-    /**
-     * Returns {@code false} if text is in "false", "0", "off", "no"; else, {@code true}.
-     *
-     * @deprecated Only kept to provide automatic upgrades for pre 6.0 indices. Use {@link #parseBoolean(char[], int, int, boolean)} instead
-     */
-    @Deprecated
-    public static boolean parseBooleanLenient(char[] text, int offset, int length, boolean defaultValue) {
-        if (text == null || length == 0) {
-            return defaultValue;
-        }
-        if (length == 1) {
-            return text[offset] != '0';
-        }
-        if (length == 2) {
-            return !(text[offset] == 'n' && text[offset + 1] == 'o');
-        }
-        if (length == 3) {
-            return !(text[offset] == 'o' && text[offset + 1] == 'f' && text[offset + 2] == 'f');
-        }
-        if (length == 5) {
-            return !(text[offset] == 'f'
-                && text[offset + 1] == 'a'
-                && text[offset + 2] == 'l'
-                && text[offset + 3] == 's'
-                && text[offset + 4] == 'e');
-        }
-        return true;
-    }
-
-    /**
-     * returns true if the a sequence of chars is one of "true","false","on","off","yes","no","0","1"
-     *
-     * @param text   sequence to check
-     * @param offset offset to start
-     * @param length length to check
-     *
-     * @deprecated Only kept to provide automatic upgrades for pre 6.0 indices. Use {@link #isBoolean(char[], int, int)} instead.
-     */
-    @Deprecated
-    public static boolean isBooleanLenient(char[] text, int offset, int length) {
-        if (text == null || length == 0) {
-            return false;
-        }
-        if (length == 1) {
-            return text[offset] == '0' || text[offset] == '1';
-        }
-        if (length == 2) {
-            return (text[offset] == 'n' && text[offset + 1] == 'o') || (text[offset] == 'o' && text[offset + 1] == 'n');
-        }
-        if (length == 3) {
-            return (text[offset] == 'o' && text[offset + 1] == 'f' && text[offset + 2] == 'f')
-                || (text[offset] == 'y' && text[offset + 1] == 'e' && text[offset + 2] == 's');
-        }
-        if (length == 4) {
-            return (text[offset] == 't' && text[offset + 1] == 'r' && text[offset + 2] == 'u' && text[offset + 3] == 'e');
-        }
-        if (length == 5) {
-            return (text[offset] == 'f'
-                && text[offset + 1] == 'a'
-                && text[offset + 2] == 'l'
-                && text[offset + 3] == 's'
-                && text[offset + 4] == 'e');
-        }
-        return false;
-    }
-
 }
diff --git a/libs/common/src/main/java/org/opensearch/common/CheckedBiConsumer.java b/libs/common/src/main/java/org/opensearch/common/CheckedBiConsumer.java
index 50c15bb7a95a8..c2ef08e288346 100644
--- a/libs/common/src/main/java/org/opensearch/common/CheckedBiConsumer.java
+++ b/libs/common/src/main/java/org/opensearch/common/CheckedBiConsumer.java
@@ -32,13 +32,16 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.function.BiConsumer;
 
 /**
  * A {@link BiConsumer}-like interface which allows throwing checked exceptions.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 @FunctionalInterface
 public interface CheckedBiConsumer<T, U, E extends Exception> {
     void accept(T t, U u) throws E;
diff --git a/libs/common/src/main/java/org/opensearch/common/CheckedFunction.java b/libs/common/src/main/java/org/opensearch/common/CheckedFunction.java
index 9c17ad4b4ee3f..927edd1b9905a 100644
--- a/libs/common/src/main/java/org/opensearch/common/CheckedFunction.java
+++ b/libs/common/src/main/java/org/opensearch/common/CheckedFunction.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.function.Function;
 
 /**
@@ -39,6 +41,7 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 @FunctionalInterface
 public interface CheckedFunction<T, R, E extends Exception> {
     R apply(T t) throws E;
diff --git a/libs/common/src/main/java/org/opensearch/common/Explicit.java b/libs/common/src/main/java/org/opensearch/common/Explicit.java
index 66e079c461e75..da44c6fd4dcef 100644
--- a/libs/common/src/main/java/org/opensearch/common/Explicit.java
+++ b/libs/common/src/main/java/org/opensearch/common/Explicit.java
@@ -32,19 +32,22 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.Objects;
 
 /**
  * Holds a value that is either:
  * a) set implicitly e.g. through some default value
  * b) set explicitly e.g. from a user selection
- *
+ * <p>
  * When merging conflicting configuration settings such as
  * field mapping settings it is preferable to preserve an explicit
  * choice rather than a choice made only made implicitly by defaults.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Explicit<T> {
 
     private final T value;
diff --git a/libs/common/src/main/java/org/opensearch/common/LocalTimeOffset.java b/libs/common/src/main/java/org/opensearch/common/LocalTimeOffset.java
index 7e89641927ed5..eb7b331c9aa24 100644
--- a/libs/common/src/main/java/org/opensearch/common/LocalTimeOffset.java
+++ b/libs/common/src/main/java/org/opensearch/common/LocalTimeOffset.java
@@ -514,7 +514,7 @@ public boolean anyMoveBackToPreviousDay() {
      * Builds an array that can be {@link Arrays#binarySearch(long[], long)}ed
      * for the daylight savings time transitions.
      *
-     * @openearch.internal
+     * @opensearch.internal
      */
     private static class TransitionArrayLookup extends AbstractManyTransitionsLookup {
         private final LocalTimeOffset[] offsets;
diff --git a/libs/common/src/main/java/org/opensearch/common/Nullable.java b/libs/common/src/main/java/org/opensearch/common/Nullable.java
index c663ef863ed48..70db2a3755eba 100644
--- a/libs/common/src/main/java/org/opensearch/common/Nullable.java
+++ b/libs/common/src/main/java/org/opensearch/common/Nullable.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import javax.annotation.CheckForNull;
 import javax.annotation.meta.TypeQualifierNickname;
 
@@ -53,5 +55,6 @@
 @CheckForNull
 @Retention(RetentionPolicy.RUNTIME)
 @Target({ ElementType.PARAMETER, ElementType.FIELD, ElementType.METHOD })
+@PublicApi(since = "1.0.0")
 public @interface Nullable {
 }
diff --git a/libs/common/src/main/java/org/opensearch/common/SetOnce.java b/libs/common/src/main/java/org/opensearch/common/SetOnce.java
index a596b5fcdb61d..778926ce108b7 100644
--- a/libs/common/src/main/java/org/opensearch/common/SetOnce.java
+++ b/libs/common/src/main/java/org/opensearch/common/SetOnce.java
@@ -35,7 +35,7 @@
  * A convenient class which offers a semi-immutable object wrapper implementation which allows one
  * to set the value of an object exactly once, and retrieve it many times. If {@link #set(Object)}
  * is called more than once, {@link AlreadySetException} is thrown and the operation will fail.
- *
+ * <p>
  * This is borrowed from lucene's experimental API. It is not reused to eliminate the dependency
  * on lucene core for such a simple (standalone) utility class that may change beyond OpenSearch needs.
  *
diff --git a/libs/common/src/main/java/org/opensearch/common/SuppressForbidden.java b/libs/common/src/main/java/org/opensearch/common/SuppressForbidden.java
index 1f1b28bcf6759..c479d7bd98e8a 100644
--- a/libs/common/src/main/java/org/opensearch/common/SuppressForbidden.java
+++ b/libs/common/src/main/java/org/opensearch/common/SuppressForbidden.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -43,6 +45,7 @@
  */
 @Retention(RetentionPolicy.CLASS)
 @Target({ ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.METHOD, ElementType.TYPE })
+@PublicApi(since = "1.0.0")
 public @interface SuppressForbidden {
     String reason();
 }
diff --git a/libs/common/src/main/java/org/opensearch/common/TriFunction.java b/libs/common/src/main/java/org/opensearch/common/TriFunction.java
index 7b1bbece68680..8594e8e2cd0c9 100644
--- a/libs/common/src/main/java/org/opensearch/common/TriFunction.java
+++ b/libs/common/src/main/java/org/opensearch/common/TriFunction.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Represents a function that accepts three arguments and produces a result.
  *
@@ -40,8 +42,9 @@
  * @param <U> the type of the third argument
  * @param <R> the return type
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 @FunctionalInterface
 public interface TriFunction<S, T, U, R> {
     /**
diff --git a/libs/common/src/main/java/org/opensearch/common/annotation/processor/ApiAnnotationProcessor.java b/libs/common/src/main/java/org/opensearch/common/annotation/processor/ApiAnnotationProcessor.java
new file mode 100644
index 0000000000000..1864aec4aa951
--- /dev/null
+++ b/libs/common/src/main/java/org/opensearch/common/annotation/processor/ApiAnnotationProcessor.java
@@ -0,0 +1,369 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.DeprecatedApi;
+import org.opensearch.common.annotation.ExperimentalApi;
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.common.annotation.PublicApi;
+
+import javax.annotation.processing.AbstractProcessor;
+import javax.annotation.processing.RoundEnvironment;
+import javax.annotation.processing.SupportedAnnotationTypes;
+import javax.lang.model.AnnotatedConstruct;
+import javax.lang.model.SourceVersion;
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ElementKind;
+import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.element.Modifier;
+import javax.lang.model.element.PackageElement;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.element.TypeParameterElement;
+import javax.lang.model.element.VariableElement;
+import javax.lang.model.type.ArrayType;
+import javax.lang.model.type.DeclaredType;
+import javax.lang.model.type.ReferenceType;
+import javax.lang.model.type.TypeMirror;
+import javax.lang.model.type.TypeVariable;
+import javax.lang.model.type.WildcardType;
+import javax.tools.Diagnostic.Kind;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * The annotation processor for API related annotations: {@link DeprecatedApi}, {@link ExperimentalApi},
+ * {@link InternalApi} and {@link PublicApi}.
+ * <p>
+ * The checks are built on top of the following rules:
+ * <ul>
+ *  <li>introspect each type annotated with {@link PublicApi}, {@link DeprecatedApi} or {@link ExperimentalApi},
+ *  filtering out package-private declarations</li>
+ *  <li>make sure those leak only {@link PublicApi}, {@link DeprecatedApi} or {@link ExperimentalApi} types as well (exceptions,
+ *    method return values, method arguments, method generic type arguments, class generic type arguments,  annotations)</li>
+ *  <li>recursively follow the type introspection chains to enforce the rules down the line</li>
+ * </ul>
+ */
+@InternalApi
+@SupportedAnnotationTypes("org.opensearch.common.annotation.*")
+public class ApiAnnotationProcessor extends AbstractProcessor {
+    private static final String OPTION_CONTINUE_ON_FAILING_CHECKS = "continueOnFailingChecks";
+    private static final String OPENSEARCH_PACKAGE = "org.opensearch";
+
+    private final Set<Element> reported = new HashSet<>();
+    private final Set<AnnotatedConstruct> processed = new HashSet<>();
+    private Kind reportFailureAs = Kind.ERROR;
+
+    @Override
+    public SourceVersion getSupportedSourceVersion() {
+        return SourceVersion.latest();
+    }
+
+    @Override
+    public Set<String> getSupportedOptions() {
+        return Set.of(OPTION_CONTINUE_ON_FAILING_CHECKS);
+    }
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment round) {
+        processingEnv.getMessager().printMessage(Kind.NOTE, "Processing OpenSearch Api annotations");
+
+        if (processingEnv.getOptions().containsKey(OPTION_CONTINUE_ON_FAILING_CHECKS) == true) {
+            reportFailureAs = Kind.NOTE;
+        }
+
+        final Set<? extends Element> elements = round.getElementsAnnotatedWithAny(
+            Set.of(PublicApi.class, ExperimentalApi.class, DeprecatedApi.class)
+        );
+
+        for (var element : elements) {
+            if (!checkPackage(element)) {
+                continue;
+            }
+
+            // Skip all not-public elements
+            checkPublicVisibility(null, element);
+
+            if (element instanceof TypeElement) {
+                process((TypeElement) element);
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Check top level executable element
+     * @param executable top level executable element
+     * @param enclosing enclosing element
+     */
+    private void process(ExecutableElement executable, Element enclosing) {
+        if (!inspectable(executable)) {
+            return;
+        }
+
+        // The executable element should not be internal (unless constructor for injectable core component)
+        checkNotInternal(enclosing, executable);
+
+        // Check this elements annotations
+        for (final AnnotationMirror annotation : executable.getAnnotationMirrors()) {
+            final Element element = annotation.getAnnotationType().asElement();
+            if (inspectable(element)) {
+                checkNotInternal(executable.getEnclosingElement(), element);
+                checkPublic(executable.getEnclosingElement(), element);
+            }
+        }
+
+        // Process method return types
+        final TypeMirror returnType = executable.getReturnType();
+        if (returnType instanceof ReferenceType) {
+            process(executable, (ReferenceType) returnType);
+        }
+
+        // Process method thrown types
+        for (final TypeMirror thrownType : executable.getThrownTypes()) {
+            if (thrownType instanceof ReferenceType) {
+                process(executable, (ReferenceType) thrownType);
+            }
+        }
+
+        // Process method type parameters
+        for (final TypeParameterElement typeParameter : executable.getTypeParameters()) {
+            for (final TypeMirror boundType : typeParameter.getBounds()) {
+                if (boundType instanceof ReferenceType) {
+                    process(executable, (ReferenceType) boundType);
+                }
+            }
+        }
+
+        // Process method arguments
+        for (final VariableElement parameter : executable.getParameters()) {
+            final TypeMirror parameterType = parameter.asType();
+            if (parameterType instanceof ReferenceType) {
+                process(executable, (ReferenceType) parameterType);
+            }
+        }
+    }
+
+    /**
+     * Check wildcard type bounds referred by an element
+     * @param executable element
+     * @param type wildcard type
+     */
+    private void process(ExecutableElement executable, WildcardType type) {
+        if (type.getExtendsBound() instanceof ReferenceType) {
+            process(executable, (ReferenceType) type.getExtendsBound());
+        }
+
+        if (type.getSuperBound() instanceof ReferenceType) {
+            process(executable, (ReferenceType) type.getSuperBound());
+        }
+    }
+
+    /**
+     * Check reference type bounds referred by an executable element
+     * @param executable executable element
+     * @param ref reference type
+     */
+    private void process(ExecutableElement executable, ReferenceType ref) {
+        // The element has been processed already
+        if (processed.add(ref) == false) {
+            return;
+        }
+
+        if (ref instanceof DeclaredType) {
+            final DeclaredType declaredType = (DeclaredType) ref;
+
+            final Element element = declaredType.asElement();
+            if (inspectable(element)) {
+                checkNotInternal(executable.getEnclosingElement(), element);
+                checkPublic(executable.getEnclosingElement(), element);
+            }
+
+            for (final TypeMirror type : declaredType.getTypeArguments()) {
+                if (type instanceof ReferenceType) {
+                    process(executable, (ReferenceType) type);
+                } else if (type instanceof WildcardType) {
+                    process(executable, (WildcardType) type);
+                }
+            }
+        } else if (ref instanceof ArrayType) {
+            final TypeMirror componentType = ((ArrayType) ref).getComponentType();
+            if (componentType instanceof ReferenceType) {
+                process(executable, (ReferenceType) componentType);
+            }
+        } else if (ref instanceof TypeVariable) {
+            final TypeVariable typeVariable = (TypeVariable) ref;
+            if (typeVariable.getUpperBound() instanceof ReferenceType) {
+                process(executable, (ReferenceType) typeVariable.getUpperBound());
+            }
+            if (typeVariable.getLowerBound() instanceof ReferenceType) {
+                process(executable, (ReferenceType) typeVariable.getLowerBound());
+            }
+        }
+
+        // Check this elements annotations
+        for (final AnnotationMirror annotation : ref.getAnnotationMirrors()) {
+            final Element element = annotation.getAnnotationType().asElement();
+            if (inspectable(element)) {
+                checkNotInternal(executable.getEnclosingElement(), element);
+                checkPublic(executable.getEnclosingElement(), element);
+            }
+        }
+    }
+
+    /**
+     * Check if a particular executable element should be inspected or not
+     * @param executable executable element to inspect
+     * @return {@code true} if a particular executable element should be inspected, {@code false} otherwise
+     */
+    private boolean inspectable(ExecutableElement executable) {
+        // The constructors for public APIs could use non-public APIs when those are supposed to be only
+        // consumed (not instantiated) by external consumers.
+        return executable.getKind() != ElementKind.CONSTRUCTOR && executable.getModifiers().contains(Modifier.PUBLIC);
+    }
+
+    /**
+     * Check if a particular element should be inspected or not
+     * @param element element to inspect
+     * @return {@code true} if a particular element should be inspected, {@code false} otherwise
+     */
+    private boolean inspectable(Element element) {
+        final PackageElement pckg = processingEnv.getElementUtils().getPackageOf(element);
+        return pckg.getQualifiedName().toString().startsWith(OPENSEARCH_PACKAGE);
+    }
+
+    /**
+     * Check if a particular element belongs to OpenSeach managed packages
+     * @param element element to inspect
+     * @return {@code true} if a particular element belongs to OpenSeach managed packages, {@code false} otherwise
+     */
+    private boolean checkPackage(Element element) {
+        // The element was reported already
+        if (reported.contains(element)) {
+            return false;
+        }
+
+        final PackageElement pckg = processingEnv.getElementUtils().getPackageOf(element);
+        final boolean belongsToOpenSearch = pckg.getQualifiedName().toString().startsWith(OPENSEARCH_PACKAGE);
+
+        if (!belongsToOpenSearch) {
+            reported.add(element);
+
+            processingEnv.getMessager()
+                .printMessage(
+                    reportFailureAs,
+                    "The type "
+                        + element
+                        + " is not residing in "
+                        + OPENSEARCH_PACKAGE
+                        + ".* package "
+                        + "and should not be annotated as OpenSearch APIs."
+                );
+        }
+
+        return belongsToOpenSearch;
+    }
+
+    /**
+     * Check the fields, methods, constructors, and member types that are directly
+     * declared in this class or interface.
+     * @param element class or interface
+     */
+    private void process(Element element) {
+        // Check the fields, methods, constructors, and member types that are directly
+        // declared in this class or interface.
+        for (final Element enclosed : element.getEnclosedElements()) {
+            // Skip all not-public elements
+            if (!enclosed.getModifiers().contains(Modifier.PUBLIC)) {
+                continue;
+            }
+
+            if (enclosed instanceof ExecutableElement) {
+                process((ExecutableElement) enclosed, element);
+            }
+        }
+    }
+
+    /**
+     * Check if element is public and annotated with {@link PublicApi}, {@link DeprecatedApi} or {@link ExperimentalApi}
+     * @param referencedBy the referrer for the element
+     * @param element element to check
+     */
+    private void checkPublic(@Nullable Element referencedBy, final Element element) {
+        // The element was reported already
+        if (reported.contains(element)) {
+            return;
+        }
+
+        checkPublicVisibility(referencedBy, element);
+
+        if (element.getAnnotation(PublicApi.class) == null
+            && element.getAnnotation(ExperimentalApi.class) == null
+            && element.getAnnotation(DeprecatedApi.class) == null) {
+            reported.add(element);
+
+            processingEnv.getMessager()
+                .printMessage(
+                    reportFailureAs,
+                    "The element "
+                        + element
+                        + " is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi"
+                        + ((referencedBy != null) ? " (referenced by " + referencedBy + ") " : "")
+                );
+        }
+    }
+
+    /**
+     * Check if element has public visibility (following Java visibility rules)
+     * @param referencedBy the referrer for the element
+     * @param element element to check
+     */
+    private void checkPublicVisibility(Element referencedBy, final Element element) {
+        if (!element.getModifiers().contains(Modifier.PUBLIC) && !element.getModifiers().contains(Modifier.PROTECTED)) {
+            reported.add(element);
+
+            processingEnv.getMessager()
+                .printMessage(
+                    reportFailureAs,
+                    "The element "
+                        + element
+                        + " is part of the public APIs but does not have public or protected visibility"
+                        + ((referencedBy != null) ? " (referenced by " + referencedBy + ") " : "")
+                );
+        }
+    }
+
+    /**
+     * Check if element is not annotated with {@link InternalApi}
+     * @param referencedBy the referrer for the element
+     * @param element element to check
+     */
+    private void checkNotInternal(@Nullable Element referencedBy, final Element element) {
+        // The element was reported already
+        if (reported.contains(element)) {
+            return;
+        }
+
+        if (element.getAnnotation(InternalApi.class) != null) {
+            reported.add(element);
+
+            processingEnv.getMessager()
+                .printMessage(
+                    reportFailureAs,
+                    "The element "
+                        + element
+                        + " is part of the public APIs but is marked as @InternalApi"
+                        + ((referencedBy != null) ? " (referenced by " + referencedBy + ") " : "")
+                );
+        }
+    }
+}
diff --git a/libs/common/src/main/java/org/opensearch/common/annotation/processor/package-info.java b/libs/common/src/main/java/org/opensearch/common/annotation/processor/package-info.java
new file mode 100644
index 0000000000000..fa23e4a7addce
--- /dev/null
+++ b/libs/common/src/main/java/org/opensearch/common/annotation/processor/package-info.java
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * Classes related yo OpenSearch API annotation processing
+ *
+ * @opensearch.internal
+ */
+@org.opensearch.common.annotation.InternalApi
+package org.opensearch.common.annotation.processor;
diff --git a/libs/common/src/main/java/org/opensearch/common/collect/Iterators.java b/libs/common/src/main/java/org/opensearch/common/collect/Iterators.java
index c7e7ae6a44a21..9b64932356c10 100644
--- a/libs/common/src/main/java/org/opensearch/common/collect/Iterators.java
+++ b/libs/common/src/main/java/org/opensearch/common/collect/Iterators.java
@@ -41,6 +41,15 @@
  * @opensearch.internal
  */
 public class Iterators {
+
+    /**
+     * Concat iterators
+     *
+     * @param iterators the iterators to concat
+     * @param <T> the type of iterator
+     * @return a new {@link ConcatenatedIterator}
+     * @throws NullPointerException if iterators is null
+     */
     public static <T> Iterator<T> concat(Iterator<? extends T>... iterators) {
         if (iterators == null) {
             throw new NullPointerException("iterators");
@@ -71,6 +80,11 @@ static class ConcatenatedIterator<T> implements Iterator<T> {
             this.iterators = iterators;
         }
 
+        /**
+         * Returns {@code true} if the iteration has more elements. (In other words, returns {@code true} if {@link #next} would return an
+         * element rather than throwing an exception.)
+         * @return {@code true} if the iteration has more elements
+         */
         @Override
         public boolean hasNext() {
             boolean hasNext = false;
@@ -81,6 +95,11 @@ public boolean hasNext() {
             return hasNext;
         }
 
+        /**
+         * Returns the next element in the iteration.
+         * @return the next element in the iteration
+         * @throws NoSuchElementException if the iteration has no more elements
+         */
         @Override
         public T next() {
             if (!hasNext()) {
diff --git a/libs/common/src/main/java/org/opensearch/common/collect/Tuple.java b/libs/common/src/main/java/org/opensearch/common/collect/Tuple.java
index d0b94536b0729..a5d97dcd85ef7 100644
--- a/libs/common/src/main/java/org/opensearch/common/collect/Tuple.java
+++ b/libs/common/src/main/java/org/opensearch/common/collect/Tuple.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.common.collect;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Java 9 Tuple
- *
  * todo: deprecate and remove w/ min jdk upgrade to 11?
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Tuple<V1, V2> {
 
     public static <V1, V2> Tuple<V1, V2> tuple(V1 v1, V2 v2) {
diff --git a/libs/common/src/main/java/org/opensearch/common/crypto/MasterKeyProvider.java b/libs/common/src/main/java/org/opensearch/common/crypto/MasterKeyProvider.java
index 8afa48eb92c0f..31d2dcd0dba3d 100644
--- a/libs/common/src/main/java/org/opensearch/common/crypto/MasterKeyProvider.java
+++ b/libs/common/src/main/java/org/opensearch/common/crypto/MasterKeyProvider.java
@@ -7,12 +7,17 @@
  */
 package org.opensearch.common.crypto;
 
+import org.opensearch.common.annotation.ExperimentalApi;
+
 import java.io.Closeable;
 import java.util.Map;
 
 /**
  * Master key provider responsible for management of master keys.
+ *
+ * @opensearch.experimental
  */
+@ExperimentalApi
 public interface MasterKeyProvider extends Closeable {
 
     /**
diff --git a/libs/common/src/main/java/org/opensearch/common/io/InputStreamContainer.java b/libs/common/src/main/java/org/opensearch/common/io/InputStreamContainer.java
index eb8a4e1382497..3095336338f7f 100644
--- a/libs/common/src/main/java/org/opensearch/common/io/InputStreamContainer.java
+++ b/libs/common/src/main/java/org/opensearch/common/io/InputStreamContainer.java
@@ -8,13 +8,16 @@
 
 package org.opensearch.common.io;
 
+import org.opensearch.common.annotation.ExperimentalApi;
+
 import java.io.InputStream;
 
 /**
  * Model composed of an input stream and the total content length of the stream
  *
- * @opensearch.internal
+ * @opensearch.experimental
  */
+@ExperimentalApi
 public class InputStreamContainer {
 
     private final InputStream inputStream;
diff --git a/libs/common/src/main/java/org/opensearch/common/io/PathUtils.java b/libs/common/src/main/java/org/opensearch/common/io/PathUtils.java
index b3526859933ec..ed8d50892b74a 100644
--- a/libs/common/src/main/java/org/opensearch/common/io/PathUtils.java
+++ b/libs/common/src/main/java/org/opensearch/common/io/PathUtils.java
@@ -93,7 +93,7 @@ public static Path get(URI uri) {
 
     /**
      * Tries to resolve the given path against the list of available roots.
-     *
+     * <p>
      * If path starts with one of the listed roots, it returned back by this method, otherwise null is returned.
      */
     public static Path get(Path[] roots, String path) {
@@ -109,7 +109,7 @@ public static Path get(Path[] roots, String path) {
 
     /**
      * Tries to resolve the given file uri against the list of available roots.
-     *
+     * <p>
      * If uri starts with one of the listed roots, it returned back by this method, otherwise null is returned.
      */
     public static Path get(Path[] roots, URI uri) {
diff --git a/libs/common/src/main/java/org/opensearch/common/lease/Releasable.java b/libs/common/src/main/java/org/opensearch/common/lease/Releasable.java
index 30bea6185febc..dfc4fefb9ee55 100644
--- a/libs/common/src/main/java/org/opensearch/common/lease/Releasable.java
+++ b/libs/common/src/main/java/org/opensearch/common/lease/Releasable.java
@@ -32,13 +32,16 @@
 
 package org.opensearch.common.lease;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.Closeable;
 
 /**
  * Specialization of {@link AutoCloseable} for calls that might not throw a checked exception.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface Releasable extends Closeable {
 
     @Override
diff --git a/libs/common/src/main/java/org/opensearch/common/network/InetAddresses.java b/libs/common/src/main/java/org/opensearch/common/network/InetAddresses.java
index a4fbc6cb65b0d..0f289c09bbae2 100644
--- a/libs/common/src/main/java/org/opensearch/common/network/InetAddresses.java
+++ b/libs/common/src/main/java/org/opensearch/common/network/InetAddresses.java
@@ -368,7 +368,7 @@ public static InetAddress forString(String ipString) {
 
     /**
      * Convert a byte array into an InetAddress.
-     *
+     * <p>
      * {@link InetAddress#getByAddress} is documented as throwing a checked
      * exception "if IP address is of illegal length."  We replace it with
      * an unchecked exception, for use by callers who already know that addr
@@ -423,7 +423,7 @@ public static Tuple<InetAddress, Integer> parseCidr(String maskedAddress) {
 
     /**
      * Given an address and prefix length, returns the string representation of the range in CIDR notation.
-     *
+     * <p>
      * See {@link #toAddrString} for details on how the address is represented.
      */
     public static String toCidrString(InetAddress address, int prefixLength) {
diff --git a/libs/common/src/main/java/org/opensearch/common/round/BidirectionalLinearSearcher.java b/libs/common/src/main/java/org/opensearch/common/round/BidirectionalLinearSearcher.java
new file mode 100644
index 0000000000000..5c3dcf2bd4708
--- /dev/null
+++ b/libs/common/src/main/java/org/opensearch/common/round/BidirectionalLinearSearcher.java
@@ -0,0 +1,59 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.round;
+
+import org.opensearch.common.annotation.InternalApi;
+
+/**
+ * It uses linear search on a sorted array of pre-computed round-down points.
+ * For small inputs (&le; 64 elements), this can be much faster than binary search as it avoids the penalty of
+ * branch mispredictions and pipeline stalls, and accesses memory sequentially.
+ *
+ * <p>
+ * It uses "meet in the middle" linear search to avoid the worst case scenario when the desired element is present
+ * at either side of the array. This is helpful for time-series data where velocity increases over time, so more
+ * documents are likely to find a greater timestamp which is likely to be present on the right end of the array.
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+class BidirectionalLinearSearcher implements Roundable {
+    private final long[] ascending;
+    private final long[] descending;
+
+    BidirectionalLinearSearcher(long[] values, int size) {
+        if (size <= 0) {
+            throw new IllegalArgumentException("at least one value must be present");
+        }
+
+        int len = (size + 1) >>> 1; // rounded-up to handle odd number of values
+        ascending = new long[len];
+        descending = new long[len];
+
+        for (int i = 0; i < len; i++) {
+            ascending[i] = values[i];
+            descending[i] = values[size - i - 1];
+        }
+    }
+
+    @Override
+    public long floor(long key) {
+        int i = 0;
+        for (; i < ascending.length; i++) {
+            if (descending[i] <= key) {
+                return descending[i];
+            }
+            if (ascending[i] > key) {
+                assert i > 0 : "key must be greater than or equal to " + ascending[0];
+                return ascending[i - 1];
+            }
+        }
+        return ascending[i - 1];
+    }
+}
diff --git a/libs/common/src/main/java/org/opensearch/common/round/BinarySearcher.java b/libs/common/src/main/java/org/opensearch/common/round/BinarySearcher.java
new file mode 100644
index 0000000000000..b9d76945115ed
--- /dev/null
+++ b/libs/common/src/main/java/org/opensearch/common/round/BinarySearcher.java
@@ -0,0 +1,43 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.round;
+
+import org.opensearch.common.annotation.InternalApi;
+
+import java.util.Arrays;
+
+/**
+ * It uses binary search on a sorted array of pre-computed round-down points.
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+class BinarySearcher implements Roundable {
+    private final long[] values;
+    private final int size;
+
+    BinarySearcher(long[] values, int size) {
+        if (size <= 0) {
+            throw new IllegalArgumentException("at least one value must be present");
+        }
+
+        this.values = values;
+        this.size = size;
+    }
+
+    @Override
+    public long floor(long key) {
+        int idx = Arrays.binarySearch(values, 0, size, key);
+        assert idx != -1 : "key must be greater than or equal to " + values[0];
+        if (idx < 0) {
+            idx = -2 - idx;
+        }
+        return values[idx];
+    }
+}
diff --git a/libs/common/src/main/java/org/opensearch/common/round/Roundable.java b/libs/common/src/main/java/org/opensearch/common/round/Roundable.java
new file mode 100644
index 0000000000000..ae6f9b787c1e9
--- /dev/null
+++ b/libs/common/src/main/java/org/opensearch/common/round/Roundable.java
@@ -0,0 +1,28 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.round;
+
+import org.opensearch.common.annotation.InternalApi;
+
+/**
+ * Interface to round-off values.
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+@FunctionalInterface
+public interface Roundable {
+    /**
+     * Returns the greatest lower bound of the given key.
+     * In other words, it returns the largest value such that {@code value <= key}.
+     * @param key to floor
+     * @return the floored value
+     */
+    long floor(long key);
+}
diff --git a/libs/common/src/main/java/org/opensearch/common/round/RoundableFactory.java b/libs/common/src/main/java/org/opensearch/common/round/RoundableFactory.java
new file mode 100644
index 0000000000000..b7422694c3013
--- /dev/null
+++ b/libs/common/src/main/java/org/opensearch/common/round/RoundableFactory.java
@@ -0,0 +1,39 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.round;
+
+import org.opensearch.common.annotation.InternalApi;
+
+/**
+ * Factory class to create and return the fastest implementation of {@link Roundable}.
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+public final class RoundableFactory {
+    /**
+     * The maximum limit up to which linear search is used, otherwise binary search is used.
+     * This is because linear search is much faster on small arrays.
+     * Benchmark results: <a href="https://github.com/opensearch-project/OpenSearch/pull/9727">PR #9727</a>
+     */
+    private static final int LINEAR_SEARCH_MAX_SIZE = 64;
+
+    private RoundableFactory() {}
+
+    /**
+     * Creates and returns the fastest implementation of {@link Roundable}.
+     */
+    public static Roundable create(long[] values, int size) {
+        if (size <= LINEAR_SEARCH_MAX_SIZE) {
+            return new BidirectionalLinearSearcher(values, size);
+        } else {
+            return new BinarySearcher(values, size);
+        }
+    }
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/http/package-info.java b/libs/common/src/main/java/org/opensearch/common/round/package-info.java
similarity index 72%
rename from libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/http/package-info.java
rename to libs/common/src/main/java/org/opensearch/common/round/package-info.java
index 9feb862a4e010..e79c4017de31b 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/http/package-info.java
+++ b/libs/common/src/main/java/org/opensearch/common/round/package-info.java
@@ -7,6 +7,6 @@
  */
 
 /**
- * Contains No-op implementations
+ * Contains classes to round-off values.
  */
-package org.opensearch.telemetry.tracing.http;
+package org.opensearch.common.round;
diff --git a/libs/common/src/main/java/org/opensearch/common/unit/TimeValue.java b/libs/common/src/main/java/org/opensearch/common/unit/TimeValue.java
index a3fcffb1d6a4c..30ed5bf63a748 100644
--- a/libs/common/src/main/java/org/opensearch/common/unit/TimeValue.java
+++ b/libs/common/src/main/java/org/opensearch/common/unit/TimeValue.java
@@ -224,10 +224,10 @@ public double getDaysFrac() {
 
     /**
      * Returns a {@link String} representation of the current {@link TimeValue}.
-     *
+     * <p>
      * Note that this method might produce fractional time values (ex 1.6m) which cannot be
      * parsed by method like {@link TimeValue#parse(String, String, String, String)}.
-     *
+     * <p>
      * Also note that the maximum string value that will be generated is
      * {@code 106751.9d} due to the way that values are internally converted
      * to nanoseconds (106751.9 days is Long.MAX_VALUE nanoseconds)
@@ -239,12 +239,12 @@ public String toString() {
 
     /**
      * Returns a {@link String} representation of the current {@link TimeValue}.
-     *
+     * <p>
      * Note that this method might produce fractional time values (ex 1.6m) which cannot be
      * parsed by method like {@link TimeValue#parse(String, String, String, String)}. The number of
      * fractional decimals (up to 10 maximum) are truncated to the number of fraction pieces
      * specified.
-     *
+     * <p>
      * Also note that the maximum string value that will be generated is
      * {@code 106751.9d} due to the way that values are internally converted
      * to nanoseconds (106751.9 days is Long.MAX_VALUE nanoseconds)
diff --git a/libs/common/src/main/java/org/opensearch/common/util/BitMixer.java b/libs/common/src/main/java/org/opensearch/common/util/BitMixer.java
index 8762217916c7a..d6ea4fa359df3 100644
--- a/libs/common/src/main/java/org/opensearch/common/util/BitMixer.java
+++ b/libs/common/src/main/java/org/opensearch/common/util/BitMixer.java
@@ -25,9 +25,9 @@
 
 /**
  * Bit mixing utilities from carrotsearch.hppc.
- *
+ * <p>
  * Licensed under ALv2. This is pulled in directly to avoid a full hppc dependency.
- *
+ * <p>
  * The purpose of these methods is to evenly distribute key space over int32
  * range.
  */
@@ -111,7 +111,7 @@ public static int mix32(int k) {
     /**
      * Computes David Stafford variant 9 of 64bit mix function (MH3 finalization step,
      * with different shifts and constants).
-     *
+     * <p>
      * Variant 9 is picked because it contains two 32-bit shifts which could be possibly
      * optimized into better machine code.
      *
diff --git a/libs/common/src/main/resources/META-INF/services/javax.annotation.processing.Processor b/libs/common/src/main/resources/META-INF/services/javax.annotation.processing.Processor
new file mode 100644
index 0000000000000..c4e4dfed864f2
--- /dev/null
+++ b/libs/common/src/main/resources/META-INF/services/javax.annotation.processing.Processor
@@ -0,0 +1,12 @@
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# The OpenSearch Contributors require contributions made to
+# this file be licensed under the Apache-2.0 license or a
+# compatible open source license.
+#
+# Modifications Copyright OpenSearch Contributors. See
+# GitHub history for details.
+#
+
+org.opensearch.common.annotation.processor.ApiAnnotationProcessor
\ No newline at end of file
diff --git a/server/src/test/java/org/opensearch/common/BooleansTests.java b/libs/common/src/test/java/org/opensearch/common/BooleansTests.java
similarity index 58%
rename from server/src/test/java/org/opensearch/common/BooleansTests.java
rename to libs/common/src/test/java/org/opensearch/common/BooleansTests.java
index 7e4a0ad8e456b..578ec742d126d 100644
--- a/server/src/test/java/org/opensearch/common/BooleansTests.java
+++ b/libs/common/src/test/java/org/opensearch/common/BooleansTests.java
@@ -34,10 +34,7 @@
 
 import org.opensearch.test.OpenSearchTestCase;
 
-import java.util.Locale;
-
 import static org.hamcrest.Matchers.is;
-import static org.hamcrest.Matchers.nullValue;
 
 public class BooleansTests extends OpenSearchTestCase {
     private static final String[] NON_BOOLEANS = new String[] {
@@ -81,8 +78,23 @@ public void testParseBooleanWithFallback() {
         assertFalse(Booleans.parseBoolean(null, Boolean.FALSE));
         assertTrue(Booleans.parseBoolean(null, Boolean.TRUE));
 
+        assertFalse(Booleans.parseBoolean("", false));
+        assertTrue(Booleans.parseBoolean("", true));
+        assertNull(Booleans.parseBoolean("", null));
+        assertFalse(Booleans.parseBoolean("", Boolean.FALSE));
+        assertTrue(Booleans.parseBoolean("", Boolean.TRUE));
+
+        assertFalse(Booleans.parseBoolean(" \t\n", false));
+        assertTrue(Booleans.parseBoolean(" \t\n", true));
+        assertNull(Booleans.parseBoolean(" \t\n", null));
+        assertFalse(Booleans.parseBoolean(" \t\n", Boolean.FALSE));
+        assertTrue(Booleans.parseBoolean(" \t\n", Boolean.TRUE));
+
         assertTrue(Booleans.parseBoolean("true", randomFrom(Boolean.TRUE, Boolean.FALSE, null)));
         assertFalse(Booleans.parseBoolean("false", randomFrom(Boolean.TRUE, Boolean.FALSE, null)));
+
+        assertTrue(Booleans.parseBoolean(new char[0], 0, 0, true));
+        assertFalse(Booleans.parseBoolean(new char[0], 0, 0, false));
     }
 
     public void testParseNonBooleanWithFallback() {
@@ -109,56 +121,12 @@ public void testParseNonBoolean() {
         }
     }
 
-    public void testIsBooleanLenient() {
-        String[] booleans = new String[] { "true", "false", "on", "off", "yes", "no", "0", "1" };
-        String[] notBooleans = new String[] { "11", "00", "sdfsdfsf", "F", "T" };
-        assertThat(Booleans.isBooleanLenient(null, 0, 1), is(false));
-
-        for (String b : booleans) {
-            String t = "prefix" + b + "suffix";
-            assertTrue(
-                "failed to recognize [" + b + "] as boolean",
-                Booleans.isBooleanLenient(t.toCharArray(), "prefix".length(), b.length())
-            );
-        }
-
-        for (String nb : notBooleans) {
-            String t = "prefix" + nb + "suffix";
-            assertFalse("recognized [" + nb + "] as boolean", Booleans.isBooleanLenient(t.toCharArray(), "prefix".length(), nb.length()));
-        }
-    }
-
-    public void testParseBooleanLenient() {
-        assertThat(Booleans.parseBooleanLenient(randomFrom("true", "on", "yes", "1"), randomBoolean()), is(true));
-        assertThat(Booleans.parseBooleanLenient(randomFrom("false", "off", "no", "0"), randomBoolean()), is(false));
-        assertThat(Booleans.parseBooleanLenient(randomFrom("true", "on", "yes").toUpperCase(Locale.ROOT), randomBoolean()), is(true));
-        assertThat(Booleans.parseBooleanLenient(null, false), is(false));
-        assertThat(Booleans.parseBooleanLenient(null, true), is(true));
-
-        assertThat(
-            Booleans.parseBooleanLenient(randomFrom("true", "on", "yes", "1"), randomFrom(Boolean.TRUE, Boolean.FALSE, null)),
-            is(true)
-        );
-        assertThat(
-            Booleans.parseBooleanLenient(randomFrom("false", "off", "no", "0"), randomFrom(Boolean.TRUE, Boolean.FALSE, null)),
-            is(false)
-        );
-        assertThat(
-            Booleans.parseBooleanLenient(
-                randomFrom("true", "on", "yes").toUpperCase(Locale.ROOT),
-                randomFrom(Boolean.TRUE, Boolean.FALSE, null)
-            ),
-            is(true)
-        );
-        assertThat(Booleans.parseBooleanLenient(null, Boolean.FALSE), is(false));
-        assertThat(Booleans.parseBooleanLenient(null, Boolean.TRUE), is(true));
-        assertThat(Booleans.parseBooleanLenient(null, null), nullValue());
-
-        char[] chars = randomFrom("true", "on", "yes", "1").toCharArray();
-        assertThat(Booleans.parseBooleanLenient(chars, 0, chars.length, randomBoolean()), is(true));
-        chars = randomFrom("false", "off", "no", "0").toCharArray();
-        assertThat(Booleans.parseBooleanLenient(chars, 0, chars.length, randomBoolean()), is(false));
-        chars = randomFrom("true", "on", "yes").toUpperCase(Locale.ROOT).toCharArray();
-        assertThat(Booleans.parseBooleanLenient(chars, 0, chars.length, randomBoolean()), is(true));
+    public void testParseBooleanStrict() {
+        assertTrue(Booleans.parseBooleanStrict("true", false));
+        assertFalse(Booleans.parseBooleanStrict("false", true));
+        assertTrue(Booleans.parseBooleanStrict(null, true));
+        assertFalse(Booleans.parseBooleanStrict("", false));
+        expectThrows(IllegalArgumentException.class, () -> Booleans.parseBooleanStrict("foobar", false));
+        expectThrows(IllegalArgumentException.class, () -> Booleans.parseBooleanStrict(" \t\n", false));
     }
 }
diff --git a/libs/common/src/test/java/org/opensearch/common/annotation/processor/ApiAnnotationProcessorTests.java b/libs/common/src/test/java/org/opensearch/common/annotation/processor/ApiAnnotationProcessorTests.java
new file mode 100644
index 0000000000000..df04709458b29
--- /dev/null
+++ b/libs/common/src/test/java/org/opensearch/common/annotation/processor/ApiAnnotationProcessorTests.java
@@ -0,0 +1,476 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.test.OpenSearchTestCase;
+
+import javax.tools.Diagnostic;
+
+import static org.opensearch.common.annotation.processor.CompilerSupport.HasDiagnostic.matching;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.instanceOf;
+
+@SuppressWarnings("deprecation")
+public class ApiAnnotationProcessorTests extends OpenSearchTestCase implements CompilerSupport {
+    public void testPublicApiMethodArgumentNotAnnotated() {
+        final CompilerResult result = compile("PublicApiMethodArgumentNotAnnotated.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotated is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodArgumentNotAnnotated)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodArgumentNotAnnotatedGenerics() {
+        final CompilerResult result = compile("PublicApiMethodArgumentNotAnnotatedGenerics.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotated is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodArgumentNotAnnotatedGenerics)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodThrowsNotAnnotated() {
+        final CompilerResult result = compile("PublicApiMethodThrowsNotAnnotated.java", "PublicApiAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotatedException is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodThrowsNotAnnotated)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodArgumentNotAnnotatedPackagePrivate() {
+        final CompilerResult result = compile("PublicApiMethodArgumentNotAnnotatedPackagePrivate.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(4));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotatedPackagePrivate is part of the public APIs but does not have public or protected visibility "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodArgumentNotAnnotatedPackagePrivate)"
+                    )
+                )
+            )
+        );
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotatedPackagePrivate is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodArgumentNotAnnotatedPackagePrivate)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodArgumentAnnotatedPackagePrivate() {
+        final CompilerResult result = compile("PublicApiMethodArgumentAnnotatedPackagePrivate.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.AnnotatedPackagePrivate is part of the public APIs but does not have public or protected visibility "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodArgumentAnnotatedPackagePrivate)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiWithInternalApiMethod() {
+        final CompilerResult result = compile("PublicApiWithInternalApiMethod.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element method() is part of the public APIs but is marked as @InternalApi (referenced by org.opensearch.common.annotation.processor.PublicApiWithInternalApiMethod)"
+                    )
+                )
+            )
+        );
+    }
+
+    /**
+     * The constructor arguments have relaxed semantics at the moment: those could be not annotated or be annotated as {@link InternalApi}
+     */
+    public void testPublicApiConstructorArgumentNotAnnotated() {
+        final CompilerResult result = compile("PublicApiConstructorArgumentNotAnnotated.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    /**
+     * The constructor arguments have relaxed semantics at the moment: those could be not annotated or be annotated as {@link InternalApi}
+     */
+    public void testPublicApiConstructorArgumentAnnotatedInternalApi() {
+        final CompilerResult result = compile("PublicApiConstructorArgumentAnnotatedInternalApi.java", "InternalApiAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testPublicApiWithExperimentalApiMethod() {
+        final CompilerResult result = compile("PublicApiWithExperimentalApiMethod.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testPublicApiMethodReturnNotAnnotated() {
+        final CompilerResult result = compile("PublicApiMethodReturnNotAnnotated.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotated is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodReturnNotAnnotated)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodReturnNotAnnotatedGenerics() {
+        final CompilerResult result = compile("PublicApiMethodReturnNotAnnotatedGenerics.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotated is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodReturnNotAnnotatedGenerics)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodReturnNotAnnotatedArray() {
+        final CompilerResult result = compile("PublicApiMethodReturnNotAnnotatedArray.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotated is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodReturnNotAnnotatedArray)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodReturnNotAnnotatedBoundedGenerics() {
+        final CompilerResult result = compile("PublicApiMethodReturnNotAnnotatedBoundedGenerics.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotated is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodReturnNotAnnotatedBoundedGenerics)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodReturnNotAnnotatedAnnotation() {
+        final CompilerResult result = compile(
+            "PublicApiMethodReturnNotAnnotatedAnnotation.java",
+            "PublicApiAnnotated.java",
+            "NotAnnotatedAnnotation.java"
+        );
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotatedAnnotation is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodReturnNotAnnotatedAnnotation)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodReturnNotAnnotatedWildcardGenerics() {
+        final CompilerResult result = compile("PublicApiMethodReturnNotAnnotatedWildcardGenerics.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testPublicApiWithPackagePrivateMethod() {
+        final CompilerResult result = compile("PublicApiWithPackagePrivateMethod.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testPublicApiMethodReturnSelf() {
+        final CompilerResult result = compile("PublicApiMethodReturnSelf.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testExperimentalApiMethodReturnSelf() {
+        final CompilerResult result = compile("ExperimentalApiMethodReturnSelf.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testDeprecatedApiMethodReturnSelf() {
+        final CompilerResult result = compile("DeprecatedApiMethodReturnSelf.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testPublicApiPackagePrivate() {
+        final CompilerResult result = compile("PublicApiPackagePrivate.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.PublicApiPackagePrivate is part of the public APIs but does not have public or protected visibility"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodGenericsArgumentNotAnnotated() {
+        final CompilerResult result = compile("PublicApiMethodGenericsArgumentNotAnnotated.java", "NotAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotated is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodGenericsArgumentNotAnnotated)"
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodReturnAnnotatedArray() {
+        final CompilerResult result = compile("PublicApiMethodReturnAnnotatedArray.java", "PublicApiAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testPublicApiMethodGenericsArgumentAnnotated() {
+        final CompilerResult result = compile("PublicApiMethodGenericsArgumentAnnotated.java", "PublicApiAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+
+    public void testPublicApiAnnotatedNotOpensearch() {
+        final CompilerResult result = compileWithPackage("org.acme", "PublicApiAnnotated.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The type org.acme.PublicApiAnnotated is not residing in org.opensearch.* package and should not be annotated as OpenSearch APIs."
+                    )
+                )
+            )
+        );
+    }
+
+    public void testPublicApiMethodReturnAnnotatedGenerics() {
+        final CompilerResult result = compile(
+            "PublicApiMethodReturnAnnotatedGenerics.java",
+            "PublicApiAnnotated.java",
+            "NotAnnotatedAnnotation.java"
+        );
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(3));
+
+        assertThat(
+            failure.diagnotics(),
+            hasItem(
+                matching(
+                    Diagnostic.Kind.ERROR,
+                    containsString(
+                        "The element org.opensearch.common.annotation.processor.NotAnnotatedAnnotation is part of the public APIs but is not maked as @PublicApi, @ExperimentalApi or @DeprecatedApi "
+                            + "(referenced by org.opensearch.common.annotation.processor.PublicApiMethodReturnAnnotatedGenerics)"
+                    )
+                )
+            )
+        );
+    }
+
+    /**
+     * The type could expose protected inner types which are still considered to be a public API when used
+     */
+    public void testPublicApiWithProtectedInterface() {
+        final CompilerResult result = compile("PublicApiWithProtectedInterface.java");
+        assertThat(result, instanceOf(Failure.class));
+
+        final Failure failure = (Failure) result;
+        assertThat(failure.diagnotics(), hasSize(2));
+
+        assertThat(failure.diagnotics(), not(hasItem(matching(Diagnostic.Kind.ERROR))));
+    }
+}
diff --git a/libs/common/src/test/java/org/opensearch/common/annotation/processor/CompilerSupport.java b/libs/common/src/test/java/org/opensearch/common/annotation/processor/CompilerSupport.java
new file mode 100644
index 0000000000000..dcf8dd7945012
--- /dev/null
+++ b/libs/common/src/test/java/org/opensearch/common/annotation/processor/CompilerSupport.java
@@ -0,0 +1,139 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
+
+import javax.tools.Diagnostic;
+import javax.tools.DiagnosticCollector;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaCompiler.CompilationTask;
+import javax.tools.JavaFileObject;
+import javax.tools.JavaFileObject.Kind;
+import javax.tools.SimpleJavaFileObject;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ToolProvider;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.StringWriter;
+import java.io.UncheckedIOException;
+import java.net.URI;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+interface CompilerSupport {
+    default CompilerResult compile(String name, String... names) {
+        return compileWithPackage(ApiAnnotationProcessorTests.class.getPackageName(), name, names);
+    }
+
+    default CompilerResult compileWithPackage(String pck, String name, String... names) {
+        final JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+        final DiagnosticCollector<JavaFileObject> collector = new DiagnosticCollector<>();
+
+        try (StringWriter out = new StringWriter()) {
+            final StandardJavaFileManager fileManager = compiler.getStandardFileManager(collector, null, null);
+            final List<JavaFileObject> files = Stream.concat(Stream.of(name), Arrays.stream(names))
+                .map(f -> asSource(pck, f))
+                .collect(Collectors.toList());
+
+            final CompilationTask task = compiler.getTask(out, fileManager, collector, null, null, files);
+            task.setProcessors(Collections.singleton(new ApiAnnotationProcessor()));
+
+            if (AccessController.doPrivileged((PrivilegedAction<Boolean>) () -> task.call())) {
+                return new Success();
+            } else {
+                return new Failure(collector.getDiagnostics());
+            }
+        } catch (final IOException ex) {
+            throw new UncheckedIOException(ex);
+        }
+    }
+
+    private static JavaFileObject asSource(String pkg, String name) {
+        final String resource = "/" + pkg.replaceAll("[.]", "/") + "/" + name;
+        final URL source = ApiAnnotationProcessorTests.class.getResource(resource);
+
+        return new SimpleJavaFileObject(URI.create(source.toExternalForm()), Kind.SOURCE) {
+            @Override
+            public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
+                try (final InputStream in = ApiAnnotationProcessorTests.class.getResourceAsStream(resource)) {
+                    return new String(in.readAllBytes(), StandardCharsets.UTF_8);
+                }
+            }
+        };
+    }
+
+    class CompilerResult {}
+
+    class Success extends CompilerResult {
+
+    }
+
+    class Failure extends CompilerResult {
+        private final List<Diagnostic<? extends JavaFileObject>> diagnotics;
+
+        Failure(List<Diagnostic<? extends JavaFileObject>> diagnotics) {
+            this.diagnotics = diagnotics;
+        }
+
+        List<Diagnostic<? extends JavaFileObject>> diagnotics() {
+            return diagnotics;
+        }
+    }
+
+    class HasDiagnostic extends TypeSafeMatcher<Diagnostic<? extends JavaFileObject>> {
+        private final Diagnostic.Kind kind;
+        private final Matcher<String> matcher;
+
+        HasDiagnostic(final Diagnostic.Kind kind, final Matcher<String> matcher) {
+            this.kind = kind;
+            this.matcher = matcher;
+        }
+
+        @Override
+        public void describeTo(Description description) {
+            description.appendText("diagnostic with kind ").appendValue(kind).appendText(" ");
+
+            if (matcher != null) {
+                description.appendText(" and message ");
+                matcher.describeTo(description);
+            }
+        }
+
+        @Override
+        protected boolean matchesSafely(Diagnostic<? extends JavaFileObject> item) {
+            if (!kind.equals(item.getKind())) {
+                return false;
+            } else if (matcher != null) {
+                return matcher.matches(item.getMessage(Locale.ROOT));
+            } else {
+                return true;
+            }
+        }
+
+        public static HasDiagnostic matching(final Diagnostic.Kind kind, final Matcher<String> matcher) {
+            return new HasDiagnostic(kind, matcher);
+        }
+
+        public static HasDiagnostic matching(final Diagnostic.Kind kind) {
+            return new HasDiagnostic(kind, null);
+        }
+    }
+}
diff --git a/libs/common/src/test/java/org/opensearch/common/round/RoundableTests.java b/libs/common/src/test/java/org/opensearch/common/round/RoundableTests.java
new file mode 100644
index 0000000000000..ae9f629c59024
--- /dev/null
+++ b/libs/common/src/test/java/org/opensearch/common/round/RoundableTests.java
@@ -0,0 +1,57 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.round;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+public class RoundableTests extends OpenSearchTestCase {
+
+    public void testFloor() {
+        int size = randomIntBetween(1, 256);
+        long[] values = new long[size];
+        for (int i = 1; i < values.length; i++) {
+            values[i] = values[i - 1] + (randomNonNegativeLong() % 200) + 1;
+        }
+
+        Roundable[] impls = { new BinarySearcher(values, size), new BidirectionalLinearSearcher(values, size) };
+
+        for (int i = 0; i < 100000; i++) {
+            // Index of the expected round-down point.
+            int idx = randomIntBetween(0, size - 1);
+
+            // Value of the expected round-down point.
+            long expected = values[idx];
+
+            // Delta between the expected and the next round-down point.
+            long delta = (idx < size - 1) ? (values[idx + 1] - values[idx]) : 200;
+
+            // Adding a random delta between 0 (inclusive) and delta (exclusive) to the expected
+            // round-down point, which will still floor to the same value.
+            long key = expected + (randomNonNegativeLong() % delta);
+
+            for (Roundable roundable : impls) {
+                assertEquals(expected, roundable.floor(key));
+            }
+        }
+    }
+
+    public void testFailureCases() {
+        Throwable throwable;
+
+        throwable = assertThrows(IllegalArgumentException.class, () -> new BinarySearcher(new long[0], 0));
+        assertEquals("at least one value must be present", throwable.getMessage());
+        throwable = assertThrows(IllegalArgumentException.class, () -> new BidirectionalLinearSearcher(new long[0], 0));
+        assertEquals("at least one value must be present", throwable.getMessage());
+
+        throwable = assertThrows(AssertionError.class, () -> new BinarySearcher(new long[] { 100 }, 1).floor(50));
+        assertEquals("key must be greater than or equal to 100", throwable.getMessage());
+        throwable = assertThrows(AssertionError.class, () -> new BidirectionalLinearSearcher(new long[] { 100 }, 1).floor(50));
+        assertEquals("key must be greater than or equal to 100", throwable.getMessage());
+    }
+}
diff --git a/libs/common/src/test/resources/org/acme/PublicApiAnnotated.java b/libs/common/src/test/resources/org/acme/PublicApiAnnotated.java
new file mode 100644
index 0000000000000..bc16fd996e69d
--- /dev/null
+++ b/libs/common/src/test/resources/org/acme/PublicApiAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.acme;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiAnnotated {
+
+}
diff --git a/libs/common/src/test/resources/org/opensearch/bootstrap/test.policy b/libs/common/src/test/resources/org/opensearch/bootstrap/test.policy
new file mode 100644
index 0000000000000..e0a183b7eac88
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/bootstrap/test.policy
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+grant {
+  // allow to use JVM tooling (Java Compiler) in tests for annotation processing 
+  permission java.io.FilePermission "${java.home}/lib/*", "read";
+  permission java.io.FilePermission "${java.home}/lib/modules/*", "read";
+  permission java.lang.RuntimePermission "accessSystemModules";
+  permission java.lang.RuntimePermission "accessDeclaredMembers";
+  permission java.lang.RuntimePermission "accessClassInPackage.*";
+};
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/DeprecatedApiMethodReturnSelf.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/DeprecatedApiMethodReturnSelf.java
new file mode 100644
index 0000000000000..7c5b6f6ea2f51
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/DeprecatedApiMethodReturnSelf.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.DeprecatedApi;
+
+@DeprecatedApi(since = "1.0.0")
+public class DeprecatedApiMethodReturnSelf {
+    public DeprecatedApiMethodReturnSelf method() {
+        return new DeprecatedApiMethodReturnSelf();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/ExperimentalApiAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/ExperimentalApiAnnotated.java
new file mode 100644
index 0000000000000..5be07e22c811f
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/ExperimentalApiAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+
+@ExperimentalApi
+public class ExperimentalApiAnnotated {
+
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/ExperimentalApiMethodReturnSelf.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/ExperimentalApiMethodReturnSelf.java
new file mode 100644
index 0000000000000..cde8f4f254faf
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/ExperimentalApiMethodReturnSelf.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+
+@ExperimentalApi
+public class ExperimentalApiMethodReturnSelf {
+    public ExperimentalApiMethodReturnSelf method() {
+        return new ExperimentalApiMethodReturnSelf();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/InternalApiAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/InternalApiAnnotated.java
new file mode 100644
index 0000000000000..9996ba8b736aa
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/InternalApiAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class InternalApiAnnotated {
+
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotated.java
new file mode 100644
index 0000000000000..ec16ce926ea86
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotated.java
@@ -0,0 +1,13 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+public class NotAnnotated {
+
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotatedAnnotation.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotatedAnnotation.java
new file mode 100644
index 0000000000000..a3e9c4f576d92
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotatedAnnotation.java
@@ -0,0 +1,27 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+
+@Target({
+    ElementType.TYPE,
+    ElementType.TYPE_PARAMETER,
+    ElementType.TYPE_USE,
+    ElementType.PACKAGE,
+    ElementType.METHOD,
+    ElementType.CONSTRUCTOR,
+    ElementType.PARAMETER,
+    ElementType.FIELD,
+    ElementType.ANNOTATION_TYPE,
+    ElementType.MODULE })
+public @interface NotAnnotatedAnnotation {
+
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotatedException.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotatedException.java
new file mode 100644
index 0000000000000..0aadaf8f9bf31
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/NotAnnotatedException.java
@@ -0,0 +1,13 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+public class NotAnnotatedException extends Exception {
+    private static final long serialVersionUID = 1L;
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiAnnotated.java
new file mode 100644
index 0000000000000..b2a7f03cb2d31
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiAnnotated {
+
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiConstructorArgumentAnnotatedInternalApi.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiConstructorArgumentAnnotatedInternalApi.java
new file mode 100644
index 0000000000000..6bea2961a14e6
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiConstructorArgumentAnnotatedInternalApi.java
@@ -0,0 +1,20 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiConstructorArgumentAnnotatedInternalApi {
+    /**
+     * The constructor arguments have relaxed semantics at the moment: those could be not annotated or be annotated as {@link InternalApi}
+     */
+    public PublicApiConstructorArgumentAnnotatedInternalApi(InternalApiAnnotated arg) {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiConstructorArgumentNotAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiConstructorArgumentNotAnnotated.java
new file mode 100644
index 0000000000000..6c7481d9978cd
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiConstructorArgumentNotAnnotated.java
@@ -0,0 +1,20 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiConstructorArgumentNotAnnotated {
+    /**
+     * The constructor arguments have relaxed semantics at the moment: those could be not annotated or be annotated as {@link InternalApi}
+     */
+    public PublicApiConstructorArgumentNotAnnotated(NotAnnotated arg) {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentAnnotatedPackagePrivate.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentAnnotatedPackagePrivate.java
new file mode 100644
index 0000000000000..5dae56a7cd7d3
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentAnnotatedPackagePrivate.java
@@ -0,0 +1,20 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodArgumentAnnotatedPackagePrivate {
+    public void method(AnnotatedPackagePrivate arg) {}
+}
+
+// The public API exposes this class through public method argument, it should be public
+@PublicApi(since = "1.0.0")
+class AnnotatedPackagePrivate {}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotated.java
new file mode 100644
index 0000000000000..ddfec939f79e8
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodArgumentNotAnnotated {
+    public void method(NotAnnotated arg) {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotatedGenerics.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotatedGenerics.java
new file mode 100644
index 0000000000000..d32502831d299
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotatedGenerics.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+import java.util.Collection;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodArgumentNotAnnotatedGenerics {
+    public void method(Collection<? super NotAnnotated> arg) {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotatedPackagePrivate.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotatedPackagePrivate.java
new file mode 100644
index 0000000000000..d4fb31b172ef2
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodArgumentNotAnnotatedPackagePrivate.java
@@ -0,0 +1,19 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodArgumentNotAnnotatedPackagePrivate {
+    public void method(NotAnnotatedPackagePrivate arg) {}
+}
+
+// The public API exposes this class through public method argument, it should be annotated and be public
+class NotAnnotatedPackagePrivate {}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodGenericsArgumentAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodGenericsArgumentAnnotated.java
new file mode 100644
index 0000000000000..9715748cfa659
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodGenericsArgumentAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodGenericsArgumentAnnotated {
+    public <T extends PublicApiAnnotated> void method(T arg) {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodGenericsArgumentNotAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodGenericsArgumentNotAnnotated.java
new file mode 100644
index 0000000000000..f149c1f34b067
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodGenericsArgumentNotAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodGenericsArgumentNotAnnotated {
+    public <T extends NotAnnotated> void method(T arg) {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnAnnotatedArray.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnAnnotatedArray.java
new file mode 100644
index 0000000000000..39b7e146fe1e7
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnAnnotatedArray.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnAnnotatedArray {
+    public PublicApiAnnotated[] method() {
+        return new PublicApiAnnotated[0];
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnAnnotatedGenerics.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnAnnotatedGenerics.java
new file mode 100644
index 0000000000000..2171eccee2f31
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnAnnotatedGenerics.java
@@ -0,0 +1,23 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+import java.util.Collection;
+import java.util.Collections;
+
+import org.acme.PublicApiAnnotated;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnAnnotatedGenerics {
+    public Collection<@NotAnnotatedAnnotation PublicApiAnnotated> method() {
+        return Collections.emptyList();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotated.java
new file mode 100644
index 0000000000000..725d06072d0ea
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotated.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnNotAnnotated {
+    public NotAnnotated method() {
+        return new NotAnnotated();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedAnnotation.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedAnnotation.java
new file mode 100644
index 0000000000000..b684e36a53da1
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedAnnotation.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnNotAnnotatedAnnotation {
+    public @NotAnnotatedAnnotation PublicApiAnnotated method() {
+        return new PublicApiAnnotated();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedArray.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedArray.java
new file mode 100644
index 0000000000000..e4c541dcea57f
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedArray.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnNotAnnotatedArray {
+    public NotAnnotated[] method() {
+        return new NotAnnotated[0];
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedBoundedGenerics.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedBoundedGenerics.java
new file mode 100644
index 0000000000000..0646faf152610
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedBoundedGenerics.java
@@ -0,0 +1,21 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+import java.util.Collection;
+import java.util.Collections;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnNotAnnotatedBoundedGenerics {
+    public Collection<? extends NotAnnotated> method() {
+        return Collections.emptyList();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedGenerics.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedGenerics.java
new file mode 100644
index 0000000000000..2227883c707d0
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedGenerics.java
@@ -0,0 +1,21 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+import java.util.Collection;
+import java.util.Collections;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnNotAnnotatedGenerics {
+    public Collection<NotAnnotated> method() {
+        return Collections.emptyList();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedWildcardGenerics.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedWildcardGenerics.java
new file mode 100644
index 0000000000000..f2818ebb23c4a
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnNotAnnotatedWildcardGenerics.java
@@ -0,0 +1,21 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+import java.util.Collection;
+import java.util.Collections;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnNotAnnotatedWildcardGenerics {
+    public Collection<?> method() {
+        return Collections.emptyList();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnSelf.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnSelf.java
new file mode 100644
index 0000000000000..883471b23ae0f
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodReturnSelf.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodReturnSelf {
+    public PublicApiMethodReturnSelf method() {
+        return new PublicApiMethodReturnSelf();
+    }
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodThrowsNotAnnotated.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodThrowsNotAnnotated.java
new file mode 100644
index 0000000000000..496b243276565
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiMethodThrowsNotAnnotated.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiMethodThrowsNotAnnotated {
+    public void method(PublicApiAnnotated arg) throws NotAnnotatedException {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiPackagePrivate.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiPackagePrivate.java
new file mode 100644
index 0000000000000..88c20e7f4c8f1
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiPackagePrivate.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+class PublicApiPackagePrivate {
+    void method() {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithExperimentalApiMethod.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithExperimentalApiMethod.java
new file mode 100644
index 0000000000000..faaaa1d9f4051
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithExperimentalApiMethod.java
@@ -0,0 +1,18 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiWithExperimentalApiMethod {
+    @ExperimentalApi
+    public void method() {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithInternalApiMethod.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithInternalApiMethod.java
new file mode 100644
index 0000000000000..5bfa3c9f3e008
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithInternalApiMethod.java
@@ -0,0 +1,19 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiWithInternalApiMethod {
+    // The public API exposes internal API method, it should be public API
+    @InternalApi
+    public void method() {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithPackagePrivateMethod.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithPackagePrivateMethod.java
new file mode 100644
index 0000000000000..1345467423530
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithPackagePrivateMethod.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiWithPackagePrivateMethod {
+    void method(NotAnnotated arg) {}
+}
diff --git a/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithProtectedInterface.java b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithProtectedInterface.java
new file mode 100644
index 0000000000000..222ae01fd15e6
--- /dev/null
+++ b/libs/common/src/test/resources/org/opensearch/common/annotation/processor/PublicApiWithProtectedInterface.java
@@ -0,0 +1,22 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.annotation.processor;
+
+import org.opensearch.common.annotation.PublicApi;
+
+@PublicApi(since = "1.0.0")
+public class PublicApiWithProtectedInterface {
+    public void method(ProtectedInterface iface) {}
+
+    /**
+     * The type could expose protected inner types which are still considered to be a public API when used
+     */
+    @PublicApi(since = "1.0.0")
+    protected interface ProtectedInterface {}
+}
diff --git a/libs/compress/src/main/java/org/opensearch/compress/ZstdCompressor.java b/libs/compress/src/main/java/org/opensearch/compress/ZstdCompressor.java
index 01afc368fb120..e2a740f72be93 100644
--- a/libs/compress/src/main/java/org/opensearch/compress/ZstdCompressor.java
+++ b/libs/compress/src/main/java/org/opensearch/compress/ZstdCompressor.java
@@ -30,10 +30,13 @@
  * @opensearch.experimental - class methods might change
  */
 public class ZstdCompressor implements Compressor {
-    // An arbitrary header that we use to identify compressed streams
-    // It needs to be different from other compressors and to not be specific
-    // enough so that no stream starting with these bytes could be detected as
-    // a XContent
+
+    /**
+     * An arbitrary header that we use to identify compressed streams
+     * It needs to be different from other compressors and to not be specific
+     * enough so that no stream starting with these bytes could be detected as
+     * a XContent
+     * */
     private static final byte[] HEADER = new byte[] { 'Z', 'S', 'T', 'D', '\0' };
 
     /**
@@ -44,10 +47,20 @@ public class ZstdCompressor implements Compressor {
     @PublicApi(since = "2.10.0")
     public static final String NAME = "ZSTD";
 
+    /**
+     * The compression level for {@link ZstdOutputStreamNoFinalizer}
+     */
     private static final int LEVEL = 3;
 
+    /** The buffer size for {@link BufferedInputStream} and {@link BufferedOutputStream}
+     */
     private static final int BUFFER_SIZE = 4096;
 
+    /**
+     * Compares the given bytes with the {@link ZstdCompressor#HEADER} of a compressed stream
+     * @param bytes the bytes to compare to ({@link ZstdCompressor#HEADER})
+     * @return true if the bytes are the {@link ZstdCompressor#HEADER}, false otherwise
+     */
     @Override
     public boolean isCompressed(BytesReference bytes) {
         if (bytes.length() < HEADER.length) {
@@ -61,11 +74,22 @@ public boolean isCompressed(BytesReference bytes) {
         return true;
     }
 
+    /**
+     * Returns the length of the {@link ZstdCompressor#HEADER}
+     * @return the {@link ZstdCompressor#HEADER} length
+     */
     @Override
     public int headerLength() {
         return HEADER.length;
     }
 
+    /**
+     * Returns a new {@link ZstdInputStreamNoFinalizer} from the given compressed {@link InputStream}
+     * @param in the compressed {@link InputStream}
+     * @return a new {@link ZstdInputStreamNoFinalizer} from the given compressed {@link InputStream}
+     * @throws IOException if an I/O error occurs
+     * @throws IllegalArgumentException if the input stream is not compressed with ZSTD
+     */
     @Override
     public InputStream threadLocalInputStream(InputStream in) throws IOException {
         final byte[] header = in.readNBytes(HEADER.length);
@@ -75,17 +99,36 @@ public InputStream threadLocalInputStream(InputStream in) throws IOException {
         return new ZstdInputStreamNoFinalizer(new BufferedInputStream(in, BUFFER_SIZE), RecyclingBufferPool.INSTANCE);
     }
 
+    /**
+     * Returns a new {@link ZstdOutputStreamNoFinalizer} from the given {@link OutputStream}
+     * @param out the {@link OutputStream}
+     * @return a new {@link ZstdOutputStreamNoFinalizer} from the given {@link OutputStream}
+     * @throws IOException if an I/O error occurs
+     */
     @Override
     public OutputStream threadLocalOutputStream(OutputStream out) throws IOException {
         out.write(HEADER);
         return new ZstdOutputStreamNoFinalizer(new BufferedOutputStream(out, BUFFER_SIZE), RecyclingBufferPool.INSTANCE, LEVEL);
     }
 
+    /**
+     * Always throws an {@link UnsupportedOperationException} as ZSTD compression is supported only for snapshotting
+     * @param bytesReference a reference to the bytes to uncompress
+     * @return always throws an exception
+     * @throws UnsupportedOperationException if the method is called
+     * @throws IOException is never thrown
+     */
     @Override
     public BytesReference uncompress(BytesReference bytesReference) throws IOException {
         throw new UnsupportedOperationException("ZSTD compression is supported only for snapshotting");
     }
 
+    /**
+     * Always throws an {@link UnsupportedOperationException} as ZSTD compression is supported only for snapshotting
+     * @param bytesReference a reference to the bytes to compress
+     * @return always throws an exception
+     * @throws UnsupportedOperationException if the method is called
+     */
     @Override
     public BytesReference compress(BytesReference bytesReference) throws IOException {
         throw new UnsupportedOperationException("ZSTD compression is supported only for snapshotting");
diff --git a/libs/core/build.gradle b/libs/core/build.gradle
index 46b6f4471731f..4850b5aea5c85 100644
--- a/libs/core/build.gradle
+++ b/libs/core/build.gradle
@@ -33,7 +33,7 @@ import org.opensearch.gradle.info.BuildParams
 apply plugin: 'opensearch.publish'
 
 base {
-  archivesBaseName = 'opensearch-core'
+  archivesName = 'opensearch-core'
 }
 
 // we want to keep the JDKs in our IDEs set to JDK 8 until minimum JDK is bumped to 11 so we do not include this source set in our IDEs
diff --git a/libs/core/licenses/jackson-core-2.15.2.jar.sha1 b/libs/core/licenses/jackson-core-2.15.2.jar.sha1
deleted file mode 100644
index ec6781b968eed..0000000000000
--- a/libs/core/licenses/jackson-core-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-a6fe1836469a69b3ff66037c324d75fc66ef137c
\ No newline at end of file
diff --git a/libs/core/licenses/jackson-core-2.16.0.jar.sha1 b/libs/core/licenses/jackson-core-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..c2b70fb4ae202
--- /dev/null
+++ b/libs/core/licenses/jackson-core-2.16.0.jar.sha1
@@ -0,0 +1 @@
+899e5cf01be55fbf094ad72b2edb0c5df99111ee
\ No newline at end of file
diff --git a/libs/core/licenses/log4j-api-2.20.0.jar.sha1 b/libs/core/licenses/log4j-api-2.20.0.jar.sha1
deleted file mode 100644
index 37154d9861ac0..0000000000000
--- a/libs/core/licenses/log4j-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-1fe6082e660daf07c689a89c94dc0f49c26b44bb
\ No newline at end of file
diff --git a/libs/core/licenses/log4j-api-2.21.0.jar.sha1 b/libs/core/licenses/log4j-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..51446052594aa
--- /dev/null
+++ b/libs/core/licenses/log4j-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+760192f2b69eacf4a4afc78e5a1d7a8de054fcbd
\ No newline at end of file
diff --git a/libs/core/licenses/lucene-core-9.8.0-snapshot-4373c3b.jar.sha1 b/libs/core/licenses/lucene-core-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index dc363f2776429..0000000000000
--- a/libs/core/licenses/lucene-core-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-30c3afcf058532d3d2b8820375043000e7f34a9b
\ No newline at end of file
diff --git a/libs/core/licenses/lucene-core-9.8.0.jar.sha1 b/libs/core/licenses/lucene-core-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..f9a3e2f3cbee6
--- /dev/null
+++ b/libs/core/licenses/lucene-core-9.8.0.jar.sha1
@@ -0,0 +1 @@
+5e8421c5f8573bcf22e9265fc7e19469545a775a
\ No newline at end of file
diff --git a/libs/core/src/main/java/org/opensearch/Build.java b/libs/core/src/main/java/org/opensearch/Build.java
index 67a50a8a31a0e..b5d67f5501725 100644
--- a/libs/core/src/main/java/org/opensearch/Build.java
+++ b/libs/core/src/main/java/org/opensearch/Build.java
@@ -216,7 +216,7 @@ public String getDistribution() {
 
     /**
      * Get the version as considered at build time
-     *
+     * <p>
      * Offers a way to get the fully qualified version as configured by the build.
      * This will be the same as {@link Version} for production releases, but may include on of the qualifier ( e.x alpha1 )
      * or -SNAPSHOT for others.
diff --git a/libs/core/src/main/java/org/opensearch/LegacyESVersion.java b/libs/core/src/main/java/org/opensearch/LegacyESVersion.java
index 32eae654cf975..5d8e067a8fd8b 100644
--- a/libs/core/src/main/java/org/opensearch/LegacyESVersion.java
+++ b/libs/core/src/main/java/org/opensearch/LegacyESVersion.java
@@ -40,7 +40,7 @@
 
 /**
  * The Contents of this file were originally moved from {@link Version}.
- *
+ * <p>
  * This class keeps all the supported OpenSearch predecessor versions for
  * backward compatibility purpose.
  *
diff --git a/libs/core/src/main/java/org/opensearch/OpenSearchException.java b/libs/core/src/main/java/org/opensearch/OpenSearchException.java
index 5bad711a15032..cce86b452f698 100644
--- a/libs/core/src/main/java/org/opensearch/OpenSearchException.java
+++ b/libs/core/src/main/java/org/opensearch/OpenSearchException.java
@@ -168,7 +168,7 @@ public OpenSearchException(Throwable cause) {
 
     /**
      * Construct a <code>OpenSearchException</code> with the specified detail message.
-     *
+     * <p>
      * The message can be parameterized using <code>{}</code> as placeholders for the given
      * arguments
      *
@@ -182,7 +182,7 @@ public OpenSearchException(String msg, Object... args) {
     /**
      * Construct a <code>OpenSearchException</code> with the specified detail message
      * and nested exception.
-     *
+     * <p>
      * The message can be parameterized using <code>{}</code> as placeholders for the given
      * arguments
      *
@@ -587,7 +587,7 @@ public static OpenSearchException innerFromXContent(XContentParser parser, boole
      * Static toXContent helper method that renders {@link OpenSearchException} or {@link Throwable} instances
      * as XContent, delegating the rendering to {@link OpenSearchException#toXContent(XContentBuilder, ToXContent.Params)}
      * or {@link #innerToXContent(XContentBuilder, ToXContent.Params, Throwable, String, String, Map, Map, Throwable)}.
-     *
+     * <p>
      * This method is usually used when the {@link Throwable} is rendered as a part of another XContent object, and its result can
      * be parsed back using the {@code OpenSearchException.fromXContent(XContentParser)} method.
      */
@@ -606,7 +606,7 @@ public static void generateThrowableXContent(XContentBuilder builder, ToXContent
      * depends on the value of the "detailed" parameter: when it's false only a simple message based on the type and message of the
      * exception is rendered. When it's true all detail are provided including guesses root causes, cause and potentially stack
      * trace.
-     *
+     * <p>
      * This method is usually used when the {@link Exception} is rendered as a full XContent object, and its output can be parsed
      * by the {@code #OpenSearchException.failureFromXContent(XContentParser)} method.
      */
diff --git a/libs/core/src/main/java/org/opensearch/OpenSearchParseException.java b/libs/core/src/main/java/org/opensearch/OpenSearchParseException.java
index c2516402b0d30..26aff04b30a56 100644
--- a/libs/core/src/main/java/org/opensearch/OpenSearchParseException.java
+++ b/libs/core/src/main/java/org/opensearch/OpenSearchParseException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.rest.RestStatus;
 
@@ -40,8 +41,9 @@
 /**
  * Unchecked exception that is translated into a {@code 400 BAD REQUEST} error when it bubbles out over HTTP.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class OpenSearchParseException extends OpenSearchException {
 
     public OpenSearchParseException(String msg, Object... args) {
diff --git a/libs/core/src/main/java/org/opensearch/Version.java b/libs/core/src/main/java/org/opensearch/Version.java
index 32f4ca0317907..d94be3f25b53d 100644
--- a/libs/core/src/main/java/org/opensearch/Version.java
+++ b/libs/core/src/main/java/org/opensearch/Version.java
@@ -94,7 +94,11 @@ public class Version implements Comparable<Version>, ToXContentFragment {
     public static final Version V_2_9_0 = new Version(2090099, org.apache.lucene.util.Version.LUCENE_9_7_0);
     public static final Version V_2_9_1 = new Version(2090199, org.apache.lucene.util.Version.LUCENE_9_7_0);
     public static final Version V_2_10_0 = new Version(2100099, org.apache.lucene.util.Version.LUCENE_9_7_0);
+    public static final Version V_2_10_1 = new Version(2100199, org.apache.lucene.util.Version.LUCENE_9_7_0);
     public static final Version V_2_11_0 = new Version(2110099, org.apache.lucene.util.Version.LUCENE_9_7_0);
+    public static final Version V_2_11_1 = new Version(2110199, org.apache.lucene.util.Version.LUCENE_9_7_0);
+    public static final Version V_2_11_2 = new Version(2110299, org.apache.lucene.util.Version.LUCENE_9_7_0);
+    public static final Version V_2_12_0 = new Version(2120099, org.apache.lucene.util.Version.LUCENE_9_8_0);
     public static final Version V_3_0_0 = new Version(3000099, org.apache.lucene.util.Version.LUCENE_9_8_0);
     public static final Version CURRENT = V_3_0_0;
 
diff --git a/libs/core/src/main/java/org/opensearch/core/action/ActionListener.java b/libs/core/src/main/java/org/opensearch/core/action/ActionListener.java
index 119e56cfe0bf2..4fd55898a2cb5 100644
--- a/libs/core/src/main/java/org/opensearch/core/action/ActionListener.java
+++ b/libs/core/src/main/java/org/opensearch/core/action/ActionListener.java
@@ -154,9 +154,9 @@ static <Response> ActionListener<Response> wrap(Runnable runnable) {
     /**
      * Creates a listener that wraps another listener, mapping response values via the given mapping function and passing along
      * exceptions to the delegate.
-     *
+     * <p>
      * Notice that it is considered a bug if the listener's onResponse or onFailure fails. onResponse failures will not call onFailure.
-     *
+     * <p>
      * If the function fails, the listener's onFailure handler will be called. The principle is that the mapped listener will handle
      * exceptions from the mapping function {@code fn} but it is the responsibility of {@code delegate} to handle its own exceptions
      * inside `onResponse` and `onFailure`.
@@ -334,7 +334,7 @@ protected void innerOnFailure(Exception e) {
     /**
      * Completes the given listener with the result from the provided supplier accordingly.
      * This method is mainly used to complete a listener with a block of synchronous code.
-     *
+     * <p>
      * If the supplier fails, the listener's onFailure handler will be called.
      * It is the responsibility of {@code delegate} to handle its own exceptions inside `onResponse` and `onFailure`.
      */
diff --git a/libs/core/src/main/java/org/opensearch/core/action/ActionResponse.java b/libs/core/src/main/java/org/opensearch/core/action/ActionResponse.java
index 041d8b1bffb4a..7525bfb243aae 100644
--- a/libs/core/src/main/java/org/opensearch/core/action/ActionResponse.java
+++ b/libs/core/src/main/java/org/opensearch/core/action/ActionResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.core.action;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.transport.TransportResponse;
 
@@ -42,6 +43,7 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class ActionResponse extends TransportResponse {
 
     public ActionResponse() {}
diff --git a/libs/core/src/main/java/org/opensearch/core/action/NotifyOnceListener.java b/libs/core/src/main/java/org/opensearch/core/action/NotifyOnceListener.java
index 6af9ca005d171..f087322e0024c 100644
--- a/libs/core/src/main/java/org/opensearch/core/action/NotifyOnceListener.java
+++ b/libs/core/src/main/java/org/opensearch/core/action/NotifyOnceListener.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.core.action;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
@@ -39,8 +41,9 @@
  * the is called is only called once. Subclasses should implement notification logic with
  * innerOnResponse and innerOnFailure.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class NotifyOnceListener<Response> implements ActionListener<Response> {
 
     private final AtomicBoolean hasBeenCalled = new AtomicBoolean(false);
diff --git a/libs/core/src/main/java/org/opensearch/core/common/Strings.java b/libs/core/src/main/java/org/opensearch/core/common/Strings.java
index 6227716af9cc9..8fdec670bd9f2 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/Strings.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/Strings.java
@@ -38,7 +38,7 @@
 
 /**
  * String utility class.
- *
+ * <p>
  * TODO replace Strings in :server
  *
  * @opensearch.internal
diff --git a/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreaker.java b/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreaker.java
index 0f75f763d21c1..846950ff17c63 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreaker.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreaker.java
@@ -71,17 +71,23 @@ public interface CircuitBreaker {
 
     /**
      * The type of breaker
-     *
+     * can be {@link #MEMORY}, {@link #PARENT}, or {@link #NOOP}
      * @opensearch.internal
      */
     enum Type {
-        // A regular or ChildMemoryCircuitBreaker
+        /** A regular or ChildMemoryCircuitBreaker */
         MEMORY,
-        // A special parent-type for the hierarchy breaker service
+        /** A special parent-type for the hierarchy breaker service */
         PARENT,
-        // A breaker where every action is a noop, it never breaks
+        /** A breaker where every action is a noop, it never breaks */
         NOOP;
 
+        /**
+         * Converts string (case-insensitive) to breaker {@link Type}
+         * @param value "noop", "parent", or "memory" (case-insensitive)
+         * @return the breaker {@link Type}
+         * @throws IllegalArgumentException if value is not "noop", "parent", or "memory"
+         */
         public static Type parseValue(String value) {
             switch (value.toLowerCase(Locale.ROOT)) {
                 case "noop":
@@ -98,13 +104,13 @@ public static Type parseValue(String value) {
 
     /**
      * The breaker durability
-     *
+     * can be {@link #TRANSIENT} or {@link #PERMANENT}
      * @opensearch.internal
      */
     enum Durability {
-        // The condition that tripped the circuit breaker fixes itself eventually.
+        /** The condition that tripped the circuit breaker fixes itself eventually. */
         TRANSIENT,
-        // The condition that tripped the circuit breaker requires manual intervention.
+        /** The condition that tripped the circuit breaker requires manual intervention. */
         PERMANENT
     }
 
@@ -120,11 +126,14 @@ enum Durability {
      * @param bytes number of bytes to add
      * @param label string label describing the bytes being added
      * @return the number of "used" bytes for the circuit breaker
+     * @throws CircuitBreakingException if the breaker tripped
      */
     double addEstimateBytesAndMaybeBreak(long bytes, String label) throws CircuitBreakingException;
 
     /**
      * Adjust the circuit breaker without tripping
+     * @param bytes number of bytes to add
+     * @return the number of "used" bytes for the circuit breaker
      */
     long addWithoutBreaking(long bytes);
 
@@ -154,7 +163,10 @@ enum Durability {
     String getName();
 
     /**
-     * @return whether a tripped circuit breaker will reset itself (transient) or requires manual intervention (permanent).
+     * Returns the {@link Durability} of this breaker
+     * @return whether a tripped circuit breaker will
+     * reset itself ({@link Durability#TRANSIENT})
+     * or requires manual intervention ({@link Durability#PERMANENT}).
      */
     Durability getDurability();
 
diff --git a/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreakingException.java b/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreakingException.java
index e6443a0d48ce0..2df116dcad076 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreakingException.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/breaker/CircuitBreakingException.java
@@ -46,8 +46,11 @@
  */
 public class CircuitBreakingException extends OpenSearchException {
 
+    /** The number of bytes wanted */
     private final long bytesWanted;
+    /** The circuit breaker limit */
     private final long byteLimit;
+    /** The {@link CircuitBreaker.Durability} of the circuit breaker */
     private final CircuitBreaker.Durability durability;
 
     public CircuitBreakingException(StreamInput in) throws IOException {
@@ -88,6 +91,7 @@ public CircuitBreaker.Durability getDurability() {
         return durability;
     }
 
+    /** Always returns {@link RestStatus#TOO_MANY_REQUESTS} */
     @Override
     public RestStatus status() {
         return RestStatus.TOO_MANY_REQUESTS;
diff --git a/libs/core/src/main/java/org/opensearch/core/common/breaker/NoopCircuitBreaker.java b/libs/core/src/main/java/org/opensearch/core/common/breaker/NoopCircuitBreaker.java
index 86a0a7ccb96fd..17b9fefd27c99 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/breaker/NoopCircuitBreaker.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/breaker/NoopCircuitBreaker.java
@@ -33,65 +33,120 @@
 package org.opensearch.core.common.breaker;
 
 /**
- * A CircuitBreaker that doesn't increment or adjust, and all operations are
- * basically noops
- *
+ * A {@link CircuitBreaker} that doesn't increment or adjust, and all operations are
+ * basically noops.
+ * It never trips, limit is always -1, always returns 0 for all metrics.
  * @opensearch.internal
  */
 public class NoopCircuitBreaker implements CircuitBreaker {
-    public static final int LIMIT = -1;
 
+    /** The limit of this breaker is always -1 */
+    public static final int LIMIT = -1;
+    /** Name of this breaker */
     private final String name;
 
+    /**
+     * Creates a new NoopCircuitBreaker (that never trip) with the given name
+     * @param name the name of this breaker
+     */
     public NoopCircuitBreaker(String name) {
         this.name = name;
     }
 
+    /**
+     * This is a noop, a noop breaker never trip
+     * @param fieldName name of this noop breaker
+     * @param bytesNeeded bytes needed
+     */
     @Override
     public void circuitBreak(String fieldName, long bytesNeeded) {
         // noop
     }
 
+    /**
+     * This is a noop, always return 0 and never throw/trip
+     * @param bytes number of bytes to add
+     * @param label string label describing the bytes being added
+     * @return always return 0
+     * @throws CircuitBreakingException never thrown
+     */
     @Override
     public double addEstimateBytesAndMaybeBreak(long bytes, String label) throws CircuitBreakingException {
         return 0;
     }
 
+    /**
+     * This is a noop, nothing is added, always return 0
+     * @param bytes number of bytes to add (ignored)
+     * @return always return 0
+     */
     @Override
     public long addWithoutBreaking(long bytes) {
         return 0;
     }
 
+    /**
+     * This is a noop, always return 0
+     * @return always return 0
+     */
     @Override
     public long getUsed() {
         return 0;
     }
 
+    /**
+     * A noop breaker have a constant limit of -1
+     * @return always return -1
+     */
     @Override
     public long getLimit() {
         return LIMIT;
     }
 
+    /**
+     * A noop breaker have no overhead, always return 0
+     * @return always return 0
+     */
     @Override
     public double getOverhead() {
         return 0;
     }
 
+    /**
+     * A noop breaker never trip, always return 0
+     * @return always return 0
+     */
     @Override
     public long getTrippedCount() {
         return 0;
     }
 
+    /**
+     * return the name of this breaker
+     * @return the name of this breaker
+     */
     @Override
     public String getName() {
         return this.name;
     }
 
+    /**
+     * A noop breaker {@link Durability} is always {@link Durability#PERMANENT}
+     * @return always return {@link Durability#PERMANENT }
+     */
     @Override
     public Durability getDurability() {
         return Durability.PERMANENT;
     }
 
+    /**
+     * Limit and overhead are constant for a noop breaker.
+     * this is a noop.
+     * @param limit the desired limit (ignored)
+     * @param overhead the desired overhead (ignored)
+     */
     @Override
-    public void setLimitAndOverhead(long limit, double overhead) {}
+    public void setLimitAndOverhead(long limit, double overhead) {
+        // noop
+    }
 }
diff --git a/libs/core/src/main/java/org/opensearch/core/common/bytes/AbstractBytesReference.java b/libs/core/src/main/java/org/opensearch/core/common/bytes/AbstractBytesReference.java
index e054776d67fdc..a2bf7e499dee8 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/bytes/AbstractBytesReference.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/bytes/AbstractBytesReference.java
@@ -49,14 +49,10 @@
  */
 public abstract class AbstractBytesReference implements BytesReference {
 
-    private Integer hash = null; // we cache the hash of this reference since it can be quite costly to re-calculated it
+    /** we cache the hash of this reference since it can be quite costly to re-calculated it */
+    private Integer hash = null;
     private static final int MAX_UTF16_LENGTH = Integer.MAX_VALUE >> 1;
 
-    @Override
-    public int getInt(int index) {
-        return (get(index) & 0xFF) << 24 | (get(index + 1) & 0xFF) << 16 | (get(index + 2) & 0xFF) << 8 | get(index + 3) & 0xFF;
-    }
-
     @Override
     public int indexOf(byte marker, int from) {
         final int to = length();
diff --git a/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesArray.java b/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesArray.java
index ae04ddcc19eee..d7a8414935143 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesArray.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesArray.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.core.common.bytes;
 
+import org.apache.lucene.util.BitUtil;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.core.common.io.stream.StreamInput;
 
@@ -83,6 +84,11 @@ public byte get(int index) {
         return bytes[offset + index];
     }
 
+    @Override
+    public int getInt(int index) {
+        return (int) BitUtil.VH_BE_INT.get(bytes, offset + index);
+    }
+
     @Override
     public int length() {
         return length;
diff --git a/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesReference.java b/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesReference.java
index 9d24d3653397b..8cb65c9feb1ca 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesReference.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/bytes/BytesReference.java
@@ -153,9 +153,11 @@ static BytesReference fromByteArray(ByteArray byteArray, int length) {
     byte get(int index);
 
     /**
-     * Returns the integer read from the 4 bytes (BE) starting at the given index.
+     * Returns the integer read from the 4 bytes (big endian) starting at the given index.
      */
-    int getInt(int index);
+    default int getInt(int index) {
+        return ((get(index) & 0xFF) << 24) | ((get(index + 1) & 0xFF) << 16) | ((get(index + 2) & 0xFF) << 8) | (get(index + 3) & 0xFF);
+    }
 
     /**
      * Finds the index of the first occurrence of the given marker between within the given bounds.
diff --git a/libs/core/src/main/java/org/opensearch/core/common/bytes/CompositeBytesReference.java b/libs/core/src/main/java/org/opensearch/core/common/bytes/CompositeBytesReference.java
index 53915a3da824c..1a48abee2dbf8 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/bytes/CompositeBytesReference.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/bytes/CompositeBytesReference.java
@@ -45,7 +45,7 @@
 /**
  * A composite {@link BytesReference} that allows joining multiple bytes references
  * into one without copying.
- *
+ * <p>
  * Note, {@link #toBytesRef()} will materialize all pages in this BytesReference.
  *
  * @opensearch.internal
diff --git a/libs/core/src/main/java/org/opensearch/core/common/io/stream/BytesStreamInput.java b/libs/core/src/main/java/org/opensearch/core/common/io/stream/BytesStreamInput.java
index a50d1c165ed72..cad43f817faaf 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/io/stream/BytesStreamInput.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/io/stream/BytesStreamInput.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.core.common.io.stream;
 
+import org.apache.lucene.util.BitUtil;
 import org.apache.lucene.util.BytesRef;
 
 import java.io.EOFException;
@@ -17,7 +18,7 @@
  * {@link StreamInput} version of Lucene's {@link org.apache.lucene.store.ByteArrayDataInput}
  * This is used as a replacement of Lucene ByteArrayDataInput for abstracting byte order changes
  * in Lucene's API
- *
+ * <p>
  * Attribution given to apache lucene project under ALv2:
  *
  * Licensed to the Apache Software Foundation (ASF) under one or more
@@ -121,4 +122,33 @@ public int read() throws IOException {
         return bytes[pos++] & 0xFF;
     }
 
+    @Override
+    public short readShort() throws IOException {
+        if (available() < Short.BYTES) {
+            throw new EOFException();
+        }
+        short value = (short) BitUtil.VH_BE_SHORT.get(bytes, pos);
+        pos += Short.BYTES;
+        return value;
+    }
+
+    @Override
+    public int readInt() throws IOException {
+        if (available() < Integer.BYTES) {
+            throw new EOFException();
+        }
+        int value = (int) BitUtil.VH_BE_INT.get(bytes, pos);
+        pos += Integer.BYTES;
+        return value;
+    }
+
+    @Override
+    public long readLong() throws IOException {
+        if (available() < Long.BYTES) {
+            throw new EOFException();
+        }
+        long value = (long) BitUtil.VH_BE_LONG.get(bytes, pos);
+        pos += Long.BYTES;
+        return value;
+    }
 }
diff --git a/libs/core/src/main/java/org/opensearch/core/common/io/stream/NamedWriteableRegistry.java b/libs/core/src/main/java/org/opensearch/core/common/io/stream/NamedWriteableRegistry.java
index abac76c8b6c27..123b52eb92876 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/io/stream/NamedWriteableRegistry.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/io/stream/NamedWriteableRegistry.java
@@ -43,7 +43,7 @@
 
 /**
  * A registry for {@link Writeable.Reader} readers of {@link NamedWriteable}.
- *
+ * <p>
  * The registration is keyed by the combination of the category class of {@link NamedWriteable}, and a name unique
  * to that category.
  *
diff --git a/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamInput.java b/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamInput.java
index ece2012302919..3e996bdee83a2 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamInput.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamInput.java
@@ -96,7 +96,7 @@
 
 /**
  * A stream from this node to another node. Technically, it can also be streamed to a byte array but that is mostly for testing.
- *
+ * <p>
  * This class's methods are optimized so you can put the methods that read and write a class next to each other and you can scan them
  * visually for differences. That means that most variables should be read and written in a single line so even large objects fit both
  * reading and writing on the screen. It also means that the methods on this class are named very similarly to {@link StreamOutput}. Finally
@@ -1128,7 +1128,7 @@ public <C extends NamedWriteable> C readNamedWriteable(@SuppressWarnings("unused
      * the corresponding entry in the registry by name, so that the proper object can be read and returned.
      * Default implementation throws {@link UnsupportedOperationException} as StreamInput doesn't hold a registry.
      * Use {@link FilterInputStream} instead which wraps a stream and supports a {@link NamedWriteableRegistry} too.
-     *
+     * <p>
      * Prefer {@link StreamInput#readNamedWriteable(Class)} and {@link StreamOutput#writeNamedWriteable(NamedWriteable)} unless you
      * have a compelling reason to use this method instead.
      */
diff --git a/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamOutput.java b/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamOutput.java
index 94b813246bc7e..2d69e1c686df3 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamOutput.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/io/stream/StreamOutput.java
@@ -88,7 +88,7 @@
 
 /**
  * A stream from another node to this node. Technically, it can also be streamed from a byte array but that is mostly for testing.
- *
+ * <p>
  * This class's methods are optimized so you can put the methods that read and write a class next to each other and you can scan them
  * visually for differences. That means that most variables should be read and written in a single line so even large objects fit both
  * reading and writing on the screen. It also means that the methods on this class are named very similarly to {@link StreamInput}. Finally
diff --git a/libs/core/src/main/java/org/opensearch/core/common/io/stream/Writeable.java b/libs/core/src/main/java/org/opensearch/core/common/io/stream/Writeable.java
index af9df51655414..960f4bec5eeb5 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/io/stream/Writeable.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/io/stream/Writeable.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.core.common.io.stream;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -41,8 +43,9 @@
  * across the wire" using OpenSearch's internal protocol. If the implementer also implements equals and hashCode then a copy made by
  * serializing and deserializing must be equal and have the same hashCode. It isn't required that such a copy be entirely unchanged.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public interface Writeable {
     /**
      * A WriteableRegistry registers {@link Writer} methods for writing data types over a
@@ -135,8 +138,11 @@ public static Class<?> getCustomClassFromInstance(final Object value) {
      *     out.writeMapOfLists(someMap, StreamOutput::writeString, StreamOutput::writeString);
      * }
      * </code></pre>
+     *
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "2.8.0")
     interface Writer<V> {
 
         /**
@@ -161,8 +167,11 @@ interface Writer<V> {
      *     this.someMap = in.readMapOfLists(StreamInput::readString, StreamInput::readString);
      * }
      * </code></pre>
+     *
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "2.8.0")
     interface Reader<V> {
 
         /**
diff --git a/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java b/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java
index 59492193d16dc..c7b9bee3cbf4d 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java
@@ -30,6 +30,13 @@
  * GitHub history for details.
  */
 
+/*
+ * This code is based on code from SFL4J 1.5.11
+ * Copyright (c) 2004-2007 QOS.ch
+ * All rights reserved.
+ * SPDX-License-Identifier: MIT
+ */
+
 package org.opensearch.core.common.logging;
 
 import java.util.HashSet;
@@ -37,6 +44,10 @@
 
 /**
  * Format string for OpenSearch log messages.
+ * <p>
+ * This class is almost a copy of {@code org.slf4j.helpers.MessageFormatter}<p>
+ * The original code is licensed under the MIT License and is available at :
+ * <a href="https://github.com/qos-ch/slf4j/blob/7c164fab8d54f823dd55c01a5a839c153f578297/slf4j-api/src/main/java/org/slf4j/helpers/MessageFormatter.java">MessageFormatter.java</a>
  *
  * @opensearch.internal
  */
@@ -51,6 +62,17 @@ public static String format(final String messagePattern, final Object... argArra
         return format(null, messagePattern, argArray);
     }
 
+    /**
+     * (this is almost a copy of {@code org.slf4j.helpers.MessageFormatter.arrayFormat})
+     *
+     * @param prefix the prefix to prepend to the formatted message (can be null)
+     * @param messagePattern the message pattern which will be parsed and formatted
+     * @param argArray an array of arguments to be substituted in place of formatting anchors
+     * @return null if messagePattern is null <p>
+     *         messagePattern if argArray is (null or empty) and prefix is null <p>
+     *         prefix + messagePattern if argArray is (null or empty) and prefix is not null <p>
+     *         formatted message otherwise (even if prefix is null)
+     */
     public static String format(final String prefix, final String messagePattern, final Object... argArray) {
         if (messagePattern == null) {
             return null;
@@ -110,6 +132,13 @@ public static String format(final String prefix, final String messagePattern, fi
         return sbuf.toString();
     }
 
+    /**
+     * Checks if (delimterStartIndex - 1) in messagePattern is an escape character.
+     * @param messagePattern the message pattern
+     * @param delimiterStartIndex the index of the character to check
+     * @return true if there is an escape char before the character at delimiterStartIndex.<p>
+     *         Always returns false if delimiterStartIndex == 0 (edge case)
+     */
     static boolean isEscapedDelimiter(String messagePattern, int delimiterStartIndex) {
 
         if (delimiterStartIndex == 0) {
@@ -119,6 +148,13 @@ static boolean isEscapedDelimiter(String messagePattern, int delimiterStartIndex
         return potentialEscape == ESCAPE_CHAR;
     }
 
+    /**
+     * Checks if (delimterStartIndex - 2) in messagePattern is an escape character.
+     * @param messagePattern the message pattern
+     * @param delimiterStartIndex the index of the character to check
+     * @return true if (delimterStartIndex - 2) in messagePattern is an escape character.
+     *         Always returns false if delimiterStartIndex is less than 2 (edge case)
+     */
     static boolean isDoubleEscaped(String messagePattern, int delimiterStartIndex) {
         return delimiterStartIndex >= 2 && messagePattern.charAt(delimiterStartIndex - 2) == ESCAPE_CHAR;
     }
diff --git a/libs/core/src/main/java/org/opensearch/core/common/settings/SecureString.java b/libs/core/src/main/java/org/opensearch/core/common/settings/SecureString.java
index 322300a554284..45ee72f558724 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/settings/SecureString.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/settings/SecureString.java
@@ -50,7 +50,7 @@ public final class SecureString implements CharSequence, Closeable {
 
     /**
      * Constructs a new SecureString which controls the passed in char array.
-     *
+     * <p>
      * Note: When this instance is closed, the array will be zeroed out.
      */
     public SecureString(char[] chars) {
@@ -59,7 +59,7 @@ public SecureString(char[] chars) {
 
     /**
      * Constructs a new SecureString from an existing String.
-     *
+     * <p>
      * NOTE: This is not actually secure, since the provided String cannot be deallocated, but
      * this constructor allows for easy compatibility between new and old apis.
      *
diff --git a/libs/core/src/main/java/org/opensearch/core/common/text/Text.java b/libs/core/src/main/java/org/opensearch/core/common/text/Text.java
index ca5402edae59e..3a46bd4602297 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/text/Text.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/text/Text.java
@@ -32,6 +32,7 @@
 package org.opensearch.core.common.text;
 
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -44,8 +45,9 @@
  * Both {@link String} and {@link BytesReference} representation of the text. Starts with one of those, and if
  * the other is requests, caches the other one in a local reference so no additional conversion will be needed.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class Text implements Comparable<Text>, ToXContentFragment {
 
     public static final Text[] EMPTY_ARRAY = new Text[0];
diff --git a/libs/core/src/main/java/org/opensearch/core/common/transport/TransportAddress.java b/libs/core/src/main/java/org/opensearch/core/common/transport/TransportAddress.java
index 1a853877ed0b9..3b5fbb7d76307 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/transport/TransportAddress.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/transport/TransportAddress.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.core.common.transport;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.network.NetworkAddress;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * A transport address used for IP socket address (wraps {@link java.net.InetSocketAddress}).
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class TransportAddress implements Writeable, ToXContentFragment {
 
     /**
@@ -71,6 +73,12 @@ public TransportAddress(InetAddress address, int port) {
         this(new InetSocketAddress(address, port));
     }
 
+    /**
+     * Creates a new {@link TransportAddress} from a {@link InetSocketAddress}.
+     * @param address the address to wrap
+     * @throws IllegalArgumentException if the address is null or not resolved
+     * @see InetSocketAddress#getAddress()
+     */
     public TransportAddress(InetSocketAddress address) {
         if (address == null) {
             throw new IllegalArgumentException("InetSocketAddress must not be null");
@@ -82,7 +90,9 @@ public TransportAddress(InetSocketAddress address) {
     }
 
     /**
-     * Read from a stream.
+     * Creates a new {@link TransportAddress} from a {@link StreamInput}.
+     * @param in the stream to read from
+     * @throws IOException if an I/O error occurs
      */
     public TransportAddress(StreamInput in) throws IOException {
         final int len = in.readByte();
@@ -116,6 +126,8 @@ public String getAddress() {
 
     /**
      * Returns the addresses port
+     * @return the port number, or 0 if the socket is not bound yet.
+     * @see InetSocketAddress#getPort()
      */
     public int getPort() {
         return address.getPort();
diff --git a/libs/core/src/main/java/org/opensearch/core/common/unit/ByteSizeUnit.java b/libs/core/src/main/java/org/opensearch/core/common/unit/ByteSizeUnit.java
index 1f49a3531986c..49eadbbb2bc00 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/unit/ByteSizeUnit.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/unit/ByteSizeUnit.java
@@ -45,6 +45,13 @@
  * A {@code SizeUnit} does not maintain size information, but only
  * helps organize and use size representations that may be maintained
  * separately across various contexts.
+ * <p>
+ * It use conventional data storage values (base-2) :
+ * <ul>
+ *     <li>1KB = 1024 bytes</li>
+ *     <li>1MB = 1024KB</li>
+ *     <li> ... </li>
+ * </ul>
  *
  * @opensearch.api
  */
diff --git a/libs/core/src/main/java/org/opensearch/core/common/util/ByteArray.java b/libs/core/src/main/java/org/opensearch/core/common/util/ByteArray.java
index e50f24417f8bc..f4d81c4ca4363 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/util/ByteArray.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/util/ByteArray.java
@@ -33,14 +33,16 @@
 package org.opensearch.core.common.util;
 
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.nio.ByteBuffer;
 
 /**
  * Abstraction of an array of byte values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ByteArray extends BigArray {
 
     /**
diff --git a/libs/core/src/main/java/org/opensearch/core/common/util/CollectionUtils.java b/libs/core/src/main/java/org/opensearch/core/common/util/CollectionUtils.java
index e8dd31fcf1869..5335c98182b64 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/util/CollectionUtils.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/util/CollectionUtils.java
@@ -73,6 +73,16 @@ public static boolean isEmpty(Object[] array) {
 
     /**
      * Return a rotated view of the given list with the given distance.
+     * <ul>
+     * <li>The distance can be negative, in which case the list is rotated to the left.</li>
+     * <li>The distance can be larger than the size of the list, in which case the list is rotated multiple times.</li>
+     * <li>The distance can be zero, in which case the list is not rotated.</li>
+     * <li>The list can be empty, in which case it remains empty.</li>
+     * </ul>
+     * @param list the list to rotate
+     * @param distance the distance to rotate (positive rotates right, negative rotates left)
+     * @return a rotated view of the given list with the given distance
+     * @see RotatedList
      */
     public static <T> List<T> rotate(final List<T> list, int distance) {
         if (list.isEmpty()) {
@@ -92,7 +102,13 @@ public static <T> List<T> rotate(final List<T> list, int distance) {
     }
 
     /**
-     * in place de-duplicates items in a list
+     * In place de-duplicates items in a list
+     * Noop if the list is empty or has one item.
+     *
+     * @throws NullPointerException if the list is `null` or comparator is `null`
+     * @param array the list to de-duplicate
+     * @param comparator the comparator to use to compare items
+     * @param <T> the type of the items in the list
      */
     public static <T> void sortAndDedup(final List<T> array, Comparator<T> comparator) {
         // base case: one item
@@ -115,6 +131,12 @@ public static <T> void sortAndDedup(final List<T> array, Comparator<T> comparato
         array.subList(deduped.nextIndex(), array.size()).clear();
     }
 
+    /**
+     * Converts a collection of Integers to an array of ints.
+     * @param ints The collection of Integers to convert
+     * @return The array of ints
+     * @throws NullPointerException if ints is null
+     */
     public static int[] toArray(Collection<Integer> ints) {
         Objects.requireNonNull(ints);
         return ints.stream().mapToInt(s -> s).toArray();
@@ -134,6 +156,11 @@ public static void ensureNoSelfReferences(Object value, String messageHint) {
         }
     }
 
+    /**
+     * Converts an object to an Iterable, if possible.
+     * @param value The object to convert
+     * @return The Iterable, or null if the object cannot be converted
+     */
     @SuppressWarnings("unchecked")
     private static Iterable<?> convert(Object value) {
         if (value == null) {
@@ -192,6 +219,13 @@ private static class RotatedList<T> extends AbstractList<T> implements RandomAcc
         private final List<T> in;
         private final int distance;
 
+        /**
+         * Creates a rotated list
+         * @param list The list to rotate
+         * @param distance The distance to rotate to the right
+         * @throws IllegalArgumentException if the distance is negative or greater than the size of the list;
+         *                                  or if the list is not a {@link RandomAccess} list
+         */
         RotatedList(List<T> list, int distance) {
             if (distance < 0 || distance >= list.size()) {
                 throw new IllegalArgumentException();
@@ -218,6 +252,13 @@ public int size() {
         }
     }
 
+    /**
+     * Converts an {@link Iterable} to an {@link ArrayList}.
+     * @param elements The iterable to convert
+     * @param <E> the type the elements
+     * @return an {@link ArrayList}
+     * @throws NullPointerException if elements is null
+     */
     @SuppressWarnings("unchecked")
     public static <E> ArrayList<E> iterableAsArrayList(Iterable<? extends E> elements) {
         if (elements == null) {
@@ -297,11 +338,11 @@ public static <E> List<List<E>> eagerPartition(List<E> list, int size) {
     }
 
     /**
-     * Check if a collection is empty or not. Empty collection mean either it is null or it has no elements in it. If
-     * collection contains a null element it means it is not empty.
+     * Checks if a collection is empty or not. Empty collection mean either it is null or it has no elements in it.
+     * If collection contains a null element it means it is not empty.
      *
      * @param collection {@link Collection}
-     * @return boolean
+     * @return true if collection is null or {@code isEmpty()}, false otherwise
      * @param <E> Element
      */
     public static <E> boolean isEmpty(final Collection<E> collection) {
diff --git a/libs/core/src/main/java/org/opensearch/core/compress/Compressor.java b/libs/core/src/main/java/org/opensearch/core/compress/Compressor.java
index 27d5b5dfdfa15..5324ea6151e51 100644
--- a/libs/core/src/main/java/org/opensearch/core/compress/Compressor.java
+++ b/libs/core/src/main/java/org/opensearch/core/compress/Compressor.java
@@ -43,7 +43,7 @@
 /**
  * Compressor interface used for compressing {@link org.opensearch.core.xcontent.MediaType} and
  * {@code org.opensearch.repositories.blobstore.BlobStoreRepository} implementations.
- *
+ * <p>
  * This is not to be confused with {@link org.apache.lucene.codecs.compressing.Compressor} which is used
  * for codec implementations such as {@code org.opensearch.index.codec.customcodecs.Lucene95CustomCodec}
  * for compressing {@link org.apache.lucene.document.StoredField}s
diff --git a/libs/core/src/main/java/org/opensearch/core/compress/CompressorRegistry.java b/libs/core/src/main/java/org/opensearch/core/compress/CompressorRegistry.java
index 9290254c30d8d..af09a7aebba79 100644
--- a/libs/core/src/main/java/org/opensearch/core/compress/CompressorRegistry.java
+++ b/libs/core/src/main/java/org/opensearch/core/compress/CompressorRegistry.java
@@ -23,7 +23,7 @@
 /**
  * A registry that wraps a static Map singleton which holds a mapping of unique String names (typically the
  * compressor header as a string) to registerd {@link Compressor} implementations.
- *
+ * <p>
  * This enables plugins, modules, extensions to register their own compression implementations through SPI
  *
  * @opensearch.experimental
@@ -105,7 +105,7 @@ public static Compressor getCompressor(final String name) {
 
     /**
      * Returns the registered compressors as an Immutable collection
-     *
+     * <p>
      * note: used for testing
      */
     public static Map<String, Compressor> registeredCompressors() {
diff --git a/libs/core/src/main/java/org/opensearch/core/compress/spi/CompressorProvider.java b/libs/core/src/main/java/org/opensearch/core/compress/spi/CompressorProvider.java
index 019e282444d64..9b806618fe0a0 100644
--- a/libs/core/src/main/java/org/opensearch/core/compress/spi/CompressorProvider.java
+++ b/libs/core/src/main/java/org/opensearch/core/compress/spi/CompressorProvider.java
@@ -18,7 +18,7 @@
 /**
  * Service Provider Interface for plugins, modules, extensions providing custom
  * compression algorithms
- *
+ * <p>
  * see {@link Compressor} for implementing methods
  * and {@link org.opensearch.core.compress.CompressorRegistry} for the registration of custom
  * Compressors
diff --git a/libs/core/src/main/java/org/opensearch/core/index/Index.java b/libs/core/src/main/java/org/opensearch/core/index/Index.java
index fdff43f3c9139..a927179114188 100644
--- a/libs/core/src/main/java/org/opensearch/core/index/Index.java
+++ b/libs/core/src/main/java/org/opensearch/core/index/Index.java
@@ -48,6 +48,8 @@
 
 /**
  * A value class representing the basic required properties of an OpenSearch index.
+ * <p>
+ * (This class is immutable.)
  *
  * @opensearch.api
  */
@@ -57,6 +59,8 @@ public class Index implements Writeable, ToXContentObject {
     public static final Index[] EMPTY_ARRAY = new Index[0];
     private static final String INDEX_UUID_KEY = "index_uuid";
     private static final String INDEX_NAME_KEY = "index_name";
+    public static final String UNKNOWN_INDEX_NAME = "_unknown_";
+
     private static final ObjectParser<Builder, Void> INDEX_PARSER = new ObjectParser<>("index", Builder::new);
     static {
         INDEX_PARSER.declareString(Builder::name, new ParseField(INDEX_NAME_KEY));
@@ -66,39 +70,74 @@ public class Index implements Writeable, ToXContentObject {
     private final String name;
     private final String uuid;
 
+    /**
+     * Creates a new Index instance with name and unique identifier
+     *
+     * @param name the name of the index
+     * @param uuid the unique identifier of the index
+     * @throws NullPointerException if either name or uuid are null
+     */
     public Index(String name, String uuid) {
         this.name = Objects.requireNonNull(name);
         this.uuid = Objects.requireNonNull(uuid);
     }
 
     /**
-     * Read from a stream.
+     * Creates a new Index instance from a {@link StreamInput}.
+     * Reads the name and unique identifier from the stream.
+     *
+     * @param in the stream to read from
+     * @throws IOException if an error occurs while reading from the stream
+     * @see #writeTo(StreamOutput)
      */
     public Index(StreamInput in) throws IOException {
         this.name = in.readString();
         this.uuid = in.readString();
     }
 
+    /**
+     * Gets the name of the index.
+     *
+     * @return the name of the index.
+     */
     public String getName() {
         return this.name;
     }
 
+    /**
+     * Gets the unique identifier of the index.
+     *
+     * @return the unique identifier of the index. "_na_" if {@link Strings#UNKNOWN_UUID_VALUE}.
+     */
     public String getUUID() {
         return uuid;
     }
 
+    /**
+     * Returns either the name and unique identifier of the index
+     * or only the name if the uuid is {@link Strings#UNKNOWN_UUID_VALUE}.
+     * <p>
+     * If we have a uuid we put it in the toString so it'll show up in logs
+     * which is useful as more and more things use the uuid rather
+     * than the name as the lookup key for the index.
+     *
+     * @return {@code "[name/uuid]"} or {@code "[name]"}
+     */
     @Override
     public String toString() {
-        /*
-         * If we have a uuid we put it in the toString so it'll show up in logs which is useful as more and more things use the uuid rather
-         * than the name as the lookup key for the index.
-         */
         if (Strings.UNKNOWN_UUID_VALUE.equals(uuid)) {
             return "[" + name + "]";
         }
         return "[" + name + "/" + uuid + "]";
     }
 
+    /**
+     * Checks if this index is the same as another index by comparing the name and unique identifier.
+     * If both uuid are {@link Strings#UNKNOWN_UUID_VALUE} then only the name is compared.
+     *
+     * @param o the index to compare to
+     * @return true if the name and unique identifier are the same, false otherwise.
+     */
     @Override
     public boolean equals(Object o) {
         if (this == o) {
@@ -118,6 +157,10 @@ public int hashCode() {
         return result;
     }
 
+    /** Writes the name and unique identifier to the {@link StreamOutput}
+     *
+     * @param out The stream to write to
+     */
     @Override
     public void writeTo(final StreamOutput out) throws IOException {
         out.writeString(name);
diff --git a/libs/core/src/main/java/org/opensearch/core/index/shard/ShardId.java b/libs/core/src/main/java/org/opensearch/core/index/shard/ShardId.java
index adea6cd8f0687..c0abad7ed727f 100644
--- a/libs/core/src/main/java/org/opensearch/core/index/shard/ShardId.java
+++ b/libs/core/src/main/java/org/opensearch/core/index/shard/ShardId.java
@@ -55,44 +55,87 @@ public class ShardId implements Comparable<ShardId>, ToXContentFragment, Writeab
     private final int shardId;
     private final int hashCode;
 
+    /**
+     * Constructs a new shard id.
+     * @param index the index name
+     * @param shardId the shard id
+     */
     public ShardId(Index index, int shardId) {
         this.index = index;
         this.shardId = shardId;
         this.hashCode = computeHashCode();
     }
 
+    /**
+     * Constructs a new shard id with the given index name, index unique identifier, and shard id.
+     * @param index the index name
+     * @param indexUUID  the index unique identifier
+     * @param shardId the shard id
+     */
     public ShardId(String index, String indexUUID, int shardId) {
         this(new Index(index, indexUUID), shardId);
     }
 
+    /**
+     * Constructs a new shardId from a stream.
+     * @param in the stream to read from
+     * @throws IOException if an error occurs while reading from the stream
+     * @see #writeTo(StreamOutput)
+     */
     public ShardId(StreamInput in) throws IOException {
         index = new Index(in);
         shardId = in.readVInt();
         hashCode = computeHashCode();
     }
 
+    /**
+     * Writes this shard id to a stream.
+     * @param out the stream to write to
+     * @throws IOException if an error occurs while writing to the stream
+     */
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         index.writeTo(out);
         out.writeVInt(shardId);
     }
 
+    /**
+     * Returns the index of this shard id.
+     * @return the index of this shard id
+     */
     public Index getIndex() {
         return index;
     }
 
+    /**
+     * Returns the name of the index of this shard id.
+     * @return the name of the index of this shard id
+     */
     public String getIndexName() {
         return index.getName();
     }
 
+    /**
+     *  Return the shardId of this shard id.
+     * @return the shardId of this shard id
+     * @see #getId()
+     */
     public int id() {
         return this.shardId;
     }
 
+    /**
+     * Returns the shard id of this shard id.
+     * @return the shard id of this shard id
+     */
     public int getId() {
         return id();
     }
 
+    /**
+     * Returns a string representation of this shard id.
+     * @return "[indexName][shardId]"
+     */
     @Override
     public String toString() {
         return "[" + index.getName() + "][" + shardId + "]";
@@ -100,9 +143,13 @@ public String toString() {
 
     /**
      * Parse the string representation of this shardId back to an object.
+     * <p>
      * We lose index uuid information here, but since we use toString in
      * rest responses, this is the best we can do to reconstruct the object
      * on the client side.
+     *
+     * @param shardIdString the string representation of the shard id
+     *                      (Expect a string of format "[indexName][shardId]" (square brackets included))
      */
     public static ShardId fromString(String shardIdString) {
         int splitPosition = shardIdString.indexOf("][");
@@ -122,17 +169,30 @@ public boolean equals(Object o) {
         return shardId == shardId1.shardId && index.equals(shardId1.index);
     }
 
+    /** Returns the hash code of this shard id.
+     *
+     * @return the hash code of this shard id
+     */
     @Override
     public int hashCode() {
         return hashCode;
     }
 
+    /** Computes the hash code of this shard id.
+     *
+     * @return the hash code of this shard id.
+     */
     private int computeHashCode() {
         int result = index != null ? index.hashCode() : 0;
         result = 31 * result + shardId;
         return result;
     }
 
+    /**
+     * Compares this ShardId with the specified ShardId.
+     * @param o the ShardId to be compared.
+     * @return a negative integer, zero, or a positive integer if this ShardId is less than, equal to, or greater than the specified ShardId
+     */
     @Override
     public int compareTo(ShardId o) {
         if (o.getId() == shardId) {
diff --git a/libs/core/src/main/java/org/opensearch/core/indices/breaker/AllCircuitBreakerStats.java b/libs/core/src/main/java/org/opensearch/core/indices/breaker/AllCircuitBreakerStats.java
index ab887acb85a87..992655efec8f0 100644
--- a/libs/core/src/main/java/org/opensearch/core/indices/breaker/AllCircuitBreakerStats.java
+++ b/libs/core/src/main/java/org/opensearch/core/indices/breaker/AllCircuitBreakerStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.core.indices.breaker;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -43,29 +44,56 @@
 /**
  * Stats class encapsulating all of the different circuit breaker stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AllCircuitBreakerStats implements Writeable, ToXContentFragment {
 
+    /** An array of all the circuit breaker stats */
     private final CircuitBreakerStats[] allStats;
 
+    /**
+     * Constructs the instance
+     *
+     * @param allStats an array of all the circuit breaker stats
+     */
     public AllCircuitBreakerStats(CircuitBreakerStats[] allStats) {
         this.allStats = allStats;
     }
 
+    /**
+     * Constructs the new instance from {@link StreamInput}
+     * @param in the  {@link StreamInput} to read from
+     * @throws IOException If an error occurs while reading from the StreamInput
+     * @see #writeTo(StreamOutput)
+     */
     public AllCircuitBreakerStats(StreamInput in) throws IOException {
         allStats = in.readArray(CircuitBreakerStats::new, CircuitBreakerStats[]::new);
     }
 
+    /**
+     * Writes this instance into a {@link StreamOutput}
+     * @param out the {@link StreamOutput} to write to
+     * @throws IOException if an error occurs while writing to the StreamOutput
+     */
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeArray(allStats);
     }
 
+    /**
+     * Returns inner stats instances for all circuit breakers
+     * @return inner stats instances for all circuit breakers
+     */
     public CircuitBreakerStats[] getAllStats() {
         return this.allStats;
     }
 
+    /**
+     * Returns the stats for a specific circuit breaker
+     * @param name the name of the circuit breaker
+     * @return  the {@link CircuitBreakerStats} for the circuit breaker, null if the circuit breaker with such name does not exist
+     */
     public CircuitBreakerStats getStats(String name) {
         for (CircuitBreakerStats stats : allStats) {
             if (stats.getName().equals(name)) {
diff --git a/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerService.java b/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerService.java
index ee9c94f432a36..dedeb0803271f 100644
--- a/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerService.java
+++ b/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerService.java
@@ -32,8 +32,7 @@
 
 package org.opensearch.core.indices.breaker;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
 import org.opensearch.core.common.breaker.CircuitBreaker;
 
@@ -41,11 +40,10 @@
  * Interface for Circuit Breaker services, which provide breakers to classes
  * that load field data.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class CircuitBreakerService extends AbstractLifecycleComponent {
-    private static final Logger logger = LogManager.getLogger(CircuitBreakerService.class);
-
     protected CircuitBreakerService() {}
 
     /**
diff --git a/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerStats.java b/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerStats.java
index 0e53a38908a96..ee71cf8d2ac0e 100644
--- a/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerStats.java
+++ b/libs/core/src/main/java/org/opensearch/core/indices/breaker/CircuitBreakerStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.core.indices.breaker;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -43,18 +44,34 @@
 import java.util.Locale;
 
 /**
- * Class encapsulating stats about the circuit breaker
+ * Class encapsulating stats about the {@link org.opensearch.core.common.breaker.CircuitBreaker}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CircuitBreakerStats implements Writeable, ToXContentObject {
 
+    /** The name of the circuit breaker */
     private final String name;
+    /** The limit size in byte of the circuit breaker. Field : "limit_size_in_bytes" */
     private final long limit;
+    /** The estimated size in byte of the breaker. Field : "estimated_size_in_bytes" */
     private final long estimated;
+    /** The number of times the breaker has been tripped. Field : "tripped" */
     private final long trippedCount;
+    /** The overhead of the breaker. Field : "overhead" */
     private final double overhead;
 
+    /**
+     * Constructs new instance
+     *
+     * @param name The name of the circuit breaker
+     * @param limit The limit size in byte of the circuit breaker
+     * @param estimated The estimated size in byte of the breaker
+     * @param overhead The overhead of the breaker
+     * @param trippedCount The number of times the breaker has been tripped
+     * @see org.opensearch.core.common.breaker.CircuitBreaker
+     */
     public CircuitBreakerStats(String name, long limit, long estimated, double overhead, long trippedCount) {
         this.name = name;
         this.limit = limit;
@@ -63,6 +80,14 @@ public CircuitBreakerStats(String name, long limit, long estimated, double overh
         this.overhead = overhead;
     }
 
+    /**
+     * Constructs new instance from the {@link StreamInput}
+     *
+     * @param in The StreamInput
+     * @throws IOException if an error occurs while reading from the StreamInput
+     * @see org.opensearch.core.common.breaker.CircuitBreaker
+     * @see #writeTo(StreamOutput)
+     */
     public CircuitBreakerStats(StreamInput in) throws IOException {
         this.limit = in.readLong();
         this.estimated = in.readLong();
@@ -71,6 +96,13 @@ public CircuitBreakerStats(StreamInput in) throws IOException {
         this.name = in.readString();
     }
 
+    /**
+     * Writes this instance into a {@link StreamOutput}
+     *
+     * @param out The StreamOutput
+     * @throws IOException if an error occurs while writing to the StreamOutput
+     * @see #CircuitBreakerStats(StreamInput)
+     */
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeLong(limit);
@@ -80,22 +112,42 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeString(name);
     }
 
+    /**
+     * Returns the name of the circuit breaker
+     * @return The name of the circuit breaker
+     */
     public String getName() {
         return this.name;
     }
 
+    /**
+     * Returns the limit size in byte of the circuit breaker
+     * @return The limit size in byte of the circuit breaker
+     */
     public long getLimit() {
         return this.limit;
     }
 
+    /**
+     * Returns the estimated size in byte of the breaker
+     * @return The estimated size in byte of the breaker
+     */
     public long getEstimated() {
         return this.estimated;
     }
 
+    /**
+     * Returns the number of times the breaker has been tripped
+     * @return The number of times the breaker has been tripped
+     */
     public long getTrippedCount() {
         return this.trippedCount;
     }
 
+    /**
+     * Returns the overhead of the breaker
+     * @return The overhead of the breaker
+     */
     public double getOverhead() {
         return this.overhead;
     }
@@ -113,6 +165,10 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         return builder;
     }
 
+    /**
+     * Returns a String representation of this CircuitBreakerStats
+     * @return "[name,limit=limit/limit_human,estimated=estimated/estimated_human,overhead=overhead,tripped=trippedCount]"
+     */
     @Override
     public String toString() {
         return "["
diff --git a/libs/core/src/main/java/org/opensearch/core/indices/breaker/NoneCircuitBreakerService.java b/libs/core/src/main/java/org/opensearch/core/indices/breaker/NoneCircuitBreakerService.java
index 4095fd32b6d3c..49c5a393328b9 100644
--- a/libs/core/src/main/java/org/opensearch/core/indices/breaker/NoneCircuitBreakerService.java
+++ b/libs/core/src/main/java/org/opensearch/core/indices/breaker/NoneCircuitBreakerService.java
@@ -36,8 +36,9 @@
 import org.opensearch.core.common.breaker.NoopCircuitBreaker;
 
 /**
- * Class that returns a breaker that never breaks
+ * Class that returns a breaker that use the NoopCircuitBreaker and never breaks
  *
+ * @see org.opensearch.core.common.breaker.NoopCircuitBreaker
  * @opensearch.internal
  */
 public class NoneCircuitBreakerService extends CircuitBreakerService {
@@ -48,6 +49,12 @@ public NoneCircuitBreakerService() {
         super();
     }
 
+    /**
+     * Returns a breaker that use the NoopCircuitBreaker and never breaks
+     *
+     * @param name name of the breaker (ignored)
+     * @return a NoopCircuitBreaker
+     */
     @Override
     public CircuitBreaker getBreaker(String name) {
         return breaker;
@@ -58,6 +65,12 @@ public AllCircuitBreakerStats stats() {
         return new AllCircuitBreakerStats(new CircuitBreakerStats[] { stats(CircuitBreaker.FIELDDATA) });
     }
 
+    /**
+     * Always returns the same stats, a NoopCircuitBreaker never breaks and all operations are noops.
+     *
+     * @param name name of the breaker (ignored)
+     * @return always "fielddata", limit: -1, estimated: -1, overhead: 0, trippedCount: 0
+     */
     @Override
     public CircuitBreakerStats stats(String name) {
         return new CircuitBreakerStats(CircuitBreaker.FIELDDATA, -1, -1, 0, 0);
diff --git a/libs/core/src/main/java/org/opensearch/core/rest/RestStatus.java b/libs/core/src/main/java/org/opensearch/core/rest/RestStatus.java
index 313bc23bedc90..8441ce8b1b622 100644
--- a/libs/core/src/main/java/org/opensearch/core/rest/RestStatus.java
+++ b/libs/core/src/main/java/org/opensearch/core/rest/RestStatus.java
@@ -527,6 +527,15 @@ public int getStatus() {
         return status;
     }
 
+    /**
+     * Get category class of a rest status code.
+     *
+     * @return Integer representing class category of the concrete rest status code
+     */
+    public int getStatusFamilyCode() {
+        return status / 100;
+    }
+
     public static RestStatus readFrom(StreamInput in) throws IOException {
         return RestStatus.valueOf(in.readString());
     }
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStats.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStats.java
index d65f75581dd1b..e99afbb759031 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStats.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStats.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.core.tasks.resourcetracker;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  *  Different resource stats are defined.
  *
- *  @opensearch.internal
+ *  @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public enum ResourceStats {
     CPU("cpu_time_in_nanos"),
     MEMORY("memory_in_bytes");
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStatsType.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStatsType.java
index fce8cc65e9bc5..2aedff2940d83 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStatsType.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceStatsType.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.core.tasks.resourcetracker;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Defines the different types of resource stats.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public enum ResourceStatsType {
     // resource stats of the worker thread reported directly from runnable.
     WORKER_STATS("worker_stats", false);
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageInfo.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageInfo.java
index 2cbc3d4b2f5c3..a278b61894a65 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageInfo.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageInfo.java
@@ -10,6 +10,7 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Collections;
 import java.util.EnumMap;
@@ -22,8 +23,9 @@
  * It captures the resource usage information like memory, CPU about a particular execution of thread
  * for a specific stats type.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public class ResourceUsageInfo {
     private static final Logger logger = LogManager.getLogger(ResourceUsageInfo.class);
     private final EnumMap<ResourceStats, ResourceStatsInfo> statsInfo = new EnumMap<>(ResourceStats.class);
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageMetric.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageMetric.java
index 262dbe20dabda..f4cce2de820a0 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageMetric.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ResourceUsageMetric.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.core.tasks.resourcetracker;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Information about resource usage
  *
- * @opensearch.internal
+ *  @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public class ResourceUsageMetric {
     private final ResourceStats stats;
     private final long value;
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceStats.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceStats.java
index d0d26550a4742..048c4a228fbd5 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceStats.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceStats.java
@@ -9,6 +9,7 @@
 package org.opensearch.core.tasks.resourcetracker;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -29,8 +30,9 @@
  * Writeable TaskResourceStats objects are used to represent resource
  * snapshot information about currently running task.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public class TaskResourceStats implements Writeable, ToXContentFragment {
     private final Map<String, TaskResourceUsage> resourceUsage;
     private final TaskThreadUsage threadUsage;
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceUsage.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceUsage.java
index 7d6cadbef23d7..654f1c5695937 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceUsage.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskResourceUsage.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.core.tasks.resourcetracker;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -30,8 +31,9 @@
  * Writeable TaskResourceUsage objects are used to represent resource usage
  * information of running tasks.
  *
- * @opensearch.internal
+ *  @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public class TaskResourceUsage implements Writeable, ToXContentFragment {
     private static final ParseField CPU_TIME_IN_NANOS = new ParseField("cpu_time_in_nanos");
     private static final ParseField MEMORY_IN_BYTES = new ParseField("memory_in_bytes");
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskThreadUsage.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskThreadUsage.java
index b593ec96e5996..abe03e3c520e0 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskThreadUsage.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/TaskThreadUsage.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.core.tasks.resourcetracker;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -29,8 +30,9 @@
  * Writeable TaskThreadExecutions objects are used to represent thread related resource usage of running tasks.
  * asd
  *
- * @opensearch.internal
+ *  @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public class TaskThreadUsage implements Writeable, ToXContentFragment {
 
     private static final String THREAD_EXECUTIONS = "thread_executions";
diff --git a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ThreadResourceInfo.java b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ThreadResourceInfo.java
index 4b341a94256c4..703fdfdf8a784 100644
--- a/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ThreadResourceInfo.java
+++ b/libs/core/src/main/java/org/opensearch/core/tasks/resourcetracker/ThreadResourceInfo.java
@@ -8,14 +8,17 @@
 
 package org.opensearch.core.tasks.resourcetracker;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Resource consumption information about a particular execution of thread.
  * <p>
  * It captures the resource usage information about a particular execution of thread
  * for a specific stats type like worker_stats or response_stats etc.,
  *
- * @opensearch.internal
+ *  @opensearch.api
  */
+@PublicApi(since = "2.1.0")
 public class ThreadResourceInfo {
     private final long threadId;
     private volatile boolean isActive = true;
diff --git a/libs/core/src/main/java/org/opensearch/core/util/BytesRefUtils.java b/libs/core/src/main/java/org/opensearch/core/util/BytesRefUtils.java
index 30c9f182fcae6..2aad068534b9d 100644
--- a/libs/core/src/main/java/org/opensearch/core/util/BytesRefUtils.java
+++ b/libs/core/src/main/java/org/opensearch/core/util/BytesRefUtils.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.core.util;
 
+import org.apache.lucene.util.BitUtil;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefArray;
 import org.apache.lucene.util.BytesRefBuilder;
@@ -103,12 +104,12 @@ public static int sortAndDedup(final BytesRefArray bytes, final int[] indices) {
         return uniqueCount;
     }
 
+    /**
+     * Decodes a long value written as bytes in big endian order.
+     * @param bytes in big endian order
+     * @return long value
+     */
     public static long bytesToLong(BytesRef bytes) {
-        int high = (bytes.bytes[bytes.offset + 0] << 24) | ((bytes.bytes[bytes.offset + 1] & 0xff) << 16) | ((bytes.bytes[bytes.offset + 2]
-            & 0xff) << 8) | (bytes.bytes[bytes.offset + 3] & 0xff);
-        int low = (bytes.bytes[bytes.offset + 4] << 24) | ((bytes.bytes[bytes.offset + 5] & 0xff) << 16) | ((bytes.bytes[bytes.offset + 6]
-            & 0xff) << 8) | (bytes.bytes[bytes.offset + 7] & 0xff);
-        return (((long) high) << 32) | (low & 0x0ffffffffL);
+        return (long) BitUtil.VH_BE_LONG.get(bytes.bytes, bytes.offset);
     }
-
 }
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/AbstractObjectParser.java b/libs/core/src/main/java/org/opensearch/core/xcontent/AbstractObjectParser.java
index a0e2a54fce91c..32bbfc600f1f0 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/AbstractObjectParser.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/AbstractObjectParser.java
@@ -33,6 +33,7 @@
 package org.opensearch.core.xcontent;
 
 import org.opensearch.common.CheckedFunction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.xcontent.ObjectParser.NamedObjectParser;
 import org.opensearch.core.xcontent.ObjectParser.ValueType;
@@ -47,8 +48,9 @@
 /**
  * Superclass for {@link ObjectParser} and {@link ConstructingObjectParser}. Defines most of the "declare" methods so they can be shared.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class AbstractObjectParser<Value, Context> {
 
     /**
@@ -108,7 +110,7 @@ public abstract <T> void declareNamedObject(
      *
      * Unlike the other version of this method, "ordered" mode (arrays of
      * objects) is not supported.
-     *
+     * <p>
      * See NamedObjectHolder in ObjectParserTests for examples of how to invoke
      * this.
      *
@@ -163,7 +165,7 @@ public abstract <T> void declareNamedObjects(
      * the order sent but tools that generate json are free to put object
      * members in an unordered Map, jumbling them. Thus, if you care about order
      * you can send the object in the second way.
-     *
+     * <p>
      * See NamedObjectHolder in ObjectParserTests for examples of how to invoke
      * this.
      *
@@ -366,10 +368,10 @@ public <T> void declareFieldArray(
     /**
      * Declares a set of fields that are required for parsing to succeed. Only one of the values
      * provided per String[] must be matched.
-     *
+     * <p>
      * E.g. <code>declareRequiredFieldSet("foo", "bar");</code> means at least one of "foo" or
      * "bar" fields must be present.  If neither of those fields are present, an exception will be thrown.
-     *
+     * <p>
      * Multiple required sets can be configured:
      *
      * <pre><code>
@@ -379,7 +381,7 @@ public <T> void declareFieldArray(
      *
      * requires that one of "foo" or "bar" fields are present, and also that one of "bizz" or
      * "buzz" fields are present.
-     *
+     * <p>
      * In JSON, it means any of these combinations are acceptable:
      *
      * <ul>
@@ -415,12 +417,12 @@ public <T> void declareFieldArray(
 
     /**
      * Declares a set of fields of which at most one must appear for parsing to succeed
-     *
+     * <p>
      * E.g. <code>declareExclusiveFieldSet("foo", "bar");</code> means that only one of 'foo'
      * or 'bar' must be present, and if both appear then an exception will be thrown.  Note
      * that this does not make 'foo' or 'bar' required - see {@link #declareRequiredFieldSet(String...)}
      * for required fields.
-     *
+     * <p>
      * Multiple exclusive sets may be declared
      *
      * @param exclusiveSet a set of field names, at most one of which must appear
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/ContextParser.java b/libs/core/src/main/java/org/opensearch/core/xcontent/ContextParser.java
index d50dd2e68d890..f6e5647532bee 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/ContextParser.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/ContextParser.java
@@ -32,11 +32,16 @@
 
 package org.opensearch.core.xcontent;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 
 /**
  * Reads an object from a parser using some context.
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 @FunctionalInterface
 public interface ContextParser<Context, T> {
     T parse(XContentParser p, Context c) throws IOException;
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/DeprecationHandler.java b/libs/core/src/main/java/org/opensearch/core/xcontent/DeprecationHandler.java
index 570a13ad8e093..a0e4027290742 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/DeprecationHandler.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/DeprecationHandler.java
@@ -32,12 +32,17 @@
 
 package org.opensearch.core.xcontent;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.function.Supplier;
 
 /**
  * Callback for notifying the creator of the {@link XContentParser} that
  * parsing hit a deprecated field.
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface DeprecationHandler {
     /**
      * Throws an {@link UnsupportedOperationException} when parsing hits a
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/MapXContentParser.java b/libs/core/src/main/java/org/opensearch/core/xcontent/MapXContentParser.java
index 254c340f8836f..0a5cda324ddb7 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/MapXContentParser.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/MapXContentParser.java
@@ -277,7 +277,7 @@ public Token currentToken() {
 
         /**
          * field name that the child element needs to inherit.
-         *
+         * <p>
          * In most cases this is the same as currentName() except with embedded arrays. In "foo": [[42]] the first START_ARRAY
          * token will have the name "foo", but the second START_ARRAY will have no name.
          */
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/ObjectParser.java b/libs/core/src/main/java/org/opensearch/core/xcontent/ObjectParser.java
index 365b36c755dd2..04d0bce27c04f 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/ObjectParser.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/ObjectParser.java
@@ -32,6 +32,7 @@
 package org.opensearch.core.xcontent;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 
 import java.io.IOException;
@@ -83,8 +84,9 @@
  * It's highly recommended to use the high level declare methods like {@link #declareString(BiConsumer, ParseField)} instead of
  * {@link #declareField} which can be used to implement exceptional parsing operations not covered by the high level methods.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ObjectParser<Value, Context> extends AbstractObjectParser<Value, Context>
     implements
         BiFunction<XContentParser, Context, Value>,
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/ToXContent.java b/libs/core/src/main/java/org/opensearch/core/xcontent/ToXContent.java
index 90dd0cbfb9a1a..ee8dad198df09 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/ToXContent.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/ToXContent.java
@@ -33,6 +33,7 @@
 package org.opensearch.core.xcontent;
 
 import org.opensearch.common.Booleans;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 import java.util.Map;
@@ -42,15 +43,17 @@
  * The output may or may not be a value object. Objects implementing {@link ToXContentObject} output a valid value
  * but those that don't may or may not require emitting a startObject and an endObject.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ToXContent {
 
     /**
      * Base parameters class
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface Params {
         String param(String key);
 
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/XContent.java b/libs/core/src/main/java/org/opensearch/core/xcontent/XContent.java
index dbc0041af42b5..1ebdd69d2b7a3 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/XContent.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/XContent.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.core.xcontent;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -41,7 +43,10 @@
 
 /**
  * A generic abstraction on top of handling content, inspired by JSON and pull parsing.
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface XContent {
     /**
      * The type this content handles and produces.
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilder.java b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilder.java
index a38bdd049ee88..976f353100c55 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilder.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilder.java
@@ -726,7 +726,7 @@ public XContentBuilder value(byte[] value, int offset, int length) throws IOExce
 
     /**
      * Writes the binary content of the given byte array as UTF-8 bytes.
-     *
+     * <p>
      * Use {@link XContentParser#charBuffer()} to read the value back
      */
     public XContentBuilder utf8Value(byte[] bytes, int offset, int length) throws IOException {
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilderExtension.java b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilderExtension.java
index 0535da1a584be..9b13ebb23be86 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilderExtension.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentBuilderExtension.java
@@ -37,7 +37,7 @@
 
 /**
  * This interface provides a way for non-JDK classes to plug in a way to serialize to xcontent.
- *
+ * <p>
  * It is <b>greatly</b> preferred that you implement {@link ToXContentFragment}
  * in the class for encoding, however, in some situations you may not own the
  * class, in which case you can add an implementation here for encoding it.
@@ -63,7 +63,7 @@ public interface XContentBuilderExtension {
      * Used for plugging in a human readable version of a class's encoding. It is assumed that
      * the human readable equivalent is <b>always</b> behind the {@code toString()} method, so
      * this transformer returns the raw value to be used.
-     *
+     * <p>
      * An example implementation:
      *
      * <pre>
@@ -79,7 +79,7 @@ public interface XContentBuilderExtension {
     /**
      * Used for plugging a transformer for a date or time type object into a String (or other
      * encodable object).
-     *
+     * <p>
      * For example:
      *
      * <pre>
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParser.java b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParser.java
index a2f16209a5b7f..85c3579b74cd5 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParser.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParser.java
@@ -33,6 +33,7 @@
 package org.opensearch.core.xcontent;
 
 import org.opensearch.common.CheckedFunction;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -44,7 +45,7 @@
 
 /**
  * Interface for pull - parsing {@link XContent} see {@code XContentType} for supported types.
- *
+ * <p>
  * To obtain an instance of this class use the following pattern:
  *
  * <pre>
@@ -53,8 +54,9 @@
  *          NamedXContentRegistry.EMPTY, ParserField."{\"key\" : \"value\"}");
  * </pre>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface XContentParser extends Closeable {
 
     /**
@@ -202,11 +204,11 @@ <T> Map<String, T> map(Supplier<Map<String, T>> mapFactory, CheckedFunction<XCon
     /**
      * Method that can be used to determine whether calling of textCharacters() would be the most efficient way to
      * access textual content for the event parser currently points to.
-     *
+     * <p>
      * Default implementation simply returns false since only actual
      * implementation class has knowledge of its internal buffering
      * state.
-     *
+     * <p>
      * This method shouldn't be used to check if the token contains text or not.
      */
     boolean hasTextCharacters();
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParserUtils.java b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParserUtils.java
index 13e2f6a695d1b..b10be393f9adb 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParserUtils.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentParserUtils.java
@@ -142,10 +142,10 @@ public static Object parseFieldsValue(XContentParser parser) throws IOException
      * This method expects that the current field name is the concatenation of a type, a delimiter and a name
      * (ex: terms#foo where "terms" refers to the type of a registered {@link NamedXContentRegistry.Entry},
      * "#" is the delimiter and "foo" the name of the object to parse).
-     *
+     * <p>
      * It also expected that following this field name is either an Object or an array xContent structure and
      * the cursor points to the start token of this structure.
-     *
+     * <p>
      * The method splits the field's name to extract the type and name and then parses the object
      * using the {@link XContentParser#namedObject(Class, String, Object)} method.
      *
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentSubParser.java b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentSubParser.java
index d1cdda4aeb8be..337cf9f95fe5f 100644
--- a/libs/core/src/main/java/org/opensearch/core/xcontent/XContentSubParser.java
+++ b/libs/core/src/main/java/org/opensearch/core/xcontent/XContentSubParser.java
@@ -43,7 +43,7 @@
 
 /**
  * Wrapper for a XContentParser that makes a single object/array look like a complete document.
- *
+ * <p>
  * The wrapper prevents the parsing logic to consume tokens outside of the wrapped object as well
  * as skipping to the end of the object in case of a parsing error. The wrapper is intended to be
  * used for parsing objects that should be ignored if they are malformed.
diff --git a/libs/core/src/test/java/org/opensearch/core/util/BytesRefUtilsTests.java b/libs/core/src/test/java/org/opensearch/core/util/BytesRefUtilsTests.java
index 421263b883f2a..214f9292ae3a5 100644
--- a/libs/core/src/test/java/org/opensearch/core/util/BytesRefUtilsTests.java
+++ b/libs/core/src/test/java/org/opensearch/core/util/BytesRefUtilsTests.java
@@ -12,7 +12,6 @@
 import org.apache.lucene.util.BytesRefArray;
 import org.apache.lucene.util.BytesRefBuilder;
 import org.apache.lucene.util.Counter;
-import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.test.OpenSearchTestCase;
 
 import java.nio.ByteBuffer;
@@ -90,8 +89,12 @@ public void testSortByteRefArray() {
     }
 
     public void testBytesToLong() {
-        final long value = randomLong();
-        final BytesReference buffer = BytesReference.fromByteBuffer(ByteBuffer.allocate(8).putLong(value).flip());
-        assertThat(BytesRefUtils.bytesToLong(buffer.toBytesRef()), equalTo(value));
+        long value = randomLong();
+        int paddingStart = randomIntBetween(0, 10);
+        int paddingEnd = randomIntBetween(0, 10);
+        byte[] bytes = new byte[paddingStart + Long.BYTES + paddingEnd];
+        ByteBuffer.wrap(bytes).putLong(paddingStart, value);
+        BytesRef bytesRef = new BytesRef(bytes, paddingStart, Long.BYTES);
+        assertThat(BytesRefUtils.bytesToLong(bytesRef), equalTo(value));
     }
 }
diff --git a/libs/dissect/src/main/java/org/opensearch/dissect/DissectParser.java b/libs/dissect/src/main/java/org/opensearch/dissect/DissectParser.java
index 9861847c9e1ea..828d4b7de450e 100644
--- a/libs/dissect/src/main/java/org/opensearch/dissect/DissectParser.java
+++ b/libs/dissect/src/main/java/org/opensearch/dissect/DissectParser.java
@@ -194,26 +194,25 @@ public DissectParser(String pattern, String appendSeparator) {
      * @throws DissectException if unable to dissect a pair into it's parts.
      */
     public Map<String, String> parse(String inputString) {
-        /**
-         *
-         * This implements a naive string matching algorithm. The string is walked left to right, comparing each byte against
-         * another string's bytes looking for matches. If the bytes match, then a second cursor looks ahead to see if all the bytes
-         * of the other string matches. If they all match, record it and advances the primary cursor to the match point. If it can not match
-         * all of the bytes then progress the main cursor. Repeat till the end of the input string. Since the string being searching for
-         * (the delimiter) is generally small and rare the naive approach is efficient.
-         *
-         * In this case the string that is walked is the input string, and the string being searched for is the current delimiter.
-         * For example for a dissect pattern of {@code %{a},%{b}:%{c}} the delimiters (comma then colon) are searched for in the
-         * input string. At class construction the list of keys+delimiters are found (dissectPairs), which allows the use of that ordered
-         * list to know which delimiter to use for the search. The delimiters is progressed once the current delimiter is matched.
-         *
-         * There are two special cases that requires additional parsing beyond the standard naive algorithm. Consecutive delimiters should
-         * results in a empty matches unless the {@code ->} is provided. For example given the dissect pattern of
-         * {@code %{a},%{b},%{c},%{d}} and input string of {@code foo,,,} the match should be successful with empty values for b,c and d.
-         * However, if the key modifier {@code ->}, is present it will simply skip over any delimiters just to the right of the key
-         * without assigning any values. For example {@code %{a->},{%b}} will match the input string of {@code foo,,,,,,bar} with a=foo and
-         * b=bar.
-         *
+        /*
+
+          This implements a naive string matching algorithm. The string is walked left to right, comparing each byte against
+          another string's bytes looking for matches. If the bytes match, then a second cursor looks ahead to see if all the bytes
+          of the other string matches. If they all match, record it and advances the primary cursor to the match point. If it can not match
+          all of the bytes then progress the main cursor. Repeat till the end of the input string. Since the string being searching for
+          (the delimiter) is generally small and rare the naive approach is efficient.
+
+          In this case the string that is walked is the input string, and the string being searched for is the current delimiter.
+          For example for a dissect pattern of {@code %{a},%{b}:%{c}} the delimiters (comma then colon) are searched for in the
+          input string. At class construction the list of keys+delimiters are found (dissectPairs), which allows the use of that ordered
+          list to know which delimiter to use for the search. The delimiters is progressed once the current delimiter is matched.
+
+          There are two special cases that requires additional parsing beyond the standard naive algorithm. Consecutive delimiters should
+          results in a empty matches unless the {@code ->} is provided. For example given the dissect pattern of
+          {@code %{a},%{b},%{c},%{d}} and input string of {@code foo,,,} the match should be successful with empty values for b,c and d.
+          However, if the key modifier {@code ->}, is present it will simply skip over any delimiters just to the right of the key
+          without assigning any values. For example {@code %{a->},{%b}} will match the input string of {@code foo,,,,,,bar} with a=foo and
+          b=bar.
          */
         DissectMatch dissectMatch = new DissectMatch(appendSeparator, maxMatches, maxResults, appendCount, referenceCount);
         Iterator<DissectPair> it = matchPairs.iterator();
@@ -232,7 +231,10 @@ public Map<String, String> parse(String inputString) {
             int lookAheadMatches;
             // start walking the input string byte by byte, look ahead for matches where needed
             // if a match is found jump forward to the end of the match
-            for (; i < input.length; i++) {
+            while (i < input.length) {
+                // start is only used to record the value of i
+                int start = i;
+
                 lookAheadMatches = 0;
                 // potential match between delimiter and input string
                 if (delimiter.length > 0 && input[i] == delimiter[0]) {
@@ -284,8 +286,14 @@ public Map<String, String> parse(String inputString) {
                         delimiter = dissectPair.getDelimiter().getBytes(StandardCharsets.UTF_8);
                         // i is always one byte after the last found delimiter, aka the start of the next value
                         valueStart = i;
+                    } else {
+                        i++;
                     }
+                } else {
+                    i++;
                 }
+                // i should change anyway
+                assert (i != start);
             }
             // the last key, grab the rest of the input (unless consecutive delimiters already grabbed the last key)
             // and there is no trailing delimiter
diff --git a/libs/geo/src/main/java/org/opensearch/geometry/Circle.java b/libs/geo/src/main/java/org/opensearch/geometry/Circle.java
index 6f8b0dc6929cc..c05f316b53b9c 100644
--- a/libs/geo/src/main/java/org/opensearch/geometry/Circle.java
+++ b/libs/geo/src/main/java/org/opensearch/geometry/Circle.java
@@ -39,12 +39,19 @@
  * and optional altitude in meters.
  */
 public class Circle implements Geometry {
+
+    /** Empty circle : x=0, y=0, z=NaN radius=-1 */
     public static final Circle EMPTY = new Circle();
+    /** Latitude of the center of the circle in degrees */
     private final double y;
+    /** Longitude of the center of the circle in degrees */
     private final double x;
+    /** Altitude of the center of the circle in meters (NaN if irrelevant) */
     private final double z;
+    /** Radius of the circle in meters */
     private final double radiusMeters;
 
+    /** Create an {@link #EMPTY} circle */
     private Circle() {
         y = 0;
         x = 0;
@@ -52,10 +59,23 @@ private Circle() {
         radiusMeters = -1;
     }
 
+    /**
+     * Create a circle with no altitude.
+     * @param x Longitude of the center of the circle in degrees
+     * @param y Latitude of the center of the circle in degrees
+     * @param radiusMeters Radius of the circle in meters
+     */
     public Circle(final double x, final double y, final double radiusMeters) {
         this(x, y, Double.NaN, radiusMeters);
     }
 
+    /**
+     * Create a circle with altitude.
+     * @param x Longitude of the center of the circle in degrees
+     * @param y Latitude of the center of the circle in degrees
+     * @param z Altitude of the center of the circle in meters
+     * @param radiusMeters Radius of the circle in meters
+     */
     public Circle(final double x, final double y, final double z, final double radiusMeters) {
         this.y = y;
         this.x = x;
@@ -66,39 +86,68 @@ public Circle(final double x, final double y, final double z, final double radiu
         }
     }
 
+    /**
+     * @return The type of this geometry (always {@link ShapeType#CIRCLE})
+     */
     @Override
     public ShapeType type() {
         return ShapeType.CIRCLE;
     }
 
+    /**
+     * @return The y (latitude) of the center of the circle in degrees
+     */
     public double getY() {
         return y;
     }
 
+    /**
+     * @return The x (longitude) of the center of the circle in degrees
+     */
     public double getX() {
         return x;
     }
 
+    /**
+     * @return The radius of the circle in meters
+     */
     public double getRadiusMeters() {
         return radiusMeters;
     }
 
+    /**
+     * @return The altitude of the center of the circle in meters (NaN if irrelevant)
+     */
     public double getZ() {
         return z;
     }
 
+    /**
+     * @return The latitude (y) of the center of the circle in degrees
+     */
     public double getLat() {
         return y;
     }
 
+    /**
+     * @return The longitude (x) of the center of the circle in degrees
+     */
     public double getLon() {
         return x;
     }
 
+    /**
+     * @return The altitude (z) of the center of the circle in meters (NaN if irrelevant)
+     */
     public double getAlt() {
         return z;
     }
 
+    /**
+     * Compare this circle to another circle.
+     * @param o The other circle
+     * @return True if the two circles are equal in all their properties. False if null or different.
+     */
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
@@ -111,6 +160,9 @@ public boolean equals(Object o) {
         return (Double.compare(circle.z, z) == 0);
     }
 
+    /**
+     * @return The hashcode of this circle.
+     */
     @Override
     public int hashCode() {
         int result;
@@ -126,11 +178,23 @@ public int hashCode() {
         return result;
     }
 
+    /**
+     * Visit this circle with a {@link GeometryVisitor}.
+     *
+     * @param visitor The visitor
+     * @param <T> The return type of the visitor
+     * @param <E> The exception type of the visitor
+     * @return The result of the visitor
+     * @throws E The exception thrown by the visitor
+     */
     @Override
     public <T, E extends Exception> T visit(GeometryVisitor<T, E> visitor) throws E {
         return visitor.visit(this);
     }
 
+    /**
+     * @return True if this circle is empty (radius less than 0)
+     */
     @Override
     public boolean isEmpty() {
         return radiusMeters < 0;
@@ -141,6 +205,9 @@ public String toString() {
         return WellKnownText.INSTANCE.toWKT(this);
     }
 
+    /**
+     * @return True if this circle has an altitude. False if NaN.
+     */
     @Override
     public boolean hasZ() {
         return Double.isNaN(z) == false;
diff --git a/libs/geo/src/main/java/org/opensearch/geometry/utils/BitUtil.java b/libs/geo/src/main/java/org/opensearch/geometry/utils/BitUtil.java
index 664e7e68d96a5..c946cc2473202 100644
--- a/libs/geo/src/main/java/org/opensearch/geometry/utils/BitUtil.java
+++ b/libs/geo/src/main/java/org/opensearch/geometry/utils/BitUtil.java
@@ -48,8 +48,8 @@ public class BitUtil {  // magic numbers for bit interleaving
 
     /**
      * Interleaves the first 32 bits of each long value
-     *
-     * Adapted from: http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN
+     * <p>
+     * Adapted from: <a href="http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN">bithacks.html#InterleaveBMN</a>
      */
     public static long interleave(int even, int odd) {
         long v1 = 0x00000000FFFFFFFFL & even;
diff --git a/libs/geo/src/main/java/org/opensearch/geometry/utils/Geohash.java b/libs/geo/src/main/java/org/opensearch/geometry/utils/Geohash.java
index 8b3b841e221e5..33c423e136613 100644
--- a/libs/geo/src/main/java/org/opensearch/geometry/utils/Geohash.java
+++ b/libs/geo/src/main/java/org/opensearch/geometry/utils/Geohash.java
@@ -39,12 +39,12 @@
 
 /**
  * Utilities for converting to/from the GeoHash standard
- *
+ * <p>
  * The geohash long format is represented as lon/lat (x/y) interleaved with the 4 least significant bits
  * representing the level (1-12) [xyxy...xyxyllll]
- *
+ * <p>
  * This differs from a morton encoded value which interleaves lat/lon (y/x).
- *
+ * <p>
  * NOTE: this will replace {@code org.opensearch.common.geo.GeoHashUtils}
  */
 public class Geohash {
diff --git a/libs/grok/src/main/java/org/opensearch/grok/Grok.java b/libs/grok/src/main/java/org/opensearch/grok/Grok.java
index cd786b74be039..7aa3347ba4f4b 100644
--- a/libs/grok/src/main/java/org/opensearch/grok/Grok.java
+++ b/libs/grok/src/main/java/org/opensearch/grok/Grok.java
@@ -151,7 +151,7 @@ private void validatePatternBank() {
     /**
      * Checks whether patterns reference each other in a circular manner and, if so, fail with an exception.
      * Also checks for malformed pattern definitions and fails with an exception.
-     *
+     * <p>
      * In a pattern, anything between <code>%{</code> and <code>}</code> or <code>:</code> is considered
      * a reference to another named pattern. This method will navigate to all these named patterns and
      * check for a circular reference.
diff --git a/libs/grok/src/main/java/org/opensearch/grok/MatcherWatchdog.java b/libs/grok/src/main/java/org/opensearch/grok/MatcherWatchdog.java
index 5c7eaca2a634a..d5b7566ecc90f 100644
--- a/libs/grok/src/main/java/org/opensearch/grok/MatcherWatchdog.java
+++ b/libs/grok/src/main/java/org/opensearch/grok/MatcherWatchdog.java
@@ -44,7 +44,7 @@
  * Protects against long running operations that happen between the register and unregister invocations.
  * Threads that invoke {@link #register(Matcher)}, but take too long to invoke the {@link #unregister(Matcher)} method
  * will be interrupted.
- *
+ * <p>
  * This is needed for Joni's {@link org.joni.Matcher#search(int, int, int)} method, because
  * it can end up spinning endlessly if the regular expression is too complex. Joni has checks
  * that for every 30k iterations it checks if the current thread is interrupted and if so
diff --git a/libs/nio/src/main/java/org/opensearch/nio/ChannelContext.java b/libs/nio/src/main/java/org/opensearch/nio/ChannelContext.java
index 797dfe859fa6c..0e29661978716 100644
--- a/libs/nio/src/main/java/org/opensearch/nio/ChannelContext.java
+++ b/libs/nio/src/main/java/org/opensearch/nio/ChannelContext.java
@@ -116,10 +116,10 @@ protected void handleException(Exception e) {
 
     /**
      * Schedules a channel to be closed by the selector event loop with which it is registered.
-     *
+     * <p>
      * If the channel is open and the state can be transitioned to closed, the close operation will
      * be scheduled with the event loop.
-     *
+     * <p>
      * Depending on the underlying protocol of the channel, a close operation might simply close the socket
      * channel or may involve reading and writing messages.
      */
diff --git a/libs/nio/src/main/java/org/opensearch/nio/NioSelector.java b/libs/nio/src/main/java/org/opensearch/nio/NioSelector.java
index a38a33182afea..4ed745723515c 100644
--- a/libs/nio/src/main/java/org/opensearch/nio/NioSelector.java
+++ b/libs/nio/src/main/java/org/opensearch/nio/NioSelector.java
@@ -512,12 +512,12 @@ private void handleQueuedWrites() {
      * This is a convenience method to be called after some object (normally channels) are enqueued with this
      * selector. This method will check if the selector is still open. If it is open, normal operation can
      * proceed.
-     *
+     * <p>
      * If the selector is closed, then we attempt to remove the object from the queue. If the removal
      * succeeds then we throw an {@link IllegalStateException} indicating that normal operation failed. If
      * the object cannot be removed from the queue, then the object has already been handled by the selector
      * and operation can proceed normally.
-     *
+     * <p>
      * If this method is called from the selector thread, we will not allow the queuing to occur as the
      * selector thread can manipulate its queues internally even if it is no longer open.
      *
diff --git a/libs/nio/src/main/java/org/opensearch/nio/SocketChannelContext.java b/libs/nio/src/main/java/org/opensearch/nio/SocketChannelContext.java
index 12a1e80055823..3df8e42fe4f14 100644
--- a/libs/nio/src/main/java/org/opensearch/nio/SocketChannelContext.java
+++ b/libs/nio/src/main/java/org/opensearch/nio/SocketChannelContext.java
@@ -59,7 +59,7 @@
  * that it is ready to perform certain operations (read, write, etc) the {@link SocketChannelContext} will
  * be called. This context will need to implement all protocol related logic. Additionally, if any special
  * close behavior is required, it should be implemented in this context.
- *
+ * <p>
  * The only methods of the context that should ever be called from a non-selector thread are
  * {@link #closeChannel()} and {@link #sendMessage(Object, BiConsumer)}.
  */
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/Counter.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/Counter.java
new file mode 100644
index 0000000000000..c62288d280e2f
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/Counter.java
@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+import org.opensearch.telemetry.metrics.tags.Tags;
+
+/**
+ * Counter adds the value to the existing metric.
+ * {@opensearch.experimental}
+ */
+@ExperimentalApi
+public interface Counter {
+
+    /**
+     * add value.
+     * @param value value to be added.
+     */
+    void add(double value);
+
+    /**
+     * add value along with the attributes.
+     *
+     * @param value value to be added.
+     * @param tags  attributes/dimensions of the metric.
+     */
+    void add(double value, Tags tags);
+
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/DefaultMetricsRegistry.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/DefaultMetricsRegistry.java
new file mode 100644
index 0000000000000..d57def9406b17
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/DefaultMetricsRegistry.java
@@ -0,0 +1,41 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import java.io.IOException;
+
+/**
+ * Default implementation for {@link MetricsRegistry}
+ */
+class DefaultMetricsRegistry implements MetricsRegistry {
+    private final MetricsTelemetry metricsTelemetry;
+
+    /**
+     * Constructor
+     * @param metricsTelemetry metrics telemetry.
+     */
+    public DefaultMetricsRegistry(MetricsTelemetry metricsTelemetry) {
+        this.metricsTelemetry = metricsTelemetry;
+    }
+
+    @Override
+    public Counter createCounter(String name, String description, String unit) {
+        return metricsTelemetry.createCounter(name, description, unit);
+    }
+
+    @Override
+    public Counter createUpDownCounter(String name, String description, String unit) {
+        return metricsTelemetry.createUpDownCounter(name, description, unit);
+    }
+
+    @Override
+    public void close() throws IOException {
+        metricsTelemetry.close();
+    }
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/MetricsRegistry.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/MetricsRegistry.java
new file mode 100644
index 0000000000000..61b3df089928b
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/MetricsRegistry.java
@@ -0,0 +1,39 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+
+import java.io.Closeable;
+
+/**
+ * MetricsRegistry helps in creating the metric instruments.
+ * @opensearch.experimental
+ */
+@ExperimentalApi
+public interface MetricsRegistry extends Closeable {
+
+    /**
+     * Creates the counter.
+     * @param name name of the counter.
+     * @param description any description about the metric.
+     * @param unit unit of the metric.
+     * @return counter.
+     */
+    Counter createCounter(String name, String description, String unit);
+
+    /**
+     * Creates the upDown counter.
+     * @param name name of the upDown counter.
+     * @param description any description about the metric.
+     * @param unit unit of the metric.
+     * @return counter.
+     */
+    Counter createUpDownCounter(String name, String description, String unit);
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/MetricsTelemetry.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/MetricsTelemetry.java
index 0bf9482fe58d8..fb3dec8152b4f 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/MetricsTelemetry.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/MetricsTelemetry.java
@@ -16,6 +16,6 @@
  * @opensearch.experimental
  */
 @ExperimentalApi
-public interface MetricsTelemetry {
+public interface MetricsTelemetry extends MetricsRegistry {
 
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/NoopCounter.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/NoopCounter.java
new file mode 100644
index 0000000000000..c1daf564dd3bc
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/NoopCounter.java
@@ -0,0 +1,38 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics.noop;
+
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.telemetry.metrics.Counter;
+import org.opensearch.telemetry.metrics.tags.Tags;
+
+/**
+ * No-op {@link Counter}
+ * {@opensearch.internal}
+ */
+@InternalApi
+public class NoopCounter implements Counter {
+
+    /**
+     * No-op Counter instance
+     */
+    public final static NoopCounter INSTANCE = new NoopCounter();
+
+    private NoopCounter() {}
+
+    @Override
+    public void add(double value) {
+
+    }
+
+    @Override
+    public void add(double value, Tags tags) {
+
+    }
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/NoopMetricsRegistry.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/NoopMetricsRegistry.java
new file mode 100644
index 0000000000000..640c6842a8960
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/NoopMetricsRegistry.java
@@ -0,0 +1,45 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics.noop;
+
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.telemetry.metrics.Counter;
+import org.opensearch.telemetry.metrics.MetricsRegistry;
+
+import java.io.IOException;
+
+/**
+ *No-op {@link MetricsRegistry}
+ * {@opensearch.internal}
+ */
+@InternalApi
+public class NoopMetricsRegistry implements MetricsRegistry {
+
+    /**
+     * No-op Meter instance
+     */
+    public final static NoopMetricsRegistry INSTANCE = new NoopMetricsRegistry();
+
+    private NoopMetricsRegistry() {}
+
+    @Override
+    public Counter createCounter(String name, String description, String unit) {
+        return NoopCounter.INSTANCE;
+    }
+
+    @Override
+    public Counter createUpDownCounter(String name, String description, String unit) {
+        return NoopCounter.INSTANCE;
+    }
+
+    @Override
+    public void close() throws IOException {
+
+    }
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/package-info.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/package-info.java
new file mode 100644
index 0000000000000..7c7ed08044993
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/noop/package-info.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * Contains metrics related classes
+ * {@opensearch.internal}
+ */
+@InternalApi
+package org.opensearch.telemetry.metrics.noop;
+
+import org.opensearch.common.annotation.InternalApi;
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/tags/Tags.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/tags/Tags.java
new file mode 100644
index 0000000000000..f2a8764f8021d
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/tags/Tags.java
@@ -0,0 +1,99 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics.tags;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * Class to create tags for a meter.
+ *
+ * @opensearch.experimental
+ */
+@ExperimentalApi
+public class Tags {
+    private final Map<String, Object> tagsMap;
+    /**
+     * Empty value.
+     */
+    public final static Tags EMPTY = new Tags(Collections.emptyMap());
+
+    /**
+     * Factory method.
+     * @return tags.
+     */
+    public static Tags create() {
+        return new Tags(new HashMap<>());
+    }
+
+    /**
+     * Constructor.
+     */
+    private Tags(Map<String, Object> tagsMap) {
+        this.tagsMap = tagsMap;
+    }
+
+    /**
+     * Add String attribute.
+     * @param key key
+     * @param value value
+     * @return Same instance.
+     */
+    public Tags addTag(String key, String value) {
+        Objects.requireNonNull(value, "value cannot be null");
+        tagsMap.put(key, value);
+        return this;
+    }
+
+    /**
+     * Add long attribute.
+     * @param key key
+     * @param value value
+     * @return Same instance.
+     */
+    public Tags addTag(String key, long value) {
+        tagsMap.put(key, value);
+        return this;
+    };
+
+    /**
+     * Add double attribute.
+     * @param key key
+     * @param value value
+     * @return Same instance.
+     */
+    public Tags addTag(String key, double value) {
+        tagsMap.put(key, value);
+        return this;
+    };
+
+    /**
+     * Add boolean attribute.
+     * @param key key
+     * @param value value
+     * @return Same instance.
+     */
+    public Tags addTag(String key, boolean value) {
+        tagsMap.put(key, value);
+        return this;
+    };
+
+    /**
+     * Returns the attribute map.
+     * @return tags map
+     */
+    public Map<String, ?> getTagsMap() {
+        return Collections.unmodifiableMap(tagsMap);
+    }
+
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/tags/package-info.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/tags/package-info.java
new file mode 100644
index 0000000000000..70bc9be992b32
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/metrics/tags/package-info.java
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * Contains metrics related classes
+ * @opensearch.experimental
+ */
+@ExperimentalApi
+package org.opensearch.telemetry.metrics.tags;
+
+import org.opensearch.common.annotation.ExperimentalApi;
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultSpanScope.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultSpanScope.java
index a5d515443b54d..93600da510977 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultSpanScope.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultSpanScope.java
@@ -21,6 +21,7 @@
 class DefaultSpanScope implements SpanScope {
     private final Span span;
     private final SpanScope previousSpanScope;
+    private final Span beforeSpan;
     private static final ThreadLocal<SpanScope> spanScopeThreadLocal = new ThreadLocal<>();
     private final TracerContextStorage<String, Span> tracerContextStorage;
 
@@ -29,8 +30,14 @@ class DefaultSpanScope implements SpanScope {
      * @param span span
      * @param previousSpanScope before attached span scope.
      */
-    private DefaultSpanScope(Span span, SpanScope previousSpanScope, TracerContextStorage<String, Span> tracerContextStorage) {
+    private DefaultSpanScope(
+        Span span,
+        final Span beforeSpan,
+        SpanScope previousSpanScope,
+        TracerContextStorage<String, Span> tracerContextStorage
+    ) {
         this.span = Objects.requireNonNull(span);
+        this.beforeSpan = beforeSpan;
         this.previousSpanScope = previousSpanScope;
         this.tracerContextStorage = tracerContextStorage;
     }
@@ -43,26 +50,27 @@ private DefaultSpanScope(Span span, SpanScope previousSpanScope, TracerContextSt
      */
     public static SpanScope create(Span span, TracerContextStorage<String, Span> tracerContextStorage) {
         final SpanScope beforeSpanScope = spanScopeThreadLocal.get();
-        SpanScope newSpanScope = new DefaultSpanScope(span, beforeSpanScope, tracerContextStorage);
-        spanScopeThreadLocal.set(newSpanScope);
+        final Span beforeSpan = tracerContextStorage.get(TracerContextStorage.CURRENT_SPAN);
+        SpanScope newSpanScope = new DefaultSpanScope(span, beforeSpan, beforeSpanScope, tracerContextStorage);
         return newSpanScope;
     }
 
     @Override
     public void close() {
         detach();
-        spanScopeThreadLocal.set(previousSpanScope);
     }
 
     @Override
     public SpanScope attach() {
+        spanScopeThreadLocal.set(this);
         tracerContextStorage.put(TracerContextStorage.CURRENT_SPAN, this.span);
         return this;
     }
 
     private void detach() {
-        if (previousSpanScope != null) {
-            tracerContextStorage.put(TracerContextStorage.CURRENT_SPAN, previousSpanScope.getSpan());
+        spanScopeThreadLocal.set(previousSpanScope);
+        if (beforeSpan != null) {
+            tracerContextStorage.put(TracerContextStorage.CURRENT_SPAN, beforeSpan);
         } else {
             tracerContextStorage.put(TracerContextStorage.CURRENT_SPAN, null);
         }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java
index 5b7795a5647f5..8f1a26d99e725 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java
@@ -9,11 +9,10 @@
 package org.opensearch.telemetry.tracing;
 
 import org.opensearch.common.annotation.InternalApi;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
 
 import java.io.Closeable;
 import java.io.IOException;
-import java.util.List;
+import java.util.Collection;
 import java.util.Map;
 import java.util.Optional;
 
@@ -26,7 +25,10 @@
  */
 @InternalApi
 class DefaultTracer implements Tracer {
-    static final String THREAD_NAME = "th_name";
+    /**
+     * Current thread name.
+     */
+    static final String THREAD_NAME = "thread.name";
 
     private final TracingTelemetry tracingTelemetry;
     private final TracerContextStorage<String, Span> tracerContextStorage;
@@ -44,28 +46,13 @@ public DefaultTracer(TracingTelemetry tracingTelemetry, TracerContextStorage<Str
 
     @Override
     public Span startSpan(SpanCreationContext context) {
-        return startSpan(context.getSpanName(), context.getAttributes());
-    }
-
-    @Override
-    public Span startSpan(String spanName) {
-        return startSpan(spanName, Attributes.EMPTY);
-    }
-
-    @Override
-    public Span startSpan(String spanName, Attributes attributes) {
-        return startSpan(spanName, (SpanContext) null, attributes);
-    }
-
-    @Override
-    public Span startSpan(String spanName, SpanContext parentSpan, Attributes attributes) {
-        Span span = null;
-        if (parentSpan != null) {
-            span = createSpan(spanName, parentSpan.getSpan(), attributes);
+        Span parentSpan = null;
+        if (context.getParent() != null) {
+            parentSpan = context.getParent().getSpan();
         } else {
-            span = createSpan(spanName, getCurrentSpanInternal(), attributes);
+            parentSpan = getCurrentSpanInternal();
         }
-        setCurrentSpanInContext(span);
+        Span span = createSpan(context, parentSpan);
         addDefaultAttributes(span);
         return span;
     }
@@ -87,12 +74,7 @@ public SpanContext getCurrentSpan() {
 
     @Override
     public ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext) {
-        return startScopedSpan(spanCreationContext, null);
-    }
-
-    @Override
-    public ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext, SpanContext parentSpan) {
-        Span span = startSpan(spanCreationContext.getSpanName(), parentSpan, spanCreationContext.getAttributes());
+        Span span = startSpan(spanCreationContext);
         SpanScope spanScope = withSpanInScope(span);
         return new DefaultScopedSpan(span, spanScope);
     }
@@ -102,12 +84,13 @@ public SpanScope withSpanInScope(Span span) {
         return DefaultSpanScope.create(span, tracerContextStorage).attach();
     }
 
-    private Span createSpan(String spanName, Span parentSpan, Attributes attributes) {
-        return tracingTelemetry.createSpan(spanName, parentSpan, attributes);
+    @Override
+    public boolean isRecording() {
+        return true;
     }
 
-    private void setCurrentSpanInContext(Span span) {
-        tracerContextStorage.put(TracerContextStorage.CURRENT_SPAN, span);
+    private Span createSpan(SpanCreationContext spanCreationContext, Span parentSpan) {
+        return tracingTelemetry.createSpan(spanCreationContext, parentSpan);
     }
 
     /**
@@ -119,13 +102,9 @@ protected void addDefaultAttributes(Span span) {
     }
 
     @Override
-    public Span startSpan(SpanCreationContext spanCreationContext, Map<String, List<String>> headers) {
+    public Span startSpan(SpanCreationContext spanCreationContext, Map<String, Collection<String>> headers) {
         Optional<Span> propagatedSpan = tracingTelemetry.getContextPropagator().extractFromHeaders(headers);
-        return startSpan(
-            spanCreationContext.getSpanName(),
-            propagatedSpan.map(SpanContext::new).orElse(null),
-            spanCreationContext.getAttributes()
-        );
+        return startSpan(spanCreationContext.parent(propagatedSpan.map(SpanContext::new).orElse(null)));
     }
 
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanCreationContext.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanCreationContext.java
index 10cb665e83b01..cbbcfe7a85d57 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanCreationContext.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanCreationContext.java
@@ -18,17 +18,74 @@
  */
 @ExperimentalApi
 public final class SpanCreationContext {
-    private final String spanName;
-    private final Attributes attributes;
+    private String spanName;
+    private Attributes attributes;
+    private SpanKind spanKind = SpanKind.INTERNAL;
+    private SpanContext parent;
 
     /**
      * Constructor.
+     */
+    private SpanCreationContext() {}
+
+    /**
+     * Sets the span type to server.
+     * @return spanCreationContext
+     */
+    public static SpanCreationContext server() {
+        SpanCreationContext spanCreationContext = new SpanCreationContext();
+        spanCreationContext.spanKind = SpanKind.SERVER;
+        return spanCreationContext;
+    }
+
+    /**
+     * Sets the span type to client.
+     * @return spanCreationContext
+     */
+    public static SpanCreationContext client() {
+        SpanCreationContext spanCreationContext = new SpanCreationContext();
+        spanCreationContext.spanKind = SpanKind.CLIENT;
+        return spanCreationContext;
+    }
+
+    /**
+     * Sets the span type to internal.
+     * @return spanCreationContext
+     */
+    public static SpanCreationContext internal() {
+        SpanCreationContext spanCreationContext = new SpanCreationContext();
+        spanCreationContext.spanKind = SpanKind.INTERNAL;
+        return spanCreationContext;
+    }
+
+    /**
+     * Sets the span name.
      * @param spanName span name.
-     * @param attributes attributes.
+     * @return spanCreationContext
      */
-    public SpanCreationContext(String spanName, Attributes attributes) {
+    public SpanCreationContext name(String spanName) {
         this.spanName = spanName;
+        return this;
+    }
+
+    /**
+     * Sets the span attributes.
+     * @param attributes attributes.
+     * @return spanCreationContext
+     */
+    public SpanCreationContext attributes(Attributes attributes) {
         this.attributes = attributes;
+        return this;
+    }
+
+    /**
+     * Sets the parent for spann
+     * @param parent parent
+     * @return spanCreationContext
+     */
+    public SpanCreationContext parent(SpanContext parent) {
+        this.parent = parent;
+        return this;
     }
 
     /**
@@ -46,4 +103,20 @@ public String getSpanName() {
     public Attributes getAttributes() {
         return attributes;
     }
+
+    /**
+     * Returns the span kind.
+     * @return spankind.
+     */
+    public SpanKind getSpanKind() {
+        return spanKind;
+    }
+
+    /**
+     * Returns the parent span
+     * @return parent.
+     */
+    public SpanContext getParent() {
+        return parent;
+    }
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanKind.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanKind.java
new file mode 100644
index 0000000000000..d674bb2c866f2
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanKind.java
@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing;
+
+import org.opensearch.common.annotation.PublicApi;
+
+/**
+ * Type of Span.
+ */
+@PublicApi(since = "2.11.0")
+public enum SpanKind {
+    /**
+     * Span represents the client side code.
+     */
+    CLIENT,
+    /**
+     * Span represents the server side code.
+     */
+    SERVER,
+
+    /**
+     * Span represents the internal calls. This is the default value of a span type.
+     */
+    INTERNAL;
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java
index 19ffc68a62df0..9b49ca7668992 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java
@@ -9,21 +9,20 @@
 package org.opensearch.telemetry.tracing;
 
 import org.opensearch.common.annotation.ExperimentalApi;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
-import org.opensearch.telemetry.tracing.http.HttpTracer;
+import org.opensearch.telemetry.tracing.transport.TransportTracer;
 
 import java.io.Closeable;
 
 /**
  * Tracer is the interface used to create a {@link Span}
  * It automatically handles the context propagation between threads, tasks, nodes etc.
- *
+ * <p>
  * All methods on the Tracer object are multi-thread safe.
  *
  * @opensearch.experimental
  */
 @ExperimentalApi
-public interface Tracer extends HttpTracer, Closeable {
+public interface Tracer extends TransportTracer, Closeable {
     /**
      * Starts the {@link Span} with given {@link SpanCreationContext}
      *
@@ -32,34 +31,6 @@ public interface Tracer extends HttpTracer, Closeable {
      */
     Span startSpan(SpanCreationContext context);
 
-    /**
-     * Starts the {@link Span} with given name
-     *
-     * @param spanName span name
-     * @return span, must be closed.
-     */
-    Span startSpan(String spanName);
-
-    /**
-     * Starts the {@link Span} with given name and attributes. This is required in cases when some attribute based
-     * decision needs to be made before starting the span. Very useful in the case of Sampling.
-     *
-     * @param spanName   span name.
-     * @param attributes attributes to be added.
-     * @return span, must be closed.
-     */
-    Span startSpan(String spanName, Attributes attributes);
-
-    /**
-     * Starts the {@link Span} with the given name, parent and attributes.
-     *
-     * @param spanName   span name.
-     * @param parentSpan parent span.
-     * @param attributes attributes to be added.
-     * @return span, must be closed.
-     */
-    Span startSpan(String spanName, SpanContext parentSpan, Attributes attributes);
-
     /**
      * Returns the current span.
      * @return current wrapped span.
@@ -74,15 +45,6 @@ public interface Tracer extends HttpTracer, Closeable {
      */
     ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext);
 
-    /**
-     * Start the span and scoped it. This must be used for scenarios where {@link SpanScope} and {@link Span} lifecycles
-     * are same and ends within the same thread where created.
-     * @param spanCreationContext span creation context
-     * @param parentSpan parent span.
-     * @return scope of the span, must be closed with explicit close or with try-with-resource
-     */
-    ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext, SpanContext parentSpan);
-
     /**
      * Creates the Span Scope for a current thread. It's mandatory to scope the span just after creation so that it will
      * automatically manage the attach /detach to the current thread.
@@ -91,4 +53,10 @@ public interface Tracer extends HttpTracer, Closeable {
      */
     SpanScope withSpanInScope(Span span);
 
+    /**
+     * Tells if the traces are being recorded or not
+     * @return boolean
+     */
+    boolean isRecording();
+
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingContextPropagator.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingContextPropagator.java
index 5fbc5d329e227..d7d48d1db10d6 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingContextPropagator.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingContextPropagator.java
@@ -10,7 +10,7 @@
 
 import org.opensearch.common.annotation.ExperimentalApi;
 
-import java.util.List;
+import java.util.Collection;
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.BiConsumer;
@@ -36,7 +36,7 @@ public interface TracingContextPropagator {
      * @param headers request headers to extract the context from
      * @return current span
      */
-    Optional<Span> extractFromHeaders(Map<String, List<String>> headers);
+    Optional<Span> extractFromHeaders(Map<String, Collection<String>> headers);
 
     /**
      * Injects tracing context
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingTelemetry.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingTelemetry.java
index e1811e85f8890..f04a505088424 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingTelemetry.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/TracingTelemetry.java
@@ -9,7 +9,6 @@
 package org.opensearch.telemetry.tracing;
 
 import org.opensearch.common.annotation.ExperimentalApi;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
 
 import java.io.Closeable;
 
@@ -24,12 +23,11 @@ public interface TracingTelemetry extends Closeable {
     /**
      * Creates span with provided arguments
      *
-     * @param spanName   name of the span
-     * @param parentSpan span's parent span
-     * @param attributes attributes to be added.
+     * @param spanCreationContext span creation context.
+     * @param parentSpan parent span.
      * @return span instance
      */
-    Span createSpan(String spanName, Span parentSpan, Attributes attributes);
+    Span createSpan(SpanCreationContext spanCreationContext, Span parentSpan);
 
     /**
      * provides tracing context propagator
@@ -37,9 +35,4 @@ public interface TracingTelemetry extends Closeable {
      */
     TracingContextPropagator getContextPropagator();
 
-    /**
-     * closes the resource
-     */
-    void close();
-
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java
index d7206a3c6b094..c57eaccf1f3df 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java
@@ -15,9 +15,8 @@
 import org.opensearch.telemetry.tracing.SpanCreationContext;
 import org.opensearch.telemetry.tracing.SpanScope;
 import org.opensearch.telemetry.tracing.Tracer;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
 
-import java.util.List;
+import java.util.Collection;
 import java.util.Map;
 
 /**
@@ -40,21 +39,6 @@ public Span startSpan(SpanCreationContext context) {
         return NoopSpan.INSTANCE;
     }
 
-    @Override
-    public Span startSpan(String spanName) {
-        return NoopSpan.INSTANCE;
-    }
-
-    @Override
-    public Span startSpan(String spanName, Attributes attributes) {
-        return NoopSpan.INSTANCE;
-    }
-
-    @Override
-    public Span startSpan(String spanName, SpanContext parentSpan, Attributes attributes) {
-        return NoopSpan.INSTANCE;
-    }
-
     @Override
     public SpanContext getCurrentSpan() {
         return new SpanContext(NoopSpan.INSTANCE);
@@ -66,13 +50,13 @@ public ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext) {
     }
 
     @Override
-    public ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext, SpanContext parentSpan) {
-        return ScopedSpan.NO_OP;
+    public SpanScope withSpanInScope(Span span) {
+        return SpanScope.NO_OP;
     }
 
     @Override
-    public SpanScope withSpanInScope(Span span) {
-        return SpanScope.NO_OP;
+    public boolean isRecording() {
+        return false;
     }
 
     @Override
@@ -81,7 +65,7 @@ public void close() {
     }
 
     @Override
-    public Span startSpan(SpanCreationContext spanCreationContext, Map<String, List<String>> header) {
+    public Span startSpan(SpanCreationContext spanCreationContext, Map<String, Collection<String>> header) {
         return NoopSpan.INSTANCE;
     }
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/runnable/TraceableRunnable.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/runnable/TraceableRunnable.java
index 4672574e9f4ca..8a61dd70d6d54 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/runnable/TraceableRunnable.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/runnable/TraceableRunnable.java
@@ -9,40 +9,32 @@
 package org.opensearch.telemetry.tracing.runnable;
 
 import org.opensearch.telemetry.tracing.ScopedSpan;
-import org.opensearch.telemetry.tracing.SpanContext;
 import org.opensearch.telemetry.tracing.SpanCreationContext;
 import org.opensearch.telemetry.tracing.Tracer;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
 
 /**
  * Wraps the runnable and add instrumentation to trace the {@link Runnable}
  */
 public class TraceableRunnable implements Runnable {
     private final Runnable runnable;
-    private final SpanContext parent;
+    private final SpanCreationContext spanCreationContext;
     private final Tracer tracer;
-    private final String spanName;
-    private final Attributes attributes;
 
     /**
      * Constructor.
      * @param tracer tracer
-     * @param spanName spanName
-     * @param parent parent Span.
-     * @param attributes attributes.
+     * @param spanCreationContext spanCreationContext
      * @param runnable runnable.
      */
-    public TraceableRunnable(Tracer tracer, String spanName, SpanContext parent, Attributes attributes, Runnable runnable) {
+    public TraceableRunnable(Tracer tracer, SpanCreationContext spanCreationContext, Runnable runnable) {
         this.tracer = tracer;
-        this.spanName = spanName;
-        this.parent = parent;
-        this.attributes = attributes;
+        this.spanCreationContext = spanCreationContext;
         this.runnable = runnable;
     }
 
     @Override
     public void run() {
-        try (ScopedSpan spanScope = tracer.startScopedSpan(new SpanCreationContext(spanName, attributes), parent)) {
+        try (ScopedSpan spanScope = tracer.startScopedSpan(spanCreationContext)) {
             runnable.run();
         }
     }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/http/HttpTracer.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/transport/TransportTracer.java
similarity index 64%
rename from libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/http/HttpTracer.java
rename to libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/transport/TransportTracer.java
index b0692f1b62a48..5883d7de8e83a 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/http/HttpTracer.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/transport/TransportTracer.java
@@ -6,31 +6,31 @@
  * compatible open source license.
  */
 
-package org.opensearch.telemetry.tracing.http;
+package org.opensearch.telemetry.tracing.transport;
 
 import org.opensearch.common.annotation.ExperimentalApi;
 import org.opensearch.telemetry.tracing.Span;
 import org.opensearch.telemetry.tracing.SpanCreationContext;
 
-import java.util.List;
+import java.util.Collection;
 import java.util.Map;
 
 /**
- * HttpTracer helps in creating a {@link Span} which reads the incoming tracing information
- * from the HttpRequest header and propagate the span accordingly.
- *
+ * TransportTracer helps in creating a {@link Span} which reads the incoming tracing information
+ * from the HTTP or TCP transport headers and propagate the span accordingly.
+ * <p>
  * All methods on the Tracer object are multi-thread safe.
  *
  * @opensearch.experimental
  */
 @ExperimentalApi
-public interface HttpTracer {
+public interface TransportTracer {
     /**
      * Start the span with propagating the tracing info from the HttpRequest header.
      *
      * @param spanCreationContext span name.
-     * @param header http request header.
-     * @return span.
+     * @param headers transport headers
+     * @return the span instance
      */
-    Span startSpan(SpanCreationContext spanCreationContext, Map<String, List<String>> header);
+    Span startSpan(SpanCreationContext spanCreationContext, Map<String, Collection<String>> headers);
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/transport/package-info.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/transport/package-info.java
new file mode 100644
index 0000000000000..87ffcc43184bb
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/transport/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * Contains HTTP or TCP transport related tracer capabilities
+ */
+package org.opensearch.telemetry.tracing.transport;
diff --git a/libs/telemetry/src/test/java/org/opensearch/telemetry/metrics/DefaultMetricsRegistryTests.java b/libs/telemetry/src/test/java/org/opensearch/telemetry/metrics/DefaultMetricsRegistryTests.java
new file mode 100644
index 0000000000000..6171641db5f07
--- /dev/null
+++ b/libs/telemetry/src/test/java/org/opensearch/telemetry/metrics/DefaultMetricsRegistryTests.java
@@ -0,0 +1,51 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class DefaultMetricsRegistryTests extends OpenSearchTestCase {
+
+    private MetricsTelemetry metricsTelemetry;
+    private DefaultMetricsRegistry defaultMeterRegistry;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        metricsTelemetry = mock(MetricsTelemetry.class);
+        defaultMeterRegistry = new DefaultMetricsRegistry(metricsTelemetry);
+    }
+
+    public void testCounter() {
+        Counter mockCounter = mock(Counter.class);
+        when(defaultMeterRegistry.createCounter(any(String.class), any(String.class), any(String.class))).thenReturn(mockCounter);
+        Counter counter = defaultMeterRegistry.createCounter(
+            "org.opensearch.telemetry.metrics.DefaultMeterRegistryTests.testCounter",
+            "test counter",
+            "1"
+        );
+        assertSame(mockCounter, counter);
+    }
+
+    public void testUpDownCounter() {
+        Counter mockCounter = mock(Counter.class);
+        when(defaultMeterRegistry.createUpDownCounter(any(String.class), any(String.class), any(String.class))).thenReturn(mockCounter);
+        Counter counter = defaultMeterRegistry.createUpDownCounter(
+            "org.opensearch.telemetry.metrics.DefaultMeterRegistryTests.testUpDownCounter",
+            "test up-down counter",
+            "1"
+        );
+        assertSame(mockCounter, counter);
+    }
+
+}
diff --git a/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java
index 48b72e1f673fe..2182b3ea28ac8 100644
--- a/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java
+++ b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java
@@ -22,7 +22,8 @@
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutorService;
 
-import static org.mockito.ArgumentMatchers.any;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.nullValue;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -36,9 +37,9 @@ public class DefaultTracerTests extends OpenSearchTestCase {
     private Span mockSpan;
     private Span mockParentSpan;
 
-    private SpanScope mockSpanScope;
     private ThreadPool threadPool;
     private ExecutorService executorService;
+    private SpanCreationContext spanCreationContext;
 
     @Override
     public void setUp() throws Exception {
@@ -58,27 +59,31 @@ public void tearDown() throws Exception {
     public void testCreateSpan() {
         DefaultTracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
 
-        defaultTracer.startSpan("span_name");
+        defaultTracer.startSpan(spanCreationContext);
 
-        assertEquals("span_name", defaultTracer.getCurrentSpan().getSpan().getSpanName());
+        String spanName = defaultTracer.getCurrentSpan().getSpan().getSpanName();
+        assertEquals("span_name", spanName);
+        assertTrue(defaultTracer.isRecording());
     }
 
     @SuppressWarnings("unchecked")
     public void testCreateSpanWithAttributesWithMock() {
         DefaultTracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
         Attributes attributes = Attributes.create().addAttribute("name", "value");
-        when(mockTracingTelemetry.createSpan(eq("span_name"), eq(mockParentSpan), eq(attributes))).thenReturn(mockSpan);
-        defaultTracer.startSpan("span_name", attributes);
-        verify(mockTracingTelemetry).createSpan(eq("span_name"), eq(mockParentSpan), eq(attributes));
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", attributes, mockParentSpan);
+        when(mockTracingTelemetry.createSpan(eq(spanCreationContext), eq(mockParentSpan))).thenReturn(mockSpan);
+        defaultTracer.startSpan(spanCreationContext);
+        verify(mockTracingTelemetry).createSpan(eq(spanCreationContext), eq(mockParentSpan));
     }
 
     @SuppressWarnings("unchecked")
     public void testCreateSpanWithAttributesWithParentMock() {
         DefaultTracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
         Attributes attributes = Attributes.create().addAttribute("name", "value");
-        when(mockTracingTelemetry.createSpan(eq("span_name"), eq(mockParentSpan), eq(attributes))).thenReturn(mockSpan);
-        defaultTracer.startSpan("span_name", new SpanContext(mockParentSpan), attributes);
-        verify(mockTracingTelemetry).createSpan(eq("span_name"), eq(mockParentSpan), eq(attributes));
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", attributes, mockParentSpan);
+        when(mockTracingTelemetry.createSpan(eq(spanCreationContext), eq(mockParentSpan))).thenReturn(mockSpan);
+        defaultTracer.startSpan(spanCreationContext);
+        verify(mockTracingTelemetry).createSpan(eq(spanCreationContext), eq(mockParentSpan));
         verify(mockTracerContextStorage, never()).get(TracerContextStorage.CURRENT_SPAN);
     }
 
@@ -90,16 +95,19 @@ public void testCreateSpanWithAttributes() {
             new ThreadContextBasedTracerContextStorage(threadContext, tracingTelemetry)
         );
 
-        Span span = defaultTracer.startSpan(
+        SpanCreationContext spanCreationContext = buildSpanCreationContext(
             "span_name",
-            Attributes.create().addAttribute("key1", 1.0).addAttribute("key2", 2l).addAttribute("key3", true).addAttribute("key4", "key4")
+            Attributes.create().addAttribute("key1", 1.0).addAttribute("key2", 2l).addAttribute("key3", true).addAttribute("key4", "key4"),
+            null
         );
 
-        assertEquals("span_name", defaultTracer.getCurrentSpan().getSpan().getSpanName());
-        assertEquals(1.0, ((MockSpan) defaultTracer.getCurrentSpan().getSpan()).getAttribute("key1"));
-        assertEquals(2l, ((MockSpan) defaultTracer.getCurrentSpan().getSpan()).getAttribute("key2"));
-        assertEquals(true, ((MockSpan) defaultTracer.getCurrentSpan().getSpan()).getAttribute("key3"));
-        assertEquals("key4", ((MockSpan) defaultTracer.getCurrentSpan().getSpan()).getAttribute("key4"));
+        Span span = defaultTracer.startSpan(spanCreationContext);
+
+        assertThat(defaultTracer.getCurrentSpan(), is(nullValue()));
+        assertEquals(1.0, ((MockSpan) span).getAttribute("key1"));
+        assertEquals(2l, ((MockSpan) span).getAttribute("key2"));
+        assertEquals(true, ((MockSpan) span).getAttribute("key3"));
+        assertEquals("key4", ((MockSpan) span).getAttribute("key4"));
         span.endSpan();
     }
 
@@ -110,25 +118,32 @@ public void testCreateSpanWithParent() {
             new ThreadContextBasedTracerContextStorage(new ThreadContext(Settings.EMPTY), tracingTelemetry)
         );
 
-        Span span = defaultTracer.startSpan("span_name", null);
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", null, null);
 
-        SpanContext parentSpan = defaultTracer.getCurrentSpan();
+        Span span = defaultTracer.startSpan(spanCreationContext, null);
 
-        Span span1 = defaultTracer.startSpan("span_name_1", parentSpan, Attributes.EMPTY);
+        try (final SpanScope scope = defaultTracer.withSpanInScope(span)) {
+            SpanContext parentSpan = defaultTracer.getCurrentSpan();
 
-        assertEquals("span_name_1", defaultTracer.getCurrentSpan().getSpan().getSpanName());
-        assertEquals(parentSpan.getSpan(), defaultTracer.getCurrentSpan().getSpan().getParentSpan());
-        span1.endSpan();
-        span.endSpan();
+            SpanCreationContext spanCreationContext1 = buildSpanCreationContext("span_name_1", Attributes.EMPTY, parentSpan.getSpan());
+
+            try (final ScopedSpan span1 = defaultTracer.startScopedSpan(spanCreationContext1)) {
+                assertEquals("span_name_1", defaultTracer.getCurrentSpan().getSpan().getSpanName());
+                assertEquals(parentSpan.getSpan(), defaultTracer.getCurrentSpan().getSpan().getParentSpan());
+            }
+        } finally {
+            span.endSpan();
+        }
     }
 
     @SuppressWarnings("unchecked")
     public void testCreateSpanWithContext() {
         DefaultTracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
         Attributes attributes = Attributes.create().addAttribute("name", "value");
-        when(mockTracingTelemetry.createSpan(eq("span_name"), eq(mockParentSpan), eq(attributes))).thenReturn(mockSpan);
-        defaultTracer.startSpan(new SpanCreationContext("span_name", attributes));
-        verify(mockTracingTelemetry).createSpan(eq("span_name"), eq(mockParentSpan), eq(attributes));
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", attributes, mockParentSpan);
+        when(mockTracingTelemetry.createSpan(eq(spanCreationContext), eq(mockParentSpan))).thenReturn(mockSpan);
+        defaultTracer.startSpan(spanCreationContext);
+        verify(mockTracingTelemetry).createSpan(eq(spanCreationContext), eq(mockParentSpan));
     }
 
     public void testCreateSpanWithNullParent() {
@@ -139,10 +154,11 @@ public void testCreateSpanWithNullParent() {
             new ThreadContextBasedTracerContextStorage(threadContext, tracingTelemetry)
         );
 
-        Span span = defaultTracer.startSpan("span_name", (SpanContext) null, Attributes.EMPTY);
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", Attributes.EMPTY, null);
 
-        assertEquals("span_name", defaultTracer.getCurrentSpan().getSpan().getSpanName());
-        assertEquals(null, defaultTracer.getCurrentSpan().getSpan().getParentSpan());
+        Span span = defaultTracer.startSpan(spanCreationContext);
+
+        assertThat(defaultTracer.getCurrentSpan(), is(nullValue()));
         span.endSpan();
     }
 
@@ -154,7 +170,10 @@ public void testEndSpanByClosingScopedSpan() {
             tracingTelemetry
         );
         DefaultTracer defaultTracer = new DefaultTracer(tracingTelemetry, spanTracerStorage);
-        ScopedSpan scopedSpan = defaultTracer.startScopedSpan(new SpanCreationContext("span_name", Attributes.EMPTY));
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", Attributes.EMPTY, null);
+
+        ScopedSpan scopedSpan = defaultTracer.startScopedSpan(spanCreationContext);
+
         assertEquals("span_name", defaultTracer.getCurrentSpan().getSpan().getSpanName());
         assertEquals(((DefaultScopedSpan) scopedSpan).getSpanScope(), DefaultSpanScope.getCurrentSpanScope());
         scopedSpan.close();
@@ -172,8 +191,11 @@ public void testEndSpanByClosingScopedSpanMultiple() {
             tracingTelemetry
         );
         DefaultTracer defaultTracer = new DefaultTracer(tracingTelemetry, spanTracerStorage);
-        ScopedSpan scopedSpan = defaultTracer.startScopedSpan(new SpanCreationContext("span_name", Attributes.EMPTY));
-        ScopedSpan scopedSpan1 = defaultTracer.startScopedSpan(new SpanCreationContext("span_name_1", Attributes.EMPTY));
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", Attributes.EMPTY, null);
+        SpanCreationContext spanCreationContext1 = buildSpanCreationContext("span_name_1", Attributes.EMPTY, null);
+
+        ScopedSpan scopedSpan = defaultTracer.startScopedSpan(spanCreationContext);
+        ScopedSpan scopedSpan1 = defaultTracer.startScopedSpan(spanCreationContext1);
 
         assertEquals("span_name_1", defaultTracer.getCurrentSpan().getSpan().getSpanName());
         assertEquals(((DefaultScopedSpan) scopedSpan1).getSpanScope(), DefaultSpanScope.getCurrentSpanScope());
@@ -198,7 +220,8 @@ public void testEndSpanByClosingSpanScope() {
             tracingTelemetry
         );
         DefaultTracer defaultTracer = new DefaultTracer(tracingTelemetry, spanTracerStorage);
-        Span span = defaultTracer.startSpan(new SpanCreationContext("span_name", Attributes.EMPTY));
+        SpanCreationContext spanCreationContext = buildSpanCreationContext("span_name", Attributes.EMPTY, null);
+        Span span = defaultTracer.startSpan(spanCreationContext);
         SpanScope spanScope = defaultTracer.withSpanInScope(span);
         assertEquals("span_name", defaultTracer.getCurrentSpan().getSpan().getSpanName());
         assertEquals(spanScope, DefaultSpanScope.getCurrentSpanScope());
@@ -218,8 +241,8 @@ public void testEndSpanByClosingSpanScopeMultiple() {
             tracingTelemetry
         );
         DefaultTracer defaultTracer = new DefaultTracer(tracingTelemetry, spanTracerStorage);
-        Span span = defaultTracer.startSpan(new SpanCreationContext("span_name", Attributes.EMPTY));
-        Span span1 = defaultTracer.startSpan(new SpanCreationContext("span_name_1", Attributes.EMPTY));
+        Span span = defaultTracer.startSpan(buildSpanCreationContext("span_name", Attributes.EMPTY, null));
+        Span span1 = defaultTracer.startSpan(buildSpanCreationContext("span_name_1", Attributes.EMPTY, null));
         SpanScope spanScope = defaultTracer.withSpanInScope(span);
         SpanScope spanScope1 = defaultTracer.withSpanInScope(span1);
         assertEquals("span_name_1", defaultTracer.getCurrentSpan().getSpan().getSpanName());
@@ -261,11 +284,11 @@ public void testSpanAcrossThreads() {
 
         CompletableFuture<?> asyncTask = CompletableFuture.runAsync(() -> {
             // create a span
-            Span span = defaultTracer.startSpan(new SpanCreationContext("span_name_t_1", Attributes.EMPTY));
+            Span span = defaultTracer.startSpan(buildSpanCreationContext("span_name_t_1", Attributes.EMPTY, null));
             SpanScope spanScope = defaultTracer.withSpanInScope(span);
 
             CompletableFuture<?> asyncTask1 = CompletableFuture.runAsync(() -> {
-                Span spanT2 = defaultTracer.startSpan(new SpanCreationContext("span_name_t_2", Attributes.EMPTY));
+                Span spanT2 = defaultTracer.startSpan(buildSpanCreationContext("span_name_t_2", Attributes.EMPTY, null));
                 SpanScope spanScopeT2 = defaultTracer.withSpanInScope(spanT2);
                 assertEquals(spanT2, defaultTracer.getCurrentSpan().getSpan());
 
@@ -289,7 +312,7 @@ public void testSpanCloseOnThread2() {
             tracingTelemetry
         );
         DefaultTracer defaultTracer = new DefaultTracer(tracingTelemetry, spanTracerStorage);
-        final Span span = defaultTracer.startSpan(new SpanCreationContext("span_name_t1", Attributes.EMPTY));
+        final Span span = defaultTracer.startSpan(buildSpanCreationContext("span_name_t1", Attributes.EMPTY, null));
         try (SpanScope spanScope = defaultTracer.withSpanInScope(span)) {
             CompletableFuture<?> asyncTask = CompletableFuture.runAsync(() -> async(new ActionListener<Boolean>() {
                 @Override
@@ -337,16 +360,16 @@ public void testSpanAcrossThreadsMultipleSpans() {
 
         CompletableFuture<?> asyncTask = CompletableFuture.runAsync(() -> {
             // create a parent span
-            Span parentSpan = defaultTracer.startSpan(new SpanCreationContext("p_span_name", Attributes.EMPTY));
+            Span parentSpan = defaultTracer.startSpan(buildSpanCreationContext("p_span_name", Attributes.EMPTY, null));
             SpanScope parentSpanScope = defaultTracer.withSpanInScope(parentSpan);
             // create a span
-            Span span = defaultTracer.startSpan(new SpanCreationContext("span_name_t_1", Attributes.EMPTY));
+            Span span = defaultTracer.startSpan(buildSpanCreationContext("span_name_t_1", Attributes.EMPTY, null));
             SpanScope spanScope = defaultTracer.withSpanInScope(span);
 
             CompletableFuture<?> asyncTask1 = CompletableFuture.runAsync(() -> {
-                Span spanT2 = defaultTracer.startSpan(new SpanCreationContext("span_name_t_2", Attributes.EMPTY));
+                Span spanT2 = defaultTracer.startSpan(buildSpanCreationContext("span_name_t_2", Attributes.EMPTY, null));
                 SpanScope spanScopeT2 = defaultTracer.withSpanInScope(spanT2);
-                Span spanT21 = defaultTracer.startSpan(new SpanCreationContext("span_name_t_2", Attributes.EMPTY));
+                Span spanT21 = defaultTracer.startSpan(buildSpanCreationContext("span_name_t_2", Attributes.EMPTY, null));
                 SpanScope spanScopeT21 = defaultTracer.withSpanInScope(spanT21);
                 assertEquals(spanT21, defaultTracer.getCurrentSpan().getSpan());
                 spanScopeT21.close();
@@ -382,7 +405,6 @@ private void setupMocks() {
         mockTracingTelemetry = mock(TracingTelemetry.class);
         mockSpan = mock(Span.class);
         mockParentSpan = mock(Span.class);
-        mockSpanScope = mock(SpanScope.class);
         mockTracerContextStorage = mock(TracerContextStorage.class);
         when(mockSpan.getSpanName()).thenReturn("span_name");
         when(mockSpan.getSpanId()).thenReturn("span_id");
@@ -390,7 +412,16 @@ private void setupMocks() {
         when(mockSpan.getParentSpan()).thenReturn(mockParentSpan);
         when(mockParentSpan.getSpanId()).thenReturn("parent_span_id");
         when(mockParentSpan.getTraceId()).thenReturn("trace_id");
-        when(mockTracerContextStorage.get(TracerContextStorage.CURRENT_SPAN)).thenReturn(mockParentSpan, mockSpan);
-        when(mockTracingTelemetry.createSpan(eq("span_name"), eq(mockParentSpan), any(Attributes.class))).thenReturn(mockSpan);
+        spanCreationContext = buildSpanCreationContext("span_name", Attributes.EMPTY, mockParentSpan);
+        when(mockTracerContextStorage.get(TracerContextStorage.CURRENT_SPAN)).thenReturn(mockSpan, mockParentSpan);
+        when(mockTracingTelemetry.createSpan(eq(spanCreationContext), eq(mockParentSpan))).thenReturn(mockSpan);
+    }
+
+    private SpanCreationContext buildSpanCreationContext(String spanName, Attributes attributes, Span parentSpan) {
+        SpanCreationContext spanCreationContext = SpanCreationContext.internal().name(spanName).attributes(attributes);
+        if (parentSpan != null) {
+            spanCreationContext.parent(new SpanContext(parentSpan));
+        }
+        return spanCreationContext;
     }
 }
diff --git a/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/TraceableRunnableTests.java b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/TraceableRunnableTests.java
index a67d9b22ca738..4c4f762653d57 100644
--- a/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/TraceableRunnableTests.java
+++ b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/TraceableRunnableTests.java
@@ -34,9 +34,7 @@ public void testRunnableWithNullParent() throws Exception {
         final AtomicReference<String> attributeValue = new AtomicReference<>();
         TraceableRunnable traceableRunnable = new TraceableRunnable(
             defaultTracer,
-            spanName,
-            null,
-            Attributes.create().addAttribute("name", "value"),
+            SpanCreationContext.internal().name(spanName).attributes(Attributes.create().addAttribute("name", "value")),
             () -> {
                 spanNameCaptured.set(defaultTracer.getCurrentSpan().getSpan().getSpanName());
                 attributeValue.set((String) ((MockSpan) defaultTracer.getCurrentSpan().getSpan()).getAttribute("name"));
@@ -55,14 +53,23 @@ public void testRunnableWithParent() throws Exception {
         String spanName = "testRunnable";
         String parentSpanName = "parentSpan";
         DefaultTracer defaultTracer = new DefaultTracer(new MockTracingTelemetry(), contextStorage);
-        ScopedSpan scopedSpan = defaultTracer.startScopedSpan(new SpanCreationContext(parentSpanName, Attributes.EMPTY));
+        ScopedSpan scopedSpan = defaultTracer.startScopedSpan(
+            SpanCreationContext.internal().name(parentSpanName).attributes(Attributes.EMPTY)
+        );
         SpanContext parentSpanContext = defaultTracer.getCurrentSpan();
         AtomicReference<SpanContext> currentSpan = new AtomicReference<>();
         final AtomicBoolean isRunnableCompleted = new AtomicBoolean(false);
-        TraceableRunnable traceableRunnable = new TraceableRunnable(defaultTracer, spanName, parentSpanContext, Attributes.EMPTY, () -> {
-            isRunnableCompleted.set(true);
-            currentSpan.set(defaultTracer.getCurrentSpan());
-        });
+        TraceableRunnable traceableRunnable = new TraceableRunnable(
+            defaultTracer,
+            SpanCreationContext.internal()
+                .name(spanName)
+                .attributes(Attributes.create().addAttribute("name", "value"))
+                .parent(parentSpanContext),
+            () -> {
+                isRunnableCompleted.set(true);
+                currentSpan.set(defaultTracer.getCurrentSpan());
+            }
+        );
         traceableRunnable.run();
         assertTrue(isRunnableCompleted.get());
         assertEquals(spanName, currentSpan.get().getSpan().getSpanName());
diff --git a/libs/x-content/licenses/jackson-core-2.15.2.jar.sha1 b/libs/x-content/licenses/jackson-core-2.15.2.jar.sha1
deleted file mode 100644
index ec6781b968eed..0000000000000
--- a/libs/x-content/licenses/jackson-core-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-a6fe1836469a69b3ff66037c324d75fc66ef137c
\ No newline at end of file
diff --git a/libs/x-content/licenses/jackson-core-2.16.0.jar.sha1 b/libs/x-content/licenses/jackson-core-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..c2b70fb4ae202
--- /dev/null
+++ b/libs/x-content/licenses/jackson-core-2.16.0.jar.sha1
@@ -0,0 +1 @@
+899e5cf01be55fbf094ad72b2edb0c5df99111ee
\ No newline at end of file
diff --git a/libs/x-content/licenses/jackson-dataformat-cbor-2.15.2.jar.sha1 b/libs/x-content/licenses/jackson-dataformat-cbor-2.15.2.jar.sha1
deleted file mode 100644
index 0022265a84b68..0000000000000
--- a/libs/x-content/licenses/jackson-dataformat-cbor-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-baafc85c70765594add14bd93f3efd68e1945b76
\ No newline at end of file
diff --git a/libs/x-content/licenses/jackson-dataformat-cbor-2.16.0.jar.sha1 b/libs/x-content/licenses/jackson-dataformat-cbor-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..8da478fc6013d
--- /dev/null
+++ b/libs/x-content/licenses/jackson-dataformat-cbor-2.16.0.jar.sha1
@@ -0,0 +1 @@
+35e8b7bf4fc1d078766bb155103d433ed5bb1627
\ No newline at end of file
diff --git a/libs/x-content/licenses/jackson-dataformat-smile-2.15.2.jar.sha1 b/libs/x-content/licenses/jackson-dataformat-smile-2.15.2.jar.sha1
deleted file mode 100644
index 2b8caad846fec..0000000000000
--- a/libs/x-content/licenses/jackson-dataformat-smile-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-16d1dd22f7d641459ed056399d4f7df0220f1176
\ No newline at end of file
diff --git a/libs/x-content/licenses/jackson-dataformat-smile-2.16.0.jar.sha1 b/libs/x-content/licenses/jackson-dataformat-smile-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..3e952ffe92418
--- /dev/null
+++ b/libs/x-content/licenses/jackson-dataformat-smile-2.16.0.jar.sha1
@@ -0,0 +1 @@
+3c422d7f3901c9a1becf9df3cf41efc68a5ab95c
\ No newline at end of file
diff --git a/libs/x-content/licenses/jackson-dataformat-yaml-2.15.2.jar.sha1 b/libs/x-content/licenses/jackson-dataformat-yaml-2.15.2.jar.sha1
deleted file mode 100644
index 4ad7255e2318f..0000000000000
--- a/libs/x-content/licenses/jackson-dataformat-yaml-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-58194ff9f51915ad6bf6b6f24818232d7566418a
\ No newline at end of file
diff --git a/libs/x-content/licenses/jackson-dataformat-yaml-2.16.0.jar.sha1 b/libs/x-content/licenses/jackson-dataformat-yaml-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..d62b5874ab023
--- /dev/null
+++ b/libs/x-content/licenses/jackson-dataformat-yaml-2.16.0.jar.sha1
@@ -0,0 +1 @@
+2033e2c5f531785d17f3a2bc31842e3bbb7983b2
\ No newline at end of file
diff --git a/libs/x-content/src/main/java/org/opensearch/common/xcontent/XContentType.java b/libs/x-content/src/main/java/org/opensearch/common/xcontent/XContentType.java
index 9d1581a3a1517..453107fe4ff65 100644
--- a/libs/x-content/src/main/java/org/opensearch/common/xcontent/XContentType.java
+++ b/libs/x-content/src/main/java/org/opensearch/common/xcontent/XContentType.java
@@ -35,6 +35,7 @@
 import com.fasterxml.jackson.dataformat.cbor.CBORConstants;
 import com.fasterxml.jackson.dataformat.smile.SmileConstants;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.cbor.CborXContent;
 import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.common.xcontent.smile.SmileXContent;
@@ -49,7 +50,9 @@
 
 /**
  * The content type of {@link XContent}.
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum XContentType implements MediaType {
 
     /**
diff --git a/libs/x-content/src/test/java/org/opensearch/common/xcontent/XContentParserTests.java b/libs/x-content/src/test/java/org/opensearch/common/xcontent/XContentParserTests.java
index 3b857a2c690b9..d3d9ea174cf1b 100644
--- a/libs/x-content/src/test/java/org/opensearch/common/xcontent/XContentParserTests.java
+++ b/libs/x-content/src/test/java/org/opensearch/common/xcontent/XContentParserTests.java
@@ -628,7 +628,7 @@ public void testCreateRootSubParser() throws IOException {
 
     /**
      * Generates a random object {"first_field": "foo", "marked_field": {...random...}, "last_field": "bar}
-     *
+     * <p>
      * Returns the number of tokens in the marked field
      */
     private static int generateRandomObjectForMarking(XContentBuilder builder) throws IOException {
diff --git a/modules/aggs-matrix-stats/src/main/java/org/opensearch/search/aggregations/matrix/stats/RunningStats.java b/modules/aggs-matrix-stats/src/main/java/org/opensearch/search/aggregations/matrix/stats/RunningStats.java
index de67cc2930652..de6b59b1546a5 100644
--- a/modules/aggs-matrix-stats/src/main/java/org/opensearch/search/aggregations/matrix/stats/RunningStats.java
+++ b/modules/aggs-matrix-stats/src/main/java/org/opensearch/search/aggregations/matrix/stats/RunningStats.java
@@ -46,7 +46,7 @@
 /**
  * Descriptive stats gathered per shard. Coordinating node computes final correlation and covariance stats
  * based on these descriptive stats. This single pass, parallel approach is based on:
- *
+ * <p>
  * http://prod.sandia.gov/techlib/access-control.cgi/2008/086212.pdf
  */
 public class RunningStats implements Writeable, Cloneable {
@@ -222,7 +222,7 @@ private void updateCovariance(final String[] fieldNames, final Map<String, Doubl
 
     /**
      * Merges the descriptive statistics of a second data set (e.g., per shard)
-     *
+     * <p>
      * running computations taken from: http://prod.sandia.gov/techlib/access-control.cgi/2008/086212.pdf
      **/
     public void merge(final RunningStats other) {
diff --git a/modules/analysis-common/src/internalClusterTest/java/org/opensearch/analysis/common/QueryStringWithAnalyzersIT.java b/modules/analysis-common/src/internalClusterTest/java/org/opensearch/analysis/common/QueryStringWithAnalyzersIT.java
index 785e597857825..71af708f2e1dc 100644
--- a/modules/analysis-common/src/internalClusterTest/java/org/opensearch/analysis/common/QueryStringWithAnalyzersIT.java
+++ b/modules/analysis-common/src/internalClusterTest/java/org/opensearch/analysis/common/QueryStringWithAnalyzersIT.java
@@ -32,20 +32,42 @@
 
 package org.opensearch.analysis.common;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.Operator;
 import org.opensearch.plugins.Plugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.Arrays;
 import java.util.Collection;
 
 import static org.opensearch.index.query.QueryBuilders.queryStringQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 
-public class QueryStringWithAnalyzersIT extends OpenSearchIntegTestCase {
+public class QueryStringWithAnalyzersIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public QueryStringWithAnalyzersIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(CommonAnalysisModulePlugin.class);
diff --git a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java
index b0d9c1765190a..cf2736a8583d2 100644
--- a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java
+++ b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java
@@ -394,7 +394,17 @@ public Map<String, AnalysisProvider<TokenizerFactory>> getTokenizers() {
         // TODO deprecate and remove in API
         tokenizers.put("lowercase", XLowerCaseTokenizerFactory::new);
         tokenizers.put("path_hierarchy", PathHierarchyTokenizerFactory::new);
-        tokenizers.put("PathHierarchy", PathHierarchyTokenizerFactory::new);
+        tokenizers.put("PathHierarchy", (IndexSettings indexSettings, Environment environment, String name, Settings settings) -> {
+            // TODO Remove "PathHierarchy" tokenizer name in 4.0 and throw exception
+            if (indexSettings.getIndexVersionCreated().onOrAfter(Version.V_3_0_0)) {
+                deprecationLogger.deprecate(
+                    "PathHierarchy_tokenizer_deprecation",
+                    "The [PathHierarchy] tokenizer name is deprecated and will be removed in a future version. "
+                        + "Please change the tokenizer name to [path_hierarchy] instead."
+                );
+            }
+            return new PathHierarchyTokenizerFactory(indexSettings, environment, name, settings);
+        });
         tokenizers.put("pattern", PatternTokenizerFactory::new);
         tokenizers.put("uax_url_email", UAX29URLEmailTokenizerFactory::new);
         tokenizers.put("whitespace", WhitespaceTokenizerFactory::new);
@@ -555,7 +565,7 @@ public List<PreConfiguredTokenFilter> getPreConfiguredTokenFilters() {
         filters.add(PreConfiguredTokenFilter.singleton("scandinavian_normalization", true, ScandinavianNormalizationFilter::new));
         filters.add(PreConfiguredTokenFilter.singleton("shingle", false, false, input -> {
             TokenStream ts = new ShingleFilter(input);
-            /**
+            /*
              * We disable the graph analysis on this token stream
              * because it produces shingles of different size.
              * Graph analysis on such token stream is useless and dangerous as it may create too many paths
@@ -662,8 +672,17 @@ public List<PreConfiguredTokenizer> getPreConfiguredTokenizers() {
             }
             return new EdgeNGramTokenizer(NGramTokenizer.DEFAULT_MIN_NGRAM_SIZE, NGramTokenizer.DEFAULT_MAX_NGRAM_SIZE);
         }));
-        tokenizers.add(PreConfiguredTokenizer.singleton("PathHierarchy", PathHierarchyTokenizer::new));
-
+        tokenizers.add(PreConfiguredTokenizer.openSearchVersion("PathHierarchy", (version) -> {
+            // TODO Remove "PathHierarchy" tokenizer name in 4.0 and throw exception
+            if (version.onOrAfter(Version.V_3_0_0)) {
+                deprecationLogger.deprecate(
+                    "PathHierarchy_tokenizer_deprecation",
+                    "The [PathHierarchy] tokenizer name is deprecated and will be removed in a future version. "
+                        + "Please change the tokenizer name to [path_hierarchy] instead."
+                );
+            }
+            return new PathHierarchyTokenizer();
+        }));
         return tokenizers;
     }
 }
diff --git a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/KeywordMarkerTokenFilterFactory.java b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/KeywordMarkerTokenFilterFactory.java
index ad968aeee62cb..e9f3fd96dd69d 100644
--- a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/KeywordMarkerTokenFilterFactory.java
+++ b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/KeywordMarkerTokenFilterFactory.java
@@ -49,12 +49,12 @@
  * A factory for creating keyword marker token filters that prevent tokens from
  * being modified by stemmers.  Two types of keyword marker filters are available:
  * the {@link SetKeywordMarkerFilter} and the {@link PatternKeywordMarkerFilter}.
- *
+ * <p>
  * The {@link SetKeywordMarkerFilter} uses a set of keywords to denote which tokens
  * should be excluded from stemming.  This filter is created if the settings include
  * {@code keywords}, which contains the list of keywords, or {@code `keywords_path`},
  * which contains a path to a file in the config directory with the keywords.
- *
+ * <p>
  * The {@link PatternKeywordMarkerFilter} uses a regular expression pattern to match
  * against tokens that should be excluded from stemming.  This filter is created if
  * the settings include {@code keywords_pattern}, which contains the regular expression
diff --git a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/MappingCharFilterFactory.java b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/MappingCharFilterFactory.java
index bd241de749f11..d6d9f8975f2fc 100644
--- a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/MappingCharFilterFactory.java
+++ b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/MappingCharFilterFactory.java
@@ -54,7 +54,7 @@ public class MappingCharFilterFactory extends AbstractCharFilterFactory implemen
     MappingCharFilterFactory(IndexSettings indexSettings, Environment env, String name, Settings settings) {
         super(indexSettings, name);
 
-        List<MappingRule<String, String>> rules = Analysis.parseWordList(env, settings, "mappings", this::parse, false);
+        List<MappingRule<String, String>> rules = Analysis.parseWordList(env, settings, "mappings", this::parse);
         if (rules == null) {
             throw new IllegalArgumentException("mapping requires either `mappings` or `mappings_path` to be configured");
         }
diff --git a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/SnowballAnalyzer.java b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/SnowballAnalyzer.java
index 78d151ee16c3b..04786689b50f0 100644
--- a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/SnowballAnalyzer.java
+++ b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/SnowballAnalyzer.java
@@ -45,7 +45,7 @@
 
 /** Filters {@link StandardTokenizer} with {@link
  * LowerCaseFilter}, {@link StopFilter} and {@link SnowballFilter}.
- *
+ * <p>
  * Available stemmers are listed in org.tartarus.snowball.ext.  The name of a
  * stemmer is the part of the class name before "Stemmer", e.g., the stemmer in
  * {@link org.tartarus.snowball.ext.EnglishStemmer} is named "English".
diff --git a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/BaseWordDelimiterTokenFilterFactoryTestCase.java b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/BaseWordDelimiterTokenFilterFactoryTestCase.java
index 94c7d63f2bee7..f37d5862b9d3f 100644
--- a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/BaseWordDelimiterTokenFilterFactoryTestCase.java
+++ b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/BaseWordDelimiterTokenFilterFactoryTestCase.java
@@ -211,8 +211,8 @@ private void createTokenFilterFactoryWithTypeTable(String[] rules) throws IOExce
     }
 
     public void testTypeTableParsingError() {
-        String[] rules = { "# This is a comment", "$ => DIGIT", "\\u200D => ALPHANUM", "abc => ALPHA" };
+        String[] rules = { "# This is a comment", "# => ALPHANUM", "$ => DIGIT", "\\u200D => ALPHANUM", "abc => ALPHA" };
         RuntimeException ex = expectThrows(RuntimeException.class, () -> createTokenFilterFactoryWithTypeTable(rules));
-        assertEquals("Line [4]: Invalid mapping rule: [abc => ALPHA]. Only a single character is allowed.", ex.getMessage());
+        assertEquals("Line [5]: Invalid mapping rule: [abc => ALPHA]. Only a single character is allowed.", ex.getMessage());
     }
 }
diff --git a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/HighlighterWithAnalyzersTests.java b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/HighlighterWithAnalyzersTests.java
index 46e57faec3a69..26f4acb2b1e6a 100644
--- a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/HighlighterWithAnalyzersTests.java
+++ b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/HighlighterWithAnalyzersTests.java
@@ -32,8 +32,11 @@
 
 package org.opensearch.analysis.common;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexSettings;
@@ -41,7 +44,7 @@
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.builder.SearchSourceBuilder;
 import org.opensearch.search.fetch.subphase.highlight.HighlightBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.Arrays;
@@ -55,6 +58,7 @@
 import static org.opensearch.index.query.QueryBuilders.matchPhraseQuery;
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.builder.SearchSourceBuilder.highlight;
 import static org.opensearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
@@ -64,7 +68,25 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.startsWith;
 
-public class HighlighterWithAnalyzersTests extends OpenSearchIntegTestCase {
+public class HighlighterWithAnalyzersTests extends ParameterizedOpenSearchIntegTestCase {
+
+    public HighlighterWithAnalyzersTests(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(CommonAnalysisModulePlugin.class);
diff --git a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/MappingCharFilterFactoryTests.java b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/MappingCharFilterFactoryTests.java
index 387eb4a377007..28e041ac8c92d 100644
--- a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/MappingCharFilterFactoryTests.java
+++ b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/MappingCharFilterFactoryTests.java
@@ -37,6 +37,7 @@ public static CharFilterFactory create(String... rules) throws IOException {
 
     public void testRulesOk() throws IOException {
         MappingCharFilterFactory mappingCharFilterFactory = (MappingCharFilterFactory) create(
+            "# This is a comment",
             "# => _hashtag_",
             ":) => _happy_",
             ":( => _sad_"
@@ -64,7 +65,10 @@ public void testRuleError() {
     }
 
     public void testRulePartError() {
-        RuntimeException ex = expectThrows(RuntimeException.class, () -> create("# => _hashtag_", ":) => _happy_", "a:b"));
-        assertEquals("Line [3]: Invalid mapping rule : [a:b]", ex.getMessage());
+        RuntimeException ex = expectThrows(
+            RuntimeException.class,
+            () -> create("# This is a comment", "# => _hashtag_", ":) => _happy_", "a:b")
+        );
+        assertEquals("Line [4]: Invalid mapping rule : [a:b]", ex.getMessage());
     }
 }
diff --git a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/PathHierarchyTokenizerFactoryTests.java b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/PathHierarchyTokenizerFactoryTests.java
index 1fe7c582449ec..555d6c78b6ec5 100644
--- a/modules/analysis-common/src/test/java/org/opensearch/analysis/common/PathHierarchyTokenizerFactoryTests.java
+++ b/modules/analysis-common/src/test/java/org/opensearch/analysis/common/PathHierarchyTokenizerFactoryTests.java
@@ -35,16 +35,61 @@
 import com.carrotsearch.randomizedtesting.generators.RandomPicks;
 
 import org.apache.lucene.analysis.Tokenizer;
+import org.opensearch.Version;
+import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.index.Index;
+import org.opensearch.env.Environment;
+import org.opensearch.env.TestEnvironment;
+import org.opensearch.index.IndexSettings;
+import org.opensearch.index.analysis.IndexAnalyzers;
+import org.opensearch.index.analysis.NamedAnalyzer;
+import org.opensearch.indices.analysis.AnalysisModule;
 import org.opensearch.test.IndexSettingsModule;
 import org.opensearch.test.OpenSearchTokenStreamTestCase;
+import org.opensearch.test.VersionUtils;
 
 import java.io.IOException;
 import java.io.StringReader;
+import java.util.Collections;
 
 public class PathHierarchyTokenizerFactoryTests extends OpenSearchTokenStreamTestCase {
 
+    private IndexAnalyzers buildAnalyzers(Version version, String tokenizer) throws IOException {
+        Settings settings = Settings.builder().put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toString()).build();
+        Settings indexSettings = Settings.builder()
+            .put(IndexMetadata.SETTING_VERSION_CREATED, version)
+            .put("index.analysis.analyzer.my_analyzer.tokenizer", tokenizer)
+            .build();
+        IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("index", indexSettings);
+        return new AnalysisModule(TestEnvironment.newEnvironment(settings), Collections.singletonList(new CommonAnalysisModulePlugin()))
+            .getAnalysisRegistry()
+            .build(idxSettings);
+    }
+
+    /**
+     * Test that deprecated "PathHierarchy" tokenizer name is still available via {@link CommonAnalysisModulePlugin} starting in 3.x.
+     */
+    public void testPreConfiguredTokenizer() throws IOException {
+
+        {
+            try (
+                IndexAnalyzers indexAnalyzers = buildAnalyzers(
+                    VersionUtils.randomVersionBetween(random(), Version.V_3_0_0, Version.CURRENT),
+                    "PathHierarchy"
+                )
+            ) {
+                NamedAnalyzer analyzer = indexAnalyzers.get("my_analyzer");
+                assertNotNull(analyzer);
+                assertTokenStreamContents(analyzer.tokenStream("dummy", "/a/b/c"), new String[] { "/a", "/a/b", "/a/b/c" });
+                // Once LUCENE-12750 is fixed we can use the following testing method instead.
+                // Similar testing approach has been used for deprecation of (Edge)NGrams tokenizers as well.
+                // assertAnalyzesTo(analyzer, "/a/b/c", new String[] { "/a", "/a/b", "/a/b/c" });
+
+            }
+        }
+    }
+
     public void testDefaults() throws IOException {
         final Index index = new Index("test", "_na_");
         final Settings indexSettings = newAnalysisSettingsBuilder().build();
diff --git a/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/30_tokenizers.yml b/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/30_tokenizers.yml
index 56ed2175df60a..179de835a4105 100644
--- a/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/30_tokenizers.yml
+++ b/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/30_tokenizers.yml
@@ -298,6 +298,9 @@
 
 ---
 "path_hierarchy":
+    - skip:
+        features: "allowed_warnings"
+
     - do:
         indices.analyze:
           body:
@@ -312,6 +315,8 @@
     - match:  { detail.tokenizer.tokens.2.token: a/b/c }
 
     - do:
+        allowed_warnings:
+          - 'The [PathHierarchy] tokenizer name is deprecated and will be removed in a future version. Please change the tokenizer name to [path_hierarchy] instead.'
         indices.analyze:
           body:
             text: "a/b/c"
@@ -337,11 +342,13 @@
     - match:  { detail.tokenizer.tokens.2.token: a/b/c }
 
     - do:
+        allowed_warnings:
+          - 'The [PathHierarchy] tokenizer name is deprecated and will be removed in a future version. Please change the tokenizer name to [path_hierarchy] instead.'
         indices.analyze:
           body:
             text: "a/b/c"
             explain: true
-            tokenizer:  PathHierarchy
+            tokenizer: PathHierarchy
     - length: { detail.tokenizer.tokens: 3 }
     - match:  { detail.tokenizer.name: PathHierarchy }
     - match:  { detail.tokenizer.tokens.0.token: a }
diff --git a/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/40_token_filters.yml b/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/40_token_filters.yml
index e92cc0c4838c7..802c79c780689 100644
--- a/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/40_token_filters.yml
+++ b/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/40_token_filters.yml
@@ -127,6 +127,69 @@
     - match:  { tokens.2.token: brown }
     - match:  { tokens.3.token: fox }
 
+    - do:
+        indices.analyze:
+          body:
+            text: 'text1 #text2'
+            tokenizer: whitespace
+            filter:
+              - type: word_delimiter
+                split_on_numerics: false
+                type_table:
+                  - "\\u0023 => ALPHANUM"
+    - length: { tokens: 2 }
+    - match: { tokens.0.token: text1 }
+    - match: { tokens.0.start_offset: 0 }
+    - match: { tokens.0.end_offset: 5 }
+    - match: { tokens.0.position: 0 }
+    - match: { tokens.1.token: "#text2" }
+    - match: { tokens.1.start_offset: 6 }
+    - match: { tokens.1.end_offset: 12 }
+    - match: { tokens.1.position: 1 }
+
+    - do:
+        indices.analyze:
+          body:
+            text: 'text1 #text2'
+            tokenizer: whitespace
+            filter:
+              - type: word_delimiter
+                split_on_numerics: false
+                type_table:
+                  - "# This is a comment"
+                  - "# => ALPHANUM"
+    - length: { tokens: 2 }
+    - match: { tokens.0.token: text1 }
+    - match: { tokens.0.start_offset: 0 }
+    - match: { tokens.0.end_offset: 5 }
+    - match: { tokens.0.position: 0 }
+    - match: { tokens.1.token: "#text2" }
+    - match: { tokens.1.start_offset: 6 }
+    - match: { tokens.1.end_offset: 12 }
+    - match: { tokens.1.position: 1 }
+
+    - do:
+        indices.analyze:
+          body:
+            text: 'text1 #text2'
+            tokenizer: whitespace
+            filter:
+              - type: word_delimiter
+                split_on_numerics: false
+                type_table:
+                  - "# This is a comment"
+                  - "# => ALPHANUM"
+                  - "@ => ALPHANUM"
+    - length: { tokens: 2 }
+    - match: { tokens.0.token: text1 }
+    - match: { tokens.0.start_offset: 0 }
+    - match: { tokens.0.end_offset: 5 }
+    - match: { tokens.0.position: 0 }
+    - match: { tokens.1.token: "#text2" }
+    - match: { tokens.1.start_offset: 6 }
+    - match: { tokens.1.end_offset: 12 }
+    - match: { tokens.1.position: 1 }
+
 ---
 "word_delimiter_graph":
     - do:
@@ -231,6 +294,69 @@
     - match:  { detail.tokenfilters.0.tokens.5.end_offset: 19 }
     - match:  { detail.tokenfilters.0.tokens.5.position: 5 }
 
+    - do:
+        indices.analyze:
+          body:
+            text: 'text1 #text2'
+            tokenizer: whitespace
+            filter:
+              - type: word_delimiter_graph
+                split_on_numerics: false
+                type_table:
+                  - "\\u0023 => ALPHANUM"
+    - length: { tokens: 2 }
+    - match: { tokens.0.token: text1 }
+    - match: { tokens.0.start_offset: 0 }
+    - match: { tokens.0.end_offset: 5 }
+    - match: { tokens.0.position: 0 }
+    - match: { tokens.1.token: "#text2" }
+    - match: { tokens.1.start_offset: 6 }
+    - match: { tokens.1.end_offset: 12 }
+    - match: { tokens.1.position: 1 }
+
+    - do:
+        indices.analyze:
+          body:
+            text: 'text1 #text2'
+            tokenizer: whitespace
+            filter:
+              - type: word_delimiter_graph
+                split_on_numerics: false
+                type_table:
+                  - "# This is a comment"
+                  - "# => ALPHANUM"
+    - length: { tokens: 2 }
+    - match: { tokens.0.token: text1 }
+    - match: { tokens.0.start_offset: 0 }
+    - match: { tokens.0.end_offset: 5 }
+    - match: { tokens.0.position: 0 }
+    - match: { tokens.1.token: "#text2" }
+    - match: { tokens.1.start_offset: 6 }
+    - match: { tokens.1.end_offset: 12 }
+    - match: { tokens.1.position: 1 }
+
+    - do:
+        indices.analyze:
+          body:
+            text: 'text1 #text2'
+            tokenizer: whitespace
+            filter:
+              - type: word_delimiter_graph
+                split_on_numerics: false
+                type_table:
+                  - "# This is a comment"
+                  - "# => ALPHANUM"
+                  - "@ => ALPHANUM"
+    - length: { tokens: 2 }
+    - match: { tokens.0.token: text1 }
+    - match: { tokens.0.start_offset: 0 }
+    - match: { tokens.0.end_offset: 5 }
+    - match: { tokens.0.position: 0 }
+    - match: { tokens.1.token: "#text2" }
+    - match: { tokens.1.start_offset: 6 }
+    - match: { tokens.1.end_offset: 12 }
+    - match: { tokens.1.position: 1 }
+
 ---
 "unique":
     - do:
diff --git a/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/50_char_filters.yml b/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/50_char_filters.yml
index 0078575ae8e57..5e266c10cba8f 100644
--- a/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/50_char_filters.yml
+++ b/modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/50_char_filters.yml
@@ -69,6 +69,7 @@
           char_filter:
             - type: mapping
               mappings:
+                - "# This is a comment"
                 - "# => _hashsign_"
                 - "@ => _atsign_"
   - length: { tokens: 3 }
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/GeoModulePluginIntegTestCase.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/GeoModulePluginIntegTestCase.java
index b17f4804d4d50..c38b29502e282 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/GeoModulePluginIntegTestCase.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/GeoModulePluginIntegTestCase.java
@@ -8,26 +8,50 @@
 
 package org.opensearch.geo;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.geometry.utils.StandardValidator;
 import org.opensearch.geometry.utils.WellKnownText;
 import org.opensearch.index.mapper.GeoShapeFieldMapper;
 import org.opensearch.plugins.Plugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.TestGeoShapeFieldMapperPlugin;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
+
 /**
  * This is the base class for all the Geo related integration tests. Use this class to add the features and settings
  * for the test cluster on which integration tests are running.
  */
-public abstract class GeoModulePluginIntegTestCase extends OpenSearchIntegTestCase {
+public abstract class GeoModulePluginIntegTestCase extends ParameterizedOpenSearchIntegTestCase {
 
     protected static final double GEOHASH_TOLERANCE = 1E-5D;
 
     protected static final WellKnownText WKT = new WellKnownText(true, new StandardValidator(true));
 
+    public GeoModulePluginIntegTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     /**
      * Returns a collection of plugins that should be loaded on each node for doing the integration tests. As this
      * geo plugin is not getting packaged in a zip, we need to load it before the tests run.
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/MissingValueIT.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/MissingValueIT.java
index a9dd7d1fd22e7..7344903fd5220 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/MissingValueIT.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/MissingValueIT.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.geo.GeoPoint;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.geo.GeoModulePluginIntegTestCase;
 import org.opensearch.geo.search.aggregations.common.GeoBoundsHelper;
 import org.opensearch.geo.search.aggregations.metrics.GeoBounds;
@@ -43,6 +44,10 @@ public class MissingValueIT extends GeoModulePluginIntegTestCase {
     private GeoPoint bottomRight;
     private GeoPoint topLeft;
 
+    public MissingValueIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected void setupSuiteScopeCluster() throws Exception {
         assertAcked(
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java
index d9ff3e8f473ef..7316847ac6046 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java
@@ -67,6 +67,10 @@ public abstract class AbstractGeoBucketAggregationIntegTest extends GeoModulePlu
 
     protected final Version version = VersionUtils.randomIndexCompatibleVersion(random());
 
+    public AbstractGeoBucketAggregationIntegTest(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected boolean forbidPrivateIndexSettings() {
         return false;
@@ -83,7 +87,7 @@ protected boolean forbidPrivateIndexSettings() {
      */
     protected void prepareGeoShapeIndexForAggregations(final Random random) throws Exception {
         expectedDocsCountForGeoShapes = new HashMap<>();
-        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
+        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build();
         final List<IndexRequestBuilder> geoshapes = new ArrayList<>();
         assertAcked(prepareCreate(GEO_SHAPE_INDEX_NAME).setSettings(settings).setMapping(GEO_SHAPE_FIELD_NAME, "type" + "=geo_shape"));
         boolean isShapeIntersectingBB = false;
@@ -132,7 +136,7 @@ protected void prepareSingleValueGeoPointIndex(final Random random) throws Excep
         expectedDocCountsForSingleGeoPoint = new HashMap<>();
         createIndex("idx_unmapped");
         final Settings settings = Settings.builder()
-            .put(IndexMetadata.SETTING_VERSION_CREATED, version)
+            .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
             .put("index.number_of_shards", 4)
             .put("index.number_of_replicas", 0)
             .build();
@@ -156,7 +160,7 @@ protected void prepareSingleValueGeoPointIndex(final Random random) throws Excep
 
     protected void prepareMultiValuedGeoPointIndex(final Random random) throws Exception {
         multiValuedExpectedDocCountsGeoPoint = new HashMap<>();
-        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
+        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build();
         final List<IndexRequestBuilder> cities = new ArrayList<>();
         assertAcked(
             prepareCreate("multi_valued_idx").setSettings(settings)
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoHashGridIT.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoHashGridIT.java
index 459a0986d3103..4048bb62f8818 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoHashGridIT.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoHashGridIT.java
@@ -35,6 +35,7 @@
 import org.opensearch.common.geo.GeoBoundingBox;
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.geo.GeoShapeDocValue;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.geo.search.aggregations.bucket.geogrid.GeoGrid;
 import org.opensearch.geo.search.aggregations.bucket.geogrid.GeoGridAggregationBuilder;
 import org.opensearch.geo.search.aggregations.common.GeoBoundsHelper;
@@ -64,6 +65,10 @@ public class GeoHashGridIT extends AbstractGeoBucketAggregationIntegTest {
 
     private static final String AGG_NAME = "geohashgrid";
 
+    public GeoHashGridIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         Random random = random();
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoTileGridIT.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoTileGridIT.java
index 6b09a843af566..2a5772d417530 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoTileGridIT.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/GeoTileGridIT.java
@@ -12,6 +12,7 @@
 import org.opensearch.common.geo.GeoBoundingBox;
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.geo.GeoShapeDocValue;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.geo.search.aggregations.bucket.geogrid.GeoGrid;
 import org.opensearch.geo.search.aggregations.bucket.geogrid.GeoGridAggregationBuilder;
 import org.opensearch.geo.search.aggregations.common.GeoBoundsHelper;
@@ -38,6 +39,10 @@ public class GeoTileGridIT extends AbstractGeoBucketAggregationIntegTest {
 
     private static final String AGG_NAME = "geotilegrid";
 
+    public GeoTileGridIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         final Random random = random();
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/ShardReduceIT.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/ShardReduceIT.java
index d22d2089a3ae3..85541c60f133c 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/ShardReduceIT.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/ShardReduceIT.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.geo.GeoModulePluginIntegTestCase;
 import org.opensearch.geo.search.aggregations.bucket.geogrid.GeoGrid;
 import org.opensearch.geo.tests.common.AggregationBuilders;
@@ -34,6 +35,10 @@
 @OpenSearchIntegTestCase.SuiteScopeTestCase
 public class ShardReduceIT extends GeoModulePluginIntegTestCase {
 
+    public ShardReduceIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     private IndexRequestBuilder indexDoc(String date, int value) throws Exception {
         return client().prepareIndex("idx")
             .setSource(
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/AbstractGeoAggregatorModulePluginTestCase.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/AbstractGeoAggregatorModulePluginTestCase.java
index d76104882d676..711744b944ce3 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/AbstractGeoAggregatorModulePluginTestCase.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/AbstractGeoAggregatorModulePluginTestCase.java
@@ -65,6 +65,10 @@ public abstract class AbstractGeoAggregatorModulePluginTestCase extends GeoModul
     protected static Map<String, Integer> expectedDocCountsForGeoHash = null;
     protected static Map<String, GeoPoint> expectedCentroidsForGeoHash = null;
 
+    public AbstractGeoAggregatorModulePluginTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex(UNMAPPED_IDX_NAME);
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoBoundsITTestCase.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoBoundsITTestCase.java
index d95cd85b49cd4..1c28df6bc4ea2 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoBoundsITTestCase.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoBoundsITTestCase.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.geo.GeoPoint;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.util.BigArray;
 import org.opensearch.search.aggregations.InternalAggregation;
 import org.opensearch.search.aggregations.bucket.global.Global;
@@ -61,6 +62,10 @@
 public class GeoBoundsITTestCase extends AbstractGeoAggregatorModulePluginTestCase {
     private static final String aggName = "geoBounds";
 
+    public GeoBoundsITTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     public void testSingleValuedField() throws Exception {
         SearchResponse response = client().prepareSearch(IDX_NAME)
             .addAggregation(geoBounds(aggName).field(SINGLE_VALUED_FIELD_NAME).wrapLongitude(false))
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoCentroidITTestCase.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoCentroidITTestCase.java
index 01d2656adb750..2dc8a91600419 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoCentroidITTestCase.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/metrics/GeoCentroidITTestCase.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.geo.GeoPoint;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.geo.search.aggregations.bucket.geogrid.GeoGrid;
 import org.opensearch.geo.tests.common.AggregationBuilders;
 import org.opensearch.search.aggregations.metrics.GeoCentroid;
@@ -51,6 +52,10 @@
 public class GeoCentroidITTestCase extends AbstractGeoAggregatorModulePluginTestCase {
     private static final String aggName = "geoCentroid";
 
+    public GeoCentroidITTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     public void testSingleValueFieldAsSubAggToGeohashGrid() throws Exception {
         SearchResponse response = client().prepareSearch(HIGH_CARD_IDX_NAME)
             .addAggregation(
diff --git a/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/composite/GeoTileValuesSource.java b/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/composite/GeoTileValuesSource.java
index 9149b8939b739..665ea6c5f2f37 100644
--- a/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/composite/GeoTileValuesSource.java
+++ b/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/composite/GeoTileValuesSource.java
@@ -48,7 +48,7 @@
 
 /**
  * A {@link SingleDimensionValuesSource} for geotile values.
- *
+ * <p>
  * Since geotile values can be represented as long values, this class is almost the same as {@link LongValuesSource}
  * The main differences is {@link GeoTileValuesSource#setAfter(Comparable)} as it needs to accept geotile string values i.e. "zoom/x/y".
  *
diff --git a/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/geogrid/cells/BoundedCellValues.java b/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/geogrid/cells/BoundedCellValues.java
index 588c8bc59c2e0..6ff38fa28978e 100644
--- a/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/geogrid/cells/BoundedCellValues.java
+++ b/modules/geo/src/main/java/org/opensearch/geo/search/aggregations/bucket/geogrid/cells/BoundedCellValues.java
@@ -37,7 +37,7 @@
 /**
  * Class representing {@link CellValues} whose values are filtered
  * according to whether they are within the specified {@link GeoBoundingBox}.
- *
+ * <p>
  * The specified bounding box is assumed to be bounded.
  *
  * @opensearch.internal
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java
index 39c2d67ac0b85..0eab6334854ab 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java
@@ -118,25 +118,15 @@ public Processor create(
         ) throws Exception {
             String field = ConfigurationUtils.readStringProperty(TYPE, tag, config, "field");
             if (field.contains(".") == false) {
-                throw ConfigurationUtils.newConfigurationException(
-                    ConfigurationUtils.TAG_KEY,
-                    tag,
-                    "field",
-                    "field does not contain a dot"
-                );
+                throw ConfigurationUtils.newConfigurationException(TYPE, tag, "field", "field does not contain a dot");
             }
             if (field.indexOf('.') == 0 || field.lastIndexOf('.') == field.length() - 1) {
-                throw ConfigurationUtils.newConfigurationException(
-                    ConfigurationUtils.TAG_KEY,
-                    tag,
-                    "field",
-                    "Field can't start or end with a dot"
-                );
+                throw ConfigurationUtils.newConfigurationException(TYPE, tag, "field", "Field can't start or end with a dot");
             }
             int firstIndex = -1;
             for (int index = field.indexOf('.'); index != -1; index = field.indexOf('.', index + 1)) {
                 if (index - firstIndex == 1) {
-                    throw ConfigurationUtils.newConfigurationException(ConfigurationUtils.TAG_KEY, tag, "field", "No space between dots");
+                    throw ConfigurationUtils.newConfigurationException(TYPE, tag, "field", "No space between dots");
                 }
                 firstIndex = index;
             }
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/FailProcessorException.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/FailProcessorException.java
index 37320c0e900a5..7e114023fb86f 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/FailProcessorException.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/FailProcessorException.java
@@ -37,7 +37,7 @@
 
 /**
  * Exception class thrown by {@link FailProcessor}.
- *
+ * <p>
  * This exception is caught in the {@link CompoundProcessor} and
  * then changes the state of {@link IngestDocument}. This
  * exception should get serialized.
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/ForEachProcessor.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/ForEachProcessor.java
index 741a4fb29cfb8..b7c417f5f44a5 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/ForEachProcessor.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/ForEachProcessor.java
@@ -53,10 +53,10 @@
 
 /**
  * A processor that for each value in a list executes a one or more processors.
- *
+ * <p>
  * This can be useful in cases to do string operations on json array of strings,
  * or remove a field from objects inside a json array.
- *
+ * <p>
  * Note that this processor is experimental.
  */
 public final class ForEachProcessor extends AbstractProcessor implements WrappingProcessor {
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/IngestCommonModulePlugin.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/IngestCommonModulePlugin.java
index 0f8422ea474d2..a2a51d968e078 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/IngestCommonModulePlugin.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/IngestCommonModulePlugin.java
@@ -98,7 +98,7 @@ public Map<String, Processor.Factory> getProcessors(Processor.Parameters paramet
         processors.put(ScriptProcessor.TYPE, new ScriptProcessor.Factory(parameters.scriptService));
         processors.put(DotExpanderProcessor.TYPE, new DotExpanderProcessor.Factory());
         processors.put(JsonProcessor.TYPE, new JsonProcessor.Factory());
-        processors.put(KeyValueProcessor.TYPE, new KeyValueProcessor.Factory());
+        processors.put(KeyValueProcessor.TYPE, new KeyValueProcessor.Factory(parameters.scriptService));
         processors.put(URLDecodeProcessor.TYPE, new URLDecodeProcessor.Factory());
         processors.put(BytesProcessor.TYPE, new BytesProcessor.Factory());
         processors.put(PipelineProcessor.TYPE, new PipelineProcessor.Factory(parameters.ingestService));
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/KeyValueProcessor.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/KeyValueProcessor.java
index ff3cca4ce111f..73f03b3cb2e0f 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/KeyValueProcessor.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/KeyValueProcessor.java
@@ -33,10 +33,13 @@
 package org.opensearch.ingest.common;
 
 import org.opensearch.common.util.set.Sets;
+import org.opensearch.core.common.Strings;
 import org.opensearch.ingest.AbstractProcessor;
 import org.opensearch.ingest.ConfigurationUtils;
 import org.opensearch.ingest.IngestDocument;
 import org.opensearch.ingest.Processor;
+import org.opensearch.script.ScriptService;
+import org.opensearch.script.TemplateScript;
 
 import java.util.Collections;
 import java.util.List;
@@ -56,24 +59,24 @@ public final class KeyValueProcessor extends AbstractProcessor {
 
     private static final Pattern STRIP_BRACKETS = Pattern.compile("(^[\\(\\[<\"'])|([\\]\\)>\"']$)");
 
-    private final String field;
+    private final TemplateScript.Factory field;
     private final String fieldSplit;
     private final String valueSplit;
     private final Set<String> includeKeys;
     private final Set<String> excludeKeys;
-    private final String targetField;
+    private final TemplateScript.Factory targetField;
     private final boolean ignoreMissing;
     private final Consumer<IngestDocument> execution;
 
     KeyValueProcessor(
         String tag,
         String description,
-        String field,
+        TemplateScript.Factory field,
         String fieldSplit,
         String valueSplit,
         Set<String> includeKeys,
         Set<String> excludeKeys,
-        String targetField,
+        TemplateScript.Factory targetField,
         boolean ignoreMissing,
         String trimKey,
         String trimValue,
@@ -106,10 +109,10 @@ public final class KeyValueProcessor extends AbstractProcessor {
     private static Consumer<IngestDocument> buildExecution(
         String fieldSplit,
         String valueSplit,
-        String field,
+        TemplateScript.Factory field,
         Set<String> includeKeys,
         Set<String> excludeKeys,
-        String targetField,
+        TemplateScript.Factory targetField,
         boolean ignoreMissing,
         String trimKey,
         String trimValue,
@@ -130,41 +133,62 @@ private static Consumer<IngestDocument> buildExecution(
                 keyFilter = key -> includeKeys.contains(key) && excludeKeys.contains(key) == false;
             }
         }
-        final String fieldPathPrefix;
-        String keyPrefix = prefix == null ? "" : prefix;
-        if (targetField == null) {
-            fieldPathPrefix = keyPrefix;
-        } else {
-            fieldPathPrefix = targetField + "." + keyPrefix;
-        }
-        final Function<String, String> keyPrefixer;
-        if (fieldPathPrefix.isEmpty()) {
-            keyPrefixer = val -> val;
-        } else {
-            keyPrefixer = val -> fieldPathPrefix + val;
-        }
-        final Function<String, String[]> fieldSplitter = buildSplitter(fieldSplit, true);
-        Function<String, String[]> valueSplitter = buildSplitter(valueSplit, false);
-        final Function<String, String> keyTrimmer = buildTrimmer(trimKey);
-        final Function<String, String> bracketStrip;
-        if (stripBrackets) {
-            bracketStrip = val -> STRIP_BRACKETS.matcher(val).replaceAll("");
-        } else {
-            bracketStrip = val -> val;
-        }
-        final Function<String, String> valueTrimmer = buildTrimmer(trimValue);
+
         return document -> {
-            String value = document.getFieldValue(field, String.class, ignoreMissing);
+            final String fieldPathPrefix;
+            String keyPrefix = prefix == null ? "" : prefix;
+            if (targetField != null) {
+                String targetFieldPath = document.renderTemplate(targetField);
+                if (!Strings.isNullOrEmpty((targetFieldPath))) {
+                    fieldPathPrefix = targetFieldPath + "." + keyPrefix;
+                } else {
+                    fieldPathPrefix = keyPrefix;
+                }
+            } else {
+                fieldPathPrefix = keyPrefix;
+            }
+
+            final Function<String, String> keyPrefixer;
+            if (fieldPathPrefix.isEmpty()) {
+                keyPrefixer = val -> val;
+            } else {
+                keyPrefixer = val -> fieldPathPrefix + val;
+            }
+            final Function<String, String[]> fieldSplitter = buildSplitter(fieldSplit, true);
+            Function<String, String[]> valueSplitter = buildSplitter(valueSplit, false);
+            final Function<String, String> keyTrimmer = buildTrimmer(trimKey);
+            final Function<String, String> bracketStrip;
+            if (stripBrackets) {
+                bracketStrip = val -> STRIP_BRACKETS.matcher(val).replaceAll("");
+            } else {
+                bracketStrip = val -> val;
+            }
+            final Function<String, String> valueTrimmer = buildTrimmer(trimValue);
+
+            String path = document.renderTemplate(field);
+            final boolean fieldPathNullOrEmpty = Strings.isNullOrEmpty(path);
+            if (fieldPathNullOrEmpty || document.hasField(path, true) == false) {
+                if (ignoreMissing) {
+                    return;
+                } else if (fieldPathNullOrEmpty) {
+                    throw new IllegalArgumentException("field path cannot be null nor empty");
+                } else {
+                    throw new IllegalArgumentException("field [" + path + "] doesn't exist");
+                }
+            }
+
+            String value = document.getFieldValue(path, String.class, ignoreMissing);
             if (value == null) {
                 if (ignoreMissing) {
                     return;
                 }
-                throw new IllegalArgumentException("field [" + field + "] is null, cannot extract key-value pairs.");
+                throw new IllegalArgumentException("field [" + path + "] is null, cannot extract key-value pairs. ");
             }
+
             for (String part : fieldSplitter.apply(value)) {
                 String[] kv = valueSplitter.apply(part);
                 if (kv.length != 2) {
-                    throw new IllegalArgumentException("field [" + field + "] does not contain value_split [" + valueSplit + "]");
+                    throw new IllegalArgumentException("field [" + path + "] does not contain value_split [" + valueSplit + "]");
                 }
                 String key = keyTrimmer.apply(kv[0]);
                 if (keyFilter.test(key)) {
@@ -193,7 +217,7 @@ private static Function<String, String[]> buildSplitter(String split, boolean fi
         }
     }
 
-    String getField() {
+    TemplateScript.Factory getField() {
         return field;
     }
 
@@ -213,7 +237,7 @@ Set<String> getExcludeKeys() {
         return excludeKeys;
     }
 
-    String getTargetField() {
+    TemplateScript.Factory getTargetField() {
         return targetField;
     }
 
@@ -241,6 +265,12 @@ public String getType() {
     }
 
     public static class Factory implements Processor.Factory {
+        private final ScriptService scriptService;
+
+        public Factory(ScriptService scriptService) {
+            this.scriptService = scriptService;
+        }
+
         @Override
         public KeyValueProcessor create(
             Map<String, Processor.Factory> registry,
@@ -249,7 +279,13 @@ public KeyValueProcessor create(
             Map<String, Object> config
         ) throws Exception {
             String field = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "field");
+            TemplateScript.Factory fieldTemplate = ConfigurationUtils.compileTemplate(TYPE, processorTag, "field", field, scriptService);
             String targetField = ConfigurationUtils.readOptionalStringProperty(TYPE, processorTag, config, "target_field");
+            TemplateScript.Factory targetFieldTemplate = null;
+            if (!Strings.isNullOrEmpty(targetField)) {
+                targetFieldTemplate = ConfigurationUtils.compileTemplate(TYPE, processorTag, "target_field", targetField, scriptService);
+            }
+
             String fieldSplit = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "field_split");
             String valueSplit = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "value_split");
             String trimKey = ConfigurationUtils.readOptionalStringProperty(TYPE, processorTag, config, "trim_key");
@@ -270,12 +306,12 @@ public KeyValueProcessor create(
             return new KeyValueProcessor(
                 processorTag,
                 description,
-                field,
+                fieldTemplate,
                 fieldSplit,
                 valueSplit,
                 includeKeys,
                 excludeKeys,
-                targetField,
+                targetFieldTemplate,
                 ignoreMissing,
                 trimKey,
                 trimValue,
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RemoveProcessor.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RemoveProcessor.java
index 5da3b6bea7bc2..bb3d4bca47859 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RemoveProcessor.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RemoveProcessor.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.ingest.common;
 
+import org.opensearch.core.common.Strings;
+import org.opensearch.index.VersionType;
 import org.opensearch.ingest.AbstractProcessor;
 import org.opensearch.ingest.ConfigurationUtils;
 import org.opensearch.ingest.IngestDocument;
@@ -42,6 +44,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 /**
@@ -66,16 +69,38 @@ public List<TemplateScript.Factory> getFields() {
 
     @Override
     public IngestDocument execute(IngestDocument document) {
-        if (ignoreMissing) {
-            fields.forEach(field -> {
-                String path = document.renderTemplate(field);
-                if (document.hasField(path)) {
-                    document.removeField(path);
+        fields.forEach(field -> {
+            String path = document.renderTemplate(field);
+            final boolean fieldPathIsNullOrEmpty = Strings.isNullOrEmpty(path);
+            if (fieldPathIsNullOrEmpty || document.hasField(path) == false) {
+                if (ignoreMissing) {
+                    return;
+                } else if (fieldPathIsNullOrEmpty) {
+                    throw new IllegalArgumentException("field path cannot be null nor empty");
+                } else {
+                    throw new IllegalArgumentException("field [" + path + "] doesn't exist");
                 }
-            });
-        } else {
-            fields.forEach(document::removeField);
-        }
+            }
+            // cannot remove _index, _version and _version_type.
+            if (path.equals(IngestDocument.Metadata.INDEX.getFieldName())
+                || path.equals(IngestDocument.Metadata.VERSION.getFieldName())
+                || path.equals(IngestDocument.Metadata.VERSION_TYPE.getFieldName())) {
+                throw new IllegalArgumentException("cannot remove metadata field [" + path + "]");
+            }
+            // removing _id is disallowed when there's an external version specified in the request
+            String versionType = document.getFieldValue(IngestDocument.Metadata.VERSION_TYPE.getFieldName(), String.class);
+            if (path.equals(IngestDocument.Metadata.ID.getFieldName())
+                && !Objects.equals(versionType, VersionType.toString(VersionType.INTERNAL))) {
+                Long version = document.getFieldValue(IngestDocument.Metadata.VERSION.getFieldName(), Long.class);
+                throw new IllegalArgumentException(
+                    "cannot remove metadata field [_id] when specifying external version for the document, version: "
+                        + version
+                        + ", version_type: "
+                        + versionType
+                );
+            }
+            document.removeField(path);
+        });
         return document;
     }
 
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RenameProcessor.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RenameProcessor.java
index af356eb10d79c..7564bbdf95f45 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RenameProcessor.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/RenameProcessor.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.ingest.common;
 
+import org.opensearch.core.common.Strings;
 import org.opensearch.ingest.AbstractProcessor;
 import org.opensearch.ingest.ConfigurationUtils;
 import org.opensearch.ingest.IngestDocument;
@@ -80,9 +81,12 @@ boolean isIgnoreMissing() {
     @Override
     public IngestDocument execute(IngestDocument document) {
         String path = document.renderTemplate(field);
-        if (document.hasField(path, true) == false) {
+        final boolean fieldPathIsNullOrEmpty = Strings.isNullOrEmpty(path);
+        if (fieldPathIsNullOrEmpty || document.hasField(path, true) == false) {
             if (ignoreMissing) {
                 return document;
+            } else if (fieldPathIsNullOrEmpty) {
+                throw new IllegalArgumentException("field path cannot be null nor empty");
             } else {
                 throw new IllegalArgumentException("field [" + path + "] doesn't exist");
             }
diff --git a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/DissectProcessorTests.java b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/DissectProcessorTests.java
index ca0c0df40f009..e42a1147825d1 100644
--- a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/DissectProcessorTests.java
+++ b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/DissectProcessorTests.java
@@ -155,4 +155,28 @@ public void testNullValueWithOutIgnoreMissing() {
         IngestDocument ingestDocument = new IngestDocument(originalIngestDocument);
         expectThrows(IllegalArgumentException.class, () -> processor.execute(ingestDocument));
     }
+
+    public void testMatchEmptyBrackets() {
+        IngestDocument ingestDocument = new IngestDocument(
+            "_index",
+            "_id",
+            null,
+            null,
+            null,
+            Collections.singletonMap("message", "[foo],[bar],[]")
+        );
+        DissectProcessor dissectProcessor = new DissectProcessor("", null, "message", "[%{a}],[%{b}],[%{c}]", "", true);
+        dissectProcessor.execute(ingestDocument);
+        assertEquals("foo", ingestDocument.getFieldValue("a", String.class));
+        assertEquals("bar", ingestDocument.getFieldValue("b", String.class));
+        assertEquals("", ingestDocument.getFieldValue("c", String.class));
+
+        ingestDocument = new IngestDocument("_index", "_id", null, null, null, Collections.singletonMap("message", "{}{}{}{baz}"));
+        dissectProcessor = new DissectProcessor("", null, "message", "{%{a}}{%{b}}{%{c}}{%{d}}", "", true);
+        dissectProcessor.execute(ingestDocument);
+        assertEquals("", ingestDocument.getFieldValue("a", String.class));
+        assertEquals("", ingestDocument.getFieldValue("b", String.class));
+        assertEquals("", ingestDocument.getFieldValue("c", String.class));
+        assertEquals("baz", ingestDocument.getFieldValue("d", String.class));
+    }
 }
diff --git a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorFactoryTests.java b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorFactoryTests.java
index 62060a682c0cb..78972ff8d5dea 100644
--- a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorFactoryTests.java
+++ b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorFactoryTests.java
@@ -35,7 +35,9 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.common.util.set.Sets;
+import org.opensearch.ingest.TestTemplateService;
 import org.opensearch.test.OpenSearchTestCase;
+import org.junit.Before;
 
 import java.util.Arrays;
 import java.util.Collections;
@@ -48,8 +50,14 @@
 
 public class KeyValueProcessorFactoryTests extends OpenSearchTestCase {
 
+    private KeyValueProcessor.Factory factory;
+
+    @Before
+    public void init() {
+        factory = new KeyValueProcessor.Factory(TestTemplateService.instance());
+    }
+
     public void testCreateWithDefaults() throws Exception {
-        KeyValueProcessor.Factory factory = new KeyValueProcessor.Factory();
         Map<String, Object> config = new HashMap<>();
         config.put("field", "field1");
         config.put("field_split", "&");
@@ -57,7 +65,7 @@ public void testCreateWithDefaults() throws Exception {
         String processorTag = randomAlphaOfLength(10);
         KeyValueProcessor processor = factory.create(null, processorTag, null, config);
         assertThat(processor.getTag(), equalTo(processorTag));
-        assertThat(processor.getField(), equalTo("field1"));
+        assertThat(processor.getField().newInstance(Collections.emptyMap()).execute(), equalTo("field1"));
         assertThat(processor.getFieldSplit(), equalTo("&"));
         assertThat(processor.getValueSplit(), equalTo("="));
         assertThat(processor.getIncludeKeys(), is(nullValue()));
@@ -66,7 +74,6 @@ public void testCreateWithDefaults() throws Exception {
     }
 
     public void testCreateWithAllFieldsSet() throws Exception {
-        KeyValueProcessor.Factory factory = new KeyValueProcessor.Factory();
         Map<String, Object> config = new HashMap<>();
         config.put("field", "field1");
         config.put("field_split", "&");
@@ -78,17 +85,16 @@ public void testCreateWithAllFieldsSet() throws Exception {
         String processorTag = randomAlphaOfLength(10);
         KeyValueProcessor processor = factory.create(null, processorTag, null, config);
         assertThat(processor.getTag(), equalTo(processorTag));
-        assertThat(processor.getField(), equalTo("field1"));
+        assertThat(processor.getField().newInstance(Collections.emptyMap()).execute(), equalTo("field1"));
         assertThat(processor.getFieldSplit(), equalTo("&"));
         assertThat(processor.getValueSplit(), equalTo("="));
         assertThat(processor.getIncludeKeys(), equalTo(Sets.newHashSet("a", "b")));
         assertThat(processor.getExcludeKeys(), equalTo(Collections.emptySet()));
-        assertThat(processor.getTargetField(), equalTo("target"));
+        assertThat(processor.getTargetField().newInstance(Collections.emptyMap()).execute(), equalTo("target"));
         assertTrue(processor.isIgnoreMissing());
     }
 
     public void testCreateWithMissingField() {
-        KeyValueProcessor.Factory factory = new KeyValueProcessor.Factory();
         Map<String, Object> config = new HashMap<>();
         String processorTag = randomAlphaOfLength(10);
         OpenSearchException exception = expectThrows(
@@ -99,7 +105,6 @@ public void testCreateWithMissingField() {
     }
 
     public void testCreateWithMissingFieldSplit() {
-        KeyValueProcessor.Factory factory = new KeyValueProcessor.Factory();
         Map<String, Object> config = new HashMap<>();
         config.put("field", "field1");
         String processorTag = randomAlphaOfLength(10);
@@ -111,7 +116,6 @@ public void testCreateWithMissingFieldSplit() {
     }
 
     public void testCreateWithMissingValueSplit() {
-        KeyValueProcessor.Factory factory = new KeyValueProcessor.Factory();
         Map<String, Object> config = new HashMap<>();
         config.put("field", "field1");
         config.put("field_split", "&");
diff --git a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorTests.java b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorTests.java
index 685a78e2e769b..5f71ea6f16a4f 100644
--- a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorTests.java
+++ b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/KeyValueProcessorTests.java
@@ -36,6 +36,7 @@
 import org.opensearch.ingest.IngestDocument;
 import org.opensearch.ingest.Processor;
 import org.opensearch.ingest.RandomDocumentPicks;
+import org.opensearch.ingest.TestTemplateService;
 import org.opensearch.test.OpenSearchTestCase;
 
 import java.util.ArrayList;
@@ -51,7 +52,7 @@
 
 public class KeyValueProcessorTests extends OpenSearchTestCase {
 
-    private static final KeyValueProcessor.Factory FACTORY = new KeyValueProcessor.Factory();
+    private static final KeyValueProcessor.Factory FACTORY = new KeyValueProcessor.Factory(TestTemplateService.instance());
 
     public void test() throws Exception {
         IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random());
@@ -123,7 +124,12 @@ public void testMissingField() throws Exception {
         IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random(), Collections.emptyMap());
         Processor processor = createKvProcessor("unknown", "&", "=", null, null, "target", false);
         IllegalArgumentException exception = expectThrows(IllegalArgumentException.class, () -> processor.execute(ingestDocument));
-        assertThat(exception.getMessage(), equalTo("field [unknown] not present as part of path [unknown]"));
+        assertThat(exception.getMessage(), equalTo("field [unknown] doesn't exist"));
+
+        // when using template snippet, the resolved field path maybe empty
+        Processor processorWithEmptyFieldPath = createKvProcessor("", "&", "=", null, null, "target", false);
+        exception = expectThrows(IllegalArgumentException.class, () -> processorWithEmptyFieldPath.execute(ingestDocument));
+        assertThat(exception.getMessage(), equalTo("field path cannot be null nor empty"));
     }
 
     public void testNullValueWithIgnoreMissing() throws Exception {
diff --git a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RemoveProcessorTests.java b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RemoveProcessorTests.java
index cf65236157111..1a5630a4730f2 100644
--- a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RemoveProcessorTests.java
+++ b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RemoveProcessorTests.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.ingest.common;
 
+import org.opensearch.index.VersionType;
 import org.opensearch.ingest.IngestDocument;
 import org.opensearch.ingest.Processor;
 import org.opensearch.ingest.RandomDocumentPicks;
@@ -40,16 +41,17 @@
 
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
-import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 
 public class RemoveProcessorTests extends OpenSearchTestCase {
 
     public void testRemoveFields() throws Exception {
         IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random());
-        String field = RandomDocumentPicks.randomExistingFieldName(random(), ingestDocument);
+        String field = RandomDocumentPicks.addRandomField(random(), ingestDocument, randomAlphaOfLength(10));
         Processor processor = new RemoveProcessor(
             randomAlphaOfLength(10),
             null,
@@ -67,12 +69,44 @@ public void testRemoveNonExistingField() throws Exception {
         config.put("field", fieldName);
         String processorTag = randomAlphaOfLength(10);
         Processor processor = new RemoveProcessor.Factory(TestTemplateService.instance()).create(null, processorTag, null, config);
-        try {
-            processor.execute(ingestDocument);
-            fail("remove field should have failed");
-        } catch (IllegalArgumentException e) {
-            assertThat(e.getMessage(), containsString("not present as part of path [" + fieldName + "]"));
-        }
+        assertThrows(
+            "field [" + fieldName + "] doesn't exist",
+            IllegalArgumentException.class,
+            () -> { processor.execute(ingestDocument); }
+        );
+
+        Map<String, Object> configWithEmptyField = new HashMap<>();
+        configWithEmptyField.put("field", "");
+        processorTag = randomAlphaOfLength(10);
+        Processor removeProcessorWithEmptyField = new RemoveProcessor.Factory(TestTemplateService.instance()).create(
+            null,
+            processorTag,
+            null,
+            configWithEmptyField
+        );
+        assertThrows(
+            "field path cannot be null nor empty",
+            IllegalArgumentException.class,
+            () -> removeProcessorWithEmptyField.execute(ingestDocument)
+        );
+    }
+
+    public void testRemoveEmptyField() throws Exception {
+        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random(), new HashMap<>());
+        Map<String, Object> config = new HashMap<>();
+        config.put("field", "");
+        String processorTag = randomAlphaOfLength(10);
+        Processor removeProcessorWithEmptyField = new RemoveProcessor.Factory(TestTemplateService.instance()).create(
+            null,
+            processorTag,
+            null,
+            config
+        );
+        assertThrows(
+            "field path cannot be null nor empty",
+            IllegalArgumentException.class,
+            () -> removeProcessorWithEmptyField.execute(ingestDocument)
+        );
     }
 
     public void testIgnoreMissing() throws Exception {
@@ -84,5 +118,67 @@ public void testIgnoreMissing() throws Exception {
         String processorTag = randomAlphaOfLength(10);
         Processor processor = new RemoveProcessor.Factory(TestTemplateService.instance()).create(null, processorTag, null, config);
         processor.execute(ingestDocument);
+
+        // when using template snippet, the resolved field path maybe empty
+        Map<String, Object> configWithEmptyField = new HashMap<>();
+        configWithEmptyField.put("field", "");
+        configWithEmptyField.put("ignore_missing", true);
+        processorTag = randomAlphaOfLength(10);
+        processor = new RemoveProcessor.Factory(TestTemplateService.instance()).create(null, processorTag, null, configWithEmptyField);
+        processor.execute(ingestDocument);
+    }
+
+    public void testRemoveMetadataField() throws Exception {
+        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random(), new HashMap<>());
+        List<String> metadataFields = ingestDocument.getMetadata()
+            .keySet()
+            .stream()
+            .map(IngestDocument.Metadata::getFieldName)
+            .collect(Collectors.toList());
+
+        for (String metadataFieldName : metadataFields) {
+            Map<String, Object> config = new HashMap<>();
+            config.put("field", metadataFieldName);
+            String processorTag = randomAlphaOfLength(10);
+            Processor processor = new RemoveProcessor.Factory(TestTemplateService.instance()).create(null, processorTag, null, config);
+            // _if_seq_no and _if_primary_term do not exist in the enriched document, removing them will throw IllegalArgumentException
+            if (metadataFieldName.equals(IngestDocument.Metadata.IF_SEQ_NO.getFieldName())
+                || metadataFieldName.equals(IngestDocument.Metadata.IF_PRIMARY_TERM.getFieldName())) {
+                assertThrows(
+                    "field: [" + metadataFieldName + "] doesn't exist",
+                    IllegalArgumentException.class,
+                    () -> processor.execute(ingestDocument)
+                );
+            } else if (metadataFieldName.equals(IngestDocument.Metadata.INDEX.getFieldName())
+                || metadataFieldName.equals(IngestDocument.Metadata.VERSION.getFieldName())
+                || metadataFieldName.equals(IngestDocument.Metadata.VERSION_TYPE.getFieldName())) {
+                    // _index, _version and _version_type cannot be removed
+                    assertThrows(
+                        "cannot remove metadata field [" + metadataFieldName + "]",
+                        IllegalArgumentException.class,
+                        () -> processor.execute(ingestDocument)
+                    );
+                } else if (metadataFieldName.equals(IngestDocument.Metadata.ID.getFieldName())) {
+                    Long version = ingestDocument.getFieldValue(IngestDocument.Metadata.VERSION.getFieldName(), Long.class);
+                    String versionType = ingestDocument.getFieldValue(IngestDocument.Metadata.VERSION_TYPE.getFieldName(), String.class);
+                    if (!versionType.equals(VersionType.toString(VersionType.INTERNAL))) {
+                        assertThrows(
+                            "cannot remove metadata field [_id] when specifying external version for the document, version: "
+                                + version
+                                + ", version_type: "
+                                + versionType,
+                            IllegalArgumentException.class,
+                            () -> processor.execute(ingestDocument)
+                        );
+                    } else {
+                        processor.execute(ingestDocument);
+                        assertThat(ingestDocument.hasField(metadataFieldName), equalTo(false));
+                    }
+                } else if (metadataFieldName.equals(IngestDocument.Metadata.ROUTING.getFieldName())
+                    && ingestDocument.hasField(IngestDocument.Metadata.ROUTING.getFieldName())) {
+                        processor.execute(ingestDocument);
+                        assertThat(ingestDocument.hasField(metadataFieldName), equalTo(false));
+                    }
+        }
     }
 }
diff --git a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RenameProcessorTests.java b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RenameProcessorTests.java
index fc95693024cb0..a600464371af8 100644
--- a/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RenameProcessorTests.java
+++ b/modules/ingest-common/src/test/java/org/opensearch/ingest/common/RenameProcessorTests.java
@@ -112,6 +112,15 @@ public void testRenameNonExistingField() throws Exception {
         } catch (IllegalArgumentException e) {
             assertThat(e.getMessage(), equalTo("field [" + fieldName + "] doesn't exist"));
         }
+
+        // when using template snippet, the resolved field path maybe empty
+        processor = createRenameProcessor("", RandomDocumentPicks.randomFieldName(random()), false);
+        try {
+            processor.execute(ingestDocument);
+            fail("processor execute should have failed");
+        } catch (IllegalArgumentException e) {
+            assertThat(e.getMessage(), equalTo("field path cannot be null nor empty"));
+        }
     }
 
     public void testRenameNonExistingFieldWithIgnoreMissing() throws Exception {
@@ -121,6 +130,11 @@ public void testRenameNonExistingFieldWithIgnoreMissing() throws Exception {
         Processor processor = createRenameProcessor(fieldName, RandomDocumentPicks.randomFieldName(random()), true);
         processor.execute(ingestDocument);
         assertIngestDocument(originalIngestDocument, ingestDocument);
+
+        // when using template snippet, the resolved field path maybe empty
+        processor = createRenameProcessor("", RandomDocumentPicks.randomFieldName(random()), true);
+        processor.execute(ingestDocument);
+        assertIngestDocument(originalIngestDocument, ingestDocument);
     }
 
     public void testRenameNewFieldAlreadyExists() throws Exception {
diff --git a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/150_kv.yml b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/150_kv.yml
index 836243652b2e0..30a0a520b5c40 100644
--- a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/150_kv.yml
+++ b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/150_kv.yml
@@ -39,3 +39,151 @@ teardown:
         id: 1
   - match: { _source.goodbye: "everybody" }
   - match: { _source.hello: "world" }
+
+---
+"Test KV Processor with template snippets":
+  - skip:
+      version: " - 2.11.99"
+      reason: "KV Processor with template snippets is only supported since 2.12.0"
+
+  - do:
+      ingest.put_pipeline:
+        id: "1"
+        body:  >
+          {
+            "processors": [
+              {
+                "kv" : {
+                  "field" : "{{source}}",
+                  "target_field" : "{{target}}",
+                  "field_split": " ",
+                  "value_split": "="
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        pipeline: "1"
+        body: {
+          source: "foo",
+          target: "zoo",
+          foo: "goodbye=everybody hello=world"
+        }
+
+  - do:
+      get:
+        index: test
+        id: 1
+  - match: { _source.zoo.goodbye: "everybody" }
+  - match: { _source.zoo.hello: "world" }
+
+---
+"Test KV Processor with non-existing field and without ignore_missing":
+  - skip:
+      version: " - 2.11.99"
+      reason: "KV Processor with template snippets is only supported since 2.12.0"
+
+  - do:
+      ingest.put_pipeline:
+        id: "1"
+        body:  >
+          {
+            "processors": [
+              {
+                "kv" : {
+                  "field" : "{{source}}",
+                  "target_field" : "{{target}}",
+                  "field_split": " ",
+                  "value_split": "="
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /field path cannot be null nor empty/
+      index:
+        index: test
+        id: 1
+        pipeline: "1"
+        body: {
+          target: "zoo",
+          foo: "goodbye=everybody hello=world"
+        }
+
+  - do:
+      ingest.put_pipeline:
+        id: "1"
+        body:  >
+          {
+            "processors": [
+              {
+                "kv" : {
+                  "field" : "{{source}}",
+                  "target_field" : "{{target}}",
+                  "field_split": " ",
+                  "value_split": "="
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /field \[unknown\] doesn\'t exist/
+      index:
+        index: test
+        id: 1
+        pipeline: "1"
+        body: {
+          source: "unknown",
+          target: "zoo",
+          foo: "goodbye=everybody hello=world"
+        }
+
+---
+"Test KV Processor with non-existing field and ignore_missing":
+  - skip:
+      version: " - 2.11.99"
+      reason: "KV Processor with template snippets is only supported since 2.12.0"
+
+  - do:
+      ingest.put_pipeline:
+        id: "1"
+        body:  >
+          {
+            "processors": [
+              {
+                "kv" : {
+                  "field" : "{{source}}",
+                  "target_field" : "{{target}}",
+                  "field_split": " ",
+                  "value_split": "=",
+                  "ignore_missing": true
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        pipeline: "1"
+        body: {
+          target: "zoo",
+          foo: "goodbye=everybody hello=world"
+        }
+
+  - do:
+      get:
+        index: test
+        id: 1
+  - match:   { _source: { target: "zoo", foo: "goodbye=everybody hello=world"}}
diff --git a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/200_dissect_processor.yml b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/200_dissect_processor.yml
index 916a7fe656cc2..d90e5fbf2362b 100644
--- a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/200_dissect_processor.yml
+++ b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/200_dissect_processor.yml
@@ -84,3 +84,38 @@ teardown:
             }
           ]
         }
+
+---
+"Test dissect processor can match empty brackets":
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "dissect" : {
+                  "field" : "message",
+                  "pattern" : "[%{a}][%{b}][%{c}]"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: {message: "[foo][bar][]"}
+
+  - do:
+      get:
+        index: test
+        id: 1
+  - match: { _source.message: "[foo][bar][]" }
+  - match: { _source.a: "foo" }
+  - match: { _source.b: "bar" }
+  - match: { _source.c: "" }
diff --git a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/280_rename_processor.yml b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/280_rename_processor.yml
new file mode 100644
index 0000000000000..96b2256bcc1dc
--- /dev/null
+++ b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/280_rename_processor.yml
@@ -0,0 +1,66 @@
+---
+teardown:
+  - do:
+      ingest.delete_pipeline:
+        id: "my_pipeline"
+        ignore: 404
+
+---
+"Test rename processor with non-existing field and without ignore_missing":
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "rename" : {
+                  "field" : "{{field_foo}}",
+                  "target_field" : "bar"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: '/field path cannot be null nor empty/'
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: { message: "foo bar baz" }
+
+---
+"Test rename processor with non-existing field and ignore_missing":
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "rename" : {
+                  "field" : "{{field_foo}}",
+                  "target_field" : "bar",
+                  "ignore_missing" : true
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: { message: "foo bar baz" }
+
+  - do:
+      get:
+        index: test
+        id: 1
+  - match: { _source.message: "foo bar baz" }
diff --git a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/290_remove_processor.yml b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/290_remove_processor.yml
new file mode 100644
index 0000000000000..4811769d04f0e
--- /dev/null
+++ b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/290_remove_processor.yml
@@ -0,0 +1,229 @@
+---
+teardown:
+  - do:
+      ingest.delete_pipeline:
+        id: "my_pipeline"
+        ignore: 404
+
+---
+"Test remove processor with non-existing field and without ignore_missing":
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : "{{unknown}}"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /field path cannot be null nor empty/
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: { message: "foo bar baz" }
+
+---
+"Test remove processor with resolved field path doesn't exist":
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : "{{foo}}"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /field \[bar\] doesn\'t exist/
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: {
+          message: "foo bar baz",
+          foo: "bar"
+        }
+
+---
+"Test remove processor with non-existing field and ignore_missing":
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : "{{unknown}}",
+                  "ignore_missing" : true
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: { message: "foo bar baz" }
+
+  - do:
+      get:
+        index: test
+        id: 1
+  - match: { _source.message: "foo bar baz" }
+
+#Related issue: https://github.com/opensearch-project/OpenSearch/issues/10732
+---
+"Test remove metadata field":
+  - skip:
+      version: " - 2.11.99"
+      reason: "The bug was fixed in 2.12"
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : "{{foo}}"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /cannot remove metadata field \[\_index\]/
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: {
+          foo: "_index"
+        }
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : "_version"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /cannot remove metadata field \[\_version\]/
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: {
+          foo: "bar"
+        }
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : "_version_type"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /cannot remove metadata field \[\_version\_type\]/
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: {
+          foo: "bar"
+        }
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : ["_id", "_routing"]
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        routing: abc
+        pipeline: "my_pipeline"
+        body: { message: "foo bar baz" }
+  - match: { result: created }
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "remove" : {
+                  "field" : "_id"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      catch: /cannot remove metadata field \[\_id\] when specifying external version for the document/
+      index:
+        index: test
+        id: "test_id_10000"
+        pipeline: "my_pipeline"
+        version: 1
+        version_type: "external"
+        body: { message: "foo bar baz" }
diff --git a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/90_simulate.yml b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/90_simulate.yml
index e012a82b15927..7c073739f6a1f 100644
--- a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/90_simulate.yml
+++ b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/90_simulate.yml
@@ -976,3 +976,140 @@ teardown:
           }
   - match: { error.root_cause.0.type: "illegal_argument_exception" }
   - match: { error.root_cause.0.reason: "Pipeline processor configured for non-existent pipeline [____pipeline_doesnot_exist___]" }
+
+---
+"Test simulate with docs containing metadata fields":
+  - do:
+      ingest.simulate:
+        body: >
+          {
+            "pipeline": {
+              "description": "_description",
+              "processors": [
+                {
+                  "set" : {
+                    "field": "field2",
+                    "value": "foo"
+                  }
+                }
+              ]
+            },
+            "docs": [
+              {
+                "_index": "index",
+                "_id": "id",
+                "_routing": "foo",
+                "_version": 100,
+                "_if_seq_no": 12333333333333333,
+                "_if_primary_term": 1,
+                "_source": {
+                  "foo": "bar"
+                }
+              }
+            ]
+          }
+
+  - length: { docs: 1 }
+  - match: { docs.0.doc._index: "index" }
+  - match: { docs.0.doc._id: "id" }
+  - match: { docs.0.doc._routing: "foo" }
+  - match: { docs.0.doc._version: "100" }
+  - match: { docs.0.doc._if_seq_no: "12333333333333333" }
+  - match: { docs.0.doc._if_primary_term: "1" }
+  - match: { docs.0.doc._source.foo: "bar" }
+
+  - do:
+      catch: bad_request
+      ingest.simulate:
+        body: >
+          {
+            "pipeline": {
+              "description": "_description",
+              "processors": [
+                {
+                  "set" : {
+                    "field" : "field2",
+                    "value": "foo"
+                  }
+                }
+              ]
+            },
+            "docs": [
+              {
+                "_index": "index",
+                "_id": "id",
+                "_routing": "foo",
+                "_version": "bar",
+                "_source": {
+                  "foo": "bar"
+                }
+              }
+            ]
+          }
+  - match: { status: 400 }
+  - match: { error.root_cause.0.type: "illegal_argument_exception" }
+  - match: { error.root_cause.0.reason: "Failed to parse parameter [_version], only int or long is accepted" }
+
+  - do:
+      catch: bad_request
+      ingest.simulate:
+        body: >
+          {
+            "pipeline": {
+              "description": "_description",
+              "processors": [
+                {
+                  "set" : {
+                    "field" : "field2",
+                    "value": "foo"
+                  }
+                }
+              ]
+            },
+            "docs": [
+              {
+                "_index": "index",
+                "_id": "id",
+                "_routing": "foo",
+                "_if_seq_no": "123",
+                "_source": {
+                  "foo": "bar"
+                }
+              }
+            ]
+          }
+  - match: { status: 400 }
+  - match: { error.root_cause.0.type: "illegal_argument_exception" }
+  - match: { error.root_cause.0.reason: "Failed to parse parameter [_if_seq_no], only int or long is accepted" }
+
+  - do:
+      catch: bad_request
+      ingest.simulate:
+        body: >
+          {
+            "pipeline": {
+              "description": "_description",
+              "processors": [
+                {
+                  "set" : {
+                    "field" : "field2",
+                    "value": "foo"
+                  }
+                }
+              ]
+            },
+            "docs": [
+              {
+                "_index": "index",
+                "_id": "id",
+                "_routing": "foo",
+                "_if_primary_term": "1",
+                "_source": {
+                  "foo": "bar"
+                }
+              }
+            ]
+          }
+  - match: { status: 400 }
+  - match: { error.root_cause.0.type: "illegal_argument_exception" }
+  - match: { error.root_cause.0.reason: "Failed to parse parameter [_if_primary_term], only int or long is accepted" }
diff --git a/modules/ingest-geoip/licenses/jackson-annotations-2.15.2.jar.sha1 b/modules/ingest-geoip/licenses/jackson-annotations-2.15.2.jar.sha1
deleted file mode 100644
index f63416ddb8ceb..0000000000000
--- a/modules/ingest-geoip/licenses/jackson-annotations-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4724a65ac8e8d156a24898d50fd5dbd3642870b8
\ No newline at end of file
diff --git a/modules/ingest-geoip/licenses/jackson-annotations-2.16.0.jar.sha1 b/modules/ingest-geoip/licenses/jackson-annotations-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..79ed9e0c63fc8
--- /dev/null
+++ b/modules/ingest-geoip/licenses/jackson-annotations-2.16.0.jar.sha1
@@ -0,0 +1 @@
+dc30995f7428c0a405eba9b8c619b20d2b3b9905
\ No newline at end of file
diff --git a/modules/ingest-geoip/licenses/jackson-databind-2.15.2.jar.sha1 b/modules/ingest-geoip/licenses/jackson-databind-2.15.2.jar.sha1
deleted file mode 100644
index f16d80af8dce6..0000000000000
--- a/modules/ingest-geoip/licenses/jackson-databind-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9353b021f10c307c00328f52090de2bdb4b6ff9c
\ No newline at end of file
diff --git a/modules/ingest-geoip/licenses/jackson-databind-2.16.0.jar.sha1 b/modules/ingest-geoip/licenses/jackson-databind-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..da00d281934b1
--- /dev/null
+++ b/modules/ingest-geoip/licenses/jackson-databind-2.16.0.jar.sha1
@@ -0,0 +1 @@
+3a6b7f8ff7b30d518bbd65678e9c30cd881f19a7
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/asm-9.5.jar.sha1 b/modules/lang-expression/licenses/asm-9.5.jar.sha1
deleted file mode 100644
index ea4aa3581dc87..0000000000000
--- a/modules/lang-expression/licenses/asm-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-dc6ea1875f4d64fbc85e1691c95b96a3d8569c90
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/asm-9.6.jar.sha1 b/modules/lang-expression/licenses/asm-9.6.jar.sha1
new file mode 100644
index 0000000000000..2d9e6a9d3cfd6
--- /dev/null
+++ b/modules/lang-expression/licenses/asm-9.6.jar.sha1
@@ -0,0 +1 @@
+aa205cf0a06dbd8e04ece91c0b37c3f5d567546a
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/asm-commons-9.5.jar.sha1 b/modules/lang-expression/licenses/asm-commons-9.5.jar.sha1
deleted file mode 100644
index 5be792660c19f..0000000000000
--- a/modules/lang-expression/licenses/asm-commons-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-19ab5b5800a3910d30d3a3e64fdb00fd0cb42de0
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/asm-commons-9.6.jar.sha1 b/modules/lang-expression/licenses/asm-commons-9.6.jar.sha1
new file mode 100644
index 0000000000000..a0814f495771f
--- /dev/null
+++ b/modules/lang-expression/licenses/asm-commons-9.6.jar.sha1
@@ -0,0 +1 @@
+f1a9e5508eff490744144565c47326c8648be309
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/asm-tree-9.5.jar.sha1 b/modules/lang-expression/licenses/asm-tree-9.5.jar.sha1
deleted file mode 100644
index fb42db6a9d15c..0000000000000
--- a/modules/lang-expression/licenses/asm-tree-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-fd33c8b6373abaa675be407082fdfda35021254a
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/asm-tree-9.6.jar.sha1 b/modules/lang-expression/licenses/asm-tree-9.6.jar.sha1
new file mode 100644
index 0000000000000..101eb03b4b736
--- /dev/null
+++ b/modules/lang-expression/licenses/asm-tree-9.6.jar.sha1
@@ -0,0 +1 @@
+c0cdda9d211e965d2a4448aa3fd86110f2f8c2de
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/lucene-expressions-9.8.0-snapshot-4373c3b.jar.sha1 b/modules/lang-expression/licenses/lucene-expressions-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 6eaa40708e4ae..0000000000000
--- a/modules/lang-expression/licenses/lucene-expressions-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9f8a34fc3d450343ab05ccb5af318a836a6a5fb3
\ No newline at end of file
diff --git a/modules/lang-expression/licenses/lucene-expressions-9.8.0.jar.sha1 b/modules/lang-expression/licenses/lucene-expressions-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..892865a017f48
--- /dev/null
+++ b/modules/lang-expression/licenses/lucene-expressions-9.8.0.jar.sha1
@@ -0,0 +1 @@
+7725476acfcb9bdfeff1b813ce15c39c6b857dc2
\ No newline at end of file
diff --git a/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/MoreExpressionIT.java b/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/MoreExpressionIT.java
index 46cac9afa38fc..8ca28a905f216 100644
--- a/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/MoreExpressionIT.java
+++ b/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/MoreExpressionIT.java
@@ -32,12 +32,16 @@
 
 package org.opensearch.script.expression;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchType;
 import org.opensearch.action.update.UpdateRequestBuilder;
 import org.opensearch.common.lucene.search.function.CombineFunction;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilders;
@@ -53,9 +57,10 @@
 import org.opensearch.search.aggregations.pipeline.SimpleValue;
 import org.opensearch.search.sort.SortBuilders;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -64,6 +69,7 @@
 
 import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.PipelineAggregatorBuilders.bucketScript;
@@ -74,7 +80,24 @@
 import static org.hamcrest.Matchers.notNullValue;
 
 // TODO: please convert to unit tests!
-public class MoreExpressionIT extends OpenSearchIntegTestCase {
+public class MoreExpressionIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MoreExpressionIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/StoredExpressionIT.java b/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/StoredExpressionIT.java
index 665ebf3c2caea..b1cb5356a4405 100644
--- a/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/StoredExpressionIT.java
+++ b/modules/lang-expression/src/internalClusterTest/java/org/opensearch/script/expression/StoredExpressionIT.java
@@ -32,7 +32,10 @@
 
 package org.opensearch.script.expression;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.plugins.Plugin;
@@ -40,16 +43,36 @@
 import org.opensearch.script.ScriptType;
 import org.opensearch.search.aggregations.AggregationBuilders;
 import org.opensearch.search.builder.SearchSourceBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.hamcrest.Matchers.containsString;
 
 //TODO: please convert to unit tests!
-public class StoredExpressionIT extends OpenSearchIntegTestCase {
+public class StoredExpressionIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public StoredExpressionIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Settings nodeSettings(int nodeOrdinal) {
         Settings.Builder builder = Settings.builder().put(super.nodeSettings(nodeOrdinal));
diff --git a/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionAggregationScript.java b/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionAggregationScript.java
index 5eebb9c4d60ad..a2af636ffdc8a 100644
--- a/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionAggregationScript.java
+++ b/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionAggregationScript.java
@@ -53,9 +53,9 @@ class ExpressionAggregationScript implements AggregationScript.LeafFactory {
     final SimpleBindings bindings;
     final DoubleValuesSource source;
     final boolean needsScore;
-    final ReplaceableConstDoubleValueSource specialValue; // _value
+    final PerThreadReplaceableConstDoubleValueSource specialValue; // _value
 
-    ExpressionAggregationScript(Expression e, SimpleBindings b, boolean n, ReplaceableConstDoubleValueSource v) {
+    ExpressionAggregationScript(Expression e, SimpleBindings b, boolean n, PerThreadReplaceableConstDoubleValueSource v) {
         exprScript = e;
         bindings = b;
         source = exprScript.getDoubleValuesSource(bindings);
diff --git a/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionScriptEngine.java b/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionScriptEngine.java
index 035d2402857e0..5629b3b4a6972 100644
--- a/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionScriptEngine.java
+++ b/modules/lang-expression/src/main/java/org/opensearch/script/expression/ExpressionScriptEngine.java
@@ -73,7 +73,7 @@
 
 /**
  * Provides the infrastructure for Lucene expressions as a scripting language for OpenSearch.
- *
+ * <p>
  * Only contexts returning numeric types or {@link Object} are supported.
  */
 public class ExpressionScriptEngine implements ScriptEngine {
@@ -316,14 +316,14 @@ private static AggregationScript.LeafFactory newAggregationScript(
         // instead of complicating SimpleBindings (which should stay simple)
         SimpleBindings bindings = new SimpleBindings();
         boolean needsScores = false;
-        ReplaceableConstDoubleValueSource specialValue = null;
+        PerThreadReplaceableConstDoubleValueSource specialValue = null;
         for (String variable : expr.variables) {
             try {
                 if (variable.equals("_score")) {
                     bindings.add("_score", DoubleValuesSource.SCORES);
                     needsScores = true;
                 } else if (variable.equals("_value")) {
-                    specialValue = new ReplaceableConstDoubleValueSource();
+                    specialValue = new PerThreadReplaceableConstDoubleValueSource();
                     bindings.add("_value", specialValue);
                     // noop: _value is special for aggregations, and is handled in ExpressionScriptBindings
                     // TODO: if some uses it in a scoring expression, they will get a nasty failure when evaluating...need a
@@ -388,7 +388,7 @@ private static ScoreScript.LeafFactory newScoreScript(Expression expr, SearchLoo
         // NOTE: if we need to do anything complicated with bindings in the future, we can just extend Bindings,
         // instead of complicating SimpleBindings (which should stay simple)
         SimpleBindings bindings = new SimpleBindings();
-        ReplaceableConstDoubleValueSource specialValue = null;
+        PerThreadReplaceableConstDoubleValueSource specialValue = null;
         boolean needsScores = false;
         for (String variable : expr.variables) {
             try {
@@ -396,7 +396,7 @@ private static ScoreScript.LeafFactory newScoreScript(Expression expr, SearchLoo
                     bindings.add("_score", DoubleValuesSource.SCORES);
                     needsScores = true;
                 } else if (variable.equals("_value")) {
-                    specialValue = new ReplaceableConstDoubleValueSource();
+                    specialValue = new PerThreadReplaceableConstDoubleValueSource();
                     bindings.add("_value", specialValue);
                     // noop: _value is special for aggregations, and is handled in ExpressionScriptBindings
                     // TODO: if some uses it in a scoring expression, they will get a nasty failure when evaluating...need a
diff --git a/modules/lang-expression/src/main/java/org/opensearch/script/expression/ReplaceableConstDoubleValueSource.java b/modules/lang-expression/src/main/java/org/opensearch/script/expression/PerThreadReplaceableConstDoubleValueSource.java
similarity index 62%
rename from modules/lang-expression/src/main/java/org/opensearch/script/expression/ReplaceableConstDoubleValueSource.java
rename to modules/lang-expression/src/main/java/org/opensearch/script/expression/PerThreadReplaceableConstDoubleValueSource.java
index 28e4707a07192..40bb957c248f2 100644
--- a/modules/lang-expression/src/main/java/org/opensearch/script/expression/ReplaceableConstDoubleValueSource.java
+++ b/modules/lang-expression/src/main/java/org/opensearch/script/expression/PerThreadReplaceableConstDoubleValueSource.java
@@ -39,20 +39,25 @@
 import org.apache.lucene.search.IndexSearcher;
 
 import java.io.IOException;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
- * A {@link DoubleValuesSource} which has a stub {@link DoubleValues} that holds a dynamically replaceable constant double.
+ * A {@link DoubleValuesSource} which has a stub {@link DoubleValues} that holds a dynamically replaceable constant double. This is made
+ * thread-safe for concurrent segment search use case by keeping the {@link DoubleValues} per thread. Any update to the value happens in
+ * thread specific {@link DoubleValuesSource} instance.
  */
-final class ReplaceableConstDoubleValueSource extends DoubleValuesSource {
-    final ReplaceableConstDoubleValues fv;
+final class PerThreadReplaceableConstDoubleValueSource extends DoubleValuesSource {
+    // Multiple slices can be processed by same thread but that will be sequential, so keeping per thread is fine
+    final Map<Long, ReplaceableConstDoubleValues> perThreadDoubleValues;
 
-    ReplaceableConstDoubleValueSource() {
-        fv = new ReplaceableConstDoubleValues();
+    PerThreadReplaceableConstDoubleValueSource() {
+        perThreadDoubleValues = new ConcurrentHashMap<>();
     }
 
     @Override
     public DoubleValues getValues(LeafReaderContext ctx, DoubleValues scores) throws IOException {
-        return fv;
+        return perThreadDoubleValues.computeIfAbsent(Thread.currentThread().getId(), threadId -> new ReplaceableConstDoubleValues());
     }
 
     @Override
@@ -62,7 +67,11 @@ public boolean needsScores() {
 
     @Override
     public Explanation explain(LeafReaderContext ctx, int docId, Explanation scoreExplanation) throws IOException {
-        if (fv.advanceExact(docId)) return Explanation.match((float) fv.doubleValue(), "ReplaceableConstDoubleValues");
+        final ReplaceableConstDoubleValues currentFv = perThreadDoubleValues.computeIfAbsent(
+            Thread.currentThread().getId(),
+            threadId -> new ReplaceableConstDoubleValues()
+        );
+        if (currentFv.advanceExact(docId)) return Explanation.match((float) currentFv.doubleValue(), "ReplaceableConstDoubleValues");
         else return Explanation.noMatch("ReplaceableConstDoubleValues");
     }
 
@@ -77,7 +86,11 @@ public int hashCode() {
     }
 
     public void setValue(double v) {
-        fv.setValue(v);
+        final ReplaceableConstDoubleValues currentFv = perThreadDoubleValues.computeIfAbsent(
+            Thread.currentThread().getId(),
+            threadId -> new ReplaceableConstDoubleValues()
+        );
+        currentFv.setValue(v);
     }
 
     @Override
diff --git a/modules/lang-mustache/src/internalClusterTest/java/org/opensearch/script/mustache/MultiSearchTemplateIT.java b/modules/lang-mustache/src/internalClusterTest/java/org/opensearch/script/mustache/MultiSearchTemplateIT.java
index bb11e493ba3d1..e480fbbd22ad2 100644
--- a/modules/lang-mustache/src/internalClusterTest/java/org/opensearch/script/mustache/MultiSearchTemplateIT.java
+++ b/modules/lang-mustache/src/internalClusterTest/java/org/opensearch/script/mustache/MultiSearchTemplateIT.java
@@ -32,12 +32,16 @@
 
 package org.opensearch.script.mustache;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchRequest;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.ScriptType;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.Arrays;
 import java.util.Collection;
@@ -46,6 +50,7 @@
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.arrayWithSize;
 import static org.hamcrest.Matchers.equalTo;
@@ -53,7 +58,24 @@
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.core.Is.is;
 
-public class MultiSearchTemplateIT extends OpenSearchIntegTestCase {
+public class MultiSearchTemplateIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MultiSearchTemplateIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheModulePlugin.java b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheModulePlugin.java
index 434a117d9b47e..6b33ac3b6be08 100644
--- a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheModulePlugin.java
+++ b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheModulePlugin.java
@@ -65,6 +65,7 @@ public ScriptEngine getScriptEngine(Settings settings, Collection<ScriptContext<
     public List<ActionHandler<? extends ActionRequest, ? extends ActionResponse>> getActions() {
         return Arrays.asList(
             new ActionHandler<>(SearchTemplateAction.INSTANCE, TransportSearchTemplateAction.class),
+            new ActionHandler<>(RenderSearchTemplateAction.INSTANCE, TransportRenderSearchTemplateAction.class),
             new ActionHandler<>(MultiSearchTemplateAction.INSTANCE, TransportMultiSearchTemplateAction.class)
         );
     }
diff --git a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheScriptEngine.java b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheScriptEngine.java
index f4d7198dc2124..ec84475b70bb6 100644
--- a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheScriptEngine.java
+++ b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/MustacheScriptEngine.java
@@ -59,7 +59,7 @@
 /**
  * Main entry point handling template registration, compilation and
  * execution.
- *
+ * <p>
  * Template handling is based on Mustache. Template handling is a two step
  * process: First compile the string representing the template, the resulting
  * {@link Mustache} object can then be re-used for subsequent executions.
diff --git a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/RenderSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/RenderSearchTemplateAction.java
new file mode 100644
index 0000000000000..1feb916c4ce73
--- /dev/null
+++ b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/RenderSearchTemplateAction.java
@@ -0,0 +1,21 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.script.mustache;
+
+import org.opensearch.action.ActionType;
+
+public class RenderSearchTemplateAction extends ActionType<SearchTemplateResponse> {
+
+    public static final RenderSearchTemplateAction INSTANCE = new RenderSearchTemplateAction();
+    public static final String NAME = "indices:data/read/search/template/render";
+
+    private RenderSearchTemplateAction() {
+        super(NAME, SearchTemplateResponse::new);
+    }
+}
diff --git a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/RestRenderSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/RestRenderSearchTemplateAction.java
index 7a94fc45837d9..9ffa2c94cb56f 100644
--- a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/RestRenderSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/RestRenderSearchTemplateAction.java
@@ -81,6 +81,6 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
             renderRequest.setScript(id);
         }
 
-        return channel -> client.execute(SearchTemplateAction.INSTANCE, renderRequest, new RestToXContentListener<>(channel));
+        return channel -> client.execute(RenderSearchTemplateAction.INSTANCE, renderRequest, new RestToXContentListener<>(channel));
     }
 }
diff --git a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/SearchTemplateRequest.java b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/SearchTemplateRequest.java
index 1aabea30fc651..d02c5f1efa591 100644
--- a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/SearchTemplateRequest.java
+++ b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/SearchTemplateRequest.java
@@ -259,16 +259,25 @@ public void writeTo(StreamOutput out) throws IOException {
 
     @Override
     public String[] indices() {
+        if (request == null) {
+            return new String[0];
+        }
         return request.indices();
     }
 
     @Override
     public IndicesOptions indicesOptions() {
+        if (request == null) {
+            return SearchRequest.DEFAULT_INDICES_OPTIONS;
+        }
         return request.indicesOptions();
     }
 
     @Override
     public IndicesRequest indices(String... indices) {
+        if (request == null) {
+            return new SearchRequest(new String[0]).indices(indices);
+        }
         return request.indices(indices);
     }
 }
diff --git a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/TransportRenderSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/TransportRenderSearchTemplateAction.java
new file mode 100644
index 0000000000000..993d77ffaa75c
--- /dev/null
+++ b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/TransportRenderSearchTemplateAction.java
@@ -0,0 +1,30 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.script.mustache;
+
+import org.opensearch.action.support.ActionFilters;
+import org.opensearch.client.node.NodeClient;
+import org.opensearch.common.inject.Inject;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.script.ScriptService;
+import org.opensearch.transport.TransportService;
+
+public class TransportRenderSearchTemplateAction extends TransportSearchTemplateAction {
+
+    @Inject
+    public TransportRenderSearchTemplateAction(
+        TransportService transportService,
+        ActionFilters actionFilters,
+        ScriptService scriptService,
+        NamedXContentRegistry xContentRegistry,
+        NodeClient client
+    ) {
+        super(RenderSearchTemplateAction.NAME, transportService, actionFilters, scriptService, xContentRegistry, client);
+    }
+}
diff --git a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/TransportSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/TransportSearchTemplateAction.java
index 6e8b9d059b583..d75cc0337b66c 100644
--- a/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/TransportSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/opensearch/script/mustache/TransportSearchTemplateAction.java
@@ -61,9 +61,9 @@ public class TransportSearchTemplateAction extends HandledTransportAction<Search
 
     private static final String TEMPLATE_LANG = MustacheScriptEngine.NAME;
 
-    private final ScriptService scriptService;
-    private final NamedXContentRegistry xContentRegistry;
-    private final NodeClient client;
+    protected final ScriptService scriptService;
+    protected final NamedXContentRegistry xContentRegistry;
+    protected final NodeClient client;
 
     @Inject
     public TransportSearchTemplateAction(
@@ -79,6 +79,20 @@ public TransportSearchTemplateAction(
         this.client = client;
     }
 
+    public TransportSearchTemplateAction(
+        String actionName,
+        TransportService transportService,
+        ActionFilters actionFilters,
+        ScriptService scriptService,
+        NamedXContentRegistry xContentRegistry,
+        NodeClient client
+    ) {
+        super(actionName, transportService, actionFilters, SearchTemplateRequest::new);
+        this.scriptService = scriptService;
+        this.xContentRegistry = xContentRegistry;
+        this.client = client;
+    }
+
     @Override
     protected void doExecute(Task task, SearchTemplateRequest request, ActionListener<SearchTemplateResponse> listener) {
         final SearchTemplateResponse response = new SearchTemplateResponse();
diff --git a/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/MustacheScriptEngineTests.java b/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/MustacheScriptEngineTests.java
index 9e97863306148..fbb7d09709a91 100644
--- a/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/MustacheScriptEngineTests.java
+++ b/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/MustacheScriptEngineTests.java
@@ -200,7 +200,7 @@ private String getChars() {
 
     /**
      * From https://www.ietf.org/rfc/rfc4627.txt:
-     *
+     * <p>
      * All Unicode characters may be placed within the
      * quotation marks except for the characters that must be escaped:
      * quotation mark, reverse solidus, and the control characters (U+0000
diff --git a/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/SearchTemplateRequestTests.java b/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/SearchTemplateRequestTests.java
index 72443d1323b44..71ce616fd5d94 100644
--- a/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/SearchTemplateRequestTests.java
+++ b/modules/lang-mustache/src/test/java/org/opensearch/script/mustache/SearchTemplateRequestTests.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.script.mustache;
 
+import org.opensearch.action.search.SearchRequest;
 import org.opensearch.core.common.io.stream.Writeable;
 import org.opensearch.script.ScriptType;
 import org.opensearch.search.RandomSearchRequestGenerator;
@@ -110,4 +111,19 @@ public static SearchTemplateRequest createRandomRequest() {
         request.setRequest(RandomSearchRequestGenerator.randomSearchRequest(SearchSourceBuilder::searchSource));
         return request;
     }
+
+    public void testSimulatedSearchTemplateRequest() {
+        SearchTemplateRequest request = new SearchTemplateRequest();
+        request.setSimulate(true);
+
+        assertEquals(0, request.indices().length);
+        assertEquals(SearchRequest.DEFAULT_INDICES_OPTIONS, request.indicesOptions());
+        assertEquals(2, request.indices("index1", "index2").indices().length);
+
+        SearchTemplateRequest randomRequest = createRandomRequest();
+        int expectedIndicesLength = randomRequest.indices().length;
+        request.setSimulate(true);
+
+        assertEquals(expectedIndicesLength, randomRequest.indices().length);
+    }
 }
diff --git a/modules/lang-painless/build.gradle b/modules/lang-painless/build.gradle
index d7af8621c478a..fb51a0bb7f157 100644
--- a/modules/lang-painless/build.gradle
+++ b/modules/lang-painless/build.gradle
@@ -33,7 +33,6 @@ import com.github.jengelman.gradle.plugins.shadow.ShadowBasePlugin
 
 apply plugin: 'opensearch.validate-rest-spec'
 apply plugin: 'opensearch.yaml-rest-test'
-apply plugin: 'com.github.johnrengelman.shadow'
 
 opensearchplugin {
   description 'An easy, safe and fast scripting language for OpenSearch'
@@ -62,30 +61,6 @@ dependencies {
   api project('spi')
 }
 
-test {
-  doFirst {
-    test.classpath -= project.files(project.tasks.named('shadowJar'))
-    test.classpath -= project.configurations.getByName(ShadowBasePlugin.CONFIGURATION_NAME)
-    test.classpath += project.extensions.getByType(SourceSetContainer).getByName(SourceSet.MAIN_SOURCE_SET_NAME).runtimeClasspath
-  }
-}
-
-shadowJar {
-  archiveClassifier.set('')
-  relocate 'org.objectweb', 'org.opensearch.repackage.org.objectweb'
-  dependencies {
-    include(dependency("org.ow2.asm:asm:${versions.asm}"))
-    include(dependency("org.ow2.asm:asm-util:${versions.asm}"))
-    include(dependency("org.ow2.asm:asm-tree:${versions.asm}"))
-    include(dependency("org.ow2.asm:asm-commons:${versions.asm}"))
-    include(dependency("org.ow2.asm:asm-analysis:${versions.asm}"))
-  }
-}
-
-tasks.validateNebulaPom.dependsOn tasks.generatePomFileForShadowPublication
-tasks.validateShadowPom.dependsOn tasks.generatePomFileForNebulaPublication
-tasks.withType(AbstractPublishToMaven)*.dependsOn "generatePomFileForShadowPublication", "generatePomFileForNebulaPublication"
-
 tasks.named("dependencyLicenses").configure {
   mapping from: /asm-.*/, to: 'asm'
 }
diff --git a/modules/lang-painless/licenses/asm-9.5.jar.sha1 b/modules/lang-painless/licenses/asm-9.5.jar.sha1
deleted file mode 100644
index ea4aa3581dc87..0000000000000
--- a/modules/lang-painless/licenses/asm-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-dc6ea1875f4d64fbc85e1691c95b96a3d8569c90
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-9.6.jar.sha1 b/modules/lang-painless/licenses/asm-9.6.jar.sha1
new file mode 100644
index 0000000000000..2d9e6a9d3cfd6
--- /dev/null
+++ b/modules/lang-painless/licenses/asm-9.6.jar.sha1
@@ -0,0 +1 @@
+aa205cf0a06dbd8e04ece91c0b37c3f5d567546a
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-analysis-9.5.jar.sha1 b/modules/lang-painless/licenses/asm-analysis-9.5.jar.sha1
deleted file mode 100644
index 9e87d3ce7d719..0000000000000
--- a/modules/lang-painless/licenses/asm-analysis-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-490bacc77de7cbc0be1a30bb3471072d705be4a4
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-analysis-9.6.jar.sha1 b/modules/lang-painless/licenses/asm-analysis-9.6.jar.sha1
new file mode 100644
index 0000000000000..fa42ea1198165
--- /dev/null
+++ b/modules/lang-painless/licenses/asm-analysis-9.6.jar.sha1
@@ -0,0 +1 @@
+9ce6c7b174bd997fc2552dff47964546bd7a5ec3
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-commons-9.5.jar.sha1 b/modules/lang-painless/licenses/asm-commons-9.5.jar.sha1
deleted file mode 100644
index 5be792660c19f..0000000000000
--- a/modules/lang-painless/licenses/asm-commons-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-19ab5b5800a3910d30d3a3e64fdb00fd0cb42de0
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-commons-9.6.jar.sha1 b/modules/lang-painless/licenses/asm-commons-9.6.jar.sha1
new file mode 100644
index 0000000000000..a0814f495771f
--- /dev/null
+++ b/modules/lang-painless/licenses/asm-commons-9.6.jar.sha1
@@ -0,0 +1 @@
+f1a9e5508eff490744144565c47326c8648be309
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-tree-9.5.jar.sha1 b/modules/lang-painless/licenses/asm-tree-9.5.jar.sha1
deleted file mode 100644
index fb42db6a9d15c..0000000000000
--- a/modules/lang-painless/licenses/asm-tree-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-fd33c8b6373abaa675be407082fdfda35021254a
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-tree-9.6.jar.sha1 b/modules/lang-painless/licenses/asm-tree-9.6.jar.sha1
new file mode 100644
index 0000000000000..101eb03b4b736
--- /dev/null
+++ b/modules/lang-painless/licenses/asm-tree-9.6.jar.sha1
@@ -0,0 +1 @@
+c0cdda9d211e965d2a4448aa3fd86110f2f8c2de
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-util-9.5.jar.sha1 b/modules/lang-painless/licenses/asm-util-9.5.jar.sha1
deleted file mode 100644
index 5fffbfe655deb..0000000000000
--- a/modules/lang-painless/licenses/asm-util-9.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-64b5a1fc8c1b15ed2efd6a063e976bc8d3dc5ffe
\ No newline at end of file
diff --git a/modules/lang-painless/licenses/asm-util-9.6.jar.sha1 b/modules/lang-painless/licenses/asm-util-9.6.jar.sha1
new file mode 100644
index 0000000000000..1f42ac62dc69c
--- /dev/null
+++ b/modules/lang-painless/licenses/asm-util-9.6.jar.sha1
@@ -0,0 +1 @@
+f77caf84eb93786a749b2baa40865b9613e3eaee
\ No newline at end of file
diff --git a/modules/lang-painless/spi/build.gradle b/modules/lang-painless/spi/build.gradle
index 59a77870b4987..32556f907fdc0 100644
--- a/modules/lang-painless/spi/build.gradle
+++ b/modules/lang-painless/spi/build.gradle
@@ -33,7 +33,7 @@ apply plugin: 'opensearch.publish'
 
 base {
   group = 'org.opensearch.plugin'
-  archivesBaseName = 'opensearch-scripting-painless-spi'
+  archivesName = 'opensearch-scripting-painless-spi'
 }
 
 dependencies {
diff --git a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/Allowlist.java b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/Allowlist.java
index 56ade63efa5e2..265263b41ca89 100644
--- a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/Allowlist.java
+++ b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/Allowlist.java
@@ -42,7 +42,7 @@
  * Allowlist contains data structures designed to be used to generate an allowlist of Java classes,
  * constructors, methods, and fields that can be used within a Painless script at both compile-time
  * and run-time.
- *
+ * <p>
  * A Allowlist consists of several pieces with {@link AllowlistClass}s as the top level. Each
  * {@link AllowlistClass} will contain zero-to-many {@link AllowlistConstructor}s, {@link AllowlistMethod}s, and
  * {@link AllowlistField}s which are what will be available with a Painless script.  See each individual
diff --git a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistClass.java b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistClass.java
index 17e6814addf3b..67f5a07846c53 100644
--- a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistClass.java
+++ b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistClass.java
@@ -45,12 +45,12 @@
  * classes. Though, since multiple allowlists may be combined into a single allowlist for a
  * specific context, as long as multiple classes representing the same Java class have the same
  * class name and have legal constructor/method overloading they can be merged together.
- *
+ * <p>
  * Classes in Painless allow for arity overloading for constructors and methods. Arity overloading
  * means that multiple constructors are allowed for a single class as long as they have a different
  * number of parameters, and multiples methods with the same name are allowed for a single class
  * as long as they have the same return type and a different number of parameters.
- *
+ * <p>
  * Classes will automatically extend other allowlisted classes if the Java class they represent is a
  * subclass of other classes including Java interfaces.
  */
diff --git a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistLoader.java b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistLoader.java
index 71265f82acacc..632fee9187eba 100644
--- a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistLoader.java
+++ b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistLoader.java
@@ -67,11 +67,11 @@ public static Allowlist loadFromResourceFiles(Class<?> resource, String... filep
      * is the path of a single text file. The {@link Class}'s {@link ClassLoader} will be used to lookup the Java
      * reflection objects for each individual {@link Class}, {@link Constructor}, {@link Method}, and {@link Field}
      * specified as part of the allowlist in the text file.
-     *
+     * <p>
      * A single pass is made through each file to collect all the information about each class, constructor, method,
      * and field. Most validation will be done at a later point after all allowlists have been gathered and their
      * merging takes place.
-     *
+     * <p>
      * A painless type name is one of the following:
      * <ul>
      *     <li> def - The Painless dynamic type which is automatically included without a need to be
@@ -129,13 +129,13 @@ public static Allowlist loadFromResourceFiles(Class<?> resource, String... filep
      * be appropriately parsed and handled. Painless complex types must be specified with the
      * fully-qualified Java class name. Method argument types, method return types, and field types
      * must be specified with Painless type names (def, fully-qualified, or short) as described earlier.
-     *
+     * <p>
      * The following example is used to create a single allowlist text file:
      *
-     * {@code
+     * <pre>
      * # primitive types
      *
-     * class int -> int {
+     * class int -&gt; int {
      * }
      *
      * # complex types
@@ -161,7 +161,7 @@ public static Allowlist loadFromResourceFiles(Class<?> resource, String... filep
      *   int value1
      *   def value2
      * }
-     * }
+     * </pre>
      */
     public static Allowlist loadFromResourceFiles(Class<?> resource, Map<String, AllowlistAnnotationParser> parsers, String... filepaths) {
         List<AllowlistClass> allowlistClasses = new ArrayList<>();
diff --git a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistMethod.java b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistMethod.java
index 8bb0231ff3f4f..9fcaec3dbf7b6 100644
--- a/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistMethod.java
+++ b/modules/lang-painless/spi/src/main/java/org/opensearch/painless/spi/AllowlistMethod.java
@@ -45,7 +45,7 @@
  * are using the '.' operator on an existing class variable/field. Painless classes may have multiple
  * methods with the same name as long as they comply with arity overloading described in
  * {@link AllowlistClass}.
- *
+ * <p>
  * Classes may also have additional methods that are not part of the Java class the class represents -
  * these are known as augmented methods. An augmented method can be added to a class as a part of any
  * Java class as long as the method is static and the first parameter of the method is the Java class
diff --git a/modules/lang-painless/src/main/java/org/opensearch/painless/Compiler.java b/modules/lang-painless/src/main/java/org/opensearch/painless/Compiler.java
index 35c676653fdc3..c19d4f361b2b6 100644
--- a/modules/lang-painless/src/main/java/org/opensearch/painless/Compiler.java
+++ b/modules/lang-painless/src/main/java/org/opensearch/painless/Compiler.java
@@ -73,9 +73,7 @@ final class Compiler {
      */
     private static final CodeSource CODESOURCE;
 
-    /**
-     * Setup the code privileges.
-     */
+    /* Setup the code privileges. */
     static {
         try {
             // Setup the code privileges.
diff --git a/modules/lang-painless/src/main/java/org/opensearch/painless/lookup/PainlessLookupUtility.java b/modules/lang-painless/src/main/java/org/opensearch/painless/lookup/PainlessLookupUtility.java
index cae425ad1fe3b..3164f5e6388c7 100644
--- a/modules/lang-painless/src/main/java/org/opensearch/painless/lookup/PainlessLookupUtility.java
+++ b/modules/lang-painless/src/main/java/org/opensearch/painless/lookup/PainlessLookupUtility.java
@@ -42,13 +42,13 @@
 /**
  * PainlessLookupUtility contains methods shared by {@link PainlessLookupBuilder}, {@link PainlessLookup}, and other classes within
  * Painless for conversion between type names and types along with some other various utility methods.
- *
+ * <p>
  * The following terminology is used for variable names throughout the lookup package:
- *
+ * <p>
  * A class is a set of methods and fields under a specific class name. A type is either a class or an array under a specific type name.
  * Note the distinction between class versus type is class means that no array classes will be be represented whereas type allows array
  * classes to be represented. The set of available classes will always be a subset of the available types.
- *
+ * <p>
  * Under ambiguous circumstances most variable names are prefixed with asm, java, or painless. If the variable value is the same for asm,
  * java, and painless, no prefix is used. Target is used as a prefix to represent if a constructor, method, or field is being
  * called/accessed on that specific class.  Parameter is often a postfix used to represent if a type is used as a parameter to a
diff --git a/modules/lang-painless/src/main/java/org/opensearch/painless/phase/PainlessSemanticAnalysisPhase.java b/modules/lang-painless/src/main/java/org/opensearch/painless/phase/PainlessSemanticAnalysisPhase.java
index 04165f44ba212..8a05d6742af97 100644
--- a/modules/lang-painless/src/main/java/org/opensearch/painless/phase/PainlessSemanticAnalysisPhase.java
+++ b/modules/lang-painless/src/main/java/org/opensearch/painless/phase/PainlessSemanticAnalysisPhase.java
@@ -126,9 +126,9 @@ public void visitFunction(SFunction userFunctionNode, ScriptScope scriptScope) {
 
     /**
      * Visits an expression that is also considered a statement.
-     *
+     * <p>
      * If the statement is a return from the execute method, performs return value conversion.
-     *
+     * <p>
      * Checks: control flow, type validation
      */
     @Override
@@ -168,9 +168,9 @@ public void visitExpression(SExpression userExpressionNode, SemanticScope semant
 
     /**
      * Visits a return statement and casts the value to the return type if possible.
-     *
+     * <p>
      * If the statement is a return from the execute method, performs return value conversion.
-     *
+     * <p>
      * Checks: type validation
      */
     @Override
diff --git a/modules/lang-painless/src/main/java/org/opensearch/painless/symbol/SemanticScope.java b/modules/lang-painless/src/main/java/org/opensearch/painless/symbol/SemanticScope.java
index e27530d745e8f..5ac802038afa6 100644
--- a/modules/lang-painless/src/main/java/org/opensearch/painless/symbol/SemanticScope.java
+++ b/modules/lang-painless/src/main/java/org/opensearch/painless/symbol/SemanticScope.java
@@ -49,7 +49,7 @@
  * Tracks information within a scope required for compilation during the
  * semantic phase in the user tree. There are three types of scopes -
  * {@link FunctionScope}, {@link LambdaScope}, and {@link BlockScope}.
- *
+ * <p>
  * Scopes are stacked as they are created during the user tree's semantic
  * phase with each scope beyond the top-level containing a reference to
  * its parent. As a scope is no longer necessary, it's dropped automatically
diff --git a/modules/lang-painless/src/main/resources/org/opensearch/painless/spi/org.opensearch.score.txt b/modules/lang-painless/src/main/resources/org/opensearch/painless/spi/org.opensearch.score.txt
index 5533f0bc55522..9bce617099c6f 100644
--- a/modules/lang-painless/src/main/resources/org/opensearch/painless/spi/org.opensearch.score.txt
+++ b/modules/lang-painless/src/main/resources/org/opensearch/painless/spi/org.opensearch.score.txt
@@ -24,7 +24,6 @@ class org.opensearch.script.ScoreScript @no_import {
 
 static_import {
     int termFreq(org.opensearch.script.ScoreScript, String, String) bound_to org.opensearch.script.ScoreScriptUtils$TermFreq
-    float tf(org.opensearch.script.ScoreScript, String, String) bound_to org.opensearch.script.ScoreScriptUtils$TF
     long totalTermFreq(org.opensearch.script.ScoreScript, String, String) bound_to org.opensearch.script.ScoreScriptUtils$TotalTermFreq
     long sumTotalTermFreq(org.opensearch.script.ScoreScript, String) bound_to org.opensearch.script.ScoreScriptUtils$SumTotalTermFreq
     double saturation(double, double) from_class org.opensearch.script.ScoreScriptUtils
diff --git a/modules/mapper-extras/src/main/java/org/opensearch/index/mapper/SearchAsYouTypeFieldMapper.java b/modules/mapper-extras/src/main/java/org/opensearch/index/mapper/SearchAsYouTypeFieldMapper.java
index 397a7b48b472a..366e848416328 100644
--- a/modules/mapper-extras/src/main/java/org/opensearch/index/mapper/SearchAsYouTypeFieldMapper.java
+++ b/modules/mapper-extras/src/main/java/org/opensearch/index/mapper/SearchAsYouTypeFieldMapper.java
@@ -82,7 +82,7 @@
 /**
  * Mapper for a text field that optimizes itself for as-you-type completion by indexing its content into subfields. Each subfield
  * modifies the analysis chain of the root field to index terms the user would create as they type out the value in the root field
- *
+ * <p>
  * The structure of these fields is
  *
  * <pre>
diff --git a/modules/parent-join/src/main/java/org/opensearch/join/query/HasChildQueryBuilder.java b/modules/parent-join/src/main/java/org/opensearch/join/query/HasChildQueryBuilder.java
index 1a51259e9e4e4..e930780613ed6 100644
--- a/modules/parent-join/src/main/java/org/opensearch/join/query/HasChildQueryBuilder.java
+++ b/modules/parent-join/src/main/java/org/opensearch/join/query/HasChildQueryBuilder.java
@@ -373,7 +373,7 @@ protected Query doToQuery(QueryShardContext context) throws IOException {
      * A query that rewrites into another query using
      * {@link JoinUtil#createJoinQuery(String, Query, Query, IndexSearcher, ScoreMode, OrdinalMap, int, int)}
      * that executes the actual join.
-     *
+     * <p>
      * This query is exclusively used by the {@link HasChildQueryBuilder} and {@link HasParentQueryBuilder} to get access
      * to the {@link DirectoryReader} used by the current search in order to retrieve the {@link OrdinalMap}.
      * The {@link OrdinalMap} is required by {@link JoinUtil} to execute the join.
diff --git a/modules/percolator/src/internalClusterTest/java/org/opensearch/percolator/PercolatorQuerySearchIT.java b/modules/percolator/src/internalClusterTest/java/org/opensearch/percolator/PercolatorQuerySearchIT.java
index b5c082a5667c1..c8763c2f3f749 100644
--- a/modules/percolator/src/internalClusterTest/java/org/opensearch/percolator/PercolatorQuerySearchIT.java
+++ b/modules/percolator/src/internalClusterTest/java/org/opensearch/percolator/PercolatorQuerySearchIT.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.percolator;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.join.ScoreMode;
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
@@ -39,6 +41,7 @@
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.DistanceUnit;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -54,7 +57,7 @@
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.fetch.subphase.highlight.HighlightBuilder;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.Arrays;
@@ -77,6 +80,7 @@
 import static org.opensearch.index.query.QueryBuilders.spanNotQuery;
 import static org.opensearch.index.query.QueryBuilders.spanTermQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchHits;
@@ -86,7 +90,24 @@
 import static org.hamcrest.Matchers.nullValue;
 import static org.hamcrest.core.IsNull.notNullValue;
 
-public class PercolatorQuerySearchIT extends OpenSearchIntegTestCase {
+public class PercolatorQuerySearchIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public PercolatorQuerySearchIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected boolean addMockGeoShapeFieldMapper() {
diff --git a/modules/rank-eval/src/internalClusterTest/java/org/opensearch/index/rankeval/RankEvalRequestIT.java b/modules/rank-eval/src/internalClusterTest/java/org/opensearch/index/rankeval/RankEvalRequestIT.java
index 6eb974c77a5f3..cdc3cac1a1f06 100644
--- a/modules/rank-eval/src/internalClusterTest/java/org/opensearch/index/rankeval/RankEvalRequestIT.java
+++ b/modules/rank-eval/src/internalClusterTest/java/org/opensearch/index/rankeval/RankEvalRequestIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.index.rankeval;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.indices.alias.IndicesAliasesRequest.AliasActions;
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.index.query.MatchAllQueryBuilder;
 import org.opensearch.index.query.QueryBuilders;
@@ -43,7 +47,7 @@
 import org.opensearch.indices.IndexClosedException;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.builder.SearchSourceBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.Before;
 
 import java.util.ArrayList;
@@ -54,15 +58,33 @@
 import java.util.Set;
 
 import static org.opensearch.index.rankeval.EvaluationMetric.filterUnratedDocuments;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.instanceOf;
 
-public class RankEvalRequestIT extends OpenSearchIntegTestCase {
+public class RankEvalRequestIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String TEST_INDEX = "test";
     private static final String INDEX_ALIAS = "alias0";
     private static final int RELEVANT_RATING_1 = 1;
 
+    public RankEvalRequestIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(RankEvalModulePlugin.class);
diff --git a/modules/rank-eval/src/main/java/org/opensearch/index/rankeval/TransportRankEvalAction.java b/modules/rank-eval/src/main/java/org/opensearch/index/rankeval/TransportRankEvalAction.java
index ffdea14e0873d..8e72c6ef06849 100644
--- a/modules/rank-eval/src/main/java/org/opensearch/index/rankeval/TransportRankEvalAction.java
+++ b/modules/rank-eval/src/main/java/org/opensearch/index/rankeval/TransportRankEvalAction.java
@@ -71,10 +71,10 @@
  * supplied query parameters) against a set of possible search requests (read:
  * search specifications, expressed as query/search request templates) and
  * compares the result against a set of annotated documents per search intent.
- *
+ * <p>
  * If any documents are returned that haven't been annotated the document id of
  * those is returned per search intent.
- *
+ * <p>
  * The resulting search quality is computed in terms of precision at n and
  * returned for each search specification for the full set of search intents as
  * averaged precision at n.
diff --git a/modules/rank-eval/src/test/java/org/opensearch/index/rankeval/DiscountedCumulativeGainTests.java b/modules/rank-eval/src/test/java/org/opensearch/index/rankeval/DiscountedCumulativeGainTests.java
index fcf1fa489f740..d96e3212e05a2 100644
--- a/modules/rank-eval/src/test/java/org/opensearch/index/rankeval/DiscountedCumulativeGainTests.java
+++ b/modules/rank-eval/src/test/java/org/opensearch/index/rankeval/DiscountedCumulativeGainTests.java
@@ -67,7 +67,7 @@ public class DiscountedCumulativeGainTests extends OpenSearchTestCase {
 
     /**
      * Assuming the docs are ranked in the following order:
-     *
+     * <p>
      * rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
      * -------------------------------------------------------------------------------------------
      * 1 | 3 | 7.0 | 1.0 | 7.0 | 7.0 | 
@@ -76,7 +76,7 @@ public class DiscountedCumulativeGainTests extends OpenSearchTestCase {
      * 4 | 0 | 0.0 | 2.321928094887362 | 0.0
      * 5 | 1 | 1.0 | 2.584962500721156 | 0.38685280723454163
      * 6 | 2 | 3.0 | 2.807354922057604 | 1.0686215613240666
-     *
+     * <p>
      * dcg = 13.84826362927298 (sum of last column)
      */
     public void testDCGAt() {
@@ -91,20 +91,20 @@ public void testDCGAt() {
         DiscountedCumulativeGain dcg = new DiscountedCumulativeGain();
         assertEquals(EXPECTED_DCG, dcg.evaluate("id", hits, rated).metricScore(), DELTA);
 
-        /**
-         * Check with normalization: to get the maximal possible dcg, sort documents by
-         * relevance in descending order
-         *
-         * rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
-         * ---------------------------------------------------------------------------------------
-         * 1 | 3 | 7.0 | 1.0  | 7.0
-         * 2 | 3 | 7.0 | 1.5849625007211563 | 4.416508275000202
-         * 3 | 2 | 3.0 | 2.0  | 1.5
-         * 4 | 2 | 3.0 | 2.321928094887362 | 1.2920296742201793
-         * 5 | 1 | 1.0 | 2.584962500721156  | 0.38685280723454163
-         * 6 | 0 | 0.0 | 2.807354922057604  | 0.0
-         *
-         * idcg = 14.595390756454922 (sum of last column)
+        /*
+          Check with normalization: to get the maximal possible dcg, sort documents by
+          relevance in descending order
+
+          rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
+          ---------------------------------------------------------------------------------------
+          1 | 3 | 7.0 | 1.0  | 7.0
+          2 | 3 | 7.0 | 1.5849625007211563 | 4.416508275000202
+          3 | 2 | 3.0 | 2.0  | 1.5
+          4 | 2 | 3.0 | 2.321928094887362 | 1.2920296742201793
+          5 | 1 | 1.0 | 2.584962500721156  | 0.38685280723454163
+          6 | 0 | 0.0 | 2.807354922057604  | 0.0
+
+          idcg = 14.595390756454922 (sum of last column)
          */
         dcg = new DiscountedCumulativeGain(true, null, 10);
         assertEquals(EXPECTED_NDCG, dcg.evaluate("id", hits, rated).metricScore(), DELTA);
@@ -113,7 +113,7 @@ public void testDCGAt() {
     /**
      * This tests metric when some documents in the search result don't have a
      * rating provided by the user.
-     *
+     * <p>
      * rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
      * -------------------------------------------------------------------------------------------
      * 1 | 3 | 7.0 | 1.0 | 7.0 2 | 
@@ -122,7 +122,7 @@ public void testDCGAt() {
      * 4 | n/a | n/a | n/a | n/a
      * 5 | 1 | 1.0 | 2.584962500721156 | 0.38685280723454163
      * 6 | n/a | n/a | n/a | n/a
-     *
+     * <p>
      * dcg = 12.779642067948913 (sum of last column)
      */
     public void testDCGAtSixMissingRatings() {
@@ -143,20 +143,20 @@ public void testDCGAtSixMissingRatings() {
         assertEquals(12.779642067948913, result.metricScore(), DELTA);
         assertEquals(2, filterUnratedDocuments(result.getHitsAndRatings()).size());
 
-        /**
-         * Check with normalization: to get the maximal possible dcg, sort documents by
-         * relevance in descending order
-         *
-         * rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
-         * ----------------------------------------------------------------------------------------
-         * 1 | 3 | 7.0 | 1.0  | 7.0
-         * 2 | 3 | 7.0 | 1.5849625007211563 | 4.416508275000202
-         * 3 | 2 | 3.0 | 2.0  | 1.5
-         * 4 | 1 | 1.0 | 2.321928094887362   | 0.43067655807339
-         * 5 | n.a | n.a | n.a.  | n.a.
-         * 6 | n.a | n.a | n.a  | n.a
-         *
-         * idcg = 13.347184833073591 (sum of last column)
+        /*
+          Check with normalization: to get the maximal possible dcg, sort documents by
+          relevance in descending order
+
+          rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
+          ----------------------------------------------------------------------------------------
+          1 | 3 | 7.0 | 1.0  | 7.0
+          2 | 3 | 7.0 | 1.5849625007211563 | 4.416508275000202
+          3 | 2 | 3.0 | 2.0  | 1.5
+          4 | 1 | 1.0 | 2.321928094887362   | 0.43067655807339
+          5 | n.a | n.a | n.a.  | n.a.
+          6 | n.a | n.a | n.a  | n.a
+
+          idcg = 13.347184833073591 (sum of last column)
          */
         dcg = new DiscountedCumulativeGain(true, null, 10);
         assertEquals(12.779642067948913 / 13.347184833073591, dcg.evaluate("id", hits, rated).metricScore(), DELTA);
@@ -166,7 +166,7 @@ public void testDCGAtSixMissingRatings() {
      * This tests that normalization works as expected when there are more rated
      * documents than search hits because we restrict DCG to be calculated at the
      * fourth position
-     *
+     * <p>
      * rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
      * -------------------------------------------------------------------------------------------
      * 1 | 3 | 7.0 | 1.0 | 7.0 2 | 
@@ -176,7 +176,7 @@ public void testDCGAtSixMissingRatings() {
      * -----------------------------------------------------------------
      * 5 | 1 | 1.0 | 2.584962500721156 | 0.38685280723454163
      * 6 | n/a | n/a | n/a | n/a
-     *
+     * <p>
      * dcg = 12.392789260714371 (sum of last column until position 4)
      */
     public void testDCGAtFourMoreRatings() {
@@ -200,21 +200,21 @@ public void testDCGAtFourMoreRatings() {
         assertEquals(12.392789260714371, result.metricScore(), DELTA);
         assertEquals(1, filterUnratedDocuments(result.getHitsAndRatings()).size());
 
-        /**
-         * Check with normalization: to get the maximal possible dcg, sort documents by
-         * relevance in descending order
-         *
-         * rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
-         * ---------------------------------------------------------------------------------------
-         * 1 | 3 | 7.0 | 1.0  | 7.0
-         * 2 | 3 | 7.0 | 1.5849625007211563 | 4.416508275000202
-         * 3 | 2 | 3.0 | 2.0  | 1.5
-         * 4 | 1 | 1.0 | 2.321928094887362   | 0.43067655807339
-         * ---------------------------------------------------------------------------------------
-         * 5 | n.a | n.a | n.a.  | n.a.
-         * 6 | n.a | n.a | n.a  | n.a
-         *
-         * idcg = 13.347184833073591 (sum of last column)
+        /*
+          Check with normalization: to get the maximal possible dcg, sort documents by
+          relevance in descending order
+
+          rank | relevance | 2^(relevance) - 1 | log_2(rank + 1) | (2^(relevance) - 1) / log_2(rank + 1)
+          ---------------------------------------------------------------------------------------
+          1 | 3 | 7.0 | 1.0  | 7.0
+          2 | 3 | 7.0 | 1.5849625007211563 | 4.416508275000202
+          3 | 2 | 3.0 | 2.0  | 1.5
+          4 | 1 | 1.0 | 2.321928094887362   | 0.43067655807339
+          ---------------------------------------------------------------------------------------
+          5 | n.a | n.a | n.a.  | n.a.
+          6 | n.a | n.a | n.a  | n.a
+
+          idcg = 13.347184833073591 (sum of last column)
          */
         dcg = new DiscountedCumulativeGain(true, null, 10);
         assertEquals(12.392789260714371 / 13.347184833073591, dcg.evaluate("id", hits, ratedDocs).metricScore(), DELTA);
diff --git a/modules/reindex/src/internalClusterTest/java/org/opensearch/index/codec/MultiCodecReindexIT.java b/modules/reindex/src/internalClusterTest/java/org/opensearch/index/codec/MultiCodecReindexIT.java
deleted file mode 100644
index 604c233ca49c4..0000000000000
--- a/modules/reindex/src/internalClusterTest/java/org/opensearch/index/codec/MultiCodecReindexIT.java
+++ /dev/null
@@ -1,198 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.index.codec;
-
-import org.opensearch.action.admin.indices.flush.FlushResponse;
-import org.opensearch.action.admin.indices.refresh.RefreshResponse;
-import org.opensearch.action.admin.indices.segments.IndicesSegmentsRequest;
-import org.opensearch.action.admin.indices.settings.put.UpdateSettingsRequest;
-import org.opensearch.action.support.ActiveShardCount;
-import org.opensearch.cluster.metadata.IndexMetadata;
-import org.opensearch.common.settings.Settings;
-import org.opensearch.index.engine.Segment;
-import org.opensearch.index.reindex.BulkByScrollResponse;
-import org.opensearch.index.reindex.ReindexAction;
-import org.opensearch.index.reindex.ReindexModulePlugin;
-import org.opensearch.index.reindex.ReindexRequestBuilder;
-import org.opensearch.index.reindex.ReindexTestCase;
-import org.opensearch.plugins.Plugin;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.UUID;
-import java.util.concurrent.ExecutionException;
-import java.util.stream.Collectors;
-import java.util.stream.IntStream;
-
-import static java.util.stream.Collectors.toList;
-import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_BLOCKS_METADATA;
-import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_BLOCKS_READ;
-import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_BLOCKS_WRITE;
-import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_READ_ONLY;
-import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_READ_ONLY_ALLOW_DELETE;
-import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
-import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
-
-public class MultiCodecReindexIT extends ReindexTestCase {
-
-    @Override
-    protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return List.of(ReindexModulePlugin.class);
-    }
-
-    public void testReindexingMultipleCodecs() throws InterruptedException, ExecutionException {
-        internalCluster().ensureAtLeastNumDataNodes(1);
-        Map<String, String> codecMap = Map.of(
-            "best_compression",
-            "BEST_COMPRESSION",
-            "zlib",
-            "BEST_COMPRESSION",
-            "default",
-            "BEST_SPEED",
-            "lz4",
-            "BEST_SPEED"
-        );
-
-        for (Map.Entry<String, String> codec : codecMap.entrySet()) {
-            assertReindexingWithMultipleCodecs(codec.getKey(), codec.getValue(), codecMap);
-        }
-
-    }
-
-    private void assertReindexingWithMultipleCodecs(String destCodec, String destCodecMode, Map<String, String> codecMap)
-        throws ExecutionException, InterruptedException {
-
-        final String index = "test-index" + destCodec;
-        final String destIndex = "dest-index" + destCodec;
-
-        // creating source index
-        createIndex(
-            index,
-            Settings.builder()
-                .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
-                .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
-                .put("index.codec", "default")
-                .put("index.merge.policy.max_merged_segment", "1b")
-                .build()
-        );
-        ensureGreen(index);
-
-        final int nbDocs = randomIntBetween(2, 5);
-
-        // indexing with all 4 codecs
-        for (Map.Entry<String, String> codec : codecMap.entrySet()) {
-            useCodec(index, codec.getKey());
-            ingestDocs(index, nbDocs);
-        }
-
-        assertTrue(
-            getSegments(index).stream()
-                .flatMap(s -> s.getAttributes().values().stream())
-                .collect(Collectors.toSet())
-                .containsAll(codecMap.values())
-        );
-
-        // creating destination index with destination codec
-        createIndex(
-            destIndex,
-            Settings.builder()
-                .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
-                .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
-                .put("index.codec", destCodec)
-                .build()
-        );
-
-        BulkByScrollResponse bulkResponse = new ReindexRequestBuilder(client(), ReindexAction.INSTANCE).source(index)
-            .destination(destIndex)
-            .refresh(true)
-            .waitForActiveShards(ActiveShardCount.ONE)
-            .get();
-
-        assertEquals(codecMap.size() * nbDocs, bulkResponse.getCreated());
-        assertEquals(codecMap.size() * nbDocs, bulkResponse.getTotal());
-        assertEquals(0, bulkResponse.getDeleted());
-        assertEquals(0, bulkResponse.getNoops());
-        assertEquals(0, bulkResponse.getVersionConflicts());
-        assertEquals(1, bulkResponse.getBatches());
-        assertTrue(bulkResponse.getTook().getMillis() > 0);
-        assertEquals(0, bulkResponse.getBulkFailures().size());
-        assertEquals(0, bulkResponse.getSearchFailures().size());
-        assertTrue(getSegments(destIndex).stream().allMatch(segment -> segment.attributes.containsValue(destCodecMode)));
-    }
-
-    private void useCodec(String index, String codec) throws ExecutionException, InterruptedException {
-        assertAcked(client().admin().indices().prepareClose(index).setWaitForActiveShards(1));
-
-        assertAcked(
-            client().admin()
-                .indices()
-                .updateSettings(new UpdateSettingsRequest(index).settings(Settings.builder().put("index.codec", codec)))
-                .get()
-        );
-
-        assertAcked(client().admin().indices().prepareOpen(index).setWaitForActiveShards(1));
-    }
-
-    private void flushAndRefreshIndex(String index) {
-
-        // Request is not blocked
-        for (String blockSetting : Arrays.asList(
-            SETTING_BLOCKS_READ,
-            SETTING_BLOCKS_WRITE,
-            SETTING_READ_ONLY,
-            SETTING_BLOCKS_METADATA,
-            SETTING_READ_ONLY_ALLOW_DELETE
-        )) {
-            try {
-                enableIndexBlock(index, blockSetting);
-                // flush
-                FlushResponse flushResponse = client().admin().indices().prepareFlush(index).setForce(true).execute().actionGet();
-                assertNoFailures(flushResponse);
-
-                // refresh
-                RefreshResponse refreshResponse = client().admin().indices().prepareRefresh(index).execute().actionGet();
-                assertNoFailures(refreshResponse);
-            } finally {
-                disableIndexBlock(index, blockSetting);
-            }
-        }
-    }
-
-    private void ingestDocs(String index, int nbDocs) throws InterruptedException {
-
-        indexRandom(
-            randomBoolean(),
-            false,
-            randomBoolean(),
-            IntStream.range(0, nbDocs)
-                .mapToObj(i -> client().prepareIndex(index).setId(UUID.randomUUID().toString()).setSource("num", i))
-                .collect(toList())
-        );
-        flushAndRefreshIndex(index);
-    }
-
-    private ArrayList<Segment> getSegments(String index) {
-
-        return new ArrayList<>(
-            client().admin()
-                .indices()
-                .segments(new IndicesSegmentsRequest(index))
-                .actionGet()
-                .getIndices()
-                .get(index)
-                .getShards()
-                .get(0)
-                .getShards()[0].getSegments()
-        );
-    }
-
-}
diff --git a/modules/reindex/src/main/java/org/opensearch/index/reindex/AbstractAsyncBulkByScrollAction.java b/modules/reindex/src/main/java/org/opensearch/index/reindex/AbstractAsyncBulkByScrollAction.java
index e2442e1f483f0..6ed486fbdb33b 100644
--- a/modules/reindex/src/main/java/org/opensearch/index/reindex/AbstractAsyncBulkByScrollAction.java
+++ b/modules/reindex/src/main/java/org/opensearch/index/reindex/AbstractAsyncBulkByScrollAction.java
@@ -206,7 +206,7 @@ public abstract class AbstractAsyncBulkByScrollAction<
 
     /**
      * Build the {@link BiFunction} to apply to all {@link RequestWrapper}.
-     *
+     * <p>
      * Public for testings....
      */
     public BiFunction<RequestWrapper<?>, ScrollableHitSource.Hit, RequestWrapper<?>> buildScriptApplier() {
diff --git a/modules/reindex/src/main/java/org/opensearch/index/reindex/BulkByScrollParallelizationHelper.java b/modules/reindex/src/main/java/org/opensearch/index/reindex/BulkByScrollParallelizationHelper.java
index d5a6e392f2019..7534de1408bcc 100644
--- a/modules/reindex/src/main/java/org/opensearch/index/reindex/BulkByScrollParallelizationHelper.java
+++ b/modules/reindex/src/main/java/org/opensearch/index/reindex/BulkByScrollParallelizationHelper.java
@@ -63,14 +63,14 @@ private BulkByScrollParallelizationHelper() {}
 
     /**
      * Takes an action created by a {@link BulkByScrollTask} and runs it with regard to whether the request is sliced or not.
-     *
+     * <p>
      * If the request is not sliced (i.e. the number of slices is 1), the worker action in the given {@link Runnable} will be started on
      * the local node. If the request is sliced (i.e. the number of slices is more than 1), then a subrequest will be created for each
      * slice and sent.
-     *
+     * <p>
      * If slices are set as {@code "auto"}, this class will resolve that to a specific number based on characteristics of the source
      * indices. A request with {@code "auto"} slices may end up being sliced or unsliced.
-     *
+     * <p>
      * This method is equivalent to calling {@link #initTaskState} followed by {@link #executeSlicedAction}
      */
     static <Request extends AbstractBulkByScrollRequest<Request>> void startSlicedAction(
@@ -98,11 +98,11 @@ public void onFailure(Exception e) {
     /**
      * Takes an action and a {@link BulkByScrollTask} and runs it with regard to whether this task is a
      * leader or worker.
-     *
+     * <p>
      * If this task is a worker, the worker action in the given {@link Runnable} will be started on the local
      * node. If the task is a leader (i.e. the number of slices is more than 1), then a subrequest will be
      * created for each slice and sent.
-     *
+     * <p>
      * This method can only be called after the task state is initialized {@link #initTaskState}.
      */
     static <Request extends AbstractBulkByScrollRequest<Request>> void executeSlicedAction(
@@ -125,7 +125,7 @@ static <Request extends AbstractBulkByScrollRequest<Request>> void executeSliced
 
     /**
      * Takes a {@link BulkByScrollTask} and ensures that its initial task state (leader or worker) is set.
-     *
+     * <p>
      * If slices are set as {@code "auto"}, this method will resolve that to a specific number based on
      * characteristics of the source indices. A request with {@code "auto"} slices may end up being sliced or
      * unsliced. This method does not execute the action. In order to execute the action see
diff --git a/modules/reindex/src/test/java/org/opensearch/index/reindex/MultiCodecReindexTests.java b/modules/reindex/src/test/java/org/opensearch/index/reindex/MultiCodecReindexTests.java
new file mode 100644
index 0000000000000..53a0545fd2ff7
--- /dev/null
+++ b/modules/reindex/src/test/java/org/opensearch/index/reindex/MultiCodecReindexTests.java
@@ -0,0 +1,160 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.reindex;
+
+import org.opensearch.action.admin.indices.segments.IndicesSegmentsRequest;
+import org.opensearch.action.admin.indices.settings.put.UpdateSettingsRequest;
+import org.opensearch.action.support.ActiveShardCount;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.index.MergePolicyProvider;
+import org.opensearch.index.engine.Segment;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.test.InternalSettingsPlugin;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import static java.util.stream.Collectors.toList;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+
+public class MultiCodecReindexTests extends ReindexTestCase {
+    final static Map<String, String> codecMap = Map.of(
+        "best_compression",
+        "BEST_COMPRESSION",
+        "zlib",
+        "BEST_COMPRESSION",
+        "default",
+        "BEST_SPEED",
+        "lz4",
+        "BEST_SPEED"
+    );
+    final static String[] codecChoices = codecMap.keySet().toArray(String[]::new);
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return List.of(InternalSettingsPlugin.class, ReindexModulePlugin.class);
+    }
+
+    public void testReindexingMultipleCodecs() throws InterruptedException, ExecutionException {
+        for (Map.Entry<String, String> candidate : codecMap.entrySet()) {
+            final int nbDocs = randomIntBetween(2, 5);
+
+            final String destCodec = candidate.getKey();
+            final String destCodecMode = candidate.getValue();
+
+            final String index = "test-index-" + destCodec;
+            final String destIndex = "dest-index-" + destCodec;
+
+            // create source index
+            createIndex(
+                index,
+                Settings.builder()
+                    .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+                    .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
+                    .put("index.codec", randomFrom(codecChoices))
+                    .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
+                    .build()
+            );
+            ensureGreen(index);
+
+            // index using all codecs
+            for (String codec : codecMap.keySet()) {
+                useCodec(index, codec);
+                ingestDocs(index, nbDocs);
+            }
+
+            assertTrue(
+                getSegments(index).stream()
+                    .flatMap(s -> s.getAttributes().values().stream())
+                    .collect(Collectors.toSet())
+                    .containsAll(codecMap.values())
+            );
+
+            // create destination index with destination codec
+            createIndex(
+                destIndex,
+                Settings.builder()
+                    .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+                    .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
+                    .put("index.codec", destCodec)
+                    .build()
+            );
+            ensureGreen(destIndex);
+
+            // perform reindex
+            BulkByScrollResponse response = reindex().source(index)
+                .destination(destIndex)
+                .refresh(true)
+                .waitForActiveShards(ActiveShardCount.ONE)
+                .get();
+            final int expectedResponseSize = codecMap.size() * nbDocs;
+
+            // assertions
+            assertEquals(0, response.getNoops());
+            assertEquals(1, response.getBatches());
+            assertEquals(0, response.getDeleted());
+            assertEquals(0, response.getVersionConflicts());
+            assertEquals(0, response.getBulkFailures().size());
+            assertEquals(0, response.getSearchFailures().size());
+
+            assertEquals(expectedResponseSize, response.getTotal());
+            assertEquals(expectedResponseSize, response.getCreated());
+
+            assertTrue(response.getTook().getMillis() > 0);
+            assertTrue(getSegments(destIndex).stream().allMatch(segment -> segment.attributes.containsValue(destCodecMode)));
+        }
+    }
+
+    private void useCodec(String index, String codec) throws ExecutionException, InterruptedException {
+        assertAcked(client().admin().indices().prepareClose(index).setWaitForActiveShards(1));
+
+        assertAcked(
+            client().admin()
+                .indices()
+                .updateSettings(new UpdateSettingsRequest(index).settings(Settings.builder().put("index.codec", codec)))
+                .get()
+        );
+
+        assertAcked(client().admin().indices().prepareOpen(index).setWaitForActiveShards(1));
+    }
+
+    private void ingestDocs(String index, int nbDocs) throws InterruptedException {
+        indexRandom(
+            randomBoolean(),
+            false,
+            randomBoolean(),
+            IntStream.range(0, nbDocs)
+                .mapToObj(i -> client().prepareIndex(index).setId(UUID.randomUUID().toString()).setSource("num", i))
+                .collect(toList())
+        );
+
+        flushAndRefresh(index);
+    }
+
+    private ArrayList<Segment> getSegments(String index) {
+        return new ArrayList<>(
+            client().admin()
+                .indices()
+                .segments(new IndicesSegmentsRequest(index))
+                .actionGet()
+                .getIndices()
+                .get(index)
+                .getShards()
+                .get(0)
+                .getShards()[0].getSegments()
+        );
+    }
+}
diff --git a/modules/repository-url/src/main/java/org/opensearch/repositories/url/URLRepository.java b/modules/repository-url/src/main/java/org/opensearch/repositories/url/URLRepository.java
index 9e9d94c8e8fc0..4c8d8aab4532b 100644
--- a/modules/repository-url/src/main/java/org/opensearch/repositories/url/URLRepository.java
+++ b/modules/repository-url/src/main/java/org/opensearch/repositories/url/URLRepository.java
@@ -113,7 +113,7 @@ public URLRepository(
         ClusterService clusterService,
         RecoverySettings recoverySettings
     ) {
-        super(metadata, false, namedXContentRegistry, clusterService, recoverySettings);
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings);
 
         if (URL_SETTING.exists(metadata.settings()) == false && REPOSITORIES_URL_SETTING.exists(environment.settings()) == false) {
             throw new RepositoryException(metadata.name(), "missing url");
diff --git a/modules/search-pipeline-common/README.md b/modules/search-pipeline-common/README.md
new file mode 100644
index 0000000000000..70615d846987b
--- /dev/null
+++ b/modules/search-pipeline-common/README.md
@@ -0,0 +1,202 @@
+- [Search Pipelines](#search-pipelines)
+  - [Architecture](#architecture)
+  - [Search Processors](#search-processors)
+    - [Creating a Search Processor](#creating-a-search-processor)
+    - [Creating a Pipeline](#creating-a-search-pipeline)
+
+# Search Pipelines
+
+This README briefly covers the two types of search processors, explains how you can use them to create search pipelines, and walks through the creation of a new processor.
+
+## Architecture
+
+Search pipelines allow cluster operators to create and reuse [components](#search-processors) to transform search queries and results.
+
+With search pipelines, the operator can combine multiple [search processors](#search-processors) to create a transform which acts on the search request and/or search response.
+
+Search pipelines offer numerous benefits:
+
+1. search processors living in OpenSearch can be used by _all_ calling applications;
+2. search pipeline operations occur inside the OpenSearch cluster, so large results can be processed before returning to the calling application\*;
+3. search processors can be distributed in plugins to be shared with other OpenSearch users;
+4. search pipelines only need to be modified once (and without changing or redeploying any calling applications) to have a change occur on all incoming queries\*\*;
+5. search pipelines support standard APIs for accessing metrics and disaster recovery.
+
+*Within a cluster, results are passed using a more efficient, but version-specific binary protocol. You can pass result information back to a coordinator, allow it to post-process (e.g. rerank or collapse), and finally truncate it before sending it to the client over the less efficient but flexible JSON API.
+
+**For example, the `FilterQueryRequestProcessor` could be used to exclude search results immediately, without needing to make a code change in the application layer and deploy the change across your fleet.
+
+## Search Processors
+
+You can create many search pipelines by combining search processors in various orders. There are two types of search processors:
+
+1. search request processors which transform a request _before_ it is executed;
+2. search response processors which transform the output of a request _after_ it is executed.
+
+You can find all existing search processors registered in `SearchPipelineCommonModulePlugin.java` and described on the documentation website.
+
+### Creating a search processor
+
+New search processors can be created in two different ways.
+
+Generally, a search processor can be created in your own `SearchPipelinePlugin`. This method is best for when you are creating a unique search
+processor for your niche application. This method should also be used when your processor relies on an outside service. To get started creating a search processor in a `SearchPipelinePlugin`, you can use the [plugin template](https://github.com/opensearch-project/opensearch-plugin-template-java ).
+
+Alternatively, if you think your processor may be valuable to _all_ OpenSearch users you can follow these steps:
+
+1. Create a new class in `org.opensearch.search.pipeline.common`, this class will hold your new processor and should include whether it is a request or response processor. For example, a response processor which deleted a target field could be called `DeleteFieldResponseProcessor`.
+
+2. Make the class extend the generic `AbstractProcessor` class as well as implement either the `SearchRequestProcessor` or `SearchResponseProcessor` class depending on what type of processor it is. In the `DeleteFieldResponseProcessor` example, this would look like:
+
+```public class DeleteFieldResponseProcessor extends AbstractProcessor implements SearchResponseProcessor```
+
+3. Create the main functionality of your processor and implement the methods required by the implemented interface. This will be `SearchRequest processRequest(SearchRequest request) throws Exception;` for a search request processor or `SearchResponse processResponse(SearchRequest request, SearchResponse response) throws Exception;` for a search response processor.
+
+For the example field `DeleteFieldResponseProcessor`, this will look like:
+
+```
+@Override
+public SearchResponse processResponse(SearchRequest request, SearchResponse response) throws Exception {
+
+  boolean foundField = false;
+  SearchHit[] hits = response.getHits().getHits();
+  for (SearchHit hit : hits) {
+
+    // Process each hit as desired
+
+    if (hit.hasSource()) {
+      // Change hit source if needed
+    );
+
+    Map<String, Object> sourceAsMap = typeAndSourceMap.v2();
+    if (sourceAsMap.containsKey(field)) {
+      // Handle source as map
+    }
+  }
+
+  if (!foundField && !ignoreMissing) {
+      // Handle error scenarios
+  }
+
+  return response;
+}
+```
+
+4. Create a factory to parse processor-specific JSON configurations. These are used for constructing a processor instance.
+
+In the `DeleteFieldResponseProcessor`, this would look something like:
+
+```
+public static final class Factory implements Processor.Factory<SearchResponseProcessor> {
+
+  /**
+   * Constructor for factory
+   */
+  Factory() {}
+
+  @Override
+  public DeleteFieldResponseProcessor create(
+      Map<String, Processor.Factory<SearchResponseProcessor>> processorFactories,
+      String tag,
+      String description,
+      boolean ignoreFailure,
+      Map<String, Object> config,
+      PipelineContext pipelineContext
+  ) throws Exception {
+      String field = ConfigurationUtils.readStringProperty(TYPE, tag, config, "field");
+      boolean ignoreMissing = ConfigurationUtils.readBooleanProperty(TYPE, tag, config, "ignore_missing", false);
+      return new DeleteFieldResponseProcessor(tag, description, ignoreFailure, field, ignoreMissing);
+  }
+}
+```
+
+In this example, we provide specific configurations for which field should be deleted and whether the processor should ignore attempts to remove a non-existent field.
+
+5. Add the newly added search processor to the `SearchPieplineCommonModulePlugin` getter for the corresponding processor type.
+
+For the `DeleteFieldResponseProcessor`, you would modify the response processor getter to have:
+
+```
+@Override
+public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Parameters parameters) {
+  return Map.of(
+    RenameFieldResponseProcessor.TYPE,
+    new RenameFieldResponseProcessor.Factory(),
+    DeleteFieldResponseProcessor.TYPE,
+    new DeleteFieldResponseProcessor.Factory()
+  );
+}
+```
+
+6. After creating a search processor, the processor is ready to be tested in a search pipeline.
+
+To test your new search processor, you can make use of the test [`SearchPipelineCommonYamlTestSuiteIT`](src/yamlRestTest/java/org/opensearch/search/pipeline/common).
+
+Following the format of the YAML files in [`rest-api-spec.test.search_pipeline`](src/yamlRestTest/resources/rest-api-spec/test/search_pipeline), you should be able to create your own YAML test file to exercise your new processor.
+
+To run the tests, from the root of the OpenSearch repository, you can run `./gradlew :modules:search-pipeline-common:yamlRestTest`.
+
+7. Finally, the processor is ready to used in a cluster.
+
+To use the new processor, make sure the cluster is reloaded and that the new processor is accessible.
+
+The new processor should show when calling `GET /_nodes/search_pipelines`.
+
+If the new processor is shown in the cURL response, the new processor should be available for use in a search pipeline.
+
+## Creating a Search Pipeline
+
+To create a search pipeline, you must create an ordered list of search processors in the OpenSearch cluster.
+
+An example creation request is:
+
+```
+PUT /_search/pipeline/my_pipeline
+{
+  "request_processors": [
+    {
+      "filter_query" : {
+        "tag" : "tag1",
+        "description" : "This processor is going to restrict to publicly visible documents",
+        "query" : {
+          "term": {
+            "visibility": "public"
+          }
+        }
+      }
+    }
+  ],
+  "response_processors": [
+    {
+      "rename_field": {
+        "field": "message",
+        "target_field": "notification"
+      }
+    }
+  ]
+}
+```
+
+Alternatively, if you want to use just the `DeleteFieldResponseProcessor` created before, you would use:
+
+```
+PUT /_search/pipeline/my_pipeline2
+
+{
+  "response_processors": [
+    {
+      "delete_field": {
+        "field": "message"
+      }
+    }
+  ]
+}
+```
+
+## Running a search request using a search pipeline
+
+To run a search request using a search pipeline, you first need to create the pipeline using the request format shown above.
+
+After that is completed, you can run a request using the format: `POST /myindex/_search?search_pipeline=<pipeline_name>`.
+
+In the example of the `DeleteFieldResponseProcessor` this would be called with `POST /myindex/_search?search_pipeline=my_pipeline2`.
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/BasicMap.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/BasicMap.java
new file mode 100644
index 0000000000000..6ddc22420416b
--- /dev/null
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/BasicMap.java
@@ -0,0 +1,126 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+/**
+ * Helper for map abstractions passed to scripting processors. Throws {@link UnsupportedOperationException} for almost
+ * all methods. Subclasses just need to implement get and put.
+ */
+abstract class BasicMap implements Map<String, Object> {
+
+    /**
+     * No-args constructor.
+     */
+    protected BasicMap() {}
+
+    private static final String UNSUPPORTED_OP_ERR = " Method not supported in Search pipeline script";
+
+    @Override
+    public boolean isEmpty() {
+        throw new UnsupportedOperationException("isEmpty" + UNSUPPORTED_OP_ERR);
+    }
+
+    public int size() {
+        throw new UnsupportedOperationException("size" + UNSUPPORTED_OP_ERR);
+    }
+
+    public boolean containsKey(Object key) {
+        return get(key) != null;
+    }
+
+    public boolean containsValue(Object value) {
+        throw new UnsupportedOperationException("containsValue" + UNSUPPORTED_OP_ERR);
+    }
+
+    public Object remove(Object key) {
+        throw new UnsupportedOperationException("remove" + UNSUPPORTED_OP_ERR);
+    }
+
+    public void putAll(Map<? extends String, ?> m) {
+        throw new UnsupportedOperationException("putAll" + UNSUPPORTED_OP_ERR);
+    }
+
+    public void clear() {
+        throw new UnsupportedOperationException("clear" + UNSUPPORTED_OP_ERR);
+    }
+
+    public Set<String> keySet() {
+        throw new UnsupportedOperationException("keySet" + UNSUPPORTED_OP_ERR);
+    }
+
+    public Collection<Object> values() {
+        throw new UnsupportedOperationException("values" + UNSUPPORTED_OP_ERR);
+    }
+
+    public Set<Map.Entry<String, Object>> entrySet() {
+        throw new UnsupportedOperationException("entrySet" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public Object getOrDefault(Object key, Object defaultValue) {
+        throw new UnsupportedOperationException("getOrDefault" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public void forEach(BiConsumer<? super String, ? super Object> action) {
+        throw new UnsupportedOperationException("forEach" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public void replaceAll(BiFunction<? super String, ? super Object, ?> function) {
+        throw new UnsupportedOperationException("replaceAll" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public Object putIfAbsent(String key, Object value) {
+        throw new UnsupportedOperationException("putIfAbsent" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public boolean remove(Object key, Object value) {
+        throw new UnsupportedOperationException("remove" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public boolean replace(String key, Object oldValue, Object newValue) {
+        throw new UnsupportedOperationException("replace" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public Object replace(String key, Object value) {
+        throw new UnsupportedOperationException("replace" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public Object computeIfAbsent(String key, Function<? super String, ?> mappingFunction) {
+        throw new UnsupportedOperationException("computeIfAbsent" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public Object computeIfPresent(String key, BiFunction<? super String, ? super Object, ?> remappingFunction) {
+        throw new UnsupportedOperationException("computeIfPresent" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public Object compute(String key, BiFunction<? super String, ? super Object, ?> remappingFunction) {
+        throw new UnsupportedOperationException("compute" + UNSUPPORTED_OP_ERR);
+    }
+
+    @Override
+    public Object merge(String key, Object value, BiFunction<? super Object, ? super Object, ?> remappingFunction) {
+        throw new UnsupportedOperationException("merge" + UNSUPPORTED_OP_ERR);
+    }
+}
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/CollapseResponseProcessor.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/CollapseResponseProcessor.java
new file mode 100644
index 0000000000000..3e6c4fef6a559
--- /dev/null
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/CollapseResponseProcessor.java
@@ -0,0 +1,122 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.document.DocumentField;
+import org.opensearch.ingest.ConfigurationUtils;
+import org.opensearch.search.SearchHit;
+import org.opensearch.search.SearchHits;
+import org.opensearch.search.pipeline.AbstractProcessor;
+import org.opensearch.search.pipeline.Processor;
+import org.opensearch.search.pipeline.SearchResponseProcessor;
+import org.opensearch.search.pipeline.common.helpers.SearchResponseUtil;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * A simple implementation of field collapsing on search responses. Note that this is not going to work as well as
+ * field collapsing at the shard level, as implemented with the "collapse" parameter in a search request. Mostly
+ * just using this to demo the oversample / truncate_hits processors.
+ */
+public class CollapseResponseProcessor extends AbstractProcessor implements SearchResponseProcessor {
+    /**
+     * Key to reference this processor type from a search pipeline.
+     */
+    public static final String TYPE = "collapse";
+    static final String COLLAPSE_FIELD = "field";
+    private final String collapseField;
+
+    private CollapseResponseProcessor(String tag, String description, boolean ignoreFailure, String collapseField) {
+        super(tag, description, ignoreFailure);
+        this.collapseField = Objects.requireNonNull(collapseField);
+    }
+
+    @Override
+    public String getType() {
+        return TYPE;
+    }
+
+    @Override
+    public SearchResponse processResponse(SearchRequest request, SearchResponse response) {
+
+        if (response.getHits() != null) {
+            if (response.getHits().getCollapseField() != null) {
+                throw new IllegalStateException(
+                    "Cannot collapse on " + collapseField + ". Results already collapsed on " + response.getHits().getCollapseField()
+                );
+            }
+            Map<String, SearchHit> collapsedHits = new LinkedHashMap<>();
+            List<Object> collapseValues = new ArrayList<>();
+            for (SearchHit hit : response.getHits()) {
+                Object fieldValue = null;
+                DocumentField docField = hit.getFields().get(collapseField);
+                if (docField != null) {
+                    if (docField.getValues().size() > 1) {
+                        throw new IllegalStateException(
+                            "Failed to collapse " + hit.getId() + ": doc has multiple values for field " + collapseField
+                        );
+                    }
+                    fieldValue = docField.getValues().get(0);
+                } else if (hit.getSourceAsMap() != null) {
+                    fieldValue = hit.getSourceAsMap().get(collapseField);
+                }
+                String fieldValueString;
+                if (fieldValue == null) {
+                    fieldValueString = "__missing__";
+                } else {
+                    fieldValueString = fieldValue.toString();
+                }
+
+                // Results are already sorted by sort criterion. Only keep the first hit for each field.
+                if (collapsedHits.containsKey(fieldValueString) == false) {
+                    collapsedHits.put(fieldValueString, hit);
+                    collapseValues.add(fieldValue);
+                }
+            }
+            SearchHit[] newHits = new SearchHit[collapsedHits.size()];
+            int i = 0;
+            for (SearchHit collapsedHit : collapsedHits.values()) {
+                newHits[i++] = collapsedHit;
+            }
+            SearchHits searchHits = new SearchHits(
+                newHits,
+                response.getHits().getTotalHits(),
+                response.getHits().getMaxScore(),
+                response.getHits().getSortFields(),
+                collapseField,
+                collapseValues.toArray()
+            );
+            return SearchResponseUtil.replaceHits(searchHits, response);
+        }
+        return response;
+    }
+
+    static class Factory implements Processor.Factory<SearchResponseProcessor> {
+
+        @Override
+        public CollapseResponseProcessor create(
+            Map<String, Processor.Factory<SearchResponseProcessor>> processorFactories,
+            String tag,
+            String description,
+            boolean ignoreFailure,
+            Map<String, Object> config,
+            PipelineContext pipelineContext
+        ) {
+            String collapseField = ConfigurationUtils.readStringProperty(TYPE, tag, config, COLLAPSE_FIELD);
+            return new CollapseResponseProcessor(tag, description, ignoreFailure, collapseField);
+        }
+    }
+
+}
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/OversampleRequestProcessor.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/OversampleRequestProcessor.java
new file mode 100644
index 0000000000000..182cf6ba79504
--- /dev/null
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/OversampleRequestProcessor.java
@@ -0,0 +1,83 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.ingest.ConfigurationUtils;
+import org.opensearch.search.SearchService;
+import org.opensearch.search.pipeline.AbstractProcessor;
+import org.opensearch.search.pipeline.PipelineProcessingContext;
+import org.opensearch.search.pipeline.Processor;
+import org.opensearch.search.pipeline.SearchRequestProcessor;
+import org.opensearch.search.pipeline.StatefulSearchRequestProcessor;
+import org.opensearch.search.pipeline.common.helpers.ContextUtils;
+
+import java.util.Map;
+
+import static org.opensearch.search.pipeline.common.helpers.ContextUtils.applyContextPrefix;
+
+/**
+ * Multiplies the "size" parameter on the {@link SearchRequest} by the given scaling factor, storing the original value
+ * in the request context as "original_size".
+ */
+public class OversampleRequestProcessor extends AbstractProcessor implements StatefulSearchRequestProcessor {
+
+    /**
+     * Key to reference this processor type from a search pipeline.
+     */
+    public static final String TYPE = "oversample";
+    static final String SAMPLE_FACTOR = "sample_factor";
+    static final String ORIGINAL_SIZE = "original_size";
+    private final double sampleFactor;
+    private final String contextPrefix;
+
+    private OversampleRequestProcessor(String tag, String description, boolean ignoreFailure, double sampleFactor, String contextPrefix) {
+        super(tag, description, ignoreFailure);
+        this.sampleFactor = sampleFactor;
+        this.contextPrefix = contextPrefix;
+    }
+
+    @Override
+    public SearchRequest processRequest(SearchRequest request, PipelineProcessingContext requestContext) {
+        if (request.source() != null) {
+            int originalSize = request.source().size();
+            if (originalSize == -1) {
+                originalSize = SearchService.DEFAULT_SIZE;
+            }
+            requestContext.setAttribute(applyContextPrefix(contextPrefix, ORIGINAL_SIZE), originalSize);
+            int newSize = (int) Math.ceil(originalSize * sampleFactor);
+            request.source().size(newSize);
+        }
+        return request;
+    }
+
+    @Override
+    public String getType() {
+        return TYPE;
+    }
+
+    static class Factory implements Processor.Factory<SearchRequestProcessor> {
+        @Override
+        public OversampleRequestProcessor create(
+            Map<String, Processor.Factory<SearchRequestProcessor>> processorFactories,
+            String tag,
+            String description,
+            boolean ignoreFailure,
+            Map<String, Object> config,
+            PipelineContext pipelineContext
+        ) {
+            double sampleFactor = ConfigurationUtils.readDoubleProperty(TYPE, tag, config, SAMPLE_FACTOR);
+            if (sampleFactor < 1.0) {
+                throw ConfigurationUtils.newConfigurationException(TYPE, tag, SAMPLE_FACTOR, "Value must be >= 1.0");
+            }
+            String contextPrefix = ConfigurationUtils.readOptionalStringProperty(TYPE, tag, config, ContextUtils.CONTEXT_PREFIX_PARAMETER);
+            return new OversampleRequestProcessor(tag, description, ignoreFailure, sampleFactor, contextPrefix);
+        }
+    }
+}
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java
index 90f71fd1754e4..a4052d0892ee6 100644
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java
@@ -23,9 +23,10 @@
 import org.opensearch.script.ScriptType;
 import org.opensearch.script.SearchScript;
 import org.opensearch.search.pipeline.AbstractProcessor;
+import org.opensearch.search.pipeline.PipelineProcessingContext;
 import org.opensearch.search.pipeline.Processor;
 import org.opensearch.search.pipeline.SearchRequestProcessor;
-import org.opensearch.search.pipeline.common.helpers.SearchRequestMap;
+import org.opensearch.search.pipeline.StatefulSearchRequestProcessor;
 
 import java.io.InputStream;
 import java.util.HashMap;
@@ -38,7 +39,7 @@
  * Processor that evaluates a script with a search request in its context
  * and then returns the modified search request.
  */
-public final class ScriptRequestProcessor extends AbstractProcessor implements SearchRequestProcessor {
+public final class ScriptRequestProcessor extends AbstractProcessor implements StatefulSearchRequestProcessor {
     /**
      * Key to reference this processor type from a search pipeline.
      */
@@ -72,15 +73,8 @@ public final class ScriptRequestProcessor extends AbstractProcessor implements S
         this.scriptService = scriptService;
     }
 
-    /**
-     * Executes the script with the search request in context.
-     *
-     * @param request The search request passed into the script context.
-     * @return The modified search request.
-     * @throws Exception if an error occurs while processing the request.
-     */
     @Override
-    public SearchRequest processRequest(SearchRequest request) throws Exception {
+    public SearchRequest processRequest(SearchRequest request, PipelineProcessingContext requestContext) throws Exception {
         // assert request is not null and source is not null
         if (request == null || request.source() == null) {
             throw new IllegalArgumentException("search request must not be null");
@@ -93,10 +87,33 @@ public SearchRequest processRequest(SearchRequest request) throws Exception {
             searchScript = precompiledSearchScript;
         }
         // execute the script with the search request in context
-        searchScript.execute(Map.of("_source", new SearchRequestMap(request)));
+        searchScript.execute(Map.of("_source", new SearchRequestMap(request), "request_context", new RequestContextMap(requestContext)));
         return request;
     }
 
+    private static class RequestContextMap extends BasicMap {
+        private final PipelineProcessingContext pipelinedRequestContext;
+
+        private RequestContextMap(PipelineProcessingContext pipelinedRequestContext) {
+            this.pipelinedRequestContext = pipelinedRequestContext;
+        }
+
+        @Override
+        public Object get(Object key) {
+            if (key instanceof String) {
+                return pipelinedRequestContext.getAttribute(key.toString());
+            }
+            return null;
+        }
+
+        @Override
+        public Object put(String key, Object value) {
+            Object originalValue = get(key);
+            pipelinedRequestContext.setAttribute(key, value);
+            return originalValue;
+        }
+    }
+
     /**
      * Returns the type of the processor.
      *
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java
index 49681b80fdead..5378a6721efb2 100644
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java
@@ -38,12 +38,21 @@ public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcesso
             FilterQueryRequestProcessor.TYPE,
             new FilterQueryRequestProcessor.Factory(parameters.namedXContentRegistry),
             ScriptRequestProcessor.TYPE,
-            new ScriptRequestProcessor.Factory(parameters.scriptService)
+            new ScriptRequestProcessor.Factory(parameters.scriptService),
+            OversampleRequestProcessor.TYPE,
+            new OversampleRequestProcessor.Factory()
         );
     }
 
     @Override
     public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Parameters parameters) {
-        return Map.of(RenameFieldResponseProcessor.TYPE, new RenameFieldResponseProcessor.Factory());
+        return Map.of(
+            RenameFieldResponseProcessor.TYPE,
+            new RenameFieldResponseProcessor.Factory(),
+            TruncateHitsResponseProcessor.TYPE,
+            new TruncateHitsResponseProcessor.Factory(),
+            CollapseResponseProcessor.TYPE,
+            new CollapseResponseProcessor.Factory()
+        );
     }
 }
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchRequestMap.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchRequestMap.java
new file mode 100644
index 0000000000000..c6430b96dcbed
--- /dev/null
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchRequestMap.java
@@ -0,0 +1,140 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.search.builder.SearchSourceBuilder;
+
+import java.util.Map;
+
+/**
+ * A custom implementation of {@link Map} that provides access to the properties of a {@link SearchRequest}'s
+ * {@link SearchSourceBuilder}. The class allows retrieving and modifying specific properties of the search request.
+ */
+class SearchRequestMap extends BasicMap implements Map<String, Object> {
+
+    private final SearchSourceBuilder source;
+
+    /**
+     * Constructs a new instance of the {@link SearchRequestMap} with the provided {@link SearchRequest}.
+     *
+     * @param searchRequest The SearchRequest containing the SearchSourceBuilder to be accessed.
+     */
+    public SearchRequestMap(SearchRequest searchRequest) {
+        source = searchRequest.source();
+    }
+
+    /**
+     * Checks if the SearchSourceBuilder is empty.
+     *
+     * @return {@code true} if the SearchSourceBuilder is empty, {@code false} otherwise.
+     */
+    @Override
+    public boolean isEmpty() {
+        return source == null;
+    }
+
+    /**
+     * Retrieves the value associated with the specified property from the SearchSourceBuilder.
+     *
+     * @param key The SearchSourceBuilder property whose value is to be retrieved.
+     * @return The value associated with the specified property or null if the property has not been initialized.
+     * @throws IllegalArgumentException if the property name is not a String.
+     * @throws SearchRequestMapProcessingException if the property is not supported.
+     */
+    @Override
+    public Object get(Object key) {
+        if (!(key instanceof String)) {
+            throw new IllegalArgumentException("key must be a String");
+        }
+        // This is the explicit implementation of fetch value from source
+        switch ((String) key) {
+            case "from":
+                return source.from();
+            case "size":
+                return source.size();
+            case "explain":
+                return source.explain();
+            case "version":
+                return source.version();
+            case "seq_no_primary_term":
+                return source.seqNoAndPrimaryTerm();
+            case "track_scores":
+                return source.trackScores();
+            case "track_total_hits":
+                return source.trackTotalHitsUpTo();
+            case "min_score":
+                return source.minScore();
+            case "terminate_after":
+                return source.terminateAfter();
+            case "profile":
+                return source.profile();
+            default:
+                throw new SearchRequestMapProcessingException("Unsupported key: " + key);
+        }
+    }
+
+    /**
+     * Sets the value for the specified property in the SearchSourceBuilder.
+     *
+     * @param key The property whose value is to be set.
+     * @param value The value to be set for the specified property.
+     * @return The original value associated with the property, or null if none existed.
+     * @throws IllegalArgumentException if the property is not a String.
+     * @throws SearchRequestMapProcessingException if the property is not supported or an error occurs during the setting.
+     */
+    @Override
+    public Object put(String key, Object value) {
+        Object originalValue = get(key);
+        try {
+            switch (key) {
+                case "from":
+                    source.from((Integer) value);
+                    break;
+                case "size":
+                    source.size((Integer) value);
+                    break;
+                case "explain":
+                    source.explain((Boolean) value);
+                    break;
+                case "version":
+                    source.version((Boolean) value);
+                    break;
+                case "seq_no_primary_term":
+                    source.seqNoAndPrimaryTerm((Boolean) value);
+                    break;
+                case "track_scores":
+                    source.trackScores((Boolean) value);
+                    break;
+                case "track_total_hits":
+                    source.trackTotalHitsUpTo((Integer) value);
+                    break;
+                case "min_score":
+                    source.minScore((Float) value);
+                    break;
+                case "terminate_after":
+                    source.terminateAfter((Integer) value);
+                    break;
+                case "profile":
+                    source.profile((Boolean) value);
+                    break;
+                case "stats": // Not modifying stats, sorts, docvalue_fields, etc. as they require more complex handling
+                case "sort":
+                case "timeout":
+                case "docvalue_fields":
+                case "indices_boost":
+                default:
+                    throw new SearchRequestMapProcessingException("Unsupported SearchRequest source property: " + key);
+            }
+        } catch (Exception e) {
+            throw new SearchRequestMapProcessingException("Error while setting value for SearchRequest source property: " + key, e);
+        }
+        return originalValue;
+    }
+}
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMapProcessingException.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchRequestMapProcessingException.java
similarity index 76%
rename from modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMapProcessingException.java
rename to modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchRequestMapProcessingException.java
index cb1e45a20b624..2f00d0f82c2f1 100644
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMapProcessingException.java
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchRequestMapProcessingException.java
@@ -6,7 +6,7 @@
  * compatible open source license.
  */
 
-package org.opensearch.search.pipeline.common.helpers;
+package org.opensearch.search.pipeline.common;
 
 import org.opensearch.OpenSearchException;
 import org.opensearch.OpenSearchWrapperException;
@@ -14,12 +14,12 @@
 /**
  * An exception that indicates an error occurred while processing a {@link SearchRequestMap}.
  */
-public class SearchRequestMapProcessingException extends OpenSearchException implements OpenSearchWrapperException {
+class SearchRequestMapProcessingException extends OpenSearchException implements OpenSearchWrapperException {
 
     /**
      * Constructs a new SearchRequestMapProcessingException with the specified message.
      *
-     * @param msg The error message.
+     * @param msg  The error message.
      * @param args Arguments to substitute in the error message.
      */
     public SearchRequestMapProcessingException(String msg, Object... args) {
@@ -29,9 +29,9 @@ public SearchRequestMapProcessingException(String msg, Object... args) {
     /**
      * Constructs a new SearchRequestMapProcessingException with the specified message and cause.
      *
-     * @param msg The error message.
+     * @param msg   The error message.
      * @param cause The cause of the exception.
-     * @param args Arguments to substitute in the error message.
+     * @param args  Arguments to substitute in the error message.
      */
     public SearchRequestMapProcessingException(String msg, Throwable cause, Object... args) {
         super(msg, cause, args);
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/TruncateHitsResponseProcessor.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/TruncateHitsResponseProcessor.java
new file mode 100644
index 0000000000000..e3413bf41720f
--- /dev/null
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/TruncateHitsResponseProcessor.java
@@ -0,0 +1,96 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.ingest.ConfigurationUtils;
+import org.opensearch.search.SearchHit;
+import org.opensearch.search.pipeline.AbstractProcessor;
+import org.opensearch.search.pipeline.PipelineProcessingContext;
+import org.opensearch.search.pipeline.Processor;
+import org.opensearch.search.pipeline.SearchResponseProcessor;
+import org.opensearch.search.pipeline.StatefulSearchResponseProcessor;
+import org.opensearch.search.pipeline.common.helpers.ContextUtils;
+import org.opensearch.search.pipeline.common.helpers.SearchResponseUtil;
+
+import java.util.Map;
+
+import static org.opensearch.search.pipeline.common.helpers.ContextUtils.applyContextPrefix;
+
+/**
+ * Truncates the returned search hits from the {@link SearchResponse}. If no target size is specified in the pipeline, then
+ * we try using the "original_size" value from the request context, which may have been set by {@link OversampleRequestProcessor}.
+ */
+public class TruncateHitsResponseProcessor extends AbstractProcessor implements StatefulSearchResponseProcessor {
+    /**
+     * Key to reference this processor type from a search pipeline.
+     */
+    public static final String TYPE = "truncate_hits";
+    static final String TARGET_SIZE = "target_size";
+    private final int targetSize;
+    private final String contextPrefix;
+
+    @Override
+    public String getType() {
+        return TYPE;
+    }
+
+    private TruncateHitsResponseProcessor(String tag, String description, boolean ignoreFailure, int targetSize, String contextPrefix) {
+        super(tag, description, ignoreFailure);
+        this.targetSize = targetSize;
+        this.contextPrefix = contextPrefix;
+    }
+
+    @Override
+    public SearchResponse processResponse(SearchRequest request, SearchResponse response, PipelineProcessingContext requestContext) {
+        int size;
+        if (targetSize < 0) { // No value specified in processor config. Use context value instead.
+            String key = applyContextPrefix(contextPrefix, OversampleRequestProcessor.ORIGINAL_SIZE);
+            Object o = requestContext.getAttribute(key);
+            if (o == null) {
+                throw new IllegalStateException("Must specify " + TARGET_SIZE + " unless an earlier processor set " + key);
+            }
+            size = (int) o;
+        } else {
+            size = targetSize;
+        }
+        if (response.getHits() != null && response.getHits().getHits().length > size) {
+            SearchHit[] newHits = new SearchHit[size];
+            System.arraycopy(response.getHits().getHits(), 0, newHits, 0, size);
+            return SearchResponseUtil.replaceHits(newHits, response);
+        }
+        return response;
+    }
+
+    static class Factory implements Processor.Factory<SearchResponseProcessor> {
+        @Override
+        public TruncateHitsResponseProcessor create(
+            Map<String, Processor.Factory<SearchResponseProcessor>> processorFactories,
+            String tag,
+            String description,
+            boolean ignoreFailure,
+            Map<String, Object> config,
+            PipelineContext pipelineContext
+        ) {
+            Integer targetSize = ConfigurationUtils.readIntProperty(TYPE, tag, config, TARGET_SIZE, null);
+            if (targetSize == null) {
+                // Use -1 as an "unset" marker to avoid repeated unboxing of an Integer.
+                targetSize = -1;
+            } else {
+                // Explicitly set values must be >= 0.
+                if (targetSize < 0) {
+                    throw ConfigurationUtils.newConfigurationException(TYPE, tag, TARGET_SIZE, "Value must be >= 0");
+                }
+            }
+            String contextPrefix = ConfigurationUtils.readOptionalStringProperty(TYPE, tag, config, ContextUtils.CONTEXT_PREFIX_PARAMETER);
+            return new TruncateHitsResponseProcessor(tag, description, ignoreFailure, targetSize, contextPrefix);
+        }
+    }
+}
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/ContextUtils.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/ContextUtils.java
new file mode 100644
index 0000000000000..9697da85dbecf
--- /dev/null
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/ContextUtils.java
@@ -0,0 +1,38 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common.helpers;
+
+/**
+ * Helpers for working with request-scoped context.
+ */
+public final class ContextUtils {
+    private ContextUtils() {}
+
+    /**
+     * Parameter that can be passed to a stateful processor to avoid collisions between contextual variables by
+     * prefixing them with distinct qualifiers.
+     */
+    public static final String CONTEXT_PREFIX_PARAMETER = "context_prefix";
+
+    /**
+     * Replaces a "global" variable name with one scoped to a given context prefix (unless prefix is null or empty).
+     * @param contextPrefix the prefix qualifier for the variable
+     * @param variableName the generic "global" form of the context variable
+     * @return the variableName prefixed with contextPrefix followed by ".", or just variableName if contextPrefix is null or empty
+     */
+    public static String applyContextPrefix(String contextPrefix, String variableName) {
+        String contextVariable;
+        if (contextPrefix != null && contextPrefix.isEmpty() == false) {
+            contextVariable = contextPrefix + "." + variableName;
+        } else {
+            contextVariable = variableName;
+        }
+        return contextVariable;
+    }
+}
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMap.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMap.java
deleted file mode 100644
index 7af3ac66be146..0000000000000
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMap.java
+++ /dev/null
@@ -1,395 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.search.pipeline.common.helpers;
-
-import org.opensearch.action.search.SearchRequest;
-import org.opensearch.search.builder.SearchSourceBuilder;
-
-import java.util.Collection;
-import java.util.Map;
-import java.util.Set;
-import java.util.function.BiConsumer;
-import java.util.function.BiFunction;
-import java.util.function.Function;
-
-/**
- * A custom implementation of {@link Map} that provides access to the properties of a {@link SearchRequest}'s
- * {@link SearchSourceBuilder}. The class allows retrieving and modifying specific properties of the search request.
- */
-public class SearchRequestMap implements Map<String, Object> {
-    private static final String UNSUPPORTED_OP_ERR = " Method not supported in Search pipeline script";
-
-    private final SearchSourceBuilder source;
-
-    /**
-     * Constructs a new instance of the {@link SearchRequestMap} with the provided {@link SearchRequest}.
-     *
-     * @param searchRequest The SearchRequest containing the SearchSourceBuilder to be accessed.
-     */
-    public SearchRequestMap(SearchRequest searchRequest) {
-        source = searchRequest.source();
-    }
-
-    /**
-     * Retrieves the number of properties in the SearchSourceBuilder.
-     *
-     * @return The number of properties in the SearchSourceBuilder.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public int size() {
-        throw new UnsupportedOperationException("size" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Checks if the SearchSourceBuilder is empty.
-     *
-     * @return {@code true} if the SearchSourceBuilder is empty, {@code false} otherwise.
-     */
-    @Override
-    public boolean isEmpty() {
-        return source == null;
-    }
-
-    /**
-     * Checks if the SearchSourceBuilder contains the specified property.
-     *
-     * @param key The property to check for.
-     * @return {@code true} if the SearchSourceBuilder contains the specified property, {@code false} otherwise.
-     */
-    @Override
-    public boolean containsKey(Object key) {
-        return get(key) != null;
-    }
-
-    /**
-     * Checks if the SearchSourceBuilder contains the specified value.
-     *
-     * @param value The value to check for.
-     * @return {@code true} if the SearchSourceBuilder contains the specified value, {@code false} otherwise.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public boolean containsValue(Object value) {
-        throw new UnsupportedOperationException("containsValue" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Retrieves the value associated with the specified property from the SearchSourceBuilder.
-     *
-     * @param key The SearchSourceBuilder property whose value is to be retrieved.
-     * @return The value associated with the specified property or null if the property has not been initialized.
-     * @throws IllegalArgumentException if the property name is not a String.
-     * @throws SearchRequestMapProcessingException if the property is not supported.
-     */
-    @Override
-    public Object get(Object key) {
-        if (!(key instanceof String)) {
-            throw new IllegalArgumentException("key must be a String");
-        }
-        // This is the explicit implementation of fetch value from source
-        switch ((String) key) {
-            case "from":
-                return source.from();
-            case "size":
-                return source.size();
-            case "explain":
-                return source.explain();
-            case "version":
-                return source.version();
-            case "seq_no_primary_term":
-                return source.seqNoAndPrimaryTerm();
-            case "track_scores":
-                return source.trackScores();
-            case "track_total_hits":
-                return source.trackTotalHitsUpTo();
-            case "min_score":
-                return source.minScore();
-            case "terminate_after":
-                return source.terminateAfter();
-            case "profile":
-                return source.profile();
-            default:
-                throw new SearchRequestMapProcessingException("Unsupported key: " + key);
-        }
-    }
-
-    /**
-     * Sets the value for the specified property in the SearchSourceBuilder.
-     *
-     * @param key The property whose value is to be set.
-     * @param value The value to be set for the specified property.
-     * @return The original value associated with the property, or null if none existed.
-     * @throws IllegalArgumentException if the property is not a String.
-     * @throws SearchRequestMapProcessingException if the property is not supported or an error occurs during the setting.
-     */
-    @Override
-    public Object put(String key, Object value) {
-        Object originalValue = get(key);
-        try {
-            switch (key) {
-                case "from":
-                    source.from((Integer) value);
-                    break;
-                case "size":
-                    source.size((Integer) value);
-                    break;
-                case "explain":
-                    source.explain((Boolean) value);
-                    break;
-                case "version":
-                    source.version((Boolean) value);
-                    break;
-                case "seq_no_primary_term":
-                    source.seqNoAndPrimaryTerm((Boolean) value);
-                    break;
-                case "track_scores":
-                    source.trackScores((Boolean) value);
-                    break;
-                case "track_total_hits":
-                    source.trackTotalHitsUpTo((Integer) value);
-                    break;
-                case "min_score":
-                    source.minScore((Float) value);
-                    break;
-                case "terminate_after":
-                    source.terminateAfter((Integer) value);
-                    break;
-                case "profile":
-                    source.profile((Boolean) value);
-                    break;
-                case "stats": // Not modifying stats, sorts, docvalue_fields, etc. as they require more complex handling
-                case "sort":
-                case "timeout":
-                case "docvalue_fields":
-                case "indices_boost":
-                default:
-                    throw new SearchRequestMapProcessingException("Unsupported SearchRequest source property: " + key);
-            }
-        } catch (Exception e) {
-            throw new SearchRequestMapProcessingException("Error while setting value for SearchRequest source property: " + key, e);
-        }
-        return originalValue;
-    }
-
-    /**
-     * Removes the specified property from the SearchSourceBuilder.
-     *
-     * @param key The name of the property that will be removed.
-     * @return The value associated with the property before it was removed, or null if the property was not found.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object remove(Object key) {
-        throw new UnsupportedOperationException("remove" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Sets all the properties from the specified map to the SearchSourceBuilder.
-     *
-     * @param m The map containing the properties to be set.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public void putAll(Map<? extends String, ?> m) {
-        throw new UnsupportedOperationException("putAll" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Removes all properties from the SearchSourceBuilder.
-     *
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public void clear() {
-        throw new UnsupportedOperationException("clear" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Returns a set view of the property names in the SearchSourceBuilder.
-     *
-     * @return A set view of the property names in the SearchSourceBuilder.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Set<String> keySet() {
-        throw new UnsupportedOperationException("keySet" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Returns a collection view of the property values in the SearchSourceBuilder.
-     *
-     * @return A collection view of the property values in the SearchSourceBuilder.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Collection<Object> values() {
-        throw new UnsupportedOperationException("values" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Returns a set view of the properties in the SearchSourceBuilder.
-     *
-     * @return A set view of the properties in the SearchSourceBuilder.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Set<Entry<String, Object>> entrySet() {
-        throw new UnsupportedOperationException("entrySet" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Returns the value to which the specified property has, or the defaultValue if the property is not present in the
-     * SearchSourceBuilder.
-     *
-     * @param key The property whose associated value is to be returned.
-     * @param defaultValue The default value to be returned if the property is not present.
-     * @return The value to which the specified property has, or the defaultValue if the property is not present.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object getOrDefault(Object key, Object defaultValue) {
-        throw new UnsupportedOperationException("getOrDefault" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Performs the given action for each property in the SearchSourceBuilder until all properties have been processed or the
-     * action throws an exception
-     *
-     * @param action The action to be performed for each property.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public void forEach(BiConsumer<? super String, ? super Object> action) {
-        throw new UnsupportedOperationException("forEach" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Replaces each property's value with the result of invoking the given function on that property until all properties have
-     * been processed or the function throws an exception.
-     *
-     * @param function The function to apply to each property.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public void replaceAll(BiFunction<? super String, ? super Object, ?> function) {
-        throw new UnsupportedOperationException("replaceAll" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * If the specified property is not already associated with a value, associates it with the given value and returns null,
-     * else returns the current value.
-     *
-     * @param key The property whose value is to be set if absent.
-     * @param value The value to be associated with the specified property.
-     * @return The current value associated with the property, or null if the property is not present.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object putIfAbsent(String key, Object value) {
-        throw new UnsupportedOperationException("putIfAbsent" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Removes the property only if it has the given value.
-     *
-     * @param key The property to be removed.
-     * @param value The value expected to be associated with the property.
-     * @return {@code true} if the entry was removed, {@code false} otherwise.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public boolean remove(Object key, Object value) {
-        throw new UnsupportedOperationException("remove" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Replaces the specified property only if it has the given value.
-     *
-     * @param key The property to be replaced.
-     * @param oldValue The value expected to be associated with the property.
-     * @param newValue The value to be associated with the property.
-     * @return {@code true} if the property was replaced, {@code false} otherwise.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public boolean replace(String key, Object oldValue, Object newValue) {
-        throw new UnsupportedOperationException("replace" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * Replaces the specified property only if it has the given value.
-     *
-     * @param key The property to be replaced.
-     * @param value The value to be associated with the property.
-     * @return The previous value associated with the property, or null if the property was not found.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object replace(String key, Object value) {
-        throw new UnsupportedOperationException("replace" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * The computed value associated with the property, or null if the property is not present.
-     *
-     * @param key The property whose value is to be computed if absent.
-     * @param mappingFunction The function to compute a value based on the property.
-     * @return The computed value associated with the property, or null if the property is not present.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object computeIfAbsent(String key, Function<? super String, ?> mappingFunction) {
-        throw new UnsupportedOperationException("computeIfAbsent" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * If the value for the specified property is present, attempts to compute a new mapping given the property and its current
-     * mapped value.
-     *
-     * @param key The property for which the mapping is to be computed.
-     * @param remappingFunction The function to compute a new mapping.
-     * @return The new value associated with the property, or null if the property is not present.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object computeIfPresent(String key, BiFunction<? super String, ? super Object, ?> remappingFunction) {
-        throw new UnsupportedOperationException("computeIfPresent" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * If the value for the specified property is present, attempts to compute a new mapping given the property and its current
-     * mapped value, or removes the property if the computed value is null.
-     *
-     * @param key The property for which the mapping is to be computed.
-     * @param remappingFunction The function to compute a new mapping.
-     * @return The new value associated with the property, or null if the property is not present.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object compute(String key, BiFunction<? super String, ? super Object, ?> remappingFunction) {
-        throw new UnsupportedOperationException("compute" + UNSUPPORTED_OP_ERR);
-    }
-
-    /**
-     * If the specified property is not already associated with a value or is associated with null, associates it with the
-     * given non-null value. Otherwise, replaces the associated value with the results of applying the given
-     * remapping function to the current and new values.
-     *
-     * @param key The property for which the mapping is to be merged.
-     * @param value The non-null value to be merged with the existing value.
-     * @param remappingFunction The function to merge the existing and new values.
-     * @return The new value associated with the property, or null if the property is not present.
-     * @throws UnsupportedOperationException always, as the method is not supported.
-     */
-    @Override
-    public Object merge(String key, Object value, BiFunction<? super Object, ? super Object, ?> remappingFunction) {
-        throw new UnsupportedOperationException("merge" + UNSUPPORTED_OP_ERR);
-    }
-}
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchResponseUtil.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchResponseUtil.java
new file mode 100644
index 0000000000000..0710548c6429f
--- /dev/null
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/helpers/SearchResponseUtil.java
@@ -0,0 +1,93 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common.helpers;
+
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.action.search.SearchResponseSections;
+import org.opensearch.search.SearchHit;
+import org.opensearch.search.SearchHits;
+import org.opensearch.search.aggregations.InternalAggregations;
+import org.opensearch.search.internal.InternalSearchResponse;
+import org.opensearch.search.profile.SearchProfileShardResults;
+
+/**
+ * Helper methods for manipulating {@link SearchResponse}.
+ */
+public final class SearchResponseUtil {
+    private SearchResponseUtil() {
+
+    }
+
+    /**
+     * Construct a new {@link SearchResponse} based on an existing one, replacing just the {@link SearchHits}.
+     * @param newHits new {@link SearchHits}
+     * @param response the existing search response
+     * @return a new search response where the {@link SearchHits} has been replaced
+     */
+    public static SearchResponse replaceHits(SearchHits newHits, SearchResponse response) {
+        SearchResponseSections searchResponseSections;
+        if (response.getAggregations() == null || response.getAggregations() instanceof InternalAggregations) {
+            // We either have no aggregations, or we have Writeable InternalAggregations.
+            // Either way, we can produce a Writeable InternalSearchResponse.
+            searchResponseSections = new InternalSearchResponse(
+                newHits,
+                (InternalAggregations) response.getAggregations(),
+                response.getSuggest(),
+                new SearchProfileShardResults(response.getProfileResults()),
+                response.isTimedOut(),
+                response.isTerminatedEarly(),
+                response.getNumReducePhases()
+            );
+        } else {
+            // We have non-Writeable Aggregations, so the whole SearchResponseSections is non-Writeable.
+            searchResponseSections = new SearchResponseSections(
+                newHits,
+                response.getAggregations(),
+                response.getSuggest(),
+                response.isTimedOut(),
+                response.isTerminatedEarly(),
+                new SearchProfileShardResults(response.getProfileResults()),
+                response.getNumReducePhases()
+            );
+        }
+
+        return new SearchResponse(
+            searchResponseSections,
+            response.getScrollId(),
+            response.getTotalShards(),
+            response.getSuccessfulShards(),
+            response.getSkippedShards(),
+            response.getTook().millis(),
+            response.getShardFailures(),
+            response.getClusters(),
+            response.pointInTimeId()
+        );
+    }
+
+    /**
+     * Convenience method when only replacing the {@link SearchHit} array within the {@link SearchHits} in a {@link SearchResponse}.
+     * @param newHits the new array of {@link SearchHit} elements.
+     * @param response the search response to update
+     * @return a {@link SearchResponse} where the underlying array of {@link SearchHit} within the {@link SearchHits} has been replaced.
+     */
+    public static SearchResponse replaceHits(SearchHit[] newHits, SearchResponse response) {
+        if (response.getHits() == null) {
+            throw new IllegalStateException("Response must have hits");
+        }
+        SearchHits searchHits = new SearchHits(
+            newHits,
+            response.getHits().getTotalHits(),
+            response.getHits().getMaxScore(),
+            response.getHits().getSortFields(),
+            response.getHits().getCollapseField(),
+            response.getHits().getCollapseValues()
+        );
+        return replaceHits(searchHits, response);
+    }
+}
diff --git a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/CollapseResponseProcessorTests.java b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/CollapseResponseProcessorTests.java
new file mode 100644
index 0000000000000..cda011f24fea1
--- /dev/null
+++ b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/CollapseResponseProcessorTests.java
@@ -0,0 +1,86 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import org.apache.lucene.search.TotalHits;
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.document.DocumentField;
+import org.opensearch.core.common.bytes.BytesArray;
+import org.opensearch.search.SearchHit;
+import org.opensearch.search.SearchHits;
+import org.opensearch.search.internal.InternalSearchResponse;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class CollapseResponseProcessorTests extends OpenSearchTestCase {
+    public void testWithDocumentFields() {
+        testProcessor(true);
+    }
+
+    public void testWithSourceField() {
+        testProcessor(false);
+    }
+
+    private void testProcessor(boolean includeDocField) {
+        Map<String, Object> config = new HashMap<>(Map.of(CollapseResponseProcessor.COLLAPSE_FIELD, "groupid"));
+        CollapseResponseProcessor processor = new CollapseResponseProcessor.Factory().create(
+            Collections.emptyMap(),
+            null,
+            null,
+            false,
+            config,
+            null
+        );
+        int numHits = randomIntBetween(1, 100);
+        SearchResponse inputResponse = generateResponse(numHits, includeDocField);
+
+        SearchResponse processedResponse = processor.processResponse(new SearchRequest(), inputResponse);
+        if (numHits % 2 == 0) {
+            assertEquals(numHits / 2, processedResponse.getHits().getHits().length);
+        } else {
+            assertEquals(numHits / 2 + 1, processedResponse.getHits().getHits().length);
+        }
+        for (SearchHit collapsedHit : processedResponse.getHits()) {
+            assertEquals(0, collapsedHit.docId() % 2);
+        }
+        assertEquals("groupid", processedResponse.getHits().getCollapseField());
+        assertEquals(processedResponse.getHits().getHits().length, processedResponse.getHits().getCollapseValues().length);
+        for (int i = 0; i < processedResponse.getHits().getHits().length; i++) {
+            assertEquals(i, processedResponse.getHits().getCollapseValues()[i]);
+        }
+    }
+
+    private static SearchResponse generateResponse(int numHits, boolean includeDocField) {
+        SearchHit[] hitsArray = new SearchHit[numHits];
+        for (int i = 0; i < numHits; i++) {
+            Map<String, DocumentField> docFields;
+            int groupValue = i / 2;
+            if (includeDocField) {
+                docFields = Map.of("groupid", new DocumentField("groupid", List.of(groupValue)));
+            } else {
+                docFields = Collections.emptyMap();
+            }
+            SearchHit hit = new SearchHit(i, Integer.toString(i), docFields, Collections.emptyMap());
+            hit.sourceRef(new BytesArray("{\"groupid\": " + groupValue + "}"));
+            hitsArray[i] = hit;
+        }
+        SearchHits searchHits = new SearchHits(
+            hitsArray,
+            new TotalHits(Math.max(numHits, 1000), TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO),
+            1.0f
+        );
+        InternalSearchResponse internalSearchResponse = new InternalSearchResponse(searchHits, null, null, null, false, false, 0);
+        return new SearchResponse(internalSearchResponse, null, 1, 1, 0, 10, null, null);
+    }
+}
diff --git a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/OversampleRequestProcessorTests.java b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/OversampleRequestProcessorTests.java
new file mode 100644
index 0000000000000..96e99dff9cc03
--- /dev/null
+++ b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/OversampleRequestProcessorTests.java
@@ -0,0 +1,62 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.search.builder.SearchSourceBuilder;
+import org.opensearch.search.pipeline.PipelineProcessingContext;
+import org.opensearch.search.pipeline.common.helpers.ContextUtils;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+public class OversampleRequestProcessorTests extends OpenSearchTestCase {
+
+    public void testEmptySource() {
+        OversampleRequestProcessor.Factory factory = new OversampleRequestProcessor.Factory();
+        Map<String, Object> config = new HashMap<>(Map.of(OversampleRequestProcessor.SAMPLE_FACTOR, 3.0));
+        OversampleRequestProcessor processor = factory.create(Collections.emptyMap(), null, null, false, config, null);
+
+        SearchRequest request = new SearchRequest();
+        PipelineProcessingContext context = new PipelineProcessingContext();
+        SearchRequest transformedRequest = processor.processRequest(request, context);
+        assertEquals(request, transformedRequest);
+        assertNull(context.getAttribute("original_size"));
+    }
+
+    public void testBasicBehavior() {
+        OversampleRequestProcessor.Factory factory = new OversampleRequestProcessor.Factory();
+        Map<String, Object> config = new HashMap<>(Map.of(OversampleRequestProcessor.SAMPLE_FACTOR, 3.0));
+        OversampleRequestProcessor processor = factory.create(Collections.emptyMap(), null, null, false, config, null);
+
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder().size(10);
+        SearchRequest request = new SearchRequest().source(sourceBuilder);
+        PipelineProcessingContext context = new PipelineProcessingContext();
+        SearchRequest transformedRequest = processor.processRequest(request, context);
+        assertEquals(30, transformedRequest.source().size());
+        assertEquals(10, context.getAttribute("original_size"));
+    }
+
+    public void testContextPrefix() {
+        OversampleRequestProcessor.Factory factory = new OversampleRequestProcessor.Factory();
+        Map<String, Object> config = new HashMap<>(
+            Map.of(OversampleRequestProcessor.SAMPLE_FACTOR, 3.0, ContextUtils.CONTEXT_PREFIX_PARAMETER, "foo")
+        );
+        OversampleRequestProcessor processor = factory.create(Collections.emptyMap(), null, null, false, config, null);
+
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder().size(10);
+        SearchRequest request = new SearchRequest().source(sourceBuilder);
+        PipelineProcessingContext context = new PipelineProcessingContext();
+        SearchRequest transformedRequest = processor.processRequest(request, context);
+        assertEquals(30, transformedRequest.source().size());
+        assertEquals(10, context.getAttribute("foo.original_size"));
+    }
+}
diff --git a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/ScriptRequestProcessorTests.java b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/ScriptRequestProcessorTests.java
index fde9757312e30..b372b220b71ac 100644
--- a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/ScriptRequestProcessorTests.java
+++ b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/ScriptRequestProcessorTests.java
@@ -18,7 +18,7 @@
 import org.opensearch.script.ScriptType;
 import org.opensearch.script.SearchScript;
 import org.opensearch.search.builder.SearchSourceBuilder;
-import org.opensearch.search.pipeline.common.helpers.SearchRequestMap;
+import org.opensearch.search.pipeline.PipelineProcessingContext;
 import org.opensearch.test.OpenSearchTestCase;
 import org.junit.Before;
 
@@ -27,8 +27,6 @@
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
-import static org.hamcrest.core.Is.is;
-
 public class ScriptRequestProcessorTests extends OpenSearchTestCase {
 
     private ScriptService scriptService;
@@ -87,7 +85,7 @@ public void testScriptingWithoutPrecompiledScriptFactory() throws Exception {
         searchRequest.source(createSearchSourceBuilder());
 
         assertNotNull(searchRequest);
-        processor.processRequest(searchRequest);
+        processor.processRequest(searchRequest, new PipelineProcessingContext());
         assertSearchRequest(searchRequest);
     }
 
@@ -104,7 +102,7 @@ public void testScriptingWithPrecompiledIngestScript() throws Exception {
         searchRequest.source(createSearchSourceBuilder());
 
         assertNotNull(searchRequest);
-        processor.processRequest(searchRequest);
+        processor.processRequest(searchRequest, new PipelineProcessingContext());
         assertSearchRequest(searchRequest);
     }
 
@@ -124,15 +122,15 @@ private SearchSourceBuilder createSearchSourceBuilder() {
     }
 
     private void assertSearchRequest(SearchRequest searchRequest) {
-        assertThat(searchRequest.source().from(), is(20));
-        assertThat(searchRequest.source().size(), is(30));
-        assertThat(searchRequest.source().explain(), is(false));
-        assertThat(searchRequest.source().version(), is(false));
-        assertThat(searchRequest.source().seqNoAndPrimaryTerm(), is(false));
-        assertThat(searchRequest.source().trackScores(), is(false));
-        assertThat(searchRequest.source().trackTotalHitsUpTo(), is(4));
-        assertThat(searchRequest.source().minScore(), is(2.0f));
-        assertThat(searchRequest.source().timeout(), is(new TimeValue(60, TimeUnit.SECONDS)));
-        assertThat(searchRequest.source().terminateAfter(), is(6));
+        assertEquals(20, searchRequest.source().from());
+        assertEquals(30, searchRequest.source().size());
+        assertFalse(searchRequest.source().explain());
+        assertFalse(searchRequest.source().version());
+        assertFalse(searchRequest.source().seqNoAndPrimaryTerm());
+        assertFalse(searchRequest.source().trackScores());
+        assertEquals(4, searchRequest.source().trackTotalHitsUpTo().intValue());
+        assertEquals(2.0f, searchRequest.source().minScore(), 0.0001);
+        assertEquals(new TimeValue(60, TimeUnit.SECONDS), searchRequest.source().timeout());
+        assertEquals(6, searchRequest.source().terminateAfter());
     }
 }
diff --git a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMapTests.java b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/SearchRequestMapTests.java
similarity index 99%
rename from modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMapTests.java
rename to modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/SearchRequestMapTests.java
index 5572f28335e1c..c982ada7b5ea5 100644
--- a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/helpers/SearchRequestMapTests.java
+++ b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/SearchRequestMapTests.java
@@ -5,7 +5,7 @@
  * this file be licensed under the Apache-2.0 license or a
  * compatible open source license.
  */
-package org.opensearch.search.pipeline.common.helpers;
+package org.opensearch.search.pipeline.common;
 
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.search.builder.SearchSourceBuilder;
diff --git a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/TruncateHitsResponseProcessorTests.java b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/TruncateHitsResponseProcessorTests.java
new file mode 100644
index 0000000000000..7615225c7f77e
--- /dev/null
+++ b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/TruncateHitsResponseProcessorTests.java
@@ -0,0 +1,91 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline.common;
+
+import org.apache.lucene.search.TotalHits;
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.search.SearchHit;
+import org.opensearch.search.SearchHits;
+import org.opensearch.search.internal.InternalSearchResponse;
+import org.opensearch.search.pipeline.PipelineProcessingContext;
+import org.opensearch.search.pipeline.common.helpers.ContextUtils;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+public class TruncateHitsResponseProcessorTests extends OpenSearchTestCase {
+
+    public void testBasicBehavior() {
+        int targetSize = randomInt(50);
+        TruncateHitsResponseProcessor.Factory factory = new TruncateHitsResponseProcessor.Factory();
+        Map<String, Object> config = new HashMap<>(Map.of(TruncateHitsResponseProcessor.TARGET_SIZE, targetSize));
+        TruncateHitsResponseProcessor processor = factory.create(Collections.emptyMap(), null, null, false, config, null);
+
+        int numHits = randomInt(100);
+        SearchResponse response = constructResponse(numHits);
+        SearchResponse transformedResponse = processor.processResponse(new SearchRequest(), response, new PipelineProcessingContext());
+        assertEquals(Math.min(targetSize, numHits), transformedResponse.getHits().getHits().length);
+    }
+
+    public void testTargetSizePassedViaContext() {
+        TruncateHitsResponseProcessor.Factory factory = new TruncateHitsResponseProcessor.Factory();
+        TruncateHitsResponseProcessor processor = factory.create(Collections.emptyMap(), null, null, false, Collections.emptyMap(), null);
+
+        int targetSize = randomInt(50);
+        int numHits = randomInt(100);
+        SearchResponse response = constructResponse(numHits);
+        PipelineProcessingContext requestContext = new PipelineProcessingContext();
+        requestContext.setAttribute("original_size", targetSize);
+        SearchResponse transformedResponse = processor.processResponse(new SearchRequest(), response, requestContext);
+        assertEquals(Math.min(targetSize, numHits), transformedResponse.getHits().getHits().length);
+    }
+
+    public void testTargetSizePassedViaContextWithPrefix() {
+        TruncateHitsResponseProcessor.Factory factory = new TruncateHitsResponseProcessor.Factory();
+        Map<String, Object> config = new HashMap<>(Map.of(ContextUtils.CONTEXT_PREFIX_PARAMETER, "foo"));
+        TruncateHitsResponseProcessor processor = factory.create(Collections.emptyMap(), null, null, false, config, null);
+
+        int targetSize = randomInt(50);
+        int numHits = randomInt(100);
+        SearchResponse response = constructResponse(numHits);
+        PipelineProcessingContext requestContext = new PipelineProcessingContext();
+        requestContext.setAttribute("foo.original_size", targetSize);
+        SearchResponse transformedResponse = processor.processResponse(new SearchRequest(), response, requestContext);
+        assertEquals(Math.min(targetSize, numHits), transformedResponse.getHits().getHits().length);
+    }
+
+    public void testTargetSizeMissing() {
+        TruncateHitsResponseProcessor.Factory factory = new TruncateHitsResponseProcessor.Factory();
+        TruncateHitsResponseProcessor processor = factory.create(Collections.emptyMap(), null, null, false, Collections.emptyMap(), null);
+
+        int numHits = randomInt(100);
+        SearchResponse response = constructResponse(numHits);
+        assertThrows(
+            IllegalStateException.class,
+            () -> processor.processResponse(new SearchRequest(), response, new PipelineProcessingContext())
+        );
+    }
+
+    private static SearchResponse constructResponse(int numHits) {
+        SearchHit[] hitsArray = new SearchHit[numHits];
+        for (int i = 0; i < numHits; i++) {
+            hitsArray[i] = new SearchHit(i, Integer.toString(i), Collections.emptyMap(), Collections.emptyMap());
+        }
+        SearchHits searchHits = new SearchHits(
+            hitsArray,
+            new TotalHits(Math.max(numHits, 1000), TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO),
+            1.0f
+        );
+        InternalSearchResponse internalSearchResponse = new InternalSearchResponse(searchHits, null, null, null, false, false, 0);
+        return new SearchResponse(internalSearchResponse, null, 1, 1, 0, 10, null, null);
+    }
+}
diff --git a/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/60_oversample_truncate.yml b/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/60_oversample_truncate.yml
new file mode 100644
index 0000000000000..1f9e95084322d
--- /dev/null
+++ b/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/60_oversample_truncate.yml
@@ -0,0 +1,105 @@
+---
+teardown:
+  - do:
+      search_pipeline.delete:
+        id: "my_pipeline"
+        ignore: 404
+
+---
+"Test state propagating from oversample to truncate_hits processor":
+  - do:
+      search_pipeline.put:
+        id: "my_pipeline"
+        body: >
+          {
+            "description": "_description",
+            "request_processors": [
+              {
+                "oversample" : {
+                  "sample_factor" : 2
+                }
+              }
+            ],
+            "response_processors": [
+              {
+                "collapse" : {
+                  "field" : "group_id"
+                }
+              },
+              {
+                "truncate_hits" : {}
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        body: {
+          "group_id": "a",
+          "popularity" : 1
+        }
+  - do:
+      index:
+        index: test
+        id: 2
+        body: {
+          "group_id": "a",
+          "popularity" : 2
+        }
+  - do:
+      index:
+        index: test
+        id: 3
+        body: {
+          "group_id": "b",
+          "popularity" : 3
+        }
+  - do:
+      index:
+        index: test
+        id: 4
+        body: {
+          "group_id": "b",
+          "popularity" : 4
+        }
+  - do:
+      indices.refresh:
+        index: test
+
+  - do:
+      search:
+        body: {
+          "query" : {
+            "function_score" : {
+              "field_value_factor" : {
+                "field" : "popularity"
+              }
+            }
+          },
+          "size" : 2
+        }
+  - match: { hits.total.value: 4 }
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._id: "4" }
+  - match: { hits.hits.1._id: "3" }
+
+  - do:
+      search:
+        search_pipeline: my_pipeline
+        body: {
+          "query" : {
+            "function_score" : {
+              "field_value_factor" : {
+                "field" : "popularity"
+              }
+            }
+          },
+          "size" : 2
+        }
+  - match: { hits.total.value: 4 }
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._id: "4" }
+  - match: { hits.hits.1._id: "2" }
diff --git a/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/70_script_truncate.yml b/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/70_script_truncate.yml
new file mode 100644
index 0000000000000..9c9f6747e9bdc
--- /dev/null
+++ b/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/70_script_truncate.yml
@@ -0,0 +1,70 @@
+---
+teardown:
+  - do:
+      search_pipeline.delete:
+        id: "my_pipeline"
+        ignore: 404
+
+---
+"Test state propagating from script request to truncate_hits processor":
+  - do:
+      search_pipeline.put:
+        id: "my_pipeline"
+        body: >
+          {
+            "description": "_description",
+            "request_processors": [
+              {
+                "script" : {
+                  "source" : "ctx.request_context['foo.original_size'] = 2"
+                }
+              }
+            ],
+            "response_processors": [
+              {
+                "truncate_hits" : {
+                  "context_prefix" : "foo"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        body: {}
+  - do:
+      index:
+        index: test
+        id: 2
+        body: {}
+  - do:
+      index:
+        index: test
+        id: 3
+        body: {}
+  - do:
+      index:
+        index: test
+        id: 4
+        body: {}
+  - do:
+      indices.refresh:
+        index: test
+
+  - do:
+      search:
+        body: {
+        }
+  - match: { hits.total.value: 4 }
+  - length: { hits.hits: 4 }
+
+  - do:
+      search:
+        search_pipeline: my_pipeline
+        body: {
+        }
+  - match: { hits.total.value: 4 }
+  - length: { hits.hits: 2 }
diff --git a/modules/transport-netty4/licenses/netty-buffer-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-buffer-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..7bb27bbfcb87d
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-buffer-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+a4d94fd6cdf7a37b15237e32434afd6b955cc591
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-buffer-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-buffer-4.1.97.Final.jar.sha1
deleted file mode 100644
index 8430355365996..0000000000000
--- a/modules/transport-netty4/licenses/netty-buffer-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f8f3d8644afa5e6e1a40a3a6aeb9d9aa970ecb4f
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-codec-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-codec-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..c792b4e834030
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-codec-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+642523c57c4be15b8b461be7b1532262d193bbb3
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-codec-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-codec-4.1.97.Final.jar.sha1
deleted file mode 100644
index 7a36dc1f2724f..0000000000000
--- a/modules/transport-netty4/licenses/netty-codec-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-384ba4d75670befbedb45c4d3b497a93639c206d
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-codec-http-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-codec-http-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..8bf31f6c3a2c7
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-codec-http-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+c648f863b301e3fc62d0de098ec61be7628b8ea2
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-codec-http-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-codec-http-4.1.97.Final.jar.sha1
deleted file mode 100644
index 37b78a32f741f..0000000000000
--- a/modules/transport-netty4/licenses/netty-codec-http-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-af78acec783ffd77c63d8aeecc21041fd39ac54f
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-codec-http2-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..48b42bfab9287
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+40590da6c615b852384542051330e9fd51d4c4b1
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-codec-http2-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-codec-http2-4.1.97.Final.jar.sha1
deleted file mode 100644
index cbf685a6d79d3..0000000000000
--- a/modules/transport-netty4/licenses/netty-codec-http2-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-893888d09a7bef0d0ba973d7471943e765d0fd08
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-common-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4fe86799eaff
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+bdb16e4d308b5757123decc886896815d1daf7a3
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-common-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-common-4.1.97.Final.jar.sha1
deleted file mode 100644
index 1bdfec3aae6ba..0000000000000
--- a/modules/transport-netty4/licenses/netty-common-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7cceacaf11df8dc63f23d0fb58e9d4640fc88404
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-handler-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-handler-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..cfc0befee237a
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-handler-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+7800aea949bf95f63df73166d144e49405b279dd
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-handler-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-handler-4.1.97.Final.jar.sha1
deleted file mode 100644
index 8b7b50a6fc9c6..0000000000000
--- a/modules/transport-netty4/licenses/netty-handler-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-abb86c6906bf512bf2b797a41cd7d2e8d3cd7c36
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-resolver-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-resolver-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4425d5ac8e5f
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-resolver-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+5e7eddfa4dfffcbd375d265d1fd08297df94f82f
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-resolver-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-resolver-4.1.97.Final.jar.sha1
deleted file mode 100644
index 032959e98d009..0000000000000
--- a/modules/transport-netty4/licenses/netty-resolver-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-cec8348108dc76c47cf87c669d514be52c922144
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-transport-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-transport-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..fd9199092452b
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-transport-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+0b36cc2337b4a4135df7ee2f2d77431c3b541dc5
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-transport-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-transport-4.1.97.Final.jar.sha1
deleted file mode 100644
index 107863c1b3c9d..0000000000000
--- a/modules/transport-netty4/licenses/netty-transport-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f37380d23c9bb079bc702910833b2fd532c9abd0
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..291c87ad7987b
--- /dev/null
+++ b/modules/transport-netty4/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+d0697ef1d71c6111a1b18a387fa985fd6398ace2
\ No newline at end of file
diff --git a/modules/transport-netty4/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1 b/modules/transport-netty4/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1
deleted file mode 100644
index f736d37d071b7..0000000000000
--- a/modules/transport-netty4/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-d469d84265ab70095b01b40886cabdd433b6e664
\ No newline at end of file
diff --git a/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/http/netty4/Netty4HeaderVerifierIT.java b/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/http/netty4/Netty4HeaderVerifierIT.java
new file mode 100644
index 0000000000000..c39567a005fd1
--- /dev/null
+++ b/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/http/netty4/Netty4HeaderVerifierIT.java
@@ -0,0 +1,75 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.netty4;
+
+import org.opensearch.OpenSearchNetty4IntegTestCase;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.opensearch.transport.Netty4BlockingPlugin;
+
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import io.netty.buffer.ByteBufUtil;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpVersion;
+import io.netty.handler.codec.http2.HttpConversionUtil;
+import io.netty.util.ReferenceCounted;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
+
+@ClusterScope(scope = Scope.TEST, supportsDedicatedMasters = false, numDataNodes = 1)
+public class Netty4HeaderVerifierIT extends OpenSearchNetty4IntegTestCase {
+
+    @Override
+    protected boolean addMockHttpTransport() {
+        return false; // enable http
+    }
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Collections.singletonList(Netty4BlockingPlugin.class);
+    }
+
+    public void testThatNettyHttpServerRequestBlockedWithHeaderVerifier() throws Exception {
+        HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
+        TransportAddress[] boundAddresses = httpServerTransport.boundAddress().boundAddresses();
+        TransportAddress transportAddress = randomFrom(boundAddresses);
+
+        final FullHttpRequest blockedRequest = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
+        blockedRequest.headers().add("blockme", "Not Allowed");
+        blockedRequest.headers().add(HOST, "localhost");
+        blockedRequest.headers().add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), "http");
+
+        final List<FullHttpResponse> responses = new ArrayList<>();
+        try (Netty4HttpClient nettyHttpClient = Netty4HttpClient.http2()) {
+            try {
+                FullHttpResponse blockedResponse = nettyHttpClient.send(transportAddress.address(), blockedRequest);
+                responses.add(blockedResponse);
+                String blockedResponseContent = new String(ByteBufUtil.getBytes(blockedResponse.content()), StandardCharsets.UTF_8);
+                assertThat(blockedResponseContent, containsString("Hit header_verifier"));
+                assertThat(blockedResponse.status().code(), equalTo(401));
+            } finally {
+                responses.forEach(ReferenceCounted::release);
+            }
+        }
+    }
+
+}
diff --git a/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/http/netty4/Netty4HttpRequestSizeLimitIT.java b/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/http/netty4/Netty4HttpRequestSizeLimitIT.java
index 6c8ca665424a6..826d4a7e5d61e 100644
--- a/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/http/netty4/Netty4HttpRequestSizeLimitIT.java
+++ b/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/http/netty4/Netty4HttpRequestSizeLimitIT.java
@@ -57,7 +57,7 @@
 
 /**
  * This test checks that in-flight requests are limited on HTTP level and that requests that are excluded from limiting can pass.
- *
+ * <p>
  * As the same setting is also used to limit in-flight requests on transport level, we avoid transport messages by forcing
  * a single node "cluster".
  */
diff --git a/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/transport/Netty4BlockingPlugin.java b/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/transport/Netty4BlockingPlugin.java
new file mode 100644
index 0000000000000..d5fe49952add3
--- /dev/null
+++ b/modules/transport-netty4/src/internalClusterTest/java/org/opensearch/transport/Netty4BlockingPlugin.java
@@ -0,0 +1,127 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.transport;
+
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.BigArrays;
+import org.opensearch.common.util.PageCacheRecycler;
+import org.opensearch.core.indices.breaker.CircuitBreakerService;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.netty4.Netty4HttpServerTransport;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.Map;
+import java.util.function.Supplier;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.DefaultHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.util.ReferenceCountUtil;
+
+public class Netty4BlockingPlugin extends Netty4ModulePlugin {
+
+    public class Netty4BlockingHttpServerTransport extends Netty4HttpServerTransport {
+
+        public Netty4BlockingHttpServerTransport(
+            Settings settings,
+            NetworkService networkService,
+            BigArrays bigArrays,
+            ThreadPool threadPool,
+            NamedXContentRegistry xContentRegistry,
+            Dispatcher dispatcher,
+            ClusterSettings clusterSettings,
+            SharedGroupFactory sharedGroupFactory,
+            Tracer tracer
+        ) {
+            super(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry,
+                dispatcher,
+                clusterSettings,
+                sharedGroupFactory,
+                tracer
+            );
+        }
+
+        @Override
+        protected ChannelInboundHandlerAdapter createHeaderVerifier() {
+            return new ExampleBlockingNetty4HeaderVerifier();
+        }
+    }
+
+    @Override
+    public Map<String, Supplier<HttpServerTransport>> getHttpTransports(
+        Settings settings,
+        ThreadPool threadPool,
+        BigArrays bigArrays,
+        PageCacheRecycler pageCacheRecycler,
+        CircuitBreakerService circuitBreakerService,
+        NamedXContentRegistry xContentRegistry,
+        NetworkService networkService,
+        HttpServerTransport.Dispatcher dispatcher,
+        ClusterSettings clusterSettings,
+        Tracer tracer
+    ) {
+        return Collections.singletonMap(
+            NETTY_HTTP_TRANSPORT_NAME,
+            () -> new Netty4BlockingHttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry,
+                dispatcher,
+                clusterSettings,
+                getSharedGroupFactory(settings),
+                tracer
+            )
+        );
+    }
+
+    /** POC for how an external header verifier would be implemented */
+    public class ExampleBlockingNetty4HeaderVerifier extends SimpleChannelInboundHandler<DefaultHttpRequest> {
+
+        @Override
+        public void channelRead0(ChannelHandlerContext ctx, DefaultHttpRequest msg) throws Exception {
+            ReferenceCountUtil.retain(msg);
+            if (isBlocked(msg)) {
+                ByteBuf buf = Unpooled.copiedBuffer("Hit header_verifier".getBytes(StandardCharsets.UTF_8));
+                final FullHttpResponse response = new DefaultFullHttpResponse(msg.protocolVersion(), HttpResponseStatus.UNAUTHORIZED, buf);
+                ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
+                ReferenceCountUtil.release(msg);
+            } else {
+                // Lets the request pass to the next channel handler
+                ctx.fireChannelRead(msg);
+            }
+        }
+
+        private boolean isBlocked(HttpRequest request) {
+            final boolean shouldBlock = request.headers().contains("blockme");
+
+            return shouldBlock;
+        }
+    }
+}
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpChannel.java b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpChannel.java
index a83330356e35e..6475a0b744c60 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpChannel.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpChannel.java
@@ -40,6 +40,7 @@
 import org.opensearch.transport.netty4.Netty4TcpChannel;
 
 import java.net.InetSocketAddress;
+import java.util.Optional;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelPipeline;
@@ -98,6 +99,22 @@ public Channel getNettyChannel() {
         return channel;
     }
 
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> Optional<T> get(String name, Class<T> clazz) {
+        Object handler = getNettyChannel().pipeline().get(name);
+
+        if (handler == null && inboundPipeline() != null) {
+            handler = inboundPipeline().get(name);
+        }
+
+        if (handler != null && clazz.isInstance(handler) == true) {
+            return Optional.of((T) handler);
+        }
+
+        return Optional.empty();
+    }
+
     @Override
     public String toString() {
         return "Netty4HttpChannel{" + "localAddress=" + getLocalAddress() + ", remoteAddress=" + getRemoteAddress() + '}';
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpRequest.java b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpRequest.java
index 7d937157c1034..3c96affb7adf7 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpRequest.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpRequest.java
@@ -258,7 +258,7 @@ public FullHttpRequest nettyRequest() {
     /**
      * A wrapper of {@link HttpHeaders} that implements a map to prevent copying unnecessarily. This class does not support modifications
      * and due to the underlying implementation, it performs case insensitive lookups of key to values.
-     *
+     * <p>
      * It is important to note that this implementation does have some downsides in that each invocation of the
      * {@link #values()} and {@link #entrySet()} methods will perform a copy of the values in the HttpHeaders rather than returning a
      * view of the underlying values.
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java
index 0271472125814..4970c42163ac3 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java
@@ -116,6 +116,9 @@
 import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_SEND_BUFFER_SIZE;
 import static org.opensearch.http.HttpTransportSettings.SETTING_PIPELINING_MAX_EVENTS;
 
+/**
+ * The HTTP transport implementations based on Netty 4.
+ */
 public class Netty4HttpServerTransport extends AbstractHttpServerTransport {
     private static final Logger logger = LogManager.getLogger(Netty4HttpServerTransport.class);
 
@@ -184,6 +187,17 @@ public class Netty4HttpServerTransport extends AbstractHttpServerTransport {
     private volatile ServerBootstrap serverBootstrap;
     private volatile SharedGroupFactory.SharedGroup sharedGroup;
 
+    /**
+     * Creates new HTTP transport implementations based on Netty 4
+     * @param settings seetings
+     * @param networkService network service
+     * @param bigArrays big array allocator
+     * @param threadPool thread pool instance
+     * @param xContentRegistry XContent registry instance
+     * @param dispatcher dispatcher instance
+     * @param clusterSettings cluster settings
+     * @param sharedGroupFactory shared group factory
+     */
     public Netty4HttpServerTransport(
         Settings settings,
         NetworkService networkService,
@@ -334,7 +348,7 @@ public ChannelHandler configureServerChannelHandler() {
         return new HttpChannelHandler(this, handlingSettings);
     }
 
-    protected static final AttributeKey<Netty4HttpChannel> HTTP_CHANNEL_KEY = AttributeKey.newInstance("opensearch-http-channel");
+    public static final AttributeKey<Netty4HttpChannel> HTTP_CHANNEL_KEY = AttributeKey.newInstance("opensearch-http-channel");
     protected static final AttributeKey<Netty4HttpServerChannel> HTTP_SERVER_CHANNEL_KEY = AttributeKey.newInstance(
         "opensearch-http-server-channel"
     );
@@ -419,8 +433,8 @@ protected void channelRead0(ChannelHandlerContext ctx, HttpMessage msg) throws E
                     // If this handler is hit then no upgrade has been attempted and the client is just talking HTTP
                     final ChannelPipeline pipeline = ctx.pipeline();
                     pipeline.addAfter(ctx.name(), "handler", getRequestHandler());
-                    pipeline.replace(this, "decoder_compress", new HttpContentDecompressor());
-
+                    pipeline.replace(this, "header_verifier", transport.createHeaderVerifier());
+                    pipeline.addAfter("header_verifier", "decoder_compress", transport.createDecompressor());
                     pipeline.addAfter("decoder_compress", "aggregator", aggregator);
                     if (handlingSettings.isCompression()) {
                         pipeline.addAfter(
@@ -446,7 +460,8 @@ protected void configureDefaultHttpPipeline(ChannelPipeline pipeline) {
             );
             decoder.setCumulator(ByteToMessageDecoder.COMPOSITE_CUMULATOR);
             pipeline.addLast("decoder", decoder);
-            pipeline.addLast("decoder_compress", new HttpContentDecompressor());
+            pipeline.addLast("header_verifier", transport.createHeaderVerifier());
+            pipeline.addLast("decoder_compress", transport.createDecompressor());
             pipeline.addLast("encoder", new HttpResponseEncoder());
             final HttpObjectAggregator aggregator = new HttpObjectAggregator(handlingSettings.getMaxContentLength());
             aggregator.setMaxCumulationBufferComponents(transport.maxCompositeBufferComponents);
@@ -487,13 +502,13 @@ protected void initChannel(Channel childChannel) throws Exception {
 
                     final HttpObjectAggregator aggregator = new HttpObjectAggregator(handlingSettings.getMaxContentLength());
                     aggregator.setMaxCumulationBufferComponents(transport.maxCompositeBufferComponents);
-
                     childChannel.pipeline()
                         .addLast(new LoggingHandler(LogLevel.DEBUG))
                         .addLast(new Http2StreamFrameToHttpObjectCodec(true))
                         .addLast("byte_buf_sizer", byteBufSizer)
                         .addLast("read_timeout", new ReadTimeoutHandler(transport.readTimeoutMillis, TimeUnit.MILLISECONDS))
-                        .addLast("decoder_decompress", new HttpContentDecompressor());
+                        .addLast("header_verifier", transport.createHeaderVerifier())
+                        .addLast("decoder_decompress", transport.createDecompressor());
 
                     if (handlingSettings.isCompression()) {
                         childChannel.pipeline()
@@ -531,4 +546,21 @@ public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
             }
         }
     }
+
+    /**
+     * Extension point that allows a NetworkPlugin to extend the netty pipeline and inspect headers after request decoding
+     */
+    protected ChannelInboundHandlerAdapter createHeaderVerifier() {
+        // pass-through
+        return new ChannelInboundHandlerAdapter();
+    }
+
+    /**
+     * Extension point that allows a NetworkPlugin to override the default netty HttpContentDecompressor and supply a custom decompressor.
+     *
+     * Used in instances to conditionally decompress depending on the outcome from header verification
+     */
+    protected ChannelInboundHandlerAdapter createDecompressor() {
+        return new HttpContentDecompressor();
+    }
 }
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/transport/CopyBytesSocketChannel.java b/modules/transport-netty4/src/main/java/org/opensearch/transport/CopyBytesSocketChannel.java
index b73f74d187a2a..4bab91565d3ad 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/transport/CopyBytesSocketChannel.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/transport/CopyBytesSocketChannel.java
@@ -65,7 +65,7 @@
  * This class is adapted from {@link NioSocketChannel} class in the Netty project. It overrides the channel
  * read/write behavior to ensure that the bytes are always copied to a thread-local direct bytes buffer. This
  * happens BEFORE the call to the Java {@link SocketChannel} is issued.
- *
+ * <p>
  * The purpose of this class is to allow the disabling of netty direct buffer pooling while allowing us to
  * control how bytes end up being copied to direct memory. If we simply disabled netty pooling, we would rely
  * on the JDK's internal thread local buffer pooling. Instead, this class allows us to create a one thread
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/transport/Netty4ModulePlugin.java b/modules/transport-netty4/src/main/java/org/opensearch/transport/Netty4ModulePlugin.java
index ca51d70702a82..2bc795d11ed5d 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/transport/Netty4ModulePlugin.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/transport/Netty4ModulePlugin.java
@@ -96,7 +96,8 @@ public Map<String, Supplier<Transport>> getTransports(
         PageCacheRecycler pageCacheRecycler,
         CircuitBreakerService circuitBreakerService,
         NamedWriteableRegistry namedWriteableRegistry,
-        NetworkService networkService
+        NetworkService networkService,
+        Tracer tracer
     ) {
         return Collections.singletonMap(
             NETTY_TRANSPORT_NAME,
@@ -108,7 +109,8 @@ public Map<String, Supplier<Transport>> getTransports(
                 pageCacheRecycler,
                 namedWriteableRegistry,
                 circuitBreakerService,
-                getSharedGroupFactory(settings)
+                getSharedGroupFactory(settings),
+                tracer
             )
         );
     }
@@ -142,7 +144,7 @@ public Map<String, Supplier<HttpServerTransport>> getHttpTransports(
         );
     }
 
-    private SharedGroupFactory getSharedGroupFactory(Settings settings) {
+    SharedGroupFactory getSharedGroupFactory(Settings settings) {
         SharedGroupFactory groupFactory = this.groupFactory.get();
         if (groupFactory != null) {
             assert groupFactory.getSettings().equals(settings) : "Different settings than originally provided";
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4TcpChannel.java b/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4TcpChannel.java
index 5db1f7c333157..79a5bf9e95121 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4TcpChannel.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4TcpChannel.java
@@ -41,6 +41,7 @@
 import org.opensearch.transport.TransportException;
 
 import java.net.InetSocketAddress;
+import java.util.Optional;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
@@ -164,6 +165,18 @@ public void sendMessage(BytesReference reference, ActionListener<Void> listener)
         }
     }
 
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> Optional<T> get(String name, Class<T> clazz) {
+        final Object handler = getNettyChannel().pipeline().get(name);
+
+        if (handler != null && clazz.isInstance(handler) == true) {
+            return Optional.of((T) handler);
+        }
+
+        return Optional.empty();
+    }
+
     public Channel getNettyChannel() {
         return channel;
     }
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4Transport.java b/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4Transport.java
index f77c29c8bfa60..e76a227630dc1 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4Transport.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4Transport.java
@@ -50,6 +50,7 @@
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.core.indices.breaker.CircuitBreakerService;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.Netty4NioSocketChannel;
 import org.opensearch.transport.NettyAllocator;
@@ -131,9 +132,10 @@ public Netty4Transport(
         PageCacheRecycler pageCacheRecycler,
         NamedWriteableRegistry namedWriteableRegistry,
         CircuitBreakerService circuitBreakerService,
-        SharedGroupFactory sharedGroupFactory
+        SharedGroupFactory sharedGroupFactory,
+        Tracer tracer
     ) {
-        super(settings, version, threadPool, pageCacheRecycler, circuitBreakerService, namedWriteableRegistry, networkService);
+        super(settings, version, threadPool, pageCacheRecycler, circuitBreakerService, namedWriteableRegistry, networkService, tracer);
         Netty4Utils.setAvailableProcessors(OpenSearchExecutors.NODE_PROCESSORS_SETTING.get(settings));
         NettyAllocator.logAllocatorDescriptionIfNeeded();
         this.sharedGroupFactory = sharedGroupFactory;
diff --git a/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/Netty4SizeHeaderFrameDecoderTests.java b/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/Netty4SizeHeaderFrameDecoderTests.java
index 3e5f71f1464a1..c92ccba82835f 100644
--- a/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/Netty4SizeHeaderFrameDecoderTests.java
+++ b/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/Netty4SizeHeaderFrameDecoderTests.java
@@ -40,6 +40,7 @@
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.SharedGroupFactory;
@@ -86,7 +87,8 @@ public void startThreadPool() {
             recycler,
             new NamedWriteableRegistry(Collections.emptyList()),
             new NoneCircuitBreakerService(),
-            new SharedGroupFactory(settings)
+            new SharedGroupFactory(settings),
+            NoopTracer.INSTANCE
         );
         nettyTransport.start();
 
diff --git a/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/NettyTransportMultiPortTests.java b/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/NettyTransportMultiPortTests.java
index 98a001b8ae4bb..7cca00db68559 100644
--- a/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/NettyTransportMultiPortTests.java
+++ b/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/NettyTransportMultiPortTests.java
@@ -40,6 +40,7 @@
 import org.opensearch.common.util.PageCacheRecycler;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.threadpool.TestThreadPool;
 import org.opensearch.threadpool.ThreadPool;
@@ -141,7 +142,8 @@ private TcpTransport startTransport(Settings settings, ThreadPool threadPool) {
             recycler,
             new NamedWriteableRegistry(Collections.emptyList()),
             new NoneCircuitBreakerService(),
-            new SharedGroupFactory(settings)
+            new SharedGroupFactory(settings),
+            NoopTracer.INSTANCE
         );
         transport.start();
 
diff --git a/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/SimpleNetty4TransportTests.java b/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/SimpleNetty4TransportTests.java
index 35b19002dce8d..710b3ff6bd0ca 100644
--- a/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/SimpleNetty4TransportTests.java
+++ b/modules/transport-netty4/src/test/java/org/opensearch/transport/netty4/SimpleNetty4TransportTests.java
@@ -44,6 +44,7 @@
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.transport.MockTransportService;
 import org.opensearch.test.transport.StubbableTransport;
 import org.opensearch.transport.AbstractSimpleTransportTestCase;
@@ -82,7 +83,8 @@ protected Transport build(Settings settings, final Version version, ClusterSetti
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             namedWriteableRegistry,
             new NoneCircuitBreakerService(),
-            new SharedGroupFactory(settings)
+            new SharedGroupFactory(settings),
+            NoopTracer.INSTANCE
         ) {
 
             @Override
diff --git a/plugins/analysis-icu/licenses/lucene-analysis-icu-9.8.0-snapshot-4373c3b.jar.sha1 b/plugins/analysis-icu/licenses/lucene-analysis-icu-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 8a3332c950b6d..0000000000000
--- a/plugins/analysis-icu/licenses/lucene-analysis-icu-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-fde64e3b23bc9a0849b9897febfe9f13c5113143
\ No newline at end of file
diff --git a/plugins/analysis-icu/licenses/lucene-analysis-icu-9.8.0.jar.sha1 b/plugins/analysis-icu/licenses/lucene-analysis-icu-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..ef410899981ca
--- /dev/null
+++ b/plugins/analysis-icu/licenses/lucene-analysis-icu-9.8.0.jar.sha1
@@ -0,0 +1 @@
+7133d34e92770f59eb28686f4d511b9f3f32e970
\ No newline at end of file
diff --git a/plugins/analysis-kuromoji/licenses/lucene-analysis-kuromoji-9.8.0-snapshot-4373c3b.jar.sha1 b/plugins/analysis-kuromoji/licenses/lucene-analysis-kuromoji-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 33c2afacf2395..0000000000000
--- a/plugins/analysis-kuromoji/licenses/lucene-analysis-kuromoji-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-b01a791705fa01fce48dd02ea79fa8045de8dd5e
\ No newline at end of file
diff --git a/plugins/analysis-kuromoji/licenses/lucene-analysis-kuromoji-9.8.0.jar.sha1 b/plugins/analysis-kuromoji/licenses/lucene-analysis-kuromoji-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..46b83c9e40b3a
--- /dev/null
+++ b/plugins/analysis-kuromoji/licenses/lucene-analysis-kuromoji-9.8.0.jar.sha1
@@ -0,0 +1 @@
+be44282e1f6b91a0650fcceb558053d6bdd4863d
\ No newline at end of file
diff --git a/plugins/analysis-nori/licenses/lucene-analysis-nori-9.8.0-snapshot-4373c3b.jar.sha1 b/plugins/analysis-nori/licenses/lucene-analysis-nori-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 1e7986dafa11e..0000000000000
--- a/plugins/analysis-nori/licenses/lucene-analysis-nori-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-43d19320b1b9cd18638b1602fa87d5f21ee043bc
\ No newline at end of file
diff --git a/plugins/analysis-nori/licenses/lucene-analysis-nori-9.8.0.jar.sha1 b/plugins/analysis-nori/licenses/lucene-analysis-nori-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..36664695a7818
--- /dev/null
+++ b/plugins/analysis-nori/licenses/lucene-analysis-nori-9.8.0.jar.sha1
@@ -0,0 +1 @@
+bd1f80d33346f7e588685484ef29a304db5190e4
\ No newline at end of file
diff --git a/plugins/analysis-phonetic/licenses/lucene-analysis-phonetic-9.8.0-snapshot-4373c3b.jar.sha1 b/plugins/analysis-phonetic/licenses/lucene-analysis-phonetic-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 14880d9c2d243..0000000000000
--- a/plugins/analysis-phonetic/licenses/lucene-analysis-phonetic-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9244dc232f175010b480d4d88e13945c17a0b28b
\ No newline at end of file
diff --git a/plugins/analysis-phonetic/licenses/lucene-analysis-phonetic-9.8.0.jar.sha1 b/plugins/analysis-phonetic/licenses/lucene-analysis-phonetic-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..003ccdf8b0727
--- /dev/null
+++ b/plugins/analysis-phonetic/licenses/lucene-analysis-phonetic-9.8.0.jar.sha1
@@ -0,0 +1 @@
+b9ffdc7a52d2087ecb03318ec06305b480cdfe82
\ No newline at end of file
diff --git a/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/HaasePhonetik.java b/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/HaasePhonetik.java
index c80d32228feeb..b875fab7d4006 100644
--- a/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/HaasePhonetik.java
+++ b/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/HaasePhonetik.java
@@ -35,13 +35,13 @@
 /**
  * Ge&auml;nderter Algorithmus aus der Matching Toolbox von Rainer Schnell
  * Java-Programmierung von J&ouml;rg Reiher
- *
+ * <p>
  * Die Kölner Phonetik wurde für den Einsatz in Namensdatenbanken wie
  * der Verwaltung eines Krankenhauses durch Martin Haase (Institut für
  * Sprachwissenschaft, Universität zu Köln) und Kai Heitmann (Insitut für
  * medizinische Statistik, Informatik und Epidemiologie, Köln)  überarbeitet.
  * M. Haase und K. Heitmann. Die Erweiterte Kölner Phonetik. 526, 2000.
- *
+ * <p>
  * nach: Martin Wilz, Aspekte der Kodierung phonetischer Ähnlichkeiten
  * in deutschen Eigennamen, Magisterarbeit.
  * http://www.uni-koeln.de/phil-fak/phonetik/Lehre/MA-Arbeiten/magister_wilz.pdf
diff --git a/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/KoelnerPhonetik.java b/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/KoelnerPhonetik.java
index 33e386af9f364..4bcc10ff73b0a 100644
--- a/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/KoelnerPhonetik.java
+++ b/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/KoelnerPhonetik.java
@@ -46,13 +46,13 @@
 
 /**
  * K&ouml;lner Phonetik
- *
+ * <p>
  * H.J. Postel, Die K&ouml;lner Phonetik. Ein Verfahren zu Identifizierung
  * von Personennamen auf der Grundlage der Gestaltanalyse. IBM-Nachrichten 19 (1969), 925-931
- *
+ * <p>
  * Algorithmus aus der Matching Toolbox von Rainer Schnell
  * Java-Programmierung von J&ouml;rg Reiher
- *
+ * <p>
  * mit &Auml;nderungen von Jörg Prante
  *
  */
diff --git a/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/Nysiis.java b/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/Nysiis.java
index 818dbba85e2de..c3237114c65d5 100644
--- a/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/Nysiis.java
+++ b/plugins/analysis-phonetic/src/main/java/org/opensearch/index/analysis/phonetic/Nysiis.java
@@ -40,7 +40,7 @@
 /**
  *
  * Taken from commons-codec trunk (unreleased yet)
- *
+ * <p>
  * Encodes a string into a NYSIIS value. NYSIIS is an encoding used to relate
  * similar names, but can also be used as a general purpose scheme to find word
  * with similar phonemes.
diff --git a/plugins/analysis-smartcn/licenses/lucene-analysis-smartcn-9.8.0-snapshot-4373c3b.jar.sha1 b/plugins/analysis-smartcn/licenses/lucene-analysis-smartcn-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index edc4de3fffe28..0000000000000
--- a/plugins/analysis-smartcn/licenses/lucene-analysis-smartcn-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3101a4f79820c1ca3dfb8f49b74c5fb5b32940e1
\ No newline at end of file
diff --git a/plugins/analysis-smartcn/licenses/lucene-analysis-smartcn-9.8.0.jar.sha1 b/plugins/analysis-smartcn/licenses/lucene-analysis-smartcn-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..e22eaa474016f
--- /dev/null
+++ b/plugins/analysis-smartcn/licenses/lucene-analysis-smartcn-9.8.0.jar.sha1
@@ -0,0 +1 @@
+f73e2007b133fb699e517ef13b4952844f0150d8
\ No newline at end of file
diff --git a/plugins/analysis-stempel/licenses/lucene-analysis-stempel-9.8.0-snapshot-4373c3b.jar.sha1 b/plugins/analysis-stempel/licenses/lucene-analysis-stempel-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 54c310277b09b..0000000000000
--- a/plugins/analysis-stempel/licenses/lucene-analysis-stempel-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f12b2a22cd5ebcd84f40a40e78fdd4e268b3b26d
\ No newline at end of file
diff --git a/plugins/analysis-stempel/licenses/lucene-analysis-stempel-9.8.0.jar.sha1 b/plugins/analysis-stempel/licenses/lucene-analysis-stempel-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..1ebe42a2a2f56
--- /dev/null
+++ b/plugins/analysis-stempel/licenses/lucene-analysis-stempel-9.8.0.jar.sha1
@@ -0,0 +1 @@
+2c09cbc021a8f81a01600a1d2a999361e70f7aed
\ No newline at end of file
diff --git a/plugins/analysis-ukrainian/licenses/lucene-analysis-morfologik-9.8.0-snapshot-4373c3b.jar.sha1 b/plugins/analysis-ukrainian/licenses/lucene-analysis-morfologik-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 358db9ea3f0f5..0000000000000
--- a/plugins/analysis-ukrainian/licenses/lucene-analysis-morfologik-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7dbf5cc3dff93cc1ffe45d79b129859590d001dd
\ No newline at end of file
diff --git a/plugins/analysis-ukrainian/licenses/lucene-analysis-morfologik-9.8.0.jar.sha1 b/plugins/analysis-ukrainian/licenses/lucene-analysis-morfologik-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..3c4523d45c0f5
--- /dev/null
+++ b/plugins/analysis-ukrainian/licenses/lucene-analysis-morfologik-9.8.0.jar.sha1
@@ -0,0 +1 @@
+b054f2c7b11fc7c5601b4c3cdf18aa7508612898
\ No newline at end of file
diff --git a/plugins/crypto-kms/licenses/jackson-annotations-2.15.2.jar.sha1 b/plugins/crypto-kms/licenses/jackson-annotations-2.15.2.jar.sha1
deleted file mode 100644
index f63416ddb8ceb..0000000000000
--- a/plugins/crypto-kms/licenses/jackson-annotations-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4724a65ac8e8d156a24898d50fd5dbd3642870b8
\ No newline at end of file
diff --git a/plugins/crypto-kms/licenses/jackson-annotations-2.16.0.jar.sha1 b/plugins/crypto-kms/licenses/jackson-annotations-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..79ed9e0c63fc8
--- /dev/null
+++ b/plugins/crypto-kms/licenses/jackson-annotations-2.16.0.jar.sha1
@@ -0,0 +1 @@
+dc30995f7428c0a405eba9b8c619b20d2b3b9905
\ No newline at end of file
diff --git a/plugins/crypto-kms/licenses/jackson-databind-2.15.2.jar.sha1 b/plugins/crypto-kms/licenses/jackson-databind-2.15.2.jar.sha1
deleted file mode 100644
index f16d80af8dce6..0000000000000
--- a/plugins/crypto-kms/licenses/jackson-databind-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9353b021f10c307c00328f52090de2bdb4b6ff9c
\ No newline at end of file
diff --git a/plugins/crypto-kms/licenses/jackson-databind-2.16.0.jar.sha1 b/plugins/crypto-kms/licenses/jackson-databind-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..da00d281934b1
--- /dev/null
+++ b/plugins/crypto-kms/licenses/jackson-databind-2.16.0.jar.sha1
@@ -0,0 +1 @@
+3a6b7f8ff7b30d518bbd65678e9c30cd881f19a7
\ No newline at end of file
diff --git a/plugins/crypto-kms/licenses/log4j-1.2-api-2.20.0.jar.sha1 b/plugins/crypto-kms/licenses/log4j-1.2-api-2.20.0.jar.sha1
deleted file mode 100644
index 9829576d38ce0..0000000000000
--- a/plugins/crypto-kms/licenses/log4j-1.2-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-689151374756cb809cb029f2501015bdc7733179
\ No newline at end of file
diff --git a/plugins/crypto-kms/licenses/log4j-1.2-api-2.21.0.jar.sha1 b/plugins/crypto-kms/licenses/log4j-1.2-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..39d9177cb2fac
--- /dev/null
+++ b/plugins/crypto-kms/licenses/log4j-1.2-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+12bad3819a9570807f3c97315930699584c12152
\ No newline at end of file
diff --git a/plugins/crypto-kms/src/main/java/org/opensearch/crypto/kms/KmsMasterKeyProvider.java b/plugins/crypto-kms/src/main/java/org/opensearch/crypto/kms/KmsMasterKeyProvider.java
index 9003e8bebd5ff..19e000628a9c8 100644
--- a/plugins/crypto-kms/src/main/java/org/opensearch/crypto/kms/KmsMasterKeyProvider.java
+++ b/plugins/crypto-kms/src/main/java/org/opensearch/crypto/kms/KmsMasterKeyProvider.java
@@ -59,7 +59,10 @@ public DataKeyPair generateDataPair() {
     @Override
     public byte[] decryptKey(byte[] encryptedKey) {
         try (AmazonKmsClientReference clientReference = clientReferenceSupplier.get()) {
-            DecryptRequest decryptRequest = DecryptRequest.builder().ciphertextBlob(SdkBytes.fromByteArray(encryptedKey)).build();
+            DecryptRequest decryptRequest = DecryptRequest.builder()
+                .ciphertextBlob(SdkBytes.fromByteArray(encryptedKey))
+                .encryptionContext(encryptionContext)
+                .build();
             DecryptResponse decryptResponse = SocketAccess.doPrivileged(() -> clientReference.get().decrypt(decryptRequest));
             return decryptResponse.plaintext().asByteArray();
         }
diff --git a/plugins/discovery-azure-classic/build.gradle b/plugins/discovery-azure-classic/build.gradle
index 1fed446016647..c3d70e9c64968 100644
--- a/plugins/discovery-azure-classic/build.gradle
+++ b/plugins/discovery-azure-classic/build.gradle
@@ -53,7 +53,7 @@ dependencies {
   api "org.apache.logging.log4j:log4j-1.2-api:${versions.log4j}"
   api "commons-codec:commons-codec:${versions.commonscodec}"
   api "commons-lang:commons-lang:2.6"
-  api "commons-io:commons-io:2.13.0"
+  api "commons-io:commons-io:2.15.1"
   api 'javax.mail:mail:1.4.7'
   api 'javax.inject:javax.inject:1'
   api "com.sun.jersey:jersey-client:${versions.jersey}"
diff --git a/plugins/discovery-azure-classic/licenses/commons-io-2.13.0.jar.sha1 b/plugins/discovery-azure-classic/licenses/commons-io-2.13.0.jar.sha1
deleted file mode 100644
index c165136eb5822..0000000000000
--- a/plugins/discovery-azure-classic/licenses/commons-io-2.13.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-8bb2bc9b4df17e2411533a0708a69f983bf5e83b
\ No newline at end of file
diff --git a/plugins/discovery-azure-classic/licenses/commons-io-2.15.1.jar.sha1 b/plugins/discovery-azure-classic/licenses/commons-io-2.15.1.jar.sha1
new file mode 100644
index 0000000000000..47c5d13812a36
--- /dev/null
+++ b/plugins/discovery-azure-classic/licenses/commons-io-2.15.1.jar.sha1
@@ -0,0 +1 @@
+f11560da189ab563a5c8e351941415430e9304ea
\ No newline at end of file
diff --git a/plugins/discovery-azure-classic/licenses/log4j-1.2-api-2.20.0.jar.sha1 b/plugins/discovery-azure-classic/licenses/log4j-1.2-api-2.20.0.jar.sha1
deleted file mode 100644
index 9829576d38ce0..0000000000000
--- a/plugins/discovery-azure-classic/licenses/log4j-1.2-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-689151374756cb809cb029f2501015bdc7733179
\ No newline at end of file
diff --git a/plugins/discovery-azure-classic/licenses/log4j-1.2-api-2.21.0.jar.sha1 b/plugins/discovery-azure-classic/licenses/log4j-1.2-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..39d9177cb2fac
--- /dev/null
+++ b/plugins/discovery-azure-classic/licenses/log4j-1.2-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+12bad3819a9570807f3c97315930699584c12152
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/jackson-annotations-2.15.2.jar.sha1 b/plugins/discovery-ec2/licenses/jackson-annotations-2.15.2.jar.sha1
deleted file mode 100644
index f63416ddb8ceb..0000000000000
--- a/plugins/discovery-ec2/licenses/jackson-annotations-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4724a65ac8e8d156a24898d50fd5dbd3642870b8
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/jackson-annotations-2.16.0.jar.sha1 b/plugins/discovery-ec2/licenses/jackson-annotations-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..79ed9e0c63fc8
--- /dev/null
+++ b/plugins/discovery-ec2/licenses/jackson-annotations-2.16.0.jar.sha1
@@ -0,0 +1 @@
+dc30995f7428c0a405eba9b8c619b20d2b3b9905
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/jackson-databind-2.15.2.jar.sha1 b/plugins/discovery-ec2/licenses/jackson-databind-2.15.2.jar.sha1
deleted file mode 100644
index f16d80af8dce6..0000000000000
--- a/plugins/discovery-ec2/licenses/jackson-databind-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9353b021f10c307c00328f52090de2bdb4b6ff9c
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/jackson-databind-2.16.0.jar.sha1 b/plugins/discovery-ec2/licenses/jackson-databind-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..da00d281934b1
--- /dev/null
+++ b/plugins/discovery-ec2/licenses/jackson-databind-2.16.0.jar.sha1
@@ -0,0 +1 @@
+3a6b7f8ff7b30d518bbd65678e9c30cd881f19a7
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/log4j-1.2-api-2.20.0.jar.sha1 b/plugins/discovery-ec2/licenses/log4j-1.2-api-2.20.0.jar.sha1
deleted file mode 100644
index 9829576d38ce0..0000000000000
--- a/plugins/discovery-ec2/licenses/log4j-1.2-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-689151374756cb809cb029f2501015bdc7733179
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/log4j-1.2-api-2.21.0.jar.sha1 b/plugins/discovery-ec2/licenses/log4j-1.2-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..39d9177cb2fac
--- /dev/null
+++ b/plugins/discovery-ec2/licenses/log4j-1.2-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+12bad3819a9570807f3c97315930699584c12152
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/reactive-streams-1.0.4.jar.sha1 b/plugins/discovery-ec2/licenses/reactive-streams-1.0.4.jar.sha1
deleted file mode 100644
index 45a80e3f7e361..0000000000000
--- a/plugins/discovery-ec2/licenses/reactive-streams-1.0.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3864a1320d97d7b045f729a326e1e077661f31b7
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/reactive-streams-LICENSE.txt b/plugins/discovery-ec2/licenses/reactive-streams-LICENSE.txt
deleted file mode 100644
index 1e3c7e7c77495..0000000000000
--- a/plugins/discovery-ec2/licenses/reactive-streams-LICENSE.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-MIT No Attribution
-
-Copyright 2014 Reactive Streams
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
\ No newline at end of file
diff --git a/plugins/discovery-ec2/src/main/java/org/opensearch/discovery/ec2/AwsEc2ServiceImpl.java b/plugins/discovery-ec2/src/main/java/org/opensearch/discovery/ec2/AwsEc2ServiceImpl.java
index 51f0ad9526e55..a2e920761b655 100644
--- a/plugins/discovery-ec2/src/main/java/org/opensearch/discovery/ec2/AwsEc2ServiceImpl.java
+++ b/plugins/discovery-ec2/src/main/java/org/opensearch/discovery/ec2/AwsEc2ServiceImpl.java
@@ -99,7 +99,7 @@ protected Ec2Client buildClient(
 
         if (Strings.hasText(endpoint)) {
             logger.debug("using explicit ec2 endpoint [{}]", endpoint);
-            builder.endpointOverride(URI.create(endpoint));
+            builder.endpointOverride(URI.create(getFullEndpoint(endpoint)));
         }
 
         if (Strings.hasText(region)) {
@@ -110,6 +110,19 @@ protected Ec2Client buildClient(
         return SocketAccess.doPrivileged(builder::build);
     }
 
+    protected String getFullEndpoint(String endpoint) {
+        if (!Strings.hasText(endpoint)) {
+            return null;
+        }
+        if (endpoint.startsWith("http://") || endpoint.startsWith("https://")) {
+            return endpoint;
+        }
+
+        // if no scheme is provided, default to https
+        logger.debug("no scheme found in endpoint [{}], defaulting to https", endpoint);
+        return "https://" + endpoint;
+    }
+
     static ProxyConfiguration buildProxyConfiguration(Logger logger, Ec2ClientSettings clientSettings) {
         if (Strings.hasText(clientSettings.proxyHost)) {
             try {
diff --git a/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/AwsEc2ServiceImplTests.java b/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/AwsEc2ServiceImplTests.java
index 81310f7e2e3c3..3164abe456515 100644
--- a/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/AwsEc2ServiceImplTests.java
+++ b/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/AwsEc2ServiceImplTests.java
@@ -202,4 +202,32 @@ public void testAWSConfigurationWithAwsSettings() {
         assertTrue(clientOverrideConfiguration.retryPolicy().isPresent());
         assertThat(clientOverrideConfiguration.retryPolicy().get().numRetries(), is(10));
     }
+
+    public void testGetFullEndpointWithScheme() {
+        final Settings settings = Settings.builder().put("discovery.ec2.endpoint", "http://ec2.us-west-2.amazonaws.com").build();
+        Ec2ClientSettings clientSettings = Ec2ClientSettings.getClientSettings(settings);
+
+        AwsEc2ServiceImpl awsEc2ServiceImpl = new AwsEc2ServiceImpl();
+
+        String endpoint = awsEc2ServiceImpl.getFullEndpoint(clientSettings.endpoint);
+        assertEquals("http://ec2.us-west-2.amazonaws.com", endpoint);
+
+        assertEquals("http://httpserver.example.com", awsEc2ServiceImpl.getFullEndpoint("http://httpserver.example.com"));
+
+        assertEquals("https://httpserver.example.com", awsEc2ServiceImpl.getFullEndpoint("https://httpserver.example.com"));
+    }
+
+    public void testGetFullEndpointWithoutScheme() {
+        final Settings settings = Settings.builder().put("discovery.ec2.endpoint", "ec2.us-west-2.amazonaws.com").build();
+        Ec2ClientSettings clientSettings = Ec2ClientSettings.getClientSettings(settings);
+
+        AwsEc2ServiceImpl awsEc2ServiceImpl = new AwsEc2ServiceImpl();
+
+        String endpoint = awsEc2ServiceImpl.getFullEndpoint(clientSettings.endpoint);
+        assertEquals("https://ec2.us-west-2.amazonaws.com", endpoint);
+
+        assertEquals("https://httpserver.example.com", awsEc2ServiceImpl.getFullEndpoint("httpserver.example.com"));
+
+        assertNull(awsEc2ServiceImpl.getFullEndpoint(""));
+    }
 }
diff --git a/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2DiscoveryTests.java b/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2DiscoveryTests.java
index 6bed6564cfd36..02e1ff40f7ed6 100644
--- a/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2DiscoveryTests.java
+++ b/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2DiscoveryTests.java
@@ -92,7 +92,8 @@ protected MockTransportService createTransportService() {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             writableRegistry(),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
             @Override
             public TransportAddress[] addressesFromString(String address) {
diff --git a/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2RetriesTests.java b/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2RetriesTests.java
index 3311ddc8842f2..ce097667f9c4b 100644
--- a/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2RetriesTests.java
+++ b/plugins/discovery-ec2/src/test/java/org/opensearch/discovery/ec2/Ec2RetriesTests.java
@@ -77,7 +77,8 @@ protected MockTransportService createTransportService() {
                 networkService,
                 PageCacheRecycler.NON_RECYCLING_INSTANCE,
                 new NamedWriteableRegistry(Collections.emptyList()),
-                new NoneCircuitBreakerService()
+                new NoneCircuitBreakerService(),
+                NoopTracer.INSTANCE
             ),
             threadPool,
             TransportService.NOOP_TRANSPORT_INTERCEPTOR,
diff --git a/plugins/discovery-gce/licenses/log4j-1.2-api-2.20.0.jar.sha1 b/plugins/discovery-gce/licenses/log4j-1.2-api-2.20.0.jar.sha1
deleted file mode 100644
index 9829576d38ce0..0000000000000
--- a/plugins/discovery-gce/licenses/log4j-1.2-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-689151374756cb809cb029f2501015bdc7733179
\ No newline at end of file
diff --git a/plugins/discovery-gce/licenses/log4j-1.2-api-2.21.0.jar.sha1 b/plugins/discovery-gce/licenses/log4j-1.2-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..39d9177cb2fac
--- /dev/null
+++ b/plugins/discovery-gce/licenses/log4j-1.2-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+12bad3819a9570807f3c97315930699584c12152
\ No newline at end of file
diff --git a/plugins/discovery-gce/src/test/java/org/opensearch/discovery/gce/GceDiscoveryTests.java b/plugins/discovery-gce/src/test/java/org/opensearch/discovery/gce/GceDiscoveryTests.java
index b4af9773f33de..2208c78bef67a 100644
--- a/plugins/discovery-gce/src/test/java/org/opensearch/discovery/gce/GceDiscoveryTests.java
+++ b/plugins/discovery-gce/src/test/java/org/opensearch/discovery/gce/GceDiscoveryTests.java
@@ -66,7 +66,6 @@
  * compute/v1/projects/[project-id]/zones/[zone]
  *
  * By default, project-id is the test method name, lowercase and missing the "test" prefix.
- *
  * For example, if you create a test `myNewAwesomeTest` with following settings:
  *
  * Settings nodeSettings = Settings.builder()
@@ -75,7 +74,6 @@
  *  .build();
  *
  *  You need to create a file under `src/test/resources/org/opensearch/discovery/gce/` named:
- *
  *  compute/v1/projects/mynewawesometest/zones/europe-west1-b/instances.json
  *
  */
diff --git a/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/codec/BasePerFieldCorrelationVectorsFormat.java b/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/codec/BasePerFieldCorrelationVectorsFormat.java
index 7763b1e42d63e..00b55eb75995c 100644
--- a/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/codec/BasePerFieldCorrelationVectorsFormat.java
+++ b/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/codec/BasePerFieldCorrelationVectorsFormat.java
@@ -27,12 +27,12 @@
 public abstract class BasePerFieldCorrelationVectorsFormat extends PerFieldKnnVectorsFormat {
     /**
      * the hyper-parameters for constructing HNSW graphs.
-     * https://lucene.apache.org/core/9_4_0/core/org/apache/lucene/util/hnsw/HnswGraph.html
+     * <a href="https://lucene.apache.org/core/9_4_0/core/org/apache/lucene/util/hnsw/HnswGraph.html">HnswGraph.html</a>
      */
     public static final String METHOD_PARAMETER_M = "m";
     /**
      * the hyper-parameters for constructing HNSW graphs.
-     * https://lucene.apache.org/core/9_4_0/core/org/apache/lucene/util/hnsw/HnswGraph.html
+     * <a href="https://lucene.apache.org/core/9_4_0/core/org/apache/lucene/util/hnsw/HnswGraph.html">HnswGraph.html</a>
      */
     public static final String METHOD_PARAMETER_EF_CONSTRUCTION = "ef_construction";
 
diff --git a/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapper.java b/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapper.java
index a1918f3c954d0..18c9dd222e2cf 100644
--- a/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapper.java
+++ b/plugins/events-correlation-engine/src/main/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapper.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.plugin.correlation.core.index.mapper;
 
+import org.apache.lucene.codecs.KnnVectorsFormat;
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.document.KnnFloatVectorField;
 import org.apache.lucene.document.StoredField;
@@ -23,8 +24,6 @@
 import java.util.Locale;
 import java.util.Optional;
 
-import static org.apache.lucene.index.FloatVectorValues.MAX_DIMENSIONS;
-
 /**
  * Field mapper for the correlation vector type
  *
@@ -32,7 +31,7 @@
  */
 public class CorrelationVectorFieldMapper extends VectorFieldMapper {
 
-    private static final int LUCENE_MAX_DIMENSION = MAX_DIMENSIONS;
+    private static final int LUCENE_MAX_DIMENSION = KnnVectorsFormat.DEFAULT_MAX_DIMENSIONS;
 
     private final FieldType vectorFieldType;
 
diff --git a/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapperTests.java b/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapperTests.java
index 70311a9279bbd..674f35069a742 100644
--- a/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapperTests.java
+++ b/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/mapper/CorrelationVectorFieldMapperTests.java
@@ -191,7 +191,7 @@ public void testTypeParser_parse_fromCorrelationParamsContext_InvalidVectorSimil
 
     /**
      * test parseCreateField in CorrelationVectorFieldMapper
-     * @throws IOException
+     * @throws IOException ioexception
      */
     public void testCorrelationVectorFieldMapper_parseCreateField() throws IOException {
         String fieldName = "test-field-name";
diff --git a/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/query/CorrelationQueryBuilderTests.java b/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/query/CorrelationQueryBuilderTests.java
index b3fcbedd74558..3e567d0c04e53 100644
--- a/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/query/CorrelationQueryBuilderTests.java
+++ b/plugins/events-correlation-engine/src/test/java/org/opensearch/plugin/correlation/core/index/query/CorrelationQueryBuilderTests.java
@@ -203,7 +203,8 @@ public void testDoToQueryInvalidFieldType() {
 
     /**
      * test serialization of Correlation Query Builder
-     * @throws Exception
+     * @throws Exception throws an IOException if serialization fails
+     * @throws Exception Exception
      */
     public void testSerialization() throws Exception {
         assertSerialization(Optional.empty());
diff --git a/plugins/examples/custom-suggester/src/main/java/org/opensearch/example/customsuggester/CustomSuggestion.java b/plugins/examples/custom-suggester/src/main/java/org/opensearch/example/customsuggester/CustomSuggestion.java
index 9255d3a2f299e..c8e9d8cfc0a12 100644
--- a/plugins/examples/custom-suggester/src/main/java/org/opensearch/example/customsuggester/CustomSuggestion.java
+++ b/plugins/examples/custom-suggester/src/main/java/org/opensearch/example/customsuggester/CustomSuggestion.java
@@ -53,7 +53,6 @@ public class CustomSuggestion extends Suggest.Suggestion<CustomSuggestion.Entry>
 
     /**
      * An integer representing the type of the suggestion formerly used for internal serialization over the network.
-     *
      * This class is now serialized as a NamedWriteable and this value only remains for backwards compatibility
      */
     public static final int TYPE = 999;
@@ -106,7 +105,7 @@ public int getWriteableType() {
 
     /**
      * A meaningless value used to test that plugin suggesters can add fields to their Suggestion types
-     *
+     * <p>
      * This can't be serialized to xcontent because Suggestions appear in xcontent as an array of entries, so there is no place
      * to add a custom field. But we can still use a custom field internally and use it to define a Suggestion's behavior
      *
diff --git a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedClass.java b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedClass.java
index ca58d97377478..ee04741eb5a03 100644
--- a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedClass.java
+++ b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedClass.java
@@ -34,7 +34,7 @@
 
 /**
  * An example of a class to be allowlisted for use by painless scripts
- *
+ * <p>
  * Each of the members and methods below are allowlisted for use in search scripts.
  * See <a href="file:example_allowlist.txt">example_allowlist.txt</a>.
  */
diff --git a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedInstance.java b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedInstance.java
index 0833f1f0c6659..35385e98187ea 100644
--- a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedInstance.java
+++ b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleAllowlistedInstance.java
@@ -34,7 +34,7 @@
 
 /**
  * An example of an instance to be allowlisted for use by painless scripts.
- *
+ * <p>
  * Each of the members and methods below are allowlisted for use in search scripts but only from this instance.
  */
 public class ExampleAllowlistedInstance {
diff --git a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExamplePainlessAnnotation.java b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExamplePainlessAnnotation.java
index 428a0cc688ad3..ac42c2b1cf9bc 100644
--- a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExamplePainlessAnnotation.java
+++ b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExamplePainlessAnnotation.java
@@ -34,7 +34,7 @@
 
 /**
  * An example of an annotation to be allowlisted for use by painless scripts
- *
+ * <p>
  * The annotation below is allowlisted for use in search scripts.
  * See <a href="file:example_allowlist.txt">example_allowlist.txt</a>.
  */
diff --git a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleStaticMethodClass.java b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleStaticMethodClass.java
index 25443977a0f66..2f6d1ad9349bc 100644
--- a/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleStaticMethodClass.java
+++ b/plugins/examples/painless-allowlist/src/main/java/org/opensearch/example/painlessallowlist/ExampleStaticMethodClass.java
@@ -34,7 +34,7 @@
 
 /**
  * An example of a class with static methods to be allowlisted for use by painless scripts
- *
+ * <p>
  * The method below is allowlisted for use in search scripts.
  * See <a href="file:example_allowlist.txt">example_allowlist.txt</a>.
  */
diff --git a/plugins/identity-shiro/licenses/bcprov-jdk15to18-1.75.jar.sha1 b/plugins/identity-shiro/licenses/bcprov-jdk15to18-1.75.jar.sha1
deleted file mode 100644
index 9911bb75f9209..0000000000000
--- a/plugins/identity-shiro/licenses/bcprov-jdk15to18-1.75.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-df22e1b6a9f6b218913f5b68dd16641344397fe0
\ No newline at end of file
diff --git a/plugins/identity-shiro/licenses/bcprov-jdk15to18-1.76.jar.sha1 b/plugins/identity-shiro/licenses/bcprov-jdk15to18-1.76.jar.sha1
new file mode 100644
index 0000000000000..2e96c404bef98
--- /dev/null
+++ b/plugins/identity-shiro/licenses/bcprov-jdk15to18-1.76.jar.sha1
@@ -0,0 +1 @@
+0cb53f10290a634808555bc4b34328fdab1001f2
\ No newline at end of file
diff --git a/plugins/identity-shiro/src/main/java/org/opensearch/identity/shiro/ShiroTokenManager.java b/plugins/identity-shiro/src/main/java/org/opensearch/identity/shiro/ShiroTokenManager.java
index 60239d609a08a..a14215aa7655b 100644
--- a/plugins/identity-shiro/src/main/java/org/opensearch/identity/shiro/ShiroTokenManager.java
+++ b/plugins/identity-shiro/src/main/java/org/opensearch/identity/shiro/ShiroTokenManager.java
@@ -10,13 +10,11 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.apache.shiro.SecurityUtils;
 import org.apache.shiro.authc.AuthenticationToken;
 import org.apache.shiro.authc.UsernamePasswordToken;
 import org.opensearch.common.Randomness;
 import org.opensearch.identity.IdentityService;
 import org.opensearch.identity.Subject;
-import org.opensearch.identity.noop.NoopSubject;
 import org.opensearch.identity.tokens.AuthToken;
 import org.opensearch.identity.tokens.BasicAuthToken;
 import org.opensearch.identity.tokens.OnBehalfOfClaims;
@@ -64,9 +62,9 @@ public Optional<AuthenticationToken> translateAuthToken(org.opensearch.identity.
     public AuthToken issueOnBehalfOfToken(Subject subject, OnBehalfOfClaims claims) {
 
         String password = generatePassword();
-        final byte[] rawEncoded = Base64.getEncoder().encode((claims.getAudience() + ":" + password).getBytes(UTF_8)); // Make a new
-                                                                                                                       // ShiroSubject w/
-                                                                                                                       // audience as name
+        // Make a new ShiroSubject audience as name
+        final byte[] rawEncoded = Base64.getUrlEncoder().encode((claims.getAudience() + ":" + password).getBytes(UTF_8));
+
         final String usernamePassword = new String(rawEncoded, UTF_8);
         final String header = "Basic " + usernamePassword;
         BasicAuthToken token = new BasicAuthToken(header);
@@ -76,17 +74,16 @@ public AuthToken issueOnBehalfOfToken(Subject subject, OnBehalfOfClaims claims)
     }
 
     @Override
-    public Subject authenticateToken(AuthToken authToken) {
-        return new NoopSubject();
-    }
+    public AuthToken issueServiceAccountToken(String audience) {
 
-    public boolean validateToken(AuthToken token) {
-        if (token instanceof BasicAuthToken) {
-            final BasicAuthToken basicAuthToken = (BasicAuthToken) token;
-            return basicAuthToken.getUser().equals(SecurityUtils.getSubject().toString())
-                && basicAuthToken.getPassword().equals(shiroTokenPasswordMap.get(basicAuthToken));
-        }
-        return false;
+        String password = generatePassword();
+        final byte[] rawEncoded = Base64.getUrlEncoder().withoutPadding().encode((audience + ":" + password).getBytes(UTF_8)); // Make a new
+        final String usernamePassword = new String(rawEncoded, UTF_8);
+        final String header = "Basic " + usernamePassword;
+
+        BasicAuthToken token = new BasicAuthToken(header);
+        shiroTokenPasswordMap.put(token, password);
+        return token;
     }
 
     public String getTokenInfo(AuthToken token) {
diff --git a/plugins/identity-shiro/src/test/java/org/opensearch/identity/shiro/AuthTokenHandlerTests.java b/plugins/identity-shiro/src/test/java/org/opensearch/identity/shiro/AuthTokenHandlerTests.java
index 7c7414843d86f..f99484083e2fb 100644
--- a/plugins/identity-shiro/src/test/java/org/opensearch/identity/shiro/AuthTokenHandlerTests.java
+++ b/plugins/identity-shiro/src/test/java/org/opensearch/identity/shiro/AuthTokenHandlerTests.java
@@ -100,11 +100,6 @@ public void testShouldFailGetTokenInfo() {
         assertThrows(UnsupportedAuthenticationToken.class, () -> shiroAuthTokenHandler.getTokenInfo(bearerAuthToken));
     }
 
-    public void testShouldFailValidateToken() {
-        final BearerAuthToken bearerAuthToken = new BearerAuthToken("header.payload.signature");
-        assertFalse(shiroAuthTokenHandler.validateToken(bearerAuthToken));
-    }
-
     public void testShoudPassMapLookupWithToken() {
         final BasicAuthToken authToken = new BasicAuthToken("Basic dGVzdDp0ZTpzdA==");
         shiroAuthTokenHandler.getShiroTokenPasswordMap().put(authToken, "te:st");
@@ -167,6 +162,18 @@ public void testTokenNoopIssuance() {
         Subject subject = new NoopSubject();
         AuthToken token = tokenManager.issueOnBehalfOfToken(subject, claims);
         assertTrue(token instanceof AuthToken);
+        AuthToken serviceAccountToken = tokenManager.issueServiceAccountToken("test");
+        assertTrue(serviceAccountToken instanceof AuthToken);
+        assertEquals(serviceAccountToken.asAuthHeaderValue(), "noopToken");
     }
 
+    public void testShouldSucceedIssueServiceAccountToken() {
+        String audience = "testExtensionName";
+        BasicAuthToken authToken = (BasicAuthToken) shiroAuthTokenHandler.issueServiceAccountToken(audience);
+        assertTrue(authToken instanceof BasicAuthToken);
+        UsernamePasswordToken translatedToken = (UsernamePasswordToken) shiroAuthTokenHandler.translateAuthToken(authToken).get();
+        assertEquals(authToken.getPassword(), new String(translatedToken.getPassword()));
+        assertTrue(shiroAuthTokenHandler.getShiroTokenPasswordMap().containsKey(authToken));
+        assertEquals(shiroAuthTokenHandler.getShiroTokenPasswordMap().get(authToken), new String(translatedToken.getPassword()));
+    }
 }
diff --git a/plugins/ingest-attachment/build.gradle b/plugins/ingest-attachment/build.gradle
index f54c80e9f76c1..57a2493053956 100644
--- a/plugins/ingest-attachment/build.gradle
+++ b/plugins/ingest-attachment/build.gradle
@@ -57,7 +57,7 @@ dependencies {
   runtimeOnly "com.google.guava:guava:${versions.guava}"
   // Other dependencies
   api 'org.tukaani:xz:1.9'
-  api 'commons-io:commons-io:2.13.0'
+  api 'commons-io:commons-io:2.15.0'
   api "org.slf4j:slf4j-api:${versions.slf4j}"
 
   // character set detection
@@ -79,7 +79,7 @@ dependencies {
   api "org.apache.poi:poi:${versions.poi}"
   api "org.apache.poi:poi-ooxml-lite:${versions.poi}"
   api "commons-codec:commons-codec:${versions.commonscodec}"
-  api 'org.apache.xmlbeans:xmlbeans:5.1.1'
+  api 'org.apache.xmlbeans:xmlbeans:5.2.0'
   api 'org.apache.commons:commons-collections4:4.4'
   // MS Office
   api "org.apache.poi:poi-scratchpad:${versions.poi}"
@@ -93,7 +93,7 @@ dependencies {
   // Microsoft Word files with visio diagrams
   api 'org.apache.commons:commons-math3:3.6.1'
   // POIs dependency
-  api 'com.zaxxer:SparseBitSet:1.2'
+  api 'com.zaxxer:SparseBitSet:1.3'
 }
 
 restResources {
diff --git a/plugins/ingest-attachment/licenses/SparseBitSet-1.2.jar.sha1 b/plugins/ingest-attachment/licenses/SparseBitSet-1.2.jar.sha1
deleted file mode 100644
index 5f1d015b87ac7..0000000000000
--- a/plugins/ingest-attachment/licenses/SparseBitSet-1.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-8467c813d442837fcaeddbc42cf5c5359fab4933
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/SparseBitSet-1.3.jar.sha1 b/plugins/ingest-attachment/licenses/SparseBitSet-1.3.jar.sha1
new file mode 100644
index 0000000000000..2803db7c91e30
--- /dev/null
+++ b/plugins/ingest-attachment/licenses/SparseBitSet-1.3.jar.sha1
@@ -0,0 +1 @@
+533eac055afe3d5f614ea95e333afd6c2bde8f26
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/bcmail-jdk15to18-1.75.jar.sha1 b/plugins/ingest-attachment/licenses/bcmail-jdk15to18-1.75.jar.sha1
deleted file mode 100644
index e6840a9b02b38..0000000000000
--- a/plugins/ingest-attachment/licenses/bcmail-jdk15to18-1.75.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-b316bcd094e3917b1ece93a6edbab93f8315fb3b
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/bcmail-jdk15to18-1.76.jar.sha1 b/plugins/ingest-attachment/licenses/bcmail-jdk15to18-1.76.jar.sha1
new file mode 100644
index 0000000000000..46010d64015ad
--- /dev/null
+++ b/plugins/ingest-attachment/licenses/bcmail-jdk15to18-1.76.jar.sha1
@@ -0,0 +1 @@
+23d8bcad6b57912e4633ca9955926ffcdf3c5c71
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/bcpkix-jdk15to18-1.75.jar.sha1 b/plugins/ingest-attachment/licenses/bcpkix-jdk15to18-1.75.jar.sha1
deleted file mode 100644
index 9181b1c3ab1b6..0000000000000
--- a/plugins/ingest-attachment/licenses/bcpkix-jdk15to18-1.75.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f16e5252ad7a46d5eaf255231b0a5da307599082
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/bcpkix-jdk15to18-1.76.jar.sha1 b/plugins/ingest-attachment/licenses/bcpkix-jdk15to18-1.76.jar.sha1
new file mode 100644
index 0000000000000..a843d972ac681
--- /dev/null
+++ b/plugins/ingest-attachment/licenses/bcpkix-jdk15to18-1.76.jar.sha1
@@ -0,0 +1 @@
+3ee440dfa1c557c1cc0c46b5dadf5ef3896ccebb
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/bcprov-jdk15to18-1.75.jar.sha1 b/plugins/ingest-attachment/licenses/bcprov-jdk15to18-1.75.jar.sha1
deleted file mode 100644
index 9911bb75f9209..0000000000000
--- a/plugins/ingest-attachment/licenses/bcprov-jdk15to18-1.75.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-df22e1b6a9f6b218913f5b68dd16641344397fe0
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/bcprov-jdk15to18-1.76.jar.sha1 b/plugins/ingest-attachment/licenses/bcprov-jdk15to18-1.76.jar.sha1
new file mode 100644
index 0000000000000..2e96c404bef98
--- /dev/null
+++ b/plugins/ingest-attachment/licenses/bcprov-jdk15to18-1.76.jar.sha1
@@ -0,0 +1 @@
+0cb53f10290a634808555bc4b34328fdab1001f2
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/commons-io-2.13.0.jar.sha1 b/plugins/ingest-attachment/licenses/commons-io-2.13.0.jar.sha1
deleted file mode 100644
index c165136eb5822..0000000000000
--- a/plugins/ingest-attachment/licenses/commons-io-2.13.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-8bb2bc9b4df17e2411533a0708a69f983bf5e83b
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/commons-io-2.15.0.jar.sha1 b/plugins/ingest-attachment/licenses/commons-io-2.15.0.jar.sha1
new file mode 100644
index 0000000000000..73709383fd130
--- /dev/null
+++ b/plugins/ingest-attachment/licenses/commons-io-2.15.0.jar.sha1
@@ -0,0 +1 @@
+5c3c2db10f6f797430a7f9c696b4d1273768c924
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/xmlbeans-5.1.1.jar.sha1 b/plugins/ingest-attachment/licenses/xmlbeans-5.1.1.jar.sha1
deleted file mode 100644
index 4d1d2ad0807e7..0000000000000
--- a/plugins/ingest-attachment/licenses/xmlbeans-5.1.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-48a369df0eccb509d46203104e4df9cb00f0f68b
\ No newline at end of file
diff --git a/plugins/ingest-attachment/licenses/xmlbeans-5.2.0.jar.sha1 b/plugins/ingest-attachment/licenses/xmlbeans-5.2.0.jar.sha1
new file mode 100644
index 0000000000000..f34274d593697
--- /dev/null
+++ b/plugins/ingest-attachment/licenses/xmlbeans-5.2.0.jar.sha1
@@ -0,0 +1 @@
+6198ac997b3f234f2b5393fa415f78fac2e06510
\ No newline at end of file
diff --git a/plugins/mapper-annotated-text/src/main/java/org/opensearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java b/plugins/mapper-annotated-text/src/main/java/org/opensearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java
index 935887261dcc9..952cff96860f2 100644
--- a/plugins/mapper-annotated-text/src/main/java/org/opensearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java
+++ b/plugins/mapper-annotated-text/src/main/java/org/opensearch/index/mapper/annotatedtext/AnnotatedTextFieldMapper.java
@@ -73,9 +73,9 @@
 import java.util.regex.Pattern;
 
 /** A {@link FieldMapper} for full-text fields with annotation markup e.g.
- *
+ * <p>
  *    "New mayor is [John Smith](type=person&amp;value=John%20Smith) "
- *
+ * <p>
  * A special Analyzer wraps the default choice of analyzer in order
  * to strip the text field of annotation markup and inject the related
  * entity annotation tokens as supplementary tokens at the relevant points
diff --git a/plugins/repository-azure/build.gradle b/plugins/repository-azure/build.gradle
index 26e2b4813b8a5..51f2057b4bedb 100644
--- a/plugins/repository-azure/build.gradle
+++ b/plugins/repository-azure/build.gradle
@@ -56,11 +56,8 @@ dependencies {
   api "io.netty:netty-transport-native-unix-common:${versions.netty}"
   implementation project(':modules:transport-netty4')
   api 'com.azure:azure-storage-blob:12.23.0'
-  api 'org.reactivestreams:reactive-streams:1.0.4'
-  api 'io.projectreactor:reactor-core:3.5.6'
-  api 'io.projectreactor.netty:reactor-netty:1.1.8'
-  api 'io.projectreactor.netty:reactor-netty-core:1.1.8'
-  api 'io.projectreactor.netty:reactor-netty-http:1.1.9'
+  api "io.projectreactor.netty:reactor-netty-core:${versions.reactor_netty}"
+  api "io.projectreactor.netty:reactor-netty-http:${versions.reactor_netty}"
   api "org.slf4j:slf4j-api:${versions.slf4j}"
   api "com.fasterxml.jackson.core:jackson-annotations:${versions.jackson}"
   api "com.fasterxml.jackson.core:jackson-databind:${versions.jackson_databind}"
@@ -101,10 +98,6 @@ thirdPartyAudit {
     'com.azure.storage.internal.avro.implementation.schema.AvroSchema',
     'com.ctc.wstx.shaded.msv_core.driver.textui.Driver',
     'io.micrometer.context.ContextAccessor',
-    'io.micrometer.context.ContextRegistry',
-    'io.micrometer.context.ContextSnapshot',
-    'io.micrometer.context.ContextSnapshot$Scope',
-    'io.micrometer.core.instrument.Clock',
     'io.micrometer.core.instrument.Counter',
     'io.micrometer.core.instrument.Counter$Builder',
     'io.micrometer.core.instrument.DistributionSummary',
@@ -114,14 +107,10 @@ thirdPartyAudit {
     'io.micrometer.core.instrument.Meter',
     'io.micrometer.core.instrument.MeterRegistry',
     'io.micrometer.core.instrument.Metrics',
-    'io.micrometer.core.instrument.Tag',
-    'io.micrometer.core.instrument.Tags',
     'io.micrometer.core.instrument.Timer',
     'io.micrometer.core.instrument.Timer$Builder',
     'io.micrometer.core.instrument.Timer$Sample',
-    'io.micrometer.core.instrument.binder.jvm.ExecutorServiceMetrics',
     'io.micrometer.core.instrument.composite.CompositeMeterRegistry',
-    'io.micrometer.core.instrument.search.Search',
     'io.netty.channel.epoll.Epoll',
     'io.netty.channel.epoll.EpollDatagramChannel',
     'io.netty.channel.epoll.EpollServerSocketChannel',
@@ -168,9 +157,6 @@ thirdPartyAudit {
     'org.slf4j.impl.StaticLoggerBinder',
     'org.slf4j.impl.StaticMDCBinder',
     'org.slf4j.impl.StaticMarkerBinder',
-    'reactor.blockhound.BlockHound$Builder',
-    'reactor.blockhound.integration.BlockHoundIntegration',
-    'io.micrometer.context.ThreadLocalAccessor',
     'io.micrometer.common.KeyValue',
     'io.micrometer.common.KeyValues',
     'io.micrometer.common.docs.KeyName',
@@ -190,6 +176,7 @@ thirdPartyAudit {
     'io.micrometer.tracing.handler.PropagatingSenderTracingObservationHandler',
     'io.micrometer.tracing.propagation.Propagator',
     'io.micrometer.core.instrument.observation.MeterObservationHandler',
+    'io.micrometer.core.instrument.Tags',
     'io.micrometer.observation.ObservationHandler',
     'io.micrometer.observation.ObservationRegistry',
     'io.micrometer.observation.ObservationRegistry$ObservationConfig',
@@ -210,8 +197,7 @@ thirdPartyAudit {
     'com.google.common.util.concurrent.AbstractFuture$UnsafeAtomicHelper$1',
     'com.google.common.hash.LittleEndianByteArray$UnsafeByteArray',
     'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator',
-    'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator$1',
-    'reactor.core.publisher.Traces$SharedSecretsCallSiteSupplierFactory$TracingException'
+    'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator$1'
   )
 }
 
diff --git a/plugins/repository-azure/licenses/jackson-annotations-2.15.2.jar.sha1 b/plugins/repository-azure/licenses/jackson-annotations-2.15.2.jar.sha1
deleted file mode 100644
index f63416ddb8ceb..0000000000000
--- a/plugins/repository-azure/licenses/jackson-annotations-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4724a65ac8e8d156a24898d50fd5dbd3642870b8
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-annotations-2.16.0.jar.sha1 b/plugins/repository-azure/licenses/jackson-annotations-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..79ed9e0c63fc8
--- /dev/null
+++ b/plugins/repository-azure/licenses/jackson-annotations-2.16.0.jar.sha1
@@ -0,0 +1 @@
+dc30995f7428c0a405eba9b8c619b20d2b3b9905
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-databind-2.15.2.jar.sha1 b/plugins/repository-azure/licenses/jackson-databind-2.15.2.jar.sha1
deleted file mode 100644
index f16d80af8dce6..0000000000000
--- a/plugins/repository-azure/licenses/jackson-databind-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9353b021f10c307c00328f52090de2bdb4b6ff9c
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-databind-2.16.0.jar.sha1 b/plugins/repository-azure/licenses/jackson-databind-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..da00d281934b1
--- /dev/null
+++ b/plugins/repository-azure/licenses/jackson-databind-2.16.0.jar.sha1
@@ -0,0 +1 @@
+3a6b7f8ff7b30d518bbd65678e9c30cd881f19a7
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-dataformat-xml-2.15.2.jar.sha1 b/plugins/repository-azure/licenses/jackson-dataformat-xml-2.15.2.jar.sha1
deleted file mode 100644
index 18c388b84f333..0000000000000
--- a/plugins/repository-azure/licenses/jackson-dataformat-xml-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-e7e9038dee5c1adb1ebd07d3669e0e1182ac5b60
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-dataformat-xml-2.16.0.jar.sha1 b/plugins/repository-azure/licenses/jackson-dataformat-xml-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..f0d165ff7cf82
--- /dev/null
+++ b/plugins/repository-azure/licenses/jackson-dataformat-xml-2.16.0.jar.sha1
@@ -0,0 +1 @@
+f3cdb002e0f2f30ad9c5fd053d78b1a485511ab1
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-datatype-jsr310-2.15.2.jar.sha1 b/plugins/repository-azure/licenses/jackson-datatype-jsr310-2.15.2.jar.sha1
deleted file mode 100644
index 6aa4f9b99c274..0000000000000
--- a/plugins/repository-azure/licenses/jackson-datatype-jsr310-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-30d16ec2aef6d8094c5e2dce1d95034ca8b6cb42
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-datatype-jsr310-2.16.0.jar.sha1 b/plugins/repository-azure/licenses/jackson-datatype-jsr310-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..40379694f5ea5
--- /dev/null
+++ b/plugins/repository-azure/licenses/jackson-datatype-jsr310-2.16.0.jar.sha1
@@ -0,0 +1 @@
+77e3a27823f795d928b897d8444744ddb044a5c3
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-module-jaxb-annotations-2.15.2.jar.sha1 b/plugins/repository-azure/licenses/jackson-module-jaxb-annotations-2.15.2.jar.sha1
deleted file mode 100644
index 80da08928f855..0000000000000
--- a/plugins/repository-azure/licenses/jackson-module-jaxb-annotations-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-6a22fd1c7b0f9788e81eea32c11dc8c1ba421f18
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/jackson-module-jaxb-annotations-2.16.0.jar.sha1 b/plugins/repository-azure/licenses/jackson-module-jaxb-annotations-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..820d14b3df8e4
--- /dev/null
+++ b/plugins/repository-azure/licenses/jackson-module-jaxb-annotations-2.16.0.jar.sha1
@@ -0,0 +1 @@
+684daae9ea45087c670b4f6511edcfdb19c3a695
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-transport-classes-epoll-4.1.97.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-codec-dns-4.1.101.Final.jar.sha1
similarity index 100%
rename from plugins/repository-s3/licenses/netty-transport-classes-epoll-4.1.97.Final.jar.sha1
rename to plugins/repository-azure/licenses/netty-codec-dns-4.1.101.Final.jar.sha1
index 8e40c8826d76d..0789dea62778a 100644
--- a/plugins/repository-s3/licenses/netty-transport-classes-epoll-4.1.97.Final.jar.sha1
+++ b/plugins/repository-azure/licenses/netty-codec-dns-4.1.101.Final.jar.sha1
@@ -1 +1 @@
-795da37ded759e862457a82d9d92c4d39ce8ecee
\ No newline at end of file
+24d0f4f2b0b0b55acc498d62f9c0921d0ea6da7b
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-codec-dns-4.1.97.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-codec-dns-4.1.97.Final.jar.sha1
deleted file mode 100644
index f592ac8312a5d..0000000000000
--- a/plugins/repository-azure/licenses/netty-codec-dns-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-d266d079ef33cf93a16b382d64dd15d562df1159
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-codec-http2-4.1.101.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..48b42bfab9287
--- /dev/null
+++ b/plugins/repository-azure/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+40590da6c615b852384542051330e9fd51d4c4b1
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-codec-http2-4.1.97.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-codec-http2-4.1.97.Final.jar.sha1
deleted file mode 100644
index cbf685a6d79d3..0000000000000
--- a/plugins/repository-azure/licenses/netty-codec-http2-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-893888d09a7bef0d0ba973d7471943e765d0fd08
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-codec-socks-4.1.101.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-codec-socks-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..fb2d1aa25a5ec
--- /dev/null
+++ b/plugins/repository-azure/licenses/netty-codec-socks-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+cbaac9e2c2d7b86e4c1bda220cde49949c9bcaee
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-codec-socks-4.1.97.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-codec-socks-4.1.97.Final.jar.sha1
deleted file mode 100644
index d06147a0ba646..0000000000000
--- a/plugins/repository-azure/licenses/netty-codec-socks-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-30e8fa29a349db5a933225d61891b8802836bb79
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-handler-proxy-4.1.101.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-handler-proxy-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..ca030677c32d0
--- /dev/null
+++ b/plugins/repository-azure/licenses/netty-handler-proxy-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+c198ee61abba7ae6b3cb6b1033f04fb0ae79d512
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-handler-proxy-4.1.97.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-handler-proxy-4.1.97.Final.jar.sha1
deleted file mode 100644
index 67c3a763d26fa..0000000000000
--- a/plugins/repository-azure/licenses/netty-handler-proxy-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-a99ecef0e1d86a92e40a7c89805c236d9cd7493e
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-resolver-dns-4.1.101.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-resolver-dns-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..450c34d975bb9
--- /dev/null
+++ b/plugins/repository-azure/licenses/netty-resolver-dns-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+d3f503d7554cf25edc6b83b9b4724b240c6e91d5
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-resolver-dns-4.1.97.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-resolver-dns-4.1.97.Final.jar.sha1
deleted file mode 100644
index 60fd706436ae7..0000000000000
--- a/plugins/repository-azure/licenses/netty-resolver-dns-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-2c50f835777ecd4535e15b552b5d9ccb26a2504f
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..291c87ad7987b
--- /dev/null
+++ b/plugins/repository-azure/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+d0697ef1d71c6111a1b18a387fa985fd6398ace2
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1 b/plugins/repository-azure/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1
deleted file mode 100644
index f736d37d071b7..0000000000000
--- a/plugins/repository-azure/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-d469d84265ab70095b01b40886cabdd433b6e664
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactive-streams-1.0.4.jar.sha1 b/plugins/repository-azure/licenses/reactive-streams-1.0.4.jar.sha1
deleted file mode 100644
index 45a80e3f7e361..0000000000000
--- a/plugins/repository-azure/licenses/reactive-streams-1.0.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3864a1320d97d7b045f729a326e1e077661f31b7
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactive-streams-LICENSE.txt b/plugins/repository-azure/licenses/reactive-streams-LICENSE.txt
deleted file mode 100644
index 1e3c7e7c77495..0000000000000
--- a/plugins/repository-azure/licenses/reactive-streams-LICENSE.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-MIT No Attribution
-
-Copyright 2014 Reactive Streams
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-core-3.5.6.jar.sha1 b/plugins/repository-azure/licenses/reactor-core-3.5.6.jar.sha1
deleted file mode 100644
index ad9b7263e7b38..0000000000000
--- a/plugins/repository-azure/licenses/reactor-core-3.5.6.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-027fdc551537b349389176a23a192f11a7a3d7de
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1
deleted file mode 100644
index 6b6bf1903b16c..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-d53a9d7d0395285f4c81664494fcd61477626e32
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-core-1.1.13.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-core-1.1.13.jar.sha1
new file mode 100644
index 0000000000000..5eaf96739ed72
--- /dev/null
+++ b/plugins/repository-azure/licenses/reactor-netty-core-1.1.13.jar.sha1
@@ -0,0 +1 @@
+faea23e582978a34f6a932b81e86206ec2314990
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1
deleted file mode 100644
index 707631f4dfe0c..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-48999c4ae27cdcee5eaff9dfd150a8b64624f0f5
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-http-1.1.13.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-http-1.1.13.jar.sha1
new file mode 100644
index 0000000000000..091125169c696
--- /dev/null
+++ b/plugins/repository-azure/licenses/reactor-netty-http-1.1.13.jar.sha1
@@ -0,0 +1 @@
+c5af7bc746050d080891a5446cca2c96a0c51d03
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-http-1.1.9.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-http-1.1.9.jar.sha1
deleted file mode 100644
index 96deead2c75d1..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-http-1.1.9.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-408b3037133f2e8ab0f195ccd3f807026be9b860
\ No newline at end of file
diff --git a/plugins/repository-azure/src/internalClusterTest/java/org/opensearch/repositories/azure/AzureBlobStoreRepositoryTests.java b/plugins/repository-azure/src/internalClusterTest/java/org/opensearch/repositories/azure/AzureBlobStoreRepositoryTests.java
index 82364d1b7b3c1..986720ec431fe 100644
--- a/plugins/repository-azure/src/internalClusterTest/java/org/opensearch/repositories/azure/AzureBlobStoreRepositoryTests.java
+++ b/plugins/repository-azure/src/internalClusterTest/java/org/opensearch/repositories/azure/AzureBlobStoreRepositoryTests.java
@@ -154,7 +154,7 @@ private static class AzureBlobStoreHttpHandler extends AzureHttpHandler implemen
 
     /**
      * HTTP handler that injects random Azure service errors
-     *
+     * <p>
      * Note: it is not a good idea to allow this handler to simulate too many errors as it would
      * slow down the test suite.
      */
diff --git a/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureRepository.java b/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureRepository.java
index 65852c4fc5bd0..47a5536a6cd8a 100644
--- a/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureRepository.java
+++ b/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureRepository.java
@@ -47,6 +47,8 @@
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.repositories.blobstore.MeteredBlobStoreRepository;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.function.Function;
@@ -114,14 +116,7 @@ public AzureRepository(
         final ClusterService clusterService,
         final RecoverySettings recoverySettings
     ) {
-        super(
-            metadata,
-            COMPRESS_SETTING.get(metadata.settings()),
-            namedXContentRegistry,
-            clusterService,
-            recoverySettings,
-            buildLocation(metadata)
-        );
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings, buildLocation(metadata));
         this.chunkSize = Repository.CHUNK_SIZE_SETTING.get(metadata.settings());
         this.storageService = storageService;
 
@@ -192,4 +187,13 @@ protected ByteSizeValue chunkSize() {
     public boolean isReadOnly() {
         return readonly;
     }
+
+    @Override
+    public List<Setting<?>> getRestrictedSystemRepositorySettings() {
+        List<Setting<?>> restrictedSettings = new ArrayList<>();
+        restrictedSettings.addAll(super.getRestrictedSystemRepositorySettings());
+        restrictedSettings.add(Repository.BASE_PATH_SETTING);
+        restrictedSettings.add(Repository.LOCATION_MODE_SETTING);
+        return restrictedSettings;
+    }
 }
diff --git a/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureStorageService.java b/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureStorageService.java
index 9dcc312f8f5a7..b60701ba5e533 100644
--- a/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureStorageService.java
+++ b/plugins/repository-azure/src/main/java/org/opensearch/repositories/azure/AzureStorageService.java
@@ -212,8 +212,8 @@ protected PasswordAuthentication getPasswordAuthentication() {
 
     /**
      * The location mode is not there in v12 APIs anymore but it is possible to mimic its semantics using
-     * retry options and combination of primary / secondary endpoints. Refer to migration guide for mode details:
-     * https://github.com/Azure/azure-sdk-for-java/blob/main/sdk/storage/azure-storage-blob/migrationGuides/V8_V12.md#miscellaneous
+     * retry options and combination of primary / secondary endpoints. Refer to
+     * <a href="https://github.com/Azure/azure-sdk-for-java/blob/main/sdk/storage/azure-storage-blob/migrationGuides/V8_V12.md#miscellaneous">migration guide</a> for mode details:
      */
     private BlobServiceClientBuilder applyLocationMode(final BlobServiceClientBuilder builder, final AzureStorageSettings settings) {
         final StorageConnectionString storageConnectionString = StorageConnectionString.create(settings.getConnectString(), logger);
@@ -335,8 +335,8 @@ private void closeInternally(ClientState state) {
     }
 
     /**
-     * Implements HTTP pipeline policy to collect statistics on API calls. See please:
-     * https://github.com/Azure/azure-sdk-for-java/blob/main/sdk/storage/azure-storage-blob/migrationGuides/V8_V12.md#miscellaneous
+     * Implements HTTP pipeline policy to collect statistics on API calls. See :
+     * <a href="https://github.com/Azure/azure-sdk-for-java/blob/main/sdk/storage/azure-storage-blob/migrationGuides/V8_V12.md#miscellaneous">migration guide</a>
      */
     private static class HttpStatsPolicy implements HttpPipelinePolicy {
         private final BiConsumer<HttpRequest, HttpResponse> statsCollector;
diff --git a/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureRepositorySettingsTests.java b/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureRepositorySettingsTests.java
index c8be30dbaf865..3356e5174592a 100644
--- a/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureRepositorySettingsTests.java
+++ b/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureRepositorySettingsTests.java
@@ -34,16 +34,20 @@
 
 import org.opensearch.cluster.metadata.RepositoryMetadata;
 import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.env.Environment;
 import org.opensearch.indices.recovery.RecoverySettings;
+import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.repositories.blobstore.BlobStoreTestUtil;
 import org.opensearch.test.OpenSearchTestCase;
 import org.junit.AfterClass;
 
+import java.util.List;
+
 import reactor.core.scheduler.Schedulers;
 
 import static org.hamcrest.Matchers.is;
@@ -179,4 +183,21 @@ public void testChunkSize() {
         );
     }
 
+    public void testSystemRepositoryDefault() {
+        assertThat(azureRepository(Settings.EMPTY).isSystemRepository(), is(false));
+    }
+
+    public void testSystemRepositoryOn() {
+        assertThat(azureRepository(Settings.builder().put("system_repository", true).build()).isSystemRepository(), is(true));
+    }
+
+    public void testRestrictedSettingsDefault() {
+        List<Setting<?>> restrictedSettings = azureRepository(Settings.EMPTY).getRestrictedSystemRepositorySettings();
+        assertThat(restrictedSettings.size(), is(5));
+        assertTrue(restrictedSettings.contains(BlobStoreRepository.SYSTEM_REPOSITORY_SETTING));
+        assertTrue(restrictedSettings.contains(BlobStoreRepository.READONLY_SETTING));
+        assertTrue(restrictedSettings.contains(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY));
+        assertTrue(restrictedSettings.contains(AzureRepository.Repository.BASE_PATH_SETTING));
+        assertTrue(restrictedSettings.contains(AzureRepository.Repository.LOCATION_MODE_SETTING));
+    }
 }
diff --git a/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureStorageServiceTests.java b/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureStorageServiceTests.java
index 264888bb7da3a..bb0eafc7d1d4a 100644
--- a/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureStorageServiceTests.java
+++ b/plugins/repository-azure/src/test/java/org/opensearch/repositories/azure/AzureStorageServiceTests.java
@@ -451,7 +451,8 @@ private static RequestRetryPolicy requestRetryOptions(BlobServiceClient client)
     }
 
     /**
-     * Extract the blob name from a URI like https://myservice.azure.net/container/path/to/myfile
+     * Extract the blob name from a URI like :
+     * {@code https://myservice.azure.net/container/path/to/myfile }
      * It should remove the container part (first part of the path) and gives path/to/myfile
      * @param uri URI to parse
      * @return The blob name relative to the container
diff --git a/plugins/repository-gcs/build.gradle b/plugins/repository-gcs/build.gradle
index e7ee980114e5e..1bef5146f1db9 100644
--- a/plugins/repository-gcs/build.gradle
+++ b/plugins/repository-gcs/build.gradle
@@ -53,21 +53,21 @@ versions << [
 
 dependencies {
   api 'com.google.api:api-common:1.8.1'
-  api 'com.google.api:gax:2.32.0'
+  api 'com.google.api:gax:2.35.0'
   api 'com.google.api:gax-httpjson:0.103.1'
 
   api 'com.google.apis:google-api-services-storage:v1-rev20230617-2.0.0'
 
   api 'com.google.api-client:google-api-client:2.2.0'
 
-  api 'com.google.api.grpc:proto-google-common-protos:2.10.0'
+  api 'com.google.api.grpc:proto-google-common-protos:2.25.1'
   api 'com.google.api.grpc:proto-google-iam-v1:0.12.0'
 
   api "com.google.auth:google-auth-library-credentials:${versions.google_auth}"
   api "com.google.auth:google-auth-library-oauth2-http:${versions.google_auth}"
 
   api 'com.google.cloud:google-cloud-core:2.5.10'
-  api 'com.google.cloud:google-cloud-core-http:2.21.1'
+  api 'com.google.cloud:google-cloud-core-http:2.23.0'
   api 'com.google.cloud:google-cloud-storage:1.113.1'
 
   api 'com.google.code.gson:gson:2.10.1'
@@ -75,10 +75,10 @@ dependencies {
   runtimeOnly "com.google.guava:guava:${versions.guava}"
   api 'com.google.guava:failureaccess:1.0.1'
 
-  api 'com.google.http-client:google-http-client:1.43.2'
-  api 'com.google.http-client:google-http-client-appengine:1.43.2'
+  api 'com.google.http-client:google-http-client:1.43.3'
+  api 'com.google.http-client:google-http-client-appengine:1.43.3'
   api 'com.google.http-client:google-http-client-gson:1.43.3'
-  api 'com.google.http-client:google-http-client-jackson2:1.43.2'
+  api 'com.google.http-client:google-http-client-jackson2:1.43.3'
 
   api 'com.google.oauth-client:google-oauth-client:1.34.1'
 
diff --git a/plugins/repository-gcs/licenses/gax-2.32.0.jar.sha1 b/plugins/repository-gcs/licenses/gax-2.32.0.jar.sha1
deleted file mode 100644
index 9cae74e1c3673..0000000000000
--- a/plugins/repository-gcs/licenses/gax-2.32.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-522bf3c2a738847b9719eac8ce572be0f84da40a
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/gax-2.35.0.jar.sha1 b/plugins/repository-gcs/licenses/gax-2.35.0.jar.sha1
new file mode 100644
index 0000000000000..778922c637dc1
--- /dev/null
+++ b/plugins/repository-gcs/licenses/gax-2.35.0.jar.sha1
@@ -0,0 +1 @@
+98d52034cfa6d1b881e16f418894afcfacd89b7a
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-cloud-core-http-2.21.1.jar.sha1 b/plugins/repository-gcs/licenses/google-cloud-core-http-2.21.1.jar.sha1
deleted file mode 100644
index cc5e7a53098ac..0000000000000
--- a/plugins/repository-gcs/licenses/google-cloud-core-http-2.21.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-88dd2b413dd06826c611e39e6e3259e069f02f66
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-cloud-core-http-2.23.0.jar.sha1 b/plugins/repository-gcs/licenses/google-cloud-core-http-2.23.0.jar.sha1
new file mode 100644
index 0000000000000..9db3cbcbec35b
--- /dev/null
+++ b/plugins/repository-gcs/licenses/google-cloud-core-http-2.23.0.jar.sha1
@@ -0,0 +1 @@
+9913d0806fcfbfbc4a775f29865126ed8465464b
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-http-client-1.43.2.jar.sha1 b/plugins/repository-gcs/licenses/google-http-client-1.43.2.jar.sha1
deleted file mode 100644
index a576a74c62542..0000000000000
--- a/plugins/repository-gcs/licenses/google-http-client-1.43.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-2520469ebd8c0675f0d2aeafd2da665228320fcf
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-http-client-1.43.3.jar.sha1 b/plugins/repository-gcs/licenses/google-http-client-1.43.3.jar.sha1
new file mode 100644
index 0000000000000..800467de8bdf3
--- /dev/null
+++ b/plugins/repository-gcs/licenses/google-http-client-1.43.3.jar.sha1
@@ -0,0 +1 @@
+a758b82e55a2f5f681e289c5ed384d3dbda6f3cd
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-http-client-appengine-1.43.2.jar.sha1 b/plugins/repository-gcs/licenses/google-http-client-appengine-1.43.2.jar.sha1
deleted file mode 100644
index d8a9dba20070b..0000000000000
--- a/plugins/repository-gcs/licenses/google-http-client-appengine-1.43.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9fb548c5264227813fd83991b94a705b0841c15f
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-http-client-appengine-1.43.3.jar.sha1 b/plugins/repository-gcs/licenses/google-http-client-appengine-1.43.3.jar.sha1
new file mode 100644
index 0000000000000..4adcca6a55902
--- /dev/null
+++ b/plugins/repository-gcs/licenses/google-http-client-appengine-1.43.3.jar.sha1
@@ -0,0 +1 @@
+09d6cbdde6ea3469a67601a811b4e83de3e68a79
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-http-client-jackson2-1.43.2.jar.sha1 b/plugins/repository-gcs/licenses/google-http-client-jackson2-1.43.2.jar.sha1
deleted file mode 100644
index 7b606a07651ed..0000000000000
--- a/plugins/repository-gcs/licenses/google-http-client-jackson2-1.43.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-5e52a9967ebd8246fc4cca64df5f03608db5ac6e
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/google-http-client-jackson2-1.43.3.jar.sha1 b/plugins/repository-gcs/licenses/google-http-client-jackson2-1.43.3.jar.sha1
new file mode 100644
index 0000000000000..8380b9fb770b5
--- /dev/null
+++ b/plugins/repository-gcs/licenses/google-http-client-jackson2-1.43.3.jar.sha1
@@ -0,0 +1 @@
+689da86469d19a01c726c8c24477b95c8a834bbe
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/log4j-1.2-api-2.20.0.jar.sha1 b/plugins/repository-gcs/licenses/log4j-1.2-api-2.20.0.jar.sha1
deleted file mode 100644
index 9829576d38ce0..0000000000000
--- a/plugins/repository-gcs/licenses/log4j-1.2-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-689151374756cb809cb029f2501015bdc7733179
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/log4j-1.2-api-2.21.0.jar.sha1 b/plugins/repository-gcs/licenses/log4j-1.2-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..39d9177cb2fac
--- /dev/null
+++ b/plugins/repository-gcs/licenses/log4j-1.2-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+12bad3819a9570807f3c97315930699584c12152
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/proto-google-common-protos-2.10.0.jar.sha1 b/plugins/repository-gcs/licenses/proto-google-common-protos-2.10.0.jar.sha1
deleted file mode 100644
index bf97707836c70..0000000000000
--- a/plugins/repository-gcs/licenses/proto-google-common-protos-2.10.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-cf5ac081c05682b0eba6659dee55352fde5852e1
\ No newline at end of file
diff --git a/plugins/repository-gcs/licenses/proto-google-common-protos-2.25.1.jar.sha1 b/plugins/repository-gcs/licenses/proto-google-common-protos-2.25.1.jar.sha1
new file mode 100644
index 0000000000000..cd065dabb8e8a
--- /dev/null
+++ b/plugins/repository-gcs/licenses/proto-google-common-protos-2.25.1.jar.sha1
@@ -0,0 +1 @@
+cb90049537b621e39610a110c58ce0b914ee3cc5
\ No newline at end of file
diff --git a/plugins/repository-gcs/src/internalClusterTest/java/org/opensearch/repositories/gcs/GoogleCloudStorageBlobStoreRepositoryTests.java b/plugins/repository-gcs/src/internalClusterTest/java/org/opensearch/repositories/gcs/GoogleCloudStorageBlobStoreRepositoryTests.java
index f8e1a1cc39ae0..d223f7989c688 100644
--- a/plugins/repository-gcs/src/internalClusterTest/java/org/opensearch/repositories/gcs/GoogleCloudStorageBlobStoreRepositoryTests.java
+++ b/plugins/repository-gcs/src/internalClusterTest/java/org/opensearch/repositories/gcs/GoogleCloudStorageBlobStoreRepositoryTests.java
@@ -298,7 +298,7 @@ private static class GoogleCloudStorageBlobStoreHttpHandler extends GoogleCloudS
 
     /**
      * HTTP handler that injects random  Google Cloud Storage service errors
-     *
+     * <p>
      * Note: it is not a good idea to allow this handler to simulate too many errors as it would
      * slow down the test suite.
      */
diff --git a/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageRepository.java b/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageRepository.java
index c42cd1802f6e9..f6d078868b875 100644
--- a/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageRepository.java
+++ b/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageRepository.java
@@ -46,6 +46,8 @@
 import org.opensearch.repositories.RepositoryException;
 import org.opensearch.repositories.blobstore.MeteredBlobStoreRepository;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
 
@@ -92,14 +94,7 @@ class GoogleCloudStorageRepository extends MeteredBlobStoreRepository {
         final ClusterService clusterService,
         final RecoverySettings recoverySettings
     ) {
-        super(
-            metadata,
-            getSetting(COMPRESS_SETTING, metadata),
-            namedXContentRegistry,
-            clusterService,
-            recoverySettings,
-            buildLocation(metadata)
-        );
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings, buildLocation(metadata));
         this.storageService = storageService;
 
         String basePath = BASE_PATH.get(metadata.settings());
@@ -138,6 +133,15 @@ protected ByteSizeValue chunkSize() {
         return chunkSize;
     }
 
+    @Override
+    public List<Setting<?>> getRestrictedSystemRepositorySettings() {
+        List<Setting<?>> restrictedSettings = new ArrayList<>();
+        restrictedSettings.addAll(super.getRestrictedSystemRepositorySettings());
+        restrictedSettings.add(BUCKET);
+        restrictedSettings.add(BASE_PATH);
+        return restrictedSettings;
+    }
+
     /**
      * Get a given setting from the repository settings, throwing a {@link RepositoryException} if the setting does not exist or is empty.
      */
diff --git a/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageService.java b/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageService.java
index 445e1d65f3d3e..c9ebb3acaf3e5 100644
--- a/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageService.java
+++ b/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/GoogleCloudStorageService.java
@@ -228,7 +228,7 @@ StorageOptions createStorageOptions(
             }
             storageOptionsBuilder.setCredentials(serviceAccountCredentials);
         }
-        return storageOptionsBuilder.build();
+        return SocketAccess.doPrivilegedException(() -> storageOptionsBuilder.build());
     }
 
     /**
diff --git a/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/SocketAccess.java b/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/SocketAccess.java
index 197e772df30d5..35127d6ea4060 100644
--- a/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/SocketAccess.java
+++ b/plugins/repository-gcs/src/main/java/org/opensearch/repositories/gcs/SocketAccess.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.repositories.gcs;
 
+import org.apache.logging.log4j.core.util.Throwables;
 import org.opensearch.SpecialPermission;
 import org.opensearch.common.CheckedRunnable;
 
@@ -71,4 +72,16 @@ public static void doPrivilegedVoidIOException(CheckedRunnable<IOException> acti
             throw (IOException) e.getCause();
         }
     }
+
+    public static <T> T doPrivilegedException(PrivilegedExceptionAction<T> operation) {
+        SpecialPermission.check();
+        try {
+            return AccessController.doPrivileged(operation);
+        } catch (PrivilegedActionException e) {
+            Throwables.rethrow(e.getCause());
+            assert false : "always throws";
+            return null;
+        }
+    }
+
 }
diff --git a/plugins/repository-hdfs/build.gradle b/plugins/repository-hdfs/build.gradle
index e2f5707ca4393..ed1f54888a26f 100644
--- a/plugins/repository-hdfs/build.gradle
+++ b/plugins/repository-hdfs/build.gradle
@@ -66,7 +66,7 @@ dependencies {
   }
   api 'org.apache.htrace:htrace-core4:4.2.0-incubating'
   api "org.apache.logging.log4j:log4j-core:${versions.log4j}"
-  api 'org.apache.avro:avro:1.11.2'
+  api 'org.apache.avro:avro:1.11.3'
   api 'com.google.code.gson:gson:2.10.1'
   runtimeOnly "com.google.guava:guava:${versions.guava}"
   api "commons-logging:commons-logging:${versions.commonslogging}"
@@ -75,7 +75,7 @@ dependencies {
   api 'commons-collections:commons-collections:3.2.2'
   api "org.apache.commons:commons-compress:${versions.commonscompress}"
   api 'org.apache.commons:commons-configuration2:2.9.0'
-  api 'commons-io:commons-io:2.13.0'
+  api 'commons-io:commons-io:2.14.0'
   api 'org.apache.commons:commons-lang3:3.13.0'
   implementation 'com.google.re2j:re2j:1.7'
   api 'javax.servlet:servlet-api:2.5'
@@ -84,7 +84,7 @@ dependencies {
   api 'net.minidev:json-smart:2.5.0'
   api "io.netty:netty-all:${versions.netty}"
   implementation "com.fasterxml.woodstox:woodstox-core:${versions.woodstox}"
-  implementation 'org.codehaus.woodstox:stax2-api:4.2.1'
+  implementation 'org.codehaus.woodstox:stax2-api:4.2.2'
 
   hdfsFixture project(':test:fixtures:hdfs-fixture')
   // Set the keytab files in the classpath so that we can access them from test code without the security manager
diff --git a/plugins/repository-hdfs/licenses/avro-1.11.2.jar.sha1 b/plugins/repository-hdfs/licenses/avro-1.11.2.jar.sha1
deleted file mode 100644
index ce1a894e0ce6d..0000000000000
--- a/plugins/repository-hdfs/licenses/avro-1.11.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-97e62e8be2b37e849f1bdb5a4f08121d47cc9806
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/avro-1.11.3.jar.sha1 b/plugins/repository-hdfs/licenses/avro-1.11.3.jar.sha1
new file mode 100644
index 0000000000000..fb43ecbcf22c9
--- /dev/null
+++ b/plugins/repository-hdfs/licenses/avro-1.11.3.jar.sha1
@@ -0,0 +1 @@
+02b463409b373bff9ece09f54a43d42da5cea55a
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/commons-io-2.13.0.jar.sha1 b/plugins/repository-hdfs/licenses/commons-io-2.13.0.jar.sha1
deleted file mode 100644
index c165136eb5822..0000000000000
--- a/plugins/repository-hdfs/licenses/commons-io-2.13.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-8bb2bc9b4df17e2411533a0708a69f983bf5e83b
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/commons-io-2.14.0.jar.sha1 b/plugins/repository-hdfs/licenses/commons-io-2.14.0.jar.sha1
new file mode 100644
index 0000000000000..33c5cfe53e01d
--- /dev/null
+++ b/plugins/repository-hdfs/licenses/commons-io-2.14.0.jar.sha1
@@ -0,0 +1 @@
+a4c6e1f6c196339473cd2e1b037f0eb97c62755b
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/log4j-slf4j-impl-2.20.0.jar.sha1 b/plugins/repository-hdfs/licenses/log4j-slf4j-impl-2.20.0.jar.sha1
deleted file mode 100644
index 800a4aa87ba0e..0000000000000
--- a/plugins/repository-hdfs/licenses/log4j-slf4j-impl-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7ab4f082fd162f60afcaf2b8744a3d959feab3e8
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/log4j-slf4j-impl-2.21.0.jar.sha1 b/plugins/repository-hdfs/licenses/log4j-slf4j-impl-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..0e22f98daa61c
--- /dev/null
+++ b/plugins/repository-hdfs/licenses/log4j-slf4j-impl-2.21.0.jar.sha1
@@ -0,0 +1 @@
+911fdb5b1a1df36719c579ecc6f2957b88bce1ab
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/netty-all-4.1.101.Final.jar.sha1 b/plugins/repository-hdfs/licenses/netty-all-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..093ced04bee4b
--- /dev/null
+++ b/plugins/repository-hdfs/licenses/netty-all-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+2761d380bc97e6ce64745dd9ca04538cedd40a5b
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/netty-all-4.1.97.Final.jar.sha1 b/plugins/repository-hdfs/licenses/netty-all-4.1.97.Final.jar.sha1
deleted file mode 100644
index c6fa4cc175222..0000000000000
--- a/plugins/repository-hdfs/licenses/netty-all-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-afec3c414a0ab7264a66a7572e9e9d3a19a3e0e5
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/stax2-api-4.2.1.jar.sha1 b/plugins/repository-hdfs/licenses/stax2-api-4.2.1.jar.sha1
deleted file mode 100644
index 2c12704cdc560..0000000000000
--- a/plugins/repository-hdfs/licenses/stax2-api-4.2.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-a3f7325c52240418c2ba257b103c3c550e140c83
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/stax2-api-4.2.2.jar.sha1 b/plugins/repository-hdfs/licenses/stax2-api-4.2.2.jar.sha1
new file mode 100644
index 0000000000000..b15a7ead0d016
--- /dev/null
+++ b/plugins/repository-hdfs/licenses/stax2-api-4.2.2.jar.sha1
@@ -0,0 +1 @@
+b0d746cadea928e5264f2ea294ea9a1bf815bbde
\ No newline at end of file
diff --git a/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsRepository.java b/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsRepository.java
index b28d28d76cfde..f0ffec5713c1d 100644
--- a/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsRepository.java
+++ b/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsRepository.java
@@ -83,7 +83,7 @@ public HdfsRepository(
         final ClusterService clusterService,
         final RecoverySettings recoverySettings
     ) {
-        super(metadata, COMPRESS_SETTING.get(metadata.settings()), namedXContentRegistry, clusterService, recoverySettings);
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings);
 
         this.environment = environment;
         this.chunkSize = metadata.settings().getAsBytesSize("chunk_size", null);
diff --git a/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsSecurityContext.java b/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsSecurityContext.java
index 068adc2cc9991..07d1d29eecfc4 100644
--- a/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsSecurityContext.java
+++ b/plugins/repository-hdfs/src/main/java/org/opensearch/repositories/hdfs/HdfsSecurityContext.java
@@ -53,7 +53,7 @@
 
 /**
  * Oversees all the security specific logic for the HDFS Repository plugin.
- *
+ * <p>
  * Keeps track of the current user for a given repository, as well as which
  * permissions to grant the blob store restricted execution methods.
  */
diff --git a/plugins/repository-hdfs/src/test/java/org/opensearch/repositories/hdfs/HdfsClientThreadLeakFilter.java b/plugins/repository-hdfs/src/test/java/org/opensearch/repositories/hdfs/HdfsClientThreadLeakFilter.java
index 2758bd020e979..856cdf1eb565e 100644
--- a/plugins/repository-hdfs/src/test/java/org/opensearch/repositories/hdfs/HdfsClientThreadLeakFilter.java
+++ b/plugins/repository-hdfs/src/test/java/org/opensearch/repositories/hdfs/HdfsClientThreadLeakFilter.java
@@ -42,7 +42,7 @@
  * thread leaks out of the client and is picked up by the test framework. This thread filter is meant
  * to ignore the offending thread until a version of Hadoop is released that addresses the incorrect
  * interrupt handling.
- *
+ * <p>
  * In Hadoop 3.3.6, the org.apache.hadoop.fs.statistics.impl.EvaluatingStatisticsMap uses ForkJoinPool
  * to perform statistics calculation, leaving dangling workers.
  *
diff --git a/plugins/repository-s3/build.gradle b/plugins/repository-s3/build.gradle
index 44fd45b265e82..560d12d14395d 100644
--- a/plugins/repository-s3/build.gradle
+++ b/plugins/repository-s3/build.gradle
@@ -70,7 +70,6 @@ dependencies {
   api "software.amazon.awssdk:sts:${versions.aws}"
   api "software.amazon.awssdk:netty-nio-client:${versions.aws}"
 
-  api "org.reactivestreams:reactive-streams:${versions.reactivestreams}"
   api "org.apache.httpcomponents:httpclient:${versions.httpclient}"
   api "org.apache.httpcomponents:httpcore:${versions.httpcore}"
   api "commons-logging:commons-logging:${versions.commonslogging}"
diff --git a/plugins/repository-s3/licenses/jackson-annotations-2.15.2.jar.sha1 b/plugins/repository-s3/licenses/jackson-annotations-2.15.2.jar.sha1
deleted file mode 100644
index f63416ddb8ceb..0000000000000
--- a/plugins/repository-s3/licenses/jackson-annotations-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4724a65ac8e8d156a24898d50fd5dbd3642870b8
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/jackson-annotations-2.16.0.jar.sha1 b/plugins/repository-s3/licenses/jackson-annotations-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..79ed9e0c63fc8
--- /dev/null
+++ b/plugins/repository-s3/licenses/jackson-annotations-2.16.0.jar.sha1
@@ -0,0 +1 @@
+dc30995f7428c0a405eba9b8c619b20d2b3b9905
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/jackson-databind-2.15.2.jar.sha1 b/plugins/repository-s3/licenses/jackson-databind-2.15.2.jar.sha1
deleted file mode 100644
index f16d80af8dce6..0000000000000
--- a/plugins/repository-s3/licenses/jackson-databind-2.15.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-9353b021f10c307c00328f52090de2bdb4b6ff9c
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/jackson-databind-2.16.0.jar.sha1 b/plugins/repository-s3/licenses/jackson-databind-2.16.0.jar.sha1
new file mode 100644
index 0000000000000..da00d281934b1
--- /dev/null
+++ b/plugins/repository-s3/licenses/jackson-databind-2.16.0.jar.sha1
@@ -0,0 +1 @@
+3a6b7f8ff7b30d518bbd65678e9c30cd881f19a7
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/log4j-1.2-api-2.20.0.jar.sha1 b/plugins/repository-s3/licenses/log4j-1.2-api-2.20.0.jar.sha1
deleted file mode 100644
index 9829576d38ce0..0000000000000
--- a/plugins/repository-s3/licenses/log4j-1.2-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-689151374756cb809cb029f2501015bdc7733179
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/log4j-1.2-api-2.21.0.jar.sha1 b/plugins/repository-s3/licenses/log4j-1.2-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..39d9177cb2fac
--- /dev/null
+++ b/plugins/repository-s3/licenses/log4j-1.2-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+12bad3819a9570807f3c97315930699584c12152
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-buffer-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-buffer-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..7bb27bbfcb87d
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-buffer-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+a4d94fd6cdf7a37b15237e32434afd6b955cc591
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-buffer-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-buffer-4.1.97.Final.jar.sha1
deleted file mode 100644
index 8430355365996..0000000000000
--- a/plugins/repository-s3/licenses/netty-buffer-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f8f3d8644afa5e6e1a40a3a6aeb9d9aa970ecb4f
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-codec-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-codec-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..c792b4e834030
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-codec-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+642523c57c4be15b8b461be7b1532262d193bbb3
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-codec-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-codec-4.1.97.Final.jar.sha1
deleted file mode 100644
index 7a36dc1f2724f..0000000000000
--- a/plugins/repository-s3/licenses/netty-codec-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-384ba4d75670befbedb45c4d3b497a93639c206d
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-codec-http-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-codec-http-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..8bf31f6c3a2c7
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-codec-http-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+c648f863b301e3fc62d0de098ec61be7628b8ea2
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-codec-http-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-codec-http-4.1.97.Final.jar.sha1
deleted file mode 100644
index 37b78a32f741f..0000000000000
--- a/plugins/repository-s3/licenses/netty-codec-http-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-af78acec783ffd77c63d8aeecc21041fd39ac54f
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-codec-http2-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..48b42bfab9287
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+40590da6c615b852384542051330e9fd51d4c4b1
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-codec-http2-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-codec-http2-4.1.97.Final.jar.sha1
deleted file mode 100644
index cbf685a6d79d3..0000000000000
--- a/plugins/repository-s3/licenses/netty-codec-http2-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-893888d09a7bef0d0ba973d7471943e765d0fd08
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-common-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4fe86799eaff
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+bdb16e4d308b5757123decc886896815d1daf7a3
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-common-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-common-4.1.97.Final.jar.sha1
deleted file mode 100644
index 1bdfec3aae6ba..0000000000000
--- a/plugins/repository-s3/licenses/netty-common-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7cceacaf11df8dc63f23d0fb58e9d4640fc88404
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-handler-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-handler-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..cfc0befee237a
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-handler-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+7800aea949bf95f63df73166d144e49405b279dd
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-handler-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-handler-4.1.97.Final.jar.sha1
deleted file mode 100644
index 8b7b50a6fc9c6..0000000000000
--- a/plugins/repository-s3/licenses/netty-handler-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-abb86c6906bf512bf2b797a41cd7d2e8d3cd7c36
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-resolver-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-resolver-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4425d5ac8e5f
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-resolver-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+5e7eddfa4dfffcbd375d265d1fd08297df94f82f
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-resolver-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-resolver-4.1.97.Final.jar.sha1
deleted file mode 100644
index 032959e98d009..0000000000000
--- a/plugins/repository-s3/licenses/netty-resolver-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-cec8348108dc76c47cf87c669d514be52c922144
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-transport-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-transport-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..fd9199092452b
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-transport-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+0b36cc2337b4a4135df7ee2f2d77431c3b541dc5
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-transport-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-transport-4.1.97.Final.jar.sha1
deleted file mode 100644
index 107863c1b3c9d..0000000000000
--- a/plugins/repository-s3/licenses/netty-transport-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f37380d23c9bb079bc702910833b2fd532c9abd0
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-transport-classes-epoll-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-transport-classes-epoll-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..a710d964c1803
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-transport-classes-epoll-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+f86303830ab65680e45cabb531e37078ecc6791e
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..291c87ad7987b
--- /dev/null
+++ b/plugins/repository-s3/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+d0697ef1d71c6111a1b18a387fa985fd6398ace2
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1 b/plugins/repository-s3/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1
deleted file mode 100644
index f736d37d071b7..0000000000000
--- a/plugins/repository-s3/licenses/netty-transport-native-unix-common-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-d469d84265ab70095b01b40886cabdd433b6e664
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/reactive-streams-1.0.4.jar.sha1 b/plugins/repository-s3/licenses/reactive-streams-1.0.4.jar.sha1
deleted file mode 100644
index 45a80e3f7e361..0000000000000
--- a/plugins/repository-s3/licenses/reactive-streams-1.0.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3864a1320d97d7b045f729a326e1e077661f31b7
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/reactive-streams-LICENSE.txt b/plugins/repository-s3/licenses/reactive-streams-LICENSE.txt
deleted file mode 100644
index 1e3c7e7c77495..0000000000000
--- a/plugins/repository-s3/licenses/reactive-streams-LICENSE.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-MIT No Attribution
-
-Copyright 2014 Reactive Streams
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
\ No newline at end of file
diff --git a/plugins/repository-s3/src/internalClusterTest/java/org/opensearch/repositories/s3/S3BlobStoreRepositoryTests.java b/plugins/repository-s3/src/internalClusterTest/java/org/opensearch/repositories/s3/S3BlobStoreRepositoryTests.java
index 4e8e7720572e8..da2c6e8c1b0ee 100644
--- a/plugins/repository-s3/src/internalClusterTest/java/org/opensearch/repositories/s3/S3BlobStoreRepositoryTests.java
+++ b/plugins/repository-s3/src/internalClusterTest/java/org/opensearch/repositories/s3/S3BlobStoreRepositoryTests.java
@@ -37,6 +37,8 @@
 
 import software.amazon.awssdk.core.internal.http.pipeline.stages.ApplyTransactionIdStage;
 
+import org.opensearch.action.admin.indices.forcemerge.ForceMergeResponse;
+import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.RepositoryMetadata;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.SuppressForbidden;
@@ -51,10 +53,15 @@
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.plugins.Plugin;
+import org.opensearch.repositories.RepositoriesService;
+import org.opensearch.repositories.Repository;
+import org.opensearch.repositories.RepositoryMissingException;
+import org.opensearch.repositories.RepositoryStats;
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.repositories.blobstore.OpenSearchMockAPIBasedRepositoryIntegTestCase;
 import org.opensearch.repositories.s3.utils.AwsRequestSigner;
 import org.opensearch.snapshots.mockstore.BlobStoreWrapper;
+import org.opensearch.test.BackgroundIndexer;
 import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.threadpool.ThreadPool;
 
@@ -63,12 +70,18 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
+import java.util.stream.StreamSupport;
 
 import fixture.s3.S3HttpHandler;
 
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
 
 @SuppressForbidden(reason = "this test uses a HttpServer to emulate an S3 endpoint")
 // Need to set up a new cluster for each test because cluster settings use randomized authentication settings
@@ -152,6 +165,67 @@ protected Settings nodeSettings(int nodeOrdinal) {
         return builder.build();
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/10735")
+    @Override
+    public void testRequestStats() throws Exception {
+        final String repository = createRepository(randomName());
+        final String index = "index-no-merges";
+        createIndex(
+            index,
+            Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1).put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0).build()
+        );
+
+        final long nbDocs = randomLongBetween(10_000L, 20_000L);
+        try (BackgroundIndexer indexer = new BackgroundIndexer(index, "_doc", client(), (int) nbDocs)) {
+            waitForDocs(nbDocs, indexer);
+        }
+
+        flushAndRefresh(index);
+        ForceMergeResponse forceMerge = client().admin().indices().prepareForceMerge(index).setFlush(true).setMaxNumSegments(1).get();
+        assertThat(forceMerge.getSuccessfulShards(), equalTo(1));
+        assertHitCount(client().prepareSearch(index).setSize(0).setTrackTotalHits(true).get(), nbDocs);
+
+        final String snapshot = "snapshot";
+        assertSuccessfulSnapshot(
+            client().admin().cluster().prepareCreateSnapshot(repository, snapshot).setWaitForCompletion(true).setIndices(index)
+        );
+
+        assertAcked(client().admin().indices().prepareDelete(index));
+
+        assertSuccessfulRestore(client().admin().cluster().prepareRestoreSnapshot(repository, snapshot).setWaitForCompletion(true));
+        ensureGreen(index);
+        assertHitCount(client().prepareSearch(index).setSize(0).setTrackTotalHits(true).get(), nbDocs);
+
+        assertAcked(client().admin().cluster().prepareDeleteSnapshot(repository, snapshot).get());
+
+        final RepositoryStats repositoryStats = StreamSupport.stream(
+            internalCluster().getInstances(RepositoriesService.class).spliterator(),
+            false
+        ).map(repositoriesService -> {
+            try {
+                return repositoriesService.repository(repository);
+            } catch (RepositoryMissingException e) {
+                return null;
+            }
+        }).filter(Objects::nonNull).map(Repository::stats).reduce(RepositoryStats::merge).get();
+
+        Map<BlobStore.Metric, Map<String, Long>> extendedStats = repositoryStats.extendedStats;
+        Map<String, Long> aggregatedStats = new HashMap<>();
+        extendedStats.forEach((k, v) -> {
+            if (k == BlobStore.Metric.RETRY_COUNT || k == BlobStore.Metric.REQUEST_SUCCESS || k == BlobStore.Metric.REQUEST_FAILURE) {
+                for (Map.Entry<String, Long> entry : v.entrySet()) {
+                    aggregatedStats.merge(entry.getKey(), entry.getValue(), Math::addExact);
+                }
+            }
+
+        });
+        final Map<String, Long> mockCalls = getMockRequestCounts();
+
+        String assertionErrorMsg = String.format("SDK sent [%s] calls and handler measured [%s] calls", aggregatedStats, mockCalls);
+
+        assertEquals(assertionErrorMsg, mockCalls, aggregatedStats);
+    }
+
     /**
      * S3RepositoryPlugin that allows to disable chunked encoding and to set a low threshold between single upload and multipart upload.
      */
@@ -175,7 +249,7 @@ protected S3Repository createRepository(
             ClusterService clusterService,
             RecoverySettings recoverySettings
         ) {
-            return new S3Repository(metadata, registry, service, clusterService, recoverySettings, null, null, null, null, false) {
+            return new S3Repository(metadata, registry, service, clusterService, recoverySettings, null, null, null, null, null, false) {
 
                 @Override
                 public BlobStore blobStore() {
@@ -225,7 +299,7 @@ private void validateAuthHeader(HttpExchange exchange) {
 
     /**
      * HTTP handler that injects random S3 service errors
-     *
+     * <p>
      * Note: it is not a good idea to allow this handler to simulate too many errors as it would
      * slow down the test suite.
      */
@@ -263,6 +337,8 @@ public void maybeTrack(final String request, Headers requestHeaders) {
                 trackRequest("PutMultipartObject");
             } else if (Regex.simpleMatch("PUT /*/*", request)) {
                 trackRequest("PutObject");
+            } else if (Regex.simpleMatch("POST /*?delete*", request)) {
+                trackRequest("DeleteObjects");
             }
         }
 
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3Reference.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3Reference.java
index 0b5fcb6df280e..45170ea1ad209 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3Reference.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3Reference.java
@@ -29,6 +29,7 @@ public class AmazonAsyncS3Reference extends RefCountedReleasable<AmazonAsyncS3Wi
         super("AWS_S3_CLIENT", client, () -> {
             client.client().close();
             client.priorityClient().close();
+            client.urgentClient().close();
             AwsCredentialsProvider credentials = client.credentials();
             if (credentials instanceof Closeable) {
                 try {
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3WithCredentials.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3WithCredentials.java
index fa2db83729d25..f8a313b55d945 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3WithCredentials.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/AmazonAsyncS3WithCredentials.java
@@ -19,16 +19,19 @@
 final class AmazonAsyncS3WithCredentials {
     private final S3AsyncClient client;
     private final S3AsyncClient priorityClient;
+    private final S3AsyncClient urgentClient;
     private final AwsCredentialsProvider credentials;
 
     private AmazonAsyncS3WithCredentials(
         final S3AsyncClient client,
         final S3AsyncClient priorityClient,
+        final S3AsyncClient urgentClient,
         @Nullable final AwsCredentialsProvider credentials
     ) {
         this.client = client;
         this.credentials = credentials;
         this.priorityClient = priorityClient;
+        this.urgentClient = urgentClient;
     }
 
     S3AsyncClient client() {
@@ -39,6 +42,10 @@ S3AsyncClient priorityClient() {
         return priorityClient;
     }
 
+    S3AsyncClient urgentClient() {
+        return urgentClient;
+    }
+
     AwsCredentialsProvider credentials() {
         return credentials;
     }
@@ -46,8 +53,9 @@ AwsCredentialsProvider credentials() {
     static AmazonAsyncS3WithCredentials create(
         final S3AsyncClient client,
         final S3AsyncClient priorityClient,
+        final S3AsyncClient urgentClient,
         @Nullable final AwsCredentialsProvider credentials
     ) {
-        return new AmazonAsyncS3WithCredentials(client, priorityClient, credentials);
+        return new AmazonAsyncS3WithCredentials(client, priorityClient, urgentClient, credentials);
     }
 }
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3AsyncService.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3AsyncService.java
index 08215ebdd45e0..d691cad9c9d03 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3AsyncService.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3AsyncService.java
@@ -103,6 +103,7 @@ public synchronized void refreshAndClearCache(Map<String, S3ClientSettings> clie
      */
     public AmazonAsyncS3Reference client(
         RepositoryMetadata repositoryMetadata,
+        AsyncExecutorContainer urgentExecutorBuilder,
         AsyncExecutorContainer priorityExecutorBuilder,
         AsyncExecutorContainer normalExecutorBuilder
     ) {
@@ -119,7 +120,7 @@ public AmazonAsyncS3Reference client(
                 return existing;
             }
             final AmazonAsyncS3Reference clientReference = new AmazonAsyncS3Reference(
-                buildClient(clientSettings, priorityExecutorBuilder, normalExecutorBuilder)
+                buildClient(clientSettings, urgentExecutorBuilder, priorityExecutorBuilder, normalExecutorBuilder)
             );
             clientReference.incRef();
             clientsCache = MapBuilder.newMapBuilder(clientsCache).put(clientSettings, clientReference).immutableMap();
@@ -165,6 +166,7 @@ S3ClientSettings settings(RepositoryMetadata repositoryMetadata) {
     // proxy for testing
     synchronized AmazonAsyncS3WithCredentials buildClient(
         final S3ClientSettings clientSettings,
+        AsyncExecutorContainer urgentExecutorBuilder,
         AsyncExecutorContainer priorityExecutorBuilder,
         AsyncExecutorContainer normalExecutorBuilder
     ) {
@@ -195,6 +197,17 @@ synchronized AmazonAsyncS3WithCredentials buildClient(
             builder.forcePathStyle(true);
         }
 
+        builder.httpClient(buildHttpClient(clientSettings, urgentExecutorBuilder.getAsyncTransferEventLoopGroup()));
+        builder.asyncConfiguration(
+            ClientAsyncConfiguration.builder()
+                .advancedOption(
+                    SdkAdvancedAsyncClientOption.FUTURE_COMPLETION_EXECUTOR,
+                    urgentExecutorBuilder.getFutureCompletionExecutor()
+                )
+                .build()
+        );
+        final S3AsyncClient urgentClient = SocketAccess.doPrivileged(builder::build);
+
         builder.httpClient(buildHttpClient(clientSettings, priorityExecutorBuilder.getAsyncTransferEventLoopGroup()));
         builder.asyncConfiguration(
             ClientAsyncConfiguration.builder()
@@ -217,7 +230,7 @@ synchronized AmazonAsyncS3WithCredentials buildClient(
         );
         final S3AsyncClient client = SocketAccess.doPrivileged(builder::build);
 
-        return AmazonAsyncS3WithCredentials.create(client, priorityClient, credentials);
+        return AmazonAsyncS3WithCredentials.create(client, priorityClient, urgentClient, credentials);
     }
 
     static ClientOverrideConfiguration buildOverrideConfiguration(final S3ClientSettings clientSettings) {
@@ -361,7 +374,7 @@ private static IrsaCredentials buildFromEnvironment(IrsaCredentials defaults) {
         return new IrsaCredentials(webIdentityTokenFile, roleArn, roleSessionName);
     }
 
-    private synchronized void releaseCachedClients() {
+    public synchronized void releaseCachedClients() {
         // the clients will shutdown when they will not be used anymore
         for (final AmazonAsyncS3Reference clientReference : clientsCache.values()) {
             clientReference.decRef();
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java
index bb1643faecc95..3a55fcb0bdbcd 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.repositories.s3;
 
+import software.amazon.awssdk.core.ResponseInputStream;
+import software.amazon.awssdk.core.async.AsyncResponseTransformer;
 import software.amazon.awssdk.core.exception.SdkException;
 import software.amazon.awssdk.core.sync.RequestBody;
 import software.amazon.awssdk.services.s3.S3AsyncClient;
@@ -44,10 +46,15 @@
 import software.amazon.awssdk.services.s3.model.Delete;
 import software.amazon.awssdk.services.s3.model.DeleteObjectsRequest;
 import software.amazon.awssdk.services.s3.model.DeleteObjectsResponse;
+import software.amazon.awssdk.services.s3.model.GetObjectAttributesRequest;
+import software.amazon.awssdk.services.s3.model.GetObjectAttributesResponse;
+import software.amazon.awssdk.services.s3.model.GetObjectRequest;
+import software.amazon.awssdk.services.s3.model.GetObjectResponse;
 import software.amazon.awssdk.services.s3.model.HeadObjectRequest;
 import software.amazon.awssdk.services.s3.model.ListObjectsV2Request;
 import software.amazon.awssdk.services.s3.model.ListObjectsV2Response;
 import software.amazon.awssdk.services.s3.model.NoSuchKeyException;
+import software.amazon.awssdk.services.s3.model.ObjectAttributes;
 import software.amazon.awssdk.services.s3.model.ObjectIdentifier;
 import software.amazon.awssdk.services.s3.model.PutObjectRequest;
 import software.amazon.awssdk.services.s3.model.S3Error;
@@ -63,6 +70,7 @@
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SetOnce;
 import org.opensearch.common.StreamContext;
+import org.opensearch.common.annotation.ExperimentalApi;
 import org.opensearch.common.blobstore.AsyncMultiStreamBlobContainer;
 import org.opensearch.common.blobstore.BlobContainer;
 import org.opensearch.common.blobstore.BlobMetadata;
@@ -75,12 +83,15 @@
 import org.opensearch.common.blobstore.support.AbstractBlobContainer;
 import org.opensearch.common.blobstore.support.PlainBlobMetadata;
 import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.repositories.s3.async.UploadRequest;
+import org.opensearch.repositories.s3.utils.HttpRangeUtils;
 
+import java.io.BufferedInputStream;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -103,13 +114,6 @@ class S3BlobContainer extends AbstractBlobContainer implements AsyncMultiStreamB
 
     private static final Logger logger = LogManager.getLogger(S3BlobContainer.class);
 
-    /**
-     * Maximum number of deletes in a {@link DeleteObjectsRequest}.
-     *
-     * @see <a href="https://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html">S3 Documentation</a>.
-     */
-    private static final int MAX_BULK_DELETES = 1000;
-
     private final S3BlobStore blobStore;
     private final String keyPath;
 
@@ -185,18 +189,51 @@ public void asyncBlobUpload(WriteContext writeContext, ActionListener<Void> comp
             writeContext.getWritePriority(),
             writeContext.getUploadFinalizer(),
             writeContext.doRemoteDataIntegrityCheck(),
-            writeContext.getExpectedChecksum()
+            writeContext.getExpectedChecksum(),
+            blobStore.isUploadRetryEnabled()
         );
         try {
-            long partSize = blobStore.getAsyncTransferManager().calculateOptimalPartSize(writeContext.getFileSize());
+            if (uploadRequest.getContentLength() > ByteSizeUnit.GB.toBytes(10) && blobStore.isRedirectLargeUploads()) {
+                StreamContext streamContext = SocketAccess.doPrivileged(
+                    () -> writeContext.getStreamProvider(uploadRequest.getContentLength())
+                );
+                InputStreamContainer inputStream = streamContext.provideStream(0);
+                try {
+                    executeMultipartUpload(
+                        blobStore,
+                        uploadRequest.getKey(),
+                        inputStream.getInputStream(),
+                        uploadRequest.getContentLength()
+                    );
+                    completionListener.onResponse(null);
+                } catch (Exception ex) {
+                    logger.error(
+                        () -> new ParameterizedMessage(
+                            "Failed to upload large file {} of size {} ",
+                            uploadRequest.getKey(),
+                            uploadRequest.getContentLength()
+                        ),
+                        ex
+                    );
+                    completionListener.onFailure(ex);
+                }
+                return;
+            }
+            long partSize = blobStore.getAsyncTransferManager()
+                .calculateOptimalPartSize(writeContext.getFileSize(), writeContext.getWritePriority(), blobStore.isUploadRetryEnabled());
             StreamContext streamContext = SocketAccess.doPrivileged(() -> writeContext.getStreamProvider(partSize));
             try (AmazonAsyncS3Reference amazonS3Reference = SocketAccess.doPrivileged(blobStore::asyncClientReference)) {
 
-                S3AsyncClient s3AsyncClient = writeContext.getWritePriority() == WritePriority.HIGH
-                    ? amazonS3Reference.get().priorityClient()
-                    : amazonS3Reference.get().client();
+                S3AsyncClient s3AsyncClient;
+                if (writeContext.getWritePriority() == WritePriority.URGENT) {
+                    s3AsyncClient = amazonS3Reference.get().urgentClient();
+                } else if (writeContext.getWritePriority() == WritePriority.HIGH) {
+                    s3AsyncClient = amazonS3Reference.get().priorityClient();
+                } else {
+                    s3AsyncClient = amazonS3Reference.get().client();
+                }
                 CompletableFuture<Void> completableFuture = blobStore.getAsyncTransferManager()
-                    .uploadObject(s3AsyncClient, uploadRequest, streamContext);
+                    .uploadObject(s3AsyncClient, uploadRequest, streamContext, blobStore.getStatsMetricPublisher());
                 completableFuture.whenComplete((response, throwable) -> {
                     if (throwable == null) {
                         completionListener.onResponse(response);
@@ -212,9 +249,50 @@ public void asyncBlobUpload(WriteContext writeContext, ActionListener<Void> comp
         }
     }
 
+    @ExperimentalApi
     @Override
     public void readBlobAsync(String blobName, ActionListener<ReadContext> listener) {
-        throw new UnsupportedOperationException();
+        try (AmazonAsyncS3Reference amazonS3Reference = SocketAccess.doPrivileged(blobStore::asyncClientReference)) {
+            final S3AsyncClient s3AsyncClient = amazonS3Reference.get().client();
+            final String bucketName = blobStore.bucket();
+            final String blobKey = buildKey(blobName);
+
+            final CompletableFuture<GetObjectAttributesResponse> blobMetadataFuture = getBlobMetadata(s3AsyncClient, bucketName, blobKey);
+
+            blobMetadataFuture.whenComplete((blobMetadata, throwable) -> {
+                if (throwable != null) {
+                    Exception ex = throwable.getCause() instanceof Exception
+                        ? (Exception) throwable.getCause()
+                        : new Exception(throwable.getCause());
+                    listener.onFailure(ex);
+                    return;
+                }
+
+                try {
+                    final List<ReadContext.StreamPartCreator> blobPartInputStreamFutures = new ArrayList<>();
+                    final long blobSize = blobMetadata.objectSize();
+                    final Integer numberOfParts = blobMetadata.objectParts() == null ? null : blobMetadata.objectParts().totalPartsCount();
+                    final String blobChecksum = blobMetadata.checksum() == null ? null : blobMetadata.checksum().checksumCRC32();
+
+                    if (numberOfParts == null) {
+                        blobPartInputStreamFutures.add(() -> getBlobPartInputStreamContainer(s3AsyncClient, bucketName, blobKey, null));
+                    } else {
+                        // S3 multipart files use 1 to n indexing
+                        for (int partNumber = 1; partNumber <= numberOfParts; partNumber++) {
+                            final int innerPartNumber = partNumber;
+                            blobPartInputStreamFutures.add(
+                                () -> getBlobPartInputStreamContainer(s3AsyncClient, bucketName, blobKey, innerPartNumber)
+                            );
+                        }
+                    }
+                    listener.onResponse(new ReadContext(blobSize, blobPartInputStreamFutures, blobChecksum));
+                } catch (Exception ex) {
+                    listener.onFailure(ex);
+                }
+            });
+        } catch (Exception ex) {
+            listener.onFailure(SdkException.create("Error occurred while fetching blob parts from the repository", ex));
+        }
     }
 
     public boolean remoteIntegrityCheckSupported() {
@@ -288,12 +366,12 @@ private void doDeleteBlobs(List<String> blobNames, boolean relative) throws IOEx
             outstanding = new HashSet<>(blobNames);
         }
         try (AmazonS3Reference clientReference = blobStore.clientReference()) {
-            // S3 API only allows 1k blobs per delete so we split up the given blobs into requests of max. 1k deletes
+            // S3 API allows 1k blobs per delete so we split up the given blobs into requests of bulk size deletes
             final List<DeleteObjectsRequest> deleteRequests = new ArrayList<>();
             final List<String> partition = new ArrayList<>();
             for (String key : outstanding) {
                 partition.add(key);
-                if (partition.size() == MAX_BULK_DELETES) {
+                if (partition.size() == blobStore.getBulkDeletesSize()) {
                     deleteRequests.add(bulkDelete(blobStore.bucket(), partition));
                     partition.clear();
                 }
@@ -340,7 +418,7 @@ private void doDeleteBlobs(List<String> blobNames, boolean relative) throws IOEx
         assert outstanding.isEmpty();
     }
 
-    private static DeleteObjectsRequest bulkDelete(String bucket, List<String> blobs) {
+    private DeleteObjectsRequest bulkDelete(String bucket, List<String> blobs) {
         return DeleteObjectsRequest.builder()
             .bucket(bucket)
             .delete(
@@ -349,6 +427,7 @@ private static DeleteObjectsRequest bulkDelete(String bucket, List<String> blobs
                     .quiet(true)
                     .build()
             )
+            .overrideConfiguration(o -> o.addMetricPublisher(blobStore.getStatsMetricPublisher().deleteObjectsMetricPublisher))
             .build();
     }
 
@@ -487,8 +566,14 @@ void executeSingleUpload(final S3BlobStore blobStore, final String blobName, fin
 
         PutObjectRequest putObjectRequest = putObjectRequestBuilder.build();
         try (AmazonS3Reference clientReference = blobStore.clientReference()) {
+            final InputStream requestInputStream;
+            if (blobStore.isUploadRetryEnabled()) {
+                requestInputStream = new BufferedInputStream(input, (int) (blobSize + 1));
+            } else {
+                requestInputStream = input;
+            }
             SocketAccess.doPrivilegedVoid(
-                () -> clientReference.get().putObject(putObjectRequest, RequestBody.fromInputStream(input, blobSize))
+                () -> clientReference.get().putObject(putObjectRequest, RequestBody.fromInputStream(requestInputStream, blobSize))
             );
         } catch (final SdkException e) {
             throw new IOException("Unable to upload object [" + blobName + "] using a single upload", e);
@@ -528,6 +613,13 @@ void executeMultipartUpload(final S3BlobStore blobStore, final String blobName,
             createMultipartUploadRequestBuilder.serverSideEncryption(ServerSideEncryption.AES256);
         }
 
+        final InputStream requestInputStream;
+        if (blobStore.isUploadRetryEnabled()) {
+            requestInputStream = new BufferedInputStream(input, (int) (partSize + 1));
+        } else {
+            requestInputStream = input;
+        }
+
         CreateMultipartUploadRequest createMultipartUploadRequest = createMultipartUploadRequestBuilder.build();
         try (AmazonS3Reference clientReference = blobStore.clientReference()) {
             uploadId.set(
@@ -551,10 +643,9 @@ void executeMultipartUpload(final S3BlobStore blobStore, final String blobName,
                     .build();
 
                 bytesCount += uploadPartRequest.contentLength();
-
                 final UploadPartResponse uploadResponse = SocketAccess.doPrivileged(
                     () -> clientReference.get()
-                        .uploadPart(uploadPartRequest, RequestBody.fromInputStream(input, uploadPartRequest.contentLength()))
+                        .uploadPart(uploadPartRequest, RequestBody.fromInputStream(requestInputStream, uploadPartRequest.contentLength()))
                 );
                 parts.add(CompletedPart.builder().partNumber(uploadPartRequest.partNumber()).eTag(uploadResponse.eTag()).build());
             }
@@ -633,4 +724,71 @@ static Tuple<Long, Long> numberOfMultiparts(final long totalSize, final long par
             return Tuple.tuple(parts + 1, remaining);
         }
     }
+
+    /**
+     * Fetches a part of the blob from the S3 bucket and transforms it to an {@link InputStreamContainer}, which holds
+     * the stream and its related metadata.
+     * @param s3AsyncClient Async client to be utilized to fetch the object part
+     * @param bucketName Name of the S3 bucket
+     * @param blobKey Identifier of the blob for which the parts will be fetched
+     * @param partNumber Optional part number for the blob to be retrieved
+     * @return A future of {@link InputStreamContainer} containing the stream and stream metadata.
+     */
+    CompletableFuture<InputStreamContainer> getBlobPartInputStreamContainer(
+        S3AsyncClient s3AsyncClient,
+        String bucketName,
+        String blobKey,
+        @Nullable Integer partNumber
+    ) {
+        final boolean isMultipartObject = partNumber != null;
+        final GetObjectRequest.Builder getObjectRequestBuilder = GetObjectRequest.builder().bucket(bucketName).key(blobKey);
+
+        if (isMultipartObject) {
+            getObjectRequestBuilder.partNumber(partNumber);
+        }
+
+        return SocketAccess.doPrivileged(
+            () -> s3AsyncClient.getObject(getObjectRequestBuilder.build(), AsyncResponseTransformer.toBlockingInputStream())
+                .thenApply(response -> transformResponseToInputStreamContainer(response, isMultipartObject))
+        );
+    }
+
+    /**
+     * Transforms the stream response object from S3 into an {@link InputStreamContainer}
+     * @param streamResponse Response stream object from S3
+     * @param isMultipartObject Flag to denote a multipart object response
+     * @return {@link InputStreamContainer} containing the stream and stream metadata
+     */
+    // Package-Private for testing.
+    static InputStreamContainer transformResponseToInputStreamContainer(
+        ResponseInputStream<GetObjectResponse> streamResponse,
+        boolean isMultipartObject
+    ) {
+        final GetObjectResponse getObjectResponse = streamResponse.response();
+        final String contentRange = getObjectResponse.contentRange();
+        final Long contentLength = getObjectResponse.contentLength();
+        if ((isMultipartObject && contentRange == null) || contentLength == null) {
+            throw SdkException.builder().message("Failed to fetch required metadata for blob part").build();
+        }
+        final long offset = isMultipartObject ? HttpRangeUtils.getStartOffsetFromRangeHeader(getObjectResponse.contentRange()) : 0L;
+        return new InputStreamContainer(streamResponse, getObjectResponse.contentLength(), offset);
+    }
+
+    /**
+     * Retrieves the metadata like checksum, object size and parts for the provided blob within the S3 bucket.
+     * @param s3AsyncClient Async client to be utilized to fetch the metadata
+     * @param bucketName Name of the S3 bucket
+     * @param blobName Identifier of the blob for which the metadata will be fetched
+     * @return A future containing the metadata within {@link GetObjectAttributesResponse}
+     */
+    CompletableFuture<GetObjectAttributesResponse> getBlobMetadata(S3AsyncClient s3AsyncClient, String bucketName, String blobName) {
+        // Fetch blob metadata - part info, size, checksum
+        final GetObjectAttributesRequest getObjectAttributesRequest = GetObjectAttributesRequest.builder()
+            .bucket(bucketName)
+            .key(blobName)
+            .objectAttributes(ObjectAttributes.CHECKSUM, ObjectAttributes.OBJECT_SIZE, ObjectAttributes.OBJECT_PARTS)
+            .build();
+
+        return SocketAccess.doPrivileged(() -> s3AsyncClient.getObjectAttributes(getObjectAttributesRequest));
+    }
 }
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobStore.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobStore.java
index 8a5b92d71bb45..fc70fbb0db00e 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobStore.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobStore.java
@@ -47,9 +47,20 @@
 import org.opensearch.repositories.s3.async.AsyncTransferManager;
 
 import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 
+import static org.opensearch.repositories.s3.S3Repository.BUCKET_SETTING;
+import static org.opensearch.repositories.s3.S3Repository.BUFFER_SIZE_SETTING;
+import static org.opensearch.repositories.s3.S3Repository.BULK_DELETE_SIZE;
+import static org.opensearch.repositories.s3.S3Repository.CANNED_ACL_SETTING;
+import static org.opensearch.repositories.s3.S3Repository.REDIRECT_LARGE_S3_UPLOAD;
+import static org.opensearch.repositories.s3.S3Repository.SERVER_SIDE_ENCRYPTION_SETTING;
+import static org.opensearch.repositories.s3.S3Repository.STORAGE_CLASS_SETTING;
+import static org.opensearch.repositories.s3.S3Repository.UPLOAD_RETRY_ENABLED;
+
 class S3BlobStore implements BlobStore {
 
     private static final Logger logger = LogManager.getLogger(S3BlobStore.class);
@@ -58,21 +69,28 @@ class S3BlobStore implements BlobStore {
 
     private final S3AsyncService s3AsyncService;
 
-    private final String bucket;
+    private volatile String bucket;
+
+    private volatile ByteSizeValue bufferSize;
+
+    private volatile boolean redirectLargeUploads;
+
+    private volatile boolean uploadRetryEnabled;
 
-    private final ByteSizeValue bufferSize;
+    private volatile boolean serverSideEncryption;
 
-    private final boolean serverSideEncryption;
+    private volatile ObjectCannedACL cannedACL;
 
-    private final ObjectCannedACL cannedACL;
+    private volatile StorageClass storageClass;
 
-    private final StorageClass storageClass;
+    private volatile int bulkDeletesSize;
 
-    private final RepositoryMetadata repositoryMetadata;
+    private volatile RepositoryMetadata repositoryMetadata;
 
     private final StatsMetricPublisher statsMetricPublisher = new StatsMetricPublisher();
 
     private final AsyncTransferManager asyncTransferManager;
+    private final AsyncExecutorContainer urgentExecutorBuilder;
     private final AsyncExecutorContainer priorityExecutorBuilder;
     private final AsyncExecutorContainer normalExecutorBuilder;
     private final boolean multipartUploadEnabled;
@@ -86,8 +104,10 @@ class S3BlobStore implements BlobStore {
         ByteSizeValue bufferSize,
         String cannedACL,
         String storageClass,
+        int bulkDeletesSize,
         RepositoryMetadata repositoryMetadata,
         AsyncTransferManager asyncTransferManager,
+        AsyncExecutorContainer urgentExecutorBuilder,
         AsyncExecutorContainer priorityExecutorBuilder,
         AsyncExecutorContainer normalExecutorBuilder
     ) {
@@ -99,14 +119,28 @@ class S3BlobStore implements BlobStore {
         this.bufferSize = bufferSize;
         this.cannedACL = initCannedACL(cannedACL);
         this.storageClass = initStorageClass(storageClass);
+        this.bulkDeletesSize = bulkDeletesSize;
         this.repositoryMetadata = repositoryMetadata;
         this.asyncTransferManager = asyncTransferManager;
         this.normalExecutorBuilder = normalExecutorBuilder;
         this.priorityExecutorBuilder = priorityExecutorBuilder;
+        this.urgentExecutorBuilder = urgentExecutorBuilder;
+        // Settings to initialize blobstore with.
+        this.redirectLargeUploads = REDIRECT_LARGE_S3_UPLOAD.get(repositoryMetadata.settings());
+        this.uploadRetryEnabled = UPLOAD_RETRY_ENABLED.get(repositoryMetadata.settings());
     }
 
-    public boolean isMultipartUploadEnabled() {
-        return multipartUploadEnabled;
+    @Override
+    public void reload(RepositoryMetadata repositoryMetadata) {
+        this.repositoryMetadata = repositoryMetadata;
+        this.bucket = BUCKET_SETTING.get(repositoryMetadata.settings());
+        this.serverSideEncryption = SERVER_SIDE_ENCRYPTION_SETTING.get(repositoryMetadata.settings());
+        this.bufferSize = BUFFER_SIZE_SETTING.get(repositoryMetadata.settings());
+        this.cannedACL = initCannedACL(CANNED_ACL_SETTING.get(repositoryMetadata.settings()));
+        this.storageClass = initStorageClass(STORAGE_CLASS_SETTING.get(repositoryMetadata.settings()));
+        this.bulkDeletesSize = BULK_DELETE_SIZE.get(repositoryMetadata.settings());
+        this.redirectLargeUploads = REDIRECT_LARGE_S3_UPLOAD.get(repositoryMetadata.settings());
+        this.uploadRetryEnabled = UPLOAD_RETRY_ENABLED.get(repositoryMetadata.settings());
     }
 
     @Override
@@ -119,13 +153,21 @@ public AmazonS3Reference clientReference() {
     }
 
     public AmazonAsyncS3Reference asyncClientReference() {
-        return s3AsyncService.client(repositoryMetadata, priorityExecutorBuilder, normalExecutorBuilder);
+        return s3AsyncService.client(repositoryMetadata, urgentExecutorBuilder, priorityExecutorBuilder, normalExecutorBuilder);
     }
 
     int getMaxRetries() {
         return service.settings(repositoryMetadata).maxRetries;
     }
 
+    public boolean isRedirectLargeUploads() {
+        return redirectLargeUploads;
+    }
+
+    public boolean isUploadRetryEnabled() {
+        return uploadRetryEnabled;
+    }
+
     public String bucket() {
         return bucket;
     }
@@ -138,6 +180,10 @@ public long bufferSizeInBytes() {
         return bufferSize.getBytes();
     }
 
+    public int getBulkDeletesSize() {
+        return bulkDeletesSize;
+    }
+
     @Override
     public BlobContainer blobContainer(BlobPath path) {
         return new S3BlobContainer(path, this);
@@ -158,6 +204,16 @@ public Map<String, Long> stats() {
         return statsMetricPublisher.getStats().toMap();
     }
 
+    @Override
+    public Map<Metric, Map<String, Long>> extendedStats() {
+        if (statsMetricPublisher.getExtendedStats() == null || statsMetricPublisher.getExtendedStats().isEmpty()) {
+            return Collections.emptyMap();
+        }
+        Map<Metric, Map<String, Long>> extendedStats = new HashMap<>();
+        statsMetricPublisher.getExtendedStats().forEach((k, v) -> extendedStats.put(k, v.toMap()));
+        return extendedStats;
+    }
+
     public ObjectCannedACL getCannedACL() {
         return cannedACL;
     }
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3ClientSettings.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3ClientSettings.java
index 933136228b1bb..4fda0ee95a3ec 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3ClientSettings.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3ClientSettings.java
@@ -177,7 +177,7 @@ final class S3ClientSettings {
     static final Setting.AffixSetting<TimeValue> REQUEST_TIMEOUT_SETTING = Setting.affixKeySetting(
         PREFIX,
         "request_timeout",
-        key -> Setting.timeSetting(key, TimeValue.timeValueMinutes(2), Property.NodeScope)
+        key -> Setting.timeSetting(key, TimeValue.timeValueMinutes(5), Property.NodeScope)
     );
 
     /** The connection timeout for connecting to s3. */
@@ -198,14 +198,14 @@ final class S3ClientSettings {
     static final Setting.AffixSetting<Integer> MAX_CONNECTIONS_SETTING = Setting.affixKeySetting(
         PREFIX,
         "max_connections",
-        key -> Setting.intSetting(key, 100, Property.NodeScope)
+        key -> Setting.intSetting(key, 500, Property.NodeScope)
     );
 
     /** Connection acquisition timeout for new connections to S3. */
     static final Setting.AffixSetting<TimeValue> CONNECTION_ACQUISITION_TIMEOUT = Setting.affixKeySetting(
         PREFIX,
         "connection_acquisition_timeout",
-        key -> Setting.timeSetting(key, TimeValue.timeValueMinutes(2), Property.NodeScope)
+        key -> Setting.timeSetting(key, TimeValue.timeValueMinutes(15), Property.NodeScope)
     );
 
     /** The maximum pending connections to S3. */
@@ -446,7 +446,7 @@ S3ClientSettings refine(Settings repositorySettings) {
 
     /**
      * Load all client settings from the given settings.
-     *
+     * <p>
      * Note this will always at least return a client named "default".
      */
     static Map<String, S3ClientSettings> load(final Settings settings, final Path configPath) {
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Repository.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Repository.java
index 59111e94df22e..f7772a57c9afd 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Repository.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Repository.java
@@ -32,6 +32,9 @@
 
 package org.opensearch.repositories.s3;
 
+import software.amazon.awssdk.services.s3.model.ObjectCannedACL;
+import software.amazon.awssdk.services.s3.model.StorageClass;
+
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.opensearch.Version;
@@ -41,9 +44,11 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.blobstore.BlobStore;
+import org.opensearch.common.blobstore.BlobStoreException;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.SecureSetting;
 import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.settings.SecureString;
@@ -62,7 +67,11 @@
 import org.opensearch.snapshots.SnapshotInfo;
 import org.opensearch.threadpool.Scheduler;
 
+import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
@@ -77,7 +86,6 @@
  * <dt>{@code concurrent_streams}</dt><dd>Number of concurrent read/write stream (per repository on each node). Defaults to 5.</dd>
  * <dt>{@code chunk_size}</dt>
  * <dd>Large file can be divided into chunks. This parameter specifies the chunk size. Defaults to not chucked.</dd>
- * <dt>{@code compress}</dt><dd>If set to true metadata files will be stored compressed. Defaults to false.</dd>
  * </dl>
  */
 class S3Repository extends MeteredBlobStoreRepository {
@@ -139,6 +147,20 @@ class S3Repository extends MeteredBlobStoreRepository {
      */
     static final ByteSizeValue MAX_FILE_SIZE_USING_MULTIPART = new ByteSizeValue(5, ByteSizeUnit.TB);
 
+    /**
+     * Whether large uploads need to be redirected to slow sync s3 client.
+     */
+    static final Setting<Boolean> REDIRECT_LARGE_S3_UPLOAD = Setting.boolSetting(
+        "redirect_large_s3_upload",
+        true,
+        Setting.Property.NodeScope
+    );
+
+    /**
+     * Whether retry on uploads are enabled. This setting wraps inputstream with buffered stream to enable retries.
+     */
+    static final Setting<Boolean> UPLOAD_RETRY_ENABLED = Setting.boolSetting("s3_upload_retry_enabled", true, Setting.Property.NodeScope);
+
     /**
      * Minimum threshold below which the chunk is uploaded using a single request. Beyond this threshold,
      * the S3 repository will use the AWS Multipart Upload API to split the chunk into several parts, each of buffer_size length, and
@@ -182,6 +204,13 @@ class S3Repository extends MeteredBlobStoreRepository {
         new ByteSizeValue(5, ByteSizeUnit.TB)
     );
 
+    /**
+     * Maximum number of deletes in a DeleteObjectsRequest.
+     *
+     * @see <a href="https://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html">S3 Documentation</a>.
+     */
+    static final Setting<Integer> BULK_DELETE_SIZE = Setting.intSetting("bulk_delete_size", 1000, 1, 1000);
+
     /**
      * Sets the S3 storage class type for the backup files. Values may be standard, reduced_redundancy,
      * standard_ia, onezone_ia and intelligent_tiering. Defaults to standard.
@@ -203,31 +232,30 @@ class S3Repository extends MeteredBlobStoreRepository {
 
     private final S3Service service;
 
-    private final String bucket;
-
-    private final ByteSizeValue bufferSize;
+    private volatile String bucket;
 
-    private final ByteSizeValue chunkSize;
+    private volatile ByteSizeValue bufferSize;
 
-    private final BlobPath basePath;
+    private volatile ByteSizeValue chunkSize;
 
-    private final boolean serverSideEncryption;
+    private volatile BlobPath basePath;
 
-    private final String storageClass;
+    private volatile boolean serverSideEncryption;
 
-    private final String cannedACL;
-
-    private final RepositoryMetadata repositoryMetadata;
+    private volatile String storageClass;
 
+    private volatile String cannedACL;
     private final AsyncTransferManager asyncUploadUtils;
     private final S3AsyncService s3AsyncService;
     private final boolean multipartUploadEnabled;
+    private final AsyncExecutorContainer urgentExecutorBuilder;
     private final AsyncExecutorContainer priorityExecutorBuilder;
     private final AsyncExecutorContainer normalExecutorBuilder;
+    private final Path pluginConfigPath;
 
-    /**
-     * Constructs an s3 backed repository
-     */
+    private volatile int bulkDeletesSize;
+
+    // Used by test classes
     S3Repository(
         final RepositoryMetadata metadata,
         final NamedXContentRegistry namedXContentRegistry,
@@ -235,82 +263,57 @@ class S3Repository extends MeteredBlobStoreRepository {
         final ClusterService clusterService,
         final RecoverySettings recoverySettings,
         final AsyncTransferManager asyncUploadUtils,
+        final AsyncExecutorContainer urgentExecutorBuilder,
         final AsyncExecutorContainer priorityExecutorBuilder,
         final AsyncExecutorContainer normalExecutorBuilder,
         final S3AsyncService s3AsyncService,
         final boolean multipartUploadEnabled
     ) {
-        super(
+        this(
             metadata,
-            COMPRESS_SETTING.get(metadata.settings()),
             namedXContentRegistry,
+            service,
             clusterService,
             recoverySettings,
-            buildLocation(metadata)
+            asyncUploadUtils,
+            urgentExecutorBuilder,
+            priorityExecutorBuilder,
+            normalExecutorBuilder,
+            s3AsyncService,
+            multipartUploadEnabled,
+            Path.of("")
         );
+    }
+
+    /**
+     * Constructs an s3 backed repository
+     */
+    S3Repository(
+        final RepositoryMetadata metadata,
+        final NamedXContentRegistry namedXContentRegistry,
+        final S3Service service,
+        final ClusterService clusterService,
+        final RecoverySettings recoverySettings,
+        final AsyncTransferManager asyncUploadUtils,
+        final AsyncExecutorContainer urgentExecutorBuilder,
+        final AsyncExecutorContainer priorityExecutorBuilder,
+        final AsyncExecutorContainer normalExecutorBuilder,
+        final S3AsyncService s3AsyncService,
+        final boolean multipartUploadEnabled,
+        Path pluginConfigPath
+    ) {
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings, buildLocation(metadata));
         this.service = service;
         this.s3AsyncService = s3AsyncService;
         this.multipartUploadEnabled = multipartUploadEnabled;
-
-        this.repositoryMetadata = metadata;
+        this.pluginConfigPath = pluginConfigPath;
         this.asyncUploadUtils = asyncUploadUtils;
+        this.urgentExecutorBuilder = urgentExecutorBuilder;
         this.priorityExecutorBuilder = priorityExecutorBuilder;
         this.normalExecutorBuilder = normalExecutorBuilder;
 
-        // Parse and validate the user's S3 Storage Class setting
-        this.bucket = BUCKET_SETTING.get(metadata.settings());
-        if (bucket == null) {
-            throw new RepositoryException(metadata.name(), "No bucket defined for s3 repository");
-        }
-
-        this.bufferSize = BUFFER_SIZE_SETTING.get(metadata.settings());
-        this.chunkSize = CHUNK_SIZE_SETTING.get(metadata.settings());
-
-        // We make sure that chunkSize is bigger or equal than/to bufferSize
-        if (this.chunkSize.getBytes() < bufferSize.getBytes()) {
-            throw new RepositoryException(
-                metadata.name(),
-                CHUNK_SIZE_SETTING.getKey()
-                    + " ("
-                    + this.chunkSize
-                    + ") can't be lower than "
-                    + BUFFER_SIZE_SETTING.getKey()
-                    + " ("
-                    + bufferSize
-                    + ")."
-            );
-        }
-
-        final String basePath = BASE_PATH_SETTING.get(metadata.settings());
-        if (Strings.hasLength(basePath)) {
-            this.basePath = new BlobPath().add(basePath);
-        } else {
-            this.basePath = BlobPath.cleanPath();
-        }
-
-        this.serverSideEncryption = SERVER_SIDE_ENCRYPTION_SETTING.get(metadata.settings());
-
-        this.storageClass = STORAGE_CLASS_SETTING.get(metadata.settings());
-        this.cannedACL = CANNED_ACL_SETTING.get(metadata.settings());
-
-        if (S3ClientSettings.checkDeprecatedCredentials(metadata.settings())) {
-            // provided repository settings
-            deprecationLogger.deprecate(
-                "s3_repository_secret_settings",
-                "Using s3 access/secret key from repository settings. Instead "
-                    + "store these in named clients and the opensearch keystore for secure settings."
-            );
-        }
-
-        logger.debug(
-            "using bucket [{}], chunk_size [{}], server_side_encryption [{}], buffer_size [{}], cannedACL [{}], storageClass [{}]",
-            bucket,
-            chunkSize,
-            serverSideEncryption,
-            bufferSize,
-            cannedACL,
-            storageClass
-        );
+        validateRepositoryMetadata(metadata);
+        readRepositoryMetadata();
     }
 
     private static Map<String, String> buildLocation(RepositoryMetadata metadata) {
@@ -365,14 +368,16 @@ protected S3BlobStore createBlobStore() {
             bufferSize,
             cannedACL,
             storageClass,
-            repositoryMetadata,
+            bulkDeletesSize,
+            metadata,
             asyncUploadUtils,
+            urgentExecutorBuilder,
             priorityExecutorBuilder,
             normalExecutorBuilder
         );
     }
 
-    // only use for testing
+    // only use for testing (S3RepositoryTests)
     @Override
     protected BlobStore getBlobStore() {
         return super.getBlobStore();
@@ -383,11 +388,144 @@ public BlobPath basePath() {
         return basePath;
     }
 
+    @Override
+    public boolean isReloadable() {
+        return true;
+    }
+
+    @Override
+    public void reload(RepositoryMetadata newRepositoryMetadata) {
+        if (isReloadable() == false) {
+            return;
+        }
+
+        // Reload configs for S3Repository
+        super.reload(newRepositoryMetadata);
+        readRepositoryMetadata();
+
+        // Reload configs for S3RepositoryPlugin
+        service.settings(metadata);
+        service.releaseCachedClients();
+        s3AsyncService.settings(metadata);
+        s3AsyncService.releaseCachedClients();
+
+        // Reload configs for S3BlobStore
+        BlobStore blobStore = getBlobStore();
+        blobStore.reload(metadata);
+    }
+
+    /**
+     * Reloads the values derived from the Repository Metadata
+     */
+    private void readRepositoryMetadata() {
+        this.bucket = BUCKET_SETTING.get(metadata.settings());
+        this.bufferSize = BUFFER_SIZE_SETTING.get(metadata.settings());
+        this.chunkSize = CHUNK_SIZE_SETTING.get(metadata.settings());
+        final String basePath = BASE_PATH_SETTING.get(metadata.settings());
+        if (Strings.hasLength(basePath)) {
+            this.basePath = new BlobPath().add(basePath);
+        } else {
+            this.basePath = BlobPath.cleanPath();
+        }
+
+        this.serverSideEncryption = SERVER_SIDE_ENCRYPTION_SETTING.get(metadata.settings());
+        this.storageClass = STORAGE_CLASS_SETTING.get(metadata.settings());
+        this.cannedACL = CANNED_ACL_SETTING.get(metadata.settings());
+        this.bulkDeletesSize = BULK_DELETE_SIZE.get(metadata.settings());
+        if (S3ClientSettings.checkDeprecatedCredentials(metadata.settings())) {
+            // provided repository settings
+            deprecationLogger.deprecate(
+                "s3_repository_secret_settings",
+                "Using s3 access/secret key from repository settings. Instead "
+                    + "store these in named clients and the opensearch keystore for secure settings."
+            );
+        }
+
+        logger.debug(
+            "using bucket [{}], chunk_size [{}], server_side_encryption [{}], buffer_size [{}], cannedACL [{}], storageClass [{}]",
+            bucket,
+            chunkSize,
+            serverSideEncryption,
+            bufferSize,
+            cannedACL,
+            storageClass
+        );
+    }
+
+    @Override
+    public void validateMetadata(RepositoryMetadata newRepositoryMetadata) {
+        super.validateMetadata(newRepositoryMetadata);
+        validateRepositoryMetadata(newRepositoryMetadata);
+    }
+
+    private void validateRepositoryMetadata(RepositoryMetadata newRepositoryMetadata) {
+        Settings settings = newRepositoryMetadata.settings();
+        if (BUCKET_SETTING.get(settings) == null) {
+            throw new RepositoryException(newRepositoryMetadata.name(), "No bucket defined for s3 repository");
+        }
+
+        // We make sure that chunkSize is bigger or equal than/to bufferSize
+        if (CHUNK_SIZE_SETTING.get(settings).getBytes() < BUFFER_SIZE_SETTING.get(settings).getBytes()) {
+            throw new RepositoryException(
+                newRepositoryMetadata.name(),
+                CHUNK_SIZE_SETTING.getKey()
+                    + " ("
+                    + CHUNK_SIZE_SETTING.get(settings)
+                    + ") can't be lower than "
+                    + BUFFER_SIZE_SETTING.getKey()
+                    + " ("
+                    + BUFFER_SIZE_SETTING.get(settings)
+                    + ")."
+            );
+        }
+
+        validateStorageClass(STORAGE_CLASS_SETTING.get(settings));
+        validateCannedACL(CANNED_ACL_SETTING.get(settings));
+    }
+
+    private static void validateStorageClass(String storageClassStringValue) {
+        if ((storageClassStringValue == null) || storageClassStringValue.equals("")) {
+            return;
+        }
+
+        final StorageClass storageClass = StorageClass.fromValue(storageClassStringValue.toUpperCase(Locale.ENGLISH));
+        if (storageClass.equals(StorageClass.GLACIER)) {
+            throw new BlobStoreException("Glacier storage class is not supported");
+        }
+
+        if (storageClass == StorageClass.UNKNOWN_TO_SDK_VERSION) {
+            throw new BlobStoreException("`" + storageClassStringValue + "` is not a valid S3 Storage Class.");
+        }
+    }
+
+    private static void validateCannedACL(String cannedACLStringValue) {
+        if ((cannedACLStringValue == null) || cannedACLStringValue.equals("")) {
+            return;
+        }
+
+        for (final ObjectCannedACL cur : ObjectCannedACL.values()) {
+            if (cur.toString().equalsIgnoreCase(cannedACLStringValue)) {
+                return;
+            }
+        }
+
+        throw new BlobStoreException("cannedACL is not valid: [" + cannedACLStringValue + "]");
+    }
+
     @Override
     protected ByteSizeValue chunkSize() {
         return chunkSize;
     }
 
+    @Override
+    public List<Setting<?>> getRestrictedSystemRepositorySettings() {
+        List<Setting<?>> restrictedSettings = new ArrayList<>();
+        restrictedSettings.addAll(super.getRestrictedSystemRepositorySettings());
+        restrictedSettings.add(BUCKET_SETTING);
+        restrictedSettings.add(BASE_PATH_SETTING);
+        return restrictedSettings;
+    }
+
     @Override
     protected void doClose() {
         final Scheduler.Cancellable cancellable = finalizationFuture.getAndSet(null);
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RepositoryPlugin.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RepositoryPlugin.java
index 6ef60474afe8c..e7d2a4d024e60 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RepositoryPlugin.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RepositoryPlugin.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.concurrent.OpenSearchExecutors;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
@@ -55,6 +56,7 @@
 import org.opensearch.script.ScriptService;
 import org.opensearch.threadpool.ExecutorBuilder;
 import org.opensearch.threadpool.FixedExecutorBuilder;
+import org.opensearch.threadpool.ScalingExecutorBuilder;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.watcher.ResourceWatcherService;
 
@@ -73,6 +75,9 @@
  * A plugin to add a repository type that writes to and from the AWS S3.
  */
 public class S3RepositoryPlugin extends Plugin implements RepositoryPlugin, ReloadablePlugin {
+
+    private static final String URGENT_FUTURE_COMPLETION = "urgent_future_completion";
+    private static final String URGENT_STREAM_READER = "urgent_stream_reader";
     private static final String PRIORITY_FUTURE_COMPLETION = "priority_future_completion";
     private static final String PRIORITY_STREAM_READER = "priority_stream_reader";
     private static final String FUTURE_COMPLETION = "future_completion";
@@ -83,6 +88,7 @@ public class S3RepositoryPlugin extends Plugin implements RepositoryPlugin, Relo
 
     private final Path configPath;
 
+    private AsyncExecutorContainer urgentExecutorBuilder;
     private AsyncExecutorContainer priorityExecutorBuilder;
     private AsyncExecutorContainer normalExecutorBuilder;
 
@@ -93,17 +99,34 @@ public S3RepositoryPlugin(final Settings settings, final Path configPath) {
     @Override
     public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settings) {
         List<ExecutorBuilder<?>> executorBuilders = new ArrayList<>();
+        int halfProc = halfNumberOfProcessors(allocatedProcessors(settings));
+        executorBuilders.add(
+            new FixedExecutorBuilder(settings, URGENT_FUTURE_COMPLETION, urgentPoolCount(settings), 10_000, URGENT_FUTURE_COMPLETION)
+        );
+        executorBuilders.add(new ScalingExecutorBuilder(URGENT_STREAM_READER, 1, halfProc, TimeValue.timeValueMinutes(5)));
+        executorBuilders.add(
+            new ScalingExecutorBuilder(PRIORITY_FUTURE_COMPLETION, 1, allocatedProcessors(settings), TimeValue.timeValueMinutes(5))
+        );
+        executorBuilders.add(new ScalingExecutorBuilder(PRIORITY_STREAM_READER, 1, halfProc, TimeValue.timeValueMinutes(5)));
+
         executorBuilders.add(
-            new FixedExecutorBuilder(settings, PRIORITY_FUTURE_COMPLETION, priorityPoolCount(settings), 10_000, PRIORITY_FUTURE_COMPLETION)
+            new ScalingExecutorBuilder(FUTURE_COMPLETION, 1, allocatedProcessors(settings), TimeValue.timeValueMinutes(5))
         );
         executorBuilders.add(
-            new FixedExecutorBuilder(settings, PRIORITY_STREAM_READER, priorityPoolCount(settings), 10_000, PRIORITY_STREAM_READER)
+            new ScalingExecutorBuilder(
+                STREAM_READER,
+                allocatedProcessors(settings),
+                4 * allocatedProcessors(settings),
+                TimeValue.timeValueMinutes(5)
+            )
         );
-        executorBuilders.add(new FixedExecutorBuilder(settings, FUTURE_COMPLETION, normalPoolCount(settings), 10_000, FUTURE_COMPLETION));
-        executorBuilders.add(new FixedExecutorBuilder(settings, STREAM_READER, normalPoolCount(settings), 10_000, STREAM_READER));
         return executorBuilders;
     }
 
+    static int halfNumberOfProcessors(int numberOfProcessors) {
+        return (numberOfProcessors + 1) / 2;
+    }
+
     S3RepositoryPlugin(final Settings settings, final Path configPath, final S3Service service, final S3AsyncService s3AsyncService) {
         this.service = Objects.requireNonNull(service, "S3 service must not be null");
         this.configPath = configPath;
@@ -122,6 +145,10 @@ private static int allocatedProcessors(Settings settings) {
         return OpenSearchExecutors.allocatedProcessors(settings);
     }
 
+    private static int urgentPoolCount(Settings settings) {
+        return boundedBy((allocatedProcessors(settings) + 7) / 8, 1, 2);
+    }
+
     private static int priorityPoolCount(Settings settings) {
         return boundedBy((allocatedProcessors(settings) + 1) / 2, 2, 4);
     }
@@ -144,8 +171,14 @@ public Collection<Object> createComponents(
         final IndexNameExpressionResolver expressionResolver,
         final Supplier<RepositoriesService> repositoriesServiceSupplier
     ) {
+        int urgentEventLoopThreads = urgentPoolCount(clusterService.getSettings());
         int priorityEventLoopThreads = priorityPoolCount(clusterService.getSettings());
         int normalEventLoopThreads = normalPoolCount(clusterService.getSettings());
+        this.urgentExecutorBuilder = new AsyncExecutorContainer(
+            threadPool.executor(URGENT_FUTURE_COMPLETION),
+            threadPool.executor(URGENT_STREAM_READER),
+            new AsyncTransferEventLoopGroup(urgentEventLoopThreads)
+        );
         this.priorityExecutorBuilder = new AsyncExecutorContainer(
             threadPool.executor(PRIORITY_FUTURE_COMPLETION),
             threadPool.executor(PRIORITY_STREAM_READER),
@@ -170,7 +203,8 @@ protected S3Repository createRepository(
         AsyncTransferManager asyncUploadUtils = new AsyncTransferManager(
             S3Repository.PARALLEL_MULTIPART_UPLOAD_MINIMUM_PART_SIZE_SETTING.get(clusterService.getSettings()).getBytes(),
             normalExecutorBuilder.getStreamReader(),
-            priorityExecutorBuilder.getStreamReader()
+            priorityExecutorBuilder.getStreamReader(),
+            urgentExecutorBuilder.getStreamReader()
         );
         return new S3Repository(
             metadata,
@@ -179,10 +213,12 @@ protected S3Repository createRepository(
             clusterService,
             recoverySettings,
             asyncUploadUtils,
+            urgentExecutorBuilder,
             priorityExecutorBuilder,
             normalExecutorBuilder,
             s3AsyncService,
-            S3Repository.PARALLEL_MULTIPART_UPLOAD_ENABLED_SETTING.get(clusterService.getSettings())
+            S3Repository.PARALLEL_MULTIPART_UPLOAD_ENABLED_SETTING.get(clusterService.getSettings()),
+            configPath
         );
     }
 
@@ -225,7 +261,9 @@ public List<Setting<?>> getSettings() {
             S3ClientSettings.IDENTITY_TOKEN_FILE_SETTING,
             S3ClientSettings.ROLE_SESSION_NAME_SETTING,
             S3Repository.PARALLEL_MULTIPART_UPLOAD_MINIMUM_PART_SIZE_SETTING,
-            S3Repository.PARALLEL_MULTIPART_UPLOAD_ENABLED_SETTING
+            S3Repository.PARALLEL_MULTIPART_UPLOAD_ENABLED_SETTING,
+            S3Repository.REDIRECT_LARGE_S3_UPLOAD,
+            S3Repository.UPLOAD_RETRY_ENABLED
         );
     }
 
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RetryingInputStream.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RetryingInputStream.java
index 3a35f6135f28b..d7e47e0ab1bcc 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RetryingInputStream.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3RetryingInputStream.java
@@ -54,7 +54,7 @@
  * Wrapper around an S3 object that will retry the {@link GetObjectRequest} if the download fails part-way through, resuming from where
  * the failure occurred. This should be handled by the SDK but it isn't today. This should be revisited in the future (e.g. before removing
  * the {@code LegacyESVersion#V_7_0_0} version constant) and removed when the SDK handles retries itself.
- *
+ * <p>
  * See https://github.com/aws/aws-sdk-java/issues/856 for the related SDK issue
  */
 class S3RetryingInputStream extends InputStream {
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Service.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Service.java
index b13672b4179f8..24387fb98a425 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Service.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3Service.java
@@ -90,6 +90,7 @@
 import java.security.SecureRandom;
 import java.time.Duration;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import static java.util.Collections.emptyMap;
 
@@ -100,7 +101,7 @@ class S3Service implements Closeable {
 
     private static final String DEFAULT_S3_ENDPOINT = "s3.amazonaws.com";
 
-    private volatile Map<S3ClientSettings, AmazonS3Reference> clientsCache = emptyMap();
+    private volatile Map<S3ClientSettings, AmazonS3Reference> clientsCache = new ConcurrentHashMap<>();
 
     /**
      * Client settings calculated from static configuration and settings in the keystore.
@@ -111,7 +112,7 @@ class S3Service implements Closeable {
      * Client settings derived from those in {@link #staticClientSettings} by combining them with settings
      * in the {@link RepositoryMetadata}.
      */
-    private volatile Map<Settings, S3ClientSettings> derivedClientSettings = emptyMap();
+    private volatile Map<Settings, S3ClientSettings> derivedClientSettings = new ConcurrentHashMap<>();
 
     S3Service(final Path configPath) {
         staticClientSettings = MapBuilder.<String, S3ClientSettings>newMapBuilder()
@@ -437,7 +438,7 @@ private static IrsaCredentials buildFromEnviroment(IrsaCredentials defaults) {
         return new IrsaCredentials(webIdentityTokenFile, roleArn, roleSessionName);
     }
 
-    private synchronized void releaseCachedClients() {
+    public synchronized void releaseCachedClients() {
         // the clients will shutdown when they will not be used anymore
         for (final AmazonS3Reference clientReference : clientsCache.values()) {
             clientReference.decRef();
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/StatsMetricPublisher.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/StatsMetricPublisher.java
index cad0037f99249..8d2772d42ebca 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/StatsMetricPublisher.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/StatsMetricPublisher.java
@@ -8,30 +8,87 @@
 
 package org.opensearch.repositories.s3;
 
-import software.amazon.awssdk.http.HttpMetric;
 import software.amazon.awssdk.metrics.MetricCollection;
 import software.amazon.awssdk.metrics.MetricPublisher;
+import software.amazon.awssdk.metrics.MetricRecord;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.common.blobstore.BlobStore;
+
+import java.time.Duration;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 
 public class StatsMetricPublisher {
 
+    private static final Logger LOGGER = LogManager.getLogger(StatsMetricPublisher.class);
     private final Stats stats = new Stats();
 
+    private final Map<BlobStore.Metric, Stats> extendedStats = new HashMap<>() {
+        {
+            put(BlobStore.Metric.REQUEST_LATENCY, new Stats());
+            put(BlobStore.Metric.REQUEST_SUCCESS, new Stats());
+            put(BlobStore.Metric.REQUEST_FAILURE, new Stats());
+            put(BlobStore.Metric.RETRY_COUNT, new Stats());
+        }
+    };
+
     public MetricPublisher listObjectsMetricPublisher = new MetricPublisher() {
         @Override
         public void publish(MetricCollection metricCollection) {
-            stats.listCount.addAndGet(
-                metricCollection.children()
-                    .stream()
-                    .filter(
-                        metricRecords -> metricRecords.name().equals("ApiCallAttempt")
-                            && !metricRecords.metricValues(HttpMetric.HTTP_STATUS_CODE).isEmpty()
-                    )
-                    .count()
-            );
+            LOGGER.debug(() -> "List objects request metrics: " + metricCollection);
+            for (MetricRecord<?> metricRecord : metricCollection) {
+                switch (metricRecord.metric().name()) {
+                    case "ApiCallDuration":
+                        extendedStats.get(BlobStore.Metric.REQUEST_LATENCY).listMetrics.addAndGet(
+                            ((Duration) metricRecord.value()).toMillis()
+                        );
+                        break;
+                    case "RetryCount":
+                        extendedStats.get(BlobStore.Metric.RETRY_COUNT).listMetrics.addAndGet(((Integer) metricRecord.value()));
+                        break;
+                    case "ApiCallSuccessful":
+                        if ((Boolean) metricRecord.value()) {
+                            extendedStats.get(BlobStore.Metric.REQUEST_SUCCESS).listMetrics.addAndGet(1);
+                        } else {
+                            extendedStats.get(BlobStore.Metric.REQUEST_FAILURE).listMetrics.addAndGet(1);
+                        }
+                        stats.listMetrics.addAndGet(1);
+                        break;
+                }
+            }
+        }
+
+        @Override
+        public void close() {}
+    };
+
+    public MetricPublisher deleteObjectsMetricPublisher = new MetricPublisher() {
+        @Override
+        public void publish(MetricCollection metricCollection) {
+            LOGGER.debug(() -> "Delete objects request metrics: " + metricCollection);
+            for (MetricRecord<?> metricRecord : metricCollection) {
+                switch (metricRecord.metric().name()) {
+                    case "ApiCallDuration":
+                        extendedStats.get(BlobStore.Metric.REQUEST_LATENCY).deleteMetrics.addAndGet(
+                            ((Duration) metricRecord.value()).toMillis()
+                        );
+                        break;
+                    case "RetryCount":
+                        extendedStats.get(BlobStore.Metric.RETRY_COUNT).deleteMetrics.addAndGet(((Integer) metricRecord.value()));
+                        break;
+                    case "ApiCallSuccessful":
+                        if ((Boolean) metricRecord.value()) {
+                            extendedStats.get(BlobStore.Metric.REQUEST_SUCCESS).deleteMetrics.addAndGet(1);
+                        } else {
+                            extendedStats.get(BlobStore.Metric.REQUEST_FAILURE).deleteMetrics.addAndGet(1);
+                        }
+                        stats.deleteMetrics.addAndGet(1);
+                        break;
+                }
+            }
         }
 
         @Override
@@ -41,15 +98,27 @@ public void close() {}
     public MetricPublisher getObjectMetricPublisher = new MetricPublisher() {
         @Override
         public void publish(MetricCollection metricCollection) {
-            stats.getCount.addAndGet(
-                metricCollection.children()
-                    .stream()
-                    .filter(
-                        metricRecords -> metricRecords.name().equals("ApiCallAttempt")
-                            && !metricRecords.metricValues(HttpMetric.HTTP_STATUS_CODE).isEmpty()
-                    )
-                    .count()
-            );
+            LOGGER.debug(() -> "Get object request metrics: " + metricCollection);
+            for (MetricRecord<?> metricRecord : metricCollection) {
+                switch (metricRecord.metric().name()) {
+                    case "ApiCallDuration":
+                        extendedStats.get(BlobStore.Metric.REQUEST_LATENCY).getMetrics.addAndGet(
+                            ((Duration) metricRecord.value()).toMillis()
+                        );
+                        break;
+                    case "RetryCount":
+                        extendedStats.get(BlobStore.Metric.RETRY_COUNT).getMetrics.addAndGet(((Integer) metricRecord.value()));
+                        break;
+                    case "ApiCallSuccessful":
+                        if ((Boolean) metricRecord.value()) {
+                            extendedStats.get(BlobStore.Metric.REQUEST_SUCCESS).getMetrics.addAndGet(1);
+                        } else {
+                            extendedStats.get(BlobStore.Metric.REQUEST_FAILURE).getMetrics.addAndGet(1);
+                        }
+                        stats.getMetrics.addAndGet(1);
+                        break;
+                }
+            }
         }
 
         @Override
@@ -59,15 +128,27 @@ public void close() {}
     public MetricPublisher putObjectMetricPublisher = new MetricPublisher() {
         @Override
         public void publish(MetricCollection metricCollection) {
-            stats.putCount.addAndGet(
-                metricCollection.children()
-                    .stream()
-                    .filter(
-                        metricRecords -> metricRecords.name().equals("ApiCallAttempt")
-                            && !metricRecords.metricValues(HttpMetric.HTTP_STATUS_CODE).isEmpty()
-                    )
-                    .count()
-            );
+            LOGGER.debug(() -> "Put object request metrics: " + metricCollection);
+            for (MetricRecord<?> metricRecord : metricCollection) {
+                switch (metricRecord.metric().name()) {
+                    case "ApiCallDuration":
+                        extendedStats.get(BlobStore.Metric.REQUEST_LATENCY).putMetrics.addAndGet(
+                            ((Duration) metricRecord.value()).toMillis()
+                        );
+                        break;
+                    case "RetryCount":
+                        extendedStats.get(BlobStore.Metric.RETRY_COUNT).putMetrics.addAndGet(((Integer) metricRecord.value()));
+                        break;
+                    case "ApiCallSuccessful":
+                        if ((Boolean) metricRecord.value()) {
+                            extendedStats.get(BlobStore.Metric.REQUEST_SUCCESS).putMetrics.addAndGet(1);
+                        } else {
+                            extendedStats.get(BlobStore.Metric.REQUEST_FAILURE).putMetrics.addAndGet(1);
+                        }
+                        stats.putMetrics.addAndGet(1);
+                        break;
+                }
+            }
         }
 
         @Override
@@ -77,15 +158,27 @@ public void close() {}
     public MetricPublisher multipartUploadMetricCollector = new MetricPublisher() {
         @Override
         public void publish(MetricCollection metricCollection) {
-            stats.postCount.addAndGet(
-                metricCollection.children()
-                    .stream()
-                    .filter(
-                        metricRecords -> metricRecords.name().equals("ApiCallAttempt")
-                            && !metricRecords.metricValues(HttpMetric.HTTP_STATUS_CODE).isEmpty()
-                    )
-                    .count()
-            );
+            LOGGER.debug(() -> "Multi-part request metrics: " + metricCollection);
+            for (MetricRecord<?> metricRecord : metricCollection) {
+                switch (metricRecord.metric().name()) {
+                    case "ApiCallDuration":
+                        extendedStats.get(BlobStore.Metric.REQUEST_LATENCY).multiPartPutMetrics.addAndGet(
+                            ((Duration) metricRecord.value()).toMillis()
+                        );
+                        break;
+                    case "RetryCount":
+                        extendedStats.get(BlobStore.Metric.RETRY_COUNT).multiPartPutMetrics.addAndGet(((Integer) metricRecord.value()));
+                        break;
+                    case "ApiCallSuccessful":
+                        if ((Boolean) metricRecord.value()) {
+                            extendedStats.get(BlobStore.Metric.REQUEST_SUCCESS).multiPartPutMetrics.addAndGet(1);
+                        } else {
+                            extendedStats.get(BlobStore.Metric.REQUEST_FAILURE).multiPartPutMetrics.addAndGet(1);
+                        }
+                        stats.multiPartPutMetrics.addAndGet(1);
+                        break;
+                }
+            }
         }
 
         @Override
@@ -96,22 +189,29 @@ public Stats getStats() {
         return stats;
     }
 
+    public Map<BlobStore.Metric, Stats> getExtendedStats() {
+        return extendedStats;
+    }
+
     static class Stats {
 
-        final AtomicLong listCount = new AtomicLong();
+        final AtomicLong listMetrics = new AtomicLong();
+
+        final AtomicLong getMetrics = new AtomicLong();
 
-        final AtomicLong getCount = new AtomicLong();
+        final AtomicLong putMetrics = new AtomicLong();
 
-        final AtomicLong putCount = new AtomicLong();
+        final AtomicLong deleteMetrics = new AtomicLong();
 
-        final AtomicLong postCount = new AtomicLong();
+        final AtomicLong multiPartPutMetrics = new AtomicLong();
 
         Map<String, Long> toMap() {
             final Map<String, Long> results = new HashMap<>();
-            results.put("GetObject", getCount.get());
-            results.put("ListObjects", listCount.get());
-            results.put("PutObject", putCount.get());
-            results.put("PutMultipartObject", postCount.get());
+            results.put("GetObject", getMetrics.get());
+            results.put("ListObjects", listMetrics.get());
+            results.put("PutObject", putMetrics.get());
+            results.put("DeleteObjects", deleteMetrics.get());
+            results.put("PutMultipartObject", multiPartPutMetrics.get());
             return results;
         }
     }
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncPartsHandler.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncPartsHandler.java
index ad6939ce299d6..b4c4ed0ecaa75 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncPartsHandler.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncPartsHandler.java
@@ -24,9 +24,12 @@
 import org.opensearch.common.blobstore.stream.write.WritePriority;
 import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.repositories.s3.SocketAccess;
+import org.opensearch.repositories.s3.StatsMetricPublisher;
 import org.opensearch.repositories.s3.io.CheckedContainer;
 
+import java.io.BufferedInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
@@ -45,11 +48,13 @@ public class AsyncPartsHandler {
      * @param s3AsyncClient S3 client to use for upload
      * @param executorService Thread pool for regular upload
      * @param priorityExecutorService Thread pool for priority uploads
+     * @param urgentExecutorService Thread pool for urgent uploads
      * @param uploadRequest request for upload
      * @param streamContext Stream context used in supplying individual file parts
      * @param uploadId Upload Id against which multi-part is being performed
      * @param completedParts Reference of completed parts
      * @param inputStreamContainers Checksum containers
+     * @param statsMetricPublisher sdk metric publisher
      * @return list of completable futures
      * @throws IOException thrown in case of an IO error
      */
@@ -57,11 +62,14 @@ public static List<CompletableFuture<CompletedPart>> uploadParts(
         S3AsyncClient s3AsyncClient,
         ExecutorService executorService,
         ExecutorService priorityExecutorService,
+        ExecutorService urgentExecutorService,
         UploadRequest uploadRequest,
         StreamContext streamContext,
         String uploadId,
         AtomicReferenceArray<CompletedPart> completedParts,
-        AtomicReferenceArray<CheckedContainer> inputStreamContainers
+        AtomicReferenceArray<CheckedContainer> inputStreamContainers,
+        StatsMetricPublisher statsMetricPublisher,
+        boolean uploadRetryEnabled
     ) throws IOException {
         List<CompletableFuture<CompletedPart>> futures = new ArrayList<>();
         for (int partIdx = 0; partIdx < streamContext.getNumberOfParts(); partIdx++) {
@@ -72,6 +80,7 @@ public static List<CompletableFuture<CompletedPart>> uploadParts(
                 .partNumber(partIdx + 1)
                 .key(uploadRequest.getKey())
                 .uploadId(uploadId)
+                .overrideConfiguration(o -> o.addMetricPublisher(statsMetricPublisher.multipartUploadMetricCollector))
                 .contentLength(inputStreamContainer.getContentLength());
             if (uploadRequest.doRemoteDataIntegrityCheck()) {
                 uploadPartRequestBuilder.checksumAlgorithm(ChecksumAlgorithm.CRC32);
@@ -80,12 +89,14 @@ public static List<CompletableFuture<CompletedPart>> uploadParts(
                 s3AsyncClient,
                 executorService,
                 priorityExecutorService,
+                urgentExecutorService,
                 completedParts,
                 inputStreamContainers,
                 futures,
                 uploadPartRequestBuilder.build(),
                 inputStreamContainer,
-                uploadRequest
+                uploadRequest,
+                uploadRetryEnabled
             );
         }
 
@@ -122,42 +133,78 @@ public static void cleanUpParts(S3AsyncClient s3AsyncClient, UploadRequest uploa
         }));
     }
 
+    public static InputStream maybeRetryInputStream(
+        InputStream inputStream,
+        WritePriority writePriority,
+        boolean uploadRetryEnabled,
+        long contentLength
+    ) {
+        if (uploadRetryEnabled == true && (writePriority == WritePriority.HIGH || writePriority == WritePriority.URGENT)) {
+            return new BufferedInputStream(inputStream, (int) (contentLength + 1));
+        }
+        return inputStream;
+    }
+
     private static void uploadPart(
         S3AsyncClient s3AsyncClient,
         ExecutorService executorService,
         ExecutorService priorityExecutorService,
+        ExecutorService urgentExecutorService,
         AtomicReferenceArray<CompletedPart> completedParts,
         AtomicReferenceArray<CheckedContainer> inputStreamContainers,
         List<CompletableFuture<CompletedPart>> futures,
         UploadPartRequest uploadPartRequest,
         InputStreamContainer inputStreamContainer,
-        UploadRequest uploadRequest
+        UploadRequest uploadRequest,
+        boolean uploadRetryEnabled
     ) {
         Integer partNumber = uploadPartRequest.partNumber();
 
-        ExecutorService streamReadExecutor = uploadRequest.getWritePriority() == WritePriority.HIGH
-            ? priorityExecutorService
-            : executorService;
+        ExecutorService streamReadExecutor;
+        if (uploadRequest.getWritePriority() == WritePriority.URGENT) {
+            streamReadExecutor = urgentExecutorService;
+        } else if (uploadRequest.getWritePriority() == WritePriority.HIGH) {
+            streamReadExecutor = priorityExecutorService;
+        } else {
+            streamReadExecutor = executorService;
+        }
+
+        InputStream inputStream = maybeRetryInputStream(
+            inputStreamContainer.getInputStream(),
+            uploadRequest.getWritePriority(),
+            uploadRetryEnabled,
+            uploadPartRequest.contentLength()
+        );
         CompletableFuture<UploadPartResponse> uploadPartResponseFuture = SocketAccess.doPrivileged(
             () -> s3AsyncClient.uploadPart(
                 uploadPartRequest,
-                AsyncRequestBody.fromInputStream(
-                    inputStreamContainer.getInputStream(),
-                    inputStreamContainer.getContentLength(),
-                    streamReadExecutor
-                )
+                AsyncRequestBody.fromInputStream(inputStream, inputStreamContainer.getContentLength(), streamReadExecutor)
             )
         );
 
-        CompletableFuture<CompletedPart> convertFuture = uploadPartResponseFuture.thenApply(
-            uploadPartResponse -> convertUploadPartResponse(
-                completedParts,
-                inputStreamContainers,
-                uploadPartResponse,
-                partNumber,
-                uploadRequest.doRemoteDataIntegrityCheck()
-            )
-        );
+        CompletableFuture<CompletedPart> convertFuture = uploadPartResponseFuture.whenComplete((resp, throwable) -> {
+            try {
+                inputStream.close();
+            } catch (IOException ex) {
+                log.error(
+                    () -> new ParameterizedMessage(
+                        "Failed to close stream while uploading a part of idx {} and file {}.",
+                        uploadPartRequest.partNumber(),
+                        uploadPartRequest.key()
+                    ),
+                    ex
+                );
+            }
+        })
+            .thenApply(
+                uploadPartResponse -> convertUploadPartResponse(
+                    completedParts,
+                    inputStreamContainers,
+                    uploadPartResponse,
+                    partNumber,
+                    uploadRequest.doRemoteDataIntegrityCheck()
+                )
+            );
         futures.add(convertFuture);
 
         CompletableFutureUtils.forwardExceptionTo(convertFuture, uploadPartResponseFuture);
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncTransferManager.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncTransferManager.java
index 8d45c2167a3d1..2259780c95276 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncTransferManager.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/AsyncTransferManager.java
@@ -34,10 +34,13 @@
 import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.common.util.ByteUtils;
 import org.opensearch.core.common.unit.ByteSizeUnit;
+import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.repositories.s3.SocketAccess;
+import org.opensearch.repositories.s3.StatsMetricPublisher;
 import org.opensearch.repositories.s3.io.CheckedContainer;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.util.Arrays;
 import java.util.Base64;
 import java.util.List;
@@ -58,6 +61,7 @@ public final class AsyncTransferManager {
     private static final Logger log = LogManager.getLogger(AsyncTransferManager.class);
     private final ExecutorService executorService;
     private final ExecutorService priorityExecutorService;
+    private final ExecutorService urgentExecutorService;
     private final long minimumPartSize;
 
     /**
@@ -72,10 +76,16 @@ public final class AsyncTransferManager {
      * @param executorService         The stream reader {@link ExecutorService} for normal priority uploads
      * @param priorityExecutorService The stream read {@link ExecutorService} for high priority uploads
      */
-    public AsyncTransferManager(long minimumPartSize, ExecutorService executorService, ExecutorService priorityExecutorService) {
+    public AsyncTransferManager(
+        long minimumPartSize,
+        ExecutorService executorService,
+        ExecutorService priorityExecutorService,
+        ExecutorService urgentExecutorService
+    ) {
         this.executorService = executorService;
         this.priorityExecutorService = priorityExecutorService;
         this.minimumPartSize = minimumPartSize;
+        this.urgentExecutorService = urgentExecutorService;
     }
 
     /**
@@ -86,16 +96,21 @@ public AsyncTransferManager(long minimumPartSize, ExecutorService executorServic
      * @param streamContext The {@link StreamContext} to supply streams during upload
      * @return A {@link CompletableFuture} to listen for upload completion
      */
-    public CompletableFuture<Void> uploadObject(S3AsyncClient s3AsyncClient, UploadRequest uploadRequest, StreamContext streamContext) {
+    public CompletableFuture<Void> uploadObject(
+        S3AsyncClient s3AsyncClient,
+        UploadRequest uploadRequest,
+        StreamContext streamContext,
+        StatsMetricPublisher statsMetricPublisher
+    ) {
 
         CompletableFuture<Void> returnFuture = new CompletableFuture<>();
         try {
             if (streamContext.getNumberOfParts() == 1) {
                 log.debug(() -> "Starting the upload as a single upload part request");
-                uploadInOneChunk(s3AsyncClient, uploadRequest, streamContext.provideStream(0), returnFuture);
+                uploadInOneChunk(s3AsyncClient, uploadRequest, streamContext.provideStream(0), returnFuture, statsMetricPublisher);
             } else {
                 log.debug(() -> "Starting the upload as multipart upload request");
-                uploadInParts(s3AsyncClient, uploadRequest, streamContext, returnFuture);
+                uploadInParts(s3AsyncClient, uploadRequest, streamContext, returnFuture, statsMetricPublisher);
             }
         } catch (Throwable throwable) {
             returnFuture.completeExceptionally(throwable);
@@ -108,12 +123,14 @@ private void uploadInParts(
         S3AsyncClient s3AsyncClient,
         UploadRequest uploadRequest,
         StreamContext streamContext,
-        CompletableFuture<Void> returnFuture
+        CompletableFuture<Void> returnFuture,
+        StatsMetricPublisher statsMetricPublisher
     ) {
 
         CreateMultipartUploadRequest.Builder createMultipartUploadRequestBuilder = CreateMultipartUploadRequest.builder()
             .bucket(uploadRequest.getBucket())
-            .key(uploadRequest.getKey());
+            .key(uploadRequest.getKey())
+            .overrideConfiguration(o -> o.addMetricPublisher(statsMetricPublisher.multipartUploadMetricCollector));
         if (uploadRequest.doRemoteDataIntegrityCheck()) {
             createMultipartUploadRequestBuilder.checksumAlgorithm(ChecksumAlgorithm.CRC32);
         }
@@ -129,7 +146,14 @@ private void uploadInParts(
                 handleException(returnFuture, () -> "Failed to initiate multipart upload", throwable);
             } else {
                 log.debug(() -> "Initiated new multipart upload, uploadId: " + createMultipartUploadResponse.uploadId());
-                doUploadInParts(s3AsyncClient, uploadRequest, streamContext, returnFuture, createMultipartUploadResponse.uploadId());
+                doUploadInParts(
+                    s3AsyncClient,
+                    uploadRequest,
+                    streamContext,
+                    returnFuture,
+                    createMultipartUploadResponse.uploadId(),
+                    statsMetricPublisher
+                );
             }
         });
     }
@@ -139,7 +163,8 @@ private void doUploadInParts(
         UploadRequest uploadRequest,
         StreamContext streamContext,
         CompletableFuture<Void> returnFuture,
-        String uploadId
+        String uploadId,
+        StatsMetricPublisher statsMetricPublisher
     ) {
 
         // The list of completed parts must be sorted
@@ -152,11 +177,14 @@ private void doUploadInParts(
                 s3AsyncClient,
                 executorService,
                 priorityExecutorService,
+                urgentExecutorService,
                 uploadRequest,
                 streamContext,
                 uploadId,
                 completedParts,
-                inputStreamContainers
+                inputStreamContainers,
+                statsMetricPublisher,
+                uploadRequest.isUploadRetryEnabled()
             );
         } catch (Exception ex) {
             try {
@@ -180,7 +208,7 @@ private void doUploadInParts(
             }
             return null;
         })
-            .thenCompose(ignore -> completeMultipartUpload(s3AsyncClient, uploadRequest, uploadId, completedParts))
+            .thenCompose(ignore -> completeMultipartUpload(s3AsyncClient, uploadRequest, uploadId, completedParts, statsMetricPublisher))
             .handle(handleExceptionOrResponse(s3AsyncClient, uploadRequest, returnFuture, uploadId))
             .exceptionally(throwable -> {
                 handleException(returnFuture, () -> "Unexpected exception occurred", throwable);
@@ -227,7 +255,8 @@ private CompletableFuture<CompleteMultipartUploadResponse> completeMultipartUplo
         S3AsyncClient s3AsyncClient,
         UploadRequest uploadRequest,
         String uploadId,
-        AtomicReferenceArray<CompletedPart> completedParts
+        AtomicReferenceArray<CompletedPart> completedParts,
+        StatsMetricPublisher statsMetricPublisher
     ) {
 
         log.debug(() -> new ParameterizedMessage("Sending completeMultipartUploadRequest, uploadId: {}", uploadId));
@@ -236,6 +265,7 @@ private CompletableFuture<CompleteMultipartUploadResponse> completeMultipartUplo
             .bucket(uploadRequest.getBucket())
             .key(uploadRequest.getKey())
             .uploadId(uploadId)
+            .overrideConfiguration(o -> o.addMetricPublisher(statsMetricPublisher.multipartUploadMetricCollector))
             .multipartUpload(CompletedMultipartUpload.builder().parts(parts).build())
             .build();
 
@@ -273,10 +303,13 @@ private static void handleException(CompletableFuture<Void> returnFuture, Suppli
     /**
      * Calculates the optimal part size of each part request if the upload operation is carried out as multipart upload.
      */
-    public long calculateOptimalPartSize(long contentLengthOfSource) {
+    public long calculateOptimalPartSize(long contentLengthOfSource, WritePriority writePriority, boolean uploadRetryEnabled) {
         if (contentLengthOfSource < ByteSizeUnit.MB.toBytes(5)) {
             return contentLengthOfSource;
         }
+        if (uploadRetryEnabled && (writePriority == WritePriority.HIGH || writePriority == WritePriority.URGENT)) {
+            return new ByteSizeValue(5, ByteSizeUnit.MB).getBytes();
+        }
         double optimalPartSize = contentLengthOfSource / (double) MAX_UPLOAD_PARTS;
         optimalPartSize = Math.ceil(optimalPartSize);
         return (long) Math.max(optimalPartSize, minimumPartSize);
@@ -286,28 +319,46 @@ private void uploadInOneChunk(
         S3AsyncClient s3AsyncClient,
         UploadRequest uploadRequest,
         InputStreamContainer inputStreamContainer,
-        CompletableFuture<Void> returnFuture
+        CompletableFuture<Void> returnFuture,
+        StatsMetricPublisher statsMetricPublisher
     ) {
         PutObjectRequest.Builder putObjectRequestBuilder = PutObjectRequest.builder()
             .bucket(uploadRequest.getBucket())
             .key(uploadRequest.getKey())
-            .contentLength(uploadRequest.getContentLength());
+            .contentLength(uploadRequest.getContentLength())
+            .overrideConfiguration(o -> o.addMetricPublisher(statsMetricPublisher.putObjectMetricPublisher));
         if (uploadRequest.doRemoteDataIntegrityCheck()) {
             putObjectRequestBuilder.checksumAlgorithm(ChecksumAlgorithm.CRC32);
             putObjectRequestBuilder.checksumCRC32(base64StringFromLong(uploadRequest.getExpectedChecksum()));
         }
-        ExecutorService streamReadExecutor = uploadRequest.getWritePriority() == WritePriority.HIGH
-            ? priorityExecutorService
-            : executorService;
+        ExecutorService streamReadExecutor;
+        if (uploadRequest.getWritePriority() == WritePriority.URGENT) {
+            streamReadExecutor = urgentExecutorService;
+        } else if (uploadRequest.getWritePriority() == WritePriority.HIGH) {
+            streamReadExecutor = priorityExecutorService;
+        } else {
+            streamReadExecutor = executorService;
+        }
+
+        InputStream inputStream = AsyncPartsHandler.maybeRetryInputStream(
+            inputStreamContainer.getInputStream(),
+            uploadRequest.getWritePriority(),
+            uploadRequest.isUploadRetryEnabled(),
+            uploadRequest.getContentLength()
+        );
         CompletableFuture<Void> putObjectFuture = SocketAccess.doPrivileged(
             () -> s3AsyncClient.putObject(
                 putObjectRequestBuilder.build(),
-                AsyncRequestBody.fromInputStream(
-                    inputStreamContainer.getInputStream(),
-                    inputStreamContainer.getContentLength(),
-                    streamReadExecutor
-                )
+                AsyncRequestBody.fromInputStream(inputStream, inputStreamContainer.getContentLength(), streamReadExecutor)
             ).handle((resp, throwable) -> {
+                try {
+                    inputStream.close();
+                } catch (IOException e) {
+                    log.error(
+                        () -> new ParameterizedMessage("Failed to close stream while uploading single file {}.", uploadRequest.getKey()),
+                        e
+                    );
+                }
                 if (throwable != null) {
                     Throwable unwrappedThrowable = ExceptionsHelper.unwrap(throwable, S3Exception.class);
                     if (unwrappedThrowable != null) {
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/UploadRequest.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/UploadRequest.java
index 3804c8417eb9f..a5304dc4a97d6 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/UploadRequest.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/async/UploadRequest.java
@@ -25,6 +25,8 @@ public class UploadRequest {
     private final boolean doRemoteDataIntegrityCheck;
     private final Long expectedChecksum;
 
+    private boolean uploadRetryEnabled;
+
     /**
      * Construct a new UploadRequest object
      *
@@ -43,7 +45,8 @@ public UploadRequest(
         WritePriority writePriority,
         CheckedConsumer<Boolean, IOException> uploadFinalizer,
         boolean doRemoteDataIntegrityCheck,
-        Long expectedChecksum
+        Long expectedChecksum,
+        boolean uploadRetryEnabled
     ) {
         this.bucket = bucket;
         this.key = key;
@@ -52,6 +55,7 @@ public UploadRequest(
         this.uploadFinalizer = uploadFinalizer;
         this.doRemoteDataIntegrityCheck = doRemoteDataIntegrityCheck;
         this.expectedChecksum = expectedChecksum;
+        this.uploadRetryEnabled = uploadRetryEnabled;
     }
 
     public String getBucket() {
@@ -81,4 +85,8 @@ public boolean doRemoteDataIntegrityCheck() {
     public Long getExpectedChecksum() {
         return expectedChecksum;
     }
+
+    public boolean isUploadRetryEnabled() {
+        return uploadRetryEnabled;
+    }
 }
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/utils/HttpRangeUtils.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/utils/HttpRangeUtils.java
index 40aec7d52847b..2e2fc9b86a45b 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/utils/HttpRangeUtils.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/utils/HttpRangeUtils.java
@@ -8,7 +8,29 @@
 
 package org.opensearch.repositories.s3.utils;
 
+import software.amazon.awssdk.core.exception.SdkException;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 public final class HttpRangeUtils {
+    private static final Pattern RANGE_PATTERN = Pattern.compile("^bytes\\s+(\\d+)-\\d+[/\\d*]+$");
+
+    /**
+     * Parses the content range header string value to calculate the start (offset) of the HTTP response.
+     * Tests against the RFC9110 specification of content range string.
+     * Sample values: "bytes 0-10/200", "bytes 0-10/*"
+     *  <a href="https://www.rfc-editor.org/rfc/rfc9110.html#name-content-range">Details here</a>
+     * @param headerValue Header content range string value from the HTTP response
+     * @return Start (Offset) value of the HTTP response
+     */
+    public static Long getStartOffsetFromRangeHeader(String headerValue) {
+        Matcher matcher = RANGE_PATTERN.matcher(headerValue);
+        if (!matcher.find()) {
+            throw SdkException.create("Regex match for Content-Range header {" + headerValue + "} failed", new RuntimeException());
+        }
+        return Long.parseLong(matcher.group(1));
+    }
 
     /**
      * Provides a byte range string per <a href="https://www.rfc-editor.org/rfc/rfc9110.html#name-byte-ranges">RFC 9110</a>
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/RepositoryCredentialsTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/RepositoryCredentialsTests.java
index a4bfe11383b4f..8e1926d40302f 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/RepositoryCredentialsTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/RepositoryCredentialsTests.java
@@ -302,7 +302,7 @@ protected S3Repository createRepository(
             ClusterService clusterService,
             RecoverySettings recoverySettings
         ) {
-            return new S3Repository(metadata, registry, service, clusterService, recoverySettings, null, null, null, null, false) {
+            return new S3Repository(metadata, registry, service, clusterService, recoverySettings, null, null, null, null, null, false) {
                 @Override
                 protected void assertSnapshotOrGenericThread() {
                     // eliminate thread name check as we create repo manually on test/main threads
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3AsyncServiceTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3AsyncServiceTests.java
index e9fe557ab751a..de9ad46bb222d 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3AsyncServiceTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3AsyncServiceTests.java
@@ -44,12 +44,12 @@ public void testCachedClientsAreReleased() {
         final S3ClientSettings otherClientSettings = s3AsyncService.settings(metadata2);
         assertSame(clientSettings, otherClientSettings);
         final AmazonAsyncS3Reference reference = SocketAccess.doPrivileged(
-            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer)
+            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer, asyncExecutorContainer)
         );
         reference.close();
         s3AsyncService.close();
         final AmazonAsyncS3Reference referenceReloaded = SocketAccess.doPrivileged(
-            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer)
+            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer, asyncExecutorContainer)
         );
         assertNotSame(referenceReloaded, reference);
         referenceReloaded.close();
@@ -79,12 +79,12 @@ public void testCachedClientsWithCredentialsAreReleased() {
         final S3ClientSettings otherClientSettings = s3AsyncService.settings(metadata2);
         assertSame(clientSettings, otherClientSettings);
         final AmazonAsyncS3Reference reference = SocketAccess.doPrivileged(
-            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer)
+            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer, asyncExecutorContainer)
         );
         reference.close();
         s3AsyncService.close();
         final AmazonAsyncS3Reference referenceReloaded = SocketAccess.doPrivileged(
-            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer)
+            () -> s3AsyncService.client(metadata1, asyncExecutorContainer, asyncExecutorContainer, asyncExecutorContainer)
         );
         assertNotSame(referenceReloaded, reference);
         referenceReloaded.close();
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerMockClientTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerMockClientTests.java
index 8c8524212e08e..8c7e196d7c812 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerMockClientTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerMockClientTests.java
@@ -9,7 +9,10 @@
 package org.opensearch.repositories.s3;
 
 import software.amazon.awssdk.core.async.AsyncRequestBody;
+import software.amazon.awssdk.core.exception.SdkException;
+import software.amazon.awssdk.core.sync.RequestBody;
 import software.amazon.awssdk.services.s3.S3AsyncClient;
+import software.amazon.awssdk.services.s3.S3Client;
 import software.amazon.awssdk.services.s3.model.AbortMultipartUploadRequest;
 import software.amazon.awssdk.services.s3.model.AbortMultipartUploadResponse;
 import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadRequest;
@@ -18,8 +21,10 @@
 import software.amazon.awssdk.services.s3.model.CreateMultipartUploadResponse;
 import software.amazon.awssdk.services.s3.model.DeleteObjectRequest;
 import software.amazon.awssdk.services.s3.model.DeleteObjectResponse;
+import software.amazon.awssdk.services.s3.model.ObjectCannedACL;
 import software.amazon.awssdk.services.s3.model.PutObjectRequest;
 import software.amazon.awssdk.services.s3.model.PutObjectResponse;
+import software.amazon.awssdk.services.s3.model.StorageClass;
 import software.amazon.awssdk.services.s3.model.UploadPartRequest;
 import software.amazon.awssdk.services.s3.model.UploadPartResponse;
 
@@ -37,6 +42,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.repositories.s3.async.AsyncExecutorContainer;
 import org.opensearch.repositories.s3.async.AsyncTransferEventLoopGroup;
@@ -61,14 +67,21 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.IntStream;
 
+import org.mockito.Mockito;
 import org.mockito.invocation.InvocationOnMock;
 
+import static org.opensearch.repositories.s3.S3Repository.BULK_DELETE_SIZE;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class S3BlobContainerMockClientTests extends OpenSearchTestCase implements ConfigPathSupport {
 
@@ -265,10 +278,11 @@ public void verifySingleChunkUploadCallCount(boolean finalizeUploadFailure) {
         @Override
         public AmazonAsyncS3Reference client(
             RepositoryMetadata repositoryMetadata,
+            AsyncExecutorContainer urgentExecutorBuilder,
             AsyncExecutorContainer priorityExecutorBuilder,
             AsyncExecutorContainer normalExecutorBuilder
         ) {
-            return new AmazonAsyncS3Reference(AmazonAsyncS3WithCredentials.create(asyncClient, asyncClient, null));
+            return new AmazonAsyncS3Reference(AmazonAsyncS3WithCredentials.create(asyncClient, asyncClient, asyncClient, null));
         }
     }
 
@@ -387,13 +401,16 @@ private S3BlobStore createBlobStore() {
             S3Repository.BUFFER_SIZE_SETTING.getDefault(Settings.EMPTY),
             S3Repository.CANNED_ACL_SETTING.getDefault(Settings.EMPTY),
             S3Repository.STORAGE_CLASS_SETTING.getDefault(Settings.EMPTY),
+            BULK_DELETE_SIZE.get(Settings.EMPTY),
             repositoryMetadata,
             new AsyncTransferManager(
                 S3Repository.PARALLEL_MULTIPART_UPLOAD_MINIMUM_PART_SIZE_SETTING.getDefault(Settings.EMPTY).getBytes(),
                 asyncExecutorContainer.getStreamReader(),
+                asyncExecutorContainer.getStreamReader(),
                 asyncExecutorContainer.getStreamReader()
             ),
             asyncExecutorContainer,
+            asyncExecutorContainer,
             asyncExecutorContainer
         );
     }
@@ -511,7 +528,7 @@ public InputStreamContainer apply(Integer partNo, Long size, Long position) thro
                     }
                 }, partSize, calculateLastPartSize(blobSize, partSize), calculateNumberOfParts(blobSize, partSize));
             }
-        }, blobSize, false, WritePriority.HIGH, uploadSuccess -> {
+        }, blobSize, false, WritePriority.NORMAL, uploadSuccess -> {
             assertTrue(uploadSuccess);
             if (throwExceptionOnFinalizeUpload) {
                 throw new RuntimeException();
@@ -541,4 +558,115 @@ private long calculateLastPartSize(long totalSize, long partSize) {
     private int calculateNumberOfParts(long contentLength, long partSize) {
         return (int) ((contentLength % partSize) == 0 ? contentLength / partSize : (contentLength / partSize) + 1);
     }
+
+    public void testFailureWhenLargeFileRedirected() throws IOException, ExecutionException, InterruptedException {
+        testLargeFilesRedirectedToSlowSyncClient(true);
+    }
+
+    public void testLargeFileRedirected() throws IOException, ExecutionException, InterruptedException {
+        testLargeFilesRedirectedToSlowSyncClient(false);
+    }
+
+    private void testLargeFilesRedirectedToSlowSyncClient(boolean expectException) throws IOException, InterruptedException {
+        final ByteSizeValue partSize = new ByteSizeValue(1024, ByteSizeUnit.MB);
+
+        int numberOfParts = 20;
+        final long lastPartSize = new ByteSizeValue(20, ByteSizeUnit.MB).getBytes();
+        final long blobSize = ((numberOfParts - 1) * partSize.getBytes()) + lastPartSize;
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+        AtomicReference<Exception> exceptionRef = new AtomicReference<>();
+        ActionListener<Void> completionListener = ActionListener.wrap(resp -> { countDownLatch.countDown(); }, ex -> {
+            exceptionRef.set(ex);
+            countDownLatch.countDown();
+        });
+
+        final String bucketName = randomAlphaOfLengthBetween(1, 10);
+
+        final BlobPath blobPath = new BlobPath();
+        if (randomBoolean()) {
+            IntStream.of(randomIntBetween(1, 5)).forEach(value -> blobPath.add("path_" + value));
+        }
+
+        final long bufferSize = ByteSizeUnit.MB.toBytes(randomIntBetween(5, 1024));
+
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        when(blobStore.bucket()).thenReturn(bucketName);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.bufferSizeInBytes()).thenReturn(bufferSize);
+
+        final boolean serverSideEncryption = randomBoolean();
+        when(blobStore.serverSideEncryption()).thenReturn(serverSideEncryption);
+
+        final StorageClass storageClass = randomFrom(StorageClass.values());
+        when(blobStore.getStorageClass()).thenReturn(storageClass);
+        when(blobStore.isRedirectLargeUploads()).thenReturn(true);
+
+        final ObjectCannedACL cannedAccessControlList = randomBoolean() ? randomFrom(ObjectCannedACL.values()) : null;
+        if (cannedAccessControlList != null) {
+            when(blobStore.getCannedACL()).thenReturn(cannedAccessControlList);
+        }
+
+        final S3Client client = mock(S3Client.class);
+        final AmazonS3Reference clientReference = Mockito.spy(new AmazonS3Reference(client));
+        doNothing().when(clientReference).close();
+        when(blobStore.clientReference()).thenReturn(clientReference);
+        final CreateMultipartUploadResponse createMultipartUploadResponse = CreateMultipartUploadResponse.builder()
+            .uploadId(randomAlphaOfLength(10))
+            .build();
+        when(client.createMultipartUpload(any(CreateMultipartUploadRequest.class))).thenReturn(createMultipartUploadResponse);
+        if (expectException) {
+            when(client.uploadPart(any(UploadPartRequest.class), any(RequestBody.class))).thenThrow(
+                SdkException.create("Expected upload part request to fail", new RuntimeException())
+            );
+        } else {
+            when(client.uploadPart(any(UploadPartRequest.class), any(RequestBody.class))).thenReturn(UploadPartResponse.builder().build());
+        }
+
+        // Fail the completion request
+        when(client.completeMultipartUpload(any(CompleteMultipartUploadRequest.class))).thenReturn(
+            CompleteMultipartUploadResponse.builder().build()
+        );
+        when(client.abortMultipartUpload(any(AbortMultipartUploadRequest.class))).thenReturn(
+            AbortMultipartUploadResponse.builder().build()
+        );
+
+        List<InputStream> openInputStreams = new ArrayList<>();
+        final S3BlobContainer s3BlobContainer = Mockito.spy(new S3BlobContainer(blobPath, blobStore));
+        s3BlobContainer.asyncBlobUpload(new WriteContext("write_large_blob", new StreamContextSupplier() {
+            @Override
+            public StreamContext supplyStreamContext(long partSize) {
+                return new StreamContext(new CheckedTriFunction<Integer, Long, Long, InputStreamContainer, IOException>() {
+                    @Override
+                    public InputStreamContainer apply(Integer partNo, Long size, Long position) throws IOException {
+                        InputStream inputStream = new OffsetRangeIndexInputStream(new ZeroIndexInput("desc", blobSize), size, position);
+                        openInputStreams.add(inputStream);
+                        return new InputStreamContainer(inputStream, size, position);
+                    }
+                }, partSize, calculateLastPartSize(blobSize, partSize), calculateNumberOfParts(blobSize, partSize));
+            }
+        }, blobSize, false, WritePriority.HIGH, uploadSuccess -> { assertTrue(uploadSuccess); }, false, null), completionListener);
+
+        assertTrue(countDownLatch.await(5000, TimeUnit.SECONDS));
+        if (expectException) {
+            assertNotNull(exceptionRef.get());
+        } else {
+            assertNull(exceptionRef.get());
+        }
+        verify(s3BlobContainer, times(1)).executeMultipartUpload(any(S3BlobStore.class), anyString(), any(InputStream.class), anyLong());
+
+        if (expectException) {
+            verify(client, times(1)).abortMultipartUpload(any(AbortMultipartUploadRequest.class));
+        } else {
+            verify(client, times(0)).abortMultipartUpload(any(AbortMultipartUploadRequest.class));
+        }
+
+        openInputStreams.forEach(inputStream -> {
+            try {
+                inputStream.close();
+            } catch (IOException ex) {
+                logger.error("Error closing input stream");
+            }
+        });
+    }
+
 }
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerRetriesTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerRetriesTests.java
index ecad68474b601..ceab06bd051e9 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerRetriesTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobContainerRetriesTests.java
@@ -95,6 +95,7 @@
 import static org.opensearch.repositories.s3.S3ClientSettings.MAX_RETRIES_SETTING;
 import static org.opensearch.repositories.s3.S3ClientSettings.READ_TIMEOUT_SETTING;
 import static org.opensearch.repositories.s3.S3ClientSettings.REGION;
+import static org.opensearch.repositories.s3.S3Repository.BULK_DELETE_SIZE;
 import static org.hamcrest.Matchers.anyOf;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
@@ -215,13 +216,16 @@ protected AsyncMultiStreamBlobContainer createBlobContainer(
                 bufferSize == null ? S3Repository.BUFFER_SIZE_SETTING.getDefault(Settings.EMPTY) : bufferSize,
                 S3Repository.CANNED_ACL_SETTING.getDefault(Settings.EMPTY),
                 S3Repository.STORAGE_CLASS_SETTING.getDefault(Settings.EMPTY),
+                BULK_DELETE_SIZE.get(Settings.EMPTY),
                 repositoryMetadata,
                 new AsyncTransferManager(
                     S3Repository.PARALLEL_MULTIPART_UPLOAD_MINIMUM_PART_SIZE_SETTING.getDefault(Settings.EMPTY).getBytes(),
                     asyncExecutorContainer.getStreamReader(),
+                    asyncExecutorContainer.getStreamReader(),
                     asyncExecutorContainer.getStreamReader()
                 ),
                 asyncExecutorContainer,
+                asyncExecutorContainer,
                 asyncExecutorContainer
             )
         ) {
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java
index 1c4936cae7eba..58ad290a31e85 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java
@@ -32,11 +32,15 @@
 
 package org.opensearch.repositories.s3;
 
+import software.amazon.awssdk.core.ResponseInputStream;
+import software.amazon.awssdk.core.async.AsyncResponseTransformer;
 import software.amazon.awssdk.core.exception.SdkException;
 import software.amazon.awssdk.core.sync.RequestBody;
+import software.amazon.awssdk.services.s3.S3AsyncClient;
 import software.amazon.awssdk.services.s3.S3Client;
 import software.amazon.awssdk.services.s3.model.AbortMultipartUploadRequest;
 import software.amazon.awssdk.services.s3.model.AbortMultipartUploadResponse;
+import software.amazon.awssdk.services.s3.model.Checksum;
 import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadRequest;
 import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadResponse;
 import software.amazon.awssdk.services.s3.model.CompletedPart;
@@ -44,6 +48,11 @@
 import software.amazon.awssdk.services.s3.model.CreateMultipartUploadResponse;
 import software.amazon.awssdk.services.s3.model.DeleteObjectsRequest;
 import software.amazon.awssdk.services.s3.model.DeleteObjectsResponse;
+import software.amazon.awssdk.services.s3.model.GetObjectAttributesParts;
+import software.amazon.awssdk.services.s3.model.GetObjectAttributesRequest;
+import software.amazon.awssdk.services.s3.model.GetObjectAttributesResponse;
+import software.amazon.awssdk.services.s3.model.GetObjectRequest;
+import software.amazon.awssdk.services.s3.model.GetObjectResponse;
 import software.amazon.awssdk.services.s3.model.HeadObjectRequest;
 import software.amazon.awssdk.services.s3.model.HeadObjectResponse;
 import software.amazon.awssdk.services.s3.model.ListObjectsV2Request;
@@ -61,13 +70,15 @@
 import software.amazon.awssdk.services.s3.model.UploadPartResponse;
 import software.amazon.awssdk.services.s3.paginators.ListObjectsV2Iterable;
 
-import org.opensearch.action.support.PlainActionFuture;
+import org.opensearch.action.LatchedActionListener;
 import org.opensearch.common.blobstore.BlobContainer;
 import org.opensearch.common.blobstore.BlobMetadata;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.blobstore.BlobStoreException;
 import org.opensearch.common.blobstore.DeleteResult;
+import org.opensearch.common.blobstore.stream.read.ReadContext;
 import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.test.OpenSearchTestCase;
@@ -86,14 +97,18 @@
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
 import org.mockito.ArgumentCaptor;
+import org.mockito.ArgumentMatchers;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
@@ -261,10 +276,12 @@ public void testDelete() throws IOException {
         final String bucketName = randomAlphaOfLengthBetween(1, 10);
 
         final BlobPath blobPath = new BlobPath();
+        int bulkDeleteSize = 5;
 
         final S3BlobStore blobStore = mock(S3BlobStore.class);
         when(blobStore.bucket()).thenReturn(bucketName);
         when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.getBulkDeletesSize()).thenReturn(bulkDeleteSize);
 
         final S3Client client = mock(S3Client.class);
         doAnswer(invocation -> new AmazonS3Reference(client)).when(blobStore).clientReference();
@@ -282,8 +299,11 @@ public void testDelete() throws IOException {
         when(client.listObjectsV2Paginator(any(ListObjectsV2Request.class))).thenReturn(listObjectsV2Iterable);
 
         final List<String> keysDeleted = new ArrayList<>();
+        AtomicInteger deleteCount = new AtomicInteger();
         doAnswer(invocation -> {
             DeleteObjectsRequest deleteObjectsRequest = invocation.getArgument(0);
+            deleteCount.getAndIncrement();
+            logger.info("Object sizes are{}", deleteObjectsRequest.delete().objects().size());
             keysDeleted.addAll(deleteObjectsRequest.delete().objects().stream().map(ObjectIdentifier::key).collect(Collectors.toList()));
             return DeleteObjectsResponse.builder().build();
         }).when(client).deleteObjects(any(DeleteObjectsRequest.class));
@@ -296,6 +316,8 @@ public void testDelete() throws IOException {
         // keysDeleted will have blobPath also
         assertEquals(listObjectsV2ResponseIterator.getKeysListed().size(), keysDeleted.size() - 1);
         assertTrue(keysDeleted.contains(blobPath.buildAsString()));
+        // keysDeleted will have blobPath also
+        assertEquals((int) Math.ceil(((double) keysDeleted.size() + 1) / bulkDeleteSize), deleteCount.get());
         keysDeleted.remove(blobPath.buildAsString());
         assertEquals(new HashSet<>(listObjectsV2ResponseIterator.getKeysListed()), new HashSet<>(keysDeleted));
     }
@@ -882,17 +904,6 @@ public void onFailure(Exception e) {}
         }
     }
 
-    public void testAsyncBlobDownload() {
-        final S3BlobStore blobStore = mock(S3BlobStore.class);
-        final BlobPath blobPath = mock(BlobPath.class);
-        final String blobName = "test-blob";
-
-        final UnsupportedOperationException e = expectThrows(UnsupportedOperationException.class, () -> {
-            final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
-            blobContainer.readBlobAsync(blobName, new PlainActionFuture<>());
-        });
-    }
-
     public void testListBlobsByPrefixInLexicographicOrderWithNegativeLimit() throws IOException {
         testListBlobsByPrefixInLexicographicOrder(-5, 0, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
     }
@@ -912,4 +923,418 @@ public void testListBlobsByPrefixInLexicographicOrderWithLimitGreaterThanPageSiz
     public void testListBlobsByPrefixInLexicographicOrderWithLimitGreaterThanNumberOfRecords() throws IOException {
         testListBlobsByPrefixInLexicographicOrder(12, 2, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
     }
+
+    public void testReadBlobAsyncMultiPart() throws Exception {
+        final String bucketName = randomAlphaOfLengthBetween(1, 10);
+        final String blobName = randomAlphaOfLengthBetween(1, 10);
+        final String checksum = randomAlphaOfLength(10);
+
+        final long objectSize = 100L;
+        final int objectPartCount = 10;
+        final int partSize = 10;
+
+        final S3AsyncClient s3AsyncClient = mock(S3AsyncClient.class);
+        final AmazonAsyncS3Reference amazonAsyncS3Reference = new AmazonAsyncS3Reference(
+            AmazonAsyncS3WithCredentials.create(s3AsyncClient, s3AsyncClient, s3AsyncClient, null)
+        );
+
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        final BlobPath blobPath = new BlobPath();
+
+        when(blobStore.bucket()).thenReturn(bucketName);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.serverSideEncryption()).thenReturn(false);
+        when(blobStore.asyncClientReference()).thenReturn(amazonAsyncS3Reference);
+
+        CompletableFuture<GetObjectAttributesResponse> getObjectAttributesResponseCompletableFuture = new CompletableFuture<>();
+        getObjectAttributesResponseCompletableFuture.complete(
+            GetObjectAttributesResponse.builder()
+                .checksum(Checksum.builder().checksumCRC32(checksum).build())
+                .objectSize(objectSize)
+                .objectParts(GetObjectAttributesParts.builder().totalPartsCount(objectPartCount).build())
+                .build()
+        );
+        when(s3AsyncClient.getObjectAttributes(any(GetObjectAttributesRequest.class))).thenReturn(
+            getObjectAttributesResponseCompletableFuture
+        );
+
+        mockObjectPartResponse(s3AsyncClient, bucketName, blobName, objectPartCount, partSize, objectSize);
+
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+        CountingCompletionListener<ReadContext> readContextActionListener = new CountingCompletionListener<>();
+        LatchedActionListener<ReadContext> listener = new LatchedActionListener<>(readContextActionListener, countDownLatch);
+
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+        blobContainer.readBlobAsync(blobName, listener);
+        countDownLatch.await();
+
+        assertEquals(1, readContextActionListener.getResponseCount());
+        assertEquals(0, readContextActionListener.getFailureCount());
+        ReadContext readContext = readContextActionListener.getResponse();
+        assertEquals(objectPartCount, readContext.getNumberOfParts());
+        assertEquals(checksum, readContext.getBlobChecksum());
+        assertEquals(objectSize, readContext.getBlobSize());
+
+        for (int partNumber = 1; partNumber < objectPartCount; partNumber++) {
+            InputStreamContainer inputStreamContainer = readContext.getPartStreams().get(partNumber).get().join();
+            final int offset = partNumber * partSize;
+            assertEquals(partSize, inputStreamContainer.getContentLength());
+            assertEquals(offset, inputStreamContainer.getOffset());
+            assertEquals(partSize, inputStreamContainer.getInputStream().readAllBytes().length);
+        }
+    }
+
+    public void testReadBlobAsyncSinglePart() throws Exception {
+        final String bucketName = randomAlphaOfLengthBetween(1, 10);
+        final String blobName = randomAlphaOfLengthBetween(1, 10);
+        final String checksum = randomAlphaOfLength(10);
+
+        final int objectSize = 100;
+
+        final S3AsyncClient s3AsyncClient = mock(S3AsyncClient.class);
+        final AmazonAsyncS3Reference amazonAsyncS3Reference = new AmazonAsyncS3Reference(
+            AmazonAsyncS3WithCredentials.create(s3AsyncClient, s3AsyncClient, s3AsyncClient, null)
+        );
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        final BlobPath blobPath = new BlobPath();
+
+        when(blobStore.bucket()).thenReturn(bucketName);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.serverSideEncryption()).thenReturn(false);
+        when(blobStore.asyncClientReference()).thenReturn(amazonAsyncS3Reference);
+
+        CompletableFuture<GetObjectAttributesResponse> getObjectAttributesResponseCompletableFuture = new CompletableFuture<>();
+        getObjectAttributesResponseCompletableFuture.complete(
+            GetObjectAttributesResponse.builder()
+                .checksum(Checksum.builder().checksumCRC32(checksum).build())
+                .objectSize((long) objectSize)
+                .build()
+        );
+        when(s3AsyncClient.getObjectAttributes(any(GetObjectAttributesRequest.class))).thenReturn(
+            getObjectAttributesResponseCompletableFuture
+        );
+
+        mockObjectResponse(s3AsyncClient, bucketName, blobName, objectSize);
+
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+        CountingCompletionListener<ReadContext> readContextActionListener = new CountingCompletionListener<>();
+        LatchedActionListener<ReadContext> listener = new LatchedActionListener<>(readContextActionListener, countDownLatch);
+
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+        blobContainer.readBlobAsync(blobName, listener);
+        countDownLatch.await();
+
+        assertEquals(1, readContextActionListener.getResponseCount());
+        assertEquals(0, readContextActionListener.getFailureCount());
+        ReadContext readContext = readContextActionListener.getResponse();
+        assertEquals(1, readContext.getNumberOfParts());
+        assertEquals(checksum, readContext.getBlobChecksum());
+        assertEquals(objectSize, readContext.getBlobSize());
+
+        InputStreamContainer inputStreamContainer = readContext.getPartStreams().stream().findFirst().get().get().join();
+        assertEquals(objectSize, inputStreamContainer.getContentLength());
+        assertEquals(0, inputStreamContainer.getOffset());
+        assertEquals(objectSize, inputStreamContainer.getInputStream().readAllBytes().length);
+
+    }
+
+    public void testReadBlobAsyncFailure() throws Exception {
+        final String bucketName = randomAlphaOfLengthBetween(1, 10);
+        final String blobName = randomAlphaOfLengthBetween(1, 10);
+        final String checksum = randomAlphaOfLength(10);
+
+        final long objectSize = 100L;
+        final int objectPartCount = 10;
+
+        final S3AsyncClient s3AsyncClient = mock(S3AsyncClient.class);
+        final AmazonAsyncS3Reference amazonAsyncS3Reference = new AmazonAsyncS3Reference(
+            AmazonAsyncS3WithCredentials.create(s3AsyncClient, s3AsyncClient, s3AsyncClient, null)
+        );
+
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        final BlobPath blobPath = new BlobPath();
+
+        when(blobStore.bucket()).thenReturn(bucketName);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.serverSideEncryption()).thenReturn(false);
+        when(blobStore.asyncClientReference()).thenReturn(amazonAsyncS3Reference);
+
+        CompletableFuture<GetObjectAttributesResponse> getObjectAttributesResponseCompletableFuture = new CompletableFuture<>();
+        getObjectAttributesResponseCompletableFuture.complete(
+            GetObjectAttributesResponse.builder()
+                .checksum(Checksum.builder().checksumCRC32(checksum).build())
+                .objectSize(objectSize)
+                .objectParts(GetObjectAttributesParts.builder().totalPartsCount(objectPartCount).build())
+                .build()
+        );
+        when(s3AsyncClient.getObjectAttributes(any(GetObjectAttributesRequest.class))).thenThrow(new RuntimeException());
+
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+        CountingCompletionListener<ReadContext> readContextActionListener = new CountingCompletionListener<>();
+        LatchedActionListener<ReadContext> listener = new LatchedActionListener<>(readContextActionListener, countDownLatch);
+
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+        blobContainer.readBlobAsync(blobName, listener);
+        countDownLatch.await();
+
+        assertEquals(0, readContextActionListener.getResponseCount());
+        assertEquals(1, readContextActionListener.getFailureCount());
+    }
+
+    public void testReadBlobAsyncOnCompleteFailureMissingData() throws Exception {
+        final String bucketName = randomAlphaOfLengthBetween(1, 10);
+        final String blobName = randomAlphaOfLengthBetween(1, 10);
+        final String checksum = randomAlphaOfLength(10);
+
+        final long objectSize = 100L;
+        final int objectPartCount = 10;
+
+        final S3AsyncClient s3AsyncClient = mock(S3AsyncClient.class);
+        final AmazonAsyncS3Reference amazonAsyncS3Reference = new AmazonAsyncS3Reference(
+            AmazonAsyncS3WithCredentials.create(s3AsyncClient, s3AsyncClient, s3AsyncClient, null)
+        );
+
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        final BlobPath blobPath = new BlobPath();
+
+        when(blobStore.bucket()).thenReturn(bucketName);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.serverSideEncryption()).thenReturn(false);
+        when(blobStore.asyncClientReference()).thenReturn(amazonAsyncS3Reference);
+
+        CompletableFuture<GetObjectAttributesResponse> getObjectAttributesResponseCompletableFuture = new CompletableFuture<>();
+        getObjectAttributesResponseCompletableFuture.complete(
+            GetObjectAttributesResponse.builder()
+                .checksum(Checksum.builder().build())
+                .objectSize(null)
+                .objectParts(GetObjectAttributesParts.builder().totalPartsCount(objectPartCount).build())
+                .build()
+        );
+        when(s3AsyncClient.getObjectAttributes(any(GetObjectAttributesRequest.class))).thenReturn(
+            getObjectAttributesResponseCompletableFuture
+        );
+
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+        CountingCompletionListener<ReadContext> readContextActionListener = new CountingCompletionListener<>();
+        LatchedActionListener<ReadContext> listener = new LatchedActionListener<>(readContextActionListener, countDownLatch);
+
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+        blobContainer.readBlobAsync(blobName, listener);
+        countDownLatch.await();
+
+        assertEquals(0, readContextActionListener.getResponseCount());
+        assertEquals(1, readContextActionListener.getFailureCount());
+    }
+
+    public void testGetBlobMetadata() throws Exception {
+        final String checksum = randomAlphaOfLengthBetween(1, 10);
+        final long objectSize = 100L;
+        final int objectPartCount = 10;
+        final String blobName = randomAlphaOfLengthBetween(1, 10);
+        final String bucketName = randomAlphaOfLengthBetween(1, 10);
+
+        final S3AsyncClient s3AsyncClient = mock(S3AsyncClient.class);
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        final BlobPath blobPath = new BlobPath();
+        when(blobStore.bucket()).thenReturn(bucketName);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.serverSideEncryption()).thenReturn(false);
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+
+        CompletableFuture<GetObjectAttributesResponse> getObjectAttributesResponseCompletableFuture = new CompletableFuture<>();
+        getObjectAttributesResponseCompletableFuture.complete(
+            GetObjectAttributesResponse.builder()
+                .checksum(Checksum.builder().checksumCRC32(checksum).build())
+                .objectSize(objectSize)
+                .objectParts(GetObjectAttributesParts.builder().totalPartsCount(objectPartCount).build())
+                .build()
+        );
+        when(s3AsyncClient.getObjectAttributes(any(GetObjectAttributesRequest.class))).thenReturn(
+            getObjectAttributesResponseCompletableFuture
+        );
+
+        CompletableFuture<GetObjectAttributesResponse> responseFuture = blobContainer.getBlobMetadata(s3AsyncClient, bucketName, blobName);
+        GetObjectAttributesResponse objectAttributesResponse = responseFuture.get();
+
+        assertEquals(checksum, objectAttributesResponse.checksum().checksumCRC32());
+        assertEquals(Long.valueOf(objectSize), objectAttributesResponse.objectSize());
+        assertEquals(Integer.valueOf(objectPartCount), objectAttributesResponse.objectParts().totalPartsCount());
+    }
+
+    public void testGetBlobPartInputStream() throws Exception {
+        final String blobName = randomAlphaOfLengthBetween(1, 10);
+        final String bucketName = randomAlphaOfLengthBetween(1, 10);
+        final long contentLength = 10L;
+        final String contentRange = "bytes 10-20/100";
+        final InputStream inputStream = ResponseInputStream.nullInputStream();
+
+        final S3AsyncClient s3AsyncClient = mock(S3AsyncClient.class);
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        final BlobPath blobPath = new BlobPath();
+        when(blobStore.bucket()).thenReturn(bucketName);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+        when(blobStore.serverSideEncryption()).thenReturn(false);
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+
+        GetObjectResponse getObjectResponse = GetObjectResponse.builder().contentLength(contentLength).contentRange(contentRange).build();
+
+        CompletableFuture<ResponseInputStream<GetObjectResponse>> getObjectPartResponse = new CompletableFuture<>();
+        ResponseInputStream<GetObjectResponse> responseInputStream = new ResponseInputStream<>(getObjectResponse, inputStream);
+        getObjectPartResponse.complete(responseInputStream);
+
+        when(
+            s3AsyncClient.getObject(
+                any(GetObjectRequest.class),
+                ArgumentMatchers.<AsyncResponseTransformer<GetObjectResponse, ResponseInputStream<GetObjectResponse>>>any()
+            )
+        ).thenReturn(getObjectPartResponse);
+
+        // Header based offset in case of a multi part object request
+        InputStreamContainer inputStreamContainer = blobContainer.getBlobPartInputStreamContainer(s3AsyncClient, bucketName, blobName, 0)
+            .get();
+
+        assertEquals(10, inputStreamContainer.getOffset());
+        assertEquals(contentLength, inputStreamContainer.getContentLength());
+        assertEquals(inputStream.available(), inputStreamContainer.getInputStream().available());
+
+        // 0 offset in case of a single part object request
+        inputStreamContainer = blobContainer.getBlobPartInputStreamContainer(s3AsyncClient, bucketName, blobName, null).get();
+
+        assertEquals(0, inputStreamContainer.getOffset());
+        assertEquals(contentLength, inputStreamContainer.getContentLength());
+        assertEquals(inputStream.available(), inputStreamContainer.getInputStream().available());
+    }
+
+    public void testTransformResponseToInputStreamContainer() throws Exception {
+        final String contentRange = "bytes 0-10/100";
+        final long contentLength = 10L;
+        final InputStream inputStream = ResponseInputStream.nullInputStream();
+
+        GetObjectResponse getObjectResponse = GetObjectResponse.builder().contentLength(contentLength).build();
+
+        // Exception when content range absent for multipart object
+        ResponseInputStream<GetObjectResponse> responseInputStreamNoRange = new ResponseInputStream<>(getObjectResponse, inputStream);
+        assertThrows(SdkException.class, () -> S3BlobContainer.transformResponseToInputStreamContainer(responseInputStreamNoRange, true));
+
+        // No exception when content range absent for single part object
+        ResponseInputStream<GetObjectResponse> responseInputStreamNoRangeSinglePart = new ResponseInputStream<>(
+            getObjectResponse,
+            inputStream
+        );
+        InputStreamContainer inputStreamContainer = S3BlobContainer.transformResponseToInputStreamContainer(
+            responseInputStreamNoRangeSinglePart,
+            false
+        );
+        assertEquals(contentLength, inputStreamContainer.getContentLength());
+        assertEquals(0, inputStreamContainer.getOffset());
+
+        // Exception when length is absent
+        getObjectResponse = GetObjectResponse.builder().contentRange(contentRange).build();
+        ResponseInputStream<GetObjectResponse> responseInputStreamNoContentLength = new ResponseInputStream<>(
+            getObjectResponse,
+            inputStream
+        );
+        assertThrows(
+            SdkException.class,
+            () -> S3BlobContainer.transformResponseToInputStreamContainer(responseInputStreamNoContentLength, true)
+        );
+
+        // No exception when range and length both are present
+        getObjectResponse = GetObjectResponse.builder().contentRange(contentRange).contentLength(contentLength).build();
+        ResponseInputStream<GetObjectResponse> responseInputStream = new ResponseInputStream<>(getObjectResponse, inputStream);
+        inputStreamContainer = S3BlobContainer.transformResponseToInputStreamContainer(responseInputStream, true);
+        assertEquals(contentLength, inputStreamContainer.getContentLength());
+        assertEquals(0, inputStreamContainer.getOffset());
+        assertEquals(inputStream.available(), inputStreamContainer.getInputStream().available());
+    }
+
+    private void mockObjectResponse(S3AsyncClient s3AsyncClient, String bucketName, String blobName, int objectSize) {
+
+        final InputStream inputStream = new ByteArrayInputStream(randomByteArrayOfLength(objectSize));
+
+        GetObjectResponse getObjectResponse = GetObjectResponse.builder().contentLength((long) objectSize).build();
+
+        CompletableFuture<ResponseInputStream<GetObjectResponse>> getObjectPartResponse = new CompletableFuture<>();
+        ResponseInputStream<GetObjectResponse> responseInputStream = new ResponseInputStream<>(getObjectResponse, inputStream);
+        getObjectPartResponse.complete(responseInputStream);
+
+        GetObjectRequest getObjectRequest = GetObjectRequest.builder().bucket(bucketName).key(blobName).build();
+
+        when(
+            s3AsyncClient.getObject(
+                eq(getObjectRequest),
+                ArgumentMatchers.<AsyncResponseTransformer<GetObjectResponse, ResponseInputStream<GetObjectResponse>>>any()
+            )
+        ).thenReturn(getObjectPartResponse);
+
+    }
+
+    private void mockObjectPartResponse(
+        S3AsyncClient s3AsyncClient,
+        String bucketName,
+        String blobName,
+        int totalNumberOfParts,
+        int partSize,
+        long objectSize
+    ) {
+        for (int partNumber = 1; partNumber <= totalNumberOfParts; partNumber++) {
+            final int start = (partNumber - 1) * partSize;
+            final int end = partNumber * partSize;
+            final String contentRange = "bytes " + start + "-" + end + "/" + objectSize;
+            final InputStream inputStream = new ByteArrayInputStream(randomByteArrayOfLength(partSize));
+
+            GetObjectResponse getObjectResponse = GetObjectResponse.builder()
+                .contentLength((long) partSize)
+                .contentRange(contentRange)
+                .build();
+
+            CompletableFuture<ResponseInputStream<GetObjectResponse>> getObjectPartResponse = new CompletableFuture<>();
+            ResponseInputStream<GetObjectResponse> responseInputStream = new ResponseInputStream<>(getObjectResponse, inputStream);
+            getObjectPartResponse.complete(responseInputStream);
+
+            GetObjectRequest getObjectRequest = GetObjectRequest.builder().bucket(bucketName).key(blobName).partNumber(partNumber).build();
+
+            when(
+                s3AsyncClient.getObject(
+                    eq(getObjectRequest),
+                    ArgumentMatchers.<AsyncResponseTransformer<GetObjectResponse, ResponseInputStream<GetObjectResponse>>>any()
+                )
+            ).thenReturn(getObjectPartResponse);
+        }
+    }
+
+    private static class CountingCompletionListener<T> implements ActionListener<T> {
+        private int responseCount;
+        private int failureCount;
+        private T response;
+        private Exception exception;
+
+        @Override
+        public void onResponse(T response) {
+            this.response = response;
+            responseCount++;
+        }
+
+        @Override
+        public void onFailure(Exception e) {
+            exception = e;
+            failureCount++;
+        }
+
+        public int getResponseCount() {
+            return responseCount;
+        }
+
+        public int getFailureCount() {
+            return failureCount;
+        }
+
+        public T getResponse() {
+            return response;
+        }
+
+        public Exception getException() {
+            return exception;
+        }
+    }
 }
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3ClientSettingsTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3ClientSettingsTests.java
index 61c9c998b1dec..f27c8387b6e45 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3ClientSettingsTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3ClientSettingsTests.java
@@ -70,10 +70,10 @@ public void testThereIsADefaultClientByDefault() {
         assertThat(defaultSettings.protocol, is(Protocol.HTTPS));
         assertThat(defaultSettings.proxySettings, is(ProxySettings.NO_PROXY_SETTINGS));
         assertThat(defaultSettings.readTimeoutMillis, is(50 * 1000));
-        assertThat(defaultSettings.requestTimeoutMillis, is(120 * 1000));
+        assertThat(defaultSettings.requestTimeoutMillis, is(5 * 60 * 1000));
         assertThat(defaultSettings.connectionTimeoutMillis, is(10 * 1000));
         assertThat(defaultSettings.connectionTTLMillis, is(5 * 1000));
-        assertThat(defaultSettings.maxConnections, is(100));
+        assertThat(defaultSettings.maxConnections, is(500));
         assertThat(defaultSettings.maxRetries, is(3));
         assertThat(defaultSettings.throttleRetries, is(true));
     }
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3RepositoryTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3RepositoryTests.java
index 533c3aa17009d..6fec535ae6301 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3RepositoryTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3RepositoryTests.java
@@ -36,17 +36,20 @@
 
 import org.opensearch.cluster.metadata.RepositoryMetadata;
 import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.repositories.RepositoryException;
+import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.repositories.blobstore.BlobStoreTestUtil;
 import org.opensearch.test.OpenSearchTestCase;
 import org.hamcrest.Matchers;
 
 import java.nio.file.Path;
+import java.util.List;
 import java.util.Map;
 
 import static org.hamcrest.Matchers.containsString;
@@ -122,7 +125,8 @@ public void testBasePathSetting() {
     }
 
     public void testDefaultBufferSize() {
-        final RepositoryMetadata metadata = new RepositoryMetadata("dummy-repo", "mock", Settings.EMPTY);
+        Settings settings = Settings.builder().build();
+        final RepositoryMetadata metadata = new RepositoryMetadata("dummy-repo", "mock", settings);
         try (S3Repository s3repo = createS3Repo(metadata)) {
             assertThat(s3repo.getBlobStore(), is(nullValue()));
             s3repo.start();
@@ -133,6 +137,26 @@ public void testDefaultBufferSize() {
         }
     }
 
+    public void testIsReloadable() {
+        final RepositoryMetadata metadata = new RepositoryMetadata("dummy-repo", "mock", Settings.EMPTY);
+        try (S3Repository s3repo = createS3Repo(metadata)) {
+            assertTrue(s3repo.isReloadable());
+        }
+    }
+
+    public void testRestrictedSettingsDefault() {
+        final RepositoryMetadata metadata = new RepositoryMetadata("dummy-repo", "mock", Settings.EMPTY);
+        try (S3Repository s3repo = createS3Repo(metadata)) {
+            List<Setting<?>> restrictedSettings = s3repo.getRestrictedSystemRepositorySettings();
+            assertThat(restrictedSettings.size(), is(5));
+            assertTrue(restrictedSettings.contains(BlobStoreRepository.SYSTEM_REPOSITORY_SETTING));
+            assertTrue(restrictedSettings.contains(BlobStoreRepository.READONLY_SETTING));
+            assertTrue(restrictedSettings.contains(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY));
+            assertTrue(restrictedSettings.contains(S3Repository.BUCKET_SETTING));
+            assertTrue(restrictedSettings.contains(S3Repository.BASE_PATH_SETTING));
+        }
+    }
+
     private S3Repository createS3Repo(RepositoryMetadata metadata) {
         return new S3Repository(
             metadata,
@@ -144,6 +168,7 @@ private S3Repository createS3Repo(RepositoryMetadata metadata) {
             null,
             null,
             null,
+            null,
             false
         ) {
             @Override
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/async/AsyncTransferManagerTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/async/AsyncTransferManagerTests.java
index 9c07b929052bc..b753b847df869 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/async/AsyncTransferManagerTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/async/AsyncTransferManagerTests.java
@@ -33,12 +33,18 @@
 import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.repositories.blobstore.ZeroInputStream;
+import org.opensearch.repositories.s3.StatsMetricPublisher;
 import org.opensearch.test.OpenSearchTestCase;
 import org.junit.Before;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicReference;
 
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
@@ -58,6 +64,7 @@ public void setUp() throws Exception {
         asyncTransferManager = new AsyncTransferManager(
             ByteSizeUnit.MB.toBytes(5),
             Executors.newSingleThreadExecutor(),
+            Executors.newSingleThreadExecutor(),
             Executors.newSingleThreadExecutor()
         );
         super.setUp();
@@ -70,17 +77,17 @@ public void testOneChunkUpload() {
             putObjectResponseCompletableFuture
         );
 
+        AtomicReference<InputStream> streamRef = new AtomicReference<>();
         CompletableFuture<Void> resultFuture = asyncTransferManager.uploadObject(
             s3AsyncClient,
             new UploadRequest("bucket", "key", ByteSizeUnit.MB.toBytes(1), WritePriority.HIGH, uploadSuccess -> {
                 // do nothing
-            }, false, null),
-            new StreamContext(
-                (partIdx, partSize, position) -> new InputStreamContainer(new ZeroInputStream(partSize), partSize, position),
-                ByteSizeUnit.MB.toBytes(1),
-                ByteSizeUnit.MB.toBytes(1),
-                1
-            )
+            }, false, null, true),
+            new StreamContext((partIdx, partSize, position) -> {
+                streamRef.set(new ZeroInputStream(partSize));
+                return new InputStreamContainer(streamRef.get(), partSize, position);
+            }, ByteSizeUnit.MB.toBytes(1), ByteSizeUnit.MB.toBytes(1), 1),
+            new StatsMetricPublisher()
         );
 
         try {
@@ -90,6 +97,14 @@ public void testOneChunkUpload() {
         }
 
         verify(s3AsyncClient, times(1)).putObject(any(PutObjectRequest.class), any(AsyncRequestBody.class));
+
+        boolean closeError = false;
+        try {
+            streamRef.get().available();
+        } catch (IOException e) {
+            closeError = e.getMessage().equals("Stream closed");
+        }
+        assertTrue("InputStream was still open after upload", closeError);
     }
 
     public void testOneChunkUploadCorruption() {
@@ -112,13 +127,14 @@ public void testOneChunkUploadCorruption() {
             s3AsyncClient,
             new UploadRequest("bucket", "key", ByteSizeUnit.MB.toBytes(1), WritePriority.HIGH, uploadSuccess -> {
                 // do nothing
-            }, false, null),
+            }, false, null, true),
             new StreamContext(
                 (partIdx, partSize, position) -> new InputStreamContainer(new ZeroInputStream(partSize), partSize, position),
                 ByteSizeUnit.MB.toBytes(1),
                 ByteSizeUnit.MB.toBytes(1),
                 1
-            )
+            ),
+            new StatsMetricPublisher()
         );
 
         try {
@@ -159,17 +175,18 @@ public void testMultipartUpload() {
             abortMultipartUploadResponseCompletableFuture
         );
 
+        List<InputStream> streams = new ArrayList<>();
         CompletableFuture<Void> resultFuture = asyncTransferManager.uploadObject(
             s3AsyncClient,
             new UploadRequest("bucket", "key", ByteSizeUnit.MB.toBytes(5), WritePriority.HIGH, uploadSuccess -> {
                 // do nothing
-            }, true, 3376132981L),
-            new StreamContext(
-                (partIdx, partSize, position) -> new InputStreamContainer(new ZeroInputStream(partSize), partSize, position),
-                ByteSizeUnit.MB.toBytes(1),
-                ByteSizeUnit.MB.toBytes(1),
-                5
-            )
+            }, true, 3376132981L, true),
+            new StreamContext((partIdx, partSize, position) -> {
+                InputStream stream = new ZeroInputStream(partSize);
+                streams.add(stream);
+                return new InputStreamContainer(stream, partSize, position);
+            }, ByteSizeUnit.MB.toBytes(1), ByteSizeUnit.MB.toBytes(1), 5),
+            new StatsMetricPublisher()
         );
 
         try {
@@ -178,6 +195,16 @@ public void testMultipartUpload() {
             fail("did not expect resultFuture to fail");
         }
 
+        streams.forEach(stream -> {
+            boolean closeError = false;
+            try {
+                stream.available();
+            } catch (IOException e) {
+                closeError = e.getMessage().equals("Stream closed");
+            }
+            assertTrue("InputStream was still open after upload", closeError);
+        });
+
         verify(s3AsyncClient, times(1)).createMultipartUpload(any(CreateMultipartUploadRequest.class));
         verify(s3AsyncClient, times(5)).uploadPart(any(UploadPartRequest.class), any(AsyncRequestBody.class));
         verify(s3AsyncClient, times(1)).completeMultipartUpload(any(CompleteMultipartUploadRequest.class));
@@ -213,13 +240,14 @@ public void testMultipartUploadCorruption() {
             s3AsyncClient,
             new UploadRequest("bucket", "key", ByteSizeUnit.MB.toBytes(5), WritePriority.HIGH, uploadSuccess -> {
                 // do nothing
-            }, true, 0L),
+            }, true, 0L, true),
             new StreamContext(
                 (partIdx, partSize, position) -> new InputStreamContainer(new ZeroInputStream(partSize), partSize, position),
                 ByteSizeUnit.MB.toBytes(1),
                 ByteSizeUnit.MB.toBytes(1),
                 5
-            )
+            ),
+            new StatsMetricPublisher()
         );
 
         try {
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/utils/HttpRangeUtilsTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/utils/HttpRangeUtilsTests.java
new file mode 100644
index 0000000000000..9a4267c5266e5
--- /dev/null
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/utils/HttpRangeUtilsTests.java
@@ -0,0 +1,29 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.repositories.s3.utils;
+
+import software.amazon.awssdk.core.exception.SdkException;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+public final class HttpRangeUtilsTests extends OpenSearchTestCase {
+
+    public void testFromHttpRangeHeader() {
+        String headerValue = "bytes 0-10/200";
+        Long offset = HttpRangeUtils.getStartOffsetFromRangeHeader(headerValue);
+        assertEquals(0L, offset.longValue());
+
+        headerValue = "bytes 0-10/*";
+        offset = HttpRangeUtils.getStartOffsetFromRangeHeader(headerValue);
+        assertEquals(0L, offset.longValue());
+
+        final String invalidHeaderValue = "bytes */*";
+        assertThrows(SdkException.class, () -> HttpRangeUtils.getStartOffsetFromRangeHeader(invalidHeaderValue));
+    }
+}
diff --git a/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbMMapDirectoryTests.java b/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbMMapDirectoryTests.java
index 2cac58262c75a..e1655cc5e0784 100644
--- a/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbMMapDirectoryTests.java
+++ b/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbMMapDirectoryTests.java
@@ -47,9 +47,9 @@ protected Directory getDirectory(Path file) throws IOException {
 
     @Override
     public void testCreateOutputForExistingFile() throws IOException {
-        /**
-         * This test is disabled because {@link SmbDirectoryWrapper} opens existing file
-         * with an explicit StandardOpenOption.TRUNCATE_EXISTING option.
+        /*
+          This test is disabled because {@link SmbDirectoryWrapper} opens existing file
+          with an explicit StandardOpenOption.TRUNCATE_EXISTING option.
          */
     }
 }
diff --git a/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbNIOFSDirectoryTests.java b/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbNIOFSDirectoryTests.java
index 7390759029dfc..6f821147c3079 100644
--- a/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbNIOFSDirectoryTests.java
+++ b/plugins/store-smb/src/test/java/org/opensearch/index/store/SmbNIOFSDirectoryTests.java
@@ -26,9 +26,9 @@ protected Directory getDirectory(Path file) throws IOException {
 
     @Override
     public void testCreateOutputForExistingFile() throws IOException {
-        /**
-         * This test is disabled because {@link SmbDirectoryWrapper} opens existing file
-         * with an explicit StandardOpenOption.TRUNCATE_EXISTING option.
+        /*
+          This test is disabled because {@link SmbDirectoryWrapper} opens existing file
+          with an explicit StandardOpenOption.TRUNCATE_EXISTING option.
          */
     }
 }
diff --git a/plugins/telemetry-otel/build.gradle b/plugins/telemetry-otel/build.gradle
index 511bae590bf13..9be83e30c3183 100644
--- a/plugins/telemetry-otel/build.gradle
+++ b/plugins/telemetry-otel/build.gradle
@@ -28,8 +28,16 @@ dependencies {
   api "io.opentelemetry:opentelemetry-sdk-trace:${versions.opentelemetry}"
   api "io.opentelemetry:opentelemetry-sdk-metrics:${versions.opentelemetry}"
   api "io.opentelemetry:opentelemetry-exporter-logging:${versions.opentelemetry}"
-  api "io.opentelemetry:opentelemetry-semconv:${versions.opentelemetry}-alpha"
+  api "io.opentelemetry.semconv:opentelemetry-semconv:${versions.opentelemetrysemconv}"
   api "io.opentelemetry:opentelemetry-sdk-logs:${versions.opentelemetry}"
+  api "io.opentelemetry:opentelemetry-exporter-otlp:${versions.opentelemetry}"
+  api "io.opentelemetry:opentelemetry-exporter-common:${versions.opentelemetry}"
+  api "io.opentelemetry:opentelemetry-exporter-otlp-common:${versions.opentelemetry}"
+  runtimeOnly "org.jetbrains.kotlin:kotlin-stdlib:${versions.kotlin}"
+  runtimeOnly "com.squareup.okhttp3:okhttp:4.11.0"
+  runtimeOnly "com.squareup.okio:okio-jvm:3.5.0"
+  runtimeOnly "io.opentelemetry:opentelemetry-exporter-sender-okhttp:${versions.opentelemetry}"
+  api "io.opentelemetry:opentelemetry-extension-incubator:${versions.opentelemetry}-alpha"
   testImplementation "io.opentelemetry:opentelemetry-sdk-testing:${versions.opentelemetry}"
 }
 
@@ -44,31 +52,43 @@ thirdPartyAudit {
   )
 
   ignoreMissingClasses(
+    'android.net.http.X509TrustManagerExtensions',
+    'android.net.ssl.SSLSockets',
+    'android.os.Build$VERSION',
+    'android.security.NetworkSecurityPolicy',
+    'android.util.Log',
+    'com.google.common.io.ByteStreams',
+    'com.google.common.util.concurrent.ListenableFuture',
+    'io.grpc.CallOptions',
+    'io.grpc.Channel',
+    'io.grpc.Drainable',
+    'io.grpc.KnownLength',
+    'io.grpc.ManagedChannel',
+    'io.grpc.MethodDescriptor',
+    'io.grpc.MethodDescriptor$Builder',
+    'io.grpc.MethodDescriptor$Marshaller',
+    'io.grpc.MethodDescriptor$MethodType',
+    'io.grpc.stub.AbstractFutureStub',
+    'io.grpc.stub.AbstractStub',
+    'io.grpc.stub.ClientCalls',
+    'org.bouncycastle.jsse.BCSSLParameters',
+    'org.bouncycastle.jsse.BCSSLSocket',
+    'org.conscrypt.Conscrypt',
+    'org.conscrypt.Conscrypt$Version',
+    'org.conscrypt.ConscryptHostnameVerifier',
+    'org.openjsse.javax.net.ssl.SSLParameters',
+    'org.openjsse.javax.net.ssl.SSLSocket',
+    'io.opentelemetry.api.events.EventBuilder',
     'io.opentelemetry.api.events.EventEmitter',
     'io.opentelemetry.api.events.EventEmitterBuilder',
     'io.opentelemetry.api.events.EventEmitterProvider',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedDoubleHistogramBuilder',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedLongHistogramBuilder',
     'io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties',
     'io.opentelemetry.sdk.autoconfigure.spi.logs.ConfigurableLogRecordExporterProvider',
     'io.opentelemetry.sdk.autoconfigure.spi.metrics.ConfigurableMetricExporterProvider',
     'io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSpanExporterProvider',
-    'io.opentelemetry.extension.incubator.metrics.DoubleCounterAdviceConfigurer',
-    'io.opentelemetry.extension.incubator.metrics.DoubleGauge',
-    'io.opentelemetry.extension.incubator.metrics.DoubleGaugeAdviceConfigurer',
-    'io.opentelemetry.extension.incubator.metrics.DoubleHistogramAdviceConfigurer',
-    'io.opentelemetry.extension.incubator.metrics.DoubleUpDownCounterAdviceConfigurer',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedDoubleCounterBuilder',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedDoubleGaugeBuilder',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedDoubleUpDownCounterBuilder',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedLongCounterBuilder',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedLongGaugeBuilder',
-    'io.opentelemetry.extension.incubator.metrics.ExtendedLongUpDownCounterBuilder',
-    'io.opentelemetry.extension.incubator.metrics.LongCounterAdviceConfigurer',
-    'io.opentelemetry.extension.incubator.metrics.LongGauge',
-    'io.opentelemetry.extension.incubator.metrics.LongGaugeAdviceConfigurer',
-    'io.opentelemetry.extension.incubator.metrics.LongHistogramAdviceConfigurer',
-    'io.opentelemetry.extension.incubator.metrics.LongUpDownCounterAdviceConfigurer'
+    'kotlin.io.path.PathsKt',
+    'io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSpanExporterProvider',
+    'io.opentelemetry.sdk.autoconfigure.spi.internal.AutoConfigureListener'
   )
 }
 
diff --git a/plugins/telemetry-otel/config/telemetry-otel/log4j2.properties b/plugins/telemetry-otel/config/telemetry-otel/log4j2.properties
index 544f42bd5513b..8dec1119eec66 100644
--- a/plugins/telemetry-otel/config/telemetry-otel/log4j2.properties
+++ b/plugins/telemetry-otel/config/telemetry-otel/log4j2.properties
@@ -25,3 +25,23 @@ logger.exporter.name = io.opentelemetry.exporter.logging.LoggingSpanExporter
 logger.exporter.level = INFO
 logger.exporter.appenderRef.tracing.ref = tracing
 logger.exporter.additivity = false
+
+
+appender.metrics.type = RollingFile
+appender.metrics.name = metrics
+appender.metrics.fileName = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs.cluster_name}_otel_metrics.log
+appender.metrics.filePermissions = rw-r-----
+appender.metrics.layout.type = PatternLayout
+appender.metrics.layout.pattern = %m%n
+appender.metrics.filePattern = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs.cluster_name}_otel_metrics-%i.log.gz
+appender.metrics.policies.type = Policies
+appender.metrics.policies.size.type = SizeBasedTriggeringPolicy
+appender.metrics.policies.size.size = 1GB
+appender.metrics.strategy.type = DefaultRolloverStrategy
+appender.metrics.strategy.max = 4
+
+
+logger.metrics_exporter.name = io.opentelemetry.exporter.logging.LoggingMetricExporter
+logger.metrics_exporter.level = INFO
+logger.metrics_exporter.appenderRef.tracing.ref = metrics
+logger.metrics_exporter.additivity = false
diff --git a/plugins/telemetry-otel/licenses/kotlin-stdlib-1.7.10.jar.sha1 b/plugins/telemetry-otel/licenses/kotlin-stdlib-1.7.10.jar.sha1
new file mode 100644
index 0000000000000..4d119fbf4df70
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/kotlin-stdlib-1.7.10.jar.sha1
@@ -0,0 +1 @@
+d2abf9e77736acc4450dc4a3f707fa2c10f5099d
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/kotlin-stdlib-LICENSE.txt b/plugins/telemetry-otel/licenses/kotlin-stdlib-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/kotlin-stdlib-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/crypto-kms/licenses/reactive-streams-NOTICE.txt b/plugins/telemetry-otel/licenses/kotlin-stdlib-NOTICE.txt
similarity index 100%
rename from plugins/crypto-kms/licenses/reactive-streams-NOTICE.txt
rename to plugins/telemetry-otel/licenses/kotlin-stdlib-NOTICE.txt
diff --git a/plugins/telemetry-otel/licenses/okhttp-4.11.0.jar.sha1 b/plugins/telemetry-otel/licenses/okhttp-4.11.0.jar.sha1
new file mode 100644
index 0000000000000..1fc0db6615cb5
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/okhttp-4.11.0.jar.sha1
@@ -0,0 +1 @@
+436932d695b2c43f2c86b8111c596179cd133d56
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/okhttp-LICENSE.txt b/plugins/telemetry-otel/licenses/okhttp-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/okhttp-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/discovery-ec2/licenses/reactive-streams-NOTICE.txt b/plugins/telemetry-otel/licenses/okhttp-NOTICE.txt
similarity index 100%
rename from plugins/discovery-ec2/licenses/reactive-streams-NOTICE.txt
rename to plugins/telemetry-otel/licenses/okhttp-NOTICE.txt
diff --git a/plugins/telemetry-otel/licenses/okio-jvm-3.5.0.jar.sha1 b/plugins/telemetry-otel/licenses/okio-jvm-3.5.0.jar.sha1
new file mode 100644
index 0000000000000..7b19d32d872fa
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/okio-jvm-3.5.0.jar.sha1
@@ -0,0 +1 @@
+d6a0bc7343210eff7dd5cfdd6eb9b5f0036638ce
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/okio-jvm-LICENSE.txt b/plugins/telemetry-otel/licenses/okio-jvm-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/okio-jvm-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/repository-azure/licenses/reactive-streams-NOTICE.txt b/plugins/telemetry-otel/licenses/okio-jvm-NOTICE.txt
similarity index 100%
rename from plugins/repository-azure/licenses/reactive-streams-NOTICE.txt
rename to plugins/telemetry-otel/licenses/okio-jvm-NOTICE.txt
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-api-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-api-1.30.1.jar.sha1
deleted file mode 100644
index b0ce00e191830..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-api-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-a32dfbd7f01de6711fd0e970f8d4b4c0405056d6
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-api-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-api-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..2c038aad4b934
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-api-1.32.0.jar.sha1
@@ -0,0 +1 @@
+a5c081d8f877225732efe13908f350029c811709
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-context-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-context-1.30.1.jar.sha1
deleted file mode 100644
index 84cb60a2f7acb..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-context-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-58f665ff01ce6b964cdf0b8cb5cd1c196dfe94ce
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-context-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-context-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..3243f524432eb
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-context-1.32.0.jar.sha1
@@ -0,0 +1 @@
+c5f8bb68084ea5709a27e935907b1bb49d0bd049
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-common-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-exporter-common-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..1d7da47286ae0
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-common-1.32.0.jar.sha1
@@ -0,0 +1 @@
+3643061da474061ffa7f2036a58a7a0d40212276
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-common-LICENSE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-common-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-common-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/repository-s3/licenses/reactive-streams-NOTICE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-common-NOTICE.txt
similarity index 100%
rename from plugins/repository-s3/licenses/reactive-streams-NOTICE.txt
rename to plugins/telemetry-otel/licenses/opentelemetry-exporter-common-NOTICE.txt
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-logging-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-exporter-logging-1.30.1.jar.sha1
deleted file mode 100644
index 40537a399ab14..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-exporter-logging-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-58f1a09e89955e6145babf8bcdf80c95174eb817
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-logging-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-exporter-logging-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..3fab0e47adcbe
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-logging-1.32.0.jar.sha1
@@ -0,0 +1 @@
+ab56c7223112fac13a66e3f667c5fc666f4a3707
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..f93cf7a63bfad
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-1.32.0.jar.sha1
@@ -0,0 +1 @@
+5752d171cd08ac84f9273258a315bc5f97e1187e
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-LICENSE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/protobuf-java-NOTICE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-NOTICE.txt
similarity index 100%
rename from protobuf-java-NOTICE.txt
rename to plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-NOTICE.txt
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..2fc33b62aee54
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-1.32.0.jar.sha1
@@ -0,0 +1 @@
+6b41cd66a385d513b58b6617f20b701435b64abd
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-LICENSE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-NOTICE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-otlp-common-NOTICE.txt
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..99f758b047aa2
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-1.32.0.jar.sha1
@@ -0,0 +1 @@
+9346006cead763247a786b5cabf3e1ae3c88eadb
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-LICENSE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-LICENSE.txt
new file mode 100644
index 0000000000000..6b0b1270ff0ca
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-LICENSE.txt
@@ -0,0 +1,203 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-NOTICE.txt b/plugins/telemetry-otel/licenses/opentelemetry-exporter-sender-okhttp-NOTICE.txt
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-1.32.0-alpha.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-1.32.0-alpha.jar.sha1
new file mode 100644
index 0000000000000..705a342a684c4
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-1.32.0-alpha.jar.sha1
@@ -0,0 +1 @@
+fab56e187e3fb3c70c18223184d53a76500114ab
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-LICENSE.txt b/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-NOTICE.txt b/plugins/telemetry-otel/licenses/opentelemetry-extension-incubator-NOTICE.txt
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-1.30.1.jar.sha1
deleted file mode 100644
index d425ed61cc4cd..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-sdk-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4d15a9ea26e8e6ea93287a9f4ee02d91e5a74392
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..31818695cc774
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-sdk-1.32.0.jar.sha1
@@ -0,0 +1 @@
+504de8cc7dc68e84c8c7c2757522d934e9c50d35
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-common-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-common-1.30.1.jar.sha1
deleted file mode 100644
index 6b32d98b0f7c7..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-sdk-common-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-8e437ba87004bb63069d04fb06beae65b98dd13a
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-common-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-common-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..3cf3080a98bd9
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-sdk-common-1.32.0.jar.sha1
@@ -0,0 +1 @@
+454c7a6afab864de9f0c166246f28f16aaa824c1
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-logs-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-logs-1.30.1.jar.sha1
deleted file mode 100644
index 13ef6de11e82d..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-sdk-logs-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-5985d0950746ad12b49cc42c063f26ddfbcaaacb
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-logs-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-logs-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..41b0dca07556e
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-sdk-logs-1.32.0.jar.sha1
@@ -0,0 +1 @@
+b054760243906af0a327a8f5bd99adc2826ccd88
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-metrics-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-metrics-1.30.1.jar.sha1
deleted file mode 100644
index fc5aad9c9011e..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-sdk-metrics-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-b12825541c5dae52a0fb35045c1b36df3ca8f632
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-metrics-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-metrics-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..2f71fd5cc780a
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-sdk-metrics-1.32.0.jar.sha1
@@ -0,0 +1 @@
+bff24f085193e105d4e23e3db27bf81ccb3d830e
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-trace-1.30.1.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-trace-1.30.1.jar.sha1
deleted file mode 100644
index ac522b765da05..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-sdk-trace-1.30.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4c5531fbc44178a7bcfeb7021ae80e70a7c43458
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-sdk-trace-1.32.0.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-sdk-trace-1.32.0.jar.sha1
new file mode 100644
index 0000000000000..f0060b8a0f78f
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-sdk-trace-1.32.0.jar.sha1
@@ -0,0 +1 @@
+d80ad3210fa890a856a1d04379d134ab44a09501
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-semconv-1.23.1-alpha.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-semconv-1.23.1-alpha.jar.sha1
new file mode 100644
index 0000000000000..e730c83af905e
--- /dev/null
+++ b/plugins/telemetry-otel/licenses/opentelemetry-semconv-1.23.1-alpha.jar.sha1
@@ -0,0 +1 @@
+218e361772670212a46be5940010222d68e66f2a
\ No newline at end of file
diff --git a/plugins/telemetry-otel/licenses/opentelemetry-semconv-1.30.1-alpha.jar.sha1 b/plugins/telemetry-otel/licenses/opentelemetry-semconv-1.30.1-alpha.jar.sha1
deleted file mode 100644
index 089a2484dd1d5..0000000000000
--- a/plugins/telemetry-otel/licenses/opentelemetry-semconv-1.30.1-alpha.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-8e8f7a97a4896a81846553275b9d61885be7ef50
\ No newline at end of file
diff --git a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/IntegrationTestOTelTelemetryPlugin.java b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/IntegrationTestOTelTelemetryPlugin.java
similarity index 85%
rename from plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/IntegrationTestOTelTelemetryPlugin.java
rename to plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/IntegrationTestOTelTelemetryPlugin.java
index ed4d13f3abb7d..45caf8bf5f60b 100644
--- a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/IntegrationTestOTelTelemetryPlugin.java
+++ b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/IntegrationTestOTelTelemetryPlugin.java
@@ -6,12 +6,9 @@
  * compatible open source license.
  */
 
-package org.opensearch.telemetry.tracing;
+package org.opensearch.telemetry;
 
 import org.opensearch.common.settings.Settings;
-import org.opensearch.telemetry.OTelTelemetryPlugin;
-import org.opensearch.telemetry.Telemetry;
-import org.opensearch.telemetry.TelemetrySettings;
 
 import java.util.Optional;
 
diff --git a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/InMemorySingletonMetricsExporter.java b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/InMemorySingletonMetricsExporter.java
new file mode 100644
index 0000000000000..74fc872cb30e3
--- /dev/null
+++ b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/InMemorySingletonMetricsExporter.java
@@ -0,0 +1,65 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import java.util.Collection;
+import java.util.List;
+
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.metrics.InstrumentType;
+import io.opentelemetry.sdk.metrics.data.AggregationTemporality;
+import io.opentelemetry.sdk.metrics.data.MetricData;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+import io.opentelemetry.sdk.testing.exporter.InMemoryMetricExporter;
+
+public class InMemorySingletonMetricsExporter implements MetricExporter {
+
+    public static final InMemorySingletonMetricsExporter INSTANCE = new InMemorySingletonMetricsExporter(InMemoryMetricExporter.create());
+
+    private static InMemoryMetricExporter delegate;
+
+    public static InMemorySingletonMetricsExporter create() {
+        return INSTANCE;
+    }
+
+    private InMemorySingletonMetricsExporter(InMemoryMetricExporter delegate) {
+        InMemorySingletonMetricsExporter.delegate = delegate;
+    }
+
+    @Override
+    public CompletableResultCode export(Collection<MetricData> metrics) {
+        return delegate.export(metrics);
+    }
+
+    @Override
+    public CompletableResultCode flush() {
+        return delegate.flush();
+    }
+
+    @Override
+    public CompletableResultCode shutdown() {
+        return delegate.shutdown();
+    }
+
+    public List<MetricData> getFinishedMetricItems() {
+        return delegate.getFinishedMetricItems();
+    }
+
+    /**
+     * Clears the state.
+     */
+    public void reset() {
+        delegate.reset();
+    }
+
+    @Override
+    public AggregationTemporality getAggregationTemporality(InstrumentType instrumentType) {
+        return delegate.getAggregationTemporality(instrumentType);
+    }
+}
diff --git a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/TelemetryMetricsDisabledSanityIT.java b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/TelemetryMetricsDisabledSanityIT.java
new file mode 100644
index 0000000000000..bcdcb657c4f42
--- /dev/null
+++ b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/TelemetryMetricsDisabledSanityIT.java
@@ -0,0 +1,62 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.telemetry.IntegrationTestOTelTelemetryPlugin;
+import org.opensearch.telemetry.OTelTelemetrySettings;
+import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.noop.NoopCounter;
+import org.opensearch.telemetry.metrics.noop.NoopMetricsRegistry;
+import org.opensearch.test.OpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, minNumDataNodes = 1)
+public class TelemetryMetricsDisabledSanityIT extends OpenSearchIntegTestCase {
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder()
+            .put(super.nodeSettings(nodeOrdinal))
+            .put(TelemetrySettings.METRICS_FEATURE_ENABLED_SETTING.getKey(), false)
+            .put(
+                OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.getKey(),
+                "org.opensearch.telemetry.metrics.InMemorySingletonMetricsExporter"
+            )
+            .put(TelemetrySettings.METRICS_PUBLISH_INTERVAL_SETTING.getKey(), TimeValue.timeValueSeconds(1))
+            .build();
+    }
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Arrays.asList(IntegrationTestOTelTelemetryPlugin.class);
+    }
+
+    @Override
+    protected boolean addMockTelemetryPlugin() {
+        return false;
+    }
+
+    public void testSanityChecksWhenMetricsDisabled() throws Exception {
+        MetricsRegistry metricsRegistry = internalCluster().getInstance(MetricsRegistry.class);
+
+        Counter counter = metricsRegistry.createCounter("test-counter", "test", "1");
+        counter.add(1.0);
+
+        Thread.sleep(2000);
+
+        assertTrue(metricsRegistry instanceof NoopMetricsRegistry);
+        assertTrue(counter instanceof NoopCounter);
+    }
+
+}
diff --git a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/TelemetryMetricsEnabledSanityIT.java b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/TelemetryMetricsEnabledSanityIT.java
new file mode 100644
index 0000000000000..ed341595d327d
--- /dev/null
+++ b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/metrics/TelemetryMetricsEnabledSanityIT.java
@@ -0,0 +1,99 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.telemetry.IntegrationTestOTelTelemetryPlugin;
+import org.opensearch.telemetry.OTelTelemetrySettings;
+import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.junit.After;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+import io.opentelemetry.sdk.metrics.data.DoublePointData;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE, minNumDataNodes = 1)
+public class TelemetryMetricsEnabledSanityIT extends OpenSearchIntegTestCase {
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder()
+            .put(super.nodeSettings(nodeOrdinal))
+            .put(TelemetrySettings.METRICS_FEATURE_ENABLED_SETTING.getKey(), true)
+            .put(
+                OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.getKey(),
+                "org.opensearch.telemetry.metrics.InMemorySingletonMetricsExporter"
+            )
+            .put(TelemetrySettings.METRICS_PUBLISH_INTERVAL_SETTING.getKey(), TimeValue.timeValueSeconds(1))
+            .build();
+    }
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Arrays.asList(IntegrationTestOTelTelemetryPlugin.class);
+    }
+
+    @Override
+    protected boolean addMockTelemetryPlugin() {
+        return false;
+    }
+
+    public void testCounter() throws Exception {
+        MetricsRegistry metricsRegistry = internalCluster().getInstance(MetricsRegistry.class);
+        InMemorySingletonMetricsExporter.INSTANCE.reset();
+
+        Counter counter = metricsRegistry.createCounter("test-counter", "test", "1");
+        counter.add(1.0);
+        // Sleep for about 2s to wait for metrics to be published.
+        Thread.sleep(2000);
+
+        InMemorySingletonMetricsExporter exporter = InMemorySingletonMetricsExporter.INSTANCE;
+        double value = ((DoublePointData) ((ArrayList) exporter.getFinishedMetricItems()
+            .stream()
+            .filter(a -> a.getName().equals("test-counter"))
+            .collect(Collectors.toList())
+            .get(0)
+            .getDoubleSumData()
+            .getPoints()).get(0)).getValue();
+        assertEquals(1.0, value, 0.0);
+    }
+
+    public void testUpDownCounter() throws Exception {
+
+        MetricsRegistry metricsRegistry = internalCluster().getInstance(MetricsRegistry.class);
+        InMemorySingletonMetricsExporter.INSTANCE.reset();
+
+        Counter counter = metricsRegistry.createUpDownCounter("test-up-down-counter", "test", "1");
+        counter.add(1.0);
+        counter.add(-2.0);
+        // Sleep for about 2s to wait for metrics to be published.
+        Thread.sleep(2000);
+
+        InMemorySingletonMetricsExporter exporter = InMemorySingletonMetricsExporter.INSTANCE;
+        double value = ((DoublePointData) ((ArrayList) exporter.getFinishedMetricItems()
+            .stream()
+            .filter(a -> a.getName().equals("test-up-down-counter"))
+            .collect(Collectors.toList())
+            .get(0)
+            .getDoubleSumData()
+            .getPoints()).get(0)).getValue();
+        assertEquals(-1.0, value, 0.0);
+    }
+
+    @After
+    public void reset() {
+        InMemorySingletonMetricsExporter.INSTANCE.reset();
+    }
+}
diff --git a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerDisabledSanityIT.java b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerDisabledSanityIT.java
index 949a58f6cab41..45ed140e1be94 100644
--- a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerDisabledSanityIT.java
+++ b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerDisabledSanityIT.java
@@ -12,6 +12,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.plugins.Plugin;
+import org.opensearch.telemetry.IntegrationTestOTelTelemetryPlugin;
 import org.opensearch.telemetry.OTelTelemetrySettings;
 import org.opensearch.telemetry.TelemetrySettings;
 import org.opensearch.test.OpenSearchIntegTestCase;
diff --git a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerEnabledSanityIT.java b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerEnabledSanityIT.java
index 2d0111e64faad..156dc344d1ae2 100644
--- a/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerEnabledSanityIT.java
+++ b/plugins/telemetry-otel/src/internalClusterTest/java/org/opensearch/telemetry/tracing/TelemetryTracerEnabledSanityIT.java
@@ -12,6 +12,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.plugins.Plugin;
+import org.opensearch.telemetry.IntegrationTestOTelTelemetryPlugin;
 import org.opensearch.telemetry.OTelTelemetrySettings;
 import org.opensearch.telemetry.TelemetrySettings;
 import org.opensearch.telemetry.tracing.attributes.Attributes;
@@ -60,20 +61,22 @@ public void testSanityChecksWhenTracingEnabled() throws Exception {
 
         // Create Index and ingest data
         String indexName = "test-index-11";
-        Settings basicSettings = Settings.builder().put("number_of_shards", 3).put("number_of_replicas", 0).build();
+        Settings basicSettings = Settings.builder()
+            .put("number_of_shards", 2)
+            .put("number_of_replicas", 0)
+            .put("index.routing.allocation.total_shards_per_node", 1)
+            .build();
         createIndex(indexName, basicSettings);
-        indexRandom(true, client.prepareIndex(indexName).setId("1").setSource("field1", "the fox jumps in the well"));
-        indexRandom(true, client.prepareIndex(indexName).setId("1").setSource("field2", "another fox did the same."));
+
+        indexRandom(false, client.prepareIndex(indexName).setId("1").setSource("field1", "the fox jumps in the well"));
+        indexRandom(false, client.prepareIndex(indexName).setId("2").setSource("field2", "another fox did the same."));
 
         ensureGreen();
         refresh();
 
         // Make the search calls; adding the searchType and PreFilterShardSize to make the query path predictable across all the runs.
-        client.prepareSearch().setSearchType("query_then_fetch").setPreFilterShardSize(3).setQuery(queryStringQuery("fox")).get();
-        client.prepareSearch().setSearchType("query_then_fetch").setPreFilterShardSize(3).setQuery(queryStringQuery("jumps")).get();
-
-        ensureGreen();
-        refresh();
+        client.prepareSearch().setSearchType("dfs_query_then_fetch").setPreFilterShardSize(2).setQuery(queryStringQuery("fox")).get();
+        client.prepareSearch().setSearchType("dfs_query_then_fetch").setPreFilterShardSize(2).setQuery(queryStringQuery("jumps")).get();
 
         // Sleep for about 3s to wait for traces are published, delay is (the delay is 1s).
         Thread.sleep(3000);
@@ -87,10 +90,10 @@ public void testSanityChecksWhenTracingEnabled() throws Exception {
             )
         );
 
+        // See please https://github.com/opensearch-project/OpenSearch/issues/10291 till local transport is not instrumented,
+        // capturing only the inter-nodes transport actions.
         InMemorySingletonSpanExporter exporter = InMemorySingletonSpanExporter.INSTANCE;
-        if (!exporter.getFinishedSpanItems().isEmpty()) {
-            validators.validate(exporter.getFinishedSpanItems(), 2);
-        }
+        validators.validate(exporter.getFinishedSpanItems(), 4);
     }
 
     private static void updateTelemetrySetting(Client client, boolean value) {
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelAttributesConverter.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelAttributesConverter.java
similarity index 71%
rename from plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelAttributesConverter.java
rename to plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelAttributesConverter.java
index 4d0966e6b5185..98d265e92ba3c 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelAttributesConverter.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelAttributesConverter.java
@@ -6,7 +6,9 @@
  * compatible open source license.
  */
 
-package org.opensearch.telemetry.tracing;
+package org.opensearch.telemetry;
+
+import org.opensearch.telemetry.metrics.tags.Tags;
 
 import java.util.Locale;
 
@@ -16,7 +18,7 @@
 /**
  * Converts {@link org.opensearch.telemetry.tracing.attributes.Attributes} to OTel {@link Attributes}
  */
-final class OTelAttributesConverter {
+public final class OTelAttributesConverter {
 
     /**
      * Constructor.
@@ -28,7 +30,7 @@ private OTelAttributesConverter() {}
      * @param attributes attributes
      * @return otel attributes.
      */
-    static Attributes convert(org.opensearch.telemetry.tracing.attributes.Attributes attributes) {
+    public static Attributes convert(org.opensearch.telemetry.tracing.attributes.Attributes attributes) {
         AttributesBuilder attributesBuilder = Attributes.builder();
         if (attributes != null) {
             attributes.getAttributesMap().forEach((x, y) -> addSpanAttribute(x, y, attributesBuilder));
@@ -49,4 +51,17 @@ private static void addSpanAttribute(String key, Object value, AttributesBuilder
             throw new IllegalArgumentException(String.format(Locale.ROOT, "Span attribute value %s type not supported", value));
         }
     }
+
+    /**
+     * Attribute converter.
+     * @param tags attributes
+     * @return otel attributes.
+     */
+    public static Attributes convert(Tags tags) {
+        AttributesBuilder attributesBuilder = Attributes.builder();
+        if (tags != null) {
+            tags.getTagsMap().forEach((x, y) -> addSpanAttribute(x, y, attributesBuilder));
+        }
+        return attributesBuilder.build();
+    }
 }
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetryPlugin.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetryPlugin.java
index 1af88196e3727..297ae8873636f 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetryPlugin.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetryPlugin.java
@@ -8,28 +8,36 @@
 
 package org.opensearch.telemetry;
 
+import org.opensearch.common.concurrent.RefCountedReleasable;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.plugins.TelemetryPlugin;
-import org.opensearch.telemetry.metrics.MetricsTelemetry;
 import org.opensearch.telemetry.tracing.OTelResourceProvider;
 import org.opensearch.telemetry.tracing.OTelTelemetry;
-import org.opensearch.telemetry.tracing.OTelTracingTelemetry;
 
 import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
 
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+
 /**
  * Telemetry plugin based on Otel
  */
 public class OTelTelemetryPlugin extends Plugin implements TelemetryPlugin {
 
+    /**
+     * Instrumentation scope name.
+     */
+    public static final String INSTRUMENTATION_SCOPE_NAME = "org.opensearch.telemetry";
+
     static final String OTEL_TRACER_NAME = "otel";
 
     private final Settings settings;
 
+    private RefCountedReleasable<OpenTelemetrySdk> refCountedOpenTelemetry;
+
     /**
      * Creates Otel plugin
      * @param settings cluster settings
@@ -44,23 +52,39 @@ public List<Setting<?>> getSettings() {
             OTelTelemetrySettings.TRACER_EXPORTER_BATCH_SIZE_SETTING,
             OTelTelemetrySettings.TRACER_EXPORTER_DELAY_SETTING,
             OTelTelemetrySettings.TRACER_EXPORTER_MAX_QUEUE_SIZE_SETTING,
-            OTelTelemetrySettings.OTEL_TRACER_SPAN_EXPORTER_CLASS_SETTING
+            OTelTelemetrySettings.OTEL_TRACER_SPAN_EXPORTER_CLASS_SETTING,
+            OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING
         );
     }
 
     @Override
     public Optional<Telemetry> getTelemetry(TelemetrySettings telemetrySettings) {
+        initializeOpenTelemetrySdk(telemetrySettings);
         return Optional.of(telemetry(telemetrySettings));
     }
 
+    private void initializeOpenTelemetrySdk(TelemetrySettings telemetrySettings) {
+        if (refCountedOpenTelemetry != null) {
+            return;
+        }
+        OpenTelemetrySdk openTelemetrySdk = OTelResourceProvider.get(telemetrySettings, settings);
+        refCountedOpenTelemetry = new RefCountedReleasable<>("openTelemetry", openTelemetrySdk, openTelemetrySdk::close);
+    }
+
     @Override
     public String getName() {
         return OTEL_TRACER_NAME;
     }
 
     private Telemetry telemetry(TelemetrySettings telemetrySettings) {
-        return new OTelTelemetry(new OTelTracingTelemetry(OTelResourceProvider.get(telemetrySettings, settings)), new MetricsTelemetry() {
-        });
+        return new OTelTelemetry(refCountedOpenTelemetry);
+    }
+
+    @Override
+    public void close() {
+        if (refCountedOpenTelemetry != null) {
+            refCountedOpenTelemetry.close();
+        }
     }
 
 }
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetrySettings.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetrySettings.java
index 59c87cca22986..8e23f724b4570 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetrySettings.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/OTelTelemetrySettings.java
@@ -11,13 +11,16 @@
 import org.opensearch.SpecialPermission;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.telemetry.metrics.exporter.OTelMetricsExporterFactory;
 import org.opensearch.telemetry.tracing.exporter.OTelSpanExporterFactory;
 
 import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
 
+import io.opentelemetry.exporter.logging.LoggingMetricExporter;
 import io.opentelemetry.exporter.logging.LoggingSpanExporter;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
 
 /**
@@ -83,4 +86,28 @@ private OTelTelemetrySettings() {}
         Setting.Property.NodeScope,
         Setting.Property.Final
     );
+
+    /**
+     * Metrics Exporter type setting.
+     */
+    @SuppressWarnings("unchecked")
+    public static final Setting<Class<MetricExporter>> OTEL_METRICS_EXPORTER_CLASS_SETTING = new Setting<>(
+        "telemetry.otel.metrics.exporter.class",
+        LoggingMetricExporter.class.getName(),
+        className -> {
+            // Check we ourselves are not being called by unprivileged code.
+            SpecialPermission.check();
+
+            try {
+                return AccessController.doPrivileged((PrivilegedExceptionAction<Class<MetricExporter>>) () -> {
+                    final ClassLoader loader = OTelMetricsExporterFactory.class.getClassLoader();
+                    return (Class<MetricExporter>) loader.loadClass(className);
+                });
+            } catch (PrivilegedActionException ex) {
+                throw new IllegalStateException("Unable to load span exporter class:" + className, ex.getCause());
+            }
+        },
+        Setting.Property.NodeScope,
+        Setting.Property.Final
+    );
 }
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelCounter.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelCounter.java
new file mode 100644
index 0000000000000..b72f63e027243
--- /dev/null
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelCounter.java
@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.telemetry.OTelAttributesConverter;
+import org.opensearch.telemetry.metrics.tags.Tags;
+
+import io.opentelemetry.api.metrics.DoubleCounter;
+
+/**
+ * OTel Counter
+ */
+class OTelCounter implements Counter {
+
+    private final DoubleCounter otelDoubleCounter;
+
+    /**
+     * Constructor
+     * @param otelDoubleCounter delegate counter.
+     */
+    public OTelCounter(DoubleCounter otelDoubleCounter) {
+        this.otelDoubleCounter = otelDoubleCounter;
+    }
+
+    @Override
+    public void add(double value) {
+        otelDoubleCounter.add(value);
+    }
+
+    @Override
+    public void add(double value, Tags tags) {
+        otelDoubleCounter.add(value, OTelAttributesConverter.convert(tags));
+    }
+}
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelMetricsTelemetry.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelMetricsTelemetry.java
new file mode 100644
index 0000000000000..6160e5106c041
--- /dev/null
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelMetricsTelemetry.java
@@ -0,0 +1,74 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.concurrent.RefCountedReleasable;
+import org.opensearch.telemetry.OTelTelemetryPlugin;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+
+import io.opentelemetry.api.metrics.DoubleCounter;
+import io.opentelemetry.api.metrics.DoubleUpDownCounter;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.metrics.MeterProvider;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+
+/**
+ * OTel implementation for {@link MetricsTelemetry}
+ */
+public class OTelMetricsTelemetry<T extends MeterProvider & Closeable> implements MetricsTelemetry {
+    private final RefCountedReleasable<OpenTelemetrySdk> refCountedOpenTelemetry;
+    private final Meter otelMeter;
+    private final T meterProvider;
+
+    /**
+     * Creates OTel based {@link MetricsTelemetry}.
+     * @param openTelemetry open telemetry.
+     * @param meterProvider {@link MeterProvider} instance
+     */
+    public OTelMetricsTelemetry(RefCountedReleasable<OpenTelemetrySdk> openTelemetry, T meterProvider) {
+        this.refCountedOpenTelemetry = openTelemetry;
+        this.refCountedOpenTelemetry.incRef();
+        this.meterProvider = meterProvider;
+        this.otelMeter = meterProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME);
+    }
+
+    @Override
+    public Counter createCounter(String name, String description, String unit) {
+        DoubleCounter doubleCounter = AccessController.doPrivileged(
+            (PrivilegedAction<DoubleCounter>) () -> otelMeter.counterBuilder(name)
+                .setUnit(unit)
+                .setDescription(description)
+                .ofDoubles()
+                .build()
+        );
+        return new OTelCounter(doubleCounter);
+    }
+
+    @Override
+    public Counter createUpDownCounter(String name, String description, String unit) {
+        DoubleUpDownCounter doubleUpDownCounter = AccessController.doPrivileged(
+            (PrivilegedAction<DoubleUpDownCounter>) () -> otelMeter.upDownCounterBuilder(name)
+                .setUnit(unit)
+                .setDescription(description)
+                .ofDoubles()
+                .build()
+        );
+        return new OTelUpDownCounter(doubleUpDownCounter);
+    }
+
+    @Override
+    public void close() throws IOException {
+        meterProvider.close();
+        refCountedOpenTelemetry.close();
+    }
+}
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelUpDownCounter.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelUpDownCounter.java
new file mode 100644
index 0000000000000..2f40881996f7e
--- /dev/null
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/OTelUpDownCounter.java
@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.telemetry.OTelAttributesConverter;
+import org.opensearch.telemetry.metrics.tags.Tags;
+
+import io.opentelemetry.api.metrics.DoubleUpDownCounter;
+
+/**
+ * OTel Counter
+ */
+public class OTelUpDownCounter implements Counter {
+
+    private final DoubleUpDownCounter doubleUpDownCounter;
+
+    /**
+     * Constructor
+     * @param doubleUpDownCounter delegate counter.
+     */
+    public OTelUpDownCounter(DoubleUpDownCounter doubleUpDownCounter) {
+        this.doubleUpDownCounter = doubleUpDownCounter;
+    }
+
+    @Override
+    public void add(double value) {
+        doubleUpDownCounter.add(value);
+    }
+
+    @Override
+    public void add(double value, Tags tags) {
+        doubleUpDownCounter.add(value, OTelAttributesConverter.convert(tags));
+    }
+}
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/exporter/OTelMetricsExporterFactory.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/exporter/OTelMetricsExporterFactory.java
new file mode 100644
index 0000000000000..ef5a31e4003ca
--- /dev/null
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/exporter/OTelMetricsExporterFactory.java
@@ -0,0 +1,90 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics.exporter;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.SpecialPermission;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.telemetry.OTelTelemetrySettings;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.lang.reflect.Method;
+import java.security.AccessController;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+
+/**
+ * Factory class to create the {@link MetricExporter} instance.
+ */
+public class OTelMetricsExporterFactory {
+
+    private static final Logger logger = LogManager.getLogger(OTelMetricsExporterFactory.class);
+
+    /**
+     * Base constructor.
+     */
+    private OTelMetricsExporterFactory() {
+
+    }
+
+    /**
+     * Creates the {@link MetricExporter} instances based on the OTEL_METRIC_EXPORTER_CLASS_SETTING value.
+     * As of now, it expects the MetricExporter implementations to have a create factory method to instantiate the
+     * MetricExporter.
+     * @param settings settings.
+     * @return MetricExporter instance.
+     */
+    public static MetricExporter create(Settings settings) {
+        Class<MetricExporter> MetricExporterProviderClass = OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.get(settings);
+        MetricExporter metricExporter = instantiateExporter(MetricExporterProviderClass);
+        logger.info("Successfully instantiated the Metrics MetricExporter class {}", MetricExporterProviderClass);
+        return metricExporter;
+    }
+
+    private static MetricExporter instantiateExporter(Class<MetricExporter> exporterProviderClass) {
+        try {
+            // Check we ourselves are not being called by unprivileged code.
+            SpecialPermission.check();
+            return AccessController.doPrivileged((PrivilegedExceptionAction<MetricExporter>) () -> {
+                String methodName = "create";
+                String getDefaultMethod = "getDefault";
+                for (Method m : exporterProviderClass.getMethods()) {
+                    if (m.getName().equals(getDefaultMethod)) {
+                        methodName = getDefaultMethod;
+                        break;
+                    }
+                }
+                try {
+                    return (MetricExporter) MethodHandles.publicLookup()
+                        .findStatic(exporterProviderClass, methodName, MethodType.methodType(exporterProviderClass))
+                        .asType(MethodType.methodType(MetricExporter.class))
+                        .invokeExact();
+                } catch (Throwable e) {
+                    if (e.getCause() instanceof NoSuchMethodException) {
+                        throw new IllegalStateException("No create factory method exist in [" + exporterProviderClass.getName() + "]");
+                    } else {
+                        throw new IllegalStateException(
+                            "MetricExporter instantiation failed for class [" + exporterProviderClass.getName() + "]",
+                            e.getCause()
+                        );
+                    }
+                }
+            });
+        } catch (PrivilegedActionException ex) {
+            throw new IllegalStateException(
+                "MetricExporter instantiation failed for class [" + exporterProviderClass.getName() + "]",
+                ex.getCause()
+            );
+        }
+    }
+}
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/exporter/package-info.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/exporter/package-info.java
new file mode 100644
index 0000000000000..b48ec3e2336c4
--- /dev/null
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/exporter/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains classes needed for tracing requests.
+ */
+package org.opensearch.telemetry.metrics.exporter;
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/package-info.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/package-info.java
new file mode 100644
index 0000000000000..803c159eb201a
--- /dev/null
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/metrics/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains classes needed for tracing requests.
+ */
+package org.opensearch.telemetry.metrics;
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java
index b395a335a4d83..14a19f122c17b 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java
@@ -10,23 +10,27 @@
 
 import org.opensearch.common.settings.Settings;
 import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.exporter.OTelMetricsExporterFactory;
 import org.opensearch.telemetry.tracing.exporter.OTelSpanExporterFactory;
 import org.opensearch.telemetry.tracing.sampler.ProbabilisticSampler;
 import org.opensearch.telemetry.tracing.sampler.RequestSampler;
 
+import java.security.AccessController;
+import java.security.PrivilegedAction;
 import java.util.concurrent.TimeUnit;
 
-import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.trace.propagation.W3CTraceContextPropagator;
 import io.opentelemetry.context.propagation.ContextPropagators;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.metrics.SdkMeterProvider;
+import io.opentelemetry.sdk.metrics.export.PeriodicMetricReader;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.trace.SdkTracerProvider;
 import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
 import io.opentelemetry.sdk.trace.samplers.Sampler;
-import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;
+import io.opentelemetry.semconv.ResourceAttributes;
 
 import static org.opensearch.telemetry.OTelTelemetrySettings.TRACER_EXPORTER_BATCH_SIZE_SETTING;
 import static org.opensearch.telemetry.OTelTelemetrySettings.TRACER_EXPORTER_DELAY_SETTING;
@@ -42,14 +46,16 @@ private OTelResourceProvider() {}
      * Creates OpenTelemetry instance with default configuration
      * @param telemetrySettings telemetry settings
      * @param settings cluster settings
-     * @return OpenTelemetry instance
+     * @return OpenTelemetrySdk instance
      */
-    public static OpenTelemetry get(TelemetrySettings telemetrySettings, Settings settings) {
-        return get(
-            settings,
-            OTelSpanExporterFactory.create(settings),
-            ContextPropagators.create(W3CTraceContextPropagator.getInstance()),
-            Sampler.parentBased(new RequestSampler(new ProbabilisticSampler(telemetrySettings)))
+    public static OpenTelemetrySdk get(TelemetrySettings telemetrySettings, Settings settings) {
+        return AccessController.doPrivileged(
+            (PrivilegedAction<OpenTelemetrySdk>) () -> get(
+                settings,
+                OTelSpanExporterFactory.create(settings),
+                ContextPropagators.create(W3CTraceContextPropagator.getInstance()),
+                Sampler.parentBased(new RequestSampler(new ProbabilisticSampler(telemetrySettings)))
+            )
         );
     }
 
@@ -59,17 +65,46 @@ public static OpenTelemetry get(TelemetrySettings telemetrySettings, Settings se
      * @param spanExporter span exporter instance
      * @param contextPropagators context propagator instance
      * @param sampler sampler instance
-     * @return Opentelemetry instance
+     * @return OpenTelemetrySdk instance
      */
-    public static OpenTelemetry get(Settings settings, SpanExporter spanExporter, ContextPropagators contextPropagators, Sampler sampler) {
+    public static OpenTelemetrySdk get(
+        Settings settings,
+        SpanExporter spanExporter,
+        ContextPropagators contextPropagators,
+        Sampler sampler
+    ) {
         Resource resource = Resource.create(Attributes.of(ResourceAttributes.SERVICE_NAME, "OpenSearch"));
-        SdkTracerProvider sdkTracerProvider = SdkTracerProvider.builder()
+        SdkTracerProvider sdkTracerProvider = createSdkTracerProvider(settings, spanExporter, sampler, resource);
+        SdkMeterProvider sdkMeterProvider = createSdkMetricProvider(settings, resource);
+        return OpenTelemetrySdk.builder()
+            .setTracerProvider(sdkTracerProvider)
+            .setMeterProvider(sdkMeterProvider)
+            .setPropagators(contextPropagators)
+            .buildAndRegisterGlobal();
+    }
+
+    private static SdkMeterProvider createSdkMetricProvider(Settings settings, Resource resource) {
+        return SdkMeterProvider.builder()
+            .setResource(resource)
+            .registerMetricReader(
+                PeriodicMetricReader.builder(OTelMetricsExporterFactory.create(settings))
+                    .setInterval(TelemetrySettings.METRICS_PUBLISH_INTERVAL_SETTING.get(settings).getSeconds(), TimeUnit.SECONDS)
+                    .build()
+            )
+            .build();
+    }
+
+    private static SdkTracerProvider createSdkTracerProvider(
+        Settings settings,
+        SpanExporter spanExporter,
+        Sampler sampler,
+        Resource resource
+    ) {
+        return SdkTracerProvider.builder()
             .addSpanProcessor(spanProcessor(settings, spanExporter))
             .setResource(resource)
             .setSampler(sampler)
             .build();
-
-        return OpenTelemetrySdk.builder().setTracerProvider(sdkTracerProvider).setPropagators(contextPropagators).buildAndRegisterGlobal();
     }
 
     private static BatchSpanProcessor spanProcessor(Settings settings, SpanExporter spanExporter) {
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java
index 8ad03d807d9da..fc917968579e1 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java
@@ -57,7 +57,9 @@ public void addAttribute(String key, Boolean value) {
 
     @Override
     public void setError(Exception exception) {
-        delegateSpan.setStatus(StatusCode.ERROR, exception.getMessage());
+        if (exception != null) {
+            delegateSpan.setStatus(StatusCode.ERROR, exception.getMessage());
+        }
     }
 
     @Override
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpanKindConverter.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpanKindConverter.java
new file mode 100644
index 0000000000000..4edb837082126
--- /dev/null
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpanKindConverter.java
@@ -0,0 +1,43 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing;
+
+import io.opentelemetry.api.trace.SpanKind;
+
+/**
+ * Converts {@link org.opensearch.telemetry.tracing.SpanKind} to OTel {@link SpanKind}
+ */
+final class OTelSpanKindConverter {
+
+    /**
+     * Constructor.
+     */
+    private OTelSpanKindConverter() {}
+
+    /**
+     * SpanKind converter.
+     * @param spanKind span kind.
+     * @return otel attributes.
+     */
+    static SpanKind convert(org.opensearch.telemetry.tracing.SpanKind spanKind) {
+        if (spanKind == null) {
+            return SpanKind.INTERNAL;
+        } else {
+            switch (spanKind) {
+                case CLIENT:
+                    return SpanKind.CLIENT;
+                case SERVER:
+                    return SpanKind.SERVER;
+                case INTERNAL:
+                default:
+                    return SpanKind.INTERNAL;
+            }
+        }
+    }
+}
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTelemetry.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTelemetry.java
index 282fabd43346b..0c697d2cc5e8c 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTelemetry.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTelemetry.java
@@ -8,34 +8,39 @@
 
 package org.opensearch.telemetry.tracing;
 
+import org.opensearch.common.concurrent.RefCountedReleasable;
 import org.opensearch.telemetry.Telemetry;
 import org.opensearch.telemetry.metrics.MetricsTelemetry;
+import org.opensearch.telemetry.metrics.OTelMetricsTelemetry;
+
+import io.opentelemetry.sdk.OpenTelemetrySdk;
 
 /**
  * Otel implementation of Telemetry
  */
 public class OTelTelemetry implements Telemetry {
 
-    private final TracingTelemetry tracingTelemetry;
-    private final MetricsTelemetry metricsTelemetry;
+    private final RefCountedReleasable<OpenTelemetrySdk> refCountedOpenTelemetry;
 
     /**
      * Creates Telemetry instance
-     * @param tracingTelemetry tracing telemetry
-     * @param metricsTelemetry metrics telemetry
+
+     */
+    /**
+     * Creates Telemetry instance
+     * @param refCountedOpenTelemetry open telemetry.
      */
-    public OTelTelemetry(TracingTelemetry tracingTelemetry, MetricsTelemetry metricsTelemetry) {
-        this.tracingTelemetry = tracingTelemetry;
-        this.metricsTelemetry = metricsTelemetry;
+    public OTelTelemetry(RefCountedReleasable<OpenTelemetrySdk> refCountedOpenTelemetry) {
+        this.refCountedOpenTelemetry = refCountedOpenTelemetry;
     }
 
     @Override
     public TracingTelemetry getTracingTelemetry() {
-        return tracingTelemetry;
+        return new OTelTracingTelemetry<>(refCountedOpenTelemetry, refCountedOpenTelemetry.get().getSdkTracerProvider());
     }
 
     @Override
     public MetricsTelemetry getMetricsTelemetry() {
-        return metricsTelemetry;
+        return new OTelMetricsTelemetry<>(refCountedOpenTelemetry, refCountedOpenTelemetry.get().getSdkMeterProvider());
     }
 }
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagator.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagator.java
index f8fe885ee450c..0fb05a08c27bb 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagator.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagator.java
@@ -10,8 +10,8 @@
 
 import org.opensearch.core.common.Strings;
 
+import java.util.Collection;
 import java.util.Collections;
-import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.BiConsumer;
@@ -51,7 +51,7 @@ private static OTelPropagatedSpan getPropagatedSpan(Context context) {
     }
 
     @Override
-    public Optional<Span> extractFromHeaders(Map<String, List<String>> headers) {
+    public Optional<Span> extractFromHeaders(Map<String, Collection<String>> headers) {
         Context context = openTelemetry.getPropagators().getTextMapPropagator().extract(Context.current(), headers, HEADER_TEXT_MAP_GETTER);
         return Optional.ofNullable(getPropagatedSpan(context));
     }
@@ -87,9 +87,9 @@ public String get(Map<String, String> headers, String key) {
         }
     };
 
-    private static final TextMapGetter<Map<String, List<String>>> HEADER_TEXT_MAP_GETTER = new TextMapGetter<>() {
+    private static final TextMapGetter<Map<String, Collection<String>>> HEADER_TEXT_MAP_GETTER = new TextMapGetter<>() {
         @Override
-        public Iterable<String> keys(Map<String, List<String>> headers) {
+        public Iterable<String> keys(Map<String, Collection<String>> headers) {
             if (headers != null) {
                 return headers.keySet();
             } else {
@@ -98,7 +98,7 @@ public Iterable<String> keys(Map<String, List<String>> headers) {
         }
 
         @Override
-        public String get(Map<String, List<String>> headers, String key) {
+        public String get(Map<String, Collection<String>> headers, String key) {
             if (headers != null && headers.containsKey(key)) {
                 return Strings.collectionToCommaDelimitedString(headers.get(key));
             }
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingTelemetry.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingTelemetry.java
index ee2f17aabb7f9..af39617a8c744 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingTelemetry.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelTracingTelemetry.java
@@ -8,66 +8,76 @@
 
 package org.opensearch.telemetry.tracing;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
+import org.opensearch.common.concurrent.RefCountedReleasable;
+import org.opensearch.telemetry.OTelAttributesConverter;
+import org.opensearch.telemetry.OTelTelemetryPlugin;
 
 import java.io.Closeable;
 import java.io.IOException;
 
-import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.trace.TracerProvider;
 import io.opentelemetry.context.Context;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
 
 /**
  * OTel based Telemetry provider
  */
-public class OTelTracingTelemetry implements TracingTelemetry {
-
-    private static final Logger logger = LogManager.getLogger(OTelTracingTelemetry.class);
-    private final OpenTelemetry openTelemetry;
+public class OTelTracingTelemetry<T extends TracerProvider & Closeable> implements TracingTelemetry {
+    private final RefCountedReleasable<OpenTelemetrySdk> refCountedOpenTelemetry;
+    private final T tracerProvider;
     private final io.opentelemetry.api.trace.Tracer otelTracer;
 
     /**
-     * Creates OTel based Telemetry
-     * @param openTelemetry OpenTelemetry instance
+     * Creates OTel based {@link TracingTelemetry}
+     * @param refCountedOpenTelemetry OpenTelemetry instance
+     * @param tracerProvider {@link TracerProvider} instance.
      */
-    public OTelTracingTelemetry(OpenTelemetry openTelemetry) {
-        this.openTelemetry = openTelemetry;
-        this.otelTracer = openTelemetry.getTracer("os-tracer");
-
+    public OTelTracingTelemetry(RefCountedReleasable<OpenTelemetrySdk> refCountedOpenTelemetry, T tracerProvider) {
+        this.refCountedOpenTelemetry = refCountedOpenTelemetry;
+        this.refCountedOpenTelemetry.incRef();
+        this.tracerProvider = tracerProvider;
+        this.otelTracer = tracerProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME);
     }
 
     @Override
-    public void close() {
-        try {
-            ((Closeable) openTelemetry).close();
-        } catch (IOException e) {
-            logger.warn("Error while closing Opentelemetry", e);
-        }
+    public void close() throws IOException {
+        tracerProvider.close();
+        refCountedOpenTelemetry.close();
     }
 
     @Override
-    public Span createSpan(String spanName, Span parentSpan, Attributes attributes) {
-        return createOtelSpan(spanName, parentSpan, attributes);
+    public Span createSpan(SpanCreationContext spanCreationContext, Span parentSpan) {
+        return createOtelSpan(spanCreationContext, parentSpan);
     }
 
     @Override
     public TracingContextPropagator getContextPropagator() {
-        return new OTelTracingContextPropagator(openTelemetry);
+        return new OTelTracingContextPropagator(refCountedOpenTelemetry.get());
     }
 
-    private Span createOtelSpan(String spanName, Span parentSpan, Attributes attributes) {
-        io.opentelemetry.api.trace.Span otelSpan = otelSpan(spanName, parentSpan, OTelAttributesConverter.convert(attributes));
-        Span newSpan = new OTelSpan(spanName, otelSpan, parentSpan);
+    private Span createOtelSpan(SpanCreationContext spanCreationContext, Span parentSpan) {
+        io.opentelemetry.api.trace.Span otelSpan = otelSpan(
+            spanCreationContext.getSpanName(),
+            parentSpan,
+            OTelAttributesConverter.convert(spanCreationContext.getAttributes()),
+            OTelSpanKindConverter.convert(spanCreationContext.getSpanKind())
+        );
+        Span newSpan = new OTelSpan(spanCreationContext.getSpanName(), otelSpan, parentSpan);
         return newSpan;
     }
 
-    io.opentelemetry.api.trace.Span otelSpan(String spanName, Span parentOTelSpan, io.opentelemetry.api.common.Attributes attributes) {
+    io.opentelemetry.api.trace.Span otelSpan(
+        String spanName,
+        Span parentOTelSpan,
+        io.opentelemetry.api.common.Attributes attributes,
+        io.opentelemetry.api.trace.SpanKind spanKind
+    ) {
         return parentOTelSpan == null || !(parentOTelSpan instanceof OTelSpan)
             ? otelTracer.spanBuilder(spanName).setAllAttributes(attributes).startSpan()
             : otelTracer.spanBuilder(spanName)
                 .setParent(Context.current().with(((OTelSpan) parentOTelSpan).getDelegateSpan()))
                 .setAllAttributes(attributes)
+                .setSpanKind(spanKind)
                 .startSpan();
     }
 }
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactory.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactory.java
index cd4ffb160903b..da7ce5c47d9ca 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactory.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactory.java
@@ -16,6 +16,7 @@
 
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
+import java.lang.reflect.Method;
 import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
@@ -55,9 +56,17 @@ private static SpanExporter instantiateSpanExporter(Class<SpanExporter> spanExpo
             // Check we ourselves are not being called by unprivileged code.
             SpecialPermission.check();
             return AccessController.doPrivileged((PrivilegedExceptionAction<SpanExporter>) () -> {
+                String methodName = "create";
+                String getDefaultMethod = "getDefault";
+                for (Method m : spanExporterProviderClass.getMethods()) {
+                    if (m.getName().equals(getDefaultMethod)) {
+                        methodName = getDefaultMethod;
+                        break;
+                    }
+                }
                 try {
                     return (SpanExporter) MethodHandles.publicLookup()
-                        .findStatic(spanExporterProviderClass, "create", MethodType.methodType(spanExporterProviderClass))
+                        .findStatic(spanExporterProviderClass, methodName, MethodType.methodType(spanExporterProviderClass))
                         .asType(MethodType.methodType(SpanExporter.class))
                         .invokeExact();
                 } catch (Throwable e) {
diff --git a/plugins/telemetry-otel/src/main/plugin-metadata/plugin-security.policy b/plugins/telemetry-otel/src/main/plugin-metadata/plugin-security.policy
index 4480cbb2bab4b..9d529ed5a2a56 100644
--- a/plugins/telemetry-otel/src/main/plugin-metadata/plugin-security.policy
+++ b/plugins/telemetry-otel/src/main/plugin-metadata/plugin-security.policy
@@ -9,6 +9,9 @@
 grant {
     permission java.lang.RuntimePermission "getClassLoader";
     permission java.lang.RuntimePermission "accessDeclaredMembers";
+    permission java.net.NetPermission "getProxySelector";
+    permission java.net.SocketPermission "*", "connect,resolve";
+    permission java.util.PropertyPermission "*", "read,write";
 };
 
 
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/OTelTelemetryPluginTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/OTelTelemetryPluginTests.java
index 8c2b5d14733e2..2fcf89947e537 100644
--- a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/OTelTelemetryPluginTests.java
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/OTelTelemetryPluginTests.java
@@ -12,12 +12,15 @@
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.FeatureFlags;
+import org.opensearch.telemetry.metrics.MetricsTelemetry;
+import org.opensearch.telemetry.metrics.OTelMetricsTelemetry;
 import org.opensearch.telemetry.tracing.OTelTracingTelemetry;
 import org.opensearch.telemetry.tracing.TracingTelemetry;
 import org.opensearch.test.OpenSearchTestCase;
 import org.junit.After;
 import org.junit.Before;
 
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
@@ -25,6 +28,7 @@
 import java.util.Set;
 
 import static org.opensearch.telemetry.OTelTelemetryPlugin.OTEL_TRACER_NAME;
+import static org.opensearch.telemetry.OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING;
 import static org.opensearch.telemetry.OTelTelemetrySettings.OTEL_TRACER_SPAN_EXPORTER_CLASS_SETTING;
 import static org.opensearch.telemetry.OTelTelemetrySettings.TRACER_EXPORTER_BATCH_SIZE_SETTING;
 import static org.opensearch.telemetry.OTelTelemetrySettings.TRACER_EXPORTER_DELAY_SETTING;
@@ -34,41 +38,47 @@
 
 public class OTelTelemetryPluginTests extends OpenSearchTestCase {
 
-    private OTelTelemetryPlugin oTelTracerModulePlugin;
+    private OTelTelemetryPlugin oTelTelemetryPlugin;
     private Optional<Telemetry> telemetry;
     private TracingTelemetry tracingTelemetry;
 
+    private MetricsTelemetry metricsTelemetry;
+
     @Before
     public void setup() {
         // TRACER_EXPORTER_DELAY_SETTING should always be less than 10 seconds because
         // io.opentelemetry.sdk.OpenTelemetrySdk.close waits only for 10 seconds for shutdown to complete.
         Settings settings = Settings.builder().put(TRACER_EXPORTER_DELAY_SETTING.getKey(), "1s").build();
-        oTelTracerModulePlugin = new OTelTelemetryPlugin(settings);
-        telemetry = oTelTracerModulePlugin.getTelemetry(
+        oTelTelemetryPlugin = new OTelTelemetryPlugin(settings);
+        telemetry = oTelTelemetryPlugin.getTelemetry(
             new TelemetrySettings(Settings.EMPTY, new ClusterSettings(settings, Set.of(TRACER_ENABLED_SETTING, TRACER_SAMPLER_PROBABILITY)))
         );
         tracingTelemetry = telemetry.get().getTracingTelemetry();
+        metricsTelemetry = telemetry.get().getMetricsTelemetry();
     }
 
     public void testGetTelemetry() {
         Set<Setting<?>> allTracerSettings = new HashSet<>();
         ClusterSettings.FEATURE_FLAGGED_CLUSTER_SETTINGS.get(List.of(FeatureFlags.TELEMETRY)).stream().forEach((allTracerSettings::add));
-        assertEquals(OTEL_TRACER_NAME, oTelTracerModulePlugin.getName());
+        assertEquals(OTEL_TRACER_NAME, oTelTelemetryPlugin.getName());
         assertTrue(tracingTelemetry instanceof OTelTracingTelemetry);
+        assertTrue(metricsTelemetry instanceof OTelMetricsTelemetry);
         assertEquals(
             Arrays.asList(
                 TRACER_EXPORTER_BATCH_SIZE_SETTING,
                 TRACER_EXPORTER_DELAY_SETTING,
                 TRACER_EXPORTER_MAX_QUEUE_SIZE_SETTING,
-                OTEL_TRACER_SPAN_EXPORTER_CLASS_SETTING
+                OTEL_TRACER_SPAN_EXPORTER_CLASS_SETTING,
+                OTEL_METRICS_EXPORTER_CLASS_SETTING
             ),
-            oTelTracerModulePlugin.getSettings()
+            oTelTelemetryPlugin.getSettings()
         );
 
     }
 
     @After
-    public void cleanup() {
+    public void cleanup() throws IOException {
         tracingTelemetry.close();
+        metricsTelemetry.close();
     }
 }
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/OTelMetricsTelemetryTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/OTelMetricsTelemetryTests.java
new file mode 100644
index 0000000000000..9de575b69774a
--- /dev/null
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/OTelMetricsTelemetryTests.java
@@ -0,0 +1,121 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.concurrent.RefCountedReleasable;
+import org.opensearch.telemetry.OTelAttributesConverter;
+import org.opensearch.telemetry.OTelTelemetryPlugin;
+import org.opensearch.telemetry.metrics.tags.Tags;
+import org.opensearch.test.OpenSearchTestCase;
+
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.metrics.DoubleCounter;
+import io.opentelemetry.api.metrics.DoubleCounterBuilder;
+import io.opentelemetry.api.metrics.DoubleUpDownCounter;
+import io.opentelemetry.api.metrics.DoubleUpDownCounterBuilder;
+import io.opentelemetry.api.metrics.LongCounterBuilder;
+import io.opentelemetry.api.metrics.LongUpDownCounterBuilder;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.metrics.MeterProvider;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class OTelMetricsTelemetryTests extends OpenSearchTestCase {
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public void testCounter() {
+        String counterName = "test-counter";
+        String description = "test";
+        String unit = "1";
+        Meter mockMeter = mock(Meter.class);
+        OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
+        DoubleCounter mockOTelDoubleCounter = mock(DoubleCounter.class);
+        LongCounterBuilder mockOTelLongCounterBuilder = mock(LongCounterBuilder.class);
+        DoubleCounterBuilder mockOTelDoubleCounterBuilder = mock(DoubleCounterBuilder.class);
+        MeterProvider meterProvider = mock(MeterProvider.class);
+        when(meterProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME)).thenReturn(mockMeter);
+        MetricsTelemetry metricsTelemetry = new OTelMetricsTelemetry(
+            new RefCountedReleasable("telemetry", mockOpenTelemetry, () -> {}),
+            meterProvider
+        );
+        when(mockMeter.counterBuilder(counterName)).thenReturn(mockOTelLongCounterBuilder);
+        when(mockOTelLongCounterBuilder.setDescription(description)).thenReturn(mockOTelLongCounterBuilder);
+        when(mockOTelLongCounterBuilder.setUnit(unit)).thenReturn(mockOTelLongCounterBuilder);
+        when(mockOTelLongCounterBuilder.ofDoubles()).thenReturn(mockOTelDoubleCounterBuilder);
+        when(mockOTelDoubleCounterBuilder.build()).thenReturn(mockOTelDoubleCounter);
+
+        Counter counter = metricsTelemetry.createCounter(counterName, description, unit);
+        counter.add(1.0);
+        verify(mockOTelDoubleCounter).add(1.0);
+        Tags tags = Tags.create().addTag("test", "test");
+        counter.add(2.0, tags);
+        verify(mockOTelDoubleCounter).add(2.0, OTelAttributesConverter.convert(tags));
+    }
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public void testCounterNegativeValue() {
+        String counterName = "test-counter";
+        String description = "test";
+        String unit = "1";
+        OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
+        Meter mockMeter = mock(Meter.class);
+        DoubleCounter mockOTelDoubleCounter = mock(DoubleCounter.class);
+        LongCounterBuilder mockOTelLongCounterBuilder = mock(LongCounterBuilder.class);
+        DoubleCounterBuilder mockOTelDoubleCounterBuilder = mock(DoubleCounterBuilder.class);
+
+        MeterProvider meterProvider = mock(MeterProvider.class);
+        when(meterProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME)).thenReturn(mockMeter);
+        MetricsTelemetry metricsTelemetry = new OTelMetricsTelemetry(
+            new RefCountedReleasable("telemetry", mockOpenTelemetry, () -> {}),
+            meterProvider
+        );
+        when(mockMeter.counterBuilder(counterName)).thenReturn(mockOTelLongCounterBuilder);
+        when(mockOTelLongCounterBuilder.setDescription(description)).thenReturn(mockOTelLongCounterBuilder);
+        when(mockOTelLongCounterBuilder.setUnit(unit)).thenReturn(mockOTelLongCounterBuilder);
+        when(mockOTelLongCounterBuilder.ofDoubles()).thenReturn(mockOTelDoubleCounterBuilder);
+        when(mockOTelDoubleCounterBuilder.build()).thenReturn(mockOTelDoubleCounter);
+
+        Counter counter = metricsTelemetry.createCounter(counterName, description, unit);
+        counter.add(-1.0);
+        verify(mockOTelDoubleCounter).add(-1.0);
+    }
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public void testUpDownCounter() {
+        String counterName = "test-counter";
+        String description = "test";
+        String unit = "1";
+        OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
+        Meter mockMeter = mock(Meter.class);
+        DoubleUpDownCounter mockOTelUpDownDoubleCounter = mock(DoubleUpDownCounter.class);
+        LongUpDownCounterBuilder mockOTelLongUpDownCounterBuilder = mock(LongUpDownCounterBuilder.class);
+        DoubleUpDownCounterBuilder mockOTelDoubleUpDownCounterBuilder = mock(DoubleUpDownCounterBuilder.class);
+
+        MeterProvider meterProvider = mock(MeterProvider.class);
+        when(meterProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME)).thenReturn(mockMeter);
+        MetricsTelemetry metricsTelemetry = new OTelMetricsTelemetry(
+            new RefCountedReleasable("telemetry", mockOpenTelemetry, () -> {}),
+            meterProvider
+        );
+        when(mockMeter.upDownCounterBuilder(counterName)).thenReturn(mockOTelLongUpDownCounterBuilder);
+        when(mockOTelLongUpDownCounterBuilder.setDescription(description)).thenReturn(mockOTelLongUpDownCounterBuilder);
+        when(mockOTelLongUpDownCounterBuilder.setUnit(unit)).thenReturn(mockOTelLongUpDownCounterBuilder);
+        when(mockOTelLongUpDownCounterBuilder.ofDoubles()).thenReturn(mockOTelDoubleUpDownCounterBuilder);
+        when(mockOTelDoubleUpDownCounterBuilder.build()).thenReturn(mockOTelUpDownDoubleCounter);
+
+        Counter counter = metricsTelemetry.createUpDownCounter(counterName, description, unit);
+        counter.add(1.0);
+        verify(mockOTelUpDownDoubleCounter).add(1.0);
+        Tags tags = Tags.create().addTag("test", "test");
+        counter.add(-2.0, tags);
+        verify(mockOTelUpDownDoubleCounter).add((-2.0), OTelAttributesConverter.convert(tags));
+    }
+}
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/exporter/DummyMetricExporter.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/exporter/DummyMetricExporter.java
new file mode 100644
index 0000000000000..65c52911dbef9
--- /dev/null
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/exporter/DummyMetricExporter.java
@@ -0,0 +1,39 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics.exporter;
+
+import java.util.Collection;
+
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.metrics.InstrumentType;
+import io.opentelemetry.sdk.metrics.data.AggregationTemporality;
+import io.opentelemetry.sdk.metrics.data.MetricData;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+
+public class DummyMetricExporter implements MetricExporter {
+    @Override
+    public CompletableResultCode export(Collection<MetricData> metrics) {
+        return null;
+    }
+
+    @Override
+    public CompletableResultCode flush() {
+        return null;
+    }
+
+    @Override
+    public CompletableResultCode shutdown() {
+        return null;
+    }
+
+    @Override
+    public AggregationTemporality getAggregationTemporality(InstrumentType instrumentType) {
+        return null;
+    }
+}
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/exporter/OTelMetricsExporterFactoryTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/exporter/OTelMetricsExporterFactoryTests.java
new file mode 100644
index 0000000000000..e68da030bfb52
--- /dev/null
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/metrics/exporter/OTelMetricsExporterFactoryTests.java
@@ -0,0 +1,78 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics.exporter;
+
+import org.opensearch.common.settings.Settings;
+import org.opensearch.telemetry.OTelTelemetrySettings;
+import org.opensearch.test.OpenSearchTestCase;
+
+import io.opentelemetry.exporter.logging.LoggingMetricExporter;
+import io.opentelemetry.exporter.otlp.metrics.OtlpGrpcMetricExporter;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+
+public class OTelMetricsExporterFactoryTests extends OpenSearchTestCase {
+
+    public void testMetricsExporterDefault() {
+        Settings settings = Settings.builder().build();
+        MetricExporter metricExporter = OTelMetricsExporterFactory.create(settings);
+        assertTrue(metricExporter instanceof LoggingMetricExporter);
+    }
+
+    public void testMetricsExporterLogging() {
+        Settings settings = Settings.builder()
+            .put(
+                OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.getKey(),
+                "io.opentelemetry.exporter.logging.LoggingMetricExporter"
+            )
+            .build();
+        MetricExporter metricExporter = OTelMetricsExporterFactory.create(settings);
+        assertTrue(metricExporter instanceof LoggingMetricExporter);
+    }
+
+    public void testMetricExporterInvalid() {
+        Settings settings = Settings.builder().put(OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.getKey(), "abc").build();
+        assertThrows(IllegalArgumentException.class, () -> OTelMetricsExporterFactory.create(settings));
+    }
+
+    public void testMetricExporterNoCreateFactoryMethod() {
+        Settings settings = Settings.builder()
+            .put(
+                OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.getKey(),
+                "org.opensearch.telemetry.metrics.exporter.DummyMetricExporter"
+            )
+            .build();
+        IllegalStateException exception = assertThrows(IllegalStateException.class, () -> OTelMetricsExporterFactory.create(settings));
+        assertEquals(
+            "MetricExporter instantiation failed for class [org.opensearch.telemetry.metrics.exporter.DummyMetricExporter]",
+            exception.getMessage()
+        );
+    }
+
+    public void testMetricExporterNonMetricExporterClass() {
+        Settings settings = Settings.builder()
+            .put(OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.getKey(), "java.lang.String")
+            .build();
+        IllegalStateException exception = assertThrows(IllegalStateException.class, () -> OTelMetricsExporterFactory.create(settings));
+        assertEquals("MetricExporter instantiation failed for class [java.lang.String]", exception.getMessage());
+        assertTrue(exception.getCause() instanceof NoSuchMethodError);
+
+    }
+
+    public void testMetricExporterGetDefaultMethod() {
+        Settings settings = Settings.builder()
+            .put(
+                OTelTelemetrySettings.OTEL_METRICS_EXPORTER_CLASS_SETTING.getKey(),
+                "io.opentelemetry.exporter.otlp.metrics.OtlpGrpcMetricExporter"
+            )
+            .build();
+
+        assertTrue(OTelMetricsExporterFactory.create(settings) instanceof OtlpGrpcMetricExporter);
+    }
+
+}
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelAttributesConverterTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelAttributesConverterTests.java
index d992daec1b7bb..ee67384d01759 100644
--- a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelAttributesConverterTests.java
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelAttributesConverterTests.java
@@ -8,6 +8,8 @@
 
 package org.opensearch.telemetry.tracing;
 
+import org.opensearch.telemetry.OTelAttributesConverter;
+import org.opensearch.telemetry.metrics.tags.Tags;
 import org.opensearch.telemetry.tracing.attributes.Attributes;
 import org.opensearch.test.OpenSearchTestCase;
 
@@ -19,13 +21,13 @@
 public class OTelAttributesConverterTests extends OpenSearchTestCase {
 
     public void testConverterNullAttributes() {
-        io.opentelemetry.api.common.Attributes otelAttributes = OTelAttributesConverter.convert(null);
+        io.opentelemetry.api.common.Attributes otelAttributes = OTelAttributesConverter.convert((Attributes) null);
         assertEquals(0, otelAttributes.size());
     }
 
     public void testConverterEmptyAttributes() {
         Attributes attributes = Attributes.EMPTY;
-        io.opentelemetry.api.common.Attributes otelAttributes = OTelAttributesConverter.convert(null);
+        io.opentelemetry.api.common.Attributes otelAttributes = OTelAttributesConverter.convert(attributes);
         assertEquals(0, otelAttributes.size());
     }
 
@@ -47,4 +49,12 @@ public void testConverterMultipleAttributes() {
         assertEquals(4, otelAttributes.size());
         otelAttributes.asMap().forEach((x, y) -> assertEquals(attributeMap.get(x.getKey()), y));
     }
+
+    public void testConverterMultipleTags() {
+        Tags tags = Tags.create().addTag("key1", 1l).addTag("key2", 1.0).addTag("key3", true).addTag("key4", "value4");
+        Map<String, ?> tagsMap = tags.getTagsMap();
+        io.opentelemetry.api.common.Attributes otelAttributes = OTelAttributesConverter.convert(tags);
+        assertEquals(4, otelAttributes.size());
+        otelAttributes.asMap().forEach((x, y) -> assertEquals(tagsMap.get(x.getKey()), y));
+    }
 }
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelSpanKindConverterTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelSpanKindConverterTests.java
new file mode 100644
index 0000000000000..d07e32d00a92a
--- /dev/null
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelSpanKindConverterTests.java
@@ -0,0 +1,27 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+import io.opentelemetry.api.trace.SpanKind;
+
+public class OTelSpanKindConverterTests extends OpenSearchTestCase {
+
+    public void testSpanKindNullConverterNull() {
+        assertEquals(SpanKind.INTERNAL, OTelSpanKindConverter.convert(null));
+    }
+
+    public void testSpanKindConverter() {
+        assertEquals(SpanKind.INTERNAL, OTelSpanKindConverter.convert(org.opensearch.telemetry.tracing.SpanKind.INTERNAL));
+        assertEquals(SpanKind.CLIENT, OTelSpanKindConverter.convert(org.opensearch.telemetry.tracing.SpanKind.CLIENT));
+        assertEquals(SpanKind.SERVER, OTelSpanKindConverter.convert(org.opensearch.telemetry.tracing.SpanKind.SERVER));
+    }
+
+}
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagatorTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagatorTests.java
index 16a3ec9493d5d..d865a329104c1 100644
--- a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagatorTests.java
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingContextPropagatorTests.java
@@ -11,8 +11,8 @@
 import org.opensearch.test.OpenSearchTestCase;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 import io.opentelemetry.api.OpenTelemetry;
@@ -57,7 +57,7 @@ public void testExtractTracerContextFromHeader() {
     }
 
     public void testExtractTracerContextFromHttpHeader() {
-        Map<String, List<String>> requestHeaders = new HashMap<>();
+        Map<String, Collection<String>> requestHeaders = new HashMap<>();
         requestHeaders.put("traceparent", Arrays.asList("00-" + TRACE_ID + "-" + SPAN_ID + "-00"));
         OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
         when(mockOpenTelemetry.getPropagators()).thenReturn(ContextPropagators.create(W3CTraceContextPropagator.getInstance()));
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingTelemetryTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingTelemetryTests.java
index 3f46cb621a8ec..1f0c2f674e655 100644
--- a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingTelemetryTests.java
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/OTelTracingTelemetryTests.java
@@ -8,16 +8,16 @@
 
 package org.opensearch.telemetry.tracing;
 
+import org.opensearch.common.concurrent.RefCountedReleasable;
+import org.opensearch.telemetry.OTelTelemetryPlugin;
 import org.opensearch.telemetry.tracing.attributes.Attributes;
 import org.opensearch.test.OpenSearchTestCase;
 
-import java.util.Collections;
-import java.util.Map;
-
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.api.trace.SpanBuilder;
 import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.api.trace.TracerProvider;
 
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
@@ -26,40 +26,49 @@
 import static org.mockito.Mockito.when;
 
 public class OTelTracingTelemetryTests extends OpenSearchTestCase {
-
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     public void testCreateSpanWithoutParent() {
         OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
         Tracer mockTracer = mock(Tracer.class);
-        when(mockOpenTelemetry.getTracer("os-tracer")).thenReturn(mockTracer);
+        TracerProvider mockTracerProvider = mock(TracerProvider.class);
+        when(mockTracerProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME)).thenReturn(mockTracer);
         SpanBuilder mockSpanBuilder = mock(SpanBuilder.class);
         when(mockTracer.spanBuilder("span_name")).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.setAllAttributes(any(io.opentelemetry.api.common.Attributes.class))).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.startSpan()).thenReturn(mock(io.opentelemetry.api.trace.Span.class));
-        Map<String, String> attributeMap = Collections.singletonMap("name", "value");
+        when(mockSpanBuilder.setSpanKind(any(io.opentelemetry.api.trace.SpanKind.class))).thenReturn(mockSpanBuilder);
         Attributes attributes = Attributes.create().addAttribute("name", "value");
-        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(mockOpenTelemetry);
-        Span span = tracingTelemetry.createSpan("span_name", null, attributes);
-
+        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(
+            new RefCountedReleasable("telemetry", mockOpenTelemetry, () -> {}),
+            mockTracerProvider
+        );
+        Span span = tracingTelemetry.createSpan(SpanCreationContext.internal().name("span_name").attributes(attributes), null);
         verify(mockSpanBuilder, never()).setParent(any());
         verify(mockSpanBuilder).setAllAttributes(createAttribute(attributes));
         assertNull(span.getParentSpan());
     }
 
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     public void testCreateSpanWithParent() {
         OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
         Tracer mockTracer = mock(Tracer.class);
-        when(mockOpenTelemetry.getTracer("os-tracer")).thenReturn(mockTracer);
+        TracerProvider mockTracerProvider = mock(TracerProvider.class);
+        when(mockTracerProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME)).thenReturn(mockTracer);
         SpanBuilder mockSpanBuilder = mock(SpanBuilder.class);
         when(mockTracer.spanBuilder("span_name")).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.setParent(any())).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.setAllAttributes(any(io.opentelemetry.api.common.Attributes.class))).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.startSpan()).thenReturn(mock(io.opentelemetry.api.trace.Span.class));
+        when(mockSpanBuilder.setSpanKind(any(io.opentelemetry.api.trace.SpanKind.class))).thenReturn(mockSpanBuilder);
 
         Span parentSpan = new OTelSpan("parent_span", mock(io.opentelemetry.api.trace.Span.class), null);
 
-        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(mockOpenTelemetry);
+        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(
+            new RefCountedReleasable("telemetry", mockOpenTelemetry, () -> {}),
+            mockTracerProvider
+        );
         Attributes attributes = Attributes.create().addAttribute("name", 1l);
-        Span span = tracingTelemetry.createSpan("span_name", parentSpan, attributes);
+        Span span = tracingTelemetry.createSpan(SpanCreationContext.internal().name("span_name").attributes(attributes), parentSpan);
 
         verify(mockSpanBuilder).setParent(any());
         verify(mockSpanBuilder).setAllAttributes(createAttributeLong(attributes));
@@ -68,25 +77,31 @@ public void testCreateSpanWithParent() {
         assertEquals("parent_span", span.getParentSpan().getSpanName());
     }
 
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     public void testCreateSpanWithParentWithMultipleAttributes() {
         OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
         Tracer mockTracer = mock(Tracer.class);
-        when(mockOpenTelemetry.getTracer("os-tracer")).thenReturn(mockTracer);
+        TracerProvider mockTracerProvider = mock(TracerProvider.class);
+        when(mockTracerProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME)).thenReturn(mockTracer);
         SpanBuilder mockSpanBuilder = mock(SpanBuilder.class);
         when(mockTracer.spanBuilder("span_name")).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.setParent(any())).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.setAllAttributes(any(io.opentelemetry.api.common.Attributes.class))).thenReturn(mockSpanBuilder);
         when(mockSpanBuilder.startSpan()).thenReturn(mock(io.opentelemetry.api.trace.Span.class));
+        when(mockSpanBuilder.setSpanKind(any(io.opentelemetry.api.trace.SpanKind.class))).thenReturn(mockSpanBuilder);
 
         Span parentSpan = new OTelSpan("parent_span", mock(io.opentelemetry.api.trace.Span.class), null);
 
-        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(mockOpenTelemetry);
+        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(
+            new RefCountedReleasable("telemetry", mockOpenTelemetry, () -> {}),
+            mockTracerProvider
+        );
         Attributes attributes = Attributes.create()
             .addAttribute("key1", 1l)
             .addAttribute("key2", 2.0)
             .addAttribute("key3", true)
             .addAttribute("key4", "key4");
-        Span span = tracingTelemetry.createSpan("span_name", parentSpan, attributes);
+        Span span = tracingTelemetry.createSpan(SpanCreationContext.internal().name("span_name").attributes(attributes), parentSpan);
 
         io.opentelemetry.api.common.Attributes otelAttributes = io.opentelemetry.api.common.Attributes.builder()
             .put("key1", 1l)
@@ -113,12 +128,17 @@ private io.opentelemetry.api.common.Attributes createAttributeLong(Attributes at
         return attributesBuilder.build();
     }
 
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     public void testGetContextPropagator() {
         OpenTelemetry mockOpenTelemetry = mock(OpenTelemetry.class);
         Tracer mockTracer = mock(Tracer.class);
-        when(mockOpenTelemetry.getTracer("os-tracer")).thenReturn(mockTracer);
+        TracerProvider mockTracerProvider = mock(TracerProvider.class);
+        when(mockTracerProvider.get(OTelTelemetryPlugin.INSTRUMENTATION_SCOPE_NAME)).thenReturn(mockTracer);
 
-        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(mockOpenTelemetry);
+        TracingTelemetry tracingTelemetry = new OTelTracingTelemetry(
+            new RefCountedReleasable("telemetry", mockOpenTelemetry, () -> {}),
+            mockTracerProvider
+        );
 
         assertTrue(tracingTelemetry.getContextPropagator() instanceof OTelTracingContextPropagator);
     }
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/exporter/DummySpanExporterWithGetDefault.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/exporter/DummySpanExporterWithGetDefault.java
new file mode 100644
index 0000000000000..225cfa6ab2d1a
--- /dev/null
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/exporter/DummySpanExporterWithGetDefault.java
@@ -0,0 +1,37 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing.exporter;
+
+import java.util.Collection;
+
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+
+public class DummySpanExporterWithGetDefault implements SpanExporter {
+
+    public static DummySpanExporterWithGetDefault getDefault() {
+        return new DummySpanExporterWithGetDefault();
+    }
+
+    @Override
+    public CompletableResultCode export(Collection<SpanData> spans) {
+        return null;
+    }
+
+    @Override
+    public CompletableResultCode flush() {
+        return null;
+    }
+
+    @Override
+    public CompletableResultCode shutdown() {
+        return null;
+    }
+}
diff --git a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactoryTests.java b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactoryTests.java
index d9a86ccd3180b..d71aef9366e21 100644
--- a/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactoryTests.java
+++ b/plugins/telemetry-otel/src/test/java/org/opensearch/telemetry/tracing/exporter/OTelSpanExporterFactoryTests.java
@@ -63,4 +63,15 @@ public void testSpanExporterNonSpanExporterClass() {
 
     }
 
+    public void testSpanExporterGetDefaultMethod() {
+        Settings settings = Settings.builder()
+            .put(
+                OTelTelemetrySettings.OTEL_TRACER_SPAN_EXPORTER_CLASS_SETTING.getKey(),
+                "org.opensearch.telemetry.tracing.exporter.DummySpanExporterWithGetDefault"
+            )
+            .build();
+
+        assertTrue(OTelSpanExporterFactory.create(settings) instanceof DummySpanExporterWithGetDefault);
+    }
+
 }
diff --git a/plugins/transport-nio/licenses/netty-buffer-4.1.101.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-buffer-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..7bb27bbfcb87d
--- /dev/null
+++ b/plugins/transport-nio/licenses/netty-buffer-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+a4d94fd6cdf7a37b15237e32434afd6b955cc591
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-buffer-4.1.97.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-buffer-4.1.97.Final.jar.sha1
deleted file mode 100644
index 8430355365996..0000000000000
--- a/plugins/transport-nio/licenses/netty-buffer-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f8f3d8644afa5e6e1a40a3a6aeb9d9aa970ecb4f
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-codec-4.1.101.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-codec-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..c792b4e834030
--- /dev/null
+++ b/plugins/transport-nio/licenses/netty-codec-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+642523c57c4be15b8b461be7b1532262d193bbb3
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-codec-4.1.97.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-codec-4.1.97.Final.jar.sha1
deleted file mode 100644
index 7a36dc1f2724f..0000000000000
--- a/plugins/transport-nio/licenses/netty-codec-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-384ba4d75670befbedb45c4d3b497a93639c206d
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-codec-http-4.1.101.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-codec-http-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..8bf31f6c3a2c7
--- /dev/null
+++ b/plugins/transport-nio/licenses/netty-codec-http-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+c648f863b301e3fc62d0de098ec61be7628b8ea2
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-codec-http-4.1.97.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-codec-http-4.1.97.Final.jar.sha1
deleted file mode 100644
index 37b78a32f741f..0000000000000
--- a/plugins/transport-nio/licenses/netty-codec-http-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-af78acec783ffd77c63d8aeecc21041fd39ac54f
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-common-4.1.101.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4fe86799eaff
--- /dev/null
+++ b/plugins/transport-nio/licenses/netty-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+bdb16e4d308b5757123decc886896815d1daf7a3
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-common-4.1.97.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-common-4.1.97.Final.jar.sha1
deleted file mode 100644
index 1bdfec3aae6ba..0000000000000
--- a/plugins/transport-nio/licenses/netty-common-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7cceacaf11df8dc63f23d0fb58e9d4640fc88404
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-handler-4.1.101.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-handler-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..cfc0befee237a
--- /dev/null
+++ b/plugins/transport-nio/licenses/netty-handler-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+7800aea949bf95f63df73166d144e49405b279dd
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-handler-4.1.97.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-handler-4.1.97.Final.jar.sha1
deleted file mode 100644
index 8b7b50a6fc9c6..0000000000000
--- a/plugins/transport-nio/licenses/netty-handler-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-abb86c6906bf512bf2b797a41cd7d2e8d3cd7c36
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-resolver-4.1.101.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-resolver-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4425d5ac8e5f
--- /dev/null
+++ b/plugins/transport-nio/licenses/netty-resolver-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+5e7eddfa4dfffcbd375d265d1fd08297df94f82f
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-resolver-4.1.97.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-resolver-4.1.97.Final.jar.sha1
deleted file mode 100644
index 032959e98d009..0000000000000
--- a/plugins/transport-nio/licenses/netty-resolver-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-cec8348108dc76c47cf87c669d514be52c922144
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-transport-4.1.101.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-transport-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..fd9199092452b
--- /dev/null
+++ b/plugins/transport-nio/licenses/netty-transport-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+0b36cc2337b4a4135df7ee2f2d77431c3b541dc5
\ No newline at end of file
diff --git a/plugins/transport-nio/licenses/netty-transport-4.1.97.Final.jar.sha1 b/plugins/transport-nio/licenses/netty-transport-4.1.97.Final.jar.sha1
deleted file mode 100644
index 107863c1b3c9d..0000000000000
--- a/plugins/transport-nio/licenses/netty-transport-4.1.97.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f37380d23c9bb079bc702910833b2fd532c9abd0
\ No newline at end of file
diff --git a/plugins/transport-nio/src/main/java/org/opensearch/http/nio/NioHttpRequest.java b/plugins/transport-nio/src/main/java/org/opensearch/http/nio/NioHttpRequest.java
index d25ef33c2ce29..5abd6f2710198 100644
--- a/plugins/transport-nio/src/main/java/org/opensearch/http/nio/NioHttpRequest.java
+++ b/plugins/transport-nio/src/main/java/org/opensearch/http/nio/NioHttpRequest.java
@@ -257,7 +257,7 @@ public FullHttpRequest nettyRequest() {
     /**
      * A wrapper of {@link HttpHeaders} that implements a map to prevent copying unnecessarily. This class does not support modifications
      * and due to the underlying implementation, it performs case insensitive lookups of key to values.
-     *
+     * <p>
      * It is important to note that this implementation does have some downsides in that each invocation of the
      * {@link #values()} and {@link #entrySet()} methods will perform a copy of the values in the HttpHeaders rather than returning a
      * view of the underlying values.
diff --git a/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransport.java b/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransport.java
index dfa72d6d59a0d..55920bab4efd3 100644
--- a/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransport.java
+++ b/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransport.java
@@ -52,6 +52,7 @@
 import org.opensearch.nio.NioSelector;
 import org.opensearch.nio.NioSocketChannel;
 import org.opensearch.nio.ServerChannelContext;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TcpTransport;
 import org.opensearch.transport.TransportSettings;
@@ -84,9 +85,10 @@ protected NioTransport(
         PageCacheRecycler pageCacheRecycler,
         NamedWriteableRegistry namedWriteableRegistry,
         CircuitBreakerService circuitBreakerService,
-        NioGroupFactory groupFactory
+        NioGroupFactory groupFactory,
+        Tracer tracer
     ) {
-        super(settings, version, threadPool, pageCacheRecycler, circuitBreakerService, namedWriteableRegistry, networkService);
+        super(settings, version, threadPool, pageCacheRecycler, circuitBreakerService, namedWriteableRegistry, networkService, tracer);
         this.pageAllocator = new PageAllocator(pageCacheRecycler);
         this.groupFactory = groupFactory;
     }
diff --git a/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransportPlugin.java b/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransportPlugin.java
index ec266d76eff3d..d4be876867651 100644
--- a/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransportPlugin.java
+++ b/plugins/transport-nio/src/main/java/org/opensearch/transport/nio/NioTransportPlugin.java
@@ -91,7 +91,8 @@ public Map<String, Supplier<Transport>> getTransports(
         PageCacheRecycler pageCacheRecycler,
         CircuitBreakerService circuitBreakerService,
         NamedWriteableRegistry namedWriteableRegistry,
-        NetworkService networkService
+        NetworkService networkService,
+        Tracer tracer
     ) {
         return Collections.singletonMap(
             NIO_TRANSPORT_NAME,
@@ -103,7 +104,8 @@ public Map<String, Supplier<Transport>> getTransports(
                 pageCacheRecycler,
                 namedWriteableRegistry,
                 circuitBreakerService,
-                getNioGroupFactory(settings)
+                getNioGroupFactory(settings),
+                tracer
             )
         );
     }
diff --git a/plugins/transport-nio/src/test/java/org/opensearch/transport/nio/SimpleNioTransportTests.java b/plugins/transport-nio/src/test/java/org/opensearch/transport/nio/SimpleNioTransportTests.java
index 24cc38c17a9d1..f5d1c618f5ace 100644
--- a/plugins/transport-nio/src/test/java/org/opensearch/transport/nio/SimpleNioTransportTests.java
+++ b/plugins/transport-nio/src/test/java/org/opensearch/transport/nio/SimpleNioTransportTests.java
@@ -44,6 +44,7 @@
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.transport.MockTransportService;
 import org.opensearch.test.transport.StubbableTransport;
 import org.opensearch.transport.AbstractSimpleTransportTestCase;
@@ -81,7 +82,8 @@ protected Transport build(Settings settings, final Version version, ClusterSetti
             new MockPageCacheRecycler(settings),
             namedWriteableRegistry,
             new NoneCircuitBreakerService(),
-            new NioGroupFactory(settings, logger)
+            new NioGroupFactory(settings, logger),
+            NoopTracer.INSTANCE
         ) {
 
             @Override
diff --git a/plugins/transport-reactor-netty4/build.gradle b/plugins/transport-reactor-netty4/build.gradle
new file mode 100644
index 0000000000000..7d7eb330b4a55
--- /dev/null
+++ b/plugins/transport-reactor-netty4/build.gradle
@@ -0,0 +1,264 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+import org.opensearch.gradle.info.BuildParams
+import org.opensearch.gradle.test.RestIntegTestTask
+import org.opensearch.gradle.test.TestTask
+import org.opensearch.gradle.test.rest.JavaRestTestPlugin
+import org.opensearch.gradle.test.InternalClusterTestPlugin
+
+apply plugin: 'opensearch.yaml-rest-test'
+apply plugin: 'opensearch.java-rest-test'
+apply plugin: 'opensearch.internal-cluster-test'
+
+// The transport-reactor-netty4 plugin is published to maven
+apply plugin: 'opensearch.publish'
+
+opensearchplugin {
+  description 'Reactor Netty 4 based transport implementation'
+  classname 'org.opensearch.transport.reactor.ReactorNetty4Plugin'
+  hasClientJar = true
+}
+
+dependencies {
+  // network stack
+  api "io.netty:netty-buffer:${versions.netty}"
+  api "io.netty:netty-codec:${versions.netty}"
+  api "io.netty:netty-codec-dns:${versions.netty}"
+  api "io.netty:netty-codec-http:${versions.netty}"
+  api "io.netty:netty-codec-http2:${versions.netty}"
+  api "io.netty:netty-common:${versions.netty}"
+  api "io.netty:netty-handler:${versions.netty}"
+  api "io.netty:netty-resolver-dns:${versions.netty}"
+  api "io.netty:netty-resolver:${versions.netty}"
+  api "io.netty:netty-transport:${versions.netty}"
+  api "io.netty:netty-transport-native-unix-common:${versions.netty}"
+
+  api "io.projectreactor.netty:reactor-netty-http:${versions.reactor_netty}"
+  api "io.projectreactor.netty:reactor-netty-core:${versions.reactor_netty}"
+
+  testImplementation "org.apache.logging.log4j:log4j-slf4j-impl:${versions.log4j}"
+  testImplementation "io.projectreactor:reactor-test:${versions.reactor}"
+  testImplementation project(":modules:transport-netty4")
+}
+
+restResources {
+  restApi {
+    includeCore '_common', 'cluster', 'nodes'
+  }
+}
+
+tasks.named("dependencyLicenses").configure {
+  mapping from: /netty-.*/, to: 'netty'
+  mapping from: /reactor-.*/, to: 'reactor'
+}
+
+// TODO: Remove that once we have a complete test suite
+testingConventions.enabled = false
+
+test {
+  /*
+   * We have to disable setting the number of available processors as tests in the same JVM randomize processors and will step on each
+   * other if we allow them to set the number of available processors as it's set-once in Netty.
+   */
+  systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
+}
+
+internalClusterTest {
+  systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
+}
+
+javaRestTest {
+  systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
+}
+
+thirdPartyAudit {
+  ignoreMissingClasses(
+    'com.aayushatharva.brotli4j.Brotli4jLoader',
+    'com.aayushatharva.brotli4j.decoder.DecoderJNI$Status',
+    'com.aayushatharva.brotli4j.decoder.DecoderJNI$Wrapper',
+    'com.aayushatharva.brotli4j.encoder.BrotliEncoderChannel',
+    'com.aayushatharva.brotli4j.encoder.Encoder$Mode',
+    'com.aayushatharva.brotli4j.encoder.Encoder$Parameters',
+    // classes are missing
+
+    // from io.netty.logging.CommonsLoggerFactory (netty)
+    'org.apache.commons.logging.Log',
+    'org.apache.commons.logging.LogFactory',
+
+    // from Log4j (deliberate, Netty will fallback to Log4j 2)
+    'org.apache.log4j.Level',
+    'org.apache.log4j.Logger',
+
+    // from io.netty.handler.ssl.OpenSslEngine (netty)
+    'io.netty.internal.tcnative.Buffer',
+    'io.netty.internal.tcnative.CertificateCompressionAlgo',
+    'io.netty.internal.tcnative.Library',
+    'io.netty.internal.tcnative.SSL',
+    'io.netty.internal.tcnative.SSLContext',
+    'io.netty.internal.tcnative.SSLPrivateKeyMethod',
+
+    // from io.netty.handler.ssl.util.BouncyCastleSelfSignedCertGenerator (netty)
+    'org.bouncycastle.cert.X509v3CertificateBuilder',
+    'org.bouncycastle.cert.jcajce.JcaX509CertificateConverter',
+    'org.bouncycastle.operator.jcajce.JcaContentSignerBuilder',
+    'org.bouncycastle.openssl.PEMEncryptedKeyPair',
+    'org.bouncycastle.openssl.PEMParser',
+    'org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter',
+    'org.bouncycastle.openssl.jcajce.JceOpenSSLPKCS8DecryptorProviderBuilder',
+    'org.bouncycastle.openssl.jcajce.JcePEMDecryptorProviderBuilder',
+    'org.bouncycastle.pkcs.PKCS8EncryptedPrivateKeyInfo',
+
+    // from io.netty.handler.ssl.JettyNpnSslEngine (netty)
+    'org.eclipse.jetty.npn.NextProtoNego$ClientProvider',
+    'org.eclipse.jetty.npn.NextProtoNego$ServerProvider',
+    'org.eclipse.jetty.npn.NextProtoNego',
+
+    // from io.netty.handler.codec.marshalling.ChannelBufferByteInput (netty)
+    'org.jboss.marshalling.ByteInput',
+
+    // from io.netty.handler.codec.marshalling.ChannelBufferByteOutput (netty)
+    'org.jboss.marshalling.ByteOutput',
+
+    // from io.netty.handler.codec.marshalling.CompatibleMarshallingEncoder (netty)
+    'org.jboss.marshalling.Marshaller',
+
+    // from io.netty.handler.codec.marshalling.ContextBoundUnmarshallerProvider (netty)
+    'org.jboss.marshalling.MarshallerFactory',
+    'org.jboss.marshalling.MarshallingConfiguration',
+    'org.jboss.marshalling.Unmarshaller',
+
+    // from io.netty.util.internal.logging.InternalLoggerFactory (netty) - it's optional
+    'org.slf4j.helpers.FormattingTuple',
+    'org.slf4j.helpers.MessageFormatter',
+    'org.slf4j.Logger',
+    'org.slf4j.LoggerFactory',
+    'org.slf4j.spi.LocationAwareLogger',
+
+    'com.google.protobuf.nano.CodedOutputByteBufferNano',
+    'com.google.protobuf.nano.MessageNano',
+    'com.ning.compress.BufferRecycler',
+    'com.ning.compress.lzf.ChunkDecoder',
+    'com.ning.compress.lzf.ChunkEncoder',
+    'com.ning.compress.lzf.LZFChunk',
+    'com.ning.compress.lzf.LZFEncoder',
+    'com.ning.compress.lzf.util.ChunkDecoderFactory',
+    'com.ning.compress.lzf.util.ChunkEncoderFactory',
+    'lzma.sdk.lzma.Encoder',
+    'net.jpountz.lz4.LZ4Compressor',
+    'net.jpountz.lz4.LZ4Factory',
+    'net.jpountz.lz4.LZ4FastDecompressor',
+    'net.jpountz.xxhash.XXHash32',
+    'net.jpountz.xxhash.XXHashFactory',
+    'io.netty.internal.tcnative.AsyncSSLPrivateKeyMethod',
+    'io.netty.internal.tcnative.AsyncTask',
+    'io.netty.internal.tcnative.CertificateCallback',
+    'io.netty.internal.tcnative.CertificateVerifier',
+    'io.netty.internal.tcnative.ResultCallback',
+    'io.netty.internal.tcnative.SessionTicketKey',
+    'io.netty.internal.tcnative.SniHostNameMatcher',
+    'io.netty.internal.tcnative.SSL',
+    'io.netty.internal.tcnative.SSLSession',
+    'io.netty.internal.tcnative.SSLSessionCache',
+    'io.netty.channel.epoll.Epoll',
+    'io.netty.channel.epoll.EpollDatagramChannel',
+    'io.netty.channel.epoll.EpollServerSocketChannel',
+    'io.netty.channel.epoll.EpollSocketChannel',
+    'io.netty.channel.kqueue.KQueue',
+    'io.netty.channel.kqueue.KQueueDatagramChannel',
+    'io.netty.channel.kqueue.KQueueServerSocketChannel',
+    'io.netty.channel.kqueue.KQueueSocketChannel',
+    'io.netty.handler.codec.haproxy.HAProxyMessage',
+    'io.netty.handler.codec.haproxy.HAProxyMessageDecoder',
+    'io.netty.handler.proxy.ProxyHandler',
+    'io.netty.incubator.channel.uring.IOUring',
+    'io.netty.incubator.channel.uring.IOUringDatagramChannel',
+    'io.netty.incubator.channel.uring.IOUringServerSocketChannel',
+    'io.netty.incubator.channel.uring.IOUringSocketChannel',
+
+    'org.eclipse.jetty.alpn.ALPN$ClientProvider',
+    'org.eclipse.jetty.alpn.ALPN$ServerProvider',
+    'org.eclipse.jetty.alpn.ALPN',
+
+    'org.conscrypt.AllocatedBuffer',
+    'org.conscrypt.BufferAllocator',
+    'org.conscrypt.Conscrypt',
+    'org.conscrypt.HandshakeListener',
+
+    'reactor.blockhound.BlockHound$Builder',
+    'reactor.blockhound.integration.BlockHoundIntegration',
+
+    'io.micrometer.common.KeyValue',
+    'io.micrometer.common.KeyValues',
+    'io.micrometer.common.docs.KeyName',
+    'io.micrometer.context.ContextAccessor',
+    'io.micrometer.core.instrument.Counter',
+    'io.micrometer.core.instrument.Counter$Builder',
+    'io.micrometer.core.instrument.DistributionSummary',
+    'io.micrometer.core.instrument.DistributionSummary$Builder',
+    'io.micrometer.core.instrument.Gauge',
+    'io.micrometer.core.instrument.Gauge$Builder',
+    'io.micrometer.core.instrument.Meter',
+    'io.micrometer.core.instrument.Meter$Type',
+    'io.micrometer.core.instrument.MeterRegistry',
+    'io.micrometer.core.instrument.Metrics',
+    'io.micrometer.core.instrument.Tags',
+    'io.micrometer.core.instrument.Timer',
+    'io.micrometer.core.instrument.Timer$Builder',
+    'io.micrometer.core.instrument.Timer$Sample',
+    'io.micrometer.core.instrument.composite.CompositeMeterRegistry',
+    'io.micrometer.core.instrument.docs.MeterDocumentation',
+    'io.micrometer.core.instrument.observation.MeterObservationHandler',
+    'io.micrometer.observation.Observation',
+    'io.micrometer.observation.Observation$Context',
+    'io.micrometer.observation.ObservationHandler',
+    'io.micrometer.observation.ObservationRegistry',
+    'io.micrometer.observation.ObservationRegistry$ObservationConfig',
+    'io.micrometer.observation.docs.ObservationDocumentation',
+    'io.micrometer.observation.transport.ReceiverContext',
+    'io.micrometer.observation.transport.RequestReplyReceiverContext',
+    'io.micrometer.observation.transport.RequestReplySenderContext',
+    'io.micrometer.observation.transport.SenderContext',
+    'io.micrometer.tracing.Span',
+    'io.micrometer.tracing.Tracer',
+    'io.micrometer.tracing.docs.SpanDocumentation',
+    'io.micrometer.tracing.handler.DefaultTracingObservationHandler',
+    'io.micrometer.tracing.handler.PropagatingReceiverTracingObservationHandler',
+    'io.micrometer.tracing.handler.PropagatingSenderTracingObservationHandler',
+    'io.micrometer.tracing.propagation.Propagator'
+  )
+
+  ignoreViolations(
+    'io.netty.util.internal.PlatformDependent0',
+    'io.netty.util.internal.PlatformDependent0$1',
+    'io.netty.util.internal.PlatformDependent0$2',
+    'io.netty.util.internal.PlatformDependent0$3',
+    'io.netty.util.internal.PlatformDependent0$4',
+    'io.netty.util.internal.PlatformDependent0$6',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseLinkedQueueConsumerNodeRef',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseLinkedQueueProducerNodeRef',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueColdProducerFields',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueConsumerFields',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueProducerFields',
+    'io.netty.util.internal.shaded.org.jctools.queues.LinkedQueueNode',
+    'io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueConsumerIndexField',
+    'io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueProducerIndexField',
+    'io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueProducerLimitField',
+    'io.netty.util.internal.shaded.org.jctools.util.UnsafeAccess',
+    'io.netty.util.internal.shaded.org.jctools.util.UnsafeRefArrayAccess',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$1',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$2',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$3',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$4',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$5'
+  )
+}
diff --git a/plugins/transport-reactor-netty4/licenses/netty-LICENSE.txt b/plugins/transport-reactor-netty4/licenses/netty-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
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+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/transport-reactor-netty4/licenses/netty-NOTICE.txt b/plugins/transport-reactor-netty4/licenses/netty-NOTICE.txt
new file mode 100644
index 0000000000000..5bbf91a14de23
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-NOTICE.txt
@@ -0,0 +1,116 @@
+
+                            The Netty Project
+                            =================
+
+Please visit the Netty web site for more information:
+
+  * http://netty.io/
+
+Copyright 2011 The Netty Project
+
+The Netty Project licenses this file to you under the Apache License,
+version 2.0 (the "License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License at:
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+License for the specific language governing permissions and limitations
+under the License.
+
+Also, please refer to each LICENSE.<component>.txt file, which is located in
+the 'license' directory of the distribution file, for the license terms of the
+components that this product depends on.
+
+-------------------------------------------------------------------------------
+This product contains the extensions to Java Collections Framework which has
+been derived from the works by JSR-166 EG, Doug Lea, and Jason T. Greene:
+
+  * LICENSE:
+    * license/LICENSE.jsr166y.txt (Public Domain)
+  * HOMEPAGE:
+    * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/
+    * http://viewvc.jboss.org/cgi-bin/viewvc.cgi/jbosscache/experimental/jsr166/
+
+This product contains a modified version of Robert Harder's Public Domain
+Base64 Encoder and Decoder, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.base64.txt (Public Domain)
+  * HOMEPAGE:
+    * http://iharder.sourceforge.net/current/java/base64/
+
+This product contains a modified version of 'JZlib', a re-implementation of
+zlib in pure Java, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.jzlib.txt (BSD Style License)
+  * HOMEPAGE:
+    * http://www.jcraft.com/jzlib/
+
+This product contains a modified version of 'Webbit', a Java event based
+WebSocket and HTTP server:
+
+  * LICENSE:
+    * license/LICENSE.webbit.txt (BSD License)
+  * HOMEPAGE:
+    * https://github.com/joewalnes/webbit
+
+This product optionally depends on 'Protocol Buffers', Google's data
+interchange format, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.protobuf.txt (New BSD License)
+  * HOMEPAGE:
+    * http://code.google.com/p/protobuf/
+
+This product optionally depends on 'Bouncy Castle Crypto APIs' to generate
+a temporary self-signed X.509 certificate when the JVM does not provide the
+equivalent functionality.  It can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.bouncycastle.txt (MIT License)
+  * HOMEPAGE:
+    * http://www.bouncycastle.org/
+
+This product optionally depends on 'SLF4J', a simple logging facade for Java,
+which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.slf4j.txt (MIT License)
+  * HOMEPAGE:
+    * http://www.slf4j.org/
+
+This product optionally depends on 'Apache Commons Logging', a logging
+framework, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.commons-logging.txt (Apache License 2.0)
+  * HOMEPAGE:
+    * http://commons.apache.org/logging/
+
+This product optionally depends on 'Apache Log4J', a logging framework,
+which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.log4j.txt (Apache License 2.0)
+  * HOMEPAGE:
+    * http://logging.apache.org/log4j/
+
+This product optionally depends on 'JBoss Logging', a logging framework,
+which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.jboss-logging.txt (GNU LGPL 2.1)
+  * HOMEPAGE:
+    * http://anonsvn.jboss.org/repos/common/common-logging-spi/
+
+This product optionally depends on 'Apache Felix', an open source OSGi
+framework implementation, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.felix.txt (Apache License 2.0)
+  * HOMEPAGE:
+    * http://felix.apache.org/
diff --git a/plugins/transport-reactor-netty4/licenses/netty-buffer-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-buffer-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..7bb27bbfcb87d
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-buffer-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+a4d94fd6cdf7a37b15237e32434afd6b955cc591
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..c792b4e834030
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+642523c57c4be15b8b461be7b1532262d193bbb3
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-dns-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-dns-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..0789dea62778a
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-dns-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+24d0f4f2b0b0b55acc498d62f9c0921d0ea6da7b
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-http-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-http-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..8bf31f6c3a2c7
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-http-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+c648f863b301e3fc62d0de098ec61be7628b8ea2
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-http2-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..48b42bfab9287
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-http2-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+40590da6c615b852384542051330e9fd51d4c4b1
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-common-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4fe86799eaff
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+bdb16e4d308b5757123decc886896815d1daf7a3
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-handler-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-handler-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..cfc0befee237a
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-handler-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+7800aea949bf95f63df73166d144e49405b279dd
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-resolver-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-resolver-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..f4425d5ac8e5f
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-resolver-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+5e7eddfa4dfffcbd375d265d1fd08297df94f82f
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-resolver-dns-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-resolver-dns-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..450c34d975bb9
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-resolver-dns-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+d3f503d7554cf25edc6b83b9b4724b240c6e91d5
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-transport-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-transport-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..fd9199092452b
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-transport-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+0b36cc2337b4a4135df7ee2f2d77431c3b541dc5
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
new file mode 100644
index 0000000000000..291c87ad7987b
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-transport-native-unix-common-4.1.101.Final.jar.sha1
@@ -0,0 +1 @@
+d0697ef1d71c6111a1b18a387fa985fd6398ace2
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/reactor-LICENSE.txt b/plugins/transport-reactor-netty4/licenses/reactor-LICENSE.txt
new file mode 100644
index 0000000000000..e5583c184e67a
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/reactor-LICENSE.txt
@@ -0,0 +1,201 @@
+Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
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+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
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+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
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+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
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+      defend, and hold each Contributor harmless for any liability
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+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
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+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       https://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/transport-reactor-netty4/licenses/reactor-NOTICE.txt b/plugins/transport-reactor-netty4/licenses/reactor-NOTICE.txt
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/plugins/transport-reactor-netty4/licenses/reactor-netty-core-1.1.13.jar.sha1 b/plugins/transport-reactor-netty4/licenses/reactor-netty-core-1.1.13.jar.sha1
new file mode 100644
index 0000000000000..5eaf96739ed72
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/reactor-netty-core-1.1.13.jar.sha1
@@ -0,0 +1 @@
+faea23e582978a34f6a932b81e86206ec2314990
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/reactor-netty-http-1.1.13.jar.sha1 b/plugins/transport-reactor-netty4/licenses/reactor-netty-http-1.1.13.jar.sha1
new file mode 100644
index 0000000000000..091125169c696
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/reactor-netty-http-1.1.13.jar.sha1
@@ -0,0 +1 @@
+c5af7bc746050d080891a5446cca2c96a0c51d03
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/OpenSearchReactorNetty4IntegTestCase.java b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/OpenSearchReactorNetty4IntegTestCase.java
new file mode 100644
index 0000000000000..abbd50bf1b235
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/OpenSearchReactorNetty4IntegTestCase.java
@@ -0,0 +1,73 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch;
+
+import org.opensearch.common.network.NetworkModule;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.transport.Netty4ModulePlugin;
+import org.opensearch.transport.reactor.ReactorNetty4Plugin;
+import org.opensearch.transport.reactor.netty4.ReactorNetty4Transport;
+
+import java.util.Collection;
+import java.util.List;
+
+public abstract class OpenSearchReactorNetty4IntegTestCase extends OpenSearchIntegTestCase {
+
+    @Override
+    protected boolean ignoreExternalCluster() {
+        return true;
+    }
+
+    @Override
+    protected boolean addMockTransportService() {
+        return false;
+    }
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        Settings.Builder builder = Settings.builder().put(super.nodeSettings(nodeOrdinal));
+        // randomize netty settings
+        if (randomBoolean()) {
+            builder.put(ReactorNetty4Transport.SETTING_WORKER_COUNT.getKey(), random().nextInt(3) + 1);
+        }
+        builder.put(NetworkModule.TRANSPORT_TYPE_KEY, Netty4ModulePlugin.NETTY_TRANSPORT_NAME);
+        builder.put(NetworkModule.HTTP_TYPE_KEY, ReactorNetty4Plugin.REACTOR_NETTY_HTTP_TRANSPORT_NAME);
+        return builder.build();
+    }
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return List.of(ReactorNetty4Plugin.class, Netty4ModulePlugin.class);
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequestSizeLimitIT.java b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequestSizeLimitIT.java
new file mode 100644
index 0000000000000..833d60375a2bd
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequestSizeLimitIT.java
@@ -0,0 +1,159 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.OpenSearchReactorNetty4IntegTestCase;
+import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.core.common.unit.ByteSizeUnit;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.indices.breaker.HierarchyCircuitBreakerService;
+import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.util.ReferenceCounted;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.hasSize;
+
+/**
+ * This test checks that in-flight requests are limited on HTTP level and that requests that are excluded from limiting can pass.
+ *
+ * As the same setting is also used to limit in-flight requests on transport level, we avoid transport messages by forcing
+ * a single node "cluster".
+ */
+@ClusterScope(scope = Scope.TEST, supportsDedicatedMasters = false, numClientNodes = 0, numDataNodes = 1)
+public class ReactorNetty4HttpRequestSizeLimitIT extends OpenSearchReactorNetty4IntegTestCase {
+
+    private static final ByteSizeValue LIMIT = new ByteSizeValue(2, ByteSizeUnit.KB);
+
+    @Override
+    protected boolean addMockHttpTransport() {
+        return false; // enable http
+    }
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder()
+            .put(super.nodeSettings(nodeOrdinal))
+            .put(HierarchyCircuitBreakerService.IN_FLIGHT_REQUESTS_CIRCUIT_BREAKER_LIMIT_SETTING.getKey(), LIMIT)
+            .build();
+    }
+
+    public void testLimitsInFlightRequests() throws Exception {
+        ensureGreen();
+
+        // we use the limit size as a (very) rough indication on how many requests we should sent to hit the limit
+        int numRequests = LIMIT.bytesAsInt() / 100;
+
+        StringBuilder bulkRequest = new StringBuilder();
+        for (int i = 0; i < numRequests; i++) {
+            bulkRequest.append("{\"index\": {}}");
+            bulkRequest.append(System.lineSeparator());
+            bulkRequest.append("{ \"field\" : \"value\" }");
+            bulkRequest.append(System.lineSeparator());
+        }
+
+        List<Tuple<String, CharSequence>> requests = new ArrayList<>();
+        for (int i = 0; i < 150; i++) {
+            requests.add(Tuple.tuple("/index/_bulk", bulkRequest));
+        }
+
+        HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
+        TransportAddress transportAddress = randomFrom(httpServerTransport.boundAddress().boundAddresses());
+
+        try (ReactorHttpClient nettyHttpClient = ReactorHttpClient.create(false)) {
+            final Collection<FullHttpResponse> singleResponse = nettyHttpClient.post(transportAddress.address(), requests.subList(0, 1));
+            try {
+                assertThat(singleResponse, hasSize(1));
+                assertAtLeastOnceExpectedStatus(singleResponse, HttpResponseStatus.OK);
+
+                final Collection<FullHttpResponse> multipleResponses = nettyHttpClient.post(transportAddress.address(), requests);
+                try {
+                    assertThat(multipleResponses, hasSize(requests.size()));
+                    assertAtLeastOnceExpectedStatus(multipleResponses, HttpResponseStatus.TOO_MANY_REQUESTS);
+                } finally {
+                    multipleResponses.forEach(ReferenceCounted::release);
+                }
+            } finally {
+                singleResponse.forEach(ReferenceCounted::release);
+            }
+        }
+    }
+
+    public void testDoesNotLimitExcludedRequests() throws Exception {
+        ensureGreen();
+
+        List<Tuple<String, CharSequence>> requestUris = new ArrayList<>();
+        for (int i = 0; i < 1500; i++) {
+            requestUris.add(Tuple.tuple("/_cluster/settings", "{ \"transient\": {\"search.default_search_timeout\": \"40s\" } }"));
+        }
+
+        HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
+        TransportAddress transportAddress = randomFrom(httpServerTransport.boundAddress().boundAddresses());
+
+        try (ReactorHttpClient nettyHttpClient = ReactorHttpClient.create(false)) {
+            final Collection<FullHttpResponse> responses = nettyHttpClient.put(transportAddress.address(), requestUris);
+            try {
+                assertThat(responses, hasSize(requestUris.size()));
+                assertAllInExpectedStatus(responses, HttpResponseStatus.OK);
+            } finally {
+                responses.forEach(ReferenceCounted::release);
+            }
+        }
+    }
+
+    private void assertAtLeastOnceExpectedStatus(Collection<FullHttpResponse> responses, HttpResponseStatus expectedStatus) {
+        long countExpectedStatus = responses.stream().filter(r -> r.status().equals(expectedStatus)).count();
+        assertThat("Expected at least one request with status [" + expectedStatus + "]", countExpectedStatus, greaterThan(0L));
+    }
+
+    private void assertAllInExpectedStatus(Collection<FullHttpResponse> responses, HttpResponseStatus expectedStatus) {
+        long countUnexpectedStatus = responses.stream().filter(r -> r.status().equals(expectedStatus) == false).count();
+        assertThat(
+            "Expected all requests with status [" + expectedStatus + "] but [" + countUnexpectedStatus + "] requests had a different one",
+            countUnexpectedStatus,
+            equalTo(0L)
+        );
+    }
+
+}
diff --git a/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4PipeliningIT.java b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4PipeliningIT.java
new file mode 100644
index 0000000000000..c0e43de06f6ff
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4PipeliningIT.java
@@ -0,0 +1,68 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.OpenSearchReactorNetty4IntegTestCase;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+
+import java.util.Collection;
+import java.util.Locale;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.util.ReferenceCounted;
+
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+
+@ClusterScope(scope = Scope.TEST, supportsDedicatedMasters = false, numDataNodes = 1)
+public class ReactorNetty4PipeliningIT extends OpenSearchReactorNetty4IntegTestCase {
+
+    @Override
+    protected boolean addMockHttpTransport() {
+        return false; // enable http
+    }
+
+    public void testThatNettyHttpServerSupportsPipelining() throws Exception {
+        String[] requests = new String[] { "/", "/_nodes/stats", "/", "/_cluster/state", "/" };
+
+        HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
+        TransportAddress[] boundAddresses = httpServerTransport.boundAddress().boundAddresses();
+        TransportAddress transportAddress = randomFrom(boundAddresses);
+
+        try (ReactorHttpClient client = ReactorHttpClient.create()) {
+            Collection<FullHttpResponse> responses = client.get(transportAddress.address(), true, requests);
+            try {
+                assertThat(responses, hasSize(5));
+
+                Collection<String> opaqueIds = ReactorHttpClient.returnOpaqueIds(responses);
+                assertOpaqueIdsInOrder(opaqueIds);
+            } finally {
+                responses.forEach(ReferenceCounted::release);
+            }
+        }
+    }
+
+    private void assertOpaqueIdsInOrder(Collection<String> opaqueIds) {
+        // check if opaque ids are monotonically increasing
+        int i = 0;
+        String msg = String.format(Locale.ROOT, "Expected list of opaque ids to be monotonically increasing, got [%s]", opaqueIds);
+        for (String opaqueId : opaqueIds) {
+            assertThat(msg, opaqueId, is(String.valueOf(i++)));
+        }
+    }
+
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/HttpConversionUtil.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/HttpConversionUtil.java
new file mode 100644
index 0000000000000..bd75227dabd08
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/HttpConversionUtil.java
@@ -0,0 +1,47 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.rest.RestRequest;
+
+import io.netty.handler.codec.http.HttpMethod;
+
+final class HttpConversionUtil {
+    private HttpConversionUtil() {}
+
+    /**
+     * Converts {@link HttpMethod} to {@link RestRequest.Method}
+     * @param method {@link HttpMethod} method
+     * @return corresponding {@link RestRequest.Method}
+     * @throws IllegalArgumentException if HTTP method is not supported
+     */
+    public static RestRequest.Method convertMethod(HttpMethod method) {
+        if (method == HttpMethod.GET) {
+            return RestRequest.Method.GET;
+        } else if (method == HttpMethod.POST) {
+            return RestRequest.Method.POST;
+        } else if (method == HttpMethod.PUT) {
+            return RestRequest.Method.PUT;
+        } else if (method == HttpMethod.DELETE) {
+            return RestRequest.Method.DELETE;
+        } else if (method == HttpMethod.HEAD) {
+            return RestRequest.Method.HEAD;
+        } else if (method == HttpMethod.OPTIONS) {
+            return RestRequest.Method.OPTIONS;
+        } else if (method == HttpMethod.PATCH) {
+            return RestRequest.Method.PATCH;
+        } else if (method == HttpMethod.TRACE) {
+            return RestRequest.Method.TRACE;
+        } else if (method == HttpMethod.CONNECT) {
+            return RestRequest.Method.CONNECT;
+        } else {
+            throw new IllegalArgumentException("Unexpected http method: " + method);
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingHttpChannel.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingHttpChannel.java
new file mode 100644
index 0000000000000..98b359319ff1b
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingHttpChannel.java
@@ -0,0 +1,76 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.concurrent.CompletableContext;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.http.HttpChannel;
+import org.opensearch.http.HttpResponse;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.net.InetSocketAddress;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import reactor.core.publisher.FluxSink;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+
+class NonStreamingHttpChannel implements HttpChannel {
+    private final HttpServerRequest request;
+    private final HttpServerResponse response;
+    private final CompletableContext<Void> closeContext = new CompletableContext<>();
+    private final FluxSink<HttpContent> emitter;
+
+    NonStreamingHttpChannel(HttpServerRequest request, HttpServerResponse response, FluxSink<HttpContent> emitter) {
+        this.request = request;
+        this.response = response;
+        this.emitter = emitter;
+        this.request.withConnection(connection -> Netty4Utils.addListener(connection.channel().closeFuture(), closeContext));
+    }
+
+    @Override
+    public boolean isOpen() {
+        final AtomicBoolean isOpen = new AtomicBoolean();
+        request.withConnection(connection -> isOpen.set(connection.channel().isOpen()));
+        return isOpen.get();
+    }
+
+    @Override
+    public void close() {
+        request.withConnection(connection -> connection.channel().close());
+    }
+
+    @Override
+    public void addCloseListener(ActionListener<Void> listener) {
+        closeContext.addListener(ActionListener.toBiConsumer(listener));
+    }
+
+    @Override
+    public void sendResponse(HttpResponse response, ActionListener<Void> listener) {
+        emitter.next(createResponse(response));
+        listener.onResponse(null);
+        emitter.complete();
+    }
+
+    @Override
+    public InetSocketAddress getRemoteAddress() {
+        return (InetSocketAddress) response.remoteAddress();
+    }
+
+    @Override
+    public InetSocketAddress getLocalAddress() {
+        return (InetSocketAddress) response.hostAddress();
+    }
+
+    FullHttpResponse createResponse(HttpResponse response) {
+        return (FullHttpResponse) response;
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingRequestConsumer.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingRequestConsumer.java
new file mode 100644
index 0000000000000..d43e23e800e65
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingRequestConsumer.java
@@ -0,0 +1,104 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.http.AbstractHttpServerTransport;
+import org.opensearch.http.HttpRequest;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+
+import io.netty.buffer.CompositeByteBuf;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.LastHttpContent;
+import org.reactivestreams.Publisher;
+import org.reactivestreams.Subscriber;
+import reactor.core.Disposable;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.FluxSink;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+
+class NonStreamingRequestConsumer<T extends HttpContent> implements Consumer<T>, Publisher<HttpContent>, Disposable {
+    private final HttpServerRequest request;
+    private final HttpServerResponse response;
+    private final CompositeByteBuf content;
+    private final Publisher<HttpContent> publisher;
+    private final AbstractHttpServerTransport transport;
+    private final AtomicBoolean disposed = new AtomicBoolean(false);
+    private volatile FluxSink<HttpContent> emitter;
+
+    NonStreamingRequestConsumer(
+        AbstractHttpServerTransport transport,
+        HttpServerRequest request,
+        HttpServerResponse response,
+        int maxCompositeBufferComponents
+    ) {
+        this.transport = transport;
+        this.request = request;
+        this.response = response;
+        this.content = response.alloc().compositeBuffer(maxCompositeBufferComponents);
+        this.publisher = Flux.create(emitter -> register(emitter));
+    }
+
+    private void register(FluxSink<HttpContent> emitter) {
+        this.emitter = emitter.onDispose(this).onCancel(this);
+    }
+
+    @Override
+    public void accept(T message) {
+        try {
+            if (message instanceof LastHttpContent) {
+                process(message, emitter);
+            } else if (message instanceof HttpContent) {
+                process(message, emitter);
+            }
+        } catch (Throwable ex) {
+            emitter.error(ex);
+        }
+    }
+
+    public void process(HttpContent in, FluxSink<HttpContent> emitter) {
+        // Consume request body in full before dispatching it
+        content.addComponent(true, in.content().retain());
+
+        if (in instanceof LastHttpContent) {
+            final NonStreamingHttpChannel channel = new NonStreamingHttpChannel(request, response, emitter);
+            final HttpRequest r = createRequest(request, content);
+
+            try {
+                transport.incomingRequest(r, channel);
+            } catch (Exception ex) {
+                emitter.error(ex);
+                transport.onException(channel, ex);
+            } finally {
+                r.release();
+                if (disposed.compareAndSet(false, true)) {
+                    this.content.release();
+                }
+            }
+        }
+    }
+
+    HttpRequest createRequest(HttpServerRequest request, CompositeByteBuf content) {
+        return new ReactorNetty4HttpRequest(request, content.retain());
+    }
+
+    @Override
+    public void subscribe(Subscriber<? super HttpContent> s) {
+        publisher.subscribe(s);
+    }
+
+    @Override
+    public void dispose() {
+        if (disposed.compareAndSet(false, true)) {
+            this.content.release();
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequest.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequest.java
new file mode 100644
index 0000000000000..4406c555a5b04
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequest.java
@@ -0,0 +1,272 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.http.HttpRequest;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.util.AbstractMap;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.stream.Collectors;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.handler.codec.http.DefaultHttpHeaders;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.cookie.Cookie;
+import io.netty.handler.codec.http.cookie.ServerCookieDecoder;
+import io.netty.handler.codec.http.cookie.ServerCookieEncoder;
+import reactor.netty.http.server.HttpServerRequest;
+
+class ReactorNetty4HttpRequest implements HttpRequest {
+    private final String protocol;
+    private final HttpMethod method;
+    private final String uri;
+    private final ByteBuf content;
+    private final HttpHeadersMap headers;
+    private final AtomicBoolean released;
+    private final Exception inboundException;
+    private final boolean pooled;
+
+    ReactorNetty4HttpRequest(HttpServerRequest request, ByteBuf content) {
+        this(request, new HttpHeadersMap(request.requestHeaders()), new AtomicBoolean(false), true, content);
+    }
+
+    ReactorNetty4HttpRequest(HttpServerRequest request, ByteBuf content, Exception inboundException) {
+        this(
+            request.protocol(),
+            request.method(),
+            request.uri(),
+            new HttpHeadersMap(request.requestHeaders()),
+            new AtomicBoolean(false),
+            true,
+            content,
+            inboundException
+        );
+    }
+
+    private ReactorNetty4HttpRequest(
+        HttpServerRequest request,
+        HttpHeadersMap headers,
+        AtomicBoolean released,
+        boolean pooled,
+        ByteBuf content
+    ) {
+        this(request.protocol(), request.method(), request.uri(), headers, released, pooled, content, null);
+    }
+
+    private ReactorNetty4HttpRequest(
+        String protocol,
+        HttpMethod method,
+        String uri,
+        HttpHeadersMap headers,
+        AtomicBoolean released,
+        boolean pooled,
+        ByteBuf content,
+        Exception inboundException
+    ) {
+
+        this.protocol = protocol;
+        this.method = method;
+        this.uri = uri;
+        this.headers = headers;
+        this.content = content;
+        this.pooled = pooled;
+        this.released = released;
+        this.inboundException = inboundException;
+    }
+
+    @Override
+    public RestRequest.Method method() {
+        return HttpConversionUtil.convertMethod(method);
+    }
+
+    @Override
+    public String uri() {
+        return uri;
+    }
+
+    @Override
+    public BytesReference content() {
+        assert released.get() == false;
+        return Netty4Utils.toBytesReference(content);
+    }
+
+    @Override
+    public void release() {
+        if (pooled && released.compareAndSet(false, true)) {
+            content.release();
+        }
+    }
+
+    @Override
+    public HttpRequest releaseAndCopy() {
+        assert released.get() == false;
+        if (pooled == false) {
+            return this;
+        }
+        try {
+            final ByteBuf copiedContent = Unpooled.copiedBuffer(content);
+            return new ReactorNetty4HttpRequest(protocol, method, uri, headers, new AtomicBoolean(false), false, copiedContent, null);
+        } finally {
+            release();
+        }
+    }
+
+    @Override
+    public final Map<String, List<String>> getHeaders() {
+        return headers;
+    }
+
+    @Override
+    public List<String> strictCookies() {
+        String cookieString = headers.httpHeaders.get(HttpHeaderNames.COOKIE);
+        if (cookieString != null) {
+            Set<Cookie> cookies = ServerCookieDecoder.STRICT.decode(cookieString);
+            if (!cookies.isEmpty()) {
+                return ServerCookieEncoder.STRICT.encode(cookies);
+            }
+        }
+        return Collections.emptyList();
+    }
+
+    @Override
+    public HttpVersion protocolVersion() {
+        if (protocol.equals(io.netty.handler.codec.http.HttpVersion.HTTP_1_0.toString())) {
+            return HttpRequest.HttpVersion.HTTP_1_0;
+        } else if (protocol.equals(io.netty.handler.codec.http.HttpVersion.HTTP_1_1.toString())) {
+            return HttpRequest.HttpVersion.HTTP_1_1;
+        } else {
+            throw new IllegalArgumentException("Unexpected http protocol version: " + protocol);
+        }
+    }
+
+    @Override
+    public HttpRequest removeHeader(String header) {
+        HttpHeaders headersWithoutContentTypeHeader = new DefaultHttpHeaders();
+        headersWithoutContentTypeHeader.add(headers.httpHeaders);
+        headersWithoutContentTypeHeader.remove(header);
+
+        return new ReactorNetty4HttpRequest(
+            protocol,
+            method,
+            uri,
+            new HttpHeadersMap(headersWithoutContentTypeHeader),
+            released,
+            pooled,
+            content,
+            null
+        );
+    }
+
+    @Override
+    public ReactorNetty4HttpResponse createResponse(RestStatus status, BytesReference content) {
+        return new ReactorNetty4HttpResponse(
+            headers.httpHeaders,
+            io.netty.handler.codec.http.HttpVersion.valueOf(protocol),
+            status,
+            content
+        );
+    }
+
+    @Override
+    public Exception getInboundException() {
+        return inboundException;
+    }
+
+    /**
+     * A wrapper of {@link HttpHeaders} that implements a map to prevent copying unnecessarily. This class does not support modifications
+     * and due to the underlying implementation, it performs case insensitive lookups of key to values.
+     *
+     * It is important to note that this implementation does have some downsides in that each invocation of the
+     * {@link #values()} and {@link #entrySet()} methods will perform a copy of the values in the HttpHeaders rather than returning a
+     * view of the underlying values.
+     */
+    private static class HttpHeadersMap implements Map<String, List<String>> {
+
+        private final HttpHeaders httpHeaders;
+
+        private HttpHeadersMap(HttpHeaders httpHeaders) {
+            this.httpHeaders = httpHeaders;
+        }
+
+        @Override
+        public int size() {
+            return httpHeaders.size();
+        }
+
+        @Override
+        public boolean isEmpty() {
+            return httpHeaders.isEmpty();
+        }
+
+        @Override
+        public boolean containsKey(Object key) {
+            return key instanceof String && httpHeaders.contains((String) key);
+        }
+
+        @Override
+        public boolean containsValue(Object value) {
+            return value instanceof List && httpHeaders.names().stream().map(httpHeaders::getAll).anyMatch(value::equals);
+        }
+
+        @Override
+        public List<String> get(Object key) {
+            return key instanceof String ? httpHeaders.getAll((String) key) : null;
+        }
+
+        @Override
+        public List<String> put(String key, List<String> value) {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public List<String> remove(Object key) {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public void putAll(Map<? extends String, ? extends List<String>> m) {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public void clear() {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public Set<String> keySet() {
+            return httpHeaders.names();
+        }
+
+        @Override
+        public Collection<List<String>> values() {
+            return httpHeaders.names().stream().map(k -> Collections.unmodifiableList(httpHeaders.getAll(k))).collect(Collectors.toList());
+        }
+
+        @Override
+        public Set<Entry<String, List<String>>> entrySet() {
+            return httpHeaders.names()
+                .stream()
+                .map(k -> new AbstractMap.SimpleImmutableEntry<>(k, httpHeaders.getAll(k)))
+                .collect(Collectors.toSet());
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpResponse.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpResponse.java
new file mode 100644
index 0000000000000..c45ad54b668a3
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpResponse.java
@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.http.HttpResponse;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.HttpVersion;
+
+class ReactorNetty4HttpResponse extends DefaultFullHttpResponse implements HttpResponse {
+    private final HttpHeaders requestHeaders;
+
+    ReactorNetty4HttpResponse(HttpHeaders requestHeaders, HttpVersion version, RestStatus status, BytesReference content) {
+        super(version, HttpResponseStatus.valueOf(status.getStatus()), Netty4Utils.toByteBuf(content));
+        this.requestHeaders = requestHeaders;
+    }
+
+    @Override
+    public void addHeader(String name, String value) {
+        headers().add(name, value);
+    }
+
+    @Override
+    public boolean containsHeader(String name) {
+        return headers().contains(name);
+    }
+
+    public HttpHeaders requestHeaders() {
+        return requestHeaders;
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerChannel.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerChannel.java
new file mode 100644
index 0000000000000..84360bf028ba9
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerChannel.java
@@ -0,0 +1,53 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.concurrent.CompletableContext;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.http.HttpServerChannel;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.net.InetSocketAddress;
+
+import io.netty.channel.Channel;
+
+class ReactorNetty4HttpServerChannel implements HttpServerChannel {
+    private final Channel channel;
+    private final CompletableContext<Void> closeContext = new CompletableContext<>();
+
+    ReactorNetty4HttpServerChannel(Channel channel) {
+        this.channel = channel;
+        Netty4Utils.addListener(this.channel.closeFuture(), closeContext);
+    }
+
+    @Override
+    public InetSocketAddress getLocalAddress() {
+        return (InetSocketAddress) channel.localAddress();
+    }
+
+    @Override
+    public void addCloseListener(ActionListener<Void> listener) {
+        closeContext.addListener(ActionListener.toBiConsumer(listener));
+    }
+
+    @Override
+    public boolean isOpen() {
+        return channel.isOpen();
+    }
+
+    @Override
+    public void close() {
+        channel.close();
+    }
+
+    @Override
+    public String toString() {
+        return "ReactorNetty4HttpChannel{localAddress=" + getLocalAddress() + "}";
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransport.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransport.java
new file mode 100644
index 0000000000000..d4a5a9ad83af6
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransport.java
@@ -0,0 +1,313 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Setting.Property;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.BigArrays;
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
+import org.opensearch.common.util.io.IOUtils;
+import org.opensearch.common.util.net.NetUtils;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.http.AbstractHttpServerTransport;
+import org.opensearch.http.HttpChannel;
+import org.opensearch.http.HttpReadTimeoutException;
+import org.opensearch.http.HttpServerChannel;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.threadpool.ThreadPool;
+import org.opensearch.transport.reactor.SharedGroupFactory;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.net.InetSocketAddress;
+import java.net.SocketOption;
+import java.time.Duration;
+
+import io.netty.channel.ChannelOption;
+import io.netty.channel.socket.nio.NioChannelOption;
+import io.netty.handler.codec.http.DefaultLastHttpContent;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.timeout.ReadTimeoutException;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Scheduler;
+import reactor.core.scheduler.Schedulers;
+import reactor.netty.DisposableServer;
+import reactor.netty.http.HttpProtocol;
+import reactor.netty.http.server.HttpServer;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_CONNECT_TIMEOUT;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_CHUNK_SIZE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_CONTENT_LENGTH;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_HEADER_SIZE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_INITIAL_LINE_LENGTH;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_READ_TIMEOUT;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_ALIVE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_COUNT;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_IDLE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_INTERVAL;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_NO_DELAY;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_RECEIVE_BUFFER_SIZE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_REUSE_ADDRESS;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_SEND_BUFFER_SIZE;
+
+/**
+ * The HTTP transport implementations based on Reactor Netty (see please {@link HttpServer}).
+ */
+public class ReactorNetty4HttpServerTransport extends AbstractHttpServerTransport {
+    private static final String SETTING_KEY_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS = "http.netty.max_composite_buffer_components";
+    private static final ByteSizeValue MTU = new ByteSizeValue(Long.parseLong(System.getProperty("opensearch.net.mtu", "1500")));
+
+    /**
+     * The number of Reactor Netty HTTP workers
+     */
+    public static final Setting<Integer> SETTING_HTTP_WORKER_COUNT = Setting.intSetting("http.netty.worker_count", 0, Property.NodeScope);
+
+    /**
+     * The maximum number of composite components for request accumulation
+     */
+    public static Setting<Integer> SETTING_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS = new Setting<>(
+        SETTING_KEY_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS,
+        (s) -> {
+            ByteSizeValue maxContentLength = SETTING_HTTP_MAX_CONTENT_LENGTH.get(s);
+            /*
+             * Netty accumulates buffers containing data from all incoming network packets that make up one HTTP request in an instance of
+             * io.netty.buffer.CompositeByteBuf (think of it as a buffer of buffers). Once its capacity is reached, the buffer will iterate
+             * over its individual entries and put them into larger buffers (see io.netty.buffer.CompositeByteBuf#consolidateIfNeeded()
+             * for implementation details). We want to to resize that buffer because this leads to additional garbage on the heap and also
+             * increases the application's native memory footprint (as direct byte buffers hold their contents off-heap).
+             *
+             * With this setting we control the CompositeByteBuf's capacity (which is by default 1024, see
+             * io.netty.handler.codec.MessageAggregator#DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS). To determine a proper default capacity for
+             * that buffer, we need to consider that the upper bound for the size of HTTP requests is determined by `maxContentLength`. The
+             * number of buffers that are needed depend on how often Netty reads network packets which depends on the network type (MTU).
+             * We assume here that OpenSearch receives HTTP requests via an Ethernet connection which has a MTU of 1500 bytes.
+             *
+             * Note that we are *not* pre-allocating any memory based on this setting but rather determine the CompositeByteBuf's capacity.
+             * The tradeoff is between less (but larger) buffers that are contained in the CompositeByteBuf and more (but smaller) buffers.
+             * With the default max content length of 100MB and a MTU of 1500 bytes we would allow 69905 entries.
+             */
+            long maxBufferComponentsEstimate = Math.round((double) (maxContentLength.getBytes() / MTU.getBytes()));
+            // clamp value to the allowed range
+            long maxBufferComponents = Math.max(2, Math.min(maxBufferComponentsEstimate, Integer.MAX_VALUE));
+            return String.valueOf(maxBufferComponents);
+            // Netty's CompositeByteBuf implementation does not allow less than two components.
+        },
+        s -> Setting.parseInt(s, 2, Integer.MAX_VALUE, SETTING_KEY_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS),
+        Property.NodeScope
+    );
+
+    private final SharedGroupFactory sharedGroupFactory;
+    private final int readTimeoutMillis;
+    private final int connectTimeoutMillis;
+    private final int maxCompositeBufferComponents;
+    private final ByteSizeValue maxInitialLineLength;
+    private final ByteSizeValue maxHeaderSize;
+    private final ByteSizeValue maxChunkSize;
+    private volatile SharedGroupFactory.SharedGroup sharedGroup;
+    private volatile DisposableServer disposableServer;
+    private volatile Scheduler scheduler;
+
+    /**
+     * Creates new HTTP transport implementations based on Reactor Netty (see please {@link HttpServer}).
+     * @param settings settings
+     * @param networkService network service
+     * @param bigArrays big array allocator
+     * @param threadPool thread pool instance
+     * @param xContentRegistry XContent registry instance
+     * @param dispatcher dispatcher instance
+     * @param clusterSettings cluster settings
+     * @param sharedGroupFactory shared group factory
+     * @param tracer tracer instance
+     */
+    public ReactorNetty4HttpServerTransport(
+        Settings settings,
+        NetworkService networkService,
+        BigArrays bigArrays,
+        ThreadPool threadPool,
+        NamedXContentRegistry xContentRegistry,
+        Dispatcher dispatcher,
+        ClusterSettings clusterSettings,
+        SharedGroupFactory sharedGroupFactory,
+        Tracer tracer
+    ) {
+        super(settings, networkService, bigArrays, threadPool, xContentRegistry, dispatcher, clusterSettings, tracer);
+        Netty4Utils.setAvailableProcessors(OpenSearchExecutors.NODE_PROCESSORS_SETTING.get(settings));
+        this.readTimeoutMillis = Math.toIntExact(SETTING_HTTP_READ_TIMEOUT.get(settings).getMillis());
+        this.connectTimeoutMillis = Math.toIntExact(SETTING_HTTP_CONNECT_TIMEOUT.get(settings).getMillis());
+        this.sharedGroupFactory = sharedGroupFactory;
+        this.maxCompositeBufferComponents = SETTING_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS.get(settings);
+        this.maxChunkSize = SETTING_HTTP_MAX_CHUNK_SIZE.get(settings);
+        this.maxHeaderSize = SETTING_HTTP_MAX_HEADER_SIZE.get(settings);
+        this.maxInitialLineLength = SETTING_HTTP_MAX_INITIAL_LINE_LENGTH.get(settings);
+    }
+
+    /**
+     * Binds the transport engine to the socket address
+     * @param socketAddress socket address to bind to
+     */
+    @Override
+    protected HttpServerChannel bind(InetSocketAddress socketAddress) throws Exception {
+        final HttpServer server = configureChannelOptions(
+            HttpServer.create()
+                .httpFormDecoder(builder -> builder.scheduler(scheduler))
+                .idleTimeout(Duration.ofMillis(connectTimeoutMillis))
+                .readTimeout(Duration.ofMillis(readTimeoutMillis))
+                .runOn(sharedGroup.getLowLevelGroup())
+                .bindAddress(() -> socketAddress)
+                .compress(true)
+                .httpRequestDecoder(
+                    spec -> spec.maxChunkSize(maxChunkSize.bytesAsInt())
+                        .maxHeaderSize(maxHeaderSize.bytesAsInt())
+                        .maxInitialLineLength(maxInitialLineLength.bytesAsInt())
+                )
+                .protocol(HttpProtocol.HTTP11, HttpProtocol.H2C)
+                .handle((req, res) -> incomingRequest(req, res))
+        );
+
+        disposableServer = server.bindNow();
+        return new ReactorNetty4HttpServerChannel(disposableServer.channel());
+    }
+
+    private HttpServer configureChannelOptions(final HttpServer server1) {
+        HttpServer configured = server1.childOption(ChannelOption.TCP_NODELAY, SETTING_HTTP_TCP_NO_DELAY.get(settings))
+            .childOption(ChannelOption.SO_KEEPALIVE, SETTING_HTTP_TCP_KEEP_ALIVE.get(settings));
+
+        if (SETTING_HTTP_TCP_KEEP_ALIVE.get(settings)) {
+            // Netty logs a warning if it can't set the option, so try this only on supported platforms
+            if (IOUtils.LINUX || IOUtils.MAC_OS_X) {
+                if (SETTING_HTTP_TCP_KEEP_IDLE.get(settings) >= 0) {
+                    final SocketOption<Integer> keepIdleOption = NetUtils.getTcpKeepIdleSocketOptionOrNull();
+                    if (keepIdleOption != null) {
+                        configured = configured.childOption(NioChannelOption.of(keepIdleOption), SETTING_HTTP_TCP_KEEP_IDLE.get(settings));
+                    }
+                }
+                if (SETTING_HTTP_TCP_KEEP_INTERVAL.get(settings) >= 0) {
+                    final SocketOption<Integer> keepIntervalOption = NetUtils.getTcpKeepIntervalSocketOptionOrNull();
+                    if (keepIntervalOption != null) {
+                        configured = configured.childOption(
+                            NioChannelOption.of(keepIntervalOption),
+                            SETTING_HTTP_TCP_KEEP_INTERVAL.get(settings)
+                        );
+                    }
+                }
+                if (SETTING_HTTP_TCP_KEEP_COUNT.get(settings) >= 0) {
+                    final SocketOption<Integer> keepCountOption = NetUtils.getTcpKeepCountSocketOptionOrNull();
+                    if (keepCountOption != null) {
+                        configured = configured.childOption(
+                            NioChannelOption.of(keepCountOption),
+                            SETTING_HTTP_TCP_KEEP_COUNT.get(settings)
+                        );
+                    }
+                }
+            }
+        }
+
+        final ByteSizeValue tcpSendBufferSize = SETTING_HTTP_TCP_SEND_BUFFER_SIZE.get(settings);
+        if (tcpSendBufferSize.getBytes() > 0) {
+            configured = configured.childOption(ChannelOption.SO_SNDBUF, Math.toIntExact(tcpSendBufferSize.getBytes()));
+        }
+
+        final ByteSizeValue tcpReceiveBufferSize = SETTING_HTTP_TCP_RECEIVE_BUFFER_SIZE.get(settings);
+        if (tcpReceiveBufferSize.getBytes() > 0) {
+            configured = configured.childOption(ChannelOption.SO_RCVBUF, Math.toIntExact(tcpReceiveBufferSize.getBytes()));
+        }
+
+        final boolean reuseAddress = SETTING_HTTP_TCP_REUSE_ADDRESS.get(settings);
+        configured = configured.option(ChannelOption.SO_REUSEADDR, reuseAddress);
+        configured = configured.childOption(ChannelOption.SO_REUSEADDR, reuseAddress);
+
+        return configured;
+    }
+
+    /**
+     * Handles incoming Reactor Netty request
+     * @param request request instance
+     * @param response response instances
+     * @return response publisher
+     */
+    protected Publisher<Void> incomingRequest(HttpServerRequest request, HttpServerResponse response) {
+        final NonStreamingRequestConsumer<HttpContent> consumer = new NonStreamingRequestConsumer<>(
+            this,
+            request,
+            response,
+            maxCompositeBufferComponents
+        );
+
+        request.receiveContent().switchIfEmpty(Mono.just(DefaultLastHttpContent.EMPTY_LAST_CONTENT)).subscribe(consumer);
+
+        return Mono.from(consumer).flatMap(hc -> {
+            final FullHttpResponse r = (FullHttpResponse) hc;
+            response.status(r.status());
+            response.trailerHeaders(c -> r.trailingHeaders().forEach(h -> c.add(h.getKey(), h.getValue())));
+            response.chunkedTransfer(false);
+            response.compression(true);
+            r.headers().forEach(h -> response.addHeader(h.getKey(), h.getValue()));
+            return Mono.from(response.sendObject(r.content()));
+        });
+    }
+
+    /**
+     * Called to tear down internal resources
+     */
+    @Override
+    protected void stopInternal() {
+        if (sharedGroup != null) {
+            sharedGroup.shutdown();
+            sharedGroup = null;
+        }
+
+        if (scheduler != null) {
+            scheduler.dispose();
+            scheduler = null;
+        }
+
+        if (disposableServer != null) {
+            disposableServer.disposeNow();
+            disposableServer = null;
+        }
+    }
+
+    /**
+     * Starts the transport
+     */
+    @Override
+    protected void doStart() {
+        boolean success = false;
+        try {
+            scheduler = Schedulers.newBoundedElastic(
+                Schedulers.DEFAULT_BOUNDED_ELASTIC_SIZE,
+                Schedulers.DEFAULT_BOUNDED_ELASTIC_QUEUESIZE,
+                "http-form-decoder"
+            );
+            sharedGroup = sharedGroupFactory.getHttpGroup();
+            bindServer();
+            success = true;
+        } finally {
+            if (success == false) {
+                doStop(); // otherwise we leak threads since we never moved to started
+            }
+        }
+    }
+
+    @Override
+    public void onException(HttpChannel channel, Exception cause) {
+        if (cause instanceof ReadTimeoutException) {
+            super.onException(channel, new HttpReadTimeoutException(readTimeoutMillis, cause));
+        } else {
+            super.onException(channel, cause);
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/package-info.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/package-info.java
new file mode 100644
index 0000000000000..b5ecb0b62f79d
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * The new HTTP transport implementations based on Reactor Netty.
+ */
+package org.opensearch.http.reactor.netty4;
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/ReactorNetty4Plugin.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/ReactorNetty4Plugin.java
new file mode 100644
index 0000000000000..dc310c3793109
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/ReactorNetty4Plugin.java
@@ -0,0 +1,109 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.transport.reactor;
+
+import org.opensearch.common.SetOnce;
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.BigArrays;
+import org.opensearch.common.util.PageCacheRecycler;
+import org.opensearch.core.indices.breaker.CircuitBreakerService;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.reactor.netty4.ReactorNetty4HttpServerTransport;
+import org.opensearch.plugins.NetworkPlugin;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Supplier;
+
+/**
+ * The experimental network plugin that introduces new transport implementations based on Reactor Netty.
+ */
+public class ReactorNetty4Plugin extends Plugin implements NetworkPlugin {
+    /**
+     * The name of new experimental HTTP transport implementations based on Reactor Netty.
+     */
+    public static final String REACTOR_NETTY_HTTP_TRANSPORT_NAME = "reactor-netty4";
+
+    private final SetOnce<SharedGroupFactory> groupFactory = new SetOnce<>();
+
+    /**
+     * Default constructor
+     */
+    public ReactorNetty4Plugin() {}
+
+    /**
+     * Returns a list of additional {@link Setting} definitions for this plugin.
+     */
+    @Override
+    public List<Setting<?>> getSettings() {
+        return Arrays.asList(/* no setting registered since we're picking the onces from Netty 4 transport */);
+    }
+
+    /**
+     * Returns a map of {@link HttpServerTransport} suppliers.
+     * See {@link org.opensearch.common.network.NetworkModule#HTTP_TYPE_SETTING} to configure a specific implementation.
+     * @param settings settings
+     * @param networkService network service
+     * @param bigArrays big array allocator
+     * @param pageCacheRecycler page cache recycler instance
+     * @param circuitBreakerService circuit breaker service instance
+     * @param threadPool thread pool instance
+     * @param xContentRegistry XContent registry instance
+     * @param dispatcher dispatcher instance
+     * @param clusterSettings cluster settings
+     * @param tracer tracer instance
+     */
+    @Override
+    public Map<String, Supplier<HttpServerTransport>> getHttpTransports(
+        Settings settings,
+        ThreadPool threadPool,
+        BigArrays bigArrays,
+        PageCacheRecycler pageCacheRecycler,
+        CircuitBreakerService circuitBreakerService,
+        NamedXContentRegistry xContentRegistry,
+        NetworkService networkService,
+        HttpServerTransport.Dispatcher dispatcher,
+        ClusterSettings clusterSettings,
+        Tracer tracer
+    ) {
+        return Collections.singletonMap(
+            REACTOR_NETTY_HTTP_TRANSPORT_NAME,
+            () -> new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry,
+                dispatcher,
+                clusterSettings,
+                getSharedGroupFactory(settings),
+                tracer
+            )
+        );
+    }
+
+    private SharedGroupFactory getSharedGroupFactory(Settings settings) {
+        final SharedGroupFactory groupFactory = this.groupFactory.get();
+        if (groupFactory != null) {
+            assert groupFactory.getSettings().equals(settings) : "Different settings than originally provided";
+            return groupFactory;
+        } else {
+            this.groupFactory.set(new SharedGroupFactory(settings));
+            return this.groupFactory.get();
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/SharedGroupFactory.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/SharedGroupFactory.java
new file mode 100644
index 0000000000000..ab7de33c8e673
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/SharedGroupFactory.java
@@ -0,0 +1,164 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.transport.reactor;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.concurrent.AbstractRefCounted;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.reactor.netty4.ReactorNetty4HttpServerTransport;
+import org.opensearch.transport.TcpTransport;
+import org.opensearch.transport.reactor.netty4.ReactorNetty4Transport;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.util.concurrent.Future;
+
+import static org.opensearch.common.util.concurrent.OpenSearchExecutors.daemonThreadFactory;
+
+/**
+ * Creates and returns {@link io.netty.channel.EventLoopGroup} instances. It will return a shared group for
+ * both {@link #getHttpGroup()} and {@link #getTransportGroup()} if
+ * {@link org.opensearch.http.reactor.netty4.ReactorNetty4HttpServerTransport#SETTING_HTTP_WORKER_COUNT} is configured to be 0.
+ * If that setting is not 0, then it will return a different group in the {@link #getHttpGroup()} call.
+ */
+public final class SharedGroupFactory {
+
+    private static final Logger logger = LogManager.getLogger(SharedGroupFactory.class);
+
+    private final Settings settings;
+    private final int workerCount;
+    private final int httpWorkerCount;
+
+    private RefCountedGroup genericGroup;
+    private SharedGroup dedicatedHttpGroup;
+
+    /**
+     * Creates new shared group factory instance from settings
+     * @param settings settings
+     */
+    public SharedGroupFactory(Settings settings) {
+        this.settings = settings;
+        this.workerCount = ReactorNetty4Transport.SETTING_WORKER_COUNT.get(settings);
+        this.httpWorkerCount = ReactorNetty4HttpServerTransport.SETTING_HTTP_WORKER_COUNT.get(settings);
+    }
+
+    Settings getSettings() {
+        return settings;
+    }
+
+    /**
+     * Gets the number of configured transport workers
+     * @return the number of configured transport workers
+     */
+    public int getTransportWorkerCount() {
+        return workerCount;
+    }
+
+    /**
+     * Gets transport shared group
+     * @return transport shared group
+     */
+    public synchronized SharedGroup getTransportGroup() {
+        return getGenericGroup();
+    }
+
+    /**
+     * Gets HTTP transport shared group
+     * @return HTTP transport shared group
+     */
+    public synchronized SharedGroup getHttpGroup() {
+        if (httpWorkerCount == 0) {
+            return getGenericGroup();
+        } else {
+            if (dedicatedHttpGroup == null) {
+                NioEventLoopGroup eventLoopGroup = new NioEventLoopGroup(
+                    httpWorkerCount,
+                    daemonThreadFactory(settings, HttpServerTransport.HTTP_SERVER_WORKER_THREAD_NAME_PREFIX)
+                );
+                dedicatedHttpGroup = new SharedGroup(new RefCountedGroup(eventLoopGroup));
+            }
+            return dedicatedHttpGroup;
+        }
+    }
+
+    private SharedGroup getGenericGroup() {
+        if (genericGroup == null) {
+            EventLoopGroup eventLoopGroup = new NioEventLoopGroup(
+                workerCount,
+                daemonThreadFactory(settings, TcpTransport.TRANSPORT_WORKER_THREAD_NAME_PREFIX)
+            );
+            this.genericGroup = new RefCountedGroup(eventLoopGroup);
+        } else {
+            genericGroup.incRef();
+        }
+        return new SharedGroup(genericGroup);
+    }
+
+    private static class RefCountedGroup extends AbstractRefCounted {
+
+        public static final String NAME = "ref-counted-event-loop-group";
+        private final EventLoopGroup eventLoopGroup;
+
+        private RefCountedGroup(EventLoopGroup eventLoopGroup) {
+            super(NAME);
+            this.eventLoopGroup = eventLoopGroup;
+        }
+
+        @Override
+        protected void closeInternal() {
+            Future<?> shutdownFuture = eventLoopGroup.shutdownGracefully(0, 5, TimeUnit.SECONDS);
+            shutdownFuture.awaitUninterruptibly();
+            if (shutdownFuture.isSuccess() == false) {
+                logger.warn("Error closing netty event loop group", shutdownFuture.cause());
+            }
+        }
+    }
+
+    /**
+     * Wraps the {@link RefCountedGroup}. Calls {@link RefCountedGroup#decRef()} on close. After close,
+     * this wrapped instance can no longer be used.
+     */
+    public static class SharedGroup {
+
+        private final RefCountedGroup refCountedGroup;
+
+        private final AtomicBoolean isOpen = new AtomicBoolean(true);
+
+        private SharedGroup(RefCountedGroup refCountedGroup) {
+            this.refCountedGroup = refCountedGroup;
+        }
+
+        /**
+         * Gets Netty's {@link EventLoopGroup} instance
+         * @return Netty's {@link EventLoopGroup} instance
+         */
+        public EventLoopGroup getLowLevelGroup() {
+            return refCountedGroup.eventLoopGroup;
+        }
+
+        /**
+         * Decreases the reference to underlying  {@link EventLoopGroup} instance
+         */
+        public void shutdown() {
+            if (isOpen.compareAndSet(true, false)) {
+                refCountedGroup.decRef();
+            }
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/Netty4Utils.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/Netty4Utils.java
new file mode 100644
index 0000000000000..8ec432b7dd5cd
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/Netty4Utils.java
@@ -0,0 +1,142 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.transport.reactor.netty4;
+
+import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.BytesRefIterator;
+import org.opensearch.ExceptionsHelper;
+import org.opensearch.common.Booleans;
+import org.opensearch.common.concurrent.CompletableContext;
+import org.opensearch.core.common.bytes.BytesArray;
+import org.opensearch.core.common.bytes.BytesReference;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.CompositeByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFuture;
+import io.netty.util.NettyRuntime;
+
+/**
+ * Shameless copy of Netty4Utils from transport-netty4 module
+ */
+public final class Netty4Utils {
+    private static final AtomicBoolean isAvailableProcessorsSet = new AtomicBoolean();
+
+    /**
+     * Utility class
+     */
+    private Netty4Utils() {}
+
+    /**
+     * Set the number of available processors that Netty uses for sizing various resources (e.g., thread pools).
+     *
+     * @param availableProcessors the number of available processors
+     * @throws IllegalStateException if available processors was set previously and the specified value does not match the already-set value
+     */
+    public static void setAvailableProcessors(final int availableProcessors) {
+        // we set this to false in tests to avoid tests that randomly set processors from stepping on each other
+        final boolean set = Booleans.parseBoolean(System.getProperty("opensearch.set.netty.runtime.available.processors", "true"));
+        if (!set) {
+            return;
+        }
+
+        /*
+         * This can be invoked twice, once from Netty4Transport and another time from Netty4HttpServerTransport; however,
+         * Netty4Runtime#availableProcessors forbids settings the number of processors twice so we prevent double invocation here.
+         */
+        if (isAvailableProcessorsSet.compareAndSet(false, true)) {
+            NettyRuntime.setAvailableProcessors(availableProcessors);
+        } else if (availableProcessors != NettyRuntime.availableProcessors()) {
+            /*
+             * We have previously set the available processors yet either we are trying to set it to a different value now or there is a bug
+             * in Netty and our previous value did not take, bail.
+             */
+            final String message = String.format(
+                Locale.ROOT,
+                "available processors value [%d] did not match current value [%d]",
+                availableProcessors,
+                NettyRuntime.availableProcessors()
+            );
+            throw new IllegalStateException(message);
+        }
+    }
+
+    /**
+     * Turns the given BytesReference into a ByteBuf. Note: the returned ByteBuf will reference the internal
+     * pages of the BytesReference. Don't free the bytes of reference before the ByteBuf goes out of scope.
+     * @param reference reference to convert
+     */
+    public static ByteBuf toByteBuf(final BytesReference reference) {
+        if (reference.length() == 0) {
+            return Unpooled.EMPTY_BUFFER;
+        }
+        final BytesRefIterator iterator = reference.iterator();
+        // usually we have one, two, or three components from the header, the message, and a buffer
+        final List<ByteBuf> buffers = new ArrayList<>(3);
+        try {
+            BytesRef slice;
+            while ((slice = iterator.next()) != null) {
+                buffers.add(Unpooled.wrappedBuffer(slice.bytes, slice.offset, slice.length));
+            }
+
+            if (buffers.size() == 1) {
+                return buffers.get(0);
+            } else {
+                CompositeByteBuf composite = Unpooled.compositeBuffer(buffers.size());
+                composite.addComponents(true, buffers);
+                return composite;
+            }
+        } catch (IOException ex) {
+            throw new AssertionError("no IO happens here", ex);
+        }
+    }
+
+    /**
+     * Wraps the given ChannelBuffer with a BytesReference
+     * @param buffer buffer to convert
+     */
+    public static BytesReference toBytesReference(final ByteBuf buffer) {
+        final int readableBytes = buffer.readableBytes();
+        if (readableBytes == 0) {
+            return BytesArray.EMPTY;
+        } else if (buffer.hasArray()) {
+            return new BytesArray(buffer.array(), buffer.arrayOffset() + buffer.readerIndex(), readableBytes);
+        } else {
+            final ByteBuffer[] byteBuffers = buffer.nioBuffers();
+            return BytesReference.fromByteBuffers(byteBuffers);
+        }
+    }
+
+    /**
+     * Add completion listener to ChannelFuture
+     * @param channelFuture ChannelFuture to add listener to
+     * @param context completion listener context
+     */
+    public static void addListener(ChannelFuture channelFuture, CompletableContext<Void> context) {
+        channelFuture.addListener(f -> {
+            if (f.isSuccess()) {
+                context.complete(null);
+            } else {
+                Throwable cause = f.cause();
+                if (cause instanceof Error) {
+                    ExceptionsHelper.maybeDieOnAnotherThread(cause);
+                    context.completeExceptionally(new Exception(cause));
+                } else {
+                    context.completeExceptionally((Exception) cause);
+                }
+            }
+        });
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/ReactorNetty4Transport.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/ReactorNetty4Transport.java
new file mode 100644
index 0000000000000..b3e92f58c540a
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/ReactorNetty4Transport.java
@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.transport.reactor.netty4;
+
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Setting.Property;
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
+
+import reactor.netty.tcp.TcpServer;
+
+/**
+ * The transport implementations based on Reactor Netty (see please {@link TcpServer}).
+ */
+public class ReactorNetty4Transport {
+    /**
+     * The number of Netty workers
+     */
+    public static final Setting<Integer> SETTING_WORKER_COUNT = new Setting<>(
+        "transport.netty.worker_count",
+        (s) -> Integer.toString(OpenSearchExecutors.allocatedProcessors(s)),
+        (s) -> Setting.parseInt(s, 1, "transport.netty.worker_count"),
+        Property.NodeScope
+    );
+
+    /**
+     * Default constructor
+     */
+    public ReactorNetty4Transport() {}
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/package-info.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/package-info.java
new file mode 100644
index 0000000000000..921bca104c6fe
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * The new transport implementations based on Reactor Netty.
+ */
+package org.opensearch.transport.reactor.netty4;
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/package-info.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/package-info.java
new file mode 100644
index 0000000000000..2f36ebb7f11f8
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * The experimental network plugin that introduces new transport implementations based on Reactor Netty.
+ */
+package org.opensearch.transport.reactor;
diff --git a/plugins/transport-reactor-netty4/src/main/plugin-metadata/plugin-security.policy b/plugins/transport-reactor-netty4/src/main/plugin-metadata/plugin-security.policy
new file mode 100644
index 0000000000000..4f2dcde995338
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/plugin-metadata/plugin-security.policy
@@ -0,0 +1,24 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+grant codeBase "${codebase.netty-common}" {
+   // for reading the system-wide configuration for the backlog of established sockets
+   permission java.io.FilePermission "/proc/sys/net/core/somaxconn", "read";
+
+   // netty makes and accepts socket connections
+   permission java.net.SocketPermission "*", "accept,connect";
+
+   // Netty sets custom classloader for some of its internal threads
+   permission java.lang.RuntimePermission "*", "setContextClassLoader";
+};
+
+grant codeBase "${codebase.netty-transport}" {
+   // Netty NioEventLoop wants to change this, because of https://bugs.openjdk.java.net/browse/JDK-6427854
+   // the bug says it only happened rarely, and that its fixed, but apparently it still happens rarely!
+   permission java.util.PropertyPermission "sun.nio.ch.bugLevel", "write";
+};
diff --git a/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorHttpClient.java b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorHttpClient.java
new file mode 100644
index 0000000000000..443ecd0f40ead
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorHttpClient.java
@@ -0,0 +1,208 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.collect.Tuple;
+import org.opensearch.tasks.Task;
+
+import java.io.Closeable;
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.EmptyHttpHeaders;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpResponse;
+import io.netty.handler.codec.http.HttpVersion;
+import io.netty.handler.codec.http2.HttpConversionUtil;
+import io.netty.resolver.DefaultAddressResolverGroup;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.publisher.ParallelFlux;
+import reactor.netty.http.client.HttpClient;
+
+import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+
+/**
+ * Tiny helper to send http requests over netty.
+ */
+class ReactorHttpClient implements Closeable {
+    private final boolean compression;
+
+    static Collection<String> returnHttpResponseBodies(Collection<FullHttpResponse> responses) {
+        List<String> list = new ArrayList<>(responses.size());
+        for (FullHttpResponse response : responses) {
+            list.add(response.content().toString(StandardCharsets.UTF_8));
+        }
+        return list;
+    }
+
+    static Collection<String> returnOpaqueIds(Collection<FullHttpResponse> responses) {
+        List<String> list = new ArrayList<>(responses.size());
+        for (HttpResponse response : responses) {
+            list.add(response.headers().get(Task.X_OPAQUE_ID));
+        }
+        return list;
+    }
+
+    ReactorHttpClient(boolean compression) {
+        this.compression = compression;
+    }
+
+    static ReactorHttpClient create() {
+        return create(true);
+    }
+
+    static ReactorHttpClient create(boolean compression) {
+        return new ReactorHttpClient(compression);
+    }
+
+    public List<FullHttpResponse> get(InetSocketAddress remoteAddress, String... uris) throws InterruptedException {
+        return get(remoteAddress, false, uris);
+    }
+
+    public List<FullHttpResponse> get(InetSocketAddress remoteAddress, boolean ordered, String... uris) throws InterruptedException {
+        final List<FullHttpRequest> requests = new ArrayList<>(uris.length);
+
+        for (int i = 0; i < uris.length; i++) {
+            final FullHttpRequest httpRequest = new DefaultFullHttpRequest(HTTP_1_1, HttpMethod.GET, uris[i]);
+            httpRequest.headers().add(HOST, "localhost");
+            httpRequest.headers().add("X-Opaque-ID", String.valueOf(i));
+            httpRequest.headers().add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), "http");
+            requests.add(httpRequest);
+        }
+
+        return sendRequests(remoteAddress, requests, ordered);
+    }
+
+    public final Collection<FullHttpResponse> post(InetSocketAddress remoteAddress, List<Tuple<String, CharSequence>> urisAndBodies)
+        throws InterruptedException {
+        return processRequestsWithBody(HttpMethod.POST, remoteAddress, urisAndBodies);
+    }
+
+    public final FullHttpResponse send(InetSocketAddress remoteAddress, FullHttpRequest httpRequest) throws InterruptedException {
+        final List<FullHttpResponse> responses = sendRequests(remoteAddress, Collections.singleton(httpRequest), false);
+        assert responses.size() == 1 : "expected 1 and only 1 http response";
+        return responses.get(0);
+    }
+
+    public final FullHttpResponse send(InetSocketAddress remoteAddress, FullHttpRequest httpRequest, HttpContent content)
+        throws InterruptedException {
+        final List<FullHttpResponse> responses = sendRequests(
+            remoteAddress,
+            Collections.singleton(
+                new DefaultFullHttpRequest(
+                    httpRequest.protocolVersion(),
+                    httpRequest.method(),
+                    httpRequest.uri(),
+                    content.content(),
+                    httpRequest.headers(),
+                    httpRequest.trailingHeaders()
+                )
+            ),
+            false
+        );
+        assert responses.size() == 1 : "expected 1 and only 1 http response";
+        return responses.get(0);
+    }
+
+    public final Collection<FullHttpResponse> put(InetSocketAddress remoteAddress, List<Tuple<String, CharSequence>> urisAndBodies)
+        throws InterruptedException {
+        return processRequestsWithBody(HttpMethod.PUT, remoteAddress, urisAndBodies);
+    }
+
+    private List<FullHttpResponse> processRequestsWithBody(
+        HttpMethod method,
+        InetSocketAddress remoteAddress,
+        List<Tuple<String, CharSequence>> urisAndBodies
+    ) throws InterruptedException {
+        List<FullHttpRequest> requests = new ArrayList<>(urisAndBodies.size());
+        for (int i = 0; i < urisAndBodies.size(); ++i) {
+            final Tuple<String, CharSequence> uriAndBody = urisAndBodies.get(i);
+            ByteBuf content = Unpooled.copiedBuffer(uriAndBody.v2(), StandardCharsets.UTF_8);
+            FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, method, uriAndBody.v1(), content);
+            request.headers().add(HttpHeaderNames.HOST, "localhost");
+            request.headers().add(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
+            request.headers().add(HttpHeaderNames.CONTENT_TYPE, "application/json");
+            request.headers().add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), "http");
+            request.headers().add("X-Opaque-ID", String.valueOf(i));
+            requests.add(request);
+        }
+        return sendRequests(remoteAddress, requests, false);
+    }
+
+    private List<FullHttpResponse> sendRequests(
+        final InetSocketAddress remoteAddress,
+        final Collection<FullHttpRequest> requests,
+        boolean orderer
+    ) {
+        final NioEventLoopGroup eventLoopGroup = new NioEventLoopGroup(1);
+        try {
+            final HttpClient client = HttpClient.newConnection()
+                .resolver(DefaultAddressResolverGroup.INSTANCE)
+                .runOn(eventLoopGroup)
+                .host(remoteAddress.getHostString())
+                .port(remoteAddress.getPort())
+                .compress(compression);
+
+            @SuppressWarnings("unchecked")
+            final Mono<FullHttpResponse>[] monos = requests.stream()
+                .map(
+                    request -> client.headers(h -> h.add(request.headers()))
+                        .baseUrl(request.getUri())
+                        .request(request.method())
+                        .send(Mono.fromSupplier(() -> request.content()))
+                        .responseSingle(
+                            (r, body) -> body.switchIfEmpty(Mono.just(Unpooled.EMPTY_BUFFER))
+                                .map(
+                                    b -> new DefaultFullHttpResponse(
+                                        r.version(),
+                                        r.status(),
+                                        b.retain(),
+                                        r.responseHeaders(),
+                                        EmptyHttpHeaders.INSTANCE
+                                    )
+                                )
+                        )
+                )
+                .toArray(Mono[]::new);
+
+            if (orderer == false) {
+                return ParallelFlux.from(monos).sequential().collectList().block();
+            } else {
+                return Flux.concat(monos).flatMapSequential(r -> Mono.just(r)).collectList().block();
+            }
+        } finally {
+            eventLoopGroup.shutdownGracefully().awaitUninterruptibly();
+        }
+    }
+
+    @Override
+    public void close() {
+
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4BadRequestTests.java b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4BadRequestTests.java
new file mode 100644
index 0000000000000..00ca378a4e46b
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4BadRequestTests.java
@@ -0,0 +1,122 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.OpenSearchException;
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.MockBigArrays;
+import org.opensearch.common.util.MockPageCacheRecycler;
+import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.HttpTransportSettings;
+import org.opensearch.rest.BytesRestResponse;
+import org.opensearch.rest.RestChannel;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.opensearch.transport.reactor.SharedGroupFactory;
+import org.junit.After;
+import org.junit.Before;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.util.ReferenceCounted;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
+
+public class ReactorNetty4BadRequestTests extends OpenSearchTestCase {
+
+    private NetworkService networkService;
+    private MockBigArrays bigArrays;
+    private ThreadPool threadPool;
+
+    @Before
+    public void setup() throws Exception {
+        networkService = new NetworkService(Collections.emptyList());
+        bigArrays = new MockBigArrays(new MockPageCacheRecycler(Settings.EMPTY), new NoneCircuitBreakerService());
+        threadPool = new TestThreadPool("test");
+    }
+
+    @After
+    public void shutdown() throws Exception {
+        terminate(threadPool);
+    }
+
+    public void testBadParameterEncoding() throws Exception {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(RestRequest request, RestChannel channel, ThreadContext threadContext) {
+                fail();
+            }
+
+            @Override
+            public void dispatchBadRequest(RestChannel channel, ThreadContext threadContext, Throwable cause) {
+                try {
+                    final Exception e = cause instanceof Exception ? (Exception) cause : new OpenSearchException(cause);
+                    channel.sendResponse(new BytesRestResponse(channel, RestStatus.BAD_REQUEST, e));
+                } catch (final IOException e) {
+                    throw new UncheckedIOException(e);
+                }
+            }
+        };
+
+        Settings settings = Settings.builder().put(HttpTransportSettings.SETTING_HTTP_PORT.getKey(), getPortRange()).build();
+        try (
+            HttpServerTransport httpServerTransport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+                new SharedGroupFactory(Settings.EMPTY),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            httpServerTransport.start();
+            final TransportAddress transportAddress = randomFrom(httpServerTransport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient nettyHttpClient = ReactorHttpClient.create()) {
+                final List<FullHttpResponse> responses = nettyHttpClient.get(transportAddress.address(), "/_cluster/settings?pretty=%");
+
+                try {
+                    assertThat(responses, hasSize(1));
+                    final FullHttpResponse response = responses.get(0);
+                    assertThat(response.status().code(), equalTo(400));
+                    final Collection<String> responseBodies = ReactorHttpClient.returnHttpResponseBodies(responses);
+                    assertThat(responseBodies, hasSize(1));
+                    final String body = responseBodies.iterator().next();
+                    assertThat(body, containsString("\"type\":\"bad_parameter_exception\""));
+                    assertThat(
+                        body,
+                        containsString("\"reason\":\"java.lang.IllegalArgumentException: partial escape sequence at end of string: %/\"")
+                    );
+                } finally {
+                    responses.forEach(ReferenceCounted::release);
+                }
+            }
+        }
+    }
+
+}
diff --git a/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransportTests.java b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransportTests.java
new file mode 100644
index 0000000000000..15a5b04c802a4
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransportTests.java
@@ -0,0 +1,579 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.opensearch.common.network.NetworkAddress;
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.MockBigArrays;
+import org.opensearch.common.util.MockPageCacheRecycler;
+import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.core.common.bytes.BytesArray;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.http.BindHttpException;
+import org.opensearch.http.CorsHandler;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.HttpTransportSettings;
+import org.opensearch.http.NullDispatcher;
+import org.opensearch.rest.BytesRestResponse;
+import org.opensearch.rest.RestChannel;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.test.rest.FakeRestRequest;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.opensearch.transport.NettyAllocator;
+import org.opensearch.transport.reactor.SharedGroupFactory;
+import org.junit.After;
+import org.junit.Before;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.buffer.ByteBufAllocator;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.PoolArenaMetric;
+import io.netty.buffer.PooledByteBufAllocator;
+import io.netty.buffer.PooledByteBufAllocatorMetric;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandlerAdapter;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.DefaultHttpContent;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaderValues;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.HttpUtil;
+import io.netty.handler.codec.http.HttpVersion;
+
+import static org.opensearch.core.rest.RestStatus.OK;
+import static org.opensearch.http.HttpTransportSettings.SETTING_CORS_ALLOW_ORIGIN;
+import static org.opensearch.http.HttpTransportSettings.SETTING_CORS_ENABLED;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+
+/**
+ * Tests for the {@link ReactorNetty4HttpServerTransport} class.
+ */
+public class ReactorNetty4HttpServerTransportTests extends OpenSearchTestCase {
+
+    private NetworkService networkService;
+    private ThreadPool threadPool;
+    private MockBigArrays bigArrays;
+    private ClusterSettings clusterSettings;
+
+    @Before
+    public void setup() throws Exception {
+        networkService = new NetworkService(Collections.emptyList());
+        threadPool = new TestThreadPool("test");
+        bigArrays = new MockBigArrays(new MockPageCacheRecycler(Settings.EMPTY), new NoneCircuitBreakerService());
+        clusterSettings = new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+    }
+
+    @After
+    public void shutdown() throws Exception {
+        if (threadPool != null) {
+            threadPool.shutdownNow();
+        }
+        threadPool = null;
+        networkService = null;
+        bigArrays = null;
+        clusterSettings = null;
+    }
+
+    /**
+     * Test that {@link ReactorNetty4HttpServerTransport} supports the "Expect: 100-continue" HTTP header
+     * @throws InterruptedException if the client communication with the server is interrupted
+     */
+    public void testExpectContinueHeader() throws InterruptedException {
+        final Settings settings = createSettings();
+        final int contentLength = randomIntBetween(1, HttpTransportSettings.SETTING_HTTP_MAX_CONTENT_LENGTH.get(settings).bytesAsInt());
+        runExpectHeaderTest(settings, HttpHeaderValues.CONTINUE.toString(), contentLength, HttpResponseStatus.CONTINUE);
+    }
+
+    /**
+     * Test that {@link ReactorNetty4HttpServerTransport} responds to a
+     * 100-continue expectation with too large a content-length
+     * with a 413 status.
+     * @throws InterruptedException if the client communication with the server is interrupted
+     */
+    public void testExpectContinueHeaderContentLengthTooLong() throws InterruptedException {
+        final String key = HttpTransportSettings.SETTING_HTTP_MAX_CONTENT_LENGTH.getKey();
+        final int maxContentLength = randomIntBetween(1, 104857600);
+        final Settings settings = createBuilderWithPort().put(key, maxContentLength + "b").build();
+        final int contentLength = randomIntBetween(maxContentLength + 1, Integer.MAX_VALUE);
+        runExpectHeaderTest(settings, HttpHeaderValues.CONTINUE.toString(), contentLength, HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE);
+    }
+
+    /**
+     * Test that {@link ReactorNetty4HttpServerTransport} responds to an unsupported expectation with a 417 status.
+     * @throws InterruptedException if the client communication with the server is interrupted
+     */
+    public void testExpectUnsupportedExpectation() throws InterruptedException {
+        Settings settings = createSettings();
+        runExpectHeaderTest(settings, "chocolate=yummy", 0, HttpResponseStatus.EXPECTATION_FAILED);
+    }
+
+    private void runExpectHeaderTest(
+        final Settings settings,
+        final String expectation,
+        final int contentLength,
+        final HttpResponseStatus expectedStatus
+    ) throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(RestRequest request, RestChannel channel, ThreadContext threadContext) {
+                channel.sendResponse(new BytesRestResponse(OK, BytesRestResponse.TEXT_CONTENT_TYPE, new BytesArray("done")));
+            }
+
+            @Override
+            public void dispatchBadRequest(RestChannel channel, ThreadContext threadContext, Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError();
+            }
+        };
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.POST, "/");
+                request.headers().set(HttpHeaderNames.EXPECT, expectation);
+                HttpUtil.setContentLength(request, contentLength);
+
+                // Reactor Netty 4 does not expose 100 CONTINUE response but instead just asks for content
+                final HttpContent continuationRequest = new DefaultHttpContent(Unpooled.EMPTY_BUFFER);
+                final FullHttpResponse continuationResponse = client.send(remoteAddress.address(), request, continuationRequest);
+                try {
+                    assertThat(continuationResponse.status(), is(HttpResponseStatus.OK));
+                    assertThat(new String(ByteBufUtil.getBytes(continuationResponse.content()), StandardCharsets.UTF_8), is("done"));
+                } finally {
+                    continuationResponse.release();
+                }
+            }
+        }
+    }
+
+    public void testBindUnavailableAddress() {
+        Settings initialSettings = createSettings();
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                initialSettings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                new NullDispatcher(),
+                clusterSettings,
+                new SharedGroupFactory(Settings.EMPTY),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+            Settings settings = Settings.builder()
+                .put("http.port", remoteAddress.getPort())
+                .put("network.host", remoteAddress.getAddress())
+                .build();
+            try (
+                ReactorNetty4HttpServerTransport otherTransport = new ReactorNetty4HttpServerTransport(
+                    settings,
+                    networkService,
+                    bigArrays,
+                    threadPool,
+                    xContentRegistry(),
+                    new NullDispatcher(),
+                    clusterSettings,
+                    new SharedGroupFactory(settings),
+                    NoopTracer.INSTANCE
+                )
+            ) {
+                BindHttpException bindHttpException = expectThrows(BindHttpException.class, otherTransport::start);
+                assertEquals("Failed to bind to " + NetworkAddress.format(remoteAddress.address()), bindHttpException.getMessage());
+            }
+        }
+    }
+
+    public void testBadRequest() throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                logger.error("--> Unexpected successful request [{}]", FakeRestRequest.requestToString(request));
+                throw new AssertionError();
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error("--> Unexpected bad request request");
+                throw new AssertionError(cause);
+            }
+        };
+
+        final Settings settings;
+        final int maxInitialLineLength;
+        final Setting<ByteSizeValue> httpMaxInitialLineLengthSetting = HttpTransportSettings.SETTING_HTTP_MAX_INITIAL_LINE_LENGTH;
+        if (randomBoolean()) {
+            maxInitialLineLength = httpMaxInitialLineLengthSetting.getDefault(Settings.EMPTY).bytesAsInt();
+            settings = createSettings();
+        } else {
+            maxInitialLineLength = randomIntBetween(1, 8192);
+            settings = createBuilderWithPort().put(httpMaxInitialLineLengthSetting.getKey(), maxInitialLineLength + "b").build();
+        }
+
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final String url = "/" + randomAlphaOfLength(maxInitialLineLength);
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, url);
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.REQUEST_URI_TOO_LONG));
+                    assertThat(response.content().array().length, equalTo(0));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    public void testDispatchFailed() throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                throw new RuntimeException("Bad things happen");
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error("--> Unexpected bad request request");
+                throw new AssertionError(cause);
+            }
+        };
+
+        final Settings settings = createSettings();
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.INTERNAL_SERVER_ERROR));
+                    assertThat(response.content().array().length, equalTo(0));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    public void testLargeCompressedResponse() throws InterruptedException {
+        final String responseString = randomAlphaOfLength(4 * 1024 * 1024);
+        final String url = "/thing/";
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                if (url.equals(request.uri())) {
+                    channel.sendResponse(new BytesRestResponse(OK, responseString));
+                } else {
+                    logger.error("--> Unexpected successful uri [{}]", request.uri());
+                    throw new AssertionError();
+                }
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError();
+            }
+
+        };
+
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                Settings.EMPTY,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(Settings.EMPTY),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                DefaultFullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, url);
+                request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, randomFrom("deflate", "gzip"));
+                long numOfHugeAllocations = getHugeAllocationCount();
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(getHugeAllocationCount(), equalTo(numOfHugeAllocations));
+                    assertThat(response.status(), equalTo(HttpResponseStatus.OK));
+                    byte[] bytes = new byte[response.content().readableBytes()];
+                    response.content().readBytes(bytes);
+                    assertThat(new String(bytes, StandardCharsets.UTF_8), equalTo(responseString));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    private long getHugeAllocationCount() {
+        long numOfHugAllocations = 0;
+        ByteBufAllocator allocator = NettyAllocator.getAllocator();
+        assert allocator instanceof NettyAllocator.NoDirectBuffers;
+        ByteBufAllocator delegate = ((NettyAllocator.NoDirectBuffers) allocator).getDelegate();
+        if (delegate instanceof PooledByteBufAllocator) {
+            PooledByteBufAllocatorMetric metric = ((PooledByteBufAllocator) delegate).metric();
+            numOfHugAllocations = metric.heapArenas().stream().mapToLong(PoolArenaMetric::numHugeAllocations).sum();
+        }
+        return numOfHugAllocations;
+    }
+
+    public void testCorsRequest() throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                logger.error("--> Unexpected successful request [{}]", FakeRestRequest.requestToString(request));
+                throw new AssertionError();
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError();
+            }
+
+        };
+
+        final Settings settings = createBuilderWithPort().put(SETTING_CORS_ENABLED.getKey(), true)
+            .put(SETTING_CORS_ALLOW_ORIGIN.getKey(), "test-cors.org")
+            .build();
+
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            // Test pre-flight request
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.OPTIONS, "/");
+                request.headers().add(CorsHandler.ORIGIN, "test-cors.org");
+                request.headers().add(CorsHandler.ACCESS_CONTROL_REQUEST_METHOD, "POST");
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.OK));
+                    assertThat(response.headers().get(CorsHandler.ACCESS_CONTROL_ALLOW_ORIGIN), equalTo("test-cors.org"));
+                    assertThat(response.headers().get(CorsHandler.VARY), equalTo(CorsHandler.ORIGIN));
+                    assertTrue(response.headers().contains(CorsHandler.DATE));
+                } finally {
+                    response.release();
+                }
+            }
+
+            // Test short-circuited request
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
+                request.headers().add(CorsHandler.ORIGIN, "google.com");
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.FORBIDDEN));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    public void testConnectTimeout() throws Exception {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                logger.error("--> Unexpected successful request [{}]", FakeRestRequest.requestToString(request));
+                throw new AssertionError("Should not have received a dispatched request");
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError("Should not have received a dispatched request");
+            }
+
+        };
+
+        Settings settings = createBuilderWithPort().put(
+            HttpTransportSettings.SETTING_HTTP_CONNECT_TIMEOUT.getKey(),
+            new TimeValue(randomIntBetween(100, 300))
+        ).build();
+
+        NioEventLoopGroup group = new NioEventLoopGroup();
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            final CountDownLatch channelClosedLatch = new CountDownLatch(1);
+
+            final Bootstrap clientBootstrap = new Bootstrap().option(ChannelOption.ALLOCATOR, NettyAllocator.getAllocator())
+                .channel(NioSocketChannel.class)
+                .handler(new ChannelInitializer<SocketChannel>() {
+
+                    @Override
+                    protected void initChannel(SocketChannel ch) {
+                        ch.pipeline().addLast(new ChannelHandlerAdapter() {
+                        });
+
+                    }
+                })
+                .group(group);
+            ChannelFuture connect = clientBootstrap.connect(remoteAddress.address());
+            connect.channel().closeFuture().addListener(future -> channelClosedLatch.countDown());
+
+            assertTrue("Channel should be closed due to read timeout", channelClosedLatch.await(1, TimeUnit.MINUTES));
+
+        } finally {
+            group.shutdownGracefully().await();
+        }
+    }
+
+    private Settings createSettings() {
+        return createBuilderWithPort().build();
+    }
+
+    private Settings.Builder createBuilderWithPort() {
+        return Settings.builder().put(HttpTransportSettings.SETTING_HTTP_PORT.getKey(), getPortRange());
+    }
+}
diff --git a/qa/full-cluster-restart/src/test/java/org/opensearch/upgrades/QueryBuilderBWCIT.java b/qa/full-cluster-restart/src/test/java/org/opensearch/upgrades/QueryBuilderBWCIT.java
index aabc3aee8887f..2675e9b62de35 100644
--- a/qa/full-cluster-restart/src/test/java/org/opensearch/upgrades/QueryBuilderBWCIT.java
+++ b/qa/full-cluster-restart/src/test/java/org/opensearch/upgrades/QueryBuilderBWCIT.java
@@ -78,7 +78,7 @@
  * PercolatorFieldMapper#createQueryBuilderField(...) method). Using the query builders writable contract. This test
  * does best effort verifying that we don't break bwc for query builders between the first previous major version and
  * the latest current major release.
- *
+ * <p>
  * The queries to test are specified in json format, which turns out to work because we tend break here rarely. If the
  * json format of a query being tested here then feel free to change this.
  */
diff --git a/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java b/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java
index 686fc78dcec8a..13c2daeec37af 100644
--- a/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java
+++ b/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java
@@ -67,13 +67,14 @@
 public class IndexingIT extends OpenSearchRestTestCase {
 
     protected static final Version UPGRADE_FROM_VERSION = Version.fromString(System.getProperty("tests.upgrade_from_version"));
+    private static final String TEST_MAPPING = createTestMapping();
 
 
     private int indexDocs(String index, final int idStart, final int numDocs) throws IOException {
         for (int i = 0; i < numDocs; i++) {
             final int id = idStart + i;
             Request request = new Request("PUT", index + "/_doc/" + id);
-            request.setJsonEntity("{\"test\": \"test_" + randomAlphaOfLength(2) + "\"}");
+            request.setJsonEntity("{\"test\": \"test_" + randomAlphaOfLength(2) + "\", \"sortfield\": \""+ randomIntBetween(0, numDocs) + "\"}");
             assertOK(client().performRequest(request));
         }
         return numDocs;
@@ -129,9 +130,10 @@ public void testIndexingWithPrimaryOnBwcNodes() throws Exception {
             .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1)
             .put(IndexMetadata.INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 0)
             .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .putList("index.sort.field", "sortfield")
             .put("index.routing.allocation.include._name", bwcNames);
         final String index = "test-index";
-        createIndex(index, settings.build());
+        createIndex(index, settings.build(), TEST_MAPPING);
         ensureNoInitializingShards(); // wait for all other shard activity to finish
 
         int docCount = 200;
@@ -178,9 +180,10 @@ public void testIndexingWithReplicaOnBwcNodes() throws Exception {
             .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1)
             .put(IndexMetadata.INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 0)
             .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .putList("index.sort.field", "sortfield")
             .put("index.routing.allocation.exclude._name", bwcNames);
         final String index = "test-index";
-        createIndex(index, settings.build());
+        createIndex(index, settings.build(), TEST_MAPPING);
         ensureNoInitializingShards(); // wait for all other shard activity to finish
         printClusterRouting();
 
@@ -214,11 +217,12 @@ public void testIndexVersionPropagation() throws Exception {
         Settings.Builder settings = Settings.builder()
                 .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1)
                 .put(IndexMetadata.INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 2)
+                .putList("index.sort.field", "sortfield")
                 .put("index.routing.allocation.include._name", bwcNames);
         final String index = "indexversionprop";
         final int minUpdates = 5;
         final int maxUpdates = 10;
-        createIndex(index, settings.build());
+        createIndex(index, settings.build(), TEST_MAPPING);
         try (RestClient newNodeClient = buildClient(restClientSettings(),
                 nodes.getNewNodes().stream().map(Node::getPublishAddress).toArray(HttpHost[]::new))) {
 
@@ -300,10 +304,11 @@ public void testSeqNoCheckpoints() throws Exception {
         Settings.Builder settings = Settings.builder()
             .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1)
             .put(IndexMetadata.INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 2)
+            .putList("index.sort.field", "sortfield")
             .put("index.routing.allocation.include._name", bwcNames);
 
         final String index = "test";
-        createIndex(index, settings.build());
+        createIndex(index, settings.build(), TEST_MAPPING);
         try (RestClient newNodeClient = buildClient(restClientSettings(),
             nodes.getNewNodes().stream().map(Node::getPublishAddress).toArray(HttpHost[]::new))) {
             int numDocs = 0;
@@ -382,10 +387,11 @@ public void testUpdateSnapshotStatus() throws Exception {
         Settings.Builder settings = Settings.builder()
             .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), between(5, 10))
             .put(IndexMetadata.INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 1)
+            .putList("index.sort.field", "sortfield")
             .put("index.routing.allocation.include._name", bwcNames);
 
         final String index = "test-snapshot-index";
-        createIndex(index, settings.build());
+        createIndex(index, settings.build(), TEST_MAPPING);
         indexDocs(index, 0, between(50, 100));
         ensureGreen(index);
         assertOK(client().performRequest(new Request("POST", index + "/_refresh")));
@@ -419,7 +425,8 @@ public void testSyncedFlushTransition() throws Exception {
         createIndex(index, Settings.builder()
             .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), numShards)
             .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, numOfReplicas)
-            .put("index.routing.allocation.include._name", newNodes).build());
+            .putList("index.sort.field", "sortfield")
+            .put("index.routing.allocation.include._name", newNodes).build(), TEST_MAPPING);
         ensureGreen(index);
         indexDocs(index, randomIntBetween(0, 100), between(1, 100));
         try (RestClient oldNodeClient = buildClient(restClientSettings(),
@@ -664,4 +671,15 @@ public String toString() {
                 '}';
         }
     }
+
+    private static String createTestMapping() {
+        return "  \"properties\": {\n"
+            + "    \"test\": {\n"
+            + "      \"type\": \"text\"\n"
+            + "    },\n"
+            + "    \"sortfield\": {\n"
+            + "      \"type\": \"integer\"\n"
+            + "    }\n"
+            + "  }";
+    }
 }
diff --git a/qa/no-bootstrap-tests/src/test/java/org/opensearch/bootstrap/SpawnerNoBootstrapTests.java b/qa/no-bootstrap-tests/src/test/java/org/opensearch/bootstrap/SpawnerNoBootstrapTests.java
index c3c332aecfd4c..8ca90791f649e 100644
--- a/qa/no-bootstrap-tests/src/test/java/org/opensearch/bootstrap/SpawnerNoBootstrapTests.java
+++ b/qa/no-bootstrap-tests/src/test/java/org/opensearch/bootstrap/SpawnerNoBootstrapTests.java
@@ -65,7 +65,7 @@
 
 /**
  * Create a simple "daemon controller", put it in the right place and check that it runs.
- *
+ * <p>
  * Extends LuceneTestCase rather than OpenSearchTestCase as OpenSearchTestCase installs a system call filter, and
  * that prevents the Spawner class from doing its job. Also needs to run in a separate JVM to other
  * tests that extend OpenSearchTestCase for the same reason.
diff --git a/qa/os/build.gradle b/qa/os/build.gradle
index 66c6525439dac..082ed5277575a 100644
--- a/qa/os/build.gradle
+++ b/qa/os/build.gradle
@@ -70,6 +70,11 @@ tasks.dependenciesInfo.enabled = false
 
 tasks.thirdPartyAudit.ignoreMissingClasses()
 
+tasks.thirdPartyAudit.ignoreViolations(
+  'org.apache.logging.log4j.core.util.internal.UnsafeUtil',
+  'org.apache.logging.log4j.core.util.internal.UnsafeUtil$1'
+)
+
 tasks.register('destructivePackagingTest') {
   dependsOn 'destructiveDistroTest'
 }
diff --git a/qa/os/src/test/java/org/opensearch/packaging/test/PackagingTestCase.java b/qa/os/src/test/java/org/opensearch/packaging/test/PackagingTestCase.java
index 02a613be320c2..4bb3877fc04a8 100644
--- a/qa/os/src/test/java/org/opensearch/packaging/test/PackagingTestCase.java
+++ b/qa/os/src/test/java/org/opensearch/packaging/test/PackagingTestCase.java
@@ -441,7 +441,7 @@ public static Path createTempDir(String prefix) throws IOException {
 
     /**
      * Run the given action with a temporary copy of the config directory.
-     *
+     * <p>
      * Files under the path passed to the action may be modified as necessary for the
      * test to execute, and running OpenSearch with {@link #startOpenSearch()} will
      * use the temporary directory.
diff --git a/qa/os/src/test/java/org/opensearch/packaging/util/FileMatcher.java b/qa/os/src/test/java/org/opensearch/packaging/util/FileMatcher.java
index 7904d1a046916..958de24848178 100644
--- a/qa/os/src/test/java/org/opensearch/packaging/util/FileMatcher.java
+++ b/qa/os/src/test/java/org/opensearch/packaging/util/FileMatcher.java
@@ -51,7 +51,7 @@
 /**
  * Asserts that a file at a path matches its status as Directory/File, and its owner. If on a posix system, also matches the permission
  * set is what we expect.
- *
+ * <p>
  * This class saves information about its failed matches in instance variables and so instances should not be reused
  */
 public class FileMatcher extends TypeSafeMatcher<Path> {
diff --git a/qa/os/src/test/java/org/opensearch/packaging/util/Installation.java b/qa/os/src/test/java/org/opensearch/packaging/util/Installation.java
index 25cefa948ff10..26af39d66cad3 100644
--- a/qa/os/src/test/java/org/opensearch/packaging/util/Installation.java
+++ b/qa/os/src/test/java/org/opensearch/packaging/util/Installation.java
@@ -137,7 +137,7 @@ public static Installation ofContainer(Shell sh, Distribution distribution) {
 
     /**
      * Returns the user that owns this installation.
-     *
+     * <p>
      * For packages this is root, and for archives it is the user doing the installation.
      */
     public String getOwner() {
diff --git a/qa/os/src/test/java/org/opensearch/packaging/util/Packages.java b/qa/os/src/test/java/org/opensearch/packaging/util/Packages.java
index b80ae422bda9a..e9ebf28042b46 100644
--- a/qa/os/src/test/java/org/opensearch/packaging/util/Packages.java
+++ b/qa/os/src/test/java/org/opensearch/packaging/util/Packages.java
@@ -194,11 +194,11 @@ private static void verifyInstallation(Installation opensearch, Distribution dis
 
         // we shell out here because java's posix file permission view doesn't support special modes
         assertThat(opensearch.config, file(Directory, "root", "opensearch", p750));
-        assertThat(sh.run("find \"" + opensearch.config + "\" -maxdepth 0 -printf \"%m\"").stdout, containsString("2750"));
+        assertThat(sh.run("find \"" + opensearch.config + "\" -maxdepth 0 -printf \"%m\"").stdout, containsString("750"));
 
         final Path jvmOptionsDirectory = opensearch.config.resolve("jvm.options.d");
         assertThat(jvmOptionsDirectory, file(Directory, "root", "opensearch", p750));
-        assertThat(sh.run("find \"" + jvmOptionsDirectory + "\" -maxdepth 0 -printf \"%m\"").stdout, containsString("2750"));
+        assertThat(sh.run("find \"" + jvmOptionsDirectory + "\" -maxdepth 0 -printf \"%m\"").stdout, containsString("750"));
 
         Stream.of("opensearch.keystore", "opensearch.yml", "jvm.options", "log4j2.properties")
             .forEach(configFile -> assertThat(opensearch.config(configFile), file(File, "root", "opensearch", p660)));
diff --git a/qa/remote-clusters/src/test/java/org/opensearch/cluster/remote/test/RemoteClustersIT.java b/qa/remote-clusters/src/test/java/org/opensearch/cluster/remote/test/RemoteClustersIT.java
index dbea8db1a12fa..c38fcc468c673 100644
--- a/qa/remote-clusters/src/test/java/org/opensearch/cluster/remote/test/RemoteClustersIT.java
+++ b/qa/remote-clusters/src/test/java/org/opensearch/cluster/remote/test/RemoteClustersIT.java
@@ -42,11 +42,13 @@
 import org.opensearch.client.cluster.RemoteInfoRequest;
 import org.opensearch.client.indices.CreateIndexRequest;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.junit.After;
 import org.junit.Before;
 
 import java.io.IOException;
+import java.util.concurrent.TimeUnit;
 
 
 public class RemoteClustersIT extends AbstractMultiClusterRemoteTestCase {
@@ -112,7 +114,7 @@ public void testSniffModeConnectionFails() throws IOException {
         assertFalse(rci.isConnected());
     }
 
-    public void testHAProxyModeConnectionWorks() throws IOException {
+    public void testHAProxyModeConnectionWorks() throws Exception {
         String proxyAddress = "haproxy:9600";
         logger.info("Configuring remote cluster [{}]", proxyAddress);
         ClusterUpdateSettingsRequest request = new ClusterUpdateSettingsRequest().persistentSettings(Settings.builder()
@@ -121,12 +123,14 @@ public void testHAProxyModeConnectionWorks() throws IOException {
             .build());
         assertTrue(cluster1Client().cluster().putSettings(request, RequestOptions.DEFAULT).isAcknowledged());
 
-        RemoteConnectionInfo rci = cluster1Client().cluster().remoteInfo(new RemoteInfoRequest(), RequestOptions.DEFAULT).getInfos().get(0);
-        logger.info("Connection info: {}", rci);
-        if (!rci.isConnected()) {    
-            logger.info("Cluster health: {}", cluster1Client().cluster().health(new ClusterHealthRequest(), RequestOptions.DEFAULT));
-        }
-        assertTrue(rci.isConnected());
+        assertBusy(() -> {
+            RemoteConnectionInfo rci = cluster1Client().cluster().remoteInfo(new RemoteInfoRequest(), RequestOptions.DEFAULT).getInfos().get(0);
+            logger.info("Connection info: {}", rci);
+            if (!rci.isConnected()) {
+                logger.info("Cluster health: {}", cluster1Client().cluster().health(new ClusterHealthRequest(), RequestOptions.DEFAULT));
+            }
+            assertTrue(rci.isConnected());
+        }, 10, TimeUnit.SECONDS);
 
         assertEquals(2L, cluster1Client().search(
             new SearchRequest("haproxynosn:test2"), RequestOptions.DEFAULT).getHits().getTotalHits().value);
diff --git a/qa/rolling-upgrade/src/test/java/org/opensearch/upgrades/IndexingIT.java b/qa/rolling-upgrade/src/test/java/org/opensearch/upgrades/IndexingIT.java
index 418d6b0eda469..f963f8d221bb5 100644
--- a/qa/rolling-upgrade/src/test/java/org/opensearch/upgrades/IndexingIT.java
+++ b/qa/rolling-upgrade/src/test/java/org/opensearch/upgrades/IndexingIT.java
@@ -98,11 +98,11 @@ private void waitForSearchableDocs(String index, int shardCount, int replicaCoun
 
         // Verify segment store
         assertBusy(() -> {
-            /**
-             * Use default tabular output and sort response based on shard,segment,primaryOrReplica columns to allow line by
-             * line parsing where records related to a segment (e.g. _0) are chunked together with first record belonging
-             * to primary while remaining *replicaCount* records belongs to replica copies
-             * */
+            /*
+              Use default tabular output and sort response based on shard,segment,primaryOrReplica columns to allow line by
+              line parsing where records related to a segment (e.g. _0) are chunked together with first record belonging
+              to primary while remaining *replicaCount* records belongs to replica copies
+              */
             Request segrepStatsRequest = new Request("GET", "/_cat/segments/" + index + "?s=shard,segment,primaryOrReplica");
             segrepStatsRequest.addParameter("h", "index,shard,primaryOrReplica,segment,docs.count");
             Response segrepStatsResponse = client().performRequest(segrepStatsRequest);
@@ -259,7 +259,8 @@ public void testIndexing() throws Exception {
      * This test verifies that during rolling upgrades the segment replication does not break when replica shards can
      * be running on older codec versions.
      *
-     * @throws Exception
+     * @throws Exception if index creation fail
+     * @throws UnsupportedOperationException if cluster type is unknown
      */
     @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/7679")
     public void testIndexingWithSegRep() throws Exception {
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/30_geoshape.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/30_geoshape.yml
new file mode 100644
index 0000000000000..e669016cad98a
--- /dev/null
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/30_geoshape.yml
@@ -0,0 +1,16 @@
+---
+"Insert Document with geoshape field":
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_old", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_old", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_old
+  - match: { hits.total: 2 }
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/30_geoshape.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/30_geoshape.yml
new file mode 100644
index 0000000000000..30a39447905c0
--- /dev/null
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/30_geoshape.yml
@@ -0,0 +1,28 @@
+---
+"Create index with Geoshape field":
+  - do:
+      indices.create:
+        index: geo_shape_index_old
+        body:
+          settings:
+            index:
+              number_of_replicas: 2
+          mappings:
+            "properties":
+              "location":
+                "type": "geo_shape"
+
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_old", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_old", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_old
+  - match: { hits.total: 2 }
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/30_geoshape.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/30_geoshape.yml
new file mode 100644
index 0000000000000..4c7b12a7f1909
--- /dev/null
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/30_geoshape.yml
@@ -0,0 +1,61 @@
+---
+"Validate we are able to index documents after upgrade":
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_old", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_old", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_old
+  - match: { hits.total: 2 }
+
+
+---
+"Create index with Geoshape field in new cluster":
+  - do:
+      indices.create:
+        index: geo_shape_index_new
+        body:
+          settings:
+            index:
+              number_of_replicas: 2
+          mappings:
+            "properties":
+              "location":
+                "type": "geo_shape"
+
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_new", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_new", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_new
+  - match: { hits.total: 2 }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_new
+        body:
+          aggregations:
+            myaggregation:
+              geo_bounds:
+                field: "location"
+  - match: { hits.total: 2 }
+  - match: { aggregations.myaggregation.bounds.top_left.lat: 0.9999999823048711 }
+  - match: { aggregations.myaggregation.bounds.top_left.lon: 99.99999999068677 }
+  - match: { aggregations.myaggregation.bounds.bottom_right.lat: 0.0 }
+  - match: { aggregations.myaggregation.bounds.bottom_right.lon: 105.99999996833503 }
diff --git a/qa/smoke-test-ingest-with-all-dependencies/src/test/resources/rest-api-spec/test/ingest/10_pipeline_with_mustache_templates.yml b/qa/smoke-test-ingest-with-all-dependencies/src/test/resources/rest-api-spec/test/ingest/10_pipeline_with_mustache_templates.yml
index e6a2a3d52e116..c043015281a9a 100644
--- a/qa/smoke-test-ingest-with-all-dependencies/src/test/resources/rest-api-spec/test/ingest/10_pipeline_with_mustache_templates.yml
+++ b/qa/smoke-test-ingest-with-all-dependencies/src/test/resources/rest-api-spec/test/ingest/10_pipeline_with_mustache_templates.yml
@@ -208,7 +208,7 @@
         id: 1
   - length: { _source: 2 }
   - match: { _source.do_nothing: "foo" }
-  - match: { _source.error: "processor first_processor [remove]: field [field_to_remove] not present as part of path [field_to_remove]" }
+  - match: { _source.error: "processor first_processor [remove]: field [field_to_remove] doesn't exist" }
 
 ---
 "Test rolling up json object arrays":
diff --git a/release-notes/opensearch.release-notes-1.3.13.md b/release-notes/opensearch.release-notes-1.3.13.md
new file mode 100644
index 0000000000000..3ece2c8f91984
--- /dev/null
+++ b/release-notes/opensearch.release-notes-1.3.13.md
@@ -0,0 +1,7 @@
+## 2023-09-14 Version 1.3.13 Release Notes
+
+### Upgrades
+- Bump `netty` from 4.1.96.Final to 4.1.97.Final ([#9553](https://github.com/opensearch-project/OpenSearch/pull/9553))
+- Bump `org.xerial.snappy:snappy-java` from 1.1.8.2 to 1.1.10.3 ([#9252](https://github.com/opensearch-project/OpenSearch/pull/9252))
+- Bump `com.squareup.okhttp3:okhttp` from 4.9.3 to 4.11.0 ([#9252](https://github.com/opensearch-project/OpenSearch/pull/9252))
+- Bump `com.squareup.okio:okio` from 2.8.0 to 3.5.0 ([#9252](https://github.com/opensearch-project/OpenSearch/pull/9252))
diff --git a/release-notes/opensearch.release-notes-1.3.14.md b/release-notes/opensearch.release-notes-1.3.14.md
new file mode 100644
index 0000000000000..319f5a79781c7
--- /dev/null
+++ b/release-notes/opensearch.release-notes-1.3.14.md
@@ -0,0 +1,18 @@
+## 2023-12-12 Version 1.3.14 Release Notes
+
+### Upgrades
+- Bump asm from 9.5 to 9.6 ([#10302](https://github.com/opensearch-project/OpenSearch/pull/10302))
+- Bump netty from 4.1.97.Final to 4.1.99.Final ([#10303](https://github.com/opensearch-project/OpenSearch/pull/10303))
+- Bump `netty` from 4.1.99.Final to 4.1.100.Final ([#10564](https://github.com/opensearch-project/OpenSearch/pull/10564))
+- Bump `netty` from 4.1.100.Final to 4.1.101.Final ([#11294](https://github.com/opensearch-project/OpenSearch/pull/11294))
+- Bump `org.apache.zookeeper:zookeper` from 3.8.0 to 3.8.3 ([#11476](https://github.com/opensearch-project/OpenSearch/pull/11476))
+- Bump `org.bouncycastle:bc-fips` from 1.0.2.3 to 1.0.2.4 ([#10297](https://github.com/opensearch-project/OpenSearch/pull/10297))
+- Bump `org.apache.avro:avro` from 1.10.2 to 1.11.3 ([#11502](https://github.com/opensearch-project/OpenSearch/pull/11502))
+- Bump `jetty` from 9.4.51.v20230217 to 9.4.52.v20230823 ([#11501](https://github.com/opensearch-project/OpenSearch/pull/11501))
+- Bump `io.projectreactor:reactor-core` from 3.4.23 to 3.4.34 and reactor-netty from 1.0.24 to 1.0.39 ([#11500](https://github.com/opensearch-project/OpenSearch/pull/11500))
+- Bump `logback-core` and `logback-classic` to 1.2.13 ([#11521](https://github.com/opensearch-project/OpenSearch/pull/11521))
+- Bumps `jetty` version from 9.4.52.v20230823 to 9.4.53.v20231009 ([#11539](https://github.com/opensearch-project/OpenSearch/pull/11539))
+
+### Bug Fixes
+- Use iterative approach to evaluate Regex.simpleMatch ([#11060](https://github.com/opensearch-project/OpenSearch/pull/11060))
+- Improve compressed request handling ([#10261](https://github.com/opensearch-project/OpenSearch/pull/10261))
diff --git a/release-notes/opensearch.release-notes-2.11.0.md b/release-notes/opensearch.release-notes-2.11.0.md
new file mode 100644
index 0000000000000..040cc053469ed
--- /dev/null
+++ b/release-notes/opensearch.release-notes-2.11.0.md
@@ -0,0 +1,68 @@
+## 2023-10-12 Version 2.11.0 Release Notes
+
+## [2.11]
+
+### Added
+- Add coordinator level stats for search latency ([#8386](https://github.com/opensearch-project/OpenSearch/issues/8386))
+- Add metrics for thread_pool task wait time ([#9681](https://github.com/opensearch-project/OpenSearch/pull/9681))
+- Add parallel file download support for remote store based replication ([#8596](https://github.com/opensearch-project/OpenSearch/pull/8596)) 
+- Async blob read support for S3 plugin ([#9694](https://github.com/opensearch-project/OpenSearch/pull/9694))
+- [Telemetry-Otel] Added support for OtlpGrpcSpanExporter exporter ([#9666](https://github.com/opensearch-project/OpenSearch/pull/9666))
+- Async blob read support for encrypted containers ([#10131](https://github.com/opensearch-project/OpenSearch/pull/10131))
+- Implement Visitor Design pattern in QueryBuilder to enable the capability to traverse through the complex QueryBuilder tree. ([#10110](https://github.com/opensearch-project/OpenSearch/pull/10110))
+- Add capability to restrict async durability mode for remote indexes ([#10189](https://github.com/opensearch-project/OpenSearch/pull/10189))
+- Add Doc Status Counter for Indexing Engine ([#4562](https://github.com/opensearch-project/OpenSearch/issues/4562))
+- Add unreferenced file cleanup count to merge stats ([#10204](https://github.com/opensearch-project/OpenSearch/pull/10204))
+- Configurable merge policy for index with an option to choose from LogByteSize and Tiered merge policy ([#9992](https://github.com/opensearch-project/OpenSearch/pull/9992))
+- [Remote Store] Add support to restrict creation & deletion if system repository and mutation of immutable settings of system repository ([#9839](https://github.com/opensearch-project/OpenSearch/pull/9839))
+- Improve compressed request handling ([#10261](https://github.com/opensearch-project/OpenSearch/pull/10261))
+
+### Dependencies
+- Bump JNA version from 5.5 to 5.13 ([#9963](https://github.com/opensearch-project/OpenSearch/pull/9963))
+- Bump `peter-evans/create-or-update-comment` from 2 to 3 ([#9575](https://github.com/opensearch-project/OpenSearch/pull/9575))
+- Bump `actions/checkout` from 2 to 4 ([#9968](https://github.com/opensearch-project/OpenSearch/pull/9968))
+- Bump OpenTelemetry from 1.26.0 to 1.30.1 ([#9950](https://github.com/opensearch-project/OpenSearch/pull/9950))
+- Bump `org.apache.commons:commons-compress` from 1.23.0 to 1.24.0 ([#9973, #9972](https://github.com/opensearch-project/OpenSearch/pull/9973, https://github.com/opensearch-project/OpenSearch/pull/9972))
+- Bump `com.google.cloud:google-cloud-core-http` from 2.21.1 to 2.23.0 ([#9971](https://github.com/opensearch-project/OpenSearch/pull/9971))
+- Bump `mockito` from 5.4.0 to 5.5.0 ([#10022](https://github.com/opensearch-project/OpenSearch/pull/10022))
+- Bump `bytebuddy` from 1.14.3 to 1.14.7 ([#10022](https://github.com/opensearch-project/OpenSearch/pull/10022))
+- Bump `com.zaxxer:SparseBitSet` from 1.2 to 1.3 ([#10098](https://github.com/opensearch-project/OpenSearch/pull/10098))
+- Bump `tibdex/github-app-token` from 1.5.0 to 2.1.0 ([#10125](https://github.com/opensearch-project/OpenSearch/pull/10125))
+- Bump `org.wiremock:wiremock-standalone` from 2.35.0 to 3.1.0 ([#9752](https://github.com/opensearch-project/OpenSearch/pull/9752))
+- Bump `org.eclipse.jgit` from 6.5.0 to 6.7.0 ([#10147](https://github.com/opensearch-project/OpenSearch/pull/10147))
+- Bump `codecov/codecov-action` from 2 to 3 ([#10209](https://github.com/opensearch-project/OpenSearch/pull/10209))
+- Bump `com.google.http-client:google-http-client-jackson2` from 1.43.2 to 1.43.3 ([#10126](https://github.com/opensearch-project/OpenSearch/pull/10126))
+- Bump `org.xerial.snappy:snappy-java` from 1.1.10.3 to 1.1.10.5 ([#10206](https://github.com/opensearch-project/OpenSearch/pull/10206), [#10299](https://github.com/opensearch-project/OpenSearch/pull/10299))
+- Bump `org.bouncycastle:bcpkix-jdk15to18` from 1.75 to 1.76 ([10219](https://github.com/opensearch-project/OpenSearch/pull/10219))`
+- Bump `org.bouncycastle:bcprov-jdk15to18` from 1.75 to 1.76 ([10219](https://github.com/opensearch-project/OpenSearch/pull/10219))`
+- Bump `org.bouncycastle:bcmail-jdk15to18` from 1.75 to 1.76 ([10219](https://github.com/opensearch-project/OpenSearch/pull/10219))`
+- Bump asm from 9.5 to 9.6 ([#10302](https://github.com/opensearch-project/OpenSearch/pull/10302))
+- Bump netty from 4.1.97.Final to 4.1.99.Final ([#10303](https://github.com/opensearch-project/OpenSearch/pull/10303))
+- Bump `peter-evans/create-pull-request` from 3 to 5 ([#10301](https://github.com/opensearch-project/OpenSearch/pull/10301))
+- Bump `org.apache.avro:avro` from 1.11.2 to 1.11.3 ([#10210](https://github.com/opensearch-project/OpenSearch/pull/10210))
+- Bump `netty` from 4.1.99.Final to 4.1.100.Final ([#10564](https://github.com/opensearch-project/OpenSearch/pull/10564))
+
+### Changed
+- Add instrumentation in rest and network layer. ([#9415](https://github.com/opensearch-project/OpenSearch/pull/9415))
+- Allow parameterization of tests with OpenSearchIntegTestCase.SuiteScopeTestCase annotation ([#9916](https://github.com/opensearch-project/OpenSearch/pull/9916))
+- Add instrumentation in transport service. ([#10042](https://github.com/opensearch-project/OpenSearch/pull/10042))
+- [Tracing Framework] Add support for SpanKind. ([#10122](https://github.com/opensearch-project/OpenSearch/pull/10122))
+- Pass parent filter to inner query in nested query ([#10246](https://github.com/opensearch-project/OpenSearch/pull/10246))
+- Disable concurrent segment search when terminate_after is used ([#10200](https://github.com/opensearch-project/OpenSearch/pull/10200))
+- Add instrumentation in Inbound Handler. ([#100143](https://github.com/opensearch-project/OpenSearch/pull/10143))
+- Enable remote segment upload backpressure by default ([#10356](https://github.com/opensearch-project/OpenSearch/pull/10356))
+- [Remote Store] Add support to reload repository metadata inplace ([#9569](https://github.com/opensearch-project/OpenSearch/pull/9569))
+- [Metrics Framework] Add Metrics framework. ([#10241](https://github.com/opensearch-project/OpenSearch/pull/10241))
+- Updating the separator for RemoteStoreLockManager since underscore is allowed in base64UUID url charset ([#10379](https://github.com/opensearch-project/OpenSearch/pull/10379))
+
+### Removed
+- Remove spurious SGID bit on directories ([#9447](https://github.com/opensearch-project/OpenSearch/pull/9447))
+
+### Fixed
+- Fix ignore_missing parameter has no effect when using template snippet in rename ingest processor ([#9725](https://github.com/opensearch-project/OpenSearch/pull/9725))
+- Fix broken backward compatibility from 2.7 for IndexSorted field indices ([#10045](https://github.com/opensearch-project/OpenSearch/pull/10045))
+- Fix concurrent search NPE when track_total_hits, terminate_after and size=0 are used ([#10082](https://github.com/opensearch-project/OpenSearch/pull/10082))
+- Fix remove ingest processor handing ignore_missing parameter not correctly ([10089](https://github.com/opensearch-project/OpenSearch/pull/10089))
+- Fix registration and initialization of multiple extensions ([10256](https://github.com/opensearch-project/OpenSearch/pull/10256))
+- Fix circular dependency in Settings initialization ([10194](https://github.com/opensearch-project/OpenSearch/pull/10194))
+- Fix Segment Replication ShardLockObtainFailedException bug during index corruption ([10370](https://github.com/opensearch-project/OpenSearch/pull/10370))
diff --git a/release-notes/opensearch.release-notes-2.11.1.md b/release-notes/opensearch.release-notes-2.11.1.md
new file mode 100644
index 0000000000000..06613558de177
--- /dev/null
+++ b/release-notes/opensearch.release-notes-2.11.1.md
@@ -0,0 +1,10 @@
+## 2023-11-20 Version 2.11.1 Release Notes
+
+## [2.11.1]
+
+### Changed
+- Use iterative approach to evaluate Regex.simpleMatch ([#11060](https://github.com/opensearch-project/OpenSearch/pull/11060))
+
+### Fixed
+- [BUG] Disable sort optimization for HALF_FLOAT ([#10999](https://github.com/opensearch-project/OpenSearch/pull/10999))
+- Adding version condition while adding geoshape doc values to the index, to ensure backward compatibility.([#11095](https://github.com/opensearch-project/OpenSearch/pull/11095))
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/cat.thread_pool/10_basic.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/cat.thread_pool/10_basic.yml
index 1ce8468cb51f9..00ec838489f63 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/cat.thread_pool/10_basic.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/cat.thread_pool/10_basic.yml
@@ -1,3 +1,29 @@
+"Test cat thread_pool total_wait_time output":
+  - skip:
+      version: " - 2.10.99"
+      reason: thread_pool total_wait_time stats were introduced in V_2.11.0
+
+  - do:
+      cat.thread_pool: {}
+
+  - match:
+      $body: |
+        /  #node_name     name     active     queue     rejected
+        ^  (\S+       \s+ \S+  \s+ \d+    \s+ \d+   \s+ \d+      \n)+  $/
+
+  - do:
+      cat.thread_pool:
+        thread_pool_patterns: search,search_throttled,index_searcher,generic
+        h: name,total_wait_time,twt
+        v: true
+
+  - match:
+      $body: |
+        /^  name              \s+ total_wait_time \s+ twt              \n
+           (generic           \s+ -1              \s+ -1               \n
+            search            \s+ \d*\.*\d*\D+    \s+ \d*\.*\d*\D+     \n
+            search_throttled  \s+ \d*\.*\d*\D+    \s+ \d*\.*\d*\D+     \n)+  $/
+
 ---
 "Test cat thread_pool output":
   - skip:
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.sort/10_basic.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.sort/10_basic.yml
index b9089689b0cf1..3b7ea15164e9f 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.sort/10_basic.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.sort/10_basic.yml
@@ -156,3 +156,23 @@
           query: {"range": { "rank": { "from": 0 } } }
           track_total_hits: false
           size: 3
+
+---
+"Index Sort half float":
+  - do:
+      catch: bad_request
+      indices.create:
+        index: test
+        body:
+          settings:
+            number_of_shards: 1
+            number_of_replicas: 0
+            index.sort.field: rank
+          mappings:
+            properties:
+              rank:
+                type: half_float
+
+  # This should failed with 400 as half_float is not supported for index sort
+  - match: { status: 400 }
+  - match: { error.type: illegal_argument_exception }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/nodes.stats/11_indices_metrics.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/nodes.stats/11_indices_metrics.yml
index 1f1f42890355e..784c7b52b18b4 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/nodes.stats/11_indices_metrics.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/nodes.stats/11_indices_metrics.yml
@@ -138,6 +138,35 @@
   - is_false:  nodes.$node_id.indices.translog
   - is_false:  nodes.$node_id.indices.recovery
 
+---
+"Metric - indexing doc_status":
+  - skip:
+      version: " - 2.10.99"
+      reason: "Doc Status Stats were introduced in v2.11.0"
+  - do:
+      nodes.info: {}
+  - set:
+      nodes._arbitrary_key_: node_id
+
+  - do:
+      nodes.stats: { metric: indices, index_metric: indexing }
+
+  - is_false: nodes.$node_id.indices.docs
+  - is_false: nodes.$node_id.indices.store
+  - is_true: nodes.$node_id.indices.indexing
+  - is_true: nodes.$node_id.indices.indexing.doc_status
+  - is_false: nodes.$node_id.indices.get
+  - is_false: nodes.$node_id.indices.search
+  - is_false: nodes.$node_id.indices.merges
+  - is_false: nodes.$node_id.indices.refresh
+  - is_false: nodes.$node_id.indices.flush
+  - is_false: nodes.$node_id.indices.warmer
+  - is_false: nodes.$node_id.indices.query_cache
+  - is_false: nodes.$node_id.indices.fielddata
+  - is_false: nodes.$node_id.indices.completion
+  - is_false: nodes.$node_id.indices.segments
+  - is_false: nodes.$node_id.indices.translog
+  - is_false: nodes.$node_id.indices.recovery
 
 ---
 "Metric - recovery":
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/10_histogram.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/10_histogram.yml
index 3b16cdb13a22f..e7da9a0bc454c 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/10_histogram.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/10_histogram.yml
@@ -598,7 +598,6 @@ setup:
   - match: { aggregations.histo.buckets.0.doc_count: 2 }
   - match: { profile.shards.0.aggregations.0.type: DateHistogramAggregator }
   - match: { profile.shards.0.aggregations.0.description: histo }
-  - match: { profile.shards.0.aggregations.0.breakdown.collect_count: 4 }
   - match: { profile.shards.0.aggregations.0.debug.total_buckets: 3 }
 
 ---
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search/240_date_nanos.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search/240_date_nanos.yml
index 1ddba45c97c72..fb5c3268a3c82 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/search/240_date_nanos.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search/240_date_nanos.yml
@@ -164,3 +164,99 @@ setup:
   - match: { aggregations.date.buckets.1.key: 1540857600000 }
   - match: { aggregations.date.buckets.1.key_as_string: "2018-10-30T00:00:00.000Z" }
   - match: { aggregations.date.buckets.1.doc_count: 2 }
+
+
+---
+"date with nested sort now":
+  - skip:
+      version: " - 2.11.99"
+      reason: fixed in 2.12.0
+
+  # This tests cover scenario where nested sort have now() in date field type.
+  # For this test, we have date field as nested field and we trigger asc/desc sort
+  # on that nested field. `filter` clause is needed when we sort any nested field,
+  # like in this case, "gte": "now/h" says sort nested field date_field only where
+  # document is having value greater than current time now().
+  # Nested field sort query doesn't sort documents if it is not qualified through
+  # `filter` clause.
+  # Only adding tests for `gte` as `lte` would be same behaviour
+
+  - do:
+      indices.create:
+        index: test
+        body:
+          mappings:
+            properties:
+              nested_field:
+                type: nested
+                properties:
+                  date_field:
+                    type: date
+                    format: date_optional_time
+  - do:
+      bulk:
+        refresh: true
+        index: test
+        body: |
+          {"index":{}}
+          {"nested_field": [{"date_field": "3023-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "3024-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "3025-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "3026-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "3027-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "2022-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "2023-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "2021-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "2020-10-26T12:00:00+09:00"}]}
+          {"index":{}}
+          {"nested_field": [{"date_field": "2019-10-26T12:00:00+09:00"}]}
+
+  # gte: now/h with the desc sort
+  - do:
+      search:
+        index: test
+        body:
+          size: 5
+          sort: [{ nested_field.date_field: { mode: max, order: desc, nested: { path: nested_field, filter: { bool: { filter : [{ range : { nested_field.date_field: { gte: now/h, time_zone: +09:00} } }] } } } } } ]
+  - match: {hits.total.value: 10 }
+  - length: {hits.hits: 5 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.nested_field.0.date_field: "3027-10-26T12:00:00+09:00" }
+  - match: { hits.hits.0.sort: [33381428400000] }
+  - match: { hits.hits.1._source.nested_field.0.date_field: "3026-10-26T12:00:00+09:00" }
+  - match: { hits.hits.1.sort: [ 33349892400000 ] }
+  - match: { hits.hits.2._source.nested_field.0.date_field: "3025-10-26T12:00:00+09:00" }
+  - match: { hits.hits.2.sort: [ 33318356400000 ] }
+  - match: { hits.hits.3._source.nested_field.0.date_field: "3024-10-26T12:00:00+09:00" }
+  - match: { hits.hits.3.sort: [ 33286820400000 ] }
+  - match: { hits.hits.4._source.nested_field.0.date_field: "3023-10-26T12:00:00+09:00" }
+  - match: { hits.hits.4.sort: [ 33255198000000 ] }
+
+  # gte: now/h with the asc sort
+  - do:
+      search:
+        index: test
+        body:
+          size: 5
+          sort: [ { nested_field.date_field: { mode: max, order: asc, nested: { path: nested_field, filter: { bool: { filter: [ { range: { nested_field.date_field: { gte: now/h, time_zone: +09:00 } } } ] } } } } } ]
+  - match: { hits.total.value: 10 }
+  - length: { hits.hits: 5 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.nested_field.0.date_field: "3023-10-26T12:00:00+09:00" }
+  - match: { hits.hits.0.sort: [ 33255198000000 ] }
+  - match: { hits.hits.1._source.nested_field.0.date_field: "3024-10-26T12:00:00+09:00" }
+  - match: { hits.hits.1.sort: [ 33286820400000 ] }
+  - match: { hits.hits.2._source.nested_field.0.date_field: "3025-10-26T12:00:00+09:00" }
+  - match: { hits.hits.2.sort: [ 33318356400000 ] }
+  - match: { hits.hits.3._source.nested_field.0.date_field: "3026-10-26T12:00:00+09:00" }
+  - match: { hits.hits.3.sort: [ 33349892400000 ] }
+  - match: { hits.hits.4._source.nested_field.0.date_field: "3027-10-26T12:00:00+09:00" }
+  - match: { hits.hits.4.sort: [ 33381428400000 ] }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search/260_sort_mixed.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search/260_sort_mixed.yml
index ba2b18eb3b6d0..7385eef051243 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/search/260_sort_mixed.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search/260_sort_mixed.yml
@@ -20,6 +20,7 @@
             properties:
               counter:
                 type: double
+
   - do:
       bulk:
         refresh: true
@@ -119,3 +120,87 @@
   - match: { status: 400 }
   - match: { error.type: search_phase_execution_exception }
   - match: { error.caused_by.reason: "Can't do sort across indices, as a field has [unsigned_long] type in one index, and different type in another index!" }
+
+---
+"search across indices with mixed long and double and float numeric types":
+  - skip:
+      version: " - 2.11.0"
+      reason: half float was broken before 2.11.1
+
+  - do:
+      indices.create:
+        index: test_1
+        body:
+          mappings:
+            properties:
+              counter:
+                type: long
+
+  - do:
+      indices.create:
+        index: test_2
+        body:
+          mappings:
+            properties:
+              counter:
+                type: double
+
+  - do:
+      indices.create:
+        index: test_3
+        body:
+          mappings:
+            properties:
+              counter:
+                type: half_float
+
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - index:
+              _index: test_1
+          - counter: 223372036854775800
+          - index:
+              _index: test_2
+          - counter: 1223372036854775800.23
+          - index:
+              _index: test_2
+          - counter: 184.4
+          - index:
+              _index: test_3
+          - counter: 187.4
+          - index:
+              _index: test_3
+          - counter: 194.4
+
+  - do:
+      search:
+        index: test_*
+        rest_total_hits_as_int: true
+        body:
+          sort: [{ counter: desc }]
+  - match: { hits.total: 5 }
+  - length: { hits.hits: 5 }
+  - match: { hits.hits.0._index: test_2 }
+  - match: { hits.hits.0._source.counter: 1223372036854775800.23 }
+  - match: { hits.hits.0.sort.0: 1223372036854775800.23 }
+  - match: { hits.hits.1._index: test_1 }
+  - match: { hits.hits.1._source.counter: 223372036854775800 }
+  - match: { hits.hits.1.sort.0: 223372036854775800  }
+  - match: { hits.hits.2._index: test_3 }
+  - match: { hits.hits.2._source.counter: 194.4 }
+
+  - do:
+      search:
+        index: test_*
+        rest_total_hits_as_int: true
+        body:
+          sort: [{ counter: asc }]
+  - match: { hits.total: 5 }
+  - length: { hits.hits: 5 }
+  - match: { hits.hits.0._index: test_2 }
+  - match: { hits.hits.0._source.counter: 184.4 }
+  - match: { hits.hits.0.sort.0: 184.4 }
+  - match: { hits.hits.1._index: test_3 }
+  - match: { hits.hits.1._source.counter: 187.4 }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search/340_keyword_doc_values.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search/340_keyword_doc_values.yml
new file mode 100644
index 0000000000000..8829e7b100fdd
--- /dev/null
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search/340_keyword_doc_values.yml
@@ -0,0 +1,46 @@
+---
+"search on keyword fields with doc_values enabled":
+  - do:
+      indices.create:
+        index: test
+        body:
+          mappings:
+            properties:
+              "some_keyword":
+                type: "keyword"
+                index: true
+                doc_values: true
+
+  - do:
+      bulk:
+        index: test
+        refresh: true
+        body:
+          - '{"index": {"_index": "test", "_id": "1" }}'
+          - '{ "some_keyword": "ingesting some random keyword data" }'
+          - '{ "index": { "_index": "test", "_id": "2" }}'
+          - '{ "some_keyword": "400" }'
+          - '{ "index": { "_index": "test", "_id": "3" } }'
+          - '{ "some_keyword": "5" }'
+
+  - do:
+      search:
+        index: test
+        body:
+          query:
+            prefix:
+              some_keyword: "ing"
+
+  - match: { hits.hits.0._source.some_keyword: "ingesting some random keyword data" }
+
+  - do:
+      search:
+        index: test
+        body:
+          query:
+            range: {
+              "some_keyword": {
+                "lt": 500
+              } }
+
+  - match: { hits.total.value: 2 }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml
index 55e1566656faf..ebecb63dedbaf 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml
@@ -219,7 +219,7 @@
   - match: {hits.hits.0._source.timestamp: "2019-10-21 08:30:04.828733" }
   - match: {hits.hits.0.sort: [1571646604828733000] }
 
-  # search_after with the sort
+  # search_after with the asc sort
   - do:
       search:
         index: test
@@ -320,3 +320,468 @@
   - length: { hits.hits: 1 }
   - match: { hits.hits.0._index: test }
   - match: { hits.hits.0._source.population: null }
+
+---
+"half float":
+  - skip:
+        version: " - 2.11.0"
+        reason: half_float was broken for 2.11.0 and earlier
+
+  - do:
+      indices.create:
+        index: test
+        body:
+          mappings:
+            properties:
+              population:
+                type: half_float
+  - do:
+      bulk:
+        refresh: true
+        index: test
+        body: |
+          {"index":{}}
+          {"population": 184.4}
+          {"index":{}}
+          {"population": 194.4}
+          {"index":{}}
+          {"population": 144.4}
+          {"index":{}}
+          {"population": 174.4}
+          {"index":{}}
+          {"population": 164.4}
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          size: 3
+          sort: [ { population: desc } ]
+  - match: { hits.total: 5 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.population: 194.4 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.population: 184.4 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.population: 174.4 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          size: 3
+          sort: [ { population: asc } ]
+  - match: { hits.total: 5 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.population: 144.4 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.population: 164.4 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.population: 174.4 }
+
+  # search_after with the asc sort
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          size: 1
+          sort: [ { population: asc } ]
+          search_after: [ 184.375 ] # this is rounded sort value in sort result
+  - match: { hits.total: 5 }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.population: 194.4 }
+
+  # search_after with the desc sort
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          size: 1
+          sort: [ { population: desc } ]
+          search_after: [ 164.375 ] # this is rounded sort value in sort result
+  - match: { hits.total: 5 }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.population: 144.4 }
+
+  # search_after with the asc sort with missing
+  - do:
+      bulk:
+        refresh: true
+        index: test
+        body: |
+          {"index":{}}
+          {"population": null}
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 5
+          "sort": [ { "population": { "order": "asc", "missing": "_last" } } ]
+          search_after: [ 200 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 6 }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.population: null }
+
+  # search_after with the desc sort with missing
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 5
+          "sort": [ { "population": { "order": "desc", "missing": "_last" } } ]
+          search_after: [ 100 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 6 }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.population: null }
+
+---
+"numeric skipping logic with competitive missing value":
+  - skip:
+      version: " - 2.12.99"
+      reason: newly added test, supported from 3.0.0
+
+# This test checks if skipping logic is skipped in case missing values are competitive
+# for all numeric type int, long, float, half_float, double, unsigned_long.
+# We are inserting 24 documents with some missing values and giving search after parameter
+# as missing value. The secondary sort field is on id which doesn't have missing value.
+# In case skipping logic is applied in Lucene, it will skipp all documents with primary sort field
+# missing value even though it should list sort by secondary field id with missing value primary field.
+# This test is addressing bugs like here https://github.com/opensearch-project/OpenSearch/issues/9537
+
+  - do:
+      indices.create:
+        index: test
+        body:
+          mappings:
+            properties:
+              halffloat:
+                type: half_float
+              long:
+                type: long
+              int:
+                type: integer
+              float:
+                type: float
+              double:
+                type: double
+              unsignedlong:
+                type: unsigned_long
+  - do:
+      bulk:
+        refresh: true
+        index: test
+        body: |
+          {"index":{}}
+          {"id": 1, "halffloat": 1, "long": 1, "int": 1, "float": 1, "double": 1, "unsignedlong": 1}
+          {"index":{}}
+          {"id": 2, "halffloat": 2, "long": 2, "int": 2, "float": 2, "double": 2, "unsignedlong": 2}
+          {"index":{}}
+          {"id": 3, "halffloat": 3, "long": 3, "int": 3, "float": 3, "double": 3, "unsignedlong": 3}
+          {"index":{}}
+          {"id": 4, "halffloat": 4, "long": 4, "int": 4, "float": 4, "double": 4, "unsignedlong": 4}
+          {"index":{}}
+          {"id": 5, "halffloat": 5, "long": 5, "int": 5, "float": 5, "double": 5, "unsignedlong": 5}
+          {"index":{}}
+          {"id": 6, "halffloat": 6, "long": 6, "int": 6, "float": 6, "double": 6, "unsignedlong": 6}
+          {"index":{}}
+          {"id": 7, "halffloat": 7, "long": 7, "int": 7, "float": 7, "double": 7, "unsignedlong": 7}
+          {"index":{}}
+          {"id": 8, "halffloat": 8, "long": 8, "int": 8, "float": 8, "double": 8, "unsignedlong": 8}
+          {"index":{}}
+          {"id": 9, "halffloat": 9, "long": 9, "int": 9, "float": 9, "double": 9, "unsignedlong": 9}
+          {"index":{}}
+          {"id": 10, "halffloat": 10, "long": 10, "int": 10, "float": 10, "double": 10, "unsignedlong": 10}
+          {"index":{}}
+          {"id": 11, "halffloat": 11, "long": 11, "int": 11, "float": 11, "double": 11, "unsignedlong": 11}
+          {"index":{}}
+          {"id": 12, "halffloat": 12, "long": 12, "int": 12, "float": 12, "double": 12, "unsignedlong": 12}
+          {"index":{}}
+          {"id": 13, "halffloat": 13, "long": 13, "int": 13, "float": 13, "double": 13, "unsignedlong": 13}
+          {"index":{}}
+          {"id": 14, "halffloat": 14, "long": 14, "int": 14, "float": 14, "double": 14, "unsignedlong": 14}
+          {"index":{}}
+          {"id": 15, "halffloat": 15, "long": 15, "int": 15, "float": 15, "double": 15, "unsignedlong": 15}
+          {"index":{}}
+          {"id": 16, "halffloat": 16, "long": 16, "int": 16, "float": 16, "double": 16, "unsignedlong": 16}
+          {"index":{}}
+          {"id": 17, "halffloat": 17, "long": 17, "int": 17, "float": 17, "double": 17, "unsignedlong": 17}
+          {"index":{}}
+          {"id": 18, "halffloat": 18, "long": 18, "int": 18, "float": 18, "double": 18, "unsignedlong": 18}
+          {"index":{}}
+          {"id": 19, "halffloat": 19, "long": 19, "int": 19, "float": 19, "double": 19, "unsignedlong": 19}
+          {"index":{}}
+          {"id": 20, "halffloat": 20, "long": 20, "int": 20, "float": 20, "double": 20, "unsignedlong": 20}
+          {"index":{}}
+          {"id": 21, "halffloat": null, "long": null, "int": null, "float": null, "double": null, "unsignedlong": null}
+          {"index":{}}
+          {"id": 22, "halffloat": null, "long": null, "int": null, "float": null, "double": null, "unsignedlong": null}
+          {"index":{}}
+          {"id": 23, "halffloat": null, "long": null, "int": null, "float": null, "double": null, "unsignedlong": null}
+          {"index":{}}
+          {"id": 24, "halffloat": null, "long": null, "int": null, "float": null, "double": null, "unsignedlong": null}
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "halffloat": { "order": "asc" } }, { "id": { "order": "asc" } } ]
+          search_after: [ 200, 0 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.halffloat: null }
+  - match: { hits.hits.0._source.id: 21 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.halffloat: null }
+  - match: { hits.hits.1._source.id: 22 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.halffloat: null }
+  - match: { hits.hits.2._source.id: 23 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "halffloat": { "order": "desc" } }, { "id": { "order": "desc" } } ]
+          search_after: [ 0, 25 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.halffloat: null }
+  - match: { hits.hits.0._source.id: 24 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.halffloat: null }
+  - match: { hits.hits.1._source.id: 23 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.halffloat: null }
+  - match: { hits.hits.2._source.id: 22 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "long": { "order": "asc" } }, { "id": { "order": "asc" } } ]
+          search_after: [ 200, 0 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.long: null }
+  - match: { hits.hits.0._source.id: 21 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.long: null }
+  - match: { hits.hits.1._source.id: 22 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.long: null }
+  - match: { hits.hits.2._source.id: 23 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "long": { "order": "desc" } }, { "id": { "order": "desc" } } ]
+          search_after: [ 0, 25 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.long: null }
+  - match: { hits.hits.0._source.id: 24 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.long: null }
+  - match: { hits.hits.1._source.id: 23 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.long: null }
+  - match: { hits.hits.2._source.id: 22 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "int": { "order": "asc" } }, { "id": { "order": "asc" } } ]
+          search_after: [ 200, 0 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.int: null }
+  - match: { hits.hits.0._source.id: 21 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.int: null }
+  - match: { hits.hits.1._source.id: 22 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.int: null }
+  - match: { hits.hits.2._source.id: 23 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "int": { "order": "desc" } }, { "id": { "order": "desc" } } ]
+          search_after: [ 0, 25 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.int: null }
+  - match: { hits.hits.0._source.id: 24 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.int: null }
+  - match: { hits.hits.1._source.id: 23 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.int: null }
+  - match: { hits.hits.2._source.id: 22 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "float": { "order": "asc" } }, { "id": { "order": "asc" } } ]
+          search_after: [ 200, 0 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.float: null }
+  - match: { hits.hits.0._source.id: 21 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.float: null }
+  - match: { hits.hits.1._source.id: 22 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.float: null }
+  - match: { hits.hits.2._source.id: 23 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "float": { "order": "desc" } }, { "id": { "order": "desc" } } ]
+          search_after: [ 0, 25 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.float: null }
+  - match: { hits.hits.0._source.id: 24 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.float: null }
+  - match: { hits.hits.1._source.id: 23 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.float: null }
+  - match: { hits.hits.2._source.id: 22 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "double": { "order": "asc" } }, { "id": { "order": "asc" } } ]
+          search_after: [ 200, 0 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.double: null }
+  - match: { hits.hits.0._source.id: 21 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.double: null }
+  - match: { hits.hits.1._source.id: 22 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.double: null }
+  - match: { hits.hits.2._source.id: 23 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "double": { "order": "desc" } }, { "id": { "order": "desc" } } ]
+          search_after: [ 0, 25 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.double: null }
+  - match: { hits.hits.0._source.id: 24 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.double: null }
+  - match: { hits.hits.1._source.id: 23 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.double: null }
+  - match: { hits.hits.2._source.id: 22 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "unsignedlong": { "order": "asc" } }, { "id": { "order": "asc" } } ]
+          search_after: [ 200, 0 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.unsignedlong: null }
+  - match: { hits.hits.0._source.id: 21 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.unsignedlong: null }
+  - match: { hits.hits.1._source.id: 22 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.unsignedlong: null }
+  - match: { hits.hits.2._source.id: 23 }
+
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 3
+          "sort": [ { "unsignedlong": { "order": "desc" } }, { "id": { "order": "desc" } } ]
+          search_after: [ 0, 25 ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 24 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.unsignedlong: null }
+  - match: { hits.hits.0._source.id: 24 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._source.unsignedlong: null }
+  - match: { hits.hits.1._source.id: 23 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._source.unsignedlong: null }
+  - match: { hits.hits.2._source.id: 22 }
diff --git a/server/build.gradle b/server/build.gradle
index f6db3d53a0dcc..bf0c7791aeb55 100644
--- a/server/build.gradle
+++ b/server/build.gradle
@@ -47,7 +47,7 @@ publishing {
 }
 
 base {
-  archivesBaseName = 'opensearch'
+  archivesName = 'opensearch'
 }
 
 sourceSets {
@@ -147,6 +147,7 @@ dependencies {
   api "org.apache.logging.log4j:log4j-jul:${versions.log4j}"
   api "org.apache.logging.log4j:log4j-core:${versions.log4j}", optional
   annotationProcessor "org.apache.logging.log4j:log4j-core:${versions.log4j}"
+  annotationProcessor project(':libs:opensearch-common')
 
   // jna
   api "net.java.dev.jna:jna:${versions.jna}"
@@ -154,6 +155,10 @@ dependencies {
   // jcraft
   api "com.jcraft:jzlib:${versions.jzlib}"
 
+  // reactor
+  api "io.projectreactor:reactor-core:${versions.reactor}"
+  api "org.reactivestreams:reactive-streams:${versions.reactivestreams}"
+
   // protobuf
   api "com.google.protobuf:protobuf-java:${versions.protobuf}"
   api "jakarta.annotation:jakarta.annotation-api:${versions.jakarta_annotation}"
@@ -174,7 +179,8 @@ tasks.withType(JavaCompile).configureEach {
 }
 
 compileJava {
-  options.compilerArgs += ['-processor', 'org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor']
+  options.compilerArgs += ['-processor', ['org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor',
+    'org.opensearch.common.annotation.processor.ApiAnnotationProcessor'].join(','), '-AcontinueOnFailingChecks']
 }
 
 tasks.named("internalClusterTest").configure {
@@ -364,11 +370,15 @@ tasks.named("thirdPartyAudit").configure {
             'com.google.protobuf.UnsafeUtil$Android32MemoryAccessor',
             'com.google.protobuf.UnsafeUtil$Android64MemoryAccessor',
             'com.google.protobuf.UnsafeUtil$JvmMemoryAccessor',
-            'com.google.protobuf.UnsafeUtil$MemoryAccessor'
+            'com.google.protobuf.UnsafeUtil$MemoryAccessor',
+            'org.apache.logging.log4j.core.util.internal.UnsafeUtil',
+            'org.apache.logging.log4j.core.util.internal.UnsafeUtil$1',
+            'reactor.core.publisher.Traces$SharedSecretsCallSiteSupplierFactory$TracingException'
     )
 }
 
 tasks.named("dependencyLicenses").configure {
+    mapping from: /reactor-.*/, to: 'reactor'
     mapping from: /lucene-.*/, to: 'lucene'
     dependencies = project.configurations.runtimeClasspath.fileCollection {
         it.group.startsWith('org.opensearch') == false ||
@@ -395,6 +405,7 @@ tasks.named("licenseHeaders").configure {
 }
 
 tasks.test {
+    environment "node.roles.test", "[]"
     if (BuildParams.runtimeJavaVersion > JavaVersion.VERSION_1_8) {
         jvmArgs += ["--add-opens", "java.base/java.nio.file=ALL-UNNAMED"]
     }
diff --git a/server/cli/build.gradle b/server/cli/build.gradle
new file mode 100644
index 0000000000000..385d5ff27433e
--- /dev/null
+++ b/server/cli/build.gradle
@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+// This file is intentionally blank. All configuration of the
+// distribution is done in the parent project.
+
+// See please https://docs.gradle.org/8.5/userguide/upgrading_version_8.html#deprecated_missing_project_directory
diff --git a/server/licenses/log4j-api-2.20.0.jar.sha1 b/server/licenses/log4j-api-2.20.0.jar.sha1
deleted file mode 100644
index 37154d9861ac0..0000000000000
--- a/server/licenses/log4j-api-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-1fe6082e660daf07c689a89c94dc0f49c26b44bb
\ No newline at end of file
diff --git a/server/licenses/log4j-api-2.21.0.jar.sha1 b/server/licenses/log4j-api-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..51446052594aa
--- /dev/null
+++ b/server/licenses/log4j-api-2.21.0.jar.sha1
@@ -0,0 +1 @@
+760192f2b69eacf4a4afc78e5a1d7a8de054fcbd
\ No newline at end of file
diff --git a/server/licenses/log4j-core-2.20.0.jar.sha1 b/server/licenses/log4j-core-2.20.0.jar.sha1
deleted file mode 100644
index 49c972626563b..0000000000000
--- a/server/licenses/log4j-core-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-eb2a9a47b1396e00b5eee1264296729a70565cc0
\ No newline at end of file
diff --git a/server/licenses/log4j-core-2.21.0.jar.sha1 b/server/licenses/log4j-core-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..c88e6f7a25ca9
--- /dev/null
+++ b/server/licenses/log4j-core-2.21.0.jar.sha1
@@ -0,0 +1 @@
+122e1a9e0603cc9eae07b0846a6ff01f2454bc49
\ No newline at end of file
diff --git a/server/licenses/log4j-jul-2.20.0.jar.sha1 b/server/licenses/log4j-jul-2.20.0.jar.sha1
deleted file mode 100644
index a456651e4569e..0000000000000
--- a/server/licenses/log4j-jul-2.20.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-8170e6118eac1ab332046c179718a0f107f688e1
\ No newline at end of file
diff --git a/server/licenses/log4j-jul-2.21.0.jar.sha1 b/server/licenses/log4j-jul-2.21.0.jar.sha1
new file mode 100644
index 0000000000000..480010840abca
--- /dev/null
+++ b/server/licenses/log4j-jul-2.21.0.jar.sha1
@@ -0,0 +1 @@
+f0da61113f4a47654677e6a98b1e13ca7de2483d
\ No newline at end of file
diff --git a/server/licenses/lucene-analysis-common-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-analysis-common-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index e7c7dc2bbc046..0000000000000
--- a/server/licenses/lucene-analysis-common-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-1446b7641743a1082b566179d1bf2960f5a0724b
\ No newline at end of file
diff --git a/server/licenses/lucene-analysis-common-9.8.0.jar.sha1 b/server/licenses/lucene-analysis-common-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..6ad304fa52c12
--- /dev/null
+++ b/server/licenses/lucene-analysis-common-9.8.0.jar.sha1
@@ -0,0 +1 @@
+36f0363325ca7bf62c180160d1ed5165c7c37795
\ No newline at end of file
diff --git a/server/licenses/lucene-backward-codecs-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-backward-codecs-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index d0f64519cd6ff..0000000000000
--- a/server/licenses/lucene-backward-codecs-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-127032ea137d2501b24f0e35e5f9a2e1c7864633
\ No newline at end of file
diff --git a/server/licenses/lucene-backward-codecs-9.8.0.jar.sha1 b/server/licenses/lucene-backward-codecs-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..f104c4207d390
--- /dev/null
+++ b/server/licenses/lucene-backward-codecs-9.8.0.jar.sha1
@@ -0,0 +1 @@
+e98fb408028f40170e6d87c16422bfdc0bb2e392
\ No newline at end of file
diff --git a/server/licenses/lucene-core-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-core-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index dc363f2776429..0000000000000
--- a/server/licenses/lucene-core-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-30c3afcf058532d3d2b8820375043000e7f34a9b
\ No newline at end of file
diff --git a/server/licenses/lucene-core-9.8.0.jar.sha1 b/server/licenses/lucene-core-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..f9a3e2f3cbee6
--- /dev/null
+++ b/server/licenses/lucene-core-9.8.0.jar.sha1
@@ -0,0 +1 @@
+5e8421c5f8573bcf22e9265fc7e19469545a775a
\ No newline at end of file
diff --git a/server/licenses/lucene-grouping-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-grouping-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 294beba43f62a..0000000000000
--- a/server/licenses/lucene-grouping-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-e6f742efe0ef3b383468fe38f88ab2dd69ed3d2c
\ No newline at end of file
diff --git a/server/licenses/lucene-grouping-9.8.0.jar.sha1 b/server/licenses/lucene-grouping-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..ab132121b2edc
--- /dev/null
+++ b/server/licenses/lucene-grouping-9.8.0.jar.sha1
@@ -0,0 +1 @@
+d39184518351178c404ed9669fc6cb6111f2288d
\ No newline at end of file
diff --git a/server/licenses/lucene-highlighter-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-highlighter-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index c2a2ef5b13946..0000000000000
--- a/server/licenses/lucene-highlighter-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3162856444777130dee2c4cabe1bf6d18710ff63
\ No newline at end of file
diff --git a/server/licenses/lucene-highlighter-9.8.0.jar.sha1 b/server/licenses/lucene-highlighter-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..c7cb678fb7b72
--- /dev/null
+++ b/server/licenses/lucene-highlighter-9.8.0.jar.sha1
@@ -0,0 +1 @@
+1ac38c8278dbd63dfab30744a41dd955a415a31c
\ No newline at end of file
diff --git a/server/licenses/lucene-join-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-join-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 7c6adaaba9cf1..0000000000000
--- a/server/licenses/lucene-join-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-5fe8383516eca7300f978ce38042e327b0a57877
\ No newline at end of file
diff --git a/server/licenses/lucene-join-9.8.0.jar.sha1 b/server/licenses/lucene-join-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..2b6cb8af4faf6
--- /dev/null
+++ b/server/licenses/lucene-join-9.8.0.jar.sha1
@@ -0,0 +1 @@
+3d64fc57bb6e718d906413a9f73c713e6d4d8bb0
\ No newline at end of file
diff --git a/server/licenses/lucene-memory-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-memory-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 586702c968a77..0000000000000
--- a/server/licenses/lucene-memory-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-b3e77970485be6d2dd59b999bbaa65a2cb993744
\ No newline at end of file
diff --git a/server/licenses/lucene-memory-9.8.0.jar.sha1 b/server/licenses/lucene-memory-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..5fdfee401dd0a
--- /dev/null
+++ b/server/licenses/lucene-memory-9.8.0.jar.sha1
@@ -0,0 +1 @@
+5283ac71d6ccecb5e00c7b52df2faec012f2625a
\ No newline at end of file
diff --git a/server/licenses/lucene-misc-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-misc-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 493598eefff5e..0000000000000
--- a/server/licenses/lucene-misc-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-86d667ea2f7fb2142d2acacf801dcea47d014a5e
\ No newline at end of file
diff --git a/server/licenses/lucene-misc-9.8.0.jar.sha1 b/server/licenses/lucene-misc-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..cf815cba15862
--- /dev/null
+++ b/server/licenses/lucene-misc-9.8.0.jar.sha1
@@ -0,0 +1 @@
+9a57b049cf51a5e9c9c1909c420f645f1b6f9a54
\ No newline at end of file
diff --git a/server/licenses/lucene-queries-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-queries-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 1bf937f10d795..0000000000000
--- a/server/licenses/lucene-queries-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-930d004de698f374da8ac5530fd80e241edeba45
\ No newline at end of file
diff --git a/server/licenses/lucene-queries-9.8.0.jar.sha1 b/server/licenses/lucene-queries-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..09f369ef18e12
--- /dev/null
+++ b/server/licenses/lucene-queries-9.8.0.jar.sha1
@@ -0,0 +1 @@
+628db4ef46f1c6a05145bdac1d1bc4ace6341b13
\ No newline at end of file
diff --git a/server/licenses/lucene-queryparser-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-queryparser-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 74458bc93f90b..0000000000000
--- a/server/licenses/lucene-queryparser-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f62882823d5aa9ed4cf0081a8c18f35e21992080
\ No newline at end of file
diff --git a/server/licenses/lucene-queryparser-9.8.0.jar.sha1 b/server/licenses/lucene-queryparser-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..2a42a8956b18b
--- /dev/null
+++ b/server/licenses/lucene-queryparser-9.8.0.jar.sha1
@@ -0,0 +1 @@
+982faf2bfa55542bf57fbadef54c19ac00f57cae
\ No newline at end of file
diff --git a/server/licenses/lucene-sandbox-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-sandbox-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 3231d0e067940..0000000000000
--- a/server/licenses/lucene-sandbox-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f1ec1527e283b423b7ff5e12cd8d889e7247199d
\ No newline at end of file
diff --git a/server/licenses/lucene-sandbox-9.8.0.jar.sha1 b/server/licenses/lucene-sandbox-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..64a0b07f72d29
--- /dev/null
+++ b/server/licenses/lucene-sandbox-9.8.0.jar.sha1
@@ -0,0 +1 @@
+06493dbd14d02537716822254866a94458f4d842
\ No newline at end of file
diff --git a/server/licenses/lucene-spatial-extras-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-spatial-extras-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index dd47faf91f206..0000000000000
--- a/server/licenses/lucene-spatial-extras-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-de787c052879893e47d21fa161c93413665d55d7
\ No newline at end of file
diff --git a/server/licenses/lucene-spatial-extras-9.8.0.jar.sha1 b/server/licenses/lucene-spatial-extras-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..d1bcb0581435c
--- /dev/null
+++ b/server/licenses/lucene-spatial-extras-9.8.0.jar.sha1
@@ -0,0 +1 @@
+9d9a731822ad6eefa1ba288a0c158d478522f165
\ No newline at end of file
diff --git a/server/licenses/lucene-spatial3d-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-spatial3d-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 2b378438bfb14..0000000000000
--- a/server/licenses/lucene-spatial3d-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7e541ed960a571f5d9a0ecff5c26fd5ca857581e
\ No newline at end of file
diff --git a/server/licenses/lucene-spatial3d-9.8.0.jar.sha1 b/server/licenses/lucene-spatial3d-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..d17459cc569a9
--- /dev/null
+++ b/server/licenses/lucene-spatial3d-9.8.0.jar.sha1
@@ -0,0 +1 @@
+ce752a52b2d4eac90633c7df7982e29504f99e76
\ No newline at end of file
diff --git a/server/licenses/lucene-suggest-9.8.0-snapshot-4373c3b.jar.sha1 b/server/licenses/lucene-suggest-9.8.0-snapshot-4373c3b.jar.sha1
deleted file mode 100644
index 1e3ed6561e3ef..0000000000000
--- a/server/licenses/lucene-suggest-9.8.0-snapshot-4373c3b.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4b222ef09a5f20896d031a8322f2e69304c16384
\ No newline at end of file
diff --git a/server/licenses/lucene-suggest-9.8.0.jar.sha1 b/server/licenses/lucene-suggest-9.8.0.jar.sha1
new file mode 100644
index 0000000000000..ff47b87672d2c
--- /dev/null
+++ b/server/licenses/lucene-suggest-9.8.0.jar.sha1
@@ -0,0 +1 @@
+f977f96f2093b7fddea6b67caa2e1c5b10edebf6
\ No newline at end of file
diff --git a/plugins/crypto-kms/licenses/reactive-streams-1.0.4.jar.sha1 b/server/licenses/reactive-streams-1.0.4.jar.sha1
similarity index 100%
rename from plugins/crypto-kms/licenses/reactive-streams-1.0.4.jar.sha1
rename to server/licenses/reactive-streams-1.0.4.jar.sha1
diff --git a/plugins/crypto-kms/licenses/reactive-streams-LICENSE.txt b/server/licenses/reactive-streams-LICENSE.txt
similarity index 100%
rename from plugins/crypto-kms/licenses/reactive-streams-LICENSE.txt
rename to server/licenses/reactive-streams-LICENSE.txt
diff --git a/server/licenses/reactive-streams-NOTICE.txt b/server/licenses/reactive-streams-NOTICE.txt
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/server/licenses/reactor-LICENSE.txt b/server/licenses/reactor-LICENSE.txt
new file mode 100644
index 0000000000000..e5583c184e67a
--- /dev/null
+++ b/server/licenses/reactor-LICENSE.txt
@@ -0,0 +1,201 @@
+Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       https://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/server/licenses/reactor-NOTICE.txt b/server/licenses/reactor-NOTICE.txt
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/server/licenses/reactor-core-3.5.11.jar.sha1 b/server/licenses/reactor-core-3.5.11.jar.sha1
new file mode 100644
index 0000000000000..e5ffdbc8a7840
--- /dev/null
+++ b/server/licenses/reactor-core-3.5.11.jar.sha1
@@ -0,0 +1 @@
+db2299757f562261eb775d13658e86ff06f91e8a
\ No newline at end of file
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/HotThreadsIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/HotThreadsIT.java
index 6343bd127c458..4c9f49df71257 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/admin/HotThreadsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/HotThreadsIT.java
@@ -60,8 +60,8 @@
 public class HotThreadsIT extends OpenSearchIntegTestCase {
 
     public void testHotThreadsDontFail() throws ExecutionException, InterruptedException {
-        /**
-         * This test just checks if nothing crashes or gets stuck etc.
+        /*
+          This test just checks if nothing crashes or gets stuck etc.
          */
         createIndex("test");
         final int iters = scaledRandomIntBetween(2, 20);
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/AbstractTasksIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/AbstractTasksIT.java
index 0197ccf059737..44ba585016d8e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/AbstractTasksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/AbstractTasksIT.java
@@ -112,7 +112,7 @@ protected int numberOfEvents(String actionMasks, Function<Tuple<Boolean, TaskInf
      * Returns all events that satisfy the criteria across all nodes
      *
      * @param actionMasks action masks to match
-     * @return number of events that satisfy the criteria
+     * @return List of events that satisfy the criteria
      */
     protected List<TaskInfo> findEvents(String actionMasks, Function<Tuple<Boolean, TaskInfo>, Boolean> criteria) {
         List<TaskInfo> events = new ArrayList<>();
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/CancellableTasksIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/CancellableTasksIT.java
index f11c696310b39..c4dcedcc722cf 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/CancellableTasksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/CancellableTasksIT.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.action.admin.cluster.node.tasks;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.ResourceNotFoundException;
 import org.opensearch.action.ActionRequest;
@@ -49,6 +51,8 @@
 import org.opensearch.common.SetOnce;
 import org.opensearch.common.action.ActionFuture;
 import org.opensearch.common.inject.Inject;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.util.concurrent.AbstractRunnable;
 import org.opensearch.common.util.concurrent.ConcurrentCollections;
 import org.opensearch.common.util.set.Sets;
@@ -65,7 +69,7 @@
 import org.opensearch.tasks.TaskInfo;
 import org.opensearch.tasks.TaskManager;
 import org.opensearch.test.InternalTestCluster;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TransportException;
 import org.opensearch.transport.TransportResponseHandler;
@@ -74,6 +78,7 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -86,6 +91,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.hamcrest.Matchers.anyOf;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.empty;
@@ -93,7 +99,7 @@
 import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.instanceOf;
 
-public class CancellableTasksIT extends OpenSearchIntegTestCase {
+public class CancellableTasksIT extends ParameterizedOpenSearchIntegTestCase {
 
     static int idGenerator = 0;
     static final Map<TestRequest, CountDownLatch> beforeSendLatches = ConcurrentCollections.newConcurrentMap();
@@ -101,6 +107,23 @@ public class CancellableTasksIT extends OpenSearchIntegTestCase {
     static final Map<TestRequest, CountDownLatch> beforeExecuteLatches = ConcurrentCollections.newConcurrentMap();
     static final Map<TestRequest, CountDownLatch> completedLatches = ConcurrentCollections.newConcurrentMap();
 
+    public CancellableTasksIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Before
     public void resetTestStates() {
         idGenerator = 0;
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/ConcurrentSearchTasksIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/ConcurrentSearchTasksIT.java
index ceacb028698de..e6fd9139d45f2 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/ConcurrentSearchTasksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/node/tasks/ConcurrentSearchTasksIT.java
@@ -30,7 +30,7 @@
 
 /**
  * Integration tests for task management API with Concurrent Segment Search
- *
+ * <p>
  * The way the test framework bootstraps the test cluster makes it difficult to parameterize the feature flag.
  * Once concurrent search is moved behind a cluster setting we can parameterize these tests behind the setting.
  */
@@ -72,7 +72,7 @@ protected Settings featureFlagSettings() {
 
     /**
      * Tests the number of threads that worked on a search task.
-     *
+     * <p>
      * Currently, we try to control concurrency by creating an index with 7 segments and rely on
      * the way concurrent search creates leaf slices from segments. Once more concurrency controls are introduced
      * we should improve this test to use those methods.
@@ -108,8 +108,9 @@ public void testConcurrentSearchTaskTracking() {
             assertEquals(mainTaskInfo.getTaskId(), taskInfo.getParentTaskId());
 
             Map<Long, List<ThreadResourceInfo>> threadStats = getThreadStats(SearchAction.NAME + "[*]", taskInfo.getTaskId());
-            // Concurrent search forks each slice of 5 segments to different thread
-            assertEquals((int) Math.ceil(getSegmentCount(INDEX_NAME) / 5.0), threadStats.size());
+            // Concurrent search forks each slice of 5 segments to different thread (see please
+            // https://github.com/apache/lucene/issues/12498)
+            assertEquals((int) Math.ceil(getSegmentCount(INDEX_NAME) / 5.0) + 1, threadStats.size());
 
             // assert that all task descriptions have non-zero length
             MatcherAssert.assertThat(taskInfo.getDescription().length(), greaterThan(0));
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/repositories/RepositoryBlocksIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/repositories/RepositoryBlocksIT.java
index aff7c5d9876ac..36fe3748e9d10 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/repositories/RepositoryBlocksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/repositories/RepositoryBlocksIT.java
@@ -46,7 +46,7 @@
 
 /**
  * This class tests that repository operations (Put, Delete, Verify) are blocked when the cluster is read-only.
- *
+ * <p>
  * The @NodeScope TEST is needed because this class updates the cluster setting "cluster.blocks.read_only".
  */
 @ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST)
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/snapshots/SnapshotBlocksIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/snapshots/SnapshotBlocksIT.java
index 347011721c728..78fb01b07b6b1 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/snapshots/SnapshotBlocksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/cluster/snapshots/SnapshotBlocksIT.java
@@ -53,7 +53,7 @@
 
 /**
  * This class tests that snapshot operations (Create, Delete, Restore) are blocked when the cluster is read-only.
- *
+ * <p>
  * The @NodeScope TEST is needed because this class updates the cluster setting "cluster.blocks.read_only".
  */
 @ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST)
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteCloneIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteCloneIndexIT.java
new file mode 100644
index 0000000000000..a081110e6c5a1
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteCloneIndexIT.java
@@ -0,0 +1,133 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.admin.indices.create;
+
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+import org.opensearch.Version;
+import org.opensearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.opensearch.action.admin.indices.shrink.ResizeType;
+import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.index.query.TermsQueryBuilder;
+import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
+import org.opensearch.test.VersionUtils;
+
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
+import static org.hamcrest.Matchers.equalTo;
+
+public class RemoteCloneIndexIT extends RemoteStoreBaseIntegTestCase {
+
+    @Override
+    protected boolean forbidPrivateIndexSettings() {
+        return false;
+    }
+
+    public void testCreateCloneIndex() {
+        Version version = VersionUtils.randomIndexCompatibleVersion(random());
+        int numPrimaryShards = randomIntBetween(1, 5);
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", numPrimaryShards).put("index.version.created", version)
+        ).get();
+        final int docs = randomIntBetween(0, 128);
+        for (int i = 0; i < docs; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin().indices().prepareUpdateSettings("source").setSettings(Settings.builder().put("index.blocks.write", true)).get();
+        ensureGreen();
+
+        final IndicesStatsResponse sourceStats = client().admin().indices().prepareStats("source").setSegments(true).get();
+
+        // disable rebalancing to be able to capture the right stats. balancing can move the target primary
+        // making it hard to pin point the source shards.
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), "none"))
+            .get();
+        try {
+            assertAcked(
+                client().admin()
+                    .indices()
+                    .prepareResizeIndex("source", "target")
+                    .setResizeType(ResizeType.CLONE)
+                    .setSettings(Settings.builder().put("index.number_of_replicas", 0).putNull("index.blocks.write").build())
+                    .get()
+            );
+            ensureGreen();
+
+            final IndicesStatsResponse targetStats = client().admin().indices().prepareStats("target").get();
+            assertThat(targetStats.getIndex("target").getIndexShards().keySet().size(), equalTo(numPrimaryShards));
+
+            final int size = docs > 0 ? 2 * docs : 1;
+            assertHitCount(client().prepareSearch("target").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+
+            for (int i = docs; i < 2 * docs; i++) {
+                client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+            }
+            flushAndRefresh();
+            assertHitCount(
+                client().prepareSearch("target").setSize(2 * size).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+                2 * docs
+            );
+            assertHitCount(client().prepareSearch("source").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+            GetSettingsResponse target = client().admin().indices().prepareGetSettings("target").get();
+            assertEquals(version, target.getIndexToSettings().get("target").getAsVersion("index.version.created", null));
+        } finally {
+            // clean up
+            client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setTransientSettings(
+                    Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), (String) null)
+                )
+                .get();
+        }
+
+    }
+
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteShrinkIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteShrinkIndexIT.java
new file mode 100644
index 0000000000000..282eb9c6ad95e
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteShrinkIndexIT.java
@@ -0,0 +1,545 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.admin.indices.create;
+
+import org.apache.lucene.search.Sort;
+import org.apache.lucene.search.SortField;
+import org.apache.lucene.search.SortedSetSelector;
+import org.apache.lucene.search.SortedSetSortField;
+import org.apache.lucene.util.Constants;
+import org.opensearch.Version;
+import org.opensearch.action.admin.cluster.reroute.ClusterRerouteResponse;
+import org.opensearch.action.admin.cluster.state.ClusterStateRequest;
+import org.opensearch.action.admin.cluster.state.ClusterStateResponse;
+import org.opensearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.opensearch.action.admin.indices.stats.CommonStats;
+import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.action.index.IndexRequest;
+import org.opensearch.action.support.ActiveShardCount;
+import org.opensearch.client.Client;
+import org.opensearch.cluster.ClusterInfoService;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.InternalClusterInfoService;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.routing.Murmur3HashFunction;
+import org.opensearch.cluster.routing.RoutingTable;
+import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.cluster.routing.UnassignedInfo;
+import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
+import org.opensearch.common.Priority;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.index.Index;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.index.IndexModule;
+import org.opensearch.index.IndexService;
+import org.opensearch.index.engine.SegmentsStats;
+import org.opensearch.index.query.TermsQueryBuilder;
+import org.opensearch.index.seqno.SeqNoStats;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
+import org.opensearch.indices.replication.common.ReplicationType;
+import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
+import org.opensearch.test.VersionUtils;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.stream.IntStream;
+
+import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+
+public class RemoteShrinkIndexIT extends RemoteStoreBaseIntegTestCase {
+    @Override
+    protected boolean forbidPrivateIndexSettings() {
+        return false;
+    }
+
+    public Settings indexSettings() {
+        return Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING.getKey(), false)
+            .put(SETTING_NUMBER_OF_REPLICAS, 0)
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .build();
+    }
+
+    public void testCreateShrinkIndexToN() {
+
+        assumeFalse("https://github.com/elastic/elasticsearch/issues/34080", Constants.WINDOWS);
+
+        int[][] possibleShardSplits = new int[][] { { 8, 4, 2 }, { 9, 3, 1 }, { 4, 2, 1 }, { 15, 5, 1 } };
+        int[] shardSplits = randomFrom(possibleShardSplits);
+        assertEquals(shardSplits[0], (shardSplits[0] / shardSplits[1]) * shardSplits[1]);
+        assertEquals(shardSplits[1], (shardSplits[1] / shardSplits[2]) * shardSplits[2]);
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(Settings.builder().put(indexSettings()).put("number_of_shards", shardSplits[0])).get();
+        for (int i = 0; i < 20; i++) {
+            client().prepareIndex("source")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        String mergeNode = discoveryNodes[0].getName();
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+        // now merge source into a 4 shard index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "first_shrink")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", shardSplits[1])
+                        .putNull("index.blocks.write")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("first_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+
+        for (int i = 0; i < 20; i++) { // now update
+            client().prepareIndex("first_shrink")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("first_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("first_shrink")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+        // now merge source into a 2 shard index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("first_shrink", "second_shrink")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", shardSplits[2])
+                        .putNull("index.blocks.write")
+                        .putNull("index.routing.allocation.require._name")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        // let it be allocated anywhere and bump replicas
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("second_shrink")
+            .setSettings(Settings.builder().putNull("index.routing.allocation.include._id").put("index.number_of_replicas", 0))
+            .get();
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+
+        for (int i = 0; i < 20; i++) { // now update
+            client().prepareIndex("second_shrink")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("second_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        assertHitCount(client().prepareSearch("first_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+    }
+
+    public void testShrinkIndexPrimaryTerm() throws Exception {
+        int numberOfShards = randomIntBetween(2, 20);
+        int numberOfTargetShards = randomValueOtherThanMany(n -> numberOfShards % n != 0, () -> randomIntBetween(1, numberOfShards - 1));
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(Settings.builder().put(indexSettings()).put("number_of_shards", numberOfShards)).get();
+
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertThat(dataNodes.size(), greaterThanOrEqualTo(2));
+        final DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        final String mergeNode = discoveryNodes[0].getName();
+        // This needs more than the default timeout if a large number of shards were created.
+        ensureGreen(TimeValue.timeValueSeconds(120));
+
+        // fail random primary shards to force primary terms to increase
+        final Index source = resolveIndex("source");
+        final int iterations = scaledRandomIntBetween(0, 16);
+        for (int i = 0; i < iterations; i++) {
+            final String node = randomSubsetOf(1, internalCluster().nodesInclude("source")).get(0);
+            final IndicesService indexServices = internalCluster().getInstance(IndicesService.class, node);
+            final IndexService indexShards = indexServices.indexServiceSafe(source);
+            for (final Integer shardId : indexShards.shardIds()) {
+                final IndexShard shard = indexShards.getShard(shardId);
+                if (shard.routingEntry().primary() && randomBoolean()) {
+                    disableAllocation("source");
+                    shard.failShard("test", new Exception("test"));
+                    // this can not succeed until the shard is failed and a replica is promoted
+                    int id = 0;
+                    while (true) {
+                        // find an ID that routes to the right shard, we will only index to the shard that saw a primary failure
+                        final String s = Integer.toString(id);
+                        final int hash = Math.floorMod(Murmur3HashFunction.hash(s), numberOfShards);
+                        if (hash == shardId) {
+                            final IndexRequest request = new IndexRequest("source").id(s)
+                                .source("{ \"f\": \"" + s + "\"}", MediaTypeRegistry.JSON);
+                            client().index(request).get();
+                            break;
+                        } else {
+                            id++;
+                        }
+                    }
+                    enableAllocation("source");
+                    ensureGreen();
+                }
+            }
+        }
+
+        // relocate all shards to one node such that we can merge it.
+        final Settings.Builder prepareShrinkSettings = Settings.builder()
+            .put("index.routing.allocation.require._name", mergeNode)
+            .put("index.blocks.write", true);
+        client().admin().indices().prepareUpdateSettings("source").setSettings(prepareShrinkSettings).get();
+        ensureGreen(TimeValue.timeValueSeconds(120)); // needs more than the default to relocate many shards
+
+        final IndexMetadata indexMetadata = indexMetadata(client(), "source");
+        final long beforeShrinkPrimaryTerm = IntStream.range(0, numberOfShards).mapToLong(indexMetadata::primaryTerm).max().getAsLong();
+
+        // now merge source into target
+        final Settings shrinkSettings = Settings.builder()
+            .put("index.number_of_replicas", 0)
+            .put("index.number_of_shards", numberOfTargetShards)
+            .build();
+        assertAcked(client().admin().indices().prepareResizeIndex("source", "target").setSettings(shrinkSettings).get());
+
+        ensureGreen(TimeValue.timeValueSeconds(120));
+
+        final IndexMetadata afterShrinkIndexMetadata = indexMetadata(client(), "target");
+        for (int shardId = 0; shardId < numberOfTargetShards; shardId++) {
+            assertThat(afterShrinkIndexMetadata.primaryTerm(shardId), equalTo(beforeShrinkPrimaryTerm + 1));
+        }
+    }
+
+    private static IndexMetadata indexMetadata(final Client client, final String index) {
+        final ClusterStateResponse clusterStateResponse = client.admin().cluster().state(new ClusterStateRequest()).actionGet();
+        return clusterStateResponse.getState().metadata().index(index);
+    }
+
+    public void testCreateShrinkIndex() {
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        Version version = VersionUtils.randomVersion(random());
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", randomIntBetween(2, 7)).put("index.version.created", version)
+        ).get();
+        final int docs = randomIntBetween(0, 128);
+        for (int i = 0; i < docs; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(
+                Settings.builder()
+                    .put("index.routing.allocation.require._name", discoveryNodes[0].getName())
+                    .put("index.blocks.write", true)
+            )
+            .get();
+        ensureGreen();
+
+        final IndicesStatsResponse sourceStats = client().admin().indices().prepareStats("source").setSegments(true).get();
+
+        // disable rebalancing to be able to capture the right stats. balancing can move the target primary
+        // making it hard to pin point the source shards.
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), "none"))
+            .get();
+
+        // now merge source into a single shard index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .putNull("index.blocks.write")
+                        .putNull("index.routing.allocation.require._name")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+
+        // resolve true merge node - this is not always the node we required as all shards may be on another node
+        final ClusterState state = client().admin().cluster().prepareState().get().getState();
+        DiscoveryNode mergeNode = state.nodes().get(state.getRoutingTable().index("target").shard(0).primaryShard().currentNodeId());
+        logger.info("merge node {}", mergeNode);
+
+        final long maxSeqNo = Arrays.stream(sourceStats.getShards())
+            .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+            .map(ShardStats::getSeqNoStats)
+            .mapToLong(SeqNoStats::getMaxSeqNo)
+            .max()
+            .getAsLong();
+        final long maxUnsafeAutoIdTimestamp = Arrays.stream(sourceStats.getShards())
+            .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+            .map(ShardStats::getStats)
+            .map(CommonStats::getSegments)
+            .mapToLong(SegmentsStats::getMaxUnsafeAutoIdTimestamp)
+            .max()
+            .getAsLong();
+
+        final IndicesStatsResponse targetStats = client().admin().indices().prepareStats("target").get();
+        for (final ShardStats shardStats : targetStats.getShards()) {
+            final SeqNoStats seqNoStats = shardStats.getSeqNoStats();
+            final ShardRouting shardRouting = shardStats.getShardRouting();
+            assertThat("failed on " + shardRouting, seqNoStats.getMaxSeqNo(), equalTo(maxSeqNo));
+            assertThat("failed on " + shardRouting, seqNoStats.getLocalCheckpoint(), equalTo(maxSeqNo));
+            assertThat(
+                "failed on " + shardRouting,
+                shardStats.getStats().getSegments().getMaxUnsafeAutoIdTimestamp(),
+                equalTo(maxUnsafeAutoIdTimestamp)
+            );
+        }
+
+        final int size = docs > 0 ? 2 * docs : 1;
+        assertHitCount(client().prepareSearch("target").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+
+        for (int i = docs; i < 2 * docs; i++) {
+            client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("target").setSize(2 * size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 2 * docs);
+        assertHitCount(client().prepareSearch("source").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+        GetSettingsResponse target = client().admin().indices().prepareGetSettings("target").get();
+        assertEquals(version, target.getIndexToSettings().get("target").getAsVersion("index.version.created", null));
+
+        // clean up
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), (String) null)
+            )
+            .get();
+    }
+
+    /**
+     * Tests that we can manually recover from a failed allocation due to shards being moved away etc.
+     */
+    public void testCreateShrinkIndexFails() throws Exception {
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", randomIntBetween(2, 7)).put("number_of_replicas", 0)
+        ).get();
+        for (int i = 0; i < 20; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        String spareNode = discoveryNodes[0].getName();
+        String mergeNode = discoveryNodes[1].getName();
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+
+        // now merge source into a single shard index
+        client().admin()
+            .indices()
+            .prepareResizeIndex("source", "target")
+            .setWaitForActiveShards(ActiveShardCount.NONE)
+            .setSettings(
+                Settings.builder()
+                    .put("index.routing.allocation.exclude._name", mergeNode) // we manually exclude the merge node to forcefully fuck it up
+                    .put("index.number_of_replicas", 0)
+                    .put("index.allocation.max_retries", 1)
+                    .build()
+            )
+            .get();
+        client().admin().cluster().prepareHealth("target").setWaitForEvents(Priority.LANGUID).get();
+
+        // now we move all shards away from the merge node
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", spareNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen("source");
+
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("target") // erase the forcefully fuckup!
+            .setSettings(Settings.builder().putNull("index.routing.allocation.exclude._name"))
+            .get();
+        // wait until it fails
+        assertBusy(() -> {
+            ClusterStateResponse clusterStateResponse = client().admin().cluster().prepareState().get();
+            RoutingTable routingTables = clusterStateResponse.getState().routingTable();
+            assertTrue(routingTables.index("target").shard(0).getShards().get(0).unassigned());
+            assertEquals(
+                UnassignedInfo.Reason.ALLOCATION_FAILED,
+                routingTables.index("target").shard(0).getShards().get(0).unassignedInfo().getReason()
+            );
+            assertEquals(1, routingTables.index("target").shard(0).getShards().get(0).unassignedInfo().getNumFailedAllocations());
+        });
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source") // now relocate them all to the right node
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode))
+            .get();
+        ensureGreen("source");
+
+        final InternalClusterInfoService infoService = (InternalClusterInfoService) internalCluster().getInstance(
+            ClusterInfoService.class,
+            internalCluster().getClusterManagerName()
+        );
+        infoService.refresh();
+        // kick off a retry and wait until it's done!
+        ClusterRerouteResponse clusterRerouteResponse = client().admin().cluster().prepareReroute().setRetryFailed(true).get();
+        long expectedShardSize = clusterRerouteResponse.getState()
+            .routingTable()
+            .index("target")
+            .shard(0)
+            .getShards()
+            .get(0)
+            .getExpectedShardSize();
+        // we support the expected shard size in the allocator to sum up over the source index shards
+        assertTrue("expected shard size must be set but wasn't: " + expectedShardSize, expectedShardSize > 0);
+        ensureGreen();
+        assertHitCount(client().prepareSearch("target").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+    }
+
+    public void testCreateShrinkWithIndexSort() throws Exception {
+        SortField expectedSortField = new SortedSetSortField("id", true, SortedSetSelector.Type.MAX);
+        expectedSortField.setMissingValue(SortedSetSortField.STRING_FIRST);
+        Sort expectedIndexSort = new Sort(expectedSortField);
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(
+            Settings.builder()
+                .put(indexSettings())
+                .put("sort.field", "id")
+                .put("sort.order", "desc")
+                .put("number_of_shards", 8)
+                .put("number_of_replicas", 0)
+        ).setMapping("id", "type=keyword,doc_values=true").get();
+        for (int i = 0; i < 20; i++) {
+            client().prepareIndex("source")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"id\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        String mergeNode = discoveryNodes[0].getName();
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+
+        flushAndRefresh();
+        assertSortedSegments("source", expectedIndexSort);
+
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+
+        // check that index sort cannot be set on the target index
+        IllegalArgumentException exc = expectThrows(
+            IllegalArgumentException.class,
+            () -> client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", "2")
+                        .put("index.sort.field", "foo")
+                        .build()
+                )
+                .get()
+        );
+        assertThat(exc.getMessage(), containsString("can't override index sort when resizing an index"));
+
+        // check that the index sort order of `source` is correctly applied to the `target`
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", "2")
+                        .putNull("index.blocks.write")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        flushAndRefresh();
+        GetSettingsResponse settingsResponse = client().admin().indices().prepareGetSettings("target").execute().actionGet();
+        assertEquals(settingsResponse.getSetting("target", "index.sort.field"), "id");
+        assertEquals(settingsResponse.getSetting("target", "index.sort.order"), "desc");
+        assertSortedSegments("target", expectedIndexSort);
+
+        // ... and that the index sort is also applied to updates
+        for (int i = 20; i < 40; i++) {
+            client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        flushAndRefresh();
+        assertSortedSegments("target", expectedIndexSort);
+    }
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteSplitIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteSplitIndexIT.java
new file mode 100644
index 0000000000000..dd4252d24f314
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteSplitIndexIT.java
@@ -0,0 +1,506 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.action.admin.indices.create;
+
+import org.apache.lucene.search.join.ScoreMode;
+import org.apache.lucene.util.Constants;
+import org.opensearch.Version;
+import org.opensearch.action.admin.cluster.state.ClusterStateRequest;
+import org.opensearch.action.admin.cluster.state.ClusterStateResponse;
+import org.opensearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.opensearch.action.admin.indices.shrink.ResizeType;
+import org.opensearch.action.admin.indices.stats.CommonStats;
+import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.action.get.GetResponse;
+import org.opensearch.action.index.IndexRequest;
+import org.opensearch.action.index.IndexRequestBuilder;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.client.Client;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.metadata.MetadataCreateIndexService;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.routing.Murmur3HashFunction;
+import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.index.Index;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.index.IndexModule;
+import org.opensearch.index.IndexService;
+import org.opensearch.index.engine.SegmentsStats;
+import org.opensearch.index.query.TermsQueryBuilder;
+import org.opensearch.index.seqno.SeqNoStats;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
+import org.opensearch.indices.replication.common.ReplicationType;
+import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
+import org.opensearch.test.VersionUtils;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.BiFunction;
+import java.util.stream.IntStream;
+
+import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
+import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.index.query.QueryBuilders.nestedQuery;
+import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
+import static org.hamcrest.Matchers.equalTo;
+
+public class RemoteSplitIndexIT extends RemoteStoreBaseIntegTestCase {
+
+    @Override
+    protected boolean forbidPrivateIndexSettings() {
+        return false;
+    }
+
+    public Settings indexSettings() {
+        return Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING.getKey(), false)
+            .put(SETTING_NUMBER_OF_REPLICAS, 0)
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .build();
+    }
+
+    public void testCreateSplitIndexToN() throws IOException {
+        int[][] possibleShardSplits = new int[][] { { 2, 4, 8 }, { 3, 6, 12 }, { 1, 2, 4 } };
+        int[] shardSplits = randomFrom(possibleShardSplits);
+        splitToN(shardSplits[0], shardSplits[1], shardSplits[2]);
+    }
+
+    public void testSplitFromOneToN() {
+
+        assumeFalse("https://github.com/elastic/elasticsearch/issues/34080", Constants.WINDOWS);
+
+        splitToN(1, 5, 10);
+        client().admin().indices().prepareDelete("*").get();
+        int randomSplit = randomIntBetween(2, 6);
+        splitToN(1, randomSplit, randomSplit * 2);
+    }
+
+    private void splitToN(int sourceShards, int firstSplitShards, int secondSplitShards) {
+
+        assertEquals(sourceShards, (sourceShards * firstSplitShards) / firstSplitShards);
+        assertEquals(firstSplitShards, (firstSplitShards * secondSplitShards) / secondSplitShards);
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        final boolean useRouting = randomBoolean();
+        final boolean useNested = randomBoolean();
+        final boolean useMixedRouting = useRouting ? randomBoolean() : false;
+        CreateIndexRequestBuilder createInitialIndex = prepareCreate("source");
+        Settings.Builder settings = Settings.builder().put(indexSettings()).put("number_of_shards", sourceShards);
+        final boolean useRoutingPartition;
+        if (randomBoolean()) {
+            // randomly set the value manually
+            int routingShards = secondSplitShards * randomIntBetween(1, 10);
+            settings.put("index.number_of_routing_shards", routingShards);
+            useRoutingPartition = false;
+        } else {
+            useRoutingPartition = randomBoolean();
+        }
+        if (useRouting && useMixedRouting == false && useRoutingPartition) {
+            int numRoutingShards = MetadataCreateIndexService.calculateNumRoutingShards(secondSplitShards, Version.CURRENT) - 1;
+            settings.put("index.routing_partition_size", randomIntBetween(1, numRoutingShards));
+            if (useNested) {
+                createInitialIndex.setMapping("_routing", "required=true", "nested1", "type=nested");
+            } else {
+                createInitialIndex.setMapping("_routing", "required=true");
+            }
+        } else if (useNested) {
+            createInitialIndex.setMapping("nested1", "type=nested");
+        }
+        logger.info("use routing {} use mixed routing {} use nested {}", useRouting, useMixedRouting, useNested);
+        createInitialIndex.setSettings(settings).get();
+
+        int numDocs = randomIntBetween(10, 50);
+        String[] routingValue = new String[numDocs];
+
+        BiFunction<String, Integer, IndexRequestBuilder> indexFunc = (index, id) -> {
+            try {
+                return client().prepareIndex(index)
+                    .setId(Integer.toString(id))
+                    .setSource(
+                        jsonBuilder().startObject()
+                            .field("foo", "bar")
+                            .field("i", id)
+                            .startArray("nested1")
+                            .startObject()
+                            .field("n_field1", "n_value1_1")
+                            .field("n_field2", "n_value2_1")
+                            .endObject()
+                            .startObject()
+                            .field("n_field1", "n_value1_2")
+                            .field("n_field2", "n_value2_2")
+                            .endObject()
+                            .endArray()
+                            .endObject()
+                    );
+            } catch (IOException e) {
+                throw new UncheckedIOException(e);
+            }
+        };
+        for (int i = 0; i < numDocs; i++) {
+            IndexRequestBuilder builder = indexFunc.apply("source", i);
+            if (useRouting) {
+                String routing = randomRealisticUnicodeOfCodepointLengthBetween(1, 10);
+                if (useMixedRouting && randomBoolean()) {
+                    routingValue[i] = null;
+                } else {
+                    routingValue[i] = routing;
+                }
+                builder.setRouting(routingValue[i]);
+            }
+            builder.get();
+        }
+
+        if (randomBoolean()) {
+            for (int i = 0; i < numDocs; i++) { // let's introduce some updates / deletes on the index
+                if (randomBoolean()) {
+                    IndexRequestBuilder builder = indexFunc.apply("source", i);
+                    if (useRouting) {
+                        builder.setRouting(routingValue[i]);
+                    }
+                    builder.get();
+                }
+            }
+        }
+
+        ensureYellow();
+        client().admin().indices().prepareUpdateSettings("source").setSettings(Settings.builder().put("index.blocks.write", true)).get();
+        ensureGreen();
+        Settings.Builder firstSplitSettingsBuilder = Settings.builder()
+            .put("index.number_of_replicas", 0)
+            .put("index.number_of_shards", firstSplitShards)
+            .putNull("index.blocks.write");
+        if (sourceShards == 1 && useRoutingPartition == false && randomBoolean()) { // try to set it if we have a source index with 1 shard
+            firstSplitSettingsBuilder.put("index.number_of_routing_shards", secondSplitShards);
+        }
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "first_split")
+                .setResizeType(ResizeType.SPLIT)
+                .setSettings(firstSplitSettingsBuilder.build())
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+
+        for (int i = 0; i < numDocs; i++) { // now update
+            IndexRequestBuilder builder = indexFunc.apply("first_split", i);
+            if (useRouting) {
+                builder.setRouting(routingValue[i]);
+            }
+            builder.get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        for (int i = 0; i < numDocs; i++) {
+            GetResponse getResponse = client().prepareGet("first_split", Integer.toString(i)).setRouting(routingValue[i]).get();
+            assertTrue(getResponse.isExists());
+        }
+
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("first_split")
+            .setSettings(Settings.builder().put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+        // now split source into a new index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("first_split", "second_split")
+                .setResizeType(ResizeType.SPLIT)
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", secondSplitShards)
+                        .putNull("index.blocks.write")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        // let it be allocated anywhere and bump replicas
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("second_split")
+            .setSettings(Settings.builder().put("index.number_of_replicas", 0))
+            .get();
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+
+        for (int i = 0; i < numDocs; i++) { // now update
+            IndexRequestBuilder builder = indexFunc.apply("second_split", i);
+            if (useRouting) {
+                builder.setRouting(routingValue[i]);
+            }
+            builder.get();
+        }
+        flushAndRefresh();
+        for (int i = 0; i < numDocs; i++) {
+            GetResponse getResponse = client().prepareGet("second_split", Integer.toString(i)).setRouting(routingValue[i]).get();
+            assertTrue(getResponse.isExists());
+        }
+        assertHitCount(client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        assertHitCount(client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        if (useNested) {
+            assertNested("source", numDocs);
+            assertNested("first_split", numDocs);
+            assertNested("second_split", numDocs);
+        }
+        assertAllUniqueDocs(
+            client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+            numDocs
+        );
+        assertAllUniqueDocs(
+            client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+            numDocs
+        );
+        assertAllUniqueDocs(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+    }
+
+    public void assertNested(String index, int numDocs) {
+        // now, do a nested query
+        SearchResponse searchResponse = client().prepareSearch(index)
+            .setQuery(nestedQuery("nested1", termQuery("nested1.n_field1", "n_value1_1"), ScoreMode.Avg))
+            .get();
+        assertNoFailures(searchResponse);
+        assertThat(searchResponse.getHits().getTotalHits().value, equalTo((long) numDocs));
+    }
+
+    public void assertAllUniqueDocs(SearchResponse response, int numDocs) {
+        Set<String> ids = new HashSet<>();
+        for (int i = 0; i < response.getHits().getHits().length; i++) {
+            String id = response.getHits().getHits()[i].getId();
+            assertTrue("found ID " + id + " more than once", ids.add(id));
+        }
+        assertEquals(numDocs, ids.size());
+    }
+
+    public void testSplitIndexPrimaryTerm() throws Exception {
+        int numberOfTargetShards = randomIntBetween(2, 20);
+        int numberOfShards = randomValueOtherThanMany(n -> numberOfTargetShards % n != 0, () -> between(1, numberOfTargetShards - 1));
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(
+            Settings.builder()
+                .put(indexSettings())
+                .put("number_of_shards", numberOfShards)
+                .put("index.number_of_routing_shards", numberOfTargetShards)
+        ).get();
+        ensureGreen(TimeValue.timeValueSeconds(120)); // needs more than the default to allocate many shards
+
+        // fail random primary shards to force primary terms to increase
+        final Index source = resolveIndex("source");
+        final int iterations = scaledRandomIntBetween(0, 16);
+        for (int i = 0; i < iterations; i++) {
+            final String node = randomSubsetOf(1, internalCluster().nodesInclude("source")).get(0);
+            final IndicesService indexServices = internalCluster().getInstance(IndicesService.class, node);
+            final IndexService indexShards = indexServices.indexServiceSafe(source);
+            for (final Integer shardId : indexShards.shardIds()) {
+                final IndexShard shard = indexShards.getShard(shardId);
+                if (shard.routingEntry().primary() && randomBoolean()) {
+                    disableAllocation("source");
+                    shard.failShard("test", new Exception("test"));
+                    // this can not succeed until the shard is failed and a replica is promoted
+                    int id = 0;
+                    while (true) {
+                        // find an ID that routes to the right shard, we will only index to the shard that saw a primary failure
+                        final String s = Integer.toString(id);
+                        final int hash = Math.floorMod(Murmur3HashFunction.hash(s), numberOfShards);
+                        if (hash == shardId) {
+                            final IndexRequest request = new IndexRequest("source").id(s)
+                                .source("{ \"f\": \"" + s + "\"}", MediaTypeRegistry.JSON);
+                            client().index(request).get();
+                            break;
+                        } else {
+                            id++;
+                        }
+                    }
+                    enableAllocation("source");
+                    ensureGreen();
+                }
+            }
+        }
+
+        final Settings.Builder prepareSplitSettings = Settings.builder().put("index.blocks.write", true);
+        client().admin().indices().prepareUpdateSettings("source").setSettings(prepareSplitSettings).get();
+        ensureYellow();
+
+        final IndexMetadata indexMetadata = indexMetadata(client(), "source");
+        final long beforeSplitPrimaryTerm = IntStream.range(0, numberOfShards).mapToLong(indexMetadata::primaryTerm).max().getAsLong();
+
+        // now split source into target
+        final Settings splitSettings = Settings.builder()
+            .put("index.number_of_replicas", 0)
+            .put("index.number_of_shards", numberOfTargetShards)
+            .putNull("index.blocks.write")
+            .build();
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setResizeType(ResizeType.SPLIT)
+                .setSettings(splitSettings)
+                .get()
+        );
+
+        ensureGreen(TimeValue.timeValueSeconds(120)); // needs more than the default to relocate many shards
+
+        final IndexMetadata aftersplitIndexMetadata = indexMetadata(client(), "target");
+        for (int shardId = 0; shardId < numberOfTargetShards; shardId++) {
+            assertThat(aftersplitIndexMetadata.primaryTerm(shardId), equalTo(beforeSplitPrimaryTerm + 1));
+        }
+    }
+
+    private static IndexMetadata indexMetadata(final Client client, final String index) {
+        final ClusterStateResponse clusterStateResponse = client.admin().cluster().state(new ClusterStateRequest()).actionGet();
+        return clusterStateResponse.getState().metadata().index(index);
+    }
+
+    public void testCreateSplitIndex() throws Exception {
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        Version version = VersionUtils.randomIndexCompatibleVersion(random());
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", 1).put("index.version.created", version)
+        ).get();
+        final int docs = randomIntBetween(0, 128);
+        for (int i = 0; i < docs; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin().indices().prepareUpdateSettings("source").setSettings(Settings.builder().put("index.blocks.write", true)).get();
+        ensureGreen();
+
+        final IndicesStatsResponse sourceStats = client().admin().indices().prepareStats("source").setSegments(true).get();
+
+        // disable rebalancing to be able to capture the right stats. balancing can move the target primary
+        // making it hard to pin point the source shards.
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), "none"))
+            .get();
+        try {
+            assertAcked(
+                client().admin()
+                    .indices()
+                    .prepareResizeIndex("source", "target")
+                    .setResizeType(ResizeType.SPLIT)
+                    .setSettings(
+                        Settings.builder()
+                            .put("index.number_of_replicas", 0)
+                            .put("index.number_of_shards", 2)
+                            .putNull("index.blocks.write")
+                            .build()
+                    )
+                    .get()
+            );
+            ensureGreen();
+
+            final ClusterState state = client().admin().cluster().prepareState().get().getState();
+            DiscoveryNode mergeNode = state.nodes().get(state.getRoutingTable().index("target").shard(0).primaryShard().currentNodeId());
+            logger.info("split node {}", mergeNode);
+
+            final long maxSeqNo = Arrays.stream(sourceStats.getShards())
+                .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+                .map(ShardStats::getSeqNoStats)
+                .mapToLong(SeqNoStats::getMaxSeqNo)
+                .max()
+                .getAsLong();
+            final long maxUnsafeAutoIdTimestamp = Arrays.stream(sourceStats.getShards())
+                .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+                .map(ShardStats::getStats)
+                .map(CommonStats::getSegments)
+                .mapToLong(SegmentsStats::getMaxUnsafeAutoIdTimestamp)
+                .max()
+                .getAsLong();
+
+            final IndicesStatsResponse targetStats = client().admin().indices().prepareStats("target").get();
+            for (final ShardStats shardStats : targetStats.getShards()) {
+                final SeqNoStats seqNoStats = shardStats.getSeqNoStats();
+                final ShardRouting shardRouting = shardStats.getShardRouting();
+                assertThat("failed on " + shardRouting, seqNoStats.getMaxSeqNo(), equalTo(maxSeqNo));
+                assertThat("failed on " + shardRouting, seqNoStats.getLocalCheckpoint(), equalTo(maxSeqNo));
+                assertThat(
+                    "failed on " + shardRouting,
+                    shardStats.getStats().getSegments().getMaxUnsafeAutoIdTimestamp(),
+                    equalTo(maxUnsafeAutoIdTimestamp)
+                );
+            }
+
+            final int size = docs > 0 ? 2 * docs : 1;
+            assertHitCount(client().prepareSearch("target").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+
+            for (int i = docs; i < 2 * docs; i++) {
+                client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+            }
+            flushAndRefresh();
+            assertHitCount(
+                client().prepareSearch("target").setSize(2 * size).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+                2 * docs
+            );
+            assertHitCount(client().prepareSearch("source").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+            GetSettingsResponse target = client().admin().indices().prepareGetSettings("target").get();
+            assertEquals(version, target.getIndexToSettings().get("target").getAsVersion("index.version.created", null));
+        } finally {
+            // clean up
+            client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setTransientSettings(
+                    Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), (String) null)
+                )
+                .get();
+        }
+
+    }
+
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/datastream/DataStreamTestCase.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/datastream/DataStreamTestCase.java
index 50ff76c6b62f3..82ab5b0118c0e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/datastream/DataStreamTestCase.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/datastream/DataStreamTestCase.java
@@ -37,6 +37,7 @@ public AcknowledgedResponse createDataStream(String name) throws Exception {
         CreateDataStreamAction.Request request = new CreateDataStreamAction.Request(name);
         AcknowledgedResponse response = client().admin().indices().createDataStream(request).get();
         assertThat(response.isAcknowledged(), is(true));
+        performRemoteStoreTestAction();
         return response;
     }
 
@@ -67,6 +68,7 @@ public RolloverResponse rolloverDataStream(String name) throws Exception {
         RolloverResponse response = client().admin().indices().rolloverIndex(request).get();
         assertThat(response.isAcknowledged(), is(true));
         assertThat(response.isRolledOver(), is(true));
+        performRemoteStoreTestAction();
         return response;
     }
 
@@ -109,5 +111,4 @@ public AcknowledgedResponse deleteIndexTemplate(String name) throws Exception {
         assertThat(response.isAcknowledged(), is(true));
         return response;
     }
-
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/bulk/BulkProcessorRetryIT.java b/server/src/internalClusterTest/java/org/opensearch/action/bulk/BulkProcessorRetryIT.java
index 737c0acc309fd..cd6cb0ca3b172 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/bulk/BulkProcessorRetryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/bulk/BulkProcessorRetryIT.java
@@ -194,7 +194,7 @@ private static void indexDocs(BulkProcessor processor, int numDocs) {
     /**
      * Internal helper class to correlate backoff states with bulk responses. This is needed to check whether we maxed out the number
      * of retries but still got rejected (which is perfectly fine and can also happen from time to time under heavy load).
-     *
+     * <p>
      * This implementation relies on an implementation detail in Retry, namely that the bulk listener is notified on the same thread
      * as the last call to the backoff policy's iterator. The advantage is that this is non-invasive to the rest of the production code.
      */
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/ingest/AsyncIngestProcessorIT.java b/server/src/internalClusterTest/java/org/opensearch/action/ingest/AsyncIngestProcessorIT.java
index c62c61d5919d6..aefabcb9bc14f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/ingest/AsyncIngestProcessorIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/ingest/AsyncIngestProcessorIT.java
@@ -69,7 +69,7 @@
 /**
  * The purpose of this test is to verify that when a processor executes an operation asynchronously that
  * the expected result is the same as if the same operation happens synchronously.
- *
+ * <p>
  * In this test two test processor are defined that basically do the same operation, but a single processor
  * executes asynchronously. The result of the operation should be the same and also the order in which the
  * bulk responses are returned should be the same as how the corresponding index requests were defined.
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/search/TransportSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/action/search/TransportSearchIT.java
index f0a3b5a5901ce..b1934f901ac65 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/search/TransportSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/search/TransportSearchIT.java
@@ -109,8 +109,8 @@ public List<AggregationSpec> getAggregations() {
 
         @Override
         public List<FetchSubPhase> getFetchSubPhases(FetchPhaseConstructionContext context) {
-            /**
-             * Set up a fetch sub phase that throws an exception on indices whose name that start with "boom".
+            /*
+              Set up a fetch sub phase that throws an exception on indices whose name that start with "boom".
              */
             return Collections.singletonList(fetchContext -> new FetchSubPhaseProcessor() {
                 @Override
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/termvectors/GetTermVectorsIT.java b/server/src/internalClusterTest/java/org/opensearch/action/termvectors/GetTermVectorsIT.java
index 9101d0b575ab6..7bd1467933e00 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/termvectors/GetTermVectorsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/termvectors/GetTermVectorsIT.java
@@ -74,6 +74,10 @@
 
 public class GetTermVectorsIT extends AbstractTermVectorsTestCase {
 
+    public GetTermVectorsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(MockKeywordPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/termvectors/MultiTermVectorsIT.java b/server/src/internalClusterTest/java/org/opensearch/action/termvectors/MultiTermVectorsIT.java
index 91d280a9c4771..7c6c47c682281 100644
--- a/server/src/internalClusterTest/java/org/opensearch/action/termvectors/MultiTermVectorsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/action/termvectors/MultiTermVectorsIT.java
@@ -52,6 +52,10 @@
 import static org.hamcrest.Matchers.nullValue;
 
 public class MultiTermVectorsIT extends AbstractTermVectorsTestCase {
+    public MultiTermVectorsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     public void testDuelESLucene() throws Exception {
         AbstractTermVectorsTestCase.TestFieldSetting[] testFieldSettings = getFieldSettings();
         createIndexBasedOnFieldSettings("test", "alias", testFieldSettings);
diff --git a/server/src/internalClusterTest/java/org/opensearch/blocks/SimpleBlocksIT.java b/server/src/internalClusterTest/java/org/opensearch/blocks/SimpleBlocksIT.java
index a7354dddfd16d..6275571cc2371 100644
--- a/server/src/internalClusterTest/java/org/opensearch/blocks/SimpleBlocksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/blocks/SimpleBlocksIT.java
@@ -47,6 +47,7 @@
 import org.opensearch.cluster.block.ClusterBlockLevel;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.IndexMetadata.APIBlock;
+import org.opensearch.cluster.metadata.ProcessClusterEventTimeoutException;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.index.IndexNotFoundException;
@@ -491,10 +492,20 @@ public void testAddBlockWhileDeletingIndices() throws Exception {
                     } catch (InterruptedException e) {
                         throw new AssertionError(e);
                     }
-                    try {
-                        assertAcked(client().admin().indices().prepareDelete(indexToDelete));
-                    } catch (final Exception e) {
-                        exceptionConsumer.accept(e);
+                    int pendingRetries = 3;
+                    boolean success = false;
+                    while (success == false && pendingRetries-- > 0) {
+                        try {
+                            assertAcked(client().admin().indices().prepareDelete(indexToDelete));
+                            success = true;
+                        } catch (final Exception e) {
+                            Throwable cause = ExceptionsHelper.unwrapCause(e);
+                            if (cause instanceof ProcessClusterEventTimeoutException && pendingRetries > 0) {
+                                // ignore error & retry
+                                continue;
+                            }
+                            exceptionConsumer.accept(e);
+                        }
                     }
                 }));
             }
diff --git a/server/src/internalClusterTest/java/org/opensearch/cluster/MinimumClusterManagerNodesIT.java b/server/src/internalClusterTest/java/org/opensearch/cluster/MinimumClusterManagerNodesIT.java
index 4c8bf24b1655a..84648eda3d38c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/cluster/MinimumClusterManagerNodesIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/cluster/MinimumClusterManagerNodesIT.java
@@ -317,8 +317,8 @@ public void testThreeNodesNoClusterManagerBlock() throws Exception {
         );
         Settings nonClusterManagerDataPathSettings1 = internalCluster().dataPathSettings(nonClusterManagerNodes.get(0));
         Settings nonClusterManagerDataPathSettings2 = internalCluster().dataPathSettings(nonClusterManagerNodes.get(1));
-        internalCluster().stopRandomNonClusterManagerNode();
-        internalCluster().stopRandomNonClusterManagerNode();
+        internalCluster().stopRandomNodeNotCurrentClusterManager();
+        internalCluster().stopRandomNodeNotCurrentClusterManager();
 
         logger.info("--> verify that there is no cluster-manager anymore on remaining node");
         // spin here to wait till the state is set
diff --git a/server/src/internalClusterTest/java/org/opensearch/cluster/coordination/UnsafeBootstrapAndDetachCommandIT.java b/server/src/internalClusterTest/java/org/opensearch/cluster/coordination/UnsafeBootstrapAndDetachCommandIT.java
index 4784441058e76..b30eb1f3e3b39 100644
--- a/server/src/internalClusterTest/java/org/opensearch/cluster/coordination/UnsafeBootstrapAndDetachCommandIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/cluster/coordination/UnsafeBootstrapAndDetachCommandIT.java
@@ -44,6 +44,7 @@
 import org.opensearch.env.TestEnvironment;
 import org.opensearch.gateway.GatewayMetaState;
 import org.opensearch.gateway.PersistedClusterStateService;
+import org.opensearch.gateway.remote.RemoteClusterStateService;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.node.Node.DiscoverySettings;
 import org.opensearch.test.InternalTestCluster;
@@ -180,6 +181,16 @@ public void testBootstrapNotClusterManagerEligible() {
         expectThrows(() -> unsafeBootstrap(environment), UnsafeBootstrapClusterManagerCommand.NOT_CLUSTER_MANAGER_NODE_MSG);
     }
 
+    public void testBootstrapRemoteClusterEnabled() {
+        final Environment environment = TestEnvironment.newEnvironment(
+            Settings.builder()
+                .put(internalCluster().getDefaultSettings())
+                .put(RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING.getKey(), true)
+                .build()
+        );
+        expectThrows(() -> unsafeBootstrap(environment), UnsafeBootstrapClusterManagerCommand.REMOTE_CLUSTER_STATE_ENABLED_NODE);
+    }
+
     public void testBootstrapNoDataFolder() {
         final Environment environment = TestEnvironment.newEnvironment(internalCluster().getDefaultSettings());
         expectThrows(() -> unsafeBootstrap(environment), OpenSearchNodeCommand.NO_NODE_FOLDER_FOUND_MSG);
diff --git a/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalIT.java b/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalIT.java
index 54824b67b7abc..25fa7ae7eb8eb 100644
--- a/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalIT.java
@@ -35,23 +35,27 @@
 import org.opensearch.action.admin.indices.get.GetIndexRequest;
 import org.opensearch.action.admin.indices.get.GetIndexResponse;
 import org.opensearch.action.admin.indices.settings.put.UpdateSettingsRequest;
+import org.opensearch.action.admin.indices.template.put.PutIndexTemplateRequest;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.index.Index;
 import org.opensearch.index.IndexService;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.indices.IndicesService;
+import org.opensearch.snapshots.AbstractSnapshotIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase;
 import org.junit.Before;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
 
 import static org.opensearch.indices.IndicesService.CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING;
 
-@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
-public class ClusterIndexRefreshIntervalIT extends OpenSearchIntegTestCase {
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 2)
+public class ClusterIndexRefreshIntervalIT extends AbstractSnapshotIntegTestCase {
 
     public static final String INDEX_NAME = "test-index";
 
@@ -69,9 +73,39 @@ public void setUp() throws Exception {
         internalCluster().startClusterManagerOnlyNode();
     }
 
+    static void putIndexTemplate(String refreshInterval) {
+        PutIndexTemplateRequest request = new PutIndexTemplateRequest("my-template"); // <1>
+        request.patterns(Arrays.asList("pattern-1", "log-*")); // <2>
+
+        request.settings(
+            Settings.builder() // <1>
+                .put("index.number_of_shards", 1)
+                .put("index.number_of_replicas", 1)
+                .put("index.refresh_interval", refreshInterval)
+        );
+        assertTrue(client().admin().indices().putTemplate(request).actionGet().isAcknowledged());
+    }
+
+    public void testIndexTemplateCreationSucceedsWhenNoMinimumRefreshInterval() throws ExecutionException, InterruptedException {
+        String clusterManagerName = internalCluster().getClusterManagerName();
+        List<String> dataNodes = new ArrayList<>(internalCluster().getDataNodeNames());
+        putIndexTemplate("2s");
+
+        // Test index creation using template with valid refresh interval
+        String indexName = "log-myindex-1";
+        createIndex(indexName);
+        ensureYellowAndNoInitializingShards(indexName);
+        ensureGreen(indexName);
+        GetIndexResponse getIndexResponse = client(clusterManagerName).admin().indices().getIndex(new GetIndexRequest()).get();
+        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, randomFrom(dataNodes));
+        String uuid = getIndexResponse.getSettings().get(indexName).get(IndexMetadata.SETTING_INDEX_UUID);
+        IndexService indexService = indicesService.indexService(new Index(indexName, uuid));
+        assertEquals(TimeValue.timeValueSeconds(2), indexService.getRefreshTaskInterval());
+    }
+
     public void testDefaultRefreshIntervalWithUpdateClusterAndIndexSettings() throws Exception {
         String clusterManagerName = internalCluster().getClusterManagerName();
-        List<String> dataNodes = internalCluster().startDataOnlyNodes(2);
+        List<String> dataNodes = new ArrayList<>(internalCluster().getDataNodeNames());
         createIndex(INDEX_NAME);
         ensureYellowAndNoInitializingShards(INDEX_NAME);
         ensureGreen(INDEX_NAME);
@@ -90,7 +124,7 @@ public void testDefaultRefreshIntervalWithUpdateClusterAndIndexSettings() throws
             .get();
         assertEquals(refreshInterval, indexService.getRefreshTaskInterval());
 
-        // Update of cluster.minimum.index.refresh_interval setting to value less than refreshInterval above will fail
+        // Update of cluster.minimum.index.refresh_interval setting to value more than default refreshInterval above will fail
         TimeValue invalidMinimumRefreshInterval = TimeValue.timeValueMillis(refreshInterval.millis() + randomIntBetween(1, 1000));
         IllegalArgumentException exceptionDuringMinUpdate = assertThrows(
             IllegalArgumentException.class,
@@ -205,7 +239,7 @@ public void testRefreshIntervalDisabled() throws ExecutionException, Interrupted
             .getAsTime(IndicesService.CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING.getKey(), TimeValue.MINUS_ONE);
         boolean createIndexSuccess = clusterMinimumRefreshInterval.equals(TimeValue.MINUS_ONE);
         String clusterManagerName = internalCluster().getClusterManagerName();
-        List<String> dataNodes = internalCluster().startDataOnlyNodes(2);
+        List<String> dataNodes = new ArrayList<>(internalCluster().getDataNodeNames());
         Settings settings = Settings.builder()
             .put(indexSettings())
             .put(IndexSettings.INDEX_REFRESH_INTERVAL_SETTING.getKey(), IndexSettings.MINIMUM_REFRESH_INTERVAL)
@@ -236,7 +270,7 @@ protected TimeValue getMinRefreshIntervalForRefreshDisabled() {
 
     public void testInvalidRefreshInterval() {
         String invalidRefreshInterval = "-10s";
-        internalCluster().startDataOnlyNodes(2);
+        List<String> dataNodes = new ArrayList<>(internalCluster().getDataNodeNames());
         Settings settings = Settings.builder()
             .put(indexSettings())
             .put(IndexSettings.INDEX_REFRESH_INTERVAL_SETTING.getKey(), invalidRefreshInterval)
@@ -251,7 +285,7 @@ public void testInvalidRefreshInterval() {
     }
 
     public void testCreateIndexWithExplicitNullRefreshInterval() throws ExecutionException, InterruptedException {
-        List<String> dataNodes = internalCluster().startDataOnlyNodes(2);
+        List<String> dataNodes = new ArrayList<>(internalCluster().getDataNodeNames());
         Settings indexSettings = Settings.builder()
             .put(indexSettings())
             .putNull(IndexSettings.INDEX_REFRESH_INTERVAL_SETTING.getKey())
@@ -278,7 +312,7 @@ public void testCreateIndexWithExplicitNullRefreshInterval() throws ExecutionExc
      * the index setting. The underlying index should continue to use the same refresh interval as earlier.
      */
     public void testClusterMinimumChangeOnIndexWithCustomRefreshInterval() throws ExecutionException, InterruptedException {
-        List<String> dataNodes = internalCluster().startDataOnlyNodes(2);
+        List<String> dataNodes = new ArrayList<>(internalCluster().getDataNodeNames());
         TimeValue customRefreshInterval = TimeValue.timeValueSeconds(getDefaultRefreshInterval().getSeconds() + randomIntBetween(1, 5));
         Settings indexSettings = Settings.builder()
             .put(indexSettings())
diff --git a/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalWithNodeSettingsIT.java b/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalWithNodeSettingsIT.java
index 5fc7bfcbcd442..2817d0e6a5951 100644
--- a/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalWithNodeSettingsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/cluster/metadata/ClusterIndexRefreshIntervalWithNodeSettingsIT.java
@@ -8,9 +8,27 @@
 
 package org.opensearch.cluster.metadata;
 
+import org.opensearch.action.admin.cluster.snapshots.restore.RestoreSnapshotResponse;
+import org.opensearch.action.admin.indices.get.GetIndexRequest;
+import org.opensearch.action.admin.indices.get.GetIndexResponse;
+import org.opensearch.action.admin.indices.template.get.GetIndexTemplatesResponse;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.indices.IndicesService;
+import org.opensearch.snapshots.SnapshotInfo;
+import org.opensearch.snapshots.SnapshotState;
+
+import java.util.Locale;
+import java.util.concurrent.ExecutionException;
+
+import static org.opensearch.cluster.metadata.IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING;
+import static org.opensearch.index.IndexSettings.INDEX_REFRESH_INTERVAL_SETTING;
+import static org.opensearch.indices.IndicesService.CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING;
+import static org.opensearch.indices.IndicesService.CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertIndexTemplateExists;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertIndexTemplateMissing;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
 
 public class ClusterIndexRefreshIntervalWithNodeSettingsIT extends ClusterIndexRefreshIntervalIT {
 
@@ -26,6 +44,166 @@ protected Settings nodeSettings(int nodeOrdinal) {
             .build();
     }
 
+    public void testIndexTemplateCreationFailsWithLessThanMinimumRefreshInterval() throws ExecutionException, InterruptedException {
+        Throwable throwable = assertThrows(IllegalArgumentException.class, () -> putIndexTemplate("0s"));
+        assertEquals(
+            throwable.getMessage(),
+            String.format(
+                Locale.ROOT,
+                "invalid index.refresh_interval [%s]: cannot be smaller than cluster.minimum.index.refresh_interval [%s]",
+                "0s",
+                getMinRefreshIntervalForRefreshDisabled()
+            )
+        );
+    }
+
+    public void testIndexTemplateSnapshotRestoreWithLessThanMinimumRefreshInterval() throws ExecutionException, InterruptedException {
+        putIndexTemplate("2s");
+        createRepository("test-repo", "fs");
+
+        final SnapshotInfo snapshotInfo = clusterAdmin().prepareCreateSnapshot("test-repo", "test-snap")
+            .setIndices()
+            .setWaitForCompletion(true)
+            .execute()
+            .get()
+            .getSnapshotInfo();
+        assertThat(snapshotInfo.state(), is(SnapshotState.SUCCESS));
+
+        assertThat(snapshotInfo.totalShards(), equalTo(0));
+        assertThat(snapshotInfo.successfulShards(), equalTo(0));
+
+        assertThat(client().admin().indices().prepareDeleteTemplate("my-template").get().isAcknowledged(), equalTo(true));
+
+        GetIndexTemplatesResponse getIndexTemplatesResponse = client().admin().indices().prepareGetTemplates().get();
+        assertIndexTemplateMissing(getIndexTemplatesResponse, "my-template");
+
+        String clusterManagerName = internalCluster().getClusterManagerName();
+        client(clusterManagerName).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder()
+                    .put(CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "5s")
+                    .put(CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "4s")
+            )
+            .get();
+
+        logger.info("--> try restore cluster state -- should fail");
+        Throwable throwable = assertThrows(
+            IllegalArgumentException.class,
+            () -> clusterAdmin().prepareRestoreSnapshot("test-repo", "test-snap")
+                .setWaitForCompletion(true)
+                .setRestoreGlobalState(true)
+                .execute()
+                .actionGet()
+        );
+        assertEquals(
+            throwable.getMessage(),
+            "invalid index.refresh_interval [2s]: cannot be smaller than cluster.minimum.index.refresh_interval [4s]"
+        );
+
+        client(clusterManagerName).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder()
+                    .put(CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "5s")
+                    .put(CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "1s")
+            )
+            .get();
+
+        logger.info("--> restore cluster state");
+        RestoreSnapshotResponse restoreSnapshotResponse = clusterAdmin().prepareRestoreSnapshot("test-repo", "test-snap")
+            .setWaitForCompletion(true)
+            .setRestoreGlobalState(true)
+            .execute()
+            .actionGet();
+        assertThat(restoreSnapshotResponse.getRestoreInfo().totalShards(), equalTo(0));
+
+        getIndexTemplatesResponse = client().admin().indices().prepareGetTemplates().get();
+        assertIndexTemplateExists(getIndexTemplatesResponse, "my-template");
+
+    }
+
+    public void testIndexSnapshotRestoreWithLessThanMinimumRefreshInterval() throws ExecutionException, InterruptedException {
+        createIndex(
+            "my-index",
+            Settings.builder()
+                .put(indexSettings())
+                .put(INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1)
+                .put(INDEX_REFRESH_INTERVAL_SETTING.getKey(), "2s")
+                .build()
+        );
+
+        createRepository("test-repo", "fs");
+
+        final SnapshotInfo snapshotInfo = clusterAdmin().prepareCreateSnapshot("test-repo", "test-snap")
+            .setIndices()
+            .setWaitForCompletion(true)
+            .execute()
+            .get()
+            .getSnapshotInfo();
+        assertThat(snapshotInfo.state(), is(SnapshotState.SUCCESS));
+
+        assertThat(snapshotInfo.totalShards(), equalTo(1));
+        assertThat(snapshotInfo.successfulShards(), equalTo(1));
+
+        GetIndexResponse getIndexResponse = client().admin().indices().getIndex(new GetIndexRequest().indices("my-index")).get();
+        assertEquals(1, getIndexResponse.indices().length);
+        assertEquals("2s", getIndexResponse.getSetting("my-index", INDEX_REFRESH_INTERVAL_SETTING.getKey()));
+
+        assertThat(client().admin().indices().prepareDelete("my-index").get().isAcknowledged(), equalTo(true));
+
+        getIndexResponse = client().admin().indices().getIndex(new GetIndexRequest()).get();
+        assertEquals(getIndexResponse.indices().length, 0);
+
+        String clusterManagerName = internalCluster().getClusterManagerName();
+        client(clusterManagerName).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder()
+                    .put(CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "5s")
+                    .put(CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "4s")
+            )
+            .get();
+
+        logger.info("--> try restore cluster state -- should fail");
+        Throwable throwable = assertThrows(
+            IllegalArgumentException.class,
+            () -> clusterAdmin().prepareRestoreSnapshot("test-repo", "test-snap")
+                .setWaitForCompletion(true)
+                .setRestoreGlobalState(true)
+                .execute()
+                .actionGet()
+        );
+        assertEquals(
+            throwable.getMessage(),
+            "invalid index.refresh_interval [2s]: cannot be smaller than cluster.minimum.index.refresh_interval [4s]"
+        );
+
+        client(clusterManagerName).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder()
+                    .put(CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "5s")
+                    .put(CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING.getKey(), "1s")
+            )
+            .get();
+
+        logger.info("--> try restore cluster state -- should pass");
+        RestoreSnapshotResponse restoreSnapshotResponse = clusterAdmin().prepareRestoreSnapshot("test-repo", "test-snap")
+            .setWaitForCompletion(true)
+            .setRestoreGlobalState(true)
+            .execute()
+            .actionGet();
+        assertThat(restoreSnapshotResponse.getRestoreInfo().totalShards(), equalTo(1));
+
+        getIndexResponse = client().admin().indices().getIndex(new GetIndexRequest().indices("my-index")).get();
+        assertEquals(getIndexResponse.indices().length, 1);
+    }
+
     @Override
     protected TimeValue getMinRefreshIntervalForRefreshDisabled() {
         return TimeValue.timeValueSeconds(1);
diff --git a/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterDisruptionIT.java b/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterDisruptionIT.java
index 38b86d307d197..737b272613a44 100644
--- a/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterDisruptionIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterDisruptionIT.java
@@ -461,7 +461,7 @@ public boolean validateClusterForming() {
 
     /**
      * Tests that indices are properly deleted even if there is a cluster-manager transition in between.
-     * Test for https://github.com/elastic/elasticsearch/issues/11665
+     * Test for <a href="https://github.com/elastic/elasticsearch/issues/11665">Elasticsearch issue #11665</a>
      */
     public void testIndicesDeleted() throws Exception {
         final String idxName = "test";
diff --git a/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterManagerDisruptionIT.java b/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterManagerDisruptionIT.java
index 1463c45aa9b2f..79f6ba6dfa642 100644
--- a/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterManagerDisruptionIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/discovery/ClusterManagerDisruptionIT.java
@@ -39,6 +39,7 @@
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.coordination.NoClusterManagerBlockService;
 import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.service.ClusterStateStats;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
@@ -199,6 +200,8 @@ public void testIsolateClusterManagerAndVerifyClusterStateConsensus() throws Exc
                 }
 
             }
+            ClusterStateStats clusterStateStats = internalCluster().clusterService().getClusterManagerService().getClusterStateStats();
+            assertTrue(clusterStateStats.getUpdateFailed() > 0);
         });
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/discovery/DiscoveryDisruptionIT.java b/server/src/internalClusterTest/java/org/opensearch/discovery/DiscoveryDisruptionIT.java
index a2864b6dfd1da..70124c8c46700 100644
--- a/server/src/internalClusterTest/java/org/opensearch/discovery/DiscoveryDisruptionIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/discovery/DiscoveryDisruptionIT.java
@@ -136,7 +136,7 @@ public void testClusterJoinDespiteOfPublishingIssues() throws Exception {
 
         // shutting down the nodes, to avoid the leakage check tripping
         // on the states associated with the commit requests we may have dropped
-        internalCluster().stopRandomNonClusterManagerNode();
+        internalCluster().stopRandomNodeNotCurrentClusterManager();
     }
 
     public void testClusterFormingWithASlowNode() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/discovery/single/SingleNodeDiscoveryIT.java b/server/src/internalClusterTest/java/org/opensearch/discovery/single/SingleNodeDiscoveryIT.java
index 90bdcf7fded11..1f6c8eac6c391 100644
--- a/server/src/internalClusterTest/java/org/opensearch/discovery/single/SingleNodeDiscoveryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/discovery/single/SingleNodeDiscoveryIT.java
@@ -76,6 +76,7 @@ public void testSingleNodesDoNotDiscoverEachOther() throws IOException, Interrup
             @Override
             public Settings nodeSettings(int nodeOrdinal) {
                 return Settings.builder()
+                    .put(featureFlagSettings())
                     .put("discovery.type", "single-node")
                     .put("transport.type", getTestTransportType())
                     /*
@@ -142,6 +143,7 @@ public boolean innerMatch(final LogEvent event) {
                 @Override
                 public Settings nodeSettings(int nodeOrdinal) {
                     return Settings.builder()
+                        .put(featureFlagSettings())
                         .put("discovery.type", "zen")
                         .put("transport.type", getTestTransportType())
                         .put(DiscoverySettings.INITIAL_STATE_TIMEOUT_SETTING.getKey(), "0s")
diff --git a/server/src/internalClusterTest/java/org/opensearch/gateway/RecoveryFromGatewayIT.java b/server/src/internalClusterTest/java/org/opensearch/gateway/RecoveryFromGatewayIT.java
index 2bab61f3e1c4c..229cd7bffad2f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/gateway/RecoveryFromGatewayIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/gateway/RecoveryFromGatewayIT.java
@@ -53,7 +53,7 @@
 import org.opensearch.env.NodeEnvironment;
 import org.opensearch.index.IndexService;
 import org.opensearch.index.IndexSettings;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.index.engine.Engine;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.index.shard.ShardPath;
@@ -519,7 +519,7 @@ public void testReuseInFileBasedPeerRecovery() throws Exception {
                     .put("number_of_replicas", 1)
 
                     // disable merges to keep segments the same
-                    .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+                    .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
 
                     // expire retention leases quickly
                     .put(IndexService.RETENTION_LEASE_SYNC_INTERVAL_SETTING.getKey(), "100ms")
diff --git a/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java b/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java
index 6fcc89cfe9e9a..dfde1b958882c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java
@@ -8,9 +8,12 @@
 
 package org.opensearch.gateway.remote;
 
+import org.opensearch.action.admin.cluster.node.stats.NodesStatsRequest;
+import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.discovery.DiscoveryStats;
 import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
@@ -19,6 +22,7 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.gateway.remote.RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING;
@@ -86,14 +90,105 @@ public void testFullClusterRestoreStaleDelete() throws Exception {
 
         assertEquals(10, repository.blobStore().blobContainer(baseMetadataPath.add("manifest")).listBlobsByPrefix("manifest").size());
 
-        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestIndexMetadata(
+        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestClusterState(
             cluster().getClusterName(),
             getClusterState().metadata().clusterUUID()
-        );
+        ).getMetadata().getIndices();
         assertEquals(0, indexMetadataMap.values().stream().findFirst().get().getNumberOfReplicas());
         assertEquals(shardCount, indexMetadataMap.values().stream().findFirst().get().getNumberOfShards());
     }
 
+    public void testRemoteStateStats() {
+        int shardCount = randomIntBetween(1, 2);
+        int replicaCount = 1;
+        int dataNodeCount = shardCount * (replicaCount + 1);
+        int clusterManagerNodeCount = 1;
+        prepareCluster(clusterManagerNodeCount, dataNodeCount, INDEX_NAME, replicaCount, shardCount);
+        String clusterManagerNode = internalCluster().getClusterManagerName();
+        String dataNode = internalCluster().getDataNodeNames().stream().collect(Collectors.toList()).get(0);
+
+        // Fetch _nodes/stats
+        NodesStatsResponse nodesStatsResponse = client().admin()
+            .cluster()
+            .prepareNodesStats(clusterManagerNode)
+            .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+            .get();
+
+        // assert cluster state stats
+        assertClusterManagerClusterStateStats(nodesStatsResponse);
+
+        NodesStatsResponse nodesStatsResponseDataNode = client().admin()
+            .cluster()
+            .prepareNodesStats(dataNode)
+            .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+            .get();
+        // assert cluster state stats for data node
+        DiscoveryStats dataNodeDiscoveryStats = nodesStatsResponseDataNode.getNodes().get(0).getDiscoveryStats();
+        assertNotNull(dataNodeDiscoveryStats.getClusterStateStats());
+        assertEquals(0, dataNodeDiscoveryStats.getClusterStateStats().getUpdateSuccess());
+
+        // call nodes/stats with nodeId filter
+        NodesStatsResponse nodesStatsNodeIdFilterResponse = client().admin()
+            .cluster()
+            .prepareNodesStats(dataNode)
+            .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+            .setNodesIds(clusterManagerNode)
+            .get();
+
+        assertClusterManagerClusterStateStats(nodesStatsNodeIdFilterResponse);
+    }
+
+    private void assertClusterManagerClusterStateStats(NodesStatsResponse nodesStatsResponse) {
+        // assert cluster state stats
+        DiscoveryStats discoveryStats = nodesStatsResponse.getNodes().get(0).getDiscoveryStats();
+
+        assertNotNull(discoveryStats.getClusterStateStats());
+        assertTrue(discoveryStats.getClusterStateStats().getUpdateSuccess() > 1);
+        assertEquals(0, discoveryStats.getClusterStateStats().getUpdateFailed());
+        assertTrue(discoveryStats.getClusterStateStats().getUpdateTotalTimeInMillis() > 0);
+        // assert remote state stats
+        assertTrue(discoveryStats.getClusterStateStats().getPersistenceStats().get(0).getSuccessCount() > 1);
+        assertEquals(0, discoveryStats.getClusterStateStats().getPersistenceStats().get(0).getFailedCount());
+        assertTrue(discoveryStats.getClusterStateStats().getPersistenceStats().get(0).getTotalTimeInMillis() > 0);
+    }
+
+    public void testRemoteStateStatsFromAllNodes() {
+        int shardCount = randomIntBetween(1, 5);
+        int replicaCount = 1;
+        int dataNodeCount = shardCount * (replicaCount + 1);
+        int clusterManagerNodeCount = 3;
+        prepareCluster(clusterManagerNodeCount, dataNodeCount, INDEX_NAME, replicaCount, shardCount);
+        String[] allNodes = internalCluster().getNodeNames();
+        // call _nodes/stats/discovery from all the nodes
+        for (String node : allNodes) {
+            NodesStatsResponse nodesStatsResponse = client().admin()
+                .cluster()
+                .prepareNodesStats(node)
+                .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+                .get();
+            validateNodesStatsResponse(nodesStatsResponse);
+        }
+
+        // call _nodes/stats/discovery from all the nodes with random nodeId filter
+        for (String node : allNodes) {
+            NodesStatsResponse nodesStatsResponse = client().admin()
+                .cluster()
+                .prepareNodesStats(node)
+                .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+                .setNodesIds(allNodes[randomIntBetween(0, allNodes.length - 1)])
+                .get();
+            validateNodesStatsResponse(nodesStatsResponse);
+        }
+    }
+
+    private void validateNodesStatsResponse(NodesStatsResponse nodesStatsResponse) {
+        // _nodes/stats/discovery must never fail due to any exception
+        assertFalse(nodesStatsResponse.toString().contains("exception"));
+        assertNotNull(nodesStatsResponse.getNodes());
+        assertNotNull(nodesStatsResponse.getNodes().get(0));
+        assertNotNull(nodesStatsResponse.getNodes().get(0).getDiscoveryStats());
+    }
+
     private void setReplicaCount(int replicaCount) {
         client().admin()
             .indices()
diff --git a/server/src/internalClusterTest/java/org/opensearch/index/IndexSortIT.java b/server/src/internalClusterTest/java/org/opensearch/index/IndexSortIT.java
index d547ded8152dd..bb6e356db188f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/index/IndexSortIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/index/IndexSortIT.java
@@ -32,22 +32,45 @@
 
 package org.opensearch.index;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.SortedNumericSortField;
 import org.apache.lucene.search.SortedSetSortField;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.hamcrest.Matchers.containsString;
 
-public class IndexSortIT extends OpenSearchIntegTestCase {
+public class IndexSortIT extends ParameterizedOpenSearchIntegTestCase {
     private static final XContentBuilder TEST_MAPPING = createTestMapping();
 
+    public IndexSortIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private static XContentBuilder createTestMapping() {
         try {
             return jsonBuilder().startObject()
diff --git a/server/src/internalClusterTest/java/org/opensearch/index/engine/MaxDocsLimitIT.java b/server/src/internalClusterTest/java/org/opensearch/index/engine/MaxDocsLimitIT.java
index 385d33c359559..8321630d34229 100644
--- a/server/src/internalClusterTest/java/org/opensearch/index/engine/MaxDocsLimitIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/index/engine/MaxDocsLimitIT.java
@@ -36,6 +36,8 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.core.index.Index;
+import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.index.IndexSettings;
@@ -65,6 +67,7 @@
 public class MaxDocsLimitIT extends OpenSearchIntegTestCase {
 
     private static final AtomicInteger maxDocs = new AtomicInteger();
+    private static final ShardId shardId = new ShardId(new Index("test", "_na_"), 0);
 
     public static class TestEnginePlugin extends Plugin implements EnginePlugin {
         @Override
@@ -122,7 +125,10 @@ public void testMaxDocsLimit() throws Exception {
             IllegalArgumentException.class,
             () -> client().prepareDelete("test", "any-id").get()
         );
-        assertThat(deleteError.getMessage(), containsString("Number of documents in the index can't exceed [" + maxDocs.get() + "]"));
+        assertThat(
+            deleteError.getMessage(),
+            containsString("Number of documents in shard " + shardId + " exceeds the limit of [" + maxDocs.get() + "] documents per shard")
+        );
         client().admin().indices().prepareRefresh("test").get();
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(new MatchAllQueryBuilder())
@@ -208,7 +214,16 @@ static IndexingResult indexDocs(int numRequests, int numThreads) throws Exceptio
                         assertThat(resp.status(), equalTo(RestStatus.CREATED));
                     } catch (IllegalArgumentException e) {
                         numFailure.incrementAndGet();
-                        assertThat(e.getMessage(), containsString("Number of documents in the index can't exceed [" + maxDocs.get() + "]"));
+                        assertThat(
+                            e.getMessage(),
+                            containsString(
+                                "Number of documents in shard "
+                                    + shardId
+                                    + " exceeds the limit of ["
+                                    + maxDocs.get()
+                                    + "] documents per shard"
+                            )
+                        );
                     }
                 }
             });
diff --git a/server/src/internalClusterTest/java/org/opensearch/index/search/MatchPhraseQueryIT.java b/server/src/internalClusterTest/java/org/opensearch/index/search/MatchPhraseQueryIT.java
index 6d76ee48a5b95..2d28578dbebcc 100644
--- a/server/src/internalClusterTest/java/org/opensearch/index/search/MatchPhraseQueryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/index/search/MatchPhraseQueryIT.java
@@ -32,26 +32,50 @@
 
 package org.opensearch.index.search;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.indices.create.CreateIndexRequestBuilder;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.MatchPhraseQueryBuilder;
 import org.opensearch.index.search.MatchQuery.ZeroTermsQuery;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.Before;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
 
 import static org.opensearch.index.query.QueryBuilders.matchPhraseQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 
-public class MatchPhraseQueryIT extends OpenSearchIntegTestCase {
+public class MatchPhraseQueryIT extends ParameterizedOpenSearchIntegTestCase {
+
     private static final String INDEX = "test";
 
+    public MatchPhraseQueryIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Before
     public void setUp() throws Exception {
         super.setUp();
diff --git a/server/src/internalClusterTest/java/org/opensearch/index/shard/IndexShardIT.java b/server/src/internalClusterTest/java/org/opensearch/index/shard/IndexShardIT.java
index bb08b19df765b..c394a1f631690 100644
--- a/server/src/internalClusterTest/java/org/opensearch/index/shard/IndexShardIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/index/shard/IndexShardIT.java
@@ -650,7 +650,15 @@ public void postDelete(ShardId shardId, Engine.Delete delete, Engine.DeleteResul
                 }
             }
         };
-        final IndexShard newShard = newIndexShard(indexService, shard, wrapper, getInstanceFromNode(CircuitBreakerService.class), listener);
+        NodeEnvironment env = getInstanceFromNode(NodeEnvironment.class);
+        final IndexShard newShard = newIndexShard(
+            indexService,
+            shard,
+            wrapper,
+            getInstanceFromNode(CircuitBreakerService.class),
+            env.nodeId(),
+            listener
+        );
         shardRef.set(newShard);
         recoverShard(newShard);
 
@@ -674,6 +682,7 @@ public static final IndexShard newIndexShard(
         final IndexShard shard,
         CheckedFunction<DirectoryReader, DirectoryReader, IOException> wrapper,
         final CircuitBreakerService cbs,
+        final String nodeId,
         final IndexingOperationListener... listeners
     ) throws IOException {
         ShardRouting initializingShardRouting = getInitializingShardRouting(shard.routingEntry());
@@ -702,7 +711,9 @@ public static final IndexShard newIndexShard(
             SegmentReplicationCheckpointPublisher.EMPTY,
             null,
             null,
-            () -> IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL
+            () -> IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL,
+            nodeId,
+            null
         );
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandIT.java b/server/src/internalClusterTest/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandIT.java
index f8c2acbf99f70..b431079476624 100644
--- a/server/src/internalClusterTest/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandIT.java
@@ -73,7 +73,7 @@
 import org.opensearch.env.TestEnvironment;
 import org.opensearch.gateway.GatewayMetaState;
 import org.opensearch.index.IndexSettings;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.index.MockEngineFactoryPlugin;
 import org.opensearch.index.seqno.SeqNoStats;
 import org.opensearch.index.translog.TestTranslog;
@@ -135,7 +135,7 @@ public void testCorruptIndex() throws Exception {
                 Settings.builder()
                     .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
                     .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
-                    .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+                    .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
                     .put(IndexSettings.INDEX_REFRESH_INTERVAL_SETTING.getKey(), "-1")
                     .put(MockEngineSupport.DISABLE_FLUSH_ON_CLOSE.getKey(), true)
                     .put(IndexSettings.INDEX_CHECK_ON_STARTUP.getKey(), "checksum")
diff --git a/server/src/internalClusterTest/java/org/opensearch/index/store/CorruptedFileIT.java b/server/src/internalClusterTest/java/org/opensearch/index/store/CorruptedFileIT.java
index 7e1d0792e3ddb..8291fef5d177b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/index/store/CorruptedFileIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/index/store/CorruptedFileIT.java
@@ -72,7 +72,7 @@
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.env.NodeEnvironment;
 import org.opensearch.index.IndexSettings;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.index.shard.IndexEventListener;
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.index.shard.IndexShardState;
@@ -167,7 +167,7 @@ public void testCorruptFileAndRecover() throws ExecutionException, InterruptedEx
                 Settings.builder()
                     .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, "1")
                     .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "1")
-                    .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+                    .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
                     // no checkindex - we corrupt shards on purpose
                     .put(MockFSIndexStore.INDEX_CHECK_INDEX_ON_CLOSE_SETTING.getKey(), false)
                     // no translog based flush - it might change the .liv / segments.N files
@@ -286,7 +286,7 @@ public void testCorruptPrimaryNoReplica() throws ExecutionException, Interrupted
             prepareCreate("test").setSettings(
                 Settings.builder()
                     .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "0")
-                    .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+                    .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
                     .put(MockFSIndexStore.INDEX_CHECK_INDEX_ON_CLOSE_SETTING.getKey(), false) // no checkindex - we corrupt shards on
                                                                                               // purpose
                     // no translog based flush - it might change the .liv / segments.N files
@@ -552,7 +552,7 @@ public void testCorruptFileThenSnapshotAndRestore() throws ExecutionException, I
             prepareCreate("test").setSettings(
                 Settings.builder()
                     .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "0") // no replicas for this test
-                    .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+                    .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
                     // no checkindex - we corrupt shards on purpose
                     .put(MockFSIndexStore.INDEX_CHECK_INDEX_ON_CLOSE_SETTING.getKey(), false)
                     // no translog based flush - it might change the .liv / segments.N files
@@ -624,7 +624,7 @@ public void testReplicaCorruption() throws Exception {
             prepareCreate("test").setSettings(
                 Settings.builder()
                     .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, cluster().numDataNodes() - 1)
-                    .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+                    .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
                     .put(MockFSIndexStore.INDEX_CHECK_INDEX_ON_CLOSE_SETTING.getKey(), false) // no checkindex - we corrupt shards on
                                                                                               // purpose
                     .put(IndexSettings.INDEX_TRANSLOG_FLUSH_THRESHOLD_SIZE_SETTING.getKey(), new ByteSizeValue(1, ByteSizeUnit.PB)) // no
diff --git a/server/src/internalClusterTest/java/org/opensearch/index/suggest/stats/SuggestStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/index/suggest/stats/SuggestStatsIT.java
index 9940b1eb13a52..6332b1b97426f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/index/suggest/stats/SuggestStatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/index/suggest/stats/SuggestStatsIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.index.suggest.stats;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.cluster.node.stats.NodeStats;
 import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
 import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
@@ -42,17 +44,22 @@
 import org.opensearch.cluster.routing.ShardIterator;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.search.stats.SearchStats;
 import org.opensearch.search.suggest.SuggestBuilder;
 import org.opensearch.search.suggest.phrase.PhraseSuggestionBuilder;
 import org.opensearch.search.suggest.term.TermSuggestionBuilder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAllSuccessful;
 import static org.hamcrest.Matchers.equalTo;
@@ -61,7 +68,25 @@
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
 
 @OpenSearchIntegTestCase.ClusterScope(minNumDataNodes = 2)
-public class SuggestStatsIT extends OpenSearchIntegTestCase {
+public class SuggestStatsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SuggestStatsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected int numberOfReplicas() {
         return 0;
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java
index 12fee85288bc2..848f6eddbb0df 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.indices;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.indices.alias.Alias;
 import org.opensearch.action.admin.indices.forcemerge.ForceMergeResponse;
 import org.opensearch.action.search.SearchResponse;
@@ -40,13 +42,14 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.cache.request.RequestCacheStats;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.aggregations.bucket.global.GlobalAggregationBuilder;
 import org.opensearch.search.aggregations.bucket.histogram.DateHistogramInterval;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 
 import java.time.ZoneId;
@@ -54,8 +57,10 @@
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateHistogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateRange;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
@@ -64,7 +69,23 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 
-public class IndicesRequestCacheIT extends OpenSearchIntegTestCase {
+public class IndicesRequestCacheIT extends ParameterizedOpenSearchIntegTestCase {
+    public IndicesRequestCacheIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     // One of the primary purposes of the query cache is to cache aggs results
     public void testCacheAggs() throws Exception {
@@ -518,7 +539,7 @@ public void testCanCache() throws Exception {
         assertCacheState(client, "index", 0, 4);
     }
 
-    public void testCacheWithFilteredAlias() {
+    public void testCacheWithFilteredAlias() throws InterruptedException {
         Client client = client();
         Settings settings = Settings.builder()
             .put(IndicesRequestCache.INDEX_CACHE_REQUEST_ENABLED_SETTING.getKey(), true)
@@ -541,6 +562,8 @@ public void testCacheWithFilteredAlias() {
         OpenSearchAssertions.assertAllSuccessful(forceMergeResponse);
         refresh();
 
+        indexRandomForConcurrentSearch("index");
+
         assertCacheState(client, "index", 0, 0);
 
         SearchResponse r1 = client.prepareSearch("index")
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java
index bdefd7a5e199a..f485d4e402b41 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java
@@ -91,7 +91,7 @@ public void testGlobalPrimaryAllocation() throws Exception {
 
     /**
      * This test verifies the happy path where primary shard allocation is balanced when multiple indices are created.
-     *
+     * <p>
      * This test in general passes without primary shard balance as well due to nature of allocation algorithm which
      * assigns all primary shards first followed by replica copies.
      */
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationBaseIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationBaseIT.java
index 8e68a8bde39d5..1d93eecd6b245 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationBaseIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationBaseIT.java
@@ -197,9 +197,10 @@ protected IndexShard getIndexShard(String node, ShardId shardId, String indexNam
     protected IndexShard getIndexShard(String node, String indexName) {
         final Index index = resolveIndex(indexName);
         IndicesService indicesService = internalCluster().getInstance(IndicesService.class, node);
-        IndexService indexService = indicesService.indexServiceSafe(index);
+        IndexService indexService = indicesService.indexService(index);
+        assertNotNull(indexService);
         final Optional<Integer> shardId = indexService.shardIds().stream().findFirst();
-        return indexService.getShard(shardId.get());
+        return shardId.map(indexService::getShard).orElse(null);
     }
 
     protected boolean segmentReplicationWithRemoteEnabled() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationDisruptionIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationDisruptionIT.java
new file mode 100644
index 0000000000000..66b26b5d25cfe
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationDisruptionIT.java
@@ -0,0 +1,167 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.indices.replication;
+
+import org.apache.lucene.tests.util.LuceneTestCase;
+import org.opensearch.action.admin.indices.recovery.RecoveryResponse;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.common.bytes.BytesArray;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.recovery.FileChunkRequest;
+import org.opensearch.indices.recovery.RecoveryState;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.transport.MockTransportService;
+import org.opensearch.transport.TransportRequest;
+import org.opensearch.transport.TransportService;
+import org.junit.Before;
+
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+
+/**
+ * These tests simulate corruption cases during replication.  They are skipped on WindowsFS simulation where file renaming
+ * can fail with an access denied IOException because deletion is not permitted.
+ */
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
+@LuceneTestCase.SuppressFileSystems("WindowsFS")
+public class SegmentReplicationDisruptionIT extends SegmentReplicationBaseIT {
+    @Before
+    private void setup() {
+        internalCluster().startClusterManagerOnlyNode();
+    }
+
+    public void testSendCorruptBytesToReplica() throws Exception {
+        final String primaryNode = internalCluster().startDataOnlyNode();
+        createIndex(
+            INDEX_NAME,
+            Settings.builder()
+                .put(indexSettings())
+                .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+                .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1)
+                .put("index.refresh_interval", -1)
+                .build()
+        );
+        ensureYellow(INDEX_NAME);
+        final String replicaNode = internalCluster().startDataOnlyNode();
+        ensureGreen(INDEX_NAME);
+
+        MockTransportService primaryTransportService = ((MockTransportService) internalCluster().getInstance(
+            TransportService.class,
+            primaryNode
+        ));
+        CountDownLatch latch = new CountDownLatch(1);
+        AtomicBoolean failed = new AtomicBoolean(false);
+        primaryTransportService.addSendBehavior(
+            internalCluster().getInstance(TransportService.class, replicaNode),
+            (connection, requestId, action, request, options) -> {
+                if (action.equals(SegmentReplicationTargetService.Actions.FILE_CHUNK) && failed.getAndSet(true) == false) {
+                    FileChunkRequest req = (FileChunkRequest) request;
+                    TransportRequest corrupt = new FileChunkRequest(
+                        req.recoveryId(),
+                        ((FileChunkRequest) request).requestSeqNo(),
+                        ((FileChunkRequest) request).shardId(),
+                        ((FileChunkRequest) request).metadata(),
+                        ((FileChunkRequest) request).position(),
+                        new BytesArray("test"),
+                        false,
+                        0,
+                        0L
+                    );
+                    connection.sendRequest(requestId, action, corrupt, options);
+                    latch.countDown();
+                } else {
+                    connection.sendRequest(requestId, action, request, options);
+                }
+            }
+        );
+        for (int i = 0; i < 100; i++) {
+            client().prepareIndex(INDEX_NAME)
+                .setId(String.valueOf(i))
+                .setSource(jsonBuilder().startObject().field("field", i).endObject())
+                .get();
+        }
+        final long originalRecoveryTime = getRecoveryStopTime(replicaNode);
+        assertNotEquals(originalRecoveryTime, 0);
+        refresh(INDEX_NAME);
+        latch.await();
+        assertTrue(failed.get());
+        waitForNewPeerRecovery(replicaNode, originalRecoveryTime);
+        // reset checkIndex to ensure our original shard doesn't throw
+        resetCheckIndexStatus();
+        waitForSearchableDocs(100, primaryNode, replicaNode);
+    }
+
+    public void testWipeSegmentBetweenSyncs() throws Exception {
+        internalCluster().startClusterManagerOnlyNode();
+        final String primaryNode = internalCluster().startDataOnlyNode();
+        createIndex(
+            INDEX_NAME,
+            Settings.builder()
+                .put(indexSettings())
+                .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+                .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1)
+                .put("index.refresh_interval", -1)
+                .build()
+        );
+        ensureYellow(INDEX_NAME);
+        final String replicaNode = internalCluster().startDataOnlyNode();
+        ensureGreen(INDEX_NAME);
+
+        for (int i = 0; i < 10; i++) {
+            client().prepareIndex(INDEX_NAME)
+                .setId(String.valueOf(i))
+                .setSource(jsonBuilder().startObject().field("field", i).endObject())
+                .get();
+        }
+        refresh(INDEX_NAME);
+        ensureGreen(INDEX_NAME);
+        final long originalRecoveryTime = getRecoveryStopTime(replicaNode);
+
+        final IndexShard indexShard = getIndexShard(replicaNode, INDEX_NAME);
+        waitForSearchableDocs(INDEX_NAME, 10, List.of(replicaNode));
+        indexShard.store().directory().deleteFile("_0.si");
+
+        for (int i = 11; i < 21; i++) {
+            client().prepareIndex(INDEX_NAME)
+                .setId(String.valueOf(i))
+                .setSource(jsonBuilder().startObject().field("field", i).endObject())
+                .get();
+        }
+        refresh(INDEX_NAME);
+        waitForNewPeerRecovery(replicaNode, originalRecoveryTime);
+        resetCheckIndexStatus();
+        waitForSearchableDocs(20, primaryNode, replicaNode);
+    }
+
+    private void waitForNewPeerRecovery(String replicaNode, long originalRecoveryTime) throws Exception {
+        assertBusy(() -> {
+            // assert we have a peer recovery after the original
+            final long time = getRecoveryStopTime(replicaNode);
+            assertNotEquals(time, 0);
+            assertNotEquals(originalRecoveryTime, time);
+
+        }, 1, TimeUnit.MINUTES);
+    }
+
+    private long getRecoveryStopTime(String nodeName) {
+        final RecoveryResponse recoveryResponse = client().admin().indices().prepareRecoveries(INDEX_NAME).get();
+        final List<RecoveryState> recoveryStates = recoveryResponse.shardRecoveryStates().get(INDEX_NAME);
+        for (RecoveryState recoveryState : recoveryStates) {
+            if (recoveryState.getTargetNode().getName().equals(nodeName)) {
+                return recoveryState.getTimer().stopTime();
+            }
+        }
+        return 0L;
+    }
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
index 33bc5a8f3afe6..5511bc7945d65 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
@@ -22,6 +22,7 @@
 import org.apache.lucene.index.StandardDirectoryReader;
 import org.apache.lucene.tests.util.TestUtil;
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.action.admin.cluster.stats.ClusterStatsResponse;
 import org.opensearch.action.admin.indices.alias.Alias;
 import org.opensearch.action.admin.indices.flush.FlushRequest;
 import org.opensearch.action.admin.indices.stats.IndicesStatsRequest;
@@ -62,6 +63,7 @@
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexModule;
+import org.opensearch.index.ReplicationStats;
 import org.opensearch.index.SegmentReplicationPerGroupStats;
 import org.opensearch.index.SegmentReplicationPressureService;
 import org.opensearch.index.SegmentReplicationShardStats;
@@ -81,6 +83,7 @@
 import org.opensearch.test.BackgroundIndexer;
 import org.opensearch.test.InternalTestCluster;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.junit.annotations.TestLogging;
 import org.opensearch.test.transport.MockTransportService;
 import org.opensearch.transport.TransportService;
 import org.junit.Before;
@@ -94,6 +97,7 @@
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 
 import static java.util.Arrays.asList;
@@ -235,7 +239,7 @@ public void testReplicationAfterPrimaryRefreshAndFlush() throws Exception {
         createIndex(INDEX_NAME, settings);
         ensureGreen(INDEX_NAME);
 
-        final int initialDocCount = scaledRandomIntBetween(0, 200);
+        final int initialDocCount = scaledRandomIntBetween(0, 10);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -252,7 +256,7 @@ public void testReplicationAfterPrimaryRefreshAndFlush() throws Exception {
             refresh(INDEX_NAME);
             waitForSearchableDocs(initialDocCount, nodeA, nodeB);
 
-            final int additionalDocCount = scaledRandomIntBetween(0, 200);
+            final int additionalDocCount = scaledRandomIntBetween(0, 10);
             final int expectedHitCount = initialDocCount + additionalDocCount;
             indexer.start(additionalDocCount);
             waitForDocs(expectedHitCount, indexer);
@@ -271,7 +275,7 @@ public void testIndexReopenClose() throws Exception {
         createIndex(INDEX_NAME);
         ensureGreen(INDEX_NAME);
 
-        final int initialDocCount = scaledRandomIntBetween(100, 200);
+        final int initialDocCount = scaledRandomIntBetween(1, 10);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -306,7 +310,7 @@ public void testScrollWithConcurrentIndexAndSearch() throws Exception {
         ensureGreen(INDEX_NAME);
         final List<ActionFuture<IndexResponse>> pendingIndexResponses = new ArrayList<>();
         final List<ActionFuture<SearchResponse>> pendingSearchResponse = new ArrayList<>();
-        final int searchCount = randomIntBetween(10, 20);
+        final int searchCount = randomIntBetween(1, 2);
         final WriteRequest.RefreshPolicy refreshPolicy = randomFrom(WriteRequest.RefreshPolicy.values());
 
         for (int i = 0; i < searchCount; i++) {
@@ -351,6 +355,7 @@ public void testScrollWithConcurrentIndexAndSearch() throws Exception {
         waitForSearchableDocs(INDEX_NAME, 2 * searchCount, List.of(primary, replica));
     }
 
+    @TestLogging(reason = "Getting trace logs from replication package", value = "org.opensearch.indices.replication:TRACE")
     public void testMultipleShards() throws Exception {
         Settings indexSettings = Settings.builder()
             .put(super.indexSettings())
@@ -364,7 +369,7 @@ public void testMultipleShards() throws Exception {
         createIndex(INDEX_NAME, indexSettings);
         ensureGreen(INDEX_NAME);
 
-        final int initialDocCount = scaledRandomIntBetween(1, 200);
+        final int initialDocCount = scaledRandomIntBetween(1, 10);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -381,7 +386,7 @@ public void testMultipleShards() throws Exception {
             refresh(INDEX_NAME);
             waitForSearchableDocs(initialDocCount, nodeA, nodeB);
 
-            final int additionalDocCount = scaledRandomIntBetween(0, 200);
+            final int additionalDocCount = scaledRandomIntBetween(0, 10);
             final int expectedHitCount = initialDocCount + additionalDocCount;
             indexer.start(additionalDocCount);
             waitForDocs(expectedHitCount, indexer);
@@ -400,8 +405,8 @@ public void testReplicationAfterForceMerge() throws Exception {
         createIndex(INDEX_NAME);
         ensureGreen(INDEX_NAME);
 
-        final int initialDocCount = scaledRandomIntBetween(0, 200);
-        final int additionalDocCount = scaledRandomIntBetween(0, 200);
+        final int initialDocCount = scaledRandomIntBetween(0, 10);
+        final int additionalDocCount = scaledRandomIntBetween(0, 10);
         final int expectedHitCount = initialDocCount + additionalDocCount;
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
@@ -506,7 +511,7 @@ public void testNodeDropWithOngoingReplication() throws Exception {
                 connection.sendRequest(requestId, action, request, options);
             }
         );
-        final int docCount = scaledRandomIntBetween(10, 200);
+        final int docCount = scaledRandomIntBetween(1, 10);
         for (int i = 0; i < docCount; i++) {
             client().prepareIndex(INDEX_NAME).setId(Integer.toString(i)).setSource("field", "value" + i).execute().get();
         }
@@ -567,7 +572,7 @@ public void testCancellation() throws Exception {
             }
         );
 
-        final int docCount = scaledRandomIntBetween(0, 200);
+        final int docCount = scaledRandomIntBetween(0, 10);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -627,13 +632,14 @@ public void testStartReplicaAfterPrimaryIndexesDocs() throws Exception {
         verifyStoreContent();
     }
 
+    @TestLogging(reason = "Getting trace logs from replication package", value = "org.opensearch.indices.replication:TRACE")
     public void testDeleteOperations() throws Exception {
         final String nodeA = internalCluster().startDataOnlyNode();
         final String nodeB = internalCluster().startDataOnlyNode();
 
         createIndex(INDEX_NAME);
         ensureGreen(INDEX_NAME);
-        final int initialDocCount = scaledRandomIntBetween(1, 20);
+        final int initialDocCount = scaledRandomIntBetween(1, 5);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -650,7 +656,7 @@ public void testDeleteOperations() throws Exception {
             refresh(INDEX_NAME);
             waitForSearchableDocs(initialDocCount, nodeA, nodeB);
 
-            final int additionalDocCount = scaledRandomIntBetween(0, 20);
+            final int additionalDocCount = scaledRandomIntBetween(0, 2);
             final int expectedHitCount = initialDocCount + additionalDocCount;
             indexer.start(additionalDocCount);
             waitForDocs(expectedHitCount, indexer);
@@ -679,14 +685,14 @@ public void testReplicationPostDeleteAndForceMerge() throws Exception {
         createIndex(INDEX_NAME);
         final String replica = internalCluster().startDataOnlyNode();
         ensureGreen(INDEX_NAME);
-        final int initialDocCount = scaledRandomIntBetween(10, 200);
+        final int initialDocCount = scaledRandomIntBetween(1, 10);
         for (int i = 0; i < initialDocCount; i++) {
             client().prepareIndex(INDEX_NAME).setId(String.valueOf(i)).setSource("foo", "bar").get();
         }
         refresh(INDEX_NAME);
         waitForSearchableDocs(initialDocCount, primary, replica);
 
-        final int deletedDocCount = randomIntBetween(10, initialDocCount);
+        final int deletedDocCount = randomIntBetween(1, initialDocCount);
         for (int i = 0; i < deletedDocCount; i++) {
             client(primary).prepareDelete(INDEX_NAME, String.valueOf(i)).setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE).get();
         }
@@ -707,7 +713,7 @@ public void testReplicationPostDeleteAndForceMerge() throws Exception {
         );
 
         // add some docs to the xlog and drop primary.
-        final int additionalDocs = randomIntBetween(1, 50);
+        final int additionalDocs = randomIntBetween(1, 5);
         for (int i = initialDocCount; i < initialDocCount + additionalDocs; i++) {
             client().prepareIndex(INDEX_NAME).setId(String.valueOf(i)).setSource("foo", "bar").get();
         }
@@ -738,7 +744,7 @@ public void testUpdateOperations() throws Exception {
         final String replica = internalCluster().startDataOnlyNode();
         ensureGreen(INDEX_NAME);
 
-        final int initialDocCount = scaledRandomIntBetween(0, 200);
+        final int initialDocCount = scaledRandomIntBetween(1, 5);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -755,7 +761,7 @@ public void testUpdateOperations() throws Exception {
             refresh(INDEX_NAME);
             waitForSearchableDocs(initialDocCount, asList(primary, replica));
 
-            final int additionalDocCount = scaledRandomIntBetween(0, 200);
+            final int additionalDocCount = scaledRandomIntBetween(0, 5);
             final int expectedHitCount = initialDocCount + additionalDocCount;
             indexer.start(additionalDocCount);
             waitForDocs(expectedHitCount, indexer);
@@ -790,7 +796,7 @@ public void testDropPrimaryDuringReplication() throws Exception {
         final List<String> dataNodes = internalCluster().startDataOnlyNodes(6);
         ensureGreen(INDEX_NAME);
 
-        int initialDocCount = scaledRandomIntBetween(100, 200);
+        int initialDocCount = scaledRandomIntBetween(5, 10);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -824,6 +830,7 @@ public void testDropPrimaryDuringReplication() throws Exception {
         }
     }
 
+    @TestLogging(reason = "Getting trace logs from replication package", value = "org.opensearch.indices.replication:TRACE")
     public void testReplicaHasDiffFilesThanPrimary() throws Exception {
         final String primaryNode = internalCluster().startDataOnlyNode();
         createIndex(INDEX_NAME, Settings.builder().put(indexSettings()).put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1).build());
@@ -835,7 +842,7 @@ public void testReplicaHasDiffFilesThanPrimary() throws Exception {
         IndexWriterConfig iwc = newIndexWriterConfig().setOpenMode(IndexWriterConfig.OpenMode.APPEND);
 
         // create a doc to index
-        int numDocs = 2 + random().nextInt(100);
+        int numDocs = 2 + random().nextInt(10);
 
         List<Document> docs = new ArrayList<>();
         for (int i = 0; i < numDocs; i++) {
@@ -864,7 +871,7 @@ public void testReplicaHasDiffFilesThanPrimary() throws Exception {
         replicaShard.finalizeReplication(segmentInfos);
         ensureYellow(INDEX_NAME);
 
-        final int docCount = scaledRandomIntBetween(10, 200);
+        final int docCount = scaledRandomIntBetween(10, 20);
         for (int i = 0; i < docCount; i++) {
             client().prepareIndex(INDEX_NAME).setId(Integer.toString(i)).setSource("field", "value" + i).execute().get();
             // Refresh, this should trigger round of segment replication
@@ -884,7 +891,7 @@ public void testPressureServiceStats() throws Exception {
         final String replicaNode = internalCluster().startDataOnlyNode();
         ensureGreen(INDEX_NAME);
 
-        int initialDocCount = scaledRandomIntBetween(100, 200);
+        int initialDocCount = scaledRandomIntBetween(10, 20);
         try (
             BackgroundIndexer indexer = new BackgroundIndexer(
                 INDEX_NAME,
@@ -990,8 +997,8 @@ public void testScrollCreatedOnReplica() throws Exception {
         final String replica = internalCluster().startDataOnlyNode();
         ensureGreen(INDEX_NAME);
 
-        // index 100 docs
-        for (int i = 0; i < 100; i++) {
+        // index 10 docs
+        for (int i = 0; i < 10; i++) {
             client().prepareIndex(INDEX_NAME)
                 .setId(String.valueOf(i))
                 .setSource(jsonBuilder().startObject().field("field", i).endObject())
@@ -1027,7 +1034,7 @@ public void testScrollCreatedOnReplica() throws Exception {
         // force call flush
         flush(INDEX_NAME);
 
-        for (int i = 3; i < 50; i++) {
+        for (int i = 3; i < 5; i++) {
             client().prepareDelete(INDEX_NAME, String.valueOf(i)).setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE).get();
             refresh(INDEX_NAME);
             if (randomBoolean()) {
@@ -1063,9 +1070,14 @@ public void testScrollCreatedOnReplica() throws Exception {
 
         client(replica).prepareClearScroll().addScrollId(searchResponse.getScrollId()).get();
 
-        currentFiles = List.of(replicaShard.store().directory().listAll());
-        assertFalse("Files should be cleaned up post scroll clear request", currentFiles.containsAll(snapshottedSegments));
-        assertEquals(100, scrollHits);
+        assertBusy(
+            () -> assertFalse(
+                "Files should be cleaned up post scroll clear request",
+                List.of(replicaShard.store().directory().listAll()).containsAll(snapshottedSegments)
+            )
+        );
+        assertEquals(10, scrollHits);
+
     }
 
     /**
@@ -1210,19 +1222,8 @@ public void testPitCreatedOnReplica() throws Exception {
         ensureYellowAndNoInitializingShards(INDEX_NAME);
         final String replica = internalCluster().startDataOnlyNode();
         ensureGreen(INDEX_NAME);
-        client().prepareIndex(INDEX_NAME)
-            .setId("1")
-            .setSource("foo", randomInt())
-            .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
-            .get();
-        refresh(INDEX_NAME);
 
-        client().prepareIndex(INDEX_NAME)
-            .setId("2")
-            .setSource("foo", randomInt())
-            .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
-            .get();
-        for (int i = 3; i < 100; i++) {
+        for (int i = 0; i < 10; i++) {
             client().prepareIndex(INDEX_NAME)
                 .setId(String.valueOf(i))
                 .setSource("foo", randomInt())
@@ -1272,7 +1273,7 @@ public void testPitCreatedOnReplica() throws Exception {
         }
 
         flush(INDEX_NAME);
-        for (int i = 101; i < 200; i++) {
+        for (int i = 11; i < 20; i++) {
             client().prepareIndex(INDEX_NAME)
                 .setId(String.valueOf(i))
                 .setSource("foo", randomInt())
@@ -1324,9 +1325,12 @@ public void testPitCreatedOnReplica() throws Exception {
         // delete the PIT
         DeletePitRequest deletePITRequest = new DeletePitRequest(pitResponse.getId());
         client().execute(DeletePitAction.INSTANCE, deletePITRequest).actionGet();
-
-        currentFiles = List.of(replicaShard.store().directory().listAll());
-        assertFalse("Files should be cleaned up", currentFiles.containsAll(snapshottedSegments));
+        assertBusy(
+            () -> assertFalse(
+                "Files should be cleaned up",
+                List.of(replicaShard.store().directory().listAll()).containsAll(snapshottedSegments)
+            )
+        );
     }
 
     /**
@@ -1777,4 +1781,57 @@ public void testRealtimeTermVectorRequestsUnSuccessful() throws IOException {
 
     }
 
+    public void testReplicaAlreadyAtCheckpoint() throws Exception {
+        final List<String> nodes = new ArrayList<>();
+        final String primaryNode = internalCluster().startDataOnlyNode();
+        nodes.add(primaryNode);
+        final Settings settings = Settings.builder().put(indexSettings()).put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0).build();
+        createIndex(INDEX_NAME, settings);
+        ensureGreen(INDEX_NAME);
+        // start a replica node, initially will be empty with no shard assignment.
+        final String replicaNode = internalCluster().startDataOnlyNode();
+        nodes.add(replicaNode);
+        final String replicaNode2 = internalCluster().startDataOnlyNode();
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareUpdateSettings(INDEX_NAME)
+                .setSettings(Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 2))
+        );
+        ensureGreen(INDEX_NAME);
+
+        // index a doc.
+        client().prepareIndex(INDEX_NAME).setId("1").setSource("foo", randomInt()).get();
+        refresh(INDEX_NAME);
+
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNode));
+        ensureYellowAndNoInitializingShards(INDEX_NAME);
+        IndexShard replica_1 = getIndexShard(replicaNode, INDEX_NAME);
+        IndexShard replica_2 = getIndexShard(replicaNode2, INDEX_NAME);
+        // wait until a replica is promoted & finishes engine flip, we don't care which one
+        AtomicReference<IndexShard> primary = new AtomicReference<>();
+        assertBusy(() -> {
+            assertTrue("replica should be promoted as a primary", replica_1.routingEntry().primary() || replica_2.routingEntry().primary());
+            primary.set(replica_1.routingEntry().primary() ? replica_1 : replica_2);
+        });
+
+        FlushRequest request = new FlushRequest(INDEX_NAME);
+        request.force(true);
+        primary.get().flush(request);
+
+        assertBusy(() -> {
+            assertEquals(
+                replica_1.getLatestReplicationCheckpoint().getSegmentInfosVersion(),
+                replica_2.getLatestReplicationCheckpoint().getSegmentInfosVersion()
+            );
+        });
+
+        assertBusy(() -> {
+            ClusterStatsResponse clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
+            ReplicationStats replicationStats = clusterStatsResponse.getIndicesStats().getSegments().getReplicationStats();
+            assertEquals(0L, replicationStats.maxBytesBehind);
+            assertEquals(0L, replicationStats.maxReplicationLag);
+            assertEquals(0L, replicationStats.totalBytesBehind);
+        });
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationRelocationIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationRelocationIT.java
index dd832a63d1e66..dbe0b43441f54 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationRelocationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationRelocationIT.java
@@ -26,6 +26,7 @@
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.junit.annotations.TestLogging;
 import org.opensearch.test.transport.MockTransportService;
 import org.opensearch.transport.TransportService;
 
@@ -55,6 +56,7 @@ private void createIndex(int replicaCount) {
      * This test verifies happy path when primary shard is relocated newly added node (target) in the cluster. Before
      * relocation and after relocation documents are indexed and documents are verified
      */
+    @TestLogging(reason = "Getting trace logs from replication,shard and allocation package", value = "org.opensearch.indices.replication:TRACE, org.opensearch.index.shard:TRACE, org.opensearch.cluster.routing.allocation:TRACE")
     public void testPrimaryRelocation() throws Exception {
         final String oldPrimary = internalCluster().startNode();
         createIndex(1);
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationSuiteIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationSuiteIT.java
index 800704eae7fa7..8c045c1560dd3 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationSuiteIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationSuiteIT.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.indices.replication;
 
+import org.apache.lucene.tests.util.LuceneTestCase;
 import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
@@ -15,6 +16,7 @@
 import org.opensearch.test.OpenSearchIntegTestCase;
 import org.junit.Before;
 
+@LuceneTestCase.AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/9499")
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE, minNumDataNodes = 2)
 public class SegmentReplicationSuiteIT extends SegmentReplicationBaseIT {
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/state/CloseIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/state/CloseIndexIT.java
index ae88dd76d54e0..547f9e7a8d380 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/state/CloseIndexIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/state/CloseIndexIT.java
@@ -509,7 +509,7 @@ public Settings onNodeStopped(String nodeName) throws Exception {
     }
 
     /**
-     * Test for https://github.com/elastic/elasticsearch/issues/47276 which checks that the persisted metadata on a data node does not
+     * Test for <a href="https://github.com/elastic/elasticsearch/issues/47276">Elasticsearch issue #47276</a> which checks that the persisted metadata on a data node does not
      * become inconsistent when using replicated closed indices.
      */
     public void testRelocatedClosedIndexIssue() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/stats/IndexStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/stats/IndexStatsIT.java
index ee904dbcb6924..9c96d4861d426 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/stats/IndexStatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/stats/IndexStatsIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.indices.stats;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.tests.util.LuceneTestCase.SuppressCodecs;
 import org.opensearch.action.DocWriteResponse;
 import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
@@ -55,6 +57,7 @@
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -63,8 +66,8 @@
 import org.opensearch.index.IndexModule;
 import org.opensearch.index.IndexService;
 import org.opensearch.index.IndexSettings;
-import org.opensearch.index.MergePolicyConfig;
 import org.opensearch.index.MergeSchedulerConfig;
+import org.opensearch.index.TieredMergePolicyProvider;
 import org.opensearch.index.VersionType;
 import org.opensearch.index.cache.query.QueryCacheStats;
 import org.opensearch.index.engine.VersionConflictEngineException;
@@ -80,9 +83,9 @@
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.InternalSettingsPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
 import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -105,6 +108,7 @@
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAllSuccessful;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
@@ -118,7 +122,23 @@
 
 @ClusterScope(scope = Scope.SUITE, numDataNodes = 2, numClientNodes = 0)
 @SuppressCodecs("*") // requires custom completion format
-public class IndexStatsIT extends OpenSearchIntegTestCase {
+public class IndexStatsIT extends ParameterizedOpenSearchIntegTestCase {
+    public IndexStatsIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -149,7 +169,7 @@ private Settings.Builder settingsBuilder() {
         return Settings.builder().put(indexSettings());
     }
 
-    public void testFieldDataStats() {
+    public void testFieldDataStats() throws InterruptedException {
         assertAcked(
             client().admin()
                 .indices()
@@ -162,6 +182,7 @@ public void testFieldDataStats() {
         client().prepareIndex("test").setId("1").setSource("field", "value1", "field2", "value1").execute().actionGet();
         client().prepareIndex("test").setId("2").setSource("field", "value2", "field2", "value2").execute().actionGet();
         client().admin().indices().prepareRefresh().execute().actionGet();
+        indexRandomForConcurrentSearch("test");
 
         NodesStatsResponse nodesStats = client().admin().cluster().prepareNodesStats("data:true").setIndices(true).execute().actionGet();
         assertThat(
@@ -285,6 +306,7 @@ public void testClearAllCaches() throws Exception {
         client().prepareIndex("test").setId("1").setSource("field", "value1").execute().actionGet();
         client().prepareIndex("test").setId("2").setSource("field", "value2").execute().actionGet();
         client().admin().indices().prepareRefresh().execute().actionGet();
+        indexRandomForConcurrentSearch("test");
 
         NodesStatsResponse nodesStats = client().admin().cluster().prepareNodesStats("data:true").setIndices(true).execute().actionGet();
         assertThat(
@@ -569,8 +591,8 @@ public void testNonThrottleStats() throws Exception {
             prepareCreate("test").setSettings(
                 settingsBuilder().put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, "1")
                     .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "0")
-                    .put(MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
-                    .put(MergePolicyConfig.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
+                    .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
+                    .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
                     .put(MergeSchedulerConfig.MAX_THREAD_COUNT_SETTING.getKey(), "1")
                     .put(MergeSchedulerConfig.MAX_MERGE_COUNT_SETTING.getKey(), "10000")
             )
@@ -601,8 +623,8 @@ public void testThrottleStats() throws Exception {
             prepareCreate("test").setSettings(
                 settingsBuilder().put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, "1")
                     .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "0")
-                    .put(MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
-                    .put(MergePolicyConfig.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
+                    .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
+                    .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
                     .put(MergeSchedulerConfig.MAX_THREAD_COUNT_SETTING.getKey(), "1")
                     .put(MergeSchedulerConfig.MAX_MERGE_COUNT_SETTING.getKey(), "1")
                     .put(IndexSettings.INDEX_TRANSLOG_DURABILITY_SETTING.getKey(), Translog.Durability.ASYNC.name())
diff --git a/server/src/internalClusterTest/java/org/opensearch/mget/SimpleMgetIT.java b/server/src/internalClusterTest/java/org/opensearch/mget/SimpleMgetIT.java
index 9e13f06983860..f77ae80a55276 100644
--- a/server/src/internalClusterTest/java/org/opensearch/mget/SimpleMgetIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/mget/SimpleMgetIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.mget;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.indices.alias.Alias;
 import org.opensearch.action.get.MultiGetItemResponse;
@@ -40,16 +42,20 @@
 import org.opensearch.action.get.MultiGetResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.search.fetch.subphase.FetchSourceContext;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Map;
 
 import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
@@ -57,7 +63,24 @@
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.nullValue;
 
-public class SimpleMgetIT extends OpenSearchIntegTestCase {
+public class SimpleMgetIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SimpleMgetIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public void testThatMgetShouldWorkWithOneIndexMissing() throws IOException {
         createIndex("test");
diff --git a/server/src/internalClusterTest/java/org/opensearch/nodestats/NodeStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/nodestats/NodeStatsIT.java
new file mode 100644
index 0000000000000..f270cb1399072
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/nodestats/NodeStatsIT.java
@@ -0,0 +1,276 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.nodestats;
+
+import org.opensearch.ExceptionsHelper;
+import org.opensearch.action.DocWriteResponse;
+import org.opensearch.action.bulk.BulkItemResponse;
+import org.opensearch.action.bulk.BulkRequest;
+import org.opensearch.action.bulk.BulkResponse;
+import org.opensearch.action.delete.DeleteRequest;
+import org.opensearch.action.delete.DeleteResponse;
+import org.opensearch.action.index.IndexRequest;
+import org.opensearch.action.index.IndexResponse;
+import org.opensearch.action.update.UpdateRequest;
+import org.opensearch.action.update.UpdateResponse;
+import org.opensearch.index.IndexNotFoundException;
+import org.opensearch.index.engine.DocumentMissingException;
+import org.opensearch.index.engine.VersionConflictEngineException;
+import org.opensearch.index.shard.IndexingStats.Stats.DocStatusStats;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.hamcrest.MatcherAssert;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static java.util.Collections.singletonMap;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+
+@ClusterScope(scope = Scope.TEST, numDataNodes = 1, numClientNodes = 0, supportsDedicatedMasters = false)
+public class NodeStatsIT extends OpenSearchIntegTestCase {
+
+    private final DocStatusStats expectedDocStatusStats = new DocStatusStats();
+    private static final String FIELD = "dummy_field";
+    private static final String VALUE = "dummy_value";
+    private static final Map<String, Object> SOURCE = singletonMap(FIELD, VALUE);
+
+    public void testNodeIndicesStatsDocStatusStatsIndexBulk() {
+        {  // Testing Index
+            final String INDEX = "test_index";
+            final String ID = "id";
+            {  // Testing Normal Index
+                IndexResponse response = client().index(new IndexRequest(INDEX).id(ID).source(SOURCE)).actionGet();
+                updateExpectedDocStatusCounter(response);
+
+                MatcherAssert.assertThat(response.getResult(), equalTo(DocWriteResponse.Result.CREATED));
+                assertDocStatusStats();
+            }
+            {  // Testing Missing Alias
+                updateExpectedDocStatusCounter(
+                    expectThrows(
+                        IndexNotFoundException.class,
+                        () -> client().index(new IndexRequest(INDEX).id("missing_alias").setRequireAlias(true).source(SOURCE)).actionGet()
+                    )
+                );
+                assertDocStatusStats();
+            }
+            {
+                // Test Missing Pipeline: Ingestion failure, not Indexing failure
+                expectThrows(
+                    IllegalArgumentException.class,
+                    () -> client().index(new IndexRequest(INDEX).id("missing_pipeline").setPipeline("missing").source(SOURCE)).actionGet()
+                );
+                assertDocStatusStats();
+            }
+            {  // Testing Version Conflict
+                final String docId = "version_conflict";
+
+                updateExpectedDocStatusCounter(client().index(new IndexRequest(INDEX).id(docId).source(SOURCE)).actionGet());
+                updateExpectedDocStatusCounter(
+                    expectThrows(
+                        VersionConflictEngineException.class,
+                        () -> client().index(new IndexRequest(INDEX).id(docId).source(SOURCE).setIfSeqNo(1L).setIfPrimaryTerm(99L))
+                            .actionGet()
+                    )
+                );
+                assertDocStatusStats();
+            }
+        }
+        {  // Testing Bulk
+            final String INDEX = "bulk_index";
+
+            int sizeOfIndexRequests = scaledRandomIntBetween(10, 20);
+            int sizeOfDeleteRequests = scaledRandomIntBetween(5, sizeOfIndexRequests);
+            int sizeOfNotFoundRequests = scaledRandomIntBetween(5, sizeOfIndexRequests);
+
+            BulkRequest bulkRequest = new BulkRequest();
+
+            for (int i = 0; i < sizeOfIndexRequests; ++i) {
+                bulkRequest.add(new IndexRequest(INDEX).id(String.valueOf(i)).source(SOURCE));
+            }
+
+            BulkResponse response = client().bulk(bulkRequest).actionGet();
+
+            MatcherAssert.assertThat(response.hasFailures(), equalTo(false));
+            MatcherAssert.assertThat(response.getItems().length, equalTo(sizeOfIndexRequests));
+
+            for (BulkItemResponse itemResponse : response.getItems()) {
+                updateExpectedDocStatusCounter(itemResponse.getResponse());
+            }
+
+            refresh(INDEX);
+            bulkRequest.requests().clear();
+
+            for (int i = 0; i < sizeOfDeleteRequests; ++i) {
+                bulkRequest.add(new DeleteRequest(INDEX, String.valueOf(i)));
+            }
+            for (int i = 0; i < sizeOfNotFoundRequests; ++i) {
+                bulkRequest.add(new DeleteRequest(INDEX, String.valueOf(25 + i)));
+            }
+
+            response = client().bulk(bulkRequest).actionGet();
+
+            MatcherAssert.assertThat(response.hasFailures(), equalTo(false));
+            MatcherAssert.assertThat(response.getItems().length, equalTo(sizeOfDeleteRequests + sizeOfNotFoundRequests));
+
+            for (BulkItemResponse itemResponse : response.getItems()) {
+                updateExpectedDocStatusCounter(itemResponse.getResponse());
+            }
+
+            refresh(INDEX);
+            assertDocStatusStats();
+        }
+    }
+
+    public void testNodeIndicesStatsDocStatusStatsCreateDeleteUpdate() {
+        {  // Testing Create
+            final String INDEX = "create_index";
+            final String ID = "id";
+            {  // Testing Creation
+                IndexResponse response = client().index(new IndexRequest(INDEX).id(ID).source(SOURCE).create(true)).actionGet();
+                updateExpectedDocStatusCounter(response);
+
+                MatcherAssert.assertThat(response.getResult(), equalTo(DocWriteResponse.Result.CREATED));
+                assertDocStatusStats();
+            }
+            {  // Testing Version Conflict
+                final String docId = "version_conflict";
+
+                updateExpectedDocStatusCounter(client().index(new IndexRequest(INDEX).id(docId).source(SOURCE)).actionGet());
+                updateExpectedDocStatusCounter(
+                    expectThrows(
+                        VersionConflictEngineException.class,
+                        () -> client().index(new IndexRequest(INDEX).id(docId).source(SOURCE).create(true)).actionGet()
+                    )
+                );
+                assertDocStatusStats();
+            }
+        }
+        {  // Testing Delete
+            final String INDEX = "delete_index";
+            final String ID = "id";
+            {  // Testing Deletion
+                IndexResponse response = client().index(new IndexRequest(INDEX).id(ID).source(SOURCE)).actionGet();
+                updateExpectedDocStatusCounter(response);
+
+                DeleteResponse deleteResponse = client().delete(new DeleteRequest(INDEX, ID)).actionGet();
+                updateExpectedDocStatusCounter(deleteResponse);
+
+                MatcherAssert.assertThat(response.getSeqNo(), greaterThanOrEqualTo(0L));
+                MatcherAssert.assertThat(deleteResponse.getResult(), equalTo(DocWriteResponse.Result.DELETED));
+                assertDocStatusStats();
+            }
+            {  // Testing Non-Existing Doc
+                updateExpectedDocStatusCounter(client().delete(new DeleteRequest(INDEX, "does_not_exist")).actionGet());
+                assertDocStatusStats();
+            }
+            {  // Testing Version Conflict
+                final String docId = "version_conflict";
+
+                updateExpectedDocStatusCounter(client().index(new IndexRequest(INDEX).id(docId).source(SOURCE)).actionGet());
+                updateExpectedDocStatusCounter(
+                    expectThrows(
+                        VersionConflictEngineException.class,
+                        () -> client().delete(new DeleteRequest(INDEX, docId).setIfSeqNo(2L).setIfPrimaryTerm(99L)).actionGet()
+                    )
+                );
+
+                assertDocStatusStats();
+            }
+        }
+        {  // Testing Update
+            final String INDEX = "update_index";
+            final String ID = "id";
+            {  // Testing Not Found
+                updateExpectedDocStatusCounter(
+                    expectThrows(
+                        DocumentMissingException.class,
+                        () -> client().update(new UpdateRequest(INDEX, ID).doc(SOURCE)).actionGet()
+                    )
+                );
+                assertDocStatusStats();
+            }
+            {  // Testing NoOp Update
+                updateExpectedDocStatusCounter(client().index(new IndexRequest(INDEX).id(ID).source(SOURCE)).actionGet());
+
+                UpdateResponse response = client().update(new UpdateRequest(INDEX, ID).doc(SOURCE)).actionGet();
+                updateExpectedDocStatusCounter(response);
+
+                MatcherAssert.assertThat(response.getResult(), equalTo(DocWriteResponse.Result.NOOP));
+                assertDocStatusStats();
+            }
+            {  // Testing Update
+                final String UPDATED_VALUE = "updated_value";
+                UpdateResponse response = client().update(new UpdateRequest(INDEX, ID).doc(singletonMap(FIELD, UPDATED_VALUE))).actionGet();
+                updateExpectedDocStatusCounter(response);
+
+                MatcherAssert.assertThat(response.getResult(), equalTo(DocWriteResponse.Result.UPDATED));
+                assertDocStatusStats();
+            }
+            {  // Testing Missing Alias
+                updateExpectedDocStatusCounter(
+                    expectThrows(
+                        IndexNotFoundException.class,
+                        () -> client().update(new UpdateRequest(INDEX, ID).setRequireAlias(true).doc(new IndexRequest().source(SOURCE)))
+                            .actionGet()
+                    )
+                );
+                assertDocStatusStats();
+            }
+            {  // Testing Version Conflict
+                final String docId = "version_conflict";
+
+                updateExpectedDocStatusCounter(client().index(new IndexRequest(INDEX).id(docId).source(SOURCE)).actionGet());
+                updateExpectedDocStatusCounter(
+                    expectThrows(
+                        VersionConflictEngineException.class,
+                        () -> client().update(new UpdateRequest(INDEX, docId).doc(SOURCE).setIfSeqNo(2L).setIfPrimaryTerm(99L)).actionGet()
+                    )
+                );
+                assertDocStatusStats();
+            }
+        }
+    }
+
+    private void assertDocStatusStats() {
+        DocStatusStats docStatusStats = client().admin()
+            .cluster()
+            .prepareNodesStats()
+            .execute()
+            .actionGet()
+            .getNodes()
+            .get(0)
+            .getIndices()
+            .getIndexing()
+            .getTotal()
+            .getDocStatusStats();
+
+        assertTrue(
+            Arrays.equals(
+                docStatusStats.getDocStatusCounter(),
+                expectedDocStatusStats.getDocStatusCounter(),
+                Comparator.comparingLong(AtomicLong::longValue)
+            )
+        );
+    }
+
+    private void updateExpectedDocStatusCounter(DocWriteResponse r) {
+        expectedDocStatusStats.inc(r.status());
+    }
+
+    private void updateExpectedDocStatusCounter(Exception e) {
+        expectedDocStatusStats.inc(ExceptionsHelper.status(e));
+    }
+
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlMultiNodeIT.java b/server/src/internalClusterTest/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlMultiNodeIT.java
new file mode 100644
index 0000000000000..0af3d31f9e846
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlMultiNodeIT.java
@@ -0,0 +1,292 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.action.admin.cluster.health.ClusterHealthRequest;
+import org.opensearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.opensearch.action.admin.cluster.node.stats.NodesStatsRequest;
+import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
+import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
+import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.action.bulk.BulkRequest;
+import org.opensearch.action.bulk.BulkResponse;
+import org.opensearch.action.index.IndexRequest;
+import org.opensearch.action.search.SearchPhaseExecutionException;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.UUIDs;
+import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.node.resource.tracker.ResourceTrackerSettings;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings;
+import org.opensearch.ratelimitting.admissioncontrol.stats.AdmissionControllerStats;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.junit.After;
+import org.junit.Before;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.stream.Stream;
+
+import static org.opensearch.ratelimitting.admissioncontrol.AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE;
+import static org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings.INDEXING_CPU_USAGE_LIMIT;
+import static org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 2, numClientNodes = 1)
+public class AdmissionControlMultiNodeIT extends OpenSearchIntegTestCase {
+
+    public static final Settings settings = Settings.builder()
+        .put(ResourceTrackerSettings.GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), TimeValue.timeValueMillis(500))
+        .put(ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), TimeValue.timeValueMillis(500))
+        .put(ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.ENFORCED)
+        .put(SEARCH_CPU_USAGE_LIMIT.getKey(), 0)
+        .put(INDEXING_CPU_USAGE_LIMIT.getKey(), 0)
+        .build();
+
+    private static final Logger LOGGER = LogManager.getLogger(AdmissionControlMultiNodeIT.class);
+
+    public static final String INDEX_NAME = "test_index";
+
+    @Before
+    public void init() {
+        assertAcked(
+            prepareCreate(
+                INDEX_NAME,
+                Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1).put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1)
+            )
+        );
+        ensureGreen(INDEX_NAME);
+    }
+
+    @After
+    public void cleanup() {
+        client().admin().indices().prepareDelete(INDEX_NAME).get();
+    }
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder().put(super.nodeSettings(nodeOrdinal)).put(settings).build();
+    }
+
+    public void testAdmissionControlRejectionOnEnforced() {
+        Tuple<String, String> primaryReplicaNodeNames = getPrimaryReplicaNodeNames(INDEX_NAME);
+        String primaryName = primaryReplicaNodeNames.v1();
+        String replicaName = primaryReplicaNodeNames.v2();
+        String coordinatingOnlyNode = getCoordinatingOnlyNode();
+        AdmissionControlService admissionControlServicePrimary = internalCluster().getInstance(AdmissionControlService.class, primaryName);
+        AdmissionControlService admissionControlServiceReplica = internalCluster().getInstance(AdmissionControlService.class, replicaName);
+        final BulkRequest bulkRequest = new BulkRequest();
+        for (int i = 0; i < 3; ++i) {
+            IndexRequest request = new IndexRequest(INDEX_NAME).id(UUIDs.base64UUID())
+                .source(Collections.singletonMap("key", randomAlphaOfLength(50)));
+            bulkRequest.add(request);
+        }
+        BulkResponse res = client(coordinatingOnlyNode).bulk(bulkRequest).actionGet();
+        assertEquals(429, res.getItems()[0].getFailure().getStatus().getStatus());
+        AdmissionControllerStats admissionControlPrimaryStats = admissionControlServicePrimary.stats()
+            .getAdmissionControllerStatsList()
+            .get(0);
+        assertEquals(admissionControlPrimaryStats.rejectionCount.get(AdmissionControlActionType.INDEXING.getType()).longValue(), 1);
+        Arrays.stream(res.getItems()).forEach(bulkItemResponse -> {
+            assertTrue(bulkItemResponse.getFailureMessage().contains("OpenSearchRejectedExecutionException"));
+        });
+        SearchResponse searchResponse;
+        try {
+            searchResponse = client(coordinatingOnlyNode).prepareSearch(INDEX_NAME).get();
+        } catch (Exception exception) {
+            assertTrue(((SearchPhaseExecutionException) exception).getDetailedMessage().contains("OpenSearchRejectedExecutionException"));
+        }
+        AdmissionControllerStats primaryStats = admissionControlServicePrimary.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(primaryStats.rejectionCount.get(AdmissionControlActionType.SEARCH.getType()).longValue(), 1);
+    }
+
+    public void testAdmissionControlEnforcedOnNonACEnabledActions() throws ExecutionException, InterruptedException {
+        String coordinatingOnlyNode = getCoordinatingOnlyNode();
+        ClusterUpdateSettingsRequest updateSettingsRequest = new ClusterUpdateSettingsRequest();
+
+        updateSettingsRequest.transientSettings(
+            Settings.builder()
+                .put(
+                    CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                    AdmissionControlMode.ENFORCED.getMode()
+                )
+        );
+        assertAcked(client().admin().cluster().updateSettings(updateSettingsRequest).actionGet());
+        NodesStatsRequest nodesStatsRequest = new NodesStatsRequest();
+        nodesStatsRequest.clear()
+            .indices(true)
+            .addMetrics(
+                NodesStatsRequest.Metric.JVM.metricName(),
+                NodesStatsRequest.Metric.OS.metricName(),
+                NodesStatsRequest.Metric.FS.metricName(),
+                NodesStatsRequest.Metric.PROCESS.metricName(),
+                NodesStatsRequest.Metric.ADMISSION_CONTROL.metricName()
+            );
+        NodesStatsResponse nodesStatsResponse = client(coordinatingOnlyNode).admin().cluster().nodesStats(nodesStatsRequest).actionGet();
+        ClusterHealthResponse clusterHealthResponse = client().admin().cluster().health(new ClusterHealthRequest()).actionGet();
+        assertEquals(200, clusterHealthResponse.status().getStatus());
+        assertFalse(nodesStatsResponse.hasFailures());
+    }
+
+    public void testAdmissionControlRejectionOnMonitor() {
+        Tuple<String, String> primaryReplicaNodeNames = getPrimaryReplicaNodeNames(INDEX_NAME);
+        String primaryName = primaryReplicaNodeNames.v1();
+        String replicaName = primaryReplicaNodeNames.v2();
+        String coordinatingOnlyNode = getCoordinatingOnlyNode();
+
+        AdmissionControlService admissionControlServicePrimary = internalCluster().getInstance(AdmissionControlService.class, primaryName);
+        AdmissionControlService admissionControlServiceReplica = internalCluster().getInstance(AdmissionControlService.class, replicaName);
+
+        ClusterUpdateSettingsRequest updateSettingsRequest = new ClusterUpdateSettingsRequest();
+
+        updateSettingsRequest.transientSettings(
+            Settings.builder()
+                .put(
+                    CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                    AdmissionControlMode.MONITOR.getMode()
+                )
+        );
+        assertAcked(client().admin().cluster().updateSettings(updateSettingsRequest).actionGet());
+
+        final BulkRequest bulkRequest = new BulkRequest();
+        for (int i = 0; i < 3; ++i) {
+            IndexRequest request = new IndexRequest(INDEX_NAME).id(UUIDs.base64UUID())
+                .source(Collections.singletonMap("key", randomAlphaOfLength(50)));
+            bulkRequest.add(request);
+        }
+        BulkResponse res = client(coordinatingOnlyNode).bulk(bulkRequest).actionGet();
+        assertFalse(res.hasFailures());
+        AdmissionControllerStats admissionControlPrimaryStats = admissionControlServicePrimary.stats()
+            .getAdmissionControllerStatsList()
+            .get(0);
+        AdmissionControllerStats admissionControlReplicaStats = admissionControlServiceReplica.stats()
+            .getAdmissionControllerStatsList()
+            .get(0);
+        long primaryRejectionCount = admissionControlPrimaryStats.rejectionCount.getOrDefault(
+            AdmissionControlActionType.INDEXING.getType(),
+            new AtomicLong(0).longValue()
+        );
+        long replicaRejectionCount = admissionControlReplicaStats.rejectionCount.getOrDefault(
+            AdmissionControlActionType.INDEXING.getType(),
+            new AtomicLong(0).longValue()
+        );
+        assertEquals(primaryRejectionCount, 1);
+        assertEquals(replicaRejectionCount, 0);
+        SearchResponse searchResponse;
+        searchResponse = client(coordinatingOnlyNode).prepareSearch(INDEX_NAME).get();
+        admissionControlPrimaryStats = admissionControlServicePrimary.stats().getAdmissionControllerStatsList().get(0);
+        admissionControlReplicaStats = admissionControlServiceReplica.stats().getAdmissionControllerStatsList().get(0);
+        primaryRejectionCount = admissionControlPrimaryStats.getRejectionCount()
+            .getOrDefault(AdmissionControlActionType.SEARCH.getType(), new AtomicLong(0).longValue());
+        replicaRejectionCount = admissionControlReplicaStats.getRejectionCount()
+            .getOrDefault(AdmissionControlActionType.SEARCH.getType(), new AtomicLong(0).longValue());
+        assertTrue(primaryRejectionCount == 1 || replicaRejectionCount == 1);
+        assertFalse(primaryRejectionCount == 1 && replicaRejectionCount == 1);
+    }
+
+    public void testAdmissionControlRejectionOnDisabled() {
+        Tuple<String, String> primaryReplicaNodeNames = getPrimaryReplicaNodeNames(INDEX_NAME);
+        String primaryName = primaryReplicaNodeNames.v1();
+        String replicaName = primaryReplicaNodeNames.v2();
+        String coordinatingOnlyNode = getCoordinatingOnlyNode();
+
+        AdmissionControlService admissionControlServicePrimary = internalCluster().getInstance(AdmissionControlService.class, primaryName);
+        AdmissionControlService admissionControlServiceReplica = internalCluster().getInstance(AdmissionControlService.class, replicaName);
+
+        ClusterUpdateSettingsRequest updateSettingsRequest = new ClusterUpdateSettingsRequest();
+
+        updateSettingsRequest.transientSettings(
+            Settings.builder()
+                .put(
+                    CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                    AdmissionControlMode.DISABLED.getMode()
+                )
+        );
+        assertAcked(client().admin().cluster().updateSettings(updateSettingsRequest).actionGet());
+
+        final BulkRequest bulkRequest = new BulkRequest();
+        for (int i = 0; i < 3; ++i) {
+            IndexRequest request = new IndexRequest(INDEX_NAME).id(UUIDs.base64UUID())
+                .source(Collections.singletonMap("key", randomAlphaOfLength(50)));
+            bulkRequest.add(request);
+        }
+        BulkResponse res = client(coordinatingOnlyNode).bulk(bulkRequest).actionGet();
+        assertFalse(res.hasFailures());
+        AdmissionControllerStats admissionControlPrimaryStats = admissionControlServicePrimary.stats()
+            .getAdmissionControllerStatsList()
+            .get(0);
+        AdmissionControllerStats admissionControlReplicaStats = admissionControlServiceReplica.stats()
+            .getAdmissionControllerStatsList()
+            .get(0);
+        long primaryRejectionCount = admissionControlPrimaryStats.rejectionCount.getOrDefault(
+            AdmissionControlActionType.INDEXING.getType(),
+            new AtomicLong(0).longValue()
+        );
+        long replicaRejectionCount = admissionControlReplicaStats.rejectionCount.getOrDefault(
+            AdmissionControlActionType.INDEXING.getType(),
+            new AtomicLong(0).longValue()
+        );
+        assertEquals(primaryRejectionCount, 0);
+        assertEquals(replicaRejectionCount, 0);
+        SearchResponse searchResponse;
+        searchResponse = client(coordinatingOnlyNode).prepareSearch(INDEX_NAME).get();
+        admissionControlPrimaryStats = admissionControlServicePrimary.stats().getAdmissionControllerStatsList().get(0);
+        admissionControlReplicaStats = admissionControlServiceReplica.stats().getAdmissionControllerStatsList().get(0);
+        primaryRejectionCount = admissionControlPrimaryStats.getRejectionCount()
+            .getOrDefault(AdmissionControlActionType.SEARCH.getType(), new AtomicLong(0).longValue());
+        replicaRejectionCount = admissionControlReplicaStats.getRejectionCount()
+            .getOrDefault(AdmissionControlActionType.SEARCH.getType(), new AtomicLong(0).longValue());
+        assertTrue(primaryRejectionCount == 0 && replicaRejectionCount == 0);
+    }
+
+    private Tuple<String, String> getPrimaryReplicaNodeNames(String indexName) {
+        IndicesStatsResponse response = client().admin().indices().prepareStats(indexName).get();
+        String primaryId = Stream.of(response.getShards())
+            .map(ShardStats::getShardRouting)
+            .filter(ShardRouting::primary)
+            .findAny()
+            .get()
+            .currentNodeId();
+        String replicaId = Stream.of(response.getShards())
+            .map(ShardStats::getShardRouting)
+            .filter(sr -> sr.primary() == false)
+            .findAny()
+            .get()
+            .currentNodeId();
+        DiscoveryNodes nodes = client().admin().cluster().prepareState().get().getState().nodes();
+        String primaryName = nodes.get(primaryId).getName();
+        String replicaName = nodes.get(replicaId).getName();
+        return new Tuple<>(primaryName, replicaName);
+    }
+
+    private String getCoordinatingOnlyNode() {
+        return client().admin()
+            .cluster()
+            .prepareState()
+            .get()
+            .getState()
+            .nodes()
+            .getCoordinatingOnlyNodes()
+            .values()
+            .iterator()
+            .next()
+            .getName();
+    }
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/recovery/FullRollingRestartIT.java b/server/src/internalClusterTest/java/org/opensearch/recovery/FullRollingRestartIT.java
index f636185fd4649..d28df90216beb 100644
--- a/server/src/internalClusterTest/java/org/opensearch/recovery/FullRollingRestartIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/recovery/FullRollingRestartIT.java
@@ -198,11 +198,11 @@ public void testNoRebalanceOnRollingRestart() throws Exception {
         // see https://github.com/elastic/elasticsearch/issues/14387
         internalCluster().startClusterManagerOnlyNode(Settings.EMPTY);
         internalCluster().startDataOnlyNodes(3);
-        /**
-         * We start 3 nodes and a dedicated cluster-manager. Restart on of the data-nodes and ensure that we got no relocations.
-         * Yet we have 6 shards 0 replica so that means if the restarting node comes back both other nodes are subject
-         * to relocating to the restarting node since all had 2 shards and now one node has nothing allocated.
-         * We have a fix for this to wait until we have allocated unallocated shards now so this shouldn't happen.
+        /*
+          We start 3 nodes and a dedicated cluster-manager. Restart on of the data-nodes and ensure that we got no relocations.
+          Yet we have 6 shards 0 replica so that means if the restarting node comes back both other nodes are subject
+          to relocating to the restarting node since all had 2 shards and now one node has nothing allocated.
+          We have a fix for this to wait until we have allocated unallocated shards now so this shouldn't happen.
          */
         prepareCreate("test").setSettings(
             Settings.builder()
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/AbstractRemoteStoreMockRepositoryIntegTestCase.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/AbstractRemoteStoreMockRepositoryIntegTestCase.java
index bc55f6cc2cbcb..8166c0008ed83 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/AbstractRemoteStoreMockRepositoryIntegTestCase.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/AbstractRemoteStoreMockRepositoryIntegTestCase.java
@@ -33,7 +33,6 @@
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_REPOSITORY_TYPE_ATTRIBUTE_KEY_FORMAT;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_SEGMENT_REPOSITORY_NAME_ATTRIBUTE_KEY;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_TRANSLOG_REPOSITORY_NAME_ATTRIBUTE_KEY;
-import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 
 public abstract class AbstractRemoteStoreMockRepositoryIntegTestCase extends AbstractSnapshotIntegTestCase {
 
@@ -107,14 +106,18 @@ public Settings buildRemoteStoreNodeAttributes(Path repoLocation, double ioFailu
             .build();
     }
 
-    protected void deleteRepo() {
-        logger.info("--> Deleting the repository={}", REPOSITORY_NAME);
-        assertAcked(clusterAdmin().prepareDeleteRepository(REPOSITORY_NAME));
-        logger.info("--> Deleting the repository={}", TRANSLOG_REPOSITORY_NAME);
-        assertAcked(clusterAdmin().prepareDeleteRepository(TRANSLOG_REPOSITORY_NAME));
+    protected void cleanupRepo() {
+        logger.info("--> Cleanup the repository={}", REPOSITORY_NAME);
+        clusterAdmin().prepareCleanupRepository(REPOSITORY_NAME).execute().actionGet();
+        logger.info("--> Cleanup the repository={}", TRANSLOG_REPOSITORY_NAME);
+        clusterAdmin().prepareCleanupRepository(TRANSLOG_REPOSITORY_NAME).execute().actionGet();
     }
 
     protected String setup(Path repoLocation, double ioFailureRate, String skipExceptionBlobList, long maxFailure) {
+        return setup(repoLocation, ioFailureRate, skipExceptionBlobList, maxFailure, 0);
+    }
+
+    protected String setup(Path repoLocation, double ioFailureRate, String skipExceptionBlobList, long maxFailure, int replicaCount) {
         // The random_control_io_exception_rate setting ensures that 10-25% of all operations to remote store results in
         /// IOException. skip_exception_on_verification_file & skip_exception_on_list_blobs settings ensures that the
         // repository creation can happen without failure.
@@ -125,8 +128,11 @@ protected String setup(Path repoLocation, double ioFailureRate, String skipExcep
             settings.put(CLUSTER_REPLICATION_TYPE_SETTING.getKey(), ReplicationType.SEGMENT);
         }
 
+        disableRepoConsistencyCheck("Remote Store Creates System Repository");
+
         internalCluster().startClusterManagerOnlyNode(settings.build());
         String dataNodeName = internalCluster().startDataOnlyNode(settings.build());
+        internalCluster().startDataOnlyNodes(replicaCount, settings.build());
         createIndex(INDEX_NAME);
         logger.info("--> Created index={}", INDEX_NAME);
         ensureYellowAndNoInitializingShards(INDEX_NAME);
@@ -159,7 +165,7 @@ private String getLocalSegmentFilename(String remoteFilename) {
         return remoteFilename.split(RemoteSegmentStoreDirectory.SEGMENT_NAME_UUID_SEPARATOR)[0];
     }
 
-    private IndexResponse indexSingleDoc() {
+    protected IndexResponse indexSingleDoc() {
         return client().prepareIndex(INDEX_NAME)
             .setId(UUIDs.randomBase64UUID())
             .setSource(randomAlphaOfLength(5), randomAlphaOfLength(5))
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/BaseRemoteStoreRestoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/BaseRemoteStoreRestoreIT.java
index ad3e99dd274ce..d29dacb001434 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/BaseRemoteStoreRestoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/BaseRemoteStoreRestoreIT.java
@@ -8,9 +8,7 @@
 
 package org.opensearch.remotestore;
 
-import org.opensearch.action.admin.cluster.remotestore.restore.RestoreRemoteStoreRequest;
 import org.opensearch.action.index.IndexResponse;
-import org.opensearch.action.support.PlainActionFuture;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.test.transport.MockTransportService;
@@ -20,7 +18,6 @@
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
-import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 
 public class BaseRemoteStoreRestoreIT extends RemoteStoreBaseIntegTestCase {
@@ -46,19 +43,10 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
     }
 
     protected void restore(String... indices) {
-        boolean restoreAllShards = randomBoolean();
-        if (restoreAllShards) {
-            assertAcked(client().admin().indices().prepareClose(indices));
-        }
-        client().admin()
-            .cluster()
-            .restoreRemoteStore(
-                new RestoreRemoteStoreRequest().indices(indices).restoreAllShards(restoreAllShards),
-                PlainActionFuture.newFuture()
-            );
+        restore(randomBoolean(), indices);
     }
 
-    protected void verifyRestoredData(Map<String, Long> indexStats, String indexName) throws Exception {
+    protected void verifyRestoredData(Map<String, Long> indexStats, String indexName, boolean indexMoreData) throws Exception {
         ensureYellowAndNoInitializingShards(indexName);
         ensureGreen(indexName);
         // This is to ensure that shards that were already assigned will get latest count
@@ -68,6 +56,8 @@ protected void verifyRestoredData(Map<String, Long> indexStats, String indexName
             30,
             TimeUnit.SECONDS
         );
+        if (indexMoreData == false) return;
+
         IndexResponse response = indexSingleDoc(indexName);
         if (indexStats.containsKey(MAX_SEQ_NO_TOTAL + "-shard-" + response.getShardId().id())) {
             assertEquals(indexStats.get(MAX_SEQ_NO_TOTAL + "-shard-" + response.getShardId().id()) + 1, response.getSeqNo());
@@ -80,6 +70,10 @@ protected void verifyRestoredData(Map<String, Long> indexStats, String indexName
         );
     }
 
+    protected void verifyRestoredData(Map<String, Long> indexStats, String indexName) throws Exception {
+        verifyRestoredData(indexStats, indexName, true);
+    }
+
     public void prepareCluster(int numClusterManagerNodes, int numDataOnlyNodes, String indices, int replicaCount, int shardCount) {
         prepareCluster(numClusterManagerNodes, numDataOnlyNodes, indices, replicaCount, shardCount, Settings.EMPTY);
     }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteIndexRecoveryIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteIndexRecoveryIT.java
index 4eb1cc7703735..c957f1b338bfe 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteIndexRecoveryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteIndexRecoveryIT.java
@@ -23,7 +23,6 @@
 import java.nio.file.Path;
 
 import static org.opensearch.remotestore.RemoteStoreBaseIntegTestCase.remoteStoreClusterSettings;
-import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class RemoteIndexRecoveryIT extends IndexRecoveryIT {
@@ -57,7 +56,7 @@ public Settings indexSettings() {
 
     @After
     public void teardown() {
-        assertAcked(clusterAdmin().prepareDeleteRepository(REPOSITORY_NAME));
+        clusterAdmin().prepareCleanupRepository(REPOSITORY_NAME).get();
     }
 
     @Override
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java
index 4ebccb9b9e551..21ce4be9981fb 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java
@@ -11,6 +11,7 @@
 import org.opensearch.action.DocWriteResponse;
 import org.opensearch.action.admin.cluster.remotestore.restore.RestoreRemoteStoreRequest;
 import org.opensearch.action.admin.cluster.snapshots.restore.RestoreSnapshotResponse;
+import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
 import org.opensearch.action.admin.indices.get.GetIndexRequest;
 import org.opensearch.action.admin.indices.get.GetIndexResponse;
 import org.opensearch.action.delete.DeleteResponse;
@@ -20,8 +21,13 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.io.PathUtils;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.io.IOUtils;
+import org.opensearch.core.index.Index;
 import org.opensearch.core.rest.RestStatus;
+import org.opensearch.index.IndexService;
 import org.opensearch.index.IndexSettings;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.snapshots.AbstractSnapshotIntegTestCase;
 import org.opensearch.snapshots.SnapshotInfo;
@@ -32,11 +38,15 @@
 import org.junit.Before;
 
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_SEGMENT_STORE_REPOSITORY;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_STORE_ENABLED;
@@ -57,7 +67,7 @@ public void setup() {
 
     @After
     public void teardown() {
-        assertAcked(clusterAdmin().prepareDeleteRepository(BASE_REMOTE_REPO));
+        clusterAdmin().prepareCleanupRepository(BASE_REMOTE_REPO).get();
     }
 
     @Override
@@ -320,6 +330,8 @@ public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
         assertEquals(restoreSnapshotResponse1.status(), RestStatus.ACCEPTED);
         assertEquals(restoreSnapshotResponse2.status(), RestStatus.ACCEPTED);
         ensureGreen(indexName1, restoredIndexName2);
+
+        assertRemoteSegmentsAndTranslogUploaded(restoredIndexName2);
         assertDocsPresentInIndex(client, indexName1, numDocsInIndex1);
         assertDocsPresentInIndex(client, restoredIndexName2, numDocsInIndex2);
         // indexing some new docs and validating
@@ -345,6 +357,97 @@ public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
         assertDocsPresentInIndex(client, indexName1, numDocsInIndex1 + 4);
     }
 
+    void assertRemoteSegmentsAndTranslogUploaded(String idx) throws IOException {
+        String indexUUID = client().admin().indices().prepareGetSettings(idx).get().getSetting(idx, IndexMetadata.SETTING_INDEX_UUID);
+
+        Path remoteTranslogMetadataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/translog/metadata");
+        Path remoteTranslogDataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/translog/data");
+        Path segmentMetadataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/segments/metadata");
+        Path segmentDataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/segments/data");
+
+        try (
+            Stream<Path> translogMetadata = Files.list(remoteTranslogMetadataPath);
+            Stream<Path> translogData = Files.list(remoteTranslogDataPath);
+            Stream<Path> segmentMetadata = Files.list(segmentMetadataPath);
+            Stream<Path> segmentData = Files.list(segmentDataPath);
+
+        ) {
+            assertTrue(translogData.count() > 0);
+            assertTrue(translogMetadata.count() > 0);
+            assertTrue(segmentMetadata.count() > 0);
+            assertTrue(segmentData.count() > 0);
+        }
+
+    }
+
+    public void testRemoteRestoreIndexRestoredFromSnapshot() throws IOException, ExecutionException, InterruptedException {
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNodes(2);
+
+        String indexName1 = "testindex1";
+        String snapshotRepoName = "test-restore-snapshot-repo";
+        String snapshotName1 = "test-restore-snapshot1";
+        Path absolutePath1 = randomRepoPath().toAbsolutePath();
+        logger.info("Snapshot Path [{}]", absolutePath1);
+
+        createRepository(snapshotRepoName, "fs", getRepositorySettings(absolutePath1, true));
+
+        Settings indexSettings = getIndexSettings(1, 0).build();
+        createIndex(indexName1, indexSettings);
+
+        final int numDocsInIndex1 = randomIntBetween(20, 30);
+        indexDocuments(client(), indexName1, numDocsInIndex1);
+        flushAndRefresh(indexName1);
+        ensureGreen(indexName1);
+
+        logger.info("--> snapshot");
+        SnapshotInfo snapshotInfo1 = createSnapshot(snapshotRepoName, snapshotName1, new ArrayList<>(Arrays.asList(indexName1)));
+        assertThat(snapshotInfo1.successfulShards(), greaterThan(0));
+        assertThat(snapshotInfo1.successfulShards(), equalTo(snapshotInfo1.totalShards()));
+        assertThat(snapshotInfo1.state(), equalTo(SnapshotState.SUCCESS));
+
+        assertAcked(client().admin().indices().delete(new DeleteIndexRequest(indexName1)).get());
+        assertFalse(indexExists(indexName1));
+
+        RestoreSnapshotResponse restoreSnapshotResponse1 = client().admin()
+            .cluster()
+            .prepareRestoreSnapshot(snapshotRepoName, snapshotName1)
+            .setWaitForCompletion(false)
+            .setIndices(indexName1)
+            .get();
+
+        assertEquals(restoreSnapshotResponse1.status(), RestStatus.ACCEPTED);
+        ensureGreen(indexName1);
+        assertDocsPresentInIndex(client(), indexName1, numDocsInIndex1);
+
+        assertRemoteSegmentsAndTranslogUploaded(indexName1);
+
+        // Clear the local data before stopping the node. This will make sure that remote translog is empty.
+        IndexShard indexShard = getIndexShard(primaryNodeName(indexName1), indexName1);
+        try (Stream<Path> files = Files.list(indexShard.shardPath().resolveTranslog())) {
+            IOUtils.deleteFilesIgnoringExceptions(files.collect(Collectors.toList()));
+        }
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNodeName(indexName1)));
+
+        ensureRed(indexName1);
+
+        client().admin()
+            .cluster()
+            .restoreRemoteStore(new RestoreRemoteStoreRequest().indices(indexName1).restoreAllShards(false), PlainActionFuture.newFuture());
+
+        ensureGreen(indexName1);
+        assertDocsPresentInIndex(client(), indexName1, numDocsInIndex1);
+    }
+
+    protected IndexShard getIndexShard(String node, String indexName) {
+        final Index index = resolveIndex(indexName);
+        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, node);
+        IndexService indexService = indicesService.indexService(index);
+        assertNotNull(indexService);
+        final Optional<Integer> shardId = indexService.shardIds().stream().findFirst();
+        return shardId.map(indexService::getShard).orElse(null);
+    }
+
     public void testRestoreShallowCopySnapshotWithDifferentRepo() throws IOException {
         String clusterManagerNode = internalCluster().startClusterManagerOnlyNode();
         String primary = internalCluster().startDataOnlyNode();
@@ -422,7 +525,7 @@ public void testRestoreShallowCopySnapshotWithDifferentRepo() throws IOException
         assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1 + 2);
     }
 
-    public void testRestoreShallowSnapshotRepositoryOverriden() throws ExecutionException, InterruptedException {
+    public void testRestoreShallowSnapshotRepository() throws ExecutionException, InterruptedException {
         String indexName1 = "testindex1";
         String snapshotRepoName = "test-restore-snapshot-repo";
         String remoteStoreRepoNameUpdated = "test-rs-repo-updated" + TEST_REMOTE_STORE_REPO_SUFFIX;
@@ -464,22 +567,74 @@ public void testRestoreShallowSnapshotRepositoryOverriden() throws ExecutionExce
         assertThat(snapshotInfo1.successfulShards(), equalTo(snapshotInfo1.totalShards()));
         assertThat(snapshotInfo1.state(), equalTo(SnapshotState.SUCCESS));
 
-        createRepository(BASE_REMOTE_REPO, "fs", absolutePath2);
-
-        RestoreSnapshotResponse restoreSnapshotResponse = client.admin()
+        client().admin().indices().close(Requests.closeIndexRequest(indexName1)).get();
+        createRepository(remoteStoreRepoNameUpdated, "fs", remoteRepoPath);
+        RestoreSnapshotResponse restoreSnapshotResponse2 = client.admin()
             .cluster()
             .prepareRestoreSnapshot(snapshotRepoName, snapshotName1)
             .setWaitForCompletion(true)
             .setIndices(indexName1)
             .setRenamePattern(indexName1)
             .setRenameReplacement(restoredIndexName1)
+            .setSourceRemoteStoreRepository(remoteStoreRepoNameUpdated)
             .get();
 
-        assertTrue(restoreSnapshotResponse.getRestoreInfo().failedShards() > 0);
+        assertTrue(restoreSnapshotResponse2.getRestoreInfo().failedShards() == 0);
+        ensureGreen(restoredIndexName1);
+        assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1);
 
-        ensureRed(restoredIndexName1);
+        // indexing some new docs and validating
+        indexDocuments(client, restoredIndexName1, numDocsInIndex1, numDocsInIndex1 + 2);
+        ensureGreen(restoredIndexName1);
+        assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1 + 2);
+    }
+
+    public void testRestoreShallowSnapshotIndexAfterSnapshot() throws ExecutionException, InterruptedException {
+        String indexName1 = "testindex1";
+        String snapshotRepoName = "test-restore-snapshot-repo";
+        String remoteStoreRepoNameUpdated = "test-rs-repo-updated" + TEST_REMOTE_STORE_REPO_SUFFIX;
+        String snapshotName1 = "test-restore-snapshot1";
+        Path absolutePath1 = randomRepoPath().toAbsolutePath();
+        Path absolutePath2 = randomRepoPath().toAbsolutePath();
+        String[] pathTokens = absolutePath1.toString().split("/");
+        String basePath = pathTokens[pathTokens.length - 1];
+        Arrays.copyOf(pathTokens, pathTokens.length - 1);
+        Path location = PathUtils.get(String.join("/", pathTokens));
+        pathTokens = absolutePath2.toString().split("/");
+        String basePath2 = pathTokens[pathTokens.length - 1];
+        Arrays.copyOf(pathTokens, pathTokens.length - 1);
+        Path location2 = PathUtils.get(String.join("/", pathTokens));
+        logger.info("Path 1 [{}]", absolutePath1);
+        logger.info("Path 2 [{}]", absolutePath2);
+        String restoredIndexName1 = indexName1 + "-restored";
+
+        createRepository(snapshotRepoName, "fs", getRepositorySettings(location, basePath, true));
+
+        Client client = client();
+        Settings indexSettings = Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
+            .build();
+        createIndex(indexName1, indexSettings);
+
+        int numDocsInIndex1 = randomIntBetween(2, 5);
+        indexDocuments(client, indexName1, numDocsInIndex1);
+
+        ensureGreen(indexName1);
+
+        logger.info("--> snapshot");
+        SnapshotInfo snapshotInfo1 = createSnapshot(snapshotRepoName, snapshotName1, new ArrayList<>(List.of(indexName1)));
+        assertThat(snapshotInfo1.successfulShards(), greaterThan(0));
+        assertThat(snapshotInfo1.successfulShards(), equalTo(snapshotInfo1.totalShards()));
+        assertThat(snapshotInfo1.state(), equalTo(SnapshotState.SUCCESS));
+
+        int extraNumDocsInIndex1 = randomIntBetween(20, 50);
+        indexDocuments(client, indexName1, extraNumDocsInIndex1);
+        refresh(indexName1);
 
-        client().admin().indices().close(Requests.closeIndexRequest(restoredIndexName1)).get();
+        client().admin().indices().close(Requests.closeIndexRequest(indexName1)).get();
         createRepository(remoteStoreRepoNameUpdated, "fs", remoteRepoPath);
         RestoreSnapshotResponse restoreSnapshotResponse2 = client.admin()
             .cluster()
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBackpressureIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBackpressureAndResiliencyIT.java
similarity index 57%
rename from server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBackpressureIT.java
rename to server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBackpressureAndResiliencyIT.java
index d02c5bf54fbed..6b6a96dc42a84 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBackpressureIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBackpressureAndResiliencyIT.java
@@ -11,13 +11,20 @@
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStats;
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStatsResponse;
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsResponse;
+import org.opensearch.action.admin.indices.flush.FlushResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.concurrent.UncategorizedExecutionException;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.concurrency.OpenSearchRejectedExecutionException;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.index.IndexService;
+import org.opensearch.index.IndexServiceTestUtils;
 import org.opensearch.index.remote.RemoteSegmentTransferTracker;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.snapshots.mockstore.MockRepository;
 import org.opensearch.test.OpenSearchIntegTestCase;
@@ -33,7 +40,7 @@
 import static org.opensearch.index.remote.RemoteStorePressureSettings.REMOTE_REFRESH_SEGMENT_PRESSURE_ENABLED;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
-public class RemoteStoreBackpressureIT extends AbstractRemoteStoreMockRepositoryIntegTestCase {
+public class RemoteStoreBackpressureAndResiliencyIT extends AbstractRemoteStoreMockRepositoryIntegTestCase {
     public void testWritesRejectedDueToConsecutiveFailureBreach() throws Exception {
         // Here the doc size of the request remains same throughout the test. After initial indexing, all remote store interactions
         // fail leading to consecutive failure limit getting exceeded and leading to rejections.
@@ -49,7 +56,7 @@ public void testWritesRejectedDueToBytesLagBreach() throws Exception {
     public void testWritesRejectedDueToTimeLagBreach() throws Exception {
         // Initially indexing happens with doc size of 1KB, then all remote store interactions start failing. Now, the
         // indexing happens with doc size of 1 byte leading to time lag limit getting exceeded and leading to rejections.
-        validateBackpressure(ByteSizeUnit.KB.toIntBytes(1), 20, ByteSizeUnit.BYTES.toIntBytes(1), 15, "time_lag");
+        validateBackpressure(ByteSizeUnit.KB.toIntBytes(1), 20, ByteSizeUnit.BYTES.toIntBytes(1), 3, "time_lag");
     }
 
     private void validateBackpressure(
@@ -112,7 +119,7 @@ private void validateBackpressure(
         stats = stats();
         indexDocAndRefresh(initialSource, initialDocsToIndex);
         assertEquals(rejectionCount, stats.rejectionCount);
-        deleteRepo();
+        cleanupRepo();
     }
 
     private RemoteSegmentTransferTracker.Stats stats() {
@@ -126,11 +133,13 @@ private RemoteSegmentTransferTracker.Stats stats() {
         return matches.get(0).getSegmentStats();
     }
 
-    private void indexDocAndRefresh(BytesReference source, int iterations) {
+    private void indexDocAndRefresh(BytesReference source, int iterations) throws InterruptedException {
         for (int i = 0; i < iterations; i++) {
             client().prepareIndex(INDEX_NAME).setSource(source, MediaTypeRegistry.JSON).get();
             refresh(INDEX_NAME);
         }
+        Thread.sleep(250);
+        client().prepareIndex(INDEX_NAME).setSource(source, MediaTypeRegistry.JSON).get();
     }
 
     /**
@@ -156,4 +165,98 @@ private String generateString(int sizeInBytes) {
         sb.append("}");
         return sb.toString();
     }
+
+    /**
+     * Fixes <a href="https://github.com/opensearch-project/OpenSearch/issues/10398">Github#10398</a>
+     */
+    public void testAsyncTrimTaskSucceeds() {
+        Path location = randomRepoPath().toAbsolutePath();
+        String dataNodeName = setup(location, 0d, "metadata", Long.MAX_VALUE);
+
+        logger.info("Increasing the frequency of async trim task to ensure it runs in background while indexing");
+        IndexService indexService = internalCluster().getInstance(IndicesService.class, dataNodeName).iterator().next();
+        IndexServiceTestUtils.setTrimTranslogTaskInterval(indexService, TimeValue.timeValueMillis(100));
+
+        logger.info("--> Indexing data");
+        indexData(randomIntBetween(2, 5), true);
+        logger.info("--> Indexing succeeded");
+
+        MockRepository translogRepo = (MockRepository) internalCluster().getInstance(RepositoriesService.class, dataNodeName)
+            .repository(TRANSLOG_REPOSITORY_NAME);
+        logger.info("--> Failing all remote store interaction");
+        translogRepo.setRandomControlIOExceptionRate(1d);
+
+        for (int i = 0; i < randomIntBetween(5, 10); i++) {
+            UncategorizedExecutionException exception = assertThrows(UncategorizedExecutionException.class, this::indexSingleDoc);
+            assertEquals("Failed execution", exception.getMessage());
+        }
+
+        translogRepo.setRandomControlIOExceptionRate(0d);
+        indexSingleDoc();
+        logger.info("Indexed single doc successfully");
+    }
+
+    /**
+     * Fixes <a href="https://github.com/opensearch-project/OpenSearch/issues/10400">Github#10400</a>
+     */
+    public void testSkipLoadGlobalCheckpointToReplicationTracker() {
+        Path location = randomRepoPath().toAbsolutePath();
+        String dataNodeName = setup(location, 0d, "metadata", Long.MAX_VALUE);
+
+        logger.info("--> Indexing data");
+        indexData(randomIntBetween(1, 2), true);
+        logger.info("--> Indexing succeeded");
+
+        IndexService indexService = internalCluster().getInstance(IndicesService.class, dataNodeName).iterator().next();
+        IndexShard indexShard = indexService.getShard(0);
+        indexShard.failShard("failing shard", null);
+
+        ensureRed(INDEX_NAME);
+
+        MockRepository translogRepo = (MockRepository) internalCluster().getInstance(RepositoriesService.class, dataNodeName)
+            .repository(TRANSLOG_REPOSITORY_NAME);
+        logger.info("--> Failing all remote store interaction");
+        translogRepo.setRandomControlIOExceptionRate(1d);
+        client().admin().cluster().prepareReroute().setRetryFailed(true).get();
+        // CLuster stays red still as the remote interactions are still failing
+        ensureRed(INDEX_NAME);
+
+        logger.info("Retrying to allocate failed shards");
+        client().admin().cluster().prepareReroute().setRetryFailed(true).get();
+        // CLuster stays red still as the remote interactions are still failing
+        ensureRed(INDEX_NAME);
+
+        logger.info("Stop failing all remote store interactions");
+        translogRepo.setRandomControlIOExceptionRate(0d);
+        client().admin().cluster().prepareReroute().setRetryFailed(true).get();
+        ensureGreen(INDEX_NAME);
+    }
+
+    public void testFlushDuringRemoteUploadFailures() {
+        Path location = randomRepoPath().toAbsolutePath();
+        String dataNodeName = setup(location, 0d, "metadata", Long.MAX_VALUE);
+
+        logger.info("--> Indexing data");
+        indexData(randomIntBetween(1, 2), true);
+        logger.info("--> Indexing succeeded");
+        ensureGreen(INDEX_NAME);
+
+        MockRepository translogRepo = (MockRepository) internalCluster().getInstance(RepositoriesService.class, dataNodeName)
+            .repository(TRANSLOG_REPOSITORY_NAME);
+        logger.info("--> Failing all remote store interaction");
+        translogRepo.setRandomControlIOExceptionRate(1d);
+
+        Exception ex = assertThrows(UncategorizedExecutionException.class, () -> indexSingleDoc());
+        assertEquals("Failed execution", ex.getMessage());
+
+        FlushResponse flushResponse = client().admin().indices().prepareFlush(INDEX_NAME).setForce(true).execute().actionGet();
+        assertEquals(1, flushResponse.getFailedShards());
+        ensureGreen(INDEX_NAME);
+
+        logger.info("--> Stop failing all remote store interactions");
+        translogRepo.setRandomControlIOExceptionRate(0d);
+        flushResponse = client().admin().indices().prepareFlush(INDEX_NAME).setForce(true).execute().actionGet();
+        assertEquals(1, flushResponse.getSuccessfulShards());
+        assertEquals(0, flushResponse.getFailedShards());
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
index 9a684ce0a1482..8c15ebd0505d9 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
@@ -8,12 +8,16 @@
 
 package org.opensearch.remotestore;
 
+import org.opensearch.action.admin.cluster.remotestore.restore.RestoreRemoteStoreRequest;
+import org.opensearch.action.admin.indices.get.GetIndexRequest;
+import org.opensearch.action.admin.indices.get.GetIndexResponse;
 import org.opensearch.action.bulk.BulkItemResponse;
 import org.opensearch.action.bulk.BulkRequest;
 import org.opensearch.action.bulk.BulkResponse;
 import org.opensearch.action.index.IndexRequest;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.index.IndexResponse;
+import org.opensearch.action.support.PlainActionFuture;
 import org.opensearch.action.support.WriteRequest;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.RepositoriesMetadata;
@@ -23,12 +27,15 @@
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.unit.ByteSizeUnit;
+import org.opensearch.core.index.Index;
 import org.opensearch.index.IndexModule;
+import org.opensearch.index.IndexService;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.mapper.MapperService;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.replication.common.ReplicationType;
-import org.opensearch.node.Node;
-import org.opensearch.node.remotestore.RemoteStoreNodeAttribute;
+import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.repositories.fs.FsRepository;
 import org.opensearch.test.OpenSearchIntegTestCase;
@@ -44,6 +51,7 @@
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 
@@ -58,7 +66,7 @@ public class RemoteStoreBaseIntegTestCase extends OpenSearchIntegTestCase {
     protected static final String REPOSITORY_NAME = "test-remote-store-repo";
     protected static final String REPOSITORY_2_NAME = "test-remote-store-repo-2";
     protected static final int SHARD_COUNT = 1;
-    protected static final int REPLICA_COUNT = 1;
+    protected static int REPLICA_COUNT = 1;
     protected static final String TOTAL_OPERATIONS = "total-operations";
     protected static final String REFRESHED_OR_FLUSHED_OPERATIONS = "refreshed-or-flushed-operations";
     protected static final String MAX_SEQ_NO_TOTAL = "max-seq-no-total";
@@ -168,6 +176,29 @@ public static Settings remoteStoreClusterSettings(String name, Path path) {
         return remoteStoreClusterSettings(name, path, name, path);
     }
 
+    public static Settings remoteStoreClusterSettings(
+        String segmentRepoName,
+        Path segmentRepoPath,
+        String segmentRepoType,
+        String translogRepoName,
+        Path translogRepoPath,
+        String translogRepoType
+    ) {
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(
+            buildRemoteStoreNodeAttributes(
+                segmentRepoName,
+                segmentRepoPath,
+                segmentRepoType,
+                translogRepoName,
+                translogRepoPath,
+                translogRepoType,
+                false
+            )
+        );
+        return settingsBuilder.build();
+    }
+
     public static Settings remoteStoreClusterSettings(
         String segmentRepoName,
         Path segmentRepoPath,
@@ -185,6 +216,26 @@ public static Settings buildRemoteStoreNodeAttributes(
         String translogRepoName,
         Path translogRepoPath,
         boolean withRateLimiterAttributes
+    ) {
+        return buildRemoteStoreNodeAttributes(
+            segmentRepoName,
+            segmentRepoPath,
+            FsRepository.TYPE,
+            translogRepoName,
+            translogRepoPath,
+            FsRepository.TYPE,
+            withRateLimiterAttributes
+        );
+    }
+
+    public static Settings buildRemoteStoreNodeAttributes(
+        String segmentRepoName,
+        Path segmentRepoPath,
+        String segmentRepoType,
+        String translogRepoName,
+        Path translogRepoPath,
+        String translogRepoType,
+        boolean withRateLimiterAttributes
     ) {
         String segmentRepoTypeAttributeKey = String.format(
             Locale.getDefault(),
@@ -219,18 +270,17 @@ public static Settings buildRemoteStoreNodeAttributes(
 
         Settings.Builder settings = Settings.builder()
             .put("node.attr." + REMOTE_STORE_SEGMENT_REPOSITORY_NAME_ATTRIBUTE_KEY, segmentRepoName)
-            .put(segmentRepoTypeAttributeKey, FsRepository.TYPE)
+            .put(segmentRepoTypeAttributeKey, segmentRepoType)
             .put(segmentRepoSettingsAttributeKeyPrefix + "location", segmentRepoPath)
             .put("node.attr." + REMOTE_STORE_TRANSLOG_REPOSITORY_NAME_ATTRIBUTE_KEY, translogRepoName)
-            .put(translogRepoTypeAttributeKey, FsRepository.TYPE)
+            .put(translogRepoTypeAttributeKey, translogRepoType)
             .put(translogRepoSettingsAttributeKeyPrefix + "location", translogRepoPath)
             .put("node.attr." + REMOTE_STORE_CLUSTER_STATE_REPOSITORY_NAME_ATTRIBUTE_KEY, segmentRepoName)
-            .put(stateRepoTypeAttributeKey, FsRepository.TYPE)
+            .put(stateRepoTypeAttributeKey, segmentRepoType)
             .put(stateRepoSettingsAttributeKeyPrefix + "location", segmentRepoPath);
 
         if (withRateLimiterAttributes) {
             settings.put(segmentRepoSettingsAttributeKeyPrefix + "compress", randomBoolean())
-                .put(segmentRepoSettingsAttributeKeyPrefix + "max_remote_download_bytes_per_sec", "2kb")
                 .put(segmentRepoSettingsAttributeKeyPrefix + "chunk_size", 200, ByteSizeUnit.BYTES);
         }
 
@@ -273,8 +323,8 @@ public void teardown() {
         clusterSettingsSuppliedByTest = false;
         assertRemoteStoreRepositoryOnAllNodes(REPOSITORY_NAME);
         assertRemoteStoreRepositoryOnAllNodes(REPOSITORY_2_NAME);
-        assertAcked(clusterAdmin().prepareDeleteRepository(REPOSITORY_NAME));
-        assertAcked(clusterAdmin().prepareDeleteRepository(REPOSITORY_2_NAME));
+        clusterAdmin().prepareCleanupRepository(REPOSITORY_NAME).get();
+        clusterAdmin().prepareCleanupRepository(REPOSITORY_2_NAME).get();
     }
 
     public RepositoryMetadata buildRepositoryMetadata(DiscoveryNode node, String name) {
@@ -302,52 +352,25 @@ public void assertRemoteStoreRepositoryOnAllNodes(String repositoryName) {
             .custom(RepositoriesMetadata.TYPE);
         RepositoryMetadata actualRepository = repositories.repository(repositoryName);
 
+        final RepositoriesService repositoriesService = internalCluster().getClusterManagerNodeInstance(RepositoriesService.class);
+        final BlobStoreRepository repository = (BlobStoreRepository) repositoriesService.repository(repositoryName);
+
         for (String nodeName : internalCluster().getNodeNames()) {
             ClusterService clusterService = internalCluster().getInstance(ClusterService.class, nodeName);
             DiscoveryNode node = clusterService.localNode();
             RepositoryMetadata expectedRepository = buildRepositoryMetadata(node, repositoryName);
-            assertTrue(actualRepository.equalsIgnoreGenerations(expectedRepository));
-        }
-    }
 
-    public Settings buildClusterSettingsWith() {
-        String segmentRepoTypeAttributeKey = String.format(
-            Locale.getDefault(),
-            "node.attr." + REMOTE_STORE_REPOSITORY_TYPE_ATTRIBUTE_KEY_FORMAT,
-            REPOSITORY_NAME
-        );
-        String segmentRepoSettingsAttributeKeyPrefix = String.format(
-            Locale.getDefault(),
-            "node.attr." + REMOTE_STORE_REPOSITORY_SETTINGS_ATTRIBUTE_KEY_PREFIX,
-            REPOSITORY_NAME
-        );
-        String translogRepoTypeAttributeKey = String.format(
-            Locale.getDefault(),
-            "node.attr." + REMOTE_STORE_REPOSITORY_TYPE_ATTRIBUTE_KEY_FORMAT,
-            REPOSITORY_2_NAME
-        );
-        String translogRepoSettingsAttributeKeyPrefix = String.format(
-            Locale.getDefault(),
-            "node.attr." + REMOTE_STORE_REPOSITORY_SETTINGS_ATTRIBUTE_KEY_PREFIX,
-            REPOSITORY_2_NAME
-        );
-        return Settings.builder()
-            .put(
-                Node.NODE_ATTRIBUTES.getKey() + RemoteStoreNodeAttribute.REMOTE_STORE_SEGMENT_REPOSITORY_NAME_ATTRIBUTE_KEY,
-                REPOSITORY_NAME
-            )
-            .put(segmentRepoTypeAttributeKey, FsRepository.TYPE)
-            .put(segmentRepoSettingsAttributeKeyPrefix + "location", randomRepoPath())
-            .put(segmentRepoSettingsAttributeKeyPrefix + "compress", randomBoolean())
-            .put(segmentRepoSettingsAttributeKeyPrefix + "max_remote_download_bytes_per_sec", "2kb")
-            .put(segmentRepoSettingsAttributeKeyPrefix + "chunk_size", 200, ByteSizeUnit.BYTES)
-            .put(
-                Node.NODE_ATTRIBUTES.getKey() + RemoteStoreNodeAttribute.REMOTE_STORE_TRANSLOG_REPOSITORY_NAME_ATTRIBUTE_KEY,
-                REPOSITORY_2_NAME
-            )
-            .put(translogRepoTypeAttributeKey, FsRepository.TYPE)
-            .put(translogRepoSettingsAttributeKeyPrefix + "location", randomRepoPath())
-            .build();
+            // Validated that all the restricted settings are entact on all the nodes.
+            repository.getRestrictedSystemRepositorySettings()
+                .stream()
+                .forEach(
+                    setting -> assertEquals(
+                        String.format(Locale.ROOT, "Restricted Settings mismatch [%s]", setting.getKey()),
+                        setting.get(actualRepository.settings()),
+                        setting.get(expectedRepository.settings())
+                    )
+                );
+        }
     }
 
     public static int getFileCount(Path path) throws Exception {
@@ -367,4 +390,25 @@ public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
 
         return filesExisting.get();
     }
+
+    protected IndexShard getIndexShard(String dataNode, String indexName) throws ExecutionException, InterruptedException {
+        String clusterManagerName = internalCluster().getClusterManagerName();
+        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, dataNode);
+        GetIndexResponse getIndexResponse = client(clusterManagerName).admin().indices().getIndex(new GetIndexRequest()).get();
+        String uuid = getIndexResponse.getSettings().get(indexName).get(IndexMetadata.SETTING_INDEX_UUID);
+        IndexService indexService = indicesService.indexService(new Index(indexName, uuid));
+        return indexService.getShard(0);
+    }
+
+    protected void restore(boolean restoreAllShards, String... indices) {
+        if (restoreAllShards) {
+            assertAcked(client().admin().indices().prepareClose(indices));
+        }
+        client().admin()
+            .cluster()
+            .restoreRemoteStore(
+                new RestoreRemoteStoreRequest().indices(indices).restoreAllShards(restoreAllShards),
+                PlainActionFuture.newFuture()
+            );
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java
index 5e92bb195680b..c61e2ec6e4f6c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java
@@ -8,23 +8,41 @@
 
 package org.opensearch.remotestore;
 
-import org.opensearch.action.admin.cluster.remotestore.restore.RestoreRemoteStoreResponse;
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
-import org.opensearch.action.support.PlainActionFuture;
+import org.opensearch.action.admin.indices.datastream.DataStreamRolloverIT;
+import org.opensearch.action.admin.indices.settings.put.UpdateSettingsRequest;
+import org.opensearch.action.admin.indices.template.put.PutIndexTemplateRequest;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.block.ClusterBlockException;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.metadata.IndexTemplateMetadata;
+import org.opensearch.cluster.metadata.Metadata;
+import org.opensearch.cluster.metadata.RepositoriesMetadata;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.gateway.remote.ClusterMetadataManifest;
+import org.opensearch.gateway.remote.ClusterMetadataManifest.UploadedIndexMetadata;
 import org.opensearch.gateway.remote.RemoteClusterStateService;
+import org.opensearch.test.InternalTestCluster;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.concurrent.ExecutionException;
 
+import static org.opensearch.cluster.coordination.ClusterBootstrapService.INITIAL_CLUSTER_MANAGER_NODES_SETTING;
+import static org.opensearch.cluster.metadata.IndexMetadata.INDEX_READ_ONLY_SETTING;
+import static org.opensearch.cluster.metadata.Metadata.CLUSTER_READ_ONLY_BLOCK;
+import static org.opensearch.cluster.metadata.Metadata.SETTING_READ_ONLY_SETTING;
 import static org.opensearch.gateway.remote.RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING;
 import static org.opensearch.indices.ShardLimitValidator.SETTING_CLUSTER_MAX_SHARDS_PER_NODE;
-import static org.opensearch.indices.ShardLimitValidator.SETTING_MAX_SHARDS_PER_CLUSTER_KEY;
+import static org.opensearch.repositories.blobstore.BlobStoreRepository.SYSTEM_REPOSITORY_SETTING;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class RemoteStoreClusterStateRestoreIT extends BaseRemoteStoreRestoreIT {
@@ -48,68 +66,122 @@ private Map<String, Long> initialTestSetup(int shardCount, int replicaCount, int
 
     private void resetCluster(int dataNodeCount, int clusterManagerNodeCount) {
         internalCluster().stopAllNodes();
-        addNewNodes(dataNodeCount, clusterManagerNodeCount);
+        internalCluster().startClusterManagerOnlyNodes(clusterManagerNodeCount);
+        internalCluster().startDataOnlyNodes(dataNodeCount);
     }
 
-    private void restoreAndValidate(String clusterUUID, Map<String, Long> indexStats) throws Exception {
-        restoreAndValidate(clusterUUID, indexStats, true);
+    protected void verifyRedIndicesAndTriggerRestore(Map<String, Long> indexStats, String indexName, boolean indexMoreDocs)
+        throws Exception {
+        ensureRed(indexName);
+        restore(false, indexName);
+        verifyRestoredData(indexStats, indexName, indexMoreDocs);
     }
 
-    private void restoreAndValidate(String clusterUUID, Map<String, Long> indexStats, boolean validate) throws Exception {
-        // TODO once auto restore is merged, the remote cluster state will be restored
+    public void testFullClusterRestore() throws Exception {
+        int shardCount = randomIntBetween(1, 2);
+        int replicaCount = 1;
+        int dataNodeCount = shardCount * (replicaCount + 1);
+        int clusterManagerNodeCount = 1;
 
-        if (validate) {
-            // Step - 4 validation restore is successful.
-            ensureGreen(INDEX_NAME);
-            verifyRestoredData(indexStats, INDEX_NAME);
-        }
-    }
+        // Step - 1 index some data to generate files in remote directory
+        Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, 1);
+        String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
 
-    private void restoreAndValidateFails(
-        String clusterUUID,
-        PlainActionFuture<RestoreRemoteStoreResponse> actionListener,
-        Class<? extends Throwable> clazz,
-        String errorSubString
-    ) {
+        // Step - 2 Replace all nodes in the cluster with new nodes. This ensures new cluster state doesn't have previous index metadata
+        resetCluster(dataNodeCount, clusterManagerNodeCount);
+
+        String newClusterUUID = clusterService().state().metadata().clusterUUID();
+        assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
+
+        // Step - 3 validate cluster state restored
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
+        validateMetadata(List.of(INDEX_NAME));
+        verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, true);
 
-        try {
-            restoreAndValidate(clusterUUID, null, false);
-        } catch (Exception e) {
-            assertTrue(
-                String.format(Locale.ROOT, "%s %s", clazz, e),
-                clazz.isAssignableFrom(e.getClass())
-                    || clazz.isAssignableFrom(e.getCause().getClass())
-                    || (e.getCause().getCause() != null && clazz.isAssignableFrom(e.getCause().getCause().getClass()))
-            );
-            assertTrue(
-                String.format(Locale.ROOT, "Error message mismatch. Expected: [%s]. Actual: [%s]", errorSubString, e.getMessage()),
-                e.getMessage().contains(errorSubString)
-            );
-        }
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/9834")
-    public void testFullClusterRestore() throws Exception {
+    /**
+     * This test scenario covers the case where right after remote state restore and persisting it to disk via LucenePersistedState, full cluster restarts.
+     * This is a special case for remote state as at this point cluster uuid in the restored state is still ClusterState.UNKNOWN_UUID as we persist it disk.
+     * After restart the local disk state will be read but should be again overridden with remote state.
+     *
+     * 1. Form a cluster and index few docs
+     * 2. Replace all nodes to remove all local disk state
+     * 3. Start cluster manager node without correct seeding to ensure local disk state is written with cluster uuid ClusterState.UNKNOWN_UUID but with remote restored Metadata
+     * 4. Restart the cluster manager node with correct seeding.
+     * 5. After restart the cluster manager picks up the local disk state with has same Metadata as remote but cluster uuid is still ClusterState.UNKNOWN_UUID
+     * 6. The cluster manager will try to restore from remote again.
+     * 7. Metadata loaded from local disk state will be overridden with remote Metadata and no conflict should arise.
+     * 8. Add data nodes to recover index data
+     * 9. Verify Metadata and index data is restored.
+     */
+    public void testFullClusterRestoreDoesntFailWithConflictingLocalState() throws Exception {
         int shardCount = randomIntBetween(1, 2);
         int replicaCount = 1;
         int dataNodeCount = shardCount * (replicaCount + 1);
         int clusterManagerNodeCount = 1;
 
-        // Step - 1 index some data to generate files in remote directory
+        // index some data to generate files in remote directory
         Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, 1);
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
 
-        // Step - 2 Replace all nodes in the cluster with new nodes. This ensures new cluster state doesn't have previous index metadata
-        resetCluster(dataNodeCount, clusterManagerNodeCount);
+        // stop all nodes
+        internalCluster().stopAllNodes();
+
+        // start a cluster manager node with no cluster manager seeding.
+        // This should fail with IllegalStateException as cluster manager fails to form without any initial seed
+        assertThrows(
+            IllegalStateException.class,
+            () -> internalCluster().startClusterManagerOnlyNodes(
+                clusterManagerNodeCount,
+                Settings.builder()
+                    .putList(INITIAL_CLUSTER_MANAGER_NODES_SETTING.getKey()) // disable seeding during bootstrapping
+                    .build()
+            )
+        );
 
+        // verify cluster manager not elected
         String newClusterUUID = clusterService().state().metadata().clusterUUID();
+        assert Objects.equals(newClusterUUID, ClusterState.UNKNOWN_UUID)
+            : "Disabling Cluster manager seeding failed. cluster uuid is not unknown";
+
+        // restart cluster manager with correct seed
+        internalCluster().fullRestart(new InternalTestCluster.RestartCallback() {
+            @Override
+            public Settings onNodeStopped(String nodeName) {
+                return Settings.builder()
+                    .putList(INITIAL_CLUSTER_MANAGER_NODES_SETTING.getKey(), nodeName)  // Seed with correct Cluster Manager node
+                    .build();
+            }
+        });
+
+        // validate new cluster state formed
+        newClusterUUID = clusterService().state().metadata().clusterUUID();
+        assert !Objects.equals(newClusterUUID, ClusterState.UNKNOWN_UUID) : "cluster restart not successful. cluster uuid is still unknown";
         assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
 
-        // Step - 3 Trigger full cluster restore and validate
-        restoreAndValidate(prevClusterUUID, indexStats);
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
+        validateMetadata(List.of(INDEX_NAME));
+
+        // start data nodes to trigger index data recovery
+        internalCluster().startDataOnlyNodes(dataNodeCount);
+        verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, true);
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/9834")
     public void testFullClusterRestoreMultipleIndices() throws Exception {
         int shardCount = randomIntBetween(1, 2);
         int replicaCount = 1;
@@ -124,8 +196,10 @@ public void testFullClusterRestoreMultipleIndices() throws Exception {
         Map<String, Long> indexStats2 = indexData(1, false, secondIndexName);
         assertEquals((shardCount + 1) * (replicaCount + 1), getNumShards(secondIndexName).totalNumShards);
         ensureGreen(secondIndexName);
+        updateIndexBlock(true, secondIndexName);
 
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
 
         // Step - 2 Replace all nodes in the cluster with new nodes. This ensures new cluster state doesn't have previous index metadata
         resetCluster(dataNodeCount, clusterManagerNodeCount);
@@ -133,99 +207,157 @@ public void testFullClusterRestoreMultipleIndices() throws Exception {
         String newClusterUUID = clusterService().state().metadata().clusterUUID();
         assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
 
-        // Step - 3 Trigger full cluster restore
-        restoreAndValidate(prevClusterUUID, indexStats);
-        ensureGreen(secondIndexName);
-        verifyRestoredData(indexStats2, secondIndexName);
+        // Step - 3 validate cluster state restored
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
+        validateMetadata(List.of(INDEX_NAME, secondIndexName));
+        verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, false);
+        verifyRedIndicesAndTriggerRestore(indexStats2, secondIndexName, false);
+        assertTrue(INDEX_READ_ONLY_SETTING.get(clusterService().state().metadata().index(secondIndexName).getSettings()));
+        assertThrows(ClusterBlockException.class, () -> indexSingleDoc(secondIndexName));
+        // Test is complete
+
+        // Remove the block to ensure proper cleanup
+        updateIndexBlock(false, secondIndexName);
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/9834")
-    public void testFullClusterRestoreFailureValidationFailures() throws Exception {
+    public void testFullClusterRestoreManifestFilePointsToInvalidIndexMetadataPathThrowsException() throws Exception {
         int shardCount = randomIntBetween(1, 2);
         int replicaCount = 1;
         int dataNodeCount = shardCount * (replicaCount + 1);
         int clusterManagerNodeCount = 1;
 
-        // index some data to generate files in remote directory
-        Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, clusterManagerNodeCount);
-        String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        // Step - 1 index some data to generate files in remote directory
+        initialTestSetup(shardCount, replicaCount, dataNodeCount, clusterManagerNodeCount);
 
-        // Start of Test - 1
-        // Test - 1 Trigger full cluster restore and validate it fails due to incorrect cluster UUID
-        PlainActionFuture<RestoreRemoteStoreResponse> future = PlainActionFuture.newFuture();
-        restoreAndValidateFails("randomUUID", future, IllegalStateException.class, "Remote Cluster State not found - randomUUID");
-        // End of Test - 1
-
-        // Start of Test - 3
-        // Test - 2 Trigger full cluster restore and validate it fails due to cluster UUID same as current cluster UUID
-        future = PlainActionFuture.newFuture();
-        restoreAndValidateFails(
-            clusterService().state().metadata().clusterUUID(),
-            future,
-            IllegalArgumentException.class,
-            "clusterUUID to restore from should be different from current cluster UUID"
-        );
-        // End of Test - 2
+        String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        String clusterName = clusterService().state().getClusterName().value();
 
-        // Start of Test - 3
         // Step - 2 Replace all nodes in the cluster with new nodes. This ensures new cluster state doesn't have previous index metadata
-        // Restarting cluster with just 1 data node helps with applying cluster settings
-        resetCluster(1, clusterManagerNodeCount);
-        String newClusterUUID = clusterService().state().metadata().clusterUUID();
-        assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
-
-        reduceShardLimits(1, 1);
-
-        // Step - 4 Trigger full cluster restore and validate it fails
-        future = PlainActionFuture.newFuture();
-        restoreAndValidateFails(
-            prevClusterUUID,
-            future,
-            IllegalArgumentException.class,
-            "this action would add [2] total shards, but this cluster currently has [0]/[1] maximum shards open"
-        );
-        resetShardLimits();
-        // End of Test - 3
+        internalCluster().stopAllNodes();
+        // Step - 3 Delete index metadata file in remote
+        try {
+            Files.move(
+                segmentRepoPath.resolve(
+                    RemoteClusterStateService.encodeString(clusterName) + "/cluster-state/" + prevClusterUUID + "/index"
+                ),
+                segmentRepoPath.resolve("cluster-state/")
+            );
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        assertThrows(IllegalStateException.class, () -> addNewNodes(dataNodeCount, clusterManagerNodeCount));
+        // Test is complete
 
-        // Start of Test - 4
-        // Test -4 Reset cluster and trigger full restore with same name index in the cluster
-        // Test -4 Add required nodes for this test after last reset.
-        addNewNodes(dataNodeCount - 1, 0);
+        // Starting a node without remote state to ensure test cleanup
+        internalCluster().startNode(Settings.builder().put(REMOTE_CLUSTER_STATE_ENABLED_SETTING.getKey(), false).build());
+    }
 
-        newClusterUUID = clusterService().state().metadata().clusterUUID();
-        assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
+    public void testRemoteStateFullRestart() throws Exception {
+        int shardCount = randomIntBetween(1, 2);
+        int replicaCount = 1;
+        int dataNodeCount = shardCount * (replicaCount + 1);
+        int clusterManagerNodeCount = 3;
 
-        // Test -4 Step - 2 Create a new index with same name
-        createIndex(INDEX_NAME, remoteStoreIndexSettings(0, 1));
-        ensureYellowAndNoInitializingShards(INDEX_NAME);
+        Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, clusterManagerNodeCount);
+        String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
+        // Delete index metadata file in remote
+        try {
+            Files.move(
+                segmentRepoPath.resolve(
+                    RemoteClusterStateService.encodeString(clusterService().state().getClusterName().value())
+                        + "/cluster-state/"
+                        + prevClusterUUID
+                        + "/manifest"
+                ),
+                segmentRepoPath.resolve("cluster-state/")
+            );
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        internalCluster().fullRestart();
         ensureGreen(INDEX_NAME);
+        String newClusterUUID = clusterService().state().metadata().clusterUUID();
+        assert Objects.equals(newClusterUUID, prevClusterUUID) : "Full restart not successful. cluster uuid has changed";
+
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
+        validateCurrentMetadata();
+        verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, true);
+    }
 
-        future = PlainActionFuture.newFuture();
+    private void validateMetadata(List<String> indexNames) {
+        assertEquals(clusterService().state().metadata().indices().size(), indexNames.size());
+        for (String indexName : indexNames) {
+            assertTrue(clusterService().state().metadata().hasIndex(indexName));
+        }
+    }
 
-        // Test -4 Step - 3 Trigger full cluster restore and validate fails
-        restoreAndValidateFails(
-            prevClusterUUID,
-            future,
-            IllegalStateException.class,
-            "cannot restore index [remote-store-test-idx-1] because an open index with same name/uuid already exists in the cluster"
+    private void validateCurrentMetadata() throws Exception {
+        RemoteClusterStateService remoteClusterStateService = internalCluster().getInstance(
+            RemoteClusterStateService.class,
+            internalCluster().getClusterManagerName()
         );
+        assertBusy(() -> {
+            ClusterMetadataManifest manifest = remoteClusterStateService.getLatestClusterMetadataManifest(
+                getClusterState().getClusterName().value(),
+                getClusterState().metadata().clusterUUID()
+            ).get();
+            ClusterState clusterState = getClusterState();
+            Metadata currentMetadata = clusterState.metadata();
+            assertEquals(currentMetadata.indices().size(), manifest.getIndices().size());
+            assertEquals(currentMetadata.coordinationMetadata().term(), manifest.getClusterTerm());
+            assertEquals(clusterState.version(), manifest.getStateVersion());
+            assertEquals(clusterState.stateUUID(), manifest.getStateUUID());
+            assertEquals(currentMetadata.clusterUUIDCommitted(), manifest.isClusterUUIDCommitted());
+            for (UploadedIndexMetadata uploadedIndexMetadata : manifest.getIndices()) {
+                IndexMetadata currentIndexMetadata = currentMetadata.index(uploadedIndexMetadata.getIndexName());
+                assertEquals(currentIndexMetadata.getIndex().getUUID(), uploadedIndexMetadata.getIndexUUID());
+            }
+        });
+    }
 
-        // Test -4 Step - 4 validation restore is successful.
-        ensureGreen(INDEX_NAME);
-        // End of Test - 4
+    public void testDataStreamPostRemoteStateRestore() throws Exception {
+        new DataStreamRolloverIT() {
+            protected boolean triggerRemoteStateRestore() {
+                return true;
+            }
+        }.testDataStreamRollover();
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/9834")
-    public void testFullClusterRestoreManifestFilePointsToInvalidIndexMetadataPathThrowsException() throws Exception {
+    public void testFullClusterRestoreGlobalMetadata() throws Exception {
         int shardCount = randomIntBetween(1, 2);
         int replicaCount = 1;
         int dataNodeCount = shardCount * (replicaCount + 1);
         int clusterManagerNodeCount = 1;
 
         // Step - 1 index some data to generate files in remote directory
-        initialTestSetup(shardCount, replicaCount, dataNodeCount, clusterManagerNodeCount);
-
+        Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, 1);
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
+
+        // Create global metadata - register a custom repo
+        Path repoPath = registerCustomRepository();
+
+        // Create global metadata - persistent settings
+        updatePersistentSettings(Settings.builder().put(SETTING_CLUSTER_MAX_SHARDS_PER_NODE.getKey(), 34).build());
+
+        // Create global metadata - index template
+        putIndexTemplate();
+
+        // Create global metadata - Put cluster block
+        addClusterLevelReadOnlyBlock();
 
         // Step - 2 Replace all nodes in the cluster with new nodes. This ensures new cluster state doesn't have previous index metadata
         resetCluster(dataNodeCount, clusterManagerNodeCount);
@@ -233,56 +365,102 @@ public void testFullClusterRestoreManifestFilePointsToInvalidIndexMetadataPathTh
         String newClusterUUID = clusterService().state().metadata().clusterUUID();
         assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
 
-        // Step - 4 Delete index metadata file in remote
-        try {
-            Files.move(
-                segmentRepoPath.resolve(
-                    RemoteClusterStateService.encodeString(clusterService().state().getClusterName().value())
-                        + "/cluster-state/"
-                        + prevClusterUUID
-                        + "/index"
-                ),
-                segmentRepoPath.resolve("cluster-state/")
-            );
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
+        // Step - 3 validate cluster state restored
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
+
+        validateCurrentMetadata();
+        assertEquals(Integer.valueOf(34), SETTING_CLUSTER_MAX_SHARDS_PER_NODE.get(clusterService().state().metadata().settings()));
+        assertEquals(true, SETTING_READ_ONLY_SETTING.get(clusterService().state().metadata().settings()));
+        assertTrue(clusterService().state().blocks().hasGlobalBlock(CLUSTER_READ_ONLY_BLOCK));
+        // Remote the cluster read only block to ensure proper cleanup
+        updatePersistentSettings(Settings.builder().put(SETTING_READ_ONLY_SETTING.getKey(), false).build());
+        assertFalse(clusterService().state().blocks().hasGlobalBlock(CLUSTER_READ_ONLY_BLOCK));
 
-        // Step - 5 Trigger full cluster restore and validate fails
-        PlainActionFuture<RestoreRemoteStoreResponse> future = PlainActionFuture.newFuture();
-        restoreAndValidateFails(prevClusterUUID, future, IllegalStateException.class, "asdsa");
+        verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, false);
+
+        // validate global metadata restored
+        verifyRestoredRepositories(repoPath);
+        verifyRestoredIndexTemplate();
     }
 
-    private void reduceShardLimits(int maxShardsPerNode, int maxShardsPerCluster) {
-        // Step 3 - Reduce shard limits to hit shard limit with less no of shards
-        try {
+    private Path registerCustomRepository() {
+        Path path = randomRepoPath();
+        assertAcked(
             client().admin()
                 .cluster()
-                .updateSettings(
-                    new ClusterUpdateSettingsRequest().transientSettings(
-                        Settings.builder()
-                            .put(SETTING_CLUSTER_MAX_SHARDS_PER_NODE.getKey(), maxShardsPerNode)
-                            .put(SETTING_MAX_SHARDS_PER_CLUSTER_KEY, maxShardsPerCluster)
-                    )
-                )
-                .get();
-        } catch (InterruptedException | ExecutionException e) {
-            throw new RuntimeException(e);
-        }
+                .preparePutRepository("custom-repo")
+                .setType("fs")
+                .setSettings(Settings.builder().put("location", path).put("compress", false))
+                .get()
+        );
+        return path;
     }
 
-    private void resetShardLimits() {
-        // Step - 5 Reset the cluster settings
+    private void verifyRestoredRepositories(Path repoPath) {
+        RepositoriesMetadata repositoriesMetadata = clusterService().state().metadata().custom(RepositoriesMetadata.TYPE);
+        assertEquals(3, repositoriesMetadata.repositories().size()); // includes remote store repo as well
+        assertTrue(SYSTEM_REPOSITORY_SETTING.get(repositoriesMetadata.repository(REPOSITORY_NAME).settings()));
+        assertTrue(SYSTEM_REPOSITORY_SETTING.get(repositoriesMetadata.repository(REPOSITORY_2_NAME).settings()));
+        assertEquals("fs", repositoriesMetadata.repository("custom-repo").type());
+        assertEquals(
+            Settings.builder().put("location", repoPath).put("compress", false).build(),
+            repositoriesMetadata.repository("custom-repo").settings()
+        );
+
+        // repo cleanup post verification
+        clusterAdmin().prepareDeleteRepository("custom-repo").get();
+    }
+
+    private void addClusterLevelReadOnlyBlock() throws InterruptedException, ExecutionException {
+        updatePersistentSettings(Settings.builder().put(SETTING_READ_ONLY_SETTING.getKey(), true).build());
+        assertTrue(clusterService().state().blocks().hasGlobalBlock(CLUSTER_READ_ONLY_BLOCK));
+    }
+
+    private void updatePersistentSettings(Settings settings) throws ExecutionException, InterruptedException {
         ClusterUpdateSettingsRequest resetRequest = new ClusterUpdateSettingsRequest();
-        resetRequest.transientSettings(
-            Settings.builder().putNull(SETTING_CLUSTER_MAX_SHARDS_PER_NODE.getKey()).putNull(SETTING_MAX_SHARDS_PER_CLUSTER_KEY)
+        resetRequest.persistentSettings(settings);
+        assertAcked(client().admin().cluster().updateSettings(resetRequest).get());
+    }
+
+    private void verifyRestoredIndexTemplate() {
+        Map<String, IndexTemplateMetadata> indexTemplateMetadataMap = clusterService().state().metadata().templates();
+        assertEquals(1, indexTemplateMetadataMap.size());
+        assertEquals(Arrays.asList("pattern-1", "log-*"), indexTemplateMetadataMap.get("my-template").patterns());
+        assertEquals(
+            Settings.builder() // <1>
+                .put("index.number_of_shards", 3)
+                .put("index.number_of_replicas", 1)
+                .build(),
+            indexTemplateMetadataMap.get("my-template").settings()
         );
+    }
 
-        try {
-            client().admin().cluster().updateSettings(resetRequest).get();
-        } catch (InterruptedException | ExecutionException e) {
-            throw new RuntimeException(e);
-        }
+    private static void putIndexTemplate() {
+        PutIndexTemplateRequest request = new PutIndexTemplateRequest("my-template"); // <1>
+        request.patterns(Arrays.asList("pattern-1", "log-*")); // <2>
+
+        request.settings(
+            Settings.builder() // <1>
+                .put("index.number_of_shards", 3)
+                .put("index.number_of_replicas", 1)
+        );
+        assertTrue(client().admin().indices().putTemplate(request).actionGet().isAcknowledged());
     }
 
+    private static void updateIndexBlock(boolean value, String secondIndexName) throws InterruptedException, ExecutionException {
+        assertAcked(
+            client().admin()
+                .indices()
+                .updateSettings(
+                    new UpdateSettingsRequest(Settings.builder().put(INDEX_READ_ONLY_SETTING.getKey(), value).build(), secondIndexName)
+                )
+                .get()
+        );
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java
index bd019693f01ff..e1997fea3433a 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java
@@ -8,41 +8,59 @@
 
 package org.opensearch.remotestore;
 
+import org.opensearch.OpenSearchException;
+import org.opensearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
+import org.opensearch.action.admin.cluster.snapshots.restore.RestoreSnapshotResponse;
 import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
-import org.opensearch.action.admin.indices.get.GetIndexRequest;
-import org.opensearch.action.admin.indices.get.GetIndexResponse;
+import org.opensearch.action.admin.indices.flush.FlushRequest;
 import org.opensearch.action.admin.indices.recovery.RecoveryResponse;
 import org.opensearch.action.admin.indices.settings.put.UpdateSettingsRequest;
 import org.opensearch.action.index.IndexResponse;
+import org.opensearch.action.search.SearchPhaseExecutionException;
+import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.routing.RecoverySource;
+import org.opensearch.cluster.routing.allocation.command.MoveAllocationCommand;
+import org.opensearch.common.Priority;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.concurrent.BufferedAsyncIOProcessor;
-import org.opensearch.core.index.Index;
-import org.opensearch.index.IndexService;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.shard.IndexShard;
+import org.opensearch.index.shard.IndexShardClosedException;
+import org.opensearch.index.translog.Translog.Durability;
 import org.opensearch.indices.IndicesService;
+import org.opensearch.indices.recovery.PeerRecoveryTargetService;
+import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.plugins.Plugin;
+import org.opensearch.test.InternalTestCluster;
 import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.transport.MockTransportService;
+import org.opensearch.transport.TransportService;
 import org.hamcrest.MatcherAssert;
 
+import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
 
-import static org.opensearch.index.shard.RemoteStoreRefreshListener.LAST_N_METADATA_FILES_TO_KEEP;
+import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
+import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
 import static org.opensearch.indices.IndicesService.CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.comparesEqualTo;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.oneOf;
 
@@ -114,6 +132,16 @@ public void testPeerRecoveryWithRemoteStoreAndRemoteTranslogFlush() throws Excep
         testPeerRecovery(randomIntBetween(2, 5), true);
     }
 
+    public void testPeerRecoveryWithLowActivityTimeout() throws Exception {
+        ClusterUpdateSettingsRequest req = new ClusterUpdateSettingsRequest().persistentSettings(
+            Settings.builder()
+                .put(RecoverySettings.INDICES_RECOVERY_MAX_BYTES_PER_SEC_SETTING.getKey(), "20kb")
+                .put(RecoverySettings.INDICES_RECOVERY_ACTIVITY_TIMEOUT_SETTING.getKey(), "1s")
+        );
+        internalCluster().client().admin().cluster().updateSettings(req).get();
+        testPeerRecovery(randomIntBetween(2, 5), true);
+    }
+
     public void testPeerRecoveryWithRemoteStoreAndRemoteTranslogNoDataRefresh() throws Exception {
         testPeerRecovery(1, false);
     }
@@ -149,7 +177,7 @@ public void testRemoteTranslogCleanup() throws Exception {
     }
 
     public void testStaleCommitDeletionWithInvokeFlush() throws Exception {
-        internalCluster().startNode();
+        String dataNode = internalCluster().startNode();
         createIndex(INDEX_NAME, remoteStoreIndexSettings(1, 10000l, -1));
         int numberOfIterations = randomIntBetween(5, 15);
         indexData(numberOfIterations, true, INDEX_NAME);
@@ -159,17 +187,20 @@ public void testStaleCommitDeletionWithInvokeFlush() throws Exception {
             .get()
             .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
         Path indexPath = Path.of(String.valueOf(segmentRepoPath), indexUUID, "/0/segments/metadata");
+
+        IndexShard indexShard = getIndexShard(dataNode, INDEX_NAME);
+        int lastNMetadataFilesToKeep = indexShard.getRecoverySettings().getMinRemoteSegmentMetadataFiles();
         // Delete is async.
         assertBusy(() -> {
             int actualFileCount = getFileCount(indexPath);
-            if (numberOfIterations <= LAST_N_METADATA_FILES_TO_KEEP) {
+            if (numberOfIterations <= lastNMetadataFilesToKeep) {
                 MatcherAssert.assertThat(actualFileCount, is(oneOf(numberOfIterations - 1, numberOfIterations, numberOfIterations + 1)));
             } else {
                 // As delete is async its possible that the file gets created before the deletion or after
                 // deletion.
                 MatcherAssert.assertThat(
                     actualFileCount,
-                    is(oneOf(LAST_N_METADATA_FILES_TO_KEEP - 1, LAST_N_METADATA_FILES_TO_KEEP, LAST_N_METADATA_FILES_TO_KEEP + 1))
+                    is(oneOf(lastNMetadataFilesToKeep - 1, lastNMetadataFilesToKeep, lastNMetadataFilesToKeep + 1))
                 );
             }
         }, 30, TimeUnit.SECONDS);
@@ -191,6 +222,44 @@ public void testStaleCommitDeletionWithoutInvokeFlush() throws Exception {
         MatcherAssert.assertThat(actualFileCount, is(oneOf(numberOfIterations - 1, numberOfIterations, numberOfIterations + 1)));
     }
 
+    public void testStaleCommitDeletionWithMinSegmentFiles_3() throws Exception {
+        Settings.Builder settings = Settings.builder()
+            .put(RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.getKey(), "3");
+        internalCluster().startNode(settings);
+
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(1, 10000l, -1));
+        int numberOfIterations = randomIntBetween(5, 15);
+        indexData(numberOfIterations, true, INDEX_NAME);
+        String indexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+        Path indexPath = Path.of(String.valueOf(segmentRepoPath), indexUUID, "/0/segments/metadata");
+        int actualFileCount = getFileCount(indexPath);
+        // We also allow (numberOfIterations + 1) as index creation also triggers refresh.
+        MatcherAssert.assertThat(actualFileCount, is(oneOf(4)));
+    }
+
+    public void testStaleCommitDeletionWithMinSegmentFiles_Disabled() throws Exception {
+        Settings.Builder settings = Settings.builder()
+            .put(RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.getKey(), "-1");
+        internalCluster().startNode(settings);
+
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(1, 10000l, -1));
+        int numberOfIterations = randomIntBetween(12, 18);
+        indexData(numberOfIterations, true, INDEX_NAME);
+        String indexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+        Path indexPath = Path.of(String.valueOf(segmentRepoPath), indexUUID, "/0/segments/metadata");
+        int actualFileCount = getFileCount(indexPath);
+        // We also allow (numberOfIterations + 1) as index creation also triggers refresh.
+        MatcherAssert.assertThat(actualFileCount, is(oneOf(numberOfIterations + 1)));
+    }
+
     /**
      * Tests that when the index setting is not passed during index creation, the buffer interval picked up is the cluster
      * default.
@@ -204,7 +273,7 @@ public void testDefaultBufferInterval() throws ExecutionException, InterruptedEx
         ensureGreen(INDEX_NAME);
         assertClusterRemoteBufferInterval(IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL, dataNode);
 
-        IndexShard indexShard = getIndexShard(dataNode);
+        IndexShard indexShard = getIndexShard(dataNode, INDEX_NAME);
         assertTrue(indexShard.getTranslogSyncProcessor() instanceof BufferedAsyncIOProcessor);
         assertBufferInterval(IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL, indexShard);
 
@@ -237,7 +306,7 @@ public void testOverriddenBufferInterval() throws ExecutionException, Interrupte
         ensureYellowAndNoInitializingShards(INDEX_NAME);
         ensureGreen(INDEX_NAME);
 
-        IndexShard indexShard = getIndexShard(dataNode);
+        IndexShard indexShard = getIndexShard(dataNode, INDEX_NAME);
         assertTrue(indexShard.getTranslogSyncProcessor() instanceof BufferedAsyncIOProcessor);
         assertBufferInterval(bufferInterval, indexShard);
 
@@ -318,13 +387,84 @@ public void testClusterBufferIntervalValidation() {
         );
     }
 
-    private IndexShard getIndexShard(String dataNode) throws ExecutionException, InterruptedException {
-        String clusterManagerName = internalCluster().getClusterManagerName();
-        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, dataNode);
-        GetIndexResponse getIndexResponse = client(clusterManagerName).admin().indices().getIndex(new GetIndexRequest()).get();
-        String uuid = getIndexResponse.getSettings().get(INDEX_NAME).get(IndexMetadata.SETTING_INDEX_UUID);
-        IndexService indexService = indicesService.indexService(new Index(INDEX_NAME, uuid));
-        return indexService.getShard(0);
+    public void testRequestDurabilityWhenRestrictSettingExplicitFalse() throws ExecutionException, InterruptedException {
+        // Explicit node settings and request durability
+        testRestrictSettingFalse(true, Durability.REQUEST);
+    }
+
+    public void testAsyncDurabilityWhenRestrictSettingExplicitFalse() throws ExecutionException, InterruptedException {
+        // Explicit node settings and async durability
+        testRestrictSettingFalse(true, Durability.ASYNC);
+    }
+
+    public void testRequestDurabilityWhenRestrictSettingImplicitFalse() throws ExecutionException, InterruptedException {
+        // No node settings and request durability
+        testRestrictSettingFalse(false, Durability.REQUEST);
+    }
+
+    public void testAsyncDurabilityWhenRestrictSettingImplicitFalse() throws ExecutionException, InterruptedException {
+        // No node settings and async durability
+        testRestrictSettingFalse(false, Durability.ASYNC);
+    }
+
+    private void testRestrictSettingFalse(boolean setRestrictFalse, Durability durability) throws ExecutionException, InterruptedException {
+        String clusterManagerName;
+        if (setRestrictFalse) {
+            clusterManagerName = internalCluster().startClusterManagerOnlyNode(
+                Settings.builder().put(IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING.getKey(), false).build()
+            );
+        } else {
+            clusterManagerName = internalCluster().startClusterManagerOnlyNode();
+        }
+        String dataNode = internalCluster().startDataOnlyNodes(1).get(0);
+        Settings indexSettings = Settings.builder()
+            .put(indexSettings())
+            .put(IndexSettings.INDEX_TRANSLOG_DURABILITY_SETTING.getKey(), durability)
+            .build();
+        createIndex(INDEX_NAME, indexSettings);
+        IndexShard indexShard = getIndexShard(dataNode, INDEX_NAME);
+        assertEquals(durability, indexShard.indexSettings().getTranslogDurability());
+
+        durability = randomFrom(Durability.values());
+        client(clusterManagerName).admin()
+            .indices()
+            .updateSettings(
+                new UpdateSettingsRequest(INDEX_NAME).settings(
+                    Settings.builder().put(IndexSettings.INDEX_TRANSLOG_DURABILITY_SETTING.getKey(), durability)
+                )
+            )
+            .get();
+        assertEquals(durability, indexShard.indexSettings().getTranslogDurability());
+    }
+
+    public void testAsyncDurabilityThrowsExceptionWhenRestrictSettingTrue() throws ExecutionException, InterruptedException {
+        String expectedExceptionMsg =
+            "index setting [index.translog.durability=async] is not allowed as cluster setting [cluster.remote_store.index.restrict.async-durability=true]";
+        String clusterManagerName = internalCluster().startClusterManagerOnlyNode(
+            Settings.builder().put(IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING.getKey(), true).build()
+        );
+        String dataNode = internalCluster().startDataOnlyNodes(1).get(0);
+
+        // Case 1 - Test create index fails
+        Settings indexSettings = Settings.builder()
+            .put(indexSettings())
+            .put(IndexSettings.INDEX_TRANSLOG_DURABILITY_SETTING.getKey(), Durability.ASYNC)
+            .build();
+        IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> createIndex(INDEX_NAME, indexSettings));
+        assertEquals(expectedExceptionMsg, exception.getMessage());
+
+        // Case 2 - Test update index fails
+        createIndex(INDEX_NAME);
+        IndexShard indexShard = getIndexShard(dataNode, INDEX_NAME);
+        assertEquals(Durability.REQUEST, indexShard.indexSettings().getTranslogDurability());
+        exception = assertThrows(
+            IllegalArgumentException.class,
+            () -> client(clusterManagerName).admin()
+                .indices()
+                .updateSettings(new UpdateSettingsRequest(INDEX_NAME).settings(indexSettings))
+                .actionGet()
+        );
+        assertEquals(expectedExceptionMsg, exception.getMessage());
     }
 
     private void assertClusterRemoteBufferInterval(TimeValue expectedBufferInterval, String dataNode) {
@@ -346,4 +486,320 @@ private void clearClusterBufferIntervalSetting(String clusterManagerName) {
             .setTransientSettings(Settings.builder().putNull(CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey()))
             .get();
     }
+
+    public void testRestoreSnapshotToIndexWithSameNameDifferentUUID() throws Exception {
+        internalCluster().startClusterManagerOnlyNode();
+        List<String> dataNodes = internalCluster().startDataOnlyNodes(2);
+
+        Path absolutePath = randomRepoPath().toAbsolutePath();
+        assertAcked(
+            clusterAdmin().preparePutRepository("test-repo").setType("fs").setSettings(Settings.builder().put("location", absolutePath))
+        );
+
+        logger.info("--> Create index and ingest 50 docs");
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(1));
+        indexBulk(INDEX_NAME, 50);
+        flushAndRefresh(INDEX_NAME);
+
+        String originalIndexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+        assertNotNull(originalIndexUUID);
+        assertNotEquals(IndexMetadata.INDEX_UUID_NA_VALUE, originalIndexUUID);
+
+        ensureGreen();
+
+        logger.info("--> take a snapshot");
+        client().admin().cluster().prepareCreateSnapshot("test-repo", "test-snap").setIndices(INDEX_NAME).setWaitForCompletion(true).get();
+
+        logger.info("--> wipe all indices");
+        cluster().wipeIndices(INDEX_NAME);
+
+        logger.info("--> Create index with the same name, different UUID");
+        assertAcked(
+            prepareCreate(INDEX_NAME).setSettings(Settings.builder().put(SETTING_NUMBER_OF_SHARDS, 1).put(SETTING_NUMBER_OF_REPLICAS, 1))
+        );
+
+        ensureGreen(TimeValue.timeValueSeconds(30), INDEX_NAME);
+
+        String newIndexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+        assertNotNull(newIndexUUID);
+        assertNotEquals(IndexMetadata.INDEX_UUID_NA_VALUE, newIndexUUID);
+        assertNotEquals(newIndexUUID, originalIndexUUID);
+
+        logger.info("--> close index");
+        client().admin().indices().prepareClose(INDEX_NAME).get();
+
+        logger.info("--> restore all indices from the snapshot");
+        RestoreSnapshotResponse restoreSnapshotResponse = clusterAdmin().prepareRestoreSnapshot("test-repo", "test-snap")
+            .setWaitForCompletion(true)
+            .execute()
+            .actionGet();
+        assertThat(restoreSnapshotResponse.getRestoreInfo().totalShards(), greaterThan(0));
+
+        flushAndRefresh(INDEX_NAME);
+
+        ensureGreen(INDEX_NAME);
+        assertBusy(() -> {
+            assertHitCount(client(dataNodes.get(0)).prepareSearch(INDEX_NAME).setSize(0).get(), 50);
+            assertHitCount(client(dataNodes.get(1)).prepareSearch(INDEX_NAME).setSize(0).get(), 50);
+        });
+    }
+
+    public void testNoSearchIdleForAnyReplicaCount() throws ExecutionException, InterruptedException {
+        internalCluster().startClusterManagerOnlyNode();
+        String primaryShardNode = internalCluster().startDataOnlyNodes(1).get(0);
+
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(0));
+        ensureGreen(INDEX_NAME);
+        IndexShard indexShard = getIndexShard(primaryShardNode, INDEX_NAME);
+        assertFalse(indexShard.isSearchIdleSupported());
+
+        String replicaShardNode = internalCluster().startDataOnlyNodes(1).get(0);
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareUpdateSettings(INDEX_NAME)
+                .setSettings(Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1))
+        );
+        ensureGreen(INDEX_NAME);
+        assertFalse(indexShard.isSearchIdleSupported());
+
+        indexShard = getIndexShard(replicaShardNode, INDEX_NAME);
+        assertFalse(indexShard.isSearchIdleSupported());
+    }
+
+    public void testFallbackToNodeToNodeSegmentCopy() throws Exception {
+        internalCluster().startClusterManagerOnlyNode();
+        List<String> dataNodes = internalCluster().startDataOnlyNodes(2);
+
+        // 1. Create index with 0 replica
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(0, 10000L, -1));
+        ensureGreen(INDEX_NAME);
+
+        // 2. Index docs
+        indexBulk(INDEX_NAME, 50);
+        flushAndRefresh(INDEX_NAME);
+
+        // 3. Delete data from remote segment store
+        String indexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+        Path segmentDataPath = Path.of(String.valueOf(segmentRepoPath), indexUUID, "/0/segments/data");
+
+        try (Stream<Path> files = Files.list(segmentDataPath)) {
+            files.forEach(p -> {
+                try {
+                    Files.delete(p);
+                } catch (IOException e) {
+                    // Ignore
+                }
+            });
+        }
+
+        // 4. Start recovery by changing number of replicas to 1
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareUpdateSettings(INDEX_NAME)
+                .setSettings(Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1))
+        );
+
+        // 5. Ensure green and verify number of docs
+        ensureGreen(INDEX_NAME);
+        assertBusy(() -> {
+            assertHitCount(client(dataNodes.get(0)).prepareSearch(INDEX_NAME).setSize(0).get(), 50);
+            assertHitCount(client(dataNodes.get(1)).prepareSearch(INDEX_NAME).setSize(0).get(), 50);
+        });
+    }
+
+    public void testNoMultipleWriterDuringPrimaryRelocation() throws ExecutionException, InterruptedException {
+        // In this test, we trigger a force flush on existing primary while the primary mode on new primary has been
+        // activated. There was a bug in primary relocation of remote store enabled indexes where the new primary
+        // starts uploading translog and segments even before the cluster manager has started this shard. With this test,
+        // we check that we do not overwrite any file on remote store. Here we will also increase the replica count to
+        // check that there are no duplicate metadata files for translog or upload.
+
+        internalCluster().startClusterManagerOnlyNode();
+        String oldPrimary = internalCluster().startDataOnlyNodes(1).get(0);
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(0));
+        ensureGreen(INDEX_NAME);
+        indexBulk(INDEX_NAME, randomIntBetween(5, 10));
+        String newPrimary = internalCluster().startDataOnlyNodes(1).get(0);
+        ensureStableCluster(3);
+
+        IndexShard oldPrimaryIndexShard = getIndexShard(oldPrimary, INDEX_NAME);
+        CountDownLatch flushLatch = new CountDownLatch(1);
+
+        MockTransportService mockTargetTransportService = ((MockTransportService) internalCluster().getInstance(
+            TransportService.class,
+            oldPrimary
+        ));
+        mockTargetTransportService.addSendBehavior((connection, requestId, action, request, options) -> {
+            if (PeerRecoveryTargetService.Actions.HANDOFF_PRIMARY_CONTEXT.equals(action)) {
+                flushLatch.countDown();
+            }
+            connection.sendRequest(requestId, action, request, options);
+        });
+
+        logger.info("--> relocate the shard");
+        client().admin()
+            .cluster()
+            .prepareReroute()
+            .add(new MoveAllocationCommand(INDEX_NAME, 0, oldPrimary, newPrimary))
+            .execute()
+            .actionGet();
+
+        CountDownLatch flushDone = new CountDownLatch(1);
+        Thread flushThread = new Thread(() -> {
+            try {
+                flushLatch.await(2, TimeUnit.SECONDS);
+                oldPrimaryIndexShard.flush(new FlushRequest().waitIfOngoing(true).force(true));
+                // newPrimaryTranslogRepo.setSleepSeconds(0);
+            } catch (IndexShardClosedException e) {
+                // this is fine
+            } catch (InterruptedException e) {
+                throw new AssertionError(e);
+            } finally {
+                flushDone.countDown();
+            }
+        });
+        flushThread.start();
+        flushDone.await(5, TimeUnit.SECONDS);
+        flushThread.join();
+
+        ClusterHealthResponse clusterHealthResponse = client().admin()
+            .cluster()
+            .prepareHealth()
+            .setWaitForStatus(ClusterHealthStatus.GREEN)
+            .setWaitForEvents(Priority.LANGUID)
+            .setWaitForNoRelocatingShards(true)
+            .setTimeout(TimeValue.timeValueSeconds(5))
+            .execute()
+            .actionGet();
+        assertFalse(clusterHealthResponse.isTimedOut());
+
+        client().admin()
+            .indices()
+            .updateSettings(
+                new UpdateSettingsRequest(INDEX_NAME).settings(Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1))
+            )
+            .get();
+
+        clusterHealthResponse = client().admin()
+            .cluster()
+            .prepareHealth()
+            .setWaitForStatus(ClusterHealthStatus.GREEN)
+            .setWaitForEvents(Priority.LANGUID)
+            .setWaitForNoRelocatingShards(true)
+            .setTimeout(TimeValue.timeValueSeconds(5))
+            .execute()
+            .actionGet();
+        assertFalse(clusterHealthResponse.isTimedOut());
+    }
+
+    public void testResumeUploadAfterFailedPrimaryRelocation() throws ExecutionException, InterruptedException, IOException {
+        // In this test, we fail the hand off during the primary relocation. This will undo the drainRefreshes and
+        // drainSync performed as part of relocation handoff (before performing the handoff transport action).
+        // We validate the same here by failing the peer recovery and ensuring we can index afterward as well.
+
+        internalCluster().startClusterManagerOnlyNode();
+        String oldPrimary = internalCluster().startDataOnlyNodes(1).get(0);
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(0));
+        ensureGreen(INDEX_NAME);
+        int docs = randomIntBetween(5, 10);
+        indexBulk(INDEX_NAME, docs);
+        flushAndRefresh(INDEX_NAME);
+        assertHitCount(client(oldPrimary).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), docs);
+        String newPrimary = internalCluster().startDataOnlyNodes(1).get(0);
+        ensureStableCluster(3);
+
+        IndexShard oldPrimaryIndexShard = getIndexShard(oldPrimary, INDEX_NAME);
+        CountDownLatch handOffLatch = new CountDownLatch(1);
+
+        MockTransportService mockTargetTransportService = ((MockTransportService) internalCluster().getInstance(
+            TransportService.class,
+            oldPrimary
+        ));
+        mockTargetTransportService.addSendBehavior((connection, requestId, action, request, options) -> {
+            if (PeerRecoveryTargetService.Actions.HANDOFF_PRIMARY_CONTEXT.equals(action)) {
+                handOffLatch.countDown();
+                throw new OpenSearchException("failing recovery for test purposes");
+            }
+            connection.sendRequest(requestId, action, request, options);
+        });
+
+        logger.info("--> relocate the shard");
+        client().admin()
+            .cluster()
+            .prepareReroute()
+            .add(new MoveAllocationCommand(INDEX_NAME, 0, oldPrimary, newPrimary))
+            .execute()
+            .actionGet();
+
+        handOffLatch.await(30, TimeUnit.SECONDS);
+
+        assertTrue(oldPrimaryIndexShard.isStartedPrimary());
+        assertEquals(oldPrimary, primaryNodeName(INDEX_NAME));
+        assertHitCount(client(oldPrimary).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), docs);
+
+        SearchPhaseExecutionException ex = assertThrows(
+            SearchPhaseExecutionException.class,
+            () -> client(newPrimary).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get()
+        );
+        assertEquals("all shards failed", ex.getMessage());
+
+        int moreDocs = randomIntBetween(5, 10);
+        indexBulk(INDEX_NAME, moreDocs);
+        flushAndRefresh(INDEX_NAME);
+        int uncommittedOps = randomIntBetween(5, 10);
+        indexBulk(INDEX_NAME, uncommittedOps);
+        assertHitCount(client(oldPrimary).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), docs + moreDocs);
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNodeName(INDEX_NAME)));
+
+        restore(true, INDEX_NAME);
+        ensureGreen(INDEX_NAME);
+        assertHitCount(
+            client(newPrimary).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(),
+            docs + moreDocs + uncommittedOps
+        );
+
+        String newNode = internalCluster().startDataOnlyNodes(1).get(0);
+        ensureStableCluster(3);
+        client().admin()
+            .cluster()
+            .prepareReroute()
+            .add(new MoveAllocationCommand(INDEX_NAME, 0, newPrimary, newNode))
+            .execute()
+            .actionGet();
+
+        ClusterHealthResponse clusterHealthResponse = client().admin()
+            .cluster()
+            .prepareHealth()
+            .setWaitForStatus(ClusterHealthStatus.GREEN)
+            .setWaitForEvents(Priority.LANGUID)
+            .setWaitForNoRelocatingShards(true)
+            .setTimeout(TimeValue.timeValueSeconds(10))
+            .execute()
+            .actionGet();
+        assertFalse(clusterHealthResponse.isTimedOut());
+
+        ex = assertThrows(
+            SearchPhaseExecutionException.class,
+            () -> client(newPrimary).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get()
+        );
+        assertEquals("all shards failed", ex.getMessage());
+        assertHitCount(
+            client(newNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(),
+            docs + moreDocs + uncommittedOps
+        );
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRefreshListenerIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRefreshListenerIT.java
index b97e93f323fb2..acdb21d072320 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRefreshListenerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRefreshListenerIT.java
@@ -28,9 +28,13 @@
 public class RemoteStoreRefreshListenerIT extends AbstractRemoteStoreMockRepositoryIntegTestCase {
 
     public void testRemoteRefreshRetryOnFailure() throws Exception {
-
         Path location = randomRepoPath().toAbsolutePath();
         setup(location, randomDoubleBetween(0.1, 0.15, true), "metadata", 10L);
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setPersistentSettings(Settings.builder().put(REMOTE_REFRESH_SEGMENT_PRESSURE_ENABLED.getKey(), false))
+            .get();
 
         // Here we are having flush/refresh after each iteration of indexing. However, the refresh will not always succeed
         // due to IOExceptions that are thrown while doing uploadBlobs.
@@ -56,7 +60,7 @@ public void testRemoteRefreshRetryOnFailure() throws Exception {
             logger.info("Local files = {}, Repo files = {}", sortedFilesInLocal, sortedFilesInRepo);
             assertTrue(filesInRepo.containsAll(filesInLocal));
         }, 90, TimeUnit.SECONDS);
-        deleteRepo();
+        cleanupRepo();
     }
 
     public void testRemoteRefreshSegmentPressureSettingChanged() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRepositoryRegistrationIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRepositoryRegistrationIT.java
index 4d56a1e94e3fc..ef2dcf3217df6 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRepositoryRegistrationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRepositoryRegistrationIT.java
@@ -8,17 +8,31 @@
 
 package org.opensearch.remotestore;
 
+import org.opensearch.action.admin.cluster.repositories.get.GetRepositoriesAction;
+import org.opensearch.action.admin.cluster.repositories.get.GetRepositoriesRequest;
+import org.opensearch.action.admin.cluster.repositories.get.GetRepositoriesResponse;
+import org.opensearch.client.Client;
+import org.opensearch.cluster.metadata.RepositoryMetadata;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.disruption.NetworkDisruption;
 import org.opensearch.test.transport.MockTransportService;
 
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import static org.opensearch.repositories.blobstore.BlobStoreRepository.SYSTEM_REPOSITORY_SETTING;
+
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class RemoteStoreRepositoryRegistrationIT extends RemoteStoreBaseIntegTestCase {
 
@@ -94,4 +108,77 @@ public void testMultiNodeClusterRandomNodeRecoverNetworkIsolation() {
 
         internalCluster().clearDisruptionScheme();
     }
+
+    public void testMultiNodeClusterRandomNodeRecoverNetworkIsolationPostNonRestrictedSettingsUpdate() {
+        Set<String> nodesInOneSide = internalCluster().startNodes(3).stream().collect(Collectors.toCollection(HashSet::new));
+        Set<String> nodesInAnotherSide = internalCluster().startNodes(3).stream().collect(Collectors.toCollection(HashSet::new));
+        ensureStableCluster(6);
+
+        NetworkDisruption networkDisruption = new NetworkDisruption(
+            new NetworkDisruption.TwoPartitions(nodesInOneSide, nodesInAnotherSide),
+            NetworkDisruption.DISCONNECT
+        );
+        internalCluster().setDisruptionScheme(networkDisruption);
+
+        networkDisruption.startDisrupting();
+
+        final Client client = client(nodesInOneSide.iterator().next());
+        RepositoryMetadata repositoryMetadata = client.admin()
+            .cluster()
+            .prepareGetRepositories(REPOSITORY_NAME)
+            .get()
+            .repositories()
+            .get(0);
+        Settings.Builder updatedSettings = Settings.builder().put(repositoryMetadata.settings()).put("chunk_size", new ByteSizeValue(20));
+        updatedSettings.remove("system_repository");
+
+        client.admin()
+            .cluster()
+            .preparePutRepository(repositoryMetadata.name())
+            .setType(repositoryMetadata.type())
+            .setSettings(updatedSettings)
+            .get();
+
+        ensureStableCluster(3, nodesInOneSide.stream().findAny().get());
+        networkDisruption.stopDisrupting();
+
+        ensureStableCluster(6);
+
+        internalCluster().clearDisruptionScheme();
+    }
+
+    public void testNodeRestartPostNonRestrictedSettingsUpdate() throws Exception {
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startNodes(3);
+
+        final Client client = client();
+        RepositoryMetadata repositoryMetadata = client.admin()
+            .cluster()
+            .prepareGetRepositories(REPOSITORY_NAME)
+            .get()
+            .repositories()
+            .get(0);
+        Settings.Builder updatedSettings = Settings.builder().put(repositoryMetadata.settings()).put("chunk_size", new ByteSizeValue(20));
+        updatedSettings.remove("system_repository");
+
+        client.admin()
+            .cluster()
+            .preparePutRepository(repositoryMetadata.name())
+            .setType(repositoryMetadata.type())
+            .setSettings(updatedSettings)
+            .get();
+
+        internalCluster().restartRandomDataNode();
+
+        ensureStableCluster(4);
+    }
+
+    public void testSystemRepositorySettingIsHiddenForGetRepositoriesRequest() throws IOException {
+        GetRepositoriesRequest request = new GetRepositoriesRequest(new String[] { REPOSITORY_NAME });
+        GetRepositoriesResponse repositoriesResponse = client().execute(GetRepositoriesAction.INSTANCE, request).actionGet();
+        XContentBuilder builder = MediaTypeRegistry.contentBuilder(randomFrom(XContentType.JSON));
+        XContentBuilder xContentBuilder = repositoriesResponse.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        repositoriesResponse = GetRepositoriesResponse.fromXContent(createParser(xContentBuilder));
+        assertEquals(false, SYSTEM_REPOSITORY_SETTING.get(repositoriesResponse.repositories().get(0).settings()));
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRestoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRestoreIT.java
index 489f4c52d4298..7626e3dba6424 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRestoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreRestoreIT.java
@@ -12,17 +12,26 @@
 import org.opensearch.action.admin.cluster.remotestore.restore.RestoreRemoteStoreResponse;
 import org.opensearch.action.support.PlainActionFuture;
 import org.opensearch.cluster.health.ClusterHealthStatus;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.repositories.RepositoriesService;
+import org.opensearch.repositories.Repository;
 import org.opensearch.test.InternalTestCluster;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.nio.file.Path;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
 
+import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_REPOSITORY_SETTINGS_ATTRIBUTE_KEY_PREFIX;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.greaterThan;
@@ -388,14 +397,41 @@ public void testRTSRestoreDataOnlyInTranslog() throws Exception {
     public void testRateLimitedRemoteDownloads() throws Exception {
         clusterSettingsSuppliedByTest = true;
         int shardCount = randomIntBetween(1, 3);
+        Path segmentRepoPath = randomRepoPath();
+        Path tlogRepoPath = randomRepoPath();
         prepareCluster(
             1,
             3,
             INDEX_NAME,
             0,
             shardCount,
-            buildRemoteStoreNodeAttributes(REPOSITORY_NAME, randomRepoPath(), REPOSITORY_2_NAME, randomRepoPath(), true)
+            buildRemoteStoreNodeAttributes(REPOSITORY_NAME, segmentRepoPath, REPOSITORY_2_NAME, tlogRepoPath, true)
         );
+
+        // validate inplace repository metadata update
+        ClusterService clusterService = internalCluster().getInstance(ClusterService.class);
+        DiscoveryNode node = clusterService.localNode();
+        String settingsAttributeKeyPrefix = String.format(
+            Locale.getDefault(),
+            REMOTE_STORE_REPOSITORY_SETTINGS_ATTRIBUTE_KEY_PREFIX,
+            REPOSITORY_NAME
+        );
+        Map<String, String> settingsMap = node.getAttributes()
+            .keySet()
+            .stream()
+            .filter(key -> key.startsWith(settingsAttributeKeyPrefix))
+            .collect(Collectors.toMap(key -> key.replace(settingsAttributeKeyPrefix, ""), key -> node.getAttributes().get(key)));
+        Settings.Builder settings = Settings.builder();
+        settingsMap.entrySet().forEach(entry -> settings.put(entry.getKey(), entry.getValue()));
+        settings.put("location", segmentRepoPath).put("max_remote_download_bytes_per_sec", 4, ByteSizeUnit.KB);
+
+        assertAcked(client().admin().cluster().preparePutRepository(REPOSITORY_NAME).setType("fs").setSettings(settings).get());
+
+        for (RepositoriesService repositoriesService : internalCluster().getDataNodeInstances(RepositoriesService.class)) {
+            Repository segmentRepo = repositoriesService.repository(REPOSITORY_NAME);
+            assertEquals("4096b", segmentRepo.getMetadata().settings().get("max_remote_download_bytes_per_sec"));
+        }
+
         Map<String, Long> indexStats = indexData(5, false, INDEX_NAME);
         assertEquals(shardCount, getNumShards(INDEX_NAME).totalNumShards);
         internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNodeName(INDEX_NAME)));
@@ -406,13 +442,23 @@ public void testRateLimitedRemoteDownloads() throws Exception {
             for (RepositoriesService repositoriesService : internalCluster().getDataNodeInstances(RepositoriesService.class)) {
                 downloadPauseTime += repositoriesService.repository(REPOSITORY_NAME).getRemoteDownloadThrottleTimeInNanos();
             }
-            assertThat(downloadPauseTime, greaterThan(TimeValue.timeValueSeconds(randomIntBetween(5, 10)).nanos()));
+            assertThat(downloadPauseTime, greaterThan(TimeValue.timeValueSeconds(randomIntBetween(3, 5)).nanos()));
         }, 30, TimeUnit.SECONDS);
-        ensureGreen(INDEX_NAME);
+        // Waiting for extended period for green state so that rate limit does not cause flakiness
+        ensureGreen(TimeValue.timeValueSeconds(120), INDEX_NAME);
         // This is required to get updated number from already active shards which were not restored
         assertEquals(shardCount, getNumShards(INDEX_NAME).totalNumShards);
         assertEquals(0, getNumShards(INDEX_NAME).numReplicas);
         verifyRestoredData(indexStats, INDEX_NAME);
+
+        // revert repo metadata to pass asserts on repo metadata vs. node attrs during teardown
+        // https://github.com/opensearch-project/OpenSearch/pull/9569#discussion_r1345668700
+        settings.remove("max_remote_download_bytes_per_sec");
+        assertAcked(client().admin().cluster().preparePutRepository(REPOSITORY_NAME).setType("fs").setSettings(settings).get());
+        for (RepositoriesService repositoriesService : internalCluster().getDataNodeInstances(RepositoriesService.class)) {
+            Repository segmentRepo = repositoriesService.repository(REPOSITORY_NAME);
+            assertNull(segmentRepo.getMetadata().settings().get("max_remote_download_bytes_per_sec"));
+        }
     }
 
     // TODO: Restore flow - index aliases
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java
index 8ae25c6758195..2d3ab135d0377 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java
@@ -15,6 +15,8 @@
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStatsResponse;
 import org.opensearch.action.support.PlainActionFuture;
 import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.coordination.FollowersChecker;
+import org.opensearch.cluster.coordination.LeaderChecker;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.routing.ShardRoutingState;
@@ -23,15 +25,20 @@
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.remote.RemoteSegmentTransferTracker;
 import org.opensearch.index.remote.RemoteTranslogTransferTracker;
+import org.opensearch.plugins.Plugin;
 import org.opensearch.test.InternalTestCluster;
 import org.opensearch.test.OpenSearchIntegTestCase;
-import org.junit.Before;
+import org.opensearch.test.disruption.NetworkDisruption;
+import org.opensearch.test.transport.MockTransportService;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -44,12 +51,17 @@ public class RemoteStoreStatsIT extends RemoteStoreBaseIntegTestCase {
 
     private static final String INDEX_NAME = "remote-store-test-idx-1";
 
-    @Before
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Arrays.asList(MockTransportService.TestPlugin.class);
+    }
+
     public void setup() {
         internalCluster().startNodes(3);
     }
 
     public void testStatsResponseFromAllNodes() {
+        setup();
 
         // Step 1 - We create cluster, create an index, and then index documents into. We also do multiple refreshes/flushes
         // during this time frame. This ensures that the segment upload has started.
@@ -118,6 +130,7 @@ public void testStatsResponseFromAllNodes() {
     }
 
     public void testStatsResponseAllShards() {
+        setup();
 
         // Step 1 - We create cluster, create an index, and then index documents into. We also do multiple refreshes/flushes
         // during this time frame. This ensures that the segment upload has started.
@@ -175,6 +188,7 @@ public void testStatsResponseAllShards() {
     }
 
     public void testStatsResponseFromLocalNode() {
+        setup();
 
         // Step 1 - We create cluster, create an index, and then index documents into. We also do multiple refreshes/flushes
         // during this time frame. This ensures that the segment upload has started.
@@ -236,6 +250,7 @@ public void testStatsResponseFromLocalNode() {
     }
 
     public void testDownloadStatsCorrectnessSinglePrimarySingleReplica() throws Exception {
+        setup();
         // Scenario:
         // - Create index with single primary and single replica shard
         // - Disable Refresh Interval for the index
@@ -325,6 +340,7 @@ public void testDownloadStatsCorrectnessSinglePrimarySingleReplica() throws Exce
     }
 
     public void testDownloadStatsCorrectnessSinglePrimaryMultipleReplicaShards() throws Exception {
+        setup();
         // Scenario:
         // - Create index with single primary and N-1 replica shards (N = no of data nodes)
         // - Disable Refresh Interval for the index
@@ -416,6 +432,7 @@ public void testDownloadStatsCorrectnessSinglePrimaryMultipleReplicaShards() thr
     }
 
     public void testStatsOnShardRelocation() {
+        setup();
         // Scenario:
         // - Create index with single primary and single replica shard
         // - Index documents
@@ -471,6 +488,7 @@ public void testStatsOnShardRelocation() {
     }
 
     public void testStatsOnShardUnassigned() throws IOException {
+        setup();
         // Scenario:
         // - Create index with single primary and two replica shard
         // - Index documents
@@ -497,6 +515,7 @@ public void testStatsOnShardUnassigned() throws IOException {
     }
 
     public void testStatsOnRemoteStoreRestore() throws IOException {
+        setup();
         // Creating an index with primary shard count == total nodes in cluster and 0 replicas
         int dataNodeCount = client().admin().cluster().prepareHealth().get().getNumberOfDataNodes();
         createIndex(INDEX_NAME, remoteStoreIndexSettings(0, dataNodeCount));
@@ -544,6 +563,7 @@ public void testStatsOnRemoteStoreRestore() throws IOException {
     }
 
     public void testNonZeroPrimaryStatsOnNewlyCreatedIndexWithZeroDocs() throws Exception {
+        setup();
         // Create an index with one primary and one replica shard
         createIndex(INDEX_NAME, remoteStoreIndexSettings(1, 1));
         ensureGreen(INDEX_NAME);
@@ -561,26 +581,103 @@ public void testNonZeroPrimaryStatsOnNewlyCreatedIndexWithZeroDocs() throws Exce
                 .getRemoteStoreStats();
             Arrays.stream(remoteStoreStats).forEach(statObject -> {
                 RemoteSegmentTransferTracker.Stats segmentStats = statObject.getSegmentStats();
+                RemoteTranslogTransferTracker.Stats translogStats = statObject.getTranslogStats();
                 if (statObject.getShardRouting().primary()) {
                     assertTrue(
                         segmentStats.totalUploadsSucceeded == 1
                             && segmentStats.totalUploadsStarted == segmentStats.totalUploadsSucceeded
                             && segmentStats.totalUploadsFailed == 0
                     );
+                    // On primary shard creation, we upload to remote translog post primary mode activation.
+                    // This changes upload stats to non-zero for primary shard.
+                    assertNonZeroTranslogUploadStatsNoFailures(translogStats);
                 } else {
                     assertTrue(
                         segmentStats.directoryFileTransferTrackerStats.transferredBytesStarted == 0
                             && segmentStats.directoryFileTransferTrackerStats.transferredBytesSucceeded == 0
                     );
+                    assertZeroTranslogUploadStats(translogStats);
                 }
-
-                RemoteTranslogTransferTracker.Stats translogStats = statObject.getTranslogStats();
-                assertZeroTranslogUploadStats(translogStats);
                 assertZeroTranslogDownloadStats(translogStats);
             });
         }, 5, TimeUnit.SECONDS);
     }
 
+    public void testStatsCorrectnessOnFailover() {
+        Settings clusterSettings = Settings.builder()
+            .put(LeaderChecker.LEADER_CHECK_TIMEOUT_SETTING.getKey(), "100ms")
+            .put(LeaderChecker.LEADER_CHECK_INTERVAL_SETTING.getKey(), "500ms")
+            .put(LeaderChecker.LEADER_CHECK_RETRY_COUNT_SETTING.getKey(), 1)
+            .put(FollowersChecker.FOLLOWER_CHECK_TIMEOUT_SETTING.getKey(), "100ms")
+            .put(FollowersChecker.FOLLOWER_CHECK_INTERVAL_SETTING.getKey(), "500ms")
+            .put(FollowersChecker.FOLLOWER_CHECK_RETRY_COUNT_SETTING.getKey(), 1)
+            .put(nodeSettings(0))
+            .build();
+        String clusterManagerNode = internalCluster().startClusterManagerOnlyNode(clusterSettings);
+        internalCluster().startDataOnlyNodes(2, clusterSettings);
+
+        // Create an index with one primary and one replica shard
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(1, 1));
+        ensureGreen(INDEX_NAME);
+
+        // Index some docs and refresh
+        indexDocs();
+        refresh(INDEX_NAME);
+
+        String primaryNode = primaryNodeName(INDEX_NAME);
+        String replicaNode = replicaNodeName(INDEX_NAME);
+
+        // Start network disruption - primary node will be isolated
+        Set<String> nodesInOneSide = Stream.of(clusterManagerNode, replicaNode).collect(Collectors.toCollection(HashSet::new));
+        Set<String> nodesInOtherSide = Stream.of(primaryNode).collect(Collectors.toCollection(HashSet::new));
+        NetworkDisruption networkDisruption = new NetworkDisruption(
+            new NetworkDisruption.TwoPartitions(nodesInOneSide, nodesInOtherSide),
+            NetworkDisruption.DISCONNECT
+        );
+        internalCluster().setDisruptionScheme(networkDisruption);
+        logger.info("--> network disruption is started");
+        networkDisruption.startDisrupting();
+        ensureStableCluster(2, clusterManagerNode);
+
+        RemoteStoreStatsResponse response = client(clusterManagerNode).admin().cluster().prepareRemoteStoreStats(INDEX_NAME, "0").get();
+        final String indexShardId = String.format(Locale.ROOT, "[%s][%s]", INDEX_NAME, "0");
+        List<RemoteStoreStats> matches = Arrays.stream(response.getRemoteStoreStats())
+            .filter(stat -> indexShardId.equals(stat.getSegmentStats().shardId.toString()))
+            .collect(Collectors.toList());
+        assertEquals(1, matches.size());
+        RemoteSegmentTransferTracker.Stats segmentStats = matches.get(0).getSegmentStats();
+        assertEquals(0, segmentStats.refreshTimeLagMs);
+
+        networkDisruption.stopDisrupting();
+        internalCluster().clearDisruptionScheme();
+        ensureStableCluster(3, clusterManagerNode);
+        ensureGreen(INDEX_NAME);
+        logger.info("Test completed");
+    }
+
+    public void testZeroLagOnCreateIndex() throws InterruptedException {
+        setup();
+        String clusterManagerNode = internalCluster().getClusterManagerName();
+
+        int numOfShards = randomIntBetween(1, 3);
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(1, numOfShards));
+        ensureGreen(INDEX_NAME);
+        long currentTimeNs = System.nanoTime();
+        while (currentTimeNs == System.nanoTime()) {
+            Thread.sleep(10);
+        }
+
+        for (int i = 0; i < numOfShards; i++) {
+            RemoteStoreStatsResponse response = client(clusterManagerNode).admin()
+                .cluster()
+                .prepareRemoteStoreStats(INDEX_NAME, String.valueOf(i))
+                .get();
+            for (RemoteStoreStats remoteStoreStats : response.getRemoteStoreStats()) {
+                assertEquals(0, remoteStoreStats.getSegmentStats().refreshTimeLagMs);
+            }
+        }
+    }
+
     private void indexDocs() {
         for (int i = 0; i < randomIntBetween(5, 10); i++) {
             if (randomBoolean()) {
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreDisruptionIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreDisruptionIT.java
new file mode 100644
index 0000000000000..d5cdc22a15478
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreDisruptionIT.java
@@ -0,0 +1,210 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.remotestore;
+
+import org.opensearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.opensearch.action.admin.cluster.stats.ClusterStatsResponse;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.routing.allocation.command.MoveAllocationCommand;
+import org.opensearch.common.Priority;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.index.Index;
+import org.opensearch.index.IndexService;
+import org.opensearch.index.ReplicationStats;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
+import org.opensearch.indices.replication.SegmentReplicationState;
+import org.opensearch.indices.replication.SegmentReplicationTarget;
+import org.opensearch.indices.replication.SegmentReplicationTargetService;
+import org.opensearch.indices.replication.common.ReplicationCollection;
+import org.opensearch.test.InternalTestCluster;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.disruption.SlowClusterStateProcessing;
+
+import java.nio.file.Path;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * This class runs tests with remote store + segRep while blocking file downloads
+ */
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
+public class SegmentReplicationUsingRemoteStoreDisruptionIT extends AbstractRemoteStoreMockRepositoryIntegTestCase {
+
+    @Override
+    public Settings indexSettings() {
+        return remoteStoreIndexSettings(1);
+    }
+
+    @Override
+    protected boolean addMockInternalEngine() {
+        return false;
+    }
+
+    public void testCancelReplicationWhileSyncingSegments() throws Exception {
+        Path location = randomRepoPath().toAbsolutePath();
+        setup(location, 0d, "metadata", Long.MAX_VALUE, 1);
+
+        final Set<String> dataNodeNames = internalCluster().getDataNodeNames();
+        final String replicaNode = getNode(dataNodeNames, false);
+        final String primaryNode = getNode(dataNodeNames, true);
+
+        SegmentReplicationTargetService targetService = internalCluster().getInstance(SegmentReplicationTargetService.class, replicaNode);
+        ensureGreen(INDEX_NAME);
+        blockNodeOnAnySegmentFile(REPOSITORY_NAME, replicaNode);
+        final IndexShard indexShard = getIndexShard(replicaNode, INDEX_NAME);
+        indexSingleDoc();
+        refresh(INDEX_NAME);
+        waitForBlock(replicaNode, REPOSITORY_NAME, TimeValue.timeValueSeconds(10));
+        final SegmentReplicationState state = targetService.getOngoingEventSegmentReplicationState(indexShard.shardId());
+        assertEquals(SegmentReplicationState.Stage.GET_FILES, state.getStage());
+        ReplicationCollection.ReplicationRef<SegmentReplicationTarget> segmentReplicationTargetReplicationRef = targetService.get(
+            state.getReplicationId()
+        );
+        final SegmentReplicationTarget segmentReplicationTarget = segmentReplicationTargetReplicationRef.get();
+        // close the target ref here otherwise it will hold a refcount
+        segmentReplicationTargetReplicationRef.close();
+        assertNotNull(segmentReplicationTarget);
+        assertTrue(segmentReplicationTarget.refCount() > 0);
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNode));
+        assertBusy(() -> {
+            assertTrue(indexShard.routingEntry().primary());
+            assertNull(targetService.getOngoingEventSegmentReplicationState(indexShard.shardId()));
+            assertEquals("Target should be closed", 0, segmentReplicationTarget.refCount());
+        });
+        unblockNode(REPOSITORY_NAME, replicaNode);
+        cleanupRepo();
+    }
+
+    public void testCancelReplicationWhileFetchingMetadata() throws Exception {
+        Path location = randomRepoPath().toAbsolutePath();
+        setup(location, 0d, "metadata", Long.MAX_VALUE, 1);
+
+        final Set<String> dataNodeNames = internalCluster().getDataNodeNames();
+        final String replicaNode = getNode(dataNodeNames, false);
+        final String primaryNode = getNode(dataNodeNames, true);
+
+        SegmentReplicationTargetService targetService = internalCluster().getInstance(SegmentReplicationTargetService.class, replicaNode);
+        ensureGreen(INDEX_NAME);
+        blockNodeOnAnyFiles(REPOSITORY_NAME, replicaNode);
+        final IndexShard indexShard = getIndexShard(replicaNode, INDEX_NAME);
+        indexSingleDoc();
+        refresh(INDEX_NAME);
+        waitForBlock(replicaNode, REPOSITORY_NAME, TimeValue.timeValueSeconds(10));
+        final SegmentReplicationState state = targetService.getOngoingEventSegmentReplicationState(indexShard.shardId());
+        assertEquals(SegmentReplicationState.Stage.GET_CHECKPOINT_INFO, state.getStage());
+        ReplicationCollection.ReplicationRef<SegmentReplicationTarget> segmentReplicationTargetReplicationRef = targetService.get(
+            state.getReplicationId()
+        );
+        final SegmentReplicationTarget segmentReplicationTarget = segmentReplicationTargetReplicationRef.get();
+        // close the target ref here otherwise it will hold a refcount
+        segmentReplicationTargetReplicationRef.close();
+        assertNotNull(segmentReplicationTarget);
+        assertTrue(segmentReplicationTarget.refCount() > 0);
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNode));
+        assertBusy(() -> {
+            assertTrue(indexShard.routingEntry().primary());
+            assertNull(targetService.getOngoingEventSegmentReplicationState(indexShard.shardId()));
+            assertEquals("Target should be closed", 0, segmentReplicationTarget.refCount());
+        });
+        unblockNode(REPOSITORY_NAME, replicaNode);
+        cleanupRepo();
+    }
+
+    public void testUpdateVisibleCheckpointWithLaggingClusterStateUpdates_primaryRelocation() throws Exception {
+        Path location = randomRepoPath().toAbsolutePath();
+        Settings nodeSettings = Settings.builder().put(buildRemoteStoreNodeAttributes(location, 0d, "metadata", Long.MAX_VALUE)).build();
+        internalCluster().startClusterManagerOnlyNode(nodeSettings);
+        internalCluster().startDataOnlyNodes(2, nodeSettings);
+        final Settings indexSettings = Settings.builder().put(indexSettings()).put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1).build();
+        createIndex(INDEX_NAME, indexSettings);
+        ensureGreen(INDEX_NAME);
+        final Set<String> dataNodeNames = internalCluster().getDataNodeNames();
+        final String replicaNode = getNode(dataNodeNames, false);
+        final String oldPrimary = getNode(dataNodeNames, true);
+
+        // index a doc.
+        client().prepareIndex(INDEX_NAME).setId("1").setSource("foo", randomInt()).get();
+        refresh(INDEX_NAME);
+
+        logger.info("--> start another node");
+        final String newPrimary = internalCluster().startDataOnlyNode(nodeSettings);
+        ClusterHealthResponse clusterHealthResponse = client().admin()
+            .cluster()
+            .prepareHealth()
+            .setWaitForEvents(Priority.LANGUID)
+            .setWaitForNodes("4")
+            .get();
+        assertEquals(clusterHealthResponse.isTimedOut(), false);
+
+        SlowClusterStateProcessing disruption = new SlowClusterStateProcessing(replicaNode, random(), 0, 0, 1000, 2000);
+        internalCluster().setDisruptionScheme(disruption);
+        disruption.startDisrupting();
+
+        // relocate the primary
+        logger.info("--> relocate the shard");
+        client().admin()
+            .cluster()
+            .prepareReroute()
+            .add(new MoveAllocationCommand(INDEX_NAME, 0, oldPrimary, newPrimary))
+            .execute()
+            .actionGet();
+        clusterHealthResponse = client().admin()
+            .cluster()
+            .prepareHealth()
+            .setWaitForEvents(Priority.LANGUID)
+            .setWaitForNoRelocatingShards(true)
+            .setTimeout(new TimeValue(5, TimeUnit.MINUTES))
+            .execute()
+            .actionGet();
+        assertEquals(clusterHealthResponse.isTimedOut(), false);
+
+        IndexShard newPrimary_shard = getIndexShard(newPrimary, INDEX_NAME);
+        IndexShard replica = getIndexShard(replicaNode, INDEX_NAME);
+        assertBusy(() -> {
+            assertEquals(
+                newPrimary_shard.getLatestReplicationCheckpoint().getSegmentInfosVersion(),
+                replica.getLatestReplicationCheckpoint().getSegmentInfosVersion()
+            );
+        });
+
+        assertBusy(() -> {
+            ClusterStatsResponse clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
+            ReplicationStats replicationStats = clusterStatsResponse.getIndicesStats().getSegments().getReplicationStats();
+            assertEquals(0L, replicationStats.maxBytesBehind);
+            assertEquals(0L, replicationStats.maxReplicationLag);
+            assertEquals(0L, replicationStats.totalBytesBehind);
+        });
+        disruption.stopDisrupting();
+        disableRepoConsistencyCheck("Remote Store Creates System Repository");
+        cleanupRepo();
+    }
+
+    private String getNode(Set<String> dataNodeNames, boolean primary) {
+        assertEquals(2, dataNodeNames.size());
+        for (String name : dataNodeNames) {
+            final IndexShard indexShard = getIndexShard(name, INDEX_NAME);
+            if (indexShard.routingEntry().primary() == primary) {
+                return name;
+            }
+        }
+        return null;
+    }
+
+    private IndexShard getIndexShard(String node, String indexName) {
+        final Index index = resolveIndex(indexName);
+        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, node);
+        IndexService indexService = indicesService.indexService(index);
+        assertNotNull(indexService);
+        final Optional<Integer> shardId = indexService.shardIds().stream().findFirst();
+        return shardId.map(indexService::getShard).orElse(null);
+    }
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java
index 45c3ef7f5bae5..23864c35ad154 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java
@@ -17,7 +17,6 @@
 import java.nio.file.Path;
 
 import static org.opensearch.remotestore.RemoteStoreBaseIntegTestCase.remoteStoreClusterSettings;
-import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 
 /**
  * This class runs Segment Replication Integ test suite with remote store enabled.
@@ -50,6 +49,6 @@ public void setup() {
 
     @After
     public void teardown() {
-        assertAcked(clusterAdmin().prepareDeleteRepository(REPOSITORY_NAME));
+        clusterAdmin().prepareCleanupRepository(REPOSITORY_NAME).get();
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationWithRemoteStorePressureIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationWithRemoteStorePressureIT.java
index 0da4d81a8871e..6cfc76b7e3223 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationWithRemoteStorePressureIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationWithRemoteStorePressureIT.java
@@ -17,7 +17,6 @@
 import java.nio.file.Path;
 
 import static org.opensearch.remotestore.RemoteStoreBaseIntegTestCase.remoteStoreClusterSettings;
-import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 
 /**
  * This class executes the SegmentReplicationPressureIT suite with remote store integration enabled.
@@ -49,6 +48,6 @@ public void setup() {
 
     @After
     public void teardown() {
-        assertAcked(clusterAdmin().prepareDeleteRepository(REPOSITORY_NAME));
+        clusterAdmin().prepareCleanupRepository(REPOSITORY_NAME).get();
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/RemoteStoreMultipartIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/RemoteStoreMultipartIT.java
index 21f48ba99e651..3dfde6f472525 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/RemoteStoreMultipartIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/RemoteStoreMultipartIT.java
@@ -46,8 +46,26 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Stream.concat(super.nodePlugins().stream(), Stream.of(MockFsRepositoryPlugin.class)).collect(Collectors.toList());
     }
 
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder()
+            .put(super.nodeSettings(nodeOrdinal))
+            .put(
+                remoteStoreClusterSettings(
+                    REPOSITORY_NAME,
+                    segmentRepoPath,
+                    MockFsRepositoryPlugin.TYPE,
+                    REPOSITORY_2_NAME,
+                    translogRepoPath,
+                    MockFsRepositoryPlugin.TYPE
+                )
+            )
+            .build();
+    }
+
     @Before
     public void setup() {
+        clusterSettingsSuppliedByTest = true;
         overrideBuildRepositoryMetadata = false;
         repositoryLocation = randomRepoPath();
         compress = randomBoolean();
@@ -86,11 +104,19 @@ public RepositoryMetadata buildRepositoryMetadata(DiscoveryNode node, String nam
         } else {
             return super.buildRepositoryMetadata(node, name);
         }
+
     }
 
     public void testRateLimitedRemoteUploads() throws Exception {
+        clusterSettingsSuppliedByTest = true;
         overrideBuildRepositoryMetadata = true;
-        internalCluster().startNode();
+        Settings.Builder clusterSettings = Settings.builder()
+            .put(remoteStoreClusterSettings(REPOSITORY_NAME, repositoryLocation, REPOSITORY_2_NAME, repositoryLocation));
+        clusterSettings.put(
+            String.format(Locale.getDefault(), "node.attr." + REMOTE_STORE_REPOSITORY_TYPE_ATTRIBUTE_KEY_FORMAT, REPOSITORY_NAME),
+            MockFsRepositoryPlugin.TYPE
+        );
+        internalCluster().startNode(clusterSettings.build());
         Client client = client();
         logger.info("-->  updating repository");
         assertAcked(
@@ -100,7 +126,6 @@ public void testRateLimitedRemoteUploads() throws Exception {
                 .setType(MockFsRepositoryPlugin.TYPE)
                 .setSettings(
                     Settings.builder()
-                        .put(BlobStoreRepository.SYSTEM_REPOSITORY_SETTING.getKey(), true)
                         .put("location", repositoryLocation)
                         .put("compress", compress)
                         .put("max_remote_upload_bytes_per_sec", "1kb")
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/mocks/MockFsAsyncBlobContainer.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/mocks/MockFsAsyncBlobContainer.java
index 079753de95680..36987ac2d4991 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/mocks/MockFsAsyncBlobContainer.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/multipart/mocks/MockFsAsyncBlobContainer.java
@@ -27,6 +27,7 @@
 import java.nio.file.StandardOpenOption;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
@@ -124,11 +125,11 @@ public void readBlobAsync(String blobName, ActionListener<ReadContext> listener)
                 long contentLength = listBlobs().get(blobName).length();
                 long partSize = contentLength / 10;
                 int numberOfParts = (int) ((contentLength % partSize) == 0 ? contentLength / partSize : (contentLength / partSize) + 1);
-                List<InputStreamContainer> blobPartStreams = new ArrayList<>();
+                List<ReadContext.StreamPartCreator> blobPartStreams = new ArrayList<>();
                 for (int partNumber = 0; partNumber < numberOfParts; partNumber++) {
                     long offset = partNumber * partSize;
                     InputStreamContainer blobPartStream = new InputStreamContainer(readBlob(blobName, offset, partSize), partSize, offset);
-                    blobPartStreams.add(blobPartStream);
+                    blobPartStreams.add(() -> CompletableFuture.completedFuture(blobPartStream));
                 }
                 ReadContext blobReadContext = new ReadContext(contentLength, blobPartStreams, null);
                 listener.onResponse(blobReadContext);
diff --git a/server/src/internalClusterTest/java/org/opensearch/repositories/RepositoriesServiceIT.java b/server/src/internalClusterTest/java/org/opensearch/repositories/RepositoriesServiceIT.java
index f149d538cc47a..b8415f4b41815 100644
--- a/server/src/internalClusterTest/java/org/opensearch/repositories/RepositoriesServiceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/repositories/RepositoriesServiceIT.java
@@ -108,4 +108,16 @@ public void testUpdateRepository() {
         final Repository updatedRepository = repositoriesService.repository(repositoryName);
         assertThat(updatedRepository, updated ? not(sameInstance(originalRepository)) : sameInstance(originalRepository));
     }
+
+    public void testSystemRepositoryCantBeCreated() {
+        internalCluster();
+        final String repositoryName = "test-repo";
+        final Client client = client();
+        final Settings.Builder repoSettings = Settings.builder().put("system_repository", true).put("location", randomRepoPath());
+
+        assertThrows(
+            RepositoryException.class,
+            () -> client.admin().cluster().preparePutRepository(repositoryName).setType(FsRepository.TYPE).setSettings(repoSettings).get()
+        );
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/script/ScriptCacheIT.java b/server/src/internalClusterTest/java/org/opensearch/script/ScriptCacheIT.java
index e125492d4b2c5..2fbaf4ea5a4d3 100644
--- a/server/src/internalClusterTest/java/org/opensearch/script/ScriptCacheIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/script/ScriptCacheIT.java
@@ -8,8 +8,11 @@
 
 package org.opensearch.script;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.index.MockEngineFactoryPlugin;
@@ -18,12 +21,13 @@
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.MockSearchService;
 import org.opensearch.test.MockHttpTransport;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.TestGeoShapeFieldMapperPlugin;
 import org.opensearch.test.store.MockFSIndexStore;
 import org.opensearch.test.transport.MockTransportService;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -31,9 +35,26 @@
 import java.util.concurrent.ExecutionException;
 import java.util.function.Function;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.apache.logging.log4j.core.util.Throwables.getRootCause;
 
-public class ScriptCacheIT extends OpenSearchIntegTestCase {
+public class ScriptCacheIT extends ParameterizedOpenSearchIntegTestCase {
+    public ScriptCacheIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     protected Settings nodeSettings(int nodeOrdinal) {
         Settings.Builder builder = Settings.builder()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/SearchTimeoutIT.java b/server/src/internalClusterTest/java/org/opensearch/search/SearchTimeoutIT.java
index 94816346e6c9e..52cc797ddd8da 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/SearchTimeoutIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/SearchTimeoutIT.java
@@ -93,6 +93,7 @@ public void testSimpleTimeout() throws Exception {
             client().prepareIndex("test").setId(Integer.toString(i)).setSource("field", "value").get();
         }
         refresh("test");
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setTimeout(new TimeValue(5, TimeUnit.MILLISECONDS))
@@ -104,12 +105,11 @@ public void testSimpleTimeout() throws Exception {
     }
 
     public void testSimpleDoesNotTimeout() throws Exception {
-        final int numDocs = 10;
+        final int numDocs = 9;
         for (int i = 0; i < numDocs; i++) {
-            client().prepareIndex("test").setId(Integer.toString(i)).setSource("field", "value").get();
+            client().prepareIndex("test").setId(Integer.toString(i)).setSource("field", "value").setRefreshPolicy(IMMEDIATE).get();
         }
-        refresh("test");
-
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch("test")
             .setTimeout(new TimeValue(10000, TimeUnit.SECONDS))
             .setQuery(scriptQuery(new Script(ScriptType.INLINE, "mockscript", SCRIPT_NAME, Collections.emptyMap())))
@@ -122,7 +122,7 @@ public void testSimpleDoesNotTimeout() throws Exception {
 
     public void testPartialResultsIntolerantTimeout() throws Exception {
         client().prepareIndex("test").setId("1").setSource("field", "value").setRefreshPolicy(IMMEDIATE).get();
-
+        indexRandomForConcurrentSearch("test");
         OpenSearchException ex = expectThrows(
             OpenSearchException.class,
             () -> client().prepareSearch("test")
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java b/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java
index 6fafdb0912470..aa1fe695ecc12 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java
@@ -16,6 +16,7 @@
 import org.opensearch.action.get.MultiGetRequest;
 import org.opensearch.action.get.MultiGetResponse;
 import org.opensearch.action.index.IndexRequestBuilder;
+import org.opensearch.action.search.SearchPhaseName;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodes;
@@ -56,9 +57,11 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import static org.opensearch.action.search.TransportSearchAction.SEARCH_REQUEST_STATS_ENABLED_KEY;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0, minNumDataNodes = 3)
@@ -74,6 +77,7 @@ public void testSearchWithWRRShardRouting() throws IOException {
             .put(AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_FORCE_GROUP_SETTING.getKey() + "zone" + ".values", "a,b,c")
             .put(AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING.getKey(), "zone")
             .put("cluster.routing.weighted.fail_open", false)
+            .put(SEARCH_REQUEST_STATS_ENABLED_KEY, true)
             .build();
 
         logger.info("--> starting 6 nodes on different zones");
@@ -180,12 +184,39 @@ public void testSearchWithWRRShardRouting() throws IOException {
             assertFalse(!hitNodes.contains(nodeId));
         }
         nodeStats = client().admin().cluster().prepareNodesStats().execute().actionGet();
+        int num = 0;
+        int coordNumber = 0;
 
         for (NodeStats stat : nodeStats.getNodes()) {
             SearchStats.Stats searchStats = stat.getIndices().getSearch().getTotal();
+            if (searchStats.getRequestStatsLongHolder()
+                .getRequestStatsHolder()
+                .get(SearchPhaseName.QUERY.getName())
+                .getTimeInMillis() > 0) {
+                assertThat(
+                    searchStats.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.QUERY.getName()).getTotal(),
+                    greaterThan(0L)
+                );
+                assertThat(
+                    searchStats.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.FETCH.getName()).getTimeInMillis(),
+                    greaterThan(0L)
+                );
+                assertThat(
+                    searchStats.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.FETCH.getName()).getTotal(),
+                    greaterThan(0L)
+                );
+                assertThat(
+                    searchStats.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.EXPAND.getName()).getTotal(),
+                    greaterThan(0L)
+                );
+                coordNumber += 1;
+            }
             Assert.assertTrue(searchStats.getQueryCount() > 0L);
             Assert.assertTrue(searchStats.getFetchCount() > 0L);
+            num++;
         }
+        assertThat(coordNumber, greaterThan(0));
+        assertThat(num, greaterThan(0));
     }
 
     private Map<String, List<String>> setupCluster(int nodeCountPerAZ, Settings commonSettings) {
@@ -470,8 +501,9 @@ public void testShardRoutingWithNetworkDisruption_FailOpenEnabled() throws Excep
 
         logger.info("--> creating network partition disruption");
         final String clusterManagerNode1 = internalCluster().getClusterManagerName();
-        Set<String> nodesInOneSide = Stream.of(clusterManagerNode1, nodeMap.get("b").get(0)).collect(Collectors.toCollection(HashSet::new));
-        Set<String> nodesInOtherSide = Stream.of(nodeMap.get("a").get(0)).collect(Collectors.toCollection(HashSet::new));
+        Set<String> nodesInOneSide = Stream.of(nodeMap.get("a").get(0)).collect(Collectors.toCollection(HashSet::new));
+        Set<String> nodesInOtherSide = Stream.of(clusterManagerNode1, nodeMap.get("b").get(0), nodeMap.get("c").get(0))
+            .collect(Collectors.toCollection(HashSet::new));
 
         NetworkDisruption networkDisruption = new NetworkDisruption(
             new NetworkDisruption.TwoPartitions(nodesInOneSide, nodesInOtherSide),
@@ -839,8 +871,7 @@ private void assertSearchInAZ(String az) {
             SearchStats.Stats searchStats = stat.getIndices().getSearch().getTotal();
             if (stat.getNode().isDataNode()) {
                 if (stat.getNode().getId().equals(dataNodeId)) {
-                    Assert.assertTrue(searchStats.getFetchCount() > 0L);
-                    Assert.assertTrue(searchStats.getQueryCount() > 0L);
+                    Assert.assertTrue(searchStats.getFetchCount() > 0L || searchStats.getQueryCount() > 0L);
                 }
             }
         }
@@ -914,7 +945,6 @@ public void testSearchAggregationWithNetworkDisruption_FailOpenEnabled() throws
         }
 
         logger.info("--> network disruption is stopped");
-        networkDisruption.stopDisrupting();
 
         for (int i = 0; i < 50; i++) {
             try {
@@ -931,6 +961,8 @@ public void testSearchAggregationWithNetworkDisruption_FailOpenEnabled() throws
                 fail("search should not fail");
             }
         }
+        networkDisruption.stopDisrupting();
+
         assertSearchInAZ("b");
         assertSearchInAZ("c");
         assertNoSearchInAZ("a");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/SearchWithRejectionsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/SearchWithRejectionsIT.java
index 87c6aa2202ff5..24c72a66da6d0 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/SearchWithRejectionsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/SearchWithRejectionsIT.java
@@ -32,20 +32,45 @@
 
 package org.opensearch.search;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchType;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.hamcrest.Matchers.equalTo;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE)
-public class SearchWithRejectionsIT extends OpenSearchIntegTestCase {
+public class SearchWithRejectionsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchWithRejectionsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public Settings nodeSettings(int nodeOrdinal) {
         return Settings.builder()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/StressSearchServiceReaperIT.java b/server/src/internalClusterTest/java/org/opensearch/search/StressSearchServiceReaperIT.java
index 42e515cca9b6b..a61102b9db144 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/StressSearchServiceReaperIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/StressSearchServiceReaperIT.java
@@ -31,23 +31,45 @@
 
 package org.opensearch.search;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.tests.util.English;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.concurrent.ExecutionException;
 
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.OpenSearchIntegTestCase.Scope.SUITE;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 
 @ClusterScope(scope = SUITE)
-public class StressSearchServiceReaperIT extends OpenSearchIntegTestCase {
+public class StressSearchServiceReaperIT extends ParameterizedOpenSearchIntegTestCase {
+    public StressSearchServiceReaperIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Settings nodeSettings(int nodeOrdinal) {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/AggregationsIntegrationIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/AggregationsIntegrationIT.java
index b73b7722f9728..257786c1e9ce5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/AggregationsIntegrationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/AggregationsIntegrationIT.java
@@ -32,11 +32,15 @@
 
 package org.opensearch.search.aggregations;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.bucket.terms.IncludeExclude;
 import org.opensearch.search.aggregations.bucket.terms.RareTermsAggregationBuilder;
 import org.opensearch.search.aggregations.bucket.terms.SignificantTermsAggregationBuilder;
@@ -45,16 +49,20 @@
 import org.opensearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
 import org.opensearch.search.aggregations.bucket.terms.TermsAggregatorFactory;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class AggregationsIntegrationIT extends OpenSearchIntegTestCase {
+public class AggregationsIntegrationIT extends ParameterizedOpenSearchIntegTestCase {
 
     static int numDocs;
 
@@ -63,6 +71,23 @@ public class AggregationsIntegrationIT extends OpenSearchIntegTestCase {
         + LARGE_STRING.length()
         + "] used in the request has exceeded the allowed maximum";
 
+    public AggregationsIntegrationIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(prepareCreate("index").setMapping("f", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/CombiIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/CombiIT.java
index d35a560b0986c..3d3cf1943dfe3 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/CombiIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/CombiIT.java
@@ -32,20 +32,27 @@
 
 package org.opensearch.search.aggregations;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.missing.Missing;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.missing;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -54,7 +61,24 @@
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.core.IsNull.notNullValue;
 
-public class CombiIT extends OpenSearchIntegTestCase {
+public class CombiIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public CombiIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     /**
      * Making sure that if there are multiple aggregations, working on the same field, yet require different
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/EquivalenceIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/EquivalenceIT.java
index 21f833d5430db..2ffdf5fb32778 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/EquivalenceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/EquivalenceIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.search.aggregations;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.index.query.RangeQueryBuilder;
@@ -52,11 +56,12 @@
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.search.aggregations.bucket.terms.TermsAggregatorFactory;
 import org.opensearch.search.aggregations.metrics.Sum;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.After;
 import org.junit.Before;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -68,6 +73,7 @@
 import java.util.function.Function;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.extendedStats;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -88,7 +94,24 @@
  * Additional tests that aim at testing more complex aggregation trees on larger random datasets, so that things like
  * the growth of dynamic arrays is tested.
  */
-public class EquivalenceIT extends OpenSearchIntegTestCase {
+public class EquivalenceIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public EquivalenceIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/MetadataIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/MetadataIT.java
index f210af7c10fb3..1bc0cb36f5fe3 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/MetadataIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/MetadataIT.java
@@ -32,25 +32,49 @@
 
 package org.opensearch.search.aggregations;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.InternalBucketMetricValue;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 import static org.opensearch.search.aggregations.PipelineAggregatorBuilders.maxBucket;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 
-public class MetadataIT extends OpenSearchIntegTestCase {
+public class MetadataIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MetadataIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public void testMetadataSetOnAggregationResult() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("name", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/AdjacencyMatrixIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/AdjacencyMatrixIT.java
index 011ebf8add92a..cd0922606ec99 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/AdjacencyMatrixIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/AdjacencyMatrixIT.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.query.BoolQueryBuilder;
@@ -47,15 +50,19 @@
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.metrics.Avg;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.adjacencyMatrix;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -68,11 +75,28 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class AdjacencyMatrixIT extends OpenSearchIntegTestCase {
+public class AdjacencyMatrixIT extends ParameterizedOpenSearchIntegTestCase {
 
     static int numDocs, numSingleTag1Docs, numSingleTag2Docs, numTag1Docs, numTag2Docs, numMultiTagDocs;
     static final int MAX_NUM_FILTERS = 3;
 
+    public AdjacencyMatrixIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/BooleanTermsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/BooleanTermsIT.java
index fc5407c4cade8..7ab1a44ce220c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/BooleanTermsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/BooleanTermsIT.java
@@ -31,26 +31,52 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class BooleanTermsIT extends OpenSearchIntegTestCase {
+public class BooleanTermsIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "b_value";
     private static final String MULTI_VALUED_FIELD_NAME = "b_values";
 
     static int numSingleTrues, numSingleFalses, numMultiTrues, numMultiFalses;
 
+    public BooleanTermsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramIT.java
index ec7278f74e8af..ee94e574228df 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramIT.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
@@ -39,6 +41,7 @@
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.time.DateFormatters;
 import org.opensearch.common.time.DateMathParser;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.mapper.DateFieldMapper;
 import org.opensearch.index.query.MatchNoneQueryBuilder;
 import org.opensearch.index.query.QueryBuilders;
@@ -56,6 +59,7 @@
 import org.opensearch.search.aggregations.metrics.Avg;
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 import org.junit.After;
 
@@ -78,6 +82,7 @@
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateHistogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -93,7 +98,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class DateHistogramIT extends OpenSearchIntegTestCase {
+public class DateHistogramIT extends ParameterizedOpenSearchIntegTestCase {
 
     static Map<ZonedDateTime, Map<String, Object>> expectedMultiSortBuckets;
 
@@ -101,8 +106,25 @@ private ZonedDateTime date(int month, int day) {
         return ZonedDateTime.of(2012, month, day, 0, 0, 0, 0, ZoneOffset.UTC);
     }
 
+    public DateHistogramIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private ZonedDateTime date(String date) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(date));
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(date));
     }
 
     private static String format(ZonedDateTime date, String pattern) {
@@ -1459,7 +1481,7 @@ public void testExceptionOnNegativeInterval() {
     /**
      * https://github.com/elastic/elasticsearch/issues/31760 shows an edge case where an unmapped "date" field in two indices
      * that are queried simultaneously can lead to the "format" parameter in the aggregation not being preserved correctly.
-     *
+     * <p>
      * The error happens when the bucket from the "unmapped" index is received first in the reduce phase, however the case can
      * be recreated when aggregating about a single index with an unmapped date field and also getting "empty" buckets.
      */
@@ -1602,8 +1624,8 @@ public void testScriptCaching() throws Exception {
                 .setSettings(Settings.builder().put("requests.cache.enable", true).put("number_of_shards", 1).put("number_of_replicas", 1))
                 .get()
         );
-        String date = DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.format(date(1, 1));
-        String date2 = DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.format(date(2, 1));
+        String date = DateFieldMapper.getDefaultDateTimeFormatter().format(date(1, 1));
+        String date2 = DateFieldMapper.getDefaultDateTimeFormatter().format(date(2, 1));
         indexRandom(
             true,
             client().prepareIndex("cache_test_idx").setId("1").setSource("d", date),
@@ -1733,6 +1755,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        cluster().wipeIndices("cache_test_idx");
     }
 
     public void testSingleValuedFieldOrderedBySingleValueSubAggregationAscAndKeyDesc() throws Exception {
@@ -1850,6 +1873,7 @@ public void testDateNanosHistogram() throws Exception {
         assertEquals(1, buckets.get(0).getDocCount());
         assertEquals(946771200000L, ((ZonedDateTime) buckets.get(1).getKey()).toEpochSecond() * 1000);
         assertEquals(1, buckets.get(1).getDocCount());
+        cluster().wipeIndices("nanos");
     }
 
     public void testDateKeyFormatting() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramOffsetIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramOffsetIT.java
index 19e5bdb8916b8..d44071e1ef9c5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramOffsetIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateHistogramOffsetIT.java
@@ -31,24 +31,32 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.time.DateFormatters;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.mapper.DateFieldMapper;
 import org.opensearch.search.aggregations.bucket.histogram.DateHistogramInterval;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.After;
 import org.junit.Before;
 
 import java.io.IOException;
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateHistogram;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.core.IsNull.notNullValue;
@@ -61,13 +69,30 @@
  */
 @OpenSearchIntegTestCase.SuiteScopeTestCase
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE)
-public class DateHistogramOffsetIT extends OpenSearchIntegTestCase {
+public class DateHistogramOffsetIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String DATE_FORMAT = "yyyy-MM-dd:hh-mm-ss";
     private static final DateFormatter FORMATTER = DateFormatter.forPattern(DATE_FORMAT);
 
+    public DateHistogramOffsetIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private ZonedDateTime date(String date) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(date));
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(date));
     }
 
     @Before
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateRangeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateRangeIT.java
index 470ee6a4d2cea..ae4243019ffb1 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateRangeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DateRangeIT.java
@@ -31,11 +31,14 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.Script;
 import org.opensearch.script.ScriptType;
@@ -46,6 +49,7 @@
 import org.opensearch.search.aggregations.bucket.range.Range.Bucket;
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.time.ZoneId;
@@ -63,6 +67,7 @@
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateRange;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
@@ -76,7 +81,24 @@
 import static org.hamcrest.core.IsNull.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class DateRangeIT extends OpenSearchIntegTestCase {
+public class DateRangeIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public DateRangeIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     private static IndexRequestBuilder indexDoc(int month, int day, int value) throws Exception {
         return client().prepareIndex("idx")
@@ -1062,6 +1084,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
     /**
@@ -1124,6 +1147,7 @@ public void testRangeWithFormatStringValue() throws Exception {
                 .get()
         );
         assertThat(e.getDetailedMessage(), containsString("failed to parse date field [1000000] with format [strict_hour_minute_second]"));
+        internalCluster().wipeIndices(indexName);
     }
 
     /**
@@ -1196,6 +1220,7 @@ public void testRangeWithFormatNumericValue() throws Exception {
         buckets = checkBuckets(searchResponse.getAggregations().get("date_range"), "date_range", 2);
         assertBucket(buckets.get(0), 2L, "1000000-3000000", 1000000L, 3000000L);
         assertBucket(buckets.get(1), 1L, "3000000-4000000", 3000000L, 4000000L);
+        internalCluster().wipeIndices(indexName);
     }
 
     private static List<Range.Bucket> checkBuckets(Range dateRange, String expectedAggName, long expectedBucketsSize) {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
index 0d133a933df1f..1d5f7f93e7410 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
@@ -31,10 +31,13 @@
 
 package org.opensearch.search.aggregations.bucket;
 
-import org.opensearch.action.admin.indices.refresh.RefreshRequest;
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchType;
+import org.opensearch.action.support.WriteRequest;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.TermQueryBuilder;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.sampler.DiversifiedAggregationBuilder;
@@ -45,12 +48,15 @@
 import org.opensearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
 import org.opensearch.search.aggregations.metrics.Max;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.max;
 import static org.opensearch.search.aggregations.AggregationBuilders.sampler;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -65,10 +71,27 @@
  * Tests the Sampler aggregation
  */
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class DiversifiedSamplerIT extends OpenSearchIntegTestCase {
+public class DiversifiedSamplerIT extends ParameterizedOpenSearchIntegTestCase {
 
     public static final int NUM_SHARDS = 2;
 
+    public DiversifiedSamplerIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     public String randomExecutionHint() {
         return randomBoolean() ? null : randomFrom(SamplerAggregator.ExecutionMode.values()).toString();
     }
@@ -109,13 +132,14 @@ public void setupSuiteScopeCluster() throws Exception {
             client().prepareIndex("test")
                 .setId("" + i)
                 .setSource("author", parts[5], "name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
             client().prepareIndex("idx_unmapped_author")
                 .setId("" + i)
                 .setSource("name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
         }
-        client().admin().indices().refresh(new RefreshRequest("test")).get();
     }
 
     public void testIssue10719() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DoubleTermsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DoubleTermsIT.java
index b740271cdef77..88bb41923e53f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DoubleTermsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DoubleTermsIT.java
@@ -88,6 +88,10 @@
 @OpenSearchIntegTestCase.SuiteScopeTestCase
 public class DoubleTermsIT extends AbstractTermsTestCase {
 
+    public DoubleTermsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
@@ -1106,5 +1110,6 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FilterIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FilterIT.java
index ef455bf353ce4..7aa98803403e0 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FilterIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FilterIT.java
@@ -31,9 +31,13 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
@@ -42,14 +46,18 @@
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.metrics.Avg;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -60,10 +68,27 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class FilterIT extends OpenSearchIntegTestCase {
+public class FilterIT extends ParameterizedOpenSearchIntegTestCase {
 
     static int numDocs, numTag1Docs;
 
+    public FilterIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FiltersIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FiltersIT.java
index 4c5033b957d00..b6cf515df78ba 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FiltersIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/FiltersIT.java
@@ -32,9 +32,13 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
@@ -44,6 +48,7 @@
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.metrics.Avg;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
@@ -56,6 +61,7 @@
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.filters;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -66,10 +72,27 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class FiltersIT extends OpenSearchIntegTestCase {
+public class FiltersIT extends ParameterizedOpenSearchIntegTestCase {
 
     static int numDocs, numTag1Docs, numTag2Docs, numOtherDocs;
 
+    public FiltersIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GeoDistanceIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GeoDistanceIT.java
index 6d99424989fd7..025bebf8b254d 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GeoDistanceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GeoDistanceIT.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.Version;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
@@ -39,6 +41,7 @@
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.DistanceUnit;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.InternalAggregation;
@@ -47,17 +50,20 @@
 import org.opensearch.search.aggregations.bucket.range.Range.Bucket;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.VersionUtils;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.geoDistance;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -70,7 +76,11 @@
 import static org.hamcrest.core.IsNull.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class GeoDistanceIT extends OpenSearchIntegTestCase {
+public class GeoDistanceIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public GeoDistanceIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
 
     @Override
     protected boolean forbidPrivateIndexSettings() {
@@ -79,6 +89,19 @@ protected boolean forbidPrivateIndexSettings() {
 
     private Version version = VersionUtils.randomIndexCompatibleVersion(random());
 
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private IndexRequestBuilder indexCity(String idx, String name, String... latLons) throws Exception {
         XContentBuilder source = jsonBuilder().startObject().field("city", name);
         source.startArray("location");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GlobalIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GlobalIT.java
index 8a97d9c9e75dd..be31a3afadad0 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GlobalIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/GlobalIT.java
@@ -31,19 +31,27 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.aggregations.InternalAggregation;
 import org.opensearch.search.aggregations.bucket.global.Global;
 import org.opensearch.search.aggregations.metrics.Stats;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.global;
 import static org.opensearch.search.aggregations.AggregationBuilders.stats;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
@@ -53,10 +61,27 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class GlobalIT extends OpenSearchIntegTestCase {
+public class GlobalIT extends ParameterizedOpenSearchIntegTestCase {
 
     static int numDocs;
 
+    public GlobalIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/HistogramIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/HistogramIT.java
index 6d5918ffa7f0d..75f57d1cc4c0e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/HistogramIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/HistogramIT.java
@@ -31,11 +31,14 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.MockScriptPlugin;
@@ -53,10 +56,12 @@
 import org.opensearch.search.aggregations.metrics.Stats;
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -69,6 +74,7 @@
 import static java.util.Collections.emptyMap;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -85,7 +91,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class HistogramIT extends OpenSearchIntegTestCase {
+public class HistogramIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
     private static final String MULTI_VALUED_FIELD_NAME = "l_values";
@@ -96,6 +102,23 @@ public class HistogramIT extends OpenSearchIntegTestCase {
     static long[] valueCounts, valuesCounts;
     static Map<Long, Map<String, Object>> expectedMultiSortBuckets;
 
+    public HistogramIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
@@ -1144,6 +1167,7 @@ public void testDecimalIntervalAndOffset() throws Exception {
         assertEquals(1, buckets.get(0).getDocCount());
         assertEquals(0.05, (double) buckets.get(1).getKey(), 0.01d);
         assertEquals(1, buckets.get(1).getDocCount());
+        internalCluster().wipeIndices("decimal_values");
     }
 
     /**
@@ -1285,6 +1309,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
     public void testSingleValuedFieldOrderedBySingleValueSubAggregationAscAndKeyDesc() throws Exception {
@@ -1388,6 +1413,7 @@ public void testHardBounds() throws Exception {
         buckets = histogram.getBuckets();
         assertEquals(1, buckets.size());
         assertEquals(0.1, (double) buckets.get(0).getKey(), 0.01d);
+        internalCluster().wipeIndices("test");
 
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpRangeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpRangeIT.java
index f8f666aaa3c1b..14a3685bd183e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpRangeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpRangeIT.java
@@ -31,9 +31,13 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.health.ClusterHealthStatus;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.MockScriptPlugin;
 import org.opensearch.script.Script;
@@ -41,6 +45,7 @@
 import org.opensearch.search.aggregations.AggregationBuilders;
 import org.opensearch.search.aggregations.bucket.range.Range;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.Arrays;
 import java.util.Collection;
@@ -48,13 +53,31 @@
 import java.util.Map;
 import java.util.function.Function;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.instanceOf;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class IpRangeIT extends OpenSearchIntegTestCase {
+public class IpRangeIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public IpRangeIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public static class DummyScriptPlugin extends MockScriptPlugin {
         @Override
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpTermsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpTermsIT.java
index cff51e74fdbd0..c712c97af5c71 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpTermsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/IpTermsIT.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.aggregations.bucket;
 
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.Script;
@@ -50,6 +51,10 @@
 
 public class IpTermsIT extends AbstractTermsTestCase {
 
+    public IpTermsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/LongTermsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/LongTermsIT.java
index f3d77ac1236be..345cbdae8ef07 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/LongTermsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/LongTermsIT.java
@@ -86,6 +86,10 @@
 @OpenSearchIntegTestCase.SuiteScopeTestCase
 public class LongTermsIT extends AbstractTermsTestCase {
 
+    public LongTermsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
@@ -1054,5 +1058,6 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MinDocCountIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MinDocCountIT.java
index 4c5d9fb60d4f7..90dafc0d57887 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MinDocCountIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MinDocCountIT.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.index.query.QueryBuilder;
@@ -81,6 +82,10 @@ public class MinDocCountIT extends AbstractTermsTestCase {
     private static final QueryBuilder QUERY = QueryBuilders.termQuery("match", true);
     private static int cardinality;
 
+    public MinDocCountIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MultiTermsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MultiTermsIT.java
index 950f7560dfea3..ea5a59d89309f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MultiTermsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/MultiTermsIT.java
@@ -9,6 +9,7 @@
 package org.opensearch.search.aggregations.bucket;
 
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.script.Script;
 import org.opensearch.script.ScriptType;
 import org.opensearch.search.aggregations.bucket.terms.BaseStringTermsTestCase;
@@ -33,6 +34,10 @@
 @OpenSearchIntegTestCase.SuiteScopeTestCase
 public class MultiTermsIT extends BaseStringTermsTestCase {
 
+    public MultiTermsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     // the main purpose of this test is to make sure we're not allocating 2GB of memory per shard
     public void testSizeIsZero() {
         final int minDocCount = randomInt(1);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java
index 3b3f169f7578b..6289cd5e36151 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NaNSortingIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.Comparators;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.search.aggregations.Aggregation;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
@@ -47,8 +51,13 @@
 import org.opensearch.search.aggregations.support.ValuesSource;
 import org.opensearch.search.aggregations.support.ValuesSourceAggregationBuilder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.extendedStats;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -58,7 +67,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class NaNSortingIT extends OpenSearchIntegTestCase {
+public class NaNSortingIT extends ParameterizedOpenSearchIntegTestCase {
 
     private enum SubAggregation {
         AVG("avg") {
@@ -130,6 +139,23 @@ public String sortKey() {
         public abstract double getValue(Aggregation aggregation);
     }
 
+    public NaNSortingIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("string_value", "type=keyword").get());
@@ -146,6 +172,7 @@ public void setupSuiteScopeCluster() throws Exception {
             client().prepareIndex("idx").setSource(source.endObject()).get();
         }
         refresh();
+        indexRandomForMultipleSlices("idx");
         ensureSearchable();
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NestedIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NestedIT.java
index 7efb16c8b719c..7af2ac218800d 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NestedIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/NestedIT.java
@@ -31,12 +31,15 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.join.ScoreMode;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -54,9 +57,12 @@
 import org.opensearch.search.aggregations.metrics.Stats;
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
@@ -66,6 +72,7 @@
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.nestedQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.max;
@@ -85,12 +92,29 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class NestedIT extends OpenSearchIntegTestCase {
+public class NestedIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static int numParents;
     private static int[] numChildren;
     private static SubAggCollectionMode aggCollectionMode;
 
+    public NestedIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
 
@@ -200,6 +224,7 @@ public void setupSuiteScopeCluster() throws Exception {
                 )
         );
         indexRandom(true, builders);
+        indexRandomForMultipleSlices("idx");
         ensureSearchable();
     }
 
@@ -330,6 +355,7 @@ public void testNestedAsSubAggregation() throws Exception {
     }
 
     public void testNestNestedAggs() throws Exception {
+        indexRandomForConcurrentSearch("idx_nested_nested_aggs");
         SearchResponse response = client().prepareSearch("idx_nested_nested_aggs")
             .addAggregation(
                 nested("level1", "nested1").subAggregation(
@@ -532,6 +558,7 @@ public void testParentFilterResolvedCorrectly() throws Exception {
         assertThat(nestedTags.getDocCount(), equalTo(0L)); // This must be 0
         tags = nestedTags.getAggregations().get("tag");
         assertThat(tags.getBuckets().size(), equalTo(0)); // and this must be empty
+        internalCluster().wipeIndices("idx2");
     }
 
     public void testNestedSameDocIdProcessedMultipleTime() throws Exception {
@@ -582,6 +609,7 @@ public void testNestedSameDocIdProcessedMultipleTime() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("idx4");
 
         SearchResponse response = client().prepareSearch("idx4")
             .addAggregation(
@@ -638,6 +666,7 @@ public void testNestedSameDocIdProcessedMultipleTime() throws Exception {
         assertThat(propertyId.getBucketByKey("1").getDocCount(), equalTo(1L));
         assertThat(propertyId.getBucketByKey("2").getDocCount(), equalTo(1L));
         assertThat(propertyId.getBucketByKey("3").getDocCount(), equalTo(1L));
+        internalCluster().wipeIndices("idx4");
     }
 
     public void testFilterAggInsideNestedAgg() throws Exception {
@@ -756,6 +785,7 @@ public void testFilterAggInsideNestedAgg() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("classes");
 
         SearchResponse response = client().prepareSearch("classes")
             .addAggregation(
@@ -800,6 +830,7 @@ public void testFilterAggInsideNestedAgg() throws Exception {
         assertThat(bucket.getDocCount(), equalTo(1L));
         numStringParams = bucket.getAggregations().get("num_string_params");
         assertThat(numStringParams.getDocCount(), equalTo(0L));
+        internalCluster().wipeIndices("classes");
     }
 
     public void testExtractInnerHitBuildersWithDuplicateHitName() throws Exception {
@@ -824,6 +855,7 @@ public void testExtractInnerHitBuildersWithDuplicateHitName() throws Exception {
             RestStatus.BAD_REQUEST,
             containsString("[inner_hits] already contains an entry for key [ih1]")
         );
+        internalCluster().wipeIndices("idxduplicatehitnames");
     }
 
     public void testExtractInnerHitBuildersWithDuplicatePath() throws Exception {
@@ -846,5 +878,6 @@ public void testExtractInnerHitBuildersWithDuplicatePath() throws Exception {
             RestStatus.BAD_REQUEST,
             containsString("[inner_hits] already contains an entry for key [property]")
         );
+        internalCluster().wipeIndices("idxnullhitnames");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/RangeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/RangeIT.java
index c46d6dcd847e1..5812b7796c33e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/RangeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/RangeIT.java
@@ -31,10 +31,13 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.Script;
@@ -48,9 +51,11 @@
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -60,6 +65,7 @@
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.range;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
@@ -73,13 +79,30 @@
 import static org.hamcrest.core.IsNull.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class RangeIT extends OpenSearchIntegTestCase {
+public class RangeIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
     private static final String MULTI_VALUED_FIELD_NAME = "l_values";
 
     static int numDocs;
 
+    public RangeIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
@@ -161,6 +184,7 @@ public void setupSuiteScopeCluster() throws Exception {
         builders.add(client().prepareIndex("new_index").setSource(Collections.emptyMap()));
 
         indexRandom(true, builders);
+        indexRandomForMultipleSlices("idx", "old_index", "new_index");
         ensureSearchable();
     }
 
@@ -894,6 +918,7 @@ public void testOverlappingRanges() throws Exception {
     }
 
     public void testEmptyAggregation() throws Exception {
+        indexRandomForConcurrentSearch("empty_bucket_idx");
         SearchResponse searchResponse = client().prepareSearch("empty_bucket_idx")
             .setQuery(matchAllQuery())
             .addAggregation(
@@ -1061,6 +1086,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
     public void testFieldAlias() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ReverseNestedIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ReverseNestedIT.java
index 749f2170dab50..2716db6b7e745 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ReverseNestedIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ReverseNestedIT.java
@@ -31,9 +31,12 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.BucketOrder;
@@ -44,9 +47,11 @@
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.search.aggregations.metrics.ValueCount;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
@@ -55,6 +60,7 @@
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.count;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.nested;
@@ -70,7 +76,24 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class ReverseNestedIT extends OpenSearchIntegTestCase {
+public class ReverseNestedIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public ReverseNestedIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     public void setupSuiteScopeCluster() throws Exception {
@@ -726,6 +749,7 @@ public void testSameParentDocHavingMultipleBuckets() throws Exception {
             ValueCount barCount = reverseToBar.getAggregations().get("sku_count");
             assertThat(barCount.getValue(), equalTo(2L));
         }
+        internalCluster().wipeIndices("idx3");
     }
 
     public void testFieldAlias() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java
index 587bf2a707710..c7b03d21cb6bb 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java
@@ -32,10 +32,13 @@
 
 package org.opensearch.search.aggregations.bucket;
 
-import org.opensearch.action.admin.indices.refresh.RefreshRequest;
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchType;
+import org.opensearch.action.support.WriteRequest;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.TermQueryBuilder;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.sampler.Sampler;
@@ -45,11 +48,15 @@
 import org.opensearch.search.aggregations.bucket.terms.Terms.Bucket;
 import org.opensearch.search.aggregations.metrics.Max;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.max;
 import static org.opensearch.search.aggregations.AggregationBuilders.sampler;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -64,7 +71,7 @@
  * Tests the Sampler aggregation
  */
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class SamplerIT extends OpenSearchIntegTestCase {
+public class SamplerIT extends ParameterizedOpenSearchIntegTestCase {
 
     public static final int NUM_SHARDS = 2;
 
@@ -72,6 +79,23 @@ public String randomExecutionHint() {
         return randomBoolean() ? null : randomFrom(SamplerAggregator.ExecutionMode.values()).toString();
     }
 
+    public SamplerIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(
@@ -108,13 +132,14 @@ public void setupSuiteScopeCluster() throws Exception {
             client().prepareIndex("test")
                 .setId("" + i)
                 .setSource("author", parts[5], "name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
             client().prepareIndex("idx_unmapped_author")
                 .setId("" + i)
                 .setSource("name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
         }
-        client().admin().indices().refresh(new RefreshRequest("test")).get();
     }
 
     public void testIssue10719() throws Exception {
@@ -171,6 +196,23 @@ public void testSimpleSampler() throws Exception {
         assertThat(maxBooksPerAuthor, equalTo(3L));
     }
 
+    public void testSimpleSamplerShardSize() throws Exception {
+        final int SHARD_SIZE = randomIntBetween(1, 3);
+        SamplerAggregationBuilder sampleAgg = sampler("sample").shardSize(SHARD_SIZE);
+        sampleAgg.subAggregation(terms("authors").field("author"));
+        SearchResponse response = client().prepareSearch("test")
+            .setSearchType(SearchType.QUERY_THEN_FETCH)
+            .setQuery(new TermQueryBuilder("genre", "fantasy"))
+            .setFrom(0)
+            .setSize(60)
+            .addAggregation(sampleAgg)
+            .get();
+        assertSearchResponse(response);
+        Sampler sample = response.getAggregations().get("sample");
+        Terms authors = sample.getAggregations().get("authors");
+        assertEquals(SHARD_SIZE * NUM_SHARDS, sample.getDocCount());
+    }
+
     public void testUnmappedChildAggNoDiversity() throws Exception {
         SamplerAggregationBuilder sampleAgg = sampler("sample").shardSize(100);
         sampleAgg.subAggregation(terms("authors").field("author"));
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardReduceIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardReduceIT.java
index faa6a54394b00..66d761c56634e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardReduceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardReduceIT.java
@@ -31,8 +31,12 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.geometry.utils.Geohash;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
@@ -45,8 +49,13 @@
 import org.opensearch.search.aggregations.bucket.range.Range;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateHistogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateRange;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
@@ -68,7 +77,24 @@
  * we can make sure that the reduce is properly propagated by checking that empty buckets were created.
  */
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class ShardReduceIT extends OpenSearchIntegTestCase {
+public class ShardReduceIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public ShardReduceIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     private IndexRequestBuilder indexDoc(String date, int value) throws Exception {
         return client().prepareIndex("idx")
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardSizeTermsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardSizeTermsIT.java
index c89a694271703..145830f02ee56 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardSizeTermsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/ShardSizeTermsIT.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.aggregations.bucket;
 
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
@@ -45,6 +46,11 @@
 import static org.hamcrest.Matchers.equalTo;
 
 public class ShardSizeTermsIT extends ShardSizeTestCase {
+
+    public ShardSizeTermsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     public void testNoShardSizeString() throws Exception {
         createIdx("type=keyword");
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java
index 5bf403d19ed9f..e914b87754865 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java
@@ -31,11 +31,14 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.ToXContent;
@@ -62,6 +65,7 @@
 import org.opensearch.search.aggregations.bucket.terms.heuristic.ScriptHeuristic;
 import org.opensearch.search.aggregations.bucket.terms.heuristic.SignificanceHeuristic;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.search.aggregations.bucket.SharedSignificantTermsTestMethods;
 
 import java.io.IOException;
@@ -78,6 +82,7 @@
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.significantTerms;
 import static org.opensearch.search.aggregations.AggregationBuilders.significantText;
@@ -90,12 +95,29 @@
 import static org.hamcrest.Matchers.is;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE)
-public class SignificantTermsSignificanceScoreIT extends OpenSearchIntegTestCase {
+public class SignificantTermsSignificanceScoreIT extends ParameterizedOpenSearchIntegTestCase {
 
     static final String INDEX_NAME = "testidx";
     static final String TEXT_FIELD = "text";
     static final String CLASS_FIELD = "class";
 
+    public SignificantTermsSignificanceScoreIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(TestScriptPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsDocCountErrorIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsDocCountErrorIT.java
index 63385b55f47e8..b355ce6d7a8dd 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsDocCountErrorIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsDocCountErrorIT.java
@@ -32,23 +32,30 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.search.aggregations.bucket.terms.Terms.Bucket;
 import org.opensearch.search.aggregations.bucket.terms.TermsAggregatorFactory.ExecutionMode;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
@@ -60,7 +67,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class TermsDocCountErrorIT extends OpenSearchIntegTestCase {
+public class TermsDocCountErrorIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String STRING_FIELD_NAME = "s_value";
     private static final String LONG_FIELD_NAME = "l_value";
@@ -72,6 +79,23 @@ public static String randomExecutionHint() {
 
     private static int numRoutingValues;
 
+    public TermsDocCountErrorIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping(STRING_FIELD_NAME, "type=keyword").get());
@@ -201,6 +225,7 @@ public void setupSuiteScopeCluster() throws Exception {
         }
 
         indexRandom(true, builders);
+        indexRandomForMultipleSlices("idx");
         ensureSearchable();
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsShardMinDocCountIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsShardMinDocCountIT.java
index e7e826d981c84..b0d8e7ea02e8f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsShardMinDocCountIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/TermsShardMinDocCountIT.java
@@ -31,9 +31,12 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.aggregations.BucketOrder;
@@ -41,13 +44,16 @@
 import org.opensearch.search.aggregations.bucket.terms.SignificantTerms;
 import org.opensearch.search.aggregations.bucket.terms.SignificantTermsAggregatorFactory;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.significantTerms;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -55,9 +61,27 @@
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 import static org.hamcrest.Matchers.equalTo;
 
-public class TermsShardMinDocCountIT extends OpenSearchIntegTestCase {
+public class TermsShardMinDocCountIT extends ParameterizedOpenSearchIntegTestCase {
+
     private static final String index = "someindex";
 
+    public TermsShardMinDocCountIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private static String randomExecutionHint() {
         return randomBoolean() ? null : randomFrom(SignificantTermsAggregatorFactory.ExecutionMode.values()).toString();
     }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/BaseStringTermsTestCase.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/BaseStringTermsTestCase.java
index 969cbf272fab0..20caa4fd076fe 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/BaseStringTermsTestCase.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/BaseStringTermsTestCase.java
@@ -9,6 +9,7 @@
 package org.opensearch.search.aggregations.bucket.terms;
 
 import org.opensearch.action.index.IndexRequestBuilder;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.Strings;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.plugins.Plugin;
@@ -37,6 +38,10 @@ public class BaseStringTermsTestCase extends AbstractTermsTestCase {
     protected static final String MULTI_VALUED_FIELD_NAME = "s_values";
     protected static Map<String, Map<String, Object>> expectedMultiSortBuckets;
 
+    public BaseStringTermsTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/StringTermsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/StringTermsIT.java
index 1f1da9627d5ea..8c727d280ec52 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/StringTermsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/terms/StringTermsIT.java
@@ -79,6 +79,10 @@
 @OpenSearchIntegTestCase.SuiteScopeTestCase
 public class StringTermsIT extends BaseStringTermsTestCase {
 
+    public StringTermsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     // the main purpose of this test is to make sure we're not allocating 2GB of memory per shard
     public void testSizeIsZero() {
         final int minDocCount = randomInt(1);
@@ -1127,6 +1131,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
     public void testScriptWithValueType() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityIT.java
index 147f451c14de8..9ebec21367164 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityIT.java
@@ -32,9 +32,12 @@
 
 package org.opensearch.search.aggregations.metrics;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.MockScriptPlugin;
@@ -45,7 +48,9 @@
 import org.opensearch.search.aggregations.bucket.global.Global;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -55,6 +60,7 @@
 import static java.util.Collections.emptyMap;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.cardinality;
 import static org.opensearch.search.aggregations.AggregationBuilders.global;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -65,7 +71,24 @@
 import static org.hamcrest.Matchers.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class CardinalityIT extends OpenSearchIntegTestCase {
+public class CardinalityIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public CardinalityIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -615,5 +638,6 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityWithRequestBreakerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityWithRequestBreakerIT.java
index a3221e128a5dc..6cbf278317b1b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityWithRequestBreakerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/CardinalityWithRequestBreakerIT.java
@@ -32,27 +32,51 @@
 
 package org.opensearch.search.aggregations.metrics;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.breaker.CircuitBreakingException;
 import org.opensearch.indices.breaker.HierarchyCircuitBreakerService;
 import org.opensearch.search.aggregations.Aggregator;
 import org.opensearch.search.aggregations.BucketOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Map;
 import java.util.stream.IntStream;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.cardinality;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 
-public class CardinalityWithRequestBreakerIT extends OpenSearchIntegTestCase {
+public class CardinalityWithRequestBreakerIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public CardinalityWithRequestBreakerIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     /**
      * Test that searches using cardinality aggregations returns all request breaker memory.
      */
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/10154")
     public void testRequestBreaker() throws Exception {
         final String requestBreaker = randomIntBetween(1, 10000) + "kb";
         logger.info("--> Using request breaker setting: {}", requestBreaker);
@@ -76,6 +100,7 @@ public void testRequestBreaker() throws Exception {
             )
             .get();
 
+        indexRandomForConcurrentSearch("test");
         try {
             client().prepareSearch("test")
                 .addAggregation(
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ExtendedStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ExtendedStatsIT.java
index 2efb49c488d76..3d804b9aa626e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ExtendedStatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ExtendedStatsIT.java
@@ -70,6 +70,10 @@
 
 public class ExtendedStatsIT extends AbstractNumericTestCase {
 
+    public ExtendedStatsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(AggregationTestScriptsPlugin.class);
@@ -995,6 +999,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/GeoCentroidIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/GeoCentroidIT.java
index ffc31b7cdb7c4..78100d1778ecf 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/GeoCentroidIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/GeoCentroidIT.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.geo.GeoPoint;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.search.aggregations.InternalAggregation;
 import org.opensearch.search.aggregations.bucket.global.Global;
 import org.opensearch.test.OpenSearchIntegTestCase;
@@ -54,6 +55,10 @@
 public class GeoCentroidIT extends AbstractGeoTestCase {
     private static final String aggName = "geoCentroid";
 
+    public GeoCentroidIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     public void testEmptyAggregation() throws Exception {
         SearchResponse response = client().prepareSearch(EMPTY_IDX_NAME)
             .setQuery(matchAllQuery())
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentileRanksIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentileRanksIT.java
index 87e5a73ef630d..7ca5130388eea 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentileRanksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentileRanksIT.java
@@ -72,6 +72,10 @@
 
 public class HDRPercentileRanksIT extends AbstractNumericTestCase {
 
+    public HDRPercentileRanksIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(AggregationTestScriptsPlugin.class);
@@ -716,6 +720,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentilesIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentilesIT.java
index ad3fd6517d1b1..ec913b3e130f5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentilesIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/HDRPercentilesIT.java
@@ -75,6 +75,10 @@
 
 public class HDRPercentilesIT extends AbstractNumericTestCase {
 
+    public HDRPercentilesIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(AggregationTestScriptsPlugin.class);
@@ -687,6 +691,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/MedianAbsoluteDeviationIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/MedianAbsoluteDeviationIT.java
index 6af65beba6124..b8447d682abae 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/MedianAbsoluteDeviationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/MedianAbsoluteDeviationIT.java
@@ -91,6 +91,10 @@ public class MedianAbsoluteDeviationIT extends AbstractNumericTestCase {
     private static double singleValueExactMAD;
     private static double multiValueExactMAD;
 
+    public MedianAbsoluteDeviationIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         final Settings settings = Settings.builder().put(SETTING_NUMBER_OF_SHARDS, 1).put(SETTING_NUMBER_OF_REPLICAS, 0).build();
@@ -643,5 +647,6 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ScriptedMetricIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ScriptedMetricIT.java
index 5c782c6d085b4..ced2358ac3f78 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ScriptedMetricIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ScriptedMetricIT.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.search.aggregations.metrics;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.support.XContentMapValues;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
@@ -53,12 +56,14 @@
 import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
 import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.Before;
 
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -69,6 +74,7 @@
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.global;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.scriptedMetric;
@@ -87,10 +93,27 @@
 
 @ClusterScope(scope = Scope.SUITE)
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class ScriptedMetricIT extends OpenSearchIntegTestCase {
+public class ScriptedMetricIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static long numDocs;
 
+    public ScriptedMetricIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
@@ -1378,6 +1401,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
     public void testConflictingAggAndScriptParams() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/StatsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/StatsIT.java
index e02657670b943..f957a74eeb9d0 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/StatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/StatsIT.java
@@ -66,6 +66,10 @@
 import static org.hamcrest.Matchers.sameInstance;
 
 public class StatsIT extends AbstractNumericTestCase {
+    public StatsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(AggregationTestScriptsPlugin.class);
@@ -384,5 +388,6 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/SumIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/SumIT.java
index fe236f04c19e8..382d656448114 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/SumIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/SumIT.java
@@ -68,6 +68,10 @@
 
 public class SumIT extends AbstractNumericTestCase {
 
+    public SumIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(MetricAggScriptPlugin.class);
@@ -359,6 +363,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
     public void testFieldAlias() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentileRanksIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentileRanksIT.java
index ab0cdbaf3047f..941d3a888db29 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentileRanksIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentileRanksIT.java
@@ -72,6 +72,10 @@
 
 public class TDigestPercentileRanksIT extends AbstractNumericTestCase {
 
+    public TDigestPercentileRanksIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(AggregationTestScriptsPlugin.class);
@@ -626,6 +630,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentilesIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentilesIT.java
index 2c05ed0bac44a..6457cf9307fa1 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentilesIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TDigestPercentilesIT.java
@@ -74,6 +74,10 @@
 
 public class TDigestPercentilesIT extends AbstractNumericTestCase {
 
+    public TDigestPercentilesIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(AggregationTestScriptsPlugin.class);
@@ -597,5 +601,6 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TopHitsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TopHitsIT.java
index 96aeccfc03fb1..10e51079cf389 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TopHitsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/TopHitsIT.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.search.aggregations.metrics;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.Explanation;
 import org.apache.lucene.search.join.ScoreMode;
 import org.apache.lucene.util.ArrayUtil;
@@ -40,6 +42,7 @@
 import org.opensearch.action.search.SearchType;
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.query.MatchAllQueryBuilder;
@@ -67,8 +70,10 @@
 import org.opensearch.search.sort.SortBuilders;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
@@ -83,6 +88,7 @@
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
 import static org.opensearch.index.query.QueryBuilders.nestedQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.global;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.max;
@@ -105,11 +111,28 @@
 import static org.hamcrest.Matchers.sameInstance;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase()
-public class TopHitsIT extends OpenSearchIntegTestCase {
+public class TopHitsIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String TERMS_AGGS_FIELD = "terms";
     private static final String SORT_FIELD = "sort";
 
+    public TopHitsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ValueCountIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ValueCountIT.java
index 82e667bccc576..833d1ce3bb4c3 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ValueCountIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/metrics/ValueCountIT.java
@@ -31,8 +31,11 @@
 
 package org.opensearch.search.aggregations.metrics;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.Script;
 import org.opensearch.script.ScriptType;
@@ -42,7 +45,9 @@
 import org.opensearch.search.aggregations.bucket.global.Global;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -51,6 +56,7 @@
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.count;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.global;
@@ -67,7 +73,25 @@
 import static org.hamcrest.Matchers.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class ValueCountIT extends OpenSearchIntegTestCase {
+public class ValueCountIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public ValueCountIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
@@ -363,6 +387,7 @@ public void testScriptCaching() throws Exception {
                 .getMissCount(),
             equalTo(2L)
         );
+        internalCluster().wipeIndices("cache_test_idx");
     }
 
     public void testOrderByEmptyAggregation() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/AvgBucketIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/AvgBucketIT.java
index 6cd16a47e98d2..bec9203384026 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/AvgBucketIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/AvgBucketIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
@@ -42,11 +46,15 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -58,7 +66,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class AvgBucketIT extends OpenSearchIntegTestCase {
+public class AvgBucketIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
 
@@ -69,6 +77,23 @@ public class AvgBucketIT extends OpenSearchIntegTestCase {
     static int numValueBuckets;
     static long[] valueCounts;
 
+    public AvgBucketIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("tag", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketScriptIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketScriptIT.java
index 926c708e99bd6..4c3129eb89e3b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketScriptIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketScriptIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
@@ -47,9 +51,11 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -58,6 +64,7 @@
 import java.util.function.Function;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateRange;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
@@ -69,7 +76,7 @@
 import static org.hamcrest.Matchers.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class BucketScriptIT extends OpenSearchIntegTestCase {
+public class BucketScriptIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String FIELD_1_NAME = "field1";
     private static final String FIELD_2_NAME = "field2";
@@ -83,6 +90,23 @@ public class BucketScriptIT extends OpenSearchIntegTestCase {
     private static int maxNumber;
     private static long date;
 
+    public BucketScriptIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSelectorIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSelectorIT.java
index 7b802478a46d8..a7b28add7373a 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSelectorIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSelectorIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -46,9 +50,11 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -57,6 +63,7 @@
 import java.util.function.Function;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.PipelineAggregatorBuilders.bucketSelector;
@@ -70,7 +77,7 @@
 import static org.hamcrest.Matchers.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class BucketSelectorIT extends OpenSearchIntegTestCase {
+public class BucketSelectorIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String FIELD_1_NAME = "field1";
     private static final String FIELD_2_NAME = "field2";
@@ -82,6 +89,23 @@ public class BucketSelectorIT extends OpenSearchIntegTestCase {
     private static int minNumber;
     private static int maxNumber;
 
+    public BucketSelectorIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSortIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSortIT.java
index 231aa2e078de6..2e4fd7a412118 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSortIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/BucketSortIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
@@ -44,15 +48,18 @@
 import org.opensearch.search.sort.FieldSortBuilder;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateHistogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -68,7 +75,7 @@
 import static org.hamcrest.Matchers.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class BucketSortIT extends OpenSearchIntegTestCase {
+public class BucketSortIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String INDEX = "bucket-sort-it-data-index";
     private static final String INDEX_WITH_GAPS = "bucket-sort-it-data-index-with-gaps";
@@ -78,6 +85,23 @@ public class BucketSortIT extends OpenSearchIntegTestCase {
     private static final String VALUE_1_FIELD = "value_1";
     private static final String VALUE_2_FIELD = "value_2";
 
+    public BucketSortIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex(INDEX, INDEX_WITH_GAPS);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DateDerivativeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DateDerivativeIT.java
index 2c7890fb7b1cb..b05ff7b4329cd 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DateDerivativeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DateDerivativeIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.time.DateFormatters;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.InternalAggregation;
 import org.opensearch.search.aggregations.InternalMultiBucketAggregation;
 import org.opensearch.search.aggregations.bucket.histogram.DateHistogramInterval;
@@ -44,6 +48,7 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.support.AggregationPath;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matcher;
 import org.junit.After;
 
@@ -55,9 +60,11 @@
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.dateHistogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.PipelineAggregatorBuilders.derivative;
@@ -69,13 +76,30 @@
 import static org.hamcrest.core.IsNull.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class DateDerivativeIT extends OpenSearchIntegTestCase {
+public class DateDerivativeIT extends ParameterizedOpenSearchIntegTestCase {
 
     // some index names used during these tests
     private static final String IDX_DST_START = "idx_dst_start";
     private static final String IDX_DST_END = "idx_dst_end";
     private static final String IDX_DST_KATHMANDU = "idx_dst_kathmandu";
 
+    public DateDerivativeIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private ZonedDateTime date(int month, int day) {
         return ZonedDateTime.of(2012, month, day, 0, 0, 0, 0, ZoneOffset.UTC);
     }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DerivativeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DerivativeIT.java
index 5cff68001c8d5..41bbffc13658b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DerivativeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/DerivativeIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.aggregations.InternalAggregation;
@@ -47,14 +51,18 @@
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.search.aggregations.support.AggregationPath;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.filters;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
@@ -70,7 +78,7 @@
 import static org.hamcrest.core.IsNull.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class DerivativeIT extends OpenSearchIntegTestCase {
+public class DerivativeIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
 
@@ -92,6 +100,23 @@ public class DerivativeIT extends OpenSearchIntegTestCase {
     private static Double[] firstDerivValueCounts_empty_rnd;
     private static long numDocsEmptyIdx_rnd;
 
+    public DerivativeIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
@@ -668,6 +693,7 @@ public void testAvgMovavgDerivNPE() throws Exception {
         }
 
         refresh();
+        indexRandomForConcurrentSearch("movavg_npe");
 
         SearchResponse response = client().prepareSearch("movavg_npe")
             .addAggregation(
@@ -680,6 +706,7 @@ public void testAvgMovavgDerivNPE() throws Exception {
             .get();
 
         assertSearchResponse(response);
+        internalCluster().wipeIndices("movavg_npe");
     }
 
     private void checkBucketKeyAndDocCount(
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/ExtendedStatsBucketIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/ExtendedStatsBucketIT.java
index 85fe794b05fc6..299827e2413d4 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/ExtendedStatsBucketIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/ExtendedStatsBucketIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
@@ -45,11 +49,15 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -61,7 +69,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class ExtendedStatsBucketIT extends OpenSearchIntegTestCase {
+public class ExtendedStatsBucketIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
 
@@ -72,6 +80,23 @@ public class ExtendedStatsBucketIT extends OpenSearchIntegTestCase {
     static int numValueBuckets;
     static long[] valueCounts;
 
+    public ExtendedStatsBucketIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("tag", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MaxBucketIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MaxBucketIT.java
index a114fa4079e21..dc3b690c7f78f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MaxBucketIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MaxBucketIT.java
@@ -32,9 +32,13 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.support.WriteRequest;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
@@ -54,12 +58,16 @@
 import org.opensearch.search.aggregations.metrics.SumAggregationBuilder;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.filter;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
@@ -72,7 +80,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class MaxBucketIT extends OpenSearchIntegTestCase {
+public class MaxBucketIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
 
@@ -83,6 +91,23 @@ public class MaxBucketIT extends OpenSearchIntegTestCase {
     static int numValueBuckets;
     static long[] valueCounts;
 
+    public MaxBucketIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("tag", "type=keyword").get());
@@ -519,13 +544,13 @@ public void testNested() throws Exception {
 
     /**
      * https://github.com/elastic/elasticsearch/issues/33514
-     *
+     * <p>
      * This bug manifests as the max_bucket agg ("peak") being added to the response twice, because
      * the pipeline agg is run twice.  This makes invalid JSON and breaks conversion to maps.
      * The bug was caused by an UnmappedTerms being the chosen as the first reduction target.  UnmappedTerms
      * delegated reduction to the first non-unmapped agg, which would reduce and run pipeline aggs.  But then
      * execution returns to the UnmappedTerms and _it_ runs pipelines as well, doubling up on the values.
-     *
+     * <p>
      * Applies to any pipeline agg, not just max.
      */
     public void testFieldIsntWrittenOutTwice() throws Exception {
@@ -587,5 +612,6 @@ public void testFieldIsntWrittenOutTwice() throws Exception {
         SearchResponse response = client().prepareSearch("foo_*").setSize(0).addAggregation(groupByLicenseAgg).get();
         BytesReference bytes = org.opensearch.core.xcontent.XContentHelper.toXContent(response, MediaTypeRegistry.JSON, false);
         XContentHelper.convertToMap(bytes, false, MediaTypeRegistry.JSON);
+        internalCluster().wipeIndices("foo_*");
     }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MinBucketIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MinBucketIT.java
index a29bfc0eaa7cb..189bfd9b5b80a 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MinBucketIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MinBucketIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
@@ -42,11 +46,15 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -58,7 +66,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class MinBucketIT extends OpenSearchIntegTestCase {
+public class MinBucketIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
 
@@ -69,6 +77,23 @@ public class MinBucketIT extends OpenSearchIntegTestCase {
     static int numValueBuckets;
     static long[] valueCounts;
 
+    public MinBucketIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("tag", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MovAvgIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MovAvgIT.java
index b53183a627ecc..8ad3107ac33ac 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MovAvgIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/MovAvgIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.bulk.BulkRequestBuilder;
 import org.opensearch.action.index.IndexRequestBuilder;
@@ -40,12 +42,15 @@
 import org.opensearch.action.support.WriteRequest;
 import org.opensearch.client.Client;
 import org.opensearch.common.collect.EvictingQueue;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
 import org.opensearch.search.aggregations.metrics.Avg;
 import org.opensearch.search.aggregations.support.ValuesSourceAggregationBuilder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
@@ -57,6 +62,7 @@
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.max;
@@ -71,7 +77,7 @@
 import static org.hamcrest.core.IsNull.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class MovAvgIT extends OpenSearchIntegTestCase {
+public class MovAvgIT extends ParameterizedOpenSearchIntegTestCase {
     private static final String INTERVAL_FIELD = "l_value";
     private static final String VALUE_FIELD = "v_value";
     private static final String VALUE_FIELD2 = "v_value2";
@@ -127,6 +133,23 @@ public String toString() {
         }
     }
 
+    public MovAvgIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         prepareCreate("idx").setMapping(
@@ -1145,7 +1168,7 @@ public void testHoltWintersMinimization() {
      * the default settings.  Which means our mock histo will match the generated result (which it won't
      * if the minimizer is actually working, since the coefficients will be different and thus generate different
      * data)
-     *
+     * <p>
      * We can simulate this by setting the window size == size of histo
      */
     public void testMinimizeNotEnoughData() {
@@ -1297,6 +1320,7 @@ public void testPredictWithNonEmptyBuckets() throws Exception {
                     .setSource(jsonBuilder().startObject().field(INTERVAL_FIELD, i).field(VALUE_FIELD2, 10).endObject())
             );
         }
+        indexRandomForConcurrentSearch("predict_non_empty");
 
         bulkBuilder.get();
         ensureSearchable();
@@ -1341,6 +1365,7 @@ public void testPredictWithNonEmptyBuckets() throws Exception {
                 assertThat(movAvgAgg, nullValue());
             }
         }
+        internalCluster().wipeIndices("predict_non_empty");
     }
 
     private void assertValidIterators(Iterator expectedBucketIter, Iterator expectedCountsIter, Iterator expectedValuesIter) {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/PercentilesBucketIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/PercentilesBucketIT.java
index 1da079781dc63..580497715ed6d 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/PercentilesBucketIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/PercentilesBucketIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.terms.IncludeExclude;
@@ -43,14 +47,17 @@
 import org.opensearch.search.aggregations.metrics.Percentile;
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -62,7 +69,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class PercentilesBucketIT extends OpenSearchIntegTestCase {
+public class PercentilesBucketIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
     private static final double[] PERCENTS = { 0.0, 1.0, 25.0, 50.0, 75.0, 99.0, 100.0 };
@@ -73,6 +80,23 @@ public class PercentilesBucketIT extends OpenSearchIntegTestCase {
     static int numValueBuckets;
     static long[] valueCounts;
 
+    public PercentilesBucketIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("tag", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SerialDiffIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SerialDiffIT.java
index f5a5d025946ec..b4da63802bc50 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SerialDiffIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SerialDiffIT.java
@@ -32,22 +32,30 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.collect.EvictingQueue;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
 import org.opensearch.search.aggregations.support.ValuesSourceAggregationBuilder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.max;
@@ -61,7 +69,7 @@
 import static org.hamcrest.core.IsNull.nullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class SerialDiffIT extends OpenSearchIntegTestCase {
+public class SerialDiffIT extends ParameterizedOpenSearchIntegTestCase {
     private static final String INTERVAL_FIELD = "l_value";
     private static final String VALUE_FIELD = "v_value";
 
@@ -90,6 +98,23 @@ public String toString() {
         }
     }
 
+    public SerialDiffIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private ValuesSourceAggregationBuilder<? extends ValuesSourceAggregationBuilder<?>> randomMetric(String name, String field) {
         int rand = randomIntBetween(0, 3);
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/StatsBucketIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/StatsBucketIT.java
index e9f34f6aa65d9..21fdd5e761e77 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/StatsBucketIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/StatsBucketIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
@@ -42,11 +46,15 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -58,10 +66,9 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class StatsBucketIT extends OpenSearchIntegTestCase {
+public class StatsBucketIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
-
     static int numDocs;
     static int interval;
     static int minRandomValue;
@@ -69,6 +76,23 @@ public class StatsBucketIT extends OpenSearchIntegTestCase {
     static int numValueBuckets;
     static long[] valueCounts;
 
+    public StatsBucketIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("tag", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SumBucketIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SumBucketIT.java
index 5bd962017c247..d4bd8f21b2a99 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SumBucketIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/pipeline/SumBucketIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram;
 import org.opensearch.search.aggregations.bucket.histogram.Histogram.Bucket;
@@ -42,11 +46,15 @@
 import org.opensearch.search.aggregations.metrics.Sum;
 import org.opensearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.histogram;
 import static org.opensearch.search.aggregations.AggregationBuilders.sum;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
@@ -58,7 +66,7 @@
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class SumBucketIT extends OpenSearchIntegTestCase {
+public class SumBucketIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final String SINGLE_VALUED_FIELD_NAME = "l_value";
 
@@ -69,6 +77,23 @@ public class SumBucketIT extends OpenSearchIntegTestCase {
     static int numValueBuckets;
     static long[] valueCounts;
 
+    public SumBucketIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("idx").setMapping("tag", "type=keyword").get());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/backpressure/SearchBackpressureIT.java b/server/src/internalClusterTest/java/org/opensearch/search/backpressure/SearchBackpressureIT.java
index 8eb5167ca9e51..28ada82a1c56b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/backpressure/SearchBackpressureIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/backpressure/SearchBackpressureIT.java
@@ -8,6 +8,8 @@
 
 package org.opensearch.search.backpressure;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.ActionType;
@@ -19,6 +21,7 @@
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -34,6 +37,7 @@
 import org.opensearch.tasks.CancellableTask;
 import org.opensearch.tasks.Task;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TransportService;
 import org.hamcrest.MatcherAssert;
@@ -42,6 +46,7 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -50,16 +55,34 @@
 import java.util.concurrent.TimeUnit;
 import java.util.function.Supplier;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.instanceOf;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE)
-public class SearchBackpressureIT extends OpenSearchIntegTestCase {
+public class SearchBackpressureIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static final TimeValue TIMEOUT = new TimeValue(10, TimeUnit.SECONDS);
     private static final int MOVING_AVERAGE_WINDOW_SIZE = 10;
 
+    public SearchBackpressureIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         final List<Class<? extends Plugin>> plugins = new ArrayList<>(super.nodePlugins());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchRedStateIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchRedStateIndexIT.java
index d88893d1bcd71..bd623ccdf2731 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchRedStateIndexIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchRedStateIndexIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.basic;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsResponse;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
@@ -40,13 +42,18 @@
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.routing.ShardRoutingState;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.search.SearchService;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.After;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
@@ -54,7 +61,24 @@
 import static org.hamcrest.Matchers.lessThan;
 
 @OpenSearchIntegTestCase.ClusterScope(minNumDataNodes = 2)
-public class SearchRedStateIndexIT extends OpenSearchIntegTestCase {
+public class SearchRedStateIndexIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchRedStateIndexIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public void testAllowPartialsWithRedState() throws Exception {
         final int numShards = cluster().numDataNodes() + 2;
@@ -129,6 +153,7 @@ private void buildRedIndex(int numShards) throws Exception {
             client().prepareIndex("test").setId("" + i).setSource("field1", "value1").get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         internalCluster().stopRandomDataNode();
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileCreatingIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileCreatingIndexIT.java
index 6099c5342a9d3..a5989b693d332 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileCreatingIndexIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileCreatingIndexIT.java
@@ -32,13 +32,21 @@
 
 package org.opensearch.search.basic;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.indices.refresh.RefreshResponse;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.client.Client;
 import org.opensearch.cluster.health.ClusterHealthStatus;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 
@@ -46,7 +54,25 @@
  * This test basically verifies that search with a single shard active (cause we indexed to it) and other
  * shards possibly not active at all (cause they haven't allocated) will still work.
  */
-public class SearchWhileCreatingIndexIT extends OpenSearchIntegTestCase {
+public class SearchWhileCreatingIndexIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchWhileCreatingIndexIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     public void testIndexCausesIndexCreation() throws Exception {
         searchWhileCreatingIndex(false, 1); // 1 replica in our default...
     }
@@ -80,6 +106,7 @@ private void searchWhileCreatingIndex(boolean createIndex, int numberOfReplicas)
         }
         client().prepareIndex("test").setId(id).setSource("field", "test").get();
         RefreshResponse refreshResponse = client().admin().indices().prepareRefresh("test").get();
+        indexRandomForConcurrentSearch("test");
         // at least one shard should be successful when refreshing
         assertThat(refreshResponse.getSuccessfulShards(), greaterThanOrEqualTo(1));
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileRelocatingIT.java b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileRelocatingIT.java
index 1f1384cc5f72d..6d2ec845afa98 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileRelocatingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWhileRelocatingIT.java
@@ -32,28 +32,52 @@
 
 package org.opensearch.search.basic;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.cluster.health.ClusterHealthResponse;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.Priority;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.SearchHits;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoTimeout;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.formatShardStatus;
 import static org.hamcrest.Matchers.equalTo;
 
 @OpenSearchIntegTestCase.ClusterScope(minNumDataNodes = 2)
-public class SearchWhileRelocatingIT extends OpenSearchIntegTestCase {
+public class SearchWhileRelocatingIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchWhileRelocatingIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public void testSearchAndRelocateConcurrentlyRandomReplicas() throws Exception {
         testSearchAndRelocateConcurrently(randomIntBetween(0, 1));
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomExceptionsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomExceptionsIT.java
index b6da477d1b23e..aa82b9d21c7fb 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomExceptionsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomExceptionsIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.basic;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.FilterDirectoryReader;
 import org.apache.lucene.index.LeafReader;
@@ -47,12 +49,14 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.settings.Settings.Builder;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.index.MockEngineFactoryPlugin;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.engine.MockEngineSupport;
 import org.opensearch.test.engine.ThrowingLeafReaderWrapper;
 
@@ -64,9 +68,27 @@
 import java.util.Random;
 import java.util.concurrent.ExecutionException;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 
-public class SearchWithRandomExceptionsIT extends OpenSearchIntegTestCase {
+public class SearchWithRandomExceptionsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchWithRandomExceptionsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomIOExceptionsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomIOExceptionsIT.java
index 0bcd945ba47b3..446a0bce58d66 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomIOExceptionsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomIOExceptionsIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.basic;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.tests.util.English;
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.DocWriteResponse;
@@ -43,11 +45,13 @@
 import org.opensearch.client.Requests;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.store.MockFSDirectoryFactory;
 import org.opensearch.test.store.MockFSIndexStore;
 
@@ -56,10 +60,28 @@
 import java.util.Collection;
 import java.util.concurrent.ExecutionException;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 
-public class SearchWithRandomIOExceptionsIT extends OpenSearchIntegTestCase {
+public class SearchWithRandomIOExceptionsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchWithRandomIOExceptionsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportSearchFailuresIT.java b/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportSearchFailuresIT.java
index 841821b5bbad6..cbe52abf5279b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportSearchFailuresIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportSearchFailuresIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.basic;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.cluster.health.ClusterHealthResponse;
 import org.opensearch.action.admin.indices.refresh.RefreshResponse;
@@ -41,23 +43,46 @@
 import org.opensearch.client.Requests;
 import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.common.Priority;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.MatchQueryBuilder;
 import org.opensearch.search.builder.SearchSourceBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.client.Requests.clusterHealthRequest;
 import static org.opensearch.client.Requests.refreshRequest;
 import static org.opensearch.client.Requests.searchRequest;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.anyOf;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 
-public class TransportSearchFailuresIT extends OpenSearchIntegTestCase {
+public class TransportSearchFailuresIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public TransportSearchFailuresIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected int maximumNumberOfReplicas() {
         return 1;
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportTwoNodesSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportTwoNodesSearchIT.java
index 069559d6d11b1..edceb0cbc0d24 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportTwoNodesSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/basic/TransportTwoNodesSearchIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.basic;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.search.MultiSearchResponse;
 import org.opensearch.action.search.SearchPhaseExecutionException;
@@ -39,6 +41,7 @@
 import org.opensearch.client.Requests;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.MatchQueryBuilder;
 import org.opensearch.index.query.QueryBuilders;
@@ -51,9 +54,11 @@
 import org.opensearch.search.aggregations.bucket.global.Global;
 import org.opensearch.search.builder.SearchSourceBuilder;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Set;
 import java.util.TreeSet;
@@ -66,6 +71,7 @@
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 import static org.hamcrest.Matchers.equalTo;
@@ -74,7 +80,24 @@
 import static org.hamcrest.Matchers.nullValue;
 import static org.hamcrest.Matchers.startsWith;
 
-public class TransportTwoNodesSearchIT extends OpenSearchIntegTestCase {
+public class TransportTwoNodesSearchIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public TransportTwoNodesSearchIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected int numberOfReplicas() {
@@ -105,6 +128,7 @@ private Set<String> prepareData(int numShards) throws Exception {
             fullExpectedIds.add(Integer.toString(i));
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
         return fullExpectedIds;
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fetch/FetchSubPhasePluginIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fetch/FetchSubPhasePluginIT.java
index 127bd3176453b..87f2153eb800f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fetch/FetchSubPhasePluginIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fetch/FetchSubPhasePluginIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.fetch;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.Terms;
@@ -39,6 +41,8 @@
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.document.DocumentField;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -48,12 +52,13 @@
 import org.opensearch.plugins.SearchPlugin;
 import org.opensearch.search.SearchExtBuilder;
 import org.opensearch.search.builder.SearchSourceBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
 import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -64,11 +69,30 @@
 import static java.util.Collections.singletonList;
 import static org.opensearch.client.Requests.indexRequest;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 import static org.hamcrest.CoreMatchers.equalTo;
 
 @ClusterScope(scope = Scope.SUITE, supportsDedicatedMasters = false, numDataNodes = 2)
-public class FetchSubPhasePluginIT extends OpenSearchIntegTestCase {
+public class FetchSubPhasePluginIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public FetchSubPhasePluginIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singletonList(FetchTermVectorsPlugin.class);
@@ -95,6 +119,7 @@ public void testPlugin() throws Exception {
             .actionGet();
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch()
             .setSource(new SearchSourceBuilder().ext(Collections.singletonList(new TermVectorsFetchBuilder("test"))))
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/InnerHitsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/InnerHitsIT.java
index f43918e28b9b5..1a730c01e4890 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/InnerHitsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/InnerHitsIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.fetch.subphase;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.join.ScoreMode;
 import org.apache.lucene.util.ArrayUtil;
 import org.opensearch.action.index.IndexRequestBuilder;
@@ -39,6 +41,7 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.query.BoolQueryBuilder;
@@ -55,7 +58,7 @@
 import org.opensearch.search.sort.FieldSortBuilder;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.InternalSettingsPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -72,6 +75,7 @@
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
 import static org.opensearch.index.query.QueryBuilders.nestedQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAllSuccessful;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
@@ -84,7 +88,24 @@
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
 
-public class InnerHitsIT extends OpenSearchIntegTestCase {
+public class InnerHitsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public InnerHitsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -876,6 +897,7 @@ public void testNestedSource() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("index1");
 
         // the field name (comments.message) used for source filtering should be the same as when using that field for
         // other features (like in the query dsl or aggs) in order for consistency:
@@ -952,6 +974,7 @@ public void testInnerHitsWithIgnoreUnmapped() throws Exception {
         client().prepareIndex("index1").setId("1").setSource("nested_type", Collections.singletonMap("key", "value")).get();
         client().prepareIndex("index2").setId("3").setSource("key", "value").get();
         refresh();
+        indexRandomForConcurrentSearch("index1", "index2");
 
         SearchResponse response = client().prepareSearch("index1", "index2")
             .setQuery(
@@ -981,6 +1004,7 @@ public void testUseMaxDocInsteadOfSize() throws Exception {
             .setRefreshPolicy(IMMEDIATE)
             .get();
 
+        indexRandomForConcurrentSearch("index2");
         QueryBuilder query = nestedQuery("nested", matchQuery("nested.field", "value1"), ScoreMode.Avg).innerHit(
             new InnerHitBuilder().setSize(ArrayUtil.MAX_ARRAY_LENGTH - 1)
         );
@@ -998,6 +1022,7 @@ public void testTooHighResultWindow() throws Exception {
             )
             .setRefreshPolicy(IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("index2");
         SearchResponse response = client().prepareSearch("index2")
             .setQuery(
                 nestedQuery("nested", matchQuery("nested.field", "value1"), ScoreMode.Avg).innerHit(
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/MatchedQueriesIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/MatchedQueriesIT.java
index e9cad63cbac94..83cedb8c20e1d 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/MatchedQueriesIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/MatchedQueriesIT.java
@@ -32,7 +32,11 @@
 
 package org.opensearch.search.fetch.subphase;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.XContentHelper;
@@ -41,7 +45,10 @@
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.index.query.TermQueryBuilder;
 import org.opensearch.search.SearchHit;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.index.query.QueryBuilders.boolQuery;
 import static org.opensearch.index.query.QueryBuilders.constantScoreQuery;
@@ -52,11 +59,30 @@
 import static org.opensearch.index.query.QueryBuilders.termQuery;
 import static org.opensearch.index.query.QueryBuilders.termsQuery;
 import static org.opensearch.index.query.QueryBuilders.wrapperQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.hasItemInArray;
 
-public class MatchedQueriesIT extends OpenSearchIntegTestCase {
+public class MatchedQueriesIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MatchedQueriesIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     public void testSimpleMatchedQueryFromFilteredQuery() throws Exception {
         createIndex("test");
         ensureGreen();
@@ -65,6 +91,7 @@ public void testSimpleMatchedQueryFromFilteredQuery() throws Exception {
         client().prepareIndex("test").setId("2").setSource("name", "test2", "number", 2).get();
         client().prepareIndex("test").setId("3").setSource("name", "test3", "number", 3).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(
@@ -115,6 +142,7 @@ public void testSimpleMatchedQueryFromTopLevelFilter() throws Exception {
         client().prepareIndex("test").setId("2").setSource("name", "test").get();
         client().prepareIndex("test").setId("3").setSource("name", "test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -166,6 +194,7 @@ public void testSimpleMatchedQueryFromTopLevelFilterAndFilteredQuery() throws Ex
         client().prepareIndex("test").setId("2").setSource("name", "test", "title", "title2").get();
         client().prepareIndex("test").setId("3").setSource("name", "test", "title", "title3").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(boolQuery().must(matchAllQuery()).filter(termsQuery("title", "title1", "title2", "title3").queryName("title")))
@@ -198,12 +227,13 @@ public void testSimpleMatchedQueryFromTopLevelFilterAndFilteredQuery() throws Ex
         }
     }
 
-    public void testRegExpQuerySupportsName() {
+    public void testRegExpQuerySupportsName() throws InterruptedException {
         createIndex("test1");
         ensureGreen();
 
         client().prepareIndex("test1").setId("1").setSource("title", "title1").get();
         refresh();
+        indexRandomForConcurrentSearch("test1");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(QueryBuilders.regexpQuery("title", "title1").queryName("regex"))
@@ -220,12 +250,13 @@ public void testRegExpQuerySupportsName() {
         }
     }
 
-    public void testPrefixQuerySupportsName() {
+    public void testPrefixQuerySupportsName() throws InterruptedException {
         createIndex("test1");
         ensureGreen();
 
         client().prepareIndex("test1").setId("1").setSource("title", "title1").get();
         refresh();
+        indexRandomForConcurrentSearch("test1");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(QueryBuilders.prefixQuery("title", "title").queryName("prefix"))
@@ -242,12 +273,13 @@ public void testPrefixQuerySupportsName() {
         }
     }
 
-    public void testFuzzyQuerySupportsName() {
+    public void testFuzzyQuerySupportsName() throws InterruptedException {
         createIndex("test1");
         ensureGreen();
 
         client().prepareIndex("test1").setId("1").setSource("title", "title1").get();
         refresh();
+        indexRandomForConcurrentSearch("test1");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(QueryBuilders.fuzzyQuery("title", "titel1").queryName("fuzzy"))
@@ -264,12 +296,13 @@ public void testFuzzyQuerySupportsName() {
         }
     }
 
-    public void testWildcardQuerySupportsName() {
+    public void testWildcardQuerySupportsName() throws InterruptedException {
         createIndex("test1");
         ensureGreen();
 
         client().prepareIndex("test1").setId("1").setSource("title", "title1").get();
         refresh();
+        indexRandomForConcurrentSearch("test1");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(QueryBuilders.wildcardQuery("title", "titl*").queryName("wildcard"))
@@ -286,12 +319,13 @@ public void testWildcardQuerySupportsName() {
         }
     }
 
-    public void testSpanFirstQuerySupportsName() {
+    public void testSpanFirstQuerySupportsName() throws InterruptedException {
         createIndex("test1");
         ensureGreen();
 
         client().prepareIndex("test1").setId("1").setSource("title", "title1 title2").get();
         refresh();
+        indexRandomForConcurrentSearch("test1");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(QueryBuilders.spanFirstQuery(QueryBuilders.spanTermQuery("title", "title1"), 10).queryName("span"))
@@ -318,6 +352,7 @@ public void testMatchedWithShould() throws Exception {
         client().prepareIndex("test").setId("1").setSource("content", "Lorem ipsum dolor sit amet").get();
         client().prepareIndex("test").setId("2").setSource("content", "consectetur adipisicing elit").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // Execute search at least two times to load it in cache
         int iter = scaledRandomIntBetween(2, 10);
@@ -352,6 +387,7 @@ public void testMatchedWithWrapperQuery() throws Exception {
 
         client().prepareIndex("test").setId("1").setSource("content", "Lorem ipsum dolor sit amet").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         MatchQueryBuilder matchQueryBuilder = matchQuery("content", "amet").queryName("abc");
         BytesReference matchBytes = XContentHelper.toXContent(matchQueryBuilder, MediaTypeRegistry.JSON, false);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/CustomHighlighterSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/CustomHighlighterSearchIT.java
index 7df5b9b88a69c..fe17c3e22d43c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/CustomHighlighterSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/CustomHighlighterSearchIT.java
@@ -31,12 +31,16 @@
 
 package org.opensearch.search.fetch.subphase.highlight;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.plugins.Plugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
 import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.Before;
 
 import java.io.IOException;
@@ -45,6 +49,7 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHighlight;
 import static org.hamcrest.Matchers.equalTo;
 
@@ -52,7 +57,24 @@
  * Integration test for highlighters registered by a plugin.
  */
 @ClusterScope(scope = Scope.SUITE, supportsDedicatedMasters = false, numDataNodes = 1)
-public class CustomHighlighterSearchIT extends OpenSearchIntegTestCase {
+public class CustomHighlighterSearchIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public CustomHighlighterSearchIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java
index 2e70029cfb9f6..2afa911223074 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.fetch.subphase.highlight;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 import com.carrotsearch.randomizedtesting.generators.RandomPicks;
 
 import org.apache.lucene.analysis.Analyzer;
@@ -48,6 +49,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.settings.Settings.Builder;
 import org.opensearch.common.time.DateFormatter;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -73,7 +75,7 @@
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.InternalSettingsPlugin;
 import org.opensearch.test.MockKeywordPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matcher;
 import org.hamcrest.Matchers;
 
@@ -107,6 +109,7 @@
 import static org.opensearch.index.query.QueryBuilders.regexpQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
 import static org.opensearch.index.query.QueryBuilders.wildcardQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.builder.SearchSourceBuilder.highlight;
 import static org.opensearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
@@ -125,16 +128,34 @@
 import static org.hamcrest.Matchers.not;
 import static org.hamcrest.Matchers.startsWith;
 
-public class HighlighterSearchIT extends OpenSearchIntegTestCase {
+public class HighlighterSearchIT extends ParameterizedOpenSearchIntegTestCase {
+
     // TODO as we move analyzers out of the core we need to move some of these into HighlighterWithAnalyzersTests
     private static final String[] ALL_TYPES = new String[] { "plain", "fvh", "unified" };
 
+    public HighlighterSearchIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(InternalSettingsPlugin.class, MockKeywordPlugin.class, MockAnalysisPlugin.class);
     }
 
-    public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOException {
+    public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
         mappings.startObject("properties")
@@ -156,6 +177,7 @@ public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOExceptio
             .setSource(jsonBuilder().startObject().array("tags", "foo baz", "foo baz", "foo baz", "foo bar").field("sort", 2).endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         for (BoundaryScannerType scanner : BoundaryScannerType.values()) {
             SearchResponse search = client().prepareSearch()
@@ -169,12 +191,13 @@ public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOExceptio
         }
     }
 
-    public void testHighlightingWithStoredKeyword() throws IOException {
+    public void testHighlightingWithStoredKeyword() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
         mappings.startObject("properties").startObject("text").field("type", "keyword").field("store", true).endObject().endObject();
         mappings.endObject();
         assertAcked(prepareCreate("test").setMapping(mappings));
+        indexRandomForConcurrentSearch("test");
         client().prepareIndex("test").setId("1").setSource(jsonBuilder().startObject().field("text", "foo").endObject()).get();
         refresh();
         SearchResponse search = client().prepareSearch()
@@ -184,7 +207,7 @@ public void testHighlightingWithStoredKeyword() throws IOException {
         assertHighlight(search, 0, "text", 0, equalTo("<em>foo</em>"));
     }
 
-    public void testHighlightingWithWildcardName() throws IOException {
+    public void testHighlightingWithWildcardName() throws IOException, InterruptedException {
         // test the kibana case with * as fieldname that will try highlight all fields including meta fields
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
@@ -200,6 +223,7 @@ public void testHighlightingWithWildcardName() throws IOException {
         assertAcked(prepareCreate("test").setMapping(mappings));
         client().prepareIndex("test").setId("1").setSource(jsonBuilder().startObject().field("text", "text").endObject()).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             SearchResponse search = client().prepareSearch()
                 .setQuery(constantScoreQuery(matchQuery("text", "text")))
@@ -209,7 +233,7 @@ public void testHighlightingWithWildcardName() throws IOException {
         }
     }
 
-    public void testFieldAlias() throws IOException {
+    public void testFieldAlias() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder().startObject()
             .startObject("properties")
             .startObject("text")
@@ -227,7 +251,7 @@ public void testFieldAlias() throws IOException {
 
         client().prepareIndex("test").setId("1").setSource("text", "foo").get();
         refresh();
-
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             HighlightBuilder builder = new HighlightBuilder().field(new Field("alias").highlighterType(type))
                 .requireFieldMatch(randomBoolean());
@@ -236,7 +260,7 @@ public void testFieldAlias() throws IOException {
         }
     }
 
-    public void testFieldAliasWithSourceLookup() throws IOException {
+    public void testFieldAliasWithSourceLookup() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder().startObject()
             .startObject("properties")
             .startObject("text")
@@ -255,7 +279,7 @@ public void testFieldAliasWithSourceLookup() throws IOException {
 
         client().prepareIndex("test").setId("1").setSource("text", "foo bar").get();
         refresh();
-
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             HighlightBuilder builder = new HighlightBuilder().field(new Field("alias").highlighterType(type))
                 .requireFieldMatch(randomBoolean());
@@ -264,7 +288,7 @@ public void testFieldAliasWithSourceLookup() throws IOException {
         }
     }
 
-    public void testFieldAliasWithWildcardField() throws IOException {
+    public void testFieldAliasWithWildcardField() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder().startObject()
             .startObject("properties")
             .startObject("keyword")
@@ -280,13 +304,14 @@ public void testFieldAliasWithWildcardField() throws IOException {
 
         client().prepareIndex("test").setId("1").setSource("keyword", "foo").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         HighlightBuilder builder = new HighlightBuilder().field(new Field("al*")).requireFieldMatch(false);
         SearchResponse search = client().prepareSearch().setQuery(matchQuery("alias", "foo")).highlighter(builder).get();
         assertHighlight(search, 0, "alias", 0, equalTo("<em>foo</em>"));
     }
 
-    public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOException {
+    public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
         mappings.startObject("_source")
@@ -313,6 +338,7 @@ public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOExc
             .setSource(jsonBuilder().startObject().field("unstored_text", "text").field("text", "text").endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             SearchResponse search = client().prepareSearch()
                 .setQuery(constantScoreQuery(matchQuery("text", "text")))
@@ -329,7 +355,7 @@ public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOExc
     }
 
     // see #3486
-    public void testHighTermFrequencyDoc() throws IOException {
+    public void testHighTermFrequencyDoc() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping("name", "type=text,term_vector=with_positions_offsets,store=" + randomBoolean()));
         StringBuilder builder = new StringBuilder();
         for (int i = 0; i < 6000; i++) {
@@ -337,6 +363,7 @@ public void testHighTermFrequencyDoc() throws IOException {
         }
         client().prepareIndex("test").setId("1").setSource("name", builder.toString()).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse search = client().prepareSearch()
             .setQuery(constantScoreQuery(matchQuery("name", "abc")))
             .highlighter(new HighlightBuilder().field("name"))
@@ -364,6 +391,7 @@ public void testEnsureNoNegativeOffsets() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse search = client().prepareSearch()
             .setQuery(matchQuery("long_term", "thisisaverylongwordandmakessurethisfails foo highlighed"))
             .highlighter(new HighlightBuilder().field("long_term", 18, 1).highlighterType("fvh"))
@@ -650,7 +678,7 @@ public void testHighlightIssue1994() throws Exception {
         assertHighlight(search, 0, "titleTV", 1, 2, equalTo("<em>highlight</em> other text"));
     }
 
-    public void testGlobalHighlightingSettingsOverriddenAtFieldLevel() {
+    public void testGlobalHighlightingSettingsOverriddenAtFieldLevel() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
@@ -663,6 +691,7 @@ public void testGlobalHighlightingSettingsOverriddenAtFieldLevel() {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1 and field2 produces different tags");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "test"))
@@ -713,6 +742,7 @@ public void testHighlightingOnWildcardFields() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field*");
         SearchSourceBuilder source = searchSource()
@@ -762,6 +792,7 @@ public void testForceSourceWithSourceDisabled() throws Exception {
             .setSource("field1", "The quick brown fox jumps over the lazy dog", "field2", "second field content")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // works using stored field
         SearchResponse searchResponse = client().prepareSearch("test")
@@ -802,6 +833,7 @@ public void testPlainHighlighter() throws Exception {
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "test"))
@@ -1004,6 +1036,7 @@ public void testFVHManyMatches() throws Exception {
         String value = new String(new char[1024 * 256 / pattern.length()]).replace("\0", pattern);
         client().prepareIndex("test").setSource("field1", value).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1 with default phrase limit");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "t"))
@@ -1095,6 +1128,7 @@ private void checkMatchedFieldsCase(boolean requireFieldMatch) throws Exception
         );
         index("test", "type1", "3", "foo", "weird", "bar", "result");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         Field fooField = new Field("foo").numOfFragments(1)
             .order("score")
@@ -1387,6 +1421,7 @@ public void testMultiMapperVectorWithStore() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1432,6 +1467,7 @@ public void testMultiMapperVectorFromSource() throws Exception {
 
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1477,6 +1513,7 @@ public void testMultiMapperNoVectorWithStore() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1521,6 +1558,7 @@ public void testMultiMapperNoVectorFromSource() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1550,6 +1588,7 @@ public void testFastVectorHighlighterShouldFailIfNoTermVectors() throws Exceptio
                 .setSource("title", "This is a test for the enabling fast vector highlighter");
         }
         indexRandom(true, indexRequestBuilders);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse search = client().prepareSearch()
             .setQuery(matchPhraseQuery("title", "this is a test"))
@@ -1587,6 +1626,7 @@ public void testDisableFastVectorHighlighter() throws Exception {
                 .setSource("title", "This is a test for the workaround for the fast vector highlighting SOLR-3724");
         }
         indexRandom(true, indexRequestBuilders);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse search = client().prepareSearch()
             .setQuery(matchPhraseQuery("title", "test for the workaround"))
@@ -1648,6 +1688,7 @@ public void testFSHHighlightAllMvFragments() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("tags", "tag"))
@@ -1665,11 +1706,12 @@ public void testFSHHighlightAllMvFragments() throws Exception {
         );
     }
 
-    public void testBoostingQuery() {
+    public void testBoostingQuery() throws InterruptedException {
         createIndex("test");
         ensureGreen();
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -1681,11 +1723,12 @@ public void testBoostingQuery() {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The quick <x>brown</x> fox jumps over the lazy dog"));
     }
 
-    public void testBoostingQueryTermVector() throws IOException {
+    public void testBoostingQueryTermVector() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1TermVectorMapping()));
         ensureGreen();
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -1697,12 +1740,13 @@ public void testBoostingQueryTermVector() throws IOException {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The quick <x>brown</x> fox jumps over the lazy dog"));
     }
 
-    public void testCommonTermsQuery() {
+    public void testCommonTermsQuery() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(commonTermsQuery("field2", "quick brown").cutoffFrequency(100))
@@ -1712,12 +1756,13 @@ public void testCommonTermsQuery() {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The <x>quick</x> <x>brown</x> fox jumps over the lazy dog"));
     }
 
-    public void testCommonTermsTermVector() throws IOException {
+    public void testCommonTermsTermVector() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1TermVectorMapping()));
         ensureGreen();
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(commonTermsQuery("field2", "quick brown").cutoffFrequency(100))
             .highlighter(highlight().field("field2").order("score").preTags("<x>").postTags("</x>"));
@@ -1743,6 +1788,7 @@ public void testPlainHighlightDifferentFragmenter() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchPhraseQuery("tags", "long tag"))
@@ -1795,12 +1841,13 @@ public void testPlainHighlightDifferentFragmenter() throws Exception {
         );
     }
 
-    public void testPlainHighlighterMultipleFields() {
+    public void testPlainHighlighterMultipleFields() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
         index("test", "type1", "1", "field1", "The <b>quick<b> brown fox", "field2", "The <b>slow<b> brown fox");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("field1", "fox"))
@@ -1813,7 +1860,7 @@ public void testPlainHighlighterMultipleFields() {
         assertHighlight(response, 0, "field2", 0, 1, equalTo("The <b>slow<b> brown <2>fox</2>"));
     }
 
-    public void testFastVectorHighlighterMultipleFields() {
+    public void testFastVectorHighlighterMultipleFields() throws InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 "field1",
@@ -1826,6 +1873,7 @@ public void testFastVectorHighlighterMultipleFields() {
 
         index("test", "type1", "1", "field1", "The <b>quick<b> brown fox", "field2", "The <b>slow<b> brown fox");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("field1", "fox"))
@@ -1843,6 +1891,7 @@ public void testMissingStoredField() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource(jsonBuilder().startObject().field("field", "highlight").endObject()).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // This query used to fail when the field to highlight was absent
         SearchResponse response = client().prepareSearch("test")
@@ -1883,6 +1932,7 @@ public void testNumericHighlighting() throws Exception {
             .setSource("text", "opensearch test", "byte", 25, "short", 42, "int", 100, "long", -1, "float", 3.2f, "double", 42.42)
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("text", "test"))
@@ -1905,6 +1955,7 @@ public void testResetTwice() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("text", "opensearch test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("text", "test"))
@@ -1914,7 +1965,7 @@ public void testResetTwice() throws Exception {
         assertHitCount(response, 1L);
     }
 
-    public void testHighlightUsesHighlightQuery() throws IOException {
+    public void testHighlightUsesHighlightQuery() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -1925,6 +1976,7 @@ public void testHighlightUsesHighlightQuery() throws IOException {
 
         index("test", "type1", "1", "text", "Testing the highlight query feature");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         for (String type : ALL_TYPES) {
             HighlightBuilder.Field field = new HighlightBuilder.Field("text");
@@ -1960,7 +2012,7 @@ private static String randomStoreField() {
         return "";
     }
 
-    public void testHighlightNoMatchSize() throws IOException {
+    public void testHighlightNoMatchSize() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -1972,6 +2024,7 @@ public void testHighlightNoMatchSize() throws IOException {
         String text = "I am pretty long so some of me should get cut off. Second sentence";
         index("test", "type1", "1", "text", text);
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // When you don't set noMatchSize you don't get any results if there isn't anything to highlight.
         HighlightBuilder.Field field = new HighlightBuilder.Field("text").fragmentSize(21).numOfFragments(1).highlighterType("plain");
@@ -2070,7 +2123,7 @@ public void testHighlightNoMatchSize() throws IOException {
         assertNotHighlighted(response, 0, "text");
     }
 
-    public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException {
+    public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -2083,6 +2136,7 @@ public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException {
         String text2 = "I am short";
         index("test", "type1", "1", "text", new String[] { text1, text2 });
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // The no match fragment should come from the first value of a multi-valued field
         HighlightBuilder.Field field = new HighlightBuilder.Field("text").fragmentSize(21)
@@ -2165,7 +2219,7 @@ public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException {
         assertNotHighlighted(response, 0, "text");
     }
 
-    public void testHighlightNoMatchSizeNumberOfFragments() throws IOException {
+    public void testHighlightNoMatchSizeNumberOfFragments() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -2179,6 +2233,7 @@ public void testHighlightNoMatchSizeNumberOfFragments() throws IOException {
         String text3 = "This is the fifth sentence";
         index("test", "type1", "1", "text", new String[] { text1, text2, text3 });
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // The no match fragment should come from the first value of a multi-valued field
         HighlightBuilder.Field field = new HighlightBuilder.Field("text").fragmentSize(1)
@@ -2222,6 +2277,7 @@ public void testPostingsHighlighter() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy quick dog")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "test"))
@@ -2299,6 +2355,7 @@ public void testPostingsHighlighterMultipleFields() throws Exception {
             "The <b>slow<b> brown fox. Second sentence."
         );
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("field1", "fox"))
@@ -2323,6 +2380,7 @@ public void testPostingsHighlighterNumberOfFragments() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "fox"))
@@ -2355,6 +2413,7 @@ public void testPostingsHighlighterNumberOfFragments() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         source = searchSource().query(termQuery("field1", "fox"))
             .highlighter(highlight().field(new Field("field1").numOfFragments(0).preTags("<field1>").postTags("</field1>")));
@@ -2391,7 +2450,7 @@ public void testPostingsHighlighterNumberOfFragments() throws Exception {
         }
     }
 
-    public void testMultiMatchQueryHighlight() throws IOException {
+    public void testMultiMatchQueryHighlight() throws IOException, InterruptedException {
         XContentBuilder mapping = XContentFactory.jsonBuilder()
             .startObject()
             .startObject("properties")
@@ -2413,6 +2472,7 @@ public void testMultiMatchQueryHighlight() throws IOException {
             .setSource("field1", "The quick brown fox jumps over", "field2", "The quick brown fox jumps over")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         final int iters = scaledRandomIntBetween(20, 30);
         for (int i = 0; i < iters; i++) {
             String highlighterType = rarely() ? null : RandomPicks.randomFrom(random(), ALL_TYPES);
@@ -2458,6 +2518,7 @@ public void testPostingsHighlighterOrderByScore() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "sentence"))
@@ -2544,6 +2605,7 @@ public void testPostingsHighlighterMultiMapperWithStore() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test . Second sentence.").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse searchResponse = client().prepareSearch()
@@ -2602,6 +2664,7 @@ public void testPostingsHighlighterMultiMapperFromSource() throws Exception {
 
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse searchResponse = client().prepareSearch()
@@ -2651,13 +2714,14 @@ public void testPostingsHighlighterShouldFailIfNoOffsets() throws Exception {
         assertNoFailures(search);
     }
 
-    public void testPostingsHighlighterBoostingQuery() throws IOException {
+    public void testPostingsHighlighterBoostingQuery() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1PostingsffsetsMapping()));
         ensureGreen();
         client().prepareIndex("test")
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -2668,7 +2732,7 @@ public void testPostingsHighlighterBoostingQuery() throws IOException {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The quick <x>brown</x> fox jumps over the lazy dog! Second sentence."));
     }
 
-    public void testPostingsHighlighterCommonTermsQuery() throws IOException {
+    public void testPostingsHighlighterCommonTermsQuery() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1PostingsffsetsMapping()));
         ensureGreen();
 
@@ -2676,6 +2740,7 @@ public void testPostingsHighlighterCommonTermsQuery() throws IOException {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(commonTermsQuery("field2", "quick brown").cutoffFrequency(100))
@@ -2717,6 +2782,7 @@ public void testPostingsHighlighterPrefixQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         logger.info("--> highlighting and searching on field2");
 
         SearchSourceBuilder source = searchSource().query(prefixQuery("field2", "qui")).highlighter(highlight().field("field2"));
@@ -2739,6 +2805,7 @@ public void testPostingsHighlighterFuzzyQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(fuzzyQuery("field2", "quck")).highlighter(highlight().field("field2"));
@@ -2762,6 +2829,7 @@ public void testPostingsHighlighterRegexpQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(regexpQuery("field2", "qu[a-l]+k")).highlighter(highlight().field("field2"));
@@ -2785,6 +2853,7 @@ public void testPostingsHighlighterWildcardQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(wildcardQuery("field2", "qui*")).highlighter(highlight().field("field2"));
@@ -2819,6 +2888,7 @@ public void testPostingsHighlighterTermRangeQuery() throws Exception {
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "aaab").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(rangeQuery("field2").gte("aaaa").lt("zzzz"))
@@ -2836,6 +2906,7 @@ public void testPostingsHighlighterQueryString() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(queryStringQuery("qui*").defaultField("field2"))
@@ -2857,6 +2928,7 @@ public void testPostingsHighlighterRegexpQueryWithinConstantScoreQuery() throws
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(constantScoreQuery(regexpQuery("field1", "pho[a-z]+")))
@@ -2871,6 +2943,7 @@ public void testPostingsHighlighterMultiTermQueryMultipleLevels() throws Excepti
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -2888,6 +2961,7 @@ public void testPostingsHighlighterPrefixQueryWithinBooleanQuery() throws Except
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -2903,6 +2977,7 @@ public void testPostingsHighlighterQueryStringWithinFilteredQuery() throws Excep
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -3007,7 +3082,7 @@ public void testFastVectorHighlighterPhraseBoost() throws Exception {
      * because it doesn't support the concept of terms having a different weight based on position.
      * @param highlighterType highlighter to test
      */
-    private void phraseBoostTestCase(String highlighterType) {
+    private void phraseBoostTestCase(String highlighterType) throws InterruptedException {
         ensureGreen();
         StringBuilder text = new StringBuilder();
         text.append("words words junk junk junk junk junk junk junk junk highlight junk junk junk junk together junk\n");
@@ -3020,6 +3095,7 @@ private void phraseBoostTestCase(String highlighterType) {
         }
         index("test", "type1", "1", "field1", text.toString());
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // Match queries
         phraseBoostTestCaseForClauses(
@@ -3088,7 +3164,7 @@ private <P extends AbstractQueryBuilder<P>> void phraseBoostTestCaseForClauses(
         assertHighlight(response, 0, "field1", 0, 1, highlightedMatcher);
     }
 
-    public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOException {
+    public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOException, InterruptedException {
         // check that we do not get an exception for geo_point fields in case someone tries to highlight
         // it accidentially with a wildcard
         // see https://github.com/elastic/elasticsearch/issues/17537
@@ -3112,6 +3188,7 @@ public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOExcepti
             .setSource(jsonBuilder().startObject().field("text", "Arbitrary text field which will should not cause a failure").endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         String highlighterType = randomFrom(ALL_TYPES);
         QueryBuilder query = QueryBuilders.boolQuery()
             .should(
@@ -3129,7 +3206,7 @@ public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOExcepti
         assertThat(search.getHits().getAt(0).getHighlightFields().get("text").fragments().length, equalTo(1));
     }
 
-    public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException {
+    public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException, InterruptedException {
         // same as above but in this example the query gets rewritten during highlighting
         // see https://github.com/elastic/elasticsearch/issues/17537#issuecomment-244939633
         XContentBuilder mappings = jsonBuilder();
@@ -3156,6 +3233,7 @@ public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         QueryBuilder query = QueryBuilders.functionScoreQuery(
             QueryBuilders.boolQuery()
@@ -3171,7 +3249,7 @@ public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException
         assertThat(search.getHits().getTotalHits().value, equalTo(1L));
     }
 
-    public void testKeywordFieldHighlighting() throws IOException {
+    public void testKeywordFieldHighlighting() throws IOException, InterruptedException {
         // check that keyword highlighting works
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
@@ -3184,6 +3262,7 @@ public void testKeywordFieldHighlighting() throws IOException {
             .setSource(jsonBuilder().startObject().field("keyword_field", "some text").endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse search = client().prepareSearch()
             .setSource(
                 new SearchSourceBuilder().query(QueryBuilders.matchQuery("keyword_field", "some text"))
@@ -3217,6 +3296,7 @@ public void testCopyToFields() throws Exception {
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse response = client().prepareSearch()
             .setQuery(matchQuery("foo_copy", "brown"))
             .highlighter(new HighlightBuilder().field(new Field("foo_copy")))
@@ -3266,7 +3346,7 @@ public void testACopyFieldWithNestedQuery() throws Exception {
             )
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
-
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(nestedQuery("foo", matchQuery("foo.text", "brown cow"), ScoreMode.None))
             .highlighter(new HighlightBuilder().field(new Field("foo_text").highlighterType("fvh")).requireFieldMatch(false))
@@ -3284,6 +3364,7 @@ public void testFunctionScoreQueryHighlight() throws Exception {
             .setSource(jsonBuilder().startObject().field("text", "brown").endObject())
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(new FunctionScoreQueryBuilder(QueryBuilders.prefixQuery("text", "bro")))
@@ -3301,6 +3382,7 @@ public void testFiltersFunctionScoreQueryHighlight() throws Exception {
             .setSource(jsonBuilder().startObject().field("text", "brown").field("enable", "yes").endObject())
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
         FunctionScoreQueryBuilder.FilterFunctionBuilder filterBuilder = new FunctionScoreQueryBuilder.FilterFunctionBuilder(
             QueryBuilders.termQuery("enable", "yes"),
             new RandomScoreFunctionBuilder()
@@ -3395,6 +3477,7 @@ public void testWithNestedQuery() throws Exception {
             )
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         for (String type : new String[] { "unified", "plain" }) {
             SearchResponse searchResponse = client().prepareSearch()
@@ -3452,6 +3535,7 @@ public void testWithNormalizer() throws Exception {
             .setSource("keyword", "Hello World")
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         for (String highlighterType : new String[] { "unified", "plain" }) {
             SearchResponse searchResponse = client().prepareSearch()
@@ -3474,6 +3558,7 @@ public void testDisableHighlightIdField() throws Exception {
             .setSource("keyword", "Hello World")
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         for (String highlighterType : new String[] { "plain", "unified" }) {
             SearchResponse searchResponse = client().prepareSearch()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fieldcaps/FieldCapabilitiesIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fieldcaps/FieldCapabilitiesIT.java
index 21efcd738ae9f..f5d1b8234558e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fieldcaps/FieldCapabilitiesIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fieldcaps/FieldCapabilitiesIT.java
@@ -32,15 +32,19 @@
 
 package org.opensearch.search.fieldcaps;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.fieldcaps.FieldCapabilities;
 import org.opensearch.action.fieldcaps.FieldCapabilitiesResponse;
 import org.opensearch.action.index.IndexRequestBuilder;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.plugins.MapperPlugin;
 import org.opensearch.plugins.Plugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.Before;
 
 import java.util.ArrayList;
@@ -52,9 +56,27 @@
 import java.util.function.Function;
 import java.util.function.Predicate;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 
-public class FieldCapabilitiesIT extends OpenSearchIntegTestCase {
+public class FieldCapabilitiesIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public FieldCapabilitiesIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Before
     public void setUp() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fields/SearchFieldsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fields/SearchFieldsIT.java
index 65798713bb577..ed8fe74504f92 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fields/SearchFieldsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fields/SearchFieldsIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.fields;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
@@ -41,6 +43,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.time.DateUtils;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.support.XContentMapValues;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -60,7 +63,7 @@
 import org.opensearch.search.lookup.FieldLookup;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.InternalSettingsPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
 import org.joda.time.format.DateTimeFormat;
@@ -88,6 +91,7 @@
 import static org.opensearch.common.util.set.Sets.newHashSet;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFailures;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
@@ -100,7 +104,24 @@
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
 
-public class SearchFieldsIT extends OpenSearchIntegTestCase {
+public class SearchFieldsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchFieldsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -230,6 +251,7 @@ public void testStoredFields() throws Exception {
             .get();
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).addStoredField("field1").get();
         assertThat(searchResponse.getHits().getTotalHits().value, equalTo(1L));
@@ -337,6 +359,7 @@ public void testScriptDocAndFields() throws Exception {
             )
             .get();
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("running doc['num1'].value");
         SearchResponse response = client().prepareSearch()
@@ -437,6 +460,7 @@ public void testScriptWithUnsignedLong() throws Exception {
             )
             .get();
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -526,6 +550,7 @@ public void testScriptFieldWithNanos() throws Exception {
                 .setSource(jsonBuilder().startObject().field("date", "1970-01-01T00:00:00.000Z").endObject()),
             client().prepareIndex("test").setId("2").setSource(jsonBuilder().startObject().field("date", date).endObject())
         );
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -611,6 +636,7 @@ public void testScriptFieldUsingSource() throws Exception {
             )
             .get();
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -653,6 +679,7 @@ public void testScriptFieldUsingSource() throws Exception {
     public void testScriptFieldsForNullReturn() throws Exception {
         client().prepareIndex("test").setId("1").setSource("foo", "bar").setRefreshPolicy("true").get();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse response = client().prepareSearch()
             .setQuery(matchAllQuery())
             .addScriptField("test_script_1", new Script(ScriptType.INLINE, CustomScriptPlugin.NAME, "return null", Collections.emptyMap()))
@@ -774,6 +801,7 @@ public void testStoredFieldsWithoutSource() throws Exception {
             .get();
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -831,6 +859,7 @@ public void testSearchFieldsMetadata() throws Exception {
             .setSource(jsonBuilder().startObject().field("field1", "value").endObject())
             .setRefreshPolicy(IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("my-index");
 
         SearchResponse searchResponse = client().prepareSearch("my-index").addStoredField("field1").addStoredField("_routing").get();
 
@@ -845,6 +874,7 @@ public void testSearchFieldsNonLeafField() throws Exception {
             .setSource(jsonBuilder().startObject().startObject("field1").field("field2", "value1").endObject().endObject())
             .setRefreshPolicy(IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("my-index");
 
         assertFailures(
             client().prepareSearch("my-index").addStoredField("field1"),
@@ -911,6 +941,7 @@ public void testGetFieldsComplexField() throws Exception {
         );
 
         client().prepareIndex("my-index").setId("1").setRefreshPolicy(IMMEDIATE).setSource(source, MediaTypeRegistry.JSON).get();
+        indexRandomForConcurrentSearch("my-index");
 
         String field = "field1.field2.field3.field4";
 
@@ -1018,6 +1049,7 @@ public void testDocValueFields() throws Exception {
             .get();
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchRequestBuilder builder = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -1250,6 +1282,7 @@ public void testScriptFields() throws Exception {
             );
         }
         indexRandom(true, reqs);
+        indexRandomForConcurrentSearch("index");
         ensureSearchable();
         SearchRequestBuilder req = client().prepareSearch("index");
         for (String field : Arrays.asList("s", "ms", "l", "ml", "d", "md")) {
@@ -1305,6 +1338,7 @@ public void testDocValueFieldsWithFieldAlias() throws Exception {
 
         index("test", MapperService.SINGLE_MAPPING_NAME, "1", "text_field", "foo", "date_field", formatter.print(date));
         refresh("test");
+        indexRandomForConcurrentSearch("test");
 
         SearchRequestBuilder builder = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -1366,6 +1400,7 @@ public void testWildcardDocValueFieldsWithFieldAlias() throws Exception {
 
         index("test", MapperService.SINGLE_MAPPING_NAME, "1", "text_field", "foo", "date_field", formatter.print(date));
         refresh("test");
+        indexRandomForConcurrentSearch("test");
 
         SearchRequestBuilder builder = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -1419,6 +1454,7 @@ public void testStoredFieldsWithFieldAlias() throws Exception {
 
         index("test", MapperService.SINGLE_MAPPING_NAME, "1", "field1", "value1", "field2", "value2");
         refresh("test");
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -1461,6 +1497,7 @@ public void testWildcardStoredFieldsWithFieldAlias() throws Exception {
 
         index("test", MapperService.SINGLE_MAPPING_NAME, "1", "field1", "value1", "field2", "value2");
         refresh("test");
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).addStoredField("field*").get();
         assertHitCount(searchResponse, 1L);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/DecayFunctionScoreIT.java b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/DecayFunctionScoreIT.java
index c888dcddb5611..3a6624c2ad2e6 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/DecayFunctionScoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/DecayFunctionScoreIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.functionscore;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.Version;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
@@ -44,6 +46,7 @@
 import org.opensearch.common.lucene.search.function.FunctionScoreQuery;
 import org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilder;
 import org.opensearch.index.query.QueryBuilders;
@@ -53,12 +56,14 @@
 import org.opensearch.search.MultiValueMode;
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.SearchHits;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.VersionUtils;
 
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.Locale;
 
@@ -72,6 +77,7 @@
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.exponentialDecayFunction;
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.gaussDecayFunction;
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.linearDecayFunction;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
@@ -85,7 +91,24 @@
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.lessThan;
 
-public class DecayFunctionScoreIT extends OpenSearchIntegTestCase {
+public class DecayFunctionScoreIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public DecayFunctionScoreIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected boolean forbidPrivateIndexSettings() {
@@ -375,6 +398,7 @@ public void testBoostModeSettingWorks() throws Exception {
                 )
         );
         indexRandom(true, false, indexBuilders); // force no dummy docs
+        indexRandomForConcurrentSearch("test");
 
         // Test Gauss
         List<Float> lonlat = new ArrayList<>();
@@ -459,6 +483,7 @@ public void testParseGeoPoint() throws Exception {
             constantScoreQuery(termQuery("test", "value")),
             ScoreFunctionBuilders.weightFactorFunction(randomIntBetween(1, 10))
         );
+        indexRandomForConcurrentSearch("test");
         GeoPoint point = new GeoPoint(20, 11);
         ActionFuture<SearchResponse> response = client().search(
             searchRequest().searchType(SearchType.QUERY_THEN_FETCH)
@@ -512,6 +537,7 @@ public void testCombineModes() throws Exception {
             .setRefreshPolicy(IMMEDIATE)
             .setSource(jsonBuilder().startObject().field("test", "value value").field("num", 1.0).endObject())
             .get();
+        indexRandomForConcurrentSearch("test");
         FunctionScoreQueryBuilder baseQuery = functionScoreQuery(
             constantScoreQuery(termQuery("test", "value")),
             ScoreFunctionBuilders.weightFactorFunction(2)
@@ -631,6 +657,7 @@ public void testCombineModesExplain() throws Exception {
             constantScoreQuery(termQuery("test", "value")).queryName("query1"),
             ScoreFunctionBuilders.weightFactorFunction(2, "weight1")
         );
+        indexRandomForConcurrentSearch("test");
         // decay score should return 0.5 for this function and baseQuery should return 2.0f as it's score
         ActionFuture<SearchResponse> response = client().search(
             searchRequest().searchType(SearchType.QUERY_THEN_FETCH)
@@ -739,6 +766,7 @@ public void testParseDateMath() throws Exception {
         ).actionGet();
         refresh();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse sr = client().search(
             searchRequest().source(
                 searchSource().query(functionScoreQuery(termQuery("test", "value"), gaussDecayFunction("num1", "now", "2d")))
@@ -794,6 +822,7 @@ public void testValueMissingLin() throws Exception {
         ).actionGet();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         ActionFuture<SearchResponse> response = client().search(
             searchRequest().searchType(SearchType.QUERY_THEN_FETCH)
@@ -870,6 +899,7 @@ public void testDateWithoutOrigin() throws Exception {
         ).actionGet();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         ActionFuture<SearchResponse> response = client().search(
             searchRequest().searchType(SearchType.QUERY_THEN_FETCH)
@@ -951,6 +981,7 @@ public void testManyDocsLin() throws Exception {
         List<Float> lonlat = new ArrayList<>();
         lonlat.add(100f);
         lonlat.add(110f);
+        indexRandomForConcurrentSearch("test");
         ActionFuture<SearchResponse> response = client().search(
             searchRequest().searchType(SearchType.QUERY_THEN_FETCH)
                 .source(
@@ -1084,6 +1115,7 @@ public void testNoQueryGiven() throws Exception {
         client().index(indexRequest("test").source(jsonBuilder().startObject().field("test", "value").field("num", 1.0).endObject()))
             .actionGet();
         refresh();
+        indexRandomForConcurrentSearch("test");
         // so, we indexed a string field, but now we try to score a num field
         ActionFuture<SearchResponse> response = client().search(
             searchRequest().searchType(SearchType.QUERY_THEN_FETCH)
@@ -1148,6 +1180,7 @@ public void testMultiFieldOptions() throws Exception {
             );
 
         indexRandom(true, doc1, doc2);
+        indexRandomForConcurrentSearch("test");
 
         ActionFuture<SearchResponse> response = client().search(searchRequest().source(searchSource().query(baseQuery)));
         SearchResponse sr = response.actionGet();
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/ExplainableScriptIT.java b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/ExplainableScriptIT.java
index f329677a94340..62d0d89c644a5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/ExplainableScriptIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/ExplainableScriptIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.functionscore;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.search.Explanation;
 import org.apache.lucene.search.IndexSearcher;
@@ -41,6 +43,7 @@
 import org.opensearch.common.lucene.search.function.CombineFunction;
 import org.opensearch.common.lucene.search.function.Functions;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.plugins.ScriptPlugin;
@@ -53,9 +56,9 @@
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.SearchHits;
 import org.opensearch.search.lookup.SearchLookup;
-import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
 import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 
 import java.io.IOException;
@@ -73,13 +76,31 @@
 import static org.opensearch.index.query.QueryBuilders.functionScoreQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.scriptFunction;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.hamcrest.Matchers.arrayWithSize;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 
 @ClusterScope(scope = Scope.SUITE, supportsDedicatedMasters = false, numDataNodes = 1)
-public class ExplainableScriptIT extends OpenSearchIntegTestCase {
+public class ExplainableScriptIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public ExplainableScriptIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public static class ExplainableScriptPlugin extends Plugin implements ScriptPlugin {
         @Override
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreFieldValueIT.java b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreFieldValueIT.java
index cf133396e6fcb..d53f55b98bd23 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreFieldValueIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreFieldValueIT.java
@@ -32,19 +32,26 @@
 
 package org.opensearch.search.functionscore;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.lucene.search.function.FieldValueFactorFunction;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.SearchHit;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.functionScoreQuery;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.simpleQueryStringQuery;
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.fieldValueFactorFunction;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFailures;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertOrderedSearchHits;
@@ -54,8 +61,26 @@
 /**
  * Tests for the {@code field_value_factor} function in a function_score query.
  */
-public class FunctionScoreFieldValueIT extends OpenSearchIntegTestCase {
-    public void testFieldValueFactor() throws IOException {
+public class FunctionScoreFieldValueIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public FunctionScoreFieldValueIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
+    public void testFieldValueFactor() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 jsonBuilder().startObject()
@@ -74,8 +99,8 @@ public void testFieldValueFactor() throws IOException {
         client().prepareIndex("test").setId("1").setSource("test", 5, "body", "foo").get();
         client().prepareIndex("test").setId("2").setSource("test", 17, "body", "foo").get();
         client().prepareIndex("test").setId("3").setSource("body", "bar").get();
-
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // document 2 scores higher because 17 > 5
         SearchResponse response = client().prepareSearch("test")
@@ -164,7 +189,7 @@ public void testFieldValueFactor() throws IOException {
         }
     }
 
-    public void testFieldValueFactorExplain() throws IOException {
+    public void testFieldValueFactorExplain() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 jsonBuilder().startObject()
@@ -185,6 +210,7 @@ public void testFieldValueFactorExplain() throws IOException {
         client().prepareIndex("test").setId("3").setSource("body", "bar").get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // document 2 scores higher because 17 > 5
         final String functionName = "func1";
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreIT.java b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreIT.java
index 3d24933f66d17..3b80d437e95c0 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScoreIT.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.search.functionscore;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.lucene.search.function.CombineFunction;
 import org.opensearch.common.lucene.search.function.FunctionScoreQuery;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.index.query.MatchAllQueryBuilder;
 import org.opensearch.index.query.functionscore.FunctionScoreQueryBuilder.FilterFunctionBuilder;
@@ -45,11 +49,12 @@
 import org.opensearch.script.ScriptType;
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
-import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -63,6 +68,7 @@
 import static org.opensearch.index.query.QueryBuilders.functionScoreQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.scriptFunction;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 import static org.opensearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
@@ -72,11 +78,28 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
 
-public class FunctionScoreIT extends OpenSearchIntegTestCase {
+public class FunctionScoreIT extends ParameterizedOpenSearchIntegTestCase {
 
     static final String TYPE = "type";
     static final String INDEX = "index";
 
+    public FunctionScoreIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
@@ -103,10 +126,11 @@ protected Map<String, Function<Map<String, Object>, Object>> pluginScripts() {
         }
     }
 
-    public void testScriptScoresNested() throws IOException {
+    public void testScriptScoresNested() throws IOException, InterruptedException {
         createIndex(INDEX);
         index(INDEX, TYPE, "1", jsonBuilder().startObject().field("dummy_field", 1).endObject());
         refresh();
+        indexRandomForConcurrentSearch(INDEX);
 
         Script scriptOne = new Script(ScriptType.INLINE, CustomScriptPlugin.NAME, "1", Collections.emptyMap());
         Script scriptTwo = new Script(ScriptType.INLINE, CustomScriptPlugin.NAME, "get score value", Collections.emptyMap());
@@ -125,10 +149,11 @@ public void testScriptScoresNested() throws IOException {
         assertThat(response.getHits().getAt(0).getScore(), equalTo(1.0f));
     }
 
-    public void testScriptScoresWithAgg() throws IOException {
+    public void testScriptScoresWithAgg() throws IOException, InterruptedException {
         createIndex(INDEX);
         index(INDEX, TYPE, "1", jsonBuilder().startObject().field("dummy_field", 1).endObject());
         refresh();
+        indexRandomForConcurrentSearch(INDEX);
 
         Script script = new Script(ScriptType.INLINE, CustomScriptPlugin.NAME, "get score value", Collections.emptyMap());
 
@@ -143,10 +168,11 @@ public void testScriptScoresWithAgg() throws IOException {
         assertThat(((Terms) response.getAggregations().asMap().get("score_agg")).getBuckets().get(0).getDocCount(), is(1L));
     }
 
-    public void testScriptScoresWithAggWithExplain() throws IOException {
+    public void testScriptScoresWithAggWithExplain() throws IOException, InterruptedException {
         createIndex(INDEX);
         index(INDEX, TYPE, "1", jsonBuilder().startObject().field("dummy_field", 1).endObject());
         refresh();
+        indexRandomForConcurrentSearch(INDEX);
 
         Script script = new Script(ScriptType.INLINE, CustomScriptPlugin.NAME, "get score value", Collections.emptyMap());
 
@@ -172,7 +198,7 @@ public void testScriptScoresWithAggWithExplain() throws IOException {
         assertThat(((Terms) response.getAggregations().asMap().get("score_agg")).getBuckets().get(0).getDocCount(), is(1L));
     }
 
-    public void testMinScoreFunctionScoreBasic() throws IOException {
+    public void testMinScoreFunctionScoreBasic() throws IOException, InterruptedException {
         float score = randomValueOtherThanMany((f) -> Float.compare(f, 0) < 0, OpenSearchTestCase::randomFloat);
         float minScore = randomValueOtherThanMany((f) -> Float.compare(f, 0) < 0, OpenSearchTestCase::randomFloat);
         index(
@@ -184,6 +210,7 @@ public void testMinScoreFunctionScoreBasic() throws IOException {
                 .endObject()
         );
         refresh();
+        indexRandomForConcurrentSearch(INDEX);
         ensureYellow();
 
         Script script = new Script(ScriptType.INLINE, CustomScriptPlugin.NAME, "doc['random_score']", Collections.emptyMap());
@@ -268,6 +295,7 @@ public void testWithEmptyFunctions() throws IOException, ExecutionException, Int
         assertAcked(prepareCreate("test"));
         index("test", "testtype", "1", jsonBuilder().startObject().field("text", "test text").endObject());
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse termQuery = client().search(searchRequest().source(searchSource().explain(true).query(termQuery("text", "text"))))
             .get();
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScorePluginIT.java b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScorePluginIT.java
index 384d9f2c61042..a91f53dae04d2 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScorePluginIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/FunctionScorePluginIT.java
@@ -32,11 +32,15 @@
 
 package org.opensearch.search.functionscore;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.Explanation;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchType;
 import org.opensearch.common.Priority;
 import org.opensearch.common.action.ActionFuture;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.index.query.functionscore.DecayFunction;
@@ -46,9 +50,9 @@
 import org.opensearch.plugins.Plugin;
 import org.opensearch.plugins.SearchPlugin;
 import org.opensearch.search.SearchHits;
-import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
 import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 
 import java.io.IOException;
@@ -62,11 +66,30 @@
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.functionScoreQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.hamcrest.Matchers.equalTo;
 
 @ClusterScope(scope = Scope.SUITE, supportsDedicatedMasters = false, numDataNodes = 1)
-public class FunctionScorePluginIT extends OpenSearchIntegTestCase {
+public class FunctionScorePluginIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public FunctionScorePluginIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(CustomDistanceScorePlugin.class);
@@ -99,6 +122,7 @@ public void testPlugin() throws Exception {
         ).actionGet();
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
         DecayFunctionBuilder<?> gfb = new CustomDistanceScoreBuilder("num1", "2013-05-28", "+1d");
 
         ActionFuture<SearchResponse> response = client().search(
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/QueryRescorerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/QueryRescorerIT.java
index 34a304615b075..bda6284d9535a 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/QueryRescorerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/QueryRescorerIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.functionscore;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.Explanation;
 import org.apache.lucene.tests.util.English;
 import org.opensearch.action.index.IndexRequestBuilder;
@@ -41,6 +43,7 @@
 import org.opensearch.common.lucene.search.function.CombineFunction;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.settings.Settings.Builder;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.Operator;
@@ -52,9 +55,10 @@
 import org.opensearch.search.rescore.QueryRescoreMode;
 import org.opensearch.search.rescore.QueryRescorerBuilder;
 import org.opensearch.search.sort.SortBuilders;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Comparator;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
@@ -70,6 +74,7 @@
 import static org.opensearch.index.query.QueryBuilders.queryStringQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.weightFactorFunction;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFirstHit;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFourthHit;
@@ -86,8 +91,26 @@
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
 import static org.hamcrest.Matchers.notNullValue;
 
-public class QueryRescorerIT extends OpenSearchIntegTestCase {
-    public void testEnforceWindowSize() {
+public class QueryRescorerIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public QueryRescorerIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
+    public void testEnforceWindowSize() throws InterruptedException {
         createIndex("test");
         // this
         int iters = scaledRandomIntBetween(10, 20);
@@ -95,6 +118,7 @@ public void testEnforceWindowSize() {
             client().prepareIndex("test").setId(Integer.toString(i)).setSource("f", Integer.toString(i)).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         int numShards = getNumShards("test").numPrimaries;
         for (int j = 0; j < iters; j++) {
@@ -146,6 +170,7 @@ public void testRescorePhrase() throws Exception {
             .setSource("field1", "quick huge brown", "field2", "the quick lazy huge brown fox jumps over the tree")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(QueryBuilders.matchQuery("field1", "the quick brown").operator(Operator.OR))
             .setRescorer(
@@ -451,6 +476,7 @@ private static void assertEquivalent(String query, SearchResponse plain, SearchR
     public void testEquivalence() throws Exception {
         // no dummy docs since merges can change scores while we run queries.
         int numDocs = indexRandomNumbers("whitespace", -1, false);
+        indexRandomForConcurrentSearch("test");
 
         final int iters = scaledRandomIntBetween(50, 100);
         for (int i = 0; i < iters; i++) {
@@ -522,6 +548,7 @@ public void testExplain() throws Exception {
             .setSource("field1", "quick huge brown", "field2", "the quick lazy huge brown fox jumps over the tree")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         {
             SearchResponse searchResponse = client().prepareSearch()
@@ -793,6 +820,7 @@ public void testFromSize() throws Exception {
             client().prepareIndex("test").setId("" + i).setSource("text", "hello world").get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchRequestBuilder request = client().prepareSearch();
         request.setQuery(QueryBuilders.termQuery("text", "hello"));
@@ -809,6 +837,7 @@ public void testRescorePhaseWithInvalidSort() throws Exception {
             client().prepareIndex("test").setId("" + i).setSource("number", 0).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         Exception exc = expectThrows(
             Exception.class,
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/RandomScoreFunctionIT.java b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/RandomScoreFunctionIT.java
index 2176b93079d02..69e30fc879dd8 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/functionscore/RandomScoreFunctionIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/functionscore/RandomScoreFunctionIT.java
@@ -31,8 +31,12 @@
 
 package org.opensearch.search.functionscore;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.util.ArrayUtil;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.index.mapper.SeqNoFieldMapper;
 import org.opensearch.index.query.functionscore.FunctionScoreQueryBuilder;
@@ -43,7 +47,7 @@
 import org.opensearch.script.Script;
 import org.opensearch.script.ScriptType;
 import org.opensearch.search.SearchHit;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.CoreMatchers;
 
 import java.util.Arrays;
@@ -60,6 +64,7 @@
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.randomFunction;
 import static org.opensearch.index.query.functionscore.ScoreFunctionBuilders.scriptFunction;
 import static org.opensearch.script.MockScriptPlugin.NAME;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 import static org.hamcrest.Matchers.allOf;
@@ -71,7 +76,24 @@
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
 import static org.hamcrest.Matchers.nullValue;
 
-public class RandomScoreFunctionIT extends OpenSearchIntegTestCase {
+public class RandomScoreFunctionIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public RandomScoreFunctionIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -113,6 +135,7 @@ public void testConsistentHitsWithSameSeed() throws Exception {
         }
         flush();
         refresh();
+        indexRandomForConcurrentSearch("test");
         int outerIters = scaledRandomIntBetween(10, 20);
         for (int o = 0; o < outerIters; o++) {
             final int seed = randomInt();
@@ -185,6 +208,7 @@ public void testScoreAccessWithinScript() throws Exception {
                 .get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         Map<String, Object> params = new HashMap<>();
         params.put("factor", randomIntBetween(2, 4));
@@ -276,6 +300,7 @@ public void testSeedReportedInExplain() throws Exception {
         index("test", "type", "1", jsonBuilder().startObject().endObject());
         flush();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         int seed = 12345678;
 
@@ -295,6 +320,7 @@ public void testSeedAndNameReportedInExplain() throws Exception {
         index("test", "type", "1", jsonBuilder().startObject().endObject());
         flush();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         int seed = 12345678;
 
@@ -346,6 +372,7 @@ public void testScoreRange() throws Exception {
         }
         flush();
         refresh();
+        indexRandomForConcurrentSearch("test");
         int iters = scaledRandomIntBetween(10, 20);
         for (int i = 0; i < iters; ++i) {
             SearchResponse searchResponse = client().prepareSearch()
@@ -368,6 +395,7 @@ public void testSeeds() throws Exception {
             index("test", "type", "" + i, jsonBuilder().startObject().endObject());
         }
         flushAndRefresh();
+        indexRandomForConcurrentSearch("test");
 
         assertNoFailures(
             client().prepareSearch()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoFilterIT.java b/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoFilterIT.java
index 9c06082db31d4..ba519be04edff 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoFilterIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoFilterIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.geo;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.apache.lucene.spatial.prefix.RecursivePrefixTreeStrategy;
@@ -54,6 +56,7 @@
 import org.opensearch.common.geo.builders.PointBuilder;
 import org.opensearch.common.geo.builders.PolygonBuilder;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.util.io.Streams;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -61,7 +64,7 @@
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.SearchHit;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.VersionUtils;
 import org.junit.BeforeClass;
 
@@ -70,6 +73,8 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Random;
 import java.util.zip.GZIPInputStream;
 
@@ -84,6 +89,7 @@
 import static org.opensearch.index.query.QueryBuilders.geoDistanceQuery;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFirstHit;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.hasId;
@@ -93,7 +99,24 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
 
-public class GeoFilterIT extends OpenSearchIntegTestCase {
+public class GeoFilterIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public GeoFilterIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected boolean forbidPrivateIndexSettings() {
@@ -243,6 +266,7 @@ public void testShapeRelations() throws Exception {
 
         client().prepareIndex("shapes").setId("1").setSource(data, MediaTypeRegistry.JSON).get();
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("shapes");
 
         // Point in polygon
         SearchResponse result = client().prepareSearch()
@@ -404,6 +428,7 @@ public void testBulk() throws Exception {
 
         client().admin().indices().prepareCreate("countries").setSettings(settings).setMapping(xContentBuilder).get();
         BulkResponse bulk = client().prepareBulk().add(bulkAction, 0, bulkAction.length, null, xContentBuilder.contentType()).get();
+        indexRandomForConcurrentSearch("countries");
 
         for (BulkItemResponse item : bulk.getItems()) {
             assertFalse("unable to index data", item.isFailed());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoPolygonIT.java b/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoPolygonIT.java
index d0b017732b270..85cb087585d31 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoPolygonIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoPolygonIT.java
@@ -32,28 +32,52 @@
 
 package org.opensearch.search.geo;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.Version;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.SearchHit;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.VersionUtils;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.boolQuery;
 import static org.opensearch.index.query.QueryBuilders.geoPolygonQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.anyOf;
 import static org.hamcrest.Matchers.equalTo;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class GeoPolygonIT extends OpenSearchIntegTestCase {
+public class GeoPolygonIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public GeoPolygonIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected boolean forbidPrivateIndexSettings() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoShapeIntegrationIT.java b/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoShapeIntegrationIT.java
index 98e9b35208f3e..1f9b6ae434f75 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoShapeIntegrationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/geo/GeoShapeIntegrationIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.geo;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.ClusterState;
@@ -39,22 +41,44 @@
 import org.opensearch.common.geo.builders.PointBuilder;
 import org.opensearch.common.geo.builders.ShapeBuilder;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.index.IndexService;
 import org.opensearch.index.mapper.GeoShapeFieldMapper;
 import org.opensearch.index.mapper.MappedFieldType;
 import org.opensearch.indices.IndicesService;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.index.query.QueryBuilders.geoShapeQuery;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 
-public class GeoShapeIntegrationIT extends OpenSearchIntegTestCase {
+public class GeoShapeIntegrationIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public GeoShapeIntegrationIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Settings nodeSettings(int nodeOrdinal) {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/geo/LegacyGeoShapeIntegrationIT.java b/server/src/internalClusterTest/java/org/opensearch/search/geo/LegacyGeoShapeIntegrationIT.java
index 4ff7f49082901..d21d6036c9673 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/geo/LegacyGeoShapeIntegrationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/geo/LegacyGeoShapeIntegrationIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.geo;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.opensearch.action.search.SearchResponse;
@@ -39,6 +41,7 @@
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
 import org.opensearch.common.geo.builders.ShapeBuilder;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.ToXContent;
@@ -47,17 +50,37 @@
 import org.opensearch.index.mapper.LegacyGeoShapeFieldMapper;
 import org.opensearch.index.mapper.MappedFieldType;
 import org.opensearch.indices.IndicesService;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.index.query.QueryBuilders.geoShapeQuery;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 
-public class LegacyGeoShapeIntegrationIT extends OpenSearchIntegTestCase {
+public class LegacyGeoShapeIntegrationIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public LegacyGeoShapeIntegrationIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     /**
      * Test that orientation parameter correctly persists across cluster restart
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/morelikethis/MoreLikeThisIT.java b/server/src/internalClusterTest/java/org/opensearch/search/morelikethis/MoreLikeThisIT.java
index 4ac8eaa8a1121..dc7c4e687c2fa 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/morelikethis/MoreLikeThisIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/morelikethis/MoreLikeThisIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.morelikethis;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.RoutingMissingException;
 import org.opensearch.action.admin.indices.create.CreateIndexRequestBuilder;
 import org.opensearch.action.index.IndexRequestBuilder;
@@ -39,6 +41,7 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.MoreLikeThisQueryBuilder;
@@ -47,10 +50,11 @@
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.test.InternalSettingsPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -63,6 +67,7 @@
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.moreLikeThisQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
@@ -74,7 +79,24 @@
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.notNullValue;
 
-public class MoreLikeThisIT extends OpenSearchIntegTestCase {
+public class MoreLikeThisIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MoreLikeThisIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -103,6 +125,7 @@ public void testSimpleMoreLikeThis() throws Exception {
         client().index(indexRequest("test").id("2").source(jsonBuilder().startObject().field("text", "lucene release").endObject()))
             .actionGet();
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("Running moreLikeThis");
         SearchResponse response = client().prepareSearch()
@@ -133,6 +156,7 @@ public void testSimpleMoreLikeThisWithTypes() throws Exception {
         client().index(indexRequest("test").id("2").source(jsonBuilder().startObject().field("text", "lucene release").endObject()))
             .actionGet();
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("Running moreLikeThis");
         SearchResponse response = client().prepareSearch()
@@ -168,6 +192,7 @@ public void testMoreLikeThisForZeroTokensInOneOfTheAnalyzedFields() throws Excep
         ).actionGet();
 
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(
@@ -234,6 +259,7 @@ public void testMoreLikeThisWithAliases() throws Exception {
         client().index(indexRequest("test").id("4").source(jsonBuilder().startObject().field("text", "opensearch release").endObject()))
             .actionGet();
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("Running moreLikeThis on index");
         SearchResponse response = client().prepareSearch()
@@ -282,6 +308,7 @@ public void testMoreLikeThisWithAliasesInLikeDocuments() throws Exception {
         client().index(indexRequest(indexName).id("3").source(jsonBuilder().startObject().field("text", "opensearch index").endObject()))
             .actionGet();
         refresh(indexName);
+        indexRandomForConcurrentSearch(indexName);
 
         SearchResponse response = client().prepareSearch()
             .setQuery(new MoreLikeThisQueryBuilder(null, new Item[] { new Item(aliasName, "1") }).minTermFreq(1).minDocFreq(1))
@@ -299,6 +326,7 @@ public void testMoreLikeThisIssue2197() throws Exception {
             .get();
         client().admin().indices().prepareRefresh("foo").get();
         assertThat(ensureGreen(), equalTo(ClusterHealthStatus.GREEN));
+        indexRandomForConcurrentSearch("foo");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(new MoreLikeThisQueryBuilder(null, new Item[] { new Item("foo", "1") }))
@@ -322,6 +350,7 @@ public void testMoreLikeWithCustomRouting() throws Exception {
             .setRouting("2")
             .get();
         client().admin().indices().prepareRefresh("foo").get();
+        indexRandomForConcurrentSearch("foo");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(new MoreLikeThisQueryBuilder(null, new Item[] { new Item("foo", "1").routing("2") }))
@@ -346,6 +375,7 @@ public void testMoreLikeThisIssueRoutingNotSerialized() throws Exception {
             .setRouting("4000")
             .get();
         client().admin().indices().prepareRefresh("foo").get();
+        indexRandomForConcurrentSearch("foo");
         SearchResponse response = client().prepareSearch()
             .setQuery(new MoreLikeThisQueryBuilder(null, new Item[] { new Item("foo", "1").routing("4000") }))
             .get();
@@ -379,6 +409,7 @@ public void testNumericField() throws Exception {
             .get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // Implicit list of fields -> ignore numeric fields
         SearchResponse searchResponse = client().prepareSearch()
@@ -486,6 +517,7 @@ public void testMoreLikeThisWithFieldAlias() throws Exception {
         index("test", "_doc", "1", "text", "lucene");
         index("test", "_doc", "2", "text", "lucene release");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         Item item = new Item("test", "1");
         QueryBuilder query = QueryBuilders.moreLikeThisQuery(new String[] { "alias" }, null, new Item[] { item })
@@ -526,6 +558,7 @@ public void testSimpleMoreLikeInclude() throws Exception {
                 .source(jsonBuilder().startObject().field("text", "Lucene has been ported to other programming languages").endObject())
         ).actionGet();
         client().admin().indices().refresh(refreshRequest()).actionGet();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("Running More Like This with include true");
         SearchResponse response = client().prepareSearch()
@@ -810,11 +843,12 @@ public void testSelectFields() throws IOException, ExecutionException, Interrupt
         assertHitCount(response, 1);
     }
 
-    public void testWithRouting() throws IOException {
+    public void testWithRouting() throws IOException, InterruptedException {
         client().prepareIndex("index").setId("1").setRouting("3").setSource("text", "this is a document").get();
         client().prepareIndex("index").setId("2").setRouting("1").setSource("text", "this is another document").get();
         client().prepareIndex("index").setId("3").setRouting("4").setSource("text", "this is yet another document").get();
         refresh("index");
+        indexRandomForConcurrentSearch("index");
 
         Item item = new Item("index", "2").routing("1");
         MoreLikeThisQueryBuilder moreLikeThisQueryBuilder = new MoreLikeThisQueryBuilder(
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/msearch/MultiSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/msearch/MultiSearchIT.java
index 9c2ddbba89903..b35208941d2a2 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/msearch/MultiSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/msearch/MultiSearchIT.java
@@ -32,26 +32,52 @@
 
 package org.opensearch.search.msearch;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.MultiSearchRequest;
 import org.opensearch.action.search.MultiSearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.index.query.QueryBuilders;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFirstHit;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.hasId;
 import static org.hamcrest.Matchers.equalTo;
 
-public class MultiSearchIT extends OpenSearchIntegTestCase {
+public class MultiSearchIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MultiSearchIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
-    public void testSimpleMultiSearch() {
+    public void testSimpleMultiSearch() throws InterruptedException {
         createIndex("test");
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("field", "xxx").get();
         client().prepareIndex("test").setId("2").setSource("field", "yyy").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         MultiSearchResponse response = client().prepareMultiSearch()
             .add(client().prepareSearch("test").setQuery(QueryBuilders.termQuery("field", "xxx")))
             .add(client().prepareSearch("test").setQuery(QueryBuilders.termQuery("field", "yyy")))
@@ -69,13 +95,14 @@ public void testSimpleMultiSearch() {
         assertFirstHit(response.getResponses()[1].getResponse(), hasId("2"));
     }
 
-    public void testSimpleMultiSearchMoreRequests() {
+    public void testSimpleMultiSearchMoreRequests() throws InterruptedException {
         createIndex("test");
         int numDocs = randomIntBetween(0, 16);
         for (int i = 0; i < numDocs; i++) {
             client().prepareIndex("test").setId(Integer.toString(i)).setSource("{}", MediaTypeRegistry.JSON).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         int numSearchRequests = randomIntBetween(1, 64);
         MultiSearchRequest request = new MultiSearchRequest();
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java b/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java
index 2db4121144bca..6d0b074c3a660 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.nested;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.Explanation;
 import org.apache.lucene.search.join.ScoreMode;
 import org.opensearch.action.DocWriteResponse;
@@ -45,6 +47,7 @@
 import org.opensearch.action.search.SearchType;
 import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -53,7 +56,10 @@
 import org.opensearch.search.sort.SortBuilders;
 import org.opensearch.search.sort.SortMode;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
@@ -61,6 +67,7 @@
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.nestedQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
@@ -70,7 +77,25 @@
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.startsWith;
 
-public class SimpleNestedIT extends OpenSearchIntegTestCase {
+public class SimpleNestedIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SimpleNestedIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     public void testSimpleNested() throws Exception {
         assertAcked(prepareCreate("test").setMapping("nested1", "type=nested"));
         ensureGreen();
@@ -101,6 +126,7 @@ public void testSimpleNested() throws Exception {
             .get();
 
         waitForRelocation(ClusterHealthStatus.GREEN);
+        indexRandomForConcurrentSearch("test");
         GetResponse getResponse = client().prepareGet("test", "1").get();
         assertThat(getResponse.isExists(), equalTo(true));
         assertThat(getResponse.getSourceAsBytes(), notNullValue());
@@ -268,6 +294,7 @@ public void testMultiNested() throws Exception {
         refresh();
         // check the numDocs
         assertDocumentCount("test", 7);
+        indexRandomForConcurrentSearch("test");
 
         // do some multi nested queries
         SearchResponse searchResponse = client().prepareSearch("test")
@@ -460,6 +487,7 @@ public void testExplain() throws Exception {
             )
             .setRefreshPolicy(IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(nestedQuery("nested1", termQuery("nested1.n_field1", "n_value1"), ScoreMode.Total))
@@ -542,6 +570,7 @@ public void testSimpleNestedSorting() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchAllQuery())
@@ -650,6 +679,7 @@ public void testSimpleNestedSortingWithNestedFilterMissing() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchRequestBuilder searchRequestBuilder = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchAllQuery())
@@ -838,6 +868,7 @@ public void testNestedSortWithMultiLevelFiltering() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // access id = 1, read, max value, asc, should use grault and quxx
         SearchResponse searchResponse = client().prepareSearch()
@@ -1010,6 +1041,7 @@ public void testLeakingSortValues() throws Exception {
             .get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(termQuery("_id", 2))
@@ -1190,6 +1222,7 @@ public void testSortNestedWithNestedFilter() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // Without nested filter
         SearchResponse searchResponse = client().prepareSearch()
@@ -1570,6 +1603,7 @@ public void testNestedSortingWithNestedFilterAsFilter() throws Exception {
             .get();
         assertTrue(indexResponse2.getShardInfo().getSuccessful() > 0);
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .addSort(SortBuilders.fieldSort("users.first").setNestedPath("users").order(SortOrder.ASC))
@@ -1602,6 +1636,7 @@ public void testCheckFixedBitSetCache() throws Exception {
         client().prepareIndex("test").setId("1").setSource("field", "value").get();
         refresh();
         ensureSearchable("test");
+        indexRandomForConcurrentSearch("test");
 
         // No nested mapping yet, there shouldn't be anything in the fixed bit set cache
         ClusterStatsResponse clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java
index 43b7179a335f8..8ae652082f653 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java
@@ -93,8 +93,8 @@ public void testDeletePit() throws Exception {
             assertTrue(deletePitInfo.isSuccessful());
         }
         validatePitStats("index", 0, 10);
-        /**
-         * Checking deleting the same PIT id again results in succeeded
+        /*
+          Checking deleting the same PIT id again results in succeeded
          */
         deleteExecute = client().execute(DeletePitAction.INSTANCE, deletePITRequest);
         deletePITResponse = deleteExecute.get();
@@ -113,8 +113,8 @@ public void testDeletePitWithValidAndDeletedIds() throws Exception {
         pitIds.add(pitResponse.getId());
         validatePitStats("index", 5, 0);
 
-        /**
-         * Delete Pit #1
+        /*
+          Delete Pit #1
          */
         DeletePitRequest deletePITRequest = new DeletePitRequest(pitIds);
         ActionFuture<DeletePitResponse> deleteExecute = client().execute(DeletePitAction.INSTANCE, deletePITRequest);
@@ -128,8 +128,8 @@ public void testDeletePitWithValidAndDeletedIds() throws Exception {
         pitResponse = execute.get();
         pitIds.add(pitResponse.getId());
         validatePitStats("index", 5, 5);
-        /**
-         * Delete PIT with both Ids #1 (which is deleted) and #2 (which is present)
+        /*
+          Delete PIT with both Ids #1 (which is deleted) and #2 (which is present)
          */
         deletePITRequest = new DeletePitRequest(pitIds);
         deleteExecute = client().execute(DeletePitAction.INSTANCE, deletePITRequest);
@@ -165,9 +165,9 @@ public void testDeleteAllPits() throws Exception {
         validatePitStats("index1", 5, 0);
         DeletePitRequest deletePITRequest = new DeletePitRequest("_all");
 
-        /**
-         * When we invoke delete again, returns success after clearing the remaining readers. Asserting reader context
-         * not found exceptions don't result in failures ( as deletion in one node is successful )
+        /*
+          When we invoke delete again, returns success after clearing the remaining readers. Asserting reader context
+          not found exceptions don't result in failures ( as deletion in one node is successful )
          */
         ActionFuture<DeletePitResponse> execute = client().execute(DeletePitAction.INSTANCE, deletePITRequest);
         DeletePitResponse deletePITResponse = execute.get();
@@ -207,9 +207,9 @@ public Settings onNodeStopped(String nodeName) throws Exception {
         });
 
         ensureGreen();
-        /**
-         * When we invoke delete again, returns success after clearing the remaining readers. Asserting reader context
-         * not found exceptions don't result in failures ( as deletion in one node is successful )
+        /*
+          When we invoke delete again, returns success after clearing the remaining readers. Asserting reader context
+          not found exceptions don't result in failures ( as deletion in one node is successful )
          */
         ActionFuture<DeletePitResponse> execute = client().execute(DeletePitAction.INSTANCE, deletePITRequest);
         DeletePitResponse deletePITResponse = execute.get();
@@ -242,9 +242,9 @@ public Settings onNodeStopped(String nodeName) throws Exception {
             }
         });
         ensureGreen();
-        /**
-         * When we invoke delete again, returns success as all readers are cleared. (Delete all on node which is Up and
-         * once the node restarts, all active contexts are cleared in the node )
+        /*
+          When we invoke delete again, returns success as all readers are cleared. (Delete all on node which is Up and
+          once the node restarts, all active contexts are cleared in the node )
          */
         ActionFuture<DeletePitResponse> execute = client().execute(DeletePitAction.INSTANCE, deletePITRequest);
         DeletePitResponse deletePITResponse = execute.get();
@@ -278,8 +278,8 @@ public void testDeleteWhileSearch() throws Exception {
                         }
                     }
                 } catch (Exception e) {
-                    /**
-                     * assert for exception once delete pit goes through. throw error in case of any exeption before that.
+                    /*
+                      assert for exception once delete pit goes through. throw error in case of any exeption before that.
                      */
                     if (deleted.get() == true) {
                         Throwable t = ExceptionsHelper.unwrapCause(e.getCause());
@@ -309,7 +309,11 @@ public void testDeleteWhileSearch() throws Exception {
     private void verifySearchContextMissingException(ShardSearchFailure[] failures) {
         for (ShardSearchFailure failure : failures) {
             Throwable cause = ExceptionsHelper.unwrapCause(failure.getCause());
-            assertTrue(failure.toString(), cause instanceof SearchContextMissingException);
+            if (failure.toString().contains("reader_context is already closed can't increment refCount current count")) {
+                // this is fine, expected search error when context is already deleted
+            } else {
+                assertTrue(failure.toString(), cause instanceof SearchContextMissingException);
+            }
         }
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java
index 61a5f76a32979..a3432bfe7e3e4 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java
@@ -8,6 +8,8 @@
 
 package org.opensearch.search.pit;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.LatchedActionListener;
 import org.opensearch.action.admin.cluster.state.ClusterStateRequest;
 import org.opensearch.action.admin.cluster.state.ClusterStateResponse;
@@ -30,10 +32,12 @@
 import org.opensearch.common.action.ActionFuture;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.search.builder.PointInTimeBuilder;
 import org.opensearch.test.InternalTestCluster;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.threadpool.TestThreadPool;
 import org.opensearch.threadpool.ThreadPool;
 import org.junit.After;
@@ -41,6 +45,8 @@
 import org.junit.Before;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
@@ -53,6 +59,7 @@
 
 import static org.opensearch.action.search.PitTestsUtil.assertSegments;
 import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.containsString;
 
@@ -60,7 +67,23 @@
  * Multi node integration tests for PIT creation and search operation with PIT ID.
  */
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE, numDataNodes = 2)
-public class PitMultiNodeIT extends OpenSearchIntegTestCase {
+public class PitMultiNodeIT extends ParameterizedOpenSearchIntegTestCase {
+    public PitMultiNodeIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Before
     public void setupIndex() throws ExecutionException, InterruptedException {
@@ -77,6 +100,7 @@ public void clearIndex() {
     public void testPit() throws Exception {
         CreatePitRequest request = new CreatePitRequest(TimeValue.timeValueDays(1), true);
         request.setIndices(new String[] { "index" });
+        indexRandomForConcurrentSearch("index");
         ActionFuture<CreatePitResponse> execute = client().execute(CreatePitAction.INSTANCE, request);
         CreatePitResponse pitResponse = execute.get();
         SearchResponse searchResponse = client().prepareSearch("index")
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java b/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java
index 911d2fcae01fe..6e40c08ed08a1 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.preference;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.cluster.node.stats.NodeStats;
 import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
 import org.opensearch.action.search.SearchRequestBuilder;
@@ -42,19 +44,23 @@
 import org.opensearch.cluster.routing.OperationRouting;
 import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.node.Node;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
-import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
@@ -64,7 +70,24 @@
 import static org.hamcrest.Matchers.not;
 
 @OpenSearchIntegTestCase.ClusterScope(minNumDataNodes = 2)
-public class SearchPreferenceIT extends OpenSearchIntegTestCase {
+public class SearchPreferenceIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchPreferenceIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     public Settings nodeSettings(int nodeOrdinal) {
@@ -75,7 +98,7 @@ public Settings nodeSettings(int nodeOrdinal) {
     }
 
     // see #2896
-    public void testStopOneNodePreferenceWithRedState() throws IOException {
+    public void testStopOneNodePreferenceWithRedState() throws Exception {
         assertAcked(
             prepareCreate("test").setSettings(
                 Settings.builder().put("index.number_of_shards", cluster().numDataNodes() + 2).put("index.number_of_replicas", 0)
@@ -86,6 +109,7 @@ public void testStopOneNodePreferenceWithRedState() throws IOException {
             client().prepareIndex("test").setId("" + i).setSource("field1", "value1").get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
         internalCluster().stopRandomDataNode();
         client().admin().cluster().prepareHealth().setWaitForStatus(ClusterHealthStatus.RED).get();
         String[] preferences = new String[] {
@@ -114,7 +138,7 @@ public void testStopOneNodePreferenceWithRedState() throws IOException {
         assertThat("_only_local", searchResponse.getFailedShards(), greaterThanOrEqualTo(0));
     }
 
-    public void testNoPreferenceRandom() {
+    public void testNoPreferenceRandom() throws Exception {
         assertAcked(
             prepareCreate("test").setSettings(
                 // this test needs at least a replica to make sure two consecutive searches go to two different copies of the same data
@@ -125,6 +149,7 @@ public void testNoPreferenceRandom() {
 
         client().prepareIndex("test").setSource("field1", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         final Client client = internalCluster().smartClient();
         SearchResponse searchResponse = client.prepareSearch("test").setQuery(matchAllQuery()).get();
@@ -135,12 +160,13 @@ public void testNoPreferenceRandom() {
         assertThat(firstNodeId, not(equalTo(secondNodeId)));
     }
 
-    public void testSimplePreference() {
+    public void testSimplePreference() throws InterruptedException {
         client().admin().indices().prepareCreate("test").setSettings("{\"number_of_replicas\": 1}", MediaTypeRegistry.JSON).get();
         ensureGreen();
 
         client().prepareIndex("test").setSource("field1", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).get();
         assertThat(searchResponse.getHits().getTotalHits().value, equalTo(1L));
@@ -177,7 +203,7 @@ public void testThatSpecifyingNonExistingNodesReturnsUsefulError() {
         }
     }
 
-    public void testNodesOnlyRandom() {
+    public void testNodesOnlyRandom() throws Exception {
         assertAcked(
             prepareCreate("test").setSettings(
                 // this test needs at least a replica to make sure two consecutive searches go to two different copies of the same data
@@ -187,6 +213,7 @@ public void testNodesOnlyRandom() {
         ensureGreen();
         client().prepareIndex("test").setSource("field1", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         final Client client = internalCluster().smartClient();
         // multiple wildchar to cover multi-param usecase
@@ -238,7 +265,7 @@ private void assertSearchOnRandomNodes(SearchRequestBuilder request) {
         assertThat(hitNodes.size(), greaterThan(1));
     }
 
-    public void testCustomPreferenceUnaffectedByOtherShardMovements() {
+    public void testCustomPreferenceUnaffectedByOtherShardMovements() throws InterruptedException {
 
         /*
          * Custom preferences can be used to encourage searches to go to a consistent set of shard copies, meaning that other copies' data
@@ -257,6 +284,7 @@ public void testCustomPreferenceUnaffectedByOtherShardMovements() {
         ensureGreen();
         client().prepareIndex("test").setSource("field1", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         final String customPreference = randomAlphaOfLength(10);
 
@@ -276,6 +304,7 @@ public void testCustomPreferenceUnaffectedByOtherShardMovements() {
             prepareCreate("test2").setSettings(Settings.builder().put(indexSettings()).put(SETTING_NUMBER_OF_REPLICAS, replicasInNewIndex))
         );
         ensureGreen();
+        indexRandomForConcurrentSearch("test2");
 
         assertSearchesSpecificNode("test", customPreference, nodeId);
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/profile/aggregation/AggregationProfilerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/profile/aggregation/AggregationProfilerIT.java
index b4d7269bab106..82dd6225fda4e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/profile/aggregation/AggregationProfilerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/profile/aggregation/AggregationProfilerIT.java
@@ -32,8 +32,12 @@
 
 package org.opensearch.search.profile.aggregation;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.BucketOrder;
 import org.opensearch.search.aggregations.InternalAggregation;
@@ -46,15 +50,19 @@
 import org.opensearch.search.profile.query.CollectorResult;
 import org.opensearch.search.profile.query.QueryProfileShardResult;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.core.IsNull;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.avg;
 import static org.opensearch.search.aggregations.AggregationBuilders.diversifiedSampler;
 import static org.opensearch.search.aggregations.AggregationBuilders.global;
@@ -75,7 +83,8 @@
 import static org.hamcrest.Matchers.sameInstance;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public class AggregationProfilerIT extends OpenSearchIntegTestCase {
+public class AggregationProfilerIT extends ParameterizedOpenSearchIntegTestCase {
+
     private static final String BUILD_LEAF_COLLECTOR = AggregationTimingType.BUILD_LEAF_COLLECTOR.toString();
     private static final String COLLECT = AggregationTimingType.COLLECT.toString();
     private static final String POST_COLLECTION = AggregationTimingType.POST_COLLECTION.toString();
@@ -157,6 +166,23 @@ public class AggregationProfilerIT extends OpenSearchIntegTestCase {
     private static final String REASON_SEARCH_TOP_HITS = "search_top_hits";
     private static final String REASON_AGGREGATION = "aggregation";
 
+    public AggregationProfilerIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected int numberOfShards() {
         return 1;
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/profile/query/QueryProfilerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/profile/query/QueryProfilerIT.java
index 5f794d2abf878..ef73438114079 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/profile/query/QueryProfilerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/profile/query/QueryProfilerIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.profile.query;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.tests.util.English;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.MultiSearchResponse;
@@ -40,20 +42,23 @@
 import org.opensearch.action.search.SearchType;
 import org.opensearch.action.search.ShardSearchFailure;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilder;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.profile.ProfileResult;
 import org.opensearch.search.profile.ProfileShardResult;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.profile.query.RandomQueryGenerator.randomQueryBuilder;
 import static org.hamcrest.Matchers.emptyOrNullString;
 import static org.hamcrest.Matchers.equalTo;
@@ -61,8 +66,32 @@
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.nullValue;
+
+public class QueryProfilerIT extends ParameterizedOpenSearchIntegTestCase {
+    private final boolean concurrentSearchEnabled;
+    private static final String MAX_PREFIX = "max_";
+    private static final String MIN_PREFIX = "min_";
+    private static final String AVG_PREFIX = "avg_";
+    private static final String TIMING_TYPE_COUNT_SUFFIX = "_count";
+
+    public QueryProfilerIT(Settings settings, boolean concurrentSearchEnabled) {
+        super(settings);
+        this.concurrentSearchEnabled = concurrentSearchEnabled;
+    }
 
-public class QueryProfilerIT extends OpenSearchIntegTestCase {
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build(), false },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build(), true }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     /**
      * This test simply checks to make sure nothing crashes.  Test indexes 100-150 documents,
@@ -229,6 +258,7 @@ public void testSimpleMatch() throws Exception {
                     assertEquals(result.getLuceneDescription(), "field1:one");
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
+                    assertQueryProfileResult(result);
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -271,6 +301,7 @@ public void testBool() throws Exception {
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
                     assertEquals(result.getProfiledChildren().size(), 2);
+                    assertQueryProfileResult(result);
 
                     // Check the children
                     List<ProfileResult> children = result.getProfiledChildren();
@@ -282,12 +313,14 @@ public void testBool() throws Exception {
                     assertThat(childProfile.getTime(), greaterThan(0L));
                     assertNotNull(childProfile.getTimeBreakdown());
                     assertEquals(childProfile.getProfiledChildren().size(), 0);
+                    assertQueryProfileResult(childProfile);
 
                     childProfile = children.get(1);
                     assertEquals(childProfile.getQueryName(), "TermQuery");
                     assertEquals(childProfile.getLuceneDescription(), "field1:two");
                     assertThat(childProfile.getTime(), greaterThan(0L));
                     assertNotNull(childProfile.getTimeBreakdown());
+                    assertQueryProfileResult(childProfile);
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -330,6 +363,7 @@ public void testEmptyBool() throws Exception {
                     assertNotNull(result.getLuceneDescription());
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
+                    assertQueryProfileResult(result);
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -375,6 +409,7 @@ public void testCollapsingBool() throws Exception {
                     assertNotNull(result.getLuceneDescription());
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
+                    assertQueryProfileResult(result);
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -415,6 +450,90 @@ public void testBoosting() throws Exception {
                     assertNotNull(result.getLuceneDescription());
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
+                    assertQueryProfileResult(result);
+                }
+
+                CollectorResult result = searchProfiles.getCollectorResult();
+                assertThat(result.getName(), is(not(emptyOrNullString())));
+                assertThat(result.getTime(), greaterThan(0L));
+            }
+        }
+    }
+
+    public void testSearchLeafForItsLeavesAndRewriteQuery() throws Exception {
+        createIndex("test");
+        ensureGreen();
+
+        int numDocs = 122;
+        IndexRequestBuilder[] docs = new IndexRequestBuilder[numDocs];
+        for (int i = 0; i < numDocs; i++) {
+            docs[i] = client().prepareIndex("test").setId(String.valueOf(i)).setSource("field1", English.intToEnglish(i), "field2", i);
+        }
+
+        List<String> terms = Arrays.asList("zero", "zero", "one");
+
+        indexRandom(true, docs);
+
+        refresh();
+
+        QueryBuilder q = QueryBuilders.boostingQuery(
+            QueryBuilders.idsQuery().addIds(String.valueOf(randomInt()), String.valueOf(randomInt())),
+            QueryBuilders.termsQuery("field1", terms)
+        ).boost(randomFloat()).negativeBoost(randomFloat());
+        logger.info("Query: {}", q);
+
+        SearchResponse resp = client().prepareSearch()
+            .setQuery(q)
+            .setTrackTotalHits(true)
+            .setProfile(true)
+            .setSearchType(SearchType.QUERY_THEN_FETCH)
+            .get();
+
+        assertNotNull("Profile response element should not be null", resp.getProfileResults());
+        assertThat("Profile response should not be an empty array", resp.getProfileResults().size(), not(0));
+
+        for (Map.Entry<String, ProfileShardResult> shardResult : resp.getProfileResults().entrySet()) {
+            assertThat(shardResult.getValue().getNetworkTime().getInboundNetworkTime(), greaterThanOrEqualTo(0L));
+            assertThat(shardResult.getValue().getNetworkTime().getOutboundNetworkTime(), greaterThanOrEqualTo(0L));
+            for (QueryProfileShardResult searchProfiles : shardResult.getValue().getQueryProfileResults()) {
+                List<ProfileResult> results = searchProfiles.getQueryResults();
+                for (ProfileResult result : results) {
+                    assertNotNull(result.getQueryName());
+                    assertNotNull(result.getLuceneDescription());
+                    assertThat(result.getTime(), greaterThan(0L));
+                    Map<String, Long> breakdown = result.getTimeBreakdown();
+                    Long maxSliceTime = result.getMaxSliceTime();
+                    Long minSliceTime = result.getMinSliceTime();
+                    Long avgSliceTime = result.getAvgSliceTime();
+                    if (concurrentSearchEnabled && results.get(0).equals(result)) {
+                        assertNotNull(maxSliceTime);
+                        assertNotNull(minSliceTime);
+                        assertNotNull(avgSliceTime);
+                        assertThat(breakdown.size(), equalTo(66));
+                        for (QueryTimingType queryTimingType : QueryTimingType.values()) {
+                            if (queryTimingType != QueryTimingType.CREATE_WEIGHT) {
+                                String maxTimingType = MAX_PREFIX + queryTimingType;
+                                String minTimingType = MIN_PREFIX + queryTimingType;
+                                String avgTimingType = AVG_PREFIX + queryTimingType;
+                                assertNotNull(breakdown.get(maxTimingType));
+                                assertNotNull(breakdown.get(minTimingType));
+                                assertNotNull(breakdown.get(avgTimingType));
+                                assertNotNull(breakdown.get(maxTimingType + TIMING_TYPE_COUNT_SUFFIX));
+                                assertNotNull(breakdown.get(minTimingType + TIMING_TYPE_COUNT_SUFFIX));
+                                assertNotNull(breakdown.get(avgTimingType + TIMING_TYPE_COUNT_SUFFIX));
+                            }
+                        }
+                    } else if (concurrentSearchEnabled) {
+                        assertThat(maxSliceTime, equalTo(0L));
+                        assertThat(minSliceTime, equalTo(0L));
+                        assertThat(avgSliceTime, equalTo(0L));
+                        assertThat(breakdown.size(), equalTo(27));
+                    } else {
+                        assertThat(maxSliceTime, is(nullValue()));
+                        assertThat(minSliceTime, is(nullValue()));
+                        assertThat(avgSliceTime, is(nullValue()));
+                        assertThat(breakdown.size(), equalTo(27));
+                    }
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -455,6 +574,7 @@ public void testDisMaxRange() throws Exception {
                     assertNotNull(result.getLuceneDescription());
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
+                    assertQueryProfileResult(result);
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -494,6 +614,7 @@ public void testRange() throws Exception {
                     assertNotNull(result.getLuceneDescription());
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
+                    assertQueryProfileResult(result);
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -547,6 +668,7 @@ public void testPhrase() throws Exception {
                     assertNotNull(result.getLuceneDescription());
                     assertThat(result.getTime(), greaterThan(0L));
                     assertNotNull(result.getTimeBreakdown());
+                    assertQueryProfileResult(result);
                 }
 
                 CollectorResult result = searchProfiles.getCollectorResult();
@@ -579,4 +701,35 @@ public void testNoProfile() throws Exception {
         assertThat("Profile response element should be an empty map", resp.getProfileResults().size(), equalTo(0));
     }
 
+    private void assertQueryProfileResult(ProfileResult result) {
+        Map<String, Long> breakdown = result.getTimeBreakdown();
+        Long maxSliceTime = result.getMaxSliceTime();
+        Long minSliceTime = result.getMinSliceTime();
+        Long avgSliceTime = result.getAvgSliceTime();
+        if (concurrentSearchEnabled) {
+            assertNotNull(maxSliceTime);
+            assertNotNull(minSliceTime);
+            assertNotNull(avgSliceTime);
+            assertThat(breakdown.size(), equalTo(66));
+            for (QueryTimingType queryTimingType : QueryTimingType.values()) {
+                if (queryTimingType != QueryTimingType.CREATE_WEIGHT) {
+                    String maxTimingType = MAX_PREFIX + queryTimingType;
+                    String minTimingType = MIN_PREFIX + queryTimingType;
+                    String avgTimingType = AVG_PREFIX + queryTimingType;
+                    assertNotNull(breakdown.get(maxTimingType));
+                    assertNotNull(breakdown.get(minTimingType));
+                    assertNotNull(breakdown.get(avgTimingType));
+                    assertNotNull(breakdown.get(maxTimingType + TIMING_TYPE_COUNT_SUFFIX));
+                    assertNotNull(breakdown.get(minTimingType + TIMING_TYPE_COUNT_SUFFIX));
+                    assertNotNull(breakdown.get(avgTimingType + TIMING_TYPE_COUNT_SUFFIX));
+                }
+            }
+        } else {
+            assertThat(maxSliceTime, is(nullValue()));
+            assertThat(minSliceTime, is(nullValue()));
+            assertThat(avgSliceTime, is(nullValue()));
+            assertThat(breakdown.size(), equalTo(27));
+        }
+    }
+
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/ExistsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/ExistsIT.java
index 0ca1780410e13..e3253ea583ac2 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/ExistsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/ExistsIT.java
@@ -32,17 +32,23 @@
 
 package org.opensearch.search.query;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.explain.ExplainResponse;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.SearchHit;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -51,11 +57,29 @@
 
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonMap;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 
-public class ExistsIT extends OpenSearchIntegTestCase {
+public class ExistsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public ExistsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     // TODO: move this to a unit test somewhere...
     public void testEmptyIndex() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/MultiMatchQueryIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/MultiMatchQueryIT.java
index 0c5fa4369da22..457114bac33b8 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/MultiMatchQueryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/MultiMatchQueryIT.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.query;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 import com.carrotsearch.randomizedtesting.generators.RandomPicks;
 
 import org.opensearch.action.admin.indices.create.CreateIndexRequestBuilder;
@@ -38,6 +39,7 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.Fuzziness;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -52,11 +54,12 @@
 import org.opensearch.search.sort.SortBuilders;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.MockKeywordPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.Before;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -73,6 +76,7 @@
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
 import static org.opensearch.index.query.QueryBuilders.multiMatchQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFirstHit;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
@@ -88,7 +92,24 @@
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 import static org.hamcrest.Matchers.lessThan;
 
-public class MultiMatchQueryIT extends OpenSearchIntegTestCase {
+public class MultiMatchQueryIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MultiMatchQueryIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java
index 53a41af46790b..1ca5859f23bca 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java
@@ -32,10 +32,13 @@
 
 package org.opensearch.search.query;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.mapper.MapperService;
@@ -44,18 +47,21 @@
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.SearchHits;
 import org.opensearch.search.SearchModule;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.Before;
 import org.junit.BeforeClass;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.queryStringQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.StreamsUtils.copyToStringFromClasspath;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
@@ -64,10 +70,27 @@
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 
-public class QueryStringIT extends OpenSearchIntegTestCase {
+public class QueryStringIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static int CLUSTER_MAX_CLAUSE_COUNT;
 
+    public QueryStringIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @BeforeClass
     public static void createRandomClusterSetting() {
         CLUSTER_MAX_CLAUSE_COUNT = randomIntBetween(50, 100);
@@ -163,6 +186,7 @@ public void testDocWithAllTypes() throws Exception {
         String docBody = copyToStringFromClasspath("/org/opensearch/search/query/all-example-document.json");
         reqs.add(client().prepareIndex("test").setId("1").setSource(docBody, MediaTypeRegistry.JSON));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(queryStringQuery("foo")).get();
         assertHits(resp.getHits(), "1");
@@ -202,6 +226,7 @@ public void testKeywordWithWhitespace() throws Exception {
         reqs.add(client().prepareIndex("test").setId("2").setSource("f1", "bar"));
         reqs.add(client().prepareIndex("test").setId("3").setSource("f1", "foo bar"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(queryStringQuery("foo")).get();
         assertHits(resp.getHits(), "3");
@@ -222,6 +247,7 @@ public void testRegexCaseInsensitivity() throws Exception {
         indexRequests.add(client().prepareIndex("messages").setId("1").setSource("message", "message: this is a TLS handshake"));
         indexRequests.add(client().prepareIndex("messages").setId("2").setSource("message", "message: this is a tcp handshake"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("messages");
 
         SearchResponse response = client().prepareSearch("messages").setQuery(queryStringQuery("/TLS/").defaultField("message")).get();
         assertNoFailures(response);
@@ -259,6 +285,7 @@ public void testAllFields() throws Exception {
         List<IndexRequestBuilder> reqs = new ArrayList<>();
         reqs.add(client().prepareIndex("test_1").setId("1").setSource("f1", "foo", "f2", "eggplant"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test_1");
 
         SearchResponse resp = client().prepareSearch("test_1")
             .setQuery(queryStringQuery("foo eggplant").defaultOperator(Operator.AND))
@@ -351,6 +378,7 @@ public void testLimitOnExpandedFields() throws Exception {
 
         client().prepareIndex("testindex").setId("1").setSource("field_A0", "foo bar baz").get();
         refresh();
+        indexRandomForConcurrentSearch("testindex");
 
         // single field shouldn't trigger the limit
         doAssertOneHitForQueryString("field_A0:foo");
@@ -442,6 +470,7 @@ public void testFieldAliasOnDisallowedFieldType() throws Exception {
         List<IndexRequestBuilder> indexRequests = new ArrayList<>();
         indexRequests.add(client().prepareIndex("test").setId("1").setSource("f3", "text", "f2", "one"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         // The wildcard field matches aliases for both a text and geo_point field.
         // By default, the geo_point field should be ignored when building the query.
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java
index d736365a6e236..55029712a061c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java
@@ -32,10 +32,13 @@
 
 package org.opensearch.search.query;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.index.query.QueryBuilder;
 import org.opensearch.index.query.RangeQueryBuilder;
@@ -43,8 +46,9 @@
 import org.opensearch.script.MockScriptPlugin;
 import org.opensearch.script.Script;
 import org.opensearch.script.ScriptType;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -54,6 +58,7 @@
 import static org.opensearch.index.query.QueryBuilders.boolQuery;
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
 import static org.opensearch.index.query.QueryBuilders.scriptScoreQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFirstHit;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
@@ -62,7 +67,24 @@
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertThirdHit;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.hasScore;
 
-public class ScriptScoreQueryIT extends OpenSearchIntegTestCase {
+public class ScriptScoreQueryIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public ScriptScoreQueryIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -87,13 +109,14 @@ protected Map<String, Function<Map<String, Object>, Object>> pluginScripts() {
     // 1) only matched docs retrieved
     // 2) score is calculated based on a script with params
     // 3) min score applied
-    public void testScriptScore() {
+    public void testScriptScore() throws Exception {
         assertAcked(prepareCreate("test-index").setMapping("field1", "type=text", "field2", "type=double"));
         int docCount = 10;
         for (int i = 1; i <= docCount; i++) {
             client().prepareIndex("test-index").setId("" + i).setSource("field1", "text" + (i % 2), "field2", i).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test-index");
 
         Map<String, Object> params = new HashMap<>();
         params.put("param1", 0.1);
@@ -113,13 +136,14 @@ public void testScriptScore() {
         assertOrderedSearchHits(resp, "10", "8", "6");
     }
 
-    public void testScriptScoreBoolQuery() {
+    public void testScriptScoreBoolQuery() throws Exception {
         assertAcked(prepareCreate("test-index").setMapping("field1", "type=text", "field2", "type=double"));
         int docCount = 10;
         for (int i = 1; i <= docCount; i++) {
             client().prepareIndex("test-index").setId("" + i).setSource("field1", "text" + i, "field2", i).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test-index");
 
         Map<String, Object> params = new HashMap<>();
         params.put("param1", 0.1);
@@ -133,7 +157,7 @@ public void testScriptScoreBoolQuery() {
     }
 
     // test that when the internal query is rewritten script_score works well
-    public void testRewrittenQuery() {
+    public void testRewrittenQuery() throws Exception {
         assertAcked(
             prepareCreate("test-index2").setSettings(Settings.builder().put("index.number_of_shards", 1))
                 .setMapping("field1", "type=date", "field2", "type=double")
@@ -142,6 +166,7 @@ public void testRewrittenQuery() {
         client().prepareIndex("test-index2").setId("2").setSource("field1", "2019-10-01", "field2", 2).get();
         client().prepareIndex("test-index2").setId("3").setSource("field1", "2019-11-01", "field2", 3).get();
         refresh();
+        indexRandomForConcurrentSearch("test-index2");
 
         RangeQueryBuilder rangeQB = new RangeQueryBuilder("field1").from("2019-01-01"); // the query should be rewritten to from:null
         Map<String, Object> params = new HashMap<>();
@@ -152,7 +177,7 @@ public void testRewrittenQuery() {
         assertOrderedSearchHits(resp, "3", "2", "1");
     }
 
-    public void testDisallowExpensiveQueries() {
+    public void testDisallowExpensiveQueries() throws Exception {
         try {
             assertAcked(prepareCreate("test-index").setMapping("field1", "type=text", "field2", "type=double"));
             int docCount = 10;
@@ -160,6 +185,7 @@ public void testDisallowExpensiveQueries() {
                 client().prepareIndex("test-index").setId("" + i).setSource("field1", "text" + (i % 2), "field2", i).get();
             }
             refresh();
+            indexRandomForConcurrentSearch("test-index");
 
             Map<String, Object> params = new HashMap<>();
             params.put("param1", 0.1);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/SearchQueryIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/SearchQueryIT.java
index 1c3a58817e48a..03312c6e1e2f7 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/SearchQueryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/SearchQueryIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.query;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.analysis.pattern.PatternReplaceCharFilter;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.search.MultiTermQuery;
@@ -49,6 +51,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.unit.Fuzziness;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
@@ -77,7 +80,7 @@
 import org.opensearch.search.SearchHits;
 import org.opensearch.search.aggregations.AggregationBuilders;
 import org.opensearch.test.InternalSettingsPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.junit.annotations.TestIssueLogging;
 
 import java.io.IOException;
@@ -126,6 +129,7 @@
 import static org.opensearch.index.query.QueryBuilders.termsQuery;
 import static org.opensearch.index.query.QueryBuilders.wildcardQuery;
 import static org.opensearch.index.query.QueryBuilders.wrapperQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFailures;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFirstHit;
@@ -143,7 +147,24 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
 
-public class SearchQueryIT extends OpenSearchIntegTestCase {
+public class SearchQueryIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchQueryIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -175,7 +196,7 @@ public void testEmptyQueryString() throws ExecutionException, InterruptedExcepti
     }
 
     // see https://github.com/elastic/elasticsearch/issues/3177
-    public void testIssue3177() {
+    public void testIssue3177() throws InterruptedException {
         createIndex("test");
         client().prepareIndex("test").setId("1").setSource("field1", "value1").get();
         client().prepareIndex("test").setId("2").setSource("field1", "value2").get();
@@ -184,6 +205,7 @@ public void testIssue3177() {
         waitForRelocation();
         forceMerge();
         refresh();
+        indexRandomForConcurrentSearch("test");
         assertHitCount(
             client().prepareSearch()
                 .setQuery(matchAllQuery())
@@ -373,7 +395,19 @@ public void testCommonTermsQuery() throws Exception {
         assertSecondHit(searchResponse, hasId("2"));
         assertThirdHit(searchResponse, hasId("3"));
 
-        searchResponse = client().prepareSearch().setQuery(commonTermsQuery("field1", "the huge fox").lowFreqMinimumShouldMatch("2")).get();
+        // cutoff frequency of 1 makes all terms high frequency so the query gets rewritten as a
+        // conjunction of all terms (the lowFreqMinimumShouldMatch parameter is effectively ignored)
+        searchResponse = client().prepareSearch()
+            .setQuery(commonTermsQuery("field1", "the huge fox").cutoffFrequency(1).lowFreqMinimumShouldMatch("2"))
+            .get();
+        assertHitCount(searchResponse, 1L);
+        assertFirstHit(searchResponse, hasId("2"));
+
+        // cutoff frequency of 100 makes all terms low frequency, so lowFreqMinimumShouldMatch=3
+        // means all terms must match
+        searchResponse = client().prepareSearch()
+            .setQuery(commonTermsQuery("field1", "the huge fox").cutoffFrequency(100).lowFreqMinimumShouldMatch("3"))
+            .get();
         assertHitCount(searchResponse, 1L);
         assertFirstHit(searchResponse, hasId("2"));
 
@@ -444,6 +478,7 @@ public void testQueryStringAnalyzedWildcard() throws Exception {
 
         client().prepareIndex("test").setId("1").setSource("field1", "value_1", "field2", "value_2").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(queryStringQuery("value*")).get();
         assertHitCount(searchResponse, 1L);
@@ -461,11 +496,12 @@ public void testQueryStringAnalyzedWildcard() throws Exception {
         assertHitCount(searchResponse, 1L);
     }
 
-    public void testLowercaseExpandedTerms() {
+    public void testLowercaseExpandedTerms() throws InterruptedException {
         createIndex("test");
 
         client().prepareIndex("test").setId("1").setSource("field1", "value_1", "field2", "value_2").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(queryStringQuery("VALUE_3~1")).get();
         assertHitCount(searchResponse, 1L);
@@ -478,7 +514,7 @@ public void testLowercaseExpandedTerms() {
     }
 
     // Issue #3540
-    public void testDateRangeInQueryString() {
+    public void testDateRangeInQueryString() throws InterruptedException {
         // the mapping needs to be provided upfront otherwise we are not sure how many failures we get back
         // as with dynamic mappings some shards might be lacking behind and parse a different query
         assertAcked(prepareCreate("test").setMapping("past", "type=date", "future", "type=date"));
@@ -489,6 +525,7 @@ public void testDateRangeInQueryString() {
         client().prepareIndex("test").setId("1").setSource("past", aMonthAgo, "future", aMonthFromNow).get();
         refresh();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch().setQuery(queryStringQuery("past:[now-2M/d TO now/d]")).get();
         assertHitCount(searchResponse, 1L);
 
@@ -504,7 +541,7 @@ public void testDateRangeInQueryString() {
     }
 
     // Issue #7880
-    public void testDateRangeInQueryStringWithTimeZone_7880() {
+    public void testDateRangeInQueryStringWithTimeZone_7880() throws InterruptedException {
         // the mapping needs to be provided upfront otherwise we are not sure how many failures we get back
         // as with dynamic mappings some shards might be lacking behind and parse a different query
         assertAcked(prepareCreate("test").setMapping("past", "type=date"));
@@ -515,6 +552,7 @@ public void testDateRangeInQueryStringWithTimeZone_7880() {
         client().prepareIndex("test").setId("1").setSource("past", now).get();
         refresh();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(queryStringQuery("past:[now-1m/m TO now+1m/m]").timeZone(timeZone.getId()))
             .get();
@@ -522,7 +560,7 @@ public void testDateRangeInQueryStringWithTimeZone_7880() {
     }
 
     // Issue #10477
-    public void testDateRangeInQueryStringWithTimeZone_10477() {
+    public void testDateRangeInQueryStringWithTimeZone_10477() throws InterruptedException {
         // the mapping needs to be provided upfront otherwise we are not sure how many failures we get back
         // as with dynamic mappings some shards might be lacking behind and parse a different query
         assertAcked(prepareCreate("test").setMapping("past", "type=date"));
@@ -531,6 +569,7 @@ public void testDateRangeInQueryStringWithTimeZone_10477() {
         client().prepareIndex("test").setId("2").setSource("past", "2015-04-06T00:00:00+0000").get();
         refresh();
 
+        indexRandomForConcurrentSearch("test");
         // Timezone set with dates
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(queryStringQuery("past:[2015-04-06T00:00:00+0200 TO 2015-04-06T23:00:00+0200]"))
@@ -704,6 +743,7 @@ public void testPassQueryOrFilterAsJSONString() throws Exception {
         createIndex("test");
 
         client().prepareIndex("test").setId("1").setSource("field1", "value1_1", "field2", "value2_1").setRefreshPolicy(IMMEDIATE).get();
+        indexRandomForConcurrentSearch("test");
 
         WrapperQueryBuilder wrapper = new WrapperQueryBuilder("{ \"term\" : { \"field1\" : \"value1_1\" } }");
         assertHitCount(client().prepareSearch().setQuery(wrapper).get(), 1L);
@@ -720,6 +760,7 @@ public void testFiltersWithCustomCacheKey() throws Exception {
 
         client().prepareIndex("test").setId("1").setSource("field1", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch("test").setQuery(constantScoreQuery(termsQuery("field1", "value1"))).get();
         assertHitCount(searchResponse, 1L);
 
@@ -761,6 +802,7 @@ public void testMatchQueryFuzzy() throws Exception {
             client().prepareIndex("test").setId("1").setSource("text", "Unit"),
             client().prepareIndex("test").setId("2").setSource("text", "Unity")
         );
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(matchQuery("text", "uniy").fuzziness(Fuzziness.ZERO)).get();
         assertHitCount(searchResponse, 0L);
@@ -847,11 +889,12 @@ public void testMultiMatchQuery() throws Exception {
         assertFirstHit(searchResponse, hasId("1"));
     }
 
-    public void testMatchQueryZeroTermsQuery() {
+    public void testMatchQueryZeroTermsQuery() throws InterruptedException {
         assertAcked(prepareCreate("test").setMapping("field1", "type=text,analyzer=classic", "field2", "type=text,analyzer=classic"));
         client().prepareIndex("test").setId("1").setSource("field1", "value1").get();
         client().prepareIndex("test").setId("2").setSource("field1", "value2").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         BoolQueryBuilder boolQuery = boolQuery().must(matchQuery("field1", "a").zeroTermsQuery(MatchQuery.ZeroTermsQuery.NONE))
             .must(matchQuery("field1", "value1").zeroTermsQuery(MatchQuery.ZeroTermsQuery.NONE));
@@ -868,11 +911,12 @@ public void testMatchQueryZeroTermsQuery() {
         assertHitCount(searchResponse, 2L);
     }
 
-    public void testMultiMatchQueryZeroTermsQuery() {
+    public void testMultiMatchQueryZeroTermsQuery() throws InterruptedException {
         assertAcked(prepareCreate("test").setMapping("field1", "type=text,analyzer=classic", "field2", "type=text,analyzer=classic"));
         client().prepareIndex("test").setId("1").setSource("field1", "value1", "field2", "value2").get();
         client().prepareIndex("test").setId("2").setSource("field1", "value3", "field2", "value4").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         BoolQueryBuilder boolQuery = boolQuery().must(
             multiMatchQuery("a", "field1", "field2").zeroTermsQuery(MatchQuery.ZeroTermsQuery.NONE)
@@ -892,11 +936,12 @@ public void testMultiMatchQueryZeroTermsQuery() {
         assertHitCount(searchResponse, 2L);
     }
 
-    public void testMultiMatchQueryMinShouldMatch() {
+    public void testMultiMatchQueryMinShouldMatch() throws InterruptedException {
         createIndex("test");
         client().prepareIndex("test").setId("1").setSource("field1", new String[] { "value1", "value2", "value3" }).get();
         client().prepareIndex("test").setId("2").setSource("field2", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         MultiMatchQueryBuilder multiMatchQuery = multiMatchQuery("value1 value2 foo", "field1", "field2");
 
@@ -938,12 +983,13 @@ public void testMultiMatchQueryMinShouldMatch() {
         assertHitCount(searchResponse, 0L);
     }
 
-    public void testBoolQueryMinShouldMatchBiggerThanNumberOfShouldClauses() throws IOException {
+    public void testBoolQueryMinShouldMatchBiggerThanNumberOfShouldClauses() throws IOException, InterruptedException {
         createIndex("test");
         client().prepareIndex("test").setId("1").setSource("field1", new String[] { "value1", "value2", "value3" }).get();
         client().prepareIndex("test").setId("2").setSource("field2", "value1").get();
         refresh();
 
+        indexRandomForConcurrentSearch("test");
         BoolQueryBuilder boolQuery = boolQuery().must(termQuery("field1", "value1"))
             .should(boolQuery().should(termQuery("field1", "value1")).should(termQuery("field1", "value2")).minimumShouldMatch(3));
         SearchResponse searchResponse = client().prepareSearch().setQuery(boolQuery).get();
@@ -970,12 +1016,13 @@ public void testBoolQueryMinShouldMatchBiggerThanNumberOfShouldClauses() throws
         assertHitCount(searchResponse, 0L);
     }
 
-    public void testFuzzyQueryString() {
+    public void testFuzzyQueryString() throws InterruptedException {
         createIndex("test");
         client().prepareIndex("test").setId("1").setSource("str", "foobar", "date", "2012-02-01", "num", 12).get();
         client().prepareIndex("test").setId("2").setSource("str", "fred", "date", "2012-02-05", "num", 20).get();
         refresh();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch().setQuery(queryStringQuery("str:foobaz~1")).get();
         assertNoFailures(searchResponse);
         assertHitCount(searchResponse, 1L);
@@ -994,6 +1041,7 @@ public void testQuotedQueryStringWithBoost() throws InterruptedException {
             client().prepareIndex("test").setId("2").setSource("important", "nothing important", "less_important", "phrase match")
         );
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(queryStringQuery("\"phrase match\"").field("important", boost).field("less_important"))
             .get();
@@ -1006,11 +1054,12 @@ public void testQuotedQueryStringWithBoost() throws InterruptedException {
         );
     }
 
-    public void testSpecialRangeSyntaxInQueryString() {
+    public void testSpecialRangeSyntaxInQueryString() throws InterruptedException {
         createIndex("test");
         client().prepareIndex("test").setId("1").setSource("str", "foobar", "date", "2012-02-01", "num", 12).get();
         client().prepareIndex("test").setId("2").setSource("str", "fred", "date", "2012-02-05", "num", 20).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(queryStringQuery("num:>19")).get();
         assertHitCount(searchResponse, 1L);
@@ -1116,6 +1165,7 @@ public void testTermsQuery() throws Exception {
 
     public void testTermsLookupFilter() throws Exception {
         assertAcked(prepareCreate("lookup").setMapping("terms", "type=text", "other", "type=text"));
+        indexRandomForConcurrentSearch("lookup");
         assertAcked(
             prepareCreate("lookup2").setMapping(
                 jsonBuilder().startObject()
@@ -1131,8 +1181,11 @@ public void testTermsLookupFilter() throws Exception {
                     .endObject()
             )
         );
+        indexRandomForConcurrentSearch("lookup2");
         assertAcked(prepareCreate("lookup3").setMapping("_source", "enabled=false", "terms", "type=text"));
+        indexRandomForConcurrentSearch("lookup3");
         assertAcked(prepareCreate("test").setMapping("term", "type=text"));
+        indexRandomForConcurrentSearch("test");
 
         indexRandom(
             true,
@@ -1258,6 +1311,7 @@ public void testBasicQueryById() throws Exception {
         client().prepareIndex("test").setId("3").setSource("field1", "value3").get();
         refresh();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch().setQuery(idsQuery().addIds("1", "2")).get();
         assertHitCount(searchResponse, 2L);
         assertThat(searchResponse.getHits().getHits().length, equalTo(2));
@@ -1312,6 +1366,7 @@ public void testNumericTermsAndRanges() throws Exception {
             .setSource("num_byte", 17, "num_short", 17, "num_integer", 17, "num_long", 17, "num_float", 17, "num_double", 17)
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse;
         logger.info("--> term query on 1");
@@ -1418,6 +1473,7 @@ public void testNumericRangeFilter_2826() throws Exception {
         client().prepareIndex("test").setId("3").setSource("field1", "test2", "num_long", 3).get();
         client().prepareIndex("test").setId("4").setSource("field1", "test2", "num_long", 4).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setPostFilter(boolQuery().should(rangeQuery("num_long").from(1).to(2)).should(rangeQuery("num_long").from(3).to(4)))
@@ -1514,7 +1570,7 @@ public void testSimpleSpan() throws IOException, ExecutionException, Interrupted
         assertHitCount(searchResponse, 3L);
     }
 
-    public void testSpanMultiTermQuery() throws IOException {
+    public void testSpanMultiTermQuery() throws IOException, InterruptedException {
         createIndex("test");
 
         client().prepareIndex("test").setId("1").setSource("description", "foo other anything bar", "count", 1).get();
@@ -1522,6 +1578,7 @@ public void testSpanMultiTermQuery() throws IOException {
         client().prepareIndex("test").setId("3").setSource("description", "foo other", "count", 3).get();
         client().prepareIndex("test").setId("4").setSource("description", "fop", "count", 4).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(spanOrQuery(spanMultiTermQueryBuilder(fuzzyQuery("description", "fop"))))
@@ -1553,6 +1610,7 @@ public void testSpanNot() throws IOException, ExecutionException, InterruptedExc
         client().prepareIndex("test").setId("1").setSource("description", "the quick brown fox jumped over the lazy dog").get();
         client().prepareIndex("test").setId("2").setSource("description", "the quick black fox leaped over the sleeping dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(
@@ -1591,7 +1649,7 @@ public void testSpanNot() throws IOException, ExecutionException, InterruptedExc
         assertHitCount(searchResponse, 1L);
     }
 
-    public void testSimpleDFSQuery() throws IOException {
+    public void testSimpleDFSQuery() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 jsonBuilder().startObject()
@@ -1636,6 +1694,7 @@ public void testSimpleDFSQuery() throws IOException {
             .setSource("online", true, "ts", System.currentTimeMillis() - 123123, "type", "bs")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
@@ -1658,8 +1717,9 @@ public void testSimpleDFSQuery() throws IOException {
         assertNoFailures(response);
     }
 
-    public void testMultiFieldQueryString() {
+    public void testMultiFieldQueryString() throws InterruptedException {
         client().prepareIndex("test").setId("1").setSource("field1", "value1", "field2", "value2").setRefreshPolicy(IMMEDIATE).get();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("regular");
         assertHitCount(client().prepareSearch("test").setQuery(queryStringQuery("value1").field("field1").field("field2")).get(), 1);
@@ -1679,11 +1739,12 @@ public void testMultiFieldQueryString() {
     }
 
     // see #3797
-    public void testMultiMatchLenientIssue3797() {
+    public void testMultiMatchLenientIssue3797() throws InterruptedException {
         createIndex("test");
 
         client().prepareIndex("test").setId("1").setSource("field1", 123, "field2", "value2").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(multiMatchQuery("value2", "field2").field("field1", 2).lenient(true))
@@ -1707,6 +1768,7 @@ public void testMinScore() throws ExecutionException, InterruptedException {
         client().prepareIndex("test").setId("3").setSource("score", 2.0).get();
         client().prepareIndex("test").setId("4").setSource("score", 0.5).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(functionScoreQuery(ScoreFunctionBuilders.fieldValueFactorFunction("score").missing(1.0)).setMinScore(1.5f))
@@ -1716,12 +1778,13 @@ public void testMinScore() throws ExecutionException, InterruptedException {
         assertSecondHit(searchResponse, hasId("1"));
     }
 
-    public void testQueryStringWithSlopAndFields() {
+    public void testQueryStringWithSlopAndFields() throws InterruptedException {
         assertAcked(prepareCreate("test"));
 
         client().prepareIndex("test").setId("1").setSource("desc", "one two three", "type", "customer").get();
         client().prepareIndex("test").setId("2").setSource("desc", "one two three", "type", "product").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         {
             SearchResponse searchResponse = client().prepareSearch("test")
                 .setQuery(QueryBuilders.queryStringQuery("\"one two\"").defaultField("desc"))
@@ -1788,6 +1851,7 @@ public void testRangeQueryWithTimeZone() throws Exception {
                 .setId("4")
                 .setSource("date", Instant.now().atZone(ZoneOffset.ofHours(1)).toInstant().toEpochMilli(), "num", 4)
         );
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(QueryBuilders.rangeQuery("date").from("2014-01-01T00:00:00").to("2014-01-01T00:59:00"))
@@ -1895,11 +1959,12 @@ public void testRangeQueryWithLocaleMapping() throws Exception {
         assertHitCount(searchResponse, 2L);
     }
 
-    public void testSearchEmptyDoc() {
+    public void testSearchEmptyDoc() throws InterruptedException {
         assertAcked(prepareCreate("test").setSettings("{\"index.analysis.analyzer.default.type\":\"keyword\"}", MediaTypeRegistry.JSON));
         client().prepareIndex("test").setId("1").setSource("{}", MediaTypeRegistry.JSON).get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
         assertHitCount(client().prepareSearch().setQuery(matchAllQuery()).get(), 1L);
     }
 
@@ -1927,6 +1992,7 @@ public void testMatchPhrasePrefixQuery() throws ExecutionException, InterruptedE
     public void testQueryStringParserCache() throws Exception {
         createIndex("test");
         indexRandom(true, false, client().prepareIndex("test").setId("1").setSource("nameTokens", "xyz"));
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
@@ -1957,6 +2023,7 @@ public void testRangeQueryRangeFields_24744() throws Exception {
             .setSource(jsonBuilder().startObject().startObject("int_range").field("gte", 10).field("lte", 20).endObject().endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         RangeQueryBuilder range = new RangeQueryBuilder("int_range").relation("intersects").from(Integer.MIN_VALUE).to(Integer.MAX_VALUE);
         SearchResponse searchResponse = client().prepareSearch("test").setQuery(range).get();
@@ -1992,6 +2059,7 @@ public void testNestedQueryWithFieldAlias() throws Exception {
 
         index("index", "_doc", "1", source);
         refresh();
+        indexRandomForConcurrentSearch("index");
 
         QueryBuilder nestedQuery = QueryBuilders.nestedQuery(
             "section",
@@ -2020,6 +2088,7 @@ public void testFieldAliasesForMetaFields() throws Exception {
 
         IndexRequestBuilder indexRequest = client().prepareIndex("test").setId("1").setRouting("custom").setSource("field", "value");
         indexRandom(true, false, indexRequest);
+        indexRandomForConcurrentSearch("test");
         client().admin()
             .cluster()
             .prepareUpdateSettings()
@@ -2052,7 +2121,7 @@ public void testFieldAliasesForMetaFields() throws Exception {
     /**
     * Test that wildcard queries on keyword fields get normalized
     */
-    public void testWildcardQueryNormalizationOnKeywordField() {
+    public void testWildcardQueryNormalizationOnKeywordField() throws InterruptedException {
         assertAcked(
             prepareCreate("test").setSettings(
                 Settings.builder()
@@ -2063,6 +2132,7 @@ public void testWildcardQueryNormalizationOnKeywordField() {
         );
         client().prepareIndex("test").setId("1").setSource("field1", "Bbb Aaa").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         {
             WildcardQueryBuilder wildCardQuery = wildcardQuery("field1", "Bb*");
@@ -2078,7 +2148,7 @@ public void testWildcardQueryNormalizationOnKeywordField() {
     /**
      * Test that wildcard queries on text fields get normalized
      */
-    public void testWildcardQueryNormalizationOnTextField() {
+    public void testWildcardQueryNormalizationOnTextField() throws InterruptedException {
         assertAcked(
             prepareCreate("test").setSettings(
                 Settings.builder()
@@ -2090,6 +2160,7 @@ public void testWildcardQueryNormalizationOnTextField() {
         );
         client().prepareIndex("test").setId("1").setSource("field1", "Bbb Aaa").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         {
             // test default case insensitivity: false
@@ -2109,10 +2180,11 @@ public void testWildcardQueryNormalizationOnTextField() {
     }
 
     /** tests wildcard case sensitivity */
-    public void testWildcardCaseSensitivity() {
+    public void testWildcardCaseSensitivity() throws InterruptedException {
         assertAcked(prepareCreate("test").setMapping("field", "type=text"));
         client().prepareIndex("test").setId("1").setSource("field", "lowercase text").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // test case sensitive
         SearchResponse response = client().prepareSearch("test").setQuery(wildcardQuery("field", "Text").caseInsensitive(false)).get();
@@ -2130,7 +2202,7 @@ public void testWildcardCaseSensitivity() {
      * Reserved characters should be excluded when the normalization is applied for keyword fields.
      * See https://github.com/elastic/elasticsearch/issues/46300 for details.
      */
-    public void testWildcardQueryNormalizationKeywordSpecialCharacters() {
+    public void testWildcardQueryNormalizationKeywordSpecialCharacters() throws InterruptedException {
         assertAcked(
             prepareCreate("test").setSettings(
                 Settings.builder()
@@ -2142,6 +2214,7 @@ public void testWildcardQueryNormalizationKeywordSpecialCharacters() {
         );
         client().prepareIndex("test").setId("1").setSource("field", "label-1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         WildcardQueryBuilder wildCardQuery = wildcardQuery("field", "la*");
         SearchResponse searchResponse = client().prepareSearch().setQuery(wildCardQuery).get();
@@ -2192,11 +2265,12 @@ public Map<String, AnalysisProvider<TokenizerFactory>> getTokenizers() {
      * set for fuzzy queries with "constant_score" rewrite nested inside a `span_multi` query and would cause NPEs due to an unset
      * {@link AttributeSource}.
      */
-    public void testIssueFuzzyInsideSpanMulti() {
+    public void testIssueFuzzyInsideSpanMulti() throws InterruptedException {
         createIndex("test");
         client().prepareIndex("test").setId("1").setSource("field", "foobarbaz").get();
         ensureGreen();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         BoolQueryBuilder query = boolQuery().filter(spanMultiTermQueryBuilder(fuzzyQuery("field", "foobarbiz").rewrite("constant_score")));
         SearchResponse response = client().prepareSearch("test").setQuery(query).get();
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java
index bccbce3b29b8e..d8902238005da 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.query;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.analysis.TokenFilter;
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
@@ -41,6 +43,7 @@
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -57,11 +60,12 @@
 import org.opensearch.search.SearchHits;
 import org.opensearch.search.SearchModule;
 import org.opensearch.search.builder.SearchSourceBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.junit.BeforeClass;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -75,6 +79,7 @@
 import static org.opensearch.index.query.QueryBuilders.queryStringQuery;
 import static org.opensearch.index.query.QueryBuilders.simpleQueryStringQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.StreamsUtils.copyToStringFromClasspath;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFailures;
@@ -90,10 +95,27 @@
 /**
  * Tests for the {@code simple_query_string} query
  */
-public class SimpleQueryStringIT extends OpenSearchIntegTestCase {
+public class SimpleQueryStringIT extends ParameterizedOpenSearchIntegTestCase {
 
     private static int CLUSTER_MAX_CLAUSE_COUNT;
 
+    public SimpleQueryStringIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @BeforeClass
     public static void createRandomClusterSetting() {
         CLUSTER_MAX_CLAUSE_COUNT = randomIntBetween(60, 100);
@@ -128,6 +150,7 @@ public void testSimpleQueryString() throws ExecutionException, InterruptedExcept
             client().prepareIndex("test").setId("5").setSource("body", "quux baz spaghetti"),
             client().prepareIndex("test").setId("6").setSource("otherbody", "spaghetti")
         );
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("foo bar")).get();
         assertHitCount(searchResponse, 3L);
@@ -177,6 +200,7 @@ public void testSimpleQueryStringMinimumShouldMatch() throws Exception {
             client().prepareIndex("test").setId("3").setSource("body", "foo bar"),
             client().prepareIndex("test").setId("4").setSource("body", "foo baz bar")
         );
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> query 1");
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("foo bar").minimumShouldMatch("2")).get();
@@ -213,6 +237,7 @@ public void testSimpleQueryStringMinimumShouldMatch() throws Exception {
             client().prepareIndex("test").setId("7").setSource("body2", "foo bar", "other", "foo"),
             client().prepareIndex("test").setId("8").setSource("body2", "foo baz bar", "other", "foo")
         );
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> query 5");
         searchResponse = client().prepareSearch()
@@ -234,7 +259,7 @@ public void testSimpleQueryStringMinimumShouldMatch() throws Exception {
         assertSearchHits(searchResponse, "6", "7", "8");
     }
 
-    public void testNestedFieldSimpleQueryString() throws IOException {
+    public void testNestedFieldSimpleQueryString() throws Exception {
         assertAcked(
             prepareCreate("test").setMapping(
                 jsonBuilder().startObject()
@@ -253,6 +278,7 @@ public void testNestedFieldSimpleQueryString() throws IOException {
         );
         client().prepareIndex("test").setId("1").setSource("body", "foo bar baz").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("foo bar baz").field("body")).get();
         assertHitCount(searchResponse, 1L);
@@ -337,6 +363,8 @@ public void testSimpleQueryStringLenient() throws ExecutionException, Interrupte
             client().prepareIndex("test2").setId("10").setSource("field", 5)
         );
         refresh();
+        indexRandomForConcurrentSearch("test1");
+        indexRandomForConcurrentSearch("test2");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setAllowPartialSearchResults(true)
@@ -397,6 +425,7 @@ public void testSimpleQueryStringUsesFieldAnalyzer() throws Exception {
         client().prepareIndex("test").setId("2").setSource("foo", 234, "bar", "bcd").get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("123").field("foo").field("bar")).get();
         assertHitCount(searchResponse, 1L);
@@ -408,6 +437,7 @@ public void testSimpleQueryStringOnIndexMetaField() throws Exception {
         client().prepareIndex("test").setId("2").setSource("foo", 234, "bar", "bcd").get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("test").field("_index")).get();
         assertHitCount(searchResponse, 2L);
@@ -447,6 +477,7 @@ public void testBasicAllQuery() throws Exception {
         reqs.add(client().prepareIndex("test").setId("2").setSource("f2", "Bar"));
         reqs.add(client().prepareIndex("test").setId("3").setSource("f3", "foo bar baz"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo")).get();
         assertHitCount(resp, 2L);
@@ -470,6 +501,7 @@ public void testWithDate() throws Exception {
         reqs.add(client().prepareIndex("test").setId("1").setSource("f1", "foo", "f_date", "2015/09/02"));
         reqs.add(client().prepareIndex("test").setId("2").setSource("f1", "bar", "f_date", "2015/09/01"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo bar")).get();
         assertHits(resp.getHits(), "1", "2");
@@ -501,6 +533,7 @@ public void testWithLotsOfTypes() throws Exception {
             client().prepareIndex("test").setId("2").setSource("f1", "bar", "f_date", "2015/09/01", "f_float", "1.8", "f_ip", "127.0.0.2")
         );
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo bar")).get();
         assertHits(resp.getHits(), "1", "2");
@@ -528,6 +561,7 @@ public void testDocWithAllTypes() throws Exception {
         String docBody = copyToStringFromClasspath("/org/opensearch/search/query/all-example-document.json");
         reqs.add(client().prepareIndex("test").setId("1").setSource(docBody, MediaTypeRegistry.JSON));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo")).get();
         assertHits(resp.getHits(), "1");
@@ -574,6 +608,7 @@ public void testKeywordWithWhitespace() throws Exception {
         reqs.add(client().prepareIndex("test").setId("2").setSource("f1", "bar"));
         reqs.add(client().prepareIndex("test").setId("3").setSource("f1", "foo bar"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo")).get();
         assertHits(resp.getHits(), "3");
@@ -641,6 +676,7 @@ public void testFieldAlias() throws Exception {
         indexRequests.add(client().prepareIndex("test").setId("2").setSource("f3", "value", "f2", "two"));
         indexRequests.add(client().prepareIndex("test").setId("3").setSource("f3", "another value", "f2", "three"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").setQuery(simpleQueryStringQuery("value").field("f3_alias")).get();
 
@@ -659,6 +695,7 @@ public void testFieldAliasWithWildcardField() throws Exception {
         indexRequests.add(client().prepareIndex("test").setId("2").setSource("f3", "value", "f2", "two"));
         indexRequests.add(client().prepareIndex("test").setId("3").setSource("f3", "another value", "f2", "three"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").setQuery(simpleQueryStringQuery("value").field("f3_*")).get();
 
@@ -675,6 +712,7 @@ public void testFieldAliasOnDisallowedFieldType() throws Exception {
         List<IndexRequestBuilder> indexRequests = new ArrayList<>();
         indexRequests.add(client().prepareIndex("test").setId("1").setSource("f3", "text", "f2", "one"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         // The wildcard field matches aliases for both a text and boolean field.
         // By default, the boolean field should be ignored when building the query.
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/scriptfilter/ScriptQuerySearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/scriptfilter/ScriptQuerySearchIT.java
index e081be0af51a2..ae00904f237a5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/scriptfilter/ScriptQuerySearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/scriptfilter/ScriptQuerySearchIT.java
@@ -32,10 +32,13 @@
 
 package org.opensearch.search.scriptfilter;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexModule;
@@ -47,6 +50,7 @@
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.InternalSettingsPlugin;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.Arrays;
@@ -61,12 +65,29 @@
 import static java.util.Collections.emptyMap;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.scriptQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 import static org.hamcrest.Matchers.equalTo;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE)
-public class ScriptQuerySearchIT extends OpenSearchIntegTestCase {
+public class ScriptQuerySearchIT extends ParameterizedOpenSearchIntegTestCase {
+    public ScriptQuerySearchIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -140,6 +161,7 @@ public void testCustomScriptBinaryField() throws Exception {
             .get();
         flush();
         refresh();
+        indexRandomForConcurrentSearch("my-index");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(
@@ -192,6 +214,7 @@ public void testCustomScriptBoost() throws Exception {
             .setSource(jsonBuilder().startObject().field("test", "value beck").field("num1", 3.0f).endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("running doc['num1'].value > 1");
         SearchResponse response = client().prepareSearch()
@@ -238,7 +261,7 @@ public void testCustomScriptBoost() throws Exception {
         assertThat(response.getHits().getAt(2).getFields().get("sNum1").getValues().get(0), equalTo(3.0));
     }
 
-    public void testDisallowExpensiveQueries() {
+    public void testDisallowExpensiveQueries() throws InterruptedException {
         try {
             assertAcked(prepareCreate("test-index").setMapping("num1", "type=double"));
             int docCount = 10;
@@ -246,6 +269,7 @@ public void testDisallowExpensiveQueries() {
                 client().prepareIndex("test-index").setId("" + i).setSource("num1", i).get();
             }
             refresh();
+            indexRandomForConcurrentSearch("test-index");
 
             // Execute with search.allow_expensive_queries = null => default value = false => success
             Script script = new Script(ScriptType.INLINE, CustomScriptPlugin.NAME, "doc['num1'].value > 1", Collections.emptyMap());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/scroll/DuelScrollIT.java b/server/src/internalClusterTest/java/org/opensearch/search/scroll/DuelScrollIT.java
index e0a54e9b4fc36..c7a6d18f881c6 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/scroll/DuelScrollIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/scroll/DuelScrollIT.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.scroll;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 import com.carrotsearch.randomizedtesting.generators.RandomPicks;
 
 import org.opensearch.action.index.IndexRequestBuilder;
@@ -39,24 +40,44 @@
 import org.opensearch.action.search.SearchType;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.SearchHits;
 import org.opensearch.search.sort.SortBuilder;
 import org.opensearch.search.sort.SortBuilders;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 import static org.hamcrest.Matchers.equalTo;
 
-public class DuelScrollIT extends OpenSearchIntegTestCase {
+public class DuelScrollIT extends ParameterizedOpenSearchIntegTestCase {
+    public DuelScrollIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     public void testDuelQueryThenFetch() throws Exception {
         TestContext context = create(SearchType.DFS_QUERY_THEN_FETCH, SearchType.QUERY_THEN_FETCH);
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollIT.java b/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollIT.java
index aec6a03d3e57f..b82048ffc924e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.scroll;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.action.search.ClearScrollResponse;
 import org.opensearch.action.search.SearchPhaseExecutionException;
@@ -43,6 +45,7 @@
 import org.opensearch.common.Priority;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -57,11 +60,13 @@
 import org.opensearch.search.sort.FieldSortBuilder;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.InternalTestCluster;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 import org.junit.After;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
 
@@ -70,6 +75,7 @@
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.queryStringQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
@@ -86,7 +92,24 @@
 /**
  * Tests for scrolling.
  */
-public class SearchScrollIT extends OpenSearchIntegTestCase {
+public class SearchScrollIT extends ParameterizedOpenSearchIntegTestCase {
+    public SearchScrollIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @After
     public void cleanup() throws Exception {
         assertAcked(
@@ -112,6 +135,7 @@ public void testSimpleScrollQueryThenFetch() throws Exception {
         }
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -165,6 +189,7 @@ public void testSimpleScrollQueryThenFetchSmallSizeUnevenDistribution() throws E
         }
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setSearchType(SearchType.QUERY_THEN_FETCH)
@@ -233,6 +258,7 @@ public void testScrollAndUpdateIndex() throws Exception {
         }
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         assertThat(client().prepareSearch().setSize(0).setQuery(matchAllQuery()).get().getHits().getTotalHits().value, equalTo(500L));
         assertThat(
@@ -305,6 +331,7 @@ public void testSimpleScrollQueryThenFetch_clearScrollIds() throws Exception {
         }
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse1 = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -425,6 +452,7 @@ public void testSimpleScrollQueryThenFetchClearAllScrollIds() throws Exception {
         }
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse1 = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -503,6 +531,7 @@ public void testDeepScrollingDoesNotBlowUp() throws Exception {
             .prepareUpdateSettings("index")
             .setSettings(Settings.builder().put(IndexSettings.MAX_RESULT_WINDOW_SETTING.getKey(), Integer.MAX_VALUE))
             .get();
+        indexRandomForConcurrentSearch("index");
 
         for (SearchType searchType : SearchType.values()) {
             SearchRequestBuilder builder = client().prepareSearch("index")
@@ -544,6 +573,7 @@ public void testStringSortMissingAscTerminates() throws Exception {
         );
         client().prepareIndex("test").setId("1").setSource("some_field", "test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .addSort(new FieldSortBuilder("no_field").order(SortOrder.ASC).missing("_last"))
@@ -569,12 +599,13 @@ public void testStringSortMissingAscTerminates() throws Exception {
         assertThat(response.getHits().getHits().length, equalTo(0));
     }
 
-    public void testCloseAndReopenOrDeleteWithActiveScroll() {
+    public void testCloseAndReopenOrDeleteWithActiveScroll() throws InterruptedException {
         createIndex("test");
         for (int i = 0; i < 100; i++) {
             client().prepareIndex("test").setId(Integer.toString(i)).setSource("field", i).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(matchAllQuery())
             .setSize(35)
@@ -660,7 +691,7 @@ public void testScrollInvalidDefaultKeepAlive() throws IOException {
         assertThat(exc.getMessage(), containsString("was (1m > 30s)"));
     }
 
-    public void testInvalidScrollKeepAlive() throws IOException {
+    public void testInvalidScrollKeepAlive() throws IOException, InterruptedException {
         createIndex("test");
         for (int i = 0; i < 2; i++) {
             client().prepareIndex("test")
@@ -669,6 +700,7 @@ public void testInvalidScrollKeepAlive() throws IOException {
                 .get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
         assertAcked(
             client().admin()
                 .cluster()
@@ -710,7 +742,7 @@ public void testInvalidScrollKeepAlive() throws IOException {
      * Ensures that we always create and retain search contexts on every target shards for a scroll request
      * regardless whether that query can be written to match_no_docs on some target shards or not.
      */
-    public void testScrollRewrittenToMatchNoDocs() {
+    public void testScrollRewrittenToMatchNoDocs() throws InterruptedException {
         final int numShards = randomIntBetween(3, 5);
         assertAcked(
             client().admin()
@@ -723,6 +755,7 @@ public void testScrollRewrittenToMatchNoDocs() {
         client().prepareIndex("test").setId("2").setSource("created_date", "2020-01-02").get();
         client().prepareIndex("test").setId("3").setSource("created_date", "2020-01-03").get();
         client().admin().indices().prepareRefresh("test").get();
+        indexRandomForConcurrentSearch("test");
         SearchResponse resp = null;
         try {
             int totalHits = 0;
@@ -770,6 +803,7 @@ public void testRestartDataNodesDuringScrollSearch() throws Exception {
             index("prod", "_doc", "prod-" + i, Collections.emptyMap());
         }
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("demo", "prod");
         SearchResponse respFromDemoIndex = client().prepareSearch("demo")
             .setSize(randomIntBetween(1, 10))
             .setQuery(new MatchAllQueryBuilder())
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollWithFailingNodesIT.java b/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollWithFailingNodesIT.java
index c6519cc3a0cb3..27002b844da1d 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollWithFailingNodesIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/scroll/SearchScrollWithFailingNodesIT.java
@@ -32,26 +32,50 @@
 
 package org.opensearch.search.scroll;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.routing.allocation.decider.ShardsLimitAllocationDecider;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAllSuccessful;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.lessThan;
 
-@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0, numClientNodes = 0)
-public class SearchScrollWithFailingNodesIT extends OpenSearchIntegTestCase {
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 2, numClientNodes = 0)
+public class SearchScrollWithFailingNodesIT extends ParameterizedOpenSearchIntegTestCase {
+    public SearchScrollWithFailingNodesIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     protected int numberOfShards() {
         return 2;
@@ -63,8 +87,6 @@ protected int numberOfReplicas() {
     }
 
     public void testScanScrollWithShardExceptions() throws Exception {
-        internalCluster().startNode();
-        internalCluster().startNode();
         assertAcked(
             prepareCreate("test")
                 // Enforces that only one shard can only be allocated to a single node
@@ -97,7 +119,7 @@ public void testScanScrollWithShardExceptions() throws Exception {
         assertThat(numHits, equalTo(100L));
         clearScroll("_all");
 
-        internalCluster().stopRandomNonClusterManagerNode();
+        internalCluster().stopRandomDataNode();
 
         searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setSize(10).setScroll(TimeValue.timeValueMinutes(1)).get();
         assertThat(searchResponse.getSuccessfulShards(), lessThan(searchResponse.getTotalShards()));
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/searchafter/SearchAfterIT.java b/server/src/internalClusterTest/java/org/opensearch/search/searchafter/SearchAfterIT.java
index 22c0a9cbbab17..b99f66850e9e3 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/searchafter/SearchAfterIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/searchafter/SearchAfterIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.searchafter;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.indices.create.CreateIndexRequestBuilder;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.CreatePitAction;
@@ -43,30 +45,51 @@
 import org.opensearch.action.search.ShardSearchFailure;
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.action.ActionFuture;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.builder.PointInTimeBuilder;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 
-public class SearchAfterIT extends OpenSearchIntegTestCase {
+public class SearchAfterIT extends ParameterizedOpenSearchIntegTestCase {
     private static final String INDEX_NAME = "test";
     private static final int NUM_DOCS = 100;
 
+    public SearchAfterIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     public void testsShouldFail() throws Exception {
         assertAcked(client().admin().indices().prepareCreate("test").setMapping("field1", "type=long", "field2", "type=keyword").get());
         ensureGreen();
@@ -197,8 +220,8 @@ public void testPitWithSearchAfter() throws Exception {
             .setPointInTime(new PointInTimeBuilder(pitResponse.getId()))
             .get();
         assertEquals(3, sr.getHits().getHits().length);
-        /**
-         * Add new data and assert PIT results remain the same and normal search results gets refreshed
+        /*
+          Add new data and assert PIT results remain the same and normal search results gets refreshed
          */
         indexRandom(true, client().prepareIndex("test").setId("4").setSource("field1", 102));
         sr = client().prepareSearch()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/simple/SimpleSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/simple/SimpleSearchIT.java
index 0e6073ad11689..7aae41d939cac 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/simple/SimpleSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/simple/SimpleSearchIT.java
@@ -32,12 +32,15 @@
 
 package org.opensearch.search.simple;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.support.WriteRequest.RefreshPolicy;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.core.rest.RestStatus;
@@ -49,9 +52,11 @@
 import org.opensearch.index.query.TermQueryBuilder;
 import org.opensearch.search.rescore.QueryRescorerBuilder;
 import org.opensearch.search.sort.SortOrder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
 
@@ -62,14 +67,34 @@
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.queryStringQuery;
 import static org.opensearch.index.query.QueryBuilders.rangeQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFailures;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
+import static org.apache.lucene.search.TotalHits.Relation.EQUAL_TO;
+import static org.apache.lucene.search.TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO;
+
+public class SimpleSearchIT extends ParameterizedOpenSearchIntegTestCase {
 
-public class SimpleSearchIT extends OpenSearchIntegTestCase {
+    public SimpleSearchIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public void testSearchNullIndex() {
         expectThrows(
@@ -258,10 +283,9 @@ public void testSimpleDateRange() throws Exception {
         assertHitCount(searchResponse, 2L);
     }
 
-    public void testSimpleTerminateAfterCount() throws Exception {
+    public void dotestSimpleTerminateAfterCountWithSize(int size, int max) throws Exception {
         prepareCreate("test").setSettings(Settings.builder().put(SETTING_NUMBER_OF_SHARDS, 1).put(SETTING_NUMBER_OF_REPLICAS, 0)).get();
         ensureGreen();
-        int max = randomIntBetween(3, 29);
         List<IndexRequestBuilder> docbuilders = new ArrayList<>(max);
 
         for (int i = 1; i <= max; i++) {
@@ -278,9 +302,12 @@ public void testSimpleTerminateAfterCount() throws Exception {
             searchResponse = client().prepareSearch("test")
                 .setQuery(QueryBuilders.rangeQuery("field").gte(1).lte(max))
                 .setTerminateAfter(i)
+                .setSize(size)
+                .setTrackTotalHits(true)
                 .get();
             assertHitCount(searchResponse, i);
             assertTrue(searchResponse.isTerminatedEarly());
+            assertEquals(Math.min(i, size), searchResponse.getHits().getHits().length);
         }
 
         searchResponse = client().prepareSearch("test")
@@ -292,6 +319,101 @@ public void testSimpleTerminateAfterCount() throws Exception {
         assertFalse(searchResponse.isTerminatedEarly());
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/10435")
+    public void testSimpleTerminateAfterCountSize0() throws Exception {
+        int max = randomIntBetween(3, 29);
+        dotestSimpleTerminateAfterCountWithSize(0, max);
+    }
+
+    public void testSimpleTerminateAfterCountRandomSize() throws Exception {
+        int max = randomIntBetween(3, 29);
+        dotestSimpleTerminateAfterCountWithSize(randomIntBetween(1, max), max);
+    }
+
+    public void doTestSimpleTerminateAfterTrackTotalHitsUpTo(int size) throws Exception {
+        prepareCreate("test").setSettings(Settings.builder().put(SETTING_NUMBER_OF_SHARDS, 1).put(SETTING_NUMBER_OF_REPLICAS, 0)).get();
+        ensureGreen();
+        int numDocs = 29;
+        List<IndexRequestBuilder> docbuilders = new ArrayList<>(numDocs);
+
+        for (int i = 1; i <= numDocs; i++) {
+            String id = String.valueOf(i);
+            docbuilders.add(client().prepareIndex("test").setId(id).setSource("field", i));
+        }
+
+        indexRandom(true, docbuilders);
+        ensureGreen();
+        refresh();
+
+        SearchResponse searchResponse;
+        searchResponse = client().prepareSearch("test")
+            .setQuery(QueryBuilders.rangeQuery("field").gte(1).lte(numDocs))
+            .setTerminateAfter(10)
+            .setSize(size)
+            .setTrackTotalHitsUpTo(5)
+            .get();
+        assertTrue(searchResponse.isTerminatedEarly());
+        assertEquals(5, searchResponse.getHits().getTotalHits().value);
+        assertEquals(GREATER_THAN_OR_EQUAL_TO, searchResponse.getHits().getTotalHits().relation);
+
+        searchResponse = client().prepareSearch("test")
+            .setQuery(QueryBuilders.rangeQuery("field").gte(1).lte(numDocs))
+            .setTerminateAfter(5)
+            .setSize(size)
+            .setTrackTotalHitsUpTo(10)
+            .get();
+        assertTrue(searchResponse.isTerminatedEarly());
+        assertEquals(5, searchResponse.getHits().getTotalHits().value);
+        assertEquals(EQUAL_TO, searchResponse.getHits().getTotalHits().relation);
+
+        searchResponse = client().prepareSearch("test")
+            .setQuery(QueryBuilders.rangeQuery("field").gte(1).lte(numDocs))
+            .setTerminateAfter(5)
+            .setSize(size)
+            .setTrackTotalHitsUpTo(5)
+            .get();
+        assertTrue(searchResponse.isTerminatedEarly());
+        assertEquals(5, searchResponse.getHits().getTotalHits().value);
+        assertEquals(EQUAL_TO, searchResponse.getHits().getTotalHits().relation);
+
+        searchResponse = client().prepareSearch("test")
+            .setQuery(QueryBuilders.rangeQuery("field").gte(1).lte(numDocs))
+            .setTerminateAfter(5)
+            .setSize(size)
+            .setTrackTotalHits(true)
+            .get();
+        assertTrue(searchResponse.isTerminatedEarly());
+        assertEquals(5, searchResponse.getHits().getTotalHits().value);
+        assertEquals(EQUAL_TO, searchResponse.getHits().getTotalHits().relation);
+
+        searchResponse = client().prepareSearch("test")
+            .setQuery(QueryBuilders.rangeQuery("field").gte(1).lte(numDocs))
+            .setTerminateAfter(numDocs * 2)
+            .setSize(size)
+            .setTrackTotalHits(true)
+            .get();
+        assertFalse(searchResponse.isTerminatedEarly());
+        assertEquals(numDocs, searchResponse.getHits().getTotalHits().value);
+        assertEquals(EQUAL_TO, searchResponse.getHits().getTotalHits().relation);
+
+        searchResponse = client().prepareSearch("test")
+            .setQuery(QueryBuilders.rangeQuery("field").gte(1).lte(numDocs))
+            .setSize(size)
+            .setTrackTotalHitsUpTo(5)
+            .get();
+        assertEquals(5, searchResponse.getHits().getTotalHits().value);
+        assertEquals(GREATER_THAN_OR_EQUAL_TO, searchResponse.getHits().getTotalHits().relation);
+    }
+
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/10435")
+    public void testSimpleTerminateAfterTrackTotalHitsUpToRandomSize() throws Exception {
+        doTestSimpleTerminateAfterTrackTotalHitsUpTo(0);
+    }
+
+    public void testSimpleTerminateAfterTrackTotalHitsUpToSize0() throws Exception {
+        doTestSimpleTerminateAfterTrackTotalHitsUpTo(randomIntBetween(1, 29));
+    }
+
     public void testSimpleIndexSortEarlyTerminate() throws Exception {
         prepareCreate("test").setSettings(
             Settings.builder().put(SETTING_NUMBER_OF_SHARDS, 1).put(SETTING_NUMBER_OF_REPLICAS, 0).put("index.sort.field", "rank")
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/slice/SearchSliceIT.java b/server/src/internalClusterTest/java/org/opensearch/search/slice/SearchSliceIT.java
index d50f750a2b2ec..27a56f9d14f08 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/slice/SearchSliceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/slice/SearchSliceIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.slice;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.indices.alias.IndicesAliasesRequest;
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.CreatePitAction;
@@ -43,6 +45,7 @@
 import org.opensearch.common.action.ActionFuture;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.search.Scroll;
@@ -50,21 +53,41 @@
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.builder.PointInTimeBuilder;
 import org.opensearch.search.sort.SortBuilders;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.startsWith;
 
-public class SearchSliceIT extends OpenSearchIntegTestCase {
+public class SearchSliceIT extends ParameterizedOpenSearchIntegTestCase {
+    public SearchSliceIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private void setupIndex(int numDocs, int numberOfShards) throws IOException, ExecutionException, InterruptedException {
         String mapping = XContentFactory.jsonBuilder()
             .startObject()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/sort/FieldSortIT.java b/server/src/internalClusterTest/java/org/opensearch/search/sort/FieldSortIT.java
index bee242b933dfd..81e948640ee94 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/sort/FieldSortIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/sort/FieldSortIT.java
@@ -154,7 +154,7 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(InternalSettingsPlugin.class, CustomScriptPlugin.class);
     }
 
-    public void testIssue8226() {
+    public void testIssue8226() throws InterruptedException {
         int numIndices = between(5, 10);
         final boolean useMapping = randomBoolean();
         for (int i = 0; i < numIndices; i++) {
@@ -168,6 +168,9 @@ public void testIssue8226() {
             }
         }
         refresh();
+        for (int i = 0; i < numIndices; i++) {
+            indexRandomForConcurrentSearch("test_" + i);
+        }
         // sort DESC
         SearchResponse searchResponse = client().prepareSearch()
             .addSort(new FieldSortBuilder("entry").order(SortOrder.DESC).unmappedType(useMapping ? null : "long"))
@@ -278,6 +281,7 @@ public void testTrackScores() throws Exception {
             jsonBuilder().startObject().field("id", "2").field("svalue", "bbb").field("ivalue", 200).field("dvalue", 0.2).endObject()
         );
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(matchAllQuery()).addSort("svalue", SortOrder.ASC).get();
 
@@ -446,6 +450,7 @@ public void testScoreSortDirection() throws Exception {
         client().prepareIndex("test").setId("3").setSource("field", 0).get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(QueryBuilders.functionScoreQuery(matchAllQuery(), ScoreFunctionBuilders.fieldValueFactorFunction("field")))
@@ -484,6 +489,7 @@ public void testScoreSortDirectionWithFunctionScore() throws Exception {
         client().prepareIndex("test").setId("3").setSource("field", 0).get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(functionScoreQuery(matchAllQuery(), fieldValueFactorFunction("field")))
@@ -531,7 +537,7 @@ public void testIssue2986() {
         }
     }
 
-    public void testIssue2991() {
+    public void testIssue2991() throws InterruptedException {
         for (int i = 1; i < 4; i++) {
             try {
                 client().admin().indices().prepareDelete("test").get();
@@ -552,6 +558,7 @@ public void testIssue2991() {
             client().prepareIndex("test").setId("2").setSource("tag", "beta").get();
 
             refresh();
+            indexRandomForConcurrentSearch("test");
             SearchResponse resp = client().prepareSearch("test")
                 .setSize(2)
                 .setQuery(matchAllQuery())
@@ -605,6 +612,9 @@ public void testSimpleSorts() throws Exception {
                     .startObject("float_value")
                     .field("type", "float")
                     .endObject()
+                    .startObject("half_float_value")
+                    .field("type", "half_float")
+                    .endObject()
                     .startObject("double_value")
                     .field("type", "double")
                     .endObject()
@@ -628,6 +638,7 @@ public void testSimpleSorts() throws Exception {
                         .field("long_value", i)
                         .field("unsigned_long_value", UNSIGNED_LONG_BASE.add(BigInteger.valueOf(10000 * i)))
                         .field("float_value", 0.1 * i)
+                        .field("half_float_value", 0.1 * i)
                         .field("double_value", 0.1 * i)
                         .endObject()
                 );
@@ -646,6 +657,7 @@ public void testSimpleSorts() throws Exception {
 
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // STRING
         int size = 1 + random.nextInt(10);
@@ -794,6 +806,28 @@ public void testSimpleSorts() throws Exception {
 
         assertThat(searchResponse.toString(), not(containsString("error")));
 
+        // HALF_FLOAT
+        size = 1 + random.nextInt(10);
+        searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setSize(size).addSort("half_float_value", SortOrder.ASC).get();
+
+        assertHitCount(searchResponse, 10L);
+        assertThat(searchResponse.getHits().getHits().length, equalTo(size));
+        for (int i = 0; i < size; i++) {
+            assertThat(searchResponse.getHits().getAt(i).getId(), equalTo(Integer.toString(i)));
+        }
+
+        assertThat(searchResponse.toString(), not(containsString("error")));
+        size = 1 + random.nextInt(10);
+        searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setSize(size).addSort("half_float_value", SortOrder.DESC).get();
+
+        assertHitCount(searchResponse, 10);
+        assertThat(searchResponse.getHits().getHits().length, equalTo(size));
+        for (int i = 0; i < size; i++) {
+            assertThat(searchResponse.getHits().getAt(i).getId(), equalTo(Integer.toString(9 - i)));
+        }
+
+        assertThat(searchResponse.toString(), not(containsString("error")));
+
         // DOUBLE
         size = 1 + random.nextInt(10);
         searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setSize(size).addSort("double_value", SortOrder.ASC).get();
@@ -896,6 +930,7 @@ public void testSortMissingNumbers() throws Exception {
 
         flush();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // DOUBLE
         logger.info("--> sort with no missing (same as missing _last)");
@@ -1057,6 +1092,7 @@ public void testSortMissingNumbersMinMax() throws Exception {
 
         flush();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // LONG
         logger.info("--> sort with no missing (same as missing _last)");
@@ -1176,7 +1212,7 @@ public void testSortMissingNumbersMinMax() throws Exception {
         assertThat(searchResponse.getHits().getAt(2).getId(), equalTo("3"));
     }
 
-    public void testSortMissingStrings() throws IOException {
+    public void testSortMissingStrings() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 XContentFactory.jsonBuilder()
@@ -1204,6 +1240,7 @@ public void testSortMissingStrings() throws IOException {
 
         flush();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // TODO: WTF?
         try {
@@ -1330,6 +1367,9 @@ public void testSortMVField() throws Exception {
                     .startObject("float_values")
                     .field("type", "float")
                     .endObject()
+                    .startObject("half_float_values")
+                    .field("type", "float")
+                    .endObject()
                     .startObject("double_values")
                     .field("type", "double")
                     .endObject()
@@ -1351,6 +1391,7 @@ public void testSortMVField() throws Exception {
                     .array("short_values", 1, 5, 10, 8)
                     .array("byte_values", 1, 5, 10, 8)
                     .array("float_values", 1f, 5f, 10f, 8f)
+                    .array("half_float_values", 1f, 5f, 10f, 8f)
                     .array("double_values", 1d, 5d, 10d, 8d)
                     .array("string_values", "01", "05", "10", "08")
                     .endObject()
@@ -1365,6 +1406,7 @@ public void testSortMVField() throws Exception {
                     .array("short_values", 11, 15, 20, 7)
                     .array("byte_values", 11, 15, 20, 7)
                     .array("float_values", 11f, 15f, 20f, 7f)
+                    .array("half_float_values", 11f, 15f, 20f, 7f)
                     .array("double_values", 11d, 15d, 20d, 7d)
                     .array("string_values", "11", "15", "20", "07")
                     .endObject()
@@ -1379,6 +1421,7 @@ public void testSortMVField() throws Exception {
                     .array("short_values", 2, 1, 3, -4)
                     .array("byte_values", 2, 1, 3, -4)
                     .array("float_values", 2f, 1f, 3f, -4f)
+                    .array("half_float_values", 2f, 1f, 3f, -4f)
                     .array("double_values", 2d, 1d, 3d, -4d)
                     .array("string_values", "02", "01", "03", "!4")
                     .endObject()
@@ -1386,6 +1429,7 @@ public void testSortMVField() throws Exception {
             .get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -1585,6 +1629,34 @@ public void testSortMVField() throws Exception {
         assertThat(searchResponse.getHits().getAt(2).getId(), equalTo(Integer.toString(3)));
         assertThat(((Number) searchResponse.getHits().getAt(2).getSortValues()[0]).floatValue(), equalTo(3f));
 
+        searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setSize(10).addSort("half_float_values", SortOrder.ASC).get();
+
+        assertThat(searchResponse.getHits().getTotalHits().value, equalTo(3L));
+        assertThat(searchResponse.getHits().getHits().length, equalTo(3));
+
+        assertThat(searchResponse.getHits().getAt(0).getId(), equalTo(Integer.toString(3)));
+        assertThat(((Number) searchResponse.getHits().getAt(0).getSortValues()[0]).floatValue(), equalTo(-4f));
+
+        assertThat(searchResponse.getHits().getAt(1).getId(), equalTo(Integer.toString(1)));
+        assertThat(((Number) searchResponse.getHits().getAt(1).getSortValues()[0]).floatValue(), equalTo(1f));
+
+        assertThat(searchResponse.getHits().getAt(2).getId(), equalTo(Integer.toString(2)));
+        assertThat(((Number) searchResponse.getHits().getAt(2).getSortValues()[0]).floatValue(), equalTo(7f));
+
+        searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setSize(10).addSort("half_float_values", SortOrder.DESC).get();
+
+        assertThat(searchResponse.getHits().getTotalHits().value, equalTo(3L));
+        assertThat(searchResponse.getHits().getHits().length, equalTo(3));
+
+        assertThat(searchResponse.getHits().getAt(0).getId(), equalTo(Integer.toString(2)));
+        assertThat(((Number) searchResponse.getHits().getAt(0).getSortValues()[0]).floatValue(), equalTo(20f));
+
+        assertThat(searchResponse.getHits().getAt(1).getId(), equalTo(Integer.toString(1)));
+        assertThat(((Number) searchResponse.getHits().getAt(1).getSortValues()[0]).floatValue(), equalTo(10f));
+
+        assertThat(searchResponse.getHits().getAt(2).getId(), equalTo(Integer.toString(3)));
+        assertThat(((Number) searchResponse.getHits().getAt(2).getSortValues()[0]).floatValue(), equalTo(3f));
+
         searchResponse = client().prepareSearch().setQuery(matchAllQuery()).setSize(10).addSort("double_values", SortOrder.ASC).get();
 
         assertThat(searchResponse.getHits().getTotalHits().value, equalTo(3L));
@@ -1642,7 +1714,7 @@ public void testSortMVField() throws Exception {
         assertThat(searchResponse.getHits().getAt(2).getSortValues()[0], equalTo("03"));
     }
 
-    public void testSortOnRareField() throws IOException {
+    public void testSortOnRareField() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 XContentFactory.jsonBuilder()
@@ -1662,6 +1734,7 @@ public void testSortOnRareField() throws IOException {
             .get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(matchAllQuery())
             .setSize(3)
@@ -1757,6 +1830,7 @@ public void testSortMetaField() throws Exception {
                 indexReqs[i] = client().prepareIndex("test").setId(Integer.toString(i)).setSource();
             }
             indexRandom(true, indexReqs);
+            indexRandomForConcurrentSearch("test");
 
             SortOrder order = randomFrom(SortOrder.values());
             SearchResponse searchResponse = client().prepareSearch()
@@ -1859,6 +1933,7 @@ public void testNestedSort() throws IOException, InterruptedException, Execution
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // We sort on nested field
         SearchResponse searchResponse = client().prepareSearch()
@@ -2044,6 +2119,7 @@ public void testFieldAlias() throws Exception {
         builders.add(client().prepareIndex("old_index").setSource("distance", 50.5));
         builders.add(client().prepareIndex("new_index").setSource("route_length_miles", 100.2));
         indexRandom(true, true, builders);
+        indexRandomForConcurrentSearch("old_index", "new_index");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -2070,6 +2146,7 @@ public void testFieldAliasesWithMissingValues() throws Exception {
         builders.add(client().prepareIndex("old_index").setSource(Collections.emptyMap()));
         builders.add(client().prepareIndex("new_index").setSource("route_length_miles", 100.2));
         indexRandom(true, true, builders);
+        indexRandomForConcurrentSearch("old_index", "new_index");
 
         SearchResponse response = client().prepareSearch()
             .setQuery(matchAllQuery())
@@ -2139,6 +2216,7 @@ public void testCastDate() throws Exception {
         builders.add(client().prepareIndex("index_date").setSource("field", "2024-04-11T23:47:17"));
         builders.add(client().prepareIndex("index_date_nanos").setSource("field", "2024-04-11T23:47:16.854775807Z"));
         indexRandom(true, true, builders);
+        indexRandomForConcurrentSearch("index_date", "index_date_nanos");
 
         {
             SearchResponse response = client().prepareSearch()
@@ -2264,7 +2342,7 @@ public void testCastNumericTypeExceptions() throws Exception {
         }
     }
 
-    public void testLongSortOptimizationCorrectResults() {
+    public void testLongSortOptimizationCorrectResults() throws InterruptedException {
         assertAcked(
             prepareCreate("test1").setSettings(Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 2))
                 .setMapping("long_field", "type=long")
@@ -2281,6 +2359,7 @@ public void testLongSortOptimizationCorrectResults() {
             bulkBuilder.add(client().prepareIndex("test1").setId(Integer.toString(i)).setSource(source, MediaTypeRegistry.JSON));
         }
         refresh();
+        indexRandomForConcurrentSearch("test1");
 
         // *** 1. sort DESC on long_field
         SearchResponse searchResponse = client().prepareSearch()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceIT.java b/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceIT.java
index 6681715981c54..766ac6139b24b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceIT.java
@@ -32,24 +32,30 @@
 
 package org.opensearch.search.sort;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.Version;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.geo.GeoDistance;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.geometry.utils.Geohash;
 import org.opensearch.index.query.QueryBuilders;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.VersionUtils;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertFirstHit;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
@@ -60,7 +66,24 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 
-public class GeoDistanceIT extends OpenSearchIntegTestCase {
+public class GeoDistanceIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public GeoDistanceIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected boolean forbidPrivateIndexSettings() {
@@ -169,6 +192,7 @@ public void testDistanceSortingMVFields() throws Exception {
             .get();
 
         client().admin().indices().prepareRefresh().get();
+        indexRandomForConcurrentSearch("test");
 
         // Order: Asc
         SearchResponse searchResponse = client().prepareSearch("test")
@@ -301,6 +325,7 @@ public void testDistanceSortingWithMissingGeoPoint() throws Exception {
             .get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // Order: Asc
         SearchResponse searchResponse = client().prepareSearch("test")
@@ -579,7 +604,7 @@ public void testDistanceSortingNestedFields() throws Exception {
     /**
      * Issue 3073
      */
-    public void testGeoDistanceFilter() throws IOException {
+    public void testGeoDistanceFilter() throws IOException, InterruptedException {
         Version version = VersionUtils.randomIndexCompatibleVersion(random());
         Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
         double lat = 40.720611;
@@ -597,6 +622,7 @@ public void testGeoDistanceFilter() throws IOException {
         assertAcked(prepareCreate("locations").setSettings(settings).setMapping(mapping));
         client().prepareIndex("locations").setId("1").setCreate(true).setSource(source).get();
         refresh();
+        indexRandomForConcurrentSearch("locations");
         client().prepareGet("locations", "1").get();
 
         SearchResponse result = client().prepareSearch("locations")
@@ -645,6 +671,7 @@ public void testDistanceSortingWithUnmappedField() throws Exception {
             .get();
 
         refresh();
+        indexRandomForConcurrentSearch("test1", "test2");
 
         // Order: Asc
         SearchResponse searchResponse = client().prepareSearch("test1", "test2")
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceSortBuilderIT.java b/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceSortBuilderIT.java
index 5a0ca1d13633e..1b8bd9694483d 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceSortBuilderIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/sort/GeoDistanceSortBuilderIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.sort;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.Version;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
@@ -39,28 +41,47 @@
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.DistanceUnit;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.GeoValidationMethod;
 import org.opensearch.search.builder.SearchSourceBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.VersionUtils;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.sort.SortBuilders.fieldSort;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertOrderedSearchHits;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSortValues;
 import static org.hamcrest.Matchers.closeTo;
 
-public class GeoDistanceSortBuilderIT extends OpenSearchIntegTestCase {
+public class GeoDistanceSortBuilderIT extends ParameterizedOpenSearchIntegTestCase {
+    public GeoDistanceSortBuilderIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     private static final String LOCATION_FIELD = "location";
 
@@ -70,16 +91,16 @@ protected boolean forbidPrivateIndexSettings() {
     }
 
     public void testManyToManyGeoPoints() throws ExecutionException, InterruptedException, IOException {
-        /**
-         * | q  |  d1    |   d2
-         * |    |        |
-         * |    |        |
-         * |    |        |
-         * |2  o|  x     |     x
-         * |    |        |
-         * |1  o|      x | x
-         * |___________________________
-         * 1   2   3   4   5   6   7
+        /*
+          | q  |  d1    |   d2
+          |    |        |
+          |    |        |
+          |    |        |
+          |2  o|  x     |     x
+          |    |        |
+          |1  o|      x | x
+          |___________________________
+          1   2   3   4   5   6   7
          */
         Version version = randomBoolean() ? Version.CURRENT : VersionUtils.randomIndexCompatibleVersion(random());
         Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
@@ -166,11 +187,10 @@ public void testManyToManyGeoPoints() throws ExecutionException, InterruptedExce
     }
 
     public void testSingeToManyAvgMedian() throws ExecutionException, InterruptedException, IOException {
-        /**
-         * q  = (0, 0)
-         *
-         * d1 = (0, 1), (0, 4), (0, 10); so avg. distance is 5, median distance is 4
-         * d2 = (0, 1), (0, 5), (0, 6); so avg. distance is 4, median distance is 5
+        /*
+          q  = (0, 0)
+          d1 = (0, 1), (0, 4), (0, 10); so avg. distance is 5, median distance is 4
+          d2 = (0, 1), (0, 5), (0, 6); so avg. distance is 4, median distance is 5
          */
         Version version = randomBoolean() ? Version.CURRENT : VersionUtils.randomIndexCompatibleVersion(random());
         Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
@@ -235,16 +255,17 @@ protected void createShuffeldJSONArray(XContentBuilder builder, GeoPoint[] point
     }
 
     public void testManyToManyGeoPointsWithDifferentFormats() throws ExecutionException, InterruptedException, IOException {
-        /**   q     d1       d2
-         * |4  o|   x    |   x
-         * |    |        |
-         * |3  o|  x     |  x
-         * |    |        |
-         * |2  o| x      | x
-         * |    |        |
-         * |1  o|x       |x
-         * |______________________
-         * 1   2   3   4   5   6
+        /*
+           q     d1       d2
+          |4  o|   x    |   x
+          |    |        |
+          |3  o|  x     |  x
+          |    |        |
+          |2  o| x      | x
+          |    |        |
+          |1  o|x       |x
+          |______________________
+          1   2   3   4   5   6
          */
         Version version = randomBoolean() ? Version.CURRENT : VersionUtils.randomIndexCompatibleVersion(random());
         Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/sort/SortFromPluginIT.java b/server/src/internalClusterTest/java/org/opensearch/search/sort/SortFromPluginIT.java
index 5b896f9a1fe57..76e68781c72ba 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/sort/SortFromPluginIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/sort/SortFromPluginIT.java
@@ -8,21 +8,42 @@
 
 package org.opensearch.search.sort;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.builder.SearchSourceBuilder;
 import org.opensearch.search.sort.plugin.CustomSortBuilder;
 import org.opensearch.search.sort.plugin.CustomSortPlugin;
 import org.opensearch.test.InternalSettingsPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.Arrays;
 import java.util.Collection;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.hamcrest.Matchers.equalTo;
 
-public class SortFromPluginIT extends OpenSearchIntegTestCase {
+public class SortFromPluginIT extends ParameterizedOpenSearchIntegTestCase {
+    public SortFromPluginIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -38,6 +59,7 @@ public void testPluginSort() throws Exception {
         client().prepareIndex("test").setId("3").setSource("field", 0).get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test").addSort(new CustomSortBuilder("field", SortOrder.ASC)).get();
         assertThat(searchResponse.getHits().getAt(0).getId(), equalTo("3"));
@@ -59,6 +81,7 @@ public void testPluginSortXContent() throws Exception {
         client().prepareIndex("test").setId("3").setSource("field", 0).get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // builder -> json -> builder
         SearchResponse searchResponse = client().prepareSearch("test")
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/source/MetadataFetchingIT.java b/server/src/internalClusterTest/java/org/opensearch/search/source/MetadataFetchingIT.java
index 4f6dd89285bee..a9c4bf841d9a1 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/source/MetadataFetchingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/source/MetadataFetchingIT.java
@@ -31,32 +31,58 @@
 
 package org.opensearch.search.source;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.search.join.ScoreMode;
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.InnerHitBuilder;
 import org.opensearch.index.query.NestedQueryBuilder;
 import org.opensearch.index.query.TermQueryBuilder;
 import org.opensearch.search.SearchException;
 import org.opensearch.search.SearchHits;
 import org.opensearch.search.fetch.subphase.FetchSourceContext;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
 
-public class MetadataFetchingIT extends OpenSearchIntegTestCase {
-    public void testSimple() {
+public class MetadataFetchingIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public MetadataFetchingIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
+    public void testSimple() throws InterruptedException {
         assertAcked(prepareCreate("test"));
         ensureGreen();
 
         client().prepareIndex("test").setId("1").setSource("field", "value").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").storedFields("_none_").setFetchSource(false).setVersion(true).get();
         assertThat(response.getHits().getAt(0).getId(), nullValue());
@@ -68,12 +94,12 @@ public void testSimple() {
         assertThat(response.getHits().getAt(0).getSourceAsString(), nullValue());
     }
 
-    public void testInnerHits() {
+    public void testInnerHits() throws InterruptedException {
         assertAcked(prepareCreate("test").setMapping("nested", "type=nested"));
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("field", "value", "nested", Collections.singletonMap("title", "foo")).get();
         refresh();
-
+        indexRandomForConcurrentSearch("test");
         SearchResponse response = client().prepareSearch("test")
             .storedFields("_none_")
             .setFetchSource(false)
@@ -94,12 +120,13 @@ public void testInnerHits() {
         assertThat(hits.getAt(0).getSourceAsString(), nullValue());
     }
 
-    public void testWithRouting() {
+    public void testWithRouting() throws InterruptedException {
         assertAcked(prepareCreate("test"));
         ensureGreen();
 
         client().prepareIndex("test").setId("1").setSource("field", "value").setRouting("toto").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").storedFields("_none_").setFetchSource(false).get();
         assertThat(response.getHits().getAt(0).getId(), nullValue());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/source/SourceFetchingIT.java b/server/src/internalClusterTest/java/org/opensearch/search/source/SourceFetchingIT.java
index 11223d11ff30d..805e82dc9850b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/source/SourceFetchingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/source/SourceFetchingIT.java
@@ -32,20 +32,47 @@
 
 package org.opensearch.search.source;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
 import static org.hamcrest.core.IsEqual.equalTo;
 
-public class SourceFetchingIT extends OpenSearchIntegTestCase {
-    public void testSourceDefaultBehavior() {
+public class SourceFetchingIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SourceFetchingIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
+    public void testSourceDefaultBehavior() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
         index("test", "type1", "1", "field", "value");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").get();
         assertThat(response.getHits().getAt(0).getSourceAsString(), notNullValue());
@@ -58,12 +85,13 @@ public void testSourceDefaultBehavior() {
 
     }
 
-    public void testSourceFiltering() {
+    public void testSourceFiltering() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
         client().prepareIndex("test").setId("1").setSource("field1", "value", "field2", "value2").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").setFetchSource(false).get();
         assertThat(response.getHits().getAt(0).getSourceAsString(), nullValue());
@@ -91,12 +119,13 @@ public void testSourceFiltering() {
      * Test Case for #5132: Source filtering with wildcards broken when given multiple patterns
      * https://github.com/elastic/elasticsearch/issues/5132
      */
-    public void testSourceWithWildcardFiltering() {
+    public void testSourceWithWildcardFiltering() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
         client().prepareIndex("test").setId("1").setSource("field", "value").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").setFetchSource(new String[] { "*.notexisting", "field" }, null).get();
         assertThat(response.getHits().getAt(0).getSourceAsString(), notNullValue());
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/stats/ConcurrentSearchStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/stats/ConcurrentSearchStatsIT.java
index 350f494c35366..f770bd9864850 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/stats/ConcurrentSearchStatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/stats/ConcurrentSearchStatsIT.java
@@ -8,6 +8,8 @@
 
 package org.opensearch.search.stats;
 
+import org.opensearch.action.admin.cluster.node.stats.NodesStatsAction;
+import org.opensearch.action.admin.cluster.node.stats.NodesStatsRequestBuilder;
 import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
 import org.opensearch.action.admin.indices.stats.IndexStats;
 import org.opensearch.action.admin.indices.stats.IndicesStatsRequestBuilder;
@@ -26,6 +28,8 @@
 import org.opensearch.search.SearchService;
 import org.opensearch.test.InternalSettingsPlugin;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.threadpool.ThreadPool;
+import org.opensearch.threadpool.ThreadPoolStats;
 
 import java.util.Arrays;
 import java.util.Collection;
@@ -35,6 +39,7 @@
 import java.util.function.Function;
 
 import static org.opensearch.index.query.QueryBuilders.scriptQuery;
+import static org.opensearch.search.SearchService.CONCURRENT_SEGMENT_SEARCH_TARGET_MAX_SLICE_COUNT_SETTING;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.lessThan;
 
@@ -307,6 +312,54 @@ public void testAvgConcurrencyIndexLevel() throws InterruptedException {
         assertEquals(expectedConcurrency, stats.getTotal().getSearch().getTotal().getConcurrentAvgSliceCount(), 0);
     }
 
+    public void testThreadPoolWaitTime() throws Exception {
+        int NUM_SHARDS = 1;
+        String INDEX = "test-" + randomAlphaOfLength(5).toLowerCase(Locale.ROOT);
+        createIndex(
+            INDEX,
+            Settings.builder()
+                .put(indexSettings())
+                .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, NUM_SHARDS)
+                .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
+                .build()
+        );
+
+        ensureGreen();
+
+        for (int i = 0; i < 10; i++) {
+            client().prepareIndex(INDEX).setId(Integer.toString(i)).setSource("field", "value" + i).get();
+            refresh();
+        }
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(CONCURRENT_SEGMENT_SEARCH_TARGET_MAX_SLICE_COUNT_SETTING.getKey(), 10))
+            .execute()
+            .actionGet();
+
+        client().prepareSearch(INDEX).execute().actionGet();
+
+        NodesStatsRequestBuilder nodesStatsRequestBuilder = new NodesStatsRequestBuilder(
+            client().admin().cluster(),
+            NodesStatsAction.INSTANCE
+        ).setNodesIds().all();
+        NodesStatsResponse nodesStatsResponse = nodesStatsRequestBuilder.execute().actionGet();
+        ThreadPoolStats threadPoolStats = nodesStatsResponse.getNodes().get(0).getThreadPool();
+
+        for (ThreadPoolStats.Stats stats : threadPoolStats) {
+            if (stats.getName().equals(ThreadPool.Names.INDEX_SEARCHER)) {
+                assertThat(stats.getWaitTime().micros(), greaterThan(0L));
+            }
+        }
+
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(CONCURRENT_SEGMENT_SEARCH_TARGET_MAX_SLICE_COUNT_SETTING.getKey(), 2))
+            .execute()
+            .actionGet();
+    }
+
     public static class ScriptedDelayedPlugin extends MockScriptPlugin {
         static final String SCRIPT_NAME = "search_timeout";
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/stats/SearchStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/search/stats/SearchStatsIT.java
index c72b5d40553b3..253a8b2b14824 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/stats/SearchStatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/stats/SearchStatsIT.java
@@ -32,9 +32,12 @@
 
 package org.opensearch.search.stats;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.admin.cluster.node.stats.NodeStats;
 import org.opensearch.action.admin.cluster.node.stats.NodesStatsResponse;
 import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.action.search.SearchPhaseName;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.routing.GroupShardsIterator;
@@ -42,6 +45,7 @@
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.index.search.stats.SearchStats.Stats;
 import org.opensearch.plugins.Plugin;
@@ -50,7 +54,9 @@
 import org.opensearch.script.ScriptType;
 import org.opensearch.search.fetch.subphase.highlight.HighlightBuilder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -58,9 +64,11 @@
 import java.util.Set;
 import java.util.function.Function;
 
+import static org.opensearch.action.search.TransportSearchAction.SEARCH_REQUEST_STATS_ENABLED_KEY;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAllSuccessful;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
@@ -72,8 +80,25 @@
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
 
-@OpenSearchIntegTestCase.ClusterScope(minNumDataNodes = 2)
-public class SearchStatsIT extends OpenSearchIntegTestCase {
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, minNumDataNodes = 2)
+public class SearchStatsIT extends ParameterizedOpenSearchIntegTestCase {
+
+    public SearchStatsIT(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -103,6 +128,11 @@ public void testSimpleStats() throws Exception {
         assertThat(numNodes, greaterThanOrEqualTo(2));
         final int shardsIdx1 = randomIntBetween(1, 10); // we make sure each node gets at least a single shard...
         final int shardsIdx2 = Math.max(numNodes - shardsIdx1, randomIntBetween(1, 10));
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setPersistentSettings(Settings.builder().put(SEARCH_REQUEST_STATS_ENABLED_KEY, true).build())
+            .get();
         assertThat(numNodes, lessThanOrEqualTo(shardsIdx1 + shardsIdx2));
         assertAcked(
             prepareCreate("test1").setSettings(
@@ -165,20 +195,40 @@ public void testSimpleStats() throws Exception {
 
         Set<String> nodeIdsWithIndex = nodeIdsWithIndex("test1", "test2");
         int num = 0;
+        int numOfCoordinators = 0;
+
         for (NodeStats stat : nodeStats.getNodes()) {
             Stats total = stat.getIndices().getSearch().getTotal();
+            if (total.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.QUERY.getName()).getTimeInMillis() > 0) {
+                assertThat(
+                    total.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.FETCH.getName()).getTimeInMillis(),
+                    greaterThan(0L)
+                );
+                assertEquals(
+                    iters,
+                    total.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.FETCH.getName()).getTotal()
+                );
+                assertEquals(
+                    iters,
+                    total.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.EXPAND.getName()).getTotal()
+                );
+                assertEquals(
+                    iters,
+                    total.getRequestStatsLongHolder().getRequestStatsHolder().get(SearchPhaseName.FETCH.getName()).getTotal()
+                );
+                numOfCoordinators += 1;
+            }
             if (nodeIdsWithIndex.contains(stat.getNode().getId())) {
                 assertThat(total.getQueryCount(), greaterThan(0L));
                 assertThat(total.getQueryTimeInMillis(), greaterThan(0L));
                 num++;
             } else {
-                assertThat(total.getQueryCount(), equalTo(0L));
+                assertThat(total.getQueryCount(), greaterThanOrEqualTo(0L));
                 assertThat(total.getQueryTimeInMillis(), equalTo(0L));
             }
         }
-
+        assertThat(numOfCoordinators, greaterThan(0));
         assertThat(num, greaterThan(0));
-
     }
 
     private Set<String> nodeIdsWithIndex(String... indices) {
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/suggest/CompletionSuggestSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/suggest/CompletionSuggestSearchIT.java
index 7183f18acbadf..b342e6d35f0b4 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/suggest/CompletionSuggestSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/suggest/CompletionSuggestSearchIT.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.suggest;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 import com.carrotsearch.randomizedtesting.generators.RandomStrings;
 
 import org.apache.lucene.analysis.TokenStreamToAutomaton;
@@ -47,6 +48,7 @@
 import org.opensearch.common.FieldMemoryStats;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.Fuzziness;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.mapper.MapperParsingException;
@@ -63,7 +65,7 @@
 import org.opensearch.search.suggest.completion.context.ContextMapping;
 import org.opensearch.search.suggest.completion.context.GeoContextMapping;
 import org.opensearch.test.InternalSettingsPlugin;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -77,10 +79,12 @@
 import java.util.Set;
 
 import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
+import static org.opensearch.action.support.WriteRequest.RefreshPolicy.WAIT_UNTIL;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.core.common.util.CollectionUtils.iterableAsArrayList;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAllSuccessful;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.hasId;
@@ -96,7 +100,24 @@
 import static org.hamcrest.Matchers.notNullValue;
 
 @SuppressCodecs("*") // requires custom completion format
-public class CompletionSuggestSearchIT extends OpenSearchIntegTestCase {
+public class CompletionSuggestSearchIT extends ParameterizedOpenSearchIntegTestCase {
+    public CompletionSuggestSearchIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     private final String INDEX = RandomStrings.randomAsciiOfLength(random(), 10).toLowerCase(Locale.ROOT);
     private final String FIELD = RandomStrings.randomAsciiOfLength(random(), 10).toLowerCase(Locale.ROOT);
     private final CompletionMappingBuilder completionMappingBuilder = new CompletionMappingBuilder();
@@ -1151,6 +1172,7 @@ public void testSkipDuplicates() throws Exception {
         createIndexAndMapping(mapping);
         int numDocs = randomIntBetween(10, 100);
         int numUnique = randomIntBetween(1, numDocs);
+        logger.info("Suggestion duplicate parameters: numDocs {} numUnique {}", numDocs, numUnique);
         List<IndexRequestBuilder> indexRequestBuilders = new ArrayList<>();
         int[] weights = new int[numUnique];
         Integer[] termIds = new Integer[numUnique];
@@ -1160,8 +1182,10 @@ public void testSkipDuplicates() throws Exception {
             int weight = randomIntBetween(0, 100);
             weights[id] = Math.max(weight, weights[id]);
             String suggestion = "suggestion-" + String.format(Locale.ENGLISH, "%03d", id);
+            logger.info("Creating {}, id {}, weight {}", suggestion, i, id, weight);
             indexRequestBuilders.add(
                 client().prepareIndex(INDEX)
+                    .setRefreshPolicy(WAIT_UNTIL)
                     .setSource(
                         jsonBuilder().startObject()
                             .startObject(FIELD)
@@ -1175,10 +1199,12 @@ public void testSkipDuplicates() throws Exception {
         indexRandom(true, indexRequestBuilders);
 
         Arrays.sort(termIds, Comparator.comparingInt(o -> weights[(int) o]).reversed().thenComparingInt(a -> (int) a));
+        logger.info("Expected terms id ordered {}", (Object[]) termIds);
         String[] expected = new String[numUnique];
         for (int i = 0; i < termIds.length; i++) {
             expected[i] = "suggestion-" + String.format(Locale.ENGLISH, "%03d", termIds[i]);
         }
+        logger.info("Expected suggestions field values {}", (Object[]) expected);
         CompletionSuggestionBuilder completionSuggestionBuilder = SuggestBuilders.completionSuggestion(FIELD)
             .prefix("sugg")
             .skipDuplicates(true)
@@ -1187,6 +1213,7 @@ public void testSkipDuplicates() throws Exception {
         SearchResponse searchResponse = client().prepareSearch(INDEX)
             .suggest(new SuggestBuilder().addSuggestion("suggestions", completionSuggestionBuilder))
             .get();
+        logger.info("Search Response with Suggestions {}", searchResponse);
         assertSuggestions(searchResponse, true, "suggestions", expected);
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/suggest/ContextCompletionSuggestSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/suggest/ContextCompletionSuggestSearchIT.java
index 7f5e8abfc3b52..bac3e7fb61683 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/suggest/ContextCompletionSuggestSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/suggest/ContextCompletionSuggestSearchIT.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.suggest;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 import com.carrotsearch.randomizedtesting.generators.RandomStrings;
 
 import org.apache.lucene.tests.util.LuceneTestCase.SuppressCodecs;
@@ -40,6 +41,7 @@
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.Fuzziness;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -51,11 +53,12 @@
 import org.opensearch.search.suggest.completion.context.ContextMapping;
 import org.opensearch.search.suggest.completion.context.GeoContextMapping;
 import org.opensearch.search.suggest.completion.context.GeoQueryContext;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -64,12 +67,29 @@
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
 import static org.hamcrest.core.IsEqual.equalTo;
 
 @SuppressCodecs("*") // requires custom completion format
-public class ContextCompletionSuggestSearchIT extends OpenSearchIntegTestCase {
+public class ContextCompletionSuggestSearchIT extends ParameterizedOpenSearchIntegTestCase {
+    public ContextCompletionSuggestSearchIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     private final String INDEX = RandomStrings.randomAsciiOfLength(random(), 10).toLowerCase(Locale.ROOT);
     private final String FIELD = RandomStrings.randomAsciiOfLength(random(), 10).toLowerCase(Locale.ROOT);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/suggest/SuggestSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/suggest/SuggestSearchIT.java
index 017dd5ea668de..bc6e49008bf6b 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/suggest/SuggestSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/suggest/SuggestSearchIT.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.search.suggest;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.admin.indices.create.CreateIndexRequestBuilder;
 import org.opensearch.action.index.IndexRequestBuilder;
@@ -39,6 +41,7 @@
 import org.opensearch.action.search.SearchRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexSettings;
@@ -54,7 +57,7 @@
 import org.opensearch.search.suggest.phrase.StupidBackoff;
 import org.opensearch.search.suggest.term.TermSuggestionBuilder;
 import org.opensearch.search.suggest.term.TermSuggestionBuilder.SuggestMode;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 
 import java.io.IOException;
@@ -73,6 +76,7 @@
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.suggest.SuggestBuilders.phraseSuggestion;
 import static org.opensearch.search.suggest.SuggestBuilders.termSuggestion;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
@@ -92,7 +96,23 @@
  * possible these tests should declare for the first request, make the request, modify the configuration for the next request, make that
  * request, modify again, request again, etc.  This makes it very obvious what changes between requests.
  */
-public class SuggestSearchIT extends OpenSearchIntegTestCase {
+public class SuggestSearchIT extends ParameterizedOpenSearchIntegTestCase {
+    public SuggestSearchIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     // see #3196
     public void testSuggestAcrossMultipleIndices() throws IOException {
@@ -267,6 +287,7 @@ public void testSizeOneShard() throws Exception {
             index("test", "type1", Integer.toString(i), "text", "abc" + i);
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse search = client().prepareSearch().setQuery(matchQuery("text", "spellchecker")).get();
         assertThat("didn't ask for suggestions but got some", search.getSuggest(), nullValue());
@@ -349,6 +370,7 @@ public void testSimple() throws Exception {
         index("test", "type1", "3", "text", "abbd");
         index("test", "type1", "4", "text", "abcc");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse search = client().prepareSearch().setQuery(matchQuery("text", "spellcecker")).get();
         assertThat("didn't ask for suggestions but got some", search.getSuggest(), nullValue());
diff --git a/server/src/internalClusterTest/java/org/opensearch/similarity/SimilarityIT.java b/server/src/internalClusterTest/java/org/opensearch/similarity/SimilarityIT.java
index 929aac388b678..8c9bff9833462 100644
--- a/server/src/internalClusterTest/java/org/opensearch/similarity/SimilarityIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/similarity/SimilarityIT.java
@@ -32,17 +32,41 @@
 
 package org.opensearch.similarity;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.common.util.FeatureFlags;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
 import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.not;
 
-public class SimilarityIT extends OpenSearchIntegTestCase {
+public class SimilarityIT extends ParameterizedOpenSearchIntegTestCase {
+    public SimilarityIT(Settings settings) {
+        super(settings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     public void testCustomBM25Similarity() throws Exception {
         try {
             client().admin().indices().prepareDelete("test").execute().actionGet();
diff --git a/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java b/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java
index 066d82483ae91..83f93ab9ff6b5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java
@@ -215,9 +215,6 @@ public void testShallowCloneNameAvailability() throws Exception {
         final Path shallowSnapshotRepoPath = randomRepoPath();
         createRepository(shallowSnapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(shallowSnapshotRepoPath));
 
-        final Path remoteStoreRepoPath = randomRepoPath();
-        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
-
         final String indexName = "index-1";
         createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/snapshots/SearchableSnapshotIT.java b/server/src/internalClusterTest/java/org/opensearch/snapshots/SearchableSnapshotIT.java
index 4478a3432e519..9a92ddc81852a 100644
--- a/server/src/internalClusterTest/java/org/opensearch/snapshots/SearchableSnapshotIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/snapshots/SearchableSnapshotIT.java
@@ -458,7 +458,9 @@ private void testUpdateIndexSettingsOnlyNotAllowedSettings(String index) {
 
     private void testUpdateIndexSettingsOnlyAllowedSettings(String index) {
         final UpdateSettingsRequestBuilder builder = client().admin().indices().prepareUpdateSettings(index);
-        builder.setSettings(Map.of("index.max_result_window", 1000, "index.search.slowlog.threshold.query.warn", "10s"));
+        builder.setSettings(
+            Map.of("index.max_result_window", 1000, "index.search.slowlog.threshold.query.warn", "10s", "index.number_of_replicas", 0)
+        );
         AcknowledgedResponse settingsResponse = builder.execute().actionGet();
         assertThat(settingsResponse, notNullValue());
     }
diff --git a/server/src/internalClusterTest/java/org/opensearch/snapshots/SharedClusterSnapshotRestoreIT.java b/server/src/internalClusterTest/java/org/opensearch/snapshots/SharedClusterSnapshotRestoreIT.java
index 5268d5ddf35af..91b0aa6438753 100644
--- a/server/src/internalClusterTest/java/org/opensearch/snapshots/SharedClusterSnapshotRestoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/snapshots/SharedClusterSnapshotRestoreIT.java
@@ -1884,7 +1884,7 @@ public void testCannotCreateSnapshotsWithSameName() throws Exception {
      * This test ensures that when a shard is removed from a node (perhaps due to the node
      * leaving the cluster, then returning), all snapshotting of that shard is aborted, so
      * all Store references held onto by the snapshot are released.
-     *
+     * <p>
      * See https://github.com/elastic/elasticsearch/issues/20876
      */
     public void testSnapshotCanceledOnRemovedShard() throws Exception {
diff --git a/server/src/internalClusterTest/java/org/opensearch/snapshots/SystemRepositoryIT.java b/server/src/internalClusterTest/java/org/opensearch/snapshots/SystemRepositoryIT.java
new file mode 100644
index 0000000000000..f50fc691fb232
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/snapshots/SystemRepositoryIT.java
@@ -0,0 +1,71 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.snapshots;
+
+import org.opensearch.client.Client;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.repositories.RepositoryException;
+import org.opensearch.repositories.fs.FsRepository;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.junit.Before;
+
+import java.nio.file.Path;
+
+import static org.opensearch.remotestore.RemoteStoreBaseIntegTestCase.remoteStoreClusterSettings;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
+public class SystemRepositoryIT extends AbstractSnapshotIntegTestCase {
+    protected Path absolutePath;
+    final String systemRepoName = "system-repo-name";
+
+    @Before
+    public void setup() {
+        absolutePath = randomRepoPath().toAbsolutePath();
+    }
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder()
+            .put(super.nodeSettings(nodeOrdinal))
+            .put(remoteStoreClusterSettings(systemRepoName, absolutePath))
+            .build();
+    }
+
+    public void testRestrictedSettingsCantBeUpdated() {
+        disableRepoConsistencyCheck("System repository is being used for the test");
+
+        internalCluster().startNode();
+        final Client client = client();
+        final Settings.Builder repoSettings = Settings.builder().put("location", randomRepoPath());
+
+        RepositoryException e = expectThrows(
+            RepositoryException.class,
+            () -> client.admin().cluster().preparePutRepository(systemRepoName).setType("mock").setSettings(repoSettings).get()
+        );
+        assertEquals(
+            e.getMessage(),
+            "[system-repo-name] trying to modify an unmodifiable attribute type of system "
+                + "repository from current value [fs] to new value [mock]"
+        );
+    }
+
+    public void testSystemRepositoryNonRestrictedSettingsCanBeUpdated() {
+        disableRepoConsistencyCheck("System repository is being used for the test");
+
+        internalCluster().startNode();
+        final Client client = client();
+        final Settings.Builder repoSettings = Settings.builder().put("location", absolutePath).put("chunk_size", new ByteSizeValue(20));
+
+        assertAcked(
+            client.admin().cluster().preparePutRepository(systemRepoName).setType(FsRepository.TYPE).setSettings(repoSettings).get()
+        );
+    }
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/update/UpdateIT.java b/server/src/internalClusterTest/java/org/opensearch/update/UpdateIT.java
index 442268d513fc3..b46d27bafb2a5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/update/UpdateIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/update/UpdateIT.java
@@ -50,7 +50,7 @@
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.rest.RestStatus;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.index.engine.DocumentMissingException;
 import org.opensearch.index.engine.VersionConflictEngineException;
 import org.opensearch.plugins.Plugin;
@@ -669,7 +669,7 @@ public void run() {
 
     public void testStressUpdateDeleteConcurrency() throws Exception {
         // We create an index with merging disabled so that deletes don't get merged away
-        assertAcked(prepareCreate("test").setSettings(Settings.builder().put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)));
+        assertAcked(prepareCreate("test").setSettings(Settings.builder().put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)));
         ensureGreen();
 
         Script fieldIncScript = new Script(ScriptType.INLINE, UPDATE_SCRIPTS, FIELD_INC_SCRIPT, Collections.singletonMap("field", "field"));
diff --git a/server/src/internalClusterTest/java/org/opensearch/versioning/ConcurrentSeqNoVersioningIT.java b/server/src/internalClusterTest/java/org/opensearch/versioning/ConcurrentSeqNoVersioningIT.java
index c651689e21d3d..7f016caf22149 100644
--- a/server/src/internalClusterTest/java/org/opensearch/versioning/ConcurrentSeqNoVersioningIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/versioning/ConcurrentSeqNoVersioningIT.java
@@ -93,7 +93,7 @@
  *     provided the primaryTerm and seqNo still matches. The reason we cannot assume it will not take place after receiving the failure
  *     is that a request can fork into two because of retries on disconnect, and now race against itself. The retry might complete (and do a
  *     dirty or stale read) before the forked off request gets to execute, and that one might still subsequently succeed.
- *
+ * <p>
  *     Such writes are not necessarily fully replicated and can be lost. There is no
  *     guarantee that the previous value did not have the specified primaryTerm and seqNo</li>
  *     <li>CAS writes with other exceptions might or might not have taken place. If they have taken place, then after invocation but not
diff --git a/server/src/main/java/org/apache/lucene/index/OneMergeHelper.java b/server/src/main/java/org/apache/lucene/index/OneMergeHelper.java
index 8f67bb87b5c42..0ada02a09d157 100644
--- a/server/src/main/java/org/apache/lucene/index/OneMergeHelper.java
+++ b/server/src/main/java/org/apache/lucene/index/OneMergeHelper.java
@@ -59,8 +59,8 @@ public static double getMbPerSec(Thread thread, MergePolicy.OneMerge merge) {
      * Returns total bytes written by this merge.
      **/
     public static long getTotalBytesWritten(Thread thread, MergePolicy.OneMerge merge) throws IOException {
-        /**
-         * TODO: The number of bytes written during the merge should be accessible in OneMerge.
+        /*
+          TODO: The number of bytes written during the merge should be accessible in OneMerge.
          */
         if (thread instanceof ConcurrentMergeScheduler.MergeThread) {
             return ((ConcurrentMergeScheduler.MergeThread) thread).rateLimiter.getTotalBytesWritten();
diff --git a/server/src/main/java/org/apache/lucene/queryparser/classic/XQueryParser.java b/server/src/main/java/org/apache/lucene/queryparser/classic/XQueryParser.java
index 9a8c295d60ec7..2f00ea69207a7 100644
--- a/server/src/main/java/org/apache/lucene/queryparser/classic/XQueryParser.java
+++ b/server/src/main/java/org/apache/lucene/queryparser/classic/XQueryParser.java
@@ -38,7 +38,7 @@
 /**
  * This class is just a workaround to make {@link QueryParser#handleBareFuzzy(String, Token, String)} accessible by sub-classes.
  * It is needed for {@link QueryParser}s that need to override the parsing of the slop in a fuzzy query (e.g. word<b>~2</b>, word<b>~</b>).
- *
+ * <p>
  * TODO: We should maybe rewrite this with the flexible query parser which matches the same syntax with more freedom.
  */
 public class XQueryParser extends QueryParser {
diff --git a/server/src/main/java/org/apache/lucene/search/grouping/CollapsingTopDocsCollector.java b/server/src/main/java/org/apache/lucene/search/grouping/CollapsingTopDocsCollector.java
index e4c299ba572b1..9ca0491bc29f5 100644
--- a/server/src/main/java/org/apache/lucene/search/grouping/CollapsingTopDocsCollector.java
+++ b/server/src/main/java/org/apache/lucene/search/grouping/CollapsingTopDocsCollector.java
@@ -50,7 +50,7 @@
  * A collector that groups documents based on field values and returns {@link CollapseTopFieldDocs}
  * output. The collapsing is done in a single pass by selecting only the top sorted document per collapse key.
  * The value used for the collapse key of each group can be found in {@link CollapseTopFieldDocs#collapseValues}.
- *
+ * <p>
  * TODO: If the sort is based on score we should propagate the mininum competitive score when <code>orderedGroups</code> is full.
  * This is safe for collapsing since the group <code>sort</code> is the same as the query sort.
  */
diff --git a/server/src/main/java/org/apache/lucene/search/uhighlight/BoundedBreakIteratorScanner.java b/server/src/main/java/org/apache/lucene/search/uhighlight/BoundedBreakIteratorScanner.java
index 6fde39b16a59a..4edcdea42b53b 100644
--- a/server/src/main/java/org/apache/lucene/search/uhighlight/BoundedBreakIteratorScanner.java
+++ b/server/src/main/java/org/apache/lucene/search/uhighlight/BoundedBreakIteratorScanner.java
@@ -43,13 +43,13 @@
  * If the {@link BreakIterator} cannot find a passage smaller than the maximum length,
  * a secondary break iterator is used to re-split the passage at the first boundary after
  * maximum length.
- *
+ * <p>
  * This is useful to split passages created by {@link BreakIterator}s like `sentence` that
  * can create big outliers on semi-structured text.
- *
+ * <p>
  *
  * WARNING: This break iterator is designed to work with the {@link UnifiedHighlighter}.
- *
+ * <p>
  * TODO: We should be able to create passages incrementally, starting from the offset of the first match and expanding or not
  * depending on the offsets of subsequent matches. This is currently impossible because {@link FieldHighlighter} uses
  * only the first matching offset to derive the start and end of each passage.
diff --git a/server/src/main/java/org/apache/lucene/util/packed/XPacked64.java b/server/src/main/java/org/apache/lucene/util/packed/XPacked64.java
index 4777b77cfbfed..9e9f6d1fd817d 100644
--- a/server/src/main/java/org/apache/lucene/util/packed/XPacked64.java
+++ b/server/src/main/java/org/apache/lucene/util/packed/XPacked64.java
@@ -38,8 +38,8 @@
 /**
  * Forked from Lucene 8.x; removed in Lucene 9.0
  *
- * @todo further investigate a better alternative
- *
+ * TODO: further investigate a better alternative
+ * <p>
  * Space optimized random access capable array of values with a fixed number of bits/value. Values
  * are packed contiguously.
  *
diff --git a/server/src/main/java/org/apache/lucene/util/packed/XPacked64SingleBlock.java b/server/src/main/java/org/apache/lucene/util/packed/XPacked64SingleBlock.java
index 0324522e9a68d..53cf4ed8e2273 100644
--- a/server/src/main/java/org/apache/lucene/util/packed/XPacked64SingleBlock.java
+++ b/server/src/main/java/org/apache/lucene/util/packed/XPacked64SingleBlock.java
@@ -25,8 +25,8 @@
 /**
  * Forked from Lucene 8.x; removed in Lucene 9.0
  *
- * @todo further investigate a better alternative
- *
+ * TODO: further investigate a better alternative
+ * <p>
  * This class is similar to {@link Packed64} except that it trades space for speed by ensuring that
  * a single block needs to be read/written in order to read/write a value.
  */
diff --git a/server/src/main/java/org/apache/lucene/util/packed/XPackedInts.java b/server/src/main/java/org/apache/lucene/util/packed/XPackedInts.java
index f94a4531a7db9..4260d34ead7c9 100644
--- a/server/src/main/java/org/apache/lucene/util/packed/XPackedInts.java
+++ b/server/src/main/java/org/apache/lucene/util/packed/XPackedInts.java
@@ -35,9 +35,9 @@
 
 /**
  * Forked from Lucene 8.x; removed in Lucene 8.9
- *
+ * <p>
  * Todo: further investigate a better alternative
- *
+ * <p>
  * Simplistic compression for array of unsigned long values. Each value is {@code >= 0} and {@code
  * <=} a specified maximum value. The values are stored as packed ints, with each value consuming a
  * fixed number of bits.
diff --git a/server/src/main/java/org/opensearch/OpenSearchGenerationException.java b/server/src/main/java/org/opensearch/OpenSearchGenerationException.java
index 50b021d41123f..51093390d57e0 100644
--- a/server/src/main/java/org/opensearch/OpenSearchGenerationException.java
+++ b/server/src/main/java/org/opensearch/OpenSearchGenerationException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -39,8 +40,9 @@
 /**
  * A generic exception indicating failure to generate.
  *
- * @opensearch.internal
+  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class OpenSearchGenerationException extends OpenSearchException {
 
     public OpenSearchGenerationException(String msg) {
diff --git a/server/src/main/java/org/opensearch/action/ActionRequestValidationException.java b/server/src/main/java/org/opensearch/action/ActionRequestValidationException.java
index ffba4d2eb50c0..c30da41066dbd 100644
--- a/server/src/main/java/org/opensearch/action/ActionRequestValidationException.java
+++ b/server/src/main/java/org/opensearch/action/ActionRequestValidationException.java
@@ -33,10 +33,12 @@
 package org.opensearch.action;
 
 import org.opensearch.common.ValidationException;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Base exception for an action request validation extendable by plugins
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ActionRequestValidationException extends ValidationException {}
diff --git a/server/src/main/java/org/opensearch/action/AliasesRequest.java b/server/src/main/java/org/opensearch/action/AliasesRequest.java
index 4c5d5628b1aac..8fe6f49c08af0 100644
--- a/server/src/main/java/org/opensearch/action/AliasesRequest.java
+++ b/server/src/main/java/org/opensearch/action/AliasesRequest.java
@@ -32,14 +32,17 @@
 
 package org.opensearch.action;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Needs to be implemented by all {@link org.opensearch.action.ActionRequest} subclasses that relate to
  * one or more indices and one or more aliases. Meant to be used for aliases management requests (e.g. add/remove alias,
  * get aliases) that hold aliases and indices in separate fields.
  * Allows to retrieve which indices and aliases the action relates to.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface AliasesRequest extends IndicesRequest.Replaceable {
 
     /**
@@ -54,7 +57,7 @@ public interface AliasesRequest extends IndicesRequest.Replaceable {
 
     /**
      * Replaces current aliases with the provided aliases.
-     *
+     * <p>
      * Sometimes aliases expressions need to be resolved to concrete aliases prior to executing the transport action.
      */
     void replaceAliases(String... aliases);
diff --git a/server/src/main/java/org/opensearch/action/DocWriteRequest.java b/server/src/main/java/org/opensearch/action/DocWriteRequest.java
index df6414470ab6b..e09c76430defc 100644
--- a/server/src/main/java/org/opensearch/action/DocWriteRequest.java
+++ b/server/src/main/java/org/opensearch/action/DocWriteRequest.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.update.UpdateRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -55,8 +56,9 @@
  * Generic interface to group ActionRequest, which perform writes to a single document
  * Action requests implementing this can be part of {@link org.opensearch.action.bulk.BulkRequest}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface DocWriteRequest<T> extends IndicesRequest, Accountable {
 
     // Flag set for disallowing index auto creation for an individual write request.
@@ -149,7 +151,7 @@ public interface DocWriteRequest<T> extends IndicesRequest, Accountable {
 
     /**
      * If set, only perform this request if the document was last modification was assigned this primary term.
-     *
+     * <p>
      * If the document last modification was assigned a different term a
      * {@link org.opensearch.index.engine.VersionConflictEngineException} will be thrown.
      */
@@ -169,7 +171,10 @@ public interface DocWriteRequest<T> extends IndicesRequest, Accountable {
 
     /**
      * Requested operation type to perform on the document
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     enum OpType {
         /**
          * Index the source. If there an existing document with the id, it will
diff --git a/server/src/main/java/org/opensearch/action/DocWriteResponse.java b/server/src/main/java/org/opensearch/action/DocWriteResponse.java
index afdb1d3a0bdd9..aada56ed93fd3 100644
--- a/server/src/main/java/org/opensearch/action/DocWriteResponse.java
+++ b/server/src/main/java/org/opensearch/action/DocWriteResponse.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.support.replication.ReplicationResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -64,8 +65,9 @@
 /**
  * A base class for the response of a write operation that involves a single doc
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class DocWriteResponse extends ReplicationResponse implements WriteResponse, StatusToXContentObject {
 
     private static final String _SHARDS = "_shards";
@@ -80,7 +82,10 @@ public abstract class DocWriteResponse extends ReplicationResponse implements Wr
     /**
      * An enum that represents the results of CRUD operations, primarily used to communicate the type of
      * operation that occurred.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Result implements Writeable {
         CREATED(0),
         UPDATED(1),
@@ -341,7 +346,7 @@ public XContentBuilder innerToXContent(XContentBuilder builder, Params params) t
 
     /**
      * Parse the output of the {@link #innerToXContent(XContentBuilder, Params)} method.
-     *
+     * <p>
      * This method is intended to be called by subclasses and must be called multiple times to parse all the information concerning
      * {@link DocWriteResponse} objects. It always parses the current token, updates the given parsing context accordingly
      * if needed and then immediately returns.
diff --git a/server/src/main/java/org/opensearch/action/IndicesRequest.java b/server/src/main/java/org/opensearch/action/IndicesRequest.java
index 7e4c2f5076cda..f42818595d3cc 100644
--- a/server/src/main/java/org/opensearch/action/IndicesRequest.java
+++ b/server/src/main/java/org/opensearch/action/IndicesRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action;
 
 import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Needs to be implemented by all {@link org.opensearch.action.ActionRequest} subclasses that relate to
@@ -40,8 +41,9 @@
  * In case of internal requests originated during the distributed execution of an external request,
  * they will still return the indices that the original request related to.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IndicesRequest {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/OriginalIndices.java b/server/src/main/java/org/opensearch/action/OriginalIndices.java
index 1e24c64bc60fc..1c26bf9d416f5 100644
--- a/server/src/main/java/org/opensearch/action/OriginalIndices.java
+++ b/server/src/main/java/org/opensearch/action/OriginalIndices.java
@@ -33,6 +33,7 @@
 package org.opensearch.action;
 
 import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -42,8 +43,9 @@
 /**
  * Used to keep track of original indices within internal (e.g. shard level) requests
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class OriginalIndices implements IndicesRequest {
 
     // constant to use when original indices are not applicable and will not be serialized across the wire
diff --git a/server/src/main/java/org/opensearch/action/TaskOperationFailure.java b/server/src/main/java/org/opensearch/action/TaskOperationFailure.java
index 0930bd2741810..5948dd3e2b7cb 100644
--- a/server/src/main/java/org/opensearch/action/TaskOperationFailure.java
+++ b/server/src/main/java/org/opensearch/action/TaskOperationFailure.java
@@ -50,7 +50,7 @@
 
 /**
  * Information about task operation failures
- *
+ * <p>
  * The class is final due to serialization limitations
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequest.java
index 625aa91e6ea7f..4a5c3b076faba 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequest.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -48,8 +49,9 @@
 /**
  * A request to explain the allocation of a shard in the cluster
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterAllocationExplainRequest extends ClusterManagerNodeRequest<ClusterAllocationExplainRequest> {
 
     private static final ObjectParser<ClusterAllocationExplainRequest, Void> PARSER = new ObjectParser<>("cluster/allocation/explain");
@@ -95,7 +97,7 @@ public ClusterAllocationExplainRequest(StreamInput in) throws IOException {
      * Create a new allocation explain request. If {@code primary} is false, the first unassigned replica
      * will be picked for explanation. If no replicas are unassigned, the first assigned replica will
      * be explained.
-     *
+     * <p>
      * Package private for testing.
      */
     ClusterAllocationExplainRequest(String index, int shard, boolean primary, @Nullable String currentNode) {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequestBuilder.java
index d85cb3929873d..31781dda04957 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for requests to explain the allocation of a shard in the cluster
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterAllocationExplainRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     ClusterAllocationExplainRequest,
     ClusterAllocationExplainResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainResponse.java
index 0eeedb9af0ab7..17afdd862cf66 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplainResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.allocation;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -41,8 +42,9 @@
 /**
  * Explanation response for a shard in the cluster
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterAllocationExplainResponse extends ActionResponse {
 
     private ClusterAllocationExplanation cae;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplanation.java b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplanation.java
index f4705a21f5014..3c8f07613561d 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplanation.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/allocation/ClusterAllocationExplanation.java
@@ -40,6 +40,7 @@
 import org.opensearch.cluster.routing.allocation.AllocationDecision;
 import org.opensearch.cluster.routing.allocation.ShardAllocationDecision;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -58,8 +59,9 @@
  * or if it is not unassigned, then which nodes it could possibly be relocated to.
  * It is an immutable class.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ClusterAllocationExplanation implements ToXContentObject, Writeable {
 
     private final ShardRouting shardRouting;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/crypto/CryptoSettings.java b/server/src/main/java/org/opensearch/action/admin/cluster/crypto/CryptoSettings.java
index bd783b349bed4..6e4d7b84f204e 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/crypto/CryptoSettings.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/crypto/CryptoSettings.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.crypto;
 
 import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -28,8 +29,9 @@
 /**
  * Crypto settings supplied during a put repository request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CryptoSettings implements Writeable, ToXContentObject {
     private String keyProviderName;
     private String keyProviderType;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequest.java
index 79b7381801da6..8243be21ba487 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -18,8 +19,9 @@
 /**
  * Request for deleting decommission request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class DeleteDecommissionStateRequest extends ClusterManagerNodeRequest<DeleteDecommissionStateRequest> {
 
     public DeleteDecommissionStateRequest() {}
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequestBuilder.java
index 08f194c53f18e..94075d6ec860d 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateRequestBuilder.java
@@ -10,12 +10,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for Delete decommission request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class DeleteDecommissionStateRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     DeleteDecommissionStateRequest,
     DeleteDecommissionStateResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateResponse.java
index 3d0404c25373b..13b056a019200 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/delete/DeleteDecommissionStateResponse.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.decommission.awareness.delete;
 
 import org.opensearch.action.support.master.AcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -17,8 +18,9 @@
 /**
  * Response returned after deletion of decommission request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class DeleteDecommissionStateResponse extends AcknowledgedResponse {
 
     public DeleteDecommissionStateResponse(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequest.java
index 15c7e165fb62f..3ecbbfbbc7285 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -21,8 +22,9 @@
 /**
  * Get Decommissioned attribute request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class GetDecommissionStateRequest extends ClusterManagerNodeReadRequest<GetDecommissionStateRequest> {
 
     private String attributeName;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequestBuilder.java
index e766e9c674ff7..13eb375f0d00e 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateRequestBuilder.java
@@ -10,12 +10,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Get decommission request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class GetDecommissionStateRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     GetDecommissionStateRequest,
     GetDecommissionStateResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateResponse.java
index bbcbd7013c299..9010c0e7d9388 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/get/GetDecommissionStateResponse.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.cluster.decommission.DecommissionStatus;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -26,8 +27,9 @@
 /**
  * Response for decommission status
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class GetDecommissionStateResponse extends ActionResponse implements ToXContentObject {
 
     private String attributeValue;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequest.java
index 18f14db3c2b8d..9070aa5a0dc55 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequest.java
@@ -11,6 +11,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
 import org.opensearch.cluster.decommission.DecommissionAttribute;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -23,8 +24,9 @@
 /**
  * Registers a decommission request with decommission attribute and timeout
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class DecommissionRequest extends ClusterManagerNodeRequest<DecommissionRequest> {
 
     public static final TimeValue DEFAULT_NODE_DRAINING_TIMEOUT = TimeValue.timeValueSeconds(120);
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequestBuilder.java
index c3591fff54885..e965110cdb9df 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionRequestBuilder.java
@@ -12,13 +12,15 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.cluster.decommission.DecommissionAttribute;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * Register decommission request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class DecommissionRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     DecommissionRequest,
     DecommissionResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionResponse.java
index 13c1775b005b3..a2401cdf91b07 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/decommission/awareness/put/DecommissionResponse.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.decommission.awareness.put;
 
 import org.opensearch.action.support.master.AcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContentObject;
@@ -18,8 +19,9 @@
 /**
  * Response for decommission request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class DecommissionResponse extends AcknowledgedResponse implements ToXContentObject {
 
     public DecommissionResponse(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequest.java
index a9532077f9129..ec8b01d853da6 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequest.java
@@ -40,6 +40,7 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
 import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -53,8 +54,9 @@
 /**
  * Transport request for requesting cluster health
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterHealthRequest extends ClusterManagerNodeReadRequest<ClusterHealthRequest> implements IndicesRequest.Replaceable {
 
     private String[] indices;
@@ -351,8 +353,9 @@ public ActionRequestValidationException validate() {
     /**
      * The level of the health request.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Level {
         CLUSTER,
         INDICES,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequestBuilder.java
index cca9d35d8aa6f..a9a3756755265 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthRequestBuilder.java
@@ -38,13 +38,15 @@
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * Builder for requesting cluster health
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterHealthRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     ClusterHealthRequest,
     ClusterHealthResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthResponse.java
index fb68012502116..1a27f161343e8 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthResponse.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.health.ClusterHealthStatus;
 import org.opensearch.cluster.health.ClusterIndexHealth;
 import org.opensearch.cluster.health.ClusterStateHealth;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.StatusToXContentObject;
@@ -67,8 +68,9 @@
 /**
  * Transport response for Cluster Health
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterHealthResponse extends ActionResponse implements StatusToXContentObject {
     private static final String CLUSTER_NAME = "cluster_name";
     private static final String STATUS = "status";
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequest.java
index 39e912a995f35..9e52b90f7bd38 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.node.hotthreads;
 
 import org.opensearch.action.support.nodes.BaseNodesRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -43,8 +44,9 @@
 /**
  * Transport request for OpenSearch Hot Threads
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesHotThreadsRequest extends BaseNodesRequest<NodesHotThreadsRequest> {
 
     int threads = 3;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequestBuilder.java
index 3639439dd3fb8..51b455b41115b 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.support.nodes.NodesOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * Builder class for requesting OpenSearch Hot Threads
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesHotThreadsRequestBuilder extends NodesOperationRequestBuilder<
     NodesHotThreadsRequest,
     NodesHotThreadsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsResponse.java
index 5af9ce50a4bfe..eeddd2deb7ff8 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/hotthreads/NodesHotThreadsResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.FailedNodeException;
 import org.opensearch.action.support.nodes.BaseNodesResponse;
 import org.opensearch.cluster.ClusterName;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -44,8 +45,9 @@
 /**
  * Transport response for OpenSearch Hot Threads
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesHotThreadsResponse extends BaseNodesResponse<NodeHotThreads> {
 
     public NodesHotThreadsResponse(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequest.java
index 31cacda7c3487..e694a5e102e02 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.node.info;
 
 import org.opensearch.action.support.nodes.BaseNodesRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -47,8 +48,9 @@
 /**
  * A request to get node (cluster) level information.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesInfoRequest extends BaseNodesRequest<NodesInfoRequest> {
 
     private Set<String> requestedMetrics = Metric.allMetrics();
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequestBuilder.java
index 76ef75b77a1cf..4c3191b017948 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.nodes.NodesOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport action for OpenSearch Node Information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesInfoRequestBuilder extends NodesOperationRequestBuilder<NodesInfoRequest, NodesInfoResponse, NodesInfoRequestBuilder> {
 
     public NodesInfoRequestBuilder(OpenSearchClient client, NodesInfoAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoResponse.java
index 5b4444053a8b7..7ddd70185e8ad 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/info/NodesInfoResponse.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.nodes.BaseNodesResponse;
 import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.node.DiscoveryNodeRole;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -59,8 +60,9 @@
 /**
  * Transport response for OpenSearch Node Information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesInfoResponse extends BaseNodesResponse<NodeInfo> implements ToXContentFragment {
 
     public NodesInfoResponse(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/reload/NodesReloadSecureSettingsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/reload/NodesReloadSecureSettingsRequestBuilder.java
index 2f2162947aeea..d970e4c9e5468 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/reload/NodesReloadSecureSettingsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/reload/NodesReloadSecureSettingsRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.support.nodes.NodesOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.settings.SecureString;
 
 /**
  * Builder for the reload secure settings nodes request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesReloadSecureSettingsRequestBuilder extends NodesOperationRequestBuilder<
     NodesReloadSecureSettingsRequest,
     NodesReloadSecureSettingsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java
index dd36b3b8db3ab..8293a5bb27612 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java
@@ -46,6 +46,7 @@
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.discovery.DiscoveryStats;
 import org.opensearch.http.HttpStats;
+import org.opensearch.index.SegmentReplicationRejectionStats;
 import org.opensearch.index.stats.IndexingPressureStats;
 import org.opensearch.index.stats.ShardIndexingPressureStats;
 import org.opensearch.index.store.remote.filecache.FileCacheStats;
@@ -56,6 +57,9 @@
 import org.opensearch.monitor.os.OsStats;
 import org.opensearch.monitor.process.ProcessStats;
 import org.opensearch.node.AdaptiveSelectionStats;
+import org.opensearch.node.NodesResourceUsageStats;
+import org.opensearch.ratelimitting.admissioncontrol.stats.AdmissionControlStats;
+import org.opensearch.repositories.RepositoriesStats;
 import org.opensearch.script.ScriptCacheStats;
 import org.opensearch.script.ScriptStats;
 import org.opensearch.search.backpressure.stats.SearchBackpressureStats;
@@ -127,6 +131,9 @@ public class NodeStats extends BaseNodeResponse implements ToXContentFragment {
     @Nullable
     private SearchBackpressureStats searchBackpressureStats;
 
+    @Nullable
+    private SegmentReplicationRejectionStats segmentReplicationRejectionStats;
+
     @Nullable
     private ClusterManagerThrottlingStats clusterManagerThrottlingStats;
 
@@ -142,6 +149,15 @@ public class NodeStats extends BaseNodeResponse implements ToXContentFragment {
     @Nullable
     private SearchPipelineStats searchPipelineStats;
 
+    @Nullable
+    private NodesResourceUsageStats resourceUsageStats;
+
+    @Nullable
+    private RepositoriesStats repositoriesStats;
+
+    @Nullable
+    private AdmissionControlStats admissionControlStats;
+
     public NodeStats(StreamInput in) throws IOException {
         super(in);
         timestamp = in.readVLong();
@@ -198,6 +214,27 @@ public NodeStats(StreamInput in) throws IOException {
         } else {
             searchPipelineStats = null;
         }
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            resourceUsageStats = in.readOptionalWriteable(NodesResourceUsageStats::new);
+        } else {
+            resourceUsageStats = null;
+        }
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            segmentReplicationRejectionStats = in.readOptionalWriteable(SegmentReplicationRejectionStats::new);
+        } else {
+            segmentReplicationRejectionStats = null;
+        }
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            repositoriesStats = in.readOptionalWriteable(RepositoriesStats::new);
+        } else {
+            repositoriesStats = null;
+        }
+        // TODO: change to V_2_12_0 on main after backport to 2.x
+        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+            admissionControlStats = in.readOptionalWriteable(AdmissionControlStats::new);
+        } else {
+            admissionControlStats = null;
+        }
     }
 
     public NodeStats(
@@ -216,6 +253,7 @@ public NodeStats(
         @Nullable DiscoveryStats discoveryStats,
         @Nullable IngestStats ingestStats,
         @Nullable AdaptiveSelectionStats adaptiveSelectionStats,
+        @Nullable NodesResourceUsageStats resourceUsageStats,
         @Nullable ScriptCacheStats scriptCacheStats,
         @Nullable IndexingPressureStats indexingPressureStats,
         @Nullable ShardIndexingPressureStats shardIndexingPressureStats,
@@ -224,7 +262,10 @@ public NodeStats(
         @Nullable WeightedRoutingStats weightedRoutingStats,
         @Nullable FileCacheStats fileCacheStats,
         @Nullable TaskCancellationStats taskCancellationStats,
-        @Nullable SearchPipelineStats searchPipelineStats
+        @Nullable SearchPipelineStats searchPipelineStats,
+        @Nullable SegmentReplicationRejectionStats segmentReplicationRejectionStats,
+        @Nullable RepositoriesStats repositoriesStats,
+        @Nullable AdmissionControlStats admissionControlStats
     ) {
         super(node);
         this.timestamp = timestamp;
@@ -241,6 +282,7 @@ public NodeStats(
         this.discoveryStats = discoveryStats;
         this.ingestStats = ingestStats;
         this.adaptiveSelectionStats = adaptiveSelectionStats;
+        this.resourceUsageStats = resourceUsageStats;
         this.scriptCacheStats = scriptCacheStats;
         this.indexingPressureStats = indexingPressureStats;
         this.shardIndexingPressureStats = shardIndexingPressureStats;
@@ -250,6 +292,9 @@ public NodeStats(
         this.fileCacheStats = fileCacheStats;
         this.taskCancellationStats = taskCancellationStats;
         this.searchPipelineStats = searchPipelineStats;
+        this.segmentReplicationRejectionStats = segmentReplicationRejectionStats;
+        this.repositoriesStats = repositoriesStats;
+        this.admissionControlStats = admissionControlStats;
     }
 
     public long getTimestamp() {
@@ -344,6 +389,11 @@ public AdaptiveSelectionStats getAdaptiveSelectionStats() {
         return adaptiveSelectionStats;
     }
 
+    @Nullable
+    public NodesResourceUsageStats getResourceUsageStats() {
+        return resourceUsageStats;
+    }
+
     @Nullable
     public ScriptCacheStats getScriptCacheStats() {
         return scriptCacheStats;
@@ -387,6 +437,21 @@ public SearchPipelineStats getSearchPipelineStats() {
         return searchPipelineStats;
     }
 
+    @Nullable
+    public SegmentReplicationRejectionStats getSegmentReplicationRejectionStats() {
+        return segmentReplicationRejectionStats;
+    }
+
+    @Nullable
+    public RepositoriesStats getRepositoriesStats() {
+        return repositoriesStats;
+    }
+
+    @Nullable
+    public AdmissionControlStats getAdmissionControlStats() {
+        return admissionControlStats;
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
@@ -430,6 +495,19 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().onOrAfter(Version.V_2_9_0)) {
             out.writeOptionalWriteable(searchPipelineStats);
         }
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeOptionalWriteable(resourceUsageStats);
+        }
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeOptionalWriteable(segmentReplicationRejectionStats);
+        }
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeOptionalWriteable(repositoriesStats);
+        }
+        // TODO: change to V_2_12_0 on main after backport to 2.x
+        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+            out.writeOptionalWriteable(admissionControlStats);
+        }
     }
 
     @Override
@@ -520,7 +598,19 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         if (getSearchPipelineStats() != null) {
             getSearchPipelineStats().toXContent(builder, params);
         }
+        if (getResourceUsageStats() != null) {
+            getResourceUsageStats().toXContent(builder, params);
+        }
+        if (getSegmentReplicationRejectionStats() != null) {
+            getSegmentReplicationRejectionStats().toXContent(builder, params);
+        }
 
+        if (getRepositoriesStats() != null) {
+            getRepositoriesStats().toXContent(builder, params);
+        }
+        if (getAdmissionControlStats() != null) {
+            getAdmissionControlStats().toXContent(builder, params);
+        }
         return builder;
     }
 }
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequest.java
index b0caa469033eb..1af56f10b95ee 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.admin.indices.stats.CommonStatsFlags;
 import org.opensearch.action.support.nodes.BaseNodesRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -48,8 +49,9 @@
 /**
  * A request to get node (cluster) level stats.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesStatsRequest extends BaseNodesRequest<NodesStatsRequest> {
 
     private CommonStatsFlags indices = new CommonStatsFlags();
@@ -213,7 +215,11 @@ public enum Metric {
         WEIGHTED_ROUTING_STATS("weighted_routing"),
         FILE_CACHE_STATS("file_cache"),
         TASK_CANCELLATION("task_cancellation"),
-        SEARCH_PIPELINE("search_pipeline");
+        SEARCH_PIPELINE("search_pipeline"),
+        RESOURCE_USAGE_STATS("resource_usage_stats"),
+        SEGMENT_REPLICATION_BACKPRESSURE("segment_replication_backpressure"),
+        REPOSITORIES("repositories"),
+        ADMISSION_CONTROL("admission_control");
 
         private String metricName;
 
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequestBuilder.java
index e382278f5ddb8..58149e9a34a34 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.admin.indices.stats.CommonStatsFlags;
 import org.opensearch.action.support.nodes.NodesOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport builder for obtaining OpenSearch Node Stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesStatsRequestBuilder extends NodesOperationRequestBuilder<
     NodesStatsRequest,
     NodesStatsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsResponse.java
index 8fbc52ad8a3f8..73a938568acc3 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.FailedNodeException;
 import org.opensearch.action.support.nodes.BaseNodesResponse;
 import org.opensearch.cluster.ClusterName;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * Transport response for obtaining OpenSearch Node Stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesStatsResponse extends BaseNodesResponse<NodeStats> implements ToXContentFragment {
 
     public NodesStatsResponse(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/TransportNodesStatsAction.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/TransportNodesStatsAction.java
index 615abbaef845d..1df73d3b4394d 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/TransportNodesStatsAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/TransportNodesStatsAction.java
@@ -124,7 +124,11 @@ protected NodeStats nodeOperation(NodeStatsRequest nodeStatsRequest) {
             NodesStatsRequest.Metric.WEIGHTED_ROUTING_STATS.containedIn(metrics),
             NodesStatsRequest.Metric.FILE_CACHE_STATS.containedIn(metrics),
             NodesStatsRequest.Metric.TASK_CANCELLATION.containedIn(metrics),
-            NodesStatsRequest.Metric.SEARCH_PIPELINE.containedIn(metrics)
+            NodesStatsRequest.Metric.SEARCH_PIPELINE.containedIn(metrics),
+            NodesStatsRequest.Metric.RESOURCE_USAGE_STATS.containedIn(metrics),
+            NodesStatsRequest.Metric.SEGMENT_REPLICATION_BACKPRESSURE.containedIn(metrics),
+            NodesStatsRequest.Metric.REPOSITORIES.containedIn(metrics),
+            NodesStatsRequest.Metric.ADMISSION_CONTROL.containedIn(metrics)
         );
     }
 
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequest.java
index 360765e8f4803..183fb2a236148 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.node.tasks.cancel;
 
 import org.opensearch.action.support.tasks.BaseTasksRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.tasks.CancellableTask;
@@ -44,8 +45,9 @@
 /**
  * A request to cancel tasks
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CancelTasksRequest extends BaseTasksRequest<CancelTasksRequest> {
 
     public static final String DEFAULT_REASON = "by user request";
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequestBuilder.java
index ee19e8b104603..ac02dfdf7381f 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.tasks.TasksRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for the request to cancel tasks running on the specified nodes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CancelTasksRequestBuilder extends TasksRequestBuilder<CancelTasksRequest, CancelTasksResponse, CancelTasksRequestBuilder> {
 
     public CancelTasksRequestBuilder(OpenSearchClient client, CancelTasksAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksResponse.java
index 979489999cc6e..1f86c7c22c2eb 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/cancel/CancelTasksResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.TaskOperationFailure;
 import org.opensearch.action.admin.cluster.node.tasks.list.ListTasksResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
@@ -49,8 +50,9 @@
 /**
  * Returns the list of tasks that were cancelled
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CancelTasksResponse extends ListTasksResponse {
 
     private static final ConstructingObjectParser<CancelTasksResponse, Void> PARSER = setupParser(
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequest.java
index 82902c55b1b0a..13c6d645d4c3a 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,8 +47,9 @@
 /**
  * A request to get node tasks
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetTaskRequest extends ActionRequest {
     private TaskId taskId = TaskId.EMPTY_TASK_ID;
     private boolean waitForCompletion = false;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequestBuilder.java
index dd429da82ebf8..ea42e1770e7f1 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskRequestBuilder.java
@@ -34,14 +34,16 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.tasks.TaskId;
 
 /**
  * Builder for the request to retrieve the list of tasks running on the specified nodes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetTaskRequestBuilder extends ActionRequestBuilder<GetTaskRequest, GetTaskResponse> {
     public GetTaskRequestBuilder(OpenSearchClient client, GetTaskAction action) {
         super(client, action, new GetTaskRequest());
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskResponse.java
index 9d4e6da8c7e62..80901373e14d5 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/GetTaskResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.node.tasks.get;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -48,8 +49,9 @@
 /**
  * Returns the list of tasks currently running on the nodes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetTaskResponse extends ActionResponse implements ToXContentObject {
 
     private final TaskResult task;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/TransportGetTaskAction.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/TransportGetTaskAction.java
index 8d82827f4ee50..e62c83490d810 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/TransportGetTaskAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/get/TransportGetTaskAction.java
@@ -67,7 +67,7 @@
 
 /**
  * ActionType to get a single task. If the task isn't running then it'll try to request the status from request index.
- *
+ * <p>
  * The general flow is:
  * <ul>
  * <li>If this isn't being executed on the node to which the requested TaskId belongs then move to that node.
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequest.java
index 070b93c788ef0..6ee56b0da7884 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.node.tasks.list;
 
 import org.opensearch.action.support.tasks.BaseTasksRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -41,8 +42,9 @@
 /**
  * A request to get node tasks
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ListTasksRequest extends BaseTasksRequest<ListTasksRequest> {
 
     private boolean detailed = false;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequestBuilder.java
index 45beb0dd899b5..a195b98d06e76 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.tasks.TasksRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for the request to retrieve the list of tasks running on the specified nodes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ListTasksRequestBuilder extends TasksRequestBuilder<ListTasksRequest, ListTasksResponse, ListTasksRequestBuilder> {
 
     public ListTasksRequestBuilder(OpenSearchClient client, ListTasksAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java
index 693566391fb25..337151a2a9268 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java
@@ -39,6 +39,7 @@
 import org.opensearch.cluster.node.DiscoveryNodeRole;
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.common.TriFunction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -64,8 +65,9 @@
 /**
  * Returns the list of tasks currently running on the nodes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ListTasksResponse extends BaseTasksResponse implements ToXContentObject {
     private static final String TASKS = "tasks";
 
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/TaskGroup.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/TaskGroup.java
index 0ca114ae0ed5c..fb23a41b8dc19 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/TaskGroup.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/tasks/list/TaskGroup.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.node.tasks.list;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.tasks.TaskInfo;
@@ -45,8 +46,9 @@
 /**
  * Information about a currently running task and all its subtasks.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TaskGroup implements ToXContentObject {
 
     private final TaskInfo task;
@@ -65,8 +67,9 @@ public static Builder builder(TaskInfo taskInfo) {
     /**
      * Builder for the Task Group
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
         private TaskInfo taskInfo;
         private List<Builder> childTasks;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequest.java
index e31b88ace953f..385f48d5690c1 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.node.usage;
 
 import org.opensearch.action.support.nodes.BaseNodesRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -41,8 +42,9 @@
 /**
  * Transport request for collecting OpenSearch telemetry
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesUsageRequest extends BaseNodesRequest<NodesUsageRequest> {
 
     private boolean restActions;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequestBuilder.java
index 7d1823b59dc04..ec1176ac634fa 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.ActionType;
 import org.opensearch.action.support.nodes.NodesOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport builder for collecting OpenSearch telemetry
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesUsageRequestBuilder extends NodesOperationRequestBuilder<
     NodesUsageRequest,
     NodesUsageResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageResponse.java
index 575d88c10317c..7dc8a318b2cf4 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/usage/NodesUsageResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.FailedNodeException;
 import org.opensearch.action.support.nodes.BaseNodesResponse;
 import org.opensearch.cluster.ClusterName;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -48,8 +49,9 @@
  * The response for the nodes usage api which contains the individual usage
  * statistics for all nodes queried.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodesUsageResponse extends BaseNodesResponse<NodeUsage> implements ToXContentFragment {
 
     public NodesUsageResponse(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreRequest.java
index 3b090415c175b..afa2058d1deba 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreRequest.java
@@ -11,6 +11,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -30,8 +31,9 @@
 /**
  * Restore remote store request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public class RestoreRemoteStoreRequest extends ClusterManagerNodeRequest<RestoreRemoteStoreRequest> implements ToXContentObject {
 
     private String[] indices = Strings.EMPTY_ARRAY;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreResponse.java
index 66908889b0641..3de926c256f46 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/restore/RestoreRemoteStoreResponse.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.remotestore.restore;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -28,8 +29,9 @@
 /**
  * Contains information about remote store restores
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public final class RestoreRemoteStoreResponse extends ActionResponse implements ToXContentObject {
 
     @Nullable
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStats.java
index f292fcec7ccac..7bddd0deb373b 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStats.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.remotestore.stats;
 
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -22,8 +23,9 @@
 /**
  * Encapsulates all remote store stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public class RemoteStoreStats implements Writeable, ToXContentFragment {
     /**
      * Stats related to Remote Segment Store operations
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequest.java
index f09cf79c5154c..12c316adc75cc 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequest.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.remotestore.stats;
 
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -17,8 +18,9 @@
 /**
  * Encapsulates all remote store stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public class RemoteStoreStatsRequest extends BroadcastRequest<RemoteStoreStatsRequest> {
 
     private String[] shards;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequestBuilder.java
index c31e4a1fd6178..4da700d3dc51b 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsRequestBuilder.java
@@ -10,13 +10,15 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * Builder for RemoteStoreStatsRequest
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public class RemoteStoreStatsRequestBuilder extends BroadcastOperationRequestBuilder<
     RemoteStoreStatsRequest,
     RemoteStoreStatsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsResponse.java
index 63a4c97d695b7..cad57d148770b 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/remotestore/stats/RemoteStoreStatsResponse.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.remotestore.stats;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -25,8 +26,9 @@
 /**
  * Remote Store stats response
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public class RemoteStoreStatsResponse extends BroadcastResponse {
 
     private final RemoteStoreStats[] remoteStoreStats;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequest.java
index 7e3f4cd95fc72..3e408c6114690 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequest.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -43,8 +44,9 @@
 /**
  * Transport request for cleaning up snapshot repositories
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CleanupRepositoryRequest extends AcknowledgedRequest<CleanupRepositoryRequest> {
 
     private String repository;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequestBuilder.java
index 95c4fb372572f..34e42b157e627 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryRequestBuilder.java
@@ -34,12 +34,14 @@
 import org.opensearch.action.ActionType;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport builder for cleaning up snapshot repositories
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CleanupRepositoryRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     CleanupRepositoryRequest,
     CleanupRepositoryResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryResponse.java
index 99af862c769e8..e6790e8cbe708 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/CleanupRepositoryResponse.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.action.admin.cluster.repositories.cleanup;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -46,8 +47,9 @@
 /**
  * Transport response for cleaning up snapshot repositories
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class CleanupRepositoryResponse extends ActionResponse implements ToXContentObject {
 
     private static final ObjectParser<CleanupRepositoryResponse, Void> PARSER = new ObjectParser<>(
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/TransportCleanupRepositoryAction.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/TransportCleanupRepositoryAction.java
index f26ccbc569cf0..774bffa10da4f 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/TransportCleanupRepositoryAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/TransportCleanupRepositoryAction.java
@@ -67,7 +67,7 @@
 
 /**
  * Repository cleanup action for repository implementations based on {@link BlobStoreRepository}.
- *
+ * <p>
  * The steps taken by the repository cleanup operation are as follows:
  * <ol>
  *     <li>Check that there are no running repository cleanup, snapshot create, or snapshot delete actions
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequest.java
index 352a3772e039b..04fdf22bee593 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -46,8 +47,9 @@
  * <p>
  * The unregister repository command just unregisters the repository. No data is getting deleted from the repository.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteRepositoryRequest extends AcknowledgedRequest<DeleteRepositoryRequest> {
 
     private String name;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequestBuilder.java
index ffef8d5b41979..6f5d0495e1c9f 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/delete/DeleteRepositoryRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for unregister repository request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteRepositoryRequestBuilder extends AcknowledgedRequestBuilder<
     DeleteRepositoryRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequest.java
index ac975e917e056..80a86f1b79209 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +46,9 @@
 /**
  * Get repository request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetRepositoriesRequest extends ClusterManagerNodeReadRequest<GetRepositoriesRequest> {
 
     private String[] repositories = Strings.EMPTY_ARRAY;
@@ -88,7 +90,7 @@ public ActionRequestValidationException validate() {
     /**
      * The names of the repositories.
      *
-     * @return list of repositories
+     * @return  array of repository names
      */
     public String[] repositories() {
         return this.repositories;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequestBuilder.java
index 4b93aff4c25bc..b0c18f952b3df 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.ArrayUtils;
 
 /**
  * Get repository request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetRepositoriesRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     GetRepositoriesRequest,
     GetRepositoriesResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesResponse.java
index 098a0e60142e7..f467b240aac31 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/get/GetRepositoriesResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.metadata.RepositoriesMetadata;
 import org.opensearch.cluster.metadata.RepositoryMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -42,16 +43,17 @@
 import org.opensearch.core.xcontent.XContentParser;
 
 import java.io.IOException;
-import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 
 import static org.opensearch.core.xcontent.XContentParserUtils.ensureExpectedToken;
 
 /**
  * Get repositories response
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetRepositoriesResponse extends ActionResponse implements ToXContentObject {
 
     private RepositoriesMetadata repositories;
@@ -83,7 +85,10 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         builder.startObject();
         repositories.toXContent(
             builder,
-            new DelegatingMapParams(Collections.singletonMap(RepositoriesMetadata.HIDE_GENERATIONS_PARAM, "true"), params)
+            new DelegatingMapParams(
+                Map.of(RepositoriesMetadata.HIDE_GENERATIONS_PARAM, "true", RepositoriesMetadata.HIDE_SYSTEM_REPOSITORY_SETTING, "true"),
+                params
+            )
         );
         builder.endObject();
         return builder;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequest.java
index 582f73f335b49..3fbd5743b5c8c 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.admin.cluster.crypto.CryptoSettings;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -57,8 +58,9 @@
  * Registers a repository with given name, type and settings. If the repository with the same name already
  * exists in the cluster, the new repository will replace the existing repository.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutRepositoryRequest extends AcknowledgedRequest<PutRepositoryRequest> implements ToXContentObject {
 
     private String name;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequestBuilder.java
index cf649ee6b4cbf..22aa6d7dc7c00 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/PutRepositoryRequestBuilder.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
 
@@ -44,8 +45,9 @@
 /**
  * Register repository request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutRepositoryRequestBuilder extends AcknowledgedRequestBuilder<
     PutRepositoryRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/TransportPutRepositoryAction.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/TransportPutRepositoryAction.java
index 644f23d2bafe6..1eadab6b1352e 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/TransportPutRepositoryAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/put/TransportPutRepositoryAction.java
@@ -100,7 +100,7 @@ protected void clusterManagerOperation(
         ClusterState state,
         final ActionListener<AcknowledgedResponse> listener
     ) {
-        repositoriesService.registerRepository(
+        repositoriesService.registerOrUpdateRepository(
             request,
             ActionListener.delegateFailure(
                 listener,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequest.java
index b84161e716f5d..ae6c92d8625ca 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -44,8 +45,9 @@
 /**
  * Verify repository request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class VerifyRepositoryRequest extends AcknowledgedRequest<VerifyRepositoryRequest> {
 
     private String name;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequestBuilder.java
index c405fb9bc12cd..023f223700775 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for verify repository request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class VerifyRepositoryRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     VerifyRepositoryRequest,
     VerifyRepositoryResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryResponse.java
index d7af3478bdac3..12d6a4cca5683 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/repositories/verify/VerifyRepositoryResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.repositories.verify;
 
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
@@ -54,8 +55,9 @@
 /**
  * Verify repository response
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class VerifyRepositoryResponse extends ActionResponse implements ToXContentObject {
 
     static final String NODES = "nodes";
@@ -64,8 +66,9 @@ public class VerifyRepositoryResponse extends ActionResponse implements ToXConte
     /**
      * Inner Node View
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class NodeView implements Writeable, ToXContentObject {
         private static final ObjectParser.NamedObjectParser<NodeView, Void> PARSER;
         static {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequest.java
index a6addce14787d..1cefaa4866110 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.master.AcknowledgedRequest;
 import org.opensearch.cluster.routing.allocation.command.AllocationCommand;
 import org.opensearch.cluster.routing.allocation.command.AllocationCommands;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -45,8 +46,9 @@
 /**
  * Request to submit cluster reroute allocation commands
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterRerouteRequest extends AcknowledgedRequest<ClusterRerouteRequest> {
     private AllocationCommands commands = new AllocationCommands();
     private boolean dryRun;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequestBuilder.java
index 01d52cb43320d..fc8310bdf7852 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.cluster.routing.allocation.command.AllocationCommand;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for a cluster reroute request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterRerouteRequestBuilder extends AcknowledgedRequestBuilder<
     ClusterRerouteRequest,
     ClusterRerouteResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteResponse.java
index a62029218ca25..ff01888040e82 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/reroute/ClusterRerouteResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.routing.allocation.RoutingExplanations;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContent;
@@ -46,8 +47,9 @@
 /**
  * Response returned after a cluster reroute request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterRerouteResponse extends AcknowledgedResponse implements ToXContentObject {
 
     private final ClusterState state;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequest.java
index 6b62a5edd8c28..77aee99c2e902 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -55,8 +56,9 @@
 /**
  * Request for an update cluster settings action
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterUpdateSettingsRequest extends AcknowledgedRequest<ClusterUpdateSettingsRequest> implements ToXContentObject {
 
     private static final ParseField PERSISTENT = new ParseField("persistent");
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequestBuilder.java
index 4d08c94f78b6a..53f1f17bbeb50 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsRequestBuilder.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
 
@@ -42,8 +43,9 @@
 /**
  * Builder for a cluster update settings request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterUpdateSettingsRequestBuilder extends AcknowledgedRequestBuilder<
     ClusterUpdateSettingsRequest,
     ClusterUpdateSettingsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsResponse.java
index 1c543260f7aee..2dfdb49736773 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/settings/ClusterUpdateSettingsResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.settings;
 
 import org.opensearch.action.support.master.AcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -49,8 +50,9 @@
 /**
  * A response for a cluster update settings action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterUpdateSettingsResponse extends AcknowledgedResponse {
 
     private static final ParseField PERSISTENT = new ParseField("persistent");
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsGroup.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsGroup.java
index 84e9554932864..eaafca21e1894 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsGroup.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsGroup.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.shards;
 
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -45,8 +46,9 @@
 /**
  * Transport action for searching shard groups
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterSearchShardsGroup implements Writeable, ToXContentObject {
 
     private final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequest.java
index 7ddb945ad911e..62e05ebb37e28 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * Transport request for searching shards
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterSearchShardsRequest extends ClusterManagerNodeReadRequest<ClusterSearchShardsRequest>
     implements
         IndicesRequest.Replaceable {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequestBuilder.java
index 674a2c2c36221..c4f8a29bbcf3d 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for searching shards
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterSearchShardsRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     ClusterSearchShardsRequest,
     ClusterSearchShardsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsResponse.java
index 2b24d870219bb..8ab6455bca4a7 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/ClusterSearchShardsResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.shards;
 
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * Transport response for searching shards
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterSearchShardsResponse extends ActionResponse implements ToXContentObject {
 
     private final ClusterSearchShardsGroup[] groups;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequest.java
index 7f69fe9fe3c72..72de28ca7e699 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequest.java
@@ -15,6 +15,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
 import org.opensearch.cluster.metadata.WeightedRoutingMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -32,8 +33,9 @@
 /**
  * Request to delete weights for weighted round-robin shard routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterDeleteWeightedRoutingRequest extends ClusterManagerNodeRequest<ClusterDeleteWeightedRoutingRequest> {
     private static final Logger logger = LogManager.getLogger(ClusterDeleteWeightedRoutingRequest.class);
 
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequestBuilder.java
index bb34fea589534..e0d4e0ad2abed 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingRequestBuilder.java
@@ -10,12 +10,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Request builder to delete weights for weighted round-robin shard routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterDeleteWeightedRoutingRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     ClusterDeleteWeightedRoutingRequest,
     ClusterDeleteWeightedRoutingResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingResponse.java
index 2a417e9f4287f..f6a18ae5055ae 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/delete/ClusterDeleteWeightedRoutingResponse.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.shards.routing.weighted.delete;
 
 import org.opensearch.action.support.master.AcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -17,8 +18,9 @@
 /**
  * Response from deleting weights for weighted round-robin search routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterDeleteWeightedRoutingResponse extends AcknowledgedResponse {
 
     ClusterDeleteWeightedRoutingResponse(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequest.java
index 7dcec15c750fc..937829de1db00 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -20,8 +21,9 @@
 /**
  * Request to get weights for weighted round-robin search routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterGetWeightedRoutingRequest extends ClusterManagerNodeReadRequest<ClusterGetWeightedRoutingRequest> {
 
     String awarenessAttribute;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequestBuilder.java
index 82f4c1106461d..3cb5e7d3d07b9 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingRequestBuilder.java
@@ -10,12 +10,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Request builder to get weights for weighted round-robin search routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterGetWeightedRoutingRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     ClusterGetWeightedRoutingRequest,
     ClusterGetWeightedRoutingResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingResponse.java
index 5ef14d0e00c49..b109ecb7de5d9 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/get/ClusterGetWeightedRoutingResponse.java
@@ -11,6 +11,7 @@
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.cluster.metadata.WeightedRoutingMetadata;
 import org.opensearch.cluster.routing.WeightedRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -28,8 +29,9 @@
 /**
  * Response from fetching weights for weighted round-robin search routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterGetWeightedRoutingResponse extends ActionResponse implements ToXContentObject {
 
     private static final String WEIGHTS = "weights";
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequest.java
index 8e8432a384aa5..c310e28610184 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequest.java
@@ -16,6 +16,7 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
 import org.opensearch.cluster.metadata.WeightedRoutingMetadata;
 import org.opensearch.cluster.routing.WeightedRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -37,8 +38,9 @@
 /**
  * Request to update weights for weighted round-robin shard routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterPutWeightedRoutingRequest extends ClusterManagerNodeRequest<ClusterPutWeightedRoutingRequest> {
     private static final Logger logger = LogManager.getLogger(ClusterPutWeightedRoutingRequest.class);
 
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequestBuilder.java
index adfb2cf02f6d9..c520b0efd9838 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingRequestBuilder.java
@@ -11,12 +11,14 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.cluster.routing.WeightedRouting;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Request builder to update weights for weighted round-robin shard routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterPutWeightedRoutingRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     ClusterPutWeightedRoutingRequest,
     ClusterPutWeightedRoutingResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingResponse.java
index cbf10aa74f8a2..4fee2f05a8715 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/shards/routing/weighted/put/ClusterPutWeightedRoutingResponse.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.cluster.shards.routing.weighted.put;
 
 import org.opensearch.action.support.master.AcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -16,8 +17,9 @@
 /**
  * Response from updating weights for weighted round-robin search routing policy.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class ClusterPutWeightedRoutingResponse extends AcknowledgedResponse {
     public ClusterPutWeightedRoutingResponse(boolean acknowledged) {
         super(acknowledged);
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequest.java
index 694b13e37bb03..4a05911610137 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -50,8 +51,9 @@
 /**
  * Transport request for cloning a snapshot
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CloneSnapshotRequest extends ClusterManagerNodeRequest<CloneSnapshotRequest>
     implements
         IndicesRequest.Replaceable,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequestBuilder.java
index 0f47d77d6a9d3..839a1b935ad1f 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/clone/CloneSnapshotRequestBuilder.java
@@ -37,13 +37,15 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 
 /**
  * Transport request builder for cloning a snapshot
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CloneSnapshotRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     CloneSnapshotRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequest.java
index 9f8fc6067f405..0ad3071a99045 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequest.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.Strings;
@@ -76,8 +77,9 @@
  * <li>must not contain invalid file name characters {@link Strings#INVALID_FILENAME_CHARS} </li>
  * </ul>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CreateSnapshotRequest extends ClusterManagerNodeRequest<CreateSnapshotRequest>
     implements
         IndicesRequest.Replaceable,
@@ -261,7 +263,7 @@ public CreateSnapshotRequest indices(List<String> indices) {
     /**
      * Returns a list of indices that should be included into the snapshot
      *
-     * @return list of indices
+     * @return array of index names
      */
     @Override
     public String[] indices() {
@@ -316,7 +318,7 @@ public CreateSnapshotRequest partial(boolean partial) {
 
     /**
      * If set to true the operation should wait for the snapshot completion before returning.
-     *
+     * <p>
      * By default, the operation will return as soon as snapshot is initialized. It can be changed by setting this
      * flag to true.
      *
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequestBuilder.java
index 40d440419819c..c378c416cc973 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotRequestBuilder.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
 
@@ -43,8 +44,9 @@
 /**
  * Create snapshot request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CreateSnapshotRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     CreateSnapshotRequest,
     CreateSnapshotResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotResponse.java
index 1517112b9b3e1..5d25cf6cacfab 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/create/CreateSnapshotResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.snapshots.create;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -51,8 +52,9 @@
 /**
  * Create snapshot response
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CreateSnapshotResponse extends ActionResponse implements ToXContentObject {
 
     private static final ObjectParser<CreateSnapshotResponse, Void> PARSER = new ObjectParser<>(
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequest.java
index d08c3033e7e10..21280381610f7 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -47,8 +48,9 @@
  * Delete snapshot request removes snapshots from the repository and cleans up all files that are associated with the snapshots.
  * All files that are shared with at least one other existing snapshot are left intact.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteSnapshotRequest extends ClusterManagerNodeRequest<DeleteSnapshotRequest> {
 
     private String repository;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequestBuilder.java
index 1fa855265ffd4..f4da1ec0f7785 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/delete/DeleteSnapshotRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Delete snapshot request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteSnapshotRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     DeleteSnapshotRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequest.java
index 8e2e2d3390058..7e95885c60f93 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +46,9 @@
 /**
  * Get snapshot request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetSnapshotsRequest extends ClusterManagerNodeRequest<GetSnapshotsRequest> {
 
     public static final String ALL_SNAPSHOTS = "_all";
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequestBuilder.java
index 3434f1cb47a99..983325aa575d7 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.ArrayUtils;
 
 /**
  * Get snapshots request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetSnapshotsRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     GetSnapshotsRequest,
     GetSnapshotsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsResponse.java
index 5d5de4c7fa85e..6b0e8ba8a372f 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/get/GetSnapshotsResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.snapshots.get;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
@@ -53,8 +54,9 @@
 /**
  * Get snapshots response
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetSnapshotsResponse extends ActionResponse implements ToXContentObject {
 
     @SuppressWarnings("unchecked")
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequest.java
index 256850da0d503..492ef86bb7843 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
@@ -63,15 +64,19 @@
 /**
  * Restore snapshot request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RestoreSnapshotRequest extends ClusterManagerNodeRequest<RestoreSnapshotRequest> implements ToXContentObject {
 
     private static final DeprecationLogger DEPRECATION_LOGGER = DeprecationLogger.getLogger(RestoreSnapshotRequest.class);
 
     /**
      * Enumeration of possible storage types
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum StorageType {
         LOCAL("local"),
         REMOTE_SNAPSHOT("remote_snapshot");
@@ -497,7 +502,7 @@ public Settings indexSettings() {
      * this is the snapshot that this request restores. If the client can only identify a snapshot by its name then there is a risk that the
      * desired snapshot may be deleted and replaced by a new snapshot with the same name which is inconsistent with the original one. This
      * method lets us fail the restore if the precise snapshot we want is not available.
-     *
+     * <p>
      * This is for internal use only and is not exposed in the REST layer.
      */
     public RestoreSnapshotRequest snapshotUuid(String snapshotUuid) {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequestBuilder.java
index d9cca536d1c41..39eaadf3c8de6 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotRequestBuilder.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
 
@@ -44,8 +45,9 @@
 /**
  * Restore snapshot request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RestoreSnapshotRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     RestoreSnapshotRequest,
     RestoreSnapshotResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotResponse.java
index f6e50c69da3dc..c94645a6deb8f 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreSnapshotResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.snapshots.restore;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -53,8 +54,9 @@
 /**
  * Contains information about restores snapshot
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RestoreSnapshotResponse extends ActionResponse implements ToXContentObject {
 
     @Nullable
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStage.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStage.java
index 6e250962d1210..cd7f4b392c61d 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStage.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStage.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.action.admin.cluster.snapshots.status;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Stage for snapshotting an Index Shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum SnapshotIndexShardStage {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStatus.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStatus.java
index fc3ffd4977da5..f991e90cb0728 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStatus.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexShardStatus.java
@@ -35,6 +35,7 @@
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.action.support.broadcast.BroadcastShardResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -56,8 +57,9 @@
 /**
  * Status for snapshotting an Index Shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotIndexShardStatus extends BroadcastShardResponse implements ToXContentFragment {
 
     private SnapshotIndexShardStage stage = SnapshotIndexShardStage.INIT;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexStatus.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexStatus.java
index 9c2db62c33bd0..402fee76bc663 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexStatus.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotIndexStatus.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.snapshots.status;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
 import org.opensearch.core.xcontent.ObjectParser;
@@ -54,8 +55,9 @@
 /**
  * Represents snapshot status of all shards in the index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotIndexStatus implements Iterable<SnapshotIndexShardStatus>, ToXContentFragment {
 
     private final String index;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotShardsStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotShardsStats.java
index ad514a13312ba..bfd0c23c579bc 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotShardsStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotShardsStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.snapshots.status;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
 import org.opensearch.core.xcontent.ToXContent;
@@ -47,8 +48,9 @@
 /**
  * Status of a snapshot shards
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotShardsStats implements ToXContentObject {
 
     private int initializingShards;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStats.java
index babdb7540a314..f287e94edd0dc 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.snapshots.status;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -50,8 +51,9 @@
 /**
  * Stats for snapshots
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotStats implements Writeable, ToXContentObject {
 
     private long startTime;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStatus.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStatus.java
index 0b101070db478..e0f380b3ebbe6 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStatus.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotStatus.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.SnapshotsInProgress;
 import org.opensearch.cluster.SnapshotsInProgress.State;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -68,8 +69,9 @@
 /**
  * Status of a snapshot
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotStatus implements ToXContentObject, Writeable {
 
     private final Snapshot snapshot;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequest.java
index 22fca3c54c604..061e73f1094b5 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +46,9 @@
 /**
  * Get snapshot status request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotsStatusRequest extends ClusterManagerNodeRequest<SnapshotsStatusRequest> {
 
     private String repository = "_all";
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequestBuilder.java
index 55f156d4a470e..9377eca60e353 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.ArrayUtils;
 
 /**
  * Snapshots status request builder
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotsStatusRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     SnapshotsStatusRequest,
     SnapshotsStatusResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusResponse.java
index 2f0e5e4b4686f..df436a587c2ad 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/SnapshotsStatusResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.snapshots.status;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -51,8 +52,9 @@
 /**
  * Snapshot status response
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotsStatusResponse extends ActionResponse implements ToXContentObject {
 
     private final List<SnapshotStatus> snapshots;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequest.java
index 7c937a1700db0..90a52f7406d57 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -46,8 +47,9 @@
 /**
  * Transport request for obtaining cluster state
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStateRequest extends ClusterManagerNodeReadRequest<ClusterStateRequest> implements IndicesRequest.Replaceable {
 
     public static final TimeValue DEFAULT_WAIT_FOR_NODE_TIMEOUT = TimeValue.timeValueMinutes(1);
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequestBuilder.java
index b9bfeca9f7386..01a49c15fc1ec 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateRequestBuilder.java
@@ -35,13 +35,15 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * Transport request builder for obtaining cluster state
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStateRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     ClusterStateRequest,
     ClusterStateResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateResponse.java
index b947ad34a8cc2..d09105b2bd0a0 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +46,9 @@
 /**
  * The response for getting the cluster state.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStateResponse extends ActionResponse {
 
     private ClusterName clusterName;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/AnalysisStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/AnalysisStats.java
index 3372448bdacae..b7054ae99361b 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/AnalysisStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/AnalysisStats.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.MappingMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -61,8 +62,9 @@
 /**
  * Statistics about analysis usage.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class AnalysisStats implements ToXContentFragment, Writeable {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsIndices.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsIndices.java
index 63ac76ae65783..26e554f44fca1 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsIndices.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsIndices.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.stats;
 
 import org.opensearch.action.admin.indices.stats.CommonStats;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.xcontent.ToXContentFragment;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.cache.query.QueryCacheStats;
@@ -50,8 +51,9 @@
 /**
  * Cluster Stats per index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStatsIndices implements ToXContentFragment {
 
     private int indexCount;
@@ -180,8 +182,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Inner Shard Stats
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ShardStats implements ToXContentFragment {
 
         int indices;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodes.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodes.java
index 5689596763cef..b44e9cfc5c74a 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodes.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodes.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.admin.cluster.node.stats.NodeStats;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodeRole;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.metrics.OperationStats;
 import org.opensearch.common.network.NetworkModule;
 import org.opensearch.common.settings.Settings;
@@ -71,8 +72,9 @@
 /**
  * Per Node Cluster Stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStatsNodes implements ToXContentFragment {
 
     private final Counts counts;
@@ -214,8 +216,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Inner Counts
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Counts implements ToXContentFragment {
         static final String COORDINATING_ONLY = "coordinating_only";
 
@@ -282,8 +285,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Inner Operating System Stats
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class OsStats implements ToXContentFragment {
         final int availableProcessors;
         final int allocatedProcessors;
@@ -395,8 +399,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Inner Process Stats
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ProcessStats implements ToXContentFragment {
 
         final int count;
@@ -498,8 +503,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Inner JVM Stats
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class JvmStats implements ToXContentFragment {
 
         private final Map<JvmVersion, Integer> versions;
@@ -626,8 +632,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Inner JVM Version
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class JvmVersion {
         String version;
         String vmName;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequest.java
index dc472c10f550b..6a99451c596ed 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.stats;
 
 import org.opensearch.action.support.nodes.BaseNodesRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -41,8 +42,9 @@
 /**
  * A request to get cluster level stats.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStatsRequest extends BaseNodesRequest<ClusterStatsRequest> {
 
     public ClusterStatsRequest(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequestBuilder.java
index aaf5e3aeffeb8..0dcb03dc26d0e 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.nodes.NodesOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for obtaining cluster stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStatsRequestBuilder extends NodesOperationRequestBuilder<
     ClusterStatsRequest,
     ClusterStatsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsResponse.java
index 1b609b1f7556d..cc002b689a2a5 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsResponse.java
@@ -37,6 +37,7 @@
 import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.health.ClusterHealthStatus;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -50,8 +51,9 @@
 /**
  * Transport response for obtaining cluster stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStatsResponse extends BaseNodesResponse<ClusterStatsNodeResponse> implements ToXContentFragment {
 
     final ClusterStatsNodes nodesStats;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/IndexFeatureStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/IndexFeatureStats.java
index f833c52493e00..f73c363b2ea60 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/IndexFeatureStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/IndexFeatureStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.stats;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * Statistics about an index feature.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class IndexFeatureStats implements ToXContent, Writeable {
 
     final String name;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/MappingStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/MappingStats.java
index 64218765a57e6..8e6fdb02b1f22 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/MappingStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/MappingStats.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.MappingMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -58,8 +59,9 @@
 /**
  * Usage statistics about mappings usage.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class MappingStats implements ToXContentFragment, Writeable {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/stats/TransportClusterStatsAction.java b/server/src/main/java/org/opensearch/action/admin/cluster/stats/TransportClusterStatsAction.java
index 18098bc31432f..9c5dcc9e9de3f 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/stats/TransportClusterStatsAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/stats/TransportClusterStatsAction.java
@@ -168,6 +168,10 @@ protected ClusterStatsNodeResponse nodeOperation(ClusterStatsNodeRequest nodeReq
             false,
             false,
             false,
+            false,
+            false,
+            false,
+            false,
             false
         );
         List<ShardStats> shardsStats = new ArrayList<>();
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequest.java
index 7d92162015950..0bb4f3625ddad 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -44,8 +45,9 @@
 /**
  * Transport request for deleting stored scripts
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteStoredScriptRequest extends AcknowledgedRequest<DeleteStoredScriptRequest> {
 
     private String id;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequestBuilder.java
index 34e0d429f2098..cbadde386d5a9 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/DeleteStoredScriptRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for deleting stored scripts
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteStoredScriptRequestBuilder extends AcknowledgedRequestBuilder<
     DeleteStoredScriptRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequest.java
index 70384b5fb648e..25bc3ecd6b7ee 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -44,8 +45,9 @@
 /**
  * Transport request for getting stored script
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetStoredScriptRequest extends ClusterManagerNodeReadRequest<GetStoredScriptRequest> {
 
     protected String id;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequestBuilder.java
index ae969963be62f..ca0bd32f1f38b 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for getting stored script
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetStoredScriptRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     GetStoredScriptRequest,
     GetStoredScriptResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptResponse.java
index cf5a3ec44e560..a81faff2abb03 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/GetStoredScriptResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.cluster.storedscripts;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -53,8 +54,9 @@
 /**
  * Transport response for getting stored script
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetStoredScriptResponse extends ActionResponse implements StatusToXContentObject {
 
     public static final ParseField _ID_PARSE_FIELD = new ParseField("_id");
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequest.java
index f45bee955da02..8731b18fff338 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequest.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.Strings;
@@ -54,8 +55,9 @@
 /**
  * Transport request for putting stored script
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutStoredScriptRequest extends AcknowledgedRequest<PutStoredScriptRequest> implements ToXContentFragment {
 
     private String id;
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequestBuilder.java
index 2a06cd23c10b6..46773177e9a74 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/storedscripts/PutStoredScriptRequestBuilder.java
@@ -35,14 +35,16 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaType;
 
 /**
  * Transport request builder for putting stored script
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutStoredScriptRequestBuilder extends AcknowledgedRequestBuilder<
     PutStoredScriptRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequest.java b/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequest.java
index 83e8b93b32e0f..16103f02be596 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -41,8 +42,9 @@
 /**
  * Transport request for getting pending cluster tasks
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PendingClusterTasksRequest extends ClusterManagerNodeReadRequest<PendingClusterTasksRequest> {
 
     public PendingClusterTasksRequest() {}
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequestBuilder.java
index b5e77f291a701..c932c2e91f314 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for getting pending cluster tasks
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PendingClusterTasksRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     PendingClusterTasksRequest,
     PendingClusterTasksResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksResponse.java b/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksResponse.java
index 118d2cf3065e6..9f4568c88b273 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/tasks/PendingClusterTasksResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.cluster.tasks;
 
 import org.opensearch.cluster.service.PendingClusterTask;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,8 +47,9 @@
 /**
  * Transport response for getting pending cluster tasks
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PendingClusterTasksResponse extends ActionResponse implements Iterable<PendingClusterTask>, ToXContentObject {
 
     private final List<PendingClusterTask> pendingTasks;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/alias/Alias.java b/server/src/main/java/org/opensearch/action/admin/indices/alias/Alias.java
index 94dbb5ff46a02..0b56216790d94 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/alias/Alias.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/alias/Alias.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.OpenSearchGenerationException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -54,8 +55,9 @@
 /**
  * Represents an alias, to be associated with an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Alias implements Writeable, ToXContentFragment {
 
     private static final ParseField FILTER = new ParseField("filter");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequest.java
index 2899e791604a5..bc27c70282368 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequest.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
 import org.opensearch.cluster.metadata.AliasAction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -72,8 +73,9 @@
 /**
  * A request to add/remove aliases for one or more indices.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesAliasesRequest extends AcknowledgedRequest<IndicesAliasesRequest> implements ToXContentObject {
 
     private List<AliasActions> allAliasActions = new ArrayList<>();
@@ -95,8 +97,9 @@ public IndicesAliasesRequest() {}
     /**
      * Request to take one or more actions on one or more indexes and alias combinations.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class AliasActions implements AliasesRequest, Writeable, ToXContentObject {
 
         private static final ParseField INDEX = new ParseField("index");
@@ -118,8 +121,9 @@ public static class AliasActions implements AliasesRequest, Writeable, ToXConten
         /**
          * The type of request.
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public enum Type {
             ADD((byte) 0, AliasActions.ADD),
             REMOVE((byte) 1, AliasActions.REMOVE),
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequestBuilder.java
index 13c57cc781925..d262c9cd42ce9 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/alias/IndicesAliasesRequestBuilder.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.query.QueryBuilder;
 
 import java.util.Map;
@@ -42,8 +43,9 @@
 /**
  * Builder for request to modify many aliases at once.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesAliasesRequestBuilder extends AcknowledgedRequestBuilder<
     IndicesAliasesRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/BaseAliasesRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/BaseAliasesRequestBuilder.java
index 7cda041b7d9cf..814a65e2a5bf0 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/BaseAliasesRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/BaseAliasesRequestBuilder.java
@@ -81,7 +81,7 @@ public Builder addIndices(String... indices) {
 
     /**
      * Specifies what type of requested indices to ignore and wildcard indices expressions.
-     *
+     * <p>
      * For example indices that don't exist.
      */
     @SuppressWarnings("unchecked")
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequest.java
index 28894baa629b3..00d754c8fb029 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequest.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.AliasesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -44,8 +45,9 @@
 /**
  * Transport request for listing index aliases
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetAliasesRequest extends ClusterManagerNodeReadRequest<GetAliasesRequest> implements AliasesRequest {
 
     private String[] indices = Strings.EMPTY_ARRAY;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequestBuilder.java
index aecbd689a647c..e9a15e9f9dfb3 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesRequestBuilder.java
@@ -33,12 +33,14 @@
 package org.opensearch.action.admin.indices.alias.get;
 
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for listing index aliases
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetAliasesRequestBuilder extends BaseAliasesRequestBuilder<GetAliasesResponse, GetAliasesRequestBuilder> {
 
     public GetAliasesRequestBuilder(OpenSearchClient client, GetAliasesAction action, String... aliases) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesResponse.java
index e50540e6b9aea..71cbbe2c6594f 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/alias/get/GetAliasesResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.alias.get;
 
 import org.opensearch.cluster.metadata.AliasMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,8 +47,9 @@
 /**
  * Transport response for listing index aliases
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetAliasesResponse extends ActionResponse {
 
     private final Map<String, List<AliasMetadata>> aliases;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeAction.java b/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeAction.java
index 274bb8bd15e08..a70f12bed4f1f 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeAction.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.ActionType;
 import org.opensearch.action.support.single.shard.SingleShardRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
@@ -62,8 +63,9 @@
 /**
  * Transport action for analyzing text
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AnalyzeAction extends ActionType<AnalyzeAction.Response> {
 
     public static final AnalyzeAction INSTANCE = new AnalyzeAction();
@@ -77,8 +79,9 @@ private AnalyzeAction() {
      * A request to analyze a text associated with a specific index. Allow to provide
      * the actual analyzer name to perform the analysis with.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Request extends SingleShardRequest<Request> {
 
         private String[] text;
@@ -308,8 +311,9 @@ public static Request fromXContent(XContentParser parser, String index) throws I
     /**
      * Inner Response
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Response extends ActionResponse implements ToXContentObject {
 
         private final DetailAnalyzeResponse detail;
@@ -404,8 +408,9 @@ static final class Fields {
     /**
      * Inner Analyze Token
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class AnalyzeToken implements Writeable, ToXContentObject {
         private final String term;
         private final int startOffset;
@@ -542,8 +547,9 @@ public void writeTo(StreamOutput out) throws IOException {
     /**
      * Inner Detail Analyze Response
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class DetailAnalyzeResponse implements Writeable, ToXContentFragment {
 
         private final boolean customAnalyzer;
@@ -709,8 +715,9 @@ public void writeTo(StreamOutput out) throws IOException {
     /**
      * Inner Analyze Token List
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class AnalyzeTokenList implements Writeable, ToXContentObject {
         private final String name;
         private final AnalyzeToken[] tokens;
@@ -783,8 +790,9 @@ public void writeTo(StreamOutput out) throws IOException {
     /**
      * Inner character filtered text
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class CharFilteredText implements Writeable, ToXContentObject {
         private final String name;
         private final String[] texts;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeRequestBuilder.java
index a7f21b2af16fc..b0240a4db82cd 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/analyze/AnalyzeRequestBuilder.java
@@ -33,14 +33,16 @@
 
 import org.opensearch.action.support.single.shard.SingleShardOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Map;
 
 /**
  * Transport request builder for analyzing text
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AnalyzeRequestBuilder extends SingleShardOperationRequestBuilder<
     AnalyzeAction.Request,
     AnalyzeAction.Response,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequest.java
index 3b69a0980e97f..57266b5aec58f 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -43,8 +44,9 @@
 /**
  * Transport request for clearing cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClearIndicesCacheRequest extends BroadcastRequest<ClearIndicesCacheRequest> {
 
     private boolean queryCache = false;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequestBuilder.java
index e0513e77a5aa5..074e2ce0b35eb 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for clearing cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClearIndicesCacheRequestBuilder extends BroadcastOperationRequestBuilder<
     ClearIndicesCacheRequest,
     ClearIndicesCacheResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheResponse.java
index 0c6c5ca27b24d..6fe180d900311 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.cache.clear;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
@@ -45,8 +46,9 @@
 /**
  * The response of a clear cache action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClearIndicesCacheResponse extends BroadcastResponse {
 
     private static final ConstructingObjectParser<ClearIndicesCacheResponse, Void> PARSER = new ConstructingObjectParser<>(
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequest.java
index 0f98550343a13..e785c31c4a0b9 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.util.CollectionUtils;
@@ -48,8 +49,9 @@
 /**
  * A request to close an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CloseIndexRequest extends AcknowledgedRequest<CloseIndexRequest> implements IndicesRequest.Replaceable {
 
     private String[] indices;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequestBuilder.java
index b3b53a0043c70..92c32c9ace490 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexRequestBuilder.java
@@ -36,12 +36,14 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for close index request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CloseIndexRequestBuilder extends AcknowledgedRequestBuilder<CloseIndexRequest, CloseIndexResponse, CloseIndexRequestBuilder> {
 
     public CloseIndexRequestBuilder(OpenSearchClient client, CloseIndexAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexResponse.java
index df6d0e4c9be39..2e0c5cb5842b4 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/close/CloseIndexResponse.java
@@ -34,6 +34,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.support.master.ShardsAcknowledgedResponse;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -54,8 +55,9 @@
 /**
  * Transport response for closing an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CloseIndexResponse extends ShardsAcknowledgedResponse {
 
     private final List<IndexResult> indices;
@@ -99,8 +101,9 @@ public String toString() {
     /**
      * Inner index result
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class IndexResult implements Writeable, ToXContentFragment {
 
         private final Index index;
@@ -199,8 +202,9 @@ public String toString() {
     /**
      * Shard Result from Close Index Response
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ShardResult implements Writeable, ToXContentFragment {
 
         private final int id;
@@ -257,8 +261,9 @@ public String toString() {
         /**
          * Inner Failure if something goes wrong
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class Failure extends DefaultShardOperationFailedException {
 
             private @Nullable String nodeId;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequest.java
index 7cda0c1948d24..e5dbefc3dba97 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequest.java
@@ -42,6 +42,7 @@
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -80,8 +81,9 @@
  * @see org.opensearch.client.Requests#createIndexRequest(String)
  * @see CreateIndexResponse
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CreateIndexRequest extends AcknowledgedRequest<CreateIndexRequest> implements IndicesRequest {
 
     public static final ParseField MAPPINGS = new ParseField("mappings");
@@ -243,7 +245,7 @@ public CreateIndexRequest settings(Map<String, ?> source) {
 
     /**
      * Set the mapping for this index
-     *
+     * <p>
      * The mapping should be in the form of a JSON string, with an outer _doc key
      * <pre>
      *     .mapping("{\"_doc\":{\"properties\": ... }}")
@@ -269,7 +271,7 @@ public CreateIndexRequest mapping(String source, XContentType xContentType) {
 
     /**
      * Adds mapping that will be added when the index gets created.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      *
      * @param source The mapping source
@@ -296,7 +298,7 @@ private CreateIndexRequest mapping(BytesReference source, XContentType xContentT
 
     /**
      * Adds mapping that will be added when the index gets created.
-     *
+     * <p>
      * Note that the definition should *not* be nested under a type name.
      *
      * @param source The mapping source
@@ -432,7 +434,7 @@ public CreateIndexRequest source(String source, XContentType xContentType) {
 
     /**
      * Sets the settings and mappings as a single source.
-     *
+     * <p>
      * Note that the mapping definition should *not* be nested under a type name.
      */
     public CreateIndexRequest source(String source, MediaType mediaType) {
@@ -458,7 +460,7 @@ public CreateIndexRequest source(byte[] source, XContentType xContentType) {
 
     /**
      * Sets the settings and mappings as a single source.
-     *
+     * <p>
      * Note that the mapping definition should *not* be nested under a type name.
      */
     public CreateIndexRequest source(byte[] source, MediaType mediaType) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequestBuilder.java
index 3493ee06827c1..b233f45422967 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexRequestBuilder.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentType;
@@ -48,8 +49,9 @@
 /**
  * Builder for a create index request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CreateIndexRequestBuilder extends AcknowledgedRequestBuilder<
     CreateIndexRequest,
     CreateIndexResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexResponse.java
index 1b3ad48402eed..3258ffd8672a1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/create/CreateIndexResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.create;
 
 import org.opensearch.action.support.master.ShardsAcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -49,8 +50,9 @@
 /**
  * A response for a create index action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CreateIndexResponse extends ShardsAcknowledgedResponse {
 
     private static final ParseField INDEX = new ParseField("index");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/dangling/delete/DeleteDanglingIndexRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/dangling/delete/DeleteDanglingIndexRequest.java
index 0443325f82778..c5c03c93785d2 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/dangling/delete/DeleteDanglingIndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/dangling/delete/DeleteDanglingIndexRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -44,8 +45,9 @@
  * Represents a request to delete a particular dangling index, specified by its UUID. The {@link #acceptDataLoss}
  * flag must also be explicitly set to true, or later validation will fail.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteDanglingIndexRequest extends AcknowledgedRequest<DeleteDanglingIndexRequest> {
     private final String indexUUID;
     private final boolean acceptDataLoss;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/dangling/import_index/ImportDanglingIndexRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/dangling/import_index/ImportDanglingIndexRequest.java
index 590f08a82c1d2..2702b6a05c4bb 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/dangling/import_index/ImportDanglingIndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/dangling/import_index/ImportDanglingIndexRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -46,8 +47,9 @@
  * by its UUID. The {@link #acceptDataLoss} flag must also be
  * explicitly set to true, or later validation will fail.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ImportDanglingIndexRequest extends AcknowledgedRequest<ImportDanglingIndexRequest> {
     private final String indexUUID;
     private final boolean acceptDataLoss;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesRequest.java
index adbfe9b760ed8..119c4acbf4160 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.dangling.list;
 
 import org.opensearch.action.support.nodes.BaseNodesRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -42,8 +43,9 @@
 /**
  * Transport request for listing a dangling indices
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ListDanglingIndicesRequest extends BaseNodesRequest<ListDanglingIndicesRequest> {
     /**
      * Filter the response by index UUID. Leave as null to find all indices.
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesResponse.java
index 0cff01af536dc..be63bee6312fe 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/dangling/list/ListDanglingIndicesResponse.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.admin.indices.dangling.DanglingIndexInfo;
 import org.opensearch.action.support.nodes.BaseNodesResponse;
 import org.opensearch.cluster.ClusterName;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -58,8 +59,9 @@
  * information for each dangling index is presented under the "dangling_indices" key. If any nodes
  * in the cluster failed to answer, the details are presented under the "_nodes.failures" key.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ListDanglingIndicesResponse extends BaseNodesResponse<NodeListDanglingIndicesResponse> implements StatusToXContentObject {
 
     public ListDanglingIndicesResponse(StreamInput in) throws IOException {
@@ -130,7 +132,7 @@ protected void writeNodesTo(StreamOutput out, List<NodeListDanglingIndicesRespon
 
     /**
      * Aggregates dangling index information
-     *
+     * <p>
      * NOTE: visible for testing
      *
      * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/datastream/CreateDataStreamAction.java b/server/src/main/java/org/opensearch/action/admin/indices/datastream/CreateDataStreamAction.java
index 14b29c4b2bbba..4c1690d25fbd9 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/datastream/CreateDataStreamAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/datastream/CreateDataStreamAction.java
@@ -47,6 +47,7 @@
 import org.opensearch.cluster.metadata.MetadataCreateDataStreamService;
 import org.opensearch.cluster.metadata.MetadataCreateDataStreamService.CreateDataStreamClusterStateUpdateRequest;
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.Strings;
@@ -61,8 +62,9 @@
 /**
  * Transport action for creating a datastream
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CreateDataStreamAction extends ActionType<AcknowledgedResponse> {
 
     public static final CreateDataStreamAction INSTANCE = new CreateDataStreamAction();
@@ -75,8 +77,9 @@ private CreateDataStreamAction() {
     /**
      * Request for Creating Data Stream
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Request extends AcknowledgedRequest<Request> implements IndicesRequest {
 
         private final String name;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/datastream/DeleteDataStreamAction.java b/server/src/main/java/org/opensearch/action/admin/indices/datastream/DeleteDataStreamAction.java
index 190194e071bc4..6b0aec6a31839 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/datastream/DeleteDataStreamAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/datastream/DeleteDataStreamAction.java
@@ -53,6 +53,7 @@
 import org.opensearch.cluster.service.ClusterManagerTaskThrottler;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.regex.Regex;
 import org.opensearch.common.unit.TimeValue;
@@ -78,8 +79,9 @@
 /**
  * Transport action for deleting a datastream
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteDataStreamAction extends ActionType<AcknowledgedResponse> {
 
     private static final Logger logger = LogManager.getLogger(DeleteDataStreamAction.class);
@@ -94,8 +96,9 @@ private DeleteDataStreamAction() {
     /**
      * Request for deleting data streams
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Request extends ClusterManagerNodeRequest<Request> implements IndicesRequest.Replaceable {
 
         private String[] names;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/datastream/GetDataStreamAction.java b/server/src/main/java/org/opensearch/action/admin/indices/datastream/GetDataStreamAction.java
index 6a7967d31653c..1db4e85887c23 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/datastream/GetDataStreamAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/datastream/GetDataStreamAction.java
@@ -51,6 +51,7 @@
 import org.opensearch.cluster.metadata.MetadataIndexTemplateService;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.ParseField;
@@ -76,8 +77,9 @@
 /**
  * Transport action for getting a datastream
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetDataStreamAction extends ActionType<GetDataStreamAction.Response> {
 
     public static final GetDataStreamAction INSTANCE = new GetDataStreamAction();
@@ -90,8 +92,9 @@ private GetDataStreamAction() {
     /**
      * Request for getting data streams
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Request extends ClusterManagerNodeReadRequest<Request> implements IndicesRequest.Replaceable {
 
         private String[] names;
@@ -156,16 +159,18 @@ public IndicesRequest indices(String... indices) {
     /**
      * Response for getting data streams
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Response extends ActionResponse implements ToXContentObject {
         public static final ParseField DATASTREAMS_FIELD = new ParseField("data_streams");
 
         /**
          * Data streams information
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class DataStreamInfo extends AbstractDiffable<DataStreamInfo> implements ToXContentObject {
 
             public static final ParseField STATUS_FIELD = new ParseField("status");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequest.java
index 006da6b3cbb09..5fbefbc6e1591 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.util.CollectionUtils;
@@ -47,8 +48,9 @@
 /**
  * A request to delete an index. Best created with {@link org.opensearch.client.Requests#deleteIndexRequest(String)}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteIndexRequest extends AcknowledgedRequest<DeleteIndexRequest> implements IndicesRequest.Replaceable {
 
     private String[] indices;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequestBuilder.java
index 33f6342e94139..6cf0920f8570f 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/delete/DeleteIndexRequestBuilder.java
@@ -36,12 +36,14 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for deleting an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteIndexRequestBuilder extends AcknowledgedRequestBuilder<
     DeleteIndexRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequest.java
index f9bd849e549b7..91fde3ec62d7b 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * Transport request for checking if an index exists
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesExistsRequest extends ClusterManagerNodeReadRequest<IndicesExistsRequest> implements IndicesRequest.Replaceable {
 
     private String[] indices = Strings.EMPTY_ARRAY;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequestBuilder.java
index 8459bbd8b874e..2e0f28cb7e3f4 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for checking if an index exists
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesExistsRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     IndicesExistsRequest,
     IndicesExistsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsResponse.java
index 4ac85492229f0..a457cca74f897 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/exists/indices/IndicesExistsResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.indices.exists.indices;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -41,8 +42,9 @@
 /**
  * Transport response for checking if an index exists
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesExistsResponse extends ActionResponse {
 
     private boolean exists;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequest.java
index c8b28efc5f294..f8cf6ab72e038 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -52,8 +53,9 @@
  * @see org.opensearch.client.IndicesAdminClient#flush(FlushRequest)
  * @see FlushResponse
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FlushRequest extends BroadcastRequest<FlushRequest> {
 
     private boolean force = false;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequestBuilder.java
index d0cbd1d27fba6..50d7a78c919f1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for flushing one or more indices
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FlushRequestBuilder extends BroadcastOperationRequestBuilder<FlushRequest, FlushResponse, FlushRequestBuilder> {
 
     public FlushRequestBuilder(OpenSearchClient client, FlushAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushResponse.java
index 4135654e66271..3881a839a6dcd 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/flush/FlushResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.flush;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
@@ -45,8 +46,9 @@
 /**
  * A response to flush action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FlushResponse extends BroadcastResponse {
 
     private static final ConstructingObjectParser<FlushResponse, Void> PARSER = new ConstructingObjectParser<>("flush", true, arg -> {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequest.java
index 89e5a57094a96..f38b49f434261 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequest.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.index.engine.Engine;
@@ -54,8 +55,9 @@
  * @see org.opensearch.client.IndicesAdminClient#forceMerge(ForceMergeRequest)
  * @see ForceMergeResponse
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ForceMergeRequest extends BroadcastRequest<ForceMergeRequest> {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequestBuilder.java
index cff05f194cac4..d8a618a1828ad 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeRequestBuilder.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A request to force merge one or more indices. In order to force merge all
@@ -42,8 +43,9 @@
  * merge down to. By default, will cause the force merge process to merge down
  * to half the configured number of segments.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ForceMergeRequestBuilder extends BroadcastOperationRequestBuilder<
     ForceMergeRequest,
     ForceMergeResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeResponse.java
index c5316f3375ad5..e6a7fe0025b87 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/forcemerge/ForceMergeResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.forcemerge;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
@@ -47,8 +48,9 @@
 /**
  * A response for force merge action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ForceMergeResponse extends BroadcastResponse {
 
     private static final ConstructingObjectParser<ForceMergeResponse, Void> PARSER = new ConstructingObjectParser<>(
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequest.java
index 0b2084865e23e..47c59791edf04 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.info.ClusterInfoRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.ArrayUtils;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -43,14 +44,16 @@
 /**
  * A request to retrieve information about an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetIndexRequest extends ClusterInfoRequest<GetIndexRequest> {
     /**
      * The features to get.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Feature {
         ALIASES((byte) 0),
         MAPPINGS((byte) 1),
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequestBuilder.java
index 3019191e5570e..e97319abe5f98 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.master.info.ClusterInfoRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder to get information about an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetIndexRequestBuilder extends ClusterInfoRequestBuilder<GetIndexRequest, GetIndexResponse, GetIndexRequestBuilder> {
 
     public GetIndexRequestBuilder(OpenSearchClient client, GetIndexAction action, String... indices) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexResponse.java
index c135b511c3315..5a237b8d3470f 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/get/GetIndexResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.AliasMetadata;
 import org.opensearch.cluster.metadata.MappingMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
@@ -57,8 +58,9 @@
 /**
  * A response for a get index action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetIndexResponse extends ActionResponse implements ToXContentObject {
 
     private Map<String, MappingMetadata> mappings = Map.of();
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequest.java
index e3c812aedcfe7..f18f973c07959 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,12 +47,13 @@
 
 /**
  * Request the mappings of specific fields
- *
+ * <p>
  * Note: there is a new class with the same name for the Java HLRC that uses a typeless format.
  * Any changes done to this class should go to that client class as well.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetFieldMappingsRequest extends ActionRequest implements IndicesRequest.Replaceable {
 
     protected boolean local = false;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequestBuilder.java
index ebc0c015c5140..d379bfbecafd0 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsRequestBuilder.java
@@ -35,13 +35,15 @@
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.ArrayUtils;
 
 /**
  * A helper class to build {@link GetFieldMappingsRequest} objects
  *
- * @opensearch.internal
- **/
+ * @opensearch.api
+ */
+@PublicApi(since = "1.0.0")
 public class GetFieldMappingsRequestBuilder extends ActionRequestBuilder<GetFieldMappingsRequest, GetFieldMappingsResponse> {
 
     public GetFieldMappingsRequestBuilder(OpenSearchClient client, GetFieldMappingsAction action, String... indices) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsResponse.java
index d874b5bb6b1ac..86533f14e83e1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetFieldMappingsResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.mapping.get;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -61,12 +62,13 @@
 
 /**
  * Response object for {@link GetFieldMappingsRequest} API
- *
+ * <p>
  * Note: there is a new class with the same name for the Java HLRC that uses a typeless format.
  * Any changes done to this class should go to that client class as well.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetFieldMappingsResponse extends ActionResponse implements ToXContentObject {
 
     private static final ParseField MAPPINGS = new ParseField("mappings");
@@ -178,8 +180,9 @@ private void addFieldMappingsToBuilder(XContentBuilder builder, Params params, M
     /**
      * Metadata for field mappings for toXContent
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class FieldMappingMetadata implements ToXContentFragment {
 
         private static final ParseField FULL_NAME = new ParseField("full_name");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequest.java
index 3988b0dd5a508..cd0ecdb30e5fa 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.info.ClusterInfoRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -41,8 +42,9 @@
 /**
  * Transport request to get field mappings.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetMappingsRequest extends ClusterInfoRequest<GetMappingsRequest> {
 
     public GetMappingsRequest() {}
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequestBuilder.java
index 85bf8c2ffd9c6..36ca1cb088cb5 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.master.info.ClusterInfoRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder to get field mappings.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetMappingsRequestBuilder extends ClusterInfoRequestBuilder<
     GetMappingsRequest,
     GetMappingsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsResponse.java
index e59f08c4fa162..56c979c20b6d9 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/get/GetMappingsResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.MappingMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
@@ -52,8 +53,9 @@
 /**
  * Transport response to get field mappings.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetMappingsResponse extends ActionResponse implements ToXContentFragment {
 
     private static final ParseField MAPPINGS = new ParseField("mappings");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequest.java
index 4a2d2fbe8e950..8122db3278795 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequest.java
@@ -39,6 +39,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
 import org.opensearch.action.support.master.AcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.common.Strings;
@@ -75,8 +76,9 @@
  * @see org.opensearch.client.IndicesAdminClient#putMapping(PutMappingRequest)
  * @see AcknowledgedResponse
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutMappingRequest extends AcknowledgedRequest<PutMappingRequest> implements IndicesRequest.Replaceable, ToXContentObject {
 
     private static final Set<String> RESERVED_FIELDS = Set.of(
@@ -210,7 +212,7 @@ public String source() {
     /**
      * A specialized simplified mapping source method, takes the form of simple properties definition:
      * ("field1", "type=string,store=true").
-     *
+     * <p>
      * Also supports metadata mapping fields such as `_all` and `_parent` as property definition, these metadata
      * mapping fields will automatically be put on the top level mapping object.
      */
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequestBuilder.java
index 9d703bf428c8e..d44b243bb0edb 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/mapping/put/PutMappingRequestBuilder.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.Index;
 import org.opensearch.core.xcontent.MediaType;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -45,8 +46,9 @@
 /**
  * Builder for a put mapping request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutMappingRequestBuilder extends AcknowledgedRequestBuilder<
     PutMappingRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequest.java
index 16451e311e7d3..f48ec1ae6fb71 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.util.CollectionUtils;
@@ -49,8 +50,9 @@
 /**
  * A request to open an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class OpenIndexRequest extends AcknowledgedRequest<OpenIndexRequest> implements IndicesRequest.Replaceable {
 
     private String[] indices;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequestBuilder.java
index bf09c3f173491..19770255b0ee1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexRequestBuilder.java
@@ -36,12 +36,14 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for for open index request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class OpenIndexRequestBuilder extends AcknowledgedRequestBuilder<OpenIndexRequest, OpenIndexResponse, OpenIndexRequestBuilder> {
 
     public OpenIndexRequestBuilder(OpenSearchClient client, OpenIndexAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexResponse.java
index bd96a1071c129..78af1abc3ce31 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/open/OpenIndexResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.open;
 
 import org.opensearch.action.support.master.ShardsAcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
@@ -43,8 +44,9 @@
 /**
  * A response for a open index action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class OpenIndexResponse extends ShardsAcknowledgedResponse {
 
     private static final ConstructingObjectParser<OpenIndexResponse, Void> PARSER = new ConstructingObjectParser<>(
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequest.java
index b5097f96fe52b..1fb8514cbf48c 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
 import org.opensearch.cluster.metadata.IndexMetadata.APIBlock;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.util.CollectionUtils;
@@ -49,8 +50,9 @@
 /**
  * A request to add a block to an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AddIndexBlockRequest extends AcknowledgedRequest<AddIndexBlockRequest> implements IndicesRequest.Replaceable {
 
     private final APIBlock block;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequestBuilder.java
index 8322ba19f433e..ebcdf700d3b6e 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockRequestBuilder.java
@@ -36,12 +36,14 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.cluster.metadata.IndexMetadata.APIBlock;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Builder for add index block request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AddIndexBlockRequestBuilder extends AcknowledgedRequestBuilder<
     AddIndexBlockRequest,
     AddIndexBlockResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockResponse.java
index 13cee3f8e0159..3ab64fa55af8b 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/readonly/AddIndexBlockResponse.java
@@ -34,6 +34,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.support.master.ShardsAcknowledgedResponse;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -54,8 +55,9 @@
 /**
  * Transport response to open an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AddIndexBlockResponse extends ShardsAcknowledgedResponse {
 
     private final List<AddBlockResult> indices;
@@ -99,8 +101,9 @@ public String toString() {
     /**
      * Result for adding a block
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class AddBlockResult implements Writeable, ToXContentFragment {
 
         private final Index index;
@@ -199,8 +202,9 @@ public String toString() {
     /**
      * Per shard result for adding a block
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class AddBlockShardResult implements Writeable, ToXContentFragment {
 
         private final int id;
@@ -258,8 +262,9 @@ public String toString() {
         /**
          * Contains failure information
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class Failure extends DefaultShardOperationFailedException {
 
             private @Nullable String nodeId;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequest.java
index 69b20b697dd9a..aca98a6d9c571 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -43,8 +44,9 @@
 /**
  * Request for recovery information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RecoveryRequest extends BroadcastRequest<RecoveryRequest> {
 
     private boolean detailed = false;       // Provides extra details in the response
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequestBuilder.java
index 99a1fb430fb28..2f44a5f2df04a 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Recovery information request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RecoveryRequestBuilder extends BroadcastOperationRequestBuilder<RecoveryRequest, RecoveryResponse, RecoveryRequestBuilder> {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryResponse.java
index e6440fd95aa39..27b6b334ef4b4 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/recovery/RecoveryResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.recovery;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -48,8 +49,9 @@
 /**
  * Information regarding the recovery state of indices and their associated shards.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RecoveryResponse extends BroadcastResponse {
 
     private final Map<String, List<RecoveryState>> shardRecoveryStates;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequest.java
index c6e230cc66373..c8000cbc40da8 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.refresh;
 
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -46,8 +47,9 @@
  * @see org.opensearch.client.IndicesAdminClient#refresh(RefreshRequest)
  * @see RefreshResponse
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RefreshRequest extends BroadcastRequest<RefreshRequest> {
 
     public RefreshRequest(String... indices) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequestBuilder.java
index 5b27ae13f24be..ebafc726bfd39 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshRequestBuilder.java
@@ -34,14 +34,16 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A refresh request making all operations performed since the last refresh available for search. The (near) real-time
  * capabilities depends on the index engine used. For example, the internal one requires refresh to be called, but by
  * default a refresh is scheduled periodically.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RefreshRequestBuilder extends BroadcastOperationRequestBuilder<RefreshRequest, RefreshResponse, RefreshRequestBuilder> {
 
     public RefreshRequestBuilder(OpenSearchClient client, RefreshAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshResponse.java
index 4c89962dfec5e..30351b8983717 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/refresh/RefreshResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.refresh;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
@@ -45,8 +46,9 @@
 /**
  * The response of a refresh action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RefreshResponse extends BroadcastResponse {
 
     private static final ConstructingObjectParser<RefreshResponse, Void> PARSER = new ConstructingObjectParser<>("refresh", true, arg -> {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequest.java
index c46940fbfecf9..9a913c6bcafff 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -19,8 +20,9 @@
 /**
  * Request for Segment Replication stats information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SegmentReplicationStatsRequest extends BroadcastRequest<SegmentReplicationStatsRequest> {
     private boolean detailed = false;       // Provides extra details in the response
     private boolean activeOnly = false;     // Only reports on active segment replication events
@@ -89,7 +91,7 @@ public void activeOnly(boolean activeOnly) {
     /**
      * Contains list of shard id's if shards are passed, empty otherwise. Array is empty by default.
      *
-     * @return  list of shard id's if shards are passed, empty otherwise
+     * @return  array of shard id's if shards are passed, empty otherwise
      */
     public String[] shards() {
         return shards;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequestBuilder.java
index 7e68d2ac59f07..9f00bff414cf5 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsRequestBuilder.java
@@ -10,12 +10,14 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Segment Replication stats information request builder.
  *
- * @opensearch.internal
+  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SegmentReplicationStatsRequestBuilder extends BroadcastOperationRequestBuilder<
     SegmentReplicationStatsRequest,
     SegmentReplicationStatsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsResponse.java
index f1b6b90e0cae1..e65e13a945abd 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/replication/SegmentReplicationStatsResponse.java
@@ -9,6 +9,7 @@
 package org.opensearch.action.admin.indices.replication;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -24,8 +25,9 @@
 /**
  * Stats Information regarding the Segment Replication state of indices and their associated shards.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SegmentReplicationStatsResponse extends BroadcastResponse {
     private final Map<String, List<SegmentReplicationPerGroupStats>> replicationStats;
 
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/resolve/ResolveIndexAction.java b/server/src/main/java/org/opensearch/action/admin/indices/resolve/ResolveIndexAction.java
index 98c2446e17998..e20e4c2d868a8 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/resolve/ResolveIndexAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/resolve/ResolveIndexAction.java
@@ -49,6 +49,7 @@
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.util.concurrent.CountDown;
 import org.opensearch.core.ParseField;
@@ -82,8 +83,9 @@
 /**
  * Transport action to resolve an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ResolveIndexAction extends ActionType<ResolveIndexAction.Response> {
 
     public static final ResolveIndexAction INSTANCE = new ResolveIndexAction();
@@ -96,8 +98,9 @@ private ResolveIndexAction() {
     /**
      * Request for resolving an index
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Request extends ActionRequest implements IndicesRequest.Replaceable {
 
         public static final IndicesOptions DEFAULT_INDICES_OPTIONS = IndicesOptions.strictExpandOpen();
@@ -196,8 +199,9 @@ public String getName() {
     /**
      * The resolved index
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ResolvedIndex extends ResolvedIndexAbstraction implements Writeable, ToXContentObject {
 
         static final ParseField ALIASES_FIELD = new ParseField("aliases");
@@ -284,8 +288,9 @@ public int hashCode() {
     /**
      * The resolved index alias
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ResolvedAlias extends ResolvedIndexAbstraction implements Writeable, ToXContentObject {
 
         static final ParseField INDICES_FIELD = new ParseField("indices");
@@ -346,8 +351,9 @@ public int hashCode() {
     /**
      * The resolved data stream
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ResolvedDataStream extends ResolvedIndexAbstraction implements Writeable, ToXContentObject {
 
         static final ParseField BACKING_INDICES_FIELD = new ParseField("backing_indices");
@@ -418,8 +424,9 @@ public int hashCode() {
     /**
      * Response for resolving an index
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Response extends ActionResponse implements ToXContentObject {
 
         static final ParseField INDICES_FIELD = new ParseField("indices");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/rollover/Condition.java b/server/src/main/java/org/opensearch/action/admin/indices/rollover/Condition.java
index e014d6d703500..4d0b7fc8c13c7 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/rollover/Condition.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/rollover/Condition.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.rollover;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.NamedWriteable;
 import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -42,8 +43,9 @@
 /**
  * Base class for rollover request conditions
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class Condition<T> implements NamedWriteable, ToXContentFragment {
 
     protected T value;
@@ -96,8 +98,9 @@ public String name() {
     /**
      * Holder for index stats used to evaluate conditions
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Stats {
         public final long numDocs;
         public final long indexCreated;
@@ -113,8 +116,9 @@ public Stats(long numDocs, long indexCreated, ByteSizeValue indexSize) {
     /**
      * Holder for evaluated condition result
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Result {
         public final Condition<?> condition;
         public final boolean matched;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverInfo.java b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverInfo.java
index 475e44e1820d5..75c68350e2204 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverInfo.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverInfo.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.Diff;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -52,8 +53,9 @@
 /**
  * Class for holding Rollover related information within an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RolloverInfo extends AbstractDiffable<RolloverInfo> implements Writeable, ToXContentFragment {
 
     public static final ParseField CONDITION_FIELD = new ParseField("met_conditions");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequest.java
index b25bc94a5c8e2..68c0076bbd302 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -54,12 +55,13 @@
 
 /**
  * Request class to swap index under an alias or increment data stream generation upon satisfying conditions
- *
+ * <p>
  * Note: there is a new class with the same name for the Java HLRC that uses a typeless format.
  * Any changes done to this class should also go to that client class.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RolloverRequest extends AcknowledgedRequest<RolloverRequest> implements IndicesRequest {
 
     private static final ObjectParser<RolloverRequest, Void> PARSER = new ObjectParser<>("rollover");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequestBuilder.java
index 9e6b8518e92d3..acac7102edbc7 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverRequestBuilder.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.unit.ByteSizeValue;
@@ -42,8 +43,9 @@
 /**
  * Transport request to rollover an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RolloverRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     RolloverRequest,
     RolloverResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverResponse.java
index 55ee65d0a4973..b7df35cd480bb 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/rollover/RolloverResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.rollover;
 
 import org.opensearch.action.support.master.ShardsAcknowledgedResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -51,12 +52,13 @@
 
 /**
  * Response object for {@link RolloverRequest} API
- *
+ * <p>
  * Note: there is a new class with the same name for the Java HLRC that uses a typeless format.
  * Any changes done to this class should also go to that client class.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RolloverResponse extends ShardsAcknowledgedResponse implements ToXContentObject {
 
     private static final ParseField NEW_INDEX = new ParseField("new_index");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexSegments.java b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexSegments.java
index 7249bc5e9d3ba..4b37da2c99850 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexSegments.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexSegments.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.action.admin.indices.segments;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -41,8 +43,9 @@
 /**
  * List of Index Segments
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexSegments implements Iterable<IndexShardSegments> {
 
     private final String index;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexShardSegments.java b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexShardSegments.java
index a6caf0649fde1..8fdc050511050 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexShardSegments.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndexShardSegments.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.indices.segments;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.shard.ShardId;
 
 import java.util.Arrays;
@@ -40,8 +41,9 @@
 /**
  * List of Index Shard Segments
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardSegments implements Iterable<ShardSegments> {
 
     private final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentResponse.java
index 36f5979552011..648f58dada4f9 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentResponse.java
@@ -37,6 +37,7 @@
 import org.apache.lucene.search.SortedNumericSortField;
 import org.apache.lucene.search.SortedSetSortField;
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -55,8 +56,9 @@
 /**
  * Transport response for retrieving indices segment information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesSegmentResponse extends BroadcastResponse {
 
     private final ShardSegments[] shards;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequest.java
index 03a41cd21572f..aff2b383df08f 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.segments;
 
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -42,8 +43,9 @@
 /**
  * Transport request for retrieving indices segment information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesSegmentsRequest extends BroadcastRequest<IndicesSegmentsRequest> {
 
     protected boolean verbose = false;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestBuilder.java
index 4b758e1f4bfb1..579b6d997acd9 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for retrieving indices segment information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesSegmentsRequestBuilder extends BroadcastOperationRequestBuilder<
     IndicesSegmentsRequest,
     IndicesSegmentResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/segments/PitSegmentsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/segments/PitSegmentsRequest.java
index a4dc901544e0b..84edec384b68a 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/segments/PitSegmentsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/segments/PitSegmentsRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -25,7 +26,10 @@
 
 /**
  * Transport request for retrieving PITs segment information
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class PitSegmentsRequest extends BroadcastRequest<PitSegmentsRequest> {
     private boolean verbose = false;
     private final List<String> pitIds = new ArrayList<>();
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/segments/ShardSegments.java b/server/src/main/java/org/opensearch/action/admin/indices/segments/ShardSegments.java
index 90317542244ff..09adda4d79108 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/segments/ShardSegments.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/segments/ShardSegments.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.segments;
 
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -45,8 +46,9 @@
 /**
  * Collection of shard segments
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardSegments implements Writeable, Iterable<Segment> {
 
     private final ShardRouting shardRouting;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequest.java
index 01383b6b6545d..547cfa8c3bce3 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.ValidateActions;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -48,8 +49,9 @@
 /**
  * Transport request for getting index segments
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetSettingsRequest extends ClusterManagerNodeReadRequest<GetSettingsRequest> implements IndicesRequest.Replaceable {
 
     private String[] indices = Strings.EMPTY_ARRAY;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequestBuilder.java
index 84cd4e8682e93..5ba42c05dccf0 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsRequestBuilder.java
@@ -35,13 +35,15 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.ArrayUtils;
 
 /**
  * Transport request builder for getting index segments
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetSettingsRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     GetSettingsRequest,
     GetSettingsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsResponse.java
index 61c9b68629194..695c98684f0f4 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/settings/get/GetSettingsResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.indices.settings.get;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.json.JsonXContent;
 import org.opensearch.core.action.ActionResponse;
@@ -53,8 +54,9 @@
 /**
  * Transport response for getting index segments
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetSettingsResponse extends ActionResponse implements ToXContentObject {
 
     private final Map<String, Settings> indexToSettings;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/settings/put/TransportUpdateSettingsAction.java b/server/src/main/java/org/opensearch/action/admin/indices/settings/put/TransportUpdateSettingsAction.java
index 1c57dc27df8c6..14c985f1d3427 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/settings/put/TransportUpdateSettingsAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/settings/put/TransportUpdateSettingsAction.java
@@ -55,6 +55,7 @@
 import org.opensearch.transport.TransportService;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Set;
 import java.util.stream.Stream;
 
@@ -77,7 +78,8 @@ public class TransportUpdateSettingsAction extends TransportClusterManagerNodeAc
         "index.max_script_fields",
         "index.max_terms_count",
         "index.max_regex_length",
-        "index.highlight.max_analyzed_offset"
+        "index.highlight.max_analyzed_offset",
+        "index.number_of_replicas"
     );
 
     private final static String[] ALLOWLIST_REMOTE_SNAPSHOT_SETTINGS_PREFIXES = { "index.search.slowlog" };
@@ -145,10 +147,10 @@ protected ClusterBlockException checkBlock(UpdateSettingsRequest request, Cluste
             }
         }
 
+        final String[] requestIndexNames = Arrays.stream(requestIndices).map(Index::getName).toArray(String[]::new);
         return allowSearchableSnapshotSettingsUpdate
             ? null
-            : state.blocks()
-                .indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, indexNameExpressionResolver.concreteIndexNames(state, request));
+            : state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, requestIndexNames);
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequest.java
index 43571dc8220f9..45172e313dfcc 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -60,8 +61,9 @@
 /**
  * Request for an update index settings action
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpdateSettingsRequest extends AcknowledgedRequest<UpdateSettingsRequest>
     implements
         IndicesRequest.Replaceable,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequestBuilder.java
index 7501f0c7798de..08d7a240aa007 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/settings/put/UpdateSettingsRequestBuilder.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
 
@@ -44,8 +45,9 @@
 /**
  * Builder for an update index settings request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpdateSettingsRequestBuilder extends AcknowledgedRequestBuilder<
     UpdateSettingsRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoreRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoreRequestBuilder.java
index bc9633f2bd2db..b986ef3c62e73 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoreRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoreRequestBuilder.java
@@ -37,12 +37,14 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.cluster.health.ClusterHealthStatus;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Request builder for {@link IndicesShardStoresRequest}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesShardStoreRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     IndicesShardStoresRequest,
     IndicesShardStoresResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresRequest.java
index d3261bea68f38..ea07325c35c3b 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
 import org.opensearch.cluster.health.ClusterHealthStatus;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,8 +47,9 @@
 /**
  * Request for {@link IndicesShardStoresAction}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesShardStoresRequest extends ClusterManagerNodeReadRequest<IndicesShardStoresRequest>
     implements
         IndicesRequest.Replaceable {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresResponse.java
index 98132b25a6d99..c2f373fcbd6a1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/shards/IndicesShardStoresResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.OpenSearchException;
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -53,15 +54,17 @@
  * Consists of {@link StoreStatus}s for requested indices grouped by
  * indices and shard ids and a list of encountered node {@link Failure}s
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesShardStoresResponse extends ActionResponse implements ToXContentFragment {
 
     /**
      * Shard store information from a node
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class StoreStatus implements Writeable, ToXContentFragment, Comparable<StoreStatus> {
         private final DiscoveryNode node;
         private final String allocationId;
@@ -70,7 +73,10 @@ public static class StoreStatus implements Writeable, ToXContentFragment, Compar
 
         /**
          * The status of the shard store with respect to the cluster
+         *
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public enum AllocationStatus {
 
             /**
@@ -232,8 +238,9 @@ public int compareTo(StoreStatus other) {
     /**
      * Single node failure while retrieving shard store information
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Failure extends DefaultShardOperationFailedException {
         private String nodeId;
 
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequest.java
index a24a33006ac1e..a5225f2243876 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequest.java
@@ -40,6 +40,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.master.AcknowledgedRequest;
 import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -57,8 +58,9 @@
 /**
  * Request class to shrink an index into a single shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ResizeRequest extends AcknowledgedRequest<ResizeRequest> implements IndicesRequest, ToXContentObject {
 
     public static final ObjectParser<ResizeRequest, Void> PARSER = new ObjectParser<>("resize_request");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequestBuilder.java
index 855e678c77b9b..f9d90d46b0904 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeRequestBuilder.java
@@ -36,14 +36,16 @@
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.action.support.master.AcknowledgedRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.unit.ByteSizeValue;
 
 /**
  * Transport request builder for resizing an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ResizeRequestBuilder extends AcknowledgedRequestBuilder<ResizeRequest, ResizeResponse, ResizeRequestBuilder> {
     public ResizeRequestBuilder(OpenSearchClient client, ActionType<ResizeResponse> action) {
         super(client, action, new ResizeRequest());
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeResponse.java
index 1aa09023e3583..a4801f84c9ef9 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.shrink;
 
 import org.opensearch.action.admin.indices.create.CreateIndexResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.xcontent.ConstructingObjectParser;
 import org.opensearch.core.xcontent.XContentParser;
@@ -42,8 +43,9 @@
 /**
  * A response for a resize index action, either shrink or split index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ResizeResponse extends CreateIndexResponse {
 
     private static final ConstructingObjectParser<ResizeResponse, Void> PARSER = new ConstructingObjectParser<>(
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeType.java b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeType.java
index 6403ed735ae49..91bcc0d62b1c6 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeType.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/shrink/ResizeType.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.action.admin.indices.shrink;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * The type of the resize operation
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum ResizeType {
     SHRINK,
     SPLIT,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStats.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStats.java
index e4abaef4ddfa8..8bfeb13b253c3 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStats.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.store.AlreadyClosedException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -68,8 +69,9 @@
 /**
  * Common Stats for OpenSearch
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CommonStats implements Writeable, ToXContentFragment {
 
     @Nullable
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStatsFlags.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStatsFlags.java
index 7503020d1c8ef..a7d9f95b80f7b 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStatsFlags.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStatsFlags.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.stats;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +46,9 @@
 /**
  * Common Stats Flags for OpenSearch
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CommonStatsFlags implements Writeable, Cloneable {
 
     public static final CommonStatsFlags ALL = new CommonStatsFlags().all();
@@ -255,8 +257,9 @@ public CommonStatsFlags clone() {
     /**
      * The flags.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Flag {
         Store("store", 0),
         Indexing("indexing", 1),
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexShardStats.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexShardStats.java
index 1635ce0bf83fc..b0143d9491087 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexShardStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexShardStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.indices.stats;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * IndexShardStats for OpenSearch
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardStats implements Iterable<ShardStats>, Writeable {
 
     private final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexStats.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexStats.java
index 1c57ca39576b0..09614ea801193 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndexStats.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.action.admin.indices.stats;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -41,8 +43,9 @@
 /**
  * Index Stats for OpenSearch
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexStats implements Iterable<IndexShardStats> {
 
     private final String index;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequest.java
index 54f3e9b7d1a24..2b64464a76899 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.stats;
 
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -46,8 +47,9 @@
  * All the stats to be returned can be cleared using {@link #clear()}, at which point, specific
  * stats can be enabled.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesStatsRequest extends BroadcastRequest<IndicesStatsRequest> {
 
     private CommonStatsFlags flags = new CommonStatsFlags();
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequestBuilder.java
index c211812b32c48..acc085a96a896 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsRequestBuilder.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
@@ -45,8 +46,9 @@
  * All the stats to be returned can be cleared using {@link #clear()}, at which point, specific
  * stats can be enabled.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesStatsRequestBuilder extends BroadcastOperationRequestBuilder<
     IndicesStatsRequest,
     IndicesStatsResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsResponse.java
index 6f051fa19c99f..6242081cd2371 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/IndicesStatsResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.admin.indices.stats.IndexStats.IndexStatsBuilder;
 import org.opensearch.action.support.broadcast.BroadcastResponse;
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -54,8 +55,9 @@
 /**
  * Transport response for retrieving indices stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesStatsResponse extends BroadcastResponse {
 
     private ShardStats[] shards;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/stats/ShardStats.java b/server/src/main/java/org/opensearch/action/admin/indices/stats/ShardStats.java
index 77562fa19b319..4ed1ce95b7de2 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/stats/ShardStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/stats/ShardStats.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -49,8 +50,9 @@
 /**
  * Shard Stats for OpenSearch
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardStats implements Writeable, ToXContentFragment {
 
     private ShardRouting shardRouting;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequest.java
index 85524bddc56d8..e93a428b0af26 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequest.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -43,8 +44,9 @@
 /**
  * A request to delete an index template.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteIndexTemplateRequest extends ClusterManagerNodeRequest<DeleteIndexTemplateRequest> {
 
     private String name;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequestBuilder.java
index 4a990b7837120..60771cfa453ae 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/delete/DeleteIndexTemplateRequestBuilder.java
@@ -34,12 +34,14 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder for deleting an index template
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteIndexTemplateRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     DeleteIndexTemplateRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequest.java
index 18142eb7b787d..fa45efdc53124 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequest.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -44,8 +45,9 @@
 /**
  * Request that allows to retrieve index templates
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetIndexTemplatesRequest extends ClusterManagerNodeReadRequest<GetIndexTemplatesRequest> {
 
     private String[] names;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequestBuilder.java
index 09de1733239fc..f8c02b4c8be08 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesRequestBuilder.java
@@ -33,12 +33,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Request builder to retrieve one or more Index templates
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetIndexTemplatesRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     GetIndexTemplatesRequest,
     GetIndexTemplatesResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesResponse.java
index 761a345b49538..009a73b615e0c 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/get/GetIndexTemplatesResponse.java
@@ -32,6 +32,7 @@
 package org.opensearch.action.admin.indices.template.get;
 
 import org.opensearch.cluster.metadata.IndexTemplateMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -49,8 +50,9 @@
 /**
  * Response for retrieving one or more Index templates
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetIndexTemplatesResponse extends ActionResponse implements ToXContentObject {
 
     private final List<IndexTemplateMetadata> indexTemplates;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateRequest.java
index 028275778538e..c4396f22d7c16 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.admin.indices.template.put.PutComposableIndexTemplateAction;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
  * Transport Request for handling simulating an index template either by name (looking it up in the
  * cluster state), or by a provided template configuration
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SimulateIndexTemplateRequest extends ClusterManagerNodeReadRequest<SimulateIndexTemplateRequest> {
 
     private String indexName;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateResponse.java
index 8a370a6845db6..c6a9d3530a8cc 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/post/SimulateIndexTemplateResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.metadata.Template;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -50,8 +51,9 @@
 /**
  * Contains the information on what V2 templates would match a given index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SimulateIndexTemplateResponse extends ActionResponse implements ToXContentObject {
 
     private static final ParseField TEMPLATE = new ParseField("template");
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutComposableIndexTemplateAction.java b/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutComposableIndexTemplateAction.java
index 1979cc39e32fb..ed209e18b64ef 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutComposableIndexTemplateAction.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutComposableIndexTemplateAction.java
@@ -41,6 +41,7 @@
 import org.opensearch.cluster.metadata.ComposableIndexTemplate;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.regex.Regex;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -54,8 +55,9 @@
 /**
  * An action for putting a composable template into the cluster state
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutComposableIndexTemplateAction extends ActionType<AcknowledgedResponse> {
 
     public static final PutComposableIndexTemplateAction INSTANCE = new PutComposableIndexTemplateAction();
@@ -68,8 +70,9 @@ private PutComposableIndexTemplateAction() {
     /**
      * A request for putting a single index template into the cluster state
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Request extends ClusterManagerNodeRequest<Request> implements IndicesRequest {
         private final String name;
         @Nullable
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequest.java
index 4f7a28a03e6fb..d4e9200508bfa 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequest.java
@@ -41,6 +41,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
@@ -78,8 +79,9 @@
 /**
  * A request to create an index template.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutIndexTemplateRequest extends ClusterManagerNodeRequest<PutIndexTemplateRequest>
     implements
         IndicesRequest,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java
index 04d2236e00e8f..931d12de574ae 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeOperationRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -47,8 +48,9 @@
 /**
  * A request builder for putting an index template into the cluster state
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutIndexTemplateRequestBuilder extends ClusterManagerNodeOperationRequestBuilder<
     PutIndexTemplateRequest,
     AcknowledgedResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexShardUpgradeStatus.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexShardUpgradeStatus.java
index 32cf6d4bfe70d..e760067e9f5be 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexShardUpgradeStatus.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexShardUpgradeStatus.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.indices.upgrade.get;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.shard.ShardId;
 
 import java.util.Arrays;
@@ -40,8 +41,9 @@
 /**
  * Status for an Index Shard Upgrade
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardUpgradeStatus implements Iterable<ShardUpgradeStatus> {
 
     private final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexUpgradeStatus.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexUpgradeStatus.java
index 4513a321e2a51..fd8ddc1293aaf 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexUpgradeStatus.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/IndexUpgradeStatus.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.action.admin.indices.upgrade.get;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -41,8 +43,9 @@
 /**
  * Status for an Index Upgrade
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexUpgradeStatus implements Iterable<IndexShardUpgradeStatus> {
 
     private final String index;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/ShardUpgradeStatus.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/ShardUpgradeStatus.java
index 57fb2513faf78..783b44ba6570d 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/ShardUpgradeStatus.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/ShardUpgradeStatus.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.support.broadcast.BroadcastShardResponse;
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -42,8 +43,9 @@
 /**
  * Status for a Shard Upgrade
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardUpgradeStatus extends BroadcastShardResponse {
 
     private ShardRouting shardRouting;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequest.java
index 987661d2129ac..2584ab6b370da 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.upgrade.get;
 
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 
@@ -41,8 +42,9 @@
 /**
  * Transport Request for retrieving status of upgrading an Index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpgradeStatusRequest extends BroadcastRequest<UpgradeStatusRequest> {
 
     public UpgradeStatusRequest() {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequestBuilder.java
index c698c38fe12d5..ac5f881c35dc5 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport Request Builder for retrieving status of upgrading an Index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpgradeStatusRequestBuilder extends BroadcastOperationRequestBuilder<
     UpgradeStatusRequest,
     UpgradeStatusResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusResponse.java
index 20dbd12287231..ba2915ee4ddf1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/get/UpgradeStatusResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.upgrade.get;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -50,8 +51,9 @@
 /**
  * Transport Response for retrieving status of upgrading an Index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpgradeStatusResponse extends BroadcastResponse {
     private ShardUpgradeStatus[] shards;
 
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequest.java
index 98c307c37ea54..4df02ad7fa8c0 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.upgrade.post;
 
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -45,8 +46,9 @@
  * @see org.opensearch.client.IndicesAdminClient#upgrade(UpgradeRequest)
  * @see UpgradeResponse
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpgradeRequest extends BroadcastRequest<UpgradeRequest> {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequestBuilder.java
index 8203f9d51b8e4..bf316504dc920 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A request to upgrade one or more indices. In order to optimize on all the indices, pass an empty array or
  * {@code null} for the indices.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpgradeRequestBuilder extends BroadcastOperationRequestBuilder<UpgradeRequest, UpgradeResponse, UpgradeRequestBuilder> {
 
     public UpgradeRequestBuilder(OpenSearchClient client, UpgradeAction action) {
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeResponse.java
index d08cc65832f8f..4bdf41dabba37 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/upgrade/post/UpgradeResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -47,8 +48,9 @@
 /**
  * A response for the upgrade action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpgradeResponse extends BroadcastResponse {
 
     private final Map<String, Tuple<Version, String>> versions;
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/QueryExplanation.java b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/QueryExplanation.java
index 248cab5e40eaf..84aa687af0fe1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/QueryExplanation.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/QueryExplanation.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.indices.validate.query;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -50,8 +51,9 @@
 /**
  * Query Explanation
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class QueryExplanation implements Writeable, ToXContentFragment {
 
     public static final String INDEX_FIELD = "index";
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequest.java b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequest.java
index ef0d14502af23..94bec696dd2c1 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequest.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.ValidateActions;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -53,8 +54,9 @@
  * <p>
  * The request requires the query to be set using {@link #query(QueryBuilder)}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ValidateQueryRequest extends BroadcastRequest<ValidateQueryRequest> implements ToXContentObject {
 
     private QueryBuilder query = new MatchAllQueryBuilder();
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequestBuilder.java b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequestBuilder.java
index 6209f41d88be2..de4cf5ae2b904 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.query.QueryBuilder;
 
 /**
  * Transport Request Builder to Validate a Query
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ValidateQueryRequestBuilder extends BroadcastOperationRequestBuilder<
     ValidateQueryRequest,
     ValidateQueryResponse,
diff --git a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryResponse.java b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryResponse.java
index 44d6d637cdc51..791128491f33d 100644
--- a/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryResponse.java
+++ b/server/src/main/java/org/opensearch/action/admin/indices/validate/query/ValidateQueryResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.admin.indices.validate.query;
 
 import org.opensearch.action.support.broadcast.BroadcastResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.support.DefaultShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -52,8 +53,9 @@
 /**
  * The response of the validate action.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ValidateQueryResponse extends BroadcastResponse {
 
     public static final String VALID_FIELD = "valid";
diff --git a/server/src/main/java/org/opensearch/action/bulk/BackoffPolicy.java b/server/src/main/java/org/opensearch/action/bulk/BackoffPolicy.java
index 0d6d122e31261..25a2c081f8441 100644
--- a/server/src/main/java/org/opensearch/action/bulk/BackoffPolicy.java
+++ b/server/src/main/java/org/opensearch/action/bulk/BackoffPolicy.java
@@ -40,9 +40,9 @@
 /**
  * Provides a backoff policy for bulk requests. Whenever a bulk request is rejected due to resource constraints (i.e. the client's internal
  * thread pool is full), the backoff policy decides how long the bulk processor will wait before the operation is retried internally.
- *
+ * <p>
  * Notes for implementing custom subclasses:
- *
+ * <p>
  * The underlying mathematical principle of <code>BackoffPolicy</code> are progressions which can be either finite or infinite although
  * the latter should not be used for retrying. A progression can be mapped to a <code>java.util.Iterator</code> with the following
  * semantics:
@@ -241,7 +241,7 @@ private static class ExponentialEqualJitterBackoffIterator implements Iterator<T
         /**
          * Retry limit to avoids integer overflow issues.
          * Post this limit, max delay will be returned with Equal Jitter.
-         *
+         * <p>
          * NOTE: If the value is greater than 30, there can be integer overflow
          * issues during delay calculation.
          **/
diff --git a/server/src/main/java/org/opensearch/action/bulk/BulkItemResponse.java b/server/src/main/java/org/opensearch/action/bulk/BulkItemResponse.java
index 138f21f1f80e5..81e8940f1b505 100644
--- a/server/src/main/java/org/opensearch/action/bulk/BulkItemResponse.java
+++ b/server/src/main/java/org/opensearch/action/bulk/BulkItemResponse.java
@@ -41,6 +41,7 @@
 import org.opensearch.action.index.IndexResponse;
 import org.opensearch.action.update.UpdateResponse;
 import org.opensearch.common.CheckedConsumer;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
@@ -68,8 +69,9 @@
  * Represents a single item response for an action executed as part of the bulk API. Holds the index/type/id
  * of the relevant action, and if it has failed or not (with the failure message in case it failed).
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class BulkItemResponse implements Writeable, StatusToXContentObject {
 
     private static final String _INDEX = "_index";
@@ -179,8 +181,9 @@ public static BulkItemResponse fromXContent(XContentParser parser, int id) throw
     /**
      * Represents a failure.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Failure implements Writeable, ToXContentFragment {
         public static final String INDEX_FIELD = "index";
         public static final String ID_FIELD = "id";
@@ -209,7 +212,7 @@ public static class Failure implements Writeable, ToXContentFragment {
 
         /**
          * For write failures before operation was assigned a sequence number.
-         *
+         * <p>
          * use @{link {@link #Failure(String, String, Exception, long, long)}}
          * to record operation sequence no with failure
          */
diff --git a/server/src/main/java/org/opensearch/action/bulk/BulkPrimaryExecutionContext.java b/server/src/main/java/org/opensearch/action/bulk/BulkPrimaryExecutionContext.java
index 896456089ee3e..4e770f5851bc6 100644
--- a/server/src/main/java/org/opensearch/action/bulk/BulkPrimaryExecutionContext.java
+++ b/server/src/main/java/org/opensearch/action/bulk/BulkPrimaryExecutionContext.java
@@ -232,6 +232,7 @@ public void resetForExecutionForRetry() {
         currentItemState = ItemProcessingState.INITIAL;
         requestToExecute = null;
         executionResult = null;
+        retryCounter++;
         assertInvariants(ItemProcessingState.INITIAL);
     }
 
diff --git a/server/src/main/java/org/opensearch/action/bulk/BulkProcessor.java b/server/src/main/java/org/opensearch/action/bulk/BulkProcessor.java
index baf64b3e80af6..141ec24fc390f 100644
--- a/server/src/main/java/org/opensearch/action/bulk/BulkProcessor.java
+++ b/server/src/main/java/org/opensearch/action/bulk/BulkProcessor.java
@@ -185,7 +185,7 @@ public Builder setGlobalPipeline(String globalPipeline) {
         /**
          * Sets a custom backoff policy. The backoff policy defines how the bulk processor should handle retries of bulk requests internally
          * in case they have failed due to resource constraints (i.e. a thread pool was full).
-         *
+         * <p>
          * The default is to back off exponentially.
          *
          * @see org.opensearch.action.bulk.BackoffPolicy#exponentialBackoff()
diff --git a/server/src/main/java/org/opensearch/action/bulk/BulkRequest.java b/server/src/main/java/org/opensearch/action/bulk/BulkRequest.java
index 65043da6c2684..47abd0337fcf9 100644
--- a/server/src/main/java/org/opensearch/action/bulk/BulkRequest.java
+++ b/server/src/main/java/org/opensearch/action/bulk/BulkRequest.java
@@ -45,6 +45,7 @@
 import org.opensearch.action.support.replication.ReplicationRequest;
 import org.opensearch.action.update.UpdateRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -67,12 +68,13 @@
 /**
  * A bulk request holds an ordered {@link IndexRequest}s, {@link DeleteRequest}s and {@link UpdateRequest}s
  * and allows to executes it in a single batch.
- *
+ * <p>
  * Note that we only support refresh on the bulk request not per item.
  * @see org.opensearch.client.Client#bulk(BulkRequest)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class BulkRequest extends ActionRequest implements CompositeIndicesRequest, WriteRequest<BulkRequest>, Accountable {
 
     private static final long SHALLOW_SIZE = RamUsageEstimator.shallowSizeOfInstance(BulkRequest.class);
@@ -123,7 +125,7 @@ public BulkRequest add(DocWriteRequest<?>... requests) {
 
     /**
      * Add a request to the current BulkRequest.
-     *
+     * <p>
      * Note for internal callers: This method does not respect all global parameters.
      *                            Only the global index is applied to the request objects.
      *                            Global parameters would be respected if the request was serialized for a REST call as it is
@@ -347,7 +349,7 @@ public final BulkRequest timeout(TimeValue timeout) {
     /**
      * Note for internal callers (NOT high level rest client),
      * the global parameter setting is ignored when used with:
-     *
+     * <p>
      * - {@link BulkRequest#add(IndexRequest)}
      * - {@link BulkRequest#add(UpdateRequest)}
      * - {@link BulkRequest#add(DocWriteRequest)}
@@ -364,7 +366,7 @@ public final BulkRequest pipeline(String globalPipeline) {
     /**
      * Note for internal callers (NOT high level rest client),
      * the global parameter setting is ignored when used with:
-     *
+     * <p>
       - {@link BulkRequest#add(IndexRequest)}
       - {@link BulkRequest#add(UpdateRequest)}
       - {@link BulkRequest#add(DocWriteRequest)}
@@ -404,7 +406,7 @@ public Boolean requireAlias() {
     /**
      * Note for internal callers (NOT high level rest client),
      * the global parameter setting is ignored when used with:
-     *
+     * <p>
      * - {@link BulkRequest#add(IndexRequest)}
      * - {@link BulkRequest#add(UpdateRequest)}
      * - {@link BulkRequest#add(DocWriteRequest)}
diff --git a/server/src/main/java/org/opensearch/action/bulk/BulkRequestBuilder.java b/server/src/main/java/org/opensearch/action/bulk/BulkRequestBuilder.java
index 08eee82a53cf9..a165d186d3878 100644
--- a/server/src/main/java/org/opensearch/action/bulk/BulkRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/bulk/BulkRequestBuilder.java
@@ -44,6 +44,7 @@
 import org.opensearch.action.update.UpdateRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.xcontent.MediaType;
@@ -52,8 +53,9 @@
  * A bulk request holds an ordered {@link IndexRequest}s and {@link DeleteRequest}s and allows to executes
  * it in a single batch.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class BulkRequestBuilder extends ActionRequestBuilder<BulkRequest, BulkResponse> implements WriteRequestBuilder<BulkRequestBuilder> {
 
     public BulkRequestBuilder(OpenSearchClient client, BulkAction action, @Nullable String globalIndex) {
diff --git a/server/src/main/java/org/opensearch/action/bulk/BulkResponse.java b/server/src/main/java/org/opensearch/action/bulk/BulkResponse.java
index 655e65bc22138..6b70e2acd41d2 100644
--- a/server/src/main/java/org/opensearch/action/bulk/BulkResponse.java
+++ b/server/src/main/java/org/opensearch/action/bulk/BulkResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.bulk;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.action.ActionResponse;
@@ -56,8 +57,9 @@
  * bulk requests. Each item holds the index/type/id is operated on, and if it failed or not (with the
  * failure message).
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class BulkResponse extends ActionResponse implements Iterable<BulkItemResponse>, StatusToXContentObject {
 
     private static final String ITEMS = "items";
diff --git a/server/src/main/java/org/opensearch/action/bulk/TransportBulkAction.java b/server/src/main/java/org/opensearch/action/bulk/TransportBulkAction.java
index d8b7facc09df2..4a9b07c12821d 100644
--- a/server/src/main/java/org/opensearch/action/bulk/TransportBulkAction.java
+++ b/server/src/main/java/org/opensearch/action/bulk/TransportBulkAction.java
@@ -78,11 +78,18 @@
 import org.opensearch.index.IndexingPressureService;
 import org.opensearch.index.VersionType;
 import org.opensearch.index.seqno.SequenceNumbers;
+import org.opensearch.index.shard.IndexingStats.Stats.DocStatusStats;
 import org.opensearch.indices.IndexClosedException;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.SystemIndices;
 import org.opensearch.ingest.IngestService;
 import org.opensearch.node.NodeClosedException;
 import org.opensearch.tasks.Task;
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanBuilder;
+import org.opensearch.telemetry.tracing.SpanScope;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.telemetry.tracing.listener.TraceableActionListener;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.threadpool.ThreadPool.Names;
 import org.opensearch.transport.TransportService;
@@ -129,7 +136,9 @@ public class TransportBulkAction extends HandledTransportAction<BulkRequest, Bul
     private final IndexNameExpressionResolver indexNameExpressionResolver;
     private static final String DROPPED_ITEM_WITH_AUTO_GENERATED_ID = "auto-generated";
     private final IndexingPressureService indexingPressureService;
+    private final IndicesService indicesService;
     private final SystemIndices systemIndices;
+    private final Tracer tracer;
 
     @Inject
     public TransportBulkAction(
@@ -143,7 +152,9 @@ public TransportBulkAction(
         IndexNameExpressionResolver indexNameExpressionResolver,
         AutoCreateIndex autoCreateIndex,
         IndexingPressureService indexingPressureService,
-        SystemIndices systemIndices
+        IndicesService indicesService,
+        SystemIndices systemIndices,
+        Tracer tracer
     ) {
         this(
             threadPool,
@@ -156,8 +167,10 @@ public TransportBulkAction(
             indexNameExpressionResolver,
             autoCreateIndex,
             indexingPressureService,
+            indicesService,
             systemIndices,
-            System::nanoTime
+            System::nanoTime,
+            tracer
         );
     }
 
@@ -172,8 +185,10 @@ public TransportBulkAction(
         IndexNameExpressionResolver indexNameExpressionResolver,
         AutoCreateIndex autoCreateIndex,
         IndexingPressureService indexingPressureService,
+        IndicesService indicesService,
         SystemIndices systemIndices,
-        LongSupplier relativeTimeProvider
+        LongSupplier relativeTimeProvider,
+        Tracer tracer
     ) {
         super(BulkAction.NAME, transportService, actionFilters, BulkRequest::new, ThreadPool.Names.SAME);
         Objects.requireNonNull(relativeTimeProvider);
@@ -187,8 +202,10 @@ public TransportBulkAction(
         this.client = client;
         this.indexNameExpressionResolver = indexNameExpressionResolver;
         this.indexingPressureService = indexingPressureService;
+        this.indicesService = indicesService;
         this.systemIndices = systemIndices;
         clusterService.addStateApplier(this.ingestForwarder);
+        this.tracer = tracer;
     }
 
     /**
@@ -595,14 +612,25 @@ protected void doRun() {
             }
 
             if (requestsByShard.isEmpty()) {
-                listener.onResponse(
-                    new BulkResponse(responses.toArray(new BulkItemResponse[responses.length()]), buildTookInMillis(startTimeNanos))
-                );
+                BulkItemResponse[] response = responses.toArray(new BulkItemResponse[responses.length()]);
+                long tookMillis = buildTookInMillis(startTimeNanos);
+
+                DocStatusStats stats = new DocStatusStats();
+                for (BulkItemResponse itemResponse : response) {
+                    if (itemResponse != null) {
+                        stats.inc(itemResponse.status());
+                    }
+                }
+
+                indicesService.addDocStatusStats(stats);
+                listener.onResponse(new BulkResponse(response, tookMillis));
                 return;
             }
 
             final AtomicInteger counter = new AtomicInteger(requestsByShard.size());
+            final DocStatusStats docStatusStats = new DocStatusStats();
             String nodeId = clusterService.localNode().getId();
+
             for (Map.Entry<ShardId, List<BulkItemRequest>> entry : requestsByShard.entrySet()) {
                 final ShardId shardId = entry.getKey();
                 final List<BulkItemRequest> requests = entry.getValue();
@@ -624,47 +652,66 @@ protected void doRun() {
                     bulkShardRequest::ramBytesUsed,
                     isOnlySystem
                 );
-                shardBulkAction.execute(bulkShardRequest, ActionListener.runBefore(new ActionListener<BulkShardResponse>() {
-                    @Override
-                    public void onResponse(BulkShardResponse bulkShardResponse) {
-                        for (BulkItemResponse bulkItemResponse : bulkShardResponse.getResponses()) {
-                            // we may have no response if item failed
-                            if (bulkItemResponse.getResponse() != null) {
-                                bulkItemResponse.getResponse().setShardInfo(bulkShardResponse.getShardInfo());
+
+                final Span span = tracer.startSpan(SpanBuilder.from("bulkShardAction", nodeId, bulkShardRequest));
+                try (SpanScope spanScope = tracer.withSpanInScope(span)) {
+                    shardBulkAction.execute(
+                        bulkShardRequest,
+                        TraceableActionListener.create(ActionListener.runBefore(new ActionListener<BulkShardResponse>() {
+                            @Override
+                            public void onResponse(BulkShardResponse bulkShardResponse) {
+                                for (BulkItemResponse bulkItemResponse : bulkShardResponse.getResponses()) {
+                                    // we may have no response if item failed
+                                    if (bulkItemResponse.getResponse() != null) {
+                                        bulkItemResponse.getResponse().setShardInfo(bulkShardResponse.getShardInfo());
+                                    }
+
+                                    docStatusStats.inc(bulkItemResponse.status());
+                                    responses.set(bulkItemResponse.getItemId(), bulkItemResponse);
+                                }
+
+                                if (counter.decrementAndGet() == 0) {
+                                    finishHim();
+                                }
                             }
-                            responses.set(bulkItemResponse.getItemId(), bulkItemResponse);
-                        }
-                        if (counter.decrementAndGet() == 0) {
-                            finishHim();
-                        }
-                    }
 
-                    @Override
-                    public void onFailure(Exception e) {
-                        // create failures for all relevant requests
-                        for (BulkItemRequest request : requests) {
-                            final String indexName = concreteIndices.getConcreteIndex(request.index()).getName();
-                            DocWriteRequest<?> docWriteRequest = request.request();
-                            responses.set(
-                                request.id(),
-                                new BulkItemResponse(
-                                    request.id(),
-                                    docWriteRequest.opType(),
-                                    new BulkItemResponse.Failure(indexName, docWriteRequest.id(), e)
-                                )
-                            );
-                        }
-                        if (counter.decrementAndGet() == 0) {
-                            finishHim();
-                        }
-                    }
+                            @Override
+                            public void onFailure(Exception e) {
+                                // create failures for all relevant requests
+                                for (BulkItemRequest request : requests) {
+                                    final String indexName = concreteIndices.getConcreteIndex(request.index()).getName();
+                                    final DocWriteRequest<?> docWriteRequest = request.request();
+                                    final BulkItemResponse bulkItemResponse = new BulkItemResponse(
+                                        request.id(),
+                                        docWriteRequest.opType(),
+                                        new BulkItemResponse.Failure(indexName, docWriteRequest.id(), e)
+                                    );
+
+                                    docStatusStats.inc(bulkItemResponse.status());
+                                    responses.set(request.id(), bulkItemResponse);
+                                }
 
-                    private void finishHim() {
-                        listener.onResponse(
-                            new BulkResponse(responses.toArray(new BulkItemResponse[responses.length()]), buildTookInMillis(startTimeNanos))
-                        );
-                    }
-                }, releasable::close));
+                                if (counter.decrementAndGet() == 0) {
+                                    finishHim();
+                                }
+                            }
+
+                            private void finishHim() {
+                                indicesService.addDocStatusStats(docStatusStats);
+                                listener.onResponse(
+                                    new BulkResponse(
+                                        responses.toArray(new BulkItemResponse[responses.length()]),
+                                        buildTookInMillis(startTimeNanos)
+                                    )
+                                );
+                            }
+                        }, releasable::close), span, tracer)
+                    );
+                } catch (Exception e) {
+                    span.setError(e);
+                    span.endSpan();
+                    throw e;
+                }
             }
             bulkRequest = null; // allow memory for bulk request items to be reclaimed before all items have been completed
         }
@@ -766,6 +813,10 @@ void executeBulk(
         final AtomicArray<BulkItemResponse> responses,
         Map<String, IndexNotFoundException> indicesThatCannotBeCreated
     ) {
+        /*
+         * We are not wrapping the listener here to capture the response codes for performance benefits. It will
+         * be saving us an iteration over the responses array
+         */
         new BulkOperation(task, bulkRequest, listener, responses, startTimeNanos, indicesThatCannotBeCreated).run();
     }
 
diff --git a/server/src/main/java/org/opensearch/action/bulk/TransportShardBulkAction.java b/server/src/main/java/org/opensearch/action/bulk/TransportShardBulkAction.java
index fddda0ef1f9a7..b8517f53ff294 100644
--- a/server/src/main/java/org/opensearch/action/bulk/TransportShardBulkAction.java
+++ b/server/src/main/java/org/opensearch/action/bulk/TransportShardBulkAction.java
@@ -98,7 +98,9 @@
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.SystemIndices;
 import org.opensearch.node.NodeClosedException;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
 import org.opensearch.tasks.Task;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.threadpool.ThreadPool.Names;
 import org.opensearch.transport.TransportChannel;
@@ -161,7 +163,8 @@ public TransportShardBulkAction(
         IndexingPressureService indexingPressureService,
         SegmentReplicationPressureService segmentReplicationPressureService,
         RemoteStorePressureService remoteStorePressureService,
-        SystemIndices systemIndices
+        SystemIndices systemIndices,
+        Tracer tracer
     ) {
         super(
             settings,
@@ -177,7 +180,9 @@ public TransportShardBulkAction(
             EXECUTOR_NAME_FUNCTION,
             false,
             indexingPressureService,
-            systemIndices
+            systemIndices,
+            tracer,
+            AdmissionControlActionType.INDEXING
         );
         this.updateHelper = updateHelper;
         this.mappingUpdatedAction = mappingUpdatedAction;
diff --git a/server/src/main/java/org/opensearch/action/delete/DeleteRequest.java b/server/src/main/java/org/opensearch/action/delete/DeleteRequest.java
index 81ae3d78e8ced..d37e049d44720 100644
--- a/server/src/main/java/org/opensearch/action/delete/DeleteRequest.java
+++ b/server/src/main/java/org/opensearch/action/delete/DeleteRequest.java
@@ -39,6 +39,7 @@
 import org.opensearch.action.DocWriteRequest;
 import org.opensearch.action.support.replication.ReplicatedWriteRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -64,8 +65,9 @@
  * @see org.opensearch.client.Client#delete(DeleteRequest)
  * @see org.opensearch.client.Requests#deleteRequest(String)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteRequest extends ReplicatedWriteRequest<DeleteRequest>
     implements
         DocWriteRequest<DeleteRequest>,
@@ -205,7 +207,7 @@ public long ifSeqNo() {
 
     /**
      * If set, only perform this delete request if the document was last modification was assigned this primary term.
-     *
+     * <p>
      * If the document last modification was assigned a different term a
      * {@link org.opensearch.index.engine.VersionConflictEngineException} will be thrown.
      */
diff --git a/server/src/main/java/org/opensearch/action/delete/DeleteRequestBuilder.java b/server/src/main/java/org/opensearch/action/delete/DeleteRequestBuilder.java
index 0436962ce01d2..66aa1c73042fe 100644
--- a/server/src/main/java/org/opensearch/action/delete/DeleteRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/delete/DeleteRequestBuilder.java
@@ -36,13 +36,15 @@
 import org.opensearch.action.support.replication.ReplicationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.VersionType;
 
 /**
  * A delete document action request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteRequestBuilder extends ReplicationRequestBuilder<DeleteRequest, DeleteResponse, DeleteRequestBuilder>
     implements
         WriteRequestBuilder<DeleteRequestBuilder> {
diff --git a/server/src/main/java/org/opensearch/action/delete/DeleteResponse.java b/server/src/main/java/org/opensearch/action/delete/DeleteResponse.java
index e4d44197a8885..c39a787ad763d 100644
--- a/server/src/main/java/org/opensearch/action/delete/DeleteResponse.java
+++ b/server/src/main/java/org/opensearch/action/delete/DeleteResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.delete;
 
 import org.opensearch.action.DocWriteResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.rest.RestStatus;
@@ -48,8 +49,9 @@
  * @see org.opensearch.action.delete.DeleteRequest
  * @see org.opensearch.client.Client#delete(DeleteRequest)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeleteResponse extends DocWriteResponse {
 
     public DeleteResponse(ShardId shardId, StreamInput in) throws IOException {
@@ -112,8 +114,9 @@ public static void parseXContentFields(XContentParser parser, Builder context) t
      * temporarily store the parsed values, then the {@link DocWriteResponse.Builder#build()} method is called to
      * instantiate the {@link DeleteResponse}.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder extends DocWriteResponse.Builder {
 
         @Override
diff --git a/server/src/main/java/org/opensearch/action/delete/TransportDeleteAction.java b/server/src/main/java/org/opensearch/action/delete/TransportDeleteAction.java
index 039214459ac21..6cbabfec6d763 100644
--- a/server/src/main/java/org/opensearch/action/delete/TransportDeleteAction.java
+++ b/server/src/main/java/org/opensearch/action/delete/TransportDeleteAction.java
@@ -40,7 +40,7 @@
 
 /**
  * Performs the delete operation.
- *
+ * <p>
  * Deprecated use TransportBulkAction with a single item instead
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/action/explain/ExplainRequest.java b/server/src/main/java/org/opensearch/action/explain/ExplainRequest.java
index aad5a9853a3c5..dd9c01b04acbb 100644
--- a/server/src/main/java/org/opensearch/action/explain/ExplainRequest.java
+++ b/server/src/main/java/org/opensearch/action/explain/ExplainRequest.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.ValidateActions;
 import org.opensearch.action.support.single.shard.SingleShardRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -54,8 +55,9 @@
 /**
  * Explain request encapsulating the explain query and document identifier to get an explanation for.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ExplainRequest extends SingleShardRequest<ExplainRequest> implements ToXContentObject {
 
     private static final ParseField QUERY_FIELD = new ParseField("query");
diff --git a/server/src/main/java/org/opensearch/action/explain/ExplainRequestBuilder.java b/server/src/main/java/org/opensearch/action/explain/ExplainRequestBuilder.java
index 3031cb6067469..681b48f7a6593 100644
--- a/server/src/main/java/org/opensearch/action/explain/ExplainRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/explain/ExplainRequestBuilder.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.single.shard.SingleShardOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.index.query.QueryBuilder;
 import org.opensearch.search.fetch.subphase.FetchSourceContext;
@@ -42,8 +43,9 @@
 /**
  * A builder for {@link ExplainRequest}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ExplainRequestBuilder extends SingleShardOperationRequestBuilder<ExplainRequest, ExplainResponse, ExplainRequestBuilder> {
 
     ExplainRequestBuilder(OpenSearchClient client, ExplainAction action) {
diff --git a/server/src/main/java/org/opensearch/action/explain/ExplainResponse.java b/server/src/main/java/org/opensearch/action/explain/ExplainResponse.java
index 895f87b83b6ff..80a8634e62d87 100644
--- a/server/src/main/java/org/opensearch/action/explain/ExplainResponse.java
+++ b/server/src/main/java/org/opensearch/action/explain/ExplainResponse.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.search.Explanation;
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -56,8 +57,9 @@
 /**
  * Response containing the score explanation.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ExplainResponse extends ActionResponse implements StatusToXContentObject {
 
     private static final ParseField _INDEX = new ParseField("_index");
diff --git a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilities.java b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilities.java
index 9b01f65f0f711..20b9789972fff 100644
--- a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilities.java
+++ b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilities.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.fieldcaps;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -60,8 +61,9 @@
 /**
  * Describes the capabilities of a field optionally merged across multiple indices.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FieldCapabilities implements Writeable, ToXContentObject {
 
     private static final ParseField TYPE_FIELD = new ParseField("type");
diff --git a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequest.java b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequest.java
index c1c54c7018bcf..71e8db73e4ecc 100644
--- a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequest.java
+++ b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.ValidateActions;
 import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -52,7 +53,10 @@
 
 /**
  * Transport request for retrieving field capabilities for an explicit list of fields
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class FieldCapabilitiesRequest extends ActionRequest implements IndicesRequest.Replaceable, ToXContentObject {
     public static final String NAME = "field_caps_request";
 
diff --git a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequestBuilder.java b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequestBuilder.java
index 70a90b98bdf25..c589d344089f3 100644
--- a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesRequestBuilder.java
@@ -34,13 +34,15 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.query.QueryBuilder;
 
 /**
  * Transport request builder for retrieving field capabilities
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FieldCapabilitiesRequestBuilder extends ActionRequestBuilder<FieldCapabilitiesRequest, FieldCapabilitiesResponse> {
     public FieldCapabilitiesRequestBuilder(OpenSearchClient client, FieldCapabilitiesAction action, String... indices) {
         super(client, action, new FieldCapabilitiesRequest().indices(indices));
diff --git a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesResponse.java b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesResponse.java
index 2dcda2bf56b8f..72fdc75686e3b 100644
--- a/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesResponse.java
+++ b/server/src/main/java/org/opensearch/action/fieldcaps/FieldCapabilitiesResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.fieldcaps;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -57,8 +58,10 @@
 /**
  * Response for {@link FieldCapabilitiesRequest} requests.
  *
- * @opensearch.internal
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FieldCapabilitiesResponse extends ActionResponse implements ToXContentObject {
     private static final ParseField INDICES_FIELD = new ParseField("indices");
     private static final ParseField FIELDS_FIELD = new ParseField("fields");
diff --git a/server/src/main/java/org/opensearch/action/get/GetRequest.java b/server/src/main/java/org/opensearch/action/get/GetRequest.java
index 62d85d6d8f352..952fa8bdab63a 100644
--- a/server/src/main/java/org/opensearch/action/get/GetRequest.java
+++ b/server/src/main/java/org/opensearch/action/get/GetRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.RealtimeRequest;
 import org.opensearch.action.ValidateActions;
 import org.opensearch.action.support.single.shard.SingleShardRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -60,8 +61,9 @@
  * @see org.opensearch.client.Requests#getRequest(String)
  * @see org.opensearch.client.Client#get(GetRequest)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetRequest extends SingleShardRequest<GetRequest> implements RealtimeRequest {
 
     private String id;
diff --git a/server/src/main/java/org/opensearch/action/get/GetRequestBuilder.java b/server/src/main/java/org/opensearch/action/get/GetRequestBuilder.java
index 6237cf73f0ca8..f50cbb16186f7 100644
--- a/server/src/main/java/org/opensearch/action/get/GetRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/get/GetRequestBuilder.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.support.single.shard.SingleShardOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.index.VersionType;
 import org.opensearch.search.fetch.subphase.FetchSourceContext;
@@ -42,8 +43,9 @@
 /**
  * A get document action request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetRequestBuilder extends SingleShardOperationRequestBuilder<GetRequest, GetResponse, GetRequestBuilder> {
 
     public GetRequestBuilder(OpenSearchClient client, GetAction action) {
diff --git a/server/src/main/java/org/opensearch/action/get/GetResponse.java b/server/src/main/java/org/opensearch/action/get/GetResponse.java
index c86128444d7eb..f7f7241933bd6 100644
--- a/server/src/main/java/org/opensearch/action/get/GetResponse.java
+++ b/server/src/main/java/org/opensearch/action/get/GetResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.get;
 
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.ParsingException;
@@ -58,8 +59,9 @@
  * @see GetRequest
  * @see org.opensearch.client.Client#get(GetRequest)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetResponse extends ActionResponse implements Iterable<DocumentField>, ToXContentObject {
 
     GetResult getResult;
diff --git a/server/src/main/java/org/opensearch/action/get/MultiGetItemResponse.java b/server/src/main/java/org/opensearch/action/get/MultiGetItemResponse.java
index 19c9b785e7ea2..09b4205ffe521 100644
--- a/server/src/main/java/org/opensearch/action/get/MultiGetItemResponse.java
+++ b/server/src/main/java/org/opensearch/action/get/MultiGetItemResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.get;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -41,8 +42,9 @@
 /**
  * A single multi get response.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiGetItemResponse implements Writeable {
 
     private final GetResponse response;
diff --git a/server/src/main/java/org/opensearch/action/get/MultiGetRequest.java b/server/src/main/java/org/opensearch/action/get/MultiGetRequest.java
index 7f0844d717488..b15c69a41972f 100644
--- a/server/src/main/java/org/opensearch/action/get/MultiGetRequest.java
+++ b/server/src/main/java/org/opensearch/action/get/MultiGetRequest.java
@@ -42,6 +42,7 @@
 import org.opensearch.action.ValidateActions;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -69,8 +70,9 @@
 /**
  * Transport request for a multi get.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiGetRequest extends ActionRequest
     implements
         Iterable<MultiGetRequest.Item>,
@@ -91,8 +93,9 @@ public class MultiGetRequest extends ActionRequest
     /**
      * A single get item.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Item implements Writeable, IndicesRequest, ToXContentObject {
 
         private String index;
diff --git a/server/src/main/java/org/opensearch/action/get/MultiGetRequestBuilder.java b/server/src/main/java/org/opensearch/action/get/MultiGetRequestBuilder.java
index c317edc07da8b..0b701c8ec11c7 100644
--- a/server/src/main/java/org/opensearch/action/get/MultiGetRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/get/MultiGetRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A multi get document action request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiGetRequestBuilder extends ActionRequestBuilder<MultiGetRequest, MultiGetResponse> {
 
     public MultiGetRequestBuilder(OpenSearchClient client, MultiGetAction action) {
diff --git a/server/src/main/java/org/opensearch/action/get/MultiGetResponse.java b/server/src/main/java/org/opensearch/action/get/MultiGetResponse.java
index 73372b85be3b2..3c3489a065d9a 100644
--- a/server/src/main/java/org/opensearch/action/get/MultiGetResponse.java
+++ b/server/src/main/java/org/opensearch/action/get/MultiGetResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.OpenSearchException;
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -55,8 +56,9 @@
 /**
  * Transport response for a multi get.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiGetResponse extends ActionResponse implements Iterable<MultiGetItemResponse>, ToXContentObject {
 
     private static final ParseField INDEX = new ParseField("_index");
@@ -71,8 +73,9 @@ public class MultiGetResponse extends ActionResponse implements Iterable<MultiGe
     /**
      * Represents a failure.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Failure implements Writeable, ToXContentObject {
 
         private final String index;
diff --git a/server/src/main/java/org/opensearch/action/index/IndexRequest.java b/server/src/main/java/org/opensearch/action/index/IndexRequest.java
index d0b78cfd49d4b..a5958f8b9f499 100644
--- a/server/src/main/java/org/opensearch/action/index/IndexRequest.java
+++ b/server/src/main/java/org/opensearch/action/index/IndexRequest.java
@@ -48,6 +48,7 @@
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
@@ -76,22 +77,23 @@
 /**
  * Index request to index a typed JSON document into a specific index and make it searchable. Best
  * created using {@link org.opensearch.client.Requests#indexRequest(String)}.
- *
+ * <p>
  * The index requires the {@link #index()}, {@link #id(String)} and
  * {@link #source(byte[], MediaType)} to be set.
- *
+ * <p>
  * The source (content to index) can be set in its bytes form using ({@link #source(byte[], MediaType)}),
  * its string form ({@link #source(String, MediaType)}) or using a {@link XContentBuilder}
  * ({@link #source(XContentBuilder)}).
- *
+ * <p>
  * If the {@link #id(String)} is not set, it will be automatically generated.
  *
  * @see IndexResponse
  * @see org.opensearch.client.Requests#indexRequest(String)
  * @see org.opensearch.client.Client#index(IndexRequest)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexRequest extends ReplicatedWriteRequest<IndexRequest> implements DocWriteRequest<IndexRequest>, CompositeIndicesRequest {
 
     private static final long SHALLOW_SIZE = RamUsageEstimator.shallowSizeOfInstance(IndexRequest.class);
@@ -388,7 +390,7 @@ public IndexRequest source(Map<String, ?> source, MediaType contentType) throws
 
     /**
      * Sets the document source to index.
-     *
+     * <p>
      * Note, its preferable to either set it using {@link #source(XContentBuilder)}
      * or using the {@link #source(byte[], MediaType)}.
      */
@@ -591,7 +593,7 @@ public long ifSeqNo() {
 
     /**
      * If set, only perform this indexing request if the document was last modification was assigned this primary term.
-     *
+     * <p>
      * If the document last modification was assigned a different term a
      * {@link org.opensearch.index.engine.VersionConflictEngineException} will be thrown.
      */
diff --git a/server/src/main/java/org/opensearch/action/index/IndexRequestBuilder.java b/server/src/main/java/org/opensearch/action/index/IndexRequestBuilder.java
index 4bf7634dcb7e1..9d4ad3c32778c 100644
--- a/server/src/main/java/org/opensearch/action/index/IndexRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/index/IndexRequestBuilder.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.support.replication.ReplicationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaType;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -47,8 +48,9 @@
 /**
  * An index document action request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexRequestBuilder extends ReplicationRequestBuilder<IndexRequest, IndexResponse, IndexRequestBuilder>
     implements
         WriteRequestBuilder<IndexRequestBuilder> {
diff --git a/server/src/main/java/org/opensearch/action/index/IndexResponse.java b/server/src/main/java/org/opensearch/action/index/IndexResponse.java
index d0aa9b57b6528..53f832fc12c43 100644
--- a/server/src/main/java/org/opensearch/action/index/IndexResponse.java
+++ b/server/src/main/java/org/opensearch/action/index/IndexResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.index;
 
 import org.opensearch.action.DocWriteResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
@@ -50,8 +51,9 @@
  * @see IndexRequest
  * @see org.opensearch.client.Client#index(IndexRequest)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexResponse extends DocWriteResponse {
 
     public IndexResponse(ShardId shardId, StreamInput in) throws IOException {
@@ -116,8 +118,9 @@ public static void parseXContentFields(XContentParser parser, Builder context) t
      * temporarily store the parsed values, then the {@link Builder#build()} method is called to
      * instantiate the {@link IndexResponse}.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder extends DocWriteResponse.Builder {
         @Override
         public IndexResponse build() {
diff --git a/server/src/main/java/org/opensearch/action/index/TransportIndexAction.java b/server/src/main/java/org/opensearch/action/index/TransportIndexAction.java
index fe4f80bf0c065..ce32840f6751b 100644
--- a/server/src/main/java/org/opensearch/action/index/TransportIndexAction.java
+++ b/server/src/main/java/org/opensearch/action/index/TransportIndexAction.java
@@ -40,7 +40,7 @@
 
 /**
  * Performs the index operation.
- *
+ * <p>
  * Allows for the following settings:
  * <ul>
  * <li><b>autoCreateIndex</b>: When set to {@code true}, will automatically create an index if one does not exists.
diff --git a/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequest.java b/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequest.java
index 2f05ce3a25320..b9d916e152c3d 100644
--- a/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequest.java
+++ b/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -43,8 +44,9 @@
 /**
  * transport request to delete a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeletePipelineRequest extends AcknowledgedRequest<DeletePipelineRequest> {
 
     private String id;
diff --git a/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequestBuilder.java b/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequestBuilder.java
index 6a2eb494e8d3f..bc253db85bb0f 100644
--- a/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/ingest/DeletePipelineRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder to delete a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeletePipelineRequestBuilder extends ActionRequestBuilder<DeletePipelineRequest, AcknowledgedResponse> {
 
     public DeletePipelineRequestBuilder(OpenSearchClient client, DeletePipelineAction action) {
diff --git a/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequest.java b/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequest.java
index 4bae98098777d..c7266c31a5022 100644
--- a/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequest.java
+++ b/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -43,8 +44,9 @@
 /**
  * transport request to get a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetPipelineRequest extends ClusterManagerNodeReadRequest<GetPipelineRequest> {
 
     private String[] ids;
diff --git a/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequestBuilder.java b/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequestBuilder.java
index bdc13523ffdc6..593ea2156d5e3 100644
--- a/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/ingest/GetPipelineRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Transport request builder to get a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetPipelineRequestBuilder extends ClusterManagerNodeReadOperationRequestBuilder<
     GetPipelineRequest,
     GetPipelineResponse,
diff --git a/server/src/main/java/org/opensearch/action/ingest/GetPipelineResponse.java b/server/src/main/java/org/opensearch/action/ingest/GetPipelineResponse.java
index bd1b18be9a828..0719842bc985f 100644
--- a/server/src/main/java/org/opensearch/action/ingest/GetPipelineResponse.java
+++ b/server/src/main/java/org/opensearch/action/ingest/GetPipelineResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.ingest;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
@@ -57,8 +58,9 @@
 /**
  * transport response for getting a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetPipelineResponse extends ActionResponse implements StatusToXContentObject {
 
     private List<PipelineConfiguration> pipelines;
diff --git a/server/src/main/java/org/opensearch/action/ingest/IngestActionForwarder.java b/server/src/main/java/org/opensearch/action/ingest/IngestActionForwarder.java
index 9927affbc7442..2821f4fd7fadb 100644
--- a/server/src/main/java/org/opensearch/action/ingest/IngestActionForwarder.java
+++ b/server/src/main/java/org/opensearch/action/ingest/IngestActionForwarder.java
@@ -46,7 +46,7 @@
 
 /**
  * A utility for forwarding ingest requests to ingest nodes in a round-robin fashion.
- *
+ * <p>
  * TODO: move this into IngestService and make index/bulk actions call that
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequest.java b/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequest.java
index f764e4b23860a..06e89b5f2908b 100644
--- a/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequest.java
+++ b/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequest.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -49,8 +50,9 @@
 /**
  * transport request to put a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutPipelineRequest extends AcknowledgedRequest<PutPipelineRequest> implements ToXContentObject {
 
     private String id;
diff --git a/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequestBuilder.java b/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequestBuilder.java
index e734abb6d7969..e8d6a4d332319 100644
--- a/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/ingest/PutPipelineRequestBuilder.java
@@ -35,14 +35,16 @@
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaType;
 
 /**
  * Transport request builder to put a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PutPipelineRequestBuilder extends ActionRequestBuilder<PutPipelineRequest, AcknowledgedResponse> {
 
     public PutPipelineRequestBuilder(OpenSearchClient client, PutPipelineAction action) {
diff --git a/server/src/main/java/org/opensearch/action/ingest/SimulateDocumentResult.java b/server/src/main/java/org/opensearch/action/ingest/SimulateDocumentResult.java
index 98a03272aff42..bc338a57f762d 100644
--- a/server/src/main/java/org/opensearch/action/ingest/SimulateDocumentResult.java
+++ b/server/src/main/java/org/opensearch/action/ingest/SimulateDocumentResult.java
@@ -31,14 +31,16 @@
 
 package org.opensearch.action.ingest;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.Writeable;
 import org.opensearch.core.xcontent.ToXContentObject;
 
 /**
  * Interface to simulate a document result
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface SimulateDocumentResult extends Writeable, ToXContentObject {
 
 }
diff --git a/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequest.java b/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequest.java
index 2234934499609..b51f25d2e62b1 100644
--- a/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequest.java
+++ b/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequest.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -60,8 +61,9 @@
 /**
  * transport request to simulate a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SimulatePipelineRequest extends ActionRequest implements ToXContentObject {
 
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(SimulatePipelineRequest.class);
@@ -218,7 +220,12 @@ private static List<IngestDocument> parseDocs(Map<String, Object> config) {
             String routing = ConfigurationUtils.readOptionalStringOrIntProperty(null, null, dataMap, Metadata.ROUTING.getFieldName());
             Long version = null;
             if (dataMap.containsKey(Metadata.VERSION.getFieldName())) {
-                version = (Long) ConfigurationUtils.readObject(null, null, dataMap, Metadata.VERSION.getFieldName());
+                Object versionFieldValue = ConfigurationUtils.readObject(null, null, dataMap, Metadata.VERSION.getFieldName());
+                if (versionFieldValue instanceof Integer || versionFieldValue instanceof Long) {
+                    version = ((Number) versionFieldValue).longValue();
+                } else {
+                    throw new IllegalArgumentException("Failed to parse parameter [_version], only int or long is accepted");
+                }
             }
             VersionType versionType = null;
             if (dataMap.containsKey(Metadata.VERSION_TYPE.getFieldName())) {
@@ -228,12 +235,25 @@ private static List<IngestDocument> parseDocs(Map<String, Object> config) {
             }
             IngestDocument ingestDocument = new IngestDocument(index, id, routing, version, versionType, document);
             if (dataMap.containsKey(Metadata.IF_SEQ_NO.getFieldName())) {
-                Long ifSeqNo = (Long) ConfigurationUtils.readObject(null, null, dataMap, Metadata.IF_SEQ_NO.getFieldName());
-                ingestDocument.setFieldValue(Metadata.IF_SEQ_NO.getFieldName(), ifSeqNo);
+                Object ifSeqNoFieldValue = ConfigurationUtils.readObject(null, null, dataMap, Metadata.IF_SEQ_NO.getFieldName());
+                if (ifSeqNoFieldValue instanceof Integer || ifSeqNoFieldValue instanceof Long) {
+                    ingestDocument.setFieldValue(Metadata.IF_SEQ_NO.getFieldName(), ((Number) ifSeqNoFieldValue).longValue());
+                } else {
+                    throw new IllegalArgumentException("Failed to parse parameter [_if_seq_no], only int or long is accepted");
+                }
             }
             if (dataMap.containsKey(Metadata.IF_PRIMARY_TERM.getFieldName())) {
-                Long ifPrimaryTerm = (Long) ConfigurationUtils.readObject(null, null, dataMap, Metadata.IF_PRIMARY_TERM.getFieldName());
-                ingestDocument.setFieldValue(Metadata.IF_PRIMARY_TERM.getFieldName(), ifPrimaryTerm);
+                Object ifPrimaryTermFieldValue = ConfigurationUtils.readObject(
+                    null,
+                    null,
+                    dataMap,
+                    Metadata.IF_PRIMARY_TERM.getFieldName()
+                );
+                if (ifPrimaryTermFieldValue instanceof Integer || ifPrimaryTermFieldValue instanceof Long) {
+                    ingestDocument.setFieldValue(Metadata.IF_PRIMARY_TERM.getFieldName(), ((Number) ifPrimaryTermFieldValue).longValue());
+                } else {
+                    throw new IllegalArgumentException("Failed to parse parameter [_if_primary_term], only int or long is accepted");
+                }
             }
             ingestDocumentList.add(ingestDocument);
         }
diff --git a/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequestBuilder.java b/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequestBuilder.java
index 55e6d95fde65c..2a5f281a5075c 100644
--- a/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineRequestBuilder.java
@@ -34,14 +34,16 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaType;
 
 /**
  * Transport request builder to simulate a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SimulatePipelineRequestBuilder extends ActionRequestBuilder<SimulatePipelineRequest, SimulatePipelineResponse> {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineResponse.java b/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineResponse.java
index 3cbbc4350c3bd..1fb3a69bd1e16 100644
--- a/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineResponse.java
+++ b/server/src/main/java/org/opensearch/action/ingest/SimulatePipelineResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.ingest;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -54,8 +55,9 @@
 /**
  * transport response for simulating a pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SimulatePipelineResponse extends ActionResponse implements ToXContentObject {
     private String pipelineId;
     private boolean verbose;
diff --git a/server/src/main/java/org/opensearch/action/resync/TransportResyncReplicationAction.java b/server/src/main/java/org/opensearch/action/resync/TransportResyncReplicationAction.java
index 032fe83e2220b..9d60706d1f100 100644
--- a/server/src/main/java/org/opensearch/action/resync/TransportResyncReplicationAction.java
+++ b/server/src/main/java/org/opensearch/action/resync/TransportResyncReplicationAction.java
@@ -54,6 +54,7 @@
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.SystemIndices;
 import org.opensearch.tasks.Task;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.threadpool.ThreadPool.Names;
 import org.opensearch.transport.TransportException;
@@ -93,7 +94,8 @@ public TransportResyncReplicationAction(
         ShardStateAction shardStateAction,
         ActionFilters actionFilters,
         IndexingPressureService indexingPressureService,
-        SystemIndices systemIndices
+        SystemIndices systemIndices,
+        Tracer tracer
     ) {
         super(
             settings,
@@ -109,7 +111,8 @@ public TransportResyncReplicationAction(
             EXECUTOR_NAME_FUNCTION,
             true, /* we should never reject resync because of thread pool capacity on primary */
             indexingPressureService,
-            systemIndices
+            systemIndices,
+            tracer
         );
     }
 
diff --git a/server/src/main/java/org/opensearch/action/search/AbstractSearchAsyncAction.java b/server/src/main/java/org/opensearch/action/search/AbstractSearchAsyncAction.java
index ee8aa10577956..f18bbb8a1cc13 100644
--- a/server/src/main/java/org/opensearch/action/search/AbstractSearchAsyncAction.java
+++ b/server/src/main/java/org/opensearch/action/search/AbstractSearchAsyncAction.java
@@ -68,6 +68,7 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.BiFunction;
@@ -107,7 +108,6 @@ abstract class AbstractSearchAsyncAction<Result extends SearchPhaseResult> exten
     private final AtomicInteger skippedOps = new AtomicInteger();
     private final TransportSearchAction.SearchTimeProvider timeProvider;
     private final SearchResponse.Clusters clusters;
-
     protected final GroupShardsIterator<SearchShardIterator> toSkipShardsIts;
     protected final GroupShardsIterator<SearchShardIterator> shardsIts;
     private final int expectedTotalOps;
@@ -115,6 +115,9 @@ abstract class AbstractSearchAsyncAction<Result extends SearchPhaseResult> exten
     private final int maxConcurrentRequestsPerNode;
     private final Map<String, PendingExecutions> pendingExecutionsPerNode = new ConcurrentHashMap<>();
     private final boolean throttleConcurrentRequests;
+    private final SearchRequestContext searchRequestContext;
+
+    private SearchPhase currentPhase;
 
     private final List<Releasable> releasables = new ArrayList<>();
 
@@ -135,7 +138,8 @@ abstract class AbstractSearchAsyncAction<Result extends SearchPhaseResult> exten
         SearchTask task,
         SearchPhaseResults<Result> resultConsumer,
         int maxConcurrentRequestsPerNode,
-        SearchResponse.Clusters clusters
+        SearchResponse.Clusters clusters,
+        SearchRequestContext searchRequestContext
     ) {
         super(name);
         final List<SearchShardIterator> toSkipIterators = new ArrayList<>();
@@ -171,6 +175,7 @@ abstract class AbstractSearchAsyncAction<Result extends SearchPhaseResult> exten
         this.indexRoutings = indexRoutings;
         this.results = resultConsumer;
         this.clusters = clusters;
+        this.searchRequestContext = searchRequestContext;
     }
 
     @Override
@@ -209,6 +214,7 @@ public final void start() {
                     0,
                     0,
                     buildTookInMillis(),
+                    timeProvider.getPhaseTook(),
                     ShardSearchFailure.EMPTY_ARRAY,
                     clusters,
                     null
@@ -371,6 +377,7 @@ public final void executeNextPhase(SearchPhase currentPhase, SearchPhase nextPha
                 : OpenSearchException.guessRootCauses(shardSearchFailures[0].getCause())[0];
             logger.debug(() -> new ParameterizedMessage("All shards failed for phase: [{}]", getName()), cause);
             onPhaseFailure(currentPhase, "all shards failed", cause);
+
         } else {
             Boolean allowPartialResults = request.allowPartialSearchResults();
             assert allowPartialResults != null : "SearchRequest missing setting for allowPartialSearchResults";
@@ -419,13 +426,32 @@ public final void executeNextPhase(SearchPhase currentPhase, SearchPhase nextPha
                     clusterState.version()
                 );
             }
+            onPhaseEnd(searchRequestContext);
             executePhase(nextPhase);
         }
     }
 
+    private void onPhaseEnd(SearchRequestContext searchRequestContext) {
+        if (getCurrentPhase() != null) {
+            long tookInNanos = System.nanoTime() - getCurrentPhase().getStartTimeInNanos();
+            searchRequestContext.updatePhaseTookMap(getCurrentPhase().getName(), TimeUnit.NANOSECONDS.toMillis(tookInNanos));
+        }
+        this.searchRequestContext.getSearchRequestOperationsListener().onPhaseEnd(this, searchRequestContext);
+    }
+
+    private void onPhaseStart(SearchPhase phase) {
+        setCurrentPhase(phase);
+        this.searchRequestContext.getSearchRequestOperationsListener().onPhaseStart(this);
+    }
+
+    private void onRequestEnd(SearchRequestContext searchRequestContext) {
+        this.searchRequestContext.getSearchRequestOperationsListener().onRequestEnd(this, searchRequestContext);
+    }
+
     private void executePhase(SearchPhase phase) {
         try {
-            phase.run();
+            onPhaseStart(phase);
+            phase.recordAndRun();
         } catch (Exception e) {
             if (logger.isDebugEnabled()) {
                 logger.debug(new ParameterizedMessage("Failed to execute [{}] while moving to [{}] phase", request, phase.getName()), e);
@@ -603,6 +629,14 @@ private void successfulShardExecution(SearchShardIterator shardsIt) {
         }
     }
 
+    public SearchPhase getCurrentPhase() {
+        return currentPhase;
+    }
+
+    private void setCurrentPhase(SearchPhase phase) {
+        currentPhase = phase;
+    }
+
     @Override
     public final int getNumShards() {
         return results.getNumShards();
@@ -636,6 +670,7 @@ protected final SearchResponse buildSearchResponse(
             successfulOps.get(),
             skippedOps.get(),
             buildTookInMillis(),
+            timeProvider.getPhaseTook(),
             failures,
             clusters,
             searchContextId
@@ -668,12 +703,18 @@ public void sendSearchResponse(InternalSearchResponse internalSearchResponse, At
                     searchContextId = null;
                 }
             }
+            searchRequestContext.setTotalHits(internalSearchResponse.hits().getTotalHits());
+            searchRequestContext.setShardStats(results.getNumShards(), successfulOps.get(), skippedOps.get(), failures.length);
+            onPhaseEnd(searchRequestContext);
+            onRequestEnd(searchRequestContext);
             listener.onResponse(buildSearchResponse(internalSearchResponse, failures, scrollId, searchContextId));
         }
+        setCurrentPhase(null);
     }
 
     @Override
     public final void onPhaseFailure(SearchPhase phase, String msg, Throwable cause) {
+        this.searchRequestContext.getSearchRequestOperationsListener().onPhaseFailure(this);
         raisePhaseFailure(new SearchPhaseExecutionException(phase.getName(), msg, cause, buildShardFailures()));
     }
 
diff --git a/server/src/main/java/org/opensearch/action/search/CanMatchPreFilterSearchPhase.java b/server/src/main/java/org/opensearch/action/search/CanMatchPreFilterSearchPhase.java
index 6c3ee652de2de..c693eea4a2c33 100644
--- a/server/src/main/java/org/opensearch/action/search/CanMatchPreFilterSearchPhase.java
+++ b/server/src/main/java/org/opensearch/action/search/CanMatchPreFilterSearchPhase.java
@@ -90,7 +90,8 @@ final class CanMatchPreFilterSearchPhase extends AbstractSearchAsyncAction<CanMa
         ClusterState clusterState,
         SearchTask task,
         Function<GroupShardsIterator<SearchShardIterator>, SearchPhase> phaseFactory,
-        SearchResponse.Clusters clusters
+        SearchResponse.Clusters clusters,
+        SearchRequestContext searchRequestContext
     ) {
         // We set max concurrent shard requests to the number of shards so no throttling happens for can_match requests
         super(
@@ -110,7 +111,8 @@ final class CanMatchPreFilterSearchPhase extends AbstractSearchAsyncAction<CanMa
             task,
             new CanMatchSearchPhaseResults(shardsIts.size()),
             shardsIts.size(),
-            clusters
+            clusters,
+            searchRequestContext
         );
         this.phaseFactory = phaseFactory;
         this.shardsIts = shardsIts;
diff --git a/server/src/main/java/org/opensearch/action/search/ClearScrollRequest.java b/server/src/main/java/org/opensearch/action/search/ClearScrollRequest.java
index cd9e33634d918..16bf0fc46c4eb 100644
--- a/server/src/main/java/org/opensearch/action/search/ClearScrollRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/ClearScrollRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContentObject;
@@ -50,8 +51,9 @@
 /**
  * Transport request for clearing a search scroll
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClearScrollRequest extends ActionRequest implements ToXContentObject {
 
     private List<String> scrollIds;
diff --git a/server/src/main/java/org/opensearch/action/search/ClearScrollRequestBuilder.java b/server/src/main/java/org/opensearch/action/search/ClearScrollRequestBuilder.java
index 63f64e02a9dd2..c10417e756dd6 100644
--- a/server/src/main/java/org/opensearch/action/search/ClearScrollRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/search/ClearScrollRequestBuilder.java
@@ -34,14 +34,16 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.List;
 
 /**
  * Transport request builder for clearing a search scroll
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClearScrollRequestBuilder extends ActionRequestBuilder<ClearScrollRequest, ClearScrollResponse> {
 
     public ClearScrollRequestBuilder(OpenSearchClient client, ClearScrollAction action) {
diff --git a/server/src/main/java/org/opensearch/action/search/ClearScrollResponse.java b/server/src/main/java/org/opensearch/action/search/ClearScrollResponse.java
index 4428f693763ed..e2580ccdd0969 100644
--- a/server/src/main/java/org/opensearch/action/search/ClearScrollResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/ClearScrollResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -52,8 +53,9 @@
 /**
  * Transport response for clearing a search scroll
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClearScrollResponse extends ActionResponse implements StatusToXContentObject {
 
     private static final ParseField SUCCEEDED = new ParseField("succeeded");
diff --git a/server/src/main/java/org/opensearch/action/search/CreatePitController.java b/server/src/main/java/org/opensearch/action/search/CreatePitController.java
index 1d11ad2760675..87eb27bdb8255 100644
--- a/server/src/main/java/org/opensearch/action/search/CreatePitController.java
+++ b/server/src/main/java/org/opensearch/action/search/CreatePitController.java
@@ -98,18 +98,18 @@ public void executeCreatePit(
             task.getParentTaskId(),
             Collections.emptyMap()
         );
-        /**
-         * This is needed for cross cluster functionality to work with PITs and current ccsMinimizeRoundTrips is
-         * not supported for point in time
+        /*
+          This is needed for cross cluster functionality to work with PITs and current ccsMinimizeRoundTrips is
+          not supported for point in time
          */
         searchRequest.setCcsMinimizeRoundtrips(false);
-        /**
-         * Phase 1 of create PIT
+        /*
+          Phase 1 of create PIT
          */
         executeCreatePit(searchTask, searchRequest, createPitListener);
 
-        /**
-         * Phase 2 of create PIT where we update pit id in pit contexts
+        /*
+          Phase 2 of create PIT where we update pit id in pit contexts
          */
         createPitListener.whenComplete(
             searchResponse -> { executeUpdatePitId(request, searchRequest, searchResponse, updatePitIdListener); },
@@ -167,9 +167,9 @@ void executeUpdatePitId(
                 searchResponse.pointInTimeId()
             )
         );
-        /**
-         * store the create time ( same create time for all PIT contexts across shards ) to be used
-         * for list PIT api
+        /*
+          store the create time ( same create time for all PIT contexts across shards ) to be used
+          for list PIT api
          */
         final long relativeStartNanos = System.nanoTime();
         final TransportSearchAction.SearchTimeProvider timeProvider = new TransportSearchAction.SearchTimeProvider(
diff --git a/server/src/main/java/org/opensearch/action/search/CreatePitRequest.java b/server/src/main/java/org/opensearch/action/search/CreatePitRequest.java
index a47127f18e18d..840d4becda714 100644
--- a/server/src/main/java/org/opensearch/action/search/CreatePitRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/CreatePitRequest.java
@@ -13,6 +13,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -30,7 +31,10 @@
 
 /**
  * A request to make create point in time against one or more indices.
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class CreatePitRequest extends ActionRequest implements IndicesRequest.Replaceable, ToXContent {
 
     // keep alive for pit reader context
diff --git a/server/src/main/java/org/opensearch/action/search/CreatePitResponse.java b/server/src/main/java/org/opensearch/action/search/CreatePitResponse.java
index aa841a02f1d20..410b93afc3e65 100644
--- a/server/src/main/java/org/opensearch/action/search/CreatePitResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/CreatePitResponse.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -26,7 +27,10 @@
 
 /**
  * Create point in time response with point in time id and shard success / failures
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class CreatePitResponse extends ActionResponse implements StatusToXContentObject {
     private static final ParseField ID = new ParseField("pit_id");
     private static final ParseField CREATION_TIME = new ParseField("creation_time");
diff --git a/server/src/main/java/org/opensearch/action/search/DeletePitInfo.java b/server/src/main/java/org/opensearch/action/search/DeletePitInfo.java
index 40098c6670b65..c534b306b1404 100644
--- a/server/src/main/java/org/opensearch/action/search/DeletePitInfo.java
+++ b/server/src/main/java/org/opensearch/action/search/DeletePitInfo.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -23,7 +24,10 @@
 
 /**
  * This class captures if deletion of pit is successful along with pit id
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class DeletePitInfo extends TransportResponse implements Writeable, ToXContent {
     /**
      * This will be true if PIT reader contexts are deleted ond also if contexts are not found.
diff --git a/server/src/main/java/org/opensearch/action/search/DeletePitRequest.java b/server/src/main/java/org/opensearch/action/search/DeletePitRequest.java
index 1a66311cd9a1b..e21a63eef9433 100644
--- a/server/src/main/java/org/opensearch/action/search/DeletePitRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/DeletePitRequest.java
@@ -11,6 +11,7 @@
 
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContent;
@@ -27,7 +28,10 @@
 
 /**
  * Request to delete one or more PIT search contexts based on IDs.
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class DeletePitRequest extends ActionRequest implements ToXContentObject {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/search/DeletePitResponse.java b/server/src/main/java/org/opensearch/action/search/DeletePitResponse.java
index 00274f0e610a9..469d78ad73bd9 100644
--- a/server/src/main/java/org/opensearch/action/search/DeletePitResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/DeletePitResponse.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -28,7 +29,10 @@
 
 /**
  * Response class for delete pits flow which clears the point in time search contexts
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class DeletePitResponse extends ActionResponse implements StatusToXContentObject {
 
     private final List<DeletePitInfo> deletePitResults;
diff --git a/server/src/main/java/org/opensearch/action/search/DeleteSearchPipelineRequest.java b/server/src/main/java/org/opensearch/action/search/DeleteSearchPipelineRequest.java
index 2c6ab6437fd2a..0cde81203063c 100644
--- a/server/src/main/java/org/opensearch/action/search/DeleteSearchPipelineRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/DeleteSearchPipelineRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -19,8 +20,9 @@
 /**
  * Request to delete a search pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class DeleteSearchPipelineRequest extends AcknowledgedRequest<DeleteSearchPipelineRequest> {
     private String id;
 
diff --git a/server/src/main/java/org/opensearch/action/search/GetAllPitNodeResponse.java b/server/src/main/java/org/opensearch/action/search/GetAllPitNodeResponse.java
index 9bbc81c0d6a4c..91353240a8156 100644
--- a/server/src/main/java/org/opensearch/action/search/GetAllPitNodeResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/GetAllPitNodeResponse.java
@@ -11,6 +11,7 @@
 
 import org.opensearch.action.support.nodes.BaseNodeResponse;
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -22,7 +23,10 @@
 
 /**
  * Inner node get all pits response
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class GetAllPitNodeResponse extends BaseNodeResponse implements ToXContentFragment {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/search/GetAllPitNodesRequest.java b/server/src/main/java/org/opensearch/action/search/GetAllPitNodesRequest.java
index 948fe72eae817..336c8139561e9 100644
--- a/server/src/main/java/org/opensearch/action/search/GetAllPitNodesRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/GetAllPitNodesRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.support.nodes.BaseNodesRequest;
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -18,7 +19,10 @@
 
 /**
  * Request to get all active PIT IDs from all nodes of cluster
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class GetAllPitNodesRequest extends BaseNodesRequest<GetAllPitNodesRequest> {
 
     @Inject
diff --git a/server/src/main/java/org/opensearch/action/search/GetAllPitNodesResponse.java b/server/src/main/java/org/opensearch/action/search/GetAllPitNodesResponse.java
index 9bb3ab6407696..8d858a00c409b 100644
--- a/server/src/main/java/org/opensearch/action/search/GetAllPitNodesResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/GetAllPitNodesResponse.java
@@ -11,6 +11,7 @@
 import org.opensearch.action.FailedNodeException;
 import org.opensearch.action.support.nodes.BaseNodesResponse;
 import org.opensearch.cluster.ClusterName;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -31,7 +32,10 @@
 
 /**
  * This class transforms active PIT objects from all nodes to unique PIT objects
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class GetAllPitNodesResponse extends BaseNodesResponse<GetAllPitNodeResponse> implements ToXContentObject {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/search/GetSearchPipelineRequest.java b/server/src/main/java/org/opensearch/action/search/GetSearchPipelineRequest.java
index f573a37fa5dab..59e95aa87985a 100644
--- a/server/src/main/java/org/opensearch/action/search/GetSearchPipelineRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/GetSearchPipelineRequest.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.clustermanager.ClusterManagerNodeReadRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -20,8 +21,9 @@
 /**
  * Request to get search pipelines
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class GetSearchPipelineRequest extends ClusterManagerNodeReadRequest<GetSearchPipelineRequest> {
     private final String[] ids;
 
diff --git a/server/src/main/java/org/opensearch/action/search/GetSearchPipelineResponse.java b/server/src/main/java/org/opensearch/action/search/GetSearchPipelineResponse.java
index 64dde763e9ff8..0379046c8275d 100644
--- a/server/src/main/java/org/opensearch/action/search/GetSearchPipelineResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/GetSearchPipelineResponse.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.Strings;
@@ -32,8 +33,9 @@
 /**
  * transport response for getting a search pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class GetSearchPipelineResponse extends ActionResponse implements StatusToXContentObject {
 
     private final List<PipelineConfiguration> pipelines;
diff --git a/server/src/main/java/org/opensearch/action/search/ListPitInfo.java b/server/src/main/java/org/opensearch/action/search/ListPitInfo.java
index 220b7247517b9..7e4ed186dd665 100644
--- a/server/src/main/java/org/opensearch/action/search/ListPitInfo.java
+++ b/server/src/main/java/org/opensearch/action/search/ListPitInfo.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -23,7 +24,10 @@
 
 /**
  * This holds information about pit reader context such as pit id and creation time
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public class ListPitInfo implements ToXContentFragment, Writeable {
     private final String pitId;
     private final long creationTime;
diff --git a/server/src/main/java/org/opensearch/action/search/MultiSearchRequest.java b/server/src/main/java/org/opensearch/action/search/MultiSearchRequest.java
index da8f8f144eaf2..5f46e0c298de4 100644
--- a/server/src/main/java/org/opensearch/action/search/MultiSearchRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/MultiSearchRequest.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.action.support.IndicesOptions.WildcardStates;
 import org.opensearch.common.CheckedBiConsumer;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -71,8 +72,9 @@
 /**
  * A multi search API request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiSearchRequest extends ActionRequest implements CompositeIndicesRequest {
 
     public static final int MAX_CONCURRENT_SEARCH_REQUESTS_DEFAULT = 0;
@@ -277,6 +279,8 @@ public static void readMultiLineFormat(
                         } else if ("cancel_after_time_interval".equals(entry.getKey())
                             || "cancelAfterTimeInterval".equals(entry.getKey())) {
                                 searchRequest.setCancelAfterTimeInterval(nodeTimeValue(value, null));
+                            } else if ("phase_took".equals(entry.getKey())) {
+                                searchRequest.setPhaseTook(nodeBooleanValue(value));
                             } else {
                                 throw new IllegalArgumentException("key [" + entry.getKey() + "] is not supported in the metadata section");
                             }
@@ -374,6 +378,9 @@ public static void writeSearchRequestParams(SearchRequest request, XContentBuild
         if (request.getCancelAfterTimeInterval() != null) {
             xContentBuilder.field("cancel_after_time_interval", request.getCancelAfterTimeInterval().getStringRep());
         }
+        if (request.isPhaseTook() != null) {
+            xContentBuilder.field("phase_took", request.isPhaseTook());
+        }
         xContentBuilder.endObject();
     }
 
diff --git a/server/src/main/java/org/opensearch/action/search/MultiSearchRequestBuilder.java b/server/src/main/java/org/opensearch/action/search/MultiSearchRequestBuilder.java
index f9bb90c69d925..3bf078e8ce793 100644
--- a/server/src/main/java/org/opensearch/action/search/MultiSearchRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/search/MultiSearchRequestBuilder.java
@@ -35,12 +35,14 @@
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A request builder for multiple search requests.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiSearchRequestBuilder extends ActionRequestBuilder<MultiSearchRequest, MultiSearchResponse> {
 
     public MultiSearchRequestBuilder(OpenSearchClient client, MultiSearchAction action) {
diff --git a/server/src/main/java/org/opensearch/action/search/MultiSearchResponse.java b/server/src/main/java/org/opensearch/action/search/MultiSearchResponse.java
index 24ce4c2406570..70bb0b99e69df 100644
--- a/server/src/main/java/org/opensearch/action/search/MultiSearchResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/MultiSearchResponse.java
@@ -35,6 +35,7 @@
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.OpenSearchException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
@@ -59,8 +60,9 @@
 /**
  * A multi search response.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiSearchResponse extends ActionResponse implements Iterable<MultiSearchResponse.Item>, ToXContentObject {
 
     private static final ParseField RESPONSES = new ParseField(Fields.RESPONSES);
@@ -78,8 +80,9 @@ public class MultiSearchResponse extends ActionResponse implements Iterable<Mult
     /**
      * A search response item, holding the actual search response, or an error message if it failed.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Item implements Writeable {
         private final SearchResponse response;
         private final Exception exception;
diff --git a/server/src/main/java/org/opensearch/action/search/ParsedScrollId.java b/server/src/main/java/org/opensearch/action/search/ParsedScrollId.java
index 70be9a0b19e08..b723b97b5c413 100644
--- a/server/src/main/java/org/opensearch/action/search/ParsedScrollId.java
+++ b/server/src/main/java/org/opensearch/action/search/ParsedScrollId.java
@@ -32,13 +32,16 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.Arrays;
 
 /**
  * Search scroll id that has been parsed
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ParsedScrollId {
 
     public static final String QUERY_THEN_FETCH_TYPE = "queryThenFetch";
diff --git a/server/src/main/java/org/opensearch/action/search/PutSearchPipelineRequest.java b/server/src/main/java/org/opensearch/action/search/PutSearchPipelineRequest.java
index 48cf8e5028f90..15b4ea648af29 100644
--- a/server/src/main/java/org/opensearch/action/search/PutSearchPipelineRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/PutSearchPipelineRequest.java
@@ -11,6 +11,7 @@
 import org.opensearch.Version;
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.support.master.AcknowledgedRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -25,8 +26,9 @@
 /**
  * Request to put a search pipeline
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class PutSearchPipelineRequest extends AcknowledgedRequest<PutSearchPipelineRequest> implements ToXContentObject {
     private String id;
     private BytesReference source;
diff --git a/server/src/main/java/org/opensearch/action/search/SearchContextIdForNode.java b/server/src/main/java/org/opensearch/action/search/SearchContextIdForNode.java
index 59c0e54bb6cbc..7c702c16030b7 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchContextIdForNode.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchContextIdForNode.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.search;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -43,8 +44,9 @@
 /**
  * Id for a search context per node.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SearchContextIdForNode implements Writeable {
     private final String node;
     private final ShardSearchContextId searchContextId;
diff --git a/server/src/main/java/org/opensearch/action/search/SearchDfsQueryThenFetchAsyncAction.java b/server/src/main/java/org/opensearch/action/search/SearchDfsQueryThenFetchAsyncAction.java
index 31e9a10b9fba3..cad092f884f53 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchDfsQueryThenFetchAsyncAction.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchDfsQueryThenFetchAsyncAction.java
@@ -76,10 +76,11 @@ final class SearchDfsQueryThenFetchAsyncAction extends AbstractSearchAsyncAction
         final TransportSearchAction.SearchTimeProvider timeProvider,
         final ClusterState clusterState,
         final SearchTask task,
-        SearchResponse.Clusters clusters
+        SearchResponse.Clusters clusters,
+        SearchRequestContext searchRequestContext
     ) {
         super(
-            "dfs",
+            SearchPhaseName.DFS_PRE_QUERY.getName(),
             logger,
             searchTransportService,
             nodeIdToConnection,
@@ -95,7 +96,8 @@ final class SearchDfsQueryThenFetchAsyncAction extends AbstractSearchAsyncAction
             task,
             new ArraySearchPhaseResults<>(shardsIts.size()),
             request.getMaxConcurrentShardRequests(),
-            clusters
+            clusters,
+            searchRequestContext
         );
         this.queryPhaseResultConsumer = queryPhaseResultConsumer;
         this.searchPhaseController = searchPhaseController;
diff --git a/server/src/main/java/org/opensearch/action/search/SearchPhase.java b/server/src/main/java/org/opensearch/action/search/SearchPhase.java
index 50b0cd8e01c1d..0890e9f5de8d4 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchPhase.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchPhase.java
@@ -32,6 +32,7 @@
 package org.opensearch.action.search;
 
 import org.opensearch.common.CheckedRunnable;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 import java.util.Locale;
@@ -40,15 +41,26 @@
 /**
  * Base class for all individual search phases like collecting distributed frequencies, fetching documents, querying shards.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
-abstract class SearchPhase implements CheckedRunnable<IOException> {
+@PublicApi(since = "1.0.0")
+public abstract class SearchPhase implements CheckedRunnable<IOException> {
     private final String name;
+    private long startTimeInNanos;
 
     protected SearchPhase(String name) {
         this.name = Objects.requireNonNull(name, "name must not be null");
     }
 
+    public long getStartTimeInNanos() {
+        return startTimeInNanos;
+    }
+
+    public void recordAndRun() throws IOException {
+        this.startTimeInNanos = System.nanoTime();
+        run();
+    }
+
     /**
      * Returns the phases name.
      */
diff --git a/server/src/main/java/org/opensearch/action/search/SearchPhaseContext.java b/server/src/main/java/org/opensearch/action/search/SearchPhaseContext.java
index 4ffd5521793f6..df451e0745e3c 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchPhaseContext.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchPhaseContext.java
@@ -34,6 +34,7 @@
 import org.apache.logging.log4j.Logger;
 import org.opensearch.action.OriginalIndices;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.InternalApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.util.concurrent.AtomicArray;
 import org.opensearch.search.SearchPhaseResult;
@@ -50,6 +51,7 @@
  *
  * @opensearch.internal
  */
+@InternalApi
 public interface SearchPhaseContext extends Executor {
     // TODO maybe we can make this concrete later - for now we just implement this in the base class for all initial phases
 
@@ -73,6 +75,8 @@ public interface SearchPhaseContext extends Executor {
      */
     SearchRequest getRequest();
 
+    SearchPhase getCurrentPhase();
+
     /**
      * Builds and sends the final search response back to the user.
      *
diff --git a/server/src/main/java/org/opensearch/action/search/SearchPhaseController.java b/server/src/main/java/org/opensearch/action/search/SearchPhaseController.java
index cca85f92d2676..161a103cdf36a 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchPhaseController.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchPhaseController.java
@@ -162,7 +162,7 @@ public AggregatedDfs aggregateDfs(Collection<DfsSearchResult> results) {
      * Returns a score doc array of top N search docs across all shards, followed by top suggest docs for each
      * named completion suggestion across all shards. If more than one named completion suggestion is specified in the
      * request, the suggest docs for a named suggestion are ordered by the suggestion name.
-     *
+     * <p>
      * Note: The order of the sorted score docs depends on the shard index in the result array if the merge process needs to disambiguate
      * the result. In oder to obtain stable results the shard index (index of the result in the result array) must be the same.
      *
@@ -284,7 +284,7 @@ public List<Integer>[] fillDocIdsToLoad(int numShards, ScoreDoc[] shardDocs) {
     /**
      * Enriches search hits and completion suggestion hits from <code>sortedDocs</code> using <code>fetchResultsArr</code>,
      * merges suggestions, aggregations and profile results
-     *
+     * <p>
      * Expects sortedDocs to have top search docs across all shards, optionally followed by top suggest docs for each named
      * completion suggestion ordered by suggestion name
      */
diff --git a/server/src/main/java/org/opensearch/action/search/SearchPhaseName.java b/server/src/main/java/org/opensearch/action/search/SearchPhaseName.java
index b6f842cf2cce1..8cf92934c8a52 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchPhaseName.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchPhaseName.java
@@ -8,11 +8,16 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Enum for different Search Phases in OpenSearch
- * @opensearch.internal
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.9.0")
 public enum SearchPhaseName {
+    DFS_PRE_QUERY("dfs_pre_query"),
     QUERY("query"),
     FETCH("fetch"),
     DFS_QUERY("dfs_query"),
diff --git a/server/src/main/java/org/opensearch/action/search/SearchProgressListener.java b/server/src/main/java/org/opensearch/action/search/SearchProgressListener.java
index ffc64682cb07d..34e8aacbad250 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchProgressListener.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchProgressListener.java
@@ -38,6 +38,7 @@
 import org.apache.lucene.search.TotalHits;
 import org.opensearch.action.search.SearchResponse.Clusters;
 import org.opensearch.cluster.routing.GroupShardsIterator;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.SearchPhaseResult;
 import org.opensearch.search.SearchShardTarget;
 import org.opensearch.search.aggregations.InternalAggregations;
@@ -53,6 +54,7 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SearchProgressListener {
     private static final Logger logger = LogManager.getLogger(SearchProgressListener.class);
 
diff --git a/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizer.java b/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizer.java
new file mode 100644
index 0000000000000..8fe1be610f9af
--- /dev/null
+++ b/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizer.java
@@ -0,0 +1,81 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.index.query.QueryBuilder;
+import org.opensearch.index.query.QueryBuilderVisitor;
+import org.opensearch.index.query.QueryShapeVisitor;
+import org.opensearch.search.aggregations.AggregatorFactories;
+import org.opensearch.search.builder.SearchSourceBuilder;
+import org.opensearch.search.sort.SortBuilder;
+import org.opensearch.telemetry.metrics.MetricsRegistry;
+import org.opensearch.telemetry.metrics.tags.Tags;
+
+import java.util.List;
+import java.util.ListIterator;
+
+/**
+ * Class to categorize the search queries based on the type and increment the relevant counters.
+ * Class also logs the query shape.
+ */
+final class SearchQueryCategorizer {
+
+    private static final Logger log = LogManager.getLogger(SearchQueryCategorizer.class);
+
+    final SearchQueryCounters searchQueryCounters;
+
+    public SearchQueryCategorizer(MetricsRegistry metricsRegistry) {
+        searchQueryCounters = new SearchQueryCounters(metricsRegistry);
+    }
+
+    public void categorize(SearchSourceBuilder source) {
+        QueryBuilder topLevelQueryBuilder = source.query();
+
+        logQueryShape(topLevelQueryBuilder);
+        incrementQueryTypeCounters(topLevelQueryBuilder);
+        incrementQueryAggregationCounters(source.aggregations());
+        incrementQuerySortCounters(source.sorts());
+    }
+
+    private void incrementQuerySortCounters(List<SortBuilder<?>> sorts) {
+        if (sorts != null && sorts.size() > 0) {
+            for (ListIterator<SortBuilder<?>> it = sorts.listIterator(); it.hasNext();) {
+                SortBuilder sortBuilder = it.next();
+                String sortOrder = sortBuilder.order().toString();
+                searchQueryCounters.sortCounter.add(1, Tags.create().addTag("sort_order", sortOrder));
+            }
+        }
+    }
+
+    private void incrementQueryAggregationCounters(AggregatorFactories.Builder aggregations) {
+        if (aggregations != null) {
+            searchQueryCounters.aggCounter.add(1);
+        }
+    }
+
+    private void incrementQueryTypeCounters(QueryBuilder topLevelQueryBuilder) {
+        if (topLevelQueryBuilder == null) {
+            return;
+        }
+        QueryBuilderVisitor searchQueryVisitor = new SearchQueryCategorizingVisitor(searchQueryCounters);
+        topLevelQueryBuilder.visit(searchQueryVisitor);
+    }
+
+    private void logQueryShape(QueryBuilder topLevelQueryBuilder) {
+        if (topLevelQueryBuilder == null) {
+            return;
+        }
+        QueryShapeVisitor shapeVisitor = new QueryShapeVisitor();
+        topLevelQueryBuilder.visit(shapeVisitor);
+        log.trace("Query shape : {}", shapeVisitor.prettyPrintTree("  "));
+    }
+
+}
diff --git a/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizingVisitor.java b/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizingVisitor.java
new file mode 100644
index 0000000000000..98f0169e69a5c
--- /dev/null
+++ b/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizingVisitor.java
@@ -0,0 +1,73 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.apache.lucene.search.BooleanClause;
+import org.opensearch.index.query.BoolQueryBuilder;
+import org.opensearch.index.query.MatchPhraseQueryBuilder;
+import org.opensearch.index.query.MatchQueryBuilder;
+import org.opensearch.index.query.MultiMatchQueryBuilder;
+import org.opensearch.index.query.QueryBuilder;
+import org.opensearch.index.query.QueryBuilderVisitor;
+import org.opensearch.index.query.QueryStringQueryBuilder;
+import org.opensearch.index.query.RangeQueryBuilder;
+import org.opensearch.index.query.RegexpQueryBuilder;
+import org.opensearch.index.query.TermQueryBuilder;
+import org.opensearch.index.query.WildcardQueryBuilder;
+import org.opensearch.index.query.functionscore.FunctionScoreQueryBuilder;
+import org.opensearch.telemetry.metrics.tags.Tags;
+
+/**
+ * Class to visit the querybuilder tree and also track the level information.
+ * Increments the counters related to Search Query type.
+ */
+final class SearchQueryCategorizingVisitor implements QueryBuilderVisitor {
+    private static final String LEVEL_TAG = "level";
+    private final int level;
+    private final SearchQueryCounters searchQueryCounters;
+
+    public SearchQueryCategorizingVisitor(SearchQueryCounters searchQueryCounters) {
+        this(searchQueryCounters, 0);
+    }
+
+    private SearchQueryCategorizingVisitor(SearchQueryCounters counters, int level) {
+        this.searchQueryCounters = counters;
+        this.level = level;
+    }
+
+    public void accept(QueryBuilder qb) {
+        if (qb instanceof BoolQueryBuilder) {
+            searchQueryCounters.boolCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof FunctionScoreQueryBuilder) {
+            searchQueryCounters.functionScoreCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof MatchQueryBuilder) {
+            searchQueryCounters.matchCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof MatchPhraseQueryBuilder) {
+            searchQueryCounters.matchPhrasePrefixCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof MultiMatchQueryBuilder) {
+            searchQueryCounters.multiMatchCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof QueryStringQueryBuilder) {
+            searchQueryCounters.queryStringQueryCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof RangeQueryBuilder) {
+            searchQueryCounters.rangeCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof RegexpQueryBuilder) {
+            searchQueryCounters.regexCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof TermQueryBuilder) {
+            searchQueryCounters.termCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else if (qb instanceof WildcardQueryBuilder) {
+            searchQueryCounters.wildcardCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        } else {
+            searchQueryCounters.otherQueryCounter.add(1, Tags.create().addTag(LEVEL_TAG, level));
+        }
+    }
+
+    public QueryBuilderVisitor getChildVisitor(BooleanClause.Occur occur) {
+        return new SearchQueryCategorizingVisitor(searchQueryCounters, level + 1);
+    }
+}
diff --git a/server/src/main/java/org/opensearch/action/search/SearchQueryCounters.java b/server/src/main/java/org/opensearch/action/search/SearchQueryCounters.java
new file mode 100644
index 0000000000000..7e0259af07701
--- /dev/null
+++ b/server/src/main/java/org/opensearch/action/search/SearchQueryCounters.java
@@ -0,0 +1,117 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.opensearch.telemetry.metrics.Counter;
+import org.opensearch.telemetry.metrics.MetricsRegistry;
+
+/**
+ * Class contains all the Counters related to search query types.
+ */
+final class SearchQueryCounters {
+    private static final String UNIT = "1";
+    private final MetricsRegistry metricsRegistry;
+
+    // Counters related to Query types
+    public final Counter aggCounter;
+    public final Counter boolCounter;
+    public final Counter functionScoreCounter;
+    public final Counter matchCounter;
+    public final Counter matchPhrasePrefixCounter;
+    public final Counter multiMatchCounter;
+    public final Counter otherQueryCounter;
+    public final Counter queryStringQueryCounter;
+    public final Counter rangeCounter;
+    public final Counter regexCounter;
+
+    public final Counter sortCounter;
+    public final Counter skippedCounter;
+    public final Counter termCounter;
+    public final Counter totalCounter;
+    public final Counter wildcardCounter;
+
+    public SearchQueryCounters(MetricsRegistry metricsRegistry) {
+        this.metricsRegistry = metricsRegistry;
+        this.aggCounter = metricsRegistry.createCounter(
+            "search.query.type.agg.count",
+            "Counter for the number of top level agg search queries",
+            UNIT
+        );
+        this.boolCounter = metricsRegistry.createCounter(
+            "search.query.type.bool.count",
+            "Counter for the number of top level and nested bool search queries",
+            UNIT
+        );
+        this.functionScoreCounter = metricsRegistry.createCounter(
+            "search.query.type.functionscore.count",
+            "Counter for the number of top level and nested function score search queries",
+            UNIT
+        );
+        this.matchCounter = metricsRegistry.createCounter(
+            "search.query.type.match.count",
+            "Counter for the number of top level and nested match search queries",
+            UNIT
+        );
+        this.matchPhrasePrefixCounter = metricsRegistry.createCounter(
+            "search.query.type.matchphrase.count",
+            "Counter for the number of top level and nested match phrase prefix search queries",
+            UNIT
+        );
+        this.multiMatchCounter = metricsRegistry.createCounter(
+            "search.query.type.multimatch.count",
+            "Counter for the number of top level and nested multi match search queries",
+            UNIT
+        );
+        this.otherQueryCounter = metricsRegistry.createCounter(
+            "search.query.type.other.count",
+            "Counter for the number of top level and nested search queries that do not match any other categories",
+            UNIT
+        );
+        this.queryStringQueryCounter = metricsRegistry.createCounter(
+            "search.query.type.querystringquery.count",
+            "Counter for the number of top level and nested queryStringQuery search queries",
+            UNIT
+        );
+        this.rangeCounter = metricsRegistry.createCounter(
+            "search.query.type.range.count",
+            "Counter for the number of top level and nested range search queries",
+            UNIT
+        );
+        this.regexCounter = metricsRegistry.createCounter(
+            "search.query.type.regex.count",
+            "Counter for the number of top level and nested regex search queries",
+            UNIT
+        );
+        this.skippedCounter = metricsRegistry.createCounter(
+            "search.query.type.skipped.count",
+            "Counter for the number queries skipped due to error",
+            UNIT
+        );
+        this.sortCounter = metricsRegistry.createCounter(
+            "search.query.type.sort.count",
+            "Counter for the number of top level sort search queries",
+            UNIT
+        );
+        this.termCounter = metricsRegistry.createCounter(
+            "search.query.type.term.count",
+            "Counter for the number of top level and nested term search queries",
+            UNIT
+        );
+        this.totalCounter = metricsRegistry.createCounter(
+            "search.query.type.total.count",
+            "Counter for the number of top level and nested search queries",
+            UNIT
+        );
+        this.wildcardCounter = metricsRegistry.createCounter(
+            "search.query.type.wildcard.count",
+            "Counter for the number of top level and nested wildcard search queries",
+            UNIT
+        );
+    }
+}
diff --git a/server/src/main/java/org/opensearch/action/search/SearchQueryThenFetchAsyncAction.java b/server/src/main/java/org/opensearch/action/search/SearchQueryThenFetchAsyncAction.java
index f75ab2554e693..c26bd5eef8c15 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchQueryThenFetchAsyncAction.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchQueryThenFetchAsyncAction.java
@@ -81,10 +81,11 @@ class SearchQueryThenFetchAsyncAction extends AbstractSearchAsyncAction<SearchPh
         final TransportSearchAction.SearchTimeProvider timeProvider,
         ClusterState clusterState,
         SearchTask task,
-        SearchResponse.Clusters clusters
+        SearchResponse.Clusters clusters,
+        SearchRequestContext searchRequestContext
     ) {
         super(
-            "query",
+            SearchPhaseName.QUERY.getName(),
             logger,
             searchTransportService,
             nodeIdToConnection,
@@ -100,7 +101,8 @@ class SearchQueryThenFetchAsyncAction extends AbstractSearchAsyncAction<SearchPh
             task,
             resultConsumer,
             request.getMaxConcurrentShardRequests(),
-            clusters
+            clusters,
+            searchRequestContext
         );
         this.topDocsSize = SearchPhaseController.getTopDocsSize(request);
         this.trackTotalHitsUpTo = request.resolveTrackTotalHitsUpTo();
diff --git a/server/src/main/java/org/opensearch/action/search/SearchRequest.java b/server/src/main/java/org/opensearch/action/search/SearchRequest.java
index 762022460ebdb..96cea17ff4972 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchRequest.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.IndicesRequest;
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -69,8 +70,9 @@
  * @see org.opensearch.client.Client#search(SearchRequest)
  * @see SearchResponse
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchRequest extends ActionRequest implements IndicesRequest.Replaceable {
 
     public static final ToXContent.Params FORMAT_PARAMS = new ToXContent.MapParams(Collections.singletonMap("pretty", "false"));
@@ -117,6 +119,8 @@ public class SearchRequest extends ActionRequest implements IndicesRequest.Repla
 
     private String pipeline;
 
+    private Boolean phaseTook = null;
+
     public SearchRequest() {
         this.localClusterAlias = null;
         this.absoluteStartMillis = DEFAULT_ABSOLUTE_START_MILLIS;
@@ -209,6 +213,7 @@ private SearchRequest(
         this.absoluteStartMillis = absoluteStartMillis;
         this.finalReduce = finalReduce;
         this.cancelAfterTimeInterval = searchRequest.cancelAfterTimeInterval;
+        this.phaseTook = searchRequest.phaseTook;
     }
 
     /**
@@ -253,6 +258,9 @@ public SearchRequest(StreamInput in) throws IOException {
         if (in.getVersion().onOrAfter(Version.V_2_7_0)) {
             pipeline = in.readOptionalString();
         }
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            phaseTook = in.readOptionalBoolean();
+        }
     }
 
     @Override
@@ -284,6 +292,9 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().onOrAfter(Version.V_2_7_0)) {
             out.writeOptionalString(pipeline);
         }
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeOptionalBoolean(phaseTook);
+        }
     }
 
     @Override
@@ -600,7 +611,7 @@ public void setMaxConcurrentShardRequests(int maxConcurrentShardRequests) {
      * the search request expands to exceeds the threshold. This filter roundtrip can limit the number of shards significantly if for
      * instance a shard can not match any documents based on its rewrite method ie. if date filters are mandatory to match but the shard
      * bounds and the query are disjoint.
-     *
+     * <p>
      * When unspecified, the pre-filter phase is executed if any of these conditions is met:
      * <ul>
      * <li>The request targets more than 128 shards</li>
@@ -615,13 +626,27 @@ public void setPreFilterShardSize(int preFilterShardSize) {
         this.preFilterShardSize = preFilterShardSize;
     }
 
+    /**
+     * Returns value of user-provided phase_took query parameter for this search request.
+     */
+    public Boolean isPhaseTook() {
+        return phaseTook;
+    }
+
+    /**
+     * Sets value of phase_took query param if provided by user. Defaults to <code>null</code>.
+     */
+    public void setPhaseTook(Boolean phaseTook) {
+        this.phaseTook = phaseTook;
+    }
+
     /**
      * Returns a threshold that enforces a pre-filter roundtrip to pre-filter search shards based on query rewriting if the number of shards
      * the search request expands to exceeds the threshold, or <code>null</code> if the threshold is unspecified.
      * This filter roundtrip can limit the number of shards significantly if for
      * instance a shard can not match any documents based on its rewrite method ie. if date filters are mandatory to match but the shard
      * bounds and the query are disjoint.
-     *
+     * <p>
      * When unspecified, the pre-filter phase is executed if any of these conditions is met:
      * <ul>
      * <li>The request targets more than 128 shards</li>
@@ -719,7 +744,8 @@ public boolean equals(Object o) {
             && absoluteStartMillis == that.absoluteStartMillis
             && ccsMinimizeRoundtrips == that.ccsMinimizeRoundtrips
             && Objects.equals(cancelAfterTimeInterval, that.cancelAfterTimeInterval)
-            && Objects.equals(pipeline, that.pipeline);
+            && Objects.equals(pipeline, that.pipeline)
+            && Objects.equals(phaseTook, that.phaseTook);
     }
 
     @Override
@@ -740,7 +766,8 @@ public int hashCode() {
             localClusterAlias,
             absoluteStartMillis,
             ccsMinimizeRoundtrips,
-            cancelAfterTimeInterval
+            cancelAfterTimeInterval,
+            phaseTook
         );
     }
 
@@ -783,6 +810,8 @@ public String toString() {
             + cancelAfterTimeInterval
             + ", pipeline="
             + pipeline
+            + ", phaseTook="
+            + phaseTook
             + "}";
     }
 }
diff --git a/server/src/main/java/org/opensearch/action/search/SearchRequestBuilder.java b/server/src/main/java/org/opensearch/action/search/SearchRequestBuilder.java
index 861e1df0203d7..e949c5e0bea29 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchRequestBuilder.java
@@ -36,6 +36,7 @@
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.index.query.QueryBuilder;
 import org.opensearch.script.Script;
@@ -58,8 +59,9 @@
 /**
  * A search action request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchRequestBuilder extends ActionRequestBuilder<SearchRequest, SearchResponse> {
 
     public SearchRequestBuilder(OpenSearchClient client, SearchAction action) {
@@ -605,7 +607,7 @@ public SearchRequestBuilder setMaxConcurrentShardRequests(int maxConcurrentShard
      * the search request expands to exceeds the threshold. This filter roundtrip can limit the number of shards significantly if for
      * instance a shard can not match any documents based on its rewrite method ie. if date filters are mandatory to match but the shard
      * bounds and the query are disjoint.
-     *
+     * <p>
      * When unspecified, the pre-filter phase is executed if any of these conditions is met:
      * <ul>
      * <li>The request targets more than 128 shards</li>
diff --git a/server/src/main/java/org/opensearch/action/search/SearchRequestContext.java b/server/src/main/java/org/opensearch/action/search/SearchRequestContext.java
new file mode 100644
index 0000000000000..674363600b251
--- /dev/null
+++ b/server/src/main/java/org/opensearch/action/search/SearchRequestContext.java
@@ -0,0 +1,126 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.lucene.search.TotalHits;
+import org.opensearch.common.annotation.InternalApi;
+
+import java.util.EnumMap;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * This class holds request-level context for search queries at the coordinator node
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+class SearchRequestContext {
+    private final SearchRequestOperationsListener searchRequestOperationsListener;
+    private long absoluteStartNanos;
+    private final Map<String, Long> phaseTookMap;
+    private TotalHits totalHits;
+    private final EnumMap<ShardStatsFieldNames, Integer> shardStats;
+
+    /**
+     * This constructor is for testing only
+     */
+    SearchRequestContext() {
+        this(new SearchRequestOperationsListener.CompositeListener(List.of(), LogManager.getLogger()));
+    }
+
+    SearchRequestContext(SearchRequestOperationsListener searchRequestOperationsListener) {
+        this.searchRequestOperationsListener = searchRequestOperationsListener;
+        this.absoluteStartNanos = System.nanoTime();
+        this.phaseTookMap = new HashMap<>();
+        this.shardStats = new EnumMap<>(ShardStatsFieldNames.class);
+    }
+
+    SearchRequestOperationsListener getSearchRequestOperationsListener() {
+        return searchRequestOperationsListener;
+    }
+
+    void updatePhaseTookMap(String phaseName, Long tookTime) {
+        this.phaseTookMap.put(phaseName, tookTime);
+    }
+
+    Map<String, Long> phaseTookMap() {
+        return phaseTookMap;
+    }
+
+    /**
+     * Override absoluteStartNanos set in constructor.
+     * For testing only
+     */
+    void setAbsoluteStartNanos(long absoluteStartNanos) {
+        this.absoluteStartNanos = absoluteStartNanos;
+    }
+
+    /**
+     * Request start time in nanos
+     */
+    long getAbsoluteStartNanos() {
+        return absoluteStartNanos;
+    }
+
+    void setTotalHits(TotalHits totalHits) {
+        this.totalHits = totalHits;
+    }
+
+    TotalHits totalHits() {
+        return totalHits;
+    }
+
+    void setShardStats(int total, int successful, int skipped, int failed) {
+        this.shardStats.put(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_TOTAL, total);
+        this.shardStats.put(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_SUCCESSFUL, successful);
+        this.shardStats.put(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_SKIPPED, skipped);
+        this.shardStats.put(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_FAILED, failed);
+    }
+
+    String formattedShardStats() {
+        if (shardStats.isEmpty()) {
+            return "";
+        } else {
+            return String.format(
+                Locale.ROOT,
+                "{%s:%s, %s:%s, %s:%s, %s:%s}",
+                ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_TOTAL.toString(),
+                shardStats.get(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_TOTAL),
+                ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_SUCCESSFUL.toString(),
+                shardStats.get(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_SUCCESSFUL),
+                ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_SKIPPED.toString(),
+                shardStats.get(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_SKIPPED),
+                ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_FAILED.toString(),
+                shardStats.get(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_FAILED)
+            );
+        }
+    }
+}
+
+enum ShardStatsFieldNames {
+    SEARCH_REQUEST_SLOWLOG_SHARD_TOTAL("total"),
+    SEARCH_REQUEST_SLOWLOG_SHARD_SUCCESSFUL("successful"),
+    SEARCH_REQUEST_SLOWLOG_SHARD_SKIPPED("skipped"),
+    SEARCH_REQUEST_SLOWLOG_SHARD_FAILED("failed");
+
+    private final String name;
+
+    ShardStatsFieldNames(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return this.name;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/action/search/SearchRequestOperationsListener.java b/server/src/main/java/org/opensearch/action/search/SearchRequestOperationsListener.java
new file mode 100644
index 0000000000000..19ce0beb3c493
--- /dev/null
+++ b/server/src/main/java/org/opensearch/action/search/SearchRequestOperationsListener.java
@@ -0,0 +1,105 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.opensearch.common.annotation.InternalApi;
+
+import java.util.List;
+
+/**
+ * A listener for search, fetch and context events at the coordinator node level
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+abstract class SearchRequestOperationsListener {
+
+    abstract void onPhaseStart(SearchPhaseContext context);
+
+    abstract void onPhaseEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext);
+
+    abstract void onPhaseFailure(SearchPhaseContext context);
+
+    void onRequestStart(SearchRequestContext searchRequestContext) {}
+
+    void onRequestEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {}
+
+    /**
+     * Holder of Composite Listeners
+     *
+     * @opensearch.internal
+     */
+
+    static final class CompositeListener extends SearchRequestOperationsListener {
+        private final List<SearchRequestOperationsListener> listeners;
+        private final Logger logger;
+
+        CompositeListener(List<SearchRequestOperationsListener> listeners, Logger logger) {
+            this.listeners = listeners;
+            this.logger = logger;
+        }
+
+        @Override
+        void onPhaseStart(SearchPhaseContext context) {
+            for (SearchRequestOperationsListener listener : listeners) {
+                try {
+                    listener.onPhaseStart(context);
+                } catch (Exception e) {
+                    logger.warn(() -> new ParameterizedMessage("onPhaseStart listener [{}] failed", listener), e);
+                }
+            }
+        }
+
+        @Override
+        void onPhaseEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {
+            for (SearchRequestOperationsListener listener : listeners) {
+                try {
+                    listener.onPhaseEnd(context, searchRequestContext);
+                } catch (Exception e) {
+                    logger.warn(() -> new ParameterizedMessage("onPhaseEnd listener [{}] failed", listener), e);
+                }
+            }
+        }
+
+        @Override
+        void onPhaseFailure(SearchPhaseContext context) {
+            for (SearchRequestOperationsListener listener : listeners) {
+                try {
+                    listener.onPhaseFailure(context);
+                } catch (Exception e) {
+                    logger.warn(() -> new ParameterizedMessage("onPhaseFailure listener [{}] failed", listener), e);
+                }
+            }
+        }
+
+        @Override
+        void onRequestStart(SearchRequestContext searchRequestContext) {
+            for (SearchRequestOperationsListener listener : listeners) {
+                try {
+                    listener.onRequestStart(searchRequestContext);
+                } catch (Exception e) {
+                    logger.warn(() -> new ParameterizedMessage("onRequestStart listener [{}] failed", listener), e);
+                }
+            }
+        }
+
+        @Override
+        public void onRequestEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {
+            for (SearchRequestOperationsListener listener : listeners) {
+                try {
+                    listener.onRequestEnd(context, searchRequestContext);
+                } catch (Exception e) {
+                    logger.warn(() -> new ParameterizedMessage("onRequestEnd listener [{}] failed", listener), e);
+                }
+            }
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/action/search/SearchRequestSlowLog.java b/server/src/main/java/org/opensearch/action/search/SearchRequestSlowLog.java
new file mode 100644
index 0000000000000..a55cfd463a78f
--- /dev/null
+++ b/server/src/main/java/org/opensearch/action/search/SearchRequestSlowLog.java
@@ -0,0 +1,273 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.action.search;
+
+import com.fasterxml.jackson.core.io.JsonStringEncoder;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.logging.Loggers;
+import org.opensearch.common.logging.OpenSearchLogMessage;
+import org.opensearch.common.logging.SlowLogLevel;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.tasks.Task;
+
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * The request-level search slow log implementation
+ *
+ * @opensearch.internal
+ */
+public final class SearchRequestSlowLog extends SearchRequestOperationsListener {
+    private static final Charset UTF_8 = StandardCharsets.UTF_8;
+
+    private long warnThreshold;
+    private long infoThreshold;
+    private long debugThreshold;
+    private long traceThreshold;
+    private SlowLogLevel level;
+
+    private final Logger logger;
+
+    static final String CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX = "cluster.search.request.slowlog";
+
+    public static final Setting<TimeValue> CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING = Setting.timeSetting(
+        CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX + ".threshold.warn",
+        TimeValue.timeValueNanos(-1),
+        TimeValue.timeValueMillis(-1),
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+    public static final Setting<TimeValue> CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING = Setting.timeSetting(
+        CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX + ".threshold.info",
+        TimeValue.timeValueNanos(-1),
+        TimeValue.timeValueMillis(-1),
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+    public static final Setting<TimeValue> CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING = Setting.timeSetting(
+        CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX + ".threshold.debug",
+        TimeValue.timeValueNanos(-1),
+        TimeValue.timeValueMillis(-1),
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+    public static final Setting<TimeValue> CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING = Setting.timeSetting(
+        CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX + ".threshold.trace",
+        TimeValue.timeValueNanos(-1),
+        TimeValue.timeValueMillis(-1),
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+    public static final Setting<SlowLogLevel> CLUSTER_SEARCH_REQUEST_SLOWLOG_LEVEL = new Setting<>(
+        CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX + ".level",
+        SlowLogLevel.TRACE.name(),
+        SlowLogLevel::parse,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    private static final ToXContent.Params FORMAT_PARAMS = new ToXContent.MapParams(Collections.singletonMap("pretty", "false"));
+
+    public SearchRequestSlowLog(ClusterService clusterService) {
+        this(clusterService, LogManager.getLogger(CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX)); // logger configured in log4j2.properties
+    }
+
+    SearchRequestSlowLog(ClusterService clusterService, Logger logger) {
+        this.logger = logger;
+        Loggers.setLevel(this.logger, SlowLogLevel.TRACE.name());
+
+        this.warnThreshold = clusterService.getClusterSettings().get(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING).nanos();
+        this.infoThreshold = clusterService.getClusterSettings().get(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING).nanos();
+        this.debugThreshold = clusterService.getClusterSettings().get(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING).nanos();
+        this.traceThreshold = clusterService.getClusterSettings().get(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING).nanos();
+        this.level = clusterService.getClusterSettings().get(CLUSTER_SEARCH_REQUEST_SLOWLOG_LEVEL);
+
+        clusterService.getClusterSettings()
+            .addSettingsUpdateConsumer(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING, this::setWarnThreshold);
+        clusterService.getClusterSettings()
+            .addSettingsUpdateConsumer(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING, this::setInfoThreshold);
+        clusterService.getClusterSettings()
+            .addSettingsUpdateConsumer(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING, this::setDebugThreshold);
+        clusterService.getClusterSettings()
+            .addSettingsUpdateConsumer(CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING, this::setTraceThreshold);
+        clusterService.getClusterSettings().addSettingsUpdateConsumer(CLUSTER_SEARCH_REQUEST_SLOWLOG_LEVEL, this::setLevel);
+    }
+
+    @Override
+    void onPhaseStart(SearchPhaseContext context) {}
+
+    @Override
+    void onPhaseEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {}
+
+    @Override
+    void onPhaseFailure(SearchPhaseContext context) {}
+
+    @Override
+    void onRequestStart(SearchRequestContext searchRequestContext) {}
+
+    @Override
+    void onRequestEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {
+        long tookInNanos = System.nanoTime() - searchRequestContext.getAbsoluteStartNanos();
+
+        if (warnThreshold >= 0 && tookInNanos > warnThreshold && level.isLevelEnabledFor(SlowLogLevel.WARN)) {
+            logger.warn(new SearchRequestSlowLogMessage(context, tookInNanos, searchRequestContext));
+        } else if (infoThreshold >= 0 && tookInNanos > infoThreshold && level.isLevelEnabledFor(SlowLogLevel.INFO)) {
+            logger.info(new SearchRequestSlowLogMessage(context, tookInNanos, searchRequestContext));
+        } else if (debugThreshold >= 0 && tookInNanos > debugThreshold && level.isLevelEnabledFor(SlowLogLevel.DEBUG)) {
+            logger.debug(new SearchRequestSlowLogMessage(context, tookInNanos, searchRequestContext));
+        } else if (traceThreshold >= 0 && tookInNanos > traceThreshold && level.isLevelEnabledFor(SlowLogLevel.TRACE)) {
+            logger.trace(new SearchRequestSlowLogMessage(context, tookInNanos, searchRequestContext));
+        }
+    }
+
+    /**
+     * Search request slow log message
+     *
+     * @opensearch.internal
+     */
+    static final class SearchRequestSlowLogMessage extends OpenSearchLogMessage {
+
+        SearchRequestSlowLogMessage(SearchPhaseContext context, long tookInNanos, SearchRequestContext searchRequestContext) {
+            super(prepareMap(context, tookInNanos, searchRequestContext), message(context, tookInNanos, searchRequestContext));
+        }
+
+        private static Map<String, Object> prepareMap(
+            SearchPhaseContext context,
+            long tookInNanos,
+            SearchRequestContext searchRequestContext
+        ) {
+            final Map<String, Object> messageFields = new HashMap<>();
+            messageFields.put("took", TimeValue.timeValueNanos(tookInNanos));
+            messageFields.put("took_millis", TimeUnit.NANOSECONDS.toMillis(tookInNanos));
+            messageFields.put("phase_took", searchRequestContext.phaseTookMap().toString());
+            if (searchRequestContext.totalHits() != null) {
+                messageFields.put("total_hits", searchRequestContext.totalHits());
+            } else {
+                messageFields.put("total_hits", "-1");
+            }
+            messageFields.put("search_type", context.getRequest().searchType());
+            messageFields.put("shards", searchRequestContext.formattedShardStats());
+
+            if (context.getRequest().source() != null) {
+                String source = escapeJson(context.getRequest().source().toString(FORMAT_PARAMS));
+                messageFields.put("source", source);
+            } else {
+                messageFields.put("source", "{}");
+            }
+
+            messageFields.put("id", context.getTask().getHeader(Task.X_OPAQUE_ID));
+            return messageFields;
+        }
+
+        // Message will be used in plaintext logs
+        private static String message(SearchPhaseContext context, long tookInNanos, SearchRequestContext searchRequestContext) {
+            final StringBuilder sb = new StringBuilder();
+            sb.append("took[").append(TimeValue.timeValueNanos(tookInNanos)).append("], ");
+            sb.append("took_millis[").append(TimeUnit.NANOSECONDS.toMillis(tookInNanos)).append("], ");
+            sb.append("phase_took_millis[").append(searchRequestContext.phaseTookMap().toString()).append("], ");
+            if (searchRequestContext.totalHits() != null) {
+                sb.append("total_hits[").append(searchRequestContext.totalHits()).append("], ");
+            } else {
+                sb.append("total_hits[-1]");
+            }
+            sb.append("search_type[").append(context.getRequest().searchType()).append("], ");
+            sb.append("shards[").append(searchRequestContext.formattedShardStats()).append("], ");
+            if (context.getRequest().source() != null) {
+                sb.append("source[").append(context.getRequest().source().toString(FORMAT_PARAMS)).append("], ");
+            } else {
+                sb.append("source[], ");
+            }
+            if (context.getTask().getHeader(Task.X_OPAQUE_ID) != null) {
+                sb.append("id[").append(context.getTask().getHeader(Task.X_OPAQUE_ID)).append("]");
+            } else {
+                sb.append("id[]");
+            }
+            return sb.toString();
+        }
+
+        private static String escapeJson(String text) {
+            byte[] sourceEscaped = JsonStringEncoder.getInstance().quoteAsUTF8(text);
+            return new String(sourceEscaped, UTF_8);
+        }
+    }
+
+    void setWarnThreshold(TimeValue warnThreshold) {
+        this.warnThreshold = warnThreshold.nanos();
+    }
+
+    void setInfoThreshold(TimeValue infoThreshold) {
+        this.infoThreshold = infoThreshold.nanos();
+    }
+
+    void setDebugThreshold(TimeValue debugThreshold) {
+        this.debugThreshold = debugThreshold.nanos();
+    }
+
+    void setTraceThreshold(TimeValue traceThreshold) {
+        this.traceThreshold = traceThreshold.nanos();
+    }
+
+    void setLevel(SlowLogLevel level) {
+        this.level = level;
+    }
+
+    protected long getWarnThreshold() {
+        return warnThreshold;
+    }
+
+    protected long getInfoThreshold() {
+        return infoThreshold;
+    }
+
+    protected long getDebugThreshold() {
+        return debugThreshold;
+    }
+
+    protected long getTraceThreshold() {
+        return traceThreshold;
+    }
+
+    SlowLogLevel getLevel() {
+        return level;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/action/search/SearchRequestStats.java b/server/src/main/java/org/opensearch/action/search/SearchRequestStats.java
new file mode 100644
index 0000000000000..262750849eaa9
--- /dev/null
+++ b/server/src/main/java/org/opensearch/action/search/SearchRequestStats.java
@@ -0,0 +1,77 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.common.inject.Inject;
+import org.opensearch.common.metrics.CounterMetric;
+import org.opensearch.common.metrics.MeanMetric;
+
+import java.util.EnumMap;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Request level search stats to track coordinator level node search latencies
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "2.11.0")
+public final class SearchRequestStats extends SearchRequestOperationsListener {
+    Map<SearchPhaseName, StatsHolder> phaseStatsMap = new EnumMap<>(SearchPhaseName.class);
+
+    @Inject
+    public SearchRequestStats() {
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            phaseStatsMap.put(searchPhaseName, new StatsHolder());
+        }
+    }
+
+    public long getPhaseCurrent(SearchPhaseName searchPhaseName) {
+        return phaseStatsMap.get(searchPhaseName).current.count();
+    }
+
+    public long getPhaseTotal(SearchPhaseName searchPhaseName) {
+        return phaseStatsMap.get(searchPhaseName).total.count();
+    }
+
+    public long getPhaseMetric(SearchPhaseName searchPhaseName) {
+        return phaseStatsMap.get(searchPhaseName).timing.sum();
+    }
+
+    @Override
+    void onPhaseStart(SearchPhaseContext context) {
+        phaseStatsMap.get(context.getCurrentPhase().getSearchPhaseName()).current.inc();
+    }
+
+    @Override
+    void onPhaseEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {
+        StatsHolder phaseStats = phaseStatsMap.get(context.getCurrentPhase().getSearchPhaseName());
+        phaseStats.current.dec();
+        phaseStats.total.inc();
+        phaseStats.timing.inc(TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - context.getCurrentPhase().getStartTimeInNanos()));
+    }
+
+    @Override
+    void onPhaseFailure(SearchPhaseContext context) {
+        phaseStatsMap.get(context.getCurrentPhase().getSearchPhaseName()).current.dec();
+    }
+
+    /**
+     * Holder of statistics values
+     *
+     * @opensearch.internal
+     */
+
+    public static final class StatsHolder {
+        CounterMetric current = new CounterMetric();
+        CounterMetric total = new CounterMetric();
+        MeanMetric timing = new MeanMetric();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/action/search/SearchResponse.java b/server/src/main/java/org/opensearch/action/search/SearchResponse.java
index a546311a1f668..899c71e91e3ab 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchResponse.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchResponse.java
@@ -33,7 +33,9 @@
 package org.opensearch.action.search;
 
 import org.apache.lucene.search.TotalHits;
+import org.opensearch.Version;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.StatusToXContentObject;
 import org.opensearch.core.ParseField;
@@ -63,7 +65,9 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.function.Supplier;
@@ -74,8 +78,9 @@
 /**
  * A response of a search request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchResponse extends ActionResponse implements StatusToXContentObject {
 
     private static final ParseField SCROLL_ID = new ParseField("_scroll_id");
@@ -94,6 +99,7 @@ public class SearchResponse extends ActionResponse implements StatusToXContentOb
     private final ShardSearchFailure[] shardFailures;
     private final Clusters clusters;
     private final long tookInMillis;
+    private final PhaseTook phaseTook;
 
     public SearchResponse(StreamInput in) throws IOException {
         super(in);
@@ -112,6 +118,11 @@ public SearchResponse(StreamInput in) throws IOException {
         clusters = new Clusters(in);
         scrollId = in.readOptionalString();
         tookInMillis = in.readVLong();
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            phaseTook = in.readOptionalWriteable(PhaseTook::new);
+        } else {
+            phaseTook = null;
+        }
         skippedShards = in.readVInt();
         pointInTimeId = in.readOptionalString();
     }
@@ -126,7 +137,32 @@ public SearchResponse(
         ShardSearchFailure[] shardFailures,
         Clusters clusters
     ) {
-        this(internalResponse, scrollId, totalShards, successfulShards, skippedShards, tookInMillis, shardFailures, clusters, null);
+        this(internalResponse, scrollId, totalShards, successfulShards, skippedShards, tookInMillis, null, shardFailures, clusters, null);
+    }
+
+    public SearchResponse(
+        SearchResponseSections internalResponse,
+        String scrollId,
+        int totalShards,
+        int successfulShards,
+        int skippedShards,
+        long tookInMillis,
+        ShardSearchFailure[] shardFailures,
+        Clusters clusters,
+        String pointInTimeId
+    ) {
+        this(
+            internalResponse,
+            scrollId,
+            totalShards,
+            successfulShards,
+            skippedShards,
+            tookInMillis,
+            null,
+            shardFailures,
+            clusters,
+            pointInTimeId
+        );
     }
 
     public SearchResponse(
@@ -136,6 +172,7 @@ public SearchResponse(
         int successfulShards,
         int skippedShards,
         long tookInMillis,
+        PhaseTook phaseTook,
         ShardSearchFailure[] shardFailures,
         Clusters clusters,
         String pointInTimeId
@@ -148,6 +185,7 @@ public SearchResponse(
         this.successfulShards = successfulShards;
         this.skippedShards = skippedShards;
         this.tookInMillis = tookInMillis;
+        this.phaseTook = phaseTook;
         this.shardFailures = shardFailures;
         assert skippedShards <= totalShards : "skipped: " + skippedShards + " total: " + totalShards;
         assert scrollId == null || pointInTimeId == null : "SearchResponse can't have both scrollId ["
@@ -210,6 +248,13 @@ public TimeValue getTook() {
         return new TimeValue(tookInMillis);
     }
 
+    /**
+     * How long the request took in each search phase.
+     */
+    public PhaseTook getPhaseTook() {
+        return phaseTook;
+    }
+
     /**
      * The total number of shards the search was executed on.
      */
@@ -298,6 +343,9 @@ public XContentBuilder innerToXContent(XContentBuilder builder, Params params) t
             builder.field(POINT_IN_TIME_ID.getPreferredName(), pointInTimeId);
         }
         builder.field(TOOK.getPreferredName(), tookInMillis);
+        if (phaseTook != null) {
+            phaseTook.toXContent(builder, params);
+        }
         builder.field(TIMED_OUT.getPreferredName(), isTimedOut());
         if (isTerminatedEarly() != null) {
             builder.field(TERMINATED_EARLY.getPreferredName(), isTerminatedEarly());
@@ -337,6 +385,7 @@ public static SearchResponse innerFromXContent(XContentParser parser) throws IOE
         Boolean terminatedEarly = null;
         int numReducePhases = 1;
         long tookInMillis = -1;
+        PhaseTook phaseTook = null;
         int successfulShards = -1;
         int totalShards = -1;
         int skippedShards = 0; // 0 for BWC
@@ -401,6 +450,24 @@ public static SearchResponse innerFromXContent(XContentParser parser) throws IOE
                             parser.skipChildren();
                         }
                     }
+                } else if (PhaseTook.PHASE_TOOK.match(currentFieldName, parser.getDeprecationHandler())) {
+                    Map<String, Long> phaseTookMap = new HashMap<>();
+
+                    while ((token = parser.nextToken()) != Token.END_OBJECT) {
+                        if (token == Token.FIELD_NAME) {
+                            currentFieldName = parser.currentName();
+                        } else if (token.isValue()) {
+                            try {
+                                SearchPhaseName.valueOf(currentFieldName.toUpperCase(Locale.ROOT));
+                                phaseTookMap.put(currentFieldName, parser.longValue());
+                            } catch (final IllegalArgumentException ex) {
+                                parser.skipChildren();
+                            }
+                        } else {
+                            parser.skipChildren();
+                        }
+                    }
+                    phaseTook = new PhaseTook(phaseTookMap);
                 } else if (Clusters._CLUSTERS_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
                     int successful = -1;
                     int total = -1;
@@ -472,6 +539,7 @@ public static SearchResponse innerFromXContent(XContentParser parser) throws IOE
             successfulShards,
             skippedShards,
             tookInMillis,
+            phaseTook,
             failures.toArray(ShardSearchFailure.EMPTY_ARRAY),
             clusters,
             searchContextId
@@ -491,6 +559,9 @@ public void writeTo(StreamOutput out) throws IOException {
         clusters.writeTo(out);
         out.writeOptionalString(scrollId);
         out.writeVLong(tookInMillis);
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeOptionalWriteable(phaseTook);
+        }
         out.writeVInt(skippedShards);
         out.writeOptionalString(pointInTimeId);
     }
@@ -504,8 +575,9 @@ public String toString() {
      * Holds info about the clusters that the search was executed on: how many in total, how many of them were successful
      * and how many of them were skipped.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Clusters implements ToXContentFragment, Writeable {
 
         public static final Clusters EMPTY = new Clusters(0, 0, 0);
@@ -604,6 +676,68 @@ public String toString() {
         }
     }
 
+    /**
+     * Holds info about the clusters that the search was executed on: how many in total, how many of them were successful
+     * and how many of them were skipped.
+     *
+     * @opensearch.api
+     */
+    @PublicApi(since = "1.0.0")
+    public static class PhaseTook implements ToXContentFragment, Writeable {
+        static final ParseField PHASE_TOOK = new ParseField("phase_took");
+        private final Map<String, Long> phaseTookMap;
+
+        public PhaseTook(Map<String, Long> phaseTookMap) {
+            this.phaseTookMap = phaseTookMap;
+        }
+
+        private PhaseTook(StreamInput in) throws IOException {
+            this(in.readMap(StreamInput::readString, StreamInput::readLong));
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            out.writeMap(phaseTookMap, StreamOutput::writeString, StreamOutput::writeLong);
+        }
+
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            builder.startObject(PHASE_TOOK.getPreferredName());
+
+            for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+                if (phaseTookMap.containsKey(searchPhaseName.getName())) {
+                    builder.field(searchPhaseName.getName(), phaseTookMap.get(searchPhaseName.getName()));
+                } else {
+                    builder.field(searchPhaseName.getName(), 0);
+                }
+            }
+            builder.endObject();
+            return builder;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (o == null || getClass() != o.getClass()) {
+                return false;
+            }
+            PhaseTook phaseTook = (PhaseTook) o;
+
+            if (phaseTook.phaseTookMap.equals(phaseTookMap)) {
+                return true;
+            } else {
+                return false;
+            }
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(phaseTookMap);
+        }
+    }
+
     static SearchResponse empty(Supplier<Long> tookInMillisSupplier, Clusters clusters) {
         SearchHits searchHits = new SearchHits(new SearchHit[0], new TotalHits(0L, TotalHits.Relation.EQUAL_TO), Float.NaN);
         InternalSearchResponse internalSearchResponse = new InternalSearchResponse(
diff --git a/server/src/main/java/org/opensearch/action/search/SearchResponseMerger.java b/server/src/main/java/org/opensearch/action/search/SearchResponseMerger.java
index f90e98106f93f..054bd578cc56c 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchResponseMerger.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchResponseMerger.java
@@ -236,6 +236,7 @@ SearchResponse getMergedResponse(SearchResponse.Clusters clusters) {
             successfulShards,
             skippedShards,
             tookInMillis,
+            searchTimeProvider.getPhaseTook(),
             shardFailures,
             clusters,
             null
diff --git a/server/src/main/java/org/opensearch/action/search/SearchResponseSections.java b/server/src/main/java/org/opensearch/action/search/SearchResponseSections.java
index 2e447abd125c5..bca2c8a52b691 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchResponseSections.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchResponseSections.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -53,13 +54,14 @@
 /**
  * Base class that holds the various sections which a search response is
  * composed of (hits, aggs, suggestions etc.) and allows to retrieve them.
- *
+ * <p>
  * The reason why this class exists is that the high level REST client uses its own classes
  * to parse aggregations into, which are not serializable. This is the common part that can be
  * shared between core and client.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchResponseSections implements ToXContentFragment {
 
     public static final ParseField EXT_FIELD = new ParseField("ext");
diff --git a/server/src/main/java/org/opensearch/action/search/SearchScrollRequest.java b/server/src/main/java/org/opensearch/action/search/SearchScrollRequest.java
index cda00811e5500..044efdc36d04f 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchScrollRequest.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchScrollRequest.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -53,8 +54,9 @@
 /**
  * Transport request for a search scroll
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchScrollRequest extends ActionRequest implements ToXContentObject {
 
     private String scrollId;
diff --git a/server/src/main/java/org/opensearch/action/search/SearchScrollRequestBuilder.java b/server/src/main/java/org/opensearch/action/search/SearchScrollRequestBuilder.java
index 638c595216631..41b34bd9c6c9e 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchScrollRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchScrollRequestBuilder.java
@@ -34,14 +34,16 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.search.Scroll;
 
 /**
  * A search scroll action request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchScrollRequestBuilder extends ActionRequestBuilder<SearchScrollRequest, SearchResponse> {
 
     public SearchScrollRequestBuilder(OpenSearchClient client, SearchScrollAction action) {
diff --git a/server/src/main/java/org/opensearch/action/search/SearchShardIterator.java b/server/src/main/java/org/opensearch/action/search/SearchShardIterator.java
index fbd85a3fc0b8f..33d9bf70021a0 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchShardIterator.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchShardIterator.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.routing.PlainShardIterator;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.Countable;
 import org.opensearch.common.util.PlainIterator;
@@ -54,8 +55,9 @@
  * the cluster alias.
  * @see OriginalIndices
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SearchShardIterator implements Comparable<SearchShardIterator>, Countable {
 
     private final OriginalIndices originalIndices;
diff --git a/server/src/main/java/org/opensearch/action/search/SearchShardTask.java b/server/src/main/java/org/opensearch/action/search/SearchShardTask.java
index 54faaf363cb70..dfecf4f462c4d 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchShardTask.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchShardTask.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.search;
 
 import org.opensearch.common.MemoizedSupplier;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.tasks.TaskId;
 import org.opensearch.search.fetch.ShardFetchSearchRequest;
 import org.opensearch.search.internal.ShardSearchRequest;
@@ -46,8 +47,9 @@
  * Task storing information about a currently running search shard request.
  * See {@link ShardSearchRequest}, {@link ShardFetchSearchRequest}, ...
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchShardTask extends CancellableTask implements SearchBackpressureTask {
     // generating metadata in a lazy way since source can be quite big
     private final MemoizedSupplier<String> metadataSupplier;
diff --git a/server/src/main/java/org/opensearch/action/search/SearchTask.java b/server/src/main/java/org/opensearch/action/search/SearchTask.java
index 20370b7b17a07..d3c1043c50cce 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchTask.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchTask.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.tasks.TaskId;
 import org.opensearch.tasks.CancellableTask;
@@ -45,8 +46,9 @@
 /**
  * Task storing information about a currently running {@link SearchRequest}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchTask extends CancellableTask implements SearchBackpressureTask {
     // generating description in a lazy way since source can be quite big
     private final Supplier<String> descriptionSupplier;
diff --git a/server/src/main/java/org/opensearch/action/search/SearchTransportService.java b/server/src/main/java/org/opensearch/action/search/SearchTransportService.java
index a723937afd2ed..64c738f633f2e 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchTransportService.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchTransportService.java
@@ -45,6 +45,7 @@
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
 import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
 import org.opensearch.search.SearchPhaseResult;
 import org.opensearch.search.SearchService;
 import org.opensearch.search.dfs.DfsSearchResult;
@@ -542,6 +543,9 @@ public static void registerRequestHandler(TransportService transportService, Sea
         transportService.registerRequestHandler(
             DFS_ACTION_NAME,
             ThreadPool.Names.SAME,
+            false,
+            true,
+            AdmissionControlActionType.SEARCH,
             ShardSearchRequest::new,
             (request, channel, task) -> searchService.executeDfsPhase(
                 request,
@@ -556,6 +560,9 @@ public static void registerRequestHandler(TransportService transportService, Sea
         transportService.registerRequestHandler(
             QUERY_ACTION_NAME,
             ThreadPool.Names.SAME,
+            false,
+            true,
+            AdmissionControlActionType.SEARCH,
             ShardSearchRequest::new,
             (request, channel, task) -> {
                 searchService.executeQueryPhase(
@@ -575,6 +582,9 @@ public static void registerRequestHandler(TransportService transportService, Sea
         transportService.registerRequestHandler(
             QUERY_ID_ACTION_NAME,
             ThreadPool.Names.SAME,
+            false,
+            true,
+            AdmissionControlActionType.SEARCH,
             QuerySearchRequest::new,
             (request, channel, task) -> {
                 searchService.executeQueryPhase(
@@ -633,6 +643,7 @@ public static void registerRequestHandler(TransportService transportService, Sea
             ThreadPool.Names.SAME,
             true,
             true,
+            AdmissionControlActionType.SEARCH,
             ShardFetchSearchRequest::new,
             (request, channel, task) -> {
                 searchService.executeFetchPhase(
diff --git a/server/src/main/java/org/opensearch/action/search/SearchType.java b/server/src/main/java/org/opensearch/action/search/SearchType.java
index cb86c0d6c1b4a..e549ec598380a 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchType.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchType.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.action.search;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Search type represent the manner at which the search operation is executed.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum SearchType {
     /**
      * Same as {@link #QUERY_THEN_FETCH}, except for an initial scatter phase which goes and computes the distributed
diff --git a/server/src/main/java/org/opensearch/action/search/ShardSearchFailure.java b/server/src/main/java/org/opensearch/action/search/ShardSearchFailure.java
index 4d3f9b71a919c..ef490844db692 100644
--- a/server/src/main/java/org/opensearch/action/search/ShardSearchFailure.java
+++ b/server/src/main/java/org/opensearch/action/search/ShardSearchFailure.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.OriginalIndices;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -56,8 +57,9 @@
 /**
  * Represents a failure to search on a specific shard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardSearchFailure extends ShardOperationFailedException {
 
     private static final String REASON_FIELD = "reason";
diff --git a/server/src/main/java/org/opensearch/action/search/TransportDeletePitAction.java b/server/src/main/java/org/opensearch/action/search/TransportDeletePitAction.java
index 614d576324026..b15a4b66e8870 100644
--- a/server/src/main/java/org/opensearch/action/search/TransportDeletePitAction.java
+++ b/server/src/main/java/org/opensearch/action/search/TransportDeletePitAction.java
@@ -76,7 +76,7 @@ private void deletePits(ActionListener<DeletePitResponse> listener, DeletePitReq
 
     /**
      * Delete all active PIT reader contexts leveraging list all PITs
-     *
+     * <p>
      * For Cross cluster PITs :
      * - mixed cluster PITs ( PIT comprising local and remote ) will be fully deleted. Since there will atleast be
      * one reader context with PIT ID present in local cluster, 'Get all PITs' will retrieve the PIT ID with which
diff --git a/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java b/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java
index 25ec0fc57d19f..05f4308df74fa 100644
--- a/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java
+++ b/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java
@@ -87,6 +87,7 @@
 import org.opensearch.search.profile.SearchProfileShardResults;
 import org.opensearch.tasks.CancellableTask;
 import org.opensearch.tasks.Task;
+import org.opensearch.telemetry.metrics.MetricsRegistry;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.RemoteClusterAware;
 import org.opensearch.transport.RemoteClusterService;
@@ -97,6 +98,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -135,6 +137,13 @@ public class TransportSearchAction extends HandledTransportAction<SearchRequest,
         Property.NodeScope
     );
 
+    public static final Setting<Boolean> SEARCH_QUERY_METRICS_ENABLED_SETTING = Setting.boolSetting(
+        "search.query.metrics.enabled",
+        false,
+        Setting.Property.NodeScope,
+        Setting.Property.Dynamic
+    );
+
     // cluster level setting for timeout based search cancellation. If search request level parameter is present then that will take
     // precedence over the cluster setting value
     public static final String SEARCH_CANCEL_AFTER_TIME_INTERVAL_SETTING_KEY = "search.cancel_after_time_interval";
@@ -145,6 +154,22 @@ public class TransportSearchAction extends HandledTransportAction<SearchRequest,
         Setting.Property.NodeScope
     );
 
+    public static final String SEARCH_REQUEST_STATS_ENABLED_KEY = "search.request_stats_enabled";
+    public static final Setting<Boolean> SEARCH_REQUEST_STATS_ENABLED = Setting.boolSetting(
+        SEARCH_REQUEST_STATS_ENABLED_KEY,
+        false,
+        Property.Dynamic,
+        Property.NodeScope
+    );
+
+    public static final String SEARCH_PHASE_TOOK_ENABLED_KEY = "search.phase_took_enabled";
+    public static final Setting<Boolean> SEARCH_PHASE_TOOK_ENABLED = Setting.boolSetting(
+        SEARCH_PHASE_TOOK_ENABLED_KEY,
+        false,
+        Property.Dynamic,
+        Property.NodeScope
+    );
+
     private final NodeClient client;
     private final ThreadPool threadPool;
     private final ClusterService clusterService;
@@ -157,6 +182,17 @@ public class TransportSearchAction extends HandledTransportAction<SearchRequest,
     private final CircuitBreaker circuitBreaker;
     private final SearchPipelineService searchPipelineService;
 
+    private volatile boolean isRequestStatsEnabled;
+
+    private volatile boolean searchQueryMetricsEnabled;
+
+    private final SearchRequestStats searchRequestStats;
+    private final SearchRequestSlowLog searchRequestSlowLog;
+
+    private final MetricsRegistry metricsRegistry;
+
+    private SearchQueryCategorizer searchQueryCategorizer;
+
     @Inject
     public TransportSearchAction(
         NodeClient client,
@@ -170,7 +206,10 @@ public TransportSearchAction(
         ActionFilters actionFilters,
         IndexNameExpressionResolver indexNameExpressionResolver,
         NamedWriteableRegistry namedWriteableRegistry,
-        SearchPipelineService searchPipelineService
+        SearchPipelineService searchPipelineService,
+        SearchRequestStats searchRequestStats,
+        SearchRequestSlowLog searchRequestSlowLog,
+        MetricsRegistry metricsRegistry
     ) {
         super(SearchAction.NAME, transportService, actionFilters, (Writeable.Reader<SearchRequest>) SearchRequest::new);
         this.client = client;
@@ -185,6 +224,25 @@ public TransportSearchAction(
         this.indexNameExpressionResolver = indexNameExpressionResolver;
         this.namedWriteableRegistry = namedWriteableRegistry;
         this.searchPipelineService = searchPipelineService;
+        this.isRequestStatsEnabled = clusterService.getClusterSettings().get(SEARCH_REQUEST_STATS_ENABLED);
+        clusterService.getClusterSettings().addSettingsUpdateConsumer(SEARCH_REQUEST_STATS_ENABLED, this::setIsRequestStatsEnabled);
+        this.searchRequestStats = searchRequestStats;
+        this.searchRequestSlowLog = searchRequestSlowLog;
+        this.metricsRegistry = metricsRegistry;
+        this.searchQueryMetricsEnabled = clusterService.getClusterSettings().get(SEARCH_QUERY_METRICS_ENABLED_SETTING);
+        clusterService.getClusterSettings()
+            .addSettingsUpdateConsumer(SEARCH_QUERY_METRICS_ENABLED_SETTING, this::setSearchQueryMetricsEnabled);
+    }
+
+    private void setSearchQueryMetricsEnabled(boolean searchQueryMetricsEnabled) {
+        this.searchQueryMetricsEnabled = searchQueryMetricsEnabled;
+        if ((this.searchQueryMetricsEnabled == true) && this.searchQueryCategorizer == null) {
+            this.searchQueryCategorizer = new SearchQueryCategorizer(metricsRegistry);
+        }
+    }
+
+    private void setIsRequestStatsEnabled(boolean isRequestStatsEnabled) {
+        this.isRequestStatsEnabled = isRequestStatsEnabled;
     }
 
     private Map<String, AliasFilter> buildPerIndexAliasFilter(
@@ -231,6 +289,8 @@ private Map<String, Float> resolveIndexBoosts(SearchRequest searchRequest, Clust
     }
 
     /**
+     * Listener to track request-level tookTime and phase tookTimes from the coordinator.
+     *
      * Search operations need two clocks. One clock is to fulfill real clock needs (e.g., resolving
      * "now" to an index name). Another clock is needed for measuring how long a search operation
      * took. These two uses are at odds with each other. There are many issues with using a real
@@ -240,11 +300,12 @@ private Map<String, Float> resolveIndexBoosts(SearchRequest searchRequest, Clust
      *
      * @opensearch.internal
      */
-    static final class SearchTimeProvider {
+    static final class SearchTimeProvider extends SearchRequestOperationsListener {
 
         private final long absoluteStartMillis;
         private final long relativeStartNanos;
         private final LongSupplier relativeCurrentNanosProvider;
+        private boolean phaseTook = false;
 
         /**
          * Instantiates a new search time provider. The absolute start time is the real clock time
@@ -270,6 +331,43 @@ long getAbsoluteStartMillis() {
         long buildTookInMillis() {
             return TimeUnit.NANOSECONDS.toMillis(relativeCurrentNanosProvider.getAsLong() - relativeStartNanos);
         }
+
+        public void setPhaseTook(boolean phaseTook) {
+            this.phaseTook = phaseTook;
+        }
+
+        SearchResponse.PhaseTook getPhaseTook() {
+            if (phaseTook) {
+                Map<String, Long> phaseTookMap = new HashMap<>();
+                // Convert Map<SearchPhaseName, Long> to Map<String, Long> for SearchResponse()
+                for (SearchPhaseName searchPhaseName : phaseStatsMap.keySet()) {
+                    phaseTookMap.put(searchPhaseName.getName(), phaseStatsMap.get(searchPhaseName));
+                }
+                return new SearchResponse.PhaseTook(phaseTookMap);
+            } else {
+                return null;
+            }
+        }
+
+        Map<SearchPhaseName, Long> phaseStatsMap = new EnumMap<>(SearchPhaseName.class);
+
+        @Override
+        void onPhaseStart(SearchPhaseContext context) {}
+
+        @Override
+        void onPhaseEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {
+            phaseStatsMap.put(
+                context.getCurrentPhase().getSearchPhaseName(),
+                TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - context.getCurrentPhase().getStartTimeInNanos())
+            );
+        }
+
+        @Override
+        void onPhaseFailure(SearchPhaseContext context) {}
+
+        public Long getPhaseTookTime(SearchPhaseName searchPhaseName) {
+            return phaseStatsMap.get(searchPhaseName);
+        }
     }
 
     @Override
@@ -327,7 +425,8 @@ public AbstractSearchAsyncAction<? extends SearchPhaseResult> asyncSearchAction(
                 ActionListener<SearchResponse> listener,
                 boolean preFilter,
                 ThreadPool threadPool,
-                SearchResponse.Clusters clusters
+                SearchResponse.Clusters clusters,
+                SearchRequestContext searchRequestContext
             ) {
                 return new AbstractSearchAsyncAction<SearchPhaseResult>(
                     actionName,
@@ -346,7 +445,8 @@ public AbstractSearchAsyncAction<? extends SearchPhaseResult> asyncSearchAction(
                     task,
                     new ArraySearchPhaseResults<>(shardsIts.size()),
                     searchRequest.getMaxConcurrentShardRequests(),
-                    clusters
+                    clusters,
+                    searchRequestContext
                 ) {
                     @Override
                     protected void executePhaseOnShard(
@@ -390,20 +490,62 @@ private void executeRequest(
             relativeStartNanos,
             System::nanoTime
         );
+
+        final List<SearchRequestOperationsListener> searchListenersList = createSearchListenerList(originalSearchRequest, timeProvider);
+        SearchRequestContext searchRequestContext = new SearchRequestContext(
+            new SearchRequestOperationsListener.CompositeListener(searchListenersList, logger)
+        );
+        searchRequestContext.getSearchRequestOperationsListener().onRequestStart(searchRequestContext);
+
         PipelinedRequest searchRequest;
         ActionListener<SearchResponse> listener;
         try {
             searchRequest = searchPipelineService.resolvePipeline(originalSearchRequest);
-            listener = ActionListener.wrap(
-                r -> originalListener.onResponse(searchRequest.transformResponse(r)),
-                originalListener::onFailure
-            );
+            listener = searchRequest.transformResponseListener(originalListener);
         } catch (Exception e) {
             originalListener.onFailure(e);
             return;
         }
 
-        ActionListener<SearchSourceBuilder> rewriteListener = ActionListener.wrap(source -> {
+        ActionListener<SearchRequest> requestTransformListener = ActionListener.wrap(sr -> {
+            if (searchQueryMetricsEnabled) {
+                try {
+                    searchQueryCategorizer.categorize(sr.source());
+                } catch (Exception e) {
+                    logger.error("Error while trying to categorize the query.", e);
+                }
+            }
+
+            ActionListener<SearchSourceBuilder> rewriteListener = buildRewriteListener(
+                sr,
+                task,
+                timeProvider,
+                searchAsyncActionProvider,
+                listener,
+                searchRequestContext
+            );
+            if (sr.source() == null) {
+                rewriteListener.onResponse(sr.source());
+            } else {
+                Rewriteable.rewriteAndFetch(
+                    sr.source(),
+                    searchService.getRewriteContext(timeProvider::getAbsoluteStartMillis),
+                    rewriteListener
+                );
+            }
+        }, listener::onFailure);
+        searchRequest.transformRequest(requestTransformListener);
+    }
+
+    private ActionListener<SearchSourceBuilder> buildRewriteListener(
+        SearchRequest searchRequest,
+        Task task,
+        SearchTimeProvider timeProvider,
+        SearchAsyncActionProvider searchAsyncActionProvider,
+        ActionListener<SearchResponse> listener,
+        SearchRequestContext searchRequestContext
+    ) {
+        return ActionListener.wrap(source -> {
             if (source != searchRequest.source()) {
                 // only set it if it changed - we don't allow null values to be set but it might be already null. this way we catch
                 // situations when source is rewritten to null due to a bug
@@ -433,7 +575,8 @@ private void executeRequest(
                     clusterState,
                     listener,
                     searchContext,
-                    searchAsyncActionProvider
+                    searchAsyncActionProvider,
+                    searchRequestContext
                 );
             } else {
                 if (shouldMinimizeRoundtrips(searchRequest)) {
@@ -454,7 +597,8 @@ private void executeRequest(
                             clusterState,
                             l,
                             searchContext,
-                            searchAsyncActionProvider
+                            searchAsyncActionProvider,
+                            searchRequestContext
                         )
                     );
                 } else {
@@ -504,22 +648,14 @@ private void executeRequest(
                                 listener,
                                 new SearchResponse.Clusters(totalClusters, successfulClusters, skippedClusters.get()),
                                 searchContext,
-                                searchAsyncActionProvider
+                                searchAsyncActionProvider,
+                                searchRequestContext
                             );
                         }, listener::onFailure)
                     );
                 }
             }
         }, listener::onFailure);
-        if (searchRequest.source() == null) {
-            rewriteListener.onResponse(searchRequest.source());
-        } else {
-            Rewriteable.rewriteAndFetch(
-                searchRequest.source(),
-                searchService.getRewriteContext(timeProvider::getAbsoluteStartMillis),
-                rewriteListener
-            );
-        }
     }
 
     static boolean shouldMinimizeRoundtrips(SearchRequest searchRequest) {
@@ -593,6 +729,7 @@ public void onResponse(SearchResponse searchResponse) {
                             searchResponse.getSuccessfulShards(),
                             searchResponse.getSkippedShards(),
                             timeProvider.buildTookInMillis(),
+                            timeProvider.getPhaseTook(),
                             searchResponse.getShardFailures(),
                             new SearchResponse.Clusters(1, 1, 0),
                             searchResponse.pointInTimeId()
@@ -782,7 +919,8 @@ private void executeLocalSearch(
         ClusterState clusterState,
         ActionListener<SearchResponse> listener,
         SearchContextId searchContext,
-        SearchAsyncActionProvider searchAsyncActionProvider
+        SearchAsyncActionProvider searchAsyncActionProvider,
+        SearchRequestContext searchRequestContext
     ) {
         executeSearch(
             (SearchTask) task,
@@ -796,7 +934,8 @@ private void executeLocalSearch(
             listener,
             SearchResponse.Clusters.EMPTY,
             searchContext,
-            searchAsyncActionProvider
+            searchAsyncActionProvider,
+            searchRequestContext
         );
     }
 
@@ -914,11 +1053,10 @@ private void executeSearch(
         ActionListener<SearchResponse> listener,
         SearchResponse.Clusters clusters,
         @Nullable SearchContextId searchContext,
-        SearchAsyncActionProvider searchAsyncActionProvider
+        SearchAsyncActionProvider searchAsyncActionProvider,
+        SearchRequestContext searchRequestContext
     ) {
-
         clusterState.blocks().globalBlockedRaiseException(ClusterBlockLevel.READ);
-
         // TODO: I think startTime() should become part of ActionRequest and that should be used both for index name
         // date math expressions and $now in scripts. This way all apis will deal with now in the same way instead
         // of just for the _search api
@@ -968,11 +1106,8 @@ private void executeSearch(
             indexRoutings = routingMap;
         }
         final GroupShardsIterator<SearchShardIterator> shardIterators = mergeShardsIterators(localShardIterators, remoteShardIterators);
-
         failIfOverShardCountLimit(clusterService, shardIterators.size());
-
         Map<String, Float> concreteIndexBoosts = resolveIndexBoosts(searchRequest, clusterState);
-
         // optimize search type for cases where there is only one shard group to search on
         if (shardIterators.size() == 1) {
             // if we only have one group, then we always want Q_T_F, no need for DFS, and no need to do THEN since we hit one shard
@@ -1020,7 +1155,8 @@ private void executeSearch(
             listener,
             preFilterSearchShards,
             threadPool,
-            clusters
+            clusters,
+            searchRequestContext
         ).start();
     }
 
@@ -1103,10 +1239,40 @@ AbstractSearchAsyncAction<? extends SearchPhaseResult> asyncSearchAction(
             ActionListener<SearchResponse> listener,
             boolean preFilter,
             ThreadPool threadPool,
-            SearchResponse.Clusters clusters
+            SearchResponse.Clusters clusters,
+            SearchRequestContext searchRequestContext
         );
     }
 
+    private List<SearchRequestOperationsListener> createSearchListenerList(SearchRequest searchRequest, SearchTimeProvider timeProvider) {
+        final List<SearchRequestOperationsListener> searchListenersList = new ArrayList<>();
+
+        if (isRequestStatsEnabled) {
+            searchListenersList.add(searchRequestStats);
+        }
+
+        // phase_took is enabled with request param and/or cluster setting
+        Boolean phaseTookRequestParam = searchRequest.isPhaseTook();
+        if (phaseTookRequestParam == null) {    // check cluster setting only when request param is undefined
+            if (clusterService.getClusterSettings().get(TransportSearchAction.SEARCH_PHASE_TOOK_ENABLED)) {
+                timeProvider.setPhaseTook(true);
+                searchListenersList.add(timeProvider);
+            }
+        } else if (phaseTookRequestParam == true) {
+            timeProvider.setPhaseTook(true);
+            searchListenersList.add(timeProvider);
+        }
+
+        if (searchRequestSlowLog.getWarnThreshold() >= 0
+            || searchRequestSlowLog.getInfoThreshold() >= 0
+            || searchRequestSlowLog.getDebugThreshold() >= 0
+            || searchRequestSlowLog.getTraceThreshold() >= 0) {
+            searchListenersList.add(searchRequestSlowLog);
+        }
+
+        return searchListenersList;
+    }
+
     private AbstractSearchAsyncAction<? extends SearchPhaseResult> searchAsyncAction(
         SearchTask task,
         SearchRequest searchRequest,
@@ -1121,7 +1287,8 @@ private AbstractSearchAsyncAction<? extends SearchPhaseResult> searchAsyncAction
         ActionListener<SearchResponse> listener,
         boolean preFilter,
         ThreadPool threadPool,
-        SearchResponse.Clusters clusters
+        SearchResponse.Clusters clusters,
+        SearchRequestContext searchRequestContext
     ) {
         if (preFilter) {
             return new CanMatchPreFilterSearchPhase(
@@ -1153,7 +1320,8 @@ private AbstractSearchAsyncAction<? extends SearchPhaseResult> searchAsyncAction
                         listener,
                         false,
                         threadPool,
-                        clusters
+                        clusters,
+                        searchRequestContext
                     );
                     return new SearchPhase(action.getName()) {
                         @Override
@@ -1162,7 +1330,8 @@ public void run() {
                         }
                     };
                 },
-                clusters
+                clusters,
+                searchRequestContext
             );
         } else {
             final QueryPhaseResultConsumer queryResultConsumer = searchPhaseController.newSearchPhaseResults(
@@ -1192,7 +1361,8 @@ public void run() {
                         timeProvider,
                         clusterState,
                         task,
-                        clusters
+                        clusters,
+                        searchRequestContext
                     );
                     break;
                 case QUERY_THEN_FETCH:
@@ -1212,7 +1382,8 @@ public void run() {
                         timeProvider,
                         clusterState,
                         task,
-                        clusters
+                        clusters,
+                        searchRequestContext
                     );
                     break;
                 default:
diff --git a/server/src/main/java/org/opensearch/action/support/ActiveShardCount.java b/server/src/main/java/org/opensearch/action/support/ActiveShardCount.java
index 15275ba48fc6e..e91342a7ce4b8 100644
--- a/server/src/main/java/org/opensearch/action/support/ActiveShardCount.java
+++ b/server/src/main/java/org/opensearch/action/support/ActiveShardCount.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.routing.IndexRoutingTable;
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -48,8 +49,9 @@
  * A class whose instances represent a value for counting the number
  * of active shard copies for a given shard in an index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ActiveShardCount implements Writeable {
 
     private static final int ACTIVE_SHARD_COUNT_DEFAULT = -2;
diff --git a/server/src/main/java/org/opensearch/action/support/IndicesOptions.java b/server/src/main/java/org/opensearch/action/support/IndicesOptions.java
index d30ee7e11bdfa..2d9fecddb6f7d 100644
--- a/server/src/main/java/org/opensearch/action/support/IndicesOptions.java
+++ b/server/src/main/java/org/opensearch/action/support/IndicesOptions.java
@@ -32,6 +32,7 @@
 package org.opensearch.action.support;
 
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -55,15 +56,17 @@
  * Controls how to deal with unavailable concrete indices (closed or missing), how wildcard expressions are expanded
  * to actual indices (all, closed or open indices) and how to deal with wildcard expressions that resolve to no indices.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesOptions implements ToXContentFragment {
 
     /**
      * The wildcard states.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum WildcardStates {
         OPEN,
         CLOSED,
diff --git a/server/src/main/java/org/opensearch/action/support/RetryableAction.java b/server/src/main/java/org/opensearch/action/support/RetryableAction.java
index fc2ee277b538a..d555a876f20fb 100644
--- a/server/src/main/java/org/opensearch/action/support/RetryableAction.java
+++ b/server/src/main/java/org/opensearch/action/support/RetryableAction.java
@@ -36,6 +36,7 @@
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.opensearch.action.ActionRunnable;
 import org.opensearch.action.bulk.BackoffPolicy;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.concurrency.OpenSearchRejectedExecutionException;
@@ -52,8 +53,9 @@
  * default. The action will be retried with exponentially increasing delay periods until the timeout period
  * has been reached.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class RetryableAction<Response> {
 
     private final Logger logger;
diff --git a/server/src/main/java/org/opensearch/action/support/TransportAction.java b/server/src/main/java/org/opensearch/action/support/TransportAction.java
index daa11c2d7d80f..72aae210d61ae 100644
--- a/server/src/main/java/org/opensearch/action/support/TransportAction.java
+++ b/server/src/main/java/org/opensearch/action/support/TransportAction.java
@@ -81,7 +81,7 @@ private Releasable registerChildNode(TaskId parentTask) {
 
     /**
      * Use this method when the transport action call should result in creation of a new task associated with the call.
-     *
+     * <p>
      * This is a typical behavior.
      */
     public final Task execute(Request request, ActionListener<Response> listener) {
diff --git a/server/src/main/java/org/opensearch/action/support/WriteRequest.java b/server/src/main/java/org/opensearch/action/support/WriteRequest.java
index f462464b99ce8..8d53f7b005d54 100644
--- a/server/src/main/java/org/opensearch/action/support/WriteRequest.java
+++ b/server/src/main/java/org/opensearch/action/support/WriteRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.action.index.IndexRequest;
 import org.opensearch.action.support.replication.ReplicatedWriteRequest;
 import org.opensearch.action.update.UpdateRequest;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -78,8 +79,9 @@ default R setRefreshPolicy(String refreshPolicy) {
     /**
      * The refresh policy of the request.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     enum RefreshPolicy implements Writeable {
         /**
          * Don't refresh after this request. The default.
diff --git a/server/src/main/java/org/opensearch/action/support/master/AcknowledgedResponse.java b/server/src/main/java/org/opensearch/action/support/master/AcknowledgedResponse.java
index 5d09d880336f1..279ad401f7e56 100644
--- a/server/src/main/java/org/opensearch/action/support/master/AcknowledgedResponse.java
+++ b/server/src/main/java/org/opensearch/action/support/master/AcknowledgedResponse.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.action.support.master;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -49,8 +50,9 @@
 /**
  * A response that indicates that a request has been acknowledged
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AcknowledgedResponse extends ActionResponse implements ToXContentObject {
 
     private static final ParseField ACKNOWLEDGED = new ParseField("acknowledged");
diff --git a/server/src/main/java/org/opensearch/action/support/nodes/BaseNodesRequest.java b/server/src/main/java/org/opensearch/action/support/nodes/BaseNodesRequest.java
index f5fb41dc5bae3..4d54ce51c923c 100644
--- a/server/src/main/java/org/opensearch/action/support/nodes/BaseNodesRequest.java
+++ b/server/src/main/java/org/opensearch/action/support/nodes/BaseNodesRequest.java
@@ -53,9 +53,9 @@ public abstract class BaseNodesRequest<Request extends BaseNodesRequest<Request>
      * the list of nodesIds that will be used to resolve this request and {@link #concreteNodes}
      * will be populated. Note that if {@link #concreteNodes} is not null, it will be used and nodeIds
      * will be ignored.
-     *
+     * <p>
      * See {@link DiscoveryNodes#resolveNodes} for a full description of the options.
-     *
+     * <p>
      * TODO: get rid of this and resolve it to concrete nodes in the rest layer
      **/
     private String[] nodesIds;
diff --git a/server/src/main/java/org/opensearch/action/support/replication/PendingReplicationActions.java b/server/src/main/java/org/opensearch/action/support/replication/PendingReplicationActions.java
index c52bc6c2c799d..bb6bfc6fd4773 100644
--- a/server/src/main/java/org/opensearch/action/support/replication/PendingReplicationActions.java
+++ b/server/src/main/java/org/opensearch/action/support/replication/PendingReplicationActions.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.support.replication;
 
 import org.opensearch.action.support.RetryableAction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.util.concurrent.ConcurrentCollections;
 import org.opensearch.core.index.shard.ShardId;
@@ -51,8 +52,9 @@
 /**
  * Pending Replication Actions
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PendingReplicationActions implements Consumer<ReplicationGroup>, Releasable {
 
     private final Map<String, Set<RetryableAction<?>>> onGoingReplicationActions = ConcurrentCollections.newConcurrentMap();
diff --git a/server/src/main/java/org/opensearch/action/support/replication/ReplicationMode.java b/server/src/main/java/org/opensearch/action/support/replication/ReplicationMode.java
index f9b85cc4bd7aa..dd3a38c1398ab 100644
--- a/server/src/main/java/org/opensearch/action/support/replication/ReplicationMode.java
+++ b/server/src/main/java/org/opensearch/action/support/replication/ReplicationMode.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.action.support.replication;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * The type of replication used for inter-node replication.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public enum ReplicationMode {
     /**
      * In this mode, a {@code TransportReplicationAction} is fanned out to underlying concerned shard and is replicated logically.
diff --git a/server/src/main/java/org/opensearch/action/support/replication/ReplicationOperation.java b/server/src/main/java/org/opensearch/action/support/replication/ReplicationOperation.java
index 60c490a50575a..9f69d41d83f5b 100644
--- a/server/src/main/java/org/opensearch/action/support/replication/ReplicationOperation.java
+++ b/server/src/main/java/org/opensearch/action/support/replication/ReplicationOperation.java
@@ -479,7 +479,7 @@ public interface Primary<
 
         /**
          * Notifies the primary of a local checkpoint for the given allocation.
-         *
+         * <p>
          * Note: The primary will use this information to advance the global checkpoint if possible.
          *
          * @param allocationId allocation ID of the shard corresponding to the supplied local checkpoint
diff --git a/server/src/main/java/org/opensearch/action/support/replication/ReplicationResponse.java b/server/src/main/java/org/opensearch/action/support/replication/ReplicationResponse.java
index 825405cb68549..67480976c500f 100644
--- a/server/src/main/java/org/opensearch/action/support/replication/ReplicationResponse.java
+++ b/server/src/main/java/org/opensearch/action/support/replication/ReplicationResponse.java
@@ -36,6 +36,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.action.ShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -57,8 +58,9 @@
 /**
  * Base class for write action responses.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ReplicationResponse extends ActionResponse {
 
     public static final ReplicationResponse.ShardInfo.Failure[] EMPTY = new ReplicationResponse.ShardInfo.Failure[0];
@@ -88,8 +90,9 @@ public void setShardInfo(ShardInfo shardInfo) {
     /**
      * Holds shard information
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ShardInfo implements Writeable, ToXContentObject {
 
         private static final String TOTAL = "total";
@@ -235,8 +238,9 @@ public String toString() {
         /**
          * Holds failure information
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class Failure extends ShardOperationFailedException implements ToXContentObject {
 
             private static final String _INDEX = "_index";
diff --git a/server/src/main/java/org/opensearch/action/support/replication/TransportReplicationAction.java b/server/src/main/java/org/opensearch/action/support/replication/TransportReplicationAction.java
index de5a92fdcc4b1..95f998e2d89c2 100644
--- a/server/src/main/java/org/opensearch/action/support/replication/TransportReplicationAction.java
+++ b/server/src/main/java/org/opensearch/action/support/replication/TransportReplicationAction.java
@@ -82,6 +82,7 @@
 import org.opensearch.indices.IndexClosedException;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.node.NodeClosedException;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
 import org.opensearch.tasks.Task;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.ConnectTransportException;
@@ -100,7 +101,7 @@
 /**
  * Base class for requests that should be executed on a primary copy followed by replica copies.
  * Subclasses can resolve the target shard and provide implementation for primary and replica operations.
- *
+ * <p>
  * The action samples cluster state on the receiving node to reroute to node with primary copy and on the
  * primary node to validate request before primary operation followed by sampling state again for resolving
  * nodes with replica copies to perform replication.
@@ -134,6 +135,12 @@ public abstract class TransportReplicationAction<
         Setting.Property.NodeScope
     );
 
+    /**
+     * Making primary and replica actions suffixes as constant
+     */
+    public static final String PRIMARY_ACTION_SUFFIX = "[p]";
+    public static final String REPLICA_ACTION_SUFFIX = "[r]";
+
     protected final ThreadPool threadPool;
     protected final TransportService transportService;
     protected final ClusterService clusterService;
@@ -195,6 +202,40 @@ protected TransportReplicationAction(
         String executor,
         boolean syncGlobalCheckpointAfterOperation,
         boolean forceExecutionOnPrimary
+    ) {
+        this(
+            settings,
+            actionName,
+            transportService,
+            clusterService,
+            indicesService,
+            threadPool,
+            shardStateAction,
+            actionFilters,
+            requestReader,
+            replicaRequestReader,
+            executor,
+            syncGlobalCheckpointAfterOperation,
+            forceExecutionOnPrimary,
+            null
+        );
+    }
+
+    protected TransportReplicationAction(
+        Settings settings,
+        String actionName,
+        TransportService transportService,
+        ClusterService clusterService,
+        IndicesService indicesService,
+        ThreadPool threadPool,
+        ShardStateAction shardStateAction,
+        ActionFilters actionFilters,
+        Writeable.Reader<Request> requestReader,
+        Writeable.Reader<ReplicaRequest> replicaRequestReader,
+        String executor,
+        boolean syncGlobalCheckpointAfterOperation,
+        boolean forceExecutionOnPrimary,
+        AdmissionControlActionType admissionControlActionType
     ) {
         super(actionName, actionFilters, transportService.getTaskManager());
         this.threadPool = threadPool;
@@ -204,8 +245,8 @@ protected TransportReplicationAction(
         this.shardStateAction = shardStateAction;
         this.executor = executor;
 
-        this.transportPrimaryAction = actionName + "[p]";
-        this.transportReplicaAction = actionName + "[r]";
+        this.transportPrimaryAction = actionName + PRIMARY_ACTION_SUFFIX;
+        this.transportReplicaAction = actionName + REPLICA_ACTION_SUFFIX;
 
         this.initialRetryBackoffBound = REPLICATION_INITIAL_RETRY_BACKOFF_BOUND.get(settings);
         this.retryTimeout = REPLICATION_RETRY_TIMEOUT.get(settings);
@@ -213,14 +254,8 @@ protected TransportReplicationAction(
 
         transportService.registerRequestHandler(actionName, ThreadPool.Names.SAME, requestReader, this::handleOperationRequest);
 
-        transportService.registerRequestHandler(
-            transportPrimaryAction,
-            executor,
-            forceExecutionOnPrimary,
-            true,
-            in -> new ConcreteShardRequest<>(requestReader, in),
-            this::handlePrimaryRequest
-        );
+        // This method will register Primary Request Handler Based on AdmissionControlActionType
+        registerPrimaryRequestHandler(requestReader, admissionControlActionType);
 
         // we must never reject on because of thread pool capacity on replicas
         transportService.registerRequestHandler(
@@ -241,6 +276,38 @@ protected TransportReplicationAction(
         clusterSettings.addSettingsUpdateConsumer(REPLICATION_RETRY_TIMEOUT, (v) -> retryTimeout = v);
     }
 
+    /**
+     *  This method will register handler as based on admissionControlActionType and AdmissionControlHandler will be
+     *  invoked for registered action
+     * @param requestReader instance of the request reader
+     * @param admissionControlActionType type of AdmissionControlActionType
+     */
+    private void registerPrimaryRequestHandler(
+        Writeable.Reader<Request> requestReader,
+        AdmissionControlActionType admissionControlActionType
+    ) {
+        if (admissionControlActionType != null) {
+            transportService.registerRequestHandler(
+                transportPrimaryAction,
+                executor,
+                forceExecutionOnPrimary,
+                true,
+                admissionControlActionType,
+                in -> new ConcreteShardRequest<>(requestReader, in),
+                this::handlePrimaryRequest
+            );
+        } else {
+            transportService.registerRequestHandler(
+                transportPrimaryAction,
+                executor,
+                forceExecutionOnPrimary,
+                true,
+                in -> new ConcreteShardRequest<>(requestReader, in),
+                this::handlePrimaryRequest
+            );
+        }
+    }
+
     @Override
     protected void doExecute(Task task, Request request, ActionListener<Response> listener) {
         assert request.shardId() != null : "request shardId must be set";
@@ -866,7 +933,7 @@ protected IndexShard getIndexShard(final ShardId shardId) {
      * Responsible for routing and retrying failed operations on the primary.
      * The actual primary operation is done in {@link ReplicationOperation} on the
      * node with primary copy.
-     *
+     * <p>
      * Resolves index and shard id for the request before routing it to target node
      *
      * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/action/support/replication/TransportWriteAction.java b/server/src/main/java/org/opensearch/action/support/replication/TransportWriteAction.java
index 62cbfbde9780a..27f9e6dee83de 100644
--- a/server/src/main/java/org/opensearch/action/support/replication/TransportWriteAction.java
+++ b/server/src/main/java/org/opensearch/action/support/replication/TransportWriteAction.java
@@ -59,6 +59,12 @@
 import org.opensearch.index.translog.Translog.Location;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.SystemIndices;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanBuilder;
+import org.opensearch.telemetry.tracing.SpanScope;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.telemetry.tracing.listener.TraceableActionListener;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TransportService;
 
@@ -82,6 +88,7 @@ public abstract class TransportWriteAction<
     protected final SystemIndices systemIndices;
 
     private final Function<IndexShard, String> executorFunction;
+    private final Tracer tracer;
 
     protected TransportWriteAction(
         Settings settings,
@@ -97,7 +104,9 @@ protected TransportWriteAction(
         Function<IndexShard, String> executorFunction,
         boolean forceExecutionOnPrimary,
         IndexingPressureService indexingPressureService,
-        SystemIndices systemIndices
+        SystemIndices systemIndices,
+        Tracer tracer,
+        AdmissionControlActionType admissionControlActionType
     ) {
         // We pass ThreadPool.Names.SAME to the super class as we control the dispatching to the
         // ThreadPool.Names.WRITE/ThreadPool.Names.SYSTEM_WRITE thread pools in this class.
@@ -114,11 +123,50 @@ protected TransportWriteAction(
             replicaRequest,
             ThreadPool.Names.SAME,
             true,
-            forceExecutionOnPrimary
+            forceExecutionOnPrimary,
+            admissionControlActionType
         );
         this.executorFunction = executorFunction;
         this.indexingPressureService = indexingPressureService;
         this.systemIndices = systemIndices;
+        this.tracer = tracer;
+    }
+
+    protected TransportWriteAction(
+        Settings settings,
+        String actionName,
+        TransportService transportService,
+        ClusterService clusterService,
+        IndicesService indicesService,
+        ThreadPool threadPool,
+        ShardStateAction shardStateAction,
+        ActionFilters actionFilters,
+        Writeable.Reader<Request> request,
+        Writeable.Reader<ReplicaRequest> replicaRequest,
+        Function<IndexShard, String> executorFunction,
+        boolean forceExecutionOnPrimary,
+        IndexingPressureService indexingPressureService,
+        SystemIndices systemIndices,
+        Tracer tracer
+    ) {
+        this(
+            settings,
+            actionName,
+            transportService,
+            clusterService,
+            indicesService,
+            threadPool,
+            shardStateAction,
+            actionFilters,
+            request,
+            replicaRequest,
+            executorFunction,
+            forceExecutionOnPrimary,
+            indexingPressureService,
+            systemIndices,
+            tracer,
+            null
+        );
     }
 
     protected String executor(IndexShard shard) {
@@ -220,7 +268,12 @@ protected void shardOperationOnPrimary(
         threadPool.executor(executor).execute(new ActionRunnable<PrimaryResult<ReplicaRequest, Response>>(listener) {
             @Override
             protected void doRun() {
-                dispatchedShardOperationOnPrimary(request, primary, listener);
+                Span span = tracer.startSpan(
+                    SpanBuilder.from("dispatchedShardOperationOnPrimary", clusterService.localNode().getId(), request)
+                );
+                try (SpanScope spanScope = tracer.withSpanInScope(span)) {
+                    dispatchedShardOperationOnPrimary(request, primary, TraceableActionListener.create(listener, span, tracer));
+                }
             }
 
             @Override
@@ -248,7 +301,12 @@ protected void shardOperationOnReplica(ReplicaRequest request, IndexShard replic
         threadPool.executor(executorFunction.apply(replica)).execute(new ActionRunnable<ReplicaResult>(listener) {
             @Override
             protected void doRun() {
-                dispatchedShardOperationOnReplica(request, replica, listener);
+                Span span = tracer.startSpan(
+                    SpanBuilder.from("dispatchedShardOperationOnReplica", clusterService.localNode().getId(), request)
+                );
+                try (SpanScope spanScope = tracer.withSpanInScope(span)) {
+                    dispatchedShardOperationOnReplica(request, replica, TraceableActionListener.create(listener, span, tracer));
+                }
             }
 
             @Override
@@ -266,7 +324,7 @@ protected abstract void dispatchedShardOperationOnReplica(
 
     /**
      * Result of taking the action on the primary.
-     *
+     * <p>
      * NOTE: public for testing
      *
      * @opensearch.internal
@@ -496,7 +554,7 @@ void run() {
      * A proxy for <b>write</b> operations that need to be performed on the
      * replicas, where a failure to execute the operation should fail
      * the replica shard and/or mark the replica as stale.
-     *
+     * <p>
      * This extends {@code TransportReplicationAction.ReplicasProxy} to do the
      * failing and stale-ing.
      *
diff --git a/server/src/main/java/org/opensearch/action/support/single/shard/SingleShardRequest.java b/server/src/main/java/org/opensearch/action/support/single/shard/SingleShardRequest.java
index c474096ff94e4..56b34aea8248d 100644
--- a/server/src/main/java/org/opensearch/action/support/single/shard/SingleShardRequest.java
+++ b/server/src/main/java/org/opensearch/action/support/single/shard/SingleShardRequest.java
@@ -55,7 +55,7 @@ public abstract class SingleShardRequest<Request extends SingleShardRequest<Requ
 
     /**
      * The concrete index name
-     *
+     * <p>
      * Whether index property is optional depends on the concrete implementation. If index property is required the
      * concrete implementation should use {@link #validateNonNullIndex()} to check if the index property has been set
      */
diff --git a/server/src/main/java/org/opensearch/action/support/tasks/BaseTasksRequest.java b/server/src/main/java/org/opensearch/action/support/tasks/BaseTasksRequest.java
index a10f74f7c2aa8..c2ae333b17055 100644
--- a/server/src/main/java/org/opensearch/action/support/tasks/BaseTasksRequest.java
+++ b/server/src/main/java/org/opensearch/action/support/tasks/BaseTasksRequest.java
@@ -128,7 +128,7 @@ public final Request setNodes(String... nodes) {
 
     /**
      * Returns the id of the task that should be processed.
-     *
+     * <p>
      * By default tasks with any ids are returned.
      */
     public TaskId getTaskId() {
diff --git a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsItemResponse.java b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsItemResponse.java
index 80ca1629417ad..8dbf3dd4df512 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsItemResponse.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsItemResponse.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.termvectors;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -41,8 +42,9 @@
 /**
  * A single multi term response.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiTermVectorsItemResponse implements Writeable {
 
     private final TermVectorsResponse response;
diff --git a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequest.java b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequest.java
index c055564c3fcbe..0eef737a54bb3 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequest.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequest.java
@@ -39,6 +39,7 @@
 import org.opensearch.action.RealtimeRequest;
 import org.opensearch.action.ValidateActions;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.XContentParser;
@@ -54,8 +55,9 @@
 /**
  * A single multi get request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiTermVectorsRequest extends ActionRequest
     implements
         Iterable<TermVectorsRequest>,
diff --git a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequestBuilder.java b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequestBuilder.java
index 04dfd39112d6e..6bfa402575885 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsRequestBuilder.java
@@ -34,12 +34,14 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A single multi get request builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiTermVectorsRequestBuilder extends ActionRequestBuilder<MultiTermVectorsRequest, MultiTermVectorsResponse> {
 
     public MultiTermVectorsRequestBuilder(OpenSearchClient client, MultiTermVectorsAction action) {
diff --git a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsResponse.java b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsResponse.java
index 5d40e64df1e3e..8a059829dda0e 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsResponse.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/MultiTermVectorsResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.OpenSearchException;
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -48,15 +49,17 @@
 /**
  * A multi get response.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MultiTermVectorsResponse extends ActionResponse implements Iterable<MultiTermVectorsItemResponse>, ToXContentObject {
 
     /**
      * Represents a failure.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Failure implements Writeable {
         private final String index;
         private final String id;
diff --git a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsFilter.java b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsFilter.java
index 0e0202777794b..89d2f8567b3cb 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsFilter.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsFilter.java
@@ -39,6 +39,7 @@
 import org.apache.lucene.search.similarities.ClassicSimilarity;
 import org.apache.lucene.search.similarities.TFIDFSimilarity;
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 import java.util.HashMap;
@@ -49,8 +50,9 @@
  * Filter the term vector (doc frequency, positions, offsets) for a
  * document.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TermVectorsFilter {
     public static final int DEFAULT_MAX_QUERY_TERMS = 25;
     public static final int DEFAULT_MIN_TERM_FREQ = 0;
@@ -179,8 +181,9 @@ public void setMaxWordLength(int maxWordLength) {
     /**
      * Internal score term
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class ScoreTerm {
         public String field;
         public String word;
diff --git a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequest.java b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequest.java
index 825b0b4982880..a761cabb9599a 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequest.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequest.java
@@ -40,6 +40,7 @@
 import org.opensearch.action.get.MultiGetRequest;
 import org.opensearch.action.support.single.shard.SingleShardRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.common.xcontent.XContentType;
@@ -74,8 +75,9 @@
  * Note, the {@link #index()}, and {@link #id(String)} are
  * required.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TermVectorsRequest extends SingleShardRequest<TermVectorsRequest> implements RealtimeRequest {
     private static final ParseField INDEX = new ParseField("_index");
     private static final ParseField ID = new ParseField("_id");
@@ -118,8 +120,9 @@ public class TermVectorsRequest extends SingleShardRequest<TermVectorsRequest> i
     /**
      * Internal filter settings
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class FilterSettings {
         public Integer maxNumTerms;
         public Integer minTermFreq;
@@ -572,8 +575,9 @@ public void writeTo(StreamOutput out) throws IOException {
     /**
      * The flags.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Flag {
         // Do not change the order of these flags we use
         // the ordinal for encoding! Only append to the end!
diff --git a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequestBuilder.java b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequestBuilder.java
index 02cfff1a6682b..ce68c06206fef 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsRequestBuilder.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.ActionRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.VersionType;
 
@@ -46,8 +47,9 @@
  * Note, the {@code index}, {@code type} and {@code id} are
  * required.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TermVectorsRequestBuilder extends ActionRequestBuilder<TermVectorsRequest, TermVectorsResponse> {
 
     public TermVectorsRequestBuilder(OpenSearchClient client, TermVectorsAction action) {
diff --git a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsResponse.java b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsResponse.java
index 3c338ce7338bb..7ad27808588ae 100644
--- a/server/src/main/java/org/opensearch/action/termvectors/TermVectorsResponse.java
+++ b/server/src/main/java/org/opensearch/action/termvectors/TermVectorsResponse.java
@@ -41,6 +41,7 @@
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.CharsRefBuilder;
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.action.ActionResponse;
@@ -62,8 +63,9 @@
  * Response returning the term vector (doc frequency, positions, offsets) for a
  * document.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TermVectorsResponse extends ActionResponse implements ToXContentObject {
 
     /**
diff --git a/server/src/main/java/org/opensearch/action/update/TransportUpdateAction.java b/server/src/main/java/org/opensearch/action/update/TransportUpdateAction.java
index 95735f71a38e7..819112eb497f6 100644
--- a/server/src/main/java/org/opensearch/action/update/TransportUpdateAction.java
+++ b/server/src/main/java/org/opensearch/action/update/TransportUpdateAction.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.action.update;
 
+import org.opensearch.ExceptionsHelper;
 import org.opensearch.ResourceAlreadyExistsException;
 import org.opensearch.action.ActionRunnable;
 import org.opensearch.action.DocWriteRequest;
@@ -62,11 +63,13 @@
 import org.opensearch.core.common.io.stream.NotSerializableExceptionWrapper;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.MediaType;
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.index.IndexService;
 import org.opensearch.index.engine.VersionConflictEngineException;
 import org.opensearch.index.shard.IndexShard;
+import org.opensearch.index.shard.IndexingStats.Stats.DocStatusStats;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.tasks.Task;
 import org.opensearch.threadpool.ThreadPool;
@@ -154,10 +157,13 @@ public static void resolveAndValidateRouting(Metadata metadata, String concreteI
     @Override
     protected void doExecute(Task task, final UpdateRequest request, final ActionListener<UpdateResponse> listener) {
         if (request.isRequireAlias() && (clusterService.state().getMetadata().hasAlias(request.index()) == false)) {
-            throw new IndexNotFoundException(
+            IndexNotFoundException e = new IndexNotFoundException(
                 "[" + DocWriteRequest.REQUIRE_ALIAS + "] request flag is [true] and [" + request.index() + "] is not an alias",
                 request.index()
             );
+
+            incDocStatusStats(e);
+            throw e;
         }
         // if we don't have a master, we don't have metadata, that's fine, let it find a cluster-manager using create index API
         if (autoCreateIndex.shouldAutoCreate(request.index(), clusterService.state())) {
@@ -193,7 +199,10 @@ public void onFailure(Exception e) {
     }
 
     private void innerExecute(final Task task, final UpdateRequest request, final ActionListener<UpdateResponse> listener) {
-        super.doExecute(task, request, listener);
+        super.doExecute(task, request, ActionListener.wrap(listener::onResponse, e -> {
+            incDocStatusStats(e);
+            listener.onFailure(e);
+        }));
     }
 
     @Override
@@ -330,7 +339,13 @@ protected void shardOperation(final UpdateRequest request, final ActionListener<
                         shard.noopUpdate();
                     }
                 }
+
+                DocStatusStats stats = new DocStatusStats();
+                stats.inc(RestStatus.OK);
+
+                indicesService.addDocStatusStats(stats);
                 listener.onResponse(update);
+
                 break;
             default:
                 throw new IllegalStateException("Illegal result " + result.getResponseResult());
@@ -361,4 +376,10 @@ private void handleUpdateFailureWithRetry(
         }
         listener.onFailure(cause instanceof Exception ? (Exception) cause : new NotSerializableExceptionWrapper(cause));
     }
+
+    private void incDocStatusStats(final Exception e) {
+        DocStatusStats stats = new DocStatusStats();
+        stats.inc(ExceptionsHelper.status(e));
+        indicesService.addDocStatusStats(stats);
+    }
 }
diff --git a/server/src/main/java/org/opensearch/action/update/UpdateRequest.java b/server/src/main/java/org/opensearch/action/update/UpdateRequest.java
index b354482871521..9654bd1c114ba 100644
--- a/server/src/main/java/org/opensearch/action/update/UpdateRequest.java
+++ b/server/src/main/java/org/opensearch/action/update/UpdateRequest.java
@@ -42,6 +42,7 @@
 import org.opensearch.action.support.replication.ReplicationRequest;
 import org.opensearch.action.support.single.instance.InstanceShardOperationRequest;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentHelper;
@@ -74,8 +75,9 @@
 /**
  * Transport request for updating an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpdateRequest extends InstanceShardOperationRequest<UpdateRequest>
     implements
         DocWriteRequest<UpdateRequest>,
@@ -589,7 +591,7 @@ public long ifSeqNo() {
 
     /**
      * If set, only perform this update request if the document was last modification was assigned this primary term.
-     *
+     * <p>
      * If the document last modification was assigned a different term a
      * {@link org.opensearch.index.engine.VersionConflictEngineException} will be thrown.
      */
diff --git a/server/src/main/java/org/opensearch/action/update/UpdateRequestBuilder.java b/server/src/main/java/org/opensearch/action/update/UpdateRequestBuilder.java
index c97d0b4f5d13d..d662381ac5e19 100644
--- a/server/src/main/java/org/opensearch/action/update/UpdateRequestBuilder.java
+++ b/server/src/main/java/org/opensearch/action/update/UpdateRequestBuilder.java
@@ -39,6 +39,7 @@
 import org.opensearch.action.support.single.instance.InstanceShardOperationRequestBuilder;
 import org.opensearch.client.OpenSearchClient;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.xcontent.MediaType;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.VersionType;
@@ -49,8 +50,9 @@
 /**
  * Transport request builder for updating an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpdateRequestBuilder extends InstanceShardOperationRequestBuilder<UpdateRequest, UpdateResponse, UpdateRequestBuilder>
     implements
         WriteRequestBuilder<UpdateRequestBuilder> {
diff --git a/server/src/main/java/org/opensearch/action/update/UpdateResponse.java b/server/src/main/java/org/opensearch/action/update/UpdateResponse.java
index d9f6ceacb0f3b..c7ee1742af0f2 100644
--- a/server/src/main/java/org/opensearch/action/update/UpdateResponse.java
+++ b/server/src/main/java/org/opensearch/action/update/UpdateResponse.java
@@ -33,6 +33,7 @@
 package org.opensearch.action.update;
 
 import org.opensearch.action.DocWriteResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.index.shard.ShardId;
@@ -48,8 +49,9 @@
 /**
  * Transport response for updating an index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class UpdateResponse extends DocWriteResponse {
 
     private static final String GET = "get";
@@ -173,8 +175,9 @@ public static void parseXContentFields(XContentParser parser, Builder context) t
      * temporarily store the parsed values, then the {@link DocWriteResponse.Builder#build()} method is called to
      * instantiate the {@link UpdateResponse}.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder extends DocWriteResponse.Builder {
 
         private GetResult getResult = null;
diff --git a/server/src/main/java/org/opensearch/bootstrap/BootstrapChecks.java b/server/src/main/java/org/opensearch/bootstrap/BootstrapChecks.java
index f9661e71d60e6..e43c42446de2c 100644
--- a/server/src/main/java/org/opensearch/bootstrap/BootstrapChecks.java
+++ b/server/src/main/java/org/opensearch/bootstrap/BootstrapChecks.java
@@ -73,7 +73,7 @@
 
 /**
  * We enforce bootstrap checks once a node has the transport protocol bound to a non-loopback interface or if the system property {@code
- * opensearch.enforce.bootstrap.checks} is set to {@true}. In this case we assume the node is running in production and
+ * opensearch.enforce.bootstrap.checks} is set to {@code true}. In this case we assume the node is running in production and
  * all bootstrap checks must pass.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/bootstrap/JNAKernel32Library.java b/server/src/main/java/org/opensearch/bootstrap/JNAKernel32Library.java
index 8e556df4b2f9b..91da34fb7216d 100644
--- a/server/src/main/java/org/opensearch/bootstrap/JNAKernel32Library.java
+++ b/server/src/main/java/org/opensearch/bootstrap/JNAKernel32Library.java
@@ -141,7 +141,7 @@ public boolean callback(long dwCtrlType) {
 
     /**
      * Memory protection constraints
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/aa366786%28v=vs.85%29.aspx
      */
     public static final int PAGE_NOACCESS = 0x0001;
@@ -151,7 +151,7 @@ public boolean callback(long dwCtrlType) {
     /**
      * Contains information about a range of pages in the virtual address space of a process.
      * The VirtualQuery and VirtualQueryEx functions use this structure.
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/aa366775%28v=vs.85%29.aspx
      */
     public static class MemoryBasicInformation extends Structure {
@@ -186,7 +186,7 @@ public SizeT() {
     /**
      * Locks the specified region of the process's virtual address space into physical
      * memory, ensuring that subsequent access to the region will not incur a page fault.
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/aa366895%28v=vs.85%29.aspx
      *
      * @param address A pointer to the base address of the region of pages to be locked.
@@ -197,7 +197,7 @@ public SizeT() {
 
     /**
      * Retrieves information about a range of pages within the virtual address space of a specified process.
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/aa366907%28v=vs.85%29.aspx
      *
      * @param handle A handle to the process whose memory information is queried.
@@ -210,7 +210,7 @@ public SizeT() {
 
     /**
      * Sets the minimum and maximum working set sizes for the specified process.
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms686234%28v=vs.85%29.aspx
      *
      * @param handle A handle to the process whose working set sizes is to be set.
@@ -222,7 +222,7 @@ public SizeT() {
 
     /**
      * Retrieves a pseudo handle for the current process.
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms683179%28v=vs.85%29.aspx
      *
      * @return a pseudo handle to the current process.
@@ -231,7 +231,7 @@ public SizeT() {
 
     /**
      * Closes an open object handle.
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms724211%28v=vs.85%29.aspx
      *
      * @param handle A valid handle to an open object.
@@ -252,7 +252,7 @@ public SizeT() {
 
     /**
      * Creates or opens a new job object
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms682409%28v=vs.85%29.aspx
      *
      * @param jobAttributes security attributes
@@ -263,7 +263,7 @@ public SizeT() {
 
     /**
      * Associates a process with an existing job
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms681949%28v=vs.85%29.aspx
      *
      * @param job job handle
@@ -274,7 +274,7 @@ public SizeT() {
 
     /**
      * Basic limit information for a job object
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms684147%28v=vs.85%29.aspx
      */
     public static class JOBOBJECT_BASIC_LIMIT_INFORMATION extends Structure implements Structure.ByReference {
@@ -316,7 +316,7 @@ protected List<String> getFieldOrder() {
 
     /**
      * Get job limit and state information
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms684925%28v=vs.85%29.aspx
      *
      * @param job job handle
@@ -330,7 +330,7 @@ protected List<String> getFieldOrder() {
 
     /**
      * Set job limit and state information
-     *
+     * <p>
      * https://msdn.microsoft.com/en-us/library/windows/desktop/ms686216%28v=vs.85%29.aspx
      *
      * @param job job handle
diff --git a/server/src/main/java/org/opensearch/bootstrap/OpenSearch.java b/server/src/main/java/org/opensearch/bootstrap/OpenSearch.java
index ab52ae5a43a2a..4d36efff0e192 100644
--- a/server/src/main/java/org/opensearch/bootstrap/OpenSearch.java
+++ b/server/src/main/java/org/opensearch/bootstrap/OpenSearch.java
@@ -188,9 +188,9 @@ void init(final boolean daemonize, final Path pidFile, final boolean quiet, Envi
     /**
      * Required method that's called by Apache Commons procrun when
      * running as a service on Windows, when the service is stopped.
-     *
+     * <p>
      * http://commons.apache.org/proper/commons-daemon/procrun.html
-     *
+     * <p>
      * NOTE: If this method is renamed and/or moved, make sure to
      * update opensearch-service.bat!
      */
diff --git a/server/src/main/java/org/opensearch/cluster/AckedClusterStateTaskListener.java b/server/src/main/java/org/opensearch/cluster/AckedClusterStateTaskListener.java
index 482087be1c8eb..28e1e7c53cb9c 100644
--- a/server/src/main/java/org/opensearch/cluster/AckedClusterStateTaskListener.java
+++ b/server/src/main/java/org/opensearch/cluster/AckedClusterStateTaskListener.java
@@ -44,7 +44,7 @@ public interface AckedClusterStateTaskListener extends ClusterStateTaskListener
 
     /**
      * Called to determine which nodes the acknowledgement is expected from.
-     *
+     * <p>
      * As this method will be called multiple times to determine the set of acking nodes,
      * it is crucial for it to return consistent results: Given the same listener instance
      * and the same node parameter, the method implementation should return the same result.
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterChangedEvent.java b/server/src/main/java/org/opensearch/cluster/ClusterChangedEvent.java
index fab104142e5bb..904083e96032f 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterChangedEvent.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterChangedEvent.java
@@ -37,6 +37,7 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.Index;
 import org.opensearch.gateway.GatewayService;
 
@@ -52,8 +53,9 @@
 /**
  * An event received by the local node, signaling that the cluster state has changed.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterChangedEvent {
 
     private final String source;
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterInfo.java b/server/src/main/java/org/opensearch/cluster/ClusterInfo.java
index 5bd858a53bee2..4c38d6fd99f5d 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterInfo.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterInfo.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -56,8 +57,9 @@
  * <code>InternalClusterInfoService.shardIdentifierFromRouting(String)</code>
  * for the key used in the shardSizes map
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterInfo implements ToXContentFragment, Writeable {
     private final Map<String, DiskUsage> leastAvailableSpaceUsage;
     private final Map<String, DiskUsage> mostAvailableSpaceUsage;
@@ -287,8 +289,9 @@ public void writeTo(StreamOutput out) throws IOException {
     /**
      * Represents the total amount of "reserved" space on a particular data path, together with the set of shards considered.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ReservedSpace implements Writeable {
 
         public static final ReservedSpace EMPTY = new ReservedSpace(0, new HashSet<>());
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterName.java b/server/src/main/java/org/opensearch/cluster/ClusterName.java
index 44321f7de9395..d6149421c3fd0 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterName.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterName.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.cluster;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -45,8 +46,9 @@
 /**
  * Cluster Name
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterName implements Writeable {
 
     public static final Setting<ClusterName> CLUSTER_NAME_SETTING = new Setting<>("cluster.name", "opensearch", (s) -> {
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterState.java b/server/src/main/java/org/opensearch/cluster/ClusterState.java
index 1b87a60c2ccf5..9e63f961d241d 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterState.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterState.java
@@ -49,6 +49,7 @@
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.Strings;
@@ -97,8 +98,9 @@
  * throws the {@link IncompatibleClusterStateVersionException}, which causes the publishing mechanism to send
  * a full version of the cluster state to the node on which this exception was thrown.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterState implements ToXContentFragment, Diffable<ClusterState> {
 
     public static final ClusterState EMPTY_STATE = builder(ClusterName.CLUSTER_NAME_SETTING.getDefault(Settings.EMPTY)).build();
@@ -139,8 +141,9 @@ static <T extends VersionedNamedWriteable & FeatureAware> boolean shouldSerializ
     /**
      * Custom cluster state.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Custom extends NamedDiffable<Custom>, ToXContentFragment, FeatureAware {
 
         /**
@@ -596,8 +599,9 @@ public static Builder builder(ClusterState state) {
     /**
      * Builder for cluster state.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private final ClusterName clusterName;
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterStateApplier.java b/server/src/main/java/org/opensearch/cluster/ClusterStateApplier.java
index 140e6426bb801..d7702729ae884 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterStateApplier.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterStateApplier.java
@@ -33,13 +33,15 @@
 package org.opensearch.cluster;
 
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A component that is in charge of applying an incoming cluster state to the node internal data structures.
  * The single apply method is called before the cluster state becomes visible via {@link ClusterService#state()}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ClusterStateApplier {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterStateListener.java b/server/src/main/java/org/opensearch/cluster/ClusterStateListener.java
index 01a8e51a3d13e..57fcfcad099ed 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterStateListener.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterStateListener.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.cluster;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * A listener to be notified when a cluster state changes.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ClusterStateListener {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterStateTaskConfig.java b/server/src/main/java/org/opensearch/cluster/ClusterStateTaskConfig.java
index 9a4b708548a7d..149d93a158007 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterStateTaskConfig.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterStateTaskConfig.java
@@ -33,13 +33,15 @@
 
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * Cluster state update task configuration for timeout and priority
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ClusterStateTaskConfig {
     /**
      * The timeout for this cluster state update task configuration. If
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterStateTaskExecutor.java b/server/src/main/java/org/opensearch/cluster/ClusterStateTaskExecutor.java
index 50beeb1f03deb..115816798959e 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterStateTaskExecutor.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterStateTaskExecutor.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.cluster.service.ClusterManagerTaskThrottler;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.IdentityHashMap;
 import java.util.List;
@@ -41,8 +42,9 @@
 /**
  * Interface that updates the cluster state based on the task
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ClusterStateTaskExecutor<T> {
     /**
      * Update the cluster state based on the current state and the given tasks. Return the *same instance* if no state
@@ -70,7 +72,7 @@ default boolean runOnlyOnMaster() {
     /**
      * Callback invoked after new cluster state is published. Note that
      * this method is not invoked if the cluster state was not updated.
-     *
+     * <p>
      * Note that this method will be executed using system context.
      *
      * @param clusterChangedEvent the change event for this cluster state change, containing
@@ -80,7 +82,7 @@ default void clusterStatePublished(ClusterChangedEvent clusterChangedEvent) {}
 
     /**
      * Builds a concise description of a list of tasks (to be used in logging etc.).
-     *
+     * <p>
      * Note that the tasks given are not necessarily the same as those that will be passed to {@link #execute(ClusterState, List)}.
      * but are guaranteed to be a subset of them. This method can be called multiple times with different lists before execution.
      * This allows groupd task description but the submitting source.
@@ -103,8 +105,9 @@ default ClusterManagerTaskThrottler.ThrottlingKey getClusterManagerThrottlingKey
      * Represents the result of a batched execution of cluster state update tasks
      * @param <T> the type of the cluster state update task
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     class ClusterTasksResult<T> {
         @Nullable
         public final ClusterState resultingState;
@@ -127,8 +130,9 @@ public static <T> Builder<T> builder() {
         /**
          * Builder for cluster state task.
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class Builder<T> {
             private final Map<T, TaskResult> executionResults = new IdentityHashMap<>();
 
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterStateTaskListener.java b/server/src/main/java/org/opensearch/cluster/ClusterStateTaskListener.java
index d6c4abfad7b8d..0cb24bd3f3eab 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterStateTaskListener.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterStateTaskListener.java
@@ -32,14 +32,16 @@
 package org.opensearch.cluster;
 
 import org.opensearch.cluster.service.ClusterManagerService;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.List;
 
 /**
  * Interface to implement a cluster state change listener
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ClusterStateTaskListener {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/ClusterStateUpdateTask.java b/server/src/main/java/org/opensearch/cluster/ClusterStateUpdateTask.java
index 9225914a931b2..ae6626dd4785d 100644
--- a/server/src/main/java/org/opensearch/cluster/ClusterStateUpdateTask.java
+++ b/server/src/main/java/org/opensearch/cluster/ClusterStateUpdateTask.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 import java.util.List;
@@ -41,8 +42,9 @@
 /**
  * A task that can update the cluster state.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class ClusterStateUpdateTask
     implements
         ClusterStateTaskConfig,
diff --git a/server/src/main/java/org/opensearch/cluster/Diff.java b/server/src/main/java/org/opensearch/cluster/Diff.java
index c0e8e7038d9b4..77301b7c04b66 100644
--- a/server/src/main/java/org/opensearch/cluster/Diff.java
+++ b/server/src/main/java/org/opensearch/cluster/Diff.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.cluster;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.Writeable;
 
 /**
  * Represents difference between states of cluster state parts
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface Diff<T> extends Writeable {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/DiffableUtils.java b/server/src/main/java/org/opensearch/cluster/DiffableUtils.java
index dd2232968114e..a38fc81bebc08 100644
--- a/server/src/main/java/org/opensearch/cluster/DiffableUtils.java
+++ b/server/src/main/java/org/opensearch/cluster/DiffableUtils.java
@@ -182,7 +182,7 @@ public Map<K, T> apply(Map<K, T> map) {
 
     /**
      * Represents differences between two maps of objects and is used as base class for different map implementations.
-     *
+     * <p>
      * Implements serialization. How differences are applied is left to subclasses.
      *
      * @param <K> the type of map keys
@@ -381,9 +381,9 @@ public Integer readKey(StreamInput in) throws IOException {
     /**
      * Provides read and write operations to serialize map values.
      * Reading of values can be made dependent on map key.
-     *
+     * <p>
      * Also provides operations to distinguish whether map values are diffable.
-     *
+     * <p>
      * Should not be directly implemented, instead implement either
      * {@link DiffableValueSerializer} or {@link NonDiffableValueSerializer}.
      *
@@ -517,7 +517,7 @@ public Diff<V> readDiff(StreamInput in, K key) throws IOException {
 
     /**
      * Implementation of the ValueSerializer that wraps value and diff readers.
-     *
+     * <p>
      * Note: this implementation is ignoring the key.
      *
      * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/cluster/DiskUsage.java b/server/src/main/java/org/opensearch/cluster/DiskUsage.java
index c472522baee51..33ed030c58a02 100644
--- a/server/src/main/java/org/opensearch/cluster/DiskUsage.java
+++ b/server/src/main/java/org/opensearch/cluster/DiskUsage.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.cluster;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,8 +47,9 @@
 /**
  * Encapsulation class used to represent the amount of disk used on a node.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DiskUsage implements ToXContentFragment, Writeable {
     final String nodeId;
     final String nodeName;
diff --git a/server/src/main/java/org/opensearch/cluster/InternalClusterInfoService.java b/server/src/main/java/org/opensearch/cluster/InternalClusterInfoService.java
index 35490d2f37a49..e381b8f244bf3 100644
--- a/server/src/main/java/org/opensearch/cluster/InternalClusterInfoService.java
+++ b/server/src/main/java/org/opensearch/cluster/InternalClusterInfoService.java
@@ -82,7 +82,7 @@
  * to 30 seconds). The InternalClusterInfoService only runs on the cluster-manager node.
  * Listens for changes in the number of data nodes and immediately submits a
  * ClusterInfoUpdateJob if a node has been added.
- *
+ * <p>
  * Every time the timer runs, gathers information about the disk usage and
  * shard sizes across the cluster.
  *
diff --git a/server/src/main/java/org/opensearch/cluster/LocalNodeClusterManagerListener.java b/server/src/main/java/org/opensearch/cluster/LocalNodeClusterManagerListener.java
index c07dcc5daaee6..0b2ed7ef66d43 100644
--- a/server/src/main/java/org/opensearch/cluster/LocalNodeClusterManagerListener.java
+++ b/server/src/main/java/org/opensearch/cluster/LocalNodeClusterManagerListener.java
@@ -31,12 +31,15 @@
 
 package org.opensearch.cluster;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Enables listening to cluster-manager changes events of the local node (when the local node becomes the cluster-manager, and when the local
  * node cease being a cluster-manager).
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface LocalNodeClusterManagerListener extends ClusterStateListener {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/LocalNodeMasterListener.java b/server/src/main/java/org/opensearch/cluster/LocalNodeMasterListener.java
index 31c0b294b8004..2487aaf0d7c51 100644
--- a/server/src/main/java/org/opensearch/cluster/LocalNodeMasterListener.java
+++ b/server/src/main/java/org/opensearch/cluster/LocalNodeMasterListener.java
@@ -31,14 +31,17 @@
 
 package org.opensearch.cluster;
 
+import org.opensearch.common.annotation.DeprecatedApi;
+
 /**
  * Enables listening to cluster-manager changes events of the local node (when the local node becomes the cluster-manager, and when the local
  * node cease being a cluster-manager).
  *
- * @opensearch.internal
+ * @opensearch.api
  * @deprecated As of 2.2, because supporting inclusive language, replaced by {@link LocalNodeClusterManagerListener}
  */
 @Deprecated
+@DeprecatedApi(since = "2.2.0")
 public interface LocalNodeMasterListener extends LocalNodeClusterManagerListener {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/NamedDiff.java b/server/src/main/java/org/opensearch/cluster/NamedDiff.java
index ce971aa723394..e994cfb224386 100644
--- a/server/src/main/java/org/opensearch/cluster/NamedDiff.java
+++ b/server/src/main/java/org/opensearch/cluster/NamedDiff.java
@@ -33,13 +33,15 @@
 package org.opensearch.cluster;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.NamedWriteable;
 
 /**
  * Diff that also support NamedWriteable interface
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface NamedDiff<T extends Diffable<T>> extends Diff<T>, NamedWriteable {
     /**
      * The minimal version of the recipient this custom object can be sent to
diff --git a/server/src/main/java/org/opensearch/cluster/NodeConnectionsService.java b/server/src/main/java/org/opensearch/cluster/NodeConnectionsService.java
index 5b7bb19a935b1..1c12c260b3929 100644
--- a/server/src/main/java/org/opensearch/cluster/NodeConnectionsService.java
+++ b/server/src/main/java/org/opensearch/cluster/NodeConnectionsService.java
@@ -43,6 +43,7 @@
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.cluster.service.ClusterApplier;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
 import org.opensearch.common.settings.Setting;
@@ -81,8 +82,9 @@
  * This component does not block on disconnections at all, because a disconnection might need to wait for an ongoing (background) connection
  * attempt to complete first.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodeConnectionsService extends AbstractLifecycleComponent {
     private static final Logger logger = LogManager.getLogger(NodeConnectionsService.class);
 
diff --git a/server/src/main/java/org/opensearch/cluster/RestoreInProgress.java b/server/src/main/java/org/opensearch/cluster/RestoreInProgress.java
index 042a4743ca25d..769f97373f7b7 100644
--- a/server/src/main/java/org/opensearch/cluster/RestoreInProgress.java
+++ b/server/src/main/java/org/opensearch/cluster/RestoreInProgress.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.cluster.ClusterState.Custom;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -54,8 +55,9 @@
 /**
  * Meta data about restore processes that are currently executing
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RestoreInProgress extends AbstractNamedDiffable<Custom> implements Custom, Iterable<RestoreInProgress.Entry> {
 
     /**
@@ -139,8 +141,9 @@ public RestoreInProgress build() {
     /**
      * Restore metadata
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Entry {
         private final String uuid;
         private final State state;
@@ -189,7 +192,7 @@ public Snapshot snapshot() {
         /**
          * Returns list of shards that being restore and their status
          *
-         * @return list of shards
+         * @return map of shard id to shard restore status
          */
         public Map<ShardId, ShardRestoreStatus> shards() {
             return this.shards;
@@ -238,8 +241,9 @@ public int hashCode() {
     /**
      * Represents status of a restored shard
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ShardRestoreStatus implements Writeable {
         private State state;
         private String nodeId;
@@ -363,8 +367,9 @@ public int hashCode() {
     /**
      * Shard restore process state
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum State {
         /**
          * Initializing state
diff --git a/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java b/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java
index 952591f346536..3de23d2490c63 100644
--- a/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java
+++ b/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.ClusterState.Custom;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -928,8 +929,9 @@ public String toString() {
     /**
      * State of the snapshots.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum State {
         INIT((byte) 0, false),
         STARTED((byte) 1, false),
diff --git a/server/src/main/java/org/opensearch/cluster/TimeoutClusterStateListener.java b/server/src/main/java/org/opensearch/cluster/TimeoutClusterStateListener.java
index eb31fa2b7e69d..f0fa5af64d157 100644
--- a/server/src/main/java/org/opensearch/cluster/TimeoutClusterStateListener.java
+++ b/server/src/main/java/org/opensearch/cluster/TimeoutClusterStateListener.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.cluster;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * An exception to cluster state listener that allows for timeouts and for post added notifications.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface TimeoutClusterStateListener extends ClusterStateListener {
 
     void postAdded();
diff --git a/server/src/main/java/org/opensearch/cluster/ack/ClusterStateUpdateResponse.java b/server/src/main/java/org/opensearch/cluster/ack/ClusterStateUpdateResponse.java
index db26496c6f263..837bf8af449ad 100644
--- a/server/src/main/java/org/opensearch/cluster/ack/ClusterStateUpdateResponse.java
+++ b/server/src/main/java/org/opensearch/cluster/ack/ClusterStateUpdateResponse.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.cluster.ack;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Base response returned after a cluster state update
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterStateUpdateResponse {
 
     private final boolean acknowledged;
diff --git a/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributeValueHealth.java b/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributeValueHealth.java
index eae79e2ac0986..b4d797a39dd2f 100644
--- a/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributeValueHealth.java
+++ b/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributeValueHealth.java
@@ -14,6 +14,7 @@
 import org.opensearch.cluster.routing.RoutingNode;
 import org.opensearch.cluster.routing.ShardRoutingState;
 import org.opensearch.cluster.routing.WeightedRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -31,7 +32,10 @@
 
 /**
  * Cluster Awareness AttributeValue Health information
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterAwarenessAttributeValueHealth implements Writeable, ToXContentFragment {
 
     private static final String ACTIVE_SHARDS = "active_shards";
diff --git a/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributesHealth.java b/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributesHealth.java
index 01d9cfc4438e3..3de2260d0e8bd 100644
--- a/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributesHealth.java
+++ b/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessAttributesHealth.java
@@ -11,6 +11,7 @@
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -34,7 +35,9 @@
 /**
  * Cluster Awareness health information
  *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterAwarenessAttributesHealth implements Iterable<ClusterAwarenessAttributeValueHealth>, Writeable, ToXContentFragment {
 
     private final String awarenessAttributeName;
diff --git a/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessHealth.java b/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessHealth.java
index 1643db5a1f460..841764110626d 100644
--- a/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessHealth.java
+++ b/server/src/main/java/org/opensearch/cluster/awarenesshealth/ClusterAwarenessHealth.java
@@ -11,6 +11,7 @@
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.routing.allocation.AwarenessReplicaBalance;
 import org.opensearch.cluster.routing.allocation.decider.AwarenessAllocationDecider;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -30,7 +31,10 @@
 
 /**
  * Cluster state Awareness health information
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterAwarenessHealth implements Writeable, ToXContentFragment, Iterable<ClusterAwarenessAttributesHealth> {
 
     private static final String AWARENESS_ATTRIBUTE = "awareness_attributes";
diff --git a/server/src/main/java/org/opensearch/cluster/block/ClusterBlock.java b/server/src/main/java/org/opensearch/cluster/block/ClusterBlock.java
index 40a5080ba74e7..5fa897c0b1185 100644
--- a/server/src/main/java/org/opensearch/cluster/block/ClusterBlock.java
+++ b/server/src/main/java/org/opensearch/cluster/block/ClusterBlock.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.block;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -48,8 +49,9 @@
 /**
  * Blocks the cluster for concurrency
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterBlock implements Writeable, ToXContentFragment {
 
     private final int id;
diff --git a/server/src/main/java/org/opensearch/cluster/block/ClusterBlockException.java b/server/src/main/java/org/opensearch/cluster/block/ClusterBlockException.java
index 4673f075e8439..ea6c0c69c523d 100644
--- a/server/src/main/java/org/opensearch/cluster/block/ClusterBlockException.java
+++ b/server/src/main/java/org/opensearch/cluster/block/ClusterBlockException.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.block;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.rest.RestStatus;
@@ -49,8 +50,9 @@
 /**
  * Internal exception on obtaining a cluster block
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterBlockException extends OpenSearchException {
     private final Set<ClusterBlock> blocks;
 
diff --git a/server/src/main/java/org/opensearch/cluster/block/ClusterBlockLevel.java b/server/src/main/java/org/opensearch/cluster/block/ClusterBlockLevel.java
index 5ec847e100c86..5d3bf94aedb19 100644
--- a/server/src/main/java/org/opensearch/cluster/block/ClusterBlockLevel.java
+++ b/server/src/main/java/org/opensearch/cluster/block/ClusterBlockLevel.java
@@ -32,13 +32,16 @@
 
 package org.opensearch.cluster.block;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.EnumSet;
 
 /**
  * What level to block the cluster
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum ClusterBlockLevel {
     READ,
     WRITE,
diff --git a/server/src/main/java/org/opensearch/cluster/block/ClusterBlocks.java b/server/src/main/java/org/opensearch/cluster/block/ClusterBlocks.java
index bcb4f7f71268e..304136166d515 100644
--- a/server/src/main/java/org/opensearch/cluster/block/ClusterBlocks.java
+++ b/server/src/main/java/org/opensearch/cluster/block/ClusterBlocks.java
@@ -37,6 +37,7 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.MetadataIndexStateService;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -59,8 +60,9 @@
 /**
  * Represents current cluster level blocks to block dirty operations done against the cluster.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterBlocks extends AbstractDiffable<ClusterBlocks> {
     public static final ClusterBlocks EMPTY_CLUSTER_BLOCK = new ClusterBlocks(emptySet(), Map.of());
 
@@ -355,8 +357,9 @@ public static Builder builder() {
     /**
      * Builder for cluster blocks.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private final Set<ClusterBlock> global = new HashSet<>();
diff --git a/server/src/main/java/org/opensearch/cluster/block/IndexCreateBlockException.java b/server/src/main/java/org/opensearch/cluster/block/IndexCreateBlockException.java
index 729d76c72e99e..3e9fa3e23a12f 100644
--- a/server/src/main/java/org/opensearch/cluster/block/IndexCreateBlockException.java
+++ b/server/src/main/java/org/opensearch/cluster/block/IndexCreateBlockException.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.cluster.block;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -16,8 +17,9 @@
 /**
  * Internal exception on obtaining an index create block
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexCreateBlockException extends ClusterBlockException {
 
     public IndexCreateBlockException(Set<ClusterBlock> globalLevelBlocks) {
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/ClusterStatePublisher.java b/server/src/main/java/org/opensearch/cluster/coordination/ClusterStatePublisher.java
index 39d05e672f977..0ef8262a216ee 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/ClusterStatePublisher.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/ClusterStatePublisher.java
@@ -34,23 +34,25 @@
 import org.opensearch.cluster.ClusterChangedEvent;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.action.ActionListener;
 
 /**
  * Publishes the cluster state
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ClusterStatePublisher {
     /**
      * Publish all the changes to the cluster from the cluster-manager (can be called just by the cluster-manager). The publish
      * process should apply this state to the cluster-manager as well!
-     *
+     * <p>
      * The publishListener allows to wait for the publication to complete, which can be either successful completion, timing out or failing.
      * The method is guaranteed to pass back a {@link FailedToCommitClusterStateException} to the publishListener if the change is not
      * committed and should be rejected. Any other exception signals that something bad happened but the change is committed.
-     *
+     * <p>
      * The {@link AckListener} allows to keep track of the ack received from nodes, and verify whether
      * they updated their own cluster state or not.
      */
@@ -59,8 +61,9 @@ public interface ClusterStatePublisher {
     /**
      * An acknowledgement listener.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface AckListener {
         /**
          * Should be called when the cluster coordination layer has committed the cluster state (i.e. even if this publication fails,
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/CoordinationMetadata.java b/server/src/main/java/org/opensearch/cluster/coordination/CoordinationMetadata.java
index 869c86ae75b90..53398d6f3f98f 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/CoordinationMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/CoordinationMetadata.java
@@ -32,6 +32,7 @@
 package org.opensearch.cluster.coordination;
 
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -55,8 +56,9 @@
 /**
  * Metadata for cluster coordination
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CoordinationMetadata implements Writeable, ToXContentFragment {
 
     public static final CoordinationMetadata EMPTY_METADATA = builder().build();
@@ -214,8 +216,9 @@ public String toString() {
     /**
      * Builder for coordination metadata.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
         private long term = 0;
         private VotingConfiguration lastCommittedConfiguration = VotingConfiguration.EMPTY_CONFIG;
@@ -266,8 +269,9 @@ public CoordinationMetadata build() {
     /**
      * Excluded nodes from voting config.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class VotingConfigExclusion implements Writeable, ToXContentFragment {
         public static final String MISSING_VALUE_MARKER = "_absent_";
         private final String nodeId;
@@ -362,8 +366,9 @@ public String toString() {
     /**
      * A collection of persistent node ids, denoting the voting configuration for cluster state changes.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class VotingConfiguration implements Writeable, ToXContentFragment {
 
         public static final VotingConfiguration EMPTY_CONFIG = new VotingConfiguration(Collections.emptySet());
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/CoordinationState.java b/server/src/main/java/org/opensearch/cluster/coordination/CoordinationState.java
index a339852e6ed8d..987a3e3ffa7d3 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/CoordinationState.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/CoordinationState.java
@@ -638,6 +638,12 @@ public interface PersistedState extends Closeable {
          */
         void setLastAcceptedState(ClusterState clusterState);
 
+        /**
+         * Returns the stats for the persistence layer for {@link CoordinationState}.
+         * @return PersistedStateStats
+         */
+        PersistedStateStats getStats();
+
         /**
          * Marks the last accepted cluster state as committed.
          * After a successful call to this method, {@link #getLastAcceptedState()} should return the last cluster state that was set,
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java b/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java
index eb30460ca1b7f..5a07f964f94a4 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java
@@ -56,6 +56,7 @@
 import org.opensearch.cluster.service.ClusterApplier;
 import org.opensearch.cluster.service.ClusterApplier.ClusterApplyListener;
 import org.opensearch.cluster.service.ClusterManagerService;
+import org.opensearch.cluster.service.ClusterStateStats;
 import org.opensearch.common.Booleans;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Priority;
@@ -260,9 +261,10 @@ public Coordinator(
             this::handlePublishRequest,
             this::handleApplyCommit
         );
-        this.leaderChecker = new LeaderChecker(settings, transportService, this::onLeaderFailure, nodeHealthService);
+        this.leaderChecker = new LeaderChecker(settings, clusterSettings, transportService, this::onLeaderFailure, nodeHealthService);
         this.followersChecker = new FollowersChecker(
             settings,
+            clusterSettings,
             transportService,
             this::onFollowerCheckRequest,
             this::removeNode,
@@ -865,7 +867,16 @@ protected void doStart() {
 
     @Override
     public DiscoveryStats stats() {
-        return new DiscoveryStats(new PendingClusterStateStats(0, 0, 0), publicationHandler.stats());
+        ClusterStateStats clusterStateStats = clusterManagerService.getClusterStateStats();
+        ArrayList<PersistedStateStats> stats = new ArrayList<>();
+        Stream.of(PersistedStateRegistry.PersistedStateType.values()).forEach(stateType -> {
+            if (persistedStateRegistry.getPersistedState(stateType) != null
+                && persistedStateRegistry.getPersistedState(stateType).getStats() != null) {
+                stats.add(persistedStateRegistry.getPersistedState(stateType).getStats());
+            }
+        });
+        clusterStateStats.setPersistenceStats(stats);
+        return new DiscoveryStats(new PendingClusterStateStats(0, 0, 0), publicationHandler.stats(), clusterStateStats);
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/FollowersChecker.java b/server/src/main/java/org/opensearch/cluster/coordination/FollowersChecker.java
index f69a4f771cf21..70bb0515bb022 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/FollowersChecker.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/FollowersChecker.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.coordination.Coordinator.Mode;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
@@ -98,7 +99,9 @@ public class FollowersChecker {
         "cluster.fault_detection.follower_check.timeout",
         TimeValue.timeValueMillis(10000),
         TimeValue.timeValueMillis(1),
-        Setting.Property.NodeScope
+        TimeValue.timeValueMillis(60000),
+        Setting.Property.NodeScope,
+        Setting.Property.Dynamic
     );
 
     // the number of failed checks that must happen before the follower is considered to have failed.
@@ -112,7 +115,7 @@ public class FollowersChecker {
     private final Settings settings;
 
     private final TimeValue followerCheckInterval;
-    private final TimeValue followerCheckTimeout;
+    private TimeValue followerCheckTimeout;
     private final int followerCheckRetryCount;
     private final BiConsumer<DiscoveryNode, String> onNodeFailure;
     private final Consumer<FollowerCheckRequest> handleRequestAndUpdateState;
@@ -127,6 +130,7 @@ public class FollowersChecker {
 
     public FollowersChecker(
         Settings settings,
+        ClusterSettings clusterSettings,
         TransportService transportService,
         Consumer<FollowerCheckRequest> handleRequestAndUpdateState,
         BiConsumer<DiscoveryNode, String> onNodeFailure,
@@ -141,7 +145,7 @@ public FollowersChecker(
         followerCheckInterval = FOLLOWER_CHECK_INTERVAL_SETTING.get(settings);
         followerCheckTimeout = FOLLOWER_CHECK_TIMEOUT_SETTING.get(settings);
         followerCheckRetryCount = FOLLOWER_CHECK_RETRY_COUNT_SETTING.get(settings);
-
+        clusterSettings.addSettingsUpdateConsumer(FOLLOWER_CHECK_TIMEOUT_SETTING, this::setFollowerCheckTimeout);
         updateFastResponseState(0, Mode.CANDIDATE);
         transportService.registerRequestHandler(
             FOLLOWER_CHECK_ACTION_NAME,
@@ -159,6 +163,10 @@ public void onNodeDisconnected(DiscoveryNode node, Transport.Connection connecti
         });
     }
 
+    private void setFollowerCheckTimeout(TimeValue followerCheckTimeout) {
+        this.followerCheckTimeout = followerCheckTimeout;
+    }
+
     /**
      * Update the set of known nodes, starting to check any new ones and stopping checking any previously-known-but-now-unknown ones.
      */
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/InMemoryPersistedState.java b/server/src/main/java/org/opensearch/cluster/coordination/InMemoryPersistedState.java
index 67ef82ee7b2e9..b77ede5471534 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/InMemoryPersistedState.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/InMemoryPersistedState.java
@@ -65,6 +65,11 @@ public void setLastAcceptedState(ClusterState clusterState) {
         this.acceptedState = clusterState;
     }
 
+    @Override
+    public PersistedStateStats getStats() {
+        return null;
+    }
+
     @Override
     public long getCurrentTerm() {
         return currentTerm;
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/JoinTaskExecutor.java b/server/src/main/java/org/opensearch/cluster/coordination/JoinTaskExecutor.java
index 15eaf9c8bcc1e..f701a2f52277d 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/JoinTaskExecutor.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/JoinTaskExecutor.java
@@ -483,10 +483,10 @@ public static void ensureNodeCommissioned(DiscoveryNode node, Metadata metadata)
      * 2. The joining node has to be a non-remote store backed if it is joining a non-remote store backed cluster.
      * Validates no remote store attributes are present in joining node as existing nodes in the cluster doesn't have
      * remote store attributes.
-     *
+     * <p>
      * A remote store backed node is the one which holds all the remote store attributes and a remote store backed
      * cluster is the one which has only homogeneous remote store backed nodes with same node attributes
-     *
+     * <p>
      * TODO: When we support moving from remote store cluster to non remote store and vice versa the this logic will
      *       needs to be modified.
      */
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/LeaderChecker.java b/server/src/main/java/org/opensearch/cluster/coordination/LeaderChecker.java
index 69ba1f977f326..8d4373b865f62 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/LeaderChecker.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/LeaderChecker.java
@@ -40,6 +40,7 @@
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.lease.Releasable;
+import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
@@ -97,7 +98,9 @@ public class LeaderChecker {
         "cluster.fault_detection.leader_check.timeout",
         TimeValue.timeValueMillis(10000),
         TimeValue.timeValueMillis(1),
-        Setting.Property.NodeScope
+        TimeValue.timeValueMillis(60000),
+        Setting.Property.NodeScope,
+        Setting.Property.Dynamic
     );
 
     // the number of failed checks that must happen before the leader is considered to have failed.
@@ -111,7 +114,7 @@ public class LeaderChecker {
     private final Settings settings;
 
     private final TimeValue leaderCheckInterval;
-    private final TimeValue leaderCheckTimeout;
+    private TimeValue leaderCheckTimeout;
     private final int leaderCheckRetryCount;
     private final TransportService transportService;
     private final Consumer<Exception> onLeaderFailure;
@@ -123,6 +126,7 @@ public class LeaderChecker {
 
     LeaderChecker(
         final Settings settings,
+        final ClusterSettings clusterSettings,
         final TransportService transportService,
         final Consumer<Exception> onLeaderFailure,
         NodeHealthService nodeHealthService
@@ -134,6 +138,7 @@ public class LeaderChecker {
         this.transportService = transportService;
         this.onLeaderFailure = onLeaderFailure;
         this.nodeHealthService = nodeHealthService;
+        clusterSettings.addSettingsUpdateConsumer(LEADER_CHECK_TIMEOUT_SETTING, this::setLeaderCheckTimeout);
 
         transportService.registerRequestHandler(
             LEADER_CHECK_ACTION_NAME,
@@ -155,6 +160,10 @@ public void onNodeDisconnected(DiscoveryNode node, Transport.Connection connecti
         });
     }
 
+    private void setLeaderCheckTimeout(TimeValue leaderCheckTimeout) {
+        this.leaderCheckTimeout = leaderCheckTimeout;
+    }
+
     public DiscoveryNode leader() {
         CheckScheduler checkScheduler = currentChecker.get();
         return checkScheduler == null ? null : checkScheduler.leader;
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/PersistedStateStats.java b/server/src/main/java/org/opensearch/cluster/coordination/PersistedStateStats.java
new file mode 100644
index 0000000000000..0b7ed4fee5775
--- /dev/null
+++ b/server/src/main/java/org/opensearch/cluster/coordination/PersistedStateStats.java
@@ -0,0 +1,134 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.cluster.coordination;
+
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.xcontent.ToXContentObject;
+import org.opensearch.core.xcontent.XContentBuilder;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * Persisted cluster state related stats.
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "2.12.0")
+public class PersistedStateStats implements Writeable, ToXContentObject {
+    private final String statsName;
+    private AtomicLong totalTimeInMillis = new AtomicLong(0);
+    private AtomicLong failedCount = new AtomicLong(0);
+    private AtomicLong successCount = new AtomicLong(0);
+    private Map<String, AtomicLong> extendedFields = new HashMap<>(); // keeping minimal extensibility
+
+    public PersistedStateStats(String statsName) {
+        this.statsName = statsName;
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeString(statsName);
+        out.writeVLong(successCount.get());
+        out.writeVLong(failedCount.get());
+        out.writeVLong(totalTimeInMillis.get());
+        if (extendedFields.size() > 0) {
+            out.writeBoolean(true);
+            out.writeVInt(extendedFields.size());
+            for (Map.Entry<String, AtomicLong> extendedField : extendedFields.entrySet()) {
+                out.writeString(extendedField.getKey());
+                out.writeVLong(extendedField.getValue().get());
+            }
+        } else {
+            out.writeBoolean(false);
+        }
+    }
+
+    public PersistedStateStats(StreamInput in) throws IOException {
+        this.statsName = in.readString();
+        this.successCount = new AtomicLong(in.readVLong());
+        this.failedCount = new AtomicLong(in.readVLong());
+        this.totalTimeInMillis = new AtomicLong(in.readVLong());
+        if (in.readBoolean()) {
+            int extendedFieldsSize = in.readVInt();
+            this.extendedFields = new HashMap<>();
+            for (int fieldNumber = 0; fieldNumber < extendedFieldsSize; fieldNumber++) {
+                extendedFields.put(in.readString(), new AtomicLong(in.readVLong()));
+            }
+        }
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(statsName);
+        builder.field(Fields.SUCCESS_COUNT, getSuccessCount());
+        builder.field(Fields.FAILED_COUNT, getFailedCount());
+        builder.field(Fields.TOTAL_TIME_IN_MILLIS, getTotalTimeInMillis());
+        if (extendedFields.size() > 0) {
+            for (Map.Entry<String, AtomicLong> extendedField : extendedFields.entrySet()) {
+                builder.field(extendedField.getKey(), extendedField.getValue().get());
+            }
+        }
+        builder.endObject();
+        return builder;
+    }
+
+    public void stateFailed() {
+        failedCount.incrementAndGet();
+    }
+
+    public void stateSucceeded() {
+        successCount.incrementAndGet();
+    }
+
+    /**
+     * Expects user to send time taken in milliseconds.
+     *
+     * @param timeTakenInUpload time taken in uploading the cluster state to remote
+     */
+    public void stateTook(long timeTakenInUpload) {
+        totalTimeInMillis.addAndGet(timeTakenInUpload);
+    }
+
+    public long getTotalTimeInMillis() {
+        return totalTimeInMillis.get();
+    }
+
+    public long getFailedCount() {
+        return failedCount.get();
+    }
+
+    public long getSuccessCount() {
+        return successCount.get();
+    }
+
+    protected void addToExtendedFields(String extendedField, AtomicLong extendedFieldValue) {
+        this.extendedFields.put(extendedField, extendedFieldValue);
+    }
+
+    public String getStatsName() {
+        return statsName;
+    }
+
+    /**
+     * Fields for parsing and toXContent
+     *
+     * @opensearch.internal
+     */
+    static final class Fields {
+        static final String SUCCESS_COUNT = "success_count";
+        static final String TOTAL_TIME_IN_MILLIS = "total_time_in_millis";
+        static final String FAILED_COUNT = "failed_count";
+    }
+}
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/Reconfigurator.java b/server/src/main/java/org/opensearch/cluster/coordination/Reconfigurator.java
index 1570a84ab871f..128bd42fd7947 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/Reconfigurator.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/Reconfigurator.java
@@ -63,7 +63,7 @@ public class Reconfigurator {
      * and still the cluster would be unavailable. However not reducing the voting configuration size can also hamper resilience: in a
      * five-node cluster we could lose two nodes and by reducing the voting configuration to the remaining three nodes we could tolerate the
      * loss of a further node before failing.
-     *
+     * <p>
      * We offer two options: either we auto-shrink the voting configuration as long as it contains more than three nodes, or we don't and we
      * require the user to control the voting configuration manually using the retirement API. The former, default, option, guarantees that
      * as long as there have been at least three cluster-manager-eligible nodes in the cluster and no more than one of them is currently unavailable,
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/UnsafeBootstrapClusterManagerCommand.java b/server/src/main/java/org/opensearch/cluster/coordination/UnsafeBootstrapClusterManagerCommand.java
index 188ea1325e806..168ae5212888f 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/UnsafeBootstrapClusterManagerCommand.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/UnsafeBootstrapClusterManagerCommand.java
@@ -53,6 +53,8 @@
 import java.util.Locale;
 import java.util.Objects;
 
+import static org.opensearch.gateway.remote.RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING;
+
 /**
  * Tool to run an unsafe bootstrap
  *
@@ -81,7 +83,11 @@ public class UnsafeBootstrapClusterManagerCommand extends OpenSearchNodeCommand
     static final Setting<String> UNSAFE_BOOTSTRAP = ClusterService.USER_DEFINED_METADATA.getConcreteSetting(
         "cluster.metadata.unsafe-bootstrap"
     );
-
+    static final String REMOTE_CLUSTER_STATE_ENABLED_NODE =
+        "Unsafe bootstrap cannot be performed when remote cluster state is enabled. The cluster state in the remote store is considered the source of truth. "
+            + "In case, you still wish to do best effort recovery with unsafe-bootstrap, then please disable the "
+            + REMOTE_CLUSTER_STATE_ENABLED_SETTING.getKey()
+            + ". For more details, please check the OpenSearch documentation.";
     private OptionSpec<Boolean> applyClusterReadOnlyBlockOption;
 
     UnsafeBootstrapClusterManagerCommand() {
@@ -101,6 +107,13 @@ protected boolean validateBeforeLock(Terminal terminal, Environment env) {
         if (clusterManager == false) {
             throw new OpenSearchException(NOT_CLUSTER_MANAGER_NODE_MSG);
         }
+        // During unsafe bootstrap, node will form a cluster with a new cluster UUID but with the existing metadata.
+        // This new state will not know about the previous cluster UUIDs and so we will not able to construct
+        // the cluster UUID chain to get the last known cluster UUID to restore from.
+        // Blocking unsafe-bootstrap below for this reason.
+        if (REMOTE_CLUSTER_STATE_ENABLED_SETTING.get(settings) == true) {
+            throw new OpenSearchException(REMOTE_CLUSTER_STATE_ENABLED_NODE);
+        }
 
         return true;
     }
diff --git a/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttribute.java b/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttribute.java
index 3f67870781580..914743299b023 100644
--- a/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttribute.java
+++ b/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttribute.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.cluster.decommission;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -18,8 +19,9 @@
 /**
  * {@link DecommissionAttribute} encapsulates information about decommissioned node attribute like attribute name, attribute value.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public final class DecommissionAttribute implements Writeable {
     private final String attributeName;
     private final String attributeValue;
diff --git a/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttributeMetadata.java b/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttributeMetadata.java
index 3df807a4f94d3..254d70b0422d7 100644
--- a/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttributeMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/decommission/DecommissionAttributeMetadata.java
@@ -14,6 +14,7 @@
 import org.opensearch.cluster.NamedDiff;
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.cluster.metadata.Metadata.Custom;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -30,8 +31,9 @@
 /**
  * Contains metadata about decommission attribute
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class DecommissionAttributeMetadata extends AbstractNamedDiffable<Custom> implements Custom {
 
     public static final String TYPE = "decommissionedAttribute";
diff --git a/server/src/main/java/org/opensearch/cluster/decommission/DecommissionStatus.java b/server/src/main/java/org/opensearch/cluster/decommission/DecommissionStatus.java
index 4ca8c3cc4286e..f4f6cbf632ae2 100644
--- a/server/src/main/java/org/opensearch/cluster/decommission/DecommissionStatus.java
+++ b/server/src/main/java/org/opensearch/cluster/decommission/DecommissionStatus.java
@@ -8,9 +8,14 @@
 
 package org.opensearch.cluster.decommission;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * An enumeration of the states during decommissioning
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public enum DecommissionStatus {
     /**
      * Decommission process is initiated, and to-be-decommissioned leader is excluded from voting config
diff --git a/server/src/main/java/org/opensearch/cluster/health/ClusterHealthStatus.java b/server/src/main/java/org/opensearch/cluster/health/ClusterHealthStatus.java
index 5ea482b8b8ffa..06f6b3d57385d 100644
--- a/server/src/main/java/org/opensearch/cluster/health/ClusterHealthStatus.java
+++ b/server/src/main/java/org/opensearch/cluster/health/ClusterHealthStatus.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.cluster.health;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -41,8 +42,9 @@
 /**
  * Cluster health status
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum ClusterHealthStatus implements Writeable {
     GREEN((byte) 0),
     YELLOW((byte) 1),
diff --git a/server/src/main/java/org/opensearch/cluster/health/ClusterIndexHealth.java b/server/src/main/java/org/opensearch/cluster/health/ClusterIndexHealth.java
index 0bb762e3ff744..19c64965e6941 100644
--- a/server/src/main/java/org/opensearch/cluster/health/ClusterIndexHealth.java
+++ b/server/src/main/java/org/opensearch/cluster/health/ClusterIndexHealth.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.routing.IndexRoutingTable;
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -61,8 +62,9 @@
 /**
  * Cluster Index Health Information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ClusterIndexHealth implements Iterable<ClusterShardHealth>, Writeable, ToXContentFragment {
     private static final String STATUS = "status";
     private static final String NUMBER_OF_SHARDS = "number_of_shards";
diff --git a/server/src/main/java/org/opensearch/cluster/health/ClusterShardHealth.java b/server/src/main/java/org/opensearch/cluster/health/ClusterShardHealth.java
index d06e89d9ea170..1fe88f65248c2 100644
--- a/server/src/main/java/org/opensearch/cluster/health/ClusterShardHealth.java
+++ b/server/src/main/java/org/opensearch/cluster/health/ClusterShardHealth.java
@@ -37,6 +37,7 @@
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.routing.UnassignedInfo;
 import org.opensearch.cluster.routing.UnassignedInfo.AllocationStatus;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -58,8 +59,9 @@
 /**
  * Cluster shard health information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ClusterShardHealth implements Writeable, ToXContentFragment {
     private static final String STATUS = "status";
     private static final String ACTIVE_SHARDS = "active_shards";
@@ -219,13 +221,13 @@ public void writeTo(final StreamOutput out) throws IOException {
 
     /**
      * Checks if an inactive primary shard should cause the cluster health to go RED.
-     *
+     * <p>
      * An inactive primary shard in an index should cause the cluster health to be RED to make it visible that some of the existing data is
      * unavailable. In case of index creation, snapshot restore or index shrinking, which are unexceptional events in the cluster lifecycle,
      * cluster health should not turn RED for the time where primaries are still in the initializing state but go to YELLOW instead.
      * However, in case of exceptional events, for example when the primary shard cannot be assigned to a node or initialization fails at
      * some point, cluster health should still turn RED.
-     *
+     * <p>
      * NB: this method should *not* be called on active shards nor on non-primary shards.
      */
     public static ClusterHealthStatus getInactivePrimaryHealth(final ShardRouting shardRouting) {
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/AliasMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/AliasMetadata.java
index 31e37078d8b6c..8b3cc3c3cc2cc 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/AliasMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/AliasMetadata.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.Diff;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -61,8 +62,9 @@
 /**
  * Metadata for index aliases
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AliasMetadata extends AbstractDiffable<AliasMetadata> implements ToXContentFragment {
 
     private final String alias;
@@ -271,8 +273,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Builder of alias metadata.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private final String alias;
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/ComponentTemplate.java b/server/src/main/java/org/opensearch/cluster/metadata/ComponentTemplate.java
index cab1b75afe3e1..abc3712ee07e3 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/ComponentTemplate.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/ComponentTemplate.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.Diff;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -55,8 +56,9 @@
  * contains a field "foo", it's expected to contain all the necessary settings/mappings/etc for the
  * "foo" field. These component templates make up the individual pieces composing an index template.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ComponentTemplate extends AbstractDiffable<ComponentTemplate> implements ToXContentObject {
     private static final ParseField TEMPLATE = new ParseField("template");
     private static final ParseField VERSION = new ParseField("version");
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/ComposableIndexTemplate.java b/server/src/main/java/org/opensearch/cluster/metadata/ComposableIndexTemplate.java
index 5f1291f6c6d82..e7f1b97f28842 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/ComposableIndexTemplate.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/ComposableIndexTemplate.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.Diff;
 import org.opensearch.cluster.metadata.DataStream.TimestampField;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -63,8 +64,9 @@
  * ids corresponding to component templates that should be composed in order when creating a new
  * index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ComposableIndexTemplate extends AbstractDiffable<ComposableIndexTemplate> implements ToXContentObject {
     private static final ParseField INDEX_PATTERNS = new ParseField("index_patterns");
     private static final ParseField TEMPLATE = new ParseField("template");
@@ -284,8 +286,9 @@ public String toString() {
     /**
      * Template for data stream.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class DataStreamTemplate implements Writeable, ToXContentObject {
 
         private static final ParseField TIMESTAMP_FIELD_FIELD = new ParseField("timestamp_field");
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/CryptoMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/CryptoMetadata.java
index 27803cb106005..8bb25ba8e8472 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/CryptoMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/CryptoMetadata.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.action.admin.cluster.crypto.CryptoSettings;
+import org.opensearch.common.annotation.ExperimentalApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -24,8 +25,9 @@
 /**
  * Metadata about encryption and decryption
  *
- * @opensearch.internal
+ * @opensearch.experimental
  */
+@ExperimentalApi
 public class CryptoMetadata implements Writeable {
     static final public String CRYPTO_METADATA_KEY = "crypto_metadata";
     static final public String KEY_PROVIDER_NAME_KEY = "key_provider_name";
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/DataStream.java b/server/src/main/java/org/opensearch/cluster/metadata/DataStream.java
index 753f872f88b22..54df245b1b835 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/DataStream.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/DataStream.java
@@ -37,6 +37,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.Diff;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -59,8 +60,9 @@
 /**
  * Primary DataStream class
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class DataStream extends AbstractDiffable<DataStream> implements ToXContentObject {
 
     public static final String BACKING_INDEX_PREFIX = ".ds-";
@@ -258,8 +260,9 @@ public int hashCode() {
     /**
      * A timestamp field.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class TimestampField implements Writeable, ToXContentObject {
 
         static ParseField NAME_FIELD = new ParseField("name");
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/DiffableStringMap.java b/server/src/main/java/org/opensearch/cluster/metadata/DiffableStringMap.java
index 8209c7bb56ad8..a8102182576ff 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/DiffableStringMap.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/DiffableStringMap.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.Diff;
 import org.opensearch.cluster.Diffable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -50,8 +51,9 @@
  * This is a {@code Map<String, String>} that implements AbstractDiffable so it
  * can be used for cluster state purposes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DiffableStringMap extends AbstractMap<String, String> implements Diffable<DiffableStringMap> {
 
     public static final DiffableStringMap EMPTY = new DiffableStringMap(Collections.emptyMap());
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/IndexAbstraction.java b/server/src/main/java/org/opensearch/cluster/metadata/IndexAbstraction.java
index 0c316373e484f..0f3ee894a7f63 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/IndexAbstraction.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/IndexAbstraction.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.core.common.Strings;
 
@@ -52,8 +53,9 @@
  * An index abstraction has a unique name and encapsulates all the  {@link IndexMetadata} instances it is pointing to.
  * Also depending on type it may refer to a single or many concrete indices and may or may not have a write index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IndexAbstraction {
 
     /**
@@ -102,7 +104,10 @@ public interface IndexAbstraction {
 
     /**
      * An index abstraction type.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     enum Type {
 
         /**
@@ -335,8 +340,9 @@ private boolean isNonEmpty(List<IndexMetadata> idxMetas) {
     /**
      * A data stream.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     class DataStream implements IndexAbstraction {
 
         private final org.opensearch.cluster.metadata.DataStream dataStream;
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/IndexGraveyard.java b/server/src/main/java/org/opensearch/cluster/metadata/IndexGraveyard.java
index 0da948dc78c5d..b4f8b6b188531 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/IndexGraveyard.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/IndexGraveyard.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.Diff;
 import org.opensearch.cluster.NamedDiff;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
@@ -61,15 +62,16 @@
 
 /**
  * A collection of tombstones for explicitly marking indices as deleted in the cluster state.
- *
+ * <p>
  * The cluster state contains a list of index tombstones for indices that have been
  * deleted in the cluster.  Because cluster states are processed asynchronously by
  * nodes and a node could be removed from the cluster for a period of time, the
  * tombstones remain in the cluster state for a fixed period of time, after which
  * they are purged.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class IndexGraveyard implements Metadata.Custom {
 
     /**
@@ -191,8 +193,9 @@ public static IndexGraveyard.Builder builder(final IndexGraveyard graveyard) {
     /**
      * A class to build an IndexGraveyard.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class Builder {
         private List<Tombstone> tombstones;
         private int numPurged = -1;
@@ -250,7 +253,7 @@ public int getNumPurged() {
 
         /**
          * Purge tombstone entries.  Returns the number of entries that were purged.
-         *
+         * <p>
          * Tombstones are purged if the number of tombstones in the list
          * is greater than the input parameter of maximum allowed tombstones.
          * Tombstones are purged until the list is equal to the maximum allowed.
@@ -367,8 +370,9 @@ public String getWriteableName() {
     /**
      * An individual tombstone entry for representing a deleted index.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class Tombstone implements ToXContentObject, Writeable {
 
         private static final String INDEX_KEY = "index";
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/IndexMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/IndexMetadata.java
index 52df72b342b3e..03784df509ed6 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/IndexMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/IndexMetadata.java
@@ -44,6 +44,7 @@
 import org.opensearch.cluster.node.DiscoveryNodeFilters;
 import org.opensearch.cluster.routing.allocation.IndexMetadataUpdater;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.MapBuilder;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.settings.Setting;
@@ -96,8 +97,9 @@
 /**
  * Index metadata information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexMetadata implements Diffable<IndexMetadata>, ToXContentFragment {
 
     public static final ClusterBlock INDEX_READ_ONLY_BLOCK = new ClusterBlock(
@@ -159,8 +161,9 @@ public class IndexMetadata implements Diffable<IndexMetadata>, ToXContentFragmen
     /**
      * The state of the index.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum State {
         OPEN((byte) 0),
         CLOSE((byte) 1);
@@ -450,8 +453,9 @@ public Iterator<Setting<?>> settings() {
     /**
      * Blocks the API.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum APIBlock implements Writeable {
         READ_ONLY("read_only", INDEX_READ_ONLY_BLOCK),
         READ("read", INDEX_READ_BLOCK),
@@ -779,7 +783,7 @@ public long getAliasesVersion() {
     /**
      * The term of the current selected primary. This is a non-negative number incremented when
      * a primary shard is assigned after a full cluster restart or a replica shard is promoted to a primary.
-     *
+     * <p>
      * Note: since we increment the term every time a shard is assigned, the term for any operational shard (i.e., a shard
      * that can be indexed into) is larger than 0. See {@link IndexMetadataUpdater#applyChanges}.
      **/
@@ -1209,8 +1213,9 @@ public static Builder builder(IndexMetadata indexMetadata) {
     /**
      * Builder of index metadata.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private String index;
@@ -1884,7 +1889,7 @@ public static Settings addHumanReadableSettings(Settings settings) {
 
     /**
      * Return the version the index was created from the provided index settings
-     *
+     * <p>
      * This looks for the presence of the {@link Version} object with key {@link IndexMetadata#SETTING_VERSION_CREATED}
      */
     public static Version indexCreated(final Settings indexSettings) {
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/IndexTemplateMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/IndexTemplateMetadata.java
index 272bb132197af..3d532208bcfe2 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/IndexTemplateMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/IndexTemplateMetadata.java
@@ -273,8 +273,9 @@ public String toString() {
     /**
      * Builder of index template metadata.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private static final Set<String> VALID_FIELDS = Sets.newHashSet(
@@ -369,7 +370,7 @@ public IndexTemplateMetadata build() {
         /**
          * Serializes the template to xContent, using the legacy format where the mappings are
          * nested under the type name.
-         *
+         * <p>
          * This method is used for serializing templates before storing them in the cluster metadata,
          * and also in the REST layer when returning a deprecated typed response.
          */
@@ -386,7 +387,7 @@ public static void toXContentWithTypes(
         /**
          * Serializes the template to xContent, making sure not to nest mappings under the
          * type name.
-         *
+         * <p>
          * Note that this method should currently only be used for creating REST responses,
          * and not when directly updating stored templates. Index templates are still stored
          * in the old, typed format, and have yet to be migrated to be typeless.
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MappingMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/MappingMetadata.java
index 2081a0035303b..e8180613c0fa3 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MappingMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MappingMetadata.java
@@ -35,6 +35,7 @@
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.Diff;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
@@ -56,8 +57,9 @@
 /**
  * Mapping configuration for a type.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MappingMetadata extends AbstractDiffable<MappingMetadata> {
     public static final MappingMetadata EMPTY_MAPPINGS = new MappingMetadata(MapperService.SINGLE_MAPPING_NAME, Collections.emptyMap());
 
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/Metadata.java b/server/src/main/java/org/opensearch/cluster/metadata/Metadata.java
index 146193b8d22c4..1871ed24973c2 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/Metadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/Metadata.java
@@ -49,6 +49,7 @@
 import org.opensearch.cluster.decommission.DecommissionAttributeMetadata;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.regex.Regex;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
@@ -98,8 +99,9 @@
 /**
  * Metadata information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Metadata implements Iterable<IndexMetadata>, Diffable<Metadata>, ToXContentFragment {
 
     private static final Logger logger = LogManager.getLogger(Metadata.class);
@@ -127,8 +129,9 @@ public boolean isSegmentReplicationEnabled(String indexName) {
     /**
      * Context of the XContent.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum XContentContext {
         /* Custom metadata should be returns as part of API call */
         API,
@@ -166,8 +169,9 @@ public enum XContentContext {
     /**
      * Custom metadata.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Custom extends NamedDiffable<Custom>, ToXContentFragment, ClusterState.FeatureAware {
 
         EnumSet<XContentContext> context();
@@ -922,19 +926,26 @@ public static boolean isGlobalStateEquals(Metadata metadata1, Metadata metadata2
         if (!metadata1.coordinationMetadata.equals(metadata2.coordinationMetadata)) {
             return false;
         }
-        if (!metadata1.persistentSettings.equals(metadata2.persistentSettings)) {
+        if (!metadata1.hashesOfConsistentSettings.equals(metadata2.hashesOfConsistentSettings)) {
             return false;
         }
-        if (!metadata1.hashesOfConsistentSettings.equals(metadata2.hashesOfConsistentSettings)) {
+        if (!metadata1.clusterUUID.equals(metadata2.clusterUUID)) {
             return false;
         }
-        if (!metadata1.templates.equals(metadata2.templates())) {
+        if (metadata1.clusterUUIDCommitted != metadata2.clusterUUIDCommitted) {
             return false;
         }
-        if (!metadata1.clusterUUID.equals(metadata2.clusterUUID)) {
+        return isGlobalResourcesMetadataEquals(metadata1, metadata2);
+    }
+
+    /**
+     * Compares Metadata entities persisted in Remote Store.
+     */
+    public static boolean isGlobalResourcesMetadataEquals(Metadata metadata1, Metadata metadata2) {
+        if (!metadata1.persistentSettings.equals(metadata2.persistentSettings)) {
             return false;
         }
-        if (metadata1.clusterUUIDCommitted != metadata2.clusterUUIDCommitted) {
+        if (!metadata1.templates.equals(metadata2.templates())) {
             return false;
         }
         // Check if any persistent metadata needs to be saved
@@ -1122,8 +1133,9 @@ public static Builder builder(Metadata metadata) {
     /**
      * Builder of metadata.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private String clusterUUID;
@@ -1666,7 +1678,7 @@ private SortedMap<String, IndexAbstraction> buildIndicesLookup() {
 
         /**
          * Validates there isn't any index with a name that would clash with the future backing indices of the existing data streams.
-         *
+         * <p>
          * E.g., if data stream `foo` has backing indices [`.ds-foo-000001`, `.ds-foo-000002`] and the indices lookup contains indices
          * `.ds-foo-000001`, `.ds-foo-000002` and `.ds-foo-000006` this will throw an IllegalStateException (as attempting to rollover the
          * `foo` data stream from generation 5 to 6 will not be possible)
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
index c43353e9e64e0..bb1bf94f5e984 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
@@ -88,6 +88,7 @@
 import org.opensearch.index.mapper.MapperService.MergeReason;
 import org.opensearch.index.query.QueryShardContext;
 import org.opensearch.index.shard.IndexSettingProvider;
+import org.opensearch.index.translog.Translog;
 import org.opensearch.indices.IndexCreationException;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.InvalidIndexNameException;
@@ -753,7 +754,7 @@ private ClusterState applyCreateIndexRequestWithExistingMetadata(
     /**
      * Parses the provided mappings json and the inheritable mappings from the templates (if any)
      * into a map.
-     *
+     * <p>
      * The template mappings are applied in the order they are encountered in the list (clients
      * should make sure the lower index, closer to the head of the list, templates have the highest
      * {@link IndexTemplateMetadata#order()}). This merging makes no distinction between field
@@ -791,7 +792,7 @@ static Map<String, Object> parseV1Mappings(
      * Validates and creates the settings for the new index based on the explicitly configured settings via the
      * {@link CreateIndexClusterStateUpdateRequest}, inherited from templates and, if recovering from another index (ie. split, shrink,
      * clone), the resize settings.
-     *
+     * <p>
      * The template mappings are applied in the order they are encountered in the list (clients should make sure the lower index, closer
      * to the head of the list, templates have the highest {@link IndexTemplateMetadata#order()})
      *
@@ -890,7 +891,7 @@ static Settings aggregateIndexSettings(
         indexSettingsBuilder.put(IndexMetadata.SETTING_INDEX_PROVIDED_NAME, request.getProvidedName());
         indexSettingsBuilder.put(SETTING_INDEX_UUID, UUIDs.randomBase64UUID());
 
-        updateReplicationStrategy(indexSettingsBuilder, request.settings(), settings);
+        updateReplicationStrategy(indexSettingsBuilder, request.settings(), settings, combinedTemplateSettings);
         updateRemoteStoreSettings(indexSettingsBuilder, settings);
 
         if (sourceMetadata != null) {
@@ -922,6 +923,7 @@ static Settings aggregateIndexSettings(
         validateTranslogRetentionSettings(indexSettings);
         validateStoreTypeSettings(indexSettings);
         validateRefreshIntervalSettings(request.settings(), clusterSettings);
+        validateTranslogDurabilitySettings(request.settings(), clusterSettings, settings);
 
         return indexSettings;
     }
@@ -932,17 +934,33 @@ static Settings aggregateIndexSettings(
      * @param settingsBuilder index settings builder to be updated with relevant settings
      * @param requestSettings settings passed in during index create request
      * @param clusterSettings cluster level settings
+     * @param combinedTemplateSettings combined template settings which satisfy the index
      */
-    private static void updateReplicationStrategy(Settings.Builder settingsBuilder, Settings requestSettings, Settings clusterSettings) {
+    private static void updateReplicationStrategy(
+        Settings.Builder settingsBuilder,
+        Settings requestSettings,
+        Settings clusterSettings,
+        Settings combinedTemplateSettings
+    ) {
+        // The replication setting is applied in the following order:
+        // 1. Explicit index creation request parameter
+        // 2. Template property for replication type
+        // 3. Defaults to segment if remote store attributes on the cluster
+        // 4. Default cluster level setting
+
+        final ReplicationType indexReplicationType;
         if (INDEX_REPLICATION_TYPE_SETTING.exists(requestSettings)) {
-            settingsBuilder.put(SETTING_REPLICATION_TYPE, INDEX_REPLICATION_TYPE_SETTING.get(requestSettings));
+            indexReplicationType = INDEX_REPLICATION_TYPE_SETTING.get(requestSettings);
+        } else if (INDEX_REPLICATION_TYPE_SETTING.exists(combinedTemplateSettings)) {
+            indexReplicationType = INDEX_REPLICATION_TYPE_SETTING.get(combinedTemplateSettings);
         } else if (CLUSTER_REPLICATION_TYPE_SETTING.exists(clusterSettings)) {
-            settingsBuilder.put(SETTING_REPLICATION_TYPE, CLUSTER_REPLICATION_TYPE_SETTING.get(clusterSettings));
+            indexReplicationType = CLUSTER_REPLICATION_TYPE_SETTING.get(clusterSettings);
         } else if (isRemoteStoreAttributePresent(clusterSettings)) {
-            settingsBuilder.put(SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT);
+            indexReplicationType = ReplicationType.SEGMENT;
         } else {
-            settingsBuilder.put(SETTING_REPLICATION_TYPE, CLUSTER_REPLICATION_TYPE_SETTING.getDefault(clusterSettings));
+            indexReplicationType = CLUSTER_REPLICATION_TYPE_SETTING.getDefault(clusterSettings);
         }
+        settingsBuilder.put(SETTING_REPLICATION_TYPE, indexReplicationType);
     }
 
     /**
@@ -1007,7 +1025,7 @@ static int getIndexNumberOfRoutingShards(Settings indexSettings, @Nullable Index
     /**
      * Validate and resolve the aliases explicitly set for the index, together with the ones inherited from the specified
      * templates.
-     *
+     * <p>
      * The template mappings are applied in the order they are encountered in the list (clients should make sure the lower index, closer
      * to the head of the list, templates have the highest {@link IndexTemplateMetadata#order()})
      *
@@ -1491,10 +1509,10 @@ public static void validateTranslogRetentionSettings(Settings indexSettings) {
     /**
      * Validates {@code index.refresh_interval} is equal or below the {@code cluster.minimum.index.refresh_interval}.
      *
-     * @param requestSettings settings passed in during index create request
+     * @param requestSettings settings passed in during index create/update request
      * @param clusterSettings cluster setting
      */
-    static void validateRefreshIntervalSettings(Settings requestSettings, ClusterSettings clusterSettings) {
+    public static void validateRefreshIntervalSettings(Settings requestSettings, ClusterSettings clusterSettings) {
         if (IndexSettings.INDEX_REFRESH_INTERVAL_SETTING.exists(requestSettings) == false) {
             return;
         }
@@ -1510,4 +1528,27 @@ static void validateRefreshIntervalSettings(Settings requestSettings, ClusterSet
             );
         }
     }
+
+    /**
+     * Validates {@code index.translog.durability} is not async if the {@code cluster.remote_store.index.restrict.async-durability} is set to true.
+     *
+     * @param requestSettings settings passed in during index create/update request
+     * @param clusterSettings cluster setting
+     */
+    static void validateTranslogDurabilitySettings(Settings requestSettings, ClusterSettings clusterSettings, Settings settings) {
+        if (isRemoteStoreAttributePresent(settings) == false
+            || IndexSettings.INDEX_TRANSLOG_DURABILITY_SETTING.exists(requestSettings) == false
+            || clusterSettings.get(IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING) == false) {
+            return;
+        }
+        Translog.Durability durability = IndexSettings.INDEX_TRANSLOG_DURABILITY_SETTING.get(requestSettings);
+        if (durability.equals(Translog.Durability.ASYNC)) {
+            throw new IllegalArgumentException(
+                "index setting [index.translog.durability=async] is not allowed as cluster setting ["
+                    + IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING.getKey()
+                    + "=true]"
+            );
+        }
+
+    }
 }
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexStateService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexStateService.java
index 91c996448ea8f..e30e878f1b31a 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexStateService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexStateService.java
@@ -166,7 +166,7 @@ public MetadataIndexStateService(
 
     /**
      * Closes one or more indices.
-     *
+     * <p>
      * Closing indices is a 3 steps process: it first adds a write block to every indices to close, then waits for the operations on shards
      * to be terminated and finally closes the indices by moving their state to CLOSE.
      */
@@ -302,7 +302,7 @@ public TimeValue timeout() {
 
     /**
      * Step 1 - Start closing indices by adding a write block
-     *
+     * <p>
      * This step builds the list of indices to close (the ones explicitly requested that are not in CLOSE state) and adds a unique cluster
      * block (or reuses an existing one) to every index to close in the cluster state. After the cluster state is published, the shards
      * should start to reject writing operations and we can proceed with step 2.
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexTemplateService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexTemplateService.java
index 71b86ec853ce4..5b03d3f7b19ce 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexTemplateService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataIndexTemplateService.java
@@ -93,6 +93,7 @@
 import java.util.stream.Collectors;
 
 import static org.opensearch.cluster.metadata.MetadataCreateDataStreamService.validateTimestampFieldMapping;
+import static org.opensearch.cluster.metadata.MetadataCreateIndexService.validateRefreshIntervalSettings;
 import static org.opensearch.indices.cluster.IndicesClusterStateService.AllocatedIndices.IndexRemovalReason.NO_LONGER_ASSIGNED;
 
 /**
@@ -747,7 +748,7 @@ public static Map<String, List<String>> findConflictingV2Templates(
     /**
      * Return a map of v2 template names to their index patterns for v2 templates that would overlap
      * with the given template's index patterns.
-     *
+     * <p>
      * Based on the provided checkPriority and priority parameters this aims to report the overlapping
      * index templates regardless of the priority (ie. checkPriority == false) or otherwise overlapping
      * templates with the same priority as the given priority parameter (this is useful when trying to
@@ -1529,6 +1530,9 @@ private void validate(String name, @Nullable Settings settings, List<String> ind
                 Optional.empty()
             );
             validationErrors.addAll(indexSettingsValidation);
+
+            // validate index refresh interval settings
+            validateRefreshIntervalSettings(settings, clusterService.getClusterSettings());
         }
 
         if (indexPatterns.stream().anyMatch(Regex::isMatchAllPattern)) {
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java
index 524980565fe39..7d4c3512ed757 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java
@@ -73,6 +73,8 @@
 import java.util.Set;
 
 import static org.opensearch.action.support.ContextPreservingActionListener.wrapPreservingContext;
+import static org.opensearch.cluster.metadata.MetadataCreateIndexService.validateRefreshIntervalSettings;
+import static org.opensearch.cluster.metadata.MetadataCreateIndexService.validateTranslogDurabilitySettings;
 import static org.opensearch.common.settings.AbstractScopedSettings.ARCHIVED_SETTINGS_PREFIX;
 import static org.opensearch.index.IndexSettings.same;
 
@@ -127,7 +129,8 @@ public void updateSettings(
             .normalizePrefix(IndexMetadata.INDEX_SETTING_PREFIX)
             .build();
 
-        MetadataCreateIndexService.validateRefreshIntervalSettings(normalizedSettings, clusterService.getClusterSettings());
+        validateRefreshIntervalSettings(normalizedSettings, clusterService.getClusterSettings());
+        validateTranslogDurabilitySettings(normalizedSettings, clusterService.getClusterSettings(), clusterService.getSettings());
 
         Settings.Builder settingsForClosedIndices = Settings.builder();
         Settings.Builder settingsForOpenIndices = Settings.builder();
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/RepositoriesMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/RepositoriesMetadata.java
index 1ab402e1bde4e..e3689d046193c 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/RepositoriesMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/RepositoriesMetadata.java
@@ -54,6 +54,8 @@
 import java.util.EnumSet;
 import java.util.List;
 
+import static org.opensearch.repositories.blobstore.BlobStoreRepository.SYSTEM_REPOSITORY_SETTING;
+
 /**
  * Contains metadata about registered snapshot repositories
  *
@@ -68,6 +70,7 @@ public class RepositoriesMetadata extends AbstractNamedDiffable<Custom> implemen
      * in {@link org.opensearch.action.admin.cluster.repositories.get.GetRepositoriesResponse}.
      */
     public static final String HIDE_GENERATIONS_PARAM = "hide_generations";
+    public static final String HIDE_SYSTEM_REPOSITORY_SETTING = "hide_system_repository_setting";
 
     private final List<RepositoryMetadata> repositories;
 
@@ -288,8 +291,12 @@ public static void toXContent(RepositoryMetadata repository, XContentBuilder bui
         if (repository.cryptoMetadata() != null) {
             repository.cryptoMetadata().toXContent(repository.cryptoMetadata(), builder, params);
         }
+        Settings settings = repository.settings();
+        if (SYSTEM_REPOSITORY_SETTING.get(settings) && params.paramAsBoolean(HIDE_SYSTEM_REPOSITORY_SETTING, false)) {
+            settings = repository.settings().filter(s -> !s.equals(SYSTEM_REPOSITORY_SETTING.getKey()));
+        }
         builder.startObject("settings");
-        repository.settings().toXContent(builder, params);
+        settings.toXContent(builder, params);
         builder.endObject();
 
         if (params.paramAsBoolean(HIDE_GENERATIONS_PARAM, false) == false) {
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/RepositoryMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/RepositoryMetadata.java
index 580643b96e411..b9d2a3edf356f 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/RepositoryMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/RepositoryMetadata.java
@@ -32,6 +32,7 @@
 package org.opensearch.cluster.metadata;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -44,8 +45,9 @@
 /**
  * Metadata about registered repository
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RepositoryMetadata implements Writeable {
 
     private final String name;
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/Template.java b/server/src/main/java/org/opensearch/cluster/metadata/Template.java
index 8e367c71ed166..bd110c6af8975 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/Template.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/Template.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentHelper;
@@ -58,8 +59,9 @@
  * it is entirely independent from an index. It's a building block forming part of a regular index
  * template and a {@link ComponentTemplate}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Template extends AbstractDiffable<Template> implements ToXContentObject {
     private static final ParseField SETTINGS = new ParseField("settings");
     private static final ParseField MAPPINGS = new ParseField("mappings");
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/WeightedRoutingMetadata.java b/server/src/main/java/org/opensearch/cluster/metadata/WeightedRoutingMetadata.java
index cc56a0daf6db7..bc24dd22f5c6e 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/WeightedRoutingMetadata.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/WeightedRoutingMetadata.java
@@ -8,13 +8,12 @@
 
 package org.opensearch.cluster.metadata;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.Version;
 import org.opensearch.cluster.AbstractNamedDiffable;
 import org.opensearch.cluster.NamedDiff;
 import org.opensearch.cluster.routing.WeightedRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -31,10 +30,10 @@
 /**
  * Contains metadata for weighted routing
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class WeightedRoutingMetadata extends AbstractNamedDiffable<Metadata.Custom> implements Metadata.Custom {
-    private static final Logger logger = LogManager.getLogger(WeightedRoutingMetadata.class);
     public static final String TYPE = "weighted_shard_routing";
     public static final String AWARENESS = "awareness";
     public static final String VERSION = "_version";
diff --git a/server/src/main/java/org/opensearch/cluster/node/DiscoveryNode.java b/server/src/main/java/org/opensearch/cluster/node/DiscoveryNode.java
index 4e49b25eb5789..5226e9570ac14 100644
--- a/server/src/main/java/org/opensearch/cluster/node/DiscoveryNode.java
+++ b/server/src/main/java/org/opensearch/cluster/node/DiscoveryNode.java
@@ -44,7 +44,6 @@
 import org.opensearch.core.xcontent.ToXContentFragment;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.node.Node;
-import org.opensearch.node.remotestore.RemoteStoreNodeService;
 
 import java.io.IOException;
 import java.util.Collections;
@@ -283,27 +282,6 @@ public static DiscoveryNode createLocal(Settings settings, TransportAddress publ
         return new DiscoveryNode(Node.NODE_NAME_SETTING.get(settings), nodeId, publishAddress, attributes, roles, Version.CURRENT);
     }
 
-    /** Creates a DiscoveryNode representing the local node and verifies the repository. */
-    public static DiscoveryNode createRemoteNodeLocal(
-        Settings settings,
-        TransportAddress publishAddress,
-        String nodeId,
-        RemoteStoreNodeService remoteStoreNodeService
-    ) {
-        Map<String, String> attributes = Node.NODE_ATTRIBUTES.getAsMap(settings);
-        Set<DiscoveryNodeRole> roles = getRolesFromSettings(settings);
-        DiscoveryNode discoveryNode = new DiscoveryNode(
-            Node.NODE_NAME_SETTING.get(settings),
-            nodeId,
-            publishAddress,
-            attributes,
-            roles,
-            Version.CURRENT
-        );
-        remoteStoreNodeService.createAndVerifyRepositories(discoveryNode);
-        return discoveryNode;
-    }
-
     /** extract node roles from the given settings */
     public static Set<DiscoveryNodeRole> getRolesFromSettings(final Settings settings) {
         if (NODE_ROLES_SETTING.exists(settings)) {
@@ -553,7 +531,13 @@ public String toString() {
             sb.append('}');
         }
         if (!attributes.isEmpty()) {
-            sb.append(attributes);
+            sb.append(
+                attributes.entrySet()
+                    .stream()
+                    .filter(entry -> !entry.getKey().startsWith(REMOTE_STORE_NODE_ATTRIBUTE_KEY_PREFIX)) // filter remote_store attributes
+                                                                                                         // from logging to reduce noise.
+                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue))
+            );
         }
         return sb.toString();
     }
diff --git a/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodeFilters.java b/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodeFilters.java
index 54f30690f18e1..b27e1aa49a803 100644
--- a/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodeFilters.java
+++ b/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodeFilters.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.node;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.network.InetAddresses;
 import org.opensearch.common.network.NetworkAddress;
 import org.opensearch.common.regex.Regex;
@@ -48,15 +49,17 @@
 /**
  * Filters Discovery nodes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DiscoveryNodeFilters {
 
     /**
      * Operation type.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum OpType {
         AND,
         OR
diff --git a/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodes.java b/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodes.java
index 675d4e09e3be0..2ebcd8096893d 100644
--- a/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodes.java
+++ b/server/src/main/java/org/opensearch/cluster/node/DiscoveryNodes.java
@@ -37,6 +37,7 @@
 import org.opensearch.cluster.Diff;
 import org.opensearch.common.Booleans;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.regex.Regex;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.common.Strings;
@@ -62,8 +63,9 @@
  * This class holds all {@link DiscoveryNode} in the cluster and provides convenience methods to
  * access, modify merge / diff discovery nodes.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DiscoveryNodes extends AbstractDiffable<DiscoveryNodes> implements Iterable<DiscoveryNode> {
 
     public static final DiscoveryNodes EMPTY_NODES = builder().build();
@@ -356,7 +358,7 @@ public DiscoveryNode findByAddress(TransportAddress address) {
 
     /**
      * Returns the version of the node with the oldest version in the cluster that is not a client node
-     *
+     * <p>
      * If there are no non-client nodes, Version.CURRENT will be returned.
      *
      * @return the oldest version in the cluster
@@ -367,7 +369,7 @@ public Version getSmallestNonClientNodeVersion() {
 
     /**
      * Returns the version of the node with the youngest version in the cluster that is not a client node.
-     *
+     * <p>
      * If there are no non-client nodes, Version.CURRENT will be returned.
      *
      * @return the youngest version in the cluster
@@ -417,16 +419,16 @@ public DiscoveryNode resolveNode(String node) {
     /**
      * Resolves a set of nodes according to the given sequence of node specifications. Implements the logic in various APIs that allow the
      * user to run the action on a subset of the nodes in the cluster. See [Node specification] in the reference manual for full details.
-     *
+     * <p>
      * Works by tracking the current set of nodes and applying each node specification in sequence. The set starts out empty and each node
      * specification may either add or remove nodes. For instance:
-     *
+     * <p>
      * - _local, _cluster_manager (_master) and _all respectively add to the subset the local node, the currently-elected cluster_manager, and all the nodes
      * - node IDs, names, hostnames and IP addresses all add to the subset any nodes which match
      * - a wildcard-based pattern of the form "attr*:value*" adds to the subset all nodes with a matching attribute with a matching value
      * - role:true adds to the subset all nodes with a matching role
      * - role:false removes from the subset all nodes with a matching role.
-     *
+     * <p>
      * An empty sequence of node specifications returns all nodes, since the corresponding actions run on all nodes by default.
      */
     public String[] resolveNodes(String... nodes) {
@@ -567,8 +569,9 @@ public String toString() {
     /**
      * Delta between nodes.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Delta {
 
         private final String localNodeId;
@@ -735,8 +738,9 @@ public static Builder builder(DiscoveryNodes nodes) {
     /**
      * Builder of a map of discovery nodes.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private final Map<String, DiscoveryNode> nodes;
@@ -813,7 +817,7 @@ public Builder localNodeId(String localNodeId) {
          * Checks that a node can be safely added to this node collection.
          *
          * @return null if all is OK or an error message explaining why a node can not be added.
-         *
+         * <p>
          * Note: if this method returns a non-null value, calling {@link #add(DiscoveryNode)} will fail with an
          * exception
          */
diff --git a/server/src/main/java/org/opensearch/cluster/routing/AllocationId.java b/server/src/main/java/org/opensearch/cluster/routing/AllocationId.java
index 6e6ea3919c813..ade3afa4a500c 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/AllocationId.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/AllocationId.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.common.Nullable;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -55,8 +56,9 @@
  * relocationId. Once relocation is done, the new allocation id is set to the relocationId. This is similar
  * behavior to how ShardRouting#currentNodeId is used.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AllocationId implements ToXContentObject, Writeable {
     private static final String ID_KEY = "id";
     private static final String RELOCATION_ID_KEY = "relocation_id";
diff --git a/server/src/main/java/org/opensearch/cluster/routing/GroupShardsIterator.java b/server/src/main/java/org/opensearch/cluster/routing/GroupShardsIterator.java
index 8e9371e6a714c..dcb60e79358e3 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/GroupShardsIterator.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/GroupShardsIterator.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.routing;
 
 import org.apache.lucene.util.CollectionUtil;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.Countable;
 
 import java.util.Iterator;
@@ -44,8 +45,9 @@
  * ShardsIterators are always returned in ascending order independently of their order at construction
  * time. The incoming iterators are sorted to ensure consistent iteration behavior across Nodes / JVMs.
  *
- * @opensearch.internal
+ * @opensearch.api
 */
+@PublicApi(since = "1.0.0")
 public final class GroupShardsIterator<ShardIt extends Comparable<ShardIt> & Countable> implements Iterable<ShardIt> {
 
     private final List<ShardIt> iterators;
diff --git a/server/src/main/java/org/opensearch/cluster/routing/IndexRoutingTable.java b/server/src/main/java/org/opensearch/cluster/routing/IndexRoutingTable.java
index b12698c8a320e..faadc3f7583fb 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/IndexRoutingTable.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/IndexRoutingTable.java
@@ -44,6 +44,7 @@
 import org.opensearch.cluster.routing.RecoverySource.RemoteStoreRecoverySource;
 import org.opensearch.cluster.routing.RecoverySource.SnapshotRecoverySource;
 import org.opensearch.common.Randomness;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.index.Index;
@@ -75,8 +76,9 @@
  * represented as {@link ShardRouting}.
  * </p>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexRoutingTable extends AbstractDiffable<IndexRoutingTable> implements Iterable<IndexShardRoutingTable> {
 
     private final Index index;
@@ -367,8 +369,9 @@ public static Builder builder(Index index) {
     /**
      * Builder of a routing table.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private final Index index;
@@ -466,12 +469,12 @@ public Builder initializeAsRemoteStoreRestore(
             }
             for (int shardNumber = 0; shardNumber < indexMetadata.getNumberOfShards(); shardNumber++) {
                 ShardId shardId = new ShardId(index, shardNumber);
-                if (forceRecoverAllPrimaries == false && indexShardRoutingTableMap.containsKey(shardId) == false) {
+                if (indexShardRoutingTableMap.containsKey(shardId) == false) {
                     throw new IllegalStateException("IndexShardRoutingTable is not present for shardId: " + shardId);
                 }
                 IndexShardRoutingTable.Builder indexShardRoutingBuilder = new IndexShardRoutingTable.Builder(shardId);
                 IndexShardRoutingTable indexShardRoutingTable = indexShardRoutingTableMap.get(shardId);
-                if (forceRecoverAllPrimaries || indexShardRoutingTable == null || indexShardRoutingTable.primaryShard().unassigned()) {
+                if (forceRecoverAllPrimaries || indexShardRoutingTable.primaryShard().unassigned()) {
                     // Primary shard to be recovered from remote store.
                     indexShardRoutingBuilder.addShard(ShardRouting.newUnassigned(shardId, true, recoverySource, unassignedInfo));
                     // All the replica shards to be recovered from peer recovery.
diff --git a/server/src/main/java/org/opensearch/cluster/routing/IndexShardRoutingTable.java b/server/src/main/java/org/opensearch/cluster/routing/IndexShardRoutingTable.java
index 9cc09c6e4c31c..36149d014ea84 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/IndexShardRoutingTable.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/IndexShardRoutingTable.java
@@ -39,6 +39,7 @@
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Randomness;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.MapBuilder;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -73,8 +74,9 @@
  * referred to as replicas of a shard. Given that, this class encapsulates all
  * replicas (instances) for a single index shard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardRoutingTable implements Iterable<ShardRouting> {
 
     final ShardShuffler shuffler;
@@ -463,7 +465,7 @@ private static Map<String, Double> rankNodes(
      * OpenSearch, however, we do not have that sort of broadcast-to-all behavior. In order to prevent a node that gets a high score and
      * then never gets any more requests, we must ensure it eventually returns to a more normal score and can be a candidate for serving
      * requests.
-     *
+     * <p>
      * This adjustment takes the "winning" node's statistics and adds the average of those statistics with each non-winning node. Let's say
      * the winning node had a queue size of 10 and a non-winning node had a queue of 18. The average queue size is (10 + 18) / 2 = 14 so the
      * non-winning node will have statistics added for a queue size of 14. This is repeated for the response time and service times as well.
@@ -921,8 +923,9 @@ public int shardsMatchingPredicateCount(Predicate<ShardRouting> predicate) {
     /**
      * Key for WeightedRouting Shard Iterator
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "2.4.0")
     public static class WeightedRoutingKey {
         private final WeightedRouting weightedRouting;
 
diff --git a/server/src/main/java/org/opensearch/cluster/routing/OperationRouting.java b/server/src/main/java/org/opensearch/cluster/routing/OperationRouting.java
index d734181beabd3..6a95c98815698 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/OperationRouting.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/OperationRouting.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.cluster.routing.allocation.decider.AwarenessAllocationDecider;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
@@ -59,8 +60,9 @@
 /**
  * Routes cluster operations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class OperationRouting {
 
     public static final Setting<Boolean> USE_ADAPTIVE_REPLICA_SELECTION_SETTING = Setting.boolSetting(
diff --git a/server/src/main/java/org/opensearch/cluster/routing/RecoverySource.java b/server/src/main/java/org/opensearch/cluster/routing/RecoverySource.java
index 5cef46689ffc7..8d407c6aff5b6 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/RecoverySource.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/RecoverySource.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -49,15 +50,16 @@
 
 /**
  * Represents the recovery source of a shard. Available recovery types are:
- *
+ * <p>
  * - {@link EmptyStoreRecoverySource} recovery from an empty store
  * - {@link ExistingStoreRecoverySource} recovery from an existing store
  * - {@link PeerRecoverySource} recovery from a primary on another node
  * - {@link SnapshotRecoverySource} recovery from a snapshot
  * - {@link LocalShardsRecoverySource} recovery from other shards of another index on the same node
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class RecoverySource implements Writeable, ToXContentObject {
 
     @Override
@@ -111,8 +113,9 @@ protected void writeAdditionalFields(StreamOutput out) throws IOException {
     /**
      * Type of recovery.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Type {
         EMPTY_STORE,
         EXISTING_STORE,
@@ -247,8 +250,9 @@ public String toString() {
     /**
      * recovery from a snapshot
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class SnapshotRecoverySource extends RecoverySource {
 
         public static final String NO_API_RESTORE_UUID = "_no_api_";
@@ -412,8 +416,9 @@ public int hashCode() {
     /**
      * Recovery from remote store
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class RemoteStoreRecoverySource extends RecoverySource {
 
         private final String restoreUUID;
diff --git a/server/src/main/java/org/opensearch/cluster/routing/RerouteService.java b/server/src/main/java/org/opensearch/cluster/routing/RerouteService.java
index fe6331aebc5a6..b6db2e7c192fe 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/RerouteService.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/RerouteService.java
@@ -33,14 +33,16 @@
 
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionListener;
 
 /**
  * Asynchronously performs a cluster reroute, updating any shard states and rebalancing the cluster if appropriate.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
 @FunctionalInterface
+@PublicApi(since = "1.0.0")
 public interface RerouteService {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/routing/RoutingChangesObserver.java b/server/src/main/java/org/opensearch/cluster/routing/RoutingChangesObserver.java
index 1ec572f7f8cc4..614cccb069048 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/RoutingChangesObserver.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/RoutingChangesObserver.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.cluster.routing;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Records changes made to {@link RoutingNodes} during an allocation round.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface RoutingChangesObserver {
     /**
      * Called when unassigned shard is initialized. Does not include initializing relocation target shards.
diff --git a/server/src/main/java/org/opensearch/cluster/routing/RoutingNode.java b/server/src/main/java/org/opensearch/cluster/routing/RoutingNode.java
index e10734eb17e0d..15ec41d5c3fbb 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/RoutingNode.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/RoutingNode.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.core.index.Index;
 import org.opensearch.core.index.shard.ShardId;
@@ -56,8 +57,9 @@
  * A {@link RoutingNode} represents a cluster node associated with a single {@link DiscoveryNode} including all shards
  * that are hosted on that nodes. Each {@link RoutingNode} has a unique node id that can be used to identify the node.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RoutingNode implements Iterable<ShardRouting> {
 
     static class BucketedShards implements Iterable<ShardRouting> {
diff --git a/server/src/main/java/org/opensearch/cluster/routing/RoutingNodes.java b/server/src/main/java/org/opensearch/cluster/routing/RoutingNodes.java
index 4f7b935f15f93..a406552f854da 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/RoutingNodes.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/RoutingNodes.java
@@ -42,6 +42,7 @@
 import org.opensearch.cluster.routing.allocation.ExistingShardsAllocator;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Randomness;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.core.Assertions;
 import org.opensearch.core.index.Index;
@@ -70,7 +71,7 @@
  * {@link RoutingNodes} represents a copy the routing information contained in the {@link ClusterState cluster state}.
  * It can be either initialized as mutable or immutable (see {@link #RoutingNodes(ClusterState, boolean)}), allowing
  * or disallowing changes to its elements.
- *
+ * <p>
  * The main methods used to update routing entries are:
  * <ul>
  * <li> {@link #initializeShard} initializes an unassigned shard.
@@ -79,8 +80,9 @@
  * <li> {@link #failShard} fails/cancels an assigned shard.
  * </ul>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RoutingNodes implements Iterable<RoutingNode> {
     private final Metadata metadata;
 
@@ -369,7 +371,7 @@ public ShardRouting activePrimary(ShardId shardId) {
     /**
      * Returns one active replica shard for the given shard id or <code>null</code> if
      * no active replica is found.
-     *
+     * <p>
      * Since replicas could possibly be on nodes with an older version of OpenSearch than
      * the primary is, this will return replicas on the highest version of OpenSearch when document
      * replication is enabled.
@@ -395,7 +397,7 @@ public ShardRouting activeReplicaWithHighestVersion(ShardId shardId) {
     /**
      * Returns one active replica shard for the given shard id or <code>null</code> if
      * no active replica is found.
-     *
+     * <p>
      * Since replicas could possibly be on nodes with a higher version of OpenSearch than
      * the primary is, this will return replicas on the oldest version of OpenSearch when segment
      * replication is enabled to allow for replica to read segments from primary.
@@ -544,9 +546,9 @@ public Tuple<ShardRouting, ShardRouting> relocateShard(
 
     /**
      * Applies the relevant logic to start an initializing shard.
-     *
+     * <p>
      * Moves the initializing shard to started. If the shard is a relocation target, also removes the relocation source.
-     *
+     * <p>
      * If the started shard is a primary relocation target, this also reinitializes currently initializing replicas as their
      * recovery source changes
      *
@@ -605,9 +607,9 @@ public ShardRouting startShard(Logger logger, ShardRouting initializingShard, Ro
 
     /**
      * Applies the relevant logic to handle a cancelled or failed shard.
-     *
+     * <p>
      * Moves the shard to unassigned or completely removes the shard (if relocation target).
-     *
+     * <p>
      * - If shard is a primary, this also fails initializing replicas.
      * - If shard is an active primary, this also promotes an active replica to primary (if such a replica exists).
      * - If shard is a relocating primary, this also removes the primary relocation target shard.
@@ -943,8 +945,9 @@ public int size() {
     /**
      * Unassigned shard list.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class UnassignedShards implements Iterable<ShardRouting> {
 
         private final RoutingNodes nodes;
@@ -1044,8 +1047,9 @@ public void ignoreShard(ShardRouting shard, AllocationStatus allocationStatus, R
         /**
          * An unassigned iterator.
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public class UnassignedIterator implements Iterator<ShardRouting>, ExistingShardsAllocator.UnassignedAllocationHandler {
 
             private final ListIterator<ShardRouting> iterator;
diff --git a/server/src/main/java/org/opensearch/cluster/routing/RoutingTable.java b/server/src/main/java/org/opensearch/cluster/routing/RoutingTable.java
index 2b56163f852e8..7f2382f8b4910 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/RoutingTable.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/RoutingTable.java
@@ -40,6 +40,7 @@
 import org.opensearch.cluster.routing.RecoverySource.RemoteStoreRecoverySource;
 import org.opensearch.cluster.routing.RecoverySource.SnapshotRecoverySource;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.iterable.Iterables;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -66,8 +67,9 @@
  *
  * @see IndexRoutingTable
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RoutingTable implements Iterable<IndexRoutingTable>, Diffable<RoutingTable> {
 
     public static final RoutingTable EMPTY_ROUTING_TABLE = builder().build();
@@ -433,8 +435,9 @@ public static Builder builder(RoutingTable routingTable) {
     /**
      * Builder for the routing table. Note that build can only be called one time.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private long version;
diff --git a/server/src/main/java/org/opensearch/cluster/routing/ShardIterator.java b/server/src/main/java/org/opensearch/cluster/routing/ShardIterator.java
index 623846b6e1dda..95055d2ffe2ad 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/ShardIterator.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/ShardIterator.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.cluster.routing;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.shard.ShardId;
 
 /**
  * Allows to iterate over a set of shard instances (routing) within a shard id group.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ShardIterator extends ShardsIterator, Comparable<ShardIterator> {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/routing/ShardMovementStrategy.java b/server/src/main/java/org/opensearch/cluster/routing/ShardMovementStrategy.java
index cfdeed5c227b6..d1ed94087e20d 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/ShardMovementStrategy.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/ShardMovementStrategy.java
@@ -9,17 +9,19 @@
 package org.opensearch.cluster.routing;
 
 import org.opensearch.cluster.routing.allocation.allocator.BalancedShardsAllocator;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Locale;
 
 /**
  * ShardMovementStrategy defines the order in which shard movement occurs.
- *
+ * <p>
  * ShardMovementStrategy values or rather their string representation to be used with
  * {@link BalancedShardsAllocator#SHARD_MOVEMENT_STRATEGY_SETTING} via cluster settings.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.9.0")
 public enum ShardMovementStrategy {
     /**
      * default behavior in which order of shard movement doesn't matter.
diff --git a/server/src/main/java/org/opensearch/cluster/routing/ShardRouting.java b/server/src/main/java/org/opensearch/cluster/routing/ShardRouting.java
index 666046d97f8d0..45de045a8fc69 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/ShardRouting.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/ShardRouting.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.routing.RecoverySource.PeerRecoverySource;
 import org.opensearch.cluster.routing.allocation.allocator.BalancedShardsAllocator;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -52,8 +53,9 @@
  * {@link ShardRouting} immutably encapsulates information about shard
  * indexRoutings like id, state, version, etc.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardRouting implements Writeable, ToXContentObject {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/routing/ShardRoutingState.java b/server/src/main/java/org/opensearch/cluster/routing/ShardRoutingState.java
index a46464d8727ee..2086159790ba9 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/ShardRoutingState.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/ShardRoutingState.java
@@ -32,12 +32,15 @@
 
 package org.opensearch.cluster.routing;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Represents the current state of a {@link ShardRouting} as defined by the
  * cluster.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum ShardRoutingState {
     /**
      * The shard is not assigned to any node.
diff --git a/server/src/main/java/org/opensearch/cluster/routing/ShardsIterator.java b/server/src/main/java/org/opensearch/cluster/routing/ShardsIterator.java
index e715be1676c6f..fc3fefbc3836c 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/ShardsIterator.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/ShardsIterator.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.cluster.routing;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.Countable;
 
 import java.util.List;
@@ -38,8 +39,9 @@
 /**
  * Allows to iterate over unrelated shards.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ShardsIterator extends Iterable<ShardRouting>, Countable {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/routing/UnassignedInfo.java b/server/src/main/java/org/opensearch/cluster/routing/UnassignedInfo.java
index de36547b10707..cf6dc9cd7306e 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/UnassignedInfo.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/UnassignedInfo.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.routing.allocation.RoutingAllocation;
 import org.opensearch.cluster.routing.allocation.decider.Decision;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.settings.Settings;
@@ -62,8 +63,9 @@
 /**
  * Holds additional information as to why the shard is in unassigned state.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class UnassignedInfo implements ToXContentFragment, Writeable {
 
     public static final DateFormatter DATE_TIME_FORMATTER = DateFormatter.forPattern("date_optional_time").withZone(ZoneOffset.UTC);
@@ -81,8 +83,9 @@ public final class UnassignedInfo implements ToXContentFragment, Writeable {
      * Note, ordering of the enum is important, make sure to add new values
      * at the end and handle version serialization properly.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Reason {
         /**
          * Unassigned as a result of an API creation of an index.
@@ -153,12 +156,13 @@ public enum Reason {
     /**
      * Captures the status of an unsuccessful allocation attempt for the shard,
      * causing it to remain in the unassigned state.
-     *
+     * <p>
      * Note, ordering of the enum is important, make sure to add new values
      * at the end and handle version serialization properly.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum AllocationStatus implements Writeable {
         /**
          * The shard was denied allocation to a node because the allocation deciders all returned a NO decision
diff --git a/server/src/main/java/org/opensearch/cluster/routing/WeightedRouting.java b/server/src/main/java/org/opensearch/cluster/routing/WeightedRouting.java
index 01471ab664294..2b93a1483b801 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/WeightedRouting.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/WeightedRouting.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.cluster.routing;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -20,8 +21,9 @@
 /**
  * Entity for Weighted Round Robin weights
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.4.0")
 public class WeightedRouting implements Writeable {
     private String attributeName;
     private Map<String, Double> weights;
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocateUnassignedDecision.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocateUnassignedDecision.java
index 2afdd930cda1f..4e77ab772f390 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocateUnassignedDecision.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocateUnassignedDecision.java
@@ -37,6 +37,7 @@
 import org.opensearch.cluster.routing.allocation.decider.Decision;
 import org.opensearch.cluster.routing.allocation.decider.Decision.Type;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -52,8 +53,9 @@
 /**
  * Represents the allocation decision by an allocator for an unassigned shard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AllocateUnassignedDecision extends AbstractAllocationDecision {
     /** a constant representing a shard decision where no decision was taken */
     public static final AllocateUnassignedDecision NOT_TAKEN = new AllocateUnassignedDecision(
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocationDecision.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocationDecision.java
index 3f1c025fce405..6aeb904fed66f 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocationDecision.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/AllocationDecision.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.routing.UnassignedInfo.AllocationStatus;
 import org.opensearch.cluster.routing.allocation.decider.Decision;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -45,8 +46,9 @@
  * An enum which represents the various decision types that can be taken by the
  * allocators and deciders for allocating a shard to a node.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum AllocationDecision implements Writeable {
     /**
      * The shard can be allocated to a node.
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/AwarenessReplicaBalance.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/AwarenessReplicaBalance.java
index 19601483d5607..6fc0e535ef4dc 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/AwarenessReplicaBalance.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/AwarenessReplicaBalance.java
@@ -26,7 +26,7 @@
  * This {@link AwarenessReplicaBalance} gives total unique values of awareness attributes
  * It takes in effect only iff cluster.routing.allocation.awareness.attributes and
  * cluster.routing.allocation.awareness.force.zone.values both are specified.
- *
+ * <p>
  * This is used in enforcing total copy of shard is a maximum of unique values of awareness attributes
  * Helps in balancing shards across all awareness attributes and ensuring high availability of data.
  */
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/ConstraintTypes.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/ConstraintTypes.java
index f209e993518c1..ae2d4a0926194 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/ConstraintTypes.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/ConstraintTypes.java
@@ -36,14 +36,14 @@ public class ConstraintTypes {
     /**
      * Constraint to control number of shards of an index allocated on a single
      * node.
-     *
+     * <p>
      * In current weight function implementation, when a node has significantly
      * fewer shards than other nodes (e.g. during single new node addition or node
      * replacement), its weight is much less than other nodes. All shard allocations
      * at this time tend to land on the new node with skewed weight. This breaks
      * index level balance in the cluster, by creating all shards of the same index
      * on one node, often resulting in a hotspot on that node.
-     *
+     * <p>
      * This constraint is breached when balancer attempts to allocate more than
      * average shards per index per node.
      */
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/IndexMetadataUpdater.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/IndexMetadataUpdater.java
index ae8d92dae6811..7fc78b05880f3 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/IndexMetadataUpdater.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/IndexMetadataUpdater.java
@@ -59,9 +59,9 @@
 /**
  * Observer that tracks changes made to RoutingNodes in order to update the primary terms and in-sync allocation ids in
  * {@link IndexMetadata} once the allocation round has completed.
- *
+ * <p>
  * Primary terms are updated on primary initialization or when an active primary fails.
- *
+ * <p>
  * Allocation ids are added for shards that become active and removed for shards that stop being active.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/MoveDecision.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/MoveDecision.java
index fc39f813ca181..13578d1a11472 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/MoveDecision.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/MoveDecision.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.routing.allocation.decider.Decision;
 import org.opensearch.cluster.routing.allocation.decider.Decision.Type;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -48,8 +49,9 @@
  * Represents a decision to move a started shard, either because it is no longer allowed to remain on its current node
  * or because moving it to another node will form a better cluster balance.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class MoveDecision extends AbstractAllocationDecision {
     /** a constant representing no decision taken */
     public static final MoveDecision NOT_TAKEN = new MoveDecision(null, null, AllocationDecision.NO_ATTEMPT, null, null, 0);
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/NodeAllocationResult.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/NodeAllocationResult.java
index ad568fc5ffa57..4163a5fd4c16f 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/NodeAllocationResult.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/NodeAllocationResult.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.routing.allocation.decider.Decision;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -52,8 +53,9 @@
 /**
  * This class represents the shard allocation decision and its explanation for a single node.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodeAllocationResult implements ToXContentObject, Writeable, Comparable<NodeAllocationResult> {
 
     private static final Comparator<NodeAllocationResult> nodeResultComparator = Comparator.comparing(NodeAllocationResult::getNodeDecision)
@@ -191,8 +193,9 @@ public int compareTo(NodeAllocationResult other) {
     /**
      * A class that captures metadata about a shard store on a node.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class ShardStoreInfo implements ToXContentFragment, Writeable {
         private final boolean inSync;
         @Nullable
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/RerouteExplanation.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/RerouteExplanation.java
index 6c84957d6a788..c07fb0135262b 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/RerouteExplanation.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/RerouteExplanation.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.routing.allocation.command.AllocationCommand;
 import org.opensearch.cluster.routing.allocation.decider.Decision;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContentObject;
@@ -45,8 +46,9 @@
  * Class encapsulating the explanation for a single {@link AllocationCommand}
  * taken from the Deciders
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RerouteExplanation implements ToXContentObject {
 
     private AllocationCommand command;
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingAllocation.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingAllocation.java
index 9e8e399384467..bf2db57128517 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingAllocation.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingAllocation.java
@@ -43,6 +43,7 @@
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.routing.allocation.decider.AllocationDeciders;
 import org.opensearch.cluster.routing.allocation.decider.Decision;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.snapshots.RestoreService.RestoreInProgressUpdater;
 import org.opensearch.snapshots.SnapshotShardSizeInfo;
@@ -60,8 +61,9 @@
  * of shards and holds the {@link AllocationDeciders} which are responsible
  *  for the current routing state.
  *
- *  @opensearch.internal
+ *  @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RoutingAllocation {
 
     private final AllocationDeciders deciders;
@@ -317,8 +319,9 @@ public void setHasPendingAsyncFetch() {
     /**
      * Debug mode.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum DebugMode {
         /**
          * debug mode is off
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingExplanations.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingExplanations.java
index 769212703b48b..490eb76ab8563 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingExplanations.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/RoutingExplanations.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.routing.allocation;
 
 import org.opensearch.cluster.routing.allocation.decider.Decision;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -48,8 +49,9 @@
  * Class used to encapsulate a number of {@link RerouteExplanation}
  * explanations.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RoutingExplanations implements ToXContentFragment {
     private final List<RerouteExplanation> explanations;
 
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/ShardAllocationDecision.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/ShardAllocationDecision.java
index e1a7fb43827f3..49e8d82c6eb97 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/ShardAllocationDecision.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/ShardAllocationDecision.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.cluster.routing.allocation;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -53,8 +54,9 @@
  * then both {@link #getAllocateDecision()} and {@link #getMoveDecision()} will return
  * objects whose {@code isDecisionTaken()} method returns {@code false}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ShardAllocationDecision implements ToXContentFragment, Writeable {
     public static final ShardAllocationDecision NOT_TAKEN = new ShardAllocationDecision(
         AllocateUnassignedDecision.NOT_TAKEN,
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/BalancedShardsAllocator.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/BalancedShardsAllocator.java
index 90eff50fd9b5d..41ace0e7661fe 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/BalancedShardsAllocator.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/BalancedShardsAllocator.java
@@ -336,7 +336,7 @@ public boolean getPreferPrimaryBalance() {
      * </li>
      * </ul>
      * <code>weight(node, index) = weight<sub>index</sub>(node, index) + weight<sub>node</sub>(node, index)</code>
-     *
+     * <p>
      * package-private for testing
      */
     static class WeightFunction {
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/LocalShardsBalancer.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/LocalShardsBalancer.java
index 3365b58d92a63..45f64a5b29b04 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/LocalShardsBalancer.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/LocalShardsBalancer.java
@@ -65,7 +65,6 @@ public class LocalShardsBalancer extends ShardsBalancer {
 
     private final float threshold;
     private final Metadata metadata;
-    private final float avgShardsPerNode;
 
     private final float avgPrimaryShardsPerNode;
     private final BalancedShardsAllocator.NodeSorter sorter;
@@ -85,7 +84,6 @@ public LocalShardsBalancer(
         this.threshold = threshold;
         this.routingNodes = allocation.routingNodes();
         this.metadata = allocation.metadata();
-        avgShardsPerNode = ((float) metadata.getTotalNumberOfShards()) / routingNodes.size();
         avgPrimaryShardsPerNode = (float) (StreamSupport.stream(metadata.spliterator(), false)
             .mapToInt(IndexMetadata::getNumberOfShards)
             .sum()) / routingNodes.size();
@@ -530,7 +528,7 @@ private void checkAndAddInEligibleTargetNode(RoutingNode targetNode) {
 
     /**
      * Move started shards that can not be allocated to a node anymore
-     *
+     * <p>
      * For each shard to be moved this function executes a move operation
      * to the minimal eligible node with respect to the
      * weight function. If a shard is moved the shard will be set to
@@ -663,7 +661,6 @@ MoveDecision decideMove(final ShardRouting shardRouting) {
         RoutingNode targetNode = null;
         final List<NodeAllocationResult> nodeExplanationMap = explain ? new ArrayList<>() : null;
         int weightRanking = 0;
-        int targetNodeProcessed = 0;
         for (BalancedShardsAllocator.ModelNode currentNode : sorter.modelNodes) {
             if (currentNode != sourceNode) {
                 RoutingNode target = currentNode.getRoutingNode();
@@ -677,7 +674,6 @@ MoveDecision decideMove(final ShardRouting shardRouting) {
                         continue;
                     }
                 }
-                targetNodeProcessed++;
                 // don't use canRebalance as we want hard filtering rules to apply. See #17698
                 Decision allocationDecision = allocation.deciders().canAllocate(shardRouting, target, allocation);
                 if (explain) {
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/RemoteShardsBalancer.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/RemoteShardsBalancer.java
index cbbcd61fc5295..8a14ce3f1a288 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/RemoteShardsBalancer.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/RemoteShardsBalancer.java
@@ -406,7 +406,7 @@ private void tryAllocateUnassignedShard(Queue<RoutingNode> nodeQueue, ShardRouti
                     allocation.metadata(),
                     allocation.routingTable()
                 );
-                ShardRouting initShard = routingNodes.initializeShard(shard, node.nodeId(), null, shardSize, allocation.changes());
+                routingNodes.initializeShard(shard, node.nodeId(), null, shardSize, allocation.changes());
                 nodeQueue.offer(node);
                 allocated = true;
                 break;
@@ -444,7 +444,6 @@ private void tryAllocateUnassignedShard(Queue<RoutingNode> nodeQueue, ShardRouti
 
                 // Break out if all nodes in the queue have been checked for this shard
                 if (nodeQueue.stream().allMatch(rn -> nodesCheckedForShard.contains(rn.nodeId()))) {
-                    throttled = true;
                     break;
                 }
             }
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/ShardsAllocator.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/ShardsAllocator.java
index 63d8c656f5049..29e9acca4e6c2 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/ShardsAllocator.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/ShardsAllocator.java
@@ -63,12 +63,12 @@ public interface ShardsAllocator {
      * Returns the decision for where a shard should reside in the cluster.  If the shard is unassigned,
      * then the {@link AllocateUnassignedDecision} will be non-null.  If the shard is not in the unassigned
      * state, then the {@link MoveDecision} will be non-null.
-     *
+     * <p>
      * This method is primarily used by the cluster allocation explain API to provide detailed explanations
      * for the allocation of a single shard.  Implementations of the {@link #allocate(RoutingAllocation)} method
      * may use the results of this method implementation to decide on allocating shards in the routing table
      * to the cluster.
-     *
+     * <p>
      * If an implementation of this interface does not support explaining decisions for a single shard through
      * the cluster explain API, then this method should throw a {@code UnsupportedOperationException}.
      */
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommand.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommand.java
index 7fffb0299af85..bce3191240323 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommand.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommand.java
@@ -35,6 +35,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.cluster.routing.allocation.RerouteExplanation;
 import org.opensearch.cluster.routing.allocation.RoutingAllocation;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.network.NetworkModule;
 import org.opensearch.core.common.io.stream.NamedWriteable;
 import org.opensearch.core.xcontent.ToXContentObject;
@@ -43,11 +44,12 @@
 
 /**
  * A command to move shards in some way.
- *
+ * <p>
  * Commands are registered in {@link NetworkModule}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface AllocationCommand extends NamedWriteable, ToXContentObject {
 
     /**
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommands.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommands.java
index ac804819443a5..2ee4124e9d909 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommands.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/command/AllocationCommands.java
@@ -36,6 +36,7 @@
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.cluster.routing.allocation.RoutingAllocation;
 import org.opensearch.cluster.routing.allocation.RoutingExplanations;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -54,8 +55,9 @@
  * A simple {@link AllocationCommand} composite managing several
  * {@link AllocationCommand} implementations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AllocationCommands implements ToXContentFragment {
     private final List<AllocationCommand> commands = new ArrayList<>();
 
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDecider.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDecider.java
index 24c3fd7f34e4a..19faacc3a3ae1 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDecider.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDecider.java
@@ -38,14 +38,16 @@
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.routing.allocation.RoutingAllocation;
 import org.opensearch.cluster.routing.allocation.decider.Decision.Type;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * {@link AllocationDecider} is an abstract base class that allows to make
  * dynamic cluster- or index-wide shard allocation decisions on a per-node
  * basis.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class AllocationDecider {
     /**
      * Returns a {@link Decision} whether the given shard routing can be
@@ -109,7 +111,7 @@ public Decision canRebalance(RoutingAllocation allocation) {
      * Returns a {@link Decision} whether the given primary shard can be
      * forcibly allocated on the given node. This method should only be called
      * for unassigned primary shards where the node has a shard copy on disk.
-     *
+     * <p>
      * Note: all implementations that override this behavior should take into account
      * the results of {@link #canAllocate(ShardRouting, RoutingNode, RoutingAllocation)}
      * before making a decision on force allocation, because force allocation should only
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDeciders.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDeciders.java
index dca82f75d6fb5..1263efd19ac46 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDeciders.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/AllocationDeciders.java
@@ -39,6 +39,7 @@
 import org.opensearch.cluster.routing.RoutingNode;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.routing.allocation.RoutingAllocation;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -47,8 +48,9 @@
  * A composite {@link AllocationDecider} combining the "decision" of multiple
  * {@link AllocationDecider} implementations into a single allocation decision.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AllocationDeciders extends AllocationDecider {
 
     private static final Logger logger = LogManager.getLogger(AllocationDeciders.class);
@@ -255,7 +257,7 @@ public Decision canAllocateAnyShardToNode(RoutingNode node, RoutingAllocation al
         Decision.Multi ret = new Decision.Multi();
         for (AllocationDecider decider : allocations) {
             Decision decision = decider.canAllocateAnyShardToNode(node, allocation);
-            if (decision.type().canPremptivelyReturn()) {
+            if (decision.type().canPreemptivelyReturn()) {
                 if (logger.isTraceEnabled()) {
                     logger.trace("Shard can not be allocated on node [{}] due to [{}]", node.nodeId(), decider.getClass().getSimpleName());
                 }
@@ -277,7 +279,7 @@ public Decision canMoveAway(ShardRouting shardRouting, RoutingAllocation allocat
         for (AllocationDecider decider : allocations) {
             Decision decision = decider.canMoveAway(shardRouting, allocation);
             // short track if a NO is returned.
-            if (decision.type().canPremptivelyReturn()) {
+            if (decision.type().canPreemptivelyReturn()) {
                 if (logger.isTraceEnabled()) {
                     logger.trace("Shard [{}] can not be moved away due to [{}]", shardRouting, decider.getClass().getSimpleName());
                 }
@@ -299,7 +301,7 @@ public Decision canMoveAnyShard(RoutingAllocation allocation) {
         for (AllocationDecider decider : allocations) {
             Decision decision = decider.canMoveAnyShard(allocation);
             // short track if a NO is returned.
-            if (decision.type().canPremptivelyReturn()) {
+            if (decision.type().canPreemptivelyReturn()) {
                 if (allocation.debugDecision() == false) {
                     return decision;
                 } else {
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/Decision.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/Decision.java
index 807ab070b82b1..938c457606c79 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/Decision.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/Decision.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.routing.allocation.decider;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -54,8 +55,9 @@
  *
  * @see AllocationDecider
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class Decision implements ToXContent, Writeable {
 
     public static final Decision ALWAYS = new Single(Type.YES);
@@ -98,8 +100,9 @@ public static Decision readFrom(StreamInput in) throws IOException {
      * This enumeration defines the
      * possible types of decisions
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Type implements Writeable {
         YES(1),
         THROTTLE(2),
@@ -141,7 +144,7 @@ public boolean higherThan(Type other) {
             return false;
         }
 
-        public boolean canPremptivelyReturn() {
+        public boolean canPreemptivelyReturn() {
             return this == THROTTLE || this == NO;
         }
 
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/DiskThresholdDecider.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/DiskThresholdDecider.java
index 1bd47f111591d..2c7df6b81e676 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/DiskThresholdDecider.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/DiskThresholdDecider.java
@@ -73,23 +73,23 @@
 /**
  * The {@link DiskThresholdDecider} checks that the node a shard is potentially
  * being allocated to has enough disk space.
- *
+ * <p>
  * It has three configurable settings, all of which can be changed dynamically:
- *
+ * <p>
  * <code>cluster.routing.allocation.disk.watermark.low</code> is the low disk
  * watermark. New shards will not allocated to a node with usage higher than this,
  * although this watermark may be passed by allocating a shard. It defaults to
  * 0.85 (85.0%).
- *
+ * <p>
  * <code>cluster.routing.allocation.disk.watermark.high</code> is the high disk
  * watermark. If a node has usage higher than this, shards are not allowed to
  * remain on the node. In addition, if allocating a shard to a node causes the
  * node to pass this watermark, it will not be allowed. It defaults to
  * 0.90 (90.0%).
- *
+ * <p>
  * Both watermark settings are expressed in terms of used disk percentage, or
  * exact byte values for free space (like "500mb")
- *
+ * <p>
  * <code>cluster.routing.allocation.disk.threshold_enabled</code> is used to
  * enable or disable this decider. It defaults to true (enabled).
  *
@@ -119,7 +119,7 @@ public DiskThresholdDecider(Settings settings, ClusterSettings clusterSettings)
     /**
      * Returns the size of all shards that are currently being relocated to
      * the node, but may not be finished transferring yet.
-     *
+     * <p>
      * If subtractShardsMovingAway is true then the size of shards moving away is subtracted from the total size of all shards
      */
     public static long sizeOfRelocatingShards(
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/SameShardAllocationDecider.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/SameShardAllocationDecider.java
index 1680f2d8cad1d..c2eccdbc6ed26 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/SameShardAllocationDecider.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/SameShardAllocationDecider.java
@@ -44,7 +44,7 @@
 /**
  * An allocation decider that prevents multiple instances of the same shard to
  * be allocated on the same {@code node}.
- *
+ * <p>
  * The {@link #CLUSTER_ROUTING_ALLOCATION_SAME_HOST_SETTING} setting allows to perform a check to prevent
  * allocation of multiple instances of the same shard on a single {@code host},
  * based on host name and host address. Defaults to `false`, meaning that no
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDecider.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDecider.java
index c11f5823cf3a7..76f9f44077ad8 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDecider.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDecider.java
@@ -44,7 +44,7 @@ public Decision canAllocate(ShardRouting shardRouting, RoutingNode node, Routing
             return allocation.decision(
                 Decision.NO,
                 NAME,
-                "Routing pools are incompatible. Shard pool: [%s], Node Pool: [%s]",
+                "Routing pools are incompatible. Shard pool: [%s], node pool: [%s]",
                 shardPool,
                 targetNodePool
             );
@@ -56,21 +56,21 @@ public Decision canAllocate(ShardRouting shardRouting, RoutingNode node, Routing
                     shardRouting,
                     shardPool,
                     node.node(),
-                    DiscoveryNodeRole.DATA_ROLE
+                    DiscoveryNodeRole.DATA_ROLE.roleName()
                 );
                 return allocation.decision(
                     Decision.NO,
                     NAME,
-                    "Routing pools are incompatible. Shard pool: [{}], Node Pool: [{}] without [{}] role",
+                    "Routing pools are incompatible. Shard pool: [%s], node pool: [%s] without [%s] role",
                     shardPool,
                     targetNodePool,
-                    DiscoveryNodeRole.DATA_ROLE
+                    DiscoveryNodeRole.DATA_ROLE.roleName()
                 );
             }
         return allocation.decision(
             Decision.YES,
             NAME,
-            "Routing pools are compatible. Shard pool: [%s], Node Pool: [%s]",
+            "Routing pools are compatible. Shard pool: [%s], node pool: [%s]",
             shardPool,
             targetNodePool
         );
@@ -106,7 +106,7 @@ private Decision canAllocateInTargetPool(IndexMetadata indexMetadata, DiscoveryN
             return allocation.decision(
                 Decision.NO,
                 NAME,
-                "Routing pools are incompatible. Index pool: [%s], Node Pool: [%s]",
+                "Routing pools are incompatible. Index pool: [%s], node pool: [%s]",
                 indexPool,
                 targetNodePool
             );
@@ -118,21 +118,21 @@ private Decision canAllocateInTargetPool(IndexMetadata indexMetadata, DiscoveryN
                     indexMetadata.getIndex().getName(),
                     indexPool,
                     node,
-                    DiscoveryNodeRole.DATA_ROLE
+                    DiscoveryNodeRole.DATA_ROLE.roleName()
                 );
                 return allocation.decision(
                     Decision.NO,
                     NAME,
-                    "Routing pools are incompatible. Index pool: [{}], Node Pool: [{}] without [{}] role",
+                    "Routing pools are incompatible. Index pool: [%s], node pool: [%s] without [%s] role",
                     indexPool,
                     targetNodePool,
-                    DiscoveryNodeRole.DATA_ROLE
+                    DiscoveryNodeRole.DATA_ROLE.roleName()
                 );
             }
         return allocation.decision(
             Decision.YES,
             NAME,
-            "Routing pools are compatible. Index pool: [%s], Node Pool: [%s]",
+            "Routing pools are compatible. Index pool: [%s], node pool: [%s]",
             indexPool,
             targetNodePool
         );
diff --git a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/ThrottlingAllocationDecider.java b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/ThrottlingAllocationDecider.java
index 3a9fdf0ea10cf..26a04de31ce39 100644
--- a/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/ThrottlingAllocationDecider.java
+++ b/server/src/main/java/org/opensearch/cluster/routing/allocation/decider/ThrottlingAllocationDecider.java
@@ -323,7 +323,7 @@ private Decision allocateShardCopies(
      * - the initializing shard routing if we want to assign the initializing shard to this node instead
      * - the started shard routing in case if we want to check if we can relocate to this node.
      * - the relocating shard routing if we want to relocate to this node now instead.
-     *
+     * <p>
      * This method returns the corresponding initializing shard that would be allocated to this node.
      */
     private ShardRouting initializingShard(ShardRouting shardRouting, String currentNodeId) {
diff --git a/server/src/main/java/org/opensearch/cluster/service/ClusterApplier.java b/server/src/main/java/org/opensearch/cluster/service/ClusterApplier.java
index 939feb89b6054..5b3f7f1001779 100644
--- a/server/src/main/java/org/opensearch/cluster/service/ClusterApplier.java
+++ b/server/src/main/java/org/opensearch/cluster/service/ClusterApplier.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.service;
 
 import org.opensearch.cluster.ClusterState;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.function.Supplier;
 
@@ -59,7 +60,10 @@ public interface ClusterApplier {
 
     /**
      * Listener for results of cluster state application
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface ClusterApplyListener {
         /**
          * Called on successful cluster state application
diff --git a/server/src/main/java/org/opensearch/cluster/service/ClusterApplierService.java b/server/src/main/java/org/opensearch/cluster/service/ClusterApplierService.java
index 007508162ba14..a55721fb13cdc 100644
--- a/server/src/main/java/org/opensearch/cluster/service/ClusterApplierService.java
+++ b/server/src/main/java/org/opensearch/cluster/service/ClusterApplierService.java
@@ -51,6 +51,7 @@
 import org.opensearch.common.Priority;
 import org.opensearch.common.StopWatch;
 import org.opensearch.common.StopWatch.TimingHandle;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
@@ -82,8 +83,9 @@
 /**
  * Service that provides callbacks when cluster state changes
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ClusterApplierService extends AbstractLifecycleComponent implements ClusterApplier {
     private static final Logger logger = LogManager.getLogger(ClusterApplierService.class);
 
@@ -294,7 +296,7 @@ public void addLocalNodeMasterListener(LocalNodeMasterListener listener) {
     /**
      * Adds a cluster state listener that is expected to be removed during a short period of time.
      * If provided, the listener will be notified once a specific time has elapsed.
-     *
+     * <p>
      * NOTE: the listener is not removed on timeout. This is the responsibility of the caller.
      */
     public void addTimeoutListener(@Nullable final TimeValue timeout, final TimeoutClusterStateListener listener) {
diff --git a/server/src/main/java/org/opensearch/cluster/service/ClusterManagerService.java b/server/src/main/java/org/opensearch/cluster/service/ClusterManagerService.java
index 74b623dd95e6f..e9224596e048d 100644
--- a/server/src/main/java/org/opensearch/cluster/service/ClusterManagerService.java
+++ b/server/src/main/java/org/opensearch/cluster/service/ClusterManagerService.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.cluster.service;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.threadpool.ThreadPool;
@@ -15,8 +16,9 @@
 /**
  * Main Cluster Manager Node Service
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public class ClusterManagerService extends MasterService {
     public ClusterManagerService(Settings settings, ClusterSettings clusterSettings, ThreadPool threadPool) {
         super(settings, clusterSettings, threadPool);
diff --git a/server/src/main/java/org/opensearch/cluster/service/ClusterManagerTaskThrottler.java b/server/src/main/java/org/opensearch/cluster/service/ClusterManagerTaskThrottler.java
index 8da6b1b941f83..827f3a12fbce4 100644
--- a/server/src/main/java/org/opensearch/cluster/service/ClusterManagerTaskThrottler.java
+++ b/server/src/main/java/org/opensearch/cluster/service/ClusterManagerTaskThrottler.java
@@ -12,6 +12,7 @@
 import org.apache.logging.log4j.Logger;
 import org.opensearch.Version;
 import org.opensearch.cluster.ClusterStateTaskExecutor;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
@@ -29,7 +30,7 @@
 /**
  * This class does throttling on task submission to cluster manager node, it uses throttling key defined in various executors
  * as key for throttling. Throttling will be performed over task executor's class level, different task types have different executors class.
- *
+ * <p>
  * Set specific setting to for setting the threshold of throttling of particular task type.
  * e.g : Set "cluster_manager.throttling.thresholds.put_mapping" to set throttling limit of "put mapping" tasks,
  *       Set it to default value(-1) to disable the throttling for this task type.
@@ -117,9 +118,9 @@ public static TimeValue getMaxDelayForRetry() {
      * * Register task to cluster service with task key,
      * * override getClusterManagerThrottlingKey method with above task key in task executor.
      * * Verify that throttled tasks would be retried from data nodes
-     *
+     * <p>
      * Added retry mechanism in TransportClusterManagerNodeAction, so it would be retried for customer generated tasks.
-     *
+     * <p>
      * If tasks are not getting retried then we can register with false flag, so user won't be able to configure threshold limits for it.
      */
     protected ThrottlingKey registerClusterManagerTask(String taskKey, boolean throttlingEnabled) {
@@ -133,7 +134,10 @@ protected ThrottlingKey registerClusterManagerTask(String taskKey, boolean throt
 
     /**
      * Class to store the throttling key for the tasks of cluster manager
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ThrottlingKey {
         private String taskThrottlingKey;
         private boolean throttlingEnabled;
@@ -236,7 +240,7 @@ public void onBeginSubmit(List<? extends TaskBatcher.BatchedTask> tasks) {
      * It may start throwing throttling exception to older nodes in cluster.
      * Older version nodes will not be equipped to handle the throttling exception and
      * this may result in unexpected behavior where internal tasks would start failing without any retries.
-     *
+     * <p>
      * For every task submission request, it will validate if nodes version is greater or equal to 2.5.0 and set the startThrottling flag.
      * Once the startThrottling flag is set, it will not perform check for next set of tasks.
      */
diff --git a/server/src/main/java/org/opensearch/cluster/service/ClusterManagerThrottlingStats.java b/server/src/main/java/org/opensearch/cluster/service/ClusterManagerThrottlingStats.java
index 7714b608c7c12..6a910e5f88536 100644
--- a/server/src/main/java/org/opensearch/cluster/service/ClusterManagerThrottlingStats.java
+++ b/server/src/main/java/org/opensearch/cluster/service/ClusterManagerThrottlingStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.cluster.service;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -23,7 +24,10 @@
 /**
  * Contains stats of Cluster Manager Task Throttling.
  * It stores the total cumulative count of throttled tasks per task type.
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.5.0")
 public class ClusterManagerThrottlingStats implements ClusterManagerTaskThrottlerListener, Writeable, ToXContentFragment {
 
     private Map<String, CounterMetric> throttledTasksCount;
diff --git a/server/src/main/java/org/opensearch/cluster/service/ClusterStateStats.java b/server/src/main/java/org/opensearch/cluster/service/ClusterStateStats.java
new file mode 100644
index 0000000000000..79263e31b8f49
--- /dev/null
+++ b/server/src/main/java/org/opensearch/cluster/service/ClusterStateStats.java
@@ -0,0 +1,122 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.cluster.service;
+
+import org.opensearch.cluster.coordination.PersistedStateStats;
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.xcontent.ToXContentObject;
+import org.opensearch.core.xcontent.XContentBuilder;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * Cluster state related stats.
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "2.12.0")
+public class ClusterStateStats implements Writeable, ToXContentObject {
+
+    private AtomicLong updateSuccess = new AtomicLong(0);
+    private AtomicLong updateTotalTimeInMillis = new AtomicLong(0);
+    private AtomicLong updateFailed = new AtomicLong(0);
+    private List<PersistedStateStats> persistenceStats = new ArrayList<>();
+
+    public ClusterStateStats() {}
+
+    public long getUpdateSuccess() {
+        return updateSuccess.get();
+    }
+
+    public long getUpdateTotalTimeInMillis() {
+        return updateTotalTimeInMillis.get();
+    }
+
+    public long getUpdateFailed() {
+        return updateFailed.get();
+    }
+
+    public List<PersistedStateStats> getPersistenceStats() {
+        return persistenceStats;
+    }
+
+    public void stateUpdated() {
+        updateSuccess.incrementAndGet();
+    }
+
+    public void stateUpdateFailed() {
+        updateFailed.incrementAndGet();
+    }
+
+    public void stateUpdateTook(long stateUpdateTime) {
+        updateTotalTimeInMillis.addAndGet(stateUpdateTime);
+    }
+
+    public ClusterStateStats setPersistenceStats(List<PersistedStateStats> persistenceStats) {
+        this.persistenceStats = persistenceStats;
+        return this;
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeVLong(updateSuccess.get());
+        out.writeVLong(updateTotalTimeInMillis.get());
+        out.writeVLong(updateFailed.get());
+        out.writeVInt(persistenceStats.size());
+        for (PersistedStateStats stats : persistenceStats) {
+            stats.writeTo(out);
+        }
+    }
+
+    public ClusterStateStats(StreamInput in) throws IOException {
+        this.updateSuccess = new AtomicLong(in.readVLong());
+        this.updateTotalTimeInMillis = new AtomicLong(in.readVLong());
+        this.updateFailed = new AtomicLong(in.readVLong());
+        int persistedStatsSize = in.readVInt();
+        this.persistenceStats = new ArrayList<>();
+        for (int statsNumber = 0; statsNumber < persistedStatsSize; statsNumber++) {
+            PersistedStateStats stats = new PersistedStateStats(in);
+            this.persistenceStats.add(stats);
+        }
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(Fields.CLUSTER_STATE_STATS);
+        builder.startObject(Fields.OVERALL);
+        builder.field(Fields.UPDATE_COUNT, getUpdateSuccess());
+        builder.field(Fields.TOTAL_TIME_IN_MILLIS, getUpdateTotalTimeInMillis());
+        builder.field(Fields.FAILED_COUNT, getUpdateFailed());
+        builder.endObject();
+        for (PersistedStateStats stats : persistenceStats) {
+            stats.toXContent(builder, params);
+        }
+        builder.endObject();
+        return builder;
+    }
+
+    /**
+     * Fields for parsing and toXContent
+     *
+     * @opensearch.internal
+     */
+    static final class Fields {
+        static final String CLUSTER_STATE_STATS = "cluster_state_stats";
+        static final String OVERALL = "overall";
+        static final String UPDATE_COUNT = "update_count";
+        static final String TOTAL_TIME_IN_MILLIS = "total_time_in_millis";
+        static final String FAILED_COUNT = "failed_count";
+    }
+}
diff --git a/server/src/main/java/org/opensearch/cluster/service/MasterService.java b/server/src/main/java/org/opensearch/cluster/service/MasterService.java
index 563b69dfd0e2a..af3e4f8437c43 100644
--- a/server/src/main/java/org/opensearch/cluster/service/MasterService.java
+++ b/server/src/main/java/org/opensearch/cluster/service/MasterService.java
@@ -54,6 +54,7 @@
 import org.opensearch.cluster.routing.RoutingTable;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.DeprecatedApi;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
@@ -87,10 +88,11 @@
 /**
  * Main Master Node Service
  *
- * @opensearch.internal
+ * @opensearch.api
  * @deprecated As of 2.2, because supporting inclusive language, replaced by {@link ClusterManagerService}.
  */
 @Deprecated
+@DeprecatedApi(since = "2.2.0")
 public class MasterService extends AbstractLifecycleComponent {
     private static final Logger logger = LogManager.getLogger(MasterService.class);
 
@@ -112,7 +114,9 @@ public class MasterService extends AbstractLifecycleComponent {
 
     static final String CLUSTER_MANAGER_UPDATE_THREAD_NAME = "clusterManagerService#updateTask";
 
-    /** @deprecated As of 2.2, because supporting inclusive language, replaced by {@link #CLUSTER_MANAGER_UPDATE_THREAD_NAME} */
+    /**
+     * @deprecated As of 2.2, because supporting inclusive language, replaced by {@link #CLUSTER_MANAGER_UPDATE_THREAD_NAME}
+     */
     @Deprecated
     static final String MASTER_UPDATE_THREAD_NAME = "masterService#updateTask";
 
@@ -130,6 +134,7 @@ public class MasterService extends AbstractLifecycleComponent {
     private volatile Batcher taskBatcher;
     protected final ClusterManagerTaskThrottler clusterManagerTaskThrottler;
     private final ClusterManagerThrottlingStats throttlingStats;
+    private final ClusterStateStats stateStats;
 
     public MasterService(Settings settings, ClusterSettings clusterSettings, ThreadPool threadPool) {
         this.nodeName = Objects.requireNonNull(Node.NODE_NAME_SETTING.get(settings));
@@ -147,6 +152,7 @@ public MasterService(Settings settings, ClusterSettings clusterSettings, ThreadP
             this::getMinNodeVersion,
             throttlingStats
         );
+        this.stateStats = new ClusterStateStats();
         this.threadPool = threadPool;
     }
 
@@ -339,7 +345,7 @@ private TimeValue getTimeSince(long startTimeNanos) {
         return TimeValue.timeValueMillis(TimeValue.nsecToMSec(threadPool.preciseRelativeTimeInNanos() - startTimeNanos));
     }
 
-    protected void publish(ClusterChangedEvent clusterChangedEvent, TaskOutputs taskOutputs, long startTimeMillis) {
+    protected void publish(ClusterChangedEvent clusterChangedEvent, TaskOutputs taskOutputs, long startTimeNanos) {
         final PlainActionFuture<Void> fut = new PlainActionFuture<Void>() {
             @Override
             protected boolean blockingAllowed() {
@@ -352,8 +358,12 @@ protected boolean blockingAllowed() {
         try {
             FutureUtils.get(fut);
             onPublicationSuccess(clusterChangedEvent, taskOutputs);
+            final long durationMillis = getTimeSince(startTimeNanos).millis();
+            stateStats.stateUpdateTook(durationMillis);
+            stateStats.stateUpdated();
         } catch (Exception e) {
-            onPublicationFailed(clusterChangedEvent, taskOutputs, startTimeMillis, e);
+            stateStats.stateUpdateFailed();
+            onPublicationFailed(clusterChangedEvent, taskOutputs, startTimeNanos, e);
         }
     }
 
@@ -464,7 +474,6 @@ public Builder incrementVersion(ClusterState clusterState) {
      * @param source     the source of the cluster state update task
      * @param updateTask the full context for the cluster state update
      *                   task
-     *
      */
     public <T extends ClusterStateTaskConfig & ClusterStateTaskExecutor<T> & ClusterStateTaskListener> void submitStateUpdateTask(
         String source,
@@ -490,7 +499,6 @@ public <T extends ClusterStateTaskConfig & ClusterStateTaskExecutor<T> & Cluster
      * @param listener callback after the cluster state update task
      *                 completes
      * @param <T>      the type of the cluster state update task state
-     *
      */
     public <T> void submitStateUpdateTask(
         String source,
@@ -947,7 +955,7 @@ void onNoLongerClusterManager() {
     /**
      * Functionality for register task key to cluster manager node.
      *
-     * @param taskKey - task key of task
+     * @param taskKey           - task key of task
      * @param throttlingEnabled - throttling is enabled for task or not i.e does data node perform retries on it or not
      * @return throttling task key which needs to be passed while submitting task to cluster manager
      */
@@ -966,7 +974,6 @@ public ClusterManagerTaskThrottler.ThrottlingKey registerClusterManagerTask(Stri
      *                 that share the same executor will be executed
      *                 batches on this executor
      * @param <T>      the type of the cluster state update task state
-     *
      */
     public <T> void submitStateUpdateTasks(
         final String source,
@@ -996,4 +1003,8 @@ public <T> void submitStateUpdateTasks(
         }
     }
 
+    public ClusterStateStats getClusterStateStats() {
+        return stateStats;
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/cluster/service/PendingClusterTask.java b/server/src/main/java/org/opensearch/cluster/service/PendingClusterTask.java
index b1723cca518fd..b06c537e7bac5 100644
--- a/server/src/main/java/org/opensearch/cluster/service/PendingClusterTask.java
+++ b/server/src/main/java/org/opensearch/cluster/service/PendingClusterTask.java
@@ -33,6 +33,7 @@
 package org.opensearch.cluster.service;
 
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -44,8 +45,9 @@
 /**
  * Represents a task that is pending in the cluster
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PendingClusterTask implements Writeable {
 
     private long insertOrder;
diff --git a/server/src/main/java/org/opensearch/common/FieldMemoryStats.java b/server/src/main/java/org/opensearch/common/FieldMemoryStats.java
index 86a2fe1397cec..2e04f39e48c4c 100644
--- a/server/src/main/java/org/opensearch/common/FieldMemoryStats.java
+++ b/server/src/main/java/org/opensearch/common/FieldMemoryStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -47,8 +48,9 @@
 /**
  * A reusable class to encode {@code field -&gt; memory size} mappings
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class FieldMemoryStats implements Writeable, Iterable<Map.Entry<String, Long>> {
 
     private final Map<String, Long> stats;
diff --git a/server/src/main/java/org/opensearch/common/Priority.java b/server/src/main/java/org/opensearch/common/Priority.java
index 09a751362c945..4f03d6e363550 100644
--- a/server/src/main/java/org/opensearch/common/Priority.java
+++ b/server/src/main/java/org/opensearch/common/Priority.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
@@ -40,8 +41,9 @@
 /**
  * Priority levels.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum Priority {
 
     IMMEDIATE((byte) 0),
diff --git a/server/src/main/java/org/opensearch/common/Randomness.java b/server/src/main/java/org/opensearch/common/Randomness.java
index 2c60e848b9db9..221bc95c41f31 100644
--- a/server/src/main/java/org/opensearch/common/Randomness.java
+++ b/server/src/main/java/org/opensearch/common/Randomness.java
@@ -127,7 +127,7 @@ public static Random get() {
 
     /**
      * Provides a secure source of randomness.
-     *
+     * <p>
      * This acts exactly similar to {@link #get()}, but returning a new {@link SecureRandom}.
      */
     public static SecureRandom createSecure() {
diff --git a/server/src/main/java/org/opensearch/common/Rounding.java b/server/src/main/java/org/opensearch/common/Rounding.java
index 667eb4529fe38..6f5f1e4328758 100644
--- a/server/src/main/java/org/opensearch/common/Rounding.java
+++ b/server/src/main/java/org/opensearch/common/Rounding.java
@@ -37,7 +37,9 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.common.LocalTimeOffset.Gap;
 import org.opensearch.common.LocalTimeOffset.Overlap;
-import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.common.round.Roundable;
+import org.opensearch.common.round.RoundableFactory;
 import org.opensearch.common.time.DateUtils;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -52,6 +54,7 @@
 import java.time.OffsetDateTime;
 import java.time.ZoneId;
 import java.time.ZoneOffset;
+import java.time.format.TextStyle;
 import java.time.temporal.ChronoField;
 import java.time.temporal.ChronoUnit;
 import java.time.temporal.IsoFields;
@@ -59,10 +62,10 @@
 import java.time.temporal.TemporalQueries;
 import java.time.zone.ZoneOffsetTransition;
 import java.time.zone.ZoneRules;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
+import java.util.OptionalLong;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ -76,16 +79,18 @@
  * blog for some background reading. Its super interesting and the links are
  * a comedy gold mine. If you like time zones. Or hate them.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class Rounding implements Writeable {
     private static final Logger logger = LogManager.getLogger(Rounding.class);
 
     /**
      * A Date Time Unit
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum DateTimeUnit {
         WEEK_OF_WEEKYEAR((byte) 1, "week", IsoFields.WEEK_OF_WEEK_BASED_YEAR, true, TimeUnit.DAYS.toMillis(7)) {
             private final long extraLocalOffsetLookup = TimeUnit.DAYS.toMillis(7);
@@ -176,7 +181,7 @@ long roundFloor(long utcMillis) {
                 return DateUtils.roundFloor(utcMillis, ratio);
             }
 
-            long extraLocalOffsetLookup() {
+            public long extraLocalOffsetLookup() {
                 return ratio;
             }
         };
@@ -268,8 +273,9 @@ public void writeTo(StreamOutput out) throws IOException {
     /**
      * A strategy for rounding milliseconds since epoch.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Prepared {
         /**
          * Rounds the given value.
@@ -359,8 +365,9 @@ public static Builder builder(TimeValue interval) {
     /**
      * Builder for rounding
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private final DateTimeUnit unit;
@@ -421,13 +428,6 @@ private abstract class PreparedRounding implements Prepared {
          */
         private static final int DEFAULT_ARRAY_ROUNDING_MAX_THRESHOLD = 128;
 
-        /**
-         * The maximum limit up to which linear search is used, otherwise binary search is used.
-         * This is because linear search is much faster on small arrays.
-         * Benchmark results: <a href="https://github.com/opensearch-project/OpenSearch/pull/9727">PR #9727</a>
-         */
-        private static final int LINEAR_SEARCH_ARRAY_ROUNDING_MAX_THRESHOLD = 64;
-
         /**
          * Attempt to build a {@link Prepared} implementation that relies on pre-calcuated
          * "round down" points. If there would be more than {@code max} points then return
@@ -451,9 +451,36 @@ protected Prepared maybeUseArray(long minUtcMillis, long maxUtcMillis, int max)
                 values = ArrayUtil.grow(values, i + 1);
                 values[i++] = rounded;
             }
-            return i <= LINEAR_SEARCH_ARRAY_ROUNDING_MAX_THRESHOLD
-                ? new BidirectionalLinearSearchArrayRounding(values, i, this)
-                : new BinarySearchArrayRounding(values, i, this);
+            return new ArrayRounding(RoundableFactory.create(values, i), this);
+        }
+    }
+
+    /**
+     * ArrayRounding is an implementation of {@link Prepared} which uses
+     * pre-calculated round-down points to speed up lookups.
+     */
+    private static class ArrayRounding implements Prepared {
+        private final Roundable roundable;
+        private final Prepared delegate;
+
+        public ArrayRounding(Roundable roundable, Prepared delegate) {
+            this.roundable = roundable;
+            this.delegate = delegate;
+        }
+
+        @Override
+        public long round(long utcMillis) {
+            return roundable.floor(utcMillis);
+        }
+
+        @Override
+        public long nextRoundingValue(long utcMillis) {
+            return delegate.nextRoundingValue(utcMillis);
+        }
+
+        @Override
+        public double roundingSize(long utcMillis, DateTimeUnit timeUnit) {
+            return delegate.roundingSize(utcMillis, timeUnit);
         }
     }
 
@@ -1345,106 +1372,38 @@ public static Rounding read(StreamInput in) throws IOException {
     }
 
     /**
-     * Implementation of {@link Prepared} using pre-calculated "round down" points.
-     *
-     * <p>
-     * It uses binary search to find the greatest round-down point less than or equal to the given timestamp.
-     *
-     * @opensearch.internal
+     * Extracts the interval value from the {@link Rounding} instance
+     * @param rounding {@link Rounding} instance
+     * @return the interval value from the {@link Rounding} instance or {@code OptionalLong.empty()}
+     * if the interval is not available
      */
-    @InternalApi
-    static class BinarySearchArrayRounding implements Prepared {
-        private final long[] values;
-        private final int max;
-        private final Prepared delegate;
+    public static OptionalLong getInterval(Rounding rounding) {
+        long interval = 0;
 
-        BinarySearchArrayRounding(long[] values, int max, Prepared delegate) {
-            assert max > 0 : "at least one round-down point must be present";
-            this.values = values;
-            this.max = max;
-            this.delegate = delegate;
-        }
-
-        @Override
-        public long round(long utcMillis) {
-            assert values[0] <= utcMillis : "utcMillis must be after " + values[0];
-            int idx = Arrays.binarySearch(values, 0, max, utcMillis);
-            assert idx != -1 : "The insertion point is before the array! This should have tripped the assertion above.";
-            assert -1 - idx <= values.length : "This insertion point is after the end of the array.";
-            if (idx < 0) {
-                idx = -2 - idx;
+        if (rounding instanceof TimeUnitRounding) {
+            interval = (((TimeUnitRounding) rounding).unit).extraLocalOffsetLookup();
+            if (!isUTCTimeZone(((TimeUnitRounding) rounding).timeZone)) {
+                // Fast filter aggregation cannot be used if it needs time zone rounding
+                return OptionalLong.empty();
             }
-            return values[idx];
-        }
-
-        @Override
-        public long nextRoundingValue(long utcMillis) {
-            return delegate.nextRoundingValue(utcMillis);
+        } else if (rounding instanceof TimeIntervalRounding) {
+            interval = ((TimeIntervalRounding) rounding).interval;
+            if (!isUTCTimeZone(((TimeIntervalRounding) rounding).timeZone)) {
+                // Fast filter aggregation cannot be used if it needs time zone rounding
+                return OptionalLong.empty();
+            }
+        } else {
+            return OptionalLong.empty();
         }
 
-        @Override
-        public double roundingSize(long utcMillis, DateTimeUnit timeUnit) {
-            return delegate.roundingSize(utcMillis, timeUnit);
-        }
+        return OptionalLong.of(interval);
     }
 
     /**
-     * Implementation of {@link Prepared} using pre-calculated "round down" points.
-     *
-     * <p>
-     * It uses linear search to find the greatest round-down point less than or equal to the given timestamp.
-     * For small inputs (&le; 64 elements), this can be much faster than binary search as it avoids the penalty of
-     * branch mispredictions and pipeline stalls, and accesses memory sequentially.
-     *
-     * <p>
-     * It uses "meet in the middle" linear search to avoid the worst case scenario when the desired element is present
-     * at either side of the array. This is helpful for time-series data where velocity increases over time, so more
-     * documents are likely to find a greater timestamp which is likely to be present on the right end of the array.
-     *
-     * @opensearch.internal
+     * Helper function for checking if the time zone requested for date histogram
+     * aggregation is utc or not
      */
-    @InternalApi
-    static class BidirectionalLinearSearchArrayRounding implements Prepared {
-        private final long[] ascending;
-        private final long[] descending;
-        private final Prepared delegate;
-
-        BidirectionalLinearSearchArrayRounding(long[] values, int max, Prepared delegate) {
-            assert max > 0 : "at least one round-down point must be present";
-            this.delegate = delegate;
-            int len = (max + 1) >>> 1; // rounded-up to handle odd number of values
-            ascending = new long[len];
-            descending = new long[len];
-
-            for (int i = 0; i < len; i++) {
-                ascending[i] = values[i];
-                descending[i] = values[max - i - 1];
-            }
-        }
-
-        @Override
-        public long round(long utcMillis) {
-            int i = 0;
-            for (; i < ascending.length; i++) {
-                if (descending[i] <= utcMillis) {
-                    return descending[i];
-                }
-                if (ascending[i] > utcMillis) {
-                    assert i > 0 : "utcMillis must be after " + ascending[0];
-                    return ascending[i - 1];
-                }
-            }
-            return ascending[i - 1];
-        }
-
-        @Override
-        public long nextRoundingValue(long utcMillis) {
-            return delegate.nextRoundingValue(utcMillis);
-        }
-
-        @Override
-        public double roundingSize(long utcMillis, DateTimeUnit timeUnit) {
-            return delegate.roundingSize(utcMillis, timeUnit);
-        }
+    private static boolean isUTCTimeZone(final ZoneId zoneId) {
+        return "Z".equals(zoneId.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
     }
 }
diff --git a/server/src/main/java/org/opensearch/common/StreamContext.java b/server/src/main/java/org/opensearch/common/StreamContext.java
index b163ba65dc7db..47a3d2b8571ea 100644
--- a/server/src/main/java/org/opensearch/common/StreamContext.java
+++ b/server/src/main/java/org/opensearch/common/StreamContext.java
@@ -57,6 +57,8 @@ protected StreamContext(StreamContext streamContext) {
     /**
      * Vendor plugins can use this method to create new streams only when they are required for processing
      * New streams won't be created till this method is called with the specific <code>partNumber</code>
+     * It is the responsibility of caller to ensure that stream is properly closed after consumption
+     * otherwise it can leak resources.
      *
      * @param partNumber The index of the part
      * @return A stream reference to the part requested
diff --git a/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamBlobContainer.java b/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamBlobContainer.java
index e73a9f5cd0bc9..97f304d776f5c 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamBlobContainer.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamBlobContainer.java
@@ -10,13 +10,10 @@
 
 import org.opensearch.common.annotation.ExperimentalApi;
 import org.opensearch.common.blobstore.stream.read.ReadContext;
-import org.opensearch.common.blobstore.stream.read.listener.ReadContextListener;
 import org.opensearch.common.blobstore.stream.write.WriteContext;
 import org.opensearch.core.action.ActionListener;
-import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
-import java.nio.file.Path;
 
 /**
  * An extension of {@link BlobContainer} that adds {@link AsyncMultiStreamBlobContainer#asyncBlobUpload} to allow
@@ -45,19 +42,6 @@ public interface AsyncMultiStreamBlobContainer extends BlobContainer {
     @ExperimentalApi
     void readBlobAsync(String blobName, ActionListener<ReadContext> listener);
 
-    /**
-     * Asynchronously downloads the blob to the specified location using an executor from the thread pool.
-     * @param blobName The name of the blob for which needs to be downloaded.
-     * @param fileLocation The path on local disk where the blob needs to be downloaded.
-     * @param threadPool The threadpool instance which will provide the executor for performing a multipart download.
-     * @param completionListener Listener which will be notified when the download is complete.
-     */
-    @ExperimentalApi
-    default void asyncBlobDownload(String blobName, Path fileLocation, ThreadPool threadPool, ActionListener<String> completionListener) {
-        ReadContextListener readContextListener = new ReadContextListener(blobName, fileLocation, threadPool, completionListener);
-        readBlobAsync(blobName, readContextListener);
-    }
-
     /*
      * Wether underlying blobContainer can verify integrity of data after transfer. If true and if expected
      * checksum is provided in WriteContext, then the checksum of transferred data is compared with expected checksum
diff --git a/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainer.java b/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainer.java
index 07a0b49df47ff..82bc7a0baed50 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainer.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainer.java
@@ -12,12 +12,14 @@
 import org.opensearch.common.blobstore.stream.read.ReadContext;
 import org.opensearch.common.blobstore.stream.write.WriteContext;
 import org.opensearch.common.crypto.CryptoHandler;
+import org.opensearch.common.crypto.DecryptedRangedStreamProvider;
 import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.core.action.ActionListener;
-import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
-import java.nio.file.Path;
+import java.io.InputStream;
+import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * EncryptedBlobContainer is an encrypted BlobContainer that is backed by a
@@ -44,12 +46,17 @@ public void asyncBlobUpload(WriteContext writeContext, ActionListener<Void> comp
 
     @Override
     public void readBlobAsync(String blobName, ActionListener<ReadContext> listener) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public void asyncBlobDownload(String blobName, Path fileLocation, ThreadPool threadPool, ActionListener<String> completionListener) {
-        throw new UnsupportedOperationException();
+        try {
+            final U cryptoContext = cryptoHandler.loadEncryptionMetadata(getEncryptedHeaderContentSupplier(blobName));
+            ActionListener<ReadContext> decryptingCompletionListener = ActionListener.map(
+                listener,
+                readContext -> new DecryptedReadContext<>(readContext, cryptoHandler, cryptoContext)
+            );
+
+            blobContainer.readBlobAsync(blobName, decryptingCompletionListener);
+        } catch (Exception e) {
+            listener.onFailure(e);
+        }
     }
 
     @Override
@@ -108,4 +115,60 @@ public InputStreamContainer provideStream(int partNumber) throws IOException {
         }
 
     }
+
+    /**
+     * DecryptedReadContext decrypts the encrypted {@link ReadContext} by acting as a transformation wrapper around
+     * the encrypted object
+     * @param <T> Encryption Metadata / CryptoContext for the {@link CryptoHandler} instance
+     * @param <U> Parsed Encryption Metadata / CryptoContext for the {@link CryptoHandler} instance
+     */
+    static class DecryptedReadContext<T, U> extends ReadContext {
+
+        private final CryptoHandler<T, U> cryptoHandler;
+        private final U cryptoContext;
+        private Long blobSize;
+
+        public DecryptedReadContext(ReadContext readContext, CryptoHandler<T, U> cryptoHandler, U cryptoContext) {
+            super(readContext);
+            this.cryptoHandler = cryptoHandler;
+            this.cryptoContext = cryptoContext;
+        }
+
+        @Override
+        public long getBlobSize() {
+            // initializes the value lazily
+            if (blobSize == null) {
+                this.blobSize = this.cryptoHandler.estimateDecryptedLength(cryptoContext, super.getBlobSize());
+            }
+            return this.blobSize;
+        }
+
+        @Override
+        public List<StreamPartCreator> getPartStreams() {
+            return super.getPartStreams().stream()
+                .map(supplier -> (StreamPartCreator) () -> supplier.get().thenApply(this::decryptInputStreamContainer))
+                .collect(Collectors.toUnmodifiableList());
+        }
+
+        /**
+         * Transforms an encrypted {@link InputStreamContainer} to a decrypted instance
+         * @param inputStreamContainer encrypted input stream container instance
+         * @return decrypted input stream container instance
+         */
+        private InputStreamContainer decryptInputStreamContainer(InputStreamContainer inputStreamContainer) {
+            long startOfStream = inputStreamContainer.getOffset();
+            long endOfStream = startOfStream + inputStreamContainer.getContentLength() - 1;
+            DecryptedRangedStreamProvider decryptedStreamProvider = cryptoHandler.createDecryptingStreamOfRange(
+                cryptoContext,
+                startOfStream,
+                endOfStream
+            );
+
+            long adjustedPos = decryptedStreamProvider.getAdjustedRange()[0];
+            long adjustedLength = decryptedStreamProvider.getAdjustedRange()[1] - adjustedPos + 1;
+            final InputStream decryptedStream = decryptedStreamProvider.getDecryptedStreamProvider()
+                .apply(inputStreamContainer.getInputStream());
+            return new InputStreamContainer(decryptedStream, adjustedLength, adjustedPos);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java b/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java
index 3cdb1ce30b68d..2e25a532b5abf 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java
@@ -93,10 +93,10 @@ public interface BlobContainer {
 
     /**
      * Provides a hint to clients for a suitable length to use with {@link BlobContainer#readBlob(String, long, long)}.
-     *
+     * <p>
      * Some blob containers have nontrivial costs attached to each readBlob call, so it is a good idea for consumers to speculatively
      * request more data than they need right now and to re-use this stream for future needs if possible.
-     *
+     * <p>
      * Also, some blob containers return streams that are expensive to close before the stream has been fully consumed, and the cost may
      * depend on the length of the data that was left unconsumed. For these containers it's best to bound the cost of a partial read by
      * bounding the length of the data requested.
@@ -131,7 +131,7 @@ default long readBlobPreferredLength() {
     /**
      * Reads blob content from the input stream and writes it to the container in a new blob with the given name,
      * using an atomic write operation if the implementation supports it.
-     *
+     * <p>
      * This method assumes the container does not already contain a blob of the same blobName.  If a blob by the
      * same name already exists, the operation will fail and an {@link IOException} will be thrown.
      *
diff --git a/server/src/main/java/org/opensearch/common/blobstore/BlobStore.java b/server/src/main/java/org/opensearch/common/blobstore/BlobStore.java
index ab40b1e2a082e..0f6646d37f950 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/BlobStore.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/BlobStore.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.common.blobstore;
 
+import org.opensearch.cluster.metadata.RepositoryMetadata;
+
 import java.io.Closeable;
 import java.util.Collections;
 import java.util.Map;
@@ -47,10 +49,46 @@ public interface BlobStore extends Closeable {
      */
     BlobContainer blobContainer(BlobPath path);
 
+    /**
+     * Returns statistics on the count of operations that have been performed on this blob store
+     */
     /**
      * Returns statistics on the count of operations that have been performed on this blob store
      */
     default Map<String, Long> stats() {
         return Collections.emptyMap();
     }
+
+    /**
+     * Returns details statistics of operations that have been performed on this blob store
+     */
+    default Map<Metric, Map<String, Long>> extendedStats() {
+        return Collections.emptyMap();
+    }
+
+    /**
+     * Reload the blob store inplace
+     */
+    default void reload(RepositoryMetadata repositoryMetadata) {}
+
+    /**
+     * Metrics for BlobStore interactions
+     */
+    enum Metric {
+        REQUEST_SUCCESS("request_success_total"),
+        REQUEST_FAILURE("request_failures_total"),
+        REQUEST_LATENCY("request_time_in_millis"),
+        RETRY_COUNT("request_retry_count_total");
+
+        private String metricName;
+
+        Metric(String name) {
+            this.metricName = name;
+        }
+
+        public String metricName() {
+            return this.metricName;
+        }
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobContainer.java b/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobContainer.java
index 475d891ea9336..d0933741339d9 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobContainer.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobContainer.java
@@ -50,7 +50,7 @@ public InputStream readBlob(String blobName) throws IOException {
         return cryptoHandler.createDecryptingStream(inputStream);
     }
 
-    private EncryptedHeaderContentSupplier getEncryptedHeaderContentSupplier(String blobName) {
+    EncryptedHeaderContentSupplier getEncryptedHeaderContentSupplier(String blobName) {
         return (start, end) -> {
             byte[] buffer;
             int length = (int) (end - start + 1);
diff --git a/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobStore.java b/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobStore.java
index 4d2d69e473438..a18ca8b9d5c39 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobStore.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/EncryptedBlobStore.java
@@ -75,6 +75,16 @@ public Map<String, Long> stats() {
         return blobStore.stats();
     }
 
+    /**
+     * Retrieves extended statistics about the BlobStore. Delegates the call to the underlying BlobStore's extendedStats() method.
+     *
+     * @return A map containing extended statistics about the BlobStore.
+     */
+    @Override
+    public Map<Metric, Map<String, Long>> extendedStats() {
+        return blobStore.extendedStats();
+    }
+
     /**
      * Closes the EncryptedBlobStore by decrementing the reference count of the CryptoManager and closing the
      * underlying BlobStore. This ensures proper cleanup of resources.
diff --git a/server/src/main/java/org/opensearch/common/blobstore/fs/FsBlobContainer.java b/server/src/main/java/org/opensearch/common/blobstore/fs/FsBlobContainer.java
index 394855671688a..b6644ffd16bab 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/fs/FsBlobContainer.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/fs/FsBlobContainer.java
@@ -69,7 +69,7 @@
 /**
  * A file system based implementation of {@link org.opensearch.common.blobstore.BlobContainer}.
  * All blobs in the container are stored on a file system, the location of which is specified by the {@link BlobPath}.
- *
+ * <p>
  * Note that the methods in this implementation of {@link org.opensearch.common.blobstore.BlobContainer} may
  * additionally throw a {@link java.lang.SecurityException} if the configured {@link java.lang.SecurityManager}
  * does not permit read and/or write access to the underlying files.
@@ -258,7 +258,7 @@ public static String tempBlobName(final String blobName) {
 
     /**
      * Returns true if the blob is a leftover temporary blob.
-     *
+     * <p>
      * The temporary blobs might be left after failed atomic write operation.
      */
     public static boolean isTempBlobName(final String blobName) {
diff --git a/server/src/main/java/org/opensearch/common/blobstore/stream/read/ReadContext.java b/server/src/main/java/org/opensearch/common/blobstore/stream/read/ReadContext.java
index 4ba17959f8040..1264551401b4c 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/stream/read/ReadContext.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/stream/read/ReadContext.java
@@ -12,35 +12,64 @@
 import org.opensearch.common.io.InputStreamContainer;
 
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Supplier;
 
 /**
  * ReadContext is used to encapsulate all data needed by <code>BlobContainer#readBlobAsync</code>
+ *
+ * @opensearch.experimental
  */
 @ExperimentalApi
 public class ReadContext {
     private final long blobSize;
-    private final List<InputStreamContainer> partStreams;
+    private final List<StreamPartCreator> asyncPartStreams;
     private final String blobChecksum;
 
-    public ReadContext(long blobSize, List<InputStreamContainer> partStreams, String blobChecksum) {
+    public ReadContext(long blobSize, List<StreamPartCreator> asyncPartStreams, String blobChecksum) {
         this.blobSize = blobSize;
-        this.partStreams = partStreams;
+        this.asyncPartStreams = asyncPartStreams;
         this.blobChecksum = blobChecksum;
     }
 
+    public ReadContext(ReadContext readContext) {
+        this.blobSize = readContext.blobSize;
+        this.asyncPartStreams = readContext.asyncPartStreams;
+        this.blobChecksum = readContext.blobChecksum;
+    }
+
     public String getBlobChecksum() {
         return blobChecksum;
     }
 
     public int getNumberOfParts() {
-        return partStreams.size();
+        return asyncPartStreams.size();
     }
 
     public long getBlobSize() {
         return blobSize;
     }
 
-    public List<InputStreamContainer> getPartStreams() {
-        return partStreams;
+    public List<StreamPartCreator> getPartStreams() {
+        return asyncPartStreams;
+    }
+
+    /**
+     * Functional interface defining an instance that can create an async action
+     * to create a part of an object represented as an InputStreamContainer.
+     *
+     * @opensearch.experimental
+     */
+    @FunctionalInterface
+    @ExperimentalApi
+    public interface StreamPartCreator extends Supplier<CompletableFuture<InputStreamContainer>> {
+        /**
+         * Kicks off a async process to start streaming.
+         *
+         * @return When the returned future is completed, streaming has
+         * just begun. Clients must fully consume the resulting stream.
+         */
+        @Override
+        CompletableFuture<InputStreamContainer> get();
     }
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/FileCompletionListener.java b/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/FileCompletionListener.java
deleted file mode 100644
index aadd6e2ab304e..0000000000000
--- a/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/FileCompletionListener.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.common.blobstore.stream.read.listener;
-
-import org.opensearch.common.annotation.InternalApi;
-import org.opensearch.core.action.ActionListener;
-
-import java.util.concurrent.atomic.AtomicInteger;
-
-/**
- * FileCompletionListener listens for completion of fetch on all the streams for a file, where
- * individual streams are handled using {@link FilePartWriter}. The {@link FilePartWriter}(s)
- * hold a reference to the file completion listener to be notified.
- */
-@InternalApi
-class FileCompletionListener implements ActionListener<Integer> {
-
-    private final int numberOfParts;
-    private final String fileName;
-    private final AtomicInteger completedPartsCount;
-    private final ActionListener<String> completionListener;
-
-    public FileCompletionListener(int numberOfParts, String fileName, ActionListener<String> completionListener) {
-        this.completedPartsCount = new AtomicInteger();
-        this.numberOfParts = numberOfParts;
-        this.fileName = fileName;
-        this.completionListener = completionListener;
-    }
-
-    @Override
-    public void onResponse(Integer unused) {
-        if (completedPartsCount.incrementAndGet() == numberOfParts) {
-            completionListener.onResponse(fileName);
-        }
-    }
-
-    @Override
-    public void onFailure(Exception e) {
-        completionListener.onFailure(e);
-    }
-}
diff --git a/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriter.java b/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriter.java
index 84fd7ed9ffebf..1a403200249cd 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriter.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriter.java
@@ -8,83 +8,37 @@
 
 package org.opensearch.common.blobstore.stream.read.listener;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.opensearch.common.annotation.InternalApi;
 import org.opensearch.common.io.Channels;
 import org.opensearch.common.io.InputStreamContainer;
-import org.opensearch.core.action.ActionListener;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.channels.FileChannel;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.UnaryOperator;
 
 /**
  * FilePartWriter transfers the provided stream into the specified file path using a {@link FileChannel}
- * instance. It performs offset based writes to the file and notifies the {@link FileCompletionListener} on completion.
+ * instance.
  */
 @InternalApi
-class FilePartWriter implements Runnable {
-
-    private final int partNumber;
-    private final InputStreamContainer blobPartStreamContainer;
-    private final Path fileLocation;
-    private final AtomicBoolean anyPartStreamFailed;
-    private final ActionListener<Integer> fileCompletionListener;
-    private static final Logger logger = LogManager.getLogger(FilePartWriter.class);
-
+class FilePartWriter {
     // 8 MB buffer for transfer
     private static final int BUFFER_SIZE = 8 * 1024 * 2024;
 
-    public FilePartWriter(
-        int partNumber,
-        InputStreamContainer blobPartStreamContainer,
-        Path fileLocation,
-        AtomicBoolean anyPartStreamFailed,
-        ActionListener<Integer> fileCompletionListener
-    ) {
-        this.partNumber = partNumber;
-        this.blobPartStreamContainer = blobPartStreamContainer;
-        this.fileLocation = fileLocation;
-        this.anyPartStreamFailed = anyPartStreamFailed;
-        this.fileCompletionListener = fileCompletionListener;
-    }
-
-    @Override
-    public void run() {
-        // Ensures no writes to the file if any stream fails.
-        if (anyPartStreamFailed.get() == false) {
-            try (FileChannel outputFileChannel = FileChannel.open(fileLocation, StandardOpenOption.WRITE, StandardOpenOption.CREATE)) {
-                try (InputStream inputStream = blobPartStreamContainer.getInputStream()) {
-                    long streamOffset = blobPartStreamContainer.getOffset();
-                    final byte[] buffer = new byte[BUFFER_SIZE];
-                    int bytesRead;
-                    while ((bytesRead = inputStream.read(buffer)) != -1) {
-                        Channels.writeToChannel(buffer, 0, bytesRead, outputFileChannel, streamOffset);
-                        streamOffset += bytesRead;
-                    }
+    public static void write(Path fileLocation, InputStreamContainer stream, UnaryOperator<InputStream> rateLimiter) throws IOException {
+        try (FileChannel outputFileChannel = FileChannel.open(fileLocation, StandardOpenOption.WRITE, StandardOpenOption.CREATE)) {
+            try (InputStream inputStream = rateLimiter.apply(stream.getInputStream())) {
+                long streamOffset = stream.getOffset();
+                final byte[] buffer = new byte[BUFFER_SIZE];
+                int bytesRead;
+                while ((bytesRead = inputStream.read(buffer)) != -1) {
+                    Channels.writeToChannel(buffer, 0, bytesRead, outputFileChannel, streamOffset);
+                    streamOffset += bytesRead;
                 }
-            } catch (IOException e) {
-                processFailure(e);
-                return;
             }
-            fileCompletionListener.onResponse(partNumber);
-        }
-    }
-
-    void processFailure(Exception e) {
-        try {
-            Files.deleteIfExists(fileLocation);
-        } catch (IOException ex) {
-            // Die silently
-            logger.info("Failed to delete file {} on stream failure: {}", fileLocation, ex);
-        }
-        if (anyPartStreamFailed.getAndSet(true) == false) {
-            fileCompletionListener.onFailure(e);
         }
     }
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListener.java b/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListener.java
index 4338bddb3fbe7..c77f2384ace0d 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListener.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListener.java
@@ -10,56 +10,190 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.apache.lucene.util.IOUtils;
+import org.opensearch.action.support.GroupedActionListener;
+import org.opensearch.common.SuppressForbidden;
+import org.opensearch.common.UUIDs;
 import org.opensearch.common.annotation.InternalApi;
 import org.opensearch.common.blobstore.stream.read.ReadContext;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.threadpool.ThreadPool;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.Collection;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.UnaryOperator;
 
 /**
  * ReadContextListener orchestrates the async file fetch from the {@link org.opensearch.common.blobstore.BlobContainer}
- * using a {@link ReadContext} callback. On response, it spawns off the download using multiple streams which are
- * spread across a {@link ThreadPool} executor.
+ * using a {@link ReadContext} callback. On response, it spawns off the download using multiple streams.
  */
 @InternalApi
 public class ReadContextListener implements ActionListener<ReadContext> {
-
-    private final String fileName;
+    private static final Logger logger = LogManager.getLogger(ReadContextListener.class);
+    private static final String DOWNLOAD_PREFIX = "download.";
+    private final String blobName;
     private final Path fileLocation;
-    private final ThreadPool threadPool;
+    private final String tmpFileName;
+    private final Path tmpFileLocation;
     private final ActionListener<String> completionListener;
-    private static final Logger logger = LogManager.getLogger(ReadContextListener.class);
+    private final ThreadPool threadPool;
+    private final UnaryOperator<InputStream> rateLimiter;
+    private final int maxConcurrentStreams;
 
-    public ReadContextListener(String fileName, Path fileLocation, ThreadPool threadPool, ActionListener<String> completionListener) {
-        this.fileName = fileName;
+    public ReadContextListener(
+        String blobName,
+        Path fileLocation,
+        ActionListener<String> completionListener,
+        ThreadPool threadPool,
+        UnaryOperator<InputStream> rateLimiter,
+        int maxConcurrentStreams
+    ) {
+        this.blobName = blobName;
         this.fileLocation = fileLocation;
-        this.threadPool = threadPool;
         this.completionListener = completionListener;
+        this.threadPool = threadPool;
+        this.rateLimiter = rateLimiter;
+        this.maxConcurrentStreams = maxConcurrentStreams;
+        this.tmpFileName = DOWNLOAD_PREFIX + UUIDs.randomBase64UUID() + "." + blobName;
+        this.tmpFileLocation = fileLocation.getParent().resolve(tmpFileName);
     }
 
     @Override
     public void onResponse(ReadContext readContext) {
-        logger.trace("Streams received for blob {}", fileName);
+        logger.debug("Received {} parts for blob {}", readContext.getNumberOfParts(), blobName);
         final int numParts = readContext.getNumberOfParts();
-        final AtomicBoolean anyPartStreamFailed = new AtomicBoolean();
-        FileCompletionListener fileCompletionListener = new FileCompletionListener(numParts, fileName, completionListener);
-
-        for (int partNumber = 0; partNumber < numParts; partNumber++) {
-            FilePartWriter filePartWriter = new FilePartWriter(
-                partNumber,
-                readContext.getPartStreams().get(partNumber),
-                fileLocation,
-                anyPartStreamFailed,
-                fileCompletionListener
-            );
-            threadPool.executor(ThreadPool.Names.GENERIC).submit(filePartWriter);
+        final AtomicBoolean anyPartStreamFailed = new AtomicBoolean(false);
+        final GroupedActionListener<String> groupedListener = new GroupedActionListener<>(getFileCompletionListener(), numParts);
+        final Queue<ReadContext.StreamPartCreator> queue = new ConcurrentLinkedQueue<>(readContext.getPartStreams());
+        final StreamPartProcessor processor = new StreamPartProcessor(
+            queue,
+            anyPartStreamFailed,
+            tmpFileLocation,
+            groupedListener,
+            threadPool.executor(ThreadPool.Names.REMOTE_RECOVERY),
+            rateLimiter
+        );
+        for (int i = 0; i < Math.min(maxConcurrentStreams, queue.size()); i++) {
+            processor.process(queue.poll());
         }
     }
 
+    @SuppressForbidden(reason = "need to fsync once all parts received")
+    private ActionListener<Collection<String>> getFileCompletionListener() {
+        return ActionListener.wrap(response -> {
+            logger.trace("renaming temp file [{}] to [{}]", tmpFileLocation, fileLocation);
+            try {
+                IOUtils.fsync(tmpFileLocation, false);
+                Files.move(tmpFileLocation, fileLocation, StandardCopyOption.ATOMIC_MOVE);
+                // sync parent dir metadata
+                IOUtils.fsync(fileLocation.getParent(), true);
+                completionListener.onResponse(blobName);
+            } catch (IOException e) {
+                logger.error("Unable to rename temp file + " + tmpFileLocation, e);
+                completionListener.onFailure(e);
+            }
+        }, e -> {
+            try {
+                Files.deleteIfExists(tmpFileLocation);
+            } catch (IOException ex) {
+                logger.warn("Unable to clean temp file {}", tmpFileLocation);
+            }
+            completionListener.onFailure(e);
+        });
+    }
+
+    /*
+     * For Tests
+     */
+    Path getTmpFileLocation() {
+        return tmpFileLocation;
+    }
+
     @Override
     public void onFailure(Exception e) {
         completionListener.onFailure(e);
     }
+
+    private static class StreamPartProcessor {
+        private static final RuntimeException CANCELED_PART_EXCEPTION = new RuntimeException(
+            "Canceled part download due to previous failure"
+        );
+        private final Queue<ReadContext.StreamPartCreator> queue;
+        private final AtomicBoolean anyPartStreamFailed;
+        private final Path fileLocation;
+        private final GroupedActionListener<String> completionListener;
+        private final Executor executor;
+        private final UnaryOperator<InputStream> rateLimiter;
+
+        private StreamPartProcessor(
+            Queue<ReadContext.StreamPartCreator> queue,
+            AtomicBoolean anyPartStreamFailed,
+            Path fileLocation,
+            GroupedActionListener<String> completionListener,
+            Executor executor,
+            UnaryOperator<InputStream> rateLimiter
+        ) {
+            this.queue = queue;
+            this.anyPartStreamFailed = anyPartStreamFailed;
+            this.fileLocation = fileLocation;
+            this.completionListener = completionListener;
+            this.executor = executor;
+            this.rateLimiter = rateLimiter;
+        }
+
+        private void process(ReadContext.StreamPartCreator supplier) {
+            if (supplier == null) {
+                return;
+            }
+            supplier.get().whenCompleteAsync((blobPartStreamContainer, throwable) -> {
+                if (throwable != null) {
+                    processFailure(throwable instanceof Exception ? (Exception) throwable : new RuntimeException(throwable));
+                } else if (anyPartStreamFailed.get()) {
+                    processFailure(CANCELED_PART_EXCEPTION);
+                } else {
+                    try {
+                        FilePartWriter.write(fileLocation, blobPartStreamContainer, rateLimiter);
+                        completionListener.onResponse(fileLocation.toString());
+
+                        // Upon successfully completing a file part, pull another
+                        // file part off the queue to trigger asynchronous processing
+                        process(queue.poll());
+                    } catch (Exception e) {
+                        processFailure(e);
+                    }
+                }
+            }, executor);
+        }
+
+        private void processFailure(Exception e) {
+            if (anyPartStreamFailed.getAndSet(true) == false) {
+                completionListener.onFailure(e);
+
+                // Drain the queue of pending part downloads. These can be discarded
+                // since they haven't started any work yet, but the listener must be
+                // notified for each part.
+                Object item = queue.poll();
+                while (item != null) {
+                    completionListener.onFailure(CANCELED_PART_EXCEPTION);
+                    item = queue.poll();
+                }
+            } else {
+                completionListener.onFailure(e);
+            }
+            try {
+                Files.deleteIfExists(fileLocation);
+            } catch (IOException ex) {
+                // Die silently
+                logger.info("Failed to delete file {} on stream failure: {}", fileLocation, ex);
+            }
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/stream/write/WritePriority.java b/server/src/main/java/org/opensearch/common/blobstore/stream/write/WritePriority.java
index b8c0b52f93a3c..3f341c878c3c7 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/stream/write/WritePriority.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/stream/write/WritePriority.java
@@ -15,5 +15,6 @@
  */
 public enum WritePriority {
     NORMAL,
-    HIGH
+    HIGH,
+    URGENT
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainer.java b/server/src/main/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainer.java
index 5808f51f01efc..2047c99d9e13b 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainer.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainer.java
@@ -19,6 +19,7 @@
 import org.opensearch.common.blobstore.stream.write.WriteContext;
 import org.opensearch.common.blobstore.stream.write.WritePriority;
 import org.opensearch.common.blobstore.transfer.stream.OffsetRangeInputStream;
+import org.opensearch.common.blobstore.transfer.stream.RateLimitingOffsetRangeInputStream;
 import org.opensearch.common.blobstore.transfer.stream.ResettableCheckedInputStream;
 import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.common.util.ByteUtils;
@@ -27,6 +28,8 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Objects;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Supplier;
 import java.util.zip.CRC32;
 
 import com.jcraft.jzlib.JZlib;
@@ -43,7 +46,7 @@ public class RemoteTransferContainer implements Closeable {
     private long lastPartSize;
 
     private final long contentLength;
-    private final SetOnce<InputStream[]> inputStreams = new SetOnce<>();
+    private final SetOnce<Supplier<Long>[]> checksumSuppliers = new SetOnce<>();
     private final String fileName;
     private final String remoteFileName;
     private final boolean failTransferIfFileExists;
@@ -51,6 +54,7 @@ public class RemoteTransferContainer implements Closeable {
     private final long expectedChecksum;
     private final OffsetRangeInputStreamSupplier offsetRangeInputStreamSupplier;
     private final boolean isRemoteDataIntegritySupported;
+    private final AtomicBoolean readBlock = new AtomicBoolean();
 
     private static final Logger log = LogManager.getLogger(RemoteTransferContainer.class);
 
@@ -120,23 +124,24 @@ StreamContext supplyStreamContext(long partSize) {
         }
     }
 
+    @SuppressWarnings({ "unchecked" })
     private StreamContext openMultipartStreams(long partSize) throws IOException {
-        if (inputStreams.get() != null) {
+        if (checksumSuppliers.get() != null) {
             throw new IOException("Multi-part streams are already created.");
         }
 
         this.partSize = partSize;
         this.lastPartSize = (contentLength % partSize) != 0 ? contentLength % partSize : partSize;
         this.numberOfParts = (int) ((contentLength % partSize) == 0 ? contentLength / partSize : (contentLength / partSize) + 1);
-        InputStream[] streams = new InputStream[numberOfParts];
-        inputStreams.set(streams);
+        Supplier<Long>[] suppliers = new Supplier[numberOfParts];
+        checksumSuppliers.set(suppliers);
 
         return new StreamContext(getTransferPartStreamSupplier(), partSize, lastPartSize, numberOfParts);
     }
 
     private CheckedTriFunction<Integer, Long, Long, InputStreamContainer, IOException> getTransferPartStreamSupplier() {
         return ((partNo, size, position) -> {
-            assert inputStreams.get() != null : "expected inputStreams to be initialised";
+            assert checksumSuppliers.get() != null : "expected container to be initialised";
             return getMultipartStreamSupplier(partNo, size, position).get();
         });
     }
@@ -160,10 +165,21 @@ private LocalStreamSupplier<InputStreamContainer> getMultipartStreamSupplier(
         return () -> {
             try {
                 OffsetRangeInputStream offsetRangeInputStream = offsetRangeInputStreamSupplier.get(size, position);
-                InputStream inputStream = !isRemoteDataIntegrityCheckPossible()
-                    ? new ResettableCheckedInputStream(offsetRangeInputStream, fileName)
-                    : offsetRangeInputStream;
-                Objects.requireNonNull(inputStreams.get())[streamIdx] = inputStream;
+                if (offsetRangeInputStream instanceof RateLimitingOffsetRangeInputStream) {
+                    RateLimitingOffsetRangeInputStream rangeIndexInputStream = (RateLimitingOffsetRangeInputStream) offsetRangeInputStream;
+                    rangeIndexInputStream.setReadBlock(readBlock);
+                }
+                InputStream inputStream;
+                if (isRemoteDataIntegrityCheckPossible() == false) {
+                    ResettableCheckedInputStream resettableCheckedInputStream = new ResettableCheckedInputStream(
+                        offsetRangeInputStream,
+                        fileName
+                    );
+                    Objects.requireNonNull(checksumSuppliers.get())[streamIdx] = resettableCheckedInputStream::getChecksum;
+                    inputStream = resettableCheckedInputStream;
+                } else {
+                    inputStream = offsetRangeInputStream;
+                }
 
                 return new InputStreamContainer(inputStream, size, position);
             } catch (IOException e) {
@@ -205,20 +221,14 @@ public long getContentLength() {
         return contentLength;
     }
 
-    private long getInputStreamChecksum(InputStream inputStream) {
-        assert inputStream instanceof ResettableCheckedInputStream
-            : "expected passed inputStream to be instance of ResettableCheckedInputStream";
-        return ((ResettableCheckedInputStream) inputStream).getChecksum();
-    }
-
     private long getActualChecksum() {
-        InputStream[] currentInputStreams = Objects.requireNonNull(inputStreams.get());
-        long checksum = getInputStreamChecksum(currentInputStreams[0]);
-        for (int checkSumIdx = 1; checkSumIdx < Objects.requireNonNull(inputStreams.get()).length - 1; checkSumIdx++) {
-            checksum = JZlib.crc32_combine(checksum, getInputStreamChecksum(currentInputStreams[checkSumIdx]), partSize);
+        Supplier<Long>[] ckSumSuppliers = Objects.requireNonNull(checksumSuppliers.get());
+        long checksum = ckSumSuppliers[0].get();
+        for (int checkSumIdx = 1; checkSumIdx < ckSumSuppliers.length - 1; checkSumIdx++) {
+            checksum = JZlib.crc32_combine(checksum, ckSumSuppliers[checkSumIdx].get(), partSize);
         }
         if (numberOfParts > 1) {
-            checksum = JZlib.crc32_combine(checksum, getInputStreamChecksum(currentInputStreams[numberOfParts - 1]), lastPartSize);
+            checksum = JZlib.crc32_combine(checksum, ckSumSuppliers[numberOfParts - 1].get(), lastPartSize);
         }
 
         return checksum;
@@ -226,27 +236,8 @@ private long getActualChecksum() {
 
     @Override
     public void close() throws IOException {
-        if (inputStreams.get() == null) {
-            log.warn("Input streams cannot be closed since they are not yet set for multi stream upload");
-            return;
-        }
-
-        boolean closeStreamException = false;
-        for (InputStream is : Objects.requireNonNull(inputStreams.get())) {
-            try {
-                if (is != null) {
-                    is.close();
-                }
-            } catch (IOException ex) {
-                closeStreamException = true;
-                // Attempting to close all streams first before throwing exception.
-                log.error("Multipart stream failed to close ", ex);
-            }
-        }
-
-        if (closeStreamException) {
-            throw new IOException("Closure of some of the multi-part streams failed.");
-        }
+        // Setting a read block on all streams ever created by the container.
+        readBlock.set(true);
     }
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeIndexInputStream.java b/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeIndexInputStream.java
index 7518f9ac569b9..520c838ba8a81 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeIndexInputStream.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeIndexInputStream.java
@@ -8,10 +8,16 @@
 
 package org.opensearch.common.blobstore.transfer.stream;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.IndexInput;
+import org.opensearch.common.concurrent.RefCountedReleasable;
 import org.opensearch.common.lucene.store.InputStreamIndexInput;
+import org.opensearch.common.util.concurrent.RunOnce;
 
 import java.io.IOException;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * OffsetRangeIndexInputStream extends InputStream to read from a specified offset using IndexInput
@@ -19,9 +25,12 @@
  * @opensearch.internal
  */
 public class OffsetRangeIndexInputStream extends OffsetRangeInputStream {
-
+    private static final Logger logger = LogManager.getLogger(OffsetRangeIndexInputStream.class);
     private final InputStreamIndexInput inputStreamIndexInput;
     private final IndexInput indexInput;
+    private AtomicBoolean readBlock;
+    private final OffsetRangeRefCount offsetRangeRefCount;
+    private final RunOnce closeOnce;
 
     /**
      * Construct a new OffsetRangeIndexInputStream object
@@ -35,16 +44,68 @@ public OffsetRangeIndexInputStream(IndexInput indexInput, long size, long positi
         indexInput.seek(position);
         this.indexInput = indexInput;
         this.inputStreamIndexInput = new InputStreamIndexInput(indexInput, size);
+        ClosingStreams closingStreams = new ClosingStreams(inputStreamIndexInput, indexInput);
+        offsetRangeRefCount = new OffsetRangeRefCount(closingStreams);
+        closeOnce = new RunOnce(offsetRangeRefCount::decRef);
+    }
+
+    @Override
+    public void setReadBlock(AtomicBoolean readBlock) {
+        this.readBlock = readBlock;
     }
 
     @Override
     public int read(byte[] b, int off, int len) throws IOException {
-        return inputStreamIndexInput.read(b, off, len);
+        // There are two levels of check to ensure that we don't read an already closed stream and
+        // to not close the stream if it is already being read.
+        // 1. First check is a coarse-grained check outside reference check which allows us to fail fast if read
+        // was invoked after the stream was closed. We need a separate atomic boolean closed because we don't want a
+        // future read to succeed when #close has been invoked even if there are on-going reads. On-going reads would
+        // hold reference and since ref count will not be 0 even after close was invoked, future reads will go through
+        // without a check on closed. Also, we do need to set closed externally. It is shared across all streams of the
+        // file. Check on closed in this class makes sure that no other stream allows subsequent reads. closed is
+        // being set to true in RemoteTransferContainer#close which is invoked when we are done processing all
+        // parts/file. Processing completes when either all parts are completed successfully or if either of the parts
+        // failed. In successful case, subsequent read will anyway not go through since all streams would have been
+        // consumed fully but in case of failure, SDK can continue to invoke read and this would be a wasted compute
+        // and IO.
+        // 2. In second check, a tryIncRef is invoked which tries to increment reference under lock and fails if ref
+        // is already closed. If reference is successfully obtained by the stream then stream will not be closed.
+        // Ref counting ensures that stream isn't closed in between reads.
+        //
+        // All these protection mechanisms are required in order to prevent invalid access to streams happening
+        // from the new S3 async SDK.
+        ensureReadable();
+        try (OffsetRangeRefCount ignored = getStreamReference()) {
+            return inputStreamIndexInput.read(b, off, len);
+        }
+    }
+
+    private OffsetRangeRefCount getStreamReference() {
+        boolean successIncrement = offsetRangeRefCount.tryIncRef();
+        if (successIncrement == false) {
+            throw alreadyClosed("OffsetRangeIndexInputStream is already unreferenced.");
+        }
+        return offsetRangeRefCount;
+    }
+
+    private void ensureReadable() {
+        if (readBlock != null && readBlock.get() == true) {
+            logger.debug("Read attempted on a stream which was read blocked!");
+            throw alreadyClosed("Read blocked stream.");
+        }
+    }
+
+    AlreadyClosedException alreadyClosed(String msg) {
+        return new AlreadyClosedException(msg + this);
     }
 
     @Override
     public int read() throws IOException {
-        return inputStreamIndexInput.read();
+        ensureReadable();
+        try (OffsetRangeRefCount ignored = getStreamReference()) {
+            return inputStreamIndexInput.read();
+        }
     }
 
     @Override
@@ -67,9 +128,42 @@ public long getFilePointer() throws IOException {
         return indexInput.getFilePointer();
     }
 
+    @Override
+    public String toString() {
+        return "OffsetRangeIndexInputStream{" + "indexInput=" + indexInput + ", readBlock=" + readBlock + '}';
+    }
+
+    private static class ClosingStreams {
+        private final InputStreamIndexInput inputStreamIndexInput;
+        private final IndexInput indexInput;
+
+        public ClosingStreams(InputStreamIndexInput inputStreamIndexInput, IndexInput indexInput) {
+            this.inputStreamIndexInput = inputStreamIndexInput;
+            this.indexInput = indexInput;
+        }
+    }
+
+    private static class OffsetRangeRefCount extends RefCountedReleasable<ClosingStreams> {
+        private static final Logger logger = LogManager.getLogger(OffsetRangeRefCount.class);
+
+        public OffsetRangeRefCount(ClosingStreams ref) {
+            super("OffsetRangeRefCount", ref, () -> {
+                try {
+                    ref.inputStreamIndexInput.close();
+                } catch (IOException ex) {
+                    logger.error("Failed to close indexStreamIndexInput", ex);
+                }
+                try {
+                    ref.indexInput.close();
+                } catch (IOException ex) {
+                    logger.error("Failed to close indexInput", ex);
+                }
+            });
+        }
+    }
+
     @Override
     public void close() throws IOException {
-        inputStreamIndexInput.close();
-        indexInput.close();
+        closeOnce.run();
     }
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeInputStream.java b/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeInputStream.java
index e8b889db1f3b0..eacb972586a5a 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeInputStream.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/OffsetRangeInputStream.java
@@ -10,6 +10,7 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * OffsetRangeInputStream is an abstract class that extends from {@link InputStream}
@@ -19,4 +20,8 @@
  */
 public abstract class OffsetRangeInputStream extends InputStream {
     public abstract long getFilePointer() throws IOException;
+
+    public void setReadBlock(AtomicBoolean readBlock) {
+        // Nothing
+    }
 }
diff --git a/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/RateLimitingOffsetRangeInputStream.java b/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/RateLimitingOffsetRangeInputStream.java
index b455999bbed0c..4a511ca1ac155 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/RateLimitingOffsetRangeInputStream.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/transfer/stream/RateLimitingOffsetRangeInputStream.java
@@ -12,6 +12,7 @@
 import org.opensearch.common.StreamLimiter;
 
 import java.io.IOException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 
 /**
@@ -40,6 +41,10 @@ public RateLimitingOffsetRangeInputStream(
         this.delegate = delegate;
     }
 
+    public void setReadBlock(AtomicBoolean readBlock) {
+        delegate.setReadBlock(readBlock);
+    }
+
     @Override
     public int read() throws IOException {
         int b = delegate.read();
diff --git a/server/src/main/java/org/opensearch/common/breaker/ChildMemoryCircuitBreaker.java b/server/src/main/java/org/opensearch/common/breaker/ChildMemoryCircuitBreaker.java
index de4e6ad433c55..c9b498c3ec6fa 100644
--- a/server/src/main/java/org/opensearch/common/breaker/ChildMemoryCircuitBreaker.java
+++ b/server/src/main/java/org/opensearch/common/breaker/ChildMemoryCircuitBreaker.java
@@ -204,7 +204,7 @@ private long limit(long bytes, String label, double overheadConstant, long memor
     /**
      * Add an <b>exact</b> number of bytes, not checking for tripping the
      * circuit breaker. This bypasses the overheadConstant multiplication.
-     *
+     * <p>
      * Also does not check with the parent breaker to see if the parent limit
      * has been exceeded.
      *
diff --git a/server/src/main/java/org/opensearch/common/cache/Cache.java b/server/src/main/java/org/opensearch/common/cache/Cache.java
index 0ebef1556424b..30e7c014a2ec0 100644
--- a/server/src/main/java/org/opensearch/common/cache/Cache.java
+++ b/server/src/main/java/org/opensearch/common/cache/Cache.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common.cache;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.util.concurrent.ReleasableLock;
 
@@ -80,8 +81,9 @@
  * @param <K> The type of the keys
  * @param <V> The type of the values
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Cache<K, V> {
 
     // positive if entries have an expiration
@@ -403,7 +405,7 @@ private V get(K key, long now, Consumer<Entry<K, V>> onExpiration) {
      * If the specified key is not already associated with a value (or is mapped to null), attempts to compute its
      * value using the given mapping function and enters it into this map unless null. The load method for a given key
      * will be invoked at most once.
-     *
+     * <p>
      * Use of different {@link CacheLoader} implementations on the same key concurrently may result in only the first
      * loader function being called and the second will be returned the result provided by the first including any exceptions
      * thrown during the execution of the first.
@@ -732,8 +734,9 @@ public CacheStats stats() {
     /**
      * Cache statistics
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class CacheStats {
         private long hits;
         private long misses;
diff --git a/server/src/main/java/org/opensearch/common/cache/CacheLoader.java b/server/src/main/java/org/opensearch/common/cache/CacheLoader.java
index 3c80fe5d66d5d..9fd43a03e7f9d 100644
--- a/server/src/main/java/org/opensearch/common/cache/CacheLoader.java
+++ b/server/src/main/java/org/opensearch/common/cache/CacheLoader.java
@@ -32,12 +32,15 @@
 
 package org.opensearch.common.cache;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * An interface for a cache loader.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
 @FunctionalInterface
+@PublicApi(since = "1.0.0")
 public interface CacheLoader<K, V> {
     V load(K key) throws Exception;
 }
diff --git a/server/src/main/java/org/opensearch/common/cache/RemovalNotification.java b/server/src/main/java/org/opensearch/common/cache/RemovalNotification.java
index 6d355b2122460..42303b8cfdc73 100644
--- a/server/src/main/java/org/opensearch/common/cache/RemovalNotification.java
+++ b/server/src/main/java/org/opensearch/common/cache/RemovalNotification.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.common.cache;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Notification when an element is removed from the cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RemovalNotification<K, V> {
 
     private final K key;
diff --git a/server/src/main/java/org/opensearch/common/cache/RemovalReason.java b/server/src/main/java/org/opensearch/common/cache/RemovalReason.java
index e5d795c093547..514b84a7823ca 100644
--- a/server/src/main/java/org/opensearch/common/cache/RemovalReason.java
+++ b/server/src/main/java/org/opensearch/common/cache/RemovalReason.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.common.cache;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Reason for notification removal
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum RemovalReason {
     REPLACED,
     INVALIDATED,
diff --git a/server/src/main/java/org/opensearch/common/collect/CopyOnWriteHashMap.java b/server/src/main/java/org/opensearch/common/collect/CopyOnWriteHashMap.java
index 5ce77cdc75fe5..de4304f0e1fba 100644
--- a/server/src/main/java/org/opensearch/common/collect/CopyOnWriteHashMap.java
+++ b/server/src/main/java/org/opensearch/common/collect/CopyOnWriteHashMap.java
@@ -49,15 +49,15 @@
 
 /**
  * An immutable map whose writes result in a new copy of the map to be created.
- *
+ * <p>
  * This is essentially a hash array mapped trie: inner nodes use a bitmap in
  * order to map hashes to slots by counting ones. In case of a collision (two
  * values having the same 32-bits hash), a leaf node is created which stores
  * and searches for values sequentially.
- *
+ * <p>
  * Reads and writes both perform in logarithmic time. Null keys and values are
  * not supported.
- *
+ * <p>
  * This structure might need to perform several object creations per write so
  * it is better suited for work-loads that are not too write-intensive.
  *
@@ -250,7 +250,7 @@ public static <T> T[] insertElement(final T[] array, final T element, final int
      * and use a bitmap in order to associate hashes to them. For example, if
      * an inner node contains 5 values, then 5 bits will be set in the bitmap
      * and the ordinal of the bit set in this bit map will be the slot number.
-     *
+     * <p>
      * As a consequence, the number of slots in an inner node is equal to the
      * number of one bits in the bitmap.
      *
diff --git a/server/src/main/java/org/opensearch/common/compress/CompressedXContent.java b/server/src/main/java/org/opensearch/common/compress/CompressedXContent.java
index 550bc5b3fd524..23fc6353dbad3 100644
--- a/server/src/main/java/org/opensearch/common/compress/CompressedXContent.java
+++ b/server/src/main/java/org/opensearch/common/compress/CompressedXContent.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common.compress;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.Streams;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -57,8 +58,9 @@
  * memory. Note that the compressed string might still sometimes need to be
  * decompressed in order to perform equality checks or to compute hash codes.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class CompressedXContent {
 
     private static int crc32(BytesReference data) {
diff --git a/server/src/main/java/org/opensearch/common/concurrent/GatedCloseable.java b/server/src/main/java/org/opensearch/common/concurrent/GatedCloseable.java
index 8bf620ee2cd50..08ebc2f8786c5 100644
--- a/server/src/main/java/org/opensearch/common/concurrent/GatedCloseable.java
+++ b/server/src/main/java/org/opensearch/common/concurrent/GatedCloseable.java
@@ -14,6 +14,7 @@
 package org.opensearch.common.concurrent;
 
 import org.opensearch.common.CheckedRunnable;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -23,8 +24,9 @@
  * invoked when {@link #close()} is called. The internal {@link OneWayGate} instance ensures
  * that this is invoked only once. See also {@link AutoCloseableRefCounted}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GatedCloseable<T> implements Closeable {
 
     private final T ref;
diff --git a/server/src/main/java/org/opensearch/common/document/DocumentField.java b/server/src/main/java/org/opensearch/common/document/DocumentField.java
index 8ce672d4fb3fc..5cdc2bba8be16 100644
--- a/server/src/main/java/org/opensearch/common/document/DocumentField.java
+++ b/server/src/main/java/org/opensearch/common/document/DocumentField.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common.document;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -56,8 +57,9 @@
  * @see SearchHit
  * @see GetResult
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DocumentField implements Writeable, ToXContentFragment, Iterable<Object> {
 
     private final String name;
diff --git a/server/src/main/java/org/opensearch/common/geo/GeoShapeType.java b/server/src/main/java/org/opensearch/common/geo/GeoShapeType.java
index 0334d367ffdbc..1622457ba27cc 100644
--- a/server/src/main/java/org/opensearch/common/geo/GeoShapeType.java
+++ b/server/src/main/java/org/opensearch/common/geo/GeoShapeType.java
@@ -221,11 +221,11 @@ void validateLinearRing(CoordinateNode coordinates, boolean coerce) {
 
         @Override
         CoordinateNode validate(CoordinateNode coordinates, boolean coerce) {
-            /**
-             * Per GeoJSON spec (http://geojson.org/geojson-spec.html#linestring)
-             * A LinearRing is closed LineString with 4 or more positions. The first and last positions
-             * are equivalent (they represent equivalent points). Though a LinearRing is not explicitly
-             * represented as a GeoJSON geometry type, it is referred to in the Polygon geometry type definition.
+            /*
+              Per GeoJSON spec (http://geojson.org/geojson-spec.html#linestring)
+              A LinearRing is closed LineString with 4 or more positions. The first and last positions
+              are equivalent (they represent equivalent points). Though a LinearRing is not explicitly
+              represented as a GeoJSON geometry type, it is referred to in the Polygon geometry type definition.
              */
             if (coordinates.children == null || coordinates.children.isEmpty()) {
                 throw new OpenSearchParseException(
diff --git a/server/src/main/java/org/opensearch/common/geo/GeoUtils.java b/server/src/main/java/org/opensearch/common/geo/GeoUtils.java
index 393c238cb3b2f..8c566c4191e4f 100644
--- a/server/src/main/java/org/opensearch/common/geo/GeoUtils.java
+++ b/server/src/main/java/org/opensearch/common/geo/GeoUtils.java
@@ -665,7 +665,7 @@ public static GeoPoint parseFromString(String val) {
 
     /**
      * Parse a precision that can be expressed as an integer or a distance measure like "1km", "10m".
-     *
+     * <p>
      * The precision is expressed as a number between 1 and 12 and indicates the length of geohash
      * used to represent geo points.
      *
@@ -696,7 +696,7 @@ public static int parsePrecision(XContentParser parser) throws IOException, Open
 
     /**
      * Checks that the precision is within range supported by opensearch - between 1 and 12
-     *
+     * <p>
      * Returns the precision value if it is in the range and throws an IllegalArgumentException if it
      * is outside the range.
      */
diff --git a/server/src/main/java/org/opensearch/common/geo/GeometryFormat.java b/server/src/main/java/org/opensearch/common/geo/GeometryFormat.java
index 56146fc8197be..93c7f4b93679a 100644
--- a/server/src/main/java/org/opensearch/common/geo/GeometryFormat.java
+++ b/server/src/main/java/org/opensearch/common/geo/GeometryFormat.java
@@ -63,7 +63,7 @@ public interface GeometryFormat<ParsedFormat> {
 
     /**
      * Serializes the geometry into a standard Java object.
-     *
+     * <p>
      * For example, the GeoJson format returns the geometry as a map, while WKT returns a string.
      */
     Object toXContentAsObject(ParsedFormat geometry);
diff --git a/server/src/main/java/org/opensearch/common/geo/ShapeRelation.java b/server/src/main/java/org/opensearch/common/geo/ShapeRelation.java
index 0a5a66ef54c9c..d5b761a531e7f 100644
--- a/server/src/main/java/org/opensearch/common/geo/ShapeRelation.java
+++ b/server/src/main/java/org/opensearch/common/geo/ShapeRelation.java
@@ -33,6 +33,7 @@
 package org.opensearch.common.geo;
 
 import org.apache.lucene.document.ShapeField.QueryRelation;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
  * Enum representing the relationship between a Query / Filter Shape and indexed Shapes
  * that will be used to determine if a Document should be matched or not
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum ShapeRelation implements Writeable {
 
     INTERSECTS("intersects"),
diff --git a/server/src/main/java/org/opensearch/common/geo/builders/PolygonBuilder.java b/server/src/main/java/org/opensearch/common/geo/builders/PolygonBuilder.java
index b436787220eb0..9e118ab2de3a5 100644
--- a/server/src/main/java/org/opensearch/common/geo/builders/PolygonBuilder.java
+++ b/server/src/main/java/org/opensearch/common/geo/builders/PolygonBuilder.java
@@ -177,11 +177,11 @@ public PolygonBuilder close() {
     }
 
     private static void validateLinearRing(LineStringBuilder lineString) {
-        /**
-         * Per GeoJSON spec (http://geojson.org/geojson-spec.html#linestring)
-         * A LinearRing is closed LineString with 4 or more positions. The first and last positions
-         * are equivalent (they represent equivalent points). Though a LinearRing is not explicitly
-         * represented as a GeoJSON geometry type, it is referred to in the Polygon geometry type definition.
+        /*
+          Per GeoJSON spec (http://geojson.org/geojson-spec.html#linestring)
+          A LinearRing is closed LineString with 4 or more positions. The first and last positions
+          are equivalent (they represent equivalent points). Though a LinearRing is not explicitly
+          represented as a GeoJSON geometry type, it is referred to in the Polygon geometry type definition.
          */
         List<Coordinate> points = lineString.coordinates;
         if (points.size() < 4) {
diff --git a/server/src/main/java/org/opensearch/common/geo/parsers/GeoJsonParser.java b/server/src/main/java/org/opensearch/common/geo/parsers/GeoJsonParser.java
index 37d42ce600b6d..8d473ae6721d2 100644
--- a/server/src/main/java/org/opensearch/common/geo/parsers/GeoJsonParser.java
+++ b/server/src/main/java/org/opensearch/common/geo/parsers/GeoJsonParser.java
@@ -52,7 +52,7 @@
 
 /**
  * Parses shape geometry represented in geojson
- *
+ * <p>
  * complies with geojson specification: https://tools.ietf.org/html/rfc7946
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/common/geo/parsers/GeoWKTParser.java b/server/src/main/java/org/opensearch/common/geo/parsers/GeoWKTParser.java
index d99d1daf46a2a..b199da0f3691a 100644
--- a/server/src/main/java/org/opensearch/common/geo/parsers/GeoWKTParser.java
+++ b/server/src/main/java/org/opensearch/common/geo/parsers/GeoWKTParser.java
@@ -58,7 +58,7 @@
 
 /**
  * Parses shape geometry represented in WKT format
- *
+ * <p>
  * complies with OGC® document: 12-063r5 and ISO/IEC 13249-3:2016 standard
  * located at http://docs.opengeospatial.org/is/12-063r5/12-063r5.html
  *
diff --git a/server/src/main/java/org/opensearch/common/hash/MurmurHash3.java b/server/src/main/java/org/opensearch/common/hash/MurmurHash3.java
index 8ba0bd7ee1be4..e481ffd460798 100644
--- a/server/src/main/java/org/opensearch/common/hash/MurmurHash3.java
+++ b/server/src/main/java/org/opensearch/common/hash/MurmurHash3.java
@@ -93,7 +93,7 @@ protected static long fmix(long k) {
 
     /**
      * Compute the hash of the MurmurHash3_x64_128 hashing function.
-     *
+     * <p>
      * Note, this hashing function might be used to persist hashes, so if the way hashes are computed
      * changes for some reason, it needs to be addressed (like in BloomFilter and MurmurHashField).
      */
diff --git a/server/src/main/java/org/opensearch/common/inject/Initializer.java b/server/src/main/java/org/opensearch/common/inject/Initializer.java
index e806eba6df707..b88b01c03c018 100644
--- a/server/src/main/java/org/opensearch/common/inject/Initializer.java
+++ b/server/src/main/java/org/opensearch/common/inject/Initializer.java
@@ -68,9 +68,8 @@ class Initializer {
     /**
      * Registers an instance for member injection when that step is performed.
      *
-     * @param instance an instance that optionally has members to be injected (each annotated with
-     * @param source   the source location that this injection was requested
-     * @Inject).
+     * @param instance an instance that optionally has members to be injected (each annotated with {@code @Inject}).
+     * @param source the source location that this injection was requested
      */
     public <T> Initializable<T> requestInjection(InjectorImpl injector, T instance, Object source, Set<InjectionPoint> injectionPoints) {
         Objects.requireNonNull(source);
diff --git a/server/src/main/java/org/opensearch/common/inject/Module.java b/server/src/main/java/org/opensearch/common/inject/Module.java
index e66044ff26c40..b1fc031192ea0 100644
--- a/server/src/main/java/org/opensearch/common/inject/Module.java
+++ b/server/src/main/java/org/opensearch/common/inject/Module.java
@@ -29,8 +29,6 @@
 
 package org.opensearch.common.inject;
 
-import org.opensearch.common.annotation.PublicApi;
-
 /**
  * A module contributes configuration information, typically interface
  * bindings, which will be used to create an {@link Injector}. A Guice-based
@@ -45,9 +43,8 @@
  * Use scope and binding annotations on these methods to configure the
  * bindings.
  *
- * @opensearch.api
+ * @opensearch.internal
  */
-@PublicApi(since = "1.0.0")
 public interface Module {
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/io/stream/BytesStreamOutput.java b/server/src/main/java/org/opensearch/common/io/stream/BytesStreamOutput.java
index ad09efde72009..bfed1f0883672 100644
--- a/server/src/main/java/org/opensearch/common/io/stream/BytesStreamOutput.java
+++ b/server/src/main/java/org/opensearch/common/io/stream/BytesStreamOutput.java
@@ -35,6 +35,7 @@
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefIterator;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.BigArrays;
 import org.opensearch.common.util.PageCacheRecycler;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -49,8 +50,9 @@
  * A @link {@link StreamOutput} that uses {@link BigArrays} to acquire pages of
  * bytes, which avoids frequent reallocation &amp; copying of the internal data.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class BytesStreamOutput extends BytesStream {
 
     protected final BigArrays bigArrays;
diff --git a/server/src/main/java/org/opensearch/common/io/stream/DelayableWriteable.java b/server/src/main/java/org/opensearch/common/io/stream/DelayableWriteable.java
index 200f3e9225834..f345a5d3a804f 100644
--- a/server/src/main/java/org/opensearch/common/io/stream/DelayableWriteable.java
+++ b/server/src/main/java/org/opensearch/common/io/stream/DelayableWriteable.java
@@ -35,6 +35,7 @@
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.common.io.stream.NamedWriteableAwareStreamInput;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
@@ -62,8 +63,9 @@
  * to force their buffering in serialized format by calling
  * {@link #asSerialized(Reader, NamedWriteableRegistry)}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class DelayableWriteable<T extends Writeable> implements Writeable {
     /**
      * Build a {@linkplain DelayableWriteable} that wraps an existing object
@@ -151,8 +153,9 @@ private BytesStreamOutput writeToBuffer(Version version) throws IOException {
     /**
      * A {@link Writeable} stored in serialized form.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Serialized<T extends Writeable> extends DelayableWriteable<T> implements Accountable {
         private final Writeable.Reader<T> reader;
         private final Version serializedAtVersion;
diff --git a/server/src/main/java/org/opensearch/common/io/stream/Streamables.java b/server/src/main/java/org/opensearch/common/io/stream/Streamables.java
index fd9ed6e5b18fe..f1e5f5f22d527 100644
--- a/server/src/main/java/org/opensearch/common/io/stream/Streamables.java
+++ b/server/src/main/java/org/opensearch/common/io/stream/Streamables.java
@@ -40,7 +40,7 @@ public static void registerStreamables() {
      * Registers writers by class type
      */
     private static void registerWriters() {
-        /** {@link GeoPoint} */
+        /* {@link GeoPoint} */
         WriteableRegistry.registerWriter(GeoPoint.class, (o, v) -> {
             o.writeByte((byte) 22);
             ((GeoPoint) v).writeTo(o);
@@ -53,7 +53,7 @@ private static void registerWriters() {
      * NOTE: see {@code StreamOutput#WRITERS} for all registered ordinals
      */
     private static void registerReaders() {
-        /** {@link GeoPoint} */
+        /* {@link GeoPoint} */
         WriteableRegistry.registerReader(Byte.valueOf((byte) 22), GeoPoint::new);
     }
 }
diff --git a/server/src/main/java/org/opensearch/common/joda/JodaDateFormatter.java b/server/src/main/java/org/opensearch/common/joda/JodaDateFormatter.java
index 12d48a0b362ce..bf25e5b1b3923 100644
--- a/server/src/main/java/org/opensearch/common/joda/JodaDateFormatter.java
+++ b/server/src/main/java/org/opensearch/common/joda/JodaDateFormatter.java
@@ -125,6 +125,11 @@ public String pattern() {
         return pattern;
     }
 
+    @Override
+    public String printPattern() {
+        throw new UnsupportedOperationException("JodaDateFormatter does not have a print pattern");
+    }
+
     @Override
     public Locale locale() {
         return printer.getLocale();
diff --git a/server/src/main/java/org/opensearch/common/joda/JodaDateMathParser.java b/server/src/main/java/org/opensearch/common/joda/JodaDateMathParser.java
index 0de6dec1c25bd..ae38e9a6a8073 100644
--- a/server/src/main/java/org/opensearch/common/joda/JodaDateMathParser.java
+++ b/server/src/main/java/org/opensearch/common/joda/JodaDateMathParser.java
@@ -46,7 +46,7 @@
 
 /**
  * A parser for date/time formatted text with optional date math.
- *
+ * <p>
  * The format of the datetime is configurable, and unix timestamps can also be used. Datemath
  * is appended to a datetime with the following syntax:
  * <code>||[+-/](\d+)?[yMwdhHms]</code>.
diff --git a/server/src/main/java/org/opensearch/common/logging/DeprecationLogger.java b/server/src/main/java/org/opensearch/common/logging/DeprecationLogger.java
index 98b4ebbc330da..d4dbb953ffe12 100644
--- a/server/src/main/java/org/opensearch/common/logging/DeprecationLogger.java
+++ b/server/src/main/java/org/opensearch/common/logging/DeprecationLogger.java
@@ -35,6 +35,7 @@
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * A logger that logs deprecation notices. Logger should be initialized with a parent logger which name will be used
@@ -50,8 +51,9 @@
  * key is combined with the <code>X-Opaque-Id</code> request header value, if supplied, which allows for per-client
  * message limiting.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DeprecationLogger {
 
     /**
@@ -108,8 +110,9 @@ public DeprecationLoggerBuilder deprecate(final String key, final String msg, fi
     /**
      * The builder for the deprecation logger
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public class DeprecationLoggerBuilder {
 
         public DeprecationLoggerBuilder withDeprecation(String key, String msg, Object[] params) {
diff --git a/server/src/main/java/org/opensearch/common/logging/JsonThrowablePatternConverter.java b/server/src/main/java/org/opensearch/common/logging/JsonThrowablePatternConverter.java
index e259d5d9e3e33..ed324e4e62d8f 100644
--- a/server/src/main/java/org/opensearch/common/logging/JsonThrowablePatternConverter.java
+++ b/server/src/main/java/org/opensearch/common/logging/JsonThrowablePatternConverter.java
@@ -47,7 +47,7 @@
 
  * Outputs the Throwable portion of the LoggingEvent as a Json formatted field with array
  * "exception": [ "stacktrace", "lines", "as", "array", "elements" ]
- *
+ * <p>
  * Reusing @link org.apache.logging.log4j.core.pattern.ExtendedThrowablePatternConverter which already converts a Throwable from
  * LoggingEvent into a multiline string
  *
diff --git a/server/src/main/java/org/opensearch/index/SlowLogLevel.java b/server/src/main/java/org/opensearch/common/logging/SlowLogLevel.java
similarity index 94%
rename from server/src/main/java/org/opensearch/index/SlowLogLevel.java
rename to server/src/main/java/org/opensearch/common/logging/SlowLogLevel.java
index 0a28edd59d491..9f744cceaa14d 100644
--- a/server/src/main/java/org/opensearch/index/SlowLogLevel.java
+++ b/server/src/main/java/org/opensearch/common/logging/SlowLogLevel.java
@@ -29,7 +29,7 @@
  * GitHub history for details.
  */
 
-package org.opensearch.index;
+package org.opensearch.common.logging;
 
 import java.util.Locale;
 
@@ -54,7 +54,7 @@ public static SlowLogLevel parse(String level) {
         return valueOf(level.toUpperCase(Locale.ROOT));
     }
 
-    boolean isLevelEnabledFor(SlowLogLevel levelToBeUsed) {
+    public boolean isLevelEnabledFor(SlowLogLevel levelToBeUsed) {
         // example: this.info(2) tries to log with levelToBeUsed.warn(3) - should allow
         return this.specificity <= levelToBeUsed.specificity;
     }
diff --git a/server/src/main/java/org/opensearch/common/lucene/ShardCoreKeyMap.java b/server/src/main/java/org/opensearch/common/lucene/ShardCoreKeyMap.java
index 0ffd633e5a967..17b75ab22f3ed 100644
--- a/server/src/main/java/org/opensearch/common/lucene/ShardCoreKeyMap.java
+++ b/server/src/main/java/org/opensearch/common/lucene/ShardCoreKeyMap.java
@@ -55,7 +55,7 @@
  * mappings as segments that were not known before are added and prevents the
  * structure from growing indefinitely by registering close listeners on these
  * segments so that at any time it only tracks live segments.
- *
+ * <p>
  * NOTE: This is heavy. Avoid using this class unless absolutely required.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/common/lucene/index/OpenSearchDirectoryReader.java b/server/src/main/java/org/opensearch/common/lucene/index/OpenSearchDirectoryReader.java
index 77609822d3d90..d6b2bb239b2a1 100644
--- a/server/src/main/java/org/opensearch/common/lucene/index/OpenSearchDirectoryReader.java
+++ b/server/src/main/java/org/opensearch/common/lucene/index/OpenSearchDirectoryReader.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.LeafReader;
 import org.opensearch.common.SuppressForbidden;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.shard.ShardId;
 
 import java.io.IOException;
@@ -44,8 +45,9 @@
  * A {@link org.apache.lucene.index.FilterDirectoryReader} that exposes
  * OpenSearch internal per shard / index information like the shard ID.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class OpenSearchDirectoryReader extends FilterDirectoryReader {
 
     private final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/common/lucene/search/FilteredCollector.java b/server/src/main/java/org/opensearch/common/lucene/search/FilteredCollector.java
index 0d7a8866f7788..b5c0e84a10308 100644
--- a/server/src/main/java/org/opensearch/common/lucene/search/FilteredCollector.java
+++ b/server/src/main/java/org/opensearch/common/lucene/search/FilteredCollector.java
@@ -40,6 +40,7 @@
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.Bits;
 import org.opensearch.common.lucene.Lucene;
+import org.opensearch.search.profile.query.ProfileWeight;
 
 import java.io.IOException;
 
@@ -64,6 +65,9 @@ public Collector getCollector() {
 
     @Override
     public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException {
+        if (filter instanceof ProfileWeight) {
+            ((ProfileWeight) filter).associateCollectorToLeaves(context, collector);
+        }
         final ScorerSupplier filterScorerSupplier = filter.scorerSupplier(context);
         final LeafCollector in = collector.getLeafCollector(context);
         final Bits bits = Lucene.asSequentialAccessBits(context.reader().maxDoc(), filterScorerSupplier);
diff --git a/server/src/main/java/org/opensearch/common/lucene/search/TopDocsAndMaxScore.java b/server/src/main/java/org/opensearch/common/lucene/search/TopDocsAndMaxScore.java
index 5f8c52676b481..5b7bae54a6fad 100644
--- a/server/src/main/java/org/opensearch/common/lucene/search/TopDocsAndMaxScore.java
+++ b/server/src/main/java/org/opensearch/common/lucene/search/TopDocsAndMaxScore.java
@@ -33,13 +33,15 @@
 package org.opensearch.common.lucene.search;
 
 import org.apache.lucene.search.TopDocs;
+import org.opensearch.common.annotation.PublicApi;
 
 /**
  * Wrapper around a {@link TopDocs} instance and the maximum score.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
 // TODO: Remove this class when https://github.com/elastic/elasticsearch/issues/32981 is addressed.
+@PublicApi(since = "1.0.0")
 public final class TopDocsAndMaxScore {
 
     public final TopDocs topDocs;
diff --git a/server/src/main/java/org/opensearch/common/lucene/store/ByteArrayIndexInput.java b/server/src/main/java/org/opensearch/common/lucene/store/ByteArrayIndexInput.java
index 6eb613daf5133..bb273b14c42e2 100644
--- a/server/src/main/java/org/opensearch/common/lucene/store/ByteArrayIndexInput.java
+++ b/server/src/main/java/org/opensearch/common/lucene/store/ByteArrayIndexInput.java
@@ -33,6 +33,7 @@
 
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.RandomAccessInput;
+import org.apache.lucene.util.BitUtil;
 
 import java.io.EOFException;
 import java.io.IOException;
@@ -121,47 +122,25 @@ public void readBytes(final byte[] b, final int offset, int len) throws IOExcept
     @Override
     public byte readByte(long pos) throws IOException {
         validatePos(pos, Byte.BYTES);
-        return internalReadByte(pos);
+        return bytes[offset + (int) pos];
     }
 
     @Override
     public short readShort(long pos) throws IOException {
         validatePos(pos, Short.BYTES);
-        return internalReadShort(pos);
+        return (short) BitUtil.VH_LE_SHORT.get(bytes, offset + (int) pos);
     }
 
     @Override
     public int readInt(long pos) throws IOException {
         validatePos(pos, Integer.BYTES);
-        return internalReadInt(pos);
+        return (int) BitUtil.VH_LE_INT.get(bytes, offset + (int) pos);
     }
 
     @Override
     public long readLong(long pos) throws IOException {
         validatePos(pos, Long.BYTES);
-        return internalReadLong(pos);
-    }
-
-    private byte internalReadByte(long pos) {
-        return bytes[offset + (int) pos];
-    }
-
-    private short internalReadShort(long pos) {
-        final byte p1 = internalReadByte(pos);
-        final byte p2 = internalReadByte(pos + 1);
-        return (short) (((p2 & 0xFF) << 8) | (p1 & 0xFF));
-    }
-
-    private int internalReadInt(long pos) {
-        final short p1 = internalReadShort(pos);
-        final short p2 = internalReadShort(pos + Short.BYTES);
-        return ((p2 & 0xFFFF) << 16) | (p1 & 0xFFFF);
-    }
-
-    public long internalReadLong(long pos) {
-        final int p1 = internalReadInt(pos);
-        final int p2 = internalReadInt(pos + Integer.BYTES);
-        return (((long) p2) << 32) | (p1 & 0xFFFFFFFFL);
+        return (long) BitUtil.VH_LE_LONG.get(bytes, offset + (int) pos);
     }
 
     private void validatePos(long pos, int len) throws EOFException {
diff --git a/server/src/main/java/org/opensearch/common/lucene/uid/VersionsAndSeqNoResolver.java b/server/src/main/java/org/opensearch/common/lucene/uid/VersionsAndSeqNoResolver.java
index 57524bc3657d9..4958267b1775b 100644
--- a/server/src/main/java/org/opensearch/common/lucene/uid/VersionsAndSeqNoResolver.java
+++ b/server/src/main/java/org/opensearch/common/lucene/uid/VersionsAndSeqNoResolver.java
@@ -37,6 +37,7 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.util.CloseableThreadLocal;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.concurrent.ConcurrentCollections;
 
 import java.io.IOException;
@@ -110,8 +111,9 @@ private VersionsAndSeqNoResolver() {}
     /**
      * Wraps an {@link LeafReaderContext}, a doc ID <b>relative to the context doc base</b> and a version.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class DocIdAndVersion {
         public final int docId;
         public final long version;
diff --git a/server/src/main/java/org/opensearch/common/metrics/CounterMetric.java b/server/src/main/java/org/opensearch/common/metrics/CounterMetric.java
index 5c48c1f772ff0..cb181840406a5 100644
--- a/server/src/main/java/org/opensearch/common/metrics/CounterMetric.java
+++ b/server/src/main/java/org/opensearch/common/metrics/CounterMetric.java
@@ -62,4 +62,5 @@ public void dec(long n) {
     public long count() {
         return counter.sum();
     }
+
 }
diff --git a/server/src/main/java/org/opensearch/common/metrics/MeanMetric.java b/server/src/main/java/org/opensearch/common/metrics/MeanMetric.java
index 33f12c8cb42d3..359facdce633b 100644
--- a/server/src/main/java/org/opensearch/common/metrics/MeanMetric.java
+++ b/server/src/main/java/org/opensearch/common/metrics/MeanMetric.java
@@ -79,4 +79,5 @@ public void clear() {
         counter.reset();
         sum.reset();
     }
+
 }
diff --git a/server/src/main/java/org/opensearch/common/network/NetworkModule.java b/server/src/main/java/org/opensearch/common/network/NetworkModule.java
index 8870e26c373e9..f97d5b2f80eeb 100644
--- a/server/src/main/java/org/opensearch/common/network/NetworkModule.java
+++ b/server/src/main/java/org/opensearch/common/network/NetworkModule.java
@@ -55,6 +55,7 @@
 import org.opensearch.http.HttpServerTransport;
 import org.opensearch.index.shard.PrimaryReplicaSyncer.ResyncTask;
 import org.opensearch.plugins.NetworkPlugin;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
 import org.opensearch.tasks.RawTaskStatus;
 import org.opensearch.tasks.Task;
 import org.opensearch.telemetry.tracing.Tracer;
@@ -131,7 +132,7 @@ public final class NetworkModule {
 
     private final Map<String, Supplier<Transport>> transportFactories = new HashMap<>();
     private final Map<String, Supplier<HttpServerTransport>> transportHttpFactories = new HashMap<>();
-    private final List<TransportInterceptor> transportIntercetors = new ArrayList<>();
+    private final List<TransportInterceptor> transportInterceptors = new ArrayList<>();
 
     /**
      * Creates a network module that custom networking classes can be plugged into.
@@ -149,7 +150,8 @@ public NetworkModule(
         NetworkService networkService,
         HttpServerTransport.Dispatcher dispatcher,
         ClusterSettings clusterSettings,
-        Tracer tracer
+        Tracer tracer,
+        List<TransportInterceptor> transportInterceptors
     ) {
         this.settings = settings;
         for (NetworkPlugin plugin : plugins) {
@@ -174,19 +176,24 @@ public NetworkModule(
                 pageCacheRecycler,
                 circuitBreakerService,
                 namedWriteableRegistry,
-                networkService
+                networkService,
+                tracer
             );
             for (Map.Entry<String, Supplier<Transport>> entry : transportFactory.entrySet()) {
                 registerTransport(entry.getKey(), entry.getValue());
             }
-            List<TransportInterceptor> transportInterceptors = plugin.getTransportInterceptors(
+            List<TransportInterceptor> pluginTransportInterceptors = plugin.getTransportInterceptors(
                 namedWriteableRegistry,
                 threadPool.getThreadContext()
             );
-            for (TransportInterceptor interceptor : transportInterceptors) {
+            for (TransportInterceptor interceptor : pluginTransportInterceptors) {
                 registerTransportInterceptor(interceptor);
             }
         }
+        // Adding last because interceptors are triggered from last to first order from the list
+        if (transportInterceptors != null) {
+            transportInterceptors.forEach(this::registerTransportInterceptor);
+        }
     }
 
     /** Adds a transport implementation that can be selected by setting {@link #TRANSPORT_TYPE_KEY}. */
@@ -263,7 +270,7 @@ public Supplier<Transport> getTransportSupplier() {
      * Registers a new {@link TransportInterceptor}
      */
     private void registerTransportInterceptor(TransportInterceptor interceptor) {
-        this.transportIntercetors.add(Objects.requireNonNull(interceptor, "interceptor must not be null"));
+        this.transportInterceptors.add(Objects.requireNonNull(interceptor, "interceptor must not be null"));
     }
 
     /**
@@ -271,7 +278,7 @@ private void registerTransportInterceptor(TransportInterceptor interceptor) {
      * @see #registerTransportInterceptor(TransportInterceptor)
      */
     public TransportInterceptor getTransportInterceptor() {
-        return new CompositeTransportInterceptor(this.transportIntercetors);
+        return new CompositeTransportInterceptor(this.transportInterceptors);
     }
 
     static final class CompositeTransportInterceptor implements TransportInterceptor {
@@ -294,6 +301,30 @@ public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
             return actualHandler;
         }
 
+        /**
+         * Intercept the transport action and perform admission control if applicable
+         * @param action The action the request handler is associated with
+         * @param executor The executor the request handling will be executed on
+         * @param forceExecution Force execution on the executor queue and never reject it
+         * @param actualHandler The handler itself that implements the request handling
+         * @param admissionControlActionType Admission control based on resource usage limits of provided action type
+         * @return returns the actual TransportRequestHandler after intercepting all previous handlers
+         * @param <T> transport request type
+         */
+        @Override
+        public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+            String action,
+            String executor,
+            boolean forceExecution,
+            TransportRequestHandler<T> actualHandler,
+            AdmissionControlActionType admissionControlActionType
+        ) {
+            for (TransportInterceptor interceptor : this.transportInterceptors) {
+                actualHandler = interceptor.interceptHandler(action, executor, forceExecution, actualHandler, admissionControlActionType);
+            }
+            return actualHandler;
+        }
+
         @Override
         public AsyncSender interceptSender(AsyncSender sender) {
             for (TransportInterceptor interceptor : this.transportInterceptors) {
diff --git a/server/src/main/java/org/opensearch/common/regex/Regex.java b/server/src/main/java/org/opensearch/common/regex/Regex.java
index 396af77c8a751..323b460af62df 100644
--- a/server/src/main/java/org/opensearch/common/regex/Regex.java
+++ b/server/src/main/java/org/opensearch/common/regex/Regex.java
@@ -129,35 +129,35 @@ public static boolean simpleMatch(String pattern, String str, boolean caseInsens
     }
 
     private static boolean simpleMatchWithNormalizedStrings(String pattern, String str) {
-        final int firstIndex = pattern.indexOf('*');
-        if (firstIndex == -1) {
-            return pattern.equals(str);
-        }
-        if (firstIndex == 0) {
-            if (pattern.length() == 1) {
-                return true;
-            }
-            final int nextIndex = pattern.indexOf('*', firstIndex + 1);
-            if (nextIndex == -1) {
-                // str.endsWith(pattern.substring(1)), but avoiding the construction of pattern.substring(1):
-                return str.regionMatches(str.length() - pattern.length() + 1, pattern, 1, pattern.length() - 1);
-            } else if (nextIndex == 1) {
-                // Double wildcard "**" - skipping the first "*"
-                return simpleMatchWithNormalizedStrings(pattern.substring(1), str);
-            }
-            final String part = pattern.substring(1, nextIndex);
-            int partIndex = str.indexOf(part);
-            while (partIndex != -1) {
-                if (simpleMatchWithNormalizedStrings(pattern.substring(nextIndex), str.substring(partIndex + part.length()))) {
-                    return true;
-                }
-                partIndex = str.indexOf(part, partIndex + 1);
+        int sIdx = 0, pIdx = 0, match = 0, wildcardIdx = -1;
+        while (sIdx < str.length()) {
+            // both chars matching, incrementing both pointers
+            if (pIdx < pattern.length() && str.charAt(sIdx) == pattern.charAt(pIdx)) {
+                sIdx++;
+                pIdx++;
+            } else if (pIdx < pattern.length() && pattern.charAt(pIdx) == '*') {
+                // wildcard found, only incrementing pattern pointer
+                wildcardIdx = pIdx;
+                match = sIdx;
+                pIdx++;
+            } else if (wildcardIdx != -1) {
+                // last pattern pointer was a wildcard, incrementing string pointer
+                pIdx = wildcardIdx + 1;
+                match++;
+                sIdx = match;
+            } else {
+                // current pattern pointer is not a wildcard, last pattern pointer was also not a wildcard
+                // characters do not match
+                return false;
             }
-            return false;
         }
-        return str.regionMatches(0, pattern, 0, firstIndex)
-            && (firstIndex == pattern.length() - 1 // only wildcard in pattern is at the end, so no need to look at the rest of the string
-                || simpleMatchWithNormalizedStrings(pattern.substring(firstIndex), str.substring(firstIndex)));
+
+        // check for remaining characters in pattern
+        while (pIdx < pattern.length() && pattern.charAt(pIdx) == '*') {
+            pIdx++;
+        }
+
+        return pIdx == pattern.length();
     }
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/rounding/DateTimeUnit.java b/server/src/main/java/org/opensearch/common/rounding/DateTimeUnit.java
deleted file mode 100644
index 47e182b3caf84..0000000000000
--- a/server/src/main/java/org/opensearch/common/rounding/DateTimeUnit.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.OpenSearchException;
-import org.opensearch.common.joda.Joda;
-import org.joda.time.DateTimeField;
-import org.joda.time.DateTimeZone;
-import org.joda.time.chrono.ISOChronology;
-
-import java.util.function.Function;
-
-/**
- * Main date time unit class.
- *
- * @opensearch.internal
- */
-public enum DateTimeUnit {
-
-    WEEK_OF_WEEKYEAR((byte) 1, tz -> ISOChronology.getInstance(tz).weekOfWeekyear()),
-    YEAR_OF_CENTURY((byte) 2, tz -> ISOChronology.getInstance(tz).yearOfCentury()),
-    QUARTER((byte) 3, tz -> Joda.QuarterOfYear.getField(ISOChronology.getInstance(tz))),
-    MONTH_OF_YEAR((byte) 4, tz -> ISOChronology.getInstance(tz).monthOfYear()),
-    DAY_OF_MONTH((byte) 5, tz -> ISOChronology.getInstance(tz).dayOfMonth()),
-    HOUR_OF_DAY((byte) 6, tz -> ISOChronology.getInstance(tz).hourOfDay()),
-    MINUTES_OF_HOUR((byte) 7, tz -> ISOChronology.getInstance(tz).minuteOfHour()),
-    SECOND_OF_MINUTE((byte) 8, tz -> ISOChronology.getInstance(tz).secondOfMinute());
-
-    private final byte id;
-    private final Function<DateTimeZone, DateTimeField> fieldFunction;
-
-    DateTimeUnit(byte id, Function<DateTimeZone, DateTimeField> fieldFunction) {
-        this.id = id;
-        this.fieldFunction = fieldFunction;
-    }
-
-    public byte id() {
-        return id;
-    }
-
-    /**
-     * @return the {@link DateTimeField} for the provided {@link DateTimeZone} for this time unit
-     */
-    public DateTimeField field(DateTimeZone tz) {
-        return fieldFunction.apply(tz);
-    }
-
-    public static DateTimeUnit resolve(byte id) {
-        switch (id) {
-            case 1:
-                return WEEK_OF_WEEKYEAR;
-            case 2:
-                return YEAR_OF_CENTURY;
-            case 3:
-                return QUARTER;
-            case 4:
-                return MONTH_OF_YEAR;
-            case 5:
-                return DAY_OF_MONTH;
-            case 6:
-                return HOUR_OF_DAY;
-            case 7:
-                return MINUTES_OF_HOUR;
-            case 8:
-                return SECOND_OF_MINUTE;
-            default:
-                throw new OpenSearchException("Unknown date time unit id [" + id + "]");
-        }
-    }
-}
diff --git a/server/src/main/java/org/opensearch/common/rounding/Rounding.java b/server/src/main/java/org/opensearch/common/rounding/Rounding.java
deleted file mode 100644
index 857031bc783f4..0000000000000
--- a/server/src/main/java/org/opensearch/common/rounding/Rounding.java
+++ /dev/null
@@ -1,459 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.OpenSearchException;
-import org.opensearch.common.unit.TimeValue;
-import org.opensearch.core.common.io.stream.StreamInput;
-import org.opensearch.core.common.io.stream.StreamOutput;
-import org.opensearch.core.common.io.stream.Writeable;
-import org.joda.time.DateTimeField;
-import org.joda.time.DateTimeZone;
-import org.joda.time.IllegalInstantException;
-
-import java.io.IOException;
-import java.util.Objects;
-
-/**
- * A strategy for rounding long values.
- *
- * Use the java based Rounding class where applicable
- *
- * @opensearch.internal
- */
-@Deprecated
-public abstract class Rounding implements Writeable {
-
-    public abstract byte id();
-
-    /**
-     * Rounds the given value.
-     */
-    public abstract long round(long value);
-
-    /**
-     * Given the rounded value (which was potentially generated by {@link #round(long)}, returns the next rounding value. For example, with
-     * interval based rounding, if the interval is 3, {@code nextRoundValue(6) = 9 }.
-     *
-     * @param value The current rounding value
-     * @return      The next rounding value;
-     */
-    public abstract long nextRoundingValue(long value);
-
-    @Override
-    public abstract boolean equals(Object obj);
-
-    @Override
-    public abstract int hashCode();
-
-    public static Builder builder(DateTimeUnit unit) {
-        return new Builder(unit);
-    }
-
-    public static Builder builder(TimeValue interval) {
-        return new Builder(interval);
-    }
-
-    /**
-     * Builder for rounding
-     *
-     * @opensearch.internal
-     */
-    public static class Builder {
-
-        private final DateTimeUnit unit;
-        private final long interval;
-
-        private DateTimeZone timeZone = DateTimeZone.UTC;
-
-        public Builder(DateTimeUnit unit) {
-            this.unit = unit;
-            this.interval = -1;
-        }
-
-        public Builder(TimeValue interval) {
-            this.unit = null;
-            if (interval.millis() < 1) throw new IllegalArgumentException("Zero or negative time interval not supported");
-            this.interval = interval.millis();
-        }
-
-        public Builder timeZone(DateTimeZone timeZone) {
-            if (timeZone == null) {
-                throw new IllegalArgumentException("Setting null as timezone is not supported");
-            }
-            this.timeZone = timeZone;
-            return this;
-        }
-
-        public Rounding build() {
-            Rounding timeZoneRounding;
-            if (unit != null) {
-                timeZoneRounding = new TimeUnitRounding(unit, timeZone);
-            } else {
-                timeZoneRounding = new TimeIntervalRounding(interval, timeZone);
-            }
-            return timeZoneRounding;
-        }
-    }
-
-    /**
-     * Rounding time units
-     *
-     * @opensearch.internal
-     */
-    static class TimeUnitRounding extends Rounding {
-
-        static final byte ID = 1;
-
-        private final DateTimeUnit unit;
-        private final DateTimeField field;
-        private final DateTimeZone timeZone;
-        private final boolean unitRoundsToMidnight;
-
-        TimeUnitRounding(DateTimeUnit unit, DateTimeZone timeZone) {
-            this.unit = unit;
-            this.field = unit.field(timeZone);
-            unitRoundsToMidnight = this.field.getDurationField().getUnitMillis() > 60L * 60L * 1000L;
-            this.timeZone = timeZone;
-        }
-
-        TimeUnitRounding(StreamInput in) throws IOException {
-            unit = DateTimeUnit.resolve(in.readByte());
-            timeZone = DateTimeZone.forID(in.readString());
-            field = unit.field(timeZone);
-            unitRoundsToMidnight = field.getDurationField().getUnitMillis() > 60L * 60L * 1000L;
-        }
-
-        @Override
-        public byte id() {
-            return ID;
-        }
-
-        /**
-         * @return The latest timestamp T which is strictly before utcMillis
-         * and such that timeZone.getOffset(T) != timeZone.getOffset(utcMillis).
-         * If there is no such T, returns Long.MAX_VALUE.
-         */
-        private long previousTransition(long utcMillis) {
-            final int offsetAtInputTime = timeZone.getOffset(utcMillis);
-            do {
-                // Some timezones have transitions that do not change the offset, so we have to
-                // repeatedly call previousTransition until a nontrivial transition is found.
-
-                long previousTransition = timeZone.previousTransition(utcMillis);
-                if (previousTransition == utcMillis) {
-                    // There are no earlier transitions
-                    return Long.MAX_VALUE;
-                }
-                assert previousTransition < utcMillis; // Progress was made
-                utcMillis = previousTransition;
-            } while (timeZone.getOffset(utcMillis) == offsetAtInputTime);
-
-            return utcMillis;
-        }
-
-        @Override
-        public long round(long utcMillis) {
-
-            // field.roundFloor() works as long as the offset doesn't change. It is worth getting this case out of the way first, as
-            // the calculations for fixing things near to offset changes are a little expensive and are unnecessary in the common case
-            // of working in UTC.
-            if (timeZone.isFixed()) {
-                return field.roundFloor(utcMillis);
-            }
-
-            // When rounding to hours we consider any local time of the form 'xx:00:00' as rounded, even though this gives duplicate
-            // bucket names for the times when the clocks go back. Shorter units behave similarly. However, longer units round down to
-            // midnight, and on the days where there are two midnights we would rather pick the earlier one, so that buckets are
-            // uniquely identified by the date.
-            if (unitRoundsToMidnight) {
-                final long anyLocalStartOfDay = field.roundFloor(utcMillis);
-                // `anyLocalStartOfDay` is _supposed_ to be the Unix timestamp for the start of the day in question in the current time
-                // zone. Mostly this just means "midnight", which is fine, and on days with no local midnight it's the first time that
-                // does occur on that day which is also ok. However, on days with >1 local midnight this is _one_ of the midnights, but
-                // may not be the first. Check whether this is happening, and fix it if so.
-
-                final long previousTransition = previousTransition(anyLocalStartOfDay);
-
-                if (previousTransition == Long.MAX_VALUE) {
-                    // No previous transitions, so there can't be another earlier local midnight.
-                    return anyLocalStartOfDay;
-                }
-
-                final long currentOffset = timeZone.getOffset(anyLocalStartOfDay);
-                final long previousOffset = timeZone.getOffset(previousTransition);
-                assert currentOffset != previousOffset;
-
-                // NB we only assume interference from one previous transition. It's theoretically possible to have two transitions in
-                // quick succession, both of which have a midnight in them, but this doesn't appear to happen in the TZDB so (a) it's
-                // pointless to implement and (b) it won't be tested. I recognise that this comment is tempting fate and will likely
-                // cause this very situation to occur in the near future, and eagerly look forward to fixing this using a loop over
-                // previous transitions when it happens.
-
-                final long alsoLocalStartOfDay = anyLocalStartOfDay + currentOffset - previousOffset;
-                // `alsoLocalStartOfDay` is the Unix timestamp for the start of the day in question if the previous offset were in
-                // effect.
-
-                if (alsoLocalStartOfDay <= previousTransition) {
-                    // Therefore the previous offset _is_ in effect at `alsoLocalStartOfDay`, and it's earlier than anyLocalStartOfDay,
-                    // so this is the answer to use.
-                    return alsoLocalStartOfDay;
-                } else {
-                    // The previous offset is not in effect at `alsoLocalStartOfDay`, so the current offset must be.
-                    return anyLocalStartOfDay;
-                }
-
-            } else {
-                do {
-                    long rounded = field.roundFloor(utcMillis);
-
-                    // field.roundFloor() mostly works as long as the offset hasn't changed in [rounded, utcMillis], so look at where
-                    // the offset most recently changed.
-
-                    final long previousTransition = previousTransition(utcMillis);
-
-                    if (previousTransition == Long.MAX_VALUE || previousTransition < rounded) {
-                        // The offset did not change in [rounded, utcMillis], so roundFloor() worked as expected.
-                        return rounded;
-                    }
-
-                    // The offset _did_ change in [rounded, utcMillis]. Put differently, this means that none of the times in
-                    // [previousTransition+1, utcMillis] were rounded, so the rounded time must be <= previousTransition. This means
-                    // it's sufficient to try and round previousTransition down.
-                    assert previousTransition < utcMillis;
-                    utcMillis = previousTransition;
-                } while (true);
-            }
-        }
-
-        @Override
-        public long nextRoundingValue(long utcMillis) {
-            long floor = round(utcMillis);
-            // add one unit and round to get to next rounded value
-            long next = round(field.add(floor, 1));
-            if (next == floor) {
-                // in rare case we need to add more than one unit
-                next = round(field.add(floor, 2));
-            }
-            return next;
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            out.writeByte(unit.id());
-            out.writeString(timeZone.getID());
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(unit, timeZone);
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj == null) {
-                return false;
-            }
-            if (getClass() != obj.getClass()) {
-                return false;
-            }
-            TimeUnitRounding other = (TimeUnitRounding) obj;
-            return Objects.equals(unit, other.unit) && Objects.equals(timeZone, other.timeZone);
-        }
-
-        @Override
-        public String toString() {
-            return "[" + timeZone + "][" + unit + "]";
-        }
-    }
-
-    /**
-     * Rounding time intervals
-     *
-     * @opensearch.internal
-     */
-    static class TimeIntervalRounding extends Rounding {
-
-        static final byte ID = 2;
-
-        private final long interval;
-        private final DateTimeZone timeZone;
-
-        TimeIntervalRounding(long interval, DateTimeZone timeZone) {
-            if (interval < 1) throw new IllegalArgumentException("Zero or negative time interval not supported");
-            this.interval = interval;
-            this.timeZone = timeZone;
-        }
-
-        TimeIntervalRounding(StreamInput in) throws IOException {
-            interval = in.readVLong();
-            timeZone = DateTimeZone.forID(in.readString());
-        }
-
-        @Override
-        public byte id() {
-            return ID;
-        }
-
-        @Override
-        public long round(long utcMillis) {
-            long timeLocal = timeZone.convertUTCToLocal(utcMillis);
-            long rounded = roundKey(timeLocal, interval) * interval;
-            long roundedUTC;
-            if (isInDSTGap(rounded) == false) {
-                roundedUTC = timeZone.convertLocalToUTC(rounded, true, utcMillis);
-                // check if we crossed DST transition, in this case we want the
-                // last rounded value before the transition
-                long transition = timeZone.previousTransition(utcMillis);
-                if (transition != utcMillis && transition > roundedUTC) {
-                    roundedUTC = round(transition - 1);
-                }
-            } else {
-                /*
-                 * Edge case where the rounded local time is illegal and landed
-                 * in a DST gap. In this case, we choose 1ms tick after the
-                 * transition date. We don't want the transition date itself
-                 * because those dates, when rounded themselves, fall into the
-                 * previous interval. This would violate the invariant that the
-                 * rounding operation should be idempotent.
-                 */
-                roundedUTC = timeZone.previousTransition(utcMillis) + 1;
-            }
-            return roundedUTC;
-        }
-
-        private static long roundKey(long value, long interval) {
-            if (value < 0) {
-                return (value - interval + 1) / interval;
-            } else {
-                return value / interval;
-            }
-        }
-
-        /**
-         * Determine whether the local instant is a valid instant in the given
-         * time zone. The logic for this is taken from
-         * {@link DateTimeZone#convertLocalToUTC(long, boolean)} for the
-         * `strict` mode case, but instead of throwing an
-         * {@link IllegalInstantException}, which is costly, we want to return a
-         * flag indicating that the value is illegal in that time zone.
-         */
-        private boolean isInDSTGap(long instantLocal) {
-            if (timeZone.isFixed()) {
-                return false;
-            }
-            // get the offset at instantLocal (first estimate)
-            int offsetLocal = timeZone.getOffset(instantLocal);
-            // adjust instantLocal using the estimate and recalc the offset
-            int offset = timeZone.getOffset(instantLocal - offsetLocal);
-            // if the offsets differ, we must be near a DST boundary
-            if (offsetLocal != offset) {
-                // determine if we are in the DST gap
-                long nextLocal = timeZone.nextTransition(instantLocal - offsetLocal);
-                if (nextLocal == (instantLocal - offsetLocal)) {
-                    nextLocal = Long.MAX_VALUE;
-                }
-                long nextAdjusted = timeZone.nextTransition(instantLocal - offset);
-                if (nextAdjusted == (instantLocal - offset)) {
-                    nextAdjusted = Long.MAX_VALUE;
-                }
-                if (nextLocal != nextAdjusted) {
-                    // we are in the DST gap
-                    return true;
-                }
-            }
-            return false;
-        }
-
-        @Override
-        public long nextRoundingValue(long time) {
-            long timeLocal = time;
-            timeLocal = timeZone.convertUTCToLocal(time);
-            long next = timeLocal + interval;
-            return timeZone.convertLocalToUTC(next, false);
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            out.writeVLong(interval);
-            out.writeString(timeZone.getID());
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(interval, timeZone);
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj == null) {
-                return false;
-            }
-            if (getClass() != obj.getClass()) {
-                return false;
-            }
-            TimeIntervalRounding other = (TimeIntervalRounding) obj;
-            return Objects.equals(interval, other.interval) && Objects.equals(timeZone, other.timeZone);
-        }
-    }
-
-    /**
-     * Rounding streams
-     *
-     * @opensearch.internal
-     */
-    public static class Streams {
-
-        public static void write(Rounding rounding, StreamOutput out) throws IOException {
-            out.writeByte(rounding.id());
-            rounding.writeTo(out);
-        }
-
-        public static Rounding read(StreamInput in) throws IOException {
-            Rounding rounding;
-            byte id = in.readByte();
-            switch (id) {
-                case TimeUnitRounding.ID:
-                    rounding = new TimeUnitRounding(in);
-                    break;
-                case TimeIntervalRounding.ID:
-                    rounding = new TimeIntervalRounding(in);
-                    break;
-                default:
-                    throw new OpenSearchException("unknown rounding id [" + id + "]");
-            }
-            return rounding;
-        }
-
-    }
-
-}
diff --git a/server/src/main/java/org/opensearch/common/settings/AbstractScopedSettings.java b/server/src/main/java/org/opensearch/common/settings/AbstractScopedSettings.java
index 8b7a2a82e5cb1..117ed66fcb451 100644
--- a/server/src/main/java/org/opensearch/common/settings/AbstractScopedSettings.java
+++ b/server/src/main/java/org/opensearch/common/settings/AbstractScopedSettings.java
@@ -254,7 +254,7 @@ public synchronized <T> void addSettingsUpdateConsumer(Setting<T> setting, Consu
     /**
      * Adds a settings consumer that is only executed if any setting in the supplied list of settings is changed. In that case all the
      * settings are specified in the argument are returned.
-     *
+     * <p>
      * Also automatically adds empty consumers for all settings in order to activate logging
      */
     public synchronized void addSettingsUpdateConsumer(Consumer<Settings> consumer, List<? extends Setting<?>> settings) {
@@ -265,7 +265,7 @@ public synchronized void addSettingsUpdateConsumer(Consumer<Settings> consumer,
      * Adds a settings consumer that is only executed if any setting in the supplied list of settings is changed. In that case all the
      * settings are specified in the argument are returned.  The validator is run across all specified settings before the settings are
      * applied.
-     *
+     * <p>
      * Also automatically adds empty consumers for all settings in order to activate logging
      */
     public synchronized void addSettingsUpdateConsumer(
diff --git a/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java b/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java
index 74224d66400da..ab0ea89f4734d 100644
--- a/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java
+++ b/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.admin.cluster.configuration.TransportAddVotingConfigExclusionsAction;
 import org.opensearch.action.admin.indices.close.TransportCloseIndexAction;
 import org.opensearch.action.search.CreatePitController;
+import org.opensearch.action.search.SearchRequestSlowLog;
 import org.opensearch.action.search.TransportSearchAction;
 import org.opensearch.action.support.AutoCreateIndex;
 import org.opensearch.action.support.DestructiveOperations;
@@ -130,9 +131,12 @@
 import org.opensearch.node.Node.DiscoverySettings;
 import org.opensearch.node.NodeRoleSettings;
 import org.opensearch.node.remotestore.RemoteStoreNodeService;
+import org.opensearch.node.resource.tracker.ResourceTrackerSettings;
 import org.opensearch.persistent.PersistentTasksClusterService;
 import org.opensearch.persistent.decider.EnableAssignmentDecider;
 import org.opensearch.plugins.PluginsService;
+import org.opensearch.ratelimitting.admissioncontrol.AdmissionControlSettings;
+import org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings;
 import org.opensearch.repositories.fs.FsRepository;
 import org.opensearch.rest.BaseRestHandler;
 import org.opensearch.script.ScriptService;
@@ -287,6 +291,8 @@ public void apply(Settings value, Settings current, Settings previous) {
                 RecoverySettings.INDICES_RECOVERY_INTERNAL_LONG_ACTION_TIMEOUT_SETTING,
                 RecoverySettings.INDICES_RECOVERY_MAX_CONCURRENT_FILE_CHUNKS_SETTING,
                 RecoverySettings.INDICES_RECOVERY_MAX_CONCURRENT_OPERATIONS_SETTING,
+                RecoverySettings.INDICES_RECOVERY_MAX_CONCURRENT_REMOTE_STORE_STREAMS_SETTING,
+                RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING,
                 ThrottlingAllocationDecider.CLUSTER_ROUTING_ALLOCATION_NODE_INITIAL_PRIMARIES_RECOVERIES_SETTING,
                 ThrottlingAllocationDecider.CLUSTER_ROUTING_ALLOCATION_NODE_INITIAL_REPLICAS_RECOVERIES_SETTING,
                 ThrottlingAllocationDecider.CLUSTER_ROUTING_ALLOCATION_NODE_CONCURRENT_INCOMING_RECOVERIES_SETTING,
@@ -344,6 +350,7 @@ public void apply(Settings value, Settings current, Settings previous) {
                 HttpTransportSettings.SETTING_HTTP_MAX_WARNING_HEADER_SIZE,
                 HttpTransportSettings.SETTING_HTTP_MAX_INITIAL_LINE_LENGTH,
                 HttpTransportSettings.SETTING_HTTP_READ_TIMEOUT,
+                HttpTransportSettings.SETTING_HTTP_CONNECT_TIMEOUT,
                 HttpTransportSettings.SETTING_HTTP_RESET_COOKIES,
                 HttpTransportSettings.OLD_SETTING_HTTP_TCP_NO_DELAY,
                 HttpTransportSettings.SETTING_HTTP_TCP_NO_DELAY,
@@ -373,6 +380,9 @@ public void apply(Settings value, Settings current, Settings previous) {
                 SearchService.DEFAULT_ALLOW_PARTIAL_SEARCH_RESULTS,
                 TransportSearchAction.SHARD_COUNT_LIMIT_SETTING,
                 TransportSearchAction.SEARCH_CANCEL_AFTER_TIME_INTERVAL_SETTING,
+                TransportSearchAction.SEARCH_REQUEST_STATS_ENABLED,
+                TransportSearchAction.SEARCH_PHASE_TOOK_ENABLED,
+                TransportSearchAction.SEARCH_QUERY_METRICS_ENABLED_SETTING,
                 RemoteClusterService.REMOTE_CLUSTER_SKIP_UNAVAILABLE,
                 SniffConnectionStrategy.REMOTE_CONNECTIONS_PER_CLUSTER,
                 RemoteClusterService.REMOTE_INITIAL_CONNECTION_TIMEOUT_SETTING,
@@ -456,6 +466,7 @@ public void apply(Settings value, Settings current, Settings previous) {
                 NetworkService.TCP_CONNECT_TIMEOUT,
                 IndexSettings.QUERY_STRING_ANALYZE_WILDCARD,
                 IndexSettings.QUERY_STRING_ALLOW_LEADING_WILDCARD,
+                IndexSettings.TIME_SERIES_INDEX_MERGE_POLICY,
                 ScriptService.SCRIPT_GENERAL_CACHE_SIZE_SETTING,
                 ScriptService.SCRIPT_GENERAL_CACHE_EXPIRE_SETTING,
                 ScriptService.SCRIPT_GENERAL_MAX_COMPILATIONS_RATE_SETTING,
@@ -651,6 +662,10 @@ public void apply(Settings value, Settings current, Settings previous) {
                 SegmentReplicationPressureService.MAX_REPLICATION_LIMIT_STALE_REPLICA_SETTING,
                 SegmentReplicationPressureService.MAX_ALLOWED_STALE_SHARDS,
 
+                // Settings related to resource trackers
+                ResourceTrackerSettings.GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING,
+                ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING,
+
                 // Settings related to Searchable Snapshots
                 Node.NODE_SEARCH_CACHE_SIZE_SETTING,
                 FileCache.DATA_TO_FILE_CACHE_SIZE_RATIO_SETTING,
@@ -668,10 +683,25 @@ public void apply(Settings value, Settings current, Settings previous) {
                 TaskCancellationMonitoringSettings.IS_ENABLED_SETTING,
                 TaskCancellationMonitoringSettings.DURATION_MILLIS_SETTING,
 
+                // Search request slow log settings
+                SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING,
+                SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING,
+                SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING,
+                SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING,
+                SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_LEVEL,
+
                 // Remote cluster state settings
                 RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING,
+                RemoteClusterStateService.INDEX_METADATA_UPLOAD_TIMEOUT_SETTING,
+                RemoteClusterStateService.GLOBAL_METADATA_UPLOAD_TIMEOUT_SETTING,
+                RemoteClusterStateService.METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING,
                 RemoteStoreNodeService.REMOTE_STORE_COMPATIBILITY_MODE_SETTING,
-                IndicesService.CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING
+                IndicesService.CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING,
+                IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING,
+                AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE,
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE,
+                CpuBasedAdmissionControllerSettings.INDEXING_CPU_USAGE_LIMIT,
+                CpuBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT
             )
         )
     );
@@ -690,6 +720,12 @@ public void apply(Settings value, Settings current, Settings previous) {
             SearchService.CONCURRENT_SEGMENT_SEARCH_TARGET_MAX_SLICE_COUNT_SETTING
         ),
         List.of(FeatureFlags.TELEMETRY),
-        List.of(TelemetrySettings.TRACER_ENABLED_SETTING, TelemetrySettings.TRACER_SAMPLER_PROBABILITY)
+        List.of(
+            TelemetrySettings.TRACER_ENABLED_SETTING,
+            TelemetrySettings.TRACER_SAMPLER_PROBABILITY,
+            TelemetrySettings.METRICS_PUBLISH_INTERVAL_SETTING,
+            TelemetrySettings.TRACER_FEATURE_ENABLED_SETTING,
+            TelemetrySettings.METRICS_FEATURE_ENABLED_SETTING
+        )
     );
 }
diff --git a/server/src/main/java/org/opensearch/common/settings/FeatureFlagSettings.java b/server/src/main/java/org/opensearch/common/settings/FeatureFlagSettings.java
index 90abc0a0765c1..387b0c9753574 100644
--- a/server/src/main/java/org/opensearch/common/settings/FeatureFlagSettings.java
+++ b/server/src/main/java/org/opensearch/common/settings/FeatureFlagSettings.java
@@ -39,7 +39,8 @@ protected FeatureFlagSettings(
                 FeatureFlags.EXTENSIONS_SETTING,
                 FeatureFlags.IDENTITY_SETTING,
                 FeatureFlags.CONCURRENT_SEGMENT_SEARCH_SETTING,
-                FeatureFlags.TELEMETRY_SETTING
+                FeatureFlags.TELEMETRY_SETTING,
+                FeatureFlags.DATETIME_FORMATTER_CACHING_SETTING
             )
         )
     );
diff --git a/server/src/main/java/org/opensearch/common/settings/IndexScopedSettings.java b/server/src/main/java/org/opensearch/common/settings/IndexScopedSettings.java
index 5b2afc44600bd..b34a2aaffe408 100644
--- a/server/src/main/java/org/opensearch/common/settings/IndexScopedSettings.java
+++ b/server/src/main/java/org/opensearch/common/settings/IndexScopedSettings.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
 import org.opensearch.cluster.routing.allocation.decider.MaxRetryAllocationDecider;
 import org.opensearch.cluster.routing.allocation.decider.ShardsLimitAllocationDecider;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.util.FeatureFlags;
@@ -45,9 +46,11 @@
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.IndexSortConfig;
 import org.opensearch.index.IndexingSlowLog;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.LogByteSizeMergePolicyProvider;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.index.MergeSchedulerConfig;
 import org.opensearch.index.SearchSlowLog;
+import org.opensearch.index.TieredMergePolicyProvider;
 import org.opensearch.index.cache.bitset.BitsetFilterCache;
 import org.opensearch.index.engine.EngineConfig;
 import org.opensearch.index.fielddata.IndexFieldDataService;
@@ -70,8 +73,9 @@
  * Encapsulates all valid index level settings.
  * @see Property#IndexScope
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class IndexScopedSettings extends AbstractScopedSettings {
 
     public static final Predicate<String> INDEX_SETTINGS_KEY_PREDICATE = (s) -> s.startsWith(IndexMetadata.INDEX_SETTING_PREFIX);
@@ -120,14 +124,14 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
                 IndexingSlowLog.INDEX_INDEXING_SLOWLOG_LEVEL_SETTING,
                 IndexingSlowLog.INDEX_INDEXING_SLOWLOG_REFORMAT_SETTING,
                 IndexingSlowLog.INDEX_INDEXING_SLOWLOG_MAX_SOURCE_CHARS_TO_LOG_SETTING,
-                MergePolicyConfig.INDEX_COMPOUND_FORMAT_SETTING,
-                MergePolicyConfig.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING,
-                MergePolicyConfig.INDEX_MERGE_POLICY_EXPUNGE_DELETES_ALLOWED_SETTING,
-                MergePolicyConfig.INDEX_MERGE_POLICY_FLOOR_SEGMENT_SETTING,
-                MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING,
-                MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGED_SEGMENT_SETTING,
-                MergePolicyConfig.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING,
-                MergePolicyConfig.INDEX_MERGE_POLICY_RECLAIM_DELETES_WEIGHT_SETTING,
+                TieredMergePolicyProvider.INDEX_COMPOUND_FORMAT_SETTING,
+                TieredMergePolicyProvider.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING,
+                TieredMergePolicyProvider.INDEX_MERGE_POLICY_EXPUNGE_DELETES_ALLOWED_SETTING,
+                TieredMergePolicyProvider.INDEX_MERGE_POLICY_FLOOR_SEGMENT_SETTING,
+                TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING,
+                TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGED_SEGMENT_SETTING,
+                TieredMergePolicyProvider.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING,
+                TieredMergePolicyProvider.INDEX_MERGE_POLICY_RECLAIM_DELETES_WEIGHT_SETTING,
                 IndexSortConfig.INDEX_SORT_FIELD_SETTING,
                 IndexSortConfig.INDEX_SORT_ORDER_SETTING,
                 IndexSortConfig.INDEX_SORT_MISSING_SETTING,
@@ -202,6 +206,13 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
                 IndexSettings.INDEX_MERGE_ON_FLUSH_ENABLED,
                 IndexSettings.INDEX_MERGE_ON_FLUSH_MAX_FULL_FLUSH_MERGE_WAIT_TIME,
                 IndexSettings.INDEX_MERGE_ON_FLUSH_POLICY,
+                IndexSettings.INDEX_MERGE_POLICY,
+                LogByteSizeMergePolicyProvider.INDEX_LBS_MERGE_POLICY_MERGE_FACTOR_SETTING,
+                LogByteSizeMergePolicyProvider.INDEX_LBS_MERGE_POLICY_MIN_MERGE_SETTING,
+                LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGE_SEGMENT_SETTING,
+                LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGE_SEGMENT_FOR_FORCED_MERGE_SETTING,
+                LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGED_DOCS_SETTING,
+                LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING,
                 IndexSettings.DEFAULT_SEARCH_PIPELINE,
 
                 // Settings for Searchable Snapshots
@@ -212,6 +223,7 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
 
                 // Settings for remote translog
                 IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING,
+                IndexSettings.INDEX_REMOTE_TRANSLOG_KEEP_EXTRA_GEN_SETTING,
 
                 // Settings for remote store enablement
                 IndexMetadata.INDEX_REMOTE_STORE_ENABLED_SETTING,
@@ -275,7 +287,7 @@ public boolean isPrivateSetting(String key) {
             case IndexMetadata.SETTING_HISTORY_UUID:
             case IndexMetadata.SETTING_VERSION_UPGRADED:
             case IndexMetadata.SETTING_INDEX_PROVIDED_NAME:
-            case MergePolicyConfig.INDEX_MERGE_ENABLED:
+            case MergePolicyProvider.INDEX_MERGE_ENABLED:
                 // we keep the shrink settings for BWC - this can be removed in 8.0
                 // we can't remove in 7 since this setting might be baked into an index coming in via a full cluster restart from 6.0
             case "index.shrink.source.uuid":
diff --git a/server/src/main/java/org/opensearch/common/settings/KeyStoreWrapper.java b/server/src/main/java/org/opensearch/common/settings/KeyStoreWrapper.java
index f25dd872fc703..1ad3b7ab8875a 100644
--- a/server/src/main/java/org/opensearch/common/settings/KeyStoreWrapper.java
+++ b/server/src/main/java/org/opensearch/common/settings/KeyStoreWrapper.java
@@ -88,7 +88,7 @@
 
 /**
  * A disk based container for sensitive settings in OpenSearch.
- *
+ * <p>
  * Loading a keystore has 2 phases. First, call {@link #load(Path)}. Then call
  * {@link #decrypt(char[])} with the keystore password, or an empty char array if
  * {@link #hasPassword()} is {@code false}.  Loading and decrypting should happen
@@ -147,7 +147,7 @@ private static class Entry {
 
     /**
      * The number of bits for the cipher key.
-     *
+     * <p>
      * Note: The Oracle JDK 8 ships with a limited JCE policy that restricts key length for AES to 128 bits.
      * This can be increased to 256 bits once minimum java 9 is the minimum java version.
      * See http://www.oracle.com/technetwork/java/javase/terms/readme/jdk9-readme-3852447.html#jce
@@ -234,7 +234,7 @@ public static KeyStoreWrapper load(Path configDir) throws IOException {
 
     /**
      * Loads information about the OpenSearch keystore from the provided config directory.
-     *
+     * <p>
      * {@link #decrypt(char[])} must be called before reading or writing any entries.
      * Returns {@code null} if no keystore exists.
      */
@@ -358,7 +358,7 @@ private Cipher createCipher(int opmode, char[] password, byte[] salt, byte[] iv)
 
     /**
      * Decrypts the underlying keystore data.
-     *
+     * <p>
      * This may only be called once.
      */
     public void decrypt(char[] password) throws GeneralSecurityException, IOException {
diff --git a/server/src/main/java/org/opensearch/common/settings/SecureSetting.java b/server/src/main/java/org/opensearch/common/settings/SecureSetting.java
index f2ccc01a4c7e6..1855270b016b3 100644
--- a/server/src/main/java/org/opensearch/common/settings/SecureSetting.java
+++ b/server/src/main/java/org/opensearch/common/settings/SecureSetting.java
@@ -45,7 +45,7 @@
 
 /**
  * A secure setting.
- *
+ * <p>
  * This class allows access to settings from the OpenSearch keystore.
  *
  * @opensearch.internal
@@ -152,7 +152,7 @@ public void diff(Settings.Builder builder, Settings source, Settings defaultSett
 
     /**
      * A setting which contains a sensitive string.
-     *
+     * <p>
      * This may be any sensitive string, e.g. a username, a password, an auth token, etc.
      */
     public static Setting<SecureString> secureString(String name, Setting<SecureString> fallback, Property... properties) {
@@ -179,7 +179,7 @@ public static Setting<SecureString> insecureString(String name, String secureNam
 
     /**
      * A setting which contains a file. Reading the setting opens an input stream to the file.
-     *
+     * <p>
      * This may be any sensitive file, e.g. a set of credentials normally in plaintext.
      */
     public static Setting<InputStream> secureFile(String name, Setting<InputStream> fallback, Property... properties) {
diff --git a/server/src/main/java/org/opensearch/common/settings/Settings.java b/server/src/main/java/org/opensearch/common/settings/Settings.java
index 91e39e38f0379..9da47ff3aa700 100644
--- a/server/src/main/java/org/opensearch/common/settings/Settings.java
+++ b/server/src/main/java/org/opensearch/common/settings/Settings.java
@@ -80,6 +80,7 @@
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.concurrent.TimeUnit;
@@ -101,7 +102,7 @@
 @PublicApi(since = "1.0.0")
 public final class Settings implements ToXContentFragment {
 
-    public static final Settings EMPTY = new Builder().build();
+    public static final Settings EMPTY = new Settings(Collections.emptyMap(), null);
 
     /** The raw settings from the full key to raw string value. */
     private final Map<String, Object> settings;
@@ -757,7 +758,7 @@ public Set<String> keySet() {
     @PublicApi(since = "1.0.0")
     public static class Builder {
 
-        public static final Settings EMPTY_SETTINGS = new Builder().build();
+        public static final Settings EMPTY_SETTINGS = Settings.EMPTY;
 
         // we use a sorted map for consistent serialization when using getAsMap()
         private final Map<String, Object> map = new TreeMap<>();
@@ -1211,8 +1212,14 @@ public boolean shouldRemoveMissingPlaceholder(String placeholderName) {
                 String value = propertyPlaceholder.replacePlaceholders(Settings.toString(entry.getValue()), placeholderResolver);
                 // if the values exists and has length, we should maintain it in the map
                 // otherwise, the replace process resolved into removing it
-                if (Strings.hasLength(value)) {
-                    entry.setValue(value);
+                if (Strings.hasLength(value) == true) {
+                    // try to parse the value as a list first
+                    final Optional<List<String>> optList = tryParseableStringToList(value);
+                    if (optList.isPresent()) {
+                        entry.setValue(optList.get());
+                    } else {
+                        entry.setValue(value);
+                    }
                 } else {
                     entryItr.remove();
                 }
@@ -1222,7 +1229,7 @@ public boolean shouldRemoveMissingPlaceholder(String placeholderName) {
 
         /**
          * Checks that all settings(except archived settings and wildcards) in the builder start with the specified prefix.
-         *
+         * <p>
          * If a setting doesn't start with the prefix, the builder appends the prefix to such setting.
          */
         public Builder normalizePrefix(String prefix) {
@@ -1248,6 +1255,34 @@ public Settings build() {
             processLegacyLists(map);
             return new Settings(map, secureSettings.get());
         }
+
+        /**
+         * Tries to parse the placeholder value as a list (fe [], ["a", "b", "c"])
+         * @param parsableString placeholder value to parse
+         * @return the {@link Optional} result of the parsing attempt
+         */
+        private static Optional<List<String>> tryParseableStringToList(String parsableString) {
+            // fromXContent doesn't use named xcontent or deprecation.
+            try (
+                XContentParser xContentParser = MediaTypeRegistry.JSON.xContent()
+                    .createParser(NamedXContentRegistry.EMPTY, DeprecationHandler.THROW_UNSUPPORTED_OPERATION, parsableString)
+            ) {
+                XContentParser.Token token = xContentParser.nextToken();
+                if (token != XContentParser.Token.START_ARRAY) {
+                    return Optional.empty();
+                }
+                ArrayList<String> list = new ArrayList<>();
+                while ((token = xContentParser.nextToken()) != XContentParser.Token.END_ARRAY) {
+                    if (token != XContentParser.Token.VALUE_STRING) {
+                        return Optional.empty();
+                    }
+                    list.add(xContentParser.text());
+                }
+                return Optional.of(list);
+            } catch (IOException e) {
+                return Optional.empty();
+            }
+        }
     }
 
     // TODO We could use an FST internally to make things even faster and more compact
diff --git a/server/src/main/java/org/opensearch/common/time/DateFormatter.java b/server/src/main/java/org/opensearch/common/time/DateFormatter.java
index d57fd441b9bf4..0712b7b050bec 100644
--- a/server/src/main/java/org/opensearch/common/time/DateFormatter.java
+++ b/server/src/main/java/org/opensearch/common/time/DateFormatter.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common.time;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.joda.time.DateTime;
 
@@ -49,8 +50,9 @@
 /**
  * Base Date formatter
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface DateFormatter {
 
     /**
@@ -126,6 +128,14 @@ default String formatJoda(DateTime dateTime) {
      */
     String pattern();
 
+    /**
+     * A name based format for this formatter. Can be one of the registered formatters like <code>epoch_millis</code> or
+     * a configured format like <code>HH:mm:ss</code>
+     *
+     * @return The name of this formatter
+     */
+    String printPattern();
+
     /**
      * Returns the configured locale of the date formatter
      *
@@ -147,7 +157,7 @@ default String formatJoda(DateTime dateTime) {
      */
     DateMathParser toDateMathParser();
 
-    static DateFormatter forPattern(String input) {
+    static DateFormatter forPattern(String input, String printPattern, Boolean canCacheFormatter) {
 
         if (Strings.hasLength(input) == false) {
             throw new IllegalArgumentException("No date pattern provided");
@@ -158,7 +168,28 @@ static DateFormatter forPattern(String input) {
         List<String> patterns = splitCombinedPatterns(format);
         List<DateFormatter> formatters = patterns.stream().map(DateFormatters::forPattern).collect(Collectors.toList());
 
-        return JavaDateFormatter.combined(input, formatters);
+        DateFormatter printFormatter = formatters.get(0);
+        if (Strings.hasLength(printPattern)) {
+            String printFormat = strip8Prefix(printPattern);
+            try {
+                printFormatter = DateFormatters.forPattern(printFormat);
+            } catch (IllegalArgumentException e) {
+                throw new IllegalArgumentException("Invalid print format: " + e.getMessage(), e);
+            }
+        }
+        return JavaDateFormatter.combined(input, formatters, printFormatter, canCacheFormatter);
+    }
+
+    static DateFormatter forPattern(String input) {
+        return forPattern(input, null, false);
+    }
+
+    static DateFormatter forPattern(String input, String printPattern) {
+        return forPattern(input, printPattern, false);
+    }
+
+    static DateFormatter forPattern(String input, Boolean canCacheFormatter) {
+        return forPattern(input, null, canCacheFormatter);
     }
 
     static String strip8Prefix(String input) {
diff --git a/server/src/main/java/org/opensearch/common/time/DateFormatters.java b/server/src/main/java/org/opensearch/common/time/DateFormatters.java
index 6c8b9282d8a77..e74ab687b903b 100644
--- a/server/src/main/java/org/opensearch/common/time/DateFormatters.java
+++ b/server/src/main/java/org/opensearch/common/time/DateFormatters.java
@@ -2172,10 +2172,10 @@ static DateFormatter forPattern(String input) {
      * or Instant.from(accessor). This results in a huge performance penalty and should be prevented
      * This method prevents exceptions by querying the accessor for certain capabilities
      * and then act on it accordingly
-     *
+     * <p>
      * This action assumes that we can reliably fall back to some defaults if not all parts of a
      * zoned date time are set
-     *
+     * <p>
      * - If a zoned date time is passed, it is returned
      * - If no timezone is found, ZoneOffset.UTC is used
      * - If we find a time and a date, converting to a ZonedDateTime is straight forward,
diff --git a/server/src/main/java/org/opensearch/common/time/DateMathParser.java b/server/src/main/java/org/opensearch/common/time/DateMathParser.java
index f6573eaa90286..8c123d7d2ebc9 100644
--- a/server/src/main/java/org/opensearch/common/time/DateMathParser.java
+++ b/server/src/main/java/org/opensearch/common/time/DateMathParser.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common.time;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.joda.time.DateTimeZone;
 
 import java.time.Instant;
@@ -41,8 +42,9 @@
 /**
  * An abstraction over date math parsing to allow different implementation for joda and java time.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface DateMathParser {
 
     /**
@@ -64,12 +66,12 @@ default Instant parse(String text, LongSupplier now, boolean roundUpProperty, Da
 
     /**
      * Parse text, that potentially contains date math into the milliseconds since the epoch
-     *
+     * <p>
      * Examples are
-     *
+     * <p>
      * <code>2014-11-18||-2y</code> subtracts two years from the input date
      * <code>now/m</code>           rounds the current time to minute granularity
-     *
+     * <p>
      * Supported rounding units are
      * y    year
      * M    month
diff --git a/server/src/main/java/org/opensearch/common/time/DateUtils.java b/server/src/main/java/org/opensearch/common/time/DateUtils.java
index 021b8a3be8b23..7ab395a1117e7 100644
--- a/server/src/main/java/org/opensearch/common/time/DateUtils.java
+++ b/server/src/main/java/org/opensearch/common/time/DateUtils.java
@@ -342,7 +342,7 @@ public static long toMilliSeconds(long nanoSecondsSinceEpoch) {
 
     /**
      * Rounds the given utc milliseconds sicne the epoch down to the next unit millis
-     *
+     * <p>
      * Note: This does not check for correctness of the result, as this only works with units smaller or equal than a day
      *       In order to ensure the performance of this methods, there are no guards or checks in it
      *
diff --git a/server/src/main/java/org/opensearch/common/time/DateUtilsRounding.java b/server/src/main/java/org/opensearch/common/time/DateUtilsRounding.java
index f3459a5857b9e..7fc39e063efb5 100644
--- a/server/src/main/java/org/opensearch/common/time/DateUtilsRounding.java
+++ b/server/src/main/java/org/opensearch/common/time/DateUtilsRounding.java
@@ -32,12 +32,12 @@
  * This class has been copied from different locations within the joda time package, as
  * these methods fast when used for rounding, as they do not require conversion to java
  * time objects
- *
+ * <p>
  * This code has been copied from jodatime 2.10.1
  * The source can be found at https://github.com/JodaOrg/joda-time/tree/v2.10.1
- *
+ * <p>
  * See following methods have been copied (along with required helper variables)
- *
+ * <p>
  * - org.joda.time.chrono.GregorianChronology.calculateFirstDayOfYearMillis(int year)
  * - org.joda.time.chrono.BasicChronology.getYear(int year)
  * - org.joda.time.chrono.BasicGJChronology.getMonthOfYear(long utcMillis, int year)
diff --git a/server/src/main/java/org/opensearch/common/time/JavaDateFormatter.java b/server/src/main/java/org/opensearch/common/time/JavaDateFormatter.java
index 07013a3dc75f2..f711b14aeb928 100644
--- a/server/src/main/java/org/opensearch/common/time/JavaDateFormatter.java
+++ b/server/src/main/java/org/opensearch/common/time/JavaDateFormatter.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.common.time;
 
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.Strings;
 
 import java.text.ParsePosition;
@@ -51,6 +52,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.function.BiConsumer;
 import java.util.stream.Collectors;
 
@@ -67,9 +69,12 @@ class JavaDateFormatter implements DateFormatter {
     }
 
     private final String format;
+    private final String printFormat;
     private final DateTimeFormatter printer;
     private final List<DateTimeFormatter> parsers;
     private final JavaDateFormatter roundupParser;
+    private final Boolean canCacheLastParsedFormatter;
+    private volatile DateTimeFormatter lastParsedformatter = null;
 
     /**
      * A round up formatter
@@ -93,8 +98,18 @@ JavaDateFormatter getRoundupParser() {
     }
 
     // named formatters use default roundUpParser
+    JavaDateFormatter(
+        String format,
+        String printFormat,
+        DateTimeFormatter printer,
+        Boolean canCacheLastParsedFormatter,
+        DateTimeFormatter... parsers
+    ) {
+        this(format, printFormat, printer, ROUND_UP_BASE_FIELDS, canCacheLastParsedFormatter, parsers);
+    }
+
     JavaDateFormatter(String format, DateTimeFormatter printer, DateTimeFormatter... parsers) {
-        this(format, printer, ROUND_UP_BASE_FIELDS, parsers);
+        this(format, format, printer, false, parsers);
     }
 
     private static final BiConsumer<DateTimeFormatterBuilder, DateTimeFormatter> ROUND_UP_BASE_FIELDS = (builder, parser) -> {
@@ -111,8 +126,10 @@ JavaDateFormatter getRoundupParser() {
     // subclasses override roundUpParser
     JavaDateFormatter(
         String format,
+        String printFormat,
         DateTimeFormatter printer,
         BiConsumer<DateTimeFormatterBuilder, DateTimeFormatter> roundupParserConsumer,
+        Boolean canCacheLastParsedFormatter,
         DateTimeFormatter... parsers
     ) {
         if (printer == null) {
@@ -128,6 +145,8 @@ JavaDateFormatter getRoundupParser() {
         }
         this.printer = printer;
         this.format = format;
+        this.printFormat = printFormat;
+        this.canCacheLastParsedFormatter = canCacheLastParsedFormatter;
 
         if (parsers.length == 0) {
             this.parsers = Collections.singletonList(printer);
@@ -138,6 +157,15 @@ JavaDateFormatter getRoundupParser() {
         this.roundupParser = new RoundUpFormatter(format, roundUp);
     }
 
+    JavaDateFormatter(
+        String format,
+        DateTimeFormatter printer,
+        BiConsumer<DateTimeFormatterBuilder, DateTimeFormatter> roundupParserConsumer,
+        DateTimeFormatter... parsers
+    ) {
+        this(format, format, printer, roundupParserConsumer, false, parsers);
+    }
+
     /**
      * This is when the RoundUp Formatters are created. In further merges (with ||) it will only append them to a list.
      * || is not expected to be provided as format when a RoundUp formatter is created. It will be splitted before in
@@ -164,36 +192,61 @@ private List<DateTimeFormatter> createRoundUpParser(
         return null;
     }
 
-    public static DateFormatter combined(String input, List<DateFormatter> formatters) {
+    public static DateFormatter combined(
+        String input,
+        List<DateFormatter> formatters,
+        DateFormatter printFormatter,
+        Boolean canCacheLastParsedFormatter
+    ) {
         assert formatters.size() > 0;
+        assert printFormatter != null;
 
         List<DateTimeFormatter> parsers = new ArrayList<>(formatters.size());
         List<DateTimeFormatter> roundUpParsers = new ArrayList<>(formatters.size());
 
-        DateTimeFormatter printer = null;
+        assert printFormatter instanceof JavaDateFormatter;
+        JavaDateFormatter javaPrintFormatter = (JavaDateFormatter) printFormatter;
+        DateTimeFormatter printer = javaPrintFormatter.getPrinter();
         for (DateFormatter formatter : formatters) {
             assert formatter instanceof JavaDateFormatter;
             JavaDateFormatter javaDateFormatter = (JavaDateFormatter) formatter;
-            if (printer == null) {
-                printer = javaDateFormatter.getPrinter();
-            }
             parsers.addAll(javaDateFormatter.getParsers());
             roundUpParsers.addAll(javaDateFormatter.getRoundupParser().getParsers());
         }
 
-        return new JavaDateFormatter(input, printer, roundUpParsers, parsers);
+        return new JavaDateFormatter(
+            input,
+            javaPrintFormatter.format,
+            printer,
+            roundUpParsers,
+            parsers,
+            canCacheLastParsedFormatter & FeatureFlags.isEnabled(FeatureFlags.DATETIME_FORMATTER_CACHING_SETTING)
+        ); // check if caching is enabled
     }
 
     private JavaDateFormatter(
         String format,
+        String printFormat,
         DateTimeFormatter printer,
         List<DateTimeFormatter> roundUpParsers,
-        List<DateTimeFormatter> parsers
+        List<DateTimeFormatter> parsers,
+        Boolean canCacheLastParsedFormatter
     ) {
         this.format = format;
+        this.printFormat = printFormat;
         this.printer = printer;
         this.roundupParser = roundUpParsers != null ? new RoundUpFormatter(format, roundUpParsers) : null;
         this.parsers = parsers;
+        this.canCacheLastParsedFormatter = canCacheLastParsedFormatter;
+    }
+
+    private JavaDateFormatter(
+        String format,
+        DateTimeFormatter printer,
+        List<DateTimeFormatter> roundUpParsers,
+        List<DateTimeFormatter> parsers
+    ) {
+        this(format, format, printer, roundUpParsers, parsers, false);
     }
 
     JavaDateFormatter getRoundupParser() {
@@ -222,7 +275,7 @@ public TemporalAccessor parse(String input) {
      * it will continue iterating if the previous parser failed. The pattern must fully match, meaning whole input was used.
      * This also means that this method depends on <code>DateTimeFormatter.ClassicFormat.parseObject</code>
      * which does not throw exceptions when parsing failed.
-     *
+     * <p>
      * The approach with collection of parsers was taken because java-time requires ordering on optional (composite)
      * patterns. Joda does not suffer from this.
      * https://bugs.openjdk.java.net/browse/JDK-8188771
@@ -233,13 +286,23 @@ public TemporalAccessor parse(String input) {
      */
     private TemporalAccessor doParse(String input) {
         if (parsers.size() > 1) {
+            Object object = null;
+            if (canCacheLastParsedFormatter && lastParsedformatter != null) {
+                ParsePosition pos = new ParsePosition(0);
+                object = lastParsedformatter.toFormat().parseObject(input, pos);
+                if (parsingSucceeded(object, input, pos)) {
+                    return (TemporalAccessor) object;
+                }
+            }
             for (DateTimeFormatter formatter : parsers) {
                 ParsePosition pos = new ParsePosition(0);
-                Object object = formatter.toFormat().parseObject(input, pos);
+                object = formatter.toFormat().parseObject(input, pos);
                 if (parsingSucceeded(object, input, pos)) {
+                    lastParsedformatter = formatter;
                     return (TemporalAccessor) object;
                 }
             }
+
             throw new DateTimeParseException("Failed to parse with all enclosed parsers", input, 0);
         }
         return this.parsers.get(0).parse(input);
@@ -255,12 +318,14 @@ public DateFormatter withZone(ZoneId zoneId) {
         if (zoneId.equals(zone())) {
             return this;
         }
-        List<DateTimeFormatter> parsers = this.parsers.stream().map(p -> p.withZone(zoneId)).collect(Collectors.toList());
+        List<DateTimeFormatter> parsers = new CopyOnWriteArrayList<>(
+            this.parsers.stream().map(p -> p.withZone(zoneId)).collect(Collectors.toList())
+        );
         List<DateTimeFormatter> roundUpParsers = this.roundupParser.getParsers()
             .stream()
             .map(p -> p.withZone(zoneId))
             .collect(Collectors.toList());
-        return new JavaDateFormatter(format, printer.withZone(zoneId), roundUpParsers, parsers);
+        return new JavaDateFormatter(format, printFormat, printer.withZone(zoneId), roundUpParsers, parsers, canCacheLastParsedFormatter);
     }
 
     @Override
@@ -269,12 +334,14 @@ public DateFormatter withLocale(Locale locale) {
         if (locale.equals(locale())) {
             return this;
         }
-        List<DateTimeFormatter> parsers = this.parsers.stream().map(p -> p.withLocale(locale)).collect(Collectors.toList());
+        List<DateTimeFormatter> parsers = new CopyOnWriteArrayList<>(
+            this.parsers.stream().map(p -> p.withLocale(locale)).collect(Collectors.toList())
+        );
         List<DateTimeFormatter> roundUpParsers = this.roundupParser.getParsers()
             .stream()
             .map(p -> p.withLocale(locale))
             .collect(Collectors.toList());
-        return new JavaDateFormatter(format, printer.withLocale(locale), roundUpParsers, parsers);
+        return new JavaDateFormatter(format, printFormat, printer.withLocale(locale), roundUpParsers, parsers, canCacheLastParsedFormatter);
     }
 
     @Override
@@ -287,6 +354,11 @@ public String pattern() {
         return format;
     }
 
+    @Override
+    public String printPattern() {
+        return printFormat;
+    }
+
     @Override
     public Locale locale() {
         return this.printer.getLocale();
diff --git a/server/src/main/java/org/opensearch/common/time/JavaDateMathParser.java b/server/src/main/java/org/opensearch/common/time/JavaDateMathParser.java
index 0536324b6516b..340901e7ac8e2 100644
--- a/server/src/main/java/org/opensearch/common/time/JavaDateMathParser.java
+++ b/server/src/main/java/org/opensearch/common/time/JavaDateMathParser.java
@@ -51,7 +51,7 @@
 
 /**
  * A parser for date/time formatted text with optional date math.
- *
+ * <p>
  * The format of the datetime is configurable, and unix timestamps can also be used. Datemath
  * is appended to a datetime with the following syntax:
  * <code>||[+-/](\d+)?[yMwdhHms]</code>.
diff --git a/server/src/main/java/org/opensearch/common/unit/Fuzziness.java b/server/src/main/java/org/opensearch/common/unit/Fuzziness.java
index 2ce86cbfd13f3..d16ec9723fb2b 100644
--- a/server/src/main/java/org/opensearch/common/unit/Fuzziness.java
+++ b/server/src/main/java/org/opensearch/common/unit/Fuzziness.java
@@ -32,6 +32,7 @@
 package org.opensearch.common.unit;
 
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -49,8 +50,9 @@
  * parsing and conversion from similarities to edit distances
  * etc.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class Fuzziness implements ToXContentFragment, Writeable {
 
     public static final String X_FIELD_NAME = "fuzziness";
diff --git a/server/src/main/java/org/opensearch/common/unit/SizeValue.java b/server/src/main/java/org/opensearch/common/unit/SizeValue.java
index 766199ebbc8f8..14f2bedde53f8 100644
--- a/server/src/main/java/org/opensearch/common/unit/SizeValue.java
+++ b/server/src/main/java/org/opensearch/common/unit/SizeValue.java
@@ -33,6 +33,7 @@
 package org.opensearch.common.unit;
 
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -43,8 +44,9 @@
 /**
  * Conversion values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SizeValue implements Writeable, Comparable<SizeValue> {
 
     private final long size;
diff --git a/server/src/main/java/org/opensearch/common/util/BigArrays.java b/server/src/main/java/org/opensearch/common/util/BigArrays.java
index 59c84ea45a65a..92371c2c77ef9 100644
--- a/server/src/main/java/org/opensearch/common/util/BigArrays.java
+++ b/server/src/main/java/org/opensearch/common/util/BigArrays.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lease.Releasables;
 import org.opensearch.common.recycler.Recycler;
@@ -47,7 +48,12 @@
 
 import java.util.Arrays;
 
-/** Utility class to work with arrays. */
+/**
+ * Utility class to work with arrays.
+ *
+ * @opensearch.api
+ * */
+@PublicApi(since = "1.0.0")
 public class BigArrays {
 
     public static final BigArrays NON_RECYCLING_INSTANCE = new BigArrays(null, null, CircuitBreaker.REQUEST);
diff --git a/server/src/main/java/org/opensearch/common/util/BinarySearcher.java b/server/src/main/java/org/opensearch/common/util/BinarySearcher.java
index ca63c170c0ccd..e4315f8699206 100644
--- a/server/src/main/java/org/opensearch/common/util/BinarySearcher.java
+++ b/server/src/main/java/org/opensearch/common/util/BinarySearcher.java
@@ -34,14 +34,14 @@
 
 /**
  * Performs binary search on an arbitrary data structure.
- *
+ * <p>
  * To do a search, create a subclass and implement custom {@link #compare(int)} and {@link #distance(int)} methods.
- *
+ * <p>
  * {@link BinarySearcher} knows nothing about the value being searched for or the underlying data structure.
  * These things should be determined by the subclass in its overridden methods.
- *
+ * <p>
  * Refer to {@link BigArrays.DoubleBinarySearcher} for an example.
- *
+ * <p>
  * NOTE: this class is not thread safe
  *
  * @opensearch.internal
@@ -74,7 +74,7 @@ private int getClosestIndex(int index1, int index2) {
     /**
      * Uses a binary search to determine the index of the element within the index range {from, ... , to} that is
      * closest to the search value.
-     *
+     * <p>
      * Unlike most binary search implementations, the value being searched for is not an argument to search method.
      * Rather, this value should be stored by the subclass along with the underlying array.
      *
diff --git a/server/src/main/java/org/opensearch/common/util/CancellableThreads.java b/server/src/main/java/org/opensearch/common/util/CancellableThreads.java
index 8bc3ca3affb12..ea206ddf980cb 100644
--- a/server/src/main/java/org/opensearch/common/util/CancellableThreads.java
+++ b/server/src/main/java/org/opensearch/common/util/CancellableThreads.java
@@ -35,6 +35,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -45,16 +46,17 @@
  * A utility class for multi threaded operation that needs to be cancellable via interrupts. Every cancellable operation should be
  * executed via {@link #execute(Interruptible)}, which will capture the executing thread and make sure it is interrupted in the case
  * of cancellation.
- *
+ * <p>
  * Cancellation policy: This class does not support external interruption via <code>Thread#interrupt()</code>. Always use #cancel() instead.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CancellableThreads {
     private final Set<Thread> threads = new HashSet<>();
     // needs to be volatile as it is also read outside of synchronized blocks.
-    private volatile boolean cancelled = false;
     private final SetOnce<OnCancel> onCancel = new SetOnce<>();
+    private volatile boolean cancelled = false;
     private String reason;
 
     public synchronized boolean isCancelled() {
@@ -183,8 +185,9 @@ public synchronized void cancel(String reason) {
     /**
      * Interruptible interface
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Interruptible extends IOInterruptible {
         void run() throws InterruptedException;
     }
@@ -192,8 +195,9 @@ public interface Interruptible extends IOInterruptible {
     /**
      * IO Interruptible
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface IOInterruptible {
         void run() throws IOException, InterruptedException;
     }
@@ -224,9 +228,10 @@ public synchronized void setOnCancel(OnCancel onCancel) {
     /**
      * Called when a thread is cancelled
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     public interface OnCancel {
         /**
          * Called when some running operations are cancelled or {@link #checkForCancel()} is explicitly called.
diff --git a/server/src/main/java/org/opensearch/common/util/Countable.java b/server/src/main/java/org/opensearch/common/util/Countable.java
index 1adf6d2fb015c..925d1b6066a99 100644
--- a/server/src/main/java/org/opensearch/common/util/Countable.java
+++ b/server/src/main/java/org/opensearch/common/util/Countable.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.common.util;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Base countable interface.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface Countable {
     int size();
 }
diff --git a/server/src/main/java/org/opensearch/common/util/CuckooFilter.java b/server/src/main/java/org/opensearch/common/util/CuckooFilter.java
index 0c792b37ccfa9..28b55f70855d6 100644
--- a/server/src/main/java/org/opensearch/common/util/CuckooFilter.java
+++ b/server/src/main/java/org/opensearch/common/util/CuckooFilter.java
@@ -46,33 +46,33 @@
 
 /**
  * An approximate set membership datastructure
- *
+ * <p>
  * CuckooFilters are similar to Bloom Filters in usage; values are inserted, and the Cuckoo
  * can be asked if it has seen a particular value before.  Because the structure is approximate,
  * it can return false positives (says it has seen an item when it has not).  False negatives
  * are not possible though; if the structure says it _has not_ seen an item, that can be
  * trusted.
- *
+ * <p>
  * The filter can "saturate" at which point the map has hit it's configured load factor (or near enough
  * that a large number of evictions are not able to find a free slot) and will refuse to accept
  * any new insertions.
- *
+ * <p>
  * NOTE: this version does not support deletions, and as such does not save duplicate
  * fingerprints (e.g. when inserting, if the fingerprint is already present in the
  * candidate buckets, it is not inserted).  By not saving duplicates, the CuckooFilter
  * loses the ability to delete values.  But not by allowing deletions, we can save space
  * (do not need to waste slots on duplicate fingerprints), and we do not need to worry
  * about inserts "overflowing" a bucket because the same item has been repeated repeatedly
- *
+ * <p>
  * NOTE: this CuckooFilter exposes a number of Expert APIs which assume the caller has
  * intimate knowledge about how the algorithm works.  It is recommended to use
  * {@link SetBackedScalingCuckooFilter} instead.
- *
+ * <p>
  * Based on the paper:
- *
+ * <p>
  * Fan, Bin, et al. "Cuckoo filter: Practically better than bloom."
  * Proceedings of the 10th ACM International on Conference on emerging Networking Experiments and Technologies. ACM, 2014.
- *
+ * <p>
  * https://www.cs.cmu.edu/~dga/papers/cuckoo-conext2014.pdf
  *
  * @opensearch.internal
@@ -200,7 +200,7 @@ public int getCount() {
     /**
      * Returns the number of buckets that has been chosen based
      * on the initial configuration
-     *
+     * <p>
      * Expert-level API
      */
     int getNumBuckets() {
@@ -209,7 +209,7 @@ int getNumBuckets() {
 
     /**
      * Returns the number of bits used per entry
-     *
+     * <p>
      * Expert-level API
      */
     int getBitsPerEntry() {
@@ -220,7 +220,7 @@ int getBitsPerEntry() {
      * Returns the cached fingerprint mask.  This is simply a mask for the
      * first bitsPerEntry bits, used by {@link CuckooFilter#fingerprint(int, int, int)}
      * to generate the fingerprint of a hash
-     *
+     * <p>
      * Expert-level API
      */
     int getFingerprintMask() {
@@ -230,7 +230,7 @@ int getFingerprintMask() {
     /**
      * Returns an iterator that returns the long[] representation of each bucket.  The value
      * inside each long will be a fingerprint (or 0L, representing empty).
-     *
+     * <p>
      * Expert-level API
      */
     Iterator<long[]> getBuckets() {
@@ -267,7 +267,7 @@ boolean mightContain(long hash) {
 
     /**
      * Returns true if the bucket or it's alternate bucket contains the fingerprint.
-     *
+     * <p>
      * Expert-level API, use {@link CuckooFilter#mightContain(long)} to check if
      * a value is in the filter.
      */
@@ -307,7 +307,7 @@ boolean add(long hash) {
     /**
      * Attempts to merge the fingerprint into the specified bucket or it's alternate bucket.
      * Returns true if the insertion was successful, false if the filter is saturated.
-     *
+     * <p>
      * Expert-level API, use {@link CuckooFilter#add(long)} to insert
      * values into the filter
      */
@@ -351,7 +351,7 @@ boolean mergeFingerprint(int bucket, int fingerprint) {
      * Low-level insert method. Attempts to write the fingerprint into an empty entry
      * at this bucket's position.  Returns true if that was sucessful, false if all entries
      * were occupied.
-     *
+     * <p>
      * If the fingerprint already exists in one of the entries, it will not duplicate the
      * fingerprint like the original paper.  This means the filter _cannot_ support deletes,
      * but is not sensitive to "overflowing" buckets with repeated inserts
@@ -376,10 +376,10 @@ private boolean tryInsert(int bucket, int fingerprint) {
 
     /**
      * Converts a hash into a bucket index (primary or alternate).
-     *
+     * <p>
      * If the hash is negative, this flips the bits.  The hash is then modulo numBuckets
      * to get the final index.
-     *
+     * <p>
      * Expert-level API
      */
     static int hashToIndex(int hash, int numBuckets) {
@@ -388,16 +388,16 @@ static int hashToIndex(int hash, int numBuckets) {
 
     /**
      * Calculates the alternate bucket for a given bucket:fingerprint tuple
-     *
+     * <p>
      * The alternate bucket is the fingerprint multiplied by a mixing constant,
      * then xor'd against the bucket.  This new value is modulo'd against
      * the buckets via {@link CuckooFilter#hashToIndex(int, int)} to get the final
      * index.
-     *
+     * <p>
      * Note that the xor makes this operation reversible as long as we have the
      * fingerprint and current bucket (regardless of if that bucket was the primary
      * or alternate).
-     *
+     * <p>
      * Expert-level API
      */
     static int alternateIndex(int bucket, int fingerprint, int numBuckets) {
@@ -424,10 +424,10 @@ private int getOffset(int bucket, int position) {
 
     /**
      * Calculates the fingerprint for a given hash.
-     *
+     * <p>
      * The fingerprint is simply the first `bitsPerEntry` number of bits that are non-zero.
      * If the entire hash is zero, `(int) 1` is used
-     *
+     * <p>
      * Expert-level API
      */
     static int fingerprint(int hash, int bitsPerEntry, int fingerprintMask) {
@@ -501,7 +501,7 @@ private double getLoadFactor(int b) {
      * Calculates the optimal number of buckets for this filter.  The xor used in the bucketing
      * algorithm requires this to be a power of two, so the optimal number of buckets will
      * be rounded to the next largest power of two where applicable.
-     *
+     * <p>
      * TODO: there are schemes to avoid powers of two, might want to investigate those
      */
     private int getNumBuckets(long capacity, double loadFactor, int b) {
diff --git a/server/src/main/java/org/opensearch/common/util/DoubleArray.java b/server/src/main/java/org/opensearch/common/util/DoubleArray.java
index ae66902f6f795..aa9238634f2c7 100644
--- a/server/src/main/java/org/opensearch/common/util/DoubleArray.java
+++ b/server/src/main/java/org/opensearch/common/util/DoubleArray.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.common.util;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.util.BigArray;
 
 /**
  * Abstraction of an array of double values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface DoubleArray extends BigArray {
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/util/FeatureFlags.java b/server/src/main/java/org/opensearch/common/util/FeatureFlags.java
index b89d2d0549823..4e9b417e3433b 100644
--- a/server/src/main/java/org/opensearch/common/util/FeatureFlags.java
+++ b/server/src/main/java/org/opensearch/common/util/FeatureFlags.java
@@ -55,6 +55,11 @@ public class FeatureFlags {
      */
     public static final String TELEMETRY = "opensearch.experimental.feature.telemetry.enabled";
 
+    /**
+     * Gates the optimization of datetime formatters caching along with change in default datetime formatter.
+     */
+    public static final String DATETIME_FORMATTER_CACHING = "opensearch.experimental.optimization.datetime_formatter_caching.enabled";
+
     /**
      * Should store the settings from opensearch.yml.
      */
@@ -83,6 +88,17 @@ public static boolean isEnabled(String featureFlagName) {
         return settings != null && settings.getAsBoolean(featureFlagName, false);
     }
 
+    public static boolean isEnabled(Setting<Boolean> featureFlag) {
+        if ("true".equalsIgnoreCase(System.getProperty(featureFlag.getKey()))) {
+            // TODO: Remove the if condition once FeatureFlags are only supported via opensearch.yml
+            return true;
+        } else if (settings != null) {
+            return featureFlag.get(settings);
+        } else {
+            return featureFlag.getDefault(Settings.EMPTY);
+        }
+    }
+
     public static final Setting<Boolean> SEGMENT_REPLICATION_EXPERIMENTAL_SETTING = Setting.boolSetting(
         SEGMENT_REPLICATION_EXPERIMENTAL,
         false,
@@ -100,4 +116,10 @@ public static boolean isEnabled(String featureFlagName) {
         false,
         Property.NodeScope
     );
+
+    public static final Setting<Boolean> DATETIME_FORMATTER_CACHING_SETTING = Setting.boolSetting(
+        DATETIME_FORMATTER_CACHING,
+        true,
+        Property.NodeScope
+    );
 }
diff --git a/server/src/main/java/org/opensearch/common/util/FloatArray.java b/server/src/main/java/org/opensearch/common/util/FloatArray.java
index 81f6bebb7508c..bda7324d19273 100644
--- a/server/src/main/java/org/opensearch/common/util/FloatArray.java
+++ b/server/src/main/java/org/opensearch/common/util/FloatArray.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.common.util;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.util.BigArray;
 
 /**
  * Abstraction of an array of double values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface FloatArray extends BigArray {
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/util/IntArray.java b/server/src/main/java/org/opensearch/common/util/IntArray.java
index eb43e013f3758..ad0173904f74a 100644
--- a/server/src/main/java/org/opensearch/common/util/IntArray.java
+++ b/server/src/main/java/org/opensearch/common/util/IntArray.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.common.util;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.util.BigArray;
 
 /**
  * Abstraction of an array of integer values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IntArray extends BigArray {
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/util/LongArray.java b/server/src/main/java/org/opensearch/common/util/LongArray.java
index 0c32effd04cdc..c2f649e49f470 100644
--- a/server/src/main/java/org/opensearch/common/util/LongArray.java
+++ b/server/src/main/java/org/opensearch/common/util/LongArray.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.common.util;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.util.BigArray;
 
 /**
  * Abstraction of an array of long values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface LongArray extends BigArray {
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/util/ObjectArray.java b/server/src/main/java/org/opensearch/common/util/ObjectArray.java
index 9c882742b56ab..f3f73b7e37485 100644
--- a/server/src/main/java/org/opensearch/common/util/ObjectArray.java
+++ b/server/src/main/java/org/opensearch/common/util/ObjectArray.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.common.util;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.util.BigArray;
 
 /**
  * Abstraction of an array of object values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ObjectArray<T> extends BigArray {
 
     /**
diff --git a/server/src/main/java/org/opensearch/common/util/SetBackedScalingCuckooFilter.java b/server/src/main/java/org/opensearch/common/util/SetBackedScalingCuckooFilter.java
index e99eb751babe8..a635160844159 100644
--- a/server/src/main/java/org/opensearch/common/util/SetBackedScalingCuckooFilter.java
+++ b/server/src/main/java/org/opensearch/common/util/SetBackedScalingCuckooFilter.java
@@ -75,7 +75,7 @@ public class SetBackedScalingCuckooFilter implements Writeable {
      * This set is used to track the insertions before we convert over to an approximate
      * filter. This gives us 100% accuracy for small cardinalities.  This will be null
      * if isSetMode = false;
-     *
+     * <p>
      * package-private for testing
      */
     Set<Long> hashes;
@@ -178,7 +178,7 @@ public void writeTo(StreamOutput out) throws IOException {
 
     /**
      * Registers a circuit breaker with the datastructure.
-     *
+     * <p>
      * CuckooFilter's can "saturate" and refuse to accept any new values.  When this happens,
      * the datastructure scales by adding a new filter.  This new filter's bytes will be tracked
      * in the registered breaker when configured.
diff --git a/server/src/main/java/org/opensearch/common/util/TokenBucket.java b/server/src/main/java/org/opensearch/common/util/TokenBucket.java
index d2e7e836bf07f..a9ebb86eed8a2 100644
--- a/server/src/main/java/org/opensearch/common/util/TokenBucket.java
+++ b/server/src/main/java/org/opensearch/common/util/TokenBucket.java
@@ -20,7 +20,7 @@
 public class TokenBucket {
     /**
      * Defines a monotonically increasing counter.
-     *
+     * <p>
      * Usage examples:
      * 1. clock = System::nanoTime can be used to perform rate-limiting per unit time
      * 2. clock = AtomicLong::get can be used to perform rate-limiting per unit number of operations
diff --git a/server/src/main/java/org/opensearch/common/util/URIPattern.java b/server/src/main/java/org/opensearch/common/util/URIPattern.java
index a3c385e5ea660..49e4b53e20740 100644
--- a/server/src/main/java/org/opensearch/common/util/URIPattern.java
+++ b/server/src/main/java/org/opensearch/common/util/URIPattern.java
@@ -39,9 +39,9 @@
 
 /**
  * URI Pattern matcher
- *
+ * <p>
  * The pattern is URI in which authority, path, query and fragment can be replace with simple pattern.
- *
+ * <p>
  * For example: foobar://*.local/some_path/*?*#* will match all uris with schema foobar in local domain
  * with any port, with path that starts some_path and with any query and fragment.
  *
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/AsyncIOProcessor.java b/server/src/main/java/org/opensearch/common/util/concurrent/AsyncIOProcessor.java
index e9b9442c555e5..7f6fef83b34a6 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/AsyncIOProcessor.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/AsyncIOProcessor.java
@@ -32,6 +32,7 @@
 package org.opensearch.common.util.concurrent;
 
 import org.apache.logging.log4j.Logger;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 
 import java.io.IOException;
@@ -50,8 +51,9 @@
  * hijack a worker if nobody else is currently processing queued items. If the internal queue has reached it's capacity incoming threads
  * might be blocked until other items are processed
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class AsyncIOProcessor<Item> {
     private final Logger logger;
     private final ArrayBlockingQueue<Tuple<Item, Consumer<Exception>>> queue;
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/AtomicArray.java b/server/src/main/java/org/opensearch/common/util/concurrent/AtomicArray.java
index dd1f71a7d2166..4c599aeae7a7c 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/AtomicArray.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/AtomicArray.java
@@ -33,6 +33,7 @@
 package org.opensearch.common.util.concurrent;
 
 import org.opensearch.OpenSearchGenerationException;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -43,8 +44,9 @@
  * A list backed by an {@link AtomicReferenceArray} with potential null values, easily allowing
  * to get the concrete values as a list using {@link #asList()}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AtomicArray<E> {
     private final AtomicReferenceArray<E> array;
     private volatile List<E> nonNullList;
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/ListenableFuture.java b/server/src/main/java/org/opensearch/common/util/concurrent/ListenableFuture.java
index b1f4714a90e8e..4357254176358 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/ListenableFuture.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/ListenableFuture.java
@@ -73,7 +73,7 @@ public void addListener(ActionListener<V> listener, ExecutorService executor) {
      * notified of a response or exception in a runnable submitted to the ExecutorService provided.
      * If the future has completed, the listener will be notified immediately without forking to
      * a different thread.
-     *
+     * <p>
      * It will apply the provided ThreadContext (if not null) when executing the listening.
      */
     public void addListener(ActionListener<V> listener, ExecutorService executor, ThreadContext threadContext) {
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/OpenSearchThreadPoolExecutor.java b/server/src/main/java/org/opensearch/common/util/concurrent/OpenSearchThreadPoolExecutor.java
index d967b7423ca80..afffec4790873 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/OpenSearchThreadPoolExecutor.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/OpenSearchThreadPoolExecutor.java
@@ -205,4 +205,15 @@ protected Runnable wrapRunnable(Runnable command) {
     protected Runnable unwrap(Runnable runnable) {
         return contextHolder.unwrap(runnable);
     }
+
+    /**
+     * Returns the cumulative wait time of the ThreadPool. If the ThreadPool does not support tracking the cumulative pool wait time
+     * then this should return -1 which will prevent the value from showing up in {@link org.opensearch.threadpool.ThreadPoolStats}.
+     * ThreadPools that do support this metric should override this method. For example, {@link QueueResizingOpenSearchThreadPoolExecutor}
+     * does so using the {@link TimedRunnable} to get the difference between Runnable creation and execution.
+     *
+     */
+    public long getPoolWaitTimeNanos() {
+        return -1;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/PrioritizedOpenSearchThreadPoolExecutor.java b/server/src/main/java/org/opensearch/common/util/concurrent/PrioritizedOpenSearchThreadPoolExecutor.java
index b4673d9534922..95df4486b9d7b 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/PrioritizedOpenSearchThreadPoolExecutor.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/PrioritizedOpenSearchThreadPoolExecutor.java
@@ -118,8 +118,9 @@ private void addPending(List<Runnable> runnables, List<Pending> pending, boolean
                 TieBreakingPrioritizedRunnable t = (TieBreakingPrioritizedRunnable) runnable;
                 Runnable innerRunnable = t.runnable;
                 if (innerRunnable != null) {
-                    /** innerRunnable can be null if task is finished but not removed from executor yet,
-                     * see {@link TieBreakingPrioritizedRunnable#run} and {@link TieBreakingPrioritizedRunnable#runAndClean}
+                    /*
+                      innerRunnable can be null if task is finished but not removed from executor yet,
+                      see {@link TieBreakingPrioritizedRunnable#run} and {@link TieBreakingPrioritizedRunnable#runAndClean}
                      */
                     pending.add(new Pending(super.unwrap(innerRunnable), t.priority(), t.insertionOrder, executing));
                 }
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizableOpenSearchThreadPoolExecutor.java b/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizableOpenSearchThreadPoolExecutor.java
index 7a0ce8244efe4..c06184f5a5483 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizableOpenSearchThreadPoolExecutor.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizableOpenSearchThreadPoolExecutor.java
@@ -9,6 +9,7 @@
 package org.opensearch.common.util.concurrent;
 
 import org.opensearch.common.ExponentiallyWeightedMovingAverage;
+import org.opensearch.common.metrics.CounterMetric;
 
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
@@ -27,6 +28,7 @@ public final class QueueResizableOpenSearchThreadPoolExecutor extends OpenSearch
     private final ResizableBlockingQueue<Runnable> workQueue;
     private final Function<Runnable, WrappedRunnable> runnableWrapper;
     private final ExponentiallyWeightedMovingAverage executionEWMA;
+    private final CounterMetric poolWaitTime;
 
     /**
      * Create new resizable at runtime thread pool executor
@@ -101,6 +103,7 @@ public final class QueueResizableOpenSearchThreadPoolExecutor extends OpenSearch
         this.workQueue = workQueue;
         this.runnableWrapper = runnableWrapper;
         this.executionEWMA = new ExponentiallyWeightedMovingAverage(ewmaAlpha, 0);
+        this.poolWaitTime = new CounterMetric();
     }
 
     @Override
@@ -156,6 +159,7 @@ protected void afterExecute(Runnable r, Throwable t) {
             // taskExecutionNanos may be -1 if the task threw an exception
             executionEWMA.addValue(taskExecutionNanos);
         }
+        poolWaitTime.inc(timedRunnable.getWaitTimeNanos());
     }
 
     /**
@@ -173,4 +177,9 @@ public synchronized int resize(int capacity) {
             capacity
         );
     }
+
+    @Override
+    public long getPoolWaitTimeNanos() {
+        return poolWaitTime.count();
+    }
 }
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizingOpenSearchThreadPoolExecutor.java b/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizingOpenSearchThreadPoolExecutor.java
index 684dd7c9d8de5..0c0b437e4f390 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizingOpenSearchThreadPoolExecutor.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/QueueResizingOpenSearchThreadPoolExecutor.java
@@ -36,6 +36,7 @@
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.opensearch.common.ExponentiallyWeightedMovingAverage;
+import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.common.unit.TimeValue;
 
 import java.util.Locale;
@@ -66,6 +67,7 @@ public final class QueueResizingOpenSearchThreadPoolExecutor extends OpenSearchT
     private final int maxQueueSize;
     private final long targetedResponseTimeNanos;
     private final ExponentiallyWeightedMovingAverage executionEWMA;
+    private final CounterMetric poolWaitTime;
 
     private final AtomicLong totalTaskNanos = new AtomicLong(0);
     private final AtomicInteger taskCount = new AtomicInteger(0);
@@ -97,6 +99,7 @@ public final class QueueResizingOpenSearchThreadPoolExecutor extends OpenSearchT
         this.maxQueueSize = maxQueueSize;
         this.targetedResponseTimeNanos = targetedResponseTime.getNanos();
         this.executionEWMA = new ExponentiallyWeightedMovingAverage(EWMA_ALPHA, 0);
+        this.poolWaitTime = new CounterMetric();
         logger.debug(
             "thread pool [{}] will adjust queue by [{}] when determining automatic queue size",
             getName(),
@@ -190,6 +193,7 @@ protected void afterExecute(Runnable r, Throwable t) {
             // taskExecutionNanos may be -1 if the task threw an exception
             executionEWMA.addValue(taskExecutionNanos);
         }
+        poolWaitTime.inc(timedRunnable.getWaitTimeNanos());
 
         if (taskCount.incrementAndGet() == this.tasksPerFrame) {
             final long endTimeNs = System.nanoTime();
@@ -290,4 +294,8 @@ protected void appendThreadPoolExecutorDetails(StringBuilder sb) {
         sb.append("adjustment amount = ").append(QUEUE_ADJUSTMENT_AMOUNT).append(", ");
     }
 
+    @Override
+    public long getPoolWaitTimeNanos() {
+        return poolWaitTime.count();
+    }
 }
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java b/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java
index 4888d25e4a640..3da21a6777456 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java
@@ -35,6 +35,7 @@
 import org.apache.logging.log4j.Logger;
 import org.opensearch.action.support.ContextPreservingActionListener;
 import org.opensearch.client.OriginSettingClient;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.MapBuilder;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.settings.Setting;
@@ -97,8 +98,9 @@
  *     // previous context is restored on StoredContext#close()
  * </pre>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ThreadContext implements Writeable {
 
     public static final String PREFIX = "request.headers";
@@ -143,10 +145,10 @@ public void unregisterThreadContextStatePropagator(final ThreadContextStatePropa
      */
     public StoredContext stashContext() {
         final ThreadContextStruct context = threadLocal.get();
-        /**
-         * X-Opaque-ID should be preserved in a threadContext in order to propagate this across threads.
-         * This is needed so the DeprecationLogger in another thread can see the value of X-Opaque-ID provided by a user.
-         * Otherwise when context is stash, it should be empty.
+        /*
+          X-Opaque-ID should be preserved in a threadContext in order to propagate this across threads.
+          This is needed so the DeprecationLogger in another thread can see the value of X-Opaque-ID provided by a user.
+          Otherwise when context is stash, it should be empty.
          */
 
         ThreadContextStruct threadContextStruct = DEFAULT_CONTEXT.putPersistent(context.persistentHeaders);
@@ -545,9 +547,10 @@ public boolean isSystemContext() {
     /**
      * A stored context
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     public interface StoredContext extends AutoCloseable {
         @Override
         void close();
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContextStatePropagator.java b/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContextStatePropagator.java
index b3fc79c5446db..dac70b0e8124e 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContextStatePropagator.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContextStatePropagator.java
@@ -8,12 +8,17 @@
 
 package org.opensearch.common.util.concurrent;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.Map;
 
 /**
  * The propagator for {@link ThreadContext} that helps to carry-over the state from one
  * thread to another (tasks, tracing context, etc).
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public interface ThreadContextStatePropagator {
     /**
      * Returns the list of transient headers that needs to be propagated from current context to new thread context.
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/TimedRunnable.java b/server/src/main/java/org/opensearch/common/util/concurrent/TimedRunnable.java
index f3bc50a33453b..2eb6657898008 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/TimedRunnable.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/TimedRunnable.java
@@ -107,6 +107,14 @@ long getTotalExecutionNanos() {
         return Math.max(finishTimeNanos - startTimeNanos, 1);
     }
 
+    long getWaitTimeNanos() {
+        if (startTimeNanos == -1) {
+            // There must have been an exception thrown, the total time is unknown (-1)
+            return -1;
+        }
+        return Math.max(startTimeNanos - creationTimeNanos, 1);
+    }
+
     /**
      * If the task was failed or rejected, return true.
      * Otherwise, false.
diff --git a/server/src/main/java/org/opensearch/common/xcontent/LoggingDeprecationHandler.java b/server/src/main/java/org/opensearch/common/xcontent/LoggingDeprecationHandler.java
index 06d139fa93195..05fc968737394 100644
--- a/server/src/main/java/org/opensearch/common/xcontent/LoggingDeprecationHandler.java
+++ b/server/src/main/java/org/opensearch/common/xcontent/LoggingDeprecationHandler.java
@@ -54,7 +54,7 @@ public class LoggingDeprecationHandler implements DeprecationHandler {
     public static final LoggingDeprecationHandler INSTANCE = new LoggingDeprecationHandler();
     /**
      * The logger to which to send deprecation messages.
-     *
+     * <p>
      * This uses ParseField's logger because that is the logger that
      * we have been using for many releases for deprecated fields.
      * Changing that will require some research to make super duper
diff --git a/server/src/main/java/org/opensearch/common/xcontent/XContentHelper.java b/server/src/main/java/org/opensearch/common/xcontent/XContentHelper.java
index 798a58551457f..17bb0a1de267b 100644
--- a/server/src/main/java/org/opensearch/common/xcontent/XContentHelper.java
+++ b/server/src/main/java/org/opensearch/common/xcontent/XContentHelper.java
@@ -494,7 +494,7 @@ public static BytesReference toXContent(ToXContent toXContent, XContentType xCon
 
     /**
      * Returns the contents of an object as an unparsed BytesReference
-     *
+     * <p>
      * This is useful for things like mappings where we're copying bytes around but don't
      * actually need to parse their contents, and so avoids building large maps of maps
      * unnecessarily
diff --git a/server/src/main/java/org/opensearch/common/xcontent/support/XContentMapValues.java b/server/src/main/java/org/opensearch/common/xcontent/support/XContentMapValues.java
index adfa871cbfcbe..a87edbb949d39 100644
--- a/server/src/main/java/org/opensearch/common/xcontent/support/XContentMapValues.java
+++ b/server/src/main/java/org/opensearch/common/xcontent/support/XContentMapValues.java
@@ -117,12 +117,11 @@ private static void extractRawValues(List values, List<Object> part, String[] pa
 
     /**
      * For the provided path, return its value in the xContent map.
-     *
+     * <p>
      * Note that in contrast with {@link XContentMapValues#extractRawValues}, array and object values
      * can be returned.
      *
      * @param path the value's path in the map.
-     *
      * @return the value associated with the path in the map or 'null' if the path does not exist.
      */
     public static Object extractValue(String path, Map<?, ?> map) {
@@ -138,7 +137,7 @@ public static Object extractValue(Map<?, ?> map, String... pathElements) {
 
     /**
      * For the provided path, return its value in the xContent map.
-     *
+     * <p>
      * Note that in contrast with {@link XContentMapValues#extractRawValues}, array and object values
      * can be returned.
      *
@@ -197,13 +196,13 @@ private static Object extractValue(String[] pathElements, int index, Object curr
      * Only keep properties in {@code map} that match the {@code includes} but
      * not the {@code excludes}. An empty list of includes is interpreted as a
      * wildcard while an empty list of excludes does not match anything.
-     *
+     * <p>
      * If a property matches both an include and an exclude, then the exclude
      * wins.
-     *
+     * <p>
      * If an object matches, then any of its sub properties are automatically
      * considered as matching as well, both for includes and excludes.
-     *
+     * <p>
      * Dots in field names are treated as sub objects. So for instance if a
      * document contains {@code a.b} as a property and {@code a} is an include,
      * then {@code a.b} will be kept in the filtered map.
@@ -555,7 +554,7 @@ public static Map<String, Object> nodeMapValue(Object node, String desc) {
 
     /**
      * Returns an array of string value from a node value.
-     *
+     * <p>
      * If the node represents an array the corresponding array of strings is returned.
      * Otherwise the node is treated as a comma-separated string.
      */
diff --git a/server/src/main/java/org/opensearch/discovery/DiscoveryStats.java b/server/src/main/java/org/opensearch/discovery/DiscoveryStats.java
index 665ecf77d7aa7..fb341ac2ac569 100644
--- a/server/src/main/java/org/opensearch/discovery/DiscoveryStats.java
+++ b/server/src/main/java/org/opensearch/discovery/DiscoveryStats.java
@@ -32,8 +32,10 @@
 
 package org.opensearch.discovery;
 
+import org.opensearch.Version;
 import org.opensearch.cluster.coordination.PendingClusterStateStats;
 import org.opensearch.cluster.coordination.PublishClusterStateStats;
+import org.opensearch.cluster.service.ClusterStateStats;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -51,21 +53,31 @@ public class DiscoveryStats implements Writeable, ToXContentFragment {
 
     private final PendingClusterStateStats queueStats;
     private final PublishClusterStateStats publishStats;
+    private final ClusterStateStats clusterStateStats;
 
-    public DiscoveryStats(PendingClusterStateStats queueStats, PublishClusterStateStats publishStats) {
+    public DiscoveryStats(PendingClusterStateStats queueStats, PublishClusterStateStats publishStats, ClusterStateStats clusterStateStats) {
         this.queueStats = queueStats;
         this.publishStats = publishStats;
+        this.clusterStateStats = clusterStateStats;
     }
 
     public DiscoveryStats(StreamInput in) throws IOException {
         queueStats = in.readOptionalWriteable(PendingClusterStateStats::new);
         publishStats = in.readOptionalWriteable(PublishClusterStateStats::new);
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            clusterStateStats = in.readOptionalWriteable(ClusterStateStats::new);
+        } else {
+            clusterStateStats = null;
+        }
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalWriteable(queueStats);
         out.writeOptionalWriteable(publishStats);
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeOptionalWriteable(clusterStateStats);
+        }
     }
 
     @Override
@@ -77,6 +89,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         if (publishStats != null) {
             publishStats.toXContent(builder, params);
         }
+        if (clusterStateStats != null) {
+            clusterStateStats.toXContent(builder, params);
+        }
         builder.endObject();
         return builder;
     }
@@ -92,4 +107,8 @@ public PendingClusterStateStats getQueueStats() {
     public PublishClusterStateStats getPublishStats() {
         return publishStats;
     }
+
+    public ClusterStateStats getClusterStateStats() {
+        return clusterStateStats;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/discovery/FileBasedSeedHostsProvider.java b/server/src/main/java/org/opensearch/discovery/FileBasedSeedHostsProvider.java
index 3159733336057..b663227978e8f 100644
--- a/server/src/main/java/org/opensearch/discovery/FileBasedSeedHostsProvider.java
+++ b/server/src/main/java/org/opensearch/discovery/FileBasedSeedHostsProvider.java
@@ -48,12 +48,12 @@
 /**
  * An implementation of {@link SeedHostsProvider} that reads hosts/ports
  * from {@link #UNICAST_HOSTS_FILE}.
- *
+ * <p>
  * Each host/port that is part of the discovery process must be listed on
  * a separate line. If the port is left off an entry, we default to the
  * first port in the {@code transport.port} range.
  * An example unicast hosts file could read:
- *
+ * <p>
  * 67.81.244.10
  * 67.81.244.11:9305
  * 67.81.244.15:9400
diff --git a/server/src/main/java/org/opensearch/discovery/InitializeExtensionRequest.java b/server/src/main/java/org/opensearch/discovery/InitializeExtensionRequest.java
index 33cdad3045780..6e9fb8b7201a4 100644
--- a/server/src/main/java/org/opensearch/discovery/InitializeExtensionRequest.java
+++ b/server/src/main/java/org/opensearch/discovery/InitializeExtensionRequest.java
@@ -25,16 +25,19 @@
 public class InitializeExtensionRequest extends TransportRequest {
     private final DiscoveryNode sourceNode;
     private final DiscoveryExtensionNode extension;
+    private final String serviceAccountHeader;
 
-    public InitializeExtensionRequest(DiscoveryNode sourceNode, DiscoveryExtensionNode extension) {
+    public InitializeExtensionRequest(DiscoveryNode sourceNode, DiscoveryExtensionNode extension, String serviceAccountHeader) {
         this.sourceNode = sourceNode;
         this.extension = extension;
+        this.serviceAccountHeader = serviceAccountHeader;
     }
 
     public InitializeExtensionRequest(StreamInput in) throws IOException {
         super(in);
         sourceNode = new DiscoveryNode(in);
         extension = new DiscoveryExtensionNode(in);
+        serviceAccountHeader = in.readString();
     }
 
     @Override
@@ -42,6 +45,7 @@ public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
         sourceNode.writeTo(out);
         extension.writeTo(out);
+        out.writeString(serviceAccountHeader);
     }
 
     public DiscoveryNode getSourceNode() {
@@ -52,6 +56,10 @@ public DiscoveryExtensionNode getExtension() {
         return extension;
     }
 
+    public String getServiceAccountHeader() {
+        return serviceAccountHeader;
+    }
+
     @Override
     public String toString() {
         return "InitializeExtensionsRequest{" + "sourceNode=" + sourceNode + ", extension=" + extension + '}';
@@ -62,7 +70,9 @@ public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         InitializeExtensionRequest that = (InitializeExtensionRequest) o;
-        return Objects.equals(sourceNode, that.sourceNode) && Objects.equals(extension, that.extension);
+        return Objects.equals(sourceNode, that.sourceNode)
+            && Objects.equals(extension, that.extension)
+            && Objects.equals(serviceAccountHeader, that.getServiceAccountHeader());
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/discovery/SettingsBasedSeedHostsProvider.java b/server/src/main/java/org/opensearch/discovery/SettingsBasedSeedHostsProvider.java
index 9785d5b21078e..10185322c2ca6 100644
--- a/server/src/main/java/org/opensearch/discovery/SettingsBasedSeedHostsProvider.java
+++ b/server/src/main/java/org/opensearch/discovery/SettingsBasedSeedHostsProvider.java
@@ -49,7 +49,7 @@
  * An implementation of {@link SeedHostsProvider} that reads hosts/ports
  * from the "discovery.seed_hosts" node setting. If the port is
  * left off an entry, we default to the first port in the {@code transport.port} range.
- *
+ * <p>
  * An example setting might look as follows:
  * [67.81.244.10, 67.81.244.11:9305, 67.81.244.15:9400]
  *
diff --git a/server/src/main/java/org/opensearch/env/Environment.java b/server/src/main/java/org/opensearch/env/Environment.java
index 3b87c756ffdae..5a40e45fb22a6 100644
--- a/server/src/main/java/org/opensearch/env/Environment.java
+++ b/server/src/main/java/org/opensearch/env/Environment.java
@@ -249,7 +249,7 @@ public Path[] repoFiles() {
 
     /**
      * Resolves the specified location against the list of configured repository roots
-     *
+     * <p>
      * If the specified location doesn't match any of the roots, returns null.
      */
     public Path resolveRepoFile(String location) {
@@ -259,7 +259,7 @@ public Path resolveRepoFile(String location) {
     /**
      * Checks if the specified URL is pointing to the local file system and if it does, resolves the specified url
      * against the list of configured repository roots
-     *
+     * <p>
      * If the specified url doesn't match any of the roots, returns null.
      */
     public URL resolveRepoURL(URL url) {
diff --git a/server/src/main/java/org/opensearch/env/NodeEnvironment.java b/server/src/main/java/org/opensearch/env/NodeEnvironment.java
index 3c5ab5ba98875..c7ba5eb040a1f 100644
--- a/server/src/main/java/org/opensearch/env/NodeEnvironment.java
+++ b/server/src/main/java/org/opensearch/env/NodeEnvironment.java
@@ -705,7 +705,7 @@ public List<ShardLock> lockAllForIndex(
      * write operation on a shards data directory like deleting files, creating a new index writer
      * or recover from a different shard instance into it. If the shard lock can not be acquired
      * a {@link ShardLockObtainFailedException} is thrown.
-     *
+     * <p>
      * Note: this method will return immediately if the lock can't be acquired.
      *
      * @param id the shard ID to lock
@@ -770,15 +770,18 @@ public void setDetails(String details) {
 
     /**
      * A functional interface that people can use to reference {@link #shardLock(ShardId, String, long)}
+     *
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     public interface ShardLocker {
         ShardLock lock(ShardId shardId, String lockDetails, long lockTimeoutMS) throws ShardLockObtainFailedException;
     }
 
     /**
      * Returns all currently lock shards.
-     *
+     * <p>
      * Note: the shard ids return do not contain a valid Index UUID
      */
     public Set<ShardId> lockedShards() {
diff --git a/server/src/main/java/org/opensearch/extensions/ExtensionReader.java b/server/src/main/java/org/opensearch/extensions/ExtensionReader.java
index 4556d6537ffdc..fc2ba817ace5f 100644
--- a/server/src/main/java/org/opensearch/extensions/ExtensionReader.java
+++ b/server/src/main/java/org/opensearch/extensions/ExtensionReader.java
@@ -17,7 +17,7 @@
  * a category class used to identify the reader defined within the JVM that the extension is running on.
  * Additionally, this method takes in the extension's corresponding DiscoveryNode and a byte array (context) that the
  * extension's reader will be applied to.
- *
+ * <p>
  * By convention the extensions' reader is a constructor that takes StreamInput as an argument for most classes and a static method for things like enums.
  * Classes will implement this via a constructor (or a static method in the case of enumerations), it's something that should
  * look like:
diff --git a/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java b/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java
index 61a6e2faa09e0..b531abcb845d7 100644
--- a/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java
+++ b/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java
@@ -41,6 +41,7 @@
 import org.opensearch.extensions.settings.CustomSettingsRequestHandler;
 import org.opensearch.extensions.settings.RegisterCustomSettingsRequest;
 import org.opensearch.identity.IdentityService;
+import org.opensearch.identity.tokens.AuthToken;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.ConnectTransportException;
 import org.opensearch.transport.TransportException;
@@ -101,6 +102,7 @@ public static enum OpenSearchRequestType {
     private Settings environmentSettings;
     private AddSettingsUpdateConsumerRequestHandler addSettingsUpdateConsumerRequestHandler;
     private NodeClient client;
+    private IdentityService identityService;
 
     /**
      * Instantiate a new ExtensionsManager object to handle requests and responses from extensions. This is called during Node bootstrap.
@@ -108,7 +110,7 @@ public static enum OpenSearchRequestType {
      * @param additionalSettings  Additional settings to read in from extension initialization request
      * @throws IOException  If the extensions discovery file is not properly retrieved.
      */
-    public ExtensionsManager(Set<Setting<?>> additionalSettings) throws IOException {
+    public ExtensionsManager(Set<Setting<?>> additionalSettings, IdentityService identityService) throws IOException {
         logger.info("ExtensionsManager initialized");
         this.initializedExtensions = new HashMap<String, DiscoveryExtensionNode>();
         this.extensionIdMap = new HashMap<String, DiscoveryExtensionNode>();
@@ -123,6 +125,7 @@ public ExtensionsManager(Set<Setting<?>> additionalSettings) throws IOException
         }
         this.client = null;
         this.extensionTransportActionsHandler = null;
+        this.identityService = identityService;
     }
 
     /**
@@ -297,7 +300,7 @@ private void registerRequestHandler(DynamicActionRegistry dynamicActionRegistry)
      * Loads a single extension
      * @param extension The extension to be loaded
      */
-    public void loadExtension(Extension extension) throws IOException {
+    public DiscoveryExtensionNode loadExtension(Extension extension) throws IOException {
         validateExtension(extension);
         DiscoveryExtensionNode discoveryExtensionNode = new DiscoveryExtensionNode(
             extension.getName(),
@@ -311,6 +314,12 @@ public void loadExtension(Extension extension) throws IOException {
         extensionIdMap.put(extension.getUniqueId(), discoveryExtensionNode);
         extensionSettingsMap.put(extension.getUniqueId(), extension);
         logger.info("Loaded extension with uniqueId " + extension.getUniqueId() + ": " + extension);
+        return discoveryExtensionNode;
+    }
+
+    public void initializeExtension(Extension extension) throws IOException {
+        DiscoveryExtensionNode node = loadExtension(extension);
+        initializeExtensionNode(node);
     }
 
     private void validateField(String fieldName, String value) throws IOException {
@@ -337,11 +346,11 @@ private void validateExtension(Extension extension) throws IOException {
      */
     public void initialize() {
         for (DiscoveryExtensionNode extension : extensionIdMap.values()) {
-            initializeExtension(extension);
+            initializeExtensionNode(extension);
         }
     }
 
-    private void initializeExtension(DiscoveryExtensionNode extension) {
+    public void initializeExtensionNode(DiscoveryExtensionNode extensionNode) {
 
         final CompletableFuture<InitializeExtensionResponse> inProgressFuture = new CompletableFuture<>();
         final TransportResponseHandler<InitializeExtensionResponse> initializeExtensionResponseHandler = new TransportResponseHandler<
@@ -381,7 +390,8 @@ public String executor() {
         transportService.getThreadPool().generic().execute(new AbstractRunnable() {
             @Override
             public void onFailure(Exception e) {
-                extensionIdMap.remove(extension.getId());
+                logger.warn("Error registering extension: " + extensionNode.getId(), e);
+                extensionIdMap.remove(extensionNode.getId());
                 if (e.getCause() instanceof ConnectTransportException) {
                     logger.info("No response from extension to request.", e);
                     throw (ConnectTransportException) e.getCause();
@@ -396,11 +406,11 @@ public void onFailure(Exception e) {
 
             @Override
             protected void doRun() throws Exception {
-                transportService.connectToExtensionNode(extension);
+                transportService.connectToExtensionNode(extensionNode);
                 transportService.sendRequest(
-                    extension,
+                    extensionNode,
                     REQUEST_EXTENSION_ACTION_NAME,
-                    new InitializeExtensionRequest(transportService.getLocalNode(), extension),
+                    new InitializeExtensionRequest(transportService.getLocalNode(), extensionNode, issueServiceAccount(extensionNode)),
                     initializeExtensionResponseHandler
                 );
             }
@@ -443,6 +453,15 @@ TransportResponse handleExtensionRequest(ExtensionRequest extensionRequest) thro
         }
     }
 
+    /**
+     * A helper method called during initialization that issues a service accounts to extensions
+     * @param extension The extension to be issued a service account
+     */
+    private String issueServiceAccount(DiscoveryExtensionNode extension) {
+        AuthToken serviceAccountToken = identityService.getTokenManager().issueServiceAccountToken(extension.getId());
+        return serviceAccountToken.asAuthHeaderValue();
+    }
+
     static String getRequestExtensionActionName() {
         return REQUEST_EXTENSION_ACTION_NAME;
     }
diff --git a/server/src/main/java/org/opensearch/extensions/NoopExtensionsManager.java b/server/src/main/java/org/opensearch/extensions/NoopExtensionsManager.java
index 34aa3ec1367a7..81b1b91b11481 100644
--- a/server/src/main/java/org/opensearch/extensions/NoopExtensionsManager.java
+++ b/server/src/main/java/org/opensearch/extensions/NoopExtensionsManager.java
@@ -20,6 +20,7 @@
 import org.opensearch.transport.TransportService;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 
@@ -31,7 +32,7 @@
 public class NoopExtensionsManager extends ExtensionsManager {
 
     public NoopExtensionsManager() throws IOException {
-        super(Set.of());
+        super(Set.of(), new IdentityService(Settings.EMPTY, List.of()));
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/extensions/rest/RestActionsRequestHandler.java b/server/src/main/java/org/opensearch/extensions/rest/RestActionsRequestHandler.java
index 97851cbd394a0..383796f0c3b44 100644
--- a/server/src/main/java/org/opensearch/extensions/rest/RestActionsRequestHandler.java
+++ b/server/src/main/java/org/opensearch/extensions/rest/RestActionsRequestHandler.java
@@ -62,6 +62,9 @@ public TransportResponse handleRegisterRestActionsRequest(
         DynamicActionRegistry dynamicActionRegistry
     ) throws Exception {
         DiscoveryExtensionNode discoveryExtensionNode = extensionIdMap.get(restActionsRequest.getUniqueId());
+        if (discoveryExtensionNode == null) {
+            throw new IllegalStateException("Missing extension node for " + restActionsRequest.getUniqueId());
+        }
         RestHandler handler = new RestSendToExtensionAction(
             restActionsRequest,
             discoveryExtensionNode,
diff --git a/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java b/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java
index 4b622b841a040..fc7c21a6eccd6 100644
--- a/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java
+++ b/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java
@@ -159,8 +159,7 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
             extAdditionalSettings
         );
         try {
-            extensionsManager.loadExtension(extension);
-            extensionsManager.initialize();
+            extensionsManager.initializeExtension(extension);
         } catch (CompletionException e) {
             Throwable cause = e.getCause();
             if (cause instanceof TimeoutException) {
diff --git a/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java b/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java
index 33f44a913dd8a..41783b89ccc69 100644
--- a/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java
+++ b/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java
@@ -150,7 +150,7 @@ public RestSendToExtensionAction(
 
     @Override
     public String getName() {
-        return SEND_TO_EXTENSION_ACTION;
+        return this.discoveryExtensionNode.getId() + ":" + SEND_TO_EXTENSION_ACTION;
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/gateway/BaseGatewayShardAllocator.java b/server/src/main/java/org/opensearch/gateway/BaseGatewayShardAllocator.java
index 59ef894958cbe..853fe03904c53 100644
--- a/server/src/main/java/org/opensearch/gateway/BaseGatewayShardAllocator.java
+++ b/server/src/main/java/org/opensearch/gateway/BaseGatewayShardAllocator.java
@@ -50,7 +50,7 @@
 /**
  * An abstract class that implements basic functionality for allocating
  * shards to nodes based on shard copies that already exist in the cluster.
- *
+ * <p>
  * Individual implementations of this class are responsible for providing
  * the logic to determine to which nodes (if any) those shards are allocated.
  *
diff --git a/server/src/main/java/org/opensearch/gateway/DanglingIndicesState.java b/server/src/main/java/org/opensearch/gateway/DanglingIndicesState.java
index e7c1ba01e7920..48479691689e5 100644
--- a/server/src/main/java/org/opensearch/gateway/DanglingIndicesState.java
+++ b/server/src/main/java/org/opensearch/gateway/DanglingIndicesState.java
@@ -244,7 +244,7 @@ List<IndexMetadata> filterDanglingIndices(Metadata metadata, Map<Index, IndexMet
 
     /**
      * Removes all aliases from the supplied index metadata.
-     *
+     * <p>
      * Dangling importing indices with aliases is dangerous, it could for instance result in inability to write to an existing alias if it
      * previously had only one index with any is_write_index indication.
      */
diff --git a/server/src/main/java/org/opensearch/gateway/GatewayMetaState.java b/server/src/main/java/org/opensearch/gateway/GatewayMetaState.java
index e42ac8daa3b1c..c3056276706a0 100644
--- a/server/src/main/java/org/opensearch/gateway/GatewayMetaState.java
+++ b/server/src/main/java/org/opensearch/gateway/GatewayMetaState.java
@@ -47,6 +47,7 @@
 import org.opensearch.cluster.coordination.InMemoryPersistedState;
 import org.opensearch.cluster.coordination.PersistedStateRegistry;
 import org.opensearch.cluster.coordination.PersistedStateRegistry.PersistedStateType;
+import org.opensearch.cluster.coordination.PersistedStateStats;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.IndexTemplateMetadata;
 import org.opensearch.cluster.metadata.Manifest;
@@ -67,7 +68,6 @@
 import org.opensearch.index.recovery.RemoteStoreRestoreService.RemoteRestoreResult;
 import org.opensearch.node.Node;
 import org.opensearch.plugins.MetadataUpgrader;
-import org.opensearch.repositories.RepositoryMissingException;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TransportService;
 
@@ -78,6 +78,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.BiConsumer;
@@ -90,7 +91,7 @@
 
 /**
  * Loads (and maybe upgrades) cluster metadata at startup, and persistently stores cluster metadata for future restarts.
- *
+ * <p>
  * When started, ensures that this version is compatible with the state stored on disk, and performs a state upgrade if necessary. Note that the state being
  * loaded when constructing the instance of this class is not necessarily the state that will be used as {@link ClusterState#metadata()} because it might be
  * stale or incomplete. Cluster-manager-eligible nodes must perform an election to find a complete and non-stale state, and cluster-manager-ineligible nodes
@@ -157,37 +158,46 @@ public void start(
                 PersistedState remotePersistedState = null;
                 boolean success = false;
                 try {
-                    ClusterState clusterState = prepareInitialClusterState(
+                    ClusterState clusterState = ClusterState.builder(ClusterName.CLUSTER_NAME_SETTING.get(settings))
+                        .version(lastAcceptedVersion)
+                        .metadata(metadata)
+                        .build();
+
+                    if (DiscoveryNode.isClusterManagerNode(settings) && isRemoteStoreClusterStateEnabled(settings)) {
+                        // If the cluster UUID loaded from local is unknown (_na_) then fetch the best state from remote
+                        // If there is no valid state on remote, continue with initial empty state
+                        // If there is a valid state, then restore index metadata using this state
+                        String lastKnownClusterUUID = ClusterState.UNKNOWN_UUID;
+                        if (ClusterState.UNKNOWN_UUID.equals(clusterState.metadata().clusterUUID())) {
+                            lastKnownClusterUUID = remoteClusterStateService.getLastKnownUUIDFromRemote(
+                                clusterState.getClusterName().value()
+                            );
+                            if (ClusterState.UNKNOWN_UUID.equals(lastKnownClusterUUID) == false) {
+                                // Load state from remote
+                                final RemoteRestoreResult remoteRestoreResult = remoteStoreRestoreService.restore(
+                                    // Remote Metadata should always override local disk Metadata
+                                    // if local disk Metadata's cluster uuid is UNKNOWN_UUID
+                                    ClusterState.builder(clusterState).metadata(Metadata.EMPTY_METADATA).build(),
+                                    lastKnownClusterUUID,
+                                    false,
+                                    new String[] {}
+                                );
+                                clusterState = remoteRestoreResult.getClusterState();
+                            }
+                        }
+                        remotePersistedState = new RemotePersistedState(remoteClusterStateService, lastKnownClusterUUID);
+                    }
+
+                    // Recovers Cluster and Index level blocks
+                    clusterState = prepareInitialClusterState(
                         transportService,
                         clusterService,
-                        ClusterState.builder(ClusterName.CLUSTER_NAME_SETTING.get(settings))
-                            .version(lastAcceptedVersion)
-                            .metadata(upgradeMetadataForNode(metadata, metadataIndexUpgradeService, metadataUpgrader))
+                        ClusterState.builder(clusterState)
+                            .metadata(upgradeMetadataForNode(clusterState.metadata(), metadataIndexUpgradeService, metadataUpgrader))
                             .build()
                     );
 
                     if (DiscoveryNode.isClusterManagerNode(settings)) {
-                        if (isRemoteStoreClusterStateEnabled(settings)) {
-                            // If the cluster UUID loaded from local is unknown (_na_) then fetch the best state from remote
-                            // If there is no valid state on remote, continue with initial empty state
-                            // If there is a valid state, then restore index metadata using this state
-                            if (ClusterState.UNKNOWN_UUID.equals(clusterState.metadata().clusterUUID())) {
-                                String lastKnownClusterUUID = remoteClusterStateService.getLastKnownUUIDFromRemote(
-                                    clusterState.getClusterName().value()
-                                );
-                                if (!ClusterState.UNKNOWN_UUID.equals(lastKnownClusterUUID)) {
-                                    // Load state from remote
-                                    final RemoteRestoreResult remoteRestoreResult = remoteStoreRestoreService.restore(
-                                        clusterState,
-                                        lastKnownClusterUUID,
-                                        false,
-                                        new String[] {}
-                                    );
-                                    clusterState = remoteRestoreResult.getClusterState();
-                                }
-                            }
-                            remotePersistedState = new RemotePersistedState(remoteClusterStateService);
-                        }
                         persistedState = new LucenePersistedState(persistedClusterStateService, currentTerm, clusterState);
                     } else {
                         persistedState = new AsyncLucenePersistedState(
@@ -542,6 +552,9 @@ static class LucenePersistedState implements PersistedState {
             // out by this version of OpenSearch. TODO TBD should we avoid indexing when possible?
             final PersistedClusterStateService.Writer writer = persistedClusterStateService.createWriter();
             try {
+                // During remote state restore, there will be non empty metadata getting persisted with cluster UUID as
+                // ClusterState.UNKOWN_UUID . The valid UUID will be generated and persisted along with the first cluster state getting
+                // published.
                 writer.writeFullStateAndCommit(currentTerm, lastAcceptedState);
             } catch (Exception e) {
                 try {
@@ -603,6 +616,12 @@ public void setLastAcceptedState(ClusterState clusterState) {
             lastAcceptedState = clusterState;
         }
 
+        @Override
+        public PersistedStateStats getStats() {
+            // Note: These stats are not published yet, will come in future
+            return null;
+        }
+
         private PersistedClusterStateService.Writer getWriterSafe() {
             final PersistedClusterStateService.Writer writer = persistenceWriter.get();
             if (writer == null) {
@@ -647,9 +666,11 @@ public static class RemotePersistedState implements PersistedState {
         private ClusterState lastAcceptedState;
         private ClusterMetadataManifest lastAcceptedManifest;
         private final RemoteClusterStateService remoteClusterStateService;
+        private String previousClusterUUID;
 
-        public RemotePersistedState(final RemoteClusterStateService remoteClusterStateService) {
+        public RemotePersistedState(final RemoteClusterStateService remoteClusterStateService, final String previousClusterUUID) {
             this.remoteClusterStateService = remoteClusterStateService;
+            this.previousClusterUUID = previousClusterUUID;
         }
 
         @Override
@@ -674,7 +695,23 @@ public void setLastAcceptedState(ClusterState clusterState) {
             try {
                 final ClusterMetadataManifest manifest;
                 if (shouldWriteFullClusterState(clusterState)) {
-                    manifest = remoteClusterStateService.writeFullMetadata(clusterState);
+                    final Optional<ClusterMetadataManifest> latestManifest = remoteClusterStateService.getLatestClusterMetadataManifest(
+                        clusterState.getClusterName().value(),
+                        clusterState.metadata().clusterUUID()
+                    );
+                    if (latestManifest.isPresent()) {
+                        // The previous UUID should not change for the current UUID. So fetching the latest manifest
+                        // from remote store and getting the previous UUID.
+                        previousClusterUUID = latestManifest.get().getPreviousClusterUUID();
+                    } else {
+                        // When the user starts the cluster with remote state disabled but later enables the remote state,
+                        // there will not be any manifest for the current cluster UUID.
+                        logger.error(
+                            "Latest manifest is not present in remote store for cluster UUID: {}",
+                            clusterState.metadata().clusterUUID()
+                        );
+                    }
+                    manifest = remoteClusterStateService.writeFullMetadata(clusterState, previousClusterUUID);
                 } else {
                     assert verifyManifestAndClusterState(lastAcceptedManifest, lastAcceptedState) == true
                         : "Previous manifest and previous ClusterState are not in sync";
@@ -683,17 +720,17 @@ assert verifyManifestAndClusterState(lastAcceptedManifest, lastAcceptedState) ==
                 assert verifyManifestAndClusterState(manifest, clusterState) == true : "Manifest and ClusterState are not in sync";
                 lastAcceptedManifest = manifest;
                 lastAcceptedState = clusterState;
-            } catch (RepositoryMissingException e) {
-                // TODO This logic needs to be modified once PR for repo registration during bootstrap is pushed
-                // https://github.com/opensearch-project/OpenSearch/pull/9105/
-                // After the above PR is pushed, we can remove this silent failure and throw the exception instead.
-                logger.error("Remote repository is not yet registered");
-                lastAcceptedState = clusterState;
             } catch (Exception e) {
+                remoteClusterStateService.writeMetadataFailed();
                 handleExceptionOnWrite(e);
             }
         }
 
+        @Override
+        public PersistedStateStats getStats() {
+            return remoteClusterStateService.getStats();
+        }
+
         private boolean verifyManifestAndClusterState(ClusterMetadataManifest manifest, ClusterState clusterState) {
             assert manifest != null : "ClusterMetadataManifest is null";
             assert clusterState != null : "ClusterState is null";
@@ -723,11 +760,19 @@ public void markLastAcceptedStateAsCommitted() {
             try {
                 assert lastAcceptedState != null : "Last accepted state is not present";
                 assert lastAcceptedManifest != null : "Last accepted manifest is not present";
+                ClusterState clusterState = lastAcceptedState;
+                if (lastAcceptedState.metadata().clusterUUID().equals(Metadata.UNKNOWN_CLUSTER_UUID) == false
+                    && lastAcceptedState.metadata().clusterUUIDCommitted() == false) {
+                    Metadata.Builder metadataBuilder = Metadata.builder(lastAcceptedState.metadata());
+                    metadataBuilder.clusterUUIDCommitted(true);
+                    clusterState = ClusterState.builder(lastAcceptedState).metadata(metadataBuilder).build();
+                }
                 final ClusterMetadataManifest committedManifest = remoteClusterStateService.markLastStateAsCommitted(
-                    lastAcceptedState,
+                    clusterState,
                     lastAcceptedManifest
                 );
                 lastAcceptedManifest = committedManifest;
+                lastAcceptedState = clusterState;
             } catch (Exception e) {
                 handleExceptionOnWrite(e);
             }
diff --git a/server/src/main/java/org/opensearch/gateway/PersistedClusterStateService.java b/server/src/main/java/org/opensearch/gateway/PersistedClusterStateService.java
index 8db4736bcdc40..75beb6e29599c 100644
--- a/server/src/main/java/org/opensearch/gateway/PersistedClusterStateService.java
+++ b/server/src/main/java/org/opensearch/gateway/PersistedClusterStateService.java
@@ -111,16 +111,16 @@
  * Stores cluster metadata in a bare Lucene index (per data path) split across a number of documents. This is used by cluster-manager-eligible nodes
  * to record the last-accepted cluster state during publication. The metadata is written incrementally where possible, leaving alone any
  * documents that have not changed. The index has the following fields:
- *
+ * <p>
  * +------------------------------+-----------------------------+----------------------------------------------+
  * | "type" (string field)        | "index_uuid" (string field) | "data" (stored binary field in SMILE format) |
  * +------------------------------+-----------------------------+----------------------------------------------+
  * | GLOBAL_TYPE_NAME == "global" | (omitted)                   | Global metadata                              |
  * | INDEX_TYPE_NAME  == "index"  | Index UUID                  | Index metadata                               |
  * +------------------------------+-----------------------------+----------------------------------------------+
- *
+ * <p>
  * Additionally each commit has the following user data:
- *
+ * <p>
  * +---------------------------+-------------------------+-------------------------------------------------------------------------------+
  * |        Key symbol         |       Key literal       |                                     Value                                     |
  * +---------------------------+-------------------------+-------------------------------------------------------------------------------+
@@ -129,7 +129,7 @@
  * | NODE_ID_KEY               | "node_id"               | The (persistent) ID of the node that wrote this metadata                      |
  * | NODE_VERSION_KEY          | "node_version"          | The (ID of the) version of the node that wrote this metadata                  |
  * +---------------------------+-------------------------+-------------------------------------------------------------------------------+
- *
+ * <p>
  * (the last-accepted term is recorded in Metadata → CoordinationMetadata so does not need repeating here)
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/gateway/PrimaryShardAllocator.java b/server/src/main/java/org/opensearch/gateway/PrimaryShardAllocator.java
index 4dc9396751fc9..2807be00feeaa 100644
--- a/server/src/main/java/org/opensearch/gateway/PrimaryShardAllocator.java
+++ b/server/src/main/java/org/opensearch/gateway/PrimaryShardAllocator.java
@@ -69,7 +69,7 @@
  * that holds a copy of the shard.  The shard metadata from each node is compared against the
  * set of valid allocation IDs and for all valid shard copies (if any), the primary shard allocator
  * executes the allocation deciders to chose a copy to assign the primary shard to.
- *
+ * <p>
  * Note that the PrimaryShardAllocator does *not* allocate primaries on index creation
  * (see {@link org.opensearch.cluster.routing.allocation.allocator.BalancedShardsAllocator}),
  * nor does it allocate primaries when a primary shard failed and there is a valid replica
@@ -386,11 +386,11 @@ protected static NodeShardsResult buildNodeShardsResult(
             }
         }
 
-        /**
-         * Orders the active shards copies based on below comparators
-         * 1. No store exception i.e. shard copy is readable
-         * 2. Prefer previous primary shard
-         * 3. Prefer shard copy with the highest replication checkpoint. It is NO-OP for doc rep enabled indices.
+        /*
+          Orders the active shards copies based on below comparators
+          1. No store exception i.e. shard copy is readable
+          2. Prefer previous primary shard
+          3. Prefer shard copy with the highest replication checkpoint. It is NO-OP for doc rep enabled indices.
          */
         final Comparator<NodeGatewayStartedShards> comparator; // allocation preference
         if (matchAnyShard) {
diff --git a/server/src/main/java/org/opensearch/gateway/ReplicaShardAllocator.java b/server/src/main/java/org/opensearch/gateway/ReplicaShardAllocator.java
index a6c9319b6dc54..f530052c5bcd1 100644
--- a/server/src/main/java/org/opensearch/gateway/ReplicaShardAllocator.java
+++ b/server/src/main/java/org/opensearch/gateway/ReplicaShardAllocator.java
@@ -295,7 +295,7 @@ public AllocateUnassignedDecision makeAllocationDecision(
 
     /**
      * Determines if the shard can be allocated on at least one node based on the allocation deciders.
-     *
+     * <p>
      * Returns the best allocation decision for allocating the shard on any node (i.e. YES if at least one
      * node decided YES, THROTTLE if at least one node decided THROTTLE, and NO if none of the nodes decided
      * YES or THROTTLE).  If in explain mode, also returns the node-level explanations as the second element
diff --git a/server/src/main/java/org/opensearch/gateway/WriteStateException.java b/server/src/main/java/org/opensearch/gateway/WriteStateException.java
index e60eb0c11310d..e1de211ade38f 100644
--- a/server/src/main/java/org/opensearch/gateway/WriteStateException.java
+++ b/server/src/main/java/org/opensearch/gateway/WriteStateException.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.gateway;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOError;
 import java.io.IOException;
 import java.io.UncheckedIOException;
@@ -38,8 +40,9 @@
 /**
  * This exception is thrown when there is a problem of writing state to disk.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class WriteStateException extends IOException {
     private final boolean dirty;
 
diff --git a/server/src/main/java/org/opensearch/gateway/remote/ClusterMetadataManifest.java b/server/src/main/java/org/opensearch/gateway/remote/ClusterMetadataManifest.java
index 040c0663efbd9..4725f40076ce2 100644
--- a/server/src/main/java/org/opensearch/gateway/remote/ClusterMetadataManifest.java
+++ b/server/src/main/java/org/opensearch/gateway/remote/ClusterMetadataManifest.java
@@ -33,6 +33,9 @@
  */
 public class ClusterMetadataManifest implements Writeable, ToXContentFragment {
 
+    public static final int CODEC_V0 = 0; // Older codec version, where we haven't introduced codec versions for manifest.
+    public static final int CODEC_V1 = 1; // In Codec V1 we have introduced global-metadata and codec version in Manifest file.
+
     private static final ParseField CLUSTER_TERM_FIELD = new ParseField("cluster_term");
     private static final ParseField STATE_VERSION_FIELD = new ParseField("state_version");
     private static final ParseField CLUSTER_UUID_FIELD = new ParseField("cluster_uuid");
@@ -40,8 +43,11 @@ public class ClusterMetadataManifest implements Writeable, ToXContentFragment {
     private static final ParseField OPENSEARCH_VERSION_FIELD = new ParseField("opensearch_version");
     private static final ParseField NODE_ID_FIELD = new ParseField("node_id");
     private static final ParseField COMMITTED_FIELD = new ParseField("committed");
+    private static final ParseField CODEC_VERSION_FIELD = new ParseField("codec_version");
+    private static final ParseField GLOBAL_METADATA_FIELD = new ParseField("global_metadata");
     private static final ParseField INDICES_FIELD = new ParseField("indices");
     private static final ParseField PREVIOUS_CLUSTER_UUID = new ParseField("previous_cluster_uuid");
+    private static final ParseField CLUSTER_UUID_COMMITTED = new ParseField("cluster_uuid_committed");
 
     private static long term(Object[] fields) {
         return (long) fields[0];
@@ -79,7 +85,37 @@ private static String previousClusterUUID(Object[] fields) {
         return (String) fields[8];
     }
 
-    private static final ConstructingObjectParser<ClusterMetadataManifest, Void> PARSER = new ConstructingObjectParser<>(
+    private static boolean clusterUUIDCommitted(Object[] fields) {
+        return (boolean) fields[9];
+    }
+
+    private static int codecVersion(Object[] fields) {
+        return (int) fields[10];
+    }
+
+    private static String globalMetadataFileName(Object[] fields) {
+        return (String) fields[11];
+    }
+
+    private static final ConstructingObjectParser<ClusterMetadataManifest, Void> PARSER_V0 = new ConstructingObjectParser<>(
+        "cluster_metadata_manifest",
+        fields -> new ClusterMetadataManifest(
+            term(fields),
+            version(fields),
+            clusterUUID(fields),
+            stateUUID(fields),
+            opensearchVersion(fields),
+            nodeId(fields),
+            committed(fields),
+            CODEC_V0,
+            null,
+            indices(fields),
+            previousClusterUUID(fields),
+            clusterUUIDCommitted(fields)
+        )
+    );
+
+    private static final ConstructingObjectParser<ClusterMetadataManifest, Void> PARSER_V1 = new ConstructingObjectParser<>(
         "cluster_metadata_manifest",
         fields -> new ClusterMetadataManifest(
             term(fields),
@@ -89,27 +125,45 @@ private static String previousClusterUUID(Object[] fields) {
             opensearchVersion(fields),
             nodeId(fields),
             committed(fields),
+            codecVersion(fields),
+            globalMetadataFileName(fields),
             indices(fields),
-            previousClusterUUID(fields)
+            previousClusterUUID(fields),
+            clusterUUIDCommitted(fields)
         )
     );
 
+    private static final ConstructingObjectParser<ClusterMetadataManifest, Void> CURRENT_PARSER = PARSER_V1;
+
     static {
-        PARSER.declareLong(ConstructingObjectParser.constructorArg(), CLUSTER_TERM_FIELD);
-        PARSER.declareLong(ConstructingObjectParser.constructorArg(), STATE_VERSION_FIELD);
-        PARSER.declareString(ConstructingObjectParser.constructorArg(), CLUSTER_UUID_FIELD);
-        PARSER.declareString(ConstructingObjectParser.constructorArg(), STATE_UUID_FIELD);
-        PARSER.declareInt(ConstructingObjectParser.constructorArg(), OPENSEARCH_VERSION_FIELD);
-        PARSER.declareString(ConstructingObjectParser.constructorArg(), NODE_ID_FIELD);
-        PARSER.declareBoolean(ConstructingObjectParser.constructorArg(), COMMITTED_FIELD);
-        PARSER.declareObjectArray(
+        declareParser(PARSER_V0, CODEC_V0);
+        declareParser(PARSER_V1, CODEC_V1);
+    }
+
+    private static void declareParser(ConstructingObjectParser<ClusterMetadataManifest, Void> parser, long codec_version) {
+        parser.declareLong(ConstructingObjectParser.constructorArg(), CLUSTER_TERM_FIELD);
+        parser.declareLong(ConstructingObjectParser.constructorArg(), STATE_VERSION_FIELD);
+        parser.declareString(ConstructingObjectParser.constructorArg(), CLUSTER_UUID_FIELD);
+        parser.declareString(ConstructingObjectParser.constructorArg(), STATE_UUID_FIELD);
+        parser.declareInt(ConstructingObjectParser.constructorArg(), OPENSEARCH_VERSION_FIELD);
+        parser.declareString(ConstructingObjectParser.constructorArg(), NODE_ID_FIELD);
+        parser.declareBoolean(ConstructingObjectParser.constructorArg(), COMMITTED_FIELD);
+        parser.declareObjectArray(
             ConstructingObjectParser.constructorArg(),
             (p, c) -> UploadedIndexMetadata.fromXContent(p),
             INDICES_FIELD
         );
-        PARSER.declareString(ConstructingObjectParser.constructorArg(), PREVIOUS_CLUSTER_UUID);
+        parser.declareString(ConstructingObjectParser.constructorArg(), PREVIOUS_CLUSTER_UUID);
+        parser.declareBoolean(ConstructingObjectParser.constructorArg(), CLUSTER_UUID_COMMITTED);
+
+        if (codec_version >= CODEC_V1) {
+            parser.declareInt(ConstructingObjectParser.constructorArg(), CODEC_VERSION_FIELD);
+            parser.declareString(ConstructingObjectParser.constructorArg(), GLOBAL_METADATA_FIELD);
+        }
     }
 
+    private final int codecVersion;
+    private final String globalMetadataFileName;
     private final List<UploadedIndexMetadata> indices;
     private final long clusterTerm;
     private final long stateVersion;
@@ -119,6 +173,7 @@ private static String previousClusterUUID(Object[] fields) {
     private final String nodeId;
     private final boolean committed;
     private final String previousClusterUUID;
+    private final boolean clusterUUIDCommitted;
 
     public List<UploadedIndexMetadata> getIndices() {
         return indices;
@@ -156,6 +211,18 @@ public String getPreviousClusterUUID() {
         return previousClusterUUID;
     }
 
+    public boolean isClusterUUIDCommitted() {
+        return clusterUUIDCommitted;
+    }
+
+    public int getCodecVersion() {
+        return codecVersion;
+    }
+
+    public String getGlobalMetadataFileName() {
+        return globalMetadataFileName;
+    }
+
     public ClusterMetadataManifest(
         long clusterTerm,
         long version,
@@ -164,8 +231,11 @@ public ClusterMetadataManifest(
         Version opensearchVersion,
         String nodeId,
         boolean committed,
+        int codecVersion,
+        String globalMetadataFileName,
         List<UploadedIndexMetadata> indices,
-        String previousClusterUUID
+        String previousClusterUUID,
+        boolean clusterUUIDCommitted
     ) {
         this.clusterTerm = clusterTerm;
         this.stateVersion = version;
@@ -174,8 +244,11 @@ public ClusterMetadataManifest(
         this.opensearchVersion = opensearchVersion;
         this.nodeId = nodeId;
         this.committed = committed;
+        this.codecVersion = codecVersion;
+        this.globalMetadataFileName = globalMetadataFileName;
         this.indices = Collections.unmodifiableList(indices);
         this.previousClusterUUID = previousClusterUUID;
+        this.clusterUUIDCommitted = clusterUUIDCommitted;
     }
 
     public ClusterMetadataManifest(StreamInput in) throws IOException {
@@ -188,6 +261,14 @@ public ClusterMetadataManifest(StreamInput in) throws IOException {
         this.committed = in.readBoolean();
         this.indices = Collections.unmodifiableList(in.readList(UploadedIndexMetadata::new));
         this.previousClusterUUID = in.readString();
+        this.clusterUUIDCommitted = in.readBoolean();
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            this.codecVersion = in.readInt();
+            this.globalMetadataFileName = in.readString();
+        } else {
+            this.codecVersion = CODEC_V0; // Default codec
+            this.globalMetadataFileName = null;
+        }
     }
 
     public static Builder builder() {
@@ -215,6 +296,11 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         }
         builder.endArray();
         builder.field(PREVIOUS_CLUSTER_UUID.getPreferredName(), getPreviousClusterUUID());
+        builder.field(CLUSTER_UUID_COMMITTED.getPreferredName(), isClusterUUIDCommitted());
+        if (onOrAfterCodecVersion(CODEC_V1)) {
+            builder.field(CODEC_VERSION_FIELD.getPreferredName(), getCodecVersion());
+            builder.field(GLOBAL_METADATA_FIELD.getPreferredName(), getGlobalMetadataFileName());
+        }
         return builder;
     }
 
@@ -229,6 +315,11 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeBoolean(committed);
         out.writeCollection(indices);
         out.writeString(previousClusterUUID);
+        out.writeBoolean(clusterUUIDCommitted);
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeInt(codecVersion);
+            out.writeString(globalMetadataFileName);
+        }
     }
 
     @Override
@@ -248,12 +339,17 @@ public boolean equals(Object o) {
             && Objects.equals(opensearchVersion, that.opensearchVersion)
             && Objects.equals(nodeId, that.nodeId)
             && Objects.equals(committed, that.committed)
-            && Objects.equals(previousClusterUUID, that.previousClusterUUID);
+            && Objects.equals(previousClusterUUID, that.previousClusterUUID)
+            && Objects.equals(clusterUUIDCommitted, that.clusterUUIDCommitted)
+            && Objects.equals(globalMetadataFileName, that.globalMetadataFileName)
+            && Objects.equals(codecVersion, that.codecVersion);
     }
 
     @Override
     public int hashCode() {
         return Objects.hash(
+            codecVersion,
+            globalMetadataFileName,
             indices,
             clusterTerm,
             stateVersion,
@@ -262,7 +358,8 @@ public int hashCode() {
             opensearchVersion,
             nodeId,
             committed,
-            previousClusterUUID
+            previousClusterUUID,
+            clusterUUIDCommitted
         );
     }
 
@@ -271,8 +368,16 @@ public String toString() {
         return Strings.toString(MediaTypeRegistry.JSON, this);
     }
 
+    public boolean onOrAfterCodecVersion(int codecVersion) {
+        return this.codecVersion >= codecVersion;
+    }
+
+    public static ClusterMetadataManifest fromXContentV0(XContentParser parser) throws IOException {
+        return PARSER_V0.parse(parser, null);
+    }
+
     public static ClusterMetadataManifest fromXContent(XContentParser parser) throws IOException {
-        return PARSER.parse(parser, null);
+        return CURRENT_PARSER.parse(parser, null);
     }
 
     /**
@@ -282,6 +387,8 @@ public static ClusterMetadataManifest fromXContent(XContentParser parser) throws
      */
     public static class Builder {
 
+        private String globalMetadataFileName;
+        private int codecVersion;
         private List<UploadedIndexMetadata> indices;
         private long clusterTerm;
         private long stateVersion;
@@ -291,12 +398,23 @@ public static class Builder {
         private String nodeId;
         private String previousClusterUUID;
         private boolean committed;
+        private boolean clusterUUIDCommitted;
 
         public Builder indices(List<UploadedIndexMetadata> indices) {
             this.indices = indices;
             return this;
         }
 
+        public Builder codecVersion(int codecVersion) {
+            this.codecVersion = codecVersion;
+            return this;
+        }
+
+        public Builder globalMetadataFileName(String globalMetadataFileName) {
+            this.globalMetadataFileName = globalMetadataFileName;
+            return this;
+        }
+
         public Builder clusterTerm(long clusterTerm) {
             this.clusterTerm = clusterTerm;
             return this;
@@ -341,6 +459,11 @@ public Builder previousClusterUUID(String previousClusterUUID) {
             return this;
         }
 
+        public Builder clusterUUIDCommitted(boolean clusterUUIDCommitted) {
+            this.clusterUUIDCommitted = clusterUUIDCommitted;
+            return this;
+        }
+
         public Builder() {
             indices = new ArrayList<>();
         }
@@ -353,8 +476,11 @@ public Builder(ClusterMetadataManifest manifest) {
             this.opensearchVersion = manifest.opensearchVersion;
             this.nodeId = manifest.nodeId;
             this.committed = manifest.committed;
+            this.globalMetadataFileName = manifest.globalMetadataFileName;
+            this.codecVersion = manifest.codecVersion;
             this.indices = new ArrayList<>(manifest.indices);
             this.previousClusterUUID = manifest.previousClusterUUID;
+            this.clusterUUIDCommitted = manifest.clusterUUIDCommitted;
         }
 
         public ClusterMetadataManifest build() {
@@ -366,8 +492,11 @@ public ClusterMetadataManifest build() {
                 opensearchVersion,
                 nodeId,
                 committed,
+                codecVersion,
+                globalMetadataFileName,
                 indices,
-                previousClusterUUID
+                previousClusterUUID,
+                clusterUUIDCommitted
             );
         }
 
diff --git a/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java b/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java
index cf750bb11f3f8..c892b475d71da 100644
--- a/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java
+++ b/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java
@@ -15,6 +15,7 @@
 import org.opensearch.action.LatchedActionListener;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.blobstore.BlobContainer;
 import org.opensearch.common.blobstore.BlobMetadata;
@@ -27,6 +28,7 @@
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.Index;
+import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.gateway.remote.ClusterMetadataManifest.UploadedIndexMetadata;
 import org.opensearch.index.remote.RemoteStoreUtils;
 import org.opensearch.index.translog.transfer.BlobStoreTransferService;
@@ -55,6 +57,7 @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
 import java.util.function.LongSupplier;
 import java.util.function.Supplier;
@@ -80,7 +83,32 @@ public class RemoteClusterStateService implements Closeable {
 
     private static final Logger logger = LogManager.getLogger(RemoteClusterStateService.class);
 
-    public static final int INDEX_METADATA_UPLOAD_WAIT_MILLIS = 20000;
+    public static final TimeValue INDEX_METADATA_UPLOAD_TIMEOUT_DEFAULT = TimeValue.timeValueMillis(20000);
+
+    public static final TimeValue GLOBAL_METADATA_UPLOAD_TIMEOUT_DEFAULT = TimeValue.timeValueMillis(20000);
+
+    public static final TimeValue METADATA_MANIFEST_UPLOAD_TIMEOUT_DEFAULT = TimeValue.timeValueMillis(20000);
+
+    public static final Setting<TimeValue> INDEX_METADATA_UPLOAD_TIMEOUT_SETTING = Setting.timeSetting(
+        "cluster.remote_store.state.index_metadata.upload_timeout",
+        INDEX_METADATA_UPLOAD_TIMEOUT_DEFAULT,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    public static final Setting<TimeValue> GLOBAL_METADATA_UPLOAD_TIMEOUT_SETTING = Setting.timeSetting(
+        "cluster.remote_store.state.global_metadata.upload_timeout",
+        GLOBAL_METADATA_UPLOAD_TIMEOUT_DEFAULT,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    public static final Setting<TimeValue> METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING = Setting.timeSetting(
+        "cluster.remote_store.state.metadata_manifest.upload_timeout",
+        METADATA_MANIFEST_UPLOAD_TIMEOUT_DEFAULT,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
 
     public static final ChecksumBlobStoreFormat<IndexMetadata> INDEX_METADATA_FORMAT = new ChecksumBlobStoreFormat<>(
         "index-metadata",
@@ -88,11 +116,27 @@ public class RemoteClusterStateService implements Closeable {
         IndexMetadata::fromXContent
     );
 
+    public static final ChecksumBlobStoreFormat<Metadata> GLOBAL_METADATA_FORMAT = new ChecksumBlobStoreFormat<>(
+        "metadata",
+        METADATA_NAME_FORMAT,
+        Metadata::fromXContent
+    );
+
+    /**
+     * Manifest format compatible with older codec v0, where codec version was missing.
+     */
+    public static final ChecksumBlobStoreFormat<ClusterMetadataManifest> CLUSTER_METADATA_MANIFEST_FORMAT_V0 =
+        new ChecksumBlobStoreFormat<>("cluster-metadata-manifest", METADATA_MANIFEST_NAME_FORMAT, ClusterMetadataManifest::fromXContentV0);
+
+    /**
+     * Manifest format compatible with codec v1, where we introduced codec versions/global metadata.
+     */
     public static final ChecksumBlobStoreFormat<ClusterMetadataManifest> CLUSTER_METADATA_MANIFEST_FORMAT = new ChecksumBlobStoreFormat<>(
         "cluster-metadata-manifest",
         METADATA_MANIFEST_NAME_FORMAT,
         ClusterMetadataManifest::fromXContent
     );
+
     /**
      * Used to specify if cluster state metadata should be published to remote store
      */
@@ -103,11 +147,13 @@ public class RemoteClusterStateService implements Closeable {
         Property.Final
     );
 
-    private static final String CLUSTER_STATE_PATH_TOKEN = "cluster-state";
-    private static final String INDEX_PATH_TOKEN = "index";
-    private static final String MANIFEST_PATH_TOKEN = "manifest";
-    private static final String MANIFEST_FILE_PREFIX = "manifest";
-    private static final String INDEX_METADATA_FILE_PREFIX = "metadata";
+    public static final String CLUSTER_STATE_PATH_TOKEN = "cluster-state";
+    public static final String INDEX_PATH_TOKEN = "index";
+    public static final String GLOBAL_METADATA_PATH_TOKEN = "global-metadata";
+    public static final String MANIFEST_PATH_TOKEN = "manifest";
+    public static final String MANIFEST_FILE_PREFIX = "manifest";
+    public static final String METADATA_FILE_PREFIX = "metadata";
+    public static final int SPLITED_MANIFEST_FILE_LENGTH = 6; // file name manifest__term__version__C/P__timestamp__codecversion
 
     private final String nodeId;
     private final Supplier<RepositoriesService> repositoriesService;
@@ -118,7 +164,24 @@ public class RemoteClusterStateService implements Closeable {
     private BlobStoreTransferService blobStoreTransferService;
     private volatile TimeValue slowWriteLoggingThreshold;
 
+    private volatile TimeValue indexMetadataUploadTimeout;
+    private volatile TimeValue globalMetadataUploadTimeout;
+    private volatile TimeValue metadataManifestUploadTimeout;
+
     private final AtomicBoolean deleteStaleMetadataRunning = new AtomicBoolean(false);
+    private final RemotePersistenceStats remoteStateStats;
+    public static final int INDEX_METADATA_CURRENT_CODEC_VERSION = 1;
+    public static final int MANIFEST_CURRENT_CODEC_VERSION = ClusterMetadataManifest.CODEC_V1;
+    public static final int GLOBAL_METADATA_CURRENT_CODEC_VERSION = 1;
+
+    // ToXContent Params with gateway mode.
+    // We are using gateway context mode to persist all custom metadata.
+    public static final ToXContent.Params FORMAT_PARAMS;
+    static {
+        Map<String, String> params = new HashMap<>(1);
+        params.put(Metadata.CONTEXT_MODE_PARAM, Metadata.CONTEXT_MODE_GATEWAY);
+        FORMAT_PARAMS = new ToXContent.MapParams(params);
+    }
 
     public RemoteClusterStateService(
         String nodeId,
@@ -135,7 +198,14 @@ public RemoteClusterStateService(
         this.relativeTimeNanosSupplier = relativeTimeNanosSupplier;
         this.threadpool = threadPool;
         this.slowWriteLoggingThreshold = clusterSettings.get(SLOW_WRITE_LOGGING_THRESHOLD);
+        this.indexMetadataUploadTimeout = clusterSettings.get(INDEX_METADATA_UPLOAD_TIMEOUT_SETTING);
+        this.globalMetadataUploadTimeout = clusterSettings.get(GLOBAL_METADATA_UPLOAD_TIMEOUT_SETTING);
+        this.metadataManifestUploadTimeout = clusterSettings.get(METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING);
         clusterSettings.addSettingsUpdateConsumer(SLOW_WRITE_LOGGING_THRESHOLD, this::setSlowWriteLoggingThreshold);
+        clusterSettings.addSettingsUpdateConsumer(INDEX_METADATA_UPLOAD_TIMEOUT_SETTING, this::setIndexMetadataUploadTimeout);
+        clusterSettings.addSettingsUpdateConsumer(GLOBAL_METADATA_UPLOAD_TIMEOUT_SETTING, this::setGlobalMetadataUploadTimeout);
+        clusterSettings.addSettingsUpdateConsumer(METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING, this::setMetadataManifestUploadTimeout);
+        this.remoteStateStats = new RemotePersistenceStats();
     }
 
     private BlobStoreTransferService getBlobStoreTransferService() {
@@ -152,27 +222,32 @@ private BlobStoreTransferService getBlobStoreTransferService() {
      * @return A manifest object which contains the details of uploaded entity metadata.
      */
     @Nullable
-    public ClusterMetadataManifest writeFullMetadata(ClusterState clusterState) throws IOException {
+    public ClusterMetadataManifest writeFullMetadata(ClusterState clusterState, String previousClusterUUID) throws IOException {
         final long startTimeNanos = relativeTimeNanosSupplier.getAsLong();
         if (clusterState.nodes().isLocalNodeElectedClusterManager() == false) {
             logger.error("Local node is not elected cluster manager. Exiting");
             return null;
         }
 
-        // should fetch the previous cluster UUID before writing full cluster state.
-        // Whenever a new election happens, a new leader will be elected and it might have stale previous UUID
-        final String previousClusterUUID = fetchPreviousClusterUUID(
-            clusterState.getClusterName().value(),
-            clusterState.metadata().clusterUUID()
-        );
+        // TODO: we can upload global metadata and index metadata in parallel. [issue: #10645]
+        // Write globalMetadata
+        String globalMetadataFile = writeGlobalMetadata(clusterState);
 
         // any validations before/after upload ?
         final List<UploadedIndexMetadata> allUploadedIndexMetadata = writeIndexMetadataParallel(
             clusterState,
             new ArrayList<>(clusterState.metadata().indices().values())
         );
-        final ClusterMetadataManifest manifest = uploadManifest(clusterState, allUploadedIndexMetadata, previousClusterUUID, false);
+        final ClusterMetadataManifest manifest = uploadManifest(
+            clusterState,
+            allUploadedIndexMetadata,
+            previousClusterUUID,
+            globalMetadataFile,
+            false
+        );
         final long durationMillis = TimeValue.nsecToMSec(relativeTimeNanosSupplier.getAsLong() - startTimeNanos);
+        remoteStateStats.stateSucceeded();
+        remoteStateStats.stateTook(durationMillis);
         if (durationMillis >= slowWriteLoggingThreshold.getMillis()) {
             logger.warn(
                 "writing cluster state took [{}ms] which is above the warn threshold of [{}]; " + "wrote full state with [{}] indices",
@@ -181,9 +256,8 @@ public ClusterMetadataManifest writeFullMetadata(ClusterState clusterState) thro
                 allUploadedIndexMetadata.size()
             );
         } else {
-            // todo change to debug
             logger.info(
-                "writing cluster state took [{}ms]; " + "wrote full state with [{}] indices",
+                "writing cluster state took [{}ms]; " + "wrote full state with [{}] indices and global metadata",
                 durationMillis,
                 allUploadedIndexMetadata.size()
             );
@@ -210,6 +284,23 @@ public ClusterMetadataManifest writeIncrementalMetadata(
             return null;
         }
         assert previousClusterState.metadata().coordinationMetadata().term() == clusterState.metadata().coordinationMetadata().term();
+
+        // Write Global Metadata
+        final boolean updateGlobalMetadata = Metadata.isGlobalStateEquals(
+            previousClusterState.metadata(),
+            clusterState.metadata()
+        ) == false;
+        String globalMetadataFile;
+        // For migration case from codec V0 to V1, we have added null check on global metadata file,
+        // If file is empty and codec is 1 then write global metadata.
+        if (updateGlobalMetadata || previousManifest.getGlobalMetadataFileName() == null) {
+            globalMetadataFile = writeGlobalMetadata(clusterState);
+        } else {
+            logger.debug("Global metadata has not updated in cluster state, skipping upload of it");
+            globalMetadataFile = previousManifest.getGlobalMetadataFileName();
+        }
+
+        // Write Index Metadata
         final Map<String, Long> previousStateIndexMetadataVersionByName = new HashMap<>();
         for (final IndexMetadata indexMetadata : previousClusterState.metadata().indices().values()) {
             previousStateIndexMetadataVersionByName.put(indexMetadata.getIndex().getName(), indexMetadata.getVersion());
@@ -226,7 +317,7 @@ public ClusterMetadataManifest writeIncrementalMetadata(
         for (final IndexMetadata indexMetadata : clusterState.metadata().indices().values()) {
             final Long previousVersion = previousStateIndexMetadataVersionByName.get(indexMetadata.getIndex().getName());
             if (previousVersion == null || indexMetadata.getVersion() != previousVersion) {
-                logger.trace(
+                logger.debug(
                     "updating metadata for [{}], changing version from [{}] to [{}]",
                     indexMetadata.getIndex(),
                     previousVersion,
@@ -252,31 +343,95 @@ public ClusterMetadataManifest writeIncrementalMetadata(
             clusterState,
             new ArrayList<>(allUploadedIndexMetadata.values()),
             previousManifest.getPreviousClusterUUID(),
+            globalMetadataFile,
             false
         );
         deleteStaleClusterMetadata(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID(), RETAINED_MANIFESTS);
 
         final long durationMillis = TimeValue.nsecToMSec(relativeTimeNanosSupplier.getAsLong() - startTimeNanos);
+        remoteStateStats.stateSucceeded();
+        remoteStateStats.stateTook(durationMillis);
         if (durationMillis >= slowWriteLoggingThreshold.getMillis()) {
             logger.warn(
                 "writing cluster state took [{}ms] which is above the warn threshold of [{}]; "
-                    + "wrote  metadata for [{}] indices and skipped [{}] unchanged indices",
+                    + "wrote  metadata for [{}] indices and skipped [{}] unchanged indices, global metadata updated : [{}]",
                 durationMillis,
                 slowWriteLoggingThreshold,
                 numIndicesUpdated,
-                numIndicesUnchanged
+                numIndicesUnchanged,
+                updateGlobalMetadata
             );
         } else {
-            logger.trace(
-                "writing cluster state took [{}ms]; " + "wrote metadata for [{}] indices and skipped [{}] unchanged indices",
+            logger.info(
+                "writing cluster state for version [{}] took [{}ms]; "
+                    + "wrote metadata for [{}] indices and skipped [{}] unchanged indices, global metadata updated : [{}]",
+                manifest.getStateVersion(),
                 durationMillis,
                 numIndicesUpdated,
-                numIndicesUnchanged
+                numIndicesUnchanged,
+                updateGlobalMetadata
             );
         }
         return manifest;
     }
 
+    /**
+     * Uploads provided ClusterState's global Metadata to remote store in parallel.
+     * The call is blocking so the method waits for upload to finish and then return.
+     *
+     * @param clusterState current ClusterState
+     * @return String file name where globalMetadata file is stored.
+     */
+    private String writeGlobalMetadata(ClusterState clusterState) throws IOException {
+
+        AtomicReference<String> result = new AtomicReference<String>();
+        AtomicReference<Exception> exceptionReference = new AtomicReference<Exception>();
+
+        final BlobContainer globalMetadataContainer = globalMetadataContainer(
+            clusterState.getClusterName().value(),
+            clusterState.metadata().clusterUUID()
+        );
+        final String globalMetadataFilename = globalMetadataFileName(clusterState.metadata());
+
+        // latch to wait until upload is not finished
+        CountDownLatch latch = new CountDownLatch(1);
+
+        LatchedActionListener completionListener = new LatchedActionListener<>(ActionListener.wrap(resp -> {
+            logger.trace(String.format(Locale.ROOT, "GlobalMetadata uploaded successfully."));
+            result.set(globalMetadataContainer.path().buildAsString() + globalMetadataFilename);
+        }, ex -> { exceptionReference.set(ex); }), latch);
+
+        GLOBAL_METADATA_FORMAT.writeAsyncWithUrgentPriority(
+            clusterState.metadata(),
+            globalMetadataContainer,
+            globalMetadataFilename,
+            blobStoreRepository.getCompressor(),
+            completionListener,
+            FORMAT_PARAMS
+        );
+
+        try {
+            if (latch.await(getGlobalMetadataUploadTimeout().millis(), TimeUnit.MILLISECONDS) == false) {
+                // TODO: We should add metrics where transfer is timing out. [Issue: #10687]
+                RemoteStateTransferException ex = new RemoteStateTransferException(
+                    String.format(Locale.ROOT, "Timed out waiting for transfer of global metadata to complete")
+                );
+                throw ex;
+            }
+        } catch (InterruptedException ex) {
+            RemoteStateTransferException exception = new RemoteStateTransferException(
+                String.format(Locale.ROOT, "Timed out waiting for transfer of global metadata to complete - %s"),
+                ex
+            );
+            Thread.currentThread().interrupt();
+            throw exception;
+        }
+        if (exceptionReference.get() != null) {
+            throw new RemoteStateTransferException(exceptionReference.get().getMessage(), exceptionReference.get());
+        }
+        return result.get();
+    }
+
     /**
      * Uploads provided IndexMetadata's to remote store in parallel. The call is blocking so the method waits for upload to finish and then return.
      *
@@ -297,7 +452,7 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
                 );
                 result.add(uploadedIndexMetadata);
             }, ex -> {
-                assert ex instanceof IndexMetadataTransferException;
+                assert ex instanceof RemoteStateTransferException;
                 logger.error(
                     () -> new ParameterizedMessage("Exception during transfer of IndexMetadata to Remote {}", ex.getMessage()),
                     ex
@@ -313,8 +468,8 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
         }
 
         try {
-            if (latch.await(INDEX_METADATA_UPLOAD_WAIT_MILLIS, TimeUnit.MILLISECONDS) == false) {
-                IndexMetadataTransferException ex = new IndexMetadataTransferException(
+            if (latch.await(getIndexMetadataUploadTimeout().millis(), TimeUnit.MILLISECONDS) == false) {
+                RemoteStateTransferException ex = new RemoteStateTransferException(
                     String.format(
                         Locale.ROOT,
                         "Timed out waiting for transfer of index metadata to complete - %s",
@@ -326,7 +481,7 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
             }
         } catch (InterruptedException ex) {
             exceptionList.forEach(ex::addSuppressed);
-            IndexMetadataTransferException exception = new IndexMetadataTransferException(
+            RemoteStateTransferException exception = new RemoteStateTransferException(
                 String.format(
                     Locale.ROOT,
                     "Timed out waiting for transfer of index metadata to complete - %s",
@@ -338,7 +493,7 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
             throw exception;
         }
         if (exceptionList.size() > 0) {
-            IndexMetadataTransferException exception = new IndexMetadataTransferException(
+            RemoteStateTransferException exception = new RemoteStateTransferException(
                 String.format(
                     Locale.ROOT,
                     "Exception during transfer of IndexMetadata to Remote %s",
@@ -377,28 +532,37 @@ private void writeIndexMetadataAsync(
                     indexMetadataContainer.path().buildAsString() + indexMetadataFilename
                 )
             ),
-            ex -> latchedActionListener.onFailure(new IndexMetadataTransferException(indexMetadata.getIndex().toString(), ex))
+            ex -> latchedActionListener.onFailure(new RemoteStateTransferException(indexMetadata.getIndex().toString(), ex))
         );
 
-        INDEX_METADATA_FORMAT.writeAsync(
+        INDEX_METADATA_FORMAT.writeAsyncWithUrgentPriority(
             indexMetadata,
             indexMetadataContainer,
             indexMetadataFilename,
             blobStoreRepository.getCompressor(),
-            completionListener
+            completionListener,
+            FORMAT_PARAMS
         );
     }
 
     @Nullable
     public ClusterMetadataManifest markLastStateAsCommitted(ClusterState clusterState, ClusterMetadataManifest previousManifest)
         throws IOException {
+        assert clusterState != null : "Last accepted cluster state is not set";
         if (clusterState.nodes().isLocalNodeElectedClusterManager() == false) {
             logger.error("Local node is not elected cluster manager. Exiting");
             return null;
         }
-        assert clusterState != null : "Last accepted cluster state is not set";
         assert previousManifest != null : "Last cluster metadata manifest is not set";
-        return uploadManifest(clusterState, previousManifest.getIndices(), previousManifest.getPreviousClusterUUID(), true);
+        ClusterMetadataManifest committedManifest = uploadManifest(
+            clusterState,
+            previousManifest.getIndices(),
+            previousManifest.getPreviousClusterUUID(),
+            previousManifest.getGlobalMetadataFileName(),
+            true
+        );
+        deleteStaleClusterUUIDs(clusterState, committedManifest);
+        return committedManifest;
     }
 
     @Override
@@ -423,10 +587,11 @@ private ClusterMetadataManifest uploadManifest(
         ClusterState clusterState,
         List<UploadedIndexMetadata> uploadedIndexMetadata,
         String previousClusterUUID,
+        String globalClusterMetadataFileName,
         boolean committed
     ) throws IOException {
         synchronized (this) {
-            final String manifestFileName = getManifestFileName(clusterState.term(), clusterState.version());
+            final String manifestFileName = getManifestFileName(clusterState.term(), clusterState.version(), committed);
             final ClusterMetadataManifest manifest = new ClusterMetadataManifest(
                 clusterState.term(),
                 clusterState.getVersion(),
@@ -435,8 +600,11 @@ private ClusterMetadataManifest uploadManifest(
                 Version.CURRENT,
                 nodeId,
                 committed,
+                MANIFEST_CURRENT_CODEC_VERSION,
+                globalClusterMetadataFileName,
                 uploadedIndexMetadata,
-                previousClusterUUID
+                previousClusterUUID,
+                clusterState.metadata().clusterUUIDCommitted()
             );
             writeMetadataManifest(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID(), manifest, manifestFileName);
             return manifest;
@@ -445,8 +613,50 @@ private ClusterMetadataManifest uploadManifest(
 
     private void writeMetadataManifest(String clusterName, String clusterUUID, ClusterMetadataManifest uploadManifest, String fileName)
         throws IOException {
+        AtomicReference<String> result = new AtomicReference<String>();
+        AtomicReference<Exception> exceptionReference = new AtomicReference<Exception>();
+
         final BlobContainer metadataManifestContainer = manifestContainer(clusterName, clusterUUID);
-        CLUSTER_METADATA_MANIFEST_FORMAT.write(uploadManifest, metadataManifestContainer, fileName, blobStoreRepository.getCompressor());
+
+        // latch to wait until upload is not finished
+        CountDownLatch latch = new CountDownLatch(1);
+
+        LatchedActionListener completionListener = new LatchedActionListener<>(ActionListener.wrap(resp -> {
+            logger.trace(String.format(Locale.ROOT, "Manifest file uploaded successfully."));
+        }, ex -> { exceptionReference.set(ex); }), latch);
+
+        CLUSTER_METADATA_MANIFEST_FORMAT.writeAsyncWithUrgentPriority(
+            uploadManifest,
+            metadataManifestContainer,
+            fileName,
+            blobStoreRepository.getCompressor(),
+            completionListener,
+            FORMAT_PARAMS
+        );
+
+        try {
+            if (latch.await(getMetadataManifestUploadTimeout().millis(), TimeUnit.MILLISECONDS) == false) {
+                RemoteStateTransferException ex = new RemoteStateTransferException(
+                    String.format(Locale.ROOT, "Timed out waiting for transfer of manifest file to complete")
+                );
+                throw ex;
+            }
+        } catch (InterruptedException ex) {
+            RemoteStateTransferException exception = new RemoteStateTransferException(
+                String.format(Locale.ROOT, "Timed out waiting for transfer of manifest file to complete - %s"),
+                ex
+            );
+            Thread.currentThread().interrupt();
+            throw exception;
+        }
+        if (exceptionReference.get() != null) {
+            throw new RemoteStateTransferException(exceptionReference.get().getMessage(), exceptionReference.get());
+        }
+        logger.debug(
+            "Metadata manifest file [{}] written during [{}] phase. ",
+            fileName,
+            uploadManifest.isCommitted() ? "commit" : "publish"
+        );
     }
 
     private String fetchPreviousClusterUUID(String clusterName, String clusterUUID) {
@@ -465,6 +675,12 @@ private BlobContainer indexMetadataContainer(String clusterName, String clusterU
             .blobContainer(getCusterMetadataBasePath(clusterName, clusterUUID).add(INDEX_PATH_TOKEN).add(indexUUID));
     }
 
+    private BlobContainer globalMetadataContainer(String clusterName, String clusterUUID) {
+        // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/global-metadata/
+        return blobStoreRepository.blobStore()
+            .blobContainer(getCusterMetadataBasePath(clusterName, clusterUUID).add(GLOBAL_METADATA_PATH_TOKEN));
+    }
+
     private BlobContainer manifestContainer(String clusterName, String clusterUUID) {
         // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/manifest
         return blobStoreRepository.blobStore().blobContainer(getManifestFolderPath(clusterName, clusterUUID));
@@ -487,22 +703,65 @@ private void setSlowWriteLoggingThreshold(TimeValue slowWriteLoggingThreshold) {
         this.slowWriteLoggingThreshold = slowWriteLoggingThreshold;
     }
 
-    private static String getManifestFileName(long term, long version) {
-        // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/manifest/manifest_2147483642_2147483637_456536447
-        return String.join(DELIMITER, getManifestFileNamePrefix(term, version), RemoteStoreUtils.invertLong(System.currentTimeMillis()));
+    private void setIndexMetadataUploadTimeout(TimeValue newIndexMetadataUploadTimeout) {
+        this.indexMetadataUploadTimeout = newIndexMetadataUploadTimeout;
+    }
+
+    private void setGlobalMetadataUploadTimeout(TimeValue newGlobalMetadataUploadTimeout) {
+        this.globalMetadataUploadTimeout = newGlobalMetadataUploadTimeout;
+    }
+
+    private void setMetadataManifestUploadTimeout(TimeValue newMetadataManifestUploadTimeout) {
+        this.metadataManifestUploadTimeout = newMetadataManifestUploadTimeout;
+    }
+
+    public TimeValue getIndexMetadataUploadTimeout() {
+        return this.indexMetadataUploadTimeout;
+    }
+
+    public TimeValue getGlobalMetadataUploadTimeout() {
+        return this.globalMetadataUploadTimeout;
     }
 
-    private static String getManifestFileNamePrefix(long term, long version) {
-        // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/manifest/manifest_2147483642_2147483637
-        return String.join(DELIMITER, MANIFEST_PATH_TOKEN, RemoteStoreUtils.invertLong(term), RemoteStoreUtils.invertLong(version));
+    public TimeValue getMetadataManifestUploadTimeout() {
+        return this.metadataManifestUploadTimeout;
     }
 
-    private static String indexMetadataFileName(IndexMetadata indexMetadata) {
+    static String getManifestFileName(long term, long version, boolean committed) {
+        // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/manifest/manifest__<inverted_term>__<inverted_version>__C/P__<inverted__timestamp>__<codec_version>
         return String.join(
             DELIMITER,
-            INDEX_METADATA_FILE_PREFIX,
-            String.valueOf(indexMetadata.getVersion()),
-            String.valueOf(System.currentTimeMillis())
+            MANIFEST_PATH_TOKEN,
+            RemoteStoreUtils.invertLong(term),
+            RemoteStoreUtils.invertLong(version),
+            (committed ? "C" : "P"), // C for committed and P for published
+            RemoteStoreUtils.invertLong(System.currentTimeMillis()),
+            String.valueOf(MANIFEST_CURRENT_CODEC_VERSION) // Keep the codec version at last place only, during read we reads last place to
+                                                           // determine codec version.
+        );
+    }
+
+    static String indexMetadataFileName(IndexMetadata indexMetadata) {
+        // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/index/<index_UUID>/metadata__<inverted_index_metadata_version>__<inverted__timestamp>__<codec
+        // version>
+        return String.join(
+            DELIMITER,
+            METADATA_FILE_PREFIX,
+            RemoteStoreUtils.invertLong(indexMetadata.getVersion()),
+            RemoteStoreUtils.invertLong(System.currentTimeMillis()),
+            String.valueOf(INDEX_METADATA_CURRENT_CODEC_VERSION) // Keep the codec version at last place only, during read we reads last
+                                                                 // place to determine codec version.
+        );
+    }
+
+    private static String globalMetadataFileName(Metadata metadata) {
+        // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/global-metadata/metadata__<inverted_metadata_version>__<inverted__timestamp>__<codec_version>
+        return String.join(
+            DELIMITER,
+            METADATA_FILE_PREFIX,
+            RemoteStoreUtils.invertLong(metadata.version()),
+            RemoteStoreUtils.invertLong(System.currentTimeMillis()),
+            String.valueOf(GLOBAL_METADATA_CURRENT_CODEC_VERSION)
         );
     }
 
@@ -515,18 +774,18 @@ private BlobPath getManifestFolderPath(String clusterName, String clusterUUID) {
      *
      * @param clusterUUID uuid of cluster state to refer to in remote
      * @param clusterName name of the cluster
+     * @param clusterMetadataManifest manifest file of cluster
      * @return {@code Map<String, IndexMetadata>} latest IndexUUID to IndexMetadata map
      */
-    public Map<String, IndexMetadata> getLatestIndexMetadata(String clusterName, String clusterUUID) throws IOException {
-        start();
-        Map<String, IndexMetadata> remoteIndexMetadata = new HashMap<>();
-        Optional<ClusterMetadataManifest> clusterMetadataManifest = getLatestClusterMetadataManifest(clusterName, clusterUUID);
-        if (!clusterMetadataManifest.isPresent()) {
-            throw new IllegalStateException("Latest index metadata is not present for the provided clusterUUID");
-        }
-        assert Objects.equals(clusterUUID, clusterMetadataManifest.get().getClusterUUID())
+    private Map<String, IndexMetadata> getIndexMetadataMap(
+        String clusterName,
+        String clusterUUID,
+        ClusterMetadataManifest clusterMetadataManifest
+    ) {
+        assert Objects.equals(clusterUUID, clusterMetadataManifest.getClusterUUID())
             : "Corrupt ClusterMetadataManifest found. Cluster UUID mismatch.";
-        for (UploadedIndexMetadata uploadedIndexMetadata : clusterMetadataManifest.get().getIndices()) {
+        Map<String, IndexMetadata> remoteIndexMetadata = new HashMap<>();
+        for (UploadedIndexMetadata uploadedIndexMetadata : clusterMetadataManifest.getIndices()) {
             IndexMetadata indexMetadata = getIndexMetadata(clusterName, clusterUUID, uploadedIndexMetadata);
             remoteIndexMetadata.put(uploadedIndexMetadata.getIndexUUID(), indexMetadata);
         }
@@ -542,10 +801,11 @@ public Map<String, IndexMetadata> getLatestIndexMetadata(String clusterName, Str
      * @return {@link IndexMetadata}
      */
     private IndexMetadata getIndexMetadata(String clusterName, String clusterUUID, UploadedIndexMetadata uploadedIndexMetadata) {
+        BlobContainer blobContainer = indexMetadataContainer(clusterName, clusterUUID, uploadedIndexMetadata.getIndexUUID());
         try {
             String[] splitPath = uploadedIndexMetadata.getUploadedFilename().split("/");
             return INDEX_METADATA_FORMAT.read(
-                indexMetadataContainer(clusterName, clusterUUID, uploadedIndexMetadata.getIndexUUID()),
+                blobContainer,
                 splitPath[splitPath.length - 1],
                 blobStoreRepository.getNamedXContentRegistry()
             );
@@ -557,6 +817,58 @@ private IndexMetadata getIndexMetadata(String clusterName, String clusterUUID, U
         }
     }
 
+    /**
+     * Fetch latest ClusterState from remote, including global metadata, index metadata and cluster state version
+     *
+     * @param clusterUUID uuid of cluster state to refer to in remote
+     * @param clusterName name of the cluster
+     * @return {@link IndexMetadata}
+     */
+    public ClusterState getLatestClusterState(String clusterName, String clusterUUID) {
+        start();
+        Optional<ClusterMetadataManifest> clusterMetadataManifest = getLatestClusterMetadataManifest(clusterName, clusterUUID);
+        if (clusterMetadataManifest.isEmpty()) {
+            throw new IllegalStateException(
+                String.format(Locale.ROOT, "Latest cluster metadata manifest is not present for the provided clusterUUID: %s", clusterUUID)
+            );
+        }
+        // Fetch Global Metadata
+        Metadata globalMetadata = getGlobalMetadata(clusterName, clusterUUID, clusterMetadataManifest.get());
+
+        // Fetch Index Metadata
+        Map<String, IndexMetadata> indices = getIndexMetadataMap(clusterName, clusterUUID, clusterMetadataManifest.get());
+
+        Map<String, IndexMetadata> indexMetadataMap = new HashMap<>();
+        indices.values().forEach(indexMetadata -> { indexMetadataMap.put(indexMetadata.getIndex().getName(), indexMetadata); });
+
+        return ClusterState.builder(ClusterState.EMPTY_STATE)
+            .version(clusterMetadataManifest.get().getStateVersion())
+            .metadata(Metadata.builder(globalMetadata).indices(indexMetadataMap).build())
+            .build();
+    }
+
+    private Metadata getGlobalMetadata(String clusterName, String clusterUUID, ClusterMetadataManifest clusterMetadataManifest) {
+        String globalMetadataFileName = clusterMetadataManifest.getGlobalMetadataFileName();
+        try {
+            // Fetch Global metadata
+            if (globalMetadataFileName != null) {
+                String[] splitPath = globalMetadataFileName.split("/");
+                return GLOBAL_METADATA_FORMAT.read(
+                    globalMetadataContainer(clusterName, clusterUUID),
+                    splitPath[splitPath.length - 1],
+                    blobStoreRepository.getNamedXContentRegistry()
+                );
+            } else {
+                return Metadata.EMPTY_METADATA;
+            }
+        } catch (IOException e) {
+            throw new IllegalStateException(
+                String.format(Locale.ROOT, "Error while downloading Global Metadata - %s", globalMetadataFileName),
+                e
+            );
+        }
+    }
+
     /**
      * Fetch latest ClusterMetadataManifest from remote state store
      *
@@ -566,10 +878,7 @@ private IndexMetadata getIndexMetadata(String clusterName, String clusterUUID, U
      */
     public Optional<ClusterMetadataManifest> getLatestClusterMetadataManifest(String clusterName, String clusterUUID) {
         Optional<String> latestManifestFileName = getLatestManifestFileName(clusterName, clusterUUID);
-        if (latestManifestFileName.isPresent()) {
-            return Optional.of(fetchRemoteClusterMetadataManifest(clusterName, clusterUUID, latestManifestFileName.get()));
-        }
-        return Optional.empty();
+        return latestManifestFileName.map(s -> fetchRemoteClusterMetadataManifest(clusterName, clusterUUID, s));
     }
 
     /**
@@ -582,14 +891,15 @@ public String getLastKnownUUIDFromRemote(String clusterName) {
         try {
             Set<String> clusterUUIDs = getAllClusterUUIDs(clusterName);
             Map<String, ClusterMetadataManifest> latestManifests = getLatestManifestForAllClusterUUIDs(clusterName, clusterUUIDs);
-            List<String> validChain = createClusterChain(latestManifests);
+            List<String> validChain = createClusterChain(latestManifests, clusterName);
             if (validChain.isEmpty()) {
                 return ClusterState.UNKNOWN_UUID;
             }
             return validChain.get(0);
         } catch (IOException e) {
             throw new IllegalStateException(
-                String.format(Locale.ROOT, "Error while fetching previous UUIDs from remote store for cluster name: %s", clusterName)
+                String.format(Locale.ROOT, "Error while fetching previous UUIDs from remote store for cluster name: %s", clusterName),
+                e
             );
         }
     }
@@ -610,7 +920,8 @@ private Map<String, ClusterMetadataManifest> getLatestManifestForAllClusterUUIDs
                 manifest.ifPresent(clusterMetadataManifest -> manifestsByClusterUUID.put(clusterUUID, clusterMetadataManifest));
             } catch (Exception e) {
                 throw new IllegalStateException(
-                    String.format(Locale.ROOT, "Exception in fetching manifest for clusterUUID: %s", clusterUUID)
+                    String.format(Locale.ROOT, "Exception in fetching manifest for clusterUUID: %s", clusterUUID),
+                    e
                 );
             }
         }
@@ -623,68 +934,155 @@ private Map<String, ClusterMetadataManifest> getLatestManifestForAllClusterUUIDs
      * @param manifestsByClusterUUID Map of latest ClusterMetadataManifest for every cluster UUID
      * @return List of cluster UUIDs. The first element is the most recent cluster UUID in the chain
      */
-    private List<String> createClusterChain(final Map<String, ClusterMetadataManifest> manifestsByClusterUUID) {
-        final Map<String, String> clusterUUIDGraph = manifestsByClusterUUID.values()
+    private List<String> createClusterChain(final Map<String, ClusterMetadataManifest> manifestsByClusterUUID, final String clusterName) {
+        final List<ClusterMetadataManifest> validClusterManifests = manifestsByClusterUUID.values()
             .stream()
+            .filter(this::isValidClusterUUID)
+            .collect(Collectors.toList());
+        final Map<String, String> clusterUUIDGraph = validClusterManifests.stream()
             .collect(Collectors.toMap(ClusterMetadataManifest::getClusterUUID, ClusterMetadataManifest::getPreviousClusterUUID));
-        final List<String> validClusterUUIDs = manifestsByClusterUUID.values()
-            .stream()
-            .filter(m -> !isInvalidClusterUUID(m) && !clusterUUIDGraph.containsValue(m.getClusterUUID()))
+        final List<String> topLevelClusterUUIDs = validClusterManifests.stream()
             .map(ClusterMetadataManifest::getClusterUUID)
+            .filter(clusterUUID -> !clusterUUIDGraph.containsValue(clusterUUID))
             .collect(Collectors.toList());
-        if (validClusterUUIDs.isEmpty()) {
-            logger.info("There is no valid previous cluster UUID");
+
+        if (topLevelClusterUUIDs.isEmpty()) {
+            // This can occur only when there are no valid cluster UUIDs
+            assert validClusterManifests.isEmpty() : "There are no top level cluster UUIDs even when there are valid cluster UUIDs";
+            logger.info("There is no valid previous cluster UUID. All cluster UUIDs evaluated are: {}", manifestsByClusterUUID.keySet());
             return Collections.emptyList();
         }
-        if (validClusterUUIDs.size() > 1) {
-            throw new IllegalStateException(
-                String.format(
-                    Locale.ROOT,
-                    "The system has ended into multiple valid cluster states in the remote store. "
-                        + "Please check their latest manifest to decide which one you want to keep. Valid Cluster UUIDs: - %s",
-                    validClusterUUIDs
-                )
+        if (topLevelClusterUUIDs.size() > 1) {
+            logger.info("Top level cluster UUIDs: {}", topLevelClusterUUIDs);
+            // If the valid cluster UUIDs are more that 1, it means there was some race condition where
+            // more then 2 cluster manager nodes tried to become active cluster manager and published
+            // 2 cluster UUIDs which followed the same previous UUID.
+            final Map<String, ClusterMetadataManifest> manifestsByClusterUUIDTrimmed = trimClusterUUIDs(
+                manifestsByClusterUUID,
+                topLevelClusterUUIDs,
+                clusterName
             );
+            if (manifestsByClusterUUID.size() == manifestsByClusterUUIDTrimmed.size()) {
+                throw new IllegalStateException(
+                    String.format(
+                        Locale.ROOT,
+                        "The system has ended into multiple valid cluster states in the remote store. "
+                            + "Please check their latest manifest to decide which one you want to keep. Valid Cluster UUIDs: - %s",
+                        topLevelClusterUUIDs
+                    )
+                );
+            }
+            return createClusterChain(manifestsByClusterUUIDTrimmed, clusterName);
         }
         final List<String> validChain = new ArrayList<>();
-        String currentUUID = validClusterUUIDs.get(0);
-        while (!ClusterState.UNKNOWN_UUID.equals(currentUUID)) {
+        String currentUUID = topLevelClusterUUIDs.get(0);
+        while (currentUUID != null && !ClusterState.UNKNOWN_UUID.equals(currentUUID)) {
             validChain.add(currentUUID);
             // Getting the previous cluster UUID of a cluster UUID from the clusterUUID Graph
             currentUUID = clusterUUIDGraph.get(currentUUID);
         }
+        logger.info("Known UUIDs found in remote store : [{}]", validChain);
         return validChain;
     }
 
-    private boolean isInvalidClusterUUID(ClusterMetadataManifest manifest) {
-        return !manifest.isCommitted() && manifest.getIndices().isEmpty();
+    /**
+     * This method take a map of manifests for different cluster UUIDs and removes the
+     * manifest of a cluster UUID if the latest metadata for that cluster UUID is equivalent
+     * to the latest metadata of its previous UUID.
+     * @return Trimmed map of manifests
+     */
+    private Map<String, ClusterMetadataManifest> trimClusterUUIDs(
+        final Map<String, ClusterMetadataManifest> latestManifestsByClusterUUID,
+        final List<String> validClusterUUIDs,
+        final String clusterName
+    ) {
+        final Map<String, ClusterMetadataManifest> trimmedUUIDs = new HashMap<>(latestManifestsByClusterUUID);
+        for (String clusterUUID : validClusterUUIDs) {
+            ClusterMetadataManifest currentManifest = trimmedUUIDs.get(clusterUUID);
+            // Here we compare the manifest of current UUID to that of previous UUID
+            // In case currentUUID's latest manifest is same as previous UUIDs latest manifest,
+            // that means it was restored from previousUUID and no IndexMetadata update was performed on it.
+            if (!ClusterState.UNKNOWN_UUID.equals(currentManifest.getPreviousClusterUUID())) {
+                ClusterMetadataManifest previousManifest = trimmedUUIDs.get(currentManifest.getPreviousClusterUUID());
+                if (isMetadataEqual(currentManifest, previousManifest, clusterName)
+                    && isGlobalMetadataEqual(currentManifest, previousManifest, clusterName)) {
+                    trimmedUUIDs.remove(clusterUUID);
+                }
+            }
+        }
+        return trimmedUUIDs;
+    }
+
+    private boolean isMetadataEqual(ClusterMetadataManifest first, ClusterMetadataManifest second, String clusterName) {
+        // todo clusterName can be set as final in the constructor
+        if (first.getIndices().size() != second.getIndices().size()) {
+            return false;
+        }
+        final Map<String, UploadedIndexMetadata> secondIndices = second.getIndices()
+            .stream()
+            .collect(Collectors.toMap(md -> md.getIndexName(), Function.identity()));
+        for (UploadedIndexMetadata uploadedIndexMetadata : first.getIndices()) {
+            final IndexMetadata firstIndexMetadata = getIndexMetadata(clusterName, first.getClusterUUID(), uploadedIndexMetadata);
+            final UploadedIndexMetadata secondUploadedIndexMetadata = secondIndices.get(uploadedIndexMetadata.getIndexName());
+            if (secondUploadedIndexMetadata == null) {
+                return false;
+            }
+            final IndexMetadata secondIndexMetadata = getIndexMetadata(clusterName, second.getClusterUUID(), secondUploadedIndexMetadata);
+            if (firstIndexMetadata.equals(secondIndexMetadata) == false) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean isGlobalMetadataEqual(ClusterMetadataManifest first, ClusterMetadataManifest second, String clusterName) {
+        Metadata secondGlobalMetadata = getGlobalMetadata(clusterName, second.getClusterUUID(), second);
+        Metadata firstGlobalMetadata = getGlobalMetadata(clusterName, first.getClusterUUID(), first);
+        return Metadata.isGlobalResourcesMetadataEquals(firstGlobalMetadata, secondGlobalMetadata);
+    }
+
+    private boolean isValidClusterUUID(ClusterMetadataManifest manifest) {
+        return manifest.isClusterUUIDCommitted();
     }
 
     /**
-     * Fetch latest ClusterMetadataManifest file from remote state store
+     * Fetch ClusterMetadataManifest files from remote state store in order
      *
      * @param clusterUUID uuid of cluster state to refer to in remote
      * @param clusterName name of the cluster
-     * @return latest ClusterMetadataManifest filename
+     * @param limit max no of files to fetch
+     * @return all manifest file names
      */
-    private Optional<String> getLatestManifestFileName(String clusterName, String clusterUUID) throws IllegalStateException {
+    private List<BlobMetadata> getManifestFileNames(String clusterName, String clusterUUID, int limit) throws IllegalStateException {
         try {
-            /**
-             * {@link BlobContainer#listBlobsByPrefixInSortedOrder} will get the latest manifest file
-             * as the manifest file name generated via {@link RemoteClusterStateService#getManifestFileName} ensures
-             * when sorted in LEXICOGRAPHIC order the latest uploaded manifest file comes on top.
+
+            /*
+              {@link BlobContainer#listBlobsByPrefixInSortedOrder} will list the latest manifest file first
+              as the manifest file name generated via {@link RemoteClusterStateService#getManifestFileName} ensures
+              when sorted in LEXICOGRAPHIC order the latest uploaded manifest file comes on top.
              */
-            List<BlobMetadata> manifestFilesMetadata = manifestContainer(clusterName, clusterUUID).listBlobsByPrefixInSortedOrder(
+            return manifestContainer(clusterName, clusterUUID).listBlobsByPrefixInSortedOrder(
                 MANIFEST_FILE_PREFIX + DELIMITER,
-                1,
+                limit,
                 BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
             );
-            if (manifestFilesMetadata != null && !manifestFilesMetadata.isEmpty()) {
-                return Optional.of(manifestFilesMetadata.get(0).name());
-            }
         } catch (IOException e) {
             throw new IllegalStateException("Error while fetching latest manifest file for remote cluster state", e);
         }
+    }
+
+    /**
+     * Fetch latest ClusterMetadataManifest file from remote state store
+     *
+     * @param clusterUUID uuid of cluster state to refer to in remote
+     * @param clusterName name of the cluster
+     * @return latest ClusterMetadataManifest filename
+     */
+    private Optional<String> getLatestManifestFileName(String clusterName, String clusterUUID) throws IllegalStateException {
+        List<BlobMetadata> manifestFilesMetadata = getManifestFileNames(clusterName, clusterUUID, 1);
+        if (manifestFilesMetadata != null && !manifestFilesMetadata.isEmpty()) {
+            return Optional.of(manifestFilesMetadata.get(0).name());
+        }
         logger.info("No manifest file present in remote store for cluster name: {}, cluster UUID: {}", clusterName, clusterUUID);
         return Optional.empty();
     }
@@ -699,7 +1097,7 @@ private Optional<String> getLatestManifestFileName(String clusterName, String cl
     private ClusterMetadataManifest fetchRemoteClusterMetadataManifest(String clusterName, String clusterUUID, String filename)
         throws IllegalStateException {
         try {
-            return RemoteClusterStateService.CLUSTER_METADATA_MANIFEST_FORMAT.read(
+            return getClusterMetadataManifestBlobStoreFormat(filename).read(
                 manifestContainer(clusterName, clusterUUID),
                 filename,
                 blobStoreRepository.getNamedXContentRegistry()
@@ -709,30 +1107,58 @@ private ClusterMetadataManifest fetchRemoteClusterMetadataManifest(String cluste
         }
     }
 
+    private ChecksumBlobStoreFormat<ClusterMetadataManifest> getClusterMetadataManifestBlobStoreFormat(String fileName) {
+        long codecVersion = getManifestCodecVersion(fileName);
+        if (codecVersion == MANIFEST_CURRENT_CODEC_VERSION) {
+            return CLUSTER_METADATA_MANIFEST_FORMAT;
+        } else if (codecVersion == ClusterMetadataManifest.CODEC_V0) {
+            return CLUSTER_METADATA_MANIFEST_FORMAT_V0;
+        }
+
+        throw new IllegalArgumentException("Cluster metadata manifest file is corrupted, don't have valid codec version");
+    }
+
+    private int getManifestCodecVersion(String fileName) {
+        String[] splitName = fileName.split(DELIMITER);
+        if (splitName.length == SPLITED_MANIFEST_FILE_LENGTH) {
+            return Integer.parseInt(splitName[splitName.length - 1]); // Last value would be codec version.
+        } else if (splitName.length < SPLITED_MANIFEST_FILE_LENGTH) { // Where codec is not part of file name, i.e. default codec version 0
+                                                                      // is used.
+            return ClusterMetadataManifest.CODEC_V0;
+        } else {
+            throw new IllegalArgumentException("Manifest file name is corrupted");
+        }
+    }
+
     public static String encodeString(String content) {
         return Base64.getUrlEncoder().withoutPadding().encodeToString(content.getBytes(StandardCharsets.UTF_8));
     }
 
+    public void writeMetadataFailed() {
+        getStats().stateFailed();
+    }
+
     /**
-     * Exception for IndexMetadata transfer failures to remote
+     * Exception for Remote state transfer.
      */
-    static class IndexMetadataTransferException extends RuntimeException {
+    static class RemoteStateTransferException extends RuntimeException {
 
-        public IndexMetadataTransferException(String errorDesc) {
+        public RemoteStateTransferException(String errorDesc) {
             super(errorDesc);
         }
 
-        public IndexMetadataTransferException(String errorDesc, Throwable cause) {
+        public RemoteStateTransferException(String errorDesc, Throwable cause) {
             super(errorDesc, cause);
         }
     }
 
     /**
      * Purges all remote cluster state against provided cluster UUIDs
+     *
      * @param clusterName name of the cluster
      * @param clusterUUIDs clusteUUIDs for which the remote state needs to be purged
      */
-    public void deleteStaleClusterMetadata(String clusterName, List<String> clusterUUIDs) {
+    void deleteStaleUUIDsClusterMetadata(String clusterName, List<String> clusterUUIDs) {
         clusterUUIDs.forEach(clusterUUID -> {
             getBlobStoreTransferService().deleteAsync(
                 ThreadPool.Names.REMOTE_PURGE,
@@ -752,6 +1178,7 @@ public void onFailure(Exception e) {
                             ),
                             e
                         );
+                        remoteStateStats.cleanUpAttemptFailed();
                     }
                 }
             );
@@ -760,11 +1187,13 @@ public void onFailure(Exception e) {
 
     /**
      * Deletes older than last {@code versionsToRetain} manifests. Also cleans up unreferenced IndexMetadata associated with older manifests
+     *
      * @param clusterName name of the cluster
      * @param clusterUUID uuid of cluster state to refer to in remote
      * @param manifestsToRetain no of latest manifest files to keep in remote
      */
-    private void deleteStaleClusterMetadata(String clusterName, String clusterUUID, int manifestsToRetain) {
+    // package private for testing
+    void deleteStaleClusterMetadata(String clusterName, String clusterUUID, int manifestsToRetain) {
         if (deleteStaleMetadataRunning.compareAndSet(false, true) == false) {
             logger.info("Delete stale cluster metadata task is already in progress.");
             return;
@@ -801,8 +1230,9 @@ public void onFailure(Exception e) {
                     }
                 }
             );
-        } finally {
+        } catch (Exception e) {
             deleteStaleMetadataRunning.set(false);
+            throw e;
         }
     }
 
@@ -816,6 +1246,7 @@ private void deleteClusterMetadata(
             Set<String> filesToKeep = new HashSet<>();
             Set<String> staleManifestPaths = new HashSet<>();
             Set<String> staleIndexMetadataPaths = new HashSet<>();
+            Set<String> staleGlobalMetadataPaths = new HashSet<>();
             activeManifestBlobMetadata.forEach(blobMetadata -> {
                 ClusterMetadataManifest clusterMetadataManifest = fetchRemoteClusterMetadataManifest(
                     clusterName,
@@ -824,6 +1255,7 @@ private void deleteClusterMetadata(
                 );
                 clusterMetadataManifest.getIndices()
                     .forEach(uploadedIndexMetadata -> filesToKeep.add(uploadedIndexMetadata.getUploadedFilename()));
+                filesToKeep.add(clusterMetadataManifest.getGlobalMetadataFileName());
             });
             staleManifestBlobMetadata.forEach(blobMetadata -> {
                 ClusterMetadataManifest clusterMetadataManifest = fetchRemoteClusterMetadataManifest(
@@ -832,30 +1264,40 @@ private void deleteClusterMetadata(
                     blobMetadata.name()
                 );
                 staleManifestPaths.add(new BlobPath().add(MANIFEST_PATH_TOKEN).buildAsString() + blobMetadata.name());
+                if (filesToKeep.contains(clusterMetadataManifest.getGlobalMetadataFileName()) == false) {
+                    String[] globalMetadataSplitPath = clusterMetadataManifest.getGlobalMetadataFileName().split("/");
+                    staleGlobalMetadataPaths.add(
+                        new BlobPath().add(GLOBAL_METADATA_PATH_TOKEN).buildAsString() + GLOBAL_METADATA_FORMAT.blobName(
+                            globalMetadataSplitPath[globalMetadataSplitPath.length - 1]
+                        )
+                    );
+                }
                 clusterMetadataManifest.getIndices().forEach(uploadedIndexMetadata -> {
                     if (filesToKeep.contains(uploadedIndexMetadata.getUploadedFilename()) == false) {
                         staleIndexMetadataPaths.add(
                             new BlobPath().add(INDEX_PATH_TOKEN).add(uploadedIndexMetadata.getIndexUUID()).buildAsString()
-                                + uploadedIndexMetadata.getUploadedFilename()
-                                + ".dat"
+                                + INDEX_METADATA_FORMAT.blobName(uploadedIndexMetadata.getUploadedFilename())
                         );
                     }
                 });
             });
 
             if (staleManifestPaths.isEmpty()) {
-                logger.info("No stale Remote Cluster Metadata files found");
+                logger.debug("No stale Remote Cluster Metadata files found");
                 return;
             }
 
+            deleteStalePaths(clusterName, clusterUUID, new ArrayList<>(staleGlobalMetadataPaths));
             deleteStalePaths(clusterName, clusterUUID, new ArrayList<>(staleIndexMetadataPaths));
             deleteStalePaths(clusterName, clusterUUID, new ArrayList<>(staleManifestPaths));
         } catch (IllegalStateException e) {
             logger.error("Error while fetching Remote Cluster Metadata manifests", e);
         } catch (IOException e) {
             logger.error("Error while deleting stale Remote Cluster Metadata files", e);
+            remoteStateStats.cleanUpAttemptFailed();
         } catch (Exception e) {
             logger.error("Unexpected error while deleting stale Remote Cluster Metadata files", e);
+            remoteStateStats.cleanUpAttemptFailed();
         }
     }
 
@@ -863,4 +1305,31 @@ private void deleteStalePaths(String clusterName, String clusterUUID, List<Strin
         logger.debug(String.format(Locale.ROOT, "Deleting stale files from remote - %s", stalePaths));
         getBlobStoreTransferService().deleteBlobs(getCusterMetadataBasePath(clusterName, clusterUUID), stalePaths);
     }
+
+    /**
+     * Purges all remote cluster state against provided cluster UUIDs
+     * @param clusterState current state of the cluster
+     * @param committedManifest last committed ClusterMetadataManifest
+     */
+    public void deleteStaleClusterUUIDs(ClusterState clusterState, ClusterMetadataManifest committedManifest) {
+        threadpool.executor(ThreadPool.Names.REMOTE_PURGE).execute(() -> {
+            String clusterName = clusterState.getClusterName().value();
+            logger.debug("Deleting stale cluster UUIDs data from remote [{}]", clusterName);
+            Set<String> allClustersUUIDsInRemote;
+            try {
+                allClustersUUIDsInRemote = new HashSet<>(getAllClusterUUIDs(clusterState.getClusterName().value()));
+            } catch (IOException e) {
+                logger.info(String.format(Locale.ROOT, "Error while fetching all cluster UUIDs for [%s]", clusterName));
+                return;
+            }
+            // Retain last 2 cluster uuids data
+            allClustersUUIDsInRemote.remove(committedManifest.getClusterUUID());
+            allClustersUUIDsInRemote.remove(committedManifest.getPreviousClusterUUID());
+            deleteStaleUUIDsClusterMetadata(clusterName, new ArrayList<>(allClustersUUIDsInRemote));
+        });
+    }
+
+    public RemotePersistenceStats getStats() {
+        return remoteStateStats;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/gateway/remote/RemotePersistenceStats.java b/server/src/main/java/org/opensearch/gateway/remote/RemotePersistenceStats.java
new file mode 100644
index 0000000000000..f2330846fa23e
--- /dev/null
+++ b/server/src/main/java/org/opensearch/gateway/remote/RemotePersistenceStats.java
@@ -0,0 +1,37 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.gateway.remote;
+
+import org.opensearch.cluster.coordination.PersistedStateStats;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * Remote state related extended stats.
+ *
+ * @opensearch.internal
+ */
+public class RemotePersistenceStats extends PersistedStateStats {
+    static final String CLEANUP_ATTEMPT_FAILED_COUNT = "cleanup_attempt_failed_count";
+    static final String REMOTE_UPLOAD = "remote_upload";
+    private AtomicLong cleanupAttemptFailedCount = new AtomicLong(0);
+
+    public RemotePersistenceStats() {
+        super(REMOTE_UPLOAD);
+        addToExtendedFields(CLEANUP_ATTEMPT_FAILED_COUNT, cleanupAttemptFailedCount);
+    }
+
+    public void cleanUpAttemptFailed() {
+        cleanupAttemptFailedCount.incrementAndGet();
+    }
+
+    public long getCleanupAttemptFailedCount() {
+        return cleanupAttemptFailedCount.get();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/http/AbstractHttpServerTransport.java b/server/src/main/java/org/opensearch/http/AbstractHttpServerTransport.java
index ed44102d0abe4..257aca2b67990 100644
--- a/server/src/main/java/org/opensearch/http/AbstractHttpServerTransport.java
+++ b/server/src/main/java/org/opensearch/http/AbstractHttpServerTransport.java
@@ -69,9 +69,11 @@
 import java.nio.channels.CancelledKeyException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
@@ -298,6 +300,7 @@ static int resolvePublishPort(Settings settings, List<TransportAddress> boundAdd
     }
 
     public void onException(HttpChannel channel, Exception e) {
+        channel.handleException(e);
         if (lifecycle.started() == false) {
             // just close and ignore - we are already stopped and just need to make sure we release all resources
             CloseableChannel.closeChannel(channel);
@@ -361,7 +364,7 @@ protected void serverAcceptedChannel(HttpChannel httpChannel) {
      * @param httpChannel that received the http request
      */
     public void incomingRequest(final HttpRequest httpRequest, final HttpChannel httpChannel) {
-        final Span span = tracer.startSpan(SpanBuilder.from(httpRequest), httpRequest.getHeaders());
+        final Span span = tracer.startSpan(SpanBuilder.from(httpRequest), extractHeaders(httpRequest.getHeaders()));
         try (final SpanScope httpRequestSpanScope = tracer.withSpanInScope(span)) {
             HttpChannel traceableHttpChannel = TraceableHttpChannel.create(httpChannel, span, tracer);
             handleIncomingRequest(httpRequest, traceableHttpChannel, httpRequest.getInboundException());
@@ -482,4 +485,9 @@ private static ActionListener<Void> earlyResponseListener(HttpRequest request, H
             return NO_OP;
         }
     }
+
+    @SuppressWarnings("unchecked")
+    private static <Values extends Collection<String>> Map<String, Collection<String>> extractHeaders(Map<String, Values> headers) {
+        return (Map<String, Collection<String>>) headers;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/http/CorsHandler.java b/server/src/main/java/org/opensearch/http/CorsHandler.java
index 862c50ae6ac1f..464ced184d10e 100644
--- a/server/src/main/java/org/opensearch/http/CorsHandler.java
+++ b/server/src/main/java/org/opensearch/http/CorsHandler.java
@@ -81,7 +81,7 @@
  * This file is forked from the https://netty.io project. In particular it combines the following three
  * files: io.netty.handler.codec.http.cors.CorsHandler, io.netty.handler.codec.http.cors.CorsConfig, and
  * io.netty.handler.codec.http.cors.CorsConfigBuilder.
- *
+ * <p>
  * It modifies the original netty code to operate on OpenSearch http request/response abstractions.
  * Additionally, it removes CORS features that are not used by OpenSearch.
  *
diff --git a/server/src/main/java/org/opensearch/http/HttpChannel.java b/server/src/main/java/org/opensearch/http/HttpChannel.java
index 99aaed23c69b8..ed20ec89a9099 100644
--- a/server/src/main/java/org/opensearch/http/HttpChannel.java
+++ b/server/src/main/java/org/opensearch/http/HttpChannel.java
@@ -32,17 +32,25 @@
 
 package org.opensearch.http;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.network.CloseableChannel;
 import org.opensearch.core.action.ActionListener;
 
 import java.net.InetSocketAddress;
+import java.util.Optional;
 
 /**
  * Represents an HTTP comms channel
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface HttpChannel extends CloseableChannel {
+    /**
+     * Notify HTTP channel that exception happens and the response may not be sent (for example, timeout)
+     * @param ex the exception being raised
+     */
+    default void handleException(Exception ex) {}
 
     /**
      * Sends an http response to the channel. The listener will be executed once the send process has been
@@ -67,4 +75,17 @@ public interface HttpChannel extends CloseableChannel {
      */
     InetSocketAddress getRemoteAddress();
 
+    /**
+     * Returns the contextual property associated with this specific HTTP channel (the
+     * implementation of how such properties are managed depends on the the particular
+     * transport engine).
+     *
+     * @param name the name of the property
+     * @param clazz the expected type of the property
+     *
+     * @return the value of the property
+     */
+    default <T> Optional<T> get(String name, Class<T> clazz) {
+        return Optional.empty();
+    }
 }
diff --git a/server/src/main/java/org/opensearch/http/HttpRequest.java b/server/src/main/java/org/opensearch/http/HttpRequest.java
index 162ef11a3d865..3dc10777b657a 100644
--- a/server/src/main/java/org/opensearch/http/HttpRequest.java
+++ b/server/src/main/java/org/opensearch/http/HttpRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.http;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.rest.RestRequest;
@@ -45,15 +46,17 @@
  * A basic http request abstraction. Http modules needs to implement this interface to integrate with the
  * server package's rest handling.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface HttpRequest {
 
     /**
      * Which HTTP version being used
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     enum HttpVersion {
         HTTP_1_0,
         HTTP_1_1
diff --git a/server/src/main/java/org/opensearch/http/HttpResponse.java b/server/src/main/java/org/opensearch/http/HttpResponse.java
index 3c8269f4400e7..b25df41698c79 100644
--- a/server/src/main/java/org/opensearch/http/HttpResponse.java
+++ b/server/src/main/java/org/opensearch/http/HttpResponse.java
@@ -32,12 +32,15 @@
 
 package org.opensearch.http;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * A basic http response abstraction. Http modules must implement this interface as the server package rest
  * handling needs to set http headers for a response.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface HttpResponse {
 
     void addHeader(String name, String value);
diff --git a/server/src/main/java/org/opensearch/http/HttpTransportSettings.java b/server/src/main/java/org/opensearch/http/HttpTransportSettings.java
index f16f06f414e28..621ef36692178 100644
--- a/server/src/main/java/org/opensearch/http/HttpTransportSettings.java
+++ b/server/src/main/java/org/opensearch/http/HttpTransportSettings.java
@@ -182,6 +182,14 @@ public final class HttpTransportSettings {
         Property.NodeScope
     );
 
+    // A default of 0 means that by default there is no connect timeout
+    public static final Setting<TimeValue> SETTING_HTTP_CONNECT_TIMEOUT = Setting.timeSetting(
+        "http.connect_timeout",
+        new TimeValue(0),
+        new TimeValue(0),
+        Property.NodeScope
+    );
+
     // Tcp socket settings
 
     public static final Setting<Boolean> OLD_SETTING_HTTP_TCP_NO_DELAY = boolSetting(
diff --git a/server/src/main/java/org/opensearch/identity/noop/NoopIdentityPlugin.java b/server/src/main/java/org/opensearch/identity/noop/NoopIdentityPlugin.java
index c2367383df595..090b1f1d025e0 100644
--- a/server/src/main/java/org/opensearch/identity/noop/NoopIdentityPlugin.java
+++ b/server/src/main/java/org/opensearch/identity/noop/NoopIdentityPlugin.java
@@ -14,7 +14,7 @@
 
 /**
  * Implementation of identity plugin that does not enforce authentication or authorization
- *
+ * <p>
  * This class and related classes in this package will not return nulls or fail access checks
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/identity/noop/NoopSubject.java b/server/src/main/java/org/opensearch/identity/noop/NoopSubject.java
index 424a10204aa19..964a218db3cf5 100644
--- a/server/src/main/java/org/opensearch/identity/noop/NoopSubject.java
+++ b/server/src/main/java/org/opensearch/identity/noop/NoopSubject.java
@@ -17,7 +17,7 @@
 
 /**
  * Implementation of subject that is always authenticated
- *
+ * <p>
  * This class and related classes in this package will not return nulls or fail permissions checks
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/identity/noop/NoopTokenManager.java b/server/src/main/java/org/opensearch/identity/noop/NoopTokenManager.java
index 1255e822cea6e..fa6643b7447dc 100644
--- a/server/src/main/java/org/opensearch/identity/noop/NoopTokenManager.java
+++ b/server/src/main/java/org/opensearch/identity/noop/NoopTokenManager.java
@@ -37,8 +37,17 @@ public String asAuthHeaderValue() {
         };
     }
 
+    /**
+     * Issue a new Noop Token
+     * @return a new Noop Token
+     */
     @Override
-    public Subject authenticateToken(AuthToken authToken) {
-        return null;
+    public AuthToken issueServiceAccountToken(final String audience) {
+        return new AuthToken() {
+            @Override
+            public String asAuthHeaderValue() {
+                return "noopToken";
+            }
+        };
     }
 }
diff --git a/server/src/main/java/org/opensearch/identity/tokens/AuthToken.java b/server/src/main/java/org/opensearch/identity/tokens/AuthToken.java
index c929e7421b3d8..88bb855a6e70d 100644
--- a/server/src/main/java/org/opensearch/identity/tokens/AuthToken.java
+++ b/server/src/main/java/org/opensearch/identity/tokens/AuthToken.java
@@ -16,4 +16,5 @@
 public interface AuthToken {
 
     String asAuthHeaderValue();
+
 }
diff --git a/server/src/main/java/org/opensearch/identity/tokens/BasicAuthToken.java b/server/src/main/java/org/opensearch/identity/tokens/BasicAuthToken.java
index 71b8fe504a5d1..4ad0bbe67d2a1 100644
--- a/server/src/main/java/org/opensearch/identity/tokens/BasicAuthToken.java
+++ b/server/src/main/java/org/opensearch/identity/tokens/BasicAuthToken.java
@@ -23,7 +23,7 @@ public final class BasicAuthToken implements AuthToken {
 
     public BasicAuthToken(final String headerValue) {
         final String base64Encoded = headerValue.substring(TOKEN_IDENTIFIER.length()).trim();
-        final byte[] rawDecoded = Base64.getDecoder().decode(base64Encoded);
+        final byte[] rawDecoded = Base64.getUrlDecoder().decode(base64Encoded);
         final String usernamepassword = new String(rawDecoded, StandardCharsets.UTF_8);
 
         final String[] tokenParts = usernamepassword.split(":", 2);
diff --git a/server/src/main/java/org/opensearch/identity/tokens/OnBehalfOfClaims.java b/server/src/main/java/org/opensearch/identity/tokens/OnBehalfOfClaims.java
index 3fef248ee6d3a..00e50a59e9486 100644
--- a/server/src/main/java/org/opensearch/identity/tokens/OnBehalfOfClaims.java
+++ b/server/src/main/java/org/opensearch/identity/tokens/OnBehalfOfClaims.java
@@ -14,46 +14,17 @@
 public class OnBehalfOfClaims {
 
     private final String audience;
-    private final String subject;
-    private final Long expiration;
-    private final Long not_before;
-    private final Long issued_at;
+    private final Long expiration_seconds;
 
     /**
      * Constructor for OnBehalfOfClaims
      * @param aud the Audience for the token
-     * @param subject the subject of the token
-     * @param expiration the expiration time in seconds for the token
-     * @param not_before the not_before time in seconds for the token
-     * @param issued_at the issued_at time in seconds for the token
-     */
-    public OnBehalfOfClaims(String aud, String subject, Long expiration, Long not_before, Long issued_at) {
-        this.audience = aud;
-        this.subject = subject;
-        this.expiration = expiration;
-        this.not_before = not_before;
-        this.issued_at = issued_at;
-    }
-
-    /**
-     * A constructor that sets a default issued at time of the current time
-     * @param aud the Audience for the token
-     * @param subject the subject of the token
-     * @param expiration the expiration time in seconds for the token
-     * @param not_before the not_before time in seconds for the token
-     */
-    public OnBehalfOfClaims(String aud, String subject, Long expiration, Long not_before) {
-        this(aud, subject, expiration, not_before, System.currentTimeMillis() / 1000);
-    }
+     * @param expiration_seconds the length of time in seconds the token is valid
 
-    /**
-     * A constructor which sets a default not before time of the current time
-     * @param aud the Audience for the token
-     * @param subject the subject of the token
-     * @param expiration the expiration time in seconds for the token
      */
-    public OnBehalfOfClaims(String aud, String subject, Long expiration) {
-        this(aud, subject, expiration, System.currentTimeMillis() / 1000);
+    public OnBehalfOfClaims(String aud, Long expiration_seconds) {
+        this.audience = aud;
+        this.expiration_seconds = expiration_seconds;
     }
 
     /**
@@ -62,26 +33,14 @@ public OnBehalfOfClaims(String aud, String subject, Long expiration) {
      * @param subject the subject of the token
      */
     public OnBehalfOfClaims(String aud, String subject) {
-        this(aud, subject, System.currentTimeMillis() / 1000 + 300);
+        this(aud, 300L);
     }
 
     public String getAudience() {
         return audience;
     }
 
-    public String getSubject() {
-        return subject;
-    }
-
     public Long getExpiration() {
-        return expiration;
-    }
-
-    public Long getNot_before() {
-        return not_before;
-    }
-
-    public Long getIssued_at() {
-        return issued_at;
+        return expiration_seconds;
     }
 }
diff --git a/server/src/main/java/org/opensearch/identity/tokens/RestTokenExtractor.java b/server/src/main/java/org/opensearch/identity/tokens/RestTokenExtractor.java
index 193966001f44c..4bd3ebdded588 100644
--- a/server/src/main/java/org/opensearch/identity/tokens/RestTokenExtractor.java
+++ b/server/src/main/java/org/opensearch/identity/tokens/RestTokenExtractor.java
@@ -26,7 +26,7 @@ public class RestTokenExtractor {
 
     /**
      * Given a rest request it will extract authentication token
-     *
+     * <p>
      * If no token was found, returns null.
      */
     public static AuthToken extractToken(final RestRequest request) {
diff --git a/server/src/main/java/org/opensearch/identity/tokens/TokenManager.java b/server/src/main/java/org/opensearch/identity/tokens/TokenManager.java
index 4f6ddeb48dea3..972a9a1080955 100644
--- a/server/src/main/java/org/opensearch/identity/tokens/TokenManager.java
+++ b/server/src/main/java/org/opensearch/identity/tokens/TokenManager.java
@@ -24,9 +24,10 @@ public interface TokenManager {
     public AuthToken issueOnBehalfOfToken(final Subject subject, final OnBehalfOfClaims claims);
 
     /**
-     * Authenticates a provided authToken
-     * @param authToken: The authToken to authenticate
-     * @return The authenticated subject
+     * Create a new service account token
+     *
+     * @param audience: A string representing the unique id of the extension for which a service account token should be generated
+     * @return a new auth token
      */
-    public Subject authenticateToken(AuthToken authToken);
+    public AuthToken issueServiceAccountToken(final String audience);
 }
diff --git a/server/src/main/java/org/opensearch/index/IndexModule.java b/server/src/main/java/org/opensearch/index/IndexModule.java
index 8692876412ea9..545623287bae8 100644
--- a/server/src/main/java/org/opensearch/index/IndexModule.java
+++ b/server/src/main/java/org/opensearch/index/IndexModule.java
@@ -81,6 +81,7 @@
 import org.opensearch.indices.IndicesQueryCache;
 import org.opensearch.indices.fielddata.cache.IndicesFieldDataCache;
 import org.opensearch.indices.mapper.MapperRegistry;
+import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.plugins.IndexStorePlugin;
 import org.opensearch.repositories.RepositoriesService;
@@ -495,8 +496,9 @@ IndexEventListener freeze() { // pkg private for testing
     /**
      * Type of file system
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Type {
         HYBRIDFS("hybridfs"),
         NIOFS("niofs"),
@@ -602,7 +604,8 @@ public IndexService newIndexService(
         IndexStorePlugin.DirectoryFactory remoteDirectoryFactory,
         BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier,
         Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier,
-        Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier
+        Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier,
+        RecoverySettings recoverySettings
     ) throws IOException {
         final IndexEventListener eventListener = freeze();
         Function<IndexService, CheckedFunction<DirectoryReader, DirectoryReader, IOException>> readerWrapperFactory = indexReaderWrapper
@@ -660,7 +663,8 @@ public IndexService newIndexService(
                 recoveryStateFactory,
                 translogFactorySupplier,
                 clusterDefaultRefreshIntervalSupplier,
-                clusterRemoteTranslogBufferIntervalSupplier
+                clusterRemoteTranslogBufferIntervalSupplier,
+                recoverySettings
             );
             success = true;
             return indexService;
diff --git a/server/src/main/java/org/opensearch/index/IndexService.java b/server/src/main/java/org/opensearch/index/IndexService.java
index 80ead0a333ba3..0909e2d5c8ff0 100644
--- a/server/src/main/java/org/opensearch/index/IndexService.java
+++ b/server/src/main/java/org/opensearch/index/IndexService.java
@@ -48,6 +48,7 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.CheckedFunction;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.settings.Settings;
@@ -95,6 +96,7 @@
 import org.opensearch.indices.cluster.IndicesClusterStateService;
 import org.opensearch.indices.fielddata.cache.IndicesFieldDataCache;
 import org.opensearch.indices.mapper.MapperRegistry;
+import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.indices.replication.checkpoint.SegmentReplicationCheckpointPublisher;
 import org.opensearch.plugins.IndexStorePlugin;
@@ -129,8 +131,9 @@
 /**
  * The main OpenSearch index service
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexService extends AbstractIndexComponent implements IndicesClusterStateService.AllocatedIndex<IndexShard> {
 
     private final IndexEventListener eventListener;
@@ -178,6 +181,7 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
     private final BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier;
     private final Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier;
     private final Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier;
+    private final RecoverySettings recoverySettings;
 
     public IndexService(
         IndexSettings indexSettings,
@@ -212,7 +216,8 @@ public IndexService(
         IndexStorePlugin.RecoveryStateFactory recoveryStateFactory,
         BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier,
         Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier,
-        Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier
+        Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier,
+        RecoverySettings recoverySettings
     ) {
         super(indexSettings);
         this.allowExpensiveQueries = allowExpensiveQueries;
@@ -240,8 +245,10 @@ public IndexService(
             if (indexSettings.getIndexSortConfig().hasIndexSort()) {
                 // we delay the actual creation of the sort order for this index because the mapping has not been merged yet.
                 // The sort order is validated right after the merge of the mapping later in the process.
+                boolean shouldWidenIndexSortType = this.indexSettings.shouldWidenIndexSortType();
                 this.indexSortSupplier = () -> indexSettings.getIndexSortConfig()
                     .buildIndexSort(
+                        shouldWidenIndexSortType,
                         mapperService::fieldType,
                         (fieldType, searchLookup) -> indexFieldData.getForField(fieldType, indexFieldData.index().getName(), searchLookup)
                     );
@@ -287,6 +294,7 @@ public IndexService(
         this.retentionLeaseSyncTask = new AsyncRetentionLeaseSyncTask(this);
         this.translogFactorySupplier = translogFactorySupplier;
         this.clusterRemoteTranslogBufferIntervalSupplier = clusterRemoteTranslogBufferIntervalSupplier;
+        this.recoverySettings = recoverySettings;
         updateFsyncTaskIfNecessary();
     }
 
@@ -298,8 +306,9 @@ static boolean needsMapperService(IndexSettings indexSettings, IndexCreationCont
     /**
      * Context for index creation
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum IndexCreationContext {
         CREATE_INDEX,
         METADATA_VERIFICATION
@@ -479,7 +488,7 @@ public synchronized IndexShard createShard(
             Store remoteStore = null;
             if (this.indexSettings.isRemoteStoreEnabled()) {
                 Directory remoteDirectory = remoteDirectoryFactory.newDirectory(this.indexSettings, path);
-                remoteStore = new Store(shardId, this.indexSettings, remoteDirectory, lock, Store.OnClose.EMPTY);
+                remoteStore = new Store(shardId, this.indexSettings, remoteDirectory, lock, Store.OnClose.EMPTY, path);
             }
 
             Directory directory = directoryFactory.newDirectory(this.indexSettings, path);
@@ -488,7 +497,8 @@ public synchronized IndexShard createShard(
                 this.indexSettings,
                 directory,
                 lock,
-                new StoreCloseListener(shardId, () -> eventListener.onStoreClosed(shardId))
+                new StoreCloseListener(shardId, () -> eventListener.onStoreClosed(shardId)),
+                path
             );
             eventListener.onStoreCreated(shardId);
             indexShard = new IndexShard(
@@ -516,7 +526,9 @@ public synchronized IndexShard createShard(
                 this.indexSettings.isSegRepEnabled() ? checkpointPublisher : null,
                 remoteStore,
                 remoteStoreStatsTrackerFactory,
-                clusterRemoteTranslogBufferIntervalSupplier
+                clusterRemoteTranslogBufferIntervalSupplier,
+                nodeEnv.nodeId(),
+                recoverySettings
             );
             eventListener.indexShardStateChanged(indexShard, null, indexShard.state(), "shard created");
             eventListener.afterIndexShardCreated(indexShard);
@@ -687,7 +699,7 @@ public IndexSettings getIndexSettings() {
 
     /**
      * Creates a new QueryShardContext.
-     *
+     * <p>
      * Passing a {@code null} {@link IndexSearcher} will return a valid context, however it won't be able to make
      * {@link IndexReader}-specific optimizations, such as rewriting containing range queries.
      */
@@ -697,7 +709,7 @@ public QueryShardContext newQueryShardContext(int shardId, IndexSearcher searche
 
     /**
      * Creates a new QueryShardContext.
-     *
+     * <p>
      * Passing a {@code null} {@link IndexSearcher} will return a valid context, however it won't be able to make
      * {@link IndexReader}-specific optimizations, such as rewriting containing range queries.
      */
@@ -970,8 +982,9 @@ private void rescheduleRefreshTasks() {
     /**
      * Shard Store Deleter Interface
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface ShardStoreDeleter {
         void deleteShardStore(String reason, ShardLock lock, IndexSettings indexSettings) throws IOException;
 
diff --git a/server/src/main/java/org/opensearch/index/IndexSettings.java b/server/src/main/java/org/opensearch/index/IndexSettings.java
index 03c71351294d5..00e765d73f77f 100644
--- a/server/src/main/java/org/opensearch/index/IndexSettings.java
+++ b/server/src/main/java/org/opensearch/index/IndexSettings.java
@@ -54,6 +54,7 @@
 import org.opensearch.node.Node;
 import org.opensearch.search.pipeline.SearchPipelineService;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
@@ -63,6 +64,7 @@
 import java.util.function.Function;
 import java.util.function.UnaryOperator;
 
+import static org.opensearch.Version.V_2_7_0;
 import static org.opensearch.common.util.FeatureFlags.SEARCHABLE_SNAPSHOT_EXTENDED_COMPATIBILITY;
 import static org.opensearch.index.mapper.MapperService.INDEX_MAPPING_DEPTH_LIMIT_SETTING;
 import static org.opensearch.index.mapper.MapperService.INDEX_MAPPING_FIELD_NAME_LENGTH_LIMIT_SETTING;
@@ -82,9 +84,42 @@
  */
 @PublicApi(since = "1.0.0")
 public final class IndexSettings {
-    private static final String MERGE_ON_FLUSH_DEFAULT_POLICY = "default";
+    private static final String DEFAULT_POLICY = "default";
     private static final String MERGE_ON_FLUSH_MERGE_POLICY = "merge-on-flush";
 
+    /**
+     * Enum representing supported merge policies
+     */
+    public enum IndexMergePolicy {
+        TIERED("tiered"),
+        LOG_BYTE_SIZE("log_byte_size"),
+        DEFAULT_POLICY(IndexSettings.DEFAULT_POLICY);
+
+        private final String value;
+
+        IndexMergePolicy(String value) {
+            this.value = value;
+        }
+
+        public String getValue() {
+            return value;
+        }
+
+        public static IndexMergePolicy fromString(String text) {
+            for (IndexMergePolicy policy : IndexMergePolicy.values()) {
+                if (policy.value.equals(text)) {
+                    return policy;
+                }
+            }
+            throw new IllegalArgumentException(
+                "The setting has unsupported policy specified: "
+                    + text
+                    + ". Please use one of: "
+                    + String.join(", ", Arrays.stream(IndexMergePolicy.values()).map(IndexMergePolicy::getValue).toArray(String[]::new))
+            );
+        }
+    }
+
     public static final Setting<List<String>> DEFAULT_FIELD_SETTING = Setting.listSetting(
         "index.query.default_field",
         Collections.singletonList("*"),
@@ -515,7 +550,7 @@ public final class IndexSettings {
 
     /**
      * This setting controls if unreferenced files will be cleaned up in case segment merge fails due to disk full.
-     *
+     * <p>
      * Defaults to true which means unreferenced files will be cleaned up in case segment merge fails.
      */
     public static final Setting<Boolean> INDEX_UNREFERENCED_FILE_CLEANUP = Setting.boolSetting(
@@ -531,7 +566,7 @@ public final class IndexSettings {
      * documents) on the grounds that a file-based peer recovery may copy all of the documents in the shard over to the new peer, but is
      * significantly faster than replaying the missing operations on the peer, so once a peer falls far enough behind the primary it makes
      * more sense to copy all the data over again instead of replaying history.
-     *
+     * <p>
      * Defaults to retaining history for up to 10% of the documents in the shard. This can only be changed in tests, since this setting is
      * intentionally unregistered.
      */
@@ -565,11 +600,25 @@ public final class IndexSettings {
 
     public static final Setting<String> INDEX_MERGE_ON_FLUSH_POLICY = Setting.simpleString(
         "index.merge_on_flush.policy",
-        MERGE_ON_FLUSH_DEFAULT_POLICY,
+        DEFAULT_POLICY,
         Property.IndexScope,
         Property.Dynamic
     );
 
+    public static final Setting<String> INDEX_MERGE_POLICY = Setting.simpleString(
+        "index.merge.policy",
+        DEFAULT_POLICY,
+        IndexMergePolicy::fromString,
+        Property.IndexScope
+    );
+
+    public static final Setting<String> TIME_SERIES_INDEX_MERGE_POLICY = Setting.simpleString(
+        "indices.time_series_index.default_index_merge_policy",
+        DEFAULT_POLICY,
+        IndexMergePolicy::fromString,
+        Property.NodeScope
+    );
+
     public static final Setting<String> SEARCHABLE_SNAPSHOT_REPOSITORY = Setting.simpleString(
         "index.searchable_snapshot.repository",
         Property.IndexScope,
@@ -619,6 +668,14 @@ public final class IndexSettings {
         Property.IndexScope
     );
 
+    public static final Setting<Integer> INDEX_REMOTE_TRANSLOG_KEEP_EXTRA_GEN_SETTING = Setting.intSetting(
+        "index.remote_store.translog.keep_extra_gen",
+        100,
+        0,
+        Property.Dynamic,
+        Property.IndexScope
+    );
+
     private final Index index;
     private final Version version;
     private final Logger logger;
@@ -631,6 +688,7 @@ public final class IndexSettings {
     private final String remoteStoreTranslogRepository;
     private final String remoteStoreRepository;
     private final boolean isRemoteSnapshot;
+    private int remoteTranslogKeepExtraGen;
     private Version extendedCompatibilitySnapshotVersion;
 
     // volatile fields are updated via #updateIndexMetadata(IndexMetadata) under lock
@@ -650,7 +708,8 @@ public final class IndexSettings {
     private volatile ByteSizeValue generationThresholdSize;
     private volatile ByteSizeValue flushAfterMergeThresholdSize;
     private final MergeSchedulerConfig mergeSchedulerConfig;
-    private final MergePolicyConfig mergePolicyConfig;
+    private final TieredMergePolicyProvider tieredMergePolicyProvider;
+    private final LogByteSizeMergePolicyProvider logByteSizeMergePolicyProvider;
     private final IndexSortConfig indexSortConfig;
     private final IndexScopedSettings scopedSettings;
     private long gcDeletesInMillis = DEFAULT_GC_DELETES.millis();
@@ -660,6 +719,7 @@ public final class IndexSettings {
     private volatile long retentionLeaseMillis;
 
     private volatile String defaultSearchPipeline;
+    private final boolean widenIndexSortType;
 
     /**
      * The maximum age of a retention lease before it is considered expired.
@@ -799,6 +859,7 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         remoteStoreTranslogRepository = settings.get(IndexMetadata.SETTING_REMOTE_TRANSLOG_STORE_REPOSITORY);
         remoteTranslogUploadBufferInterval = INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.get(settings);
         remoteStoreRepository = settings.get(IndexMetadata.SETTING_REMOTE_SEGMENT_STORE_REPOSITORY);
+        this.remoteTranslogKeepExtraGen = INDEX_REMOTE_TRANSLOG_KEEP_EXTRA_GEN_SETTING.get(settings);
         isRemoteSnapshot = IndexModule.Type.REMOTE_SNAPSHOT.match(this.settings);
 
         if (isRemoteSnapshot && FeatureFlags.isEnabled(SEARCHABLE_SNAPSHOT_EXTENDED_COMPATIBILITY)) {
@@ -842,7 +903,8 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         maxAnalyzedOffset = scopedSettings.get(MAX_ANALYZED_OFFSET_SETTING);
         maxTermsCount = scopedSettings.get(MAX_TERMS_COUNT_SETTING);
         maxRegexLength = scopedSettings.get(MAX_REGEX_LENGTH_SETTING);
-        this.mergePolicyConfig = new MergePolicyConfig(logger, this);
+        this.tieredMergePolicyProvider = new TieredMergePolicyProvider(logger, this);
+        this.logByteSizeMergePolicyProvider = new LogByteSizeMergePolicyProvider(logger, this);
         this.indexSortConfig = new IndexSortConfig(this);
         searchIdleAfter = scopedSettings.get(INDEX_SEARCH_IDLE_AFTER);
         defaultPipeline = scopedSettings.get(DEFAULT_PIPELINE);
@@ -857,33 +919,66 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         mergeOnFlushEnabled = scopedSettings.get(INDEX_MERGE_ON_FLUSH_ENABLED);
         setMergeOnFlushPolicy(scopedSettings.get(INDEX_MERGE_ON_FLUSH_POLICY));
         defaultSearchPipeline = scopedSettings.get(DEFAULT_SEARCH_PIPELINE);
-
-        scopedSettings.addSettingsUpdateConsumer(MergePolicyConfig.INDEX_COMPOUND_FORMAT_SETTING, mergePolicyConfig::setNoCFSRatio);
+        /* There was unintentional breaking change got introduced with [OpenSearch-6424](https://github.com/opensearch-project/OpenSearch/pull/6424) (version 2.7).
+         * For indices created prior version (prior to 2.7) which has IndexSort type, they used to type cast the SortField.Type
+         * to higher bytes size like integer to long. This behavior was changed from OpenSearch 2.7 version not to
+         * up cast the SortField to gain some sort query optimizations.
+         * Now this sortField (IndexSort) is stored in SegmentInfo and we need to maintain backward compatibility for them.
+         */
+        widenIndexSortType = IndexMetadata.SETTING_INDEX_VERSION_CREATED.get(settings).before(V_2_7_0);
+        scopedSettings.addSettingsUpdateConsumer(
+            TieredMergePolicyProvider.INDEX_COMPOUND_FORMAT_SETTING,
+            tieredMergePolicyProvider::setNoCFSRatio
+        );
         scopedSettings.addSettingsUpdateConsumer(
-            MergePolicyConfig.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING,
-            mergePolicyConfig::setDeletesPctAllowed
+            TieredMergePolicyProvider.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING,
+            tieredMergePolicyProvider::setDeletesPctAllowed
         );
         scopedSettings.addSettingsUpdateConsumer(
-            MergePolicyConfig.INDEX_MERGE_POLICY_EXPUNGE_DELETES_ALLOWED_SETTING,
-            mergePolicyConfig::setExpungeDeletesAllowed
+            TieredMergePolicyProvider.INDEX_MERGE_POLICY_EXPUNGE_DELETES_ALLOWED_SETTING,
+            tieredMergePolicyProvider::setExpungeDeletesAllowed
         );
         scopedSettings.addSettingsUpdateConsumer(
-            MergePolicyConfig.INDEX_MERGE_POLICY_FLOOR_SEGMENT_SETTING,
-            mergePolicyConfig::setFloorSegmentSetting
+            TieredMergePolicyProvider.INDEX_MERGE_POLICY_FLOOR_SEGMENT_SETTING,
+            tieredMergePolicyProvider::setFloorSegmentSetting
         );
         scopedSettings.addSettingsUpdateConsumer(
-            MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING,
-            mergePolicyConfig::setMaxMergesAtOnce
+            TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING,
+            tieredMergePolicyProvider::setMaxMergesAtOnce
         );
         scopedSettings.addSettingsUpdateConsumer(
-            MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGED_SEGMENT_SETTING,
-            mergePolicyConfig::setMaxMergedSegment
+            TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGED_SEGMENT_SETTING,
+            tieredMergePolicyProvider::setMaxMergedSegment
         );
         scopedSettings.addSettingsUpdateConsumer(
-            MergePolicyConfig.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING,
-            mergePolicyConfig::setSegmentsPerTier
+            TieredMergePolicyProvider.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING,
+            tieredMergePolicyProvider::setSegmentsPerTier
         );
 
+        scopedSettings.addSettingsUpdateConsumer(
+            LogByteSizeMergePolicyProvider.INDEX_LBS_MERGE_POLICY_MERGE_FACTOR_SETTING,
+            logByteSizeMergePolicyProvider::setLBSMergeFactor
+        );
+        scopedSettings.addSettingsUpdateConsumer(
+            LogByteSizeMergePolicyProvider.INDEX_LBS_MERGE_POLICY_MIN_MERGE_SETTING,
+            logByteSizeMergePolicyProvider::setLBSMinMergedMB
+        );
+        scopedSettings.addSettingsUpdateConsumer(
+            LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGE_SEGMENT_SETTING,
+            logByteSizeMergePolicyProvider::setLBSMaxMergeSegment
+        );
+        scopedSettings.addSettingsUpdateConsumer(
+            LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGE_SEGMENT_FOR_FORCED_MERGE_SETTING,
+            logByteSizeMergePolicyProvider::setLBSMaxMergeMBForForcedMerge
+        );
+        scopedSettings.addSettingsUpdateConsumer(
+            LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGED_DOCS_SETTING,
+            logByteSizeMergePolicyProvider::setLBSMaxMergeDocs
+        );
+        scopedSettings.addSettingsUpdateConsumer(
+            LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING,
+            logByteSizeMergePolicyProvider::setLBSNoCFSRatio
+        );
         scopedSettings.addSettingsUpdateConsumer(
             MergeSchedulerConfig.MAX_THREAD_COUNT_SETTING,
             MergeSchedulerConfig.MAX_MERGE_COUNT_SETTING,
@@ -936,9 +1031,13 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
             INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING,
             this::setRemoteTranslogUploadBufferInterval
         );
+        scopedSettings.addSettingsUpdateConsumer(INDEX_REMOTE_TRANSLOG_KEEP_EXTRA_GEN_SETTING, this::setRemoteTranslogKeepExtraGen);
     }
 
     private void setSearchIdleAfter(TimeValue searchIdleAfter) {
+        if (this.isRemoteStoreEnabled) {
+            logger.warn("Search idle is not supported for remote backed indices");
+        }
         if (this.replicationType == ReplicationType.SEGMENT && this.getNumberOfReplicas() > 0) {
             logger.warn("Search idle is not supported for indices with replicas using 'replication.type: SEGMENT'");
         }
@@ -1212,6 +1311,10 @@ public TimeValue getRemoteTranslogUploadBufferInterval() {
         return remoteTranslogUploadBufferInterval;
     }
 
+    public int getRemoteTranslogExtraKeep() {
+        return remoteTranslogKeepExtraGen;
+    }
+
     /**
      * Returns true iff the remote translog buffer interval setting exists or in other words is explicitly set.
      */
@@ -1223,6 +1326,10 @@ public void setRemoteTranslogUploadBufferInterval(TimeValue remoteTranslogUpload
         this.remoteTranslogUploadBufferInterval = remoteTranslogUploadBufferInterval;
     }
 
+    public void setRemoteTranslogKeepExtraGen(int extraGen) {
+        this.remoteTranslogKeepExtraGen = extraGen;
+    }
+
     /**
      * Returns this interval in which the shards of this index are asynchronously refreshed. {@code -1} means async refresh is disabled.
      */
@@ -1430,9 +1537,43 @@ public long getGcDeletesInMillis() {
 
     /**
      * Returns the merge policy that should be used for this index.
-     */
-    public MergePolicy getMergePolicy() {
-        return mergePolicyConfig.getMergePolicy();
+     * @param isTimeSeriesIndex true if index contains @timestamp field
+     */
+    public MergePolicy getMergePolicy(boolean isTimeSeriesIndex) {
+        String indexScopedPolicy = scopedSettings.get(INDEX_MERGE_POLICY);
+        MergePolicyProvider mergePolicyProvider = null;
+        IndexMergePolicy indexMergePolicy = IndexMergePolicy.fromString(indexScopedPolicy);
+        switch (indexMergePolicy) {
+            case TIERED:
+                mergePolicyProvider = tieredMergePolicyProvider;
+                break;
+            case LOG_BYTE_SIZE:
+                mergePolicyProvider = logByteSizeMergePolicyProvider;
+                break;
+            case DEFAULT_POLICY:
+                if (isTimeSeriesIndex) {
+                    String nodeScopedTimeSeriesIndexPolicy = TIME_SERIES_INDEX_MERGE_POLICY.get(nodeSettings);
+                    IndexMergePolicy nodeMergePolicy = IndexMergePolicy.fromString(nodeScopedTimeSeriesIndexPolicy);
+                    switch (nodeMergePolicy) {
+                        case TIERED:
+                        case DEFAULT_POLICY:
+                            mergePolicyProvider = tieredMergePolicyProvider;
+                            break;
+                        case LOG_BYTE_SIZE:
+                            mergePolicyProvider = logByteSizeMergePolicyProvider;
+                            break;
+                    }
+                } else {
+                    mergePolicyProvider = tieredMergePolicyProvider;
+                }
+                break;
+        }
+        assert mergePolicyProvider != null : "should not happen as validation for invalid merge policy values "
+            + "are part of setting definition";
+        if (logger.isTraceEnabled()) {
+            logger.trace("Index: " + this.index.getName() + ", Merge policy used: " + mergePolicyProvider);
+        }
+        return mergePolicyProvider.getMergePolicy();
     }
 
     public <T> T getValue(Setting<T> setting) {
@@ -1623,7 +1764,7 @@ public boolean isMergeOnFlushEnabled() {
     }
 
     private void setMergeOnFlushPolicy(String policy) {
-        if (Strings.isEmpty(policy) || MERGE_ON_FLUSH_DEFAULT_POLICY.equalsIgnoreCase(policy)) {
+        if (Strings.isEmpty(policy) || DEFAULT_POLICY.equalsIgnoreCase(policy)) {
             mergeOnFlushPolicy = null;
         } else if (MERGE_ON_FLUSH_MERGE_POLICY.equalsIgnoreCase(policy)) {
             this.mergeOnFlushPolicy = MergeOnFlushMergePolicy::new;
@@ -1634,7 +1775,7 @@ private void setMergeOnFlushPolicy(String policy) {
                     + " has unsupported policy specified: "
                     + policy
                     + ". Please use one of: "
-                    + MERGE_ON_FLUSH_DEFAULT_POLICY
+                    + DEFAULT_POLICY
                     + ", "
                     + MERGE_ON_FLUSH_MERGE_POLICY
             );
@@ -1652,4 +1793,12 @@ public String getDefaultSearchPipeline() {
     public void setDefaultSearchPipeline(String defaultSearchPipeline) {
         this.defaultSearchPipeline = defaultSearchPipeline;
     }
+
+    /**
+     * Returns true if we need to maintain backward compatibility for index sorted indices created prior to version 2.7
+     * @return boolean
+     */
+    public boolean shouldWidenIndexSortType() {
+        return this.widenIndexSortType;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/IndexSortConfig.java b/server/src/main/java/org/opensearch/index/IndexSortConfig.java
index f73f96df4f9ad..af2e22c4aad53 100644
--- a/server/src/main/java/org/opensearch/index/IndexSortConfig.java
+++ b/server/src/main/java/org/opensearch/index/IndexSortConfig.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.SortedNumericSortField;
 import org.apache.lucene.search.SortedSetSortField;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.index.fielddata.IndexFieldData;
@@ -53,7 +54,7 @@
 
 /**
  * Holds all the information that is used to build the sort order of an index.
- *
+ * <p>
  * The index sort settings are <b>final</b> and can be defined only at index creation.
  * These settings are divided in four lists that are merged during the initialization of this class:
  * <ul>
@@ -69,8 +70,10 @@
  *     </li>
  * </ul>
  *
- * @opensearch.internal
-**/
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "1.0.0")
 public final class IndexSortConfig {
     /**
      * The list of field names
@@ -200,6 +203,7 @@ public boolean hasPrimarySortOnField(String field) {
      * or returns null if this index has no sort.
      */
     public Sort buildIndexSort(
+        boolean shouldWidenIndexSortType,
         Function<String, MappedFieldType> fieldTypeLookup,
         BiFunction<MappedFieldType, Supplier<SearchLookup>, IndexFieldData<?>> fieldDataLookup
     ) {
@@ -230,7 +234,11 @@ public Sort buildIndexSort(
             if (fieldData == null) {
                 throw new IllegalArgumentException("docvalues not found for index sort field:[" + sortSpec.field + "]");
             }
-            sortFields[i] = fieldData.sortField(sortSpec.missingValue, mode, null, reverse);
+            if (shouldWidenIndexSortType == true) {
+                sortFields[i] = fieldData.wideSortField(sortSpec.missingValue, mode, null, reverse);
+            } else {
+                sortFields[i] = fieldData.sortField(sortSpec.missingValue, mode, null, reverse);
+            }
             validateIndexSortField(sortFields[i]);
         }
         return new Sort(sortFields);
diff --git a/server/src/main/java/org/opensearch/index/IndexWarmer.java b/server/src/main/java/org/opensearch/index/IndexWarmer.java
index b62afe6b6dcfc..81063cb9b9c38 100644
--- a/server/src/main/java/org/opensearch/index/IndexWarmer.java
+++ b/server/src/main/java/org/opensearch/index/IndexWarmer.java
@@ -35,6 +35,7 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.index.OpenSearchDirectoryReader;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.index.fielddata.IndexFieldData;
@@ -111,8 +112,9 @@ void warm(OpenSearchDirectoryReader reader, IndexShard shard, IndexSettings sett
     /**
      * A handle on the execution of  warm-up action.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface TerminationHandle {
 
         TerminationHandle NO_WAIT = () -> {};
@@ -124,8 +126,9 @@ public interface TerminationHandle {
     /**
      * Listener for the index warmer
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Listener {
         /** Queue tasks to warm-up the given segments and return handles that allow to wait for termination of the
          *  execution of those tasks. */
diff --git a/server/src/main/java/org/opensearch/index/IndexingPressureService.java b/server/src/main/java/org/opensearch/index/IndexingPressureService.java
index 70fb5692f5619..898c3686d7a84 100644
--- a/server/src/main/java/org/opensearch/index/IndexingPressureService.java
+++ b/server/src/main/java/org/opensearch/index/IndexingPressureService.java
@@ -7,6 +7,7 @@
 
 import org.opensearch.action.admin.indices.stats.CommonStatsFlags;
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.index.shard.ShardId;
@@ -19,8 +20,9 @@
  * Sets up classes for node/shard level indexing pressure.
  * Provides abstraction and orchestration for indexing pressure interfaces when called from Transport Actions or for Stats.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.3.0")
 public class IndexingPressureService {
 
     private final ShardIndexingPressure shardIndexingPressure;
diff --git a/server/src/main/java/org/opensearch/index/IndexingSlowLog.java b/server/src/main/java/org/opensearch/index/IndexingSlowLog.java
index 2ef4552103008..bc42fa304e2c5 100644
--- a/server/src/main/java/org/opensearch/index/IndexingSlowLog.java
+++ b/server/src/main/java/org/opensearch/index/IndexingSlowLog.java
@@ -38,6 +38,7 @@
 import org.opensearch.common.Booleans;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.logging.OpenSearchLogMessage;
+import org.opensearch.common.logging.SlowLogLevel;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.unit.TimeValue;
diff --git a/server/src/main/java/org/opensearch/index/LogByteSizeMergePolicyProvider.java b/server/src/main/java/org/opensearch/index/LogByteSizeMergePolicyProvider.java
new file mode 100644
index 0000000000000..0b762d781957c
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/LogByteSizeMergePolicyProvider.java
@@ -0,0 +1,166 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index;
+
+import org.apache.logging.log4j.Logger;
+import org.apache.lucene.index.LogByteSizeMergePolicy;
+import org.apache.lucene.index.MergePolicy;
+import org.apache.lucene.index.NoMergePolicy;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.core.common.unit.ByteSizeUnit;
+import org.opensearch.core.common.unit.ByteSizeValue;
+
+import static org.apache.lucene.index.LogMergePolicy.DEFAULT_MAX_MERGE_DOCS;
+import static org.apache.lucene.index.LogMergePolicy.DEFAULT_NO_CFS_RATIO;
+
+/**
+ * <p>
+ * The LogByteSizeMergePolicy is an alternative merge policy primarily used here to optimize the merging of segments in scenarios
+ * with index with timestamps.
+ * While the TieredMergePolicy is the default choice, the LogByteSizeMergePolicy can be configured
+ * as the default merge policy for time-index data using the <code>index.datastream_merge.policy</code> setting.
+ *
+ * <p>
+ * Unlike the TieredMergePolicy, which prioritizes merging segments of equal sizes, the LogByteSizeMergePolicy
+ * specializes in merging adjacent segments efficiently.
+ * This characteristic makes it particularly well-suited for range queries on time-index data.
+ * Typically, adjacent segments in time-index data often contain documents with similar timestamps.
+ * When these segments are merged, the resulting segment covers a range of timestamps with reduced overlap compared
+ * to the adjacent segments. This reduced overlap remains even as segments grow older and larger,
+ * which can significantly benefit range queries on timestamps.
+ *
+ * <p>
+ * In contrast, the TieredMergePolicy does not honor this timestamp range optimization. It focuses on merging segments
+ * of equal sizes and does not consider adjacency. Consequently, as segments grow older and larger,
+ * the overlap of timestamp ranges among adjacent segments managed by TieredMergePolicy can increase.
+ * This can lead to inefficiencies in range queries on timestamps, as the number of segments to be scanned
+ * within a given timestamp range could become high.
+ *
+ * @opensearch.internal
+ */
+public class LogByteSizeMergePolicyProvider implements MergePolicyProvider {
+    private final LogByteSizeMergePolicy logByteSizeMergePolicy = new LogByteSizeMergePolicy();
+
+    private final Logger logger;
+    private final boolean mergesEnabled;
+
+    public static final ByteSizeValue DEFAULT_MIN_MERGE = new ByteSizeValue(2, ByteSizeUnit.MB);
+    public static final int DEFAULT_MERGE_FACTOR = 10;
+
+    public static final ByteSizeValue DEFAULT_MAX_MERGED_SEGMENT = new ByteSizeValue(5, ByteSizeUnit.GB);
+
+    public static final ByteSizeValue DEFAULT_MAX_MERGE_SEGMENT_FORCE_MERGE = new ByteSizeValue(Long.MAX_VALUE);
+
+    public static final Setting<Integer> INDEX_LBS_MERGE_POLICY_MERGE_FACTOR_SETTING = Setting.intSetting(
+        "index.merge.log_byte_size_policy.merge_factor",
+        DEFAULT_MERGE_FACTOR, // keeping it same as default max merge at once for tiered merge policy
+        2,
+        Setting.Property.Dynamic,
+        Setting.Property.IndexScope
+    );
+
+    public static final Setting<ByteSizeValue> INDEX_LBS_MERGE_POLICY_MIN_MERGE_SETTING = Setting.byteSizeSetting(
+        "index.merge.log_byte_size_policy.min_merge",
+        DEFAULT_MIN_MERGE, // keeping it same as default floor segment for tiered merge policy
+        Setting.Property.Dynamic,
+        Setting.Property.IndexScope
+    );
+
+    public static final Setting<ByteSizeValue> INDEX_LBS_MAX_MERGE_SEGMENT_SETTING = Setting.byteSizeSetting(
+        "index.merge.log_byte_size_policy.max_merge_segment",
+        DEFAULT_MAX_MERGED_SEGMENT, // keeping default same as tiered merge policy
+        Setting.Property.Dynamic,
+        Setting.Property.IndexScope
+    );
+
+    public static final Setting<ByteSizeValue> INDEX_LBS_MAX_MERGE_SEGMENT_FOR_FORCED_MERGE_SETTING = Setting.byteSizeSetting(
+        "index.merge.log_byte_size_policy.max_merge_segment_forced_merge",
+        DEFAULT_MAX_MERGE_SEGMENT_FORCE_MERGE,
+        Setting.Property.Dynamic,
+        Setting.Property.IndexScope
+    );
+
+    public static final Setting<Integer> INDEX_LBS_MAX_MERGED_DOCS_SETTING = Setting.intSetting(
+        "index.merge.log_byte_size_policy.max_merged_docs",
+        DEFAULT_MAX_MERGE_DOCS,
+        Setting.Property.Dynamic,
+        Setting.Property.IndexScope
+    );
+
+    public static final Setting<Double> INDEX_LBS_NO_CFS_RATIO_SETTING = new Setting<>(
+        "index.merge.log_byte_size_policy.no_cfs_ratio",
+        Double.toString(DEFAULT_NO_CFS_RATIO),
+        TieredMergePolicyProvider::parseNoCFSRatio,
+        Setting.Property.Dynamic,
+        Setting.Property.IndexScope
+    );
+
+    LogByteSizeMergePolicyProvider(Logger logger, IndexSettings indexSettings) {
+        this.logger = logger;
+        this.mergesEnabled = indexSettings.getSettings().getAsBoolean(INDEX_MERGE_ENABLED, true);
+
+        // Undocumented settings, works great with defaults
+        logByteSizeMergePolicy.setMergeFactor(indexSettings.getValue(INDEX_LBS_MERGE_POLICY_MERGE_FACTOR_SETTING));
+        logByteSizeMergePolicy.setMinMergeMB(indexSettings.getValue(INDEX_LBS_MERGE_POLICY_MIN_MERGE_SETTING).getMbFrac());
+        logByteSizeMergePolicy.setMaxMergeMB(indexSettings.getValue(INDEX_LBS_MAX_MERGE_SEGMENT_SETTING).getMbFrac());
+        logByteSizeMergePolicy.setMaxMergeMBForForcedMerge(
+            indexSettings.getValue(INDEX_LBS_MAX_MERGE_SEGMENT_FOR_FORCED_MERGE_SETTING).getMbFrac()
+        );
+        logByteSizeMergePolicy.setMaxMergeDocs(indexSettings.getValue(INDEX_LBS_MAX_MERGED_DOCS_SETTING));
+        logByteSizeMergePolicy.setNoCFSRatio(indexSettings.getValue(INDEX_LBS_NO_CFS_RATIO_SETTING));
+    }
+
+    @Override
+    public MergePolicy getMergePolicy() {
+        return mergesEnabled ? logByteSizeMergePolicy : NoMergePolicy.INSTANCE;
+    }
+
+    void setLBSMergeFactor(int mergeFactor) {
+        logByteSizeMergePolicy.setMergeFactor(mergeFactor);
+    }
+
+    void setLBSMaxMergeSegment(ByteSizeValue maxMergeSegment) {
+        logByteSizeMergePolicy.setMaxMergeMB(maxMergeSegment.getMbFrac());
+    }
+
+    void setLBSMinMergedMB(ByteSizeValue minMergedSize) {
+        logByteSizeMergePolicy.setMinMergeMB(minMergedSize.getMbFrac());
+    }
+
+    void setLBSMaxMergeMBForForcedMerge(ByteSizeValue maxMergeForcedMerge) {
+        logByteSizeMergePolicy.setMaxMergeMBForForcedMerge(maxMergeForcedMerge.getMbFrac());
+    }
+
+    void setLBSMaxMergeDocs(int maxMergeDocs) {
+        logByteSizeMergePolicy.setMaxMergeDocs(maxMergeDocs);
+    }
+
+    void setLBSNoCFSRatio(Double noCFSRatio) {
+        logByteSizeMergePolicy.setNoCFSRatio(noCFSRatio);
+    }
+
+    @Override
+    public String toString() {
+        return "LogByteSizeMergePolicyProvider{"
+            + "mergeFactor="
+            + logByteSizeMergePolicy.getMergeFactor()
+            + ", minMergeMB="
+            + logByteSizeMergePolicy.getMinMergeMB()
+            + ", maxMergeMB="
+            + logByteSizeMergePolicy.getMaxMergeMB()
+            + ", maxMergeMBForForcedMerge="
+            + logByteSizeMergePolicy.getMaxMergeMBForForcedMerge()
+            + ", maxMergedDocs="
+            + logByteSizeMergePolicy.getMaxMergeDocs()
+            + ", noCFSRatio="
+            + logByteSizeMergePolicy.getNoCFSRatio()
+            + '}';
+    }
+
+}
diff --git a/server/src/main/java/org/opensearch/index/MergePolicyProvider.java b/server/src/main/java/org/opensearch/index/MergePolicyProvider.java
new file mode 100644
index 0000000000000..6f734314f758f
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/MergePolicyProvider.java
@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index;
+
+import org.apache.lucene.index.MergePolicy;
+import org.opensearch.common.annotation.InternalApi;
+
+/**
+ * A provider for obtaining merge policies used by OpenSearch indexes.
+ *
+ * @opensearch.internal
+ */
+
+@InternalApi
+public interface MergePolicyProvider {
+    // don't convert to Setting<> and register... we only set this in tests and register via a plugin
+    String INDEX_MERGE_ENABLED = "index.merge.enabled";
+
+    /**
+     * Gets the merge policy to be used for index.
+     *
+     * @return The merge policy instance.
+     */
+    MergePolicy getMergePolicy();
+}
diff --git a/server/src/main/java/org/opensearch/index/MergeSchedulerConfig.java b/server/src/main/java/org/opensearch/index/MergeSchedulerConfig.java
index 9e170b448d641..a93a362a70c78 100644
--- a/server/src/main/java/org/opensearch/index/MergeSchedulerConfig.java
+++ b/server/src/main/java/org/opensearch/index/MergeSchedulerConfig.java
@@ -33,6 +33,7 @@
 package org.opensearch.index;
 
 import org.apache.lucene.index.ConcurrentMergeScheduler;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.settings.Settings;
@@ -48,14 +49,14 @@
  *
  * <ul>
  * <li> <code>index.merge.scheduler.max_thread_count</code>:
- *
+ * <p>
  *     The maximum number of threads that may be merging at once. Defaults to
  *     <code>Math.max(1, Math.min(4, {@link OpenSearchExecutors#allocatedProcessors(Settings)} / 2))</code>
  *     which works well for a good solid-state-disk (SSD).  If your index is on
  *     spinning platter drives instead, decrease this to 1.
  *
  * <li><code>index.merge.scheduler.auto_throttle</code>:
- *
+ * <p>
  *     If this is true (the default), then the merge scheduler will rate-limit IO
  *     (writes) for merges to an adaptive value depending on how many merges are
  *     requested over time.  An application with a low indexing rate that
@@ -64,8 +65,9 @@
  *     move higher to allow merges to keep up with ongoing indexing.
  * </ul>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class MergeSchedulerConfig {
 
     public static final Setting<Integer> MAX_THREAD_COUNT_SETTING = new Setting<>(
diff --git a/server/src/main/java/org/opensearch/index/OpenSearchTieredMergePolicy.java b/server/src/main/java/org/opensearch/index/OpenSearchTieredMergePolicy.java
index 637282374de73..df1666e72f2ee 100644
--- a/server/src/main/java/org/opensearch/index/OpenSearchTieredMergePolicy.java
+++ b/server/src/main/java/org/opensearch/index/OpenSearchTieredMergePolicy.java
@@ -42,7 +42,7 @@
 
 /**
  * Wrapper around {@link TieredMergePolicy} which doesn't respect
- * {@link TieredMergePolicy#setMaxMergedSegmentMB(double)} on forced merges.
+ * {@link TieredMergePolicy#setMaxMergedSegmentMB(double)} on forced merges, but DOES respect it on only_expunge_deletes.
  * See https://issues.apache.org/jira/browse/LUCENE-7976.
  *
  * @opensearch.internal
@@ -71,7 +71,7 @@ public MergeSpecification findForcedMerges(
 
     @Override
     public MergeSpecification findForcedDeletesMerges(SegmentInfos infos, MergeContext mergeContext) throws IOException {
-        return forcedMergePolicy.findForcedDeletesMerges(infos, mergeContext);
+        return regularMergePolicy.findForcedDeletesMerges(infos, mergeContext);
     }
 
     public void setForceMergeDeletesPctAllowed(double forceMergeDeletesPctAllowed) {
@@ -80,7 +80,7 @@ public void setForceMergeDeletesPctAllowed(double forceMergeDeletesPctAllowed) {
     }
 
     public double getForceMergeDeletesPctAllowed() {
-        return forcedMergePolicy.getForceMergeDeletesPctAllowed();
+        return regularMergePolicy.getForceMergeDeletesPctAllowed();
     }
 
     public void setFloorSegmentMB(double mbFrac) {
diff --git a/server/src/main/java/org/opensearch/index/ReplicationStats.java b/server/src/main/java/org/opensearch/index/ReplicationStats.java
index 9cc6685c75f80..8987a492e9a90 100644
--- a/server/src/main/java/org/opensearch/index/ReplicationStats.java
+++ b/server/src/main/java/org/opensearch/index/ReplicationStats.java
@@ -8,11 +8,10 @@
 
 package org.opensearch.index;
 
-import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
-import org.opensearch.core.common.unit.ByteSizeValue;
 import org.opensearch.core.xcontent.ToXContentFragment;
 import org.opensearch.core.xcontent.XContentBuilder;
 
@@ -22,8 +21,9 @@
  * ReplicationStats is used to provide segment replication statistics at an index,
  * node and cluster level on a segment replication enabled cluster.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class ReplicationStats implements ToXContentFragment, Writeable {
 
     public long maxBytesBehind;
@@ -76,9 +76,9 @@ public void writeTo(StreamOutput out) throws IOException {
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(Fields.SEGMENT_REPLICATION);
-        builder.field(Fields.MAX_BYTES_BEHIND, new ByteSizeValue(maxBytesBehind).toString());
-        builder.field(Fields.TOTAL_BYTES_BEHIND, new ByteSizeValue(totalBytesBehind).toString());
-        builder.field(Fields.MAX_REPLICATION_LAG, new TimeValue(maxReplicationLag));
+        builder.field(Fields.MAX_BYTES_BEHIND, maxBytesBehind);
+        builder.field(Fields.TOTAL_BYTES_BEHIND, totalBytesBehind);
+        builder.field(Fields.MAX_REPLICATION_LAG, maxReplicationLag);
         builder.endObject();
         return builder;
     }
diff --git a/server/src/main/java/org/opensearch/index/SearchSlowLog.java b/server/src/main/java/org/opensearch/index/SearchSlowLog.java
index d8bcd6c848cef..cfdc2cf348d4d 100644
--- a/server/src/main/java/org/opensearch/index/SearchSlowLog.java
+++ b/server/src/main/java/org/opensearch/index/SearchSlowLog.java
@@ -38,6 +38,7 @@
 import org.apache.logging.log4j.Logger;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.logging.OpenSearchLogMessage;
+import org.opensearch.common.logging.SlowLogLevel;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.unit.TimeValue;
diff --git a/server/src/main/java/org/opensearch/index/SegmentReplicationPerGroupStats.java b/server/src/main/java/org/opensearch/index/SegmentReplicationPerGroupStats.java
index c3b4f8217c961..884686ee48fa1 100644
--- a/server/src/main/java/org/opensearch/index/SegmentReplicationPerGroupStats.java
+++ b/server/src/main/java/org/opensearch/index/SegmentReplicationPerGroupStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -21,8 +22,9 @@
 /**
  * Return Segment Replication stats for a Replication Group.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class SegmentReplicationPerGroupStats implements Writeable, ToXContentFragment {
 
     private final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/index/SegmentReplicationPressureService.java b/server/src/main/java/org/opensearch/index/SegmentReplicationPressureService.java
index 4284daf9ffef4..ce38dd3bb236c 100644
--- a/server/src/main/java/org/opensearch/index/SegmentReplicationPressureService.java
+++ b/server/src/main/java/org/opensearch/index/SegmentReplicationPressureService.java
@@ -98,7 +98,7 @@ public class SegmentReplicationPressureService implements Closeable {
     private final SegmentReplicationStatsTracker tracker;
     private final ShardStateAction shardStateAction;
 
-    private final AsyncFailStaleReplicaTask failStaleReplicaTask;
+    private volatile AsyncFailStaleReplicaTask failStaleReplicaTask;
 
     @Inject
     public SegmentReplicationPressureService(
@@ -106,10 +106,11 @@ public SegmentReplicationPressureService(
         ClusterService clusterService,
         IndicesService indicesService,
         ShardStateAction shardStateAction,
+        SegmentReplicationStatsTracker tracker,
         ThreadPool threadPool
     ) {
         this.indicesService = indicesService;
-        this.tracker = new SegmentReplicationStatsTracker(this.indicesService);
+        this.tracker = tracker;
         this.shardStateAction = shardStateAction;
         this.threadPool = threadPool;
 
@@ -201,6 +202,15 @@ public void setMaxAllowedStaleReplicas(double maxAllowedStaleReplicas) {
 
     public void setReplicationTimeLimitFailReplica(TimeValue replicationTimeLimitFailReplica) {
         this.replicationTimeLimitFailReplica = replicationTimeLimitFailReplica;
+        updateAsyncFailReplicaTask();
+    }
+
+    private synchronized void updateAsyncFailReplicaTask() {
+        try {
+            failStaleReplicaTask.close();
+        } finally {
+            failStaleReplicaTask = new AsyncFailStaleReplicaTask(this);
+        }
     }
 
     public void setReplicationTimeLimitBackpressure(TimeValue replicationTimeLimitBackpressure) {
@@ -227,13 +237,13 @@ final static class AsyncFailStaleReplicaTask extends AbstractAsyncTask {
 
         @Override
         protected boolean mustReschedule() {
-            return true;
+            return pressureService.shouldScheduleAsyncFailTask();
         }
 
         @Override
         protected void runInternal() {
             // Do not fail the replicas if time limit is set to 0 (i.e. disabled).
-            if (TimeValue.ZERO.equals(pressureService.replicationTimeLimitFailReplica) == false) {
+            if (pressureService.shouldScheduleAsyncFailTask()) {
                 final SegmentReplicationStats stats = pressureService.tracker.getStats();
 
                 // Find the shardId in node which is having stale replicas with highest current replication time.
@@ -301,4 +311,8 @@ public String toString() {
 
     }
 
+    boolean shouldScheduleAsyncFailTask() {
+        return TimeValue.ZERO.equals(replicationTimeLimitFailReplica) == false;
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/index/SegmentReplicationRejectionStats.java b/server/src/main/java/org/opensearch/index/SegmentReplicationRejectionStats.java
new file mode 100644
index 0000000000000..492f253bbcb7c
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/SegmentReplicationRejectionStats.java
@@ -0,0 +1,65 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index;
+
+import org.opensearch.Version;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.xcontent.ToXContentFragment;
+import org.opensearch.core.xcontent.XContentBuilder;
+
+import java.io.IOException;
+
+/**
+ * Segment replication rejection stats.
+ *
+ * @opensearch.internal
+ */
+public class SegmentReplicationRejectionStats implements Writeable, ToXContentFragment {
+
+    /**
+     * Total rejections due to segment replication backpressure
+     */
+    private long totalRejectionCount;
+
+    public SegmentReplicationRejectionStats(final long totalRejectionCount) {
+        this.totalRejectionCount = totalRejectionCount;
+    }
+
+    public SegmentReplicationRejectionStats(StreamInput in) throws IOException {
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            this.totalRejectionCount = in.readVLong();
+        }
+    }
+
+    public long getTotalRejectionCount() {
+        return totalRejectionCount;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject("segment_replication_backpressure");
+        builder.field("total_rejected_requests", totalRejectionCount);
+        return builder.endObject();
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeVLong(totalRejectionCount);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "SegmentReplicationRejectionStats{ totalRejectedRequestCount=" + totalRejectionCount + '}';
+    }
+
+}
diff --git a/server/src/main/java/org/opensearch/index/SegmentReplicationShardStats.java b/server/src/main/java/org/opensearch/index/SegmentReplicationShardStats.java
index 2be0c712f64ef..e381ade253422 100644
--- a/server/src/main/java/org/opensearch/index/SegmentReplicationShardStats.java
+++ b/server/src/main/java/org/opensearch/index/SegmentReplicationShardStats.java
@@ -9,6 +9,7 @@
 package org.opensearch.index;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -23,8 +24,9 @@
 /**
  * SegRep stats for a single shard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class SegmentReplicationShardStats implements Writeable, ToXContentFragment {
     private final String allocationId;
     private final long checkpointsBehindCount;
diff --git a/server/src/main/java/org/opensearch/index/SegmentReplicationStatsTracker.java b/server/src/main/java/org/opensearch/index/SegmentReplicationStatsTracker.java
index 6d5c00c08caff..f5fc8aa1c1eea 100644
--- a/server/src/main/java/org/opensearch/index/SegmentReplicationStatsTracker.java
+++ b/server/src/main/java/org/opensearch/index/SegmentReplicationStatsTracker.java
@@ -33,6 +33,14 @@ public SegmentReplicationStatsTracker(IndicesService indicesService) {
         rejectionCount = ConcurrentCollections.newConcurrentMap();
     }
 
+    public SegmentReplicationRejectionStats getTotalRejectionStats() {
+        return new SegmentReplicationRejectionStats(this.rejectionCount.values().stream().mapToInt(AtomicInteger::get).sum());
+    }
+
+    protected Map<ShardId, AtomicInteger> getRejectionCount() {
+        return rejectionCount;
+    }
+
     public SegmentReplicationStats getStats() {
         Map<ShardId, SegmentReplicationPerGroupStats> stats = new HashMap<>();
         for (IndexService indexService : indicesService) {
diff --git a/server/src/main/java/org/opensearch/index/ShardIndexingPressure.java b/server/src/main/java/org/opensearch/index/ShardIndexingPressure.java
index 07768c6769b71..a6135186fb5ff 100644
--- a/server/src/main/java/org/opensearch/index/ShardIndexingPressure.java
+++ b/server/src/main/java/org/opensearch/index/ShardIndexingPressure.java
@@ -34,7 +34,7 @@
  * Interfaces returns Releasable which when triggered will release the acquired accounting tokens values and also
  * perform necessary actions such as throughput evaluation once the request completes.
  * Consumers of these interfaces are expected to trigger close on releasable, reliably for consistency.
- *
+ * <p>
  * Overall ShardIndexingPressure provides:
  * 1. Memory Accounting at shard level. This can be enabled/disabled based on dynamic setting.
  * 2. Memory Accounting at Node level. Tracking is done using the IndexingPressure artefacts to support feature seamless toggling.
diff --git a/server/src/main/java/org/opensearch/index/ShardIndexingPressureMemoryManager.java b/server/src/main/java/org/opensearch/index/ShardIndexingPressureMemoryManager.java
index dea3cc8970cb5..e5c1af2e9c9f0 100644
--- a/server/src/main/java/org/opensearch/index/ShardIndexingPressureMemoryManager.java
+++ b/server/src/main/java/org/opensearch/index/ShardIndexingPressureMemoryManager.java
@@ -30,16 +30,16 @@
 /**
  * The Shard Indexing Pressure Memory Manager is the construct responsible for increasing and decreasing the allocated shard limit
  * based on incoming requests. A shard limits defines the maximum memory that a shard can occupy in the heap for request objects.
- *
+ * <p>
  * Based on the overall memory utilization on the node, and current traffic needs shard limits will be modified:
- *
+ * <p>
  * 1. If the limits assigned to a shard is breached (Primary Parameter) while the node level overall occupancy across all shards
  * is not greater than primary_parameter.node.soft_limit, MemoryManager will increase the shard limits without any deeper evaluation.
  * 2. If the limits assigned to the shard is breached(Primary Parameter) and the node level overall occupancy across all shards
  * is greater than primary_parameter.node.soft_limit, then MemoryManager will evaluate deeper parameters for shards to identify any
  * issues, such as throughput degradation (Secondary Parameter - 1) and time since last request was successful (Secondary Parameter - 2).
  * This helps identify detect any duress state with the shard, requesting more memory.
- *
+ * <p>
  * Secondary Parameters covered above:
  * 1. ThroughputDegradationLimitsBreached - When the moving window throughput average has increased by a factor compared to
  * the historical throughput average. If the factor by which it has increased is greater than the degradation limit threshold, this
@@ -47,7 +47,7 @@
  * 2. LastSuccessfulRequestDurationLimitsBreached - When the time since the last successful request completed is greater than the max
  * timeout threshold value, while there a number of outstanding requests greater than the max outstanding requests then this parameter
  * is considered to be breached.
- *
+ * <p>
  * MemoryManager attempts to increase of decrease the shard limits in case the shard utilization goes below operating_factor.lower or
  * goes above operating_factor.upper of current shard limits. MemoryManager attempts to update the new shard limit such that the new value
  * remains withing the operating_factor.optimal range of current shard utilization.
diff --git a/server/src/main/java/org/opensearch/index/ShardIndexingPressureStore.java b/server/src/main/java/org/opensearch/index/ShardIndexingPressureStore.java
index b41dd1359394b..9b24d119f24fd 100644
--- a/server/src/main/java/org/opensearch/index/ShardIndexingPressureStore.java
+++ b/server/src/main/java/org/opensearch/index/ShardIndexingPressureStore.java
@@ -22,24 +22,24 @@
  * Shard indexing pressure store acts as a central repository for all the shard-level tracker objects currently being
  * used at the Node level, for tracking indexing pressure requests.
  * Store manages the tracker lifecycle, from creation, access, until it is evicted to be collected.
- *
+ * <p>
  * Trackers are maintained at two levels for access simplicity and better memory management:
- *
+ * <p>
  * 1. shardIndexingPressureHotStore : As the name suggests, it is hot store for tracker objects which are currently live i.e. being used
  * to track an ongoing request.
- *
+ * <p>
  * 2. shardIndexingPressureColdStore : This acts as the store for all the shard tracking objects which are currently being used
  * by the framework. In addition to hot trackers, the recently used trackers which are although not currently live, but again can be used
  * in near future, are also part of this store. To limit any memory implications, this store has an upper limit on the maximum number of
  * trackers its can hold at any given time, which is a configurable dynamic setting.
- *
+ * <p>
  * Tracking objects when created are part of both the hot store as well as cold store. However, once the object
  * is no more live it is removed from the hot store. Objects in the cold store are evicted once the cold store
  * reaches its maximum limit. Think of it like a periodic purge when upper limit is hit.
  * During get if tracking object is not present in the hot store, a lookup is made into the cache store. If found,
  * object is brought into the hot store again, until it remains active. If not present in the either store, a fresh
  * object is instantiated and registered in both the stores for concurrent accesses.
- *
+ * <p>
  * Note: The implementation of shardIndexingPressureColdStore methods is such that get,
  * update and evict operations can be abstracted out to support any other strategy such as LRU, if
  * discovered a need later.
diff --git a/server/src/main/java/org/opensearch/index/ShardIndexingPressureTracker.java b/server/src/main/java/org/opensearch/index/ShardIndexingPressureTracker.java
index 7d67b47141ef5..e0edb8260fd0f 100644
--- a/server/src/main/java/org/opensearch/index/ShardIndexingPressureTracker.java
+++ b/server/src/main/java/org/opensearch/index/ShardIndexingPressureTracker.java
@@ -14,19 +14,19 @@
  * This class is responsible for all the tracking that needs to be performed at every Shard Level for Indexing Operations on the node.
  * Info is maintained at the granularity of three kinds of write operation (tasks) on the node i.e. coordinating, primary and replica.
  * This is useful in evaluating the shard indexing back-pressure on the node, to throttle requests and also to publish runtime stats.
- *
+ * <p>
  * There can be four kinds of operation tracking on a node which needs to performed for a shard:
  * 1. Coordinating Operation : To track all the individual shard bulk request on the coordinator node.
  * 2. Primary Operation : To track all the individual shard bulk request on the primary node.
  * 3. Replica Operation : To track all the individual shard bulk request on the replica node.
  * 4. Common Operation : To track values applicable across the specific shard role.
- *
+ * <p>
  * ShardIndexingPressureTracker therefore provides the construct to track all the write requests targeted for a ShardId on the node,
  * across all possible transport-write-actions i.e. Coordinator, Primary and Replica.
  * Tracker is uniquely identified against a Shard-Id on the node. Currently the knowledge of shard roles (such as primary vs replica)
  * is not explicit to the tracker, and it is able to track different values simultaneously based on the interaction hooks of the
  * operation type i.e. write-action layers.
- *
+ * <p>
  * There is room for introducing more unique identity to the trackers based on Shard-Role or Shard-Allocation-Id, but that will also
  * increase the complexity of handling shard-lister events and handling other race scenarios such as request-draining etc.
  * To prefer simplicity we have modelled by keeping explicit fields for different operation tracking, while tracker by itself is
diff --git a/server/src/main/java/org/opensearch/index/MergePolicyConfig.java b/server/src/main/java/org/opensearch/index/TieredMergePolicyProvider.java
similarity index 82%
rename from server/src/main/java/org/opensearch/index/MergePolicyConfig.java
rename to server/src/main/java/org/opensearch/index/TieredMergePolicyProvider.java
index fe2af21dfe039..d5d354c6c960a 100644
--- a/server/src/main/java/org/opensearch/index/MergePolicyConfig.java
+++ b/server/src/main/java/org/opensearch/index/TieredMergePolicyProvider.java
@@ -33,6 +33,7 @@
 package org.opensearch.index;
 
 import org.apache.logging.log4j.Logger;
+import org.apache.lucene.index.LogByteSizeMergePolicy;
 import org.apache.lucene.index.MergePolicy;
 import org.apache.lucene.index.NoMergePolicy;
 import org.apache.lucene.index.TieredMergePolicy;
@@ -47,9 +48,12 @@
  * where the index data is stored, and are immutable up to delete markers.
  * Segments are, periodically, merged into larger segments to keep the
  * index size at bay and expunge deletes.
+ * This class customizes and exposes 2 merge policies from lucene -
+ * {@link LogByteSizeMergePolicy} and  {@link TieredMergePolicy}.
+ *
  *
  * <p>
- * Merges select segments of approximately equal size, subject to an allowed
+ * Tiered merge policy select segments of approximately equal size, subject to an allowed
  * number of segments per tier. The merge policy is able to merge
  * non-adjacent segments, and separates how many segments are merged at once from how many
  * segments are allowed per tier. It also does not over-merge (i.e., cascade merges).
@@ -125,8 +129,9 @@
  * @opensearch.internal
  */
 
-public final class MergePolicyConfig {
-    private final OpenSearchTieredMergePolicy mergePolicy = new OpenSearchTieredMergePolicy();
+public final class TieredMergePolicyProvider implements MergePolicyProvider {
+    private final OpenSearchTieredMergePolicy tieredMergePolicy = new OpenSearchTieredMergePolicy();
+
     private final Logger logger;
     private final boolean mergesEnabled;
 
@@ -137,10 +142,11 @@ public final class MergePolicyConfig {
     public static final double DEFAULT_SEGMENTS_PER_TIER = 10.0d;
     public static final double DEFAULT_RECLAIM_DELETES_WEIGHT = 2.0d;
     public static final double DEFAULT_DELETES_PCT_ALLOWED = 20.0d;
+
     public static final Setting<Double> INDEX_COMPOUND_FORMAT_SETTING = new Setting<>(
         "index.compound_format",
         Double.toString(TieredMergePolicy.DEFAULT_NO_CFS_RATIO),
-        MergePolicyConfig::parseNoCFSRatio,
+        TieredMergePolicyProvider::parseNoCFSRatio,
         Property.Dynamic,
         Property.IndexScope
     );
@@ -194,10 +200,8 @@ public final class MergePolicyConfig {
         Property.Dynamic,
         Property.IndexScope
     );
-    // don't convert to Setting<> and register... we only set this in tests and register via a plugin
-    public static final String INDEX_MERGE_ENABLED = "index.merge.enabled";
 
-    MergePolicyConfig(Logger logger, IndexSettings indexSettings) {
+    TieredMergePolicyProvider(Logger logger, IndexSettings indexSettings) {
         this.logger = logger;
         double forceMergeDeletesPctAllowed = indexSettings.getValue(INDEX_MERGE_POLICY_EXPUNGE_DELETES_ALLOWED_SETTING); // percentage
         ByteSizeValue floorSegment = indexSettings.getValue(INDEX_MERGE_POLICY_FLOOR_SEGMENT_SETTING);
@@ -216,54 +220,41 @@ public final class MergePolicyConfig {
             );
         }
         maxMergeAtOnce = adjustMaxMergeAtOnceIfNeeded(maxMergeAtOnce, segmentsPerTier);
-        mergePolicy.setNoCFSRatio(indexSettings.getValue(INDEX_COMPOUND_FORMAT_SETTING));
-        mergePolicy.setForceMergeDeletesPctAllowed(forceMergeDeletesPctAllowed);
-        mergePolicy.setFloorSegmentMB(floorSegment.getMbFrac());
-        mergePolicy.setMaxMergeAtOnce(maxMergeAtOnce);
-        mergePolicy.setMaxMergedSegmentMB(maxMergedSegment.getMbFrac());
-        mergePolicy.setSegmentsPerTier(segmentsPerTier);
-        mergePolicy.setDeletesPctAllowed(deletesPctAllowed);
-        if (logger.isTraceEnabled()) {
-            logger.trace(
-                "using [tiered] merge mergePolicy with expunge_deletes_allowed[{}], floor_segment[{}],"
-                    + " max_merge_at_once[{}], max_merged_segment[{}], segments_per_tier[{}],"
-                    + " deletes_pct_allowed[{}]",
-                forceMergeDeletesPctAllowed,
-                floorSegment,
-                maxMergeAtOnce,
-                maxMergedSegment,
-                segmentsPerTier,
-                deletesPctAllowed
-            );
-        }
+        tieredMergePolicy.setNoCFSRatio(indexSettings.getValue(INDEX_COMPOUND_FORMAT_SETTING));
+        tieredMergePolicy.setForceMergeDeletesPctAllowed(forceMergeDeletesPctAllowed);
+        tieredMergePolicy.setFloorSegmentMB(floorSegment.getMbFrac());
+        tieredMergePolicy.setMaxMergeAtOnce(maxMergeAtOnce);
+        tieredMergePolicy.setMaxMergedSegmentMB(maxMergedSegment.getMbFrac());
+        tieredMergePolicy.setSegmentsPerTier(segmentsPerTier);
+        tieredMergePolicy.setDeletesPctAllowed(deletesPctAllowed);
     }
 
     void setSegmentsPerTier(Double segmentsPerTier) {
-        mergePolicy.setSegmentsPerTier(segmentsPerTier);
+        tieredMergePolicy.setSegmentsPerTier(segmentsPerTier);
     }
 
     void setMaxMergedSegment(ByteSizeValue maxMergedSegment) {
-        mergePolicy.setMaxMergedSegmentMB(maxMergedSegment.getMbFrac());
+        tieredMergePolicy.setMaxMergedSegmentMB(maxMergedSegment.getMbFrac());
     }
 
     void setMaxMergesAtOnce(Integer maxMergeAtOnce) {
-        mergePolicy.setMaxMergeAtOnce(maxMergeAtOnce);
+        tieredMergePolicy.setMaxMergeAtOnce(maxMergeAtOnce);
     }
 
     void setFloorSegmentSetting(ByteSizeValue floorSegementSetting) {
-        mergePolicy.setFloorSegmentMB(floorSegementSetting.getMbFrac());
+        tieredMergePolicy.setFloorSegmentMB(floorSegementSetting.getMbFrac());
     }
 
     void setExpungeDeletesAllowed(Double value) {
-        mergePolicy.setForceMergeDeletesPctAllowed(value);
+        tieredMergePolicy.setForceMergeDeletesPctAllowed(value);
     }
 
     void setNoCFSRatio(Double noCFSRatio) {
-        mergePolicy.setNoCFSRatio(noCFSRatio);
+        tieredMergePolicy.setNoCFSRatio(noCFSRatio);
     }
 
     void setDeletesPctAllowed(Double deletesPctAllowed) {
-        mergePolicy.setDeletesPctAllowed(deletesPctAllowed);
+        tieredMergePolicy.setDeletesPctAllowed(deletesPctAllowed);
     }
 
     private int adjustMaxMergeAtOnceIfNeeded(int maxMergeAtOnce, double segmentsPerTier) {
@@ -285,11 +276,11 @@ private int adjustMaxMergeAtOnceIfNeeded(int maxMergeAtOnce, double segmentsPerT
         return maxMergeAtOnce;
     }
 
-    MergePolicy getMergePolicy() {
-        return mergesEnabled ? mergePolicy : NoMergePolicy.INSTANCE;
+    public MergePolicy getMergePolicy() {
+        return mergesEnabled ? tieredMergePolicy : NoMergePolicy.INSTANCE;
     }
 
-    private static double parseNoCFSRatio(String noCFSRatio) {
+    public static double parseNoCFSRatio(String noCFSRatio) {
         noCFSRatio = noCFSRatio.trim();
         if (noCFSRatio.equalsIgnoreCase("true")) {
             return 1.0d;
@@ -310,4 +301,23 @@ private static double parseNoCFSRatio(String noCFSRatio) {
             }
         }
     }
+
+    @Override
+    public String toString() {
+        return "TieredMergePolicyProvider{"
+            + "expungeDeletesAllowed="
+            + tieredMergePolicy.getForceMergeDeletesPctAllowed()
+            + ", floorSegment="
+            + tieredMergePolicy.getFloorSegmentMB()
+            + ", maxMergeAtOnce="
+            + tieredMergePolicy.getMaxMergeAtOnce()
+            + ", maxMergedSegment="
+            + tieredMergePolicy.getMaxMergedSegmentMB()
+            + ", segmentsPerTier="
+            + tieredMergePolicy.getSegmentsPerTier()
+            + ", deletesPctAllowed="
+            + tieredMergePolicy.getDeletesPctAllowed()
+            + '}';
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/index/VersionType.java b/server/src/main/java/org/opensearch/index/VersionType.java
index 3ce7f600a6a5b..01cf73ca950d0 100644
--- a/server/src/main/java/org/opensearch/index/VersionType.java
+++ b/server/src/main/java/org/opensearch/index/VersionType.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.index;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.uid.Versions;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -42,8 +43,9 @@
 /**
  * Types of index versions
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum VersionType implements Writeable {
     INTERNAL((byte) 0) {
         @Override
@@ -244,7 +246,7 @@ public byte getValue() {
 
     /**
      * Returns a human readable explanation for a version conflict on write.
-     *
+     * <p>
      * Note that this method is only called if {@link #isVersionConflictForWrites(long, long, boolean)} returns true;
      *
      * @param currentVersion  the current version for the document
@@ -265,7 +267,7 @@ public byte getValue() {
 
     /**
      * Returns a human readable explanation for a version conflict on read.
-     *
+     * <p>
      * Note that this method is only called if {@link #isVersionConflictForReads(long, long)} returns true;
      *
      * @param currentVersion  the current version for the document
diff --git a/server/src/main/java/org/opensearch/index/analysis/Analysis.java b/server/src/main/java/org/opensearch/index/analysis/Analysis.java
index f4465c9dffac6..b9a219057f326 100644
--- a/server/src/main/java/org/opensearch/index/analysis/Analysis.java
+++ b/server/src/main/java/org/opensearch/index/analysis/Analysis.java
@@ -87,6 +87,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
+import java.util.regex.Pattern;
 
 import static java.util.Collections.unmodifiableMap;
 
@@ -98,6 +99,9 @@
 public class Analysis {
     private static final Logger LOGGER = LogManager.getLogger(Analysis.class);
 
+    // Regular expression to support hashtag tokenization
+    private static final Pattern HASH_TAG_RULE_PATTERN = Pattern.compile("^\\s*#\\s*=>");
+
     public static CharArraySet parseStemExclusion(Settings settings, CharArraySet defaultStemExclusion) {
         String value = settings.get("stem_exclusion");
         if ("_none_".equals(value)) {
@@ -222,16 +226,6 @@ public static <T> List<T> parseWordList(Environment env, Settings settings, Stri
         return parseWordList(env, settings, settingPrefix + "_path", settingPrefix, parser);
     }
 
-    public static <T> List<T> parseWordList(
-        Environment env,
-        Settings settings,
-        String settingPrefix,
-        CustomMappingRuleParser<T> parser,
-        boolean removeComments
-    ) {
-        return parseWordList(env, settings, settingPrefix + "_path", settingPrefix, parser, removeComments);
-    }
-
     /**
      * Parses a list of words from the specified settings or from a file, with the given parser.
      *
@@ -246,17 +240,6 @@ public static <T> List<T> parseWordList(
         String settingPath,
         String settingList,
         CustomMappingRuleParser<T> parser
-    ) {
-        return parseWordList(env, settings, settingPath, settingList, parser, true);
-    }
-
-    public static <T> List<T> parseWordList(
-        Environment env,
-        Settings settings,
-        String settingPath,
-        String settingList,
-        CustomMappingRuleParser<T> parser,
-        boolean removeComments
     ) {
         List<String> words = getWordList(env, settings, settingPath, settingList);
         if (words == null) {
@@ -266,7 +249,7 @@ public static <T> List<T> parseWordList(
         int lineNum = 0;
         for (String word : words) {
             lineNum++;
-            if (removeComments == false || word.startsWith("#") == false) {
+            if (word.startsWith("#") == false || HASH_TAG_RULE_PATTERN.matcher(word).find() == true) {
                 try {
                     rules.add(parser.apply(word));
                 } catch (RuntimeException ex) {
diff --git a/server/src/main/java/org/opensearch/index/analysis/AnalysisMode.java b/server/src/main/java/org/opensearch/index/analysis/AnalysisMode.java
index 4385680d9eb93..af71b470711a0 100644
--- a/server/src/main/java/org/opensearch/index/analysis/AnalysisMode.java
+++ b/server/src/main/java/org/opensearch/index/analysis/AnalysisMode.java
@@ -32,13 +32,16 @@
 
 package org.opensearch.index.analysis;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Enum representing the mode in which token filters and analyzers are allowed to operate.
  * While most token filters are allowed both in index and search time analyzers, some are
  * restricted to be used only at index time, others at search time.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum AnalysisMode {
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/analysis/AnalysisRegistry.java b/server/src/main/java/org/opensearch/index/analysis/AnalysisRegistry.java
index cfdf416b2d533..793cdcd5c5c1a 100644
--- a/server/src/main/java/org/opensearch/index/analysis/AnalysisRegistry.java
+++ b/server/src/main/java/org/opensearch/index/analysis/AnalysisRegistry.java
@@ -38,6 +38,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.env.Environment;
@@ -67,8 +68,9 @@
  * An internal registry for tokenizer, token filter, char filter and analyzer.
  * This class exists per node and allows to create per-index {@link IndexAnalyzers} via {@link #build(IndexSettings)}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class AnalysisRegistry implements Closeable {
     public static final String INDEX_ANALYSIS_CHAR_FILTER = "index.analysis.char_filter";
     public static final String INDEX_ANALYSIS_FILTER = "index.analysis.filter";
@@ -244,7 +246,7 @@ public IndexAnalyzers build(IndexSettings indexSettings) throws IOException {
 
     /**
      * Creates a custom analyzer from a collection of {@link NameOrDefinition} specifications for each component
-     *
+     * <p>
      * Callers are responsible for closing the returned Analyzer
      */
     public NamedAnalyzer buildCustomAnalyzer(
diff --git a/server/src/main/java/org/opensearch/index/analysis/AnalyzerProvider.java b/server/src/main/java/org/opensearch/index/analysis/AnalyzerProvider.java
index 24ddabca16f1e..db0b3e8d288d6 100644
--- a/server/src/main/java/org/opensearch/index/analysis/AnalyzerProvider.java
+++ b/server/src/main/java/org/opensearch/index/analysis/AnalyzerProvider.java
@@ -33,13 +33,15 @@
 package org.opensearch.index.analysis;
 
 import org.apache.lucene.analysis.Analyzer;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Provider;
 
 /**
  * Base interface for all analyzer providers
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface AnalyzerProvider<T extends Analyzer> extends Provider<T> {
 
     String name();
diff --git a/server/src/main/java/org/opensearch/index/analysis/AnalyzerScope.java b/server/src/main/java/org/opensearch/index/analysis/AnalyzerScope.java
index 0ee51b32aab46..b24d932123b44 100644
--- a/server/src/main/java/org/opensearch/index/analysis/AnalyzerScope.java
+++ b/server/src/main/java/org/opensearch/index/analysis/AnalyzerScope.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.index.analysis;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Enum to identify the scope of an analyzer
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum AnalyzerScope {
     INDEX,
     INDICES,
diff --git a/server/src/main/java/org/opensearch/index/analysis/CharFilterFactory.java b/server/src/main/java/org/opensearch/index/analysis/CharFilterFactory.java
index dc9d3704b1a3c..938932280a52a 100644
--- a/server/src/main/java/org/opensearch/index/analysis/CharFilterFactory.java
+++ b/server/src/main/java/org/opensearch/index/analysis/CharFilterFactory.java
@@ -32,13 +32,16 @@
 
 package org.opensearch.index.analysis;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.Reader;
 
 /**
  * Base character filter factory behavior used in analysis chain
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface CharFilterFactory {
 
     String name();
diff --git a/server/src/main/java/org/opensearch/index/analysis/IndexAnalyzers.java b/server/src/main/java/org/opensearch/index/analysis/IndexAnalyzers.java
index 4d72ee48cf33a..fe06504c71333 100644
--- a/server/src/main/java/org/opensearch/index/analysis/IndexAnalyzers.java
+++ b/server/src/main/java/org/opensearch/index/analysis/IndexAnalyzers.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.index.analysis;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.io.IOUtils;
 
 import java.io.Closeable;
@@ -52,8 +53,9 @@
  *
  * @see AnalysisRegistry
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class IndexAnalyzers implements Closeable {
     private final Map<String, NamedAnalyzer> analyzers;
     private final Map<String, NamedAnalyzer> normalizers;
diff --git a/server/src/main/java/org/opensearch/index/analysis/NameOrDefinition.java b/server/src/main/java/org/opensearch/index/analysis/NameOrDefinition.java
index 8bc5c2ce916be..b425f17a85d6a 100644
--- a/server/src/main/java/org/opensearch/index/analysis/NameOrDefinition.java
+++ b/server/src/main/java/org/opensearch/index/analysis/NameOrDefinition.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.analysis;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -48,8 +49,9 @@
 /**
  * Provides the name and settings for an analyzer
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NameOrDefinition implements Writeable, ToXContentFragment {
     // exactly one of these two members is not null
     public final String name;
diff --git a/server/src/main/java/org/opensearch/index/analysis/NamedAnalyzer.java b/server/src/main/java/org/opensearch/index/analysis/NamedAnalyzer.java
index 2a88d375a7df8..07523f9ee6dc5 100644
--- a/server/src/main/java/org/opensearch/index/analysis/NamedAnalyzer.java
+++ b/server/src/main/java/org/opensearch/index/analysis/NamedAnalyzer.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.DelegatingAnalyzerWrapper;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.mapper.MapperException;
 
 import java.util.ArrayList;
@@ -44,8 +45,9 @@
  * Named analyzer is an analyzer wrapper around an actual analyzer ({@link #analyzer} that is associated
  * with a name ({@link #name()}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NamedAnalyzer extends DelegatingAnalyzerWrapper {
 
     private final String name;
diff --git a/server/src/main/java/org/opensearch/index/analysis/NormalizingCharFilterFactory.java b/server/src/main/java/org/opensearch/index/analysis/NormalizingCharFilterFactory.java
index ab8d23339029c..30fe31105e1d9 100644
--- a/server/src/main/java/org/opensearch/index/analysis/NormalizingCharFilterFactory.java
+++ b/server/src/main/java/org/opensearch/index/analysis/NormalizingCharFilterFactory.java
@@ -36,7 +36,7 @@
 
 /**
  * A CharFilterFactory that also supports normalization
- *
+ * <p>
  * The default implementation of {@link #normalize(Reader)} delegates to
  * {@link #create(Reader)}
  *
diff --git a/server/src/main/java/org/opensearch/index/analysis/NormalizingTokenFilterFactory.java b/server/src/main/java/org/opensearch/index/analysis/NormalizingTokenFilterFactory.java
index be761aee0d36c..2ed621cdd22b1 100644
--- a/server/src/main/java/org/opensearch/index/analysis/NormalizingTokenFilterFactory.java
+++ b/server/src/main/java/org/opensearch/index/analysis/NormalizingTokenFilterFactory.java
@@ -36,7 +36,7 @@
 
 /**
  * A TokenFilterFactory that may be used for normalization
- *
+ * <p>
  * The default implementation delegates {@link #normalize(TokenStream)} to
  * {@link #create(TokenStream)}}.
  *
diff --git a/server/src/main/java/org/opensearch/index/analysis/PreBuiltAnalyzerProviderFactory.java b/server/src/main/java/org/opensearch/index/analysis/PreBuiltAnalyzerProviderFactory.java
index a65e1898bea0d..8719d127781e0 100644
--- a/server/src/main/java/org/opensearch/index/analysis/PreBuiltAnalyzerProviderFactory.java
+++ b/server/src/main/java/org/opensearch/index/analysis/PreBuiltAnalyzerProviderFactory.java
@@ -102,7 +102,7 @@ public void close() throws IOException {
 
     /**
      *  A special cache that closes the gap between PreBuiltAnalyzers and PreBuiltAnalyzerProviderFactory.
-     *
+     * <p>
      *  This can be removed when all analyzers have been moved away from PreBuiltAnalyzers to
      *  PreBuiltAnalyzerProviderFactory either in server or analysis-common.
      *
diff --git a/server/src/main/java/org/opensearch/index/analysis/ShingleTokenFilterFactory.java b/server/src/main/java/org/opensearch/index/analysis/ShingleTokenFilterFactory.java
index e66ae20508dfe..16a1f9a067998 100644
--- a/server/src/main/java/org/opensearch/index/analysis/ShingleTokenFilterFactory.java
+++ b/server/src/main/java/org/opensearch/index/analysis/ShingleTokenFilterFactory.java
@@ -155,11 +155,11 @@ public TokenStream create(TokenStream tokenStream) {
             filter.setTokenSeparator(tokenSeparator);
             filter.setFillerToken(fillerToken);
             if (outputUnigrams || (minShingleSize != maxShingleSize)) {
-                /**
-                 * We disable the graph analysis on this token stream
-                 * because it produces shingles of different size.
-                 * Graph analysis on such token stream is useless and dangerous as it may create too many paths
-                 * since shingles of different size are not aligned in terms of positions.
+                /*
+                  We disable the graph analysis on this token stream
+                  because it produces shingles of different size.
+                  Graph analysis on such token stream is useless and dangerous as it may create too many paths
+                  since shingles of different size are not aligned in terms of positions.
                  */
                 filter.addAttribute(DisableGraphAttribute.class);
             }
diff --git a/server/src/main/java/org/opensearch/index/analysis/TokenFilterFactory.java b/server/src/main/java/org/opensearch/index/analysis/TokenFilterFactory.java
index 1b9d781b177ce..af18927de8a98 100644
--- a/server/src/main/java/org/opensearch/index/analysis/TokenFilterFactory.java
+++ b/server/src/main/java/org/opensearch/index/analysis/TokenFilterFactory.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.fetch.subphase.highlight.FastVectorHighlighter;
 
 import java.util.List;
@@ -42,8 +43,9 @@
 /**
  * Base token filter factory used in analysis chain
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface TokenFilterFactory {
     String name();
 
@@ -51,7 +53,7 @@ public interface TokenFilterFactory {
 
     /**
      * Normalize a tokenStream for use in multi-term queries
-     *
+     * <p>
      * The default implementation is a no-op
      */
     default TokenStream normalize(TokenStream tokenStream) {
@@ -86,7 +88,7 @@ default TokenFilterFactory getChainAwareTokenFilterFactory(
 
     /**
      * Return a version of this TokenFilterFactory appropriate for synonym parsing
-     *
+     * <p>
      * Filters that should not be applied to synonyms (for example, those that produce
      * multiple tokens) should throw an exception
      *
diff --git a/server/src/main/java/org/opensearch/index/analysis/TokenizerFactory.java b/server/src/main/java/org/opensearch/index/analysis/TokenizerFactory.java
index b667175e89b4a..a1a9c4966865d 100644
--- a/server/src/main/java/org/opensearch/index/analysis/TokenizerFactory.java
+++ b/server/src/main/java/org/opensearch/index/analysis/TokenizerFactory.java
@@ -33,14 +33,16 @@
 package org.opensearch.index.analysis;
 
 import org.apache.lucene.analysis.Tokenizer;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.function.Supplier;
 
 /**
  * Base tokenizer factory used in analysis chain
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface TokenizerFactory {
 
     String name();
diff --git a/server/src/main/java/org/opensearch/index/cache/IndexCache.java b/server/src/main/java/org/opensearch/index/cache/IndexCache.java
index 90462e9919970..1067863fe9675 100644
--- a/server/src/main/java/org/opensearch/index/cache/IndexCache.java
+++ b/server/src/main/java/org/opensearch/index/cache/IndexCache.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.cache;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.index.AbstractIndexComponent;
 import org.opensearch.index.IndexSettings;
@@ -44,8 +45,9 @@
 /**
  * Wrapping class for the index cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexCache extends AbstractIndexComponent implements Closeable {
 
     private final QueryCache queryCache;
diff --git a/server/src/main/java/org/opensearch/index/cache/bitset/BitsetFilterCache.java b/server/src/main/java/org/opensearch/index/cache/bitset/BitsetFilterCache.java
index bd9074f77c196..88d20bca7b6d4 100644
--- a/server/src/main/java/org/opensearch/index/cache/bitset/BitsetFilterCache.java
+++ b/server/src/main/java/org/opensearch/index/cache/bitset/BitsetFilterCache.java
@@ -48,6 +48,7 @@
 import org.apache.lucene.util.BitDocIdSet;
 import org.apache.lucene.util.BitSet;
 import org.opensearch.ExceptionsHelper;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.cache.Cache;
 import org.opensearch.common.cache.CacheBuilder;
 import org.opensearch.common.cache.RemovalListener;
@@ -85,8 +86,9 @@
  * and require that it should always be around should use this cache, otherwise the
  * {@link org.opensearch.index.cache.query.QueryCache} should be used instead.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class BitsetFilterCache extends AbstractIndexComponent
     implements
         IndexReader.ClosedListener,
@@ -195,8 +197,9 @@ public void onRemoval(RemovalNotification<IndexReader.CacheKey, Cache<Query, Val
     /**
      * Value for bitset filter cache
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class Value {
 
         final BitSet bitset;
diff --git a/server/src/main/java/org/opensearch/index/cache/bitset/ShardBitsetFilterCache.java b/server/src/main/java/org/opensearch/index/cache/bitset/ShardBitsetFilterCache.java
index 5bd3ea2c13e18..2f770e4307eb8 100644
--- a/server/src/main/java/org/opensearch/index/cache/bitset/ShardBitsetFilterCache.java
+++ b/server/src/main/java/org/opensearch/index/cache/bitset/ShardBitsetFilterCache.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.cache.bitset;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.IndexSettings;
@@ -40,8 +41,9 @@
 /**
  * Bitset Filter Cache for shards
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardBitsetFilterCache extends AbstractIndexShardComponent {
 
     private final CounterMetric totalMetric = new CounterMetric();
diff --git a/server/src/main/java/org/opensearch/index/cache/query/QueryCache.java b/server/src/main/java/org/opensearch/index/cache/query/QueryCache.java
index 384f66fcfc132..2c8188a523ade 100644
--- a/server/src/main/java/org/opensearch/index/cache/query/QueryCache.java
+++ b/server/src/main/java/org/opensearch/index/cache/query/QueryCache.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.cache.query;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.IndexComponent;
 
 import java.io.Closeable;
@@ -39,8 +40,9 @@
 /**
  * Base interface for a query cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface QueryCache extends IndexComponent, Closeable, org.apache.lucene.search.QueryCache {
 
     void clear(String reason);
diff --git a/server/src/main/java/org/opensearch/index/cache/query/QueryCacheStats.java b/server/src/main/java/org/opensearch/index/cache/query/QueryCacheStats.java
index 88077aafb1495..d844e5cbb8897 100644
--- a/server/src/main/java/org/opensearch/index/cache/query/QueryCacheStats.java
+++ b/server/src/main/java/org/opensearch/index/cache/query/QueryCacheStats.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.cache.query;
 
 import org.apache.lucene.search.DocIdSet;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -46,8 +47,9 @@
 /**
  * Stats for the query cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class QueryCacheStats implements Writeable, ToXContentFragment {
 
     private long ramBytesUsed;
diff --git a/server/src/main/java/org/opensearch/index/cache/request/RequestCacheStats.java b/server/src/main/java/org/opensearch/index/cache/request/RequestCacheStats.java
index 24f68899c2ac7..6def55fcb985b 100644
--- a/server/src/main/java/org/opensearch/index/cache/request/RequestCacheStats.java
+++ b/server/src/main/java/org/opensearch/index/cache/request/RequestCacheStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.cache.request;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * Request for the query cache statistics
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RequestCacheStats implements Writeable, ToXContentFragment {
 
     private long memorySize;
diff --git a/server/src/main/java/org/opensearch/index/cache/request/ShardRequestCache.java b/server/src/main/java/org/opensearch/index/cache/request/ShardRequestCache.java
index b13eec79c2be8..bb35a09ccab46 100644
--- a/server/src/main/java/org/opensearch/index/cache/request/ShardRequestCache.java
+++ b/server/src/main/java/org/opensearch/index/cache/request/ShardRequestCache.java
@@ -33,14 +33,16 @@
 package org.opensearch.index.cache.request;
 
 import org.apache.lucene.util.Accountable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.core.common.bytes.BytesReference;
 
 /**
  * Tracks the portion of the request cache in use for a particular shard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ShardRequestCache {
 
     final CounterMetric evictionsMetric = new CounterMetric();
diff --git a/server/src/main/java/org/opensearch/index/engine/CommitStats.java b/server/src/main/java/org/opensearch/index/engine/CommitStats.java
index 4328ebed85aa1..b30ce720b2649 100644
--- a/server/src/main/java/org/opensearch/index/engine/CommitStats.java
+++ b/server/src/main/java/org/opensearch/index/engine/CommitStats.java
@@ -32,6 +32,7 @@
 package org.opensearch.index.engine;
 
 import org.apache.lucene.index.SegmentInfos;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.MapBuilder;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -47,8 +48,9 @@
 /**
  * a class the returns dynamic information with respect to the last commit point of this shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class CommitStats implements Writeable, ToXContentFragment {
 
     private final Map<String, String> userData;
diff --git a/server/src/main/java/org/opensearch/index/engine/Engine.java b/server/src/main/java/org/opensearch/index/engine/Engine.java
index a8f2f60f8cf12..c945d082c9a35 100644
--- a/server/src/main/java/org/opensearch/index/engine/Engine.java
+++ b/server/src/main/java/org/opensearch/index/engine/Engine.java
@@ -62,6 +62,7 @@
 import org.opensearch.action.index.IndexRequest;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.concurrent.GatedCloseable;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lease.Releasables;
@@ -126,8 +127,9 @@
 /**
  * Base OpenSearch Engine class
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class Engine implements LifecycleAware, Closeable {
 
     public static final String SYNC_COMMIT_ID = "sync_id";  // TODO: remove sync_id in 3.0
@@ -145,6 +147,7 @@ public abstract class Engine implements LifecycleAware, Closeable {
     protected final EngineConfig engineConfig;
     protected final Store store;
     protected final AtomicBoolean isClosed = new AtomicBoolean(false);
+    private final CounterMetric totalUnreferencedFileCleanUpsPerformed = new CounterMetric();
     private final CountDownLatch closedLatch = new CountDownLatch(1);
     protected final EventListener eventListener;
     protected final ReentrantLock failEngineLock = new ReentrantLock();
@@ -267,6 +270,13 @@ protected final DocsStats docsStats(IndexReader indexReader) {
         return new DocsStats(numDocs, numDeletedDocs, sizeInBytes);
     }
 
+    /**
+     * Returns the unreferenced file cleanup count for this engine.
+     */
+    public long unreferencedFileCleanUpsPerformed() {
+        return totalUnreferencedFileCleanUpsPerformed.count();
+    }
+
     /**
      * Performs the pre-closing checks on the {@link Engine}.
      *
@@ -456,8 +466,9 @@ public Condition newCondition() {
      * Holds result meta data (e.g. translog location, updated version)
      * for an executed write {@link Operation}
      *
-     * @opensearch.internal
+     * @opensearch.api
      **/
+    @PublicApi(since = "1.0.0")
     public abstract static class Result {
         private final Operation.TYPE operationType;
         private final Result.Type resultType;
@@ -573,8 +584,9 @@ void freeze() {
         /**
          * Type of the result
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public enum Type {
             SUCCESS,
             FAILURE,
@@ -585,8 +597,9 @@ public enum Type {
     /**
      * Index result
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class IndexResult extends Result {
 
         private final boolean created;
@@ -622,8 +635,9 @@ public boolean isCreated() {
     /**
      * The delete result
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class DeleteResult extends Result {
 
         private final boolean found;
@@ -659,8 +673,9 @@ public boolean isFound() {
     /**
      * A noop result
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class NoOpResult extends Result {
 
         NoOpResult(long term, long seqNo) {
@@ -822,8 +837,9 @@ boolean assertSearcherIsWarmedUp(String source, SearcherScope scope) {
     /**
      * Scope of the searcher
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum SearcherScope {
         EXTERNAL,
         INTERNAL
@@ -1305,6 +1321,7 @@ public void failEngine(String reason, @Nullable Exception failure) {
                     // clean all unreferenced files on best effort basis created during failed merge and reset the
                     // shard state back to last Lucene Commit.
                     if (shouldCleanupUnreferencedFiles() && isMergeFailureDueToIOException(failure, reason)) {
+                        logger.info("Cleaning up unreferenced files as merge failed due to: {}", reason);
                         cleanUpUnreferencedFiles();
                     }
 
@@ -1340,7 +1357,9 @@ private void cleanUpUnreferencedFiles() {
                     .setOpenMode(IndexWriterConfig.OpenMode.APPEND)
             )
         ) {
-            // do nothing and close this will kick off IndexFileDeleter which will remove all unreferenced files.
+            // do nothing except increasing metric count and close this will kick off IndexFileDeleter which will
+            // remove all unreferenced files
+            totalUnreferencedFileCleanUpsPerformed.inc();
         } catch (Exception ex) {
             logger.error("Error while deleting unreferenced file ", ex);
         }
@@ -1364,8 +1383,9 @@ protected boolean maybeFailEngine(String source, Exception e) {
     /**
      * Event listener for the engine
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface EventListener {
         /**
          * Called when a fatal exception occurred
@@ -1376,8 +1396,9 @@ default void onFailedEngine(String reason, @Nullable Exception e) {}
     /**
      * Supplier for the searcher
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract static class SearcherSupplier implements Releasable {
         private final Function<Searcher, Searcher> wrapper;
         private final AtomicBoolean released = new AtomicBoolean(false);
@@ -1411,8 +1432,9 @@ public final void close() {
     /**
      * The engine searcher
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class Searcher extends IndexSearcher implements Releasable {
         private final String source;
         private final Closeable onClose;
@@ -1470,8 +1492,9 @@ public abstract static class Operation {
         /**
          * type of operation (index, delete), subclasses use static types
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public enum TYPE {
             INDEX,
             DELETE,
@@ -1509,8 +1532,9 @@ public Operation(Term uid, long seqNo, long primaryTerm, long version, VersionTy
         /**
          * Origin of the operation
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public enum Origin {
             PRIMARY,
             REPLICA,
@@ -1568,8 +1592,9 @@ public long startTime() {
     /**
      * Index operation
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Index extends Operation {
 
         private final ParsedDocument doc;
@@ -1686,8 +1711,9 @@ public long getIfPrimaryTerm() {
     /**
      * Delete operation
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Delete extends Operation {
 
         private final String id;
@@ -1774,8 +1800,9 @@ public long getIfPrimaryTerm() {
     /**
      * noop operation
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class NoOp extends Operation {
 
         private final String reason;
@@ -1824,8 +1851,9 @@ public int estimatedSizeInBytes() {
     /**
      * Get operation
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Get {
         private final boolean realtime;
         private final Term uid;
@@ -1900,8 +1928,9 @@ public long getIfPrimaryTerm() {
     /**
      * The Get result
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class GetResult implements Releasable {
         private final boolean exists;
         private final long version;
@@ -2023,8 +2052,9 @@ public long getLastWriteNanos() {
      *
      * @see EngineConfig#getWarmer()
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Warmer {
         /**
          * Called once a new top-level reader is opened.
diff --git a/server/src/main/java/org/opensearch/index/engine/EngineConfig.java b/server/src/main/java/org/opensearch/index/engine/EngineConfig.java
index 00f8ff6d3cd40..bf3e10d684c94 100644
--- a/server/src/main/java/org/opensearch/index/engine/EngineConfig.java
+++ b/server/src/main/java/org/opensearch/index/engine/EngineConfig.java
@@ -41,6 +41,7 @@
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.similarities.Similarity;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.unit.MemorySizeValue;
@@ -75,8 +76,9 @@
  * Once {@link Engine} has been created with this object, changes to this
  * object will affect the {@link Engine} instance.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class EngineConfig {
     private final ShardId shardId;
     private final IndexSettings indexSettings;
@@ -106,7 +108,7 @@ public final class EngineConfig {
     private final LongSupplier globalCheckpointSupplier;
     private final Supplier<RetentionLeases> retentionLeasesSupplier;
     private final boolean isReadOnlyReplica;
-    private final BooleanSupplier primaryModeSupplier;
+    private final BooleanSupplier startedPrimarySupplier;
     private final Comparator<LeafReader> leafSorter;
 
     /**
@@ -285,7 +287,7 @@ private EngineConfig(Builder builder) {
         this.primaryTermSupplier = builder.primaryTermSupplier;
         this.tombstoneDocSupplier = builder.tombstoneDocSupplier;
         this.isReadOnlyReplica = builder.isReadOnlyReplica;
-        this.primaryModeSupplier = builder.primaryModeSupplier;
+        this.startedPrimarySupplier = builder.startedPrimarySupplier;
         this.translogFactory = builder.translogFactory;
         this.leafSorter = builder.leafSorter;
     }
@@ -493,11 +495,11 @@ public boolean isReadOnlyReplica() {
     }
 
     /**
-     * Returns the underlying primaryModeSupplier.
+     * Returns the underlying startedPrimarySupplier.
      * @return the primary mode supplier.
      */
-    public BooleanSupplier getPrimaryModeSupplier() {
-        return primaryModeSupplier;
+    public BooleanSupplier getStartedPrimarySupplier() {
+        return startedPrimarySupplier;
     }
 
     /**
@@ -512,8 +514,9 @@ public TranslogFactory getTranslogFactory() {
      * A supplier supplies tombstone documents which will be used in soft-update methods.
      * The returned document consists only _uid, _seqno, _term and _version fields; other metadata fields are excluded.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface TombstoneDocSupplier {
         /**
          * Creates a tombstone document for a delete operation.
@@ -574,7 +577,7 @@ public static class Builder {
         private TombstoneDocSupplier tombstoneDocSupplier;
         private TranslogDeletionPolicyFactory translogDeletionPolicyFactory;
         private boolean isReadOnlyReplica;
-        private BooleanSupplier primaryModeSupplier;
+        private BooleanSupplier startedPrimarySupplier;
         private TranslogFactory translogFactory = new InternalTranslogFactory();
         Comparator<LeafReader> leafSorter;
 
@@ -698,8 +701,8 @@ public Builder readOnlyReplica(boolean isReadOnlyReplica) {
             return this;
         }
 
-        public Builder primaryModeSupplier(BooleanSupplier primaryModeSupplier) {
-            this.primaryModeSupplier = primaryModeSupplier;
+        public Builder startedPrimarySupplier(BooleanSupplier startedPrimarySupplier) {
+            this.startedPrimarySupplier = startedPrimarySupplier;
             return this;
         }
 
diff --git a/server/src/main/java/org/opensearch/index/engine/EngineConfigFactory.java b/server/src/main/java/org/opensearch/index/engine/EngineConfigFactory.java
index 38eea92b6c757..77e2f1c55201d 100644
--- a/server/src/main/java/org/opensearch/index/engine/EngineConfigFactory.java
+++ b/server/src/main/java/org/opensearch/index/engine/EngineConfigFactory.java
@@ -152,7 +152,7 @@ public EngineConfig newEngineConfig(
         LongSupplier primaryTermSupplier,
         EngineConfig.TombstoneDocSupplier tombstoneDocSupplier,
         boolean isReadOnlyReplica,
-        BooleanSupplier primaryModeSupplier,
+        BooleanSupplier startedPrimarySupplier,
         TranslogFactory translogFactory,
         Comparator<LeafReader> leafSorter
     ) {
@@ -185,7 +185,7 @@ public EngineConfig newEngineConfig(
             .primaryTermSupplier(primaryTermSupplier)
             .tombstoneDocSupplier(tombstoneDocSupplier)
             .readOnlyReplica(isReadOnlyReplica)
-            .primaryModeSupplier(primaryModeSupplier)
+            .startedPrimarySupplier(startedPrimarySupplier)
             .translogFactory(translogFactory)
             .leafSorter(leafSorter)
             .build();
diff --git a/server/src/main/java/org/opensearch/index/engine/EngineException.java b/server/src/main/java/org/opensearch/index/engine/EngineException.java
index 484bc6c7eea6a..7d039d8922a19 100644
--- a/server/src/main/java/org/opensearch/index/engine/EngineException.java
+++ b/server/src/main/java/org/opensearch/index/engine/EngineException.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.engine;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -41,8 +42,9 @@
 /**
  * Exception if there are any errors in the engine
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class EngineException extends OpenSearchException {
 
     public EngineException(ShardId shardId, String msg, Object... params) {
diff --git a/server/src/main/java/org/opensearch/index/engine/EngineFactory.java b/server/src/main/java/org/opensearch/index/engine/EngineFactory.java
index ced02ab3041c9..4e7e69bd3dd53 100644
--- a/server/src/main/java/org/opensearch/index/engine/EngineFactory.java
+++ b/server/src/main/java/org/opensearch/index/engine/EngineFactory.java
@@ -31,12 +31,15 @@
 
 package org.opensearch.index.engine;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Simple Engine Factory
  *
- * @opensearch.internal
+ * @opensearch.api
  */
 @FunctionalInterface
+@PublicApi(since = "1.0.0")
 public interface EngineFactory {
 
     Engine newReadWriteEngine(EngineConfig config);
diff --git a/server/src/main/java/org/opensearch/index/engine/IndexVersionValue.java b/server/src/main/java/org/opensearch/index/engine/IndexVersionValue.java
index 803d106a2f25e..c297022f5766d 100644
--- a/server/src/main/java/org/opensearch/index/engine/IndexVersionValue.java
+++ b/server/src/main/java/org/opensearch/index/engine/IndexVersionValue.java
@@ -45,6 +45,7 @@
 final class IndexVersionValue extends VersionValue {
 
     private static final long RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(IndexVersionValue.class);
+    private static final long TRANSLOG_LOC_RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(Translog.Location.class);
 
     private final Translog.Location translogLocation;
 
@@ -55,7 +56,7 @@ final class IndexVersionValue extends VersionValue {
 
     @Override
     public long ramBytesUsed() {
-        return RAM_BYTES_USED + RamUsageEstimator.shallowSizeOf(translogLocation);
+        return RAM_BYTES_USED + (translogLocation == null ? 0L : TRANSLOG_LOC_RAM_BYTES_USED);
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/index/engine/InternalEngine.java b/server/src/main/java/org/opensearch/index/engine/InternalEngine.java
index 3eeceff2253c1..e204656d3f106 100644
--- a/server/src/main/java/org/opensearch/index/engine/InternalEngine.java
+++ b/server/src/main/java/org/opensearch/index/engine/InternalEngine.java
@@ -292,7 +292,7 @@ public void onFailure(String reason, Exception ex) {
                     new CompositeTranslogEventListener(Arrays.asList(internalTranslogEventListener, translogEventListener), shardId),
                     this::ensureOpen,
                     engineConfig.getTranslogFactory(),
-                    engineConfig.getPrimaryModeSupplier()
+                    engineConfig.getStartedPrimarySupplier()
                 );
                 this.translogManager = translogManagerRef;
                 this.softDeletesPolicy = newSoftDeletesPolicy();
@@ -402,7 +402,7 @@ public CompletionStats completionStats(String... fieldNamePatterns) {
      * The main purpose for this is that if we have external refreshes happening we don't issue extra
      * refreshes to clear version map memory etc. this can cause excessive segment creation if heavy indexing
      * is happening and the refresh interval is low (ie. 1 sec)
-     *
+     * <p>
      * This also prevents segment starvation where an internal reader holds on to old segments literally forever
      * since no indexing is happening and refreshes are only happening to the external reader manager, while with
      * this specialized implementation an external refresh will immediately be reflected on the internal reader
@@ -1412,7 +1412,9 @@ private Exception tryAcquireInFlightDocs(Operation operation, int addingDocs) {
         final long totalDocs = indexWriter.getPendingNumDocs() + inFlightDocCount.addAndGet(addingDocs);
         if (totalDocs > maxDocs) {
             releaseInFlightDocs(addingDocs);
-            return new IllegalArgumentException("Number of documents in the index can't exceed [" + maxDocs + "]");
+            return new IllegalArgumentException(
+                "Number of documents in shard " + shardId + " exceeds the limit of [" + maxDocs + "] documents per shard"
+            );
         } else {
             return null;
         }
diff --git a/server/src/main/java/org/opensearch/index/engine/NRTReplicationEngine.java b/server/src/main/java/org/opensearch/index/engine/NRTReplicationEngine.java
index 570a2b186841a..ed8dba2f8902d 100644
--- a/server/src/main/java/org/opensearch/index/engine/NRTReplicationEngine.java
+++ b/server/src/main/java/org/opensearch/index/engine/NRTReplicationEngine.java
@@ -13,6 +13,7 @@
 import org.apache.lucene.index.SegmentInfos;
 import org.apache.lucene.index.SoftDeletesDirectoryReaderWrapper;
 import org.apache.lucene.search.ReferenceManager;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.concurrent.GatedCloseable;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.common.lucene.index.OpenSearchDirectoryReader;
@@ -51,8 +52,9 @@
  * is enabled.  This Engine does not create an IndexWriter, rather it refreshes a {@link NRTReplicationReaderManager}
  * with new Segments when received from an external source.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NRTReplicationEngine extends Engine {
 
     private volatile SegmentInfos lastCommittedSegmentInfos;
@@ -123,7 +125,7 @@ public void onAfterTranslogSync() {
                 },
                 this,
                 engineConfig.getTranslogFactory(),
-                engineConfig.getPrimaryModeSupplier()
+                engineConfig.getStartedPrimarySupplier()
             );
             this.translogManager = translogManagerRef;
             success = true;
@@ -180,7 +182,7 @@ public synchronized void updateSegments(final SegmentInfos infos) throws IOExcep
 
     /**
      * Persist the latest live SegmentInfos.
-     *
+     * <p>
      * This method creates a commit point from the latest SegmentInfos.
      *
      * @throws IOException - When there is an IO error committing the SegmentInfos.
@@ -379,6 +381,7 @@ public void flush(boolean force, boolean waitIfOngoing) throws EngineException {
             try {
                 commitSegmentInfos();
             } catch (IOException e) {
+                maybeFailEngine("flush", e);
                 throw new FlushFailedEngineException(shardId, e);
             } finally {
                 flushLock.unlock();
@@ -437,13 +440,29 @@ protected final void closeNoLock(String reason, CountDownLatch closedLatch) {
                     latestSegmentInfos.counter = latestSegmentInfos.counter + SI_COUNTER_INCREMENT;
                     latestSegmentInfos.changed();
                 }
-                commitSegmentInfos(latestSegmentInfos);
-                IOUtils.close(readerManager, translogManager, store::decRef);
+                try {
+                    commitSegmentInfos(latestSegmentInfos);
+                } catch (IOException e) {
+                    // mark the store corrupted unless we are closing as result of engine failure.
+                    // in this case Engine#failShard will handle store corruption.
+                    if (failEngineLock.isHeldByCurrentThread() == false && store.isMarkedCorrupted() == false) {
+                        try {
+                            store.markStoreCorrupted(e);
+                        } catch (IOException ex) {
+                            logger.warn("Unable to mark store corrupted", ex);
+                        }
+                    }
+                }
+                IOUtils.close(readerManager, translogManager);
             } catch (Exception e) {
-                logger.warn("failed to close engine", e);
+                logger.error("failed to close engine", e);
             } finally {
-                logger.debug("engine closed [{}]", reason);
-                closedLatch.countDown();
+                try {
+                    store.decRef();
+                    logger.debug("engine closed [{}]", reason);
+                } finally {
+                    closedLatch.countDown();
+                }
             }
         }
     }
diff --git a/server/src/main/java/org/opensearch/index/engine/NoOpEngine.java b/server/src/main/java/org/opensearch/index/engine/NoOpEngine.java
index ca31d5518df47..9071b0e7a1eb3 100644
--- a/server/src/main/java/org/opensearch/index/engine/NoOpEngine.java
+++ b/server/src/main/java/org/opensearch/index/engine/NoOpEngine.java
@@ -203,7 +203,7 @@ public void trimUnreferencedTranslogFiles() throws TranslogException {
                                         engineConfig.getGlobalCheckpointSupplier(),
                                         engineConfig.getPrimaryTermSupplier(),
                                         seqNo -> {},
-                                        engineConfig.getPrimaryModeSupplier()
+                                        engineConfig.getStartedPrimarySupplier()
                                     )
                             ) {
                                 translog.trimUnreferencedReaders();
diff --git a/server/src/main/java/org/opensearch/index/engine/ReadOnlyEngine.java b/server/src/main/java/org/opensearch/index/engine/ReadOnlyEngine.java
index 80cef214a08cd..7ff3145055df8 100644
--- a/server/src/main/java/org/opensearch/index/engine/ReadOnlyEngine.java
+++ b/server/src/main/java/org/opensearch/index/engine/ReadOnlyEngine.java
@@ -278,7 +278,7 @@ private static TranslogStats translogStats(final EngineConfig config, final Segm
                     config.getGlobalCheckpointSupplier(),
                     config.getPrimaryTermSupplier(),
                     seqNo -> {},
-                    config.getPrimaryModeSupplier()
+                    config.getStartedPrimarySupplier()
                 )
         ) {
             return translog.stats();
diff --git a/server/src/main/java/org/opensearch/index/engine/ReplicaFileTracker.java b/server/src/main/java/org/opensearch/index/engine/ReplicaFileTracker.java
index 2e8bd6409c2f6..19454967f9ee3 100644
--- a/server/src/main/java/org/opensearch/index/engine/ReplicaFileTracker.java
+++ b/server/src/main/java/org/opensearch/index/engine/ReplicaFileTracker.java
@@ -22,7 +22,7 @@
 /**
  * This class is heavily influenced by Lucene's ReplicaFileDeleter class used to keep track of
  * segment files that should be preserved on replicas between replication events.
- *
+ * <p>
  * https://github.com/apache/lucene/blob/main/lucene/replicator/src/java/org/apache/lucene/replicator/nrt/ReplicaFileDeleter.java
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/index/engine/SafeCommitInfo.java b/server/src/main/java/org/opensearch/index/engine/SafeCommitInfo.java
index fcf1cb186269c..4b54033dc6728 100644
--- a/server/src/main/java/org/opensearch/index/engine/SafeCommitInfo.java
+++ b/server/src/main/java/org/opensearch/index/engine/SafeCommitInfo.java
@@ -31,13 +31,15 @@
 
 package org.opensearch.index.engine;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.seqno.SequenceNumbers;
 
 /**
  * Information about the safe commit, for making decisions about recoveries.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SafeCommitInfo {
 
     public final long localCheckpoint;
diff --git a/server/src/main/java/org/opensearch/index/engine/Segment.java b/server/src/main/java/org/opensearch/index/engine/Segment.java
index 41e6d79e8a4be..7881abcf58e0c 100644
--- a/server/src/main/java/org/opensearch/index/engine/Segment.java
+++ b/server/src/main/java/org/opensearch/index/engine/Segment.java
@@ -40,6 +40,7 @@
 import org.apache.lucene.search.SortedSetSortField;
 import org.opensearch.Version;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -53,8 +54,9 @@
 /**
  * A segment in the engine
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Segment implements Writeable {
 
     private String name;
diff --git a/server/src/main/java/org/opensearch/index/engine/SegmentsStats.java b/server/src/main/java/org/opensearch/index/engine/SegmentsStats.java
index f4fd2490c7abe..d4a97f0267222 100644
--- a/server/src/main/java/org/opensearch/index/engine/SegmentsStats.java
+++ b/server/src/main/java/org/opensearch/index/engine/SegmentsStats.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.engine;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -50,8 +51,9 @@
 /**
  * Tracker for segment stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SegmentsStats implements Writeable, ToXContentFragment {
 
     private long count;
diff --git a/server/src/main/java/org/opensearch/index/engine/TranslogLeafReader.java b/server/src/main/java/org/opensearch/index/engine/TranslogLeafReader.java
index 417cdd5a8f030..c1f69d1ef3638 100644
--- a/server/src/main/java/org/opensearch/index/engine/TranslogLeafReader.java
+++ b/server/src/main/java/org/opensearch/index/engine/TranslogLeafReader.java
@@ -52,7 +52,7 @@
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.VectorEncoding;
 import org.apache.lucene.index.VectorSimilarityFunction;
-import org.apache.lucene.search.TopDocs;
+import org.apache.lucene.search.KnnCollector;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.common.util.set.Sets;
@@ -271,12 +271,12 @@ public ByteVectorValues getByteVectorValues(String field) throws IOException {
     }
 
     @Override
-    public TopDocs searchNearestVectors(String field, float[] target, int k, Bits acceptDocs, int visitedLimit) throws IOException {
+    public void searchNearestVectors(String field, byte[] target, KnnCollector k, Bits acceptDocs) throws IOException {
         throw new UnsupportedOperationException();
     }
 
     @Override
-    public TopDocs searchNearestVectors(String field, byte[] target, int k, Bits acceptDocs, int visitedLimit) throws IOException {
+    public void searchNearestVectors(String field, float[] target, KnnCollector k, Bits acceptDocs) throws IOException {
         throw new UnsupportedOperationException();
     }
 }
diff --git a/server/src/main/java/org/opensearch/index/fielddata/DocValueBits.java b/server/src/main/java/org/opensearch/index/fielddata/DocValueBits.java
index 18fa26bd10623..cf62688b88b65 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/DocValueBits.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/DocValueBits.java
@@ -32,13 +32,16 @@
 
 package org.opensearch.index.fielddata;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 
 /**
  * Base class for doc value bit sets
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class DocValueBits {
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/fielddata/FieldDataStats.java b/server/src/main/java/org/opensearch/index/fielddata/FieldDataStats.java
index fc7db7d316214..85b435e969bfa 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/FieldDataStats.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/FieldDataStats.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.common.FieldMemoryStats;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -47,8 +48,9 @@
 /**
  * Encapsulates heap usage for field data
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FieldDataStats implements Writeable, ToXContentFragment {
 
     private static final String FIELDDATA = "fielddata";
diff --git a/server/src/main/java/org/opensearch/index/fielddata/IndexFieldData.java b/server/src/main/java/org/opensearch/index/fielddata/IndexFieldData.java
index f9db28a2c56fe..6a79679cc2f09 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/IndexFieldData.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/IndexFieldData.java
@@ -48,6 +48,7 @@
 import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.BigArrays;
 import org.opensearch.core.indices.breaker.CircuitBreakerService;
 import org.opensearch.index.fielddata.IndexFieldData.XFieldComparatorSource.Nested;
@@ -64,8 +65,9 @@
  * Thread-safe utility class that allows to get per-segment values via the
  * {@link #load(LeafReaderContext)} method.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IndexFieldData<FD extends LeafFieldData> {
 
     /**
@@ -94,6 +96,13 @@ public interface IndexFieldData<FD extends LeafFieldData> {
      */
     SortField sortField(@Nullable Object missingValue, MultiValueMode sortMode, Nested nested, boolean reverse);
 
+    /**
+     * Returns the {@link SortField} to use for index sorting where we widen the sort field type to higher or equal bytes.
+     */
+    default SortField wideSortField(@Nullable Object missingValue, MultiValueMode sortMode, Nested nested, boolean reverse) {
+        return sortField(missingValue, sortMode, nested, reverse);
+    }
+
     /**
      * Build a sort implementation specialized for aggregations.
      */
@@ -147,7 +156,10 @@ public void disableSkipping() {
          * R will be in the parent filter and its children documents will be the
          * documents that are contained in the inner set between the previous
          * parent + 1, or 0 if there is no previous parent, and R (excluded).
+         *
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class Nested {
 
             private final BitSetProducer rootFilter;
@@ -286,8 +298,9 @@ public abstract BucketedSort newBucketedSort(
     /**
      * Base builder interface
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface Builder {
 
         IndexFieldData<?> build(IndexFieldDataCache cache, CircuitBreakerService breakerService);
@@ -296,8 +309,9 @@ interface Builder {
     /**
      * Base Global field data class
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface Global<FD extends LeafFieldData> extends IndexFieldData<FD> {
 
         IndexFieldData<FD> loadGlobal(DirectoryReader indexReader);
diff --git a/server/src/main/java/org/opensearch/index/fielddata/IndexFieldDataCache.java b/server/src/main/java/org/opensearch/index/fielddata/IndexFieldDataCache.java
index 72df2453fc7fd..5cdcc3f82879f 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/IndexFieldDataCache.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/IndexFieldDataCache.java
@@ -35,13 +35,15 @@
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.util.Accountable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.shard.ShardId;
 
 /**
  * A simple field data cache abstraction on the *index* level.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IndexFieldDataCache {
 
     <FD extends LeafFieldData, IFD extends IndexFieldData<FD>> FD load(LeafReaderContext context, IFD indexFieldData) throws Exception;
@@ -62,8 +64,9 @@ <FD extends LeafFieldData, IFD extends IndexFieldData.Global<FD>> IFD load(Direc
     /**
      * The listener interface
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface Listener {
 
         /**
diff --git a/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java b/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java
index ae8ffd8fe6b97..b0ff944d014de 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java
@@ -42,6 +42,7 @@
 import org.opensearch.index.fielddata.IndexFieldData.XFieldComparatorSource.Nested;
 import org.opensearch.index.fielddata.fieldcomparator.DoubleValuesComparatorSource;
 import org.opensearch.index.fielddata.fieldcomparator.FloatValuesComparatorSource;
+import org.opensearch.index.fielddata.fieldcomparator.HalfFloatValuesComparatorSource;
 import org.opensearch.index.fielddata.fieldcomparator.IntValuesComparatorSource;
 import org.opensearch.index.fielddata.fieldcomparator.LongValuesComparatorSource;
 import org.opensearch.index.fielddata.fieldcomparator.UnsignedLongValuesComparatorSource;
@@ -151,6 +152,25 @@ public final SortField sortField(Object missingValue, MultiValueMode sortMode, N
         return sortField(getNumericType(), missingValue, sortMode, nested, reverse);
     }
 
+    @Override
+    public final SortField wideSortField(Object missingValue, MultiValueMode sortMode, Nested nested, boolean reverse) {
+        // This is to support backward compatibility, the minimum number of bytes prior to OpenSearch 2.7 were 16 bytes,
+        // i.e all sort fields were upcasted to Long/Double with 16 bytes.
+        // Now from OpenSearch 2.7, the minimum number of bytes for sort field is 8 bytes, so if it comes as SortField INT,
+        // we need to up cast it to LONG to support backward compatibility info stored in segment info
+        if (getNumericType().sortFieldType == SortField.Type.INT) {
+            XFieldComparatorSource source = comparatorSource(NumericType.LONG, missingValue, sortMode, nested);
+            SortedNumericSelector.Type selectorType = sortMode == MultiValueMode.MAX
+                ? SortedNumericSelector.Type.MAX
+                : SortedNumericSelector.Type.MIN;
+            SortField sortField = new SortedNumericSortField(getFieldName(), SortField.Type.LONG, reverse, selectorType);
+            sortField.setMissingValue(source.missingObject(missingValue, reverse));
+            return sortField;
+        }
+        // If already more than INT, up cast not needed.
+        return sortField(getNumericType(), missingValue, sortMode, nested, reverse);
+    }
+
     /**
      * Builds a {@linkplain BucketedSort} for the {@code targetNumericType},
      * casting the values if their native type doesn't match.
@@ -201,6 +221,8 @@ private XFieldComparatorSource comparatorSource(
         final XFieldComparatorSource source;
         switch (targetNumericType) {
             case HALF_FLOAT:
+                source = new HalfFloatValuesComparatorSource(this, missingValue, sortMode, nested);
+                break;
             case FLOAT:
                 source = new FloatValuesComparatorSource(this, missingValue, sortMode, nested);
                 break;
@@ -224,7 +246,7 @@ private XFieldComparatorSource comparatorSource(
                 source = new IntValuesComparatorSource(this, missingValue, sortMode, nested);
         }
         if (targetNumericType != getNumericType()) {
-            source.disableSkipping(); // disable skipping logic for caste of sort field
+            source.disableSkipping(); // disable skipping logic for cast of sort field
         }
         return source;
     }
diff --git a/server/src/main/java/org/opensearch/index/fielddata/LeafFieldData.java b/server/src/main/java/org/opensearch/index/fielddata/LeafFieldData.java
index 2982363937710..da7179254d70f 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/LeafFieldData.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/LeafFieldData.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.fielddata;
 
 import org.apache.lucene.util.Accountable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.index.mapper.DocValueFetcher;
 import org.opensearch.search.DocValueFormat;
@@ -42,8 +43,9 @@
 /**
  * The thread safe {@link org.apache.lucene.index.LeafReader} level cache of the data.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface LeafFieldData extends Accountable, Releasable {
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/fielddata/MultiGeoPointValues.java b/server/src/main/java/org/opensearch/index/fielddata/MultiGeoPointValues.java
index 2df4baeb8631b..3090b8e7f5b15 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/MultiGeoPointValues.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/MultiGeoPointValues.java
@@ -73,7 +73,7 @@ protected MultiGeoPointValues() {}
     /**
      * Return the next value associated with the current document. This must not be
      * called more than {@link #docValueCount()} times.
-     *
+     * <p>
      * Note: the returned {@link GeoPoint} might be shared across invocations.
      *
      * @return the next value for the current docID set to {@link #advanceExact(int)}.
diff --git a/server/src/main/java/org/opensearch/index/fielddata/NumericDoubleValues.java b/server/src/main/java/org/opensearch/index/fielddata/NumericDoubleValues.java
index 94ea91849ff12..b0f3400acfb3d 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/NumericDoubleValues.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/NumericDoubleValues.java
@@ -34,14 +34,16 @@
 
 import org.apache.lucene.index.NumericDocValues;
 import org.apache.lucene.search.DoubleValues;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 
 /**
  * A per-document numeric value.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class NumericDoubleValues extends DoubleValues {
 
     /** Sole constructor. (For invocation by subclass
diff --git a/server/src/main/java/org/opensearch/index/fielddata/ScriptDocValues.java b/server/src/main/java/org/opensearch/index/fielddata/ScriptDocValues.java
index a3c3774b250dc..eb3462743593d 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/ScriptDocValues.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/ScriptDocValues.java
@@ -37,6 +37,7 @@
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefBuilder;
 import org.opensearch.common.Numbers;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.geo.GeoUtils;
 import org.opensearch.common.time.DateUtils;
@@ -55,13 +56,14 @@
 /**
  * Script level doc values, the assumption is that any implementation will
  * implement a {@link Longs#getValue getValue} method.
- *
+ * <p>
  * Implementations should not internally re-use objects for the values that they
  * return as a single {@link ScriptDocValues} instance can be reused to return
  * values form multiple documents.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class ScriptDocValues<T> extends AbstractList<T> {
 
     /**
@@ -589,11 +591,11 @@ public BytesRef get(int index) {
                         + "Use doc[<field>].size()==0 to check if a document is missing a field!"
                 );
             }
-            /**
-             * We need to make a copy here because {@link BinaryScriptDocValues} might reuse the
-             * returned value and the same instance might be used to
-             * return values from multiple documents.
-             **/
+            /*
+              We need to make a copy here because {@link BinaryScriptDocValues} might reuse the
+              returned value and the same instance might be used to
+              return values from multiple documents.
+             */
             return values[index].toBytesRef();
         }
 
diff --git a/server/src/main/java/org/opensearch/index/fielddata/ShardFieldData.java b/server/src/main/java/org/opensearch/index/fielddata/ShardFieldData.java
index 87da81a0b3443..d8f49ba3d9c60 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/ShardFieldData.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/ShardFieldData.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.util.Accountable;
 import org.opensearch.common.FieldMemoryStats;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.common.regex.Regex;
 import org.opensearch.common.util.concurrent.ConcurrentCollections;
@@ -47,8 +48,9 @@
 /**
  * On heap field data for shards
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardFieldData implements IndexFieldDataCache.Listener {
 
     private final CounterMetric evictionsMetric = new CounterMetric();
diff --git a/server/src/main/java/org/opensearch/index/fielddata/SortedBinaryDocValues.java b/server/src/main/java/org/opensearch/index/fielddata/SortedBinaryDocValues.java
index bd66d1d94f33c..ba1b890f1ad1a 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/SortedBinaryDocValues.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/SortedBinaryDocValues.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.fielddata;
 
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 
@@ -41,8 +42,9 @@
  * according to {@link BytesRef#compareTo(BytesRef)}.
  * There might be dups however.
  *
- * @opensearch.internal
+  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 // TODO: Should it expose a count (current approach) or return null when there are no more values?
 public abstract class SortedBinaryDocValues {
 
diff --git a/server/src/main/java/org/opensearch/index/fielddata/SortedNumericDoubleValues.java b/server/src/main/java/org/opensearch/index/fielddata/SortedNumericDoubleValues.java
index 91d28113ae783..dce1aff9cc94f 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/SortedNumericDoubleValues.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/SortedNumericDoubleValues.java
@@ -33,14 +33,16 @@
 package org.opensearch.index.fielddata;
 
 import org.apache.lucene.index.SortedNumericDocValues;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 
 /**
  * Clone of {@link SortedNumericDocValues} for double values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SortedNumericDoubleValues {
 
     /** Sole constructor. (For invocation by subclass
diff --git a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/DoubleValuesComparatorSource.java b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/DoubleValuesComparatorSource.java
index e70916c33882c..4f9f05addc8c7 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/DoubleValuesComparatorSource.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/DoubleValuesComparatorSource.java
@@ -102,9 +102,7 @@ public FieldComparator<?> newComparator(String fieldname, int numHits, boolean e
         assert indexFieldData == null || fieldname.equals(indexFieldData.getFieldName());
 
         final double dMissingValue = (Double) missingObject(missingValue, reversed);
-        // NOTE: it's important to pass null as a missing value in the constructor so that
-        // the comparator doesn't check docsWithField since we replace missing values in select()
-        return new DoubleComparator(numHits, fieldname, null, reversed, enableSkipping && this.enableSkipping) {
+        return new DoubleComparator(numHits, fieldname, dMissingValue, reversed, enableSkipping && this.enableSkipping) {
             @Override
             public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
                 return new DoubleLeafComparator(context) {
diff --git a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/FloatValuesComparatorSource.java b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/FloatValuesComparatorSource.java
index 04a34cd418520..3fb8b5c6ce393 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/FloatValuesComparatorSource.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/FloatValuesComparatorSource.java
@@ -95,9 +95,7 @@ public FieldComparator<?> newComparator(String fieldname, int numHits, boolean e
         assert indexFieldData == null || fieldname.equals(indexFieldData.getFieldName());
 
         final float fMissingValue = (Float) missingObject(missingValue, reversed);
-        // NOTE: it's important to pass null as a missing value in the constructor so that
-        // the comparator doesn't check docsWithField since we replace missing values in select()
-        return new FloatComparator(numHits, fieldname, null, reversed, enableSkipping && this.enableSkipping) {
+        return new FloatComparator(numHits, fieldname, fMissingValue, reversed, enableSkipping && this.enableSkipping) {
             @Override
             public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
                 return new FloatLeafComparator(context) {
diff --git a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/HalfFloatValuesComparatorSource.java b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/HalfFloatValuesComparatorSource.java
new file mode 100644
index 0000000000000..e0227083f4181
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/HalfFloatValuesComparatorSource.java
@@ -0,0 +1,73 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.fielddata.fieldcomparator;
+
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.index.NumericDocValues;
+import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.FieldComparator;
+import org.apache.lucene.search.LeafFieldComparator;
+import org.apache.lucene.util.BitSet;
+import org.opensearch.index.fielddata.FieldData;
+import org.opensearch.index.fielddata.IndexNumericFieldData;
+import org.opensearch.index.fielddata.NumericDoubleValues;
+import org.opensearch.index.fielddata.SortedNumericDoubleValues;
+import org.opensearch.index.search.comparators.HalfFloatComparator;
+import org.opensearch.search.MultiValueMode;
+
+import java.io.IOException;
+
+/**
+ * Comparator source for half_float values.
+ *
+ * @opensearch.internal
+ */
+public class HalfFloatValuesComparatorSource extends FloatValuesComparatorSource {
+    private final IndexNumericFieldData indexFieldData;
+
+    public HalfFloatValuesComparatorSource(
+        IndexNumericFieldData indexFieldData,
+        Object missingValue,
+        MultiValueMode sortMode,
+        Nested nested
+    ) {
+        super(indexFieldData, missingValue, sortMode, nested);
+        this.indexFieldData = indexFieldData;
+    }
+
+    @Override
+    public FieldComparator<?> newComparator(String fieldname, int numHits, boolean enableSkipping, boolean reversed) {
+        assert indexFieldData == null || fieldname.equals(indexFieldData.getFieldName());
+
+        final float fMissingValue = (Float) missingObject(missingValue, reversed);
+        return new HalfFloatComparator(numHits, fieldname, fMissingValue, reversed, enableSkipping && this.enableSkipping) {
+            @Override
+            public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
+                return new HalfFloatLeafComparator(context) {
+                    @Override
+                    protected NumericDocValues getNumericDocValues(LeafReaderContext context, String field) throws IOException {
+                        return HalfFloatValuesComparatorSource.this.getNumericDocValues(context, fMissingValue).getRawFloatValues();
+                    }
+                };
+            }
+        };
+    }
+
+    private NumericDoubleValues getNumericDocValues(LeafReaderContext context, float missingValue) throws IOException {
+        final SortedNumericDoubleValues values = indexFieldData.load(context).getDoubleValues();
+        if (nested == null) {
+            return FieldData.replaceMissing(sortMode.select(values), missingValue);
+        } else {
+            final BitSet rootDocs = nested.rootDocs(context);
+            final DocIdSetIterator innerDocs = nested.innerDocs(context);
+            final int maxChildren = nested.getNestedSort() != null ? nested.getNestedSort().getMaxChildren() : Integer.MAX_VALUE;
+            return sortMode.select(values, missingValue, rootDocs, innerDocs, context.reader().maxDoc(), maxChildren);
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/IntValuesComparatorSource.java b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/IntValuesComparatorSource.java
index d5ea1eaf7263d..3a3fdb85c3415 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/IntValuesComparatorSource.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/IntValuesComparatorSource.java
@@ -74,9 +74,7 @@ public FieldComparator<?> newComparator(String fieldname, int numHits, boolean e
         assert indexFieldData == null || fieldname.equals(indexFieldData.getFieldName());
 
         final int iMissingValue = (Integer) missingObject(missingValue, reversed);
-        // NOTE: it's important to pass null as a missing value in the constructor so that
-        // the comparator doesn't check docsWithField since we replace missing values in select()
-        return new IntComparator(numHits, fieldname, null, reversed, enableSkipping && this.enableSkipping) {
+        return new IntComparator(numHits, fieldname, iMissingValue, reversed, enableSkipping && this.enableSkipping) {
             @Override
             public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
                 return new IntLeafComparator(context) {
diff --git a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/LongValuesComparatorSource.java b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/LongValuesComparatorSource.java
index 2c67d7ab7e86a..57568aa84fa5c 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/LongValuesComparatorSource.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/LongValuesComparatorSource.java
@@ -118,9 +118,7 @@ public FieldComparator<?> newComparator(String fieldname, int numHits, boolean e
         assert indexFieldData == null || fieldname.equals(indexFieldData.getFieldName());
 
         final long lMissingValue = (Long) missingObject(missingValue, reversed);
-        // NOTE: it's important to pass null as a missing value in the constructor so that
-        // the comparator doesn't check docsWithField since we replace missing values in select()
-        return new LongComparator(numHits, fieldname, null, reversed, enableSkipping && this.enableSkipping) {
+        return new LongComparator(numHits, fieldname, lMissingValue, reversed, enableSkipping && this.enableSkipping) {
             @Override
             public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
                 return new LongLeafComparator(context) {
diff --git a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/UnsignedLongValuesComparatorSource.java b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/UnsignedLongValuesComparatorSource.java
index 5416d4fe0fb91..9d1edde1fe08f 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/UnsignedLongValuesComparatorSource.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/fieldcomparator/UnsignedLongValuesComparatorSource.java
@@ -92,7 +92,7 @@ public FieldComparator<?> newComparator(String fieldname, int numHits, boolean e
         assert indexFieldData == null || fieldname.equals(indexFieldData.getFieldName());
 
         final BigInteger ulMissingValue = (BigInteger) missingObject(missingValue, reversed);
-        return new UnsignedLongComparator(numHits, fieldname, null, reversed, enableSkipping && this.enableSkipping) {
+        return new UnsignedLongComparator(numHits, fieldname, ulMissingValue, reversed, enableSkipping && this.enableSkipping) {
             @Override
             public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
                 return new UnsignedLongLeafComparator(context) {
diff --git a/server/src/main/java/org/opensearch/index/fielddata/plain/SortedSetOrdinalsIndexFieldData.java b/server/src/main/java/org/opensearch/index/fielddata/plain/SortedSetOrdinalsIndexFieldData.java
index 4f27c9b10f0ee..fe033fa7a3f70 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/plain/SortedSetOrdinalsIndexFieldData.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/plain/SortedSetOrdinalsIndexFieldData.java
@@ -101,9 +101,9 @@ public SortedSetOrdinalsIndexFieldData(
     @Override
     public SortField sortField(@Nullable Object missingValue, MultiValueMode sortMode, Nested nested, boolean reverse) {
         XFieldComparatorSource source = new BytesRefFieldComparatorSource(this, missingValue, sortMode, nested);
-        /**
-         * Check if we can use a simple {@link SortedSetSortField} compatible with index sorting and
-         * returns a custom sort field otherwise.
+        /*
+          Check if we can use a simple {@link SortedSetSortField} compatible with index sorting and
+          returns a custom sort field otherwise.
          */
         if (nested != null
             || (sortMode != MultiValueMode.MAX && sortMode != MultiValueMode.MIN)
diff --git a/server/src/main/java/org/opensearch/index/flush/FlushStats.java b/server/src/main/java/org/opensearch/index/flush/FlushStats.java
index aec6e9199729d..9bce46d1dd9d5 100644
--- a/server/src/main/java/org/opensearch/index/flush/FlushStats.java
+++ b/server/src/main/java/org/opensearch/index/flush/FlushStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.flush;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -44,8 +45,9 @@
 /**
  * Encapsulates statistics for flush
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FlushStats implements Writeable, ToXContentFragment {
 
     private long total;
diff --git a/server/src/main/java/org/opensearch/index/get/GetResult.java b/server/src/main/java/org/opensearch/index/get/GetResult.java
index f0f1a86cb16e7..c0dd1cd2ecb30 100644
--- a/server/src/main/java/org/opensearch/index/get/GetResult.java
+++ b/server/src/main/java/org/opensearch/index/get/GetResult.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.common.Strings;
@@ -68,6 +69,7 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetResult implements Writeable, Iterable<DocumentField>, ToXContentObject {
 
     public static final String _INDEX = "_index";
diff --git a/server/src/main/java/org/opensearch/index/get/GetStats.java b/server/src/main/java/org/opensearch/index/get/GetStats.java
index 5530a45717305..a366014fe228e 100644
--- a/server/src/main/java/org/opensearch/index/get/GetStats.java
+++ b/server/src/main/java/org/opensearch/index/get/GetStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.get;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,6 +47,7 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class GetStats implements Writeable, ToXContentFragment {
 
     private long existsCount;
diff --git a/server/src/main/java/org/opensearch/index/get/ShardGetService.java b/server/src/main/java/org/opensearch/index/get/ShardGetService.java
index 546497a2e0d19..831bb8aff3be3 100644
--- a/server/src/main/java/org/opensearch/index/get/ShardGetService.java
+++ b/server/src/main/java/org/opensearch/index/get/ShardGetService.java
@@ -43,6 +43,7 @@
 import org.apache.lucene.index.VectorSimilarityFunction;
 import org.opensearch.OpenSearchException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.common.lucene.uid.Versions;
@@ -88,8 +89,9 @@
 /**
  * Gets an index shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ShardGetService extends AbstractIndexShardComponent {
     private final MapperService mapperService;
     private final MeanMetric existsMetric = new MeanMetric();
diff --git a/server/src/main/java/org/opensearch/index/mapper/AbstractGeometryFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/AbstractGeometryFieldMapper.java
index a038cf178bb03..3b6782b34feea 100644
--- a/server/src/main/java/org/opensearch/index/mapper/AbstractGeometryFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/AbstractGeometryFieldMapper.java
@@ -121,7 +121,7 @@ public abstract static class Parser<Parsed> {
 
         /**
          * Given a parsed value and a format string, formats the value into a plain Java object.
-         *
+         * <p>
          * Supported formats include 'geojson' and 'wkt'. The different formats are defined
          * as subclasses of {@link org.opensearch.common.geo.GeometryFormat}.
          */
@@ -129,7 +129,7 @@ public abstract static class Parser<Parsed> {
 
         /**
          * Parses the given value, then formats it according to the 'format' string.
-         *
+         * <p>
          * By default, this method simply parses the value using {@link Parser#parse}, then formats
          * it with {@link Parser#format}. However some {@link Parser} implementations override this
          * as they can avoid parsing the value if it is already in the right format.
diff --git a/server/src/main/java/org/opensearch/index/mapper/ArraySourceValueFetcher.java b/server/src/main/java/org/opensearch/index/mapper/ArraySourceValueFetcher.java
index f5dc34ab8ac5d..b3112df86bab6 100644
--- a/server/src/main/java/org/opensearch/index/mapper/ArraySourceValueFetcher.java
+++ b/server/src/main/java/org/opensearch/index/mapper/ArraySourceValueFetcher.java
@@ -43,7 +43,7 @@
 /**
  * An implementation of {@link ValueFetcher} that knows how to extract values
  * from the document source.
- *
+ * <p>
  * This class differs from {@link SourceValueFetcher} in that it directly handles
  * array values in parsing. Field types should use this class if their corresponding
  * mapper returns true for {@link FieldMapper#parsesArrayValue()}.
diff --git a/server/src/main/java/org/opensearch/index/mapper/BooleanFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/BooleanFieldMapper.java
index 22eeed205e2c8..3c7925809415a 100644
--- a/server/src/main/java/org/opensearch/index/mapper/BooleanFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/BooleanFieldMapper.java
@@ -193,7 +193,7 @@ protected Boolean parseSourceValue(Object value) {
                         return (Boolean) value;
                     } else {
                         String textValue = value.toString();
-                        return Booleans.parseBoolean(textValue.toCharArray(), 0, textValue.length(), false);
+                        return Booleans.parseBooleanStrict(textValue, false);
                     }
                 }
             };
diff --git a/server/src/main/java/org/opensearch/index/mapper/CompletionFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/CompletionFieldMapper.java
index 90ef3cc1689a4..e1413fd9b4bbe 100644
--- a/server/src/main/java/org/opensearch/index/mapper/CompletionFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/CompletionFieldMapper.java
@@ -447,13 +447,13 @@ int getMaxInputLength() {
 
     /**
      * Parses and indexes inputs
-     *
+     * <p>
      * Parsing:
      *  Acceptable format:
      *   "STRING" - interpreted as field value (input)
      *   "ARRAY" - each element can be one of "OBJECT" (see below)
      *   "OBJECT" - { "input": STRING|ARRAY, "weight": STRING|INT, "contexts": ARRAY|OBJECT }
-     *
+     * <p>
      * Indexing:
      *  if context mappings are defined, delegates to {@link ContextMappings#addField(ParseContext.Document, String, String, int, Map)}
      *  else adds inputs as a {@link org.apache.lucene.search.suggest.document.SuggestField}
diff --git a/server/src/main/java/org/opensearch/index/mapper/ContentPath.java b/server/src/main/java/org/opensearch/index/mapper/ContentPath.java
index 8b0d5e24056d3..63e5731e2681b 100644
--- a/server/src/main/java/org/opensearch/index/mapper/ContentPath.java
+++ b/server/src/main/java/org/opensearch/index/mapper/ContentPath.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.index.mapper;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * JSON Path for a document / field
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ContentPath {
 
     private static final char DELIMITER = '.';
diff --git a/server/src/main/java/org/opensearch/index/mapper/CustomDocValuesField.java b/server/src/main/java/org/opensearch/index/mapper/CustomDocValuesField.java
index 2776e7515bbf6..fbb67731f581b 100644
--- a/server/src/main/java/org/opensearch/index/mapper/CustomDocValuesField.java
+++ b/server/src/main/java/org/opensearch/index/mapper/CustomDocValuesField.java
@@ -42,8 +42,7 @@
 import java.io.Reader;
 
 /**
- * Base class for constructing a custom docvalues type
- *
+ * Base class for constructing a custom docvalues type.
  * used for binary, geo, and range fields
  *
  * @opensearch.api
diff --git a/server/src/main/java/org/opensearch/index/mapper/DateFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/DateFieldMapper.java
index 393ddf2dd1de0..d98e6ea6af83d 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DateFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DateFieldMapper.java
@@ -52,6 +52,7 @@
 import org.opensearch.common.time.DateMathParser;
 import org.opensearch.common.time.DateUtils;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.util.LocaleUtils;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.fielddata.IndexNumericFieldData.NumericType;
@@ -91,7 +92,21 @@ public final class DateFieldMapper extends ParametrizedFieldMapper {
 
     public static final String CONTENT_TYPE = "date";
     public static final String DATE_NANOS_CONTENT_TYPE = "date_nanos";
-    public static final DateFormatter DEFAULT_DATE_TIME_FORMATTER = DateFormatter.forPattern("strict_date_optional_time||epoch_millis");
+    @Deprecated
+    public static final DateFormatter LEGACY_DEFAULT_DATE_TIME_FORMATTER = DateFormatter.forPattern(
+        // TODO remove in 3.0 after backporting
+        "strict_date_optional_time||epoch_millis"
+    );
+    public static final DateFormatter DEFAULT_DATE_TIME_FORMATTER = DateFormatter.forPattern(
+        "strict_date_time_no_millis||strict_date_optional_time||epoch_millis",
+        "strict_date_optional_time"
+    );
+
+    public static DateFormatter getDefaultDateTimeFormatter() {
+        return FeatureFlags.isEnabled(FeatureFlags.DATETIME_FORMATTER_CACHING_SETTING)
+            ? DEFAULT_DATE_TIME_FORMATTER
+            : LEGACY_DEFAULT_DATE_TIME_FORMATTER;
+    }
 
     /**
      * Resolution of the date time
@@ -223,8 +238,14 @@ public static class Builder extends ParametrizedFieldMapper.Builder {
             "format",
             false,
             m -> toType(m).format,
-            DEFAULT_DATE_TIME_FORMATTER.pattern()
+            getDefaultDateTimeFormatter().pattern()
         );
+        private final Parameter<String> printFormat = Parameter.stringParam(
+            "print_format",
+            false,
+            m -> toType(m).printFormat,
+            getDefaultDateTimeFormatter().printPattern()
+        ).acceptsNull();
         private final Parameter<Locale> locale = new Parameter<>(
             "locale",
             false,
@@ -253,13 +274,18 @@ public Builder(
             this.ignoreMalformed = Parameter.boolParam("ignore_malformed", true, m -> toType(m).ignoreMalformed, ignoreMalformedByDefault);
             if (dateFormatter != null) {
                 this.format.setValue(dateFormatter.pattern());
+                this.printFormat.setValue(dateFormatter.printPattern());
                 this.locale.setValue(dateFormatter.locale());
             }
         }
 
         private DateFormatter buildFormatter() {
             try {
-                return DateFormatter.forPattern(format.getValue()).withLocale(locale.getValue());
+                if (format.isConfigured() && !printFormat.isConfigured()) {
+                    return DateFormatter.forPattern(format.getValue(), null, !format.isConfigured()).withLocale(locale.getValue());
+                }
+                return DateFormatter.forPattern(format.getValue(), printFormat.getValue(), !format.isConfigured())
+                    .withLocale(locale.getValue());
             } catch (IllegalArgumentException e) {
                 throw new IllegalArgumentException("Error parsing [format] on field [" + name() + "]: " + e.getMessage(), e);
             }
@@ -267,7 +293,7 @@ private DateFormatter buildFormatter() {
 
         @Override
         protected List<Parameter<?>> getParameters() {
-            return Arrays.asList(index, docValues, store, format, locale, nullValue, ignoreMalformed, boost, meta);
+            return Arrays.asList(index, docValues, store, format, printFormat, locale, nullValue, ignoreMalformed, boost, meta);
         }
 
         private Long parseNullValue(DateFieldType fieldType) {
@@ -346,7 +372,7 @@ public DateFieldType(
         }
 
         public DateFieldType(String name) {
-            this(name, true, false, true, DEFAULT_DATE_TIME_FORMATTER, Resolution.MILLISECONDS, null, Collections.emptyMap());
+            this(name, true, false, true, getDefaultDateTimeFormatter(), Resolution.MILLISECONDS, null, Collections.emptyMap());
         }
 
         public DateFieldType(String name, DateFormatter dateFormatter) {
@@ -354,7 +380,7 @@ public DateFieldType(String name, DateFormatter dateFormatter) {
         }
 
         public DateFieldType(String name, Resolution resolution) {
-            this(name, true, false, true, DEFAULT_DATE_TIME_FORMATTER, resolution, null, Collections.emptyMap());
+            this(name, true, false, true, getDefaultDateTimeFormatter(), resolution, null, Collections.emptyMap());
         }
 
         public DateFieldType(String name, Resolution resolution, DateFormatter dateFormatter) {
@@ -383,6 +409,16 @@ public long parse(String value) {
             return resolution.convert(DateFormatters.from(dateTimeFormatter().parse(value), dateTimeFormatter().locale()).toInstant());
         }
 
+        public long convertNanosToMillis(long nanoSecondsSinceEpoch) {
+            if (resolution.numericType.equals(NumericType.DATE_NANOSECONDS)) return DateUtils.toMilliSeconds(nanoSecondsSinceEpoch);
+            return nanoSecondsSinceEpoch;
+        }
+
+        public long convertRoundedMillisToNanos(long milliSecondsSinceEpoch) {
+            if (resolution.numericType.equals(NumericType.DATE_NANOSECONDS)) return DateUtils.toNanoSeconds(milliSecondsSinceEpoch);
+            return milliSecondsSinceEpoch;
+        }
+
         @Override
         public ValueFetcher valueFetcher(QueryShardContext context, SearchLookup searchLookup, String format) {
             DateFormatter defaultFormatter = dateTimeFormatter();
@@ -610,6 +646,7 @@ public DocValueFormat docValueFormat(@Nullable String format, ZoneId timeZone) {
     private final boolean hasDocValues;
     private final Locale locale;
     private final String format;
+    private final String printFormat;
     private final boolean ignoreMalformed;
     private final Long nullValue;
     private final String nullValueAsString;
@@ -633,6 +670,7 @@ private DateFieldMapper(
         this.hasDocValues = builder.docValues.getValue();
         this.locale = builder.locale.getValue();
         this.format = builder.format.getValue();
+        this.printFormat = builder.printFormat.getValue();
         this.ignoreMalformed = builder.ignoreMalformed.getValue();
         this.nullValueAsString = builder.nullValue.getValue();
         this.nullValue = nullValue;
diff --git a/server/src/main/java/org/opensearch/index/mapper/DocValueFetcher.java b/server/src/main/java/org/opensearch/index/mapper/DocValueFetcher.java
index bf14af809fbfd..827792cdb1091 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DocValueFetcher.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DocValueFetcher.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.mapper;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.search.DocValueFormat;
 import org.opensearch.search.lookup.SourceLookup;
@@ -77,8 +78,9 @@ public List<Object> fetchValues(SourceLookup lookup) throws IOException {
     /**
      * Leaf interface
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Leaf {
         /**
          * Advance the doc values reader to the provided doc.
diff --git a/server/src/main/java/org/opensearch/index/mapper/DocumentMapper.java b/server/src/main/java/org/opensearch/index/mapper/DocumentMapper.java
index 84ef3dde24dc3..3ada04b41abd2 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DocumentMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DocumentMapper.java
@@ -40,6 +40,7 @@
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.OpenSearchGenerationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -65,15 +66,17 @@
 /**
  * The OpenSearch DocumentMapper
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DocumentMapper implements ToXContentFragment {
 
     /**
      * Builder for the Document Field Mapper
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
 
         private final Map<Class<? extends MetadataFieldMapper>, MetadataFieldMapper> metadataMappers = new LinkedHashMap<>();
@@ -236,7 +239,7 @@ public MappingLookup mappers() {
         return this.fieldMappers;
     }
 
-    public FieldTypeLookup fieldTypes() {
+    FieldTypeLookup fieldTypes() {
         return mappers().fieldTypes();
     }
 
diff --git a/server/src/main/java/org/opensearch/index/mapper/DocumentMapperForType.java b/server/src/main/java/org/opensearch/index/mapper/DocumentMapperForType.java
index b26c3f3645433..565817a450f56 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DocumentMapperForType.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DocumentMapperForType.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.index.mapper;
 
+import org.opensearch.common.annotation.DeprecatedApi;
+
 /**
  * Document mapper used for types
  *
@@ -40,6 +42,7 @@
  * @deprecated types are being removed
  */
 @Deprecated
+@DeprecatedApi(since = "2.0.0")
 public class DocumentMapperForType {
     private final DocumentMapper documentMapper;
     private final Mapping mapping;
diff --git a/server/src/main/java/org/opensearch/index/mapper/DocumentMapperParser.java b/server/src/main/java/org/opensearch/index/mapper/DocumentMapperParser.java
index dbafc2a923cf2..fa736f84895eb 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DocumentMapperParser.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DocumentMapperParser.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.time.DateFormatter;
@@ -56,8 +57,9 @@
 /**
  * Parser for a document mapper
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DocumentMapperParser {
 
     final MapperService mapperService;
@@ -197,7 +199,7 @@ private static String getRemainingFields(Map<?, ?> map) {
 
     /**
      * Given an optional type name and mapping definition, returns the type and a normalized form of the mappings.
-     *
+     * <p>
      * The provided mapping definition may or may not contain the type name as the root key in the map. This method
      * attempts to unwrap the mappings, so that they no longer contain a type name at the root. If no type name can
      * be found, through either the 'type' parameter or by examining the provided mappings, then an exception will be
@@ -205,7 +207,6 @@ private static String getRemainingFields(Map<?, ?> map) {
      *
      * @param type An optional type name.
      * @param root The mapping definition.
-     *
      * @return A tuple of the form (type, normalized mappings).
      */
     @SuppressWarnings({ "unchecked" })
diff --git a/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldMapper.java
index 94bc4806ba0e0..2e59d86f9119c 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldMapper.java
@@ -43,7 +43,7 @@
  *   to {@link DynamicKeyFieldMapper#keyedFieldType(String)}, with 'some_key' passed as the
  *   argument. The field mapper is allowed to create a new field type dynamically in order
  *   to handle the search.
- *
+ * <p>
  * To prevent conflicts between these dynamic sub-keys and multi-fields, any field mappers
  * implementing this interface should explicitly disallow multi-fields. The constructor makes
  * sure to passes an empty multi-fields list to help prevent conflicting sub-keys from being
diff --git a/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldTypeLookup.java b/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldTypeLookup.java
index 13150ddc50a51..a415078108eb6 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldTypeLookup.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DynamicKeyFieldTypeLookup.java
@@ -37,11 +37,11 @@
 
 /**
  * A container that supports looking up field types for 'dynamic key' fields ({@link DynamicKeyFieldMapper}).
- *
+ * <p>
  * Compared to standard fields, 'dynamic key' fields require special handling. Given a field name of the form
  * 'path_to_field.path_to_key', the container will dynamically return a new {@link MappedFieldType} that is
  * suitable for performing searches on the sub-key.
- *
+ * <p>
  * Note: we anticipate that 'flattened' fields will be the only implementation {@link DynamicKeyFieldMapper}.
  * Flattened object fields live in the 'mapper-flattened' module.
  *
diff --git a/server/src/main/java/org/opensearch/index/mapper/DynamicTemplate.java b/server/src/main/java/org/opensearch/index/mapper/DynamicTemplate.java
index a20ad43bd70af..da62b20c98563 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DynamicTemplate.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DynamicTemplate.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.mapper;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.regex.Regex;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -47,8 +48,9 @@
 /**
  * A template that is dynamic based on field types
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DynamicTemplate implements ToXContentObject {
 
     /**
@@ -96,8 +98,9 @@ public static MatchType fromString(String value) {
     /**
      * The type of a field as detected while parsing a json document.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum XContentFieldType {
         OBJECT {
             @Override
diff --git a/server/src/main/java/org/opensearch/index/mapper/FieldAliasMapper.java b/server/src/main/java/org/opensearch/index/mapper/FieldAliasMapper.java
index 86c92ec19a2f7..ff9cb61b85571 100644
--- a/server/src/main/java/org/opensearch/index/mapper/FieldAliasMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/FieldAliasMapper.java
@@ -43,7 +43,7 @@
 
 /**
  * A mapper for field aliases.
- *
+ * <p>
  * A field alias has no concrete field mappings of its own, but instead points to another field by
  * its path. Once defined, an alias can be used in place of the concrete field name in search requests.
  *
diff --git a/server/src/main/java/org/opensearch/index/mapper/FieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/FieldMapper.java
index f8514c86fa418..4e495c68fd822 100644
--- a/server/src/main/java/org/opensearch/index/mapper/FieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/FieldMapper.java
@@ -35,6 +35,7 @@
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.index.IndexOptions;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.settings.Settings;
@@ -61,8 +62,9 @@
 /**
  * The base OpenSearch Field Mapper
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class FieldMapper extends Mapper implements Cloneable {
     public static final Setting<Boolean> IGNORE_MALFORMED_SETTING = Setting.boolSetting(
         "index.mapping.ignore_malformed",
@@ -305,7 +307,7 @@ public void parse(ParseContext context) throws IOException {
 
     /**
      * Parse the field value and populate the fields on {@link ParseContext#doc()}.
-     *
+     * <p>
      * Implementations of this method should ensure that on failing to parse parser.currentToken() must be the
      * current failing token
      */
@@ -572,8 +574,9 @@ protected static String indexOptionToString(IndexOptions indexOption) {
     /**
      * Multi field implementation used across field mappers
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class MultiFields implements Iterable<Mapper> {
 
         public static MultiFields empty() {
@@ -702,8 +705,9 @@ public int compare(Mapper o1, Mapper o2) {
     /**
      * Represents a list of fields with optional boost factor where the current field should be copied to
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class CopyTo {
 
         private static final CopyTo EMPTY = new CopyTo(Collections.emptyList());
diff --git a/server/src/main/java/org/opensearch/index/mapper/FieldTypeLookup.java b/server/src/main/java/org/opensearch/index/mapper/FieldTypeLookup.java
index 8e1b6f2a3c08b..7a9a0c5fb5428 100644
--- a/server/src/main/java/org/opensearch/index/mapper/FieldTypeLookup.java
+++ b/server/src/main/java/org/opensearch/index/mapper/FieldTypeLookup.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.mapper;
 
+import org.opensearch.common.annotation.InternalApi;
 import org.opensearch.common.collect.Iterators;
 import org.opensearch.common.regex.Regex;
 
@@ -48,6 +49,7 @@
  *
  * @opensearch.internal
  */
+@InternalApi
 class FieldTypeLookup implements Iterable<MappedFieldType> {
 
     private final Map<String, MappedFieldType> fullNameToFieldType = new HashMap<>();
@@ -57,7 +59,7 @@ class FieldTypeLookup implements Iterable<MappedFieldType> {
      * A map from field name to all fields whose content has been copied into it
      * through copy_to. A field only be present in the map if some other field
      * has listed it as a target of copy_to.
-     *
+     * <p>
      * For convenience, the set of copied fields includes the field itself.
      */
     private final Map<String, Set<String>> fieldToCopiedFields = new HashMap<>();
@@ -133,7 +135,7 @@ public Set<String> simpleMatchToFullName(String pattern) {
 
     /**
      * Given a concrete field name, return its paths in the _source.
-     *
+     * <p>
      * For most fields, the source path is the same as the field itself. However
      * there are cases where a field's values are found elsewhere in the _source:
      *   - For a multi-field, the source path is the parent field.
diff --git a/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
index db35c3edcc4a8..00b623dddac23 100644
--- a/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
@@ -575,9 +575,9 @@ protected void parseCreateField(ParseContext context) throws IOException {
                 context,
                 fieldType().name()
             );
-            /**
-             * JsonToStringParser is the main parser class to transform JSON into stringFields in a XContentParser
-             * It reads the JSON object and parsed to a list of string
+            /*
+              JsonToStringParser is the main parser class to transform JSON into stringFields in a XContentParser
+              It reads the JSON object and parsed to a list of string
              */
             XContentParser parser = JsonToStringParser.parseObject();
 
diff --git a/server/src/main/java/org/opensearch/index/mapper/GeoPointFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/GeoPointFieldMapper.java
index e3dab3f892949..fcca7e9804bf3 100644
--- a/server/src/main/java/org/opensearch/index/mapper/GeoPointFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/GeoPointFieldMapper.java
@@ -63,7 +63,7 @@
 
 /**
  * Field Mapper for geo_point types.
- *
+ * <p>
  * Uses lucene 6 LatLonPoint encoding
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java
index 4a4b2684b5f4c..b44b4b75549c3 100644
--- a/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java
@@ -31,12 +31,15 @@
 
 package org.opensearch.index.mapper;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.document.LatLonShape;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.search.Query;
+import org.opensearch.Version;
 import org.opensearch.common.Explicit;
 import org.opensearch.common.geo.GeometryParser;
 import org.opensearch.common.geo.ShapeRelation;
@@ -77,6 +80,7 @@
  * @opensearch.internal
  */
 public class GeoShapeFieldMapper extends AbstractShapeGeometryFieldMapper<Geometry, Geometry> {
+    private static final Logger logger = LogManager.getLogger(GeoShapeFieldMapper.class);
     public static final String CONTENT_TYPE = "geo_shape";
     public static final FieldType FIELD_TYPE = new FieldType();
     static {
@@ -205,9 +209,24 @@ protected void addDocValuesFields(
         final List<IndexableField> indexableFields,
         final ParseContext context
     ) {
-        Field[] fieldsArray = new Field[indexableFields.size()];
-        fieldsArray = indexableFields.toArray(fieldsArray);
-        context.doc().add(LatLonShape.createDocValueField(name, fieldsArray));
+        /*
+         * We are adding the doc values for GeoShape only if the index is created with 2.9 and above version of
+         * OpenSearch. If we don't do that after the upgrade of OpenSearch customers are not able to index documents
+         * with GeoShape fields. Github issue: https://github.com/opensearch-project/OpenSearch/issues/10958,
+         * https://github.com/opensearch-project/OpenSearch/issues/10795
+         */
+        if (context.indexSettings().getIndexVersionCreated().onOrAfter(Version.V_2_9_0)) {
+            Field[] fieldsArray = new Field[indexableFields.size()];
+            fieldsArray = indexableFields.toArray(fieldsArray);
+            context.doc().add(LatLonShape.createDocValueField(name, fieldsArray));
+        } else {
+            logger.warn(
+                "The index was created with Version : {}, for geoshape doc values to work index must be "
+                    + "created with OpenSearch Version : {} or above",
+                context.indexSettings().getIndexVersionCreated(),
+                Version.V_2_9_0
+            );
+        }
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/index/mapper/IdFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/IdFieldMapper.java
index 38d25de8ff808..658f4228cb0c6 100644
--- a/server/src/main/java/org/opensearch/index/mapper/IdFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/IdFieldMapper.java
@@ -41,6 +41,7 @@
 import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.TermInSetQuery;
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.common.util.BigArrays;
@@ -74,8 +75,9 @@
  * stored, but we need to keep it so that its FieldType can be used to generate
  * queries.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IdFieldMapper extends MetadataFieldMapper {
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(IdFieldMapper.class);
     static final String ID_FIELD_DATA_DEPRECATION_MESSAGE =
diff --git a/server/src/main/java/org/opensearch/index/mapper/IndexFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/IndexFieldMapper.java
index 982b0eb909443..22fcb66848ed1 100644
--- a/server/src/main/java/org/opensearch/index/mapper/IndexFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/IndexFieldMapper.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.search.MatchAllDocsQuery;
 import org.apache.lucene.search.Query;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.fielddata.plain.ConstantIndexFieldData;
@@ -47,8 +48,9 @@
 /**
  * Index specific field mapper
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexFieldMapper extends MetadataFieldMapper {
 
     public static final String NAME = "_index";
diff --git a/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java
index 92ee8067ee4a0..c14b2c92c89c3 100644
--- a/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java
@@ -38,11 +38,24 @@
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.document.SortedSetDocValuesField;
 import org.apache.lucene.index.IndexOptions;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.FuzzyQuery;
+import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.MultiTermQuery;
+import org.apache.lucene.search.PrefixQuery;
 import org.apache.lucene.search.Query;
+import org.apache.lucene.search.RegexpQuery;
+import org.apache.lucene.search.TermInSetQuery;
+import org.apache.lucene.search.TermRangeQuery;
+import org.apache.lucene.search.WildcardQuery;
 import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.automaton.Operations;
+import org.opensearch.OpenSearchException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.lucene.BytesRefs;
 import org.opensearch.common.lucene.Lucene;
+import org.opensearch.common.lucene.search.AutomatonQueries;
+import org.opensearch.common.unit.Fuzziness;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.index.analysis.IndexAnalyzers;
 import org.opensearch.index.analysis.NamedAnalyzer;
@@ -62,6 +75,8 @@
 import java.util.Objects;
 import java.util.function.Supplier;
 
+import static org.opensearch.search.SearchService.ALLOW_EXPENSIVE_QUERIES;
+
 /**
  * A field mapper for keywords. This mapper accepts strings and indexes them as-is.
  *
@@ -317,7 +332,7 @@ public IndexFieldData.Builder fielddataBuilder(String fullyQualifiedIndexName, S
         @Override
         public ValueFetcher valueFetcher(QueryShardContext context, SearchLookup searchLookup, String format) {
             if (format != null) {
-                throw new IllegalArgumentException("Field [" + name() + "] of type [" + typeName() + "] doesn't support formats.");
+                throw new IllegalArgumentException("Field [" + name() + "] of type [" + typeName() + "] doesn't " + "support formats.");
             }
 
             return new SourceValueFetcher(name(), context, nullValue) {
@@ -372,17 +387,226 @@ protected BytesRef indexedValueForSearch(Object value) {
             return getTextSearchInfo().getSearchAnalyzer().normalize(name(), value.toString());
         }
 
+        @Override
+        public Query termsQuery(List<?> values, QueryShardContext context) {
+            failIfNotIndexedAndNoDocValues();
+            // has index and doc_values enabled
+            if (isSearchable() && hasDocValues()) {
+                BytesRef[] bytesRefs = new BytesRef[values.size()];
+                for (int i = 0; i < bytesRefs.length; i++) {
+                    bytesRefs[i] = indexedValueForSearch(values.get(i));
+                }
+                Query indexQuery = new TermInSetQuery(name(), bytesRefs);
+                Query dvQuery = new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, name(), bytesRefs);
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            // if we only have doc_values enabled, we construct a new query with doc_values re-written
+            if (hasDocValues()) {
+                BytesRef[] bytesRefs = new BytesRef[values.size()];
+                for (int i = 0; i < bytesRefs.length; i++) {
+                    bytesRefs[i] = indexedValueForSearch(values.get(i));
+                }
+                return new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, name(), bytesRefs);
+            }
+            // has index enabled, we're going to return the query as is
+            return super.termsQuery(values, context);
+        }
+
+        @Override
+        public Query prefixQuery(
+            String value,
+            @Nullable MultiTermQuery.RewriteMethod method,
+            boolean caseInsensitive,
+            QueryShardContext context
+        ) {
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[prefix] queries cannot be executed when '"
+                        + ALLOW_EXPENSIVE_QUERIES.getKey()
+                        + "' is set to false. For optimised prefix queries on text "
+                        + "fields please enable [index_prefixes]."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.prefixQuery(value, method, caseInsensitive, context);
+                Query dvQuery = super.prefixQuery(value, MultiTermQuery.DOC_VALUES_REWRITE, caseInsensitive, context);
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                if (caseInsensitive) {
+                    return AutomatonQueries.caseInsensitivePrefixQuery(
+                        (new Term(name(), indexedValueForSearch(value))),
+                        MultiTermQuery.DOC_VALUES_REWRITE
+                    );
+                }
+                return new PrefixQuery(new Term(name(), indexedValueForSearch(value)), MultiTermQuery.DOC_VALUES_REWRITE);
+            }
+            return super.prefixQuery(value, method, caseInsensitive, context);
+        }
+
+        @Override
+        public Query regexpQuery(
+            String value,
+            int syntaxFlags,
+            int matchFlags,
+            int maxDeterminizedStates,
+            @Nullable MultiTermQuery.RewriteMethod method,
+            QueryShardContext context
+        ) {
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[regexp] queries cannot be executed when '" + ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to " + "false."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.regexpQuery(value, syntaxFlags, matchFlags, maxDeterminizedStates, method, context);
+                Query dvQuery = super.regexpQuery(
+                    value,
+                    syntaxFlags,
+                    matchFlags,
+                    maxDeterminizedStates,
+                    MultiTermQuery.DOC_VALUES_REWRITE,
+                    context
+                );
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                return new RegexpQuery(
+                    new Term(name(), indexedValueForSearch(value)),
+                    syntaxFlags,
+                    matchFlags,
+                    RegexpQuery.DEFAULT_PROVIDER,
+                    maxDeterminizedStates,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+            }
+            return super.regexpQuery(value, syntaxFlags, matchFlags, maxDeterminizedStates, method, context);
+        }
+
+        @Override
+        public Query rangeQuery(Object lowerTerm, Object upperTerm, boolean includeLower, boolean includeUpper, QueryShardContext context) {
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[range] queries on [text] or [keyword] fields cannot be executed when '"
+                        + ALLOW_EXPENSIVE_QUERIES.getKey()
+                        + "' is set to false."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = new TermRangeQuery(
+                    name(),
+                    lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                    upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                    includeLower,
+                    includeUpper
+                );
+                Query dvQuery = new TermRangeQuery(
+                    name(),
+                    lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                    upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                    includeLower,
+                    includeUpper,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                return new TermRangeQuery(
+                    name(),
+                    lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                    upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                    includeLower,
+                    includeUpper,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+            }
+            return new TermRangeQuery(
+                name(),
+                lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                includeLower,
+                includeUpper
+            );
+        }
+
+        @Override
+        public Query fuzzyQuery(
+            Object value,
+            Fuzziness fuzziness,
+            int prefixLength,
+            int maxExpansions,
+            boolean transpositions,
+            @Nullable MultiTermQuery.RewriteMethod method,
+            QueryShardContext context
+        ) {
+            failIfNotIndexedAndNoDocValues();
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[fuzzy] queries cannot be executed when '" + ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to " + "false."
+                );
+            }
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, context);
+                Query dvQuery = super.fuzzyQuery(
+                    value,
+                    fuzziness,
+                    prefixLength,
+                    maxExpansions,
+                    transpositions,
+                    MultiTermQuery.DOC_VALUES_REWRITE,
+                    context
+                );
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                return new FuzzyQuery(
+                    new Term(name(), indexedValueForSearch(value)),
+                    fuzziness.asDistance(BytesRefs.toString(value)),
+                    prefixLength,
+                    maxExpansions,
+                    transpositions,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+            }
+            return super.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, context);
+        }
+
         @Override
         public Query wildcardQuery(
             String value,
             @Nullable MultiTermQuery.RewriteMethod method,
-            boolean caseInsensitve,
+            boolean caseInsensitive,
             QueryShardContext context
         ) {
-            // keyword field types are always normalized, so ignore case sensitivity and force normalize the wildcard
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[wildcard] queries cannot be executed when '" + ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to " + "false."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            // keyword field types are always normalized, so ignore case sensitivity and force normalize the
+            // wildcard
             // query text
-            return super.wildcardQuery(value, method, caseInsensitve, true, context);
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.wildcardQuery(value, method, caseInsensitive, true, context);
+                Query dvQuery = super.wildcardQuery(value, MultiTermQuery.DOC_VALUES_REWRITE, caseInsensitive, true, context);
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                Term term;
+                value = normalizeWildcardPattern(name(), value, getTextSearchInfo().getSearchAnalyzer());
+                term = new Term(name(), value);
+                if (caseInsensitive) {
+                    return AutomatonQueries.caseInsensitiveWildcardQuery(term, method);
+                }
+                return new WildcardQuery(term, Operations.DEFAULT_DETERMINIZE_WORK_LIMIT, MultiTermQuery.DOC_VALUES_REWRITE);
+            }
+            return super.wildcardQuery(value, method, caseInsensitive, true, context);
         }
+
     }
 
     private final boolean indexed;
@@ -422,8 +646,10 @@ protected KeywordFieldMapper(
         this.indexAnalyzers = builder.indexAnalyzers;
     }
 
-    /** Values that have more chars than the return value of this method will
-     *  be skipped at parsing time. */
+    /**
+     * Values that have more chars than the return value of this method will
+     * be skipped at parsing time.
+     */
     public int ignoreAbove() {
         return ignoreAbove;
     }
diff --git a/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java b/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java
index 58aa0bb2576e2..da62ddfd7017d 100644
--- a/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java
+++ b/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java
@@ -54,6 +54,7 @@
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.geo.ShapeRelation;
 import org.opensearch.common.time.DateMathParser;
 import org.opensearch.common.unit.Fuzziness;
@@ -79,8 +80,9 @@
 /**
  * This defines the core properties and functions to operate on a field.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class MappedFieldType {
 
     private final String name;
@@ -125,7 +127,7 @@ public IndexFieldData.Builder fielddataBuilder(String fullyQualifiedIndexName, S
 
     /**
      * Create a helper class to fetch field values during the {@link FetchFieldsPhase}.
-     *
+     * <p>
      * New field types must implement this method in order to support the search 'fields' option. Except
      * for metadata fields, field types should not throw {@link UnsupportedOperationException} since this
      * could cause a search retrieving multiple fields (like "fields": ["*"]) to fail.
@@ -269,6 +271,21 @@ public Query fuzzyQuery(
         );
     }
 
+    // Fuzzy Query with re-write method
+    public Query fuzzyQuery(
+        Object value,
+        Fuzziness fuzziness,
+        int prefixLength,
+        int maxExpansions,
+        boolean transpositions,
+        @Nullable MultiTermQuery.RewriteMethod method,
+        QueryShardContext context
+    ) {
+        throw new IllegalArgumentException(
+            "Can only use fuzzy queries on keyword and text fields - not on [" + name + "] which is of type [" + typeName() + "]"
+        );
+    }
+
     // Case sensitive form of prefix query
     public final Query prefixQuery(String value, @Nullable MultiTermQuery.RewriteMethod method, QueryShardContext context) {
         return prefixQuery(value, method, false, context);
@@ -385,8 +402,9 @@ public IntervalsSource intervals(String query, int max_gaps, IntervalMode mode,
      * An enum used to describe the relation between the range of terms in a
      * shard when compared with a query range
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Relation {
         WITHIN,
         INTERSECTS,
@@ -433,6 +451,15 @@ protected final void failIfNotIndexed() {
         }
     }
 
+    protected final void failIfNotIndexedAndNoDocValues() {
+        // we fail if a field is both not indexed and does not have doc_values enabled
+        if (isIndexed == false && hasDocValues() == false) {
+            throw new IllegalArgumentException(
+                "Cannot search on field [" + name() + "] since it is both not indexed," + " and does not have doc_values enabled."
+            );
+        }
+    }
+
     public boolean eagerGlobalOrdinals() {
         return eagerGlobalOrdinals;
     }
@@ -487,7 +514,7 @@ public Map<String, String> meta() {
 
     /**
      * Returns information on how any text in this field is indexed
-     *
+     * <p>
      * Fields that do not support any text-based queries should return
      * {@link TextSearchInfo#NONE}.  Some fields (eg numeric) may support
      * only simple match queries, and can return
diff --git a/server/src/main/java/org/opensearch/index/mapper/Mapper.java b/server/src/main/java/org/opensearch/index/mapper/Mapper.java
index 59c647d38f0de..bd5d3f15c0706 100644
--- a/server/src/main/java/org/opensearch/index/mapper/Mapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/Mapper.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -51,15 +52,17 @@
 /**
  * The foundation OpenSearch mapper
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class Mapper implements ToXContentFragment, Iterable<Mapper> {
 
     /**
      * The builder context used in field mappings
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class BuilderContext {
         private final Settings indexSettings;
         private final ContentPath contentPath;
@@ -94,8 +97,9 @@ public Version indexCreatedVersionOrDefault(@Nullable Version defaultValue) {
     /**
      * Base mapper builder
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract static class Builder<T extends Builder> {
 
         public String name;
@@ -117,15 +121,17 @@ public String name() {
     /**
      * Type parser for the mapper
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface TypeParser {
 
         /**
          * Parser context for the type parser
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         class ParserContext {
 
             private final Function<String, SimilarityProvider> similarityLookupService;
@@ -190,7 +196,7 @@ public Supplier<QueryShardContext> queryShardContextSupplier() {
 
             /**
              * Gets an optional default date format for date fields that do not have an explicit format set
-             *
+             * <p>
              * If {@code null}, then date fields will default to {@link DateFieldMapper#DEFAULT_DATE_TIME_FORMATTER}.
              */
             public DateFormatter getDateFormatter() {
diff --git a/server/src/main/java/org/opensearch/index/mapper/MapperParsingException.java b/server/src/main/java/org/opensearch/index/mapper/MapperParsingException.java
index 7dff82e2e3167..881e8c78b919d 100644
--- a/server/src/main/java/org/opensearch/index/mapper/MapperParsingException.java
+++ b/server/src/main/java/org/opensearch/index/mapper/MapperParsingException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.mapper;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.rest.RestStatus;
 
@@ -40,8 +41,9 @@
 /**
  * Exception thrown if there are any errors parsing mappings
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MapperParsingException extends MapperException {
 
     public MapperParsingException(StreamInput in) throws IOException {
diff --git a/server/src/main/java/org/opensearch/index/mapper/MapperService.java b/server/src/main/java/org/opensearch/index/mapper/MapperService.java
index 93928a464b138..8ebb007787828 100644
--- a/server/src/main/java/org/opensearch/index/mapper/MapperService.java
+++ b/server/src/main/java/org/opensearch/index/mapper/MapperService.java
@@ -38,6 +38,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.MappingMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.regex.Regex;
@@ -89,8 +90,9 @@
 /**
  * The core field mapping service
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MapperService extends AbstractIndexComponent implements Closeable {
 
     /**
@@ -98,6 +100,7 @@ public class MapperService extends AbstractIndexComponent implements Closeable {
      *
      * @opensearch.internal
      */
+    @PublicApi(since = "1.0.0")
     public enum MergeReason {
         /**
          * Pre-flight check before sending a mapping update to the cluster-manager
@@ -172,9 +175,6 @@ public enum MergeReason {
     );
 
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(MapperService.class);
-    static final String DEFAULT_MAPPING_ERROR_MESSAGE = "[_default_] mappings are not allowed on new indices and should no "
-        + "longer be used. See [https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking-changes-7.0.html"
-        + "#default-mapping-not-allowed] for more information.";
 
     private final IndexAnalyzers indexAnalyzers;
 
diff --git a/server/src/main/java/org/opensearch/index/mapper/Mapping.java b/server/src/main/java/org/opensearch/index/mapper/Mapping.java
index d68d1e62e2f92..20bd290ec8af4 100644
--- a/server/src/main/java/org/opensearch/index/mapper/Mapping.java
+++ b/server/src/main/java/org/opensearch/index/mapper/Mapping.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.mapper;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.xcontent.ToXContent;
@@ -54,8 +55,9 @@
  * Wrapper around everything that defines a mapping, without references to
  * utility classes like MapperService, ...
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class Mapping implements ToXContentFragment {
 
     final Version indexCreated;
diff --git a/server/src/main/java/org/opensearch/index/mapper/MappingLookup.java b/server/src/main/java/org/opensearch/index/mapper/MappingLookup.java
index 024f4b71584bf..fdebe24327ca0 100644
--- a/server/src/main/java/org/opensearch/index/mapper/MappingLookup.java
+++ b/server/src/main/java/org/opensearch/index/mapper/MappingLookup.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.analysis.Analyzer;
 import org.opensearch.cluster.metadata.DataStream;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.analysis.FieldNameAnalyzer;
 
@@ -49,8 +50,9 @@
 /**
  * Looks up a mapping for a field
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class MappingLookup implements Iterable<Mapper> {
 
     /** Full field name to mapper */
@@ -157,14 +159,14 @@ public MappingLookup(
     /**
      * Returns the leaf mapper associated with this field name. Note that the returned mapper
      * could be either a concrete {@link FieldMapper}, or a {@link FieldAliasMapper}.
-     *
+     * <p>
      * To access a field's type information, {@link MapperService#fieldType} should be used instead.
      */
     public Mapper getMapper(String field) {
         return fieldMappers.get(field);
     }
 
-    public FieldTypeLookup fieldTypes() {
+    FieldTypeLookup fieldTypes() {
         return fieldTypeLookup;
     }
 
diff --git a/server/src/main/java/org/opensearch/index/mapper/MetadataFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/MetadataFieldMapper.java
index 4f5aefdfeed55..c98d0c8242078 100644
--- a/server/src/main/java/org/opensearch/index/mapper/MetadataFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/MetadataFieldMapper.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.mapper;
 
 import org.opensearch.common.Explicit;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.support.XContentMapValues;
 import org.opensearch.core.xcontent.XContentBuilder;
 
@@ -43,15 +44,17 @@
 /**
  * A mapper for a builtin field containing metadata about a document.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class MetadataFieldMapper extends ParametrizedFieldMapper {
 
     /**
      * Type parser for the field mapper
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface TypeParser extends Mapper.TypeParser {
 
         @Override
@@ -70,7 +73,7 @@ public interface TypeParser extends Mapper.TypeParser {
 
     /**
      * Declares an updateable boolean parameter for a metadata field
-     *
+     * <p>
      * We need to distinguish between explicit configuration and default value for metadata
      * fields, because mapping updates will carry over the previous metadata values if a
      * metadata field is not explicitly declared in the update.  A standard boolean
@@ -152,8 +155,9 @@ public MetadataFieldMapper getDefault(MappedFieldType defaultFieldType, ParserCo
     /**
      * Base builder for internal metadata fields
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract static class Builder extends ParametrizedFieldMapper.Builder {
 
         protected Builder(String name) {
diff --git a/server/src/main/java/org/opensearch/index/mapper/ObjectMapper.java b/server/src/main/java/org/opensearch/index/mapper/ObjectMapper.java
index 1731d80585d43..39b0ec224b57c 100644
--- a/server/src/main/java/org/opensearch/index/mapper/ObjectMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/ObjectMapper.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Explicit;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.CopyOnWriteHashMap;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.Settings;
@@ -60,8 +61,9 @@
 /**
  * Field mapper for object field types
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ObjectMapper extends Mapper implements Cloneable {
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(ObjectMapper.class);
 
@@ -82,8 +84,9 @@ public static class Defaults {
     /**
      * Dynamic field mapping specification
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Dynamic {
         TRUE,
         FALSE,
@@ -93,8 +96,9 @@ public enum Dynamic {
     /**
      * Nested objects
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Nested {
 
         public static final Nested NO = new Nested(false, new Explicit<>(false, false), new Explicit<>(false, false));
diff --git a/server/src/main/java/org/opensearch/index/mapper/ParametrizedFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/ParametrizedFieldMapper.java
index fd57975831e88..f4723b6178137 100644
--- a/server/src/main/java/org/opensearch/index/mapper/ParametrizedFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/ParametrizedFieldMapper.java
@@ -36,6 +36,7 @@
 import org.opensearch.Version;
 import org.opensearch.common.Explicit;
 import org.opensearch.common.TriFunction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.support.XContentMapValues;
@@ -63,16 +64,17 @@
 
 /**
  * Defines how a particular field should be indexed and searched
- *
+ * <p>
  * Configuration {@link Parameter}s for the mapper are defined on a {@link Builder} subclass,
  * and returned by its {@link Builder#getParameters()} method.  Merging, serialization
  * and parsing of the mapper are all mediated through this set of parameters.
- *
+ * <p>
  * Subclasses should implement a {@link Builder} that is returned from the
  * {@link #getMergeBuilder()} method, initialised with the existing builder.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class ParametrizedFieldMapper extends FieldMapper {
 
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(ParametrizedFieldMapper.class);
@@ -86,7 +88,7 @@ protected ParametrizedFieldMapper(String simpleName, MappedFieldType mappedField
 
     /**
      * Returns a {@link Builder} to be used for merging and serialization
-     *
+     * <p>
      * Implement as follows:
      * {@code return new MyBuilder(simpleName()).init(this); }
      */
@@ -151,14 +153,20 @@ protected void doXContentBody(XContentBuilder builder, boolean includeDefaults,
 
     /**
      * Serializes a parameter
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     protected interface Serializer<T> {
         void serialize(XContentBuilder builder, String name, T value) throws IOException;
     }
 
     /**
      * Check on whether or not a parameter should be serialized
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     protected interface SerializerCheck<T> {
         /**
          * Check on whether or not a parameter should be serialized
@@ -174,8 +182,9 @@ protected interface SerializerCheck<T> {
      * A configurable parameter for a field mapper
      * @param <T> the type of the value the parameter holds
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class Parameter<T> implements Supplier<T> {
 
         public final String name;
@@ -256,7 +265,7 @@ public Parameter<T> acceptsNull() {
 
         /**
          * Adds a deprecated parameter name.
-         *
+         * <p>
          * If this parameter name is encountered during parsing, a deprecation warning will
          * be emitted.  The parameter will be serialized with its main name.
          */
@@ -577,8 +586,9 @@ void check() {
     /**
      * A Builder for a ParametrizedFieldMapper
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract static class Builder extends Mapper.Builder<Builder> {
 
         protected final MultiFields.Builder multiFieldsBuilder = new MultiFields.Builder();
diff --git a/server/src/main/java/org/opensearch/index/mapper/ParseContext.java b/server/src/main/java/org/opensearch/index/mapper/ParseContext.java
index 0a0c62a9b47be..5d382ff28bcf9 100644
--- a/server/src/main/java/org/opensearch/index/mapper/ParseContext.java
+++ b/server/src/main/java/org/opensearch/index/mapper/ParseContext.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.index.IndexSettings;
 
@@ -53,15 +54,17 @@
 /**
  * Holds the context at parse time
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class ParseContext implements Iterable<ParseContext.Document> {
 
     /**
      * Fork of {@link org.apache.lucene.document.Document} with additional functionality.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Document implements Iterable<IndexableField> {
 
         private final Document parent;
diff --git a/server/src/main/java/org/opensearch/index/mapper/ParsedDocument.java b/server/src/main/java/org/opensearch/index/mapper/ParsedDocument.java
index 378781151d610..16e38980f8600 100644
--- a/server/src/main/java/org/opensearch/index/mapper/ParsedDocument.java
+++ b/server/src/main/java/org/opensearch/index/mapper/ParsedDocument.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.mapper;
 
 import org.apache.lucene.document.Field;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaType;
@@ -44,8 +45,9 @@
 /**
  * The result of parsing a document.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ParsedDocument {
 
     private final Field version;
diff --git a/server/src/main/java/org/opensearch/index/mapper/RangeFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/RangeFieldMapper.java
index 10f179c964591..05ca7dee0fe4b 100644
--- a/server/src/main/java/org/opensearch/index/mapper/RangeFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/RangeFieldMapper.java
@@ -95,7 +95,7 @@ public class RangeFieldMapper extends ParametrizedFieldMapper {
      */
     public static class Defaults {
         public static final Explicit<Boolean> COERCE = new Explicit<>(true, false);
-        public static final DateFormatter DATE_FORMATTER = DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER;
+        public static final DateFormatter DATE_FORMATTER = DateFieldMapper.getDefaultDateTimeFormatter();
     }
 
     // this is private since it has a different default
diff --git a/server/src/main/java/org/opensearch/index/mapper/RangeType.java b/server/src/main/java/org/opensearch/index/mapper/RangeType.java
index c8cd317779c7c..7e29fd417845b 100644
--- a/server/src/main/java/org/opensearch/index/mapper/RangeType.java
+++ b/server/src/main/java/org/opensearch/index/mapper/RangeType.java
@@ -313,7 +313,7 @@ public Query rangeQuery(
         ) {
             ZoneId zone = (timeZone == null) ? ZoneOffset.UTC : timeZone;
 
-            DateMathParser dateMathParser = (parser == null) ? DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.toDateMathParser() : parser;
+            DateMathParser dateMathParser = (parser == null) ? DateFieldMapper.getDefaultDateTimeFormatter().toDateMathParser() : parser;
             boolean roundUp = includeLower == false; // using "gt" should round lower bound up
             Long low = lowerTerm == null
                 ? minValue()
diff --git a/server/src/main/java/org/opensearch/index/mapper/RootObjectMapper.java b/server/src/main/java/org/opensearch/index/mapper/RootObjectMapper.java
index ce3d6eef19af2..9504e6eafc046 100644
--- a/server/src/main/java/org/opensearch/index/mapper/RootObjectMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/RootObjectMapper.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.common.Explicit;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.time.DateFormatter;
@@ -60,8 +61,9 @@
 /**
  * The root object mapper for a document
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RootObjectMapper extends ObjectMapper {
     private static final DeprecationLogger DEPRECATION_LOGGER = DeprecationLogger.getLogger(RootObjectMapper.class);
 
@@ -72,7 +74,7 @@ public class RootObjectMapper extends ObjectMapper {
      */
     public static class Defaults {
         public static final DateFormatter[] DYNAMIC_DATE_TIME_FORMATTERS = new DateFormatter[] {
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             DateFormatter.forPattern("yyyy/MM/dd HH:mm:ss||yyyy/MM/dd||epoch_millis") };
         public static final boolean DATE_DETECTION = true;
         public static final boolean NUMERIC_DETECTION = false;
diff --git a/server/src/main/java/org/opensearch/index/mapper/RoutingFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/RoutingFieldMapper.java
index 222ba70a5ce0c..60decc56e0db2 100644
--- a/server/src/main/java/org/opensearch/index/mapper/RoutingFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/RoutingFieldMapper.java
@@ -35,6 +35,7 @@
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.index.IndexOptions;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.index.query.QueryShardContext;
 import org.opensearch.search.lookup.SearchLookup;
@@ -45,8 +46,9 @@
 /**
  * Internal field mapper for _routing fields
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RoutingFieldMapper extends MetadataFieldMapper {
 
     public static final String NAME = "_routing";
diff --git a/server/src/main/java/org/opensearch/index/mapper/SeqNoFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/SeqNoFieldMapper.java
index 16f76f087e403..c7e9bed7577c5 100644
--- a/server/src/main/java/org/opensearch/index/mapper/SeqNoFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/SeqNoFieldMapper.java
@@ -39,6 +39,7 @@
 import org.apache.lucene.search.Query;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.fielddata.IndexNumericFieldData.NumericType;
 import org.opensearch.index.fielddata.plain.SortedNumericIndexFieldData;
@@ -55,11 +56,11 @@
 
 /**
  * Mapper for the {@code _seq_no} field.
- *
+ * <p>
  * We expect to use the seq# for sorting, during collision checking and for
  * doing range searches. Therefore the {@code _seq_no} field is stored both
  * as a numeric doc value and as numeric indexed field.
- *
+ * <p>
  * This mapper also manages the primary term field, which has no OpenSearch named
  * equivalent. The primary term is only used during collision after receiving
  * identical seq# values for two document copies. The primary term is stored as
@@ -74,8 +75,9 @@ public class SeqNoFieldMapper extends MetadataFieldMapper {
      * A sequence ID, which is made up of a sequence number (both the searchable
      * and doc_value version of the field) and the primary term.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class SequenceIDFields {
 
         public final Field seqNo;
diff --git a/server/src/main/java/org/opensearch/index/mapper/SourceFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/SourceFieldMapper.java
index c13a0b5cec62c..a2d769d486a0f 100644
--- a/server/src/main/java/org/opensearch/index/mapper/SourceFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/SourceFieldMapper.java
@@ -39,6 +39,7 @@
 import org.apache.lucene.search.Query;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentHelper;
@@ -63,8 +64,9 @@
 /**
  * Internal field mapper for storing source (and recovery source)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SourceFieldMapper extends MetadataFieldMapper {
 
     public static final String NAME = "_source";
diff --git a/server/src/main/java/org/opensearch/index/mapper/SourceToParse.java b/server/src/main/java/org/opensearch/index/mapper/SourceToParse.java
index adacd6c450f7a..c8bb4dbefbbb1 100644
--- a/server/src/main/java/org/opensearch/index/mapper/SourceToParse.java
+++ b/server/src/main/java/org/opensearch/index/mapper/SourceToParse.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.mapper;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.MediaType;
@@ -42,8 +43,9 @@
 /**
  * Stores the document source
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SourceToParse {
 
     private final BytesReference source;
diff --git a/server/src/main/java/org/opensearch/index/mapper/SourceValueFetcher.java b/server/src/main/java/org/opensearch/index/mapper/SourceValueFetcher.java
index 69f53ba126790..a32d1c9f489ca 100644
--- a/server/src/main/java/org/opensearch/index/mapper/SourceValueFetcher.java
+++ b/server/src/main/java/org/opensearch/index/mapper/SourceValueFetcher.java
@@ -46,7 +46,7 @@
  * An implementation of {@link ValueFetcher} that knows how to extract values
  * from the document source. Most standard field mappers will use this class
  * to implement value fetching.
- *
+ * <p>
  * Field types that handle arrays directly should instead use {@link ArraySourceValueFetcher}.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/index/mapper/TextSearchInfo.java b/server/src/main/java/org/opensearch/index/mapper/TextSearchInfo.java
index 535fba6c39371..a3f5eed479b8f 100644
--- a/server/src/main/java/org/opensearch/index/mapper/TextSearchInfo.java
+++ b/server/src/main/java/org/opensearch/index/mapper/TextSearchInfo.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.index.IndexOptions;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.index.analysis.NamedAnalyzer;
 import org.opensearch.index.similarity.SimilarityProvider;
@@ -41,8 +42,9 @@
 /**
  * Encapsulates information about how to perform text searches over a field
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TextSearchInfo {
 
     private static final FieldType SIMPLE_MATCH_ONLY_FIELD_TYPE = new FieldType();
@@ -145,8 +147,9 @@ public boolean isTokenized() {
     /**
      * What sort of term vectors are available
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum TermVector {
         NONE,
         DOCS,
diff --git a/server/src/main/java/org/opensearch/index/mapper/ValueFetcher.java b/server/src/main/java/org/opensearch/index/mapper/ValueFetcher.java
index d1cea3fe7f1b0..c6bdad8b8653c 100644
--- a/server/src/main/java/org/opensearch/index/mapper/ValueFetcher.java
+++ b/server/src/main/java/org/opensearch/index/mapper/ValueFetcher.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.mapper;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.fetch.subphase.FetchFieldsPhase;
 import org.opensearch.search.lookup.SourceLookup;
 
@@ -43,16 +44,17 @@
  * A helper class for fetching field values during the {@link FetchFieldsPhase}. Each {@link MappedFieldType}
  * is in charge of defining a value fetcher through {@link MappedFieldType#valueFetcher}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ValueFetcher {
     /**
      * Given access to a document's _source, return this field's values.
-     *
+     * <p>
      * In addition to pulling out the values, they will be parsed into a standard form.
      * For example numeric field mappers make sure to parse the source value into a number
      * of the right type.
-     *
+     * <p>
      * Note that for array values, the order in which values are returned is undefined and
      * should not be relied on.
      *
diff --git a/server/src/main/java/org/opensearch/index/merge/MergeStats.java b/server/src/main/java/org/opensearch/index/merge/MergeStats.java
index 37fdca8871b18..7ecaed60735b4 100644
--- a/server/src/main/java/org/opensearch/index/merge/MergeStats.java
+++ b/server/src/main/java/org/opensearch/index/merge/MergeStats.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.index.merge;
 
+import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +47,9 @@
 /**
  * Stores stats about a merge process
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class MergeStats implements Writeable, ToXContentFragment {
 
     private long total;
@@ -65,9 +68,9 @@ public class MergeStats implements Writeable, ToXContentFragment {
 
     private long totalBytesPerSecAutoThrottle;
 
-    public MergeStats() {
+    private long unreferencedFileCleanUpsPerformed;
 
-    }
+    public MergeStats() {}
 
     public MergeStats(StreamInput in) throws IOException {
         total = in.readVLong();
@@ -81,6 +84,9 @@ public MergeStats(StreamInput in) throws IOException {
         totalStoppedTimeInMillis = in.readVLong();
         totalThrottledTimeInMillis = in.readVLong();
         totalBytesPerSecAutoThrottle = in.readVLong();
+        if (in.getVersion().onOrAfter(Version.V_2_11_0)) {
+            unreferencedFileCleanUpsPerformed = in.readOptionalVLong();
+        }
     }
 
     public void add(
@@ -133,6 +139,7 @@ public void addTotals(MergeStats mergeStats) {
         this.totalSizeInBytes += mergeStats.totalSizeInBytes;
         this.totalStoppedTimeInMillis += mergeStats.totalStoppedTimeInMillis;
         this.totalThrottledTimeInMillis += mergeStats.totalThrottledTimeInMillis;
+        addUnreferencedFileCleanUpStats(mergeStats.unreferencedFileCleanUpsPerformed);
         if (this.totalBytesPerSecAutoThrottle == Long.MAX_VALUE || mergeStats.totalBytesPerSecAutoThrottle == Long.MAX_VALUE) {
             this.totalBytesPerSecAutoThrottle = Long.MAX_VALUE;
         } else {
@@ -140,6 +147,14 @@ public void addTotals(MergeStats mergeStats) {
         }
     }
 
+    public void addUnreferencedFileCleanUpStats(long unreferencedFileCleanUpsPerformed) {
+        this.unreferencedFileCleanUpsPerformed += unreferencedFileCleanUpsPerformed;
+    }
+
+    public long getUnreferencedFileCleanUpsPerformed() {
+        return this.unreferencedFileCleanUpsPerformed;
+    }
+
     /**
      * The total number of merges executed.
      */
@@ -240,6 +255,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.field(Fields.TOTAL_THROTTLE_BYTES_PER_SEC).value(new ByteSizeValue(totalBytesPerSecAutoThrottle).toString());
         }
         builder.field(Fields.TOTAL_THROTTLE_BYTES_PER_SEC_IN_BYTES, totalBytesPerSecAutoThrottle);
+        builder.field(Fields.UNREFERENCED_FILE_CLEANUPS_PERFORMED, unreferencedFileCleanUpsPerformed);
         builder.endObject();
         return builder;
     }
@@ -267,6 +283,7 @@ static final class Fields {
         static final String TOTAL_SIZE_IN_BYTES = "total_size_in_bytes";
         static final String TOTAL_THROTTLE_BYTES_PER_SEC_IN_BYTES = "total_auto_throttle_in_bytes";
         static final String TOTAL_THROTTLE_BYTES_PER_SEC = "total_auto_throttle";
+        static final String UNREFERENCED_FILE_CLEANUPS_PERFORMED = "unreferenced_file_cleanups_performed";
     }
 
     @Override
@@ -282,5 +299,8 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(totalStoppedTimeInMillis);
         out.writeVLong(totalThrottledTimeInMillis);
         out.writeVLong(totalBytesPerSecAutoThrottle);
+        if (out.getVersion().onOrAfter(Version.V_2_11_0)) {
+            out.writeOptionalVLong(unreferencedFileCleanUpsPerformed);
+        }
     }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/AbstractQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/AbstractQueryBuilder.java
index 6b8dd08ed0d91..66c6ee115c3f0 100644
--- a/server/src/main/java/org/opensearch/index/query/AbstractQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/AbstractQueryBuilder.java
@@ -298,7 +298,7 @@ protected QueryBuilder doRewrite(QueryRewriteContext queryShardContext) throws I
 
     /**
      * For internal usage only!
-     *
+     * <p>
      * Extracts the inner hits from the query tree.
      * While it extracts inner hits, child inner hits are inlined into the inner hit builder they belong to.
      */
diff --git a/server/src/main/java/org/opensearch/index/query/BoolQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/BoolQueryBuilder.java
index 65c2dfa9c5a8b..c44a7ef6a397c 100644
--- a/server/src/main/java/org/opensearch/index/query/BoolQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/BoolQueryBuilder.java
@@ -427,4 +427,35 @@ private static boolean rewriteClauses(
         }
         return changed;
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (mustClauses.isEmpty() == false) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(Occur.MUST);
+            for (QueryBuilder mustClause : mustClauses) {
+                mustClause.visit(subVisitor);
+            }
+        }
+        if (shouldClauses.isEmpty() == false) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(Occur.SHOULD);
+            for (QueryBuilder shouldClause : shouldClauses) {
+                shouldClause.visit(subVisitor);
+            }
+        }
+        if (mustNotClauses.isEmpty() == false) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(Occur.MUST_NOT);
+            for (QueryBuilder mustNotClause : mustNotClauses) {
+                mustNotClause.visit(subVisitor);
+            }
+        }
+        if (filterClauses.isEmpty() == false) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(Occur.FILTER);
+            for (QueryBuilder filterClause : filterClauses) {
+                filterClause.visit(subVisitor);
+            }
+        }
+
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/index/query/BoostingQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/BoostingQueryBuilder.java
index 26124b422f26f..1b52ae2f03605 100644
--- a/server/src/main/java/org/opensearch/index/query/BoostingQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/BoostingQueryBuilder.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.query;
 
 import org.apache.lucene.queries.function.FunctionScoreQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -252,4 +253,15 @@ protected void extractInnerHitBuilders(Map<String, InnerHitContextBuilder> inner
         InnerHitContextBuilder.extractInnerHits(positiveQuery, innerHits);
         InnerHitContextBuilder.extractInnerHits(negativeQuery, innerHits);
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (positiveQuery != null) {
+            visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(positiveQuery);
+        }
+        if (negativeQuery != null) {
+            visitor.getChildVisitor(BooleanClause.Occur.SHOULD).accept(negativeQuery);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/ConstantScoreQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/ConstantScoreQueryBuilder.java
index 6a29ad8a0a401..b2764d29da80a 100644
--- a/server/src/main/java/org/opensearch/index/query/ConstantScoreQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/ConstantScoreQueryBuilder.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.query;
 
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.ConstantScoreQuery;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
@@ -183,4 +184,11 @@ protected QueryBuilder doRewrite(QueryRewriteContext queryRewriteContext) throws
     protected void extractInnerHitBuilders(Map<String, InnerHitContextBuilder> innerHits) {
         InnerHitContextBuilder.extractInnerHits(filterBuilder, innerHits);
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        visitor.getChildVisitor(BooleanClause.Occur.FILTER).accept(filterBuilder);
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/index/query/DisMaxQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/DisMaxQueryBuilder.java
index 91f4a02fac6c0..bd8ec62f6c43e 100644
--- a/server/src/main/java/org/opensearch/index/query/DisMaxQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/DisMaxQueryBuilder.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.query;
 
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.DisjunctionMaxQuery;
 import org.apache.lucene.search.Query;
 import org.opensearch.common.lucene.search.Queries;
@@ -246,4 +247,15 @@ protected void extractInnerHitBuilders(Map<String, InnerHitContextBuilder> inner
             InnerHitContextBuilder.extractInnerHits(query, innerHits);
         }
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (queries.isEmpty() == false) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(BooleanClause.Occur.SHOULD);
+            for (QueryBuilder subQb : queries) {
+                subVisitor.accept(subQb);
+            }
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilder.java
index 09a71795a3f27..1162689a54689 100644
--- a/server/src/main/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.queries.spans.FieldMaskingSpanQuery;
 import org.apache.lucene.queries.spans.SpanQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -207,4 +208,10 @@ protected boolean doEquals(FieldMaskingSpanQueryBuilder other) {
     public String getWriteableName() {
         return SPAN_FIELD_MASKING_FIELD.getPreferredName();
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(queryBuilder);
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/GeoBoundingBoxQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/GeoBoundingBoxQueryBuilder.java
index a4b75beab26ea..1fade8601e2a6 100644
--- a/server/src/main/java/org/opensearch/index/query/GeoBoundingBoxQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/GeoBoundingBoxQueryBuilder.java
@@ -60,7 +60,7 @@
 /**
  * Creates a Lucene query that will filter for all documents that lie within the specified
  * bounding box.
- *
+ * <p>
  * This query can only operate on fields of type geo_point that have latitude and longitude
  * enabled.
  *
diff --git a/server/src/main/java/org/opensearch/index/query/GeoShapeQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/GeoShapeQueryBuilder.java
index e029884f32531..33b896a1d5163 100644
--- a/server/src/main/java/org/opensearch/index/query/GeoShapeQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/GeoShapeQueryBuilder.java
@@ -55,7 +55,7 @@
 /**
  * Derived {@link AbstractGeometryQueryBuilder} that builds a lat, lon GeoShape Query. It
  * can be applied to any {@link MappedFieldType} that implements {@link GeoShapeQueryable}.
- *
+ * <p>
  * GeoJson and WKT shape definitions are supported
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/index/query/GeoValidationMethod.java b/server/src/main/java/org/opensearch/index/query/GeoValidationMethod.java
index 559c084325abb..bb3cd34ae629d 100644
--- a/server/src/main/java/org/opensearch/index/query/GeoValidationMethod.java
+++ b/server/src/main/java/org/opensearch/index/query/GeoValidationMethod.java
@@ -42,7 +42,7 @@
 /**
  * This enum is used to determine how to deal with invalid geo coordinates in geo related
  * queries:
- *
+ * <p>
  *  On STRICT validation invalid coordinates cause an exception to be thrown.
  *  On IGNORE_MALFORMED invalid coordinates are being accepted.
  *  On COERCE invalid coordinates are being corrected to the most likely valid coordinate.
diff --git a/server/src/main/java/org/opensearch/index/query/InnerHitBuilder.java b/server/src/main/java/org/opensearch/index/query/InnerHitBuilder.java
index 4cd042cac6fbf..1a2a554526e15 100644
--- a/server/src/main/java/org/opensearch/index/query/InnerHitBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/InnerHitBuilder.java
@@ -32,6 +32,7 @@
 package org.opensearch.index.query;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.Strings;
@@ -66,7 +67,10 @@
 
 /**
  * Query builder for inner hits
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class InnerHitBuilder implements Writeable, ToXContentObject {
 
     public static final ParseField NAME_FIELD = new ParseField("name");
diff --git a/server/src/main/java/org/opensearch/index/query/IntervalMode.java b/server/src/main/java/org/opensearch/index/query/IntervalMode.java
index 454d867b41da2..a2979135ac03f 100644
--- a/server/src/main/java/org/opensearch/index/query/IntervalMode.java
+++ b/server/src/main/java/org/opensearch/index/query/IntervalMode.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.query;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -18,8 +19,9 @@
 /**
  * Mode for Text and Mapped Field Types
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum IntervalMode implements Writeable {
     ORDERED(0),
     UNORDERED(1),
diff --git a/server/src/main/java/org/opensearch/index/query/IntervalsSourceProvider.java b/server/src/main/java/org/opensearch/index/query/IntervalsSourceProvider.java
index b5cc3238295e0..5a57dfed14f69 100644
--- a/server/src/main/java/org/opensearch/index/query/IntervalsSourceProvider.java
+++ b/server/src/main/java/org/opensearch/index/query/IntervalsSourceProvider.java
@@ -691,7 +691,7 @@ public static class Regexp extends IntervalsSourceProvider {
 
         /**
          * Constructor
-         *
+         * <p>
          * {@code flags} is Lucene's <a href="https://github.com/apache/lucene/blob/main/lucene/core/src/java/org/apache/lucene/util/automaton/RegExp.java#L391-L411">syntax flags</a>
          * and {@code caseInsensitive} enables Lucene's only <a href="https://github.com/apache/lucene/blob/main/lucene/core/src/java/org/apache/lucene/util/automaton/RegExp.java#L416">matching flag</a>.
          */
diff --git a/server/src/main/java/org/opensearch/index/query/MatchBoolPrefixQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/MatchBoolPrefixQueryBuilder.java
index 9a8d2ab104799..7ceb17203e837 100644
--- a/server/src/main/java/org/opensearch/index/query/MatchBoolPrefixQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/MatchBoolPrefixQueryBuilder.java
@@ -176,7 +176,7 @@ public String minimumShouldMatch() {
     }
 
     @Deprecated
-    /** Sets the fuzziness used when evaluated to a fuzzy query type. Defaults to "AUTO". */
+    /* Sets the fuzziness used when evaluated to a fuzzy query type. Defaults to "AUTO". */
     public MatchBoolPrefixQueryBuilder fuzziness(Object fuzziness) {
         this.fuzziness = Fuzziness.build(fuzziness);
         return this;
diff --git a/server/src/main/java/org/opensearch/index/query/MatchQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/MatchQueryBuilder.java
index 844d47070923b..5e9e6a3660e76 100644
--- a/server/src/main/java/org/opensearch/index/query/MatchQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/MatchQueryBuilder.java
@@ -209,7 +209,7 @@ public String analyzer() {
     }
 
     @Deprecated
-    /** Sets the fuzziness used when evaluated to a fuzzy query type. Defaults to "AUTO". */
+    /* Sets the fuzziness used when evaluated to a fuzzy query type. Defaults to "AUTO". */
     public MatchQueryBuilder fuzziness(Object fuzziness) {
         this.fuzziness = Fuzziness.build(fuzziness);
         return this;
diff --git a/server/src/main/java/org/opensearch/index/query/MoreLikeThisQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/MoreLikeThisQueryBuilder.java
index 84b30209f31bd..e6472afef2215 100644
--- a/server/src/main/java/org/opensearch/index/query/MoreLikeThisQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/MoreLikeThisQueryBuilder.java
@@ -87,7 +87,7 @@
 
 /**
  * A more like this query that finds documents that are "like" the provided set of document(s).
- *
+ * <p>
  * The documents are provided as a set of strings and/or a list of {@link Item}.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/index/query/MultiMatchQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/MultiMatchQueryBuilder.java
index 1aa013cb24d5e..6227e5d2fa806 100644
--- a/server/src/main/java/org/opensearch/index/query/MultiMatchQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/MultiMatchQueryBuilder.java
@@ -398,8 +398,8 @@ public int slop() {
     }
 
     @Deprecated
-    /**
-     * Sets the fuzziness used when evaluated to a fuzzy query type. Defaults to "AUTO".
+    /*
+      Sets the fuzziness used when evaluated to a fuzzy query type. Defaults to "AUTO".
      */
     public MultiMatchQueryBuilder fuzziness(Object fuzziness) {
         if (fuzziness != null) {
diff --git a/server/src/main/java/org/opensearch/index/query/NestedQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/NestedQueryBuilder.java
index 33fe96597b4f8..ac4fde7f06b16 100644
--- a/server/src/main/java/org/opensearch/index/query/NestedQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/NestedQueryBuilder.java
@@ -318,10 +318,13 @@ protected Query doToQuery(QueryShardContext context) throws IOException {
             parentFilter = context.bitsetFilter(objectMapper.nestedTypeFilter());
         }
 
+        BitSetProducer previousParentFilter = context.getParentFilter();
         try {
+            context.setParentFilter(parentFilter);
             context.nestedScope().nextLevel(nestedObjectMapper);
             innerQuery = this.query.toQuery(context);
         } finally {
+            context.setParentFilter(previousParentFilter);
             context.nestedScope().previousLevel();
         }
 
diff --git a/server/src/main/java/org/opensearch/index/query/ParsedQuery.java b/server/src/main/java/org/opensearch/index/query/ParsedQuery.java
index 5d9f67ac365b9..1a4d45178e826 100644
--- a/server/src/main/java/org/opensearch/index/query/ParsedQuery.java
+++ b/server/src/main/java/org/opensearch/index/query/ParsedQuery.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.query;
 
 import org.apache.lucene.search.Query;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.search.Queries;
 
 import java.util.Map;
@@ -42,8 +43,9 @@
 /**
  * The result of parsing a query.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ParsedQuery {
     private final Query query;
     private final Map<String, Query> namedFilters;
diff --git a/server/src/main/java/org/opensearch/index/query/QueryBuilder.java b/server/src/main/java/org/opensearch/index/query/QueryBuilder.java
index a40ccf427794a..0cdf7f31c2ebf 100644
--- a/server/src/main/java/org/opensearch/index/query/QueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/QueryBuilder.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.query;
 
 import org.apache.lucene.search.Query;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.NamedWriteable;
 import org.opensearch.core.xcontent.ToXContentObject;
 
@@ -41,8 +42,9 @@
 /**
  * Foundation class for all OpenSearch query builders
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface QueryBuilder extends NamedWriteable, ToXContentObject, Rewriteable<QueryBuilder> {
 
     /**
@@ -95,4 +97,13 @@ public interface QueryBuilder extends NamedWriteable, ToXContentObject, Rewritea
     default QueryBuilder rewrite(QueryRewriteContext queryShardContext) throws IOException {
         return this;
     }
+
+    /**
+     * Recurse through the QueryBuilder tree, visiting any child QueryBuilder.
+     * @param visitor a query builder visitor to be called by each query builder in the tree.
+     */
+    default void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+    };
+
 }
diff --git a/server/src/main/java/org/opensearch/index/query/QueryBuilderVisitor.java b/server/src/main/java/org/opensearch/index/query/QueryBuilderVisitor.java
new file mode 100644
index 0000000000000..b40dcca17e45b
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/query/QueryBuilderVisitor.java
@@ -0,0 +1,52 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.query;
+
+import org.apache.lucene.search.BooleanClause;
+import org.opensearch.common.annotation.PublicApi;
+
+/**
+ * QueryBuilderVisitor is an interface to define Visitor Object to be traversed in QueryBuilder tree.
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "2.11.0")
+public interface QueryBuilderVisitor {
+
+    /**
+     * Accept method is called when the visitor accepts the queryBuilder object to be traversed in the query tree.
+     * @param qb is a queryBuilder object which is accepeted by the visitor.
+     */
+    void accept(QueryBuilder qb);
+
+    /**
+     * Fetches the child sub visitor from the main QueryBuilderVisitor Object.
+     * @param occur defines the occurrence of the result fetched from the search query in the final search result.
+     * @return a child queryBuilder Visitor Object.
+     */
+    QueryBuilderVisitor getChildVisitor(BooleanClause.Occur occur);
+
+    /**
+     *  NoopQueryVisitor is a default implementation of QueryBuilderVisitor.
+     *  When a user does not want to implement QueryBuilderVisitor and have to just pass an empty object then this class will be used.
+     *
+     */
+    QueryBuilderVisitor NO_OP_VISITOR = new QueryBuilderVisitor() {
+        @Override
+        public void accept(QueryBuilder qb) {
+            // Do nothing
+        }
+
+        @Override
+        public QueryBuilderVisitor getChildVisitor(BooleanClause.Occur occur) {
+            return this;
+        }
+    };
+
+}
diff --git a/server/src/main/java/org/opensearch/index/query/QueryRewriteContext.java b/server/src/main/java/org/opensearch/index/query/QueryRewriteContext.java
index 1f7805ec99cd4..15a6d0b5a774e 100644
--- a/server/src/main/java/org/opensearch/index/query/QueryRewriteContext.java
+++ b/server/src/main/java/org/opensearch/index/query/QueryRewriteContext.java
@@ -32,6 +32,7 @@
 package org.opensearch.index.query;
 
 import org.opensearch.client.Client;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.concurrent.CountDown;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
@@ -46,8 +47,9 @@
 /**
  * Context object used to rewrite {@link QueryBuilder} instances into simplified version.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class QueryRewriteContext {
     private final NamedXContentRegistry xContentRegistry;
     private final NamedWriteableRegistry writeableRegistry;
diff --git a/server/src/main/java/org/opensearch/index/query/QueryShapeVisitor.java b/server/src/main/java/org/opensearch/index/query/QueryShapeVisitor.java
new file mode 100644
index 0000000000000..3ba13bc7a2da4
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/query/QueryShapeVisitor.java
@@ -0,0 +1,86 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.query;
+
+import org.apache.lucene.search.BooleanClause;
+import org.opensearch.common.SetOnce;
+
+import java.util.ArrayList;
+import java.util.EnumMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * Class to traverse the QueryBuilder tree and capture the query shape
+ */
+public final class QueryShapeVisitor implements QueryBuilderVisitor {
+    private final SetOnce<String> queryType = new SetOnce<>();
+    private final Map<BooleanClause.Occur, List<QueryShapeVisitor>> childVisitors = new EnumMap<>(BooleanClause.Occur.class);
+
+    @Override
+    public void accept(QueryBuilder qb) {
+        queryType.set(qb.getName());
+    }
+
+    @Override
+    public QueryBuilderVisitor getChildVisitor(BooleanClause.Occur occur) {
+        // Should get called once per Occur value
+        if (childVisitors.containsKey(occur)) {
+            throw new IllegalStateException("child visitor already called for " + occur);
+        }
+        final List<QueryShapeVisitor> childVisitorList = new ArrayList<>();
+        QueryBuilderVisitor childVisitorWrapper = new QueryBuilderVisitor() {
+            QueryShapeVisitor currentChild;
+
+            @Override
+            public void accept(QueryBuilder qb) {
+                currentChild = new QueryShapeVisitor();
+                childVisitorList.add(currentChild);
+                currentChild.accept(qb);
+            }
+
+            @Override
+            public QueryBuilderVisitor getChildVisitor(BooleanClause.Occur occur) {
+                return currentChild.getChildVisitor(occur);
+            }
+        };
+        childVisitors.put(occur, childVisitorList);
+        return childVisitorWrapper;
+    }
+
+    String toJson() {
+        StringBuilder outputBuilder = new StringBuilder("{\"type\":\"").append(queryType.get()).append("\"");
+        for (Map.Entry<BooleanClause.Occur, List<QueryShapeVisitor>> entry : childVisitors.entrySet()) {
+            outputBuilder.append(",\"").append(entry.getKey().name().toLowerCase(Locale.ROOT)).append("\"[");
+            boolean first = true;
+            for (QueryShapeVisitor child : entry.getValue()) {
+                if (!first) {
+                    outputBuilder.append(",");
+                }
+                outputBuilder.append(child.toJson());
+                first = false;
+            }
+            outputBuilder.append("]");
+        }
+        outputBuilder.append("}");
+        return outputBuilder.toString();
+    }
+
+    public String prettyPrintTree(String indent) {
+        StringBuilder outputBuilder = new StringBuilder(indent).append(queryType.get()).append("\n");
+        for (Map.Entry<BooleanClause.Occur, List<QueryShapeVisitor>> entry : childVisitors.entrySet()) {
+            outputBuilder.append(indent).append("  ").append(entry.getKey().name().toLowerCase(Locale.ROOT)).append(":\n");
+            for (QueryShapeVisitor child : entry.getValue()) {
+                outputBuilder.append(child.prettyPrintTree(indent + "    "));
+            }
+        }
+        return outputBuilder.toString();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/index/query/QueryShardContext.java b/server/src/main/java/org/opensearch/index/query/QueryShardContext.java
index 0bf05e633bba3..eba3ed076e82b 100644
--- a/server/src/main/java/org/opensearch/index/query/QueryShardContext.java
+++ b/server/src/main/java/org/opensearch/index/query/QueryShardContext.java
@@ -43,6 +43,7 @@
 import org.opensearch.common.CheckedFunction;
 import org.opensearch.common.SetOnce;
 import org.opensearch.common.TriFunction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.search.Queries;
 import org.opensearch.common.util.BigArrays;
 import org.opensearch.core.action.ActionListener;
@@ -90,8 +91,9 @@
 /**
  * Context object used to create lucene queries on the shard level.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class QueryShardContext extends QueryRewriteContext {
 
     private final ScriptService scriptService;
@@ -115,6 +117,7 @@ public class QueryShardContext extends QueryRewriteContext {
     private boolean mapUnmappedFieldAsString;
     private NestedScope nestedScope;
     private final ValuesSourceRegistry valuesSourceRegistry;
+    private BitSetProducer parentFilter;
 
     public QueryShardContext(
         int shardId,
@@ -509,7 +512,7 @@ public final void freezeContext() {
     /**
      * This method fails if {@link #freezeContext()} is called before on this
      * context. This is used to <i>seal</i>.
-     *
+     * <p>
      * This methods and all methods that call it should be final to ensure that
      * setting the request as not cacheable and the freezing behaviour of this
      * class cannot be bypassed. This is important so we can trust when this
@@ -622,4 +625,12 @@ public BitsetFilterCache getBitsetFilterCache() {
     public AggregationUsageService getUsageService() {
         return valuesSourceRegistry.getUsageService();
     }
+
+    public BitSetProducer getParentFilter() {
+        return parentFilter;
+    }
+
+    public void setParentFilter(BitSetProducer parentFilter) {
+        this.parentFilter = parentFilter;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/QueryStringQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/QueryStringQueryBuilder.java
index 469dc51da323a..3d8fbd5fc436d 100644
--- a/server/src/main/java/org/opensearch/index/query/QueryStringQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/QueryStringQueryBuilder.java
@@ -119,7 +119,7 @@ public class QueryStringQueryBuilder extends AbstractQueryBuilder<QueryStringQue
      * currently _ALL. Uses a TreeMap to hold the fields so boolean clauses are
      * always sorted in same order for generated Lucene query for easier
      * testing.
-     *
+     * <p>
      * Can be changed back to HashMap once https://issues.apache.org/jira/browse/LUCENE-6305 is fixed.
      */
     private final Map<String, Float> fieldsAndWeights = new TreeMap<>();
diff --git a/server/src/main/java/org/opensearch/index/query/RangeQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/RangeQueryBuilder.java
index 0d54373112904..fdbef2c732361 100644
--- a/server/src/main/java/org/opensearch/index/query/RangeQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/RangeQueryBuilder.java
@@ -504,9 +504,9 @@ protected QueryBuilder doRewrite(QueryRewriteContext queryRewriteContext) throws
     @Override
     protected Query doToQuery(QueryShardContext context) throws IOException {
         if (from == null && to == null) {
-            /**
-             * Open bounds on both side, we can rewrite to an exists query
-             * if the {@link FieldNamesFieldMapper} is enabled.
+            /*
+              Open bounds on both side, we can rewrite to an exists query
+              if the {@link FieldNamesFieldMapper} is enabled.
              */
             final FieldNamesFieldMapper.FieldNamesFieldType fieldNamesFieldType = (FieldNamesFieldMapper.FieldNamesFieldType) context
                 .getMapperService()
diff --git a/server/src/main/java/org/opensearch/index/query/Rewriteable.java b/server/src/main/java/org/opensearch/index/query/Rewriteable.java
index 3ed779b52debf..bca719c6fe857 100644
--- a/server/src/main/java/org/opensearch/index/query/Rewriteable.java
+++ b/server/src/main/java/org/opensearch/index/query/Rewriteable.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.index.query;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.ParsingException;
 
@@ -41,8 +42,9 @@
 /**
  * A basic interface for rewriteable classes.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface Rewriteable<T> {
 
     int MAX_REWRITE_ROUNDS = 16;
diff --git a/server/src/main/java/org/opensearch/index/query/SearchIndexNameMatcher.java b/server/src/main/java/org/opensearch/index/query/SearchIndexNameMatcher.java
index 00758309fc0f0..598406b4e45f2 100644
--- a/server/src/main/java/org/opensearch/index/query/SearchIndexNameMatcher.java
+++ b/server/src/main/java/org/opensearch/index/query/SearchIndexNameMatcher.java
@@ -73,7 +73,7 @@ public SearchIndexNameMatcher(
 
     /**
      *  Given an index pattern, checks whether it matches against the current shard.
-     *
+     * <p>
      *  If this shard represents a remote shard target, then in order to match the pattern contain
      *  the separator ':', and must match on both the cluster alias and index name.
      */
diff --git a/server/src/main/java/org/opensearch/index/query/SimpleQueryStringBuilder.java b/server/src/main/java/org/opensearch/index/query/SimpleQueryStringBuilder.java
index 3cd0554af49a4..57ae7dd0ea5e9 100644
--- a/server/src/main/java/org/opensearch/index/query/SimpleQueryStringBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SimpleQueryStringBuilder.java
@@ -66,7 +66,7 @@
  * <li>'{@code -}' negates a single token: {@code -token0}
  * <li>'{@code "}' creates phrases of terms: {@code "term1 term2 ..."}
  * <li>'{@code *}' at the end of terms specifies prefix query: {@code term*}
- * <li>'{@code (}' and '{@code)}' specifies precedence: {@code token1 + (token2 | token3)}
+ * <li>'{@code (}' and '{@code )}' specifies precedence: {@code token1 + (token2 | token3)}
  * <li>'{@code ~}N' at the end of terms specifies fuzzy query: {@code term~1}
  * <li>'{@code ~}N' at the end of phrases specifies near/slop query: {@code "term1 term2"~5}
  * </ul>
diff --git a/server/src/main/java/org/opensearch/index/query/SpanContainingQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/SpanContainingQueryBuilder.java
index ed4f5c6848b06..32a19ea3e9b50 100644
--- a/server/src/main/java/org/opensearch/index/query/SpanContainingQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SpanContainingQueryBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.queries.spans.SpanContainingQuery;
 import org.apache.lucene.queries.spans.SpanQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -188,4 +189,11 @@ protected boolean doEquals(SpanContainingQueryBuilder other) {
     public String getWriteableName() {
         return NAME;
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(big);
+        visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(little);
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/SpanFirstQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/SpanFirstQueryBuilder.java
index 7427b13463284..bcbc64ddf386d 100644
--- a/server/src/main/java/org/opensearch/index/query/SpanFirstQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SpanFirstQueryBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.queries.spans.SpanFirstQuery;
 import org.apache.lucene.queries.spans.SpanQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -186,4 +187,10 @@ protected boolean doEquals(SpanFirstQueryBuilder other) {
     public String getWriteableName() {
         return NAME;
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(matchBuilder);
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/SpanMultiTermQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/SpanMultiTermQueryBuilder.java
index ce28391ca478b..96d03c91964e3 100644
--- a/server/src/main/java/org/opensearch/index/query/SpanMultiTermQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SpanMultiTermQueryBuilder.java
@@ -33,6 +33,7 @@
 
 import org.apache.lucene.queries.SpanMatchNoDocsQuery;
 import org.apache.lucene.queries.spans.SpanMultiTermQueryWrapper;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.BoostQuery;
 import org.apache.lucene.search.ConstantScoreQuery;
 import org.apache.lucene.search.MatchNoDocsQuery;
@@ -213,4 +214,12 @@ protected boolean doEquals(SpanMultiTermQueryBuilder other) {
     public String getWriteableName() {
         return NAME;
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (multiTermQueryBuilder != null) {
+            visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(multiTermQueryBuilder);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/SpanNearQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/SpanNearQueryBuilder.java
index ba7625d94a5a6..30a1c29c29126 100644
--- a/server/src/main/java/org/opensearch/index/query/SpanNearQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SpanNearQueryBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.queries.spans.SpanNearQuery;
 import org.apache.lucene.queries.spans.SpanQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -299,6 +300,17 @@ public String getWriteableName() {
         return NAME;
     }
 
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (this.clauses.isEmpty() == false) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(BooleanClause.Occur.MUST);
+            for (QueryBuilder subQb : this.clauses) {
+                subVisitor.accept(subQb);
+            }
+        }
+    }
+
     /**
      * SpanGapQueryBuilder enables gaps in a SpanNearQuery.
      * Since, SpanGapQuery is private to SpanNearQuery, SpanGapQueryBuilder cannot
diff --git a/server/src/main/java/org/opensearch/index/query/SpanNotQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/SpanNotQueryBuilder.java
index 98e7f287749f5..59ec5b9d77fc8 100644
--- a/server/src/main/java/org/opensearch/index/query/SpanNotQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SpanNotQueryBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.queries.spans.SpanNotQuery;
 import org.apache.lucene.queries.spans.SpanQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -284,4 +285,16 @@ protected boolean doEquals(SpanNotQueryBuilder other) {
     public String getWriteableName() {
         return NAME;
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (include != null) {
+            visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(include);
+        }
+
+        if (exclude != null) {
+            visitor.getChildVisitor(BooleanClause.Occur.MUST_NOT).accept(exclude);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/SpanOrQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/SpanOrQueryBuilder.java
index 2f63e6d7403f7..fae1e318c66bd 100644
--- a/server/src/main/java/org/opensearch/index/query/SpanOrQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SpanOrQueryBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.queries.spans.SpanOrQuery;
 import org.apache.lucene.queries.spans.SpanQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -188,4 +189,15 @@ protected boolean doEquals(SpanOrQueryBuilder other) {
     public String getWriteableName() {
         return NAME;
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (clauses.isEmpty() == false) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(BooleanClause.Occur.SHOULD);
+            for (QueryBuilder subQb : this.clauses) {
+                subVisitor.accept(subQb);
+            }
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/SpanWithinQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/SpanWithinQueryBuilder.java
index 5d02cc0026dfd..4d5a6dde61a70 100644
--- a/server/src/main/java/org/opensearch/index/query/SpanWithinQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/SpanWithinQueryBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.queries.spans.SpanQuery;
 import org.apache.lucene.queries.spans.SpanWithinQuery;
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -197,4 +198,11 @@ protected boolean doEquals(SpanWithinQueryBuilder other) {
     public String getWriteableName() {
         return NAME;
     }
+
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(big);
+        visitor.getChildVisitor(BooleanClause.Occur.MUST).accept(little);
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/functionscore/ScriptScoreQueryBuilder.java b/server/src/main/java/org/opensearch/index/query/functionscore/ScriptScoreQueryBuilder.java
index e302ebcee4ba7..fe9ad200d44f0 100644
--- a/server/src/main/java/org/opensearch/index/query/functionscore/ScriptScoreQueryBuilder.java
+++ b/server/src/main/java/org/opensearch/index/query/functionscore/ScriptScoreQueryBuilder.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.query.functionscore;
 
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.Query;
 import org.opensearch.OpenSearchException;
 import org.opensearch.common.lucene.search.function.ScriptScoreQuery;
@@ -45,6 +46,7 @@
 import org.opensearch.index.query.InnerHitContextBuilder;
 import org.opensearch.index.query.MatchNoneQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
+import org.opensearch.index.query.QueryBuilderVisitor;
 import org.opensearch.index.query.QueryRewriteContext;
 import org.opensearch.index.query.QueryShardContext;
 import org.opensearch.script.ScoreScript;
@@ -224,4 +226,12 @@ protected void extractInnerHitBuilders(Map<String, InnerHitContextBuilder> inner
         InnerHitContextBuilder.extractInnerHits(query(), innerHits);
     }
 
+    @Override
+    public void visit(QueryBuilderVisitor visitor) {
+        visitor.accept(this);
+        if (query != null) {
+            QueryBuilderVisitor subVisitor = visitor.getChildVisitor(BooleanClause.Occur.MUST);
+            subVisitor.accept(query);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/query/functionscore/TermFrequencyFunctionFactory.java b/server/src/main/java/org/opensearch/index/query/functionscore/TermFrequencyFunctionFactory.java
index 4edcd34889abd..9db58f0f78a30 100644
--- a/server/src/main/java/org/opensearch/index/query/functionscore/TermFrequencyFunctionFactory.java
+++ b/server/src/main/java/org/opensearch/index/query/functionscore/TermFrequencyFunctionFactory.java
@@ -11,7 +11,6 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.queries.function.FunctionValues;
 import org.apache.lucene.queries.function.valuesource.SumTotalTermFreqValueSource;
-import org.apache.lucene.queries.function.valuesource.TFValueSource;
 import org.apache.lucene.queries.function.valuesource.TermFreqValueSource;
 import org.apache.lucene.queries.function.valuesource.TotalTermFreqValueSource;
 import org.apache.lucene.search.IndexSearcher;
@@ -42,15 +41,6 @@ public static TermFrequencyFunction createFunction(
                 TermFreqValueSource termFreqValueSource = new TermFreqValueSource(field, term, field, BytesRefs.toBytesRef(term));
                 FunctionValues functionValues = termFreqValueSource.getValues(null, readerContext);
                 return docId -> functionValues.intVal(docId);
-            case TF:
-                TFValueSource tfValueSource = new TFValueSource(field, term, field, BytesRefs.toBytesRef(term));
-                Map<Object, Object> tfContext = new HashMap<>() {
-                    {
-                        put("searcher", indexSearcher);
-                    }
-                };
-                functionValues = tfValueSource.getValues(tfContext, readerContext);
-                return docId -> functionValues.floatVal(docId);
             case TOTAL_TERM_FREQ:
                 TotalTermFreqValueSource totalTermFreqValueSource = new TotalTermFreqValueSource(
                     field,
@@ -78,7 +68,6 @@ public static TermFrequencyFunction createFunction(
      */
     public enum TermFrequencyFunctionName {
         TERM_FREQ("termFreq"),
-        TF("tf"),
         TOTAL_TERM_FREQ("totalTermFreq"),
         SUM_TOTAL_TERM_FREQ("sumTotalTermFreq");
 
diff --git a/server/src/main/java/org/opensearch/index/query/support/NestedScope.java b/server/src/main/java/org/opensearch/index/query/support/NestedScope.java
index 4a09b11666c18..51abe389ad686 100644
--- a/server/src/main/java/org/opensearch/index/query/support/NestedScope.java
+++ b/server/src/main/java/org/opensearch/index/query/support/NestedScope.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.query.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.mapper.ObjectMapper;
 
 import java.util.Deque;
@@ -40,8 +41,9 @@
 /**
  * During query parsing this keeps track of the current nested level.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class NestedScope {
 
     private final Deque<ObjectMapper> levelStack = new LinkedList<>();
diff --git a/server/src/main/java/org/opensearch/index/recovery/RecoveryStats.java b/server/src/main/java/org/opensearch/index/recovery/RecoveryStats.java
index 675f7c08c827c..48fe75eb54280 100644
--- a/server/src/main/java/org/opensearch/index/recovery/RecoveryStats.java
+++ b/server/src/main/java/org/opensearch/index/recovery/RecoveryStats.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.index.recovery;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,8 +47,9 @@
  * Recovery related statistics, starting at the shard level and allowing aggregation to
  * indices and node level
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RecoveryStats implements ToXContentFragment, Writeable {
 
     private final AtomicInteger currentAsSource = new AtomicInteger();
diff --git a/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java b/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java
index d05242a3aeaf7..23bb4cea17a20 100644
--- a/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java
+++ b/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java
@@ -10,15 +10,16 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.opensearch.Version;
 import org.opensearch.action.admin.cluster.remotestore.restore.RestoreRemoteStoreRequest;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.ClusterStateUpdateTask;
 import org.opensearch.cluster.block.ClusterBlocks;
 import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.metadata.IndexTemplateMetadata;
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.cluster.metadata.MetadataCreateIndexService;
 import org.opensearch.cluster.metadata.MetadataIndexUpgradeService;
+import org.opensearch.cluster.metadata.RepositoriesMetadata;
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
 import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.cluster.routing.RoutingTable;
@@ -27,6 +28,7 @@
 import org.opensearch.common.Nullable;
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.shard.ShardId;
@@ -38,15 +40,15 @@
 
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
-import java.util.Set;
+import java.util.Optional;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_STORE_ENABLED;
+import static org.opensearch.repositories.blobstore.BlobStoreRepository.SYSTEM_REPOSITORY_SETTING;
 
 /**
  * Service responsible for restoring index data from remote store
@@ -136,16 +138,22 @@ public RemoteRestoreResult restore(
         String[] indexNames
     ) {
         Map<String, Tuple<Boolean, IndexMetadata>> indexMetadataMap = new HashMap<>();
+        ClusterState remoteState = null;
         boolean metadataFromRemoteStore = (restoreClusterUUID == null
             || restoreClusterUUID.isEmpty()
             || restoreClusterUUID.isBlank()) == false;
         if (metadataFromRemoteStore) {
             try {
-                remoteClusterStateService.getLatestIndexMetadata(currentState.getClusterName().value(), restoreClusterUUID)
-                    .values()
-                    .forEach(indexMetadata -> {
-                        indexMetadataMap.put(indexMetadata.getIndex().getName(), new Tuple<>(true, indexMetadata));
-                    });
+                // Restore with current cluster UUID will fail as same indices would be present in the cluster which we are trying to
+                // restore
+                if (currentState.metadata().clusterUUID().equals(restoreClusterUUID)) {
+                    throw new IllegalArgumentException("clusterUUID to restore from should be different from current cluster UUID");
+                }
+                logger.info("Restoring cluster state from remote store from cluster UUID : [{}]", restoreClusterUUID);
+                remoteState = remoteClusterStateService.getLatestClusterState(currentState.getClusterName().value(), restoreClusterUUID);
+                remoteState.getMetadata().getIndices().values().forEach(indexMetadata -> {
+                    indexMetadataMap.put(indexMetadata.getIndex().getName(), new Tuple<>(true, indexMetadata));
+                });
             } catch (Exception e) {
                 throw new IllegalStateException("Unable to restore remote index metadata", e);
             }
@@ -154,13 +162,22 @@ public RemoteRestoreResult restore(
                 IndexMetadata indexMetadata = currentState.metadata().index(indexName);
                 if (indexMetadata == null) {
                     logger.warn("Index restore is not supported for non-existent index. Skipping: {}", indexName);
+                } else if (indexMetadata.getSettings().getAsBoolean(SETTING_REMOTE_STORE_ENABLED, false) == false) {
+                    logger.warn("Remote store is not enabled for index: {}", indexName);
+                } else if (restoreAllShards && IndexMetadata.State.CLOSE.equals(indexMetadata.getState()) == false) {
+                    throw new IllegalStateException(
+                        String.format(
+                            Locale.ROOT,
+                            "cannot restore index [%s] because an open index with same name/uuid already exists in the cluster.",
+                            indexName
+                        ) + " Close the existing index."
+                    );
                 } else {
                     indexMetadataMap.put(indexName, new Tuple<>(false, indexMetadata));
                 }
             }
         }
-        validate(currentState, indexMetadataMap, restoreClusterUUID, restoreAllShards);
-        return executeRestore(currentState, indexMetadataMap, restoreAllShards);
+        return executeRestore(currentState, indexMetadataMap, restoreAllShards, remoteState);
     }
 
     /**
@@ -173,11 +190,13 @@ public RemoteRestoreResult restore(
     private RemoteRestoreResult executeRestore(
         ClusterState currentState,
         Map<String, Tuple<Boolean, IndexMetadata>> indexMetadataMap,
-        boolean restoreAllShards
+        boolean restoreAllShards,
+        ClusterState remoteState
     ) {
         final String restoreUUID = UUIDs.randomBase64UUID();
         List<String> indicesToBeRestored = new ArrayList<>();
         int totalShards = 0;
+        boolean metadataFromRemoteStore = false;
         ClusterState.Builder builder = ClusterState.builder(currentState);
         Metadata.Builder mdBuilder = Metadata.builder(currentState.metadata());
         ClusterBlocks.Builder blocks = ClusterBlocks.builder().blocks(currentState.blocks());
@@ -185,9 +204,9 @@ private RemoteRestoreResult executeRestore(
         for (Map.Entry<String, Tuple<Boolean, IndexMetadata>> indexMetadataEntry : indexMetadataMap.entrySet()) {
             String indexName = indexMetadataEntry.getKey();
             IndexMetadata indexMetadata = indexMetadataEntry.getValue().v2();
-            boolean metadataFromRemoteStore = indexMetadataEntry.getValue().v1();
+            metadataFromRemoteStore = indexMetadataEntry.getValue().v1();
             IndexMetadata updatedIndexMetadata = indexMetadata;
-            if (restoreAllShards || metadataFromRemoteStore) {
+            if (metadataFromRemoteStore == false && restoreAllShards) {
                 updatedIndexMetadata = IndexMetadata.builder(indexMetadata)
                     .state(IndexMetadata.State.OPEN)
                     .version(1 + indexMetadata.getVersion())
@@ -199,117 +218,74 @@ private RemoteRestoreResult executeRestore(
 
             IndexId indexId = new IndexId(indexName, updatedIndexMetadata.getIndexUUID());
 
-            Map<ShardId, IndexShardRoutingTable> indexShardRoutingTableMap = new HashMap<>();
             if (metadataFromRemoteStore == false) {
-                indexShardRoutingTableMap = currentState.routingTable()
+                Map<ShardId, IndexShardRoutingTable> indexShardRoutingTableMap = currentState.routingTable()
                     .index(indexName)
                     .shards()
                     .values()
                     .stream()
                     .collect(Collectors.toMap(IndexShardRoutingTable::shardId, Function.identity()));
+
+                RecoverySource.RemoteStoreRecoverySource recoverySource = new RecoverySource.RemoteStoreRecoverySource(
+                    restoreUUID,
+                    updatedIndexMetadata.getCreationVersion(),
+                    indexId
+                );
+
+                rtBuilder.addAsRemoteStoreRestore(updatedIndexMetadata, recoverySource, indexShardRoutingTableMap, restoreAllShards);
             }
 
-            RecoverySource.RemoteStoreRecoverySource recoverySource = new RecoverySource.RemoteStoreRecoverySource(
-                restoreUUID,
-                updatedIndexMetadata.getCreationVersion(),
-                indexId
-            );
-            rtBuilder.addAsRemoteStoreRestore(
-                updatedIndexMetadata,
-                recoverySource,
-                indexShardRoutingTableMap,
-                restoreAllShards || metadataFromRemoteStore
-            );
             blocks.updateBlocks(updatedIndexMetadata);
             mdBuilder.put(updatedIndexMetadata, true);
             indicesToBeRestored.add(indexName);
             totalShards += updatedIndexMetadata.getNumberOfShards();
         }
 
+        if (remoteState != null) {
+            restoreGlobalMetadata(mdBuilder, remoteState.getMetadata());
+            // Restore ClusterState version
+            logger.info("Restoring ClusterState with Remote State version [{}]", remoteState.version());
+            builder.version(remoteState.version());
+        }
+
         RestoreInfo restoreInfo = new RestoreInfo("remote_store", indicesToBeRestored, totalShards, totalShards);
 
         RoutingTable rt = rtBuilder.build();
         ClusterState updatedState = builder.metadata(mdBuilder).blocks(blocks).routingTable(rt).build();
-        return RemoteRestoreResult.build(restoreUUID, restoreInfo, allocationService.reroute(updatedState, "restored from remote store"));
+        if (metadataFromRemoteStore == false) {
+            updatedState = allocationService.reroute(updatedState, "restored from remote store");
+        }
+        return RemoteRestoreResult.build(restoreUUID, restoreInfo, updatedState);
     }
 
-    /**
-     * Performs various validations needed before executing restore
-     * @param currentState current cluster state
-     * @param indexMetadataMap map of index metadata to restore
-     * @param restoreClusterUUID cluster UUID used to restore IndexMetadata
-     * @param restoreAllShards indicates if all shards of the index needs to be restored. This flat is ignored if remoteClusterUUID is provided
-     */
-    private void validate(
-        ClusterState currentState,
-        Map<String, Tuple<Boolean, IndexMetadata>> indexMetadataMap,
-        @Nullable String restoreClusterUUID,
-        boolean restoreAllShards
-    ) throws IllegalStateException, IllegalArgumentException {
-        String errorMsg = "cannot restore index [%s] because an open index with same name/uuid already exists in the cluster.";
-
-        // Restore with current cluster UUID will fail as same indices would be present in the cluster which we are trying to
-        // restore
-        if (currentState.metadata().clusterUUID().equals(restoreClusterUUID)) {
-            throw new IllegalArgumentException("clusterUUID to restore from should be different from current cluster UUID");
+    private void restoreGlobalMetadata(Metadata.Builder mdBuilder, Metadata remoteMetadata) {
+        if (remoteMetadata.persistentSettings() != null) {
+            Settings settings = remoteMetadata.persistentSettings();
+            clusterService.getClusterSettings().validateUpdate(settings);
+            mdBuilder.persistentSettings(settings);
         }
-        for (Map.Entry<String, Tuple<Boolean, IndexMetadata>> indexMetadataEntry : indexMetadataMap.entrySet()) {
-            String indexName = indexMetadataEntry.getKey();
-            IndexMetadata indexMetadata = indexMetadataEntry.getValue().v2();
-            String indexUUID = indexMetadata.getIndexUUID();
-            boolean metadataFromRemoteStore = indexMetadataEntry.getValue().v1();
-            if (indexMetadata.getSettings().getAsBoolean(SETTING_REMOTE_STORE_ENABLED, false)) {
-                if (metadataFromRemoteStore) {
-                    Set<String> graveyardIndexNames = new HashSet<>();
-                    Set<String> graveyardIndexUUID = new HashSet<>();
-                    Set<String> liveClusterIndexUUIDs = currentState.metadata()
-                        .indices()
-                        .values()
-                        .stream()
-                        .map(IndexMetadata::getIndexUUID)
-                        .collect(Collectors.toSet());
-
-                    currentState.metadata().indexGraveyard().getTombstones().forEach(tombstone -> {
-                        graveyardIndexNames.add(tombstone.getIndex().getName());
-                        graveyardIndexUUID.add(tombstone.getIndex().getUUID());
-                    });
-
-                    // Since updates to graveyard are synced to remote we should neven land in a situation where remote contain index
-                    // metadata for graveyard index.
-                    assert graveyardIndexNames.contains(indexName) == false : String.format(
-                        Locale.ROOT,
-                        "Index name [%s] exists in graveyard!",
-                        indexName
-                    );
-                    assert graveyardIndexUUID.contains(indexUUID) == false : String.format(
-                        Locale.ROOT,
-                        "Index UUID [%s] exists in graveyard!",
-                        indexUUID
-                    );
-
-                    // Any indices being restored from remote cluster state should not already be part of the cluster as this causes
-                    // conflict
-                    boolean sameNameIndexExists = currentState.metadata().hasIndex(indexName);
-                    boolean sameUUIDIndexExists = liveClusterIndexUUIDs.contains(indexUUID);
-                    if (sameNameIndexExists || sameUUIDIndexExists) {
-                        String finalErrorMsg = String.format(Locale.ROOT, errorMsg, indexName);
-                        logger.info(finalErrorMsg);
-                        throw new IllegalStateException(finalErrorMsg);
-                    }
-
-                    Version minIndexCompatibilityVersion = currentState.getNodes().getMaxNodeVersion().minimumIndexCompatibilityVersion();
-                    metadataIndexUpgradeService.upgradeIndexMetadata(indexMetadata, minIndexCompatibilityVersion);
-                    boolean isHidden = IndexMetadata.INDEX_HIDDEN_SETTING.get(indexMetadata.getSettings());
-                    createIndexService.validateIndexName(indexName, currentState);
-                    createIndexService.validateDotIndex(indexName, isHidden);
-                    shardLimitValidator.validateShardLimit(indexName, indexMetadata.getSettings(), currentState);
-                } else if (restoreAllShards && IndexMetadata.State.CLOSE.equals(indexMetadata.getState()) == false) {
-                    throw new IllegalStateException(String.format(Locale.ROOT, errorMsg, indexName) + " Close the existing index.");
+        if (remoteMetadata.templates() != null) {
+            for (final IndexTemplateMetadata cursor : remoteMetadata.templates().values()) {
+                mdBuilder.put(cursor);
+            }
+        }
+        if (remoteMetadata.customs() != null) {
+            for (final Map.Entry<String, Metadata.Custom> cursor : remoteMetadata.customs().entrySet()) {
+                if (RepositoriesMetadata.TYPE.equals(cursor.getKey()) == false) {
+                    mdBuilder.putCustom(cursor.getKey(), cursor.getValue());
                 }
-            } else {
-                logger.warn("Remote store is not enabled for index: {}", indexName);
             }
         }
+        Optional<RepositoriesMetadata> repositoriesMetadata = Optional.ofNullable(remoteMetadata.custom(RepositoriesMetadata.TYPE));
+        repositoriesMetadata = repositoriesMetadata.map(
+            repositoriesMetadata1 -> new RepositoriesMetadata(
+                repositoriesMetadata1.repositories()
+                    .stream()
+                    .filter(repository -> SYSTEM_REPOSITORY_SETTING.get(repository.settings()) == false)
+                    .collect(Collectors.toList())
+            )
+        );
+        repositoriesMetadata.ifPresent(metadata -> mdBuilder.putCustom(RepositoriesMetadata.TYPE, metadata));
     }
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/refresh/RefreshStats.java b/server/src/main/java/org/opensearch/index/refresh/RefreshStats.java
index 322271ace82b5..489ac386f72a0 100644
--- a/server/src/main/java/org/opensearch/index/refresh/RefreshStats.java
+++ b/server/src/main/java/org/opensearch/index/refresh/RefreshStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.refresh;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +46,9 @@
 /**
  * Encapsulates stats for index refresh
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RefreshStats implements Writeable, ToXContentFragment {
 
     private long total;
diff --git a/server/src/main/java/org/opensearch/index/reindex/BulkByScrollTask.java b/server/src/main/java/org/opensearch/index/reindex/BulkByScrollTask.java
index f33800659245f..d7c0da4773fff 100644
--- a/server/src/main/java/org/opensearch/index/reindex/BulkByScrollTask.java
+++ b/server/src/main/java/org/opensearch/index/reindex/BulkByScrollTask.java
@@ -73,13 +73,13 @@
 
 /**
  * Task storing information about a currently running BulkByScroll request.
- *
+ * <p>
  * When the request is not sliced, this task is the only task created, and starts an action to perform search requests.
- *
+ * <p>
  * When the request is sliced, this task can either represent a coordinating task (using
  * {@link BulkByScrollTask#setWorkerCount(int)}) or a worker task that performs search queries (using
  * {@link BulkByScrollTask#setWorker(float, Integer)}).
- *
+ * <p>
  * We don't always know if this task will be a leader or worker task when it's created, because if slices is set to "auto" it may
  * be either depending on the number of shards in the source indices. We figure that out when the request is handled and set it on this
  * class with {@link #setWorkerCount(int)} or {@link #setWorker(float, Integer)}.
diff --git a/server/src/main/java/org/opensearch/index/reindex/DeleteByQueryRequest.java b/server/src/main/java/org/opensearch/index/reindex/DeleteByQueryRequest.java
index aff9ec1f20e46..4963080f5916c 100644
--- a/server/src/main/java/org/opensearch/index/reindex/DeleteByQueryRequest.java
+++ b/server/src/main/java/org/opensearch/index/reindex/DeleteByQueryRequest.java
@@ -49,7 +49,7 @@
 /**
  * Creates a new {@link DeleteByQueryRequest} that uses scrolling and bulk requests to delete all documents matching
  * the query. This can have performance as well as visibility implications.
- *
+ * <p>
  * Delete-by-query now has the following semantics:
  * <ul>
  *     <li>it's {@code non-atomic}, a delete-by-query may fail at any time while some documents matching the query have already been
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteSegmentStats.java b/server/src/main/java/org/opensearch/index/remote/RemoteSegmentStats.java
index c7863536adf20..fc1f245829b84 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteSegmentStats.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteSegmentStats.java
@@ -8,7 +8,9 @@
 
 package org.opensearch.index.remote;
 
+import org.opensearch.Version;
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStats;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -25,8 +27,9 @@
  * Tracks remote store segment download and upload stats
  * Used for displaying remote store stats in IndicesStats/NodeStats API
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class RemoteSegmentStats implements Writeable, ToXContentFragment {
     /**
      * Cumulative bytes attempted to be uploaded to remote store
@@ -75,6 +78,10 @@ public class RemoteSegmentStats implements Writeable, ToXContentFragment {
      * Total time spent in downloading segments from remote store
      */
     private long totalDownloadTime;
+    /**
+     * Total rejections due to remote store upload backpressure
+     */
+    private long totalRejections;
 
     public RemoteSegmentStats() {}
 
@@ -90,6 +97,9 @@ public RemoteSegmentStats(StreamInput in) throws IOException {
         totalRefreshBytesLag = in.readLong();
         totalUploadTime = in.readLong();
         totalDownloadTime = in.readLong();
+        if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+            totalRejections = in.readVLong();
+        }
     }
 
     /**
@@ -115,6 +125,7 @@ public RemoteSegmentStats(RemoteSegmentTransferTracker.Stats trackerStats) {
         this.totalRefreshBytesLag = trackerStats.bytesLag;
         this.totalUploadTime = trackerStats.totalUploadTimeInMs;
         this.totalDownloadTime = trackerStats.directoryFileTransferTrackerStats.totalTransferTimeInMs;
+        this.totalRejections = trackerStats.rejectionCount;
     }
 
     // Getter and setters. All are visible for testing
@@ -207,6 +218,14 @@ public void addTotalDownloadTime(long totalDownloadTime) {
         this.totalDownloadTime += totalDownloadTime;
     }
 
+    public long getTotalRejections() {
+        return totalRejections;
+    }
+
+    public void addTotalRejections(long totalRejections) {
+        this.totalRejections += totalRejections;
+    }
+
     /**
      * Adds existing stats. Used for stats roll-ups at index or node level
      *
@@ -225,6 +244,7 @@ public void add(RemoteSegmentStats existingStats) {
             this.totalRefreshBytesLag += existingStats.getTotalRefreshBytesLag();
             this.totalUploadTime += existingStats.getTotalUploadTime();
             this.totalDownloadTime += existingStats.getTotalDownloadTime();
+            this.totalRejections += existingStats.totalRejections;
         }
     }
 
@@ -241,18 +261,25 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeLong(totalRefreshBytesLag);
         out.writeLong(totalUploadTime);
         out.writeLong(totalDownloadTime);
+        if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+            out.writeVLong(totalRejections);
+        }
     }
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(Fields.REMOTE_STORE);
+
         builder.startObject(Fields.UPLOAD);
         buildUploadStats(builder);
-        builder.endObject();
+        builder.endObject(); // UPLOAD
+
         builder.startObject(Fields.DOWNLOAD);
         buildDownloadStats(builder);
-        builder.endObject();
-        builder.endObject();
+        builder.endObject(); // DOWNLOAD
+
+        builder.endObject(); // REMOTE_STORE
+
         return builder;
     }
 
@@ -261,13 +288,19 @@ private void buildUploadStats(XContentBuilder builder) throws IOException {
         builder.humanReadableField(Fields.STARTED_BYTES, Fields.STARTED, new ByteSizeValue(uploadBytesStarted));
         builder.humanReadableField(Fields.SUCCEEDED_BYTES, Fields.SUCCEEDED, new ByteSizeValue(uploadBytesSucceeded));
         builder.humanReadableField(Fields.FAILED_BYTES, Fields.FAILED, new ByteSizeValue(uploadBytesFailed));
-        builder.endObject();
+        builder.endObject(); // TOTAL_UPLOAD_SIZE
+
         builder.startObject(Fields.REFRESH_SIZE_LAG);
         builder.humanReadableField(Fields.TOTAL_BYTES, Fields.TOTAL, new ByteSizeValue(totalRefreshBytesLag));
         builder.humanReadableField(Fields.MAX_BYTES, Fields.MAX, new ByteSizeValue(maxRefreshBytesLag));
-        builder.endObject();
+        builder.endObject(); // REFRESH_SIZE_LAG
+
         builder.humanReadableField(Fields.MAX_REFRESH_TIME_LAG_IN_MILLIS, Fields.MAX_REFRESH_TIME_LAG, new TimeValue(maxRefreshTimeLag));
         builder.humanReadableField(Fields.TOTAL_TIME_SPENT_IN_MILLIS, Fields.TOTAL_TIME_SPENT, new TimeValue(totalUploadTime));
+
+        builder.startObject(Fields.PRESSURE);
+        builder.field(Fields.TOTAL_REJECTIONS, totalRejections);
+        builder.endObject(); // PRESSURE
     }
 
     private void buildDownloadStats(XContentBuilder builder) throws IOException {
@@ -300,6 +333,8 @@ static final class Fields {
         static final String MAX_BYTES = "max_bytes";
         static final String TOTAL_TIME_SPENT = "total_time_spent";
         static final String TOTAL_TIME_SPENT_IN_MILLIS = "total_time_spent_in_millis";
+        static final String PRESSURE = "pressure";
+        static final String TOTAL_REJECTIONS = "total_rejections";
     }
 
     @Override
@@ -318,7 +353,8 @@ public boolean equals(Object o) {
             && maxRefreshBytesLag == that.maxRefreshBytesLag
             && totalRefreshBytesLag == that.totalRefreshBytesLag
             && totalUploadTime == that.totalUploadTime
-            && totalDownloadTime == that.totalDownloadTime;
+            && totalDownloadTime == that.totalDownloadTime
+            && totalRejections == that.totalRejections;
     }
 
     @Override
@@ -334,7 +370,8 @@ public int hashCode() {
             maxRefreshBytesLag,
             totalRefreshBytesLag,
             totalUploadTime,
-            totalDownloadTime
+            totalDownloadTime,
+            totalRejections
         );
     }
 }
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteSegmentTransferTracker.java b/server/src/main/java/org/opensearch/index/remote/RemoteSegmentTransferTracker.java
index d18462cd65fc1..fe9440813b94f 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteSegmentTransferTracker.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteSegmentTransferTracker.java
@@ -11,6 +11,7 @@
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.opensearch.common.CheckedFunction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.util.Streak;
 import org.opensearch.common.util.concurrent.ConcurrentCollections;
@@ -27,6 +28,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.stream.Collectors;
 
@@ -35,8 +37,9 @@
 /**
  * Keeps track of remote refresh which happens in {@link org.opensearch.index.shard.RemoteStoreRefreshListener}. This consist of multiple critical metrics.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class RemoteSegmentTransferTracker extends RemoteTransferTracker {
 
     private final Logger logger;
@@ -66,6 +69,12 @@ public class RemoteSegmentTransferTracker extends RemoteTransferTracker {
      */
     private volatile long remoteRefreshTimeMs;
 
+    /**
+     * This is the time of first local refresh after the last successful remote refresh. When the remote store is in
+     * sync with local refresh, this will be reset to -1.
+     */
+    private volatile long remoteRefreshStartTimeMs = -1;
+
     /**
      * The refresh time(clock) of most recent remote refresh.
      */
@@ -76,11 +85,6 @@ public class RemoteSegmentTransferTracker extends RemoteTransferTracker {
      */
     private volatile long refreshSeqNoLag;
 
-    /**
-     * Keeps the time (ms) lag computed so that we do not compute it for every request.
-     */
-    private volatile long timeMsLag;
-
     /**
      * Keeps track of the total bytes of segment files which were uploaded to remote store during last successful remote refresh
      */
@@ -132,14 +136,19 @@ public RemoteSegmentTransferTracker(
         logger = Loggers.getLogger(getClass(), shardId);
         // Both the local refresh time and remote refresh time are set with current time to give consistent view of time lag when it arises.
         long currentClockTimeMs = System.currentTimeMillis();
-        long currentTimeMs = System.nanoTime() / 1_000_000L;
+        long currentTimeMs = currentTimeMsUsingSystemNanos();
         localRefreshTimeMs = currentTimeMs;
         remoteRefreshTimeMs = currentTimeMs;
+        remoteRefreshStartTimeMs = currentTimeMs;
         localRefreshClockTimeMs = currentClockTimeMs;
         remoteRefreshClockTimeMs = currentClockTimeMs;
         this.directoryFileTransferTracker = directoryFileTransferTracker;
     }
 
+    public static long currentTimeMsUsingSystemNanos() {
+        return TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
+    }
+
     @Override
     public void incrementTotalUploadsFailed() {
         super.incrementTotalUploadsFailed();
@@ -180,19 +189,22 @@ public long getLocalRefreshClockTimeMs() {
      */
     public void updateLocalRefreshTimeAndSeqNo() {
         updateLocalRefreshClockTimeMs(System.currentTimeMillis());
-        updateLocalRefreshTimeMs(System.nanoTime() / 1_000_000L);
+        updateLocalRefreshTimeMs(currentTimeMsUsingSystemNanos());
         updateLocalRefreshSeqNo(getLocalRefreshSeqNo() + 1);
     }
 
     // Visible for testing
-    void updateLocalRefreshTimeMs(long localRefreshTimeMs) {
+    synchronized void updateLocalRefreshTimeMs(long localRefreshTimeMs) {
         assert localRefreshTimeMs >= this.localRefreshTimeMs : "newLocalRefreshTimeMs="
             + localRefreshTimeMs
             + " < "
             + "currentLocalRefreshTimeMs="
             + this.localRefreshTimeMs;
+        boolean isRemoteInSyncBeforeLocalRefresh = this.localRefreshTimeMs == this.remoteRefreshTimeMs;
         this.localRefreshTimeMs = localRefreshTimeMs;
-        computeTimeMsLag();
+        if (isRemoteInSyncBeforeLocalRefresh) {
+            this.remoteRefreshStartTimeMs = localRefreshTimeMs;
+        }
     }
 
     private void updateLocalRefreshClockTimeMs(long localRefreshClockTimeMs) {
@@ -221,14 +233,18 @@ long getRemoteRefreshClockTimeMs() {
         return remoteRefreshClockTimeMs;
     }
 
-    public void updateRemoteRefreshTimeMs(long remoteRefreshTimeMs) {
-        assert remoteRefreshTimeMs >= this.remoteRefreshTimeMs : "newRemoteRefreshTimeMs="
-            + remoteRefreshTimeMs
+    public synchronized void updateRemoteRefreshTimeMs(long refreshTimeMs) {
+        assert refreshTimeMs >= this.remoteRefreshTimeMs : "newRemoteRefreshTimeMs="
+            + refreshTimeMs
             + " < "
             + "currentRemoteRefreshTimeMs="
             + this.remoteRefreshTimeMs;
-        this.remoteRefreshTimeMs = remoteRefreshTimeMs;
-        computeTimeMsLag();
+        this.remoteRefreshTimeMs = refreshTimeMs;
+        // When multiple refreshes have failed, there is a possibility that retry is ongoing while another refresh gets
+        // triggered. After the segments have been uploaded and before the below code runs, the updateLocalRefreshTimeAndSeqNo
+        // method is triggered, which will update the local localRefreshTimeMs. Now, the lag would basically become the
+        // time since the last refresh happened locally.
+        this.remoteRefreshStartTimeMs = refreshTimeMs == this.localRefreshTimeMs ? -1 : this.localRefreshTimeMs;
     }
 
     public void updateRemoteRefreshClockTimeMs(long remoteRefreshClockTimeMs) {
@@ -243,12 +259,11 @@ public long getRefreshSeqNoLag() {
         return refreshSeqNoLag;
     }
 
-    private void computeTimeMsLag() {
-        timeMsLag = localRefreshTimeMs - remoteRefreshTimeMs;
-    }
-
     public long getTimeMsLag() {
-        return timeMsLag;
+        if (remoteRefreshTimeMs == localRefreshTimeMs) {
+            return 0;
+        }
+        return currentTimeMsUsingSystemNanos() - remoteRefreshStartTimeMs;
     }
 
     public long getBytesLag() {
@@ -267,7 +282,8 @@ public long getRejectionCount() {
         return rejectionCount.get();
     }
 
-    void incrementRejectionCount() {
+    /** public only for testing **/
+    public void incrementRejectionCount() {
         rejectionCount.incrementAndGet();
     }
 
@@ -294,6 +310,11 @@ public void updateLatestLocalFileNameLengthMap(
         Collection<String> segmentFiles,
         CheckedFunction<String, Long, IOException> fileSizeFunction
     ) {
+        logger.debug(
+            "segmentFilesPostRefresh={} latestLocalFileNamesBeforeMapUpdate={}",
+            segmentFiles,
+            latestLocalFileNameLengthMap.keySet()
+        );
         // Update the map
         segmentFiles.stream()
             .filter(file -> EXCLUDE_FILES.contains(file) == false)
@@ -348,7 +369,7 @@ public RemoteSegmentTransferTracker.Stats stats() {
             shardId,
             localRefreshClockTimeMs,
             remoteRefreshClockTimeMs,
-            timeMsLag,
+            getTimeMsLag(),
             localRefreshSeqNo,
             remoteRefreshSeqNo,
             uploadBytesStarted.get(),
@@ -372,8 +393,9 @@ public RemoteSegmentTransferTracker.Stats stats() {
     /**
      * Represents the tracker's state as seen in the stats API.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "2.10.0")
     public static class Stats implements Writeable {
 
         public final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java b/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java
index 2920b33921869..33cd40f802d43 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java
@@ -180,7 +180,6 @@ public boolean validate(RemoteSegmentTransferTracker pressureTracker, ShardId sh
                 return true;
             }
             if (pressureTracker.isUploadTimeMovingAverageReady() == false) {
-                logger.trace("upload time moving average is not ready");
                 return true;
             }
             long timeLag = pressureTracker.getTimeMsLag();
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureSettings.java b/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureSettings.java
index 864fe24c282a2..e66aa3444c214 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureSettings.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureSettings.java
@@ -30,7 +30,7 @@ static class Defaults {
 
     public static final Setting<Boolean> REMOTE_REFRESH_SEGMENT_PRESSURE_ENABLED = Setting.boolSetting(
         "remote_store.segment.pressure.enabled",
-        false,
+        true,
         Setting.Property.Dynamic,
         Setting.Property.NodeScope
     );
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteStoreStatsTrackerFactory.java b/server/src/main/java/org/opensearch/index/remote/RemoteStoreStatsTrackerFactory.java
index 6058fcc7345d2..9a146be96c9de 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteStoreStatsTrackerFactory.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteStoreStatsTrackerFactory.java
@@ -11,6 +11,7 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
@@ -24,8 +25,9 @@
 /**
  * Factory to manage stats trackers for Remote Store operations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class RemoteStoreStatsTrackerFactory implements IndexEventListener {
     static class Defaults {
         static final int MOVING_AVERAGE_WINDOW_SIZE = 20;
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java b/server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java
index 114d07589b0c0..b4c33d781af86 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java
@@ -8,7 +8,13 @@
 
 package org.opensearch.index.remote;
 
+import org.opensearch.common.collect.Tuple;
+
 import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
 
 /**
  * Utils for remote store
@@ -69,4 +75,30 @@ public static String getSegmentName(String filename) {
 
         return filename.substring(0, endIdx);
     }
+
+    /**
+     *
+     * @param mdFiles List of segment/translog metadata files
+     * @param fn Function to extract PrimaryTerm_Generation and Node Id from metadata file name .
+     *          fn returns null if node id is not part of the file name
+     */
+    public static void verifyNoMultipleWriters(List<String> mdFiles, Function<String, Tuple<String, String>> fn) {
+        Map<String, String> nodesByPrimaryTermAndGen = new HashMap<>();
+        mdFiles.forEach(mdFile -> {
+            Tuple<String, String> nodeIdByPrimaryTermAndGen = fn.apply(mdFile);
+            if (nodeIdByPrimaryTermAndGen != null) {
+                if (nodesByPrimaryTermAndGen.containsKey(nodeIdByPrimaryTermAndGen.v1())
+                    && (!nodesByPrimaryTermAndGen.get(nodeIdByPrimaryTermAndGen.v1()).equals(nodeIdByPrimaryTermAndGen.v2()))) {
+                    throw new IllegalStateException(
+                        "Multiple metadata files from different nodes"
+                            + "having same primary term and generations "
+                            + nodeIdByPrimaryTermAndGen.v1()
+                            + " detected "
+                    );
+                }
+                nodesByPrimaryTermAndGen.put(nodeIdByPrimaryTermAndGen.v1(), nodeIdByPrimaryTermAndGen.v2());
+            }
+        });
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteTranslogTransferTracker.java b/server/src/main/java/org/opensearch/index/remote/RemoteTranslogTransferTracker.java
index 1a9896540212e..25bee10e1fbe3 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteTranslogTransferTracker.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteTranslogTransferTracker.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.remote;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.MovingAverage;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -22,8 +23,9 @@
 /**
  * Stores Remote Translog Store-related stats for a given IndexShard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class RemoteTranslogTransferTracker extends RemoteTransferTracker {
     /**
      * Epoch timestamp of the last successful Remote Translog Store upload.
@@ -232,11 +234,69 @@ public RemoteTranslogTransferTracker.Stats stats() {
         );
     }
 
+    @Override
+    public String toString() {
+        return "RemoteTranslogTransferStats{"
+            + "lastSuccessfulUploadTimestamp="
+            + lastSuccessfulUploadTimestamp.get()
+            + ","
+            + "totalUploadsStarted="
+            + totalUploadsStarted.get()
+            + ","
+            + "totalUploadsSucceeded="
+            + totalUploadsSucceeded.get()
+            + ","
+            + "totalUploadsFailed="
+            + totalUploadsFailed.get()
+            + ","
+            + "uploadBytesStarted="
+            + uploadBytesStarted.get()
+            + ","
+            + "uploadBytesFailed="
+            + uploadBytesFailed.get()
+            + ","
+            + "totalUploadTimeInMillis="
+            + totalUploadTimeInMillis.get()
+            + ","
+            + "uploadBytesMovingAverage="
+            + uploadBytesMovingAverageReference.get().getAverage()
+            + ","
+            + "uploadBytesPerSecMovingAverage="
+            + uploadBytesPerSecMovingAverageReference.get().getAverage()
+            + ","
+            + "uploadTimeMovingAverage="
+            + uploadTimeMsMovingAverageReference.get().getAverage()
+            + ","
+            + "lastSuccessfulDownloadTimestamp="
+            + lastSuccessfulDownloadTimestamp.get()
+            + ","
+            + "totalDownloadsSucceeded="
+            + totalDownloadsSucceeded.get()
+            + ","
+            + "downloadBytesSucceeded="
+            + downloadBytesSucceeded.get()
+            + ","
+            + "totalDownloadTimeInMillis="
+            + totalDownloadTimeInMillis.get()
+            + ","
+            + "downloadBytesMovingAverage="
+            + downloadBytesMovingAverageReference.get().getAverage()
+            + ","
+            + "downloadBytesPerSecMovingAverage="
+            + downloadBytesPerSecMovingAverageReference.get().getAverage()
+            + ","
+            + "downloadTimeMovingAverage="
+            + downloadTimeMsMovingAverageReference.get().getAverage()
+            + ","
+            + "}";
+    }
+
     /**
      * Represents the tracker's state as seen in the stats API.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "2.10.0")
     public static class Stats implements Writeable {
 
         final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/index/search/MatchQuery.java b/server/src/main/java/org/opensearch/index/search/MatchQuery.java
index ade4fb1e69586..9e2b79971369d 100644
--- a/server/src/main/java/org/opensearch/index/search/MatchQuery.java
+++ b/server/src/main/java/org/opensearch/index/search/MatchQuery.java
@@ -753,9 +753,9 @@ private Query analyzeGraphBoolean(String field, TokenStream source, BooleanClaus
                 lastState = end;
                 final Query queryPos;
                 boolean usePrefix = isPrefix && end == -1;
-                /**
-                 * check if the GraphTokenStreamFiniteStrings graph is empty
-                 * return empty BooleanQuery result
+                /*
+                  check if the GraphTokenStreamFiniteStrings graph is empty
+                  return empty BooleanQuery result
                  */
                 Iterator<TokenStream> graphIt = graph.getFiniteStrings();
                 if (!graphIt.hasNext()) {
diff --git a/server/src/main/java/org/opensearch/index/search/comparators/HalfFloatComparator.java b/server/src/main/java/org/opensearch/index/search/comparators/HalfFloatComparator.java
new file mode 100644
index 0000000000000..6244fa647b042
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/search/comparators/HalfFloatComparator.java
@@ -0,0 +1,111 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.search.comparators;
+
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.sandbox.document.HalfFloatPoint;
+import org.apache.lucene.search.LeafFieldComparator;
+import org.apache.lucene.search.comparators.NumericComparator;
+
+import java.io.IOException;
+
+/**
+ * The comparator for half_float numeric type.
+ * Comparator based on {@link Float#compare} for {@code numHits}. This comparator provides a
+ * skipping functionality – an iterator that can skip over non-competitive documents.
+ */
+public class HalfFloatComparator extends NumericComparator<Float> {
+    private final float[] values;
+    protected float topValue;
+    protected float bottom;
+
+    public HalfFloatComparator(int numHits, String field, Float missingValue, boolean reverse, boolean enableSkipping) {
+        super(field, missingValue != null ? missingValue : 0.0f, reverse, enableSkipping, HalfFloatPoint.BYTES);
+        values = new float[numHits];
+    }
+
+    @Override
+    public int compare(int slot1, int slot2) {
+        return Float.compare(values[slot1], values[slot2]);
+    }
+
+    @Override
+    public void setTopValue(Float value) {
+        super.setTopValue(value);
+        topValue = value;
+    }
+
+    @Override
+    public Float value(int slot) {
+        return Float.valueOf(values[slot]);
+    }
+
+    @Override
+    public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
+        return new HalfFloatLeafComparator(context);
+    }
+
+    /** Leaf comparator for {@link HalfFloatComparator} that provides skipping functionality */
+    public class HalfFloatLeafComparator extends NumericLeafComparator {
+
+        public HalfFloatLeafComparator(LeafReaderContext context) throws IOException {
+            super(context);
+        }
+
+        private float getValueForDoc(int doc) throws IOException {
+            if (docValues.advanceExact(doc)) {
+                return Float.intBitsToFloat((int) docValues.longValue());
+            } else {
+                return missingValue;
+            }
+        }
+
+        @Override
+        public void setBottom(int slot) throws IOException {
+            bottom = values[slot];
+            super.setBottom(slot);
+        }
+
+        @Override
+        public int compareBottom(int doc) throws IOException {
+            return Float.compare(bottom, getValueForDoc(doc));
+        }
+
+        @Override
+        public int compareTop(int doc) throws IOException {
+            return Float.compare(topValue, getValueForDoc(doc));
+        }
+
+        @Override
+        public void copy(int slot, int doc) throws IOException {
+            values[slot] = getValueForDoc(doc);
+            super.copy(slot, doc);
+        }
+
+        @Override
+        protected int compareMissingValueWithBottomValue() {
+            return Float.compare(missingValue, bottom);
+        }
+
+        @Override
+        protected int compareMissingValueWithTopValue() {
+            return Float.compare(missingValue, topValue);
+        }
+
+        @Override
+        protected void encodeBottom(byte[] packedValue) {
+            HalfFloatPoint.encodeDimension(bottom, packedValue, 0);
+        }
+
+        @Override
+        protected void encodeTop(byte[] packedValue) {
+            HalfFloatPoint.encodeDimension(topValue, packedValue, 0);
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/index/search/comparators/UnsignedLongComparator.java b/server/src/main/java/org/opensearch/index/search/comparators/UnsignedLongComparator.java
index 78b4a5f04c955..d46b34fe97356 100644
--- a/server/src/main/java/org/opensearch/index/search/comparators/UnsignedLongComparator.java
+++ b/server/src/main/java/org/opensearch/index/search/comparators/UnsignedLongComparator.java
@@ -86,14 +86,6 @@ public void copy(int slot, int doc) throws IOException {
             super.copy(slot, doc);
         }
 
-        @Override
-        protected boolean isMissingValueCompetitive() {
-            int result = missingValue.compareTo(bottom);
-            // in reverse (desc) sort missingValue is competitive when it's greater or equal to bottom,
-            // in asc sort missingValue is competitive when it's smaller or equal to bottom
-            return reverse ? (result >= 0) : (result <= 0);
-        }
-
         @Override
         protected void encodeBottom(byte[] packedValue) {
             BigIntegerPoint.encodeDimension(bottom, packedValue, 0);
@@ -103,5 +95,15 @@ protected void encodeBottom(byte[] packedValue) {
         protected void encodeTop(byte[] packedValue) {
             BigIntegerPoint.encodeDimension(topValue, packedValue, 0);
         }
+
+        @Override
+        protected int compareMissingValueWithBottomValue() {
+            return missingValue.compareTo(bottom);
+        }
+
+        @Override
+        protected int compareMissingValueWithTopValue() {
+            return missingValue.compareTo(topValue);
+        }
     }
 }
diff --git a/server/src/main/java/org/opensearch/index/search/stats/SearchStats.java b/server/src/main/java/org/opensearch/index/search/stats/SearchStats.java
index 76b216304b3b7..b13f1eb04a941 100644
--- a/server/src/main/java/org/opensearch/index/search/stats/SearchStats.java
+++ b/server/src/main/java/org/opensearch/index/search/stats/SearchStats.java
@@ -33,7 +33,10 @@
 package org.opensearch.index.search.stats;
 
 import org.opensearch.Version;
+import org.opensearch.action.search.SearchPhaseName;
+import org.opensearch.action.search.SearchRequestStats;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.Strings;
@@ -53,15 +56,87 @@
 /**
  * Encapsulates stats for search time
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchStats implements Writeable, ToXContentFragment {
 
     /**
-     * Statistics for search
+     * Holds statistic values for a particular phase.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
+    public static class PhaseStatsLongHolder implements Writeable {
+
+        long current;
+        long total;
+        long timeInMillis;
+
+        public long getCurrent() {
+            return current;
+        }
+
+        public long getTotal() {
+            return total;
+        }
+
+        public long getTimeInMillis() {
+            return timeInMillis;
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            out.writeVLong(current);
+            out.writeVLong(total);
+            out.writeVLong(timeInMillis);
+        }
+
+        PhaseStatsLongHolder() {
+            this(0, 0, 0);
+        }
+
+        PhaseStatsLongHolder(long current, long total, long timeInMillis) {
+            this.current = current;
+            this.total = total;
+            this.timeInMillis = timeInMillis;
+        }
+
+        PhaseStatsLongHolder(StreamInput in) throws IOException {
+            this.current = in.readVLong();
+            this.total = in.readVLong();
+            this.timeInMillis = in.readVLong();
+        }
+
+    }
+
+    /**
+     * Holds requests stats for different phases.
+     *
+     * @opensearch.api
+     */
+    @PublicApi(since = "1.0.0")
+    public static class RequestStatsLongHolder {
+
+        Map<String, PhaseStatsLongHolder> requestStatsHolder = new HashMap<>();
+
+        public Map<String, PhaseStatsLongHolder> getRequestStatsHolder() {
+            return requestStatsHolder;
+        }
+
+        RequestStatsLongHolder() {
+            for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+                requestStatsHolder.put(searchPhaseName.getName(), new PhaseStatsLongHolder());
+            }
+        }
+    }
+
+    /**
+     * Holder of statistics values
+     *
+     * @opensearch.api
+     */
+    @PublicApi(since = "1.0.0")
     public static class Stats implements Writeable, ToXContentFragment {
 
         private long queryCount;
@@ -89,6 +164,13 @@ public static class Stats implements Writeable, ToXContentFragment {
         private long pitTimeInMillis;
         private long pitCurrent;
 
+        @Nullable
+        private RequestStatsLongHolder requestStatsLongHolder;
+
+        public RequestStatsLongHolder getRequestStatsLongHolder() {
+            return requestStatsLongHolder;
+        }
+
         private Stats() {
             // for internal use, initializes all counts to 0
         }
@@ -114,6 +196,7 @@ public Stats(
             long suggestTimeInMillis,
             long suggestCurrent
         ) {
+            this.requestStatsLongHolder = new RequestStatsLongHolder();
             this.queryCount = queryCount;
             this.queryTimeInMillis = queryTimeInMillis;
             this.queryCurrent = queryCurrent;
@@ -163,6 +246,10 @@ private Stats(StreamInput in) throws IOException {
                 pitCurrent = in.readVLong();
             }
 
+            if (in.getVersion().onOrAfter(Version.V_2_11_0)) {
+                this.requestStatsLongHolder = new RequestStatsLongHolder();
+                requestStatsLongHolder.requestStatsHolder = in.readMap(StreamInput::readString, PhaseStatsLongHolder::new);
+            }
             if (in.getVersion().onOrAfter(Version.V_2_10_0)) {
                 concurrentQueryCount = in.readVLong();
                 concurrentQueryTimeInMillis = in.readVLong();
@@ -354,6 +441,17 @@ public void writeTo(StreamOutput out) throws IOException {
                 out.writeVLong(pitCurrent);
             }
 
+            if (out.getVersion().onOrAfter(Version.V_2_11_0)) {
+                if (requestStatsLongHolder == null) {
+                    requestStatsLongHolder = new RequestStatsLongHolder();
+                }
+                out.writeMap(
+                    requestStatsLongHolder.getRequestStatsHolder(),
+                    StreamOutput::writeString,
+                    (stream, stats) -> stats.writeTo(stream)
+                );
+            }
+
             if (out.getVersion().onOrAfter(Version.V_2_10_0)) {
                 out.writeVLong(concurrentQueryCount);
                 out.writeVLong(concurrentQueryTimeInMillis);
@@ -391,6 +489,22 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.humanReadableField(Fields.SUGGEST_TIME_IN_MILLIS, Fields.SUGGEST_TIME, getSuggestTime());
             builder.field(Fields.SUGGEST_CURRENT, suggestCurrent);
 
+            if (requestStatsLongHolder != null) {
+                builder.startObject(Fields.REQUEST);
+
+                for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+                    PhaseStatsLongHolder statsLongHolder = requestStatsLongHolder.requestStatsHolder.get(searchPhaseName.getName());
+                    if (statsLongHolder == null) {
+                        continue;
+                    }
+                    builder.startObject(searchPhaseName.getName());
+                    builder.humanReadableField(Fields.TIME_IN_MILLIS, Fields.TIME, new TimeValue(statsLongHolder.timeInMillis));
+                    builder.field(Fields.CURRENT, statsLongHolder.current);
+                    builder.field(Fields.TOTAL, statsLongHolder.total);
+                    builder.endObject();
+                }
+                builder.endObject();
+            }
             return builder;
         }
     }
@@ -405,6 +519,24 @@ public SearchStats() {
         totalStats = new Stats();
     }
 
+    // Set the different Request Stats fields in here
+    public void setSearchRequestStats(SearchRequestStats searchRequestStats) {
+        if (totalStats.requestStatsLongHolder == null) {
+            totalStats.requestStatsLongHolder = new RequestStatsLongHolder();
+        }
+
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            totalStats.requestStatsLongHolder.requestStatsHolder.put(
+                searchPhaseName.getName(),
+                new PhaseStatsLongHolder(
+                    searchRequestStats.getPhaseCurrent(searchPhaseName),
+                    searchRequestStats.getPhaseTotal(searchPhaseName),
+                    searchRequestStats.getPhaseMetric(searchPhaseName)
+                )
+            );
+        }
+    }
+
     public SearchStats(Stats totalStats, long openContexts, @Nullable Map<String, Stats> groupStats) {
         this.totalStats = totalStats;
         this.openContexts = openContexts;
@@ -520,6 +652,12 @@ static final class Fields {
         static final String SUGGEST_TIME = "suggest_time";
         static final String SUGGEST_TIME_IN_MILLIS = "suggest_time_in_millis";
         static final String SUGGEST_CURRENT = "suggest_current";
+        static final String REQUEST = "request";
+        static final String TIME_IN_MILLIS = "time_in_millis";
+        static final String TIME = "time";
+        static final String CURRENT = "current";
+        static final String TOTAL = "total";
+
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/index/seqno/LocalCheckpointTracker.java b/server/src/main/java/org/opensearch/index/seqno/LocalCheckpointTracker.java
index 0a4c197898d3d..155866e20d007 100644
--- a/server/src/main/java/org/opensearch/index/seqno/LocalCheckpointTracker.java
+++ b/server/src/main/java/org/opensearch/index/seqno/LocalCheckpointTracker.java
@@ -147,7 +147,7 @@ public synchronized void markSeqNoAsPersisted(final long seqNo) {
 
     /**
      * Updates the processed sequence checkpoint to the given value.
-     *
+     * <p>
      * This method is only used for segment replication since indexing doesn't
      * take place on the replica allowing us to avoid the check that all sequence numbers
      * are consecutively processed.
@@ -208,7 +208,7 @@ public long getMaxSeqNo() {
 
     /**
      * constructs a {@link SeqNoStats} object, using local state and the supplied global checkpoint
-     *
+     * <p>
      * This is needed to make sure the persisted local checkpoint and max seq no are consistent
      */
     public synchronized SeqNoStats getStats(final long globalCheckpoint) {
diff --git a/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java b/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java
index 4b6d72b86ff62..7b9c1d3aa548f 100644
--- a/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java
+++ b/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java
@@ -42,6 +42,7 @@
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.SuppressForbidden;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.util.concurrent.ConcurrentCollections;
 import org.opensearch.core.action.ActionListener;
@@ -71,6 +72,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.OptionalLong;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
@@ -88,7 +90,7 @@
 
 /**
  * This class is responsible for tracking the replication group with its progress and safety markers (local and global checkpoints).
- *
+ * <p>
  * The global checkpoint is the highest sequence number for which all lower (or equal) sequence number have been processed
  * on all shards that are currently active. Since shards count as "active" when the cluster-manager starts
  * them, and before this primary shard has been notified of this fact, we also include shards that have completed recovery. These shards
@@ -112,10 +114,10 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
      *            checkpoint based on the local checkpoints of all in-sync shard copies.
      * - replica: this shard receives global checkpoint information from the primary (see
      *   {@link #updateGlobalCheckpointOnReplica(long, String)}).
-     *
+     * <p>
      * When a shard is initialized (be it a primary or replica), it initially operates in replica mode. The global checkpoint tracker is
      * then switched to primary mode in the following three scenarios:
-     *
+     * <p>
      * - An initializing primary shard that is not a relocation target is moved to primary mode (using {@link #activatePrimaryMode}) once
      *   the shard becomes active.
      * - An active replica shard is moved to primary mode (using {@link #activatePrimaryMode}) once it is promoted to primary.
@@ -140,7 +142,7 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
      * in-sync shard copies cannot grow, otherwise the relocation target might miss this information and increase the global checkpoint
      * to eagerly. As consequence, some of the methods in this class are not allowed to be called while a handoff is in progress,
      * in particular {@link #markAllocationIdAsInSync}.
-     *
+     * <p>
      * A notable exception to this is the method {@link #updateFromClusterManager}, which is still allowed to be called during a relocation handoff.
      * The reason for this is that the handoff might fail and can be aborted (using {@link #abortRelocationHandoff}), in which case
      * it is important that the global checkpoint tracker does not miss any state updates that might happened during the handoff attempt.
@@ -675,8 +677,9 @@ public synchronized void renewPeerRecoveryRetentionLeases() {
     /**
     * The state of the lucene checkpoint
     *
-    * @opensearch.internal
+    * @opensearch.api
     */
+    @PublicApi(since = "1.0.0")
     public static class CheckpointState implements Writeable {
 
         /**
@@ -1163,7 +1166,7 @@ public synchronized void updateGlobalCheckpointForShard(final String allocationI
 
     /**
      * Update the local knowledge of the visible checkpoint for the specified allocation ID.
-     *
+     * <p>
      * This method will also stop timers for each shard and compute replication lag metrics.
      *
      * @param allocationId     the allocation ID to update the global checkpoint for
@@ -1227,6 +1230,14 @@ public ReplicationCheckpoint getLatestReplicationCheckpoint() {
         return this.latestReplicationCheckpoint;
     }
 
+    private boolean isPrimaryRelocation(String allocationId) {
+        Optional<ShardRouting> shardRouting = routingTable.shards()
+            .stream()
+            .filter(routing -> routing.allocationId().getId().equals(allocationId))
+            .findAny();
+        return shardRouting.isPresent() && shardRouting.get().primary();
+    }
+
     private void createReplicationLagTimers() {
         for (Map.Entry<String, CheckpointState> entry : checkpoints.entrySet()) {
             final String allocationId = entry.getKey();
@@ -1236,6 +1247,7 @@ private void createReplicationLagTimers() {
                 // it is possible for a shard to be in-sync but not yet removed from the checkpoints collection after a failover event.
                 if (cps.inSync
                     && replicationGroup.getUnavailableInSyncShards().contains(allocationId) == false
+                    && isPrimaryRelocation(allocationId) == false
                     && latestReplicationCheckpoint.isAheadOf(cps.visibleReplicationCheckpoint)) {
                     cps.checkpointTimers.computeIfAbsent(latestReplicationCheckpoint, ignored -> new SegmentReplicationLagTimer());
                     logger.trace(
@@ -1267,6 +1279,7 @@ public synchronized void startReplicationLagTimers(ReplicationCheckpoint checkpo
                 final CheckpointState cps = e.getValue();
                 if (cps.inSync
                     && replicationGroup.getUnavailableInSyncShards().contains(allocationId) == false
+                    && isPrimaryRelocation(e.getKey()) == false
                     && latestReplicationCheckpoint.isAheadOf(cps.visibleReplicationCheckpoint)
                     && cps.checkpointTimers.containsKey(latestReplicationCheckpoint)) {
                     cps.checkpointTimers.get(latestReplicationCheckpoint).start();
@@ -1291,6 +1304,7 @@ public synchronized Set<SegmentReplicationShardStats> getSegmentReplicationStats
                     entry -> entry.getKey().equals(this.shardAllocationId) == false
                         && entry.getValue().inSync
                         && replicationGroup.getUnavailableInSyncShards().contains(entry.getKey()) == false
+                        && isPrimaryRelocation(entry.getKey()) == false
                 )
                 .map(entry -> buildShardStats(entry.getKey(), entry.getValue()))
                 .collect(Collectors.toUnmodifiableSet());
@@ -1308,8 +1322,10 @@ private SegmentReplicationShardStats buildShardStats(final String allocationId,
             allocationId,
             cps.checkpointTimers.size(),
             bytesBehind,
-            cps.checkpointTimers.values().stream().mapToLong(SegmentReplicationLagTimer::time).max().orElse(0),
-            cps.checkpointTimers.values().stream().mapToLong(SegmentReplicationLagTimer::totalElapsedTime).max().orElse(0),
+            bytesBehind > 0L ? cps.checkpointTimers.values().stream().mapToLong(SegmentReplicationLagTimer::time).max().orElse(0) : 0,
+            bytesBehind > 0L
+                ? cps.checkpointTimers.values().stream().mapToLong(SegmentReplicationLagTimer::totalElapsedTime).max().orElse(0)
+                : 0,
             cps.lastCompletedReplicationLag
         );
     }
@@ -1885,8 +1901,9 @@ private synchronized void waitForLocalCheckpointToAdvance() throws InterruptedEx
      * Represents the sequence number component of the primary context. This is the knowledge on the primary of the in-sync and initializing
      * shards and their local checkpoints.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class PrimaryContext implements Writeable {
 
         private final long clusterStateVersion;
diff --git a/server/src/main/java/org/opensearch/index/seqno/RetentionLease.java b/server/src/main/java/org/opensearch/index/seqno/RetentionLease.java
index 216b654f6ce6a..255ff115555d8 100644
--- a/server/src/main/java/org/opensearch/index/seqno/RetentionLease.java
+++ b/server/src/main/java/org/opensearch/index/seqno/RetentionLease.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.seqno;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -51,8 +52,9 @@
  * otherwise merge away operations that have been soft deleted). Each retention lease contains a unique identifier, the retaining sequence
  * number, the timestamp of when the lease was created or renewed, and the source of the retention lease (e.g., "ccr").
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RetentionLease implements ToXContentObject, Writeable {
 
     private final String id;
diff --git a/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseStats.java b/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseStats.java
index 512ef9bf4f0a5..d34d385c66eb6 100644
--- a/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseStats.java
+++ b/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.seqno;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -45,8 +46,9 @@
 /**
  * Represents retention lease stats.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RetentionLeaseStats implements ToXContentFragment, Writeable {
 
     private final RetentionLeases retentionLeases;
diff --git a/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncAction.java b/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncAction.java
index f74fc7eefe65c..ca3c7e1d49700 100644
--- a/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncAction.java
+++ b/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncAction.java
@@ -62,6 +62,7 @@
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.SystemIndices;
 import org.opensearch.tasks.Task;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TransportException;
 import org.opensearch.transport.TransportResponseHandler;
@@ -99,7 +100,8 @@ public RetentionLeaseSyncAction(
         final ShardStateAction shardStateAction,
         final ActionFilters actionFilters,
         final IndexingPressureService indexingPressureService,
-        final SystemIndices systemIndices
+        final SystemIndices systemIndices,
+        final Tracer tracer
     ) {
         super(
             settings,
@@ -115,7 +117,8 @@ public RetentionLeaseSyncAction(
             ignore -> ThreadPool.Names.MANAGEMENT,
             false,
             indexingPressureService,
-            systemIndices
+            systemIndices,
+            tracer
         );
     }
 
diff --git a/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncer.java b/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncer.java
index cefab995847b7..ece0ac2b7bf6b 100644
--- a/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncer.java
+++ b/server/src/main/java/org/opensearch/index/seqno/RetentionLeaseSyncer.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.seqno;
 
 import org.opensearch.action.support.replication.ReplicationResponse;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.shard.ShardId;
@@ -44,6 +45,7 @@
  *
  * @opensearch.internal
  */
+@PublicApi(since = "1.0.0")
 public class RetentionLeaseSyncer {
     private final SyncAction syncAction;
     private final BackgroundSyncAction backgroundSyncAction;
diff --git a/server/src/main/java/org/opensearch/index/seqno/RetentionLeases.java b/server/src/main/java/org/opensearch/index/seqno/RetentionLeases.java
index 74c4ddb6ebdb5..4e28e19c4b164 100644
--- a/server/src/main/java/org/opensearch/index/seqno/RetentionLeases.java
+++ b/server/src/main/java/org/opensearch/index/seqno/RetentionLeases.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.seqno;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -57,8 +58,9 @@
  * Represents a versioned collection of retention leases. We version the collection of retention leases to ensure that sync requests that
  * arrive out of order on the replica, using the version to ensure that older sync requests are rejected.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RetentionLeases implements ToXContentFragment, Writeable {
 
     private final long primaryTerm;
diff --git a/server/src/main/java/org/opensearch/index/seqno/SeqNoStats.java b/server/src/main/java/org/opensearch/index/seqno/SeqNoStats.java
index be7888ada2801..a8acf1fac7846 100644
--- a/server/src/main/java/org/opensearch/index/seqno/SeqNoStats.java
+++ b/server/src/main/java/org/opensearch/index/seqno/SeqNoStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.seqno;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * Sequence number statistics
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SeqNoStats implements ToXContentFragment, Writeable {
 
     private static final String SEQ_NO = "seq_no";
diff --git a/server/src/main/java/org/opensearch/index/seqno/SequenceNumbers.java b/server/src/main/java/org/opensearch/index/seqno/SequenceNumbers.java
index 210976ffba58a..b9959941d843f 100644
--- a/server/src/main/java/org/opensearch/index/seqno/SequenceNumbers.java
+++ b/server/src/main/java/org/opensearch/index/seqno/SequenceNumbers.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.index.seqno;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.Map;
 
 /**
@@ -132,8 +134,9 @@ public static long max(final long maxSeqNo, final long seqNo) {
     /**
      * Commit information
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class CommitInfo {
         public final long maxSeqNo;
         public final long localCheckpoint;
diff --git a/server/src/main/java/org/opensearch/index/shard/CheckpointRefreshListener.java b/server/src/main/java/org/opensearch/index/shard/CheckpointRefreshListener.java
index 85d744e58265f..675d60ec2b63d 100644
--- a/server/src/main/java/org/opensearch/index/shard/CheckpointRefreshListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/CheckpointRefreshListener.java
@@ -21,7 +21,7 @@
  *
  * @opensearch.internal
  */
-public class CheckpointRefreshListener extends CloseableRetryableRefreshListener {
+public class CheckpointRefreshListener extends ReleasableRetryableRefreshListener {
 
     protected static Logger logger = LogManager.getLogger(CheckpointRefreshListener.class);
 
diff --git a/server/src/main/java/org/opensearch/index/shard/DocsStats.java b/server/src/main/java/org/opensearch/index/shard/DocsStats.java
index 83cc69752db2f..4ca475a45c04b 100644
--- a/server/src/main/java/org/opensearch/index/shard/DocsStats.java
+++ b/server/src/main/java/org/opensearch/index/shard/DocsStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * Document statistics
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DocsStats implements Writeable, ToXContentFragment {
 
     private long count = 0;
diff --git a/server/src/main/java/org/opensearch/index/shard/GlobalCheckpointListeners.java b/server/src/main/java/org/opensearch/index/shard/GlobalCheckpointListeners.java
index 3948baa5d5164..c1b66909a82a9 100644
--- a/server/src/main/java/org/opensearch/index/shard/GlobalCheckpointListeners.java
+++ b/server/src/main/java/org/opensearch/index/shard/GlobalCheckpointListeners.java
@@ -34,6 +34,7 @@
 
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.concurrent.FutureUtils;
@@ -67,8 +68,9 @@ public class GlobalCheckpointListeners implements Closeable {
     /**
      * A global checkpoint listener consisting of a callback that is notified when the global checkpoint is updated or the shard is closed.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface GlobalCheckpointListener {
 
         /**
diff --git a/server/src/main/java/org/opensearch/index/shard/IllegalIndexShardStateException.java b/server/src/main/java/org/opensearch/index/shard/IllegalIndexShardStateException.java
index 47ed149913914..991481899c83f 100644
--- a/server/src/main/java/org/opensearch/index/shard/IllegalIndexShardStateException.java
+++ b/server/src/main/java/org/opensearch/index/shard/IllegalIndexShardStateException.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.shard;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.index.shard.ShardId;
@@ -43,8 +44,9 @@
 /**
  * Exception thrown when an index shard is in an illegal state
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IllegalIndexShardStateException extends OpenSearchException {
 
     private final IndexShardState currentState;
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexEventListener.java b/server/src/main/java/org/opensearch/index/shard/IndexEventListener.java
index d1cb396f55d0f..693686ec228e9 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexEventListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexEventListener.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.index.Index;
 import org.opensearch.core.index.shard.ShardId;
@@ -51,8 +52,9 @@
  * modify local state without sufficient synchronization.
  * </p>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IndexEventListener {
 
     /**
@@ -155,7 +157,7 @@ default void beforeIndexShardDeleted(ShardId shardId, Settings indexSettings) {}
 
     /**
      * Called after the index shard has been deleted from disk.
-     *
+     * <p>
      * Note: this method is only called if the deletion of the shard did finish without an exception
      *
      * @param shardId The shard id
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShard.java b/server/src/main/java/org/opensearch/index/shard/IndexShard.java
index bfb492d5a2f45..8d4c93ae48af3 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShard.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShard.java
@@ -78,6 +78,7 @@
 import org.opensearch.common.CheckedRunnable;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.concurrent.GatedCloseable;
 import org.opensearch.common.io.stream.BytesStreamOutput;
@@ -96,7 +97,6 @@
 import org.opensearch.common.util.concurrent.RunOnce;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.common.util.io.IOUtils;
-import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.Assertions;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.unit.ByteSizeValue;
@@ -161,6 +161,7 @@
 import org.opensearch.index.shard.PrimaryReplicaSyncer.ResyncTask;
 import org.opensearch.index.similarity.SimilarityService;
 import org.opensearch.index.store.RemoteSegmentStoreDirectory;
+import org.opensearch.index.store.RemoteStoreFileDownloader;
 import org.opensearch.index.store.Store;
 import org.opensearch.index.store.Store.MetadataSnapshot;
 import org.opensearch.index.store.StoreFileMetadata;
@@ -182,10 +183,12 @@
 import org.opensearch.indices.recovery.PeerRecoveryTargetService;
 import org.opensearch.indices.recovery.RecoveryFailedException;
 import org.opensearch.indices.recovery.RecoveryListener;
+import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.indices.recovery.RecoveryTarget;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 import org.opensearch.indices.replication.checkpoint.SegmentReplicationCheckpointPublisher;
+import org.opensearch.indices.replication.common.ReplicationTimer;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.Repository;
 import org.opensearch.search.suggest.completion.CompletionStats;
@@ -196,10 +199,12 @@
 import java.io.IOException;
 import java.io.PrintStream;
 import java.nio.channels.ClosedByInterruptException;
+import java.nio.channels.FileChannel;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.NoSuchFileException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.HashSet;
@@ -235,8 +240,9 @@
 /**
  * An OpenSearch index shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShard extends AbstractIndexShardComponent implements IndicesClusterStateService.Shard {
 
     private final ThreadPool threadPool;
@@ -338,6 +344,8 @@ Runnable getGlobalCheckpointSyncer() {
     private final RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory;
 
     private final List<ReferenceManager.RefreshListener> internalRefreshListener = new ArrayList<>();
+    private final RemoteStoreFileDownloader fileDownloader;
+    private final RecoverySettings recoverySettings;
 
     public IndexShard(
         final ShardRouting shardRouting,
@@ -364,7 +372,9 @@ public IndexShard(
         @Nullable final SegmentReplicationCheckpointPublisher checkpointPublisher,
         @Nullable final Store remoteStore,
         final RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory,
-        final Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier
+        final Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier,
+        final String nodeId,
+        final RecoverySettings recoverySettings
     ) throws IOException {
         super(shardRouting.shardId(), indexSettings);
         assert shardRouting.initializing();
@@ -410,7 +420,7 @@ public IndexShard(
         logger.debug("state: [CREATED]");
 
         this.checkIndexOnStartup = indexSettings.getValue(IndexSettings.INDEX_CHECK_ON_STARTUP);
-        this.translogConfig = new TranslogConfig(shardId, shardPath().resolveTranslog(), indexSettings, bigArrays);
+        this.translogConfig = new TranslogConfig(shardId, shardPath().resolveTranslog(), indexSettings, bigArrays, nodeId);
         final String aId = shardRouting.allocationId().getId();
         final long primaryTerm = indexSettings.getIndexMetadata().primaryTerm(shardId.id());
         this.pendingPrimaryTerm = primaryTerm;
@@ -460,6 +470,8 @@ public boolean shouldCache(Query query) {
             ? false
             : mapperService.documentMapper().mappers().containsTimeStampField();
         this.remoteStoreStatsTrackerFactory = remoteStoreStatsTrackerFactory;
+        this.recoverySettings = recoverySettings;
+        this.fileDownloader = new RemoteStoreFileDownloader(shardRouting.shardId(), threadPool, recoverySettings);
     }
 
     public ThreadPool getThreadPool() {
@@ -553,6 +565,18 @@ protected RemoteStoreStatsTrackerFactory getRemoteStoreStatsTrackerFactory() {
         return remoteStoreStatsTrackerFactory;
     }
 
+    public String getNodeId() {
+        return translogConfig.getNodeId();
+    }
+
+    public RecoverySettings getRecoverySettings() {
+        return recoverySettings;
+    }
+
+    public RemoteStoreFileDownloader getFileDownloader() {
+        return fileDownloader;
+    }
+
     @Override
     public void updateShardState(
         final ShardRouting newRouting,
@@ -626,7 +650,7 @@ public void updateShardState(
                     if (currentRouting.initializing() && currentRouting.isRelocationTarget() == false && newRouting.active()) {
                         // the cluster-manager started a recovering primary, activate primary mode.
                         replicationTracker.activatePrimaryMode(getLocalCheckpoint());
-                        ensurePeerRecoveryRetentionLeasesExist();
+                        postActivatePrimaryMode();
                     }
                 } else {
                     assert currentRouting.primary() == false : "term is only increased as part of primary promotion";
@@ -684,7 +708,16 @@ public void updateShardState(
                             if (indexSettings.isSegRepEnabled()) {
                                 // this Shard's engine was read only, we need to update its engine before restoring local history from xlog.
                                 assert newRouting.primary() && currentRouting.primary() == false;
+                                ReplicationTimer timer = new ReplicationTimer();
+                                timer.start();
+                                logger.debug(
+                                    "Resetting engine on promotion of shard [{}] to primary, startTime {}\n",
+                                    shardId,
+                                    timer.startTime()
+                                );
                                 resetEngineToGlobalCheckpoint();
+                                timer.stop();
+                                logger.info("Completed engine failover for shard [{}] in: {} ms", shardId, timer.time());
                                 // It is possible an engine can open with a SegmentInfos on a higher gen but the reader does not refresh to
                                 // trigger our refresh listener.
                                 // Force update the checkpoint post engine reset.
@@ -697,8 +730,7 @@ public void updateShardState(
                                 // are brought up to date.
                                 checkpointPublisher.publish(this, getLatestReplicationCheckpoint());
                             }
-
-                            ensurePeerRecoveryRetentionLeasesExist();
+                            postActivatePrimaryMode();
                             /*
                              * If this shard was serving as a replica shard when another shard was promoted to primary then
                              * its Lucene index was reset during the primary term transition. In particular, the Lucene index
@@ -819,6 +851,9 @@ public void relocated(
         final Runnable performSegRep
     ) throws IllegalIndexShardStateException, IllegalStateException, InterruptedException {
         assert shardRouting.primary() : "only primaries can be marked as relocated: " + shardRouting;
+        // The below list of releasable ensures that if the relocation does not happen, we undo the activity of close and
+        // acquire all permits. This will ensure that the remote store uploads can still be done by the existing primary shard.
+        List<Releasable> releasablesOnHandoffFailures = new ArrayList<>(2);
         try (Releasable forceRefreshes = refreshListeners.forceRefreshes()) {
             indexShardOperationPermits.blockOperations(30, TimeUnit.MINUTES, () -> {
                 forceRefreshes.close();
@@ -831,11 +866,15 @@ public void relocated(
                     maybeSync();
                 }
 
-                // Ensures all in-flight remote store operations drain, before we perform the handoff.
-                internalRefreshListener.stream()
-                    .filter(refreshListener -> refreshListener instanceof Closeable)
-                    .map(refreshListener -> (Closeable) refreshListener)
-                    .close();
+                // Ensures all in-flight remote store refreshes drain, before we perform the performSegRep.
+                for (ReferenceManager.RefreshListener refreshListener : internalRefreshListener) {
+                    if (refreshListener instanceof ReleasableRetryableRefreshListener) {
+                        releasablesOnHandoffFailures.add(((ReleasableRetryableRefreshListener) refreshListener).drainRefreshes());
+                    }
+                }
+
+                // Ensure all in-flight remote store translog upload drains, before we perform the performSegRep.
+                releasablesOnHandoffFailures.add(getEngine().translogManager().drainSync());
 
                 // no shard operation permits are being held here, move state from started to relocated
                 assert indexShardOperationPermits.getActiveOperationsCount() == OPERATIONS_BLOCKED
@@ -853,7 +892,7 @@ public void relocated(
                     synchronized (mutex) {
                         verifyRelocatingState();
                         replicationTracker.completeRelocationHandoff(); // make changes to primaryMode and relocated flag only under
-                                                                        // mutex
+                        // mutex
                     }
                 } catch (final Exception e) {
                     try {
@@ -870,6 +909,13 @@ public void relocated(
             // Fail primary relocation source and target shards.
             failShard("timed out waiting for relocation hand-off to complete", null);
             throw new IndexShardClosedException(shardId(), "timed out waiting for relocation hand-off to complete");
+        } catch (Exception ex) {
+            assert replicationTracker.isPrimaryMode();
+            // If the primary mode is still true after the end of handoff attempt, it basically means that the relocation
+            // failed. The existing primary will continue to be the primary, so we need to allow the segments and translog
+            // upload to resume.
+            Releasables.close(releasablesOnHandoffFailures);
+            throw ex;
         }
     }
 
@@ -1380,7 +1426,9 @@ public MergeStats mergeStats() {
         if (engine == null) {
             return new MergeStats();
         }
-        return engine.getMergeStats();
+        final MergeStats mergeStats = engine.getMergeStats();
+        mergeStats.addUnreferencedFileCleanUpStats(engine.unreferencedFileCleanUpsPerformed());
+        return mergeStats;
     }
 
     public SegmentsStats segmentStats(boolean includeSegmentFileSizes, boolean includeUnloadedSegments) {
@@ -1448,6 +1496,9 @@ public void flush(FlushRequest request) {
      * {@link org.opensearch.index.translog.TranslogDeletionPolicy} for details
      */
     public void trimTranslog() {
+        if (isRemoteTranslogEnabled()) {
+            return;
+        }
         verifyNotClosed();
         final Engine engine = getEngine();
         engine.translogManager().trimUnreferencedTranslogFiles();
@@ -1456,7 +1507,7 @@ public void trimTranslog() {
     /**
      * Rolls the tranlog generation and cleans unneeded.
      */
-    public void rollTranslogGeneration() {
+    public void rollTranslogGeneration() throws IOException {
         final Engine engine = getEngine();
         engine.translogManager().rollTranslogGeneration();
     }
@@ -1589,8 +1640,11 @@ public GatedCloseable<IndexCommit> acquireSafeIndexCommit() throws EngineExcepti
     }
 
     /**
-     * Compute and return the latest ReplicationCheckpoint for a particular shard.
-     * @return EMPTY checkpoint before the engine is opened and null for non-segrep enabled indices
+     * return the most recently computed ReplicationCheckpoint for a particular shard.
+     * The checkpoint is updated inside a refresh listener and may lag behind the SegmentInfos on the reader.
+     * To guarantee the checkpoint is upto date with the latest on-reader infos, use `getLatestSegmentInfosAndCheckpoint` instead.
+     *
+     * @return {@link ReplicationCheckpoint} - The most recently computed ReplicationCheckpoint.
      */
     public ReplicationCheckpoint getLatestReplicationCheckpoint() {
         return replicationTracker.getLatestReplicationCheckpoint();
@@ -1599,7 +1653,7 @@ public ReplicationCheckpoint getLatestReplicationCheckpoint() {
     /**
      * Compute and return the latest ReplicationCheckpoint for a shard and a GatedCloseable containing the corresponding SegmentInfos.
      * The segments referenced by the SegmentInfos will remain on disk until the GatedCloseable is closed.
-     *
+     * <p>
      * Primary shards compute the seqNo used in the replication checkpoint from the fetched SegmentInfos.
      * Replica shards compute the seqNo from its latest processed checkpoint, which only increases when refreshing on new segments.
      *
@@ -1609,34 +1663,12 @@ public ReplicationCheckpoint getLatestReplicationCheckpoint() {
     public Tuple<GatedCloseable<SegmentInfos>, ReplicationCheckpoint> getLatestSegmentInfosAndCheckpoint() {
         assert indexSettings.isSegRepEnabled();
 
-        Tuple<GatedCloseable<SegmentInfos>, ReplicationCheckpoint> nullSegmentInfosEmptyCheckpoint = new Tuple<>(
-            new GatedCloseable<>(null, () -> {}),
-            getLatestReplicationCheckpoint()
-        );
-
-        if (getEngineOrNull() == null) {
-            return nullSegmentInfosEmptyCheckpoint;
-        }
         // do not close the snapshot - caller will close it.
         GatedCloseable<SegmentInfos> snapshot = null;
         try {
             snapshot = getSegmentInfosSnapshot();
-            if (snapshot.get() != null) {
-                SegmentInfos segmentInfos = snapshot.get();
-                final Map<String, StoreFileMetadata> metadataMap = store.getSegmentMetadataMap(segmentInfos);
-                return new Tuple<>(
-                    snapshot,
-                    new ReplicationCheckpoint(
-                        this.shardId,
-                        getOperationPrimaryTerm(),
-                        segmentInfos.getGeneration(),
-                        segmentInfos.getVersion(),
-                        metadataMap.values().stream().mapToLong(StoreFileMetadata::length).sum(),
-                        getEngine().config().getCodec().getName(),
-                        metadataMap
-                    )
-                );
-            }
+            final SegmentInfos segmentInfos = snapshot.get();
+            return new Tuple<>(snapshot, computeReplicationCheckpoint(segmentInfos));
         } catch (IOException | AlreadyClosedException e) {
             logger.error("Error Fetching SegmentInfos and latest checkpoint", e);
             if (snapshot != null) {
@@ -1647,7 +1679,39 @@ public Tuple<GatedCloseable<SegmentInfos>, ReplicationCheckpoint> getLatestSegme
                 }
             }
         }
-        return nullSegmentInfosEmptyCheckpoint;
+        return new Tuple<>(new GatedCloseable<>(null, () -> {}), getLatestReplicationCheckpoint());
+    }
+
+    /**
+     * Compute the latest {@link ReplicationCheckpoint} from a SegmentInfos.
+     * This function fetches a metadata snapshot from the store that comes with an IO cost.
+     * We will reuse the existing stored checkpoint if it is at the same SI version.
+     *
+     * @param segmentInfos {@link SegmentInfos} infos to use to compute.
+     * @return {@link ReplicationCheckpoint} Checkpoint computed from the infos.
+     * @throws IOException When there is an error computing segment metadata from the store.
+     */
+    ReplicationCheckpoint computeReplicationCheckpoint(SegmentInfos segmentInfos) throws IOException {
+        if (segmentInfos == null) {
+            return ReplicationCheckpoint.empty(shardId);
+        }
+        final ReplicationCheckpoint latestReplicationCheckpoint = getLatestReplicationCheckpoint();
+        if (latestReplicationCheckpoint.getSegmentInfosVersion() == segmentInfos.getVersion()
+            && latestReplicationCheckpoint.getSegmentsGen() == segmentInfos.getGeneration()) {
+            return latestReplicationCheckpoint;
+        }
+        final Map<String, StoreFileMetadata> metadataMap = store.getSegmentMetadataMap(segmentInfos);
+        final ReplicationCheckpoint checkpoint = new ReplicationCheckpoint(
+            this.shardId,
+            getOperationPrimaryTerm(),
+            segmentInfos.getGeneration(),
+            segmentInfos.getVersion(),
+            metadataMap.values().stream().mapToLong(StoreFileMetadata::length).sum(),
+            getEngine().config().getCodec().getName(),
+            metadataMap
+        );
+        logger.trace("Recomputed ReplicationCheckpoint for shard {}", checkpoint);
+        return checkpoint;
     }
 
     /**
@@ -1700,8 +1764,8 @@ public final boolean shouldProcessCheckpoint(ReplicationCheckpoint requestCheckp
         if (isSegmentReplicationAllowed() == false) {
             return false;
         }
-        ReplicationCheckpoint localCheckpoint = getLatestReplicationCheckpoint();
-        if (localCheckpoint.isAheadOf(requestCheckpoint)) {
+        final ReplicationCheckpoint localCheckpoint = getLatestReplicationCheckpoint();
+        if (requestCheckpoint.isAheadOf(localCheckpoint) == false) {
             logger.trace(
                 () -> new ParameterizedMessage(
                     "Ignoring new replication checkpoint - Shard is already on checkpoint {} that is ahead of {}",
@@ -1711,12 +1775,6 @@ public final boolean shouldProcessCheckpoint(ReplicationCheckpoint requestCheckp
             );
             return false;
         }
-        if (localCheckpoint.equals(requestCheckpoint)) {
-            logger.trace(
-                () -> new ParameterizedMessage("Ignoring new replication checkpoint - Shard is already on checkpoint {}", requestCheckpoint)
-            );
-            return false;
-        }
         return true;
     }
 
@@ -1965,6 +2023,29 @@ private RemoteSegmentStoreDirectory getRemoteDirectory() {
         return ((RemoteSegmentStoreDirectory) remoteDirectory);
     }
 
+    /**
+    Returns true iff it is able to verify that remote segment store
+    is in sync with local
+     */
+    boolean isRemoteSegmentStoreInSync() {
+        assert indexSettings.isRemoteStoreEnabled();
+        try {
+            RemoteSegmentStoreDirectory directory = getRemoteDirectory();
+            if (directory.readLatestMetadataFile() != null) {
+                // verifying that all files except EXCLUDE_FILES are uploaded to the remote
+                Collection<String> uploadFiles = directory.getSegmentsUploadedToRemoteStore().keySet();
+                SegmentInfos segmentInfos = store.readLastCommittedSegmentsInfo();
+                Collection<String> localFiles = segmentInfos.files(true);
+                if (uploadFiles.containsAll(localFiles)) {
+                    return true;
+                }
+            }
+        } catch (IOException e) {
+            logger.error("Exception while reading latest metadata", e);
+        }
+        return false;
+    }
+
     public void preRecovery() {
         final IndexShardState currentState = this.state; // single volatile read
         if (currentState == IndexShardState.CLOSED) {
@@ -2297,7 +2378,7 @@ public void openEngineAndRecoverFromTranslog() throws IOException {
         };
 
         // Do not load the global checkpoint if this is a remote snapshot index
-        if (indexSettings.isRemoteSnapshot() == false) {
+        if (indexSettings.isRemoteSnapshot() == false && indexSettings.isRemoteTranslogStoreEnabled() == false) {
             loadGlobalCheckpointToReplicationTracker();
         }
 
@@ -2355,19 +2436,38 @@ private void innerOpenEngineAndTranslog(LongSupplier globalCheckpointSupplier, b
         synchronized (engineMutex) {
             assert currentEngineReference.get() == null : "engine is running";
             verifyNotClosed();
-            if (indexSettings.isRemoteStoreEnabled() && syncFromRemote) {
-                syncSegmentsFromRemoteSegmentStore(false);
-            }
-            if (indexSettings.isRemoteTranslogStoreEnabled() && shardRouting.primary()) {
+            if (indexSettings.isRemoteStoreEnabled()) {
+                // Download missing segments from remote segment store.
                 if (syncFromRemote) {
-                    syncRemoteTranslogAndUpdateGlobalCheckpoint();
-                } else {
-                    // we will enter this block when we do not want to recover from remote translog.
-                    // currently only during snapshot restore, we are coming into this block.
-                    // here, as while initiliazing remote translog we cannot skip downloading translog files,
-                    // so before that step, we are deleting the translog files present in remote store.
-                    deleteTranslogFilesFromRemoteTranslog();
-
+                    syncSegmentsFromRemoteSegmentStore(false);
+                }
+                if (shardRouting.primary()) {
+                    if (syncFromRemote) {
+                        syncRemoteTranslogAndUpdateGlobalCheckpoint();
+                    } else {
+                        // we will enter this block when we do not want to recover from remote translog.
+                        // currently only during snapshot restore, we are coming into this block.
+                        // here, as while initiliazing remote translog we cannot skip downloading translog files,
+                        // so before that step, we are deleting the translog files present in remote store.
+                        deleteTranslogFilesFromRemoteTranslog();
+                    }
+                } else if (syncFromRemote) {
+                    // For replicas, when we download segments from remote segment store, we need to make sure that local
+                    // translog is having the same UUID that is referred by the segments. If they are different, engine open
+                    // fails with TranslogCorruptedException. It is safe to create empty translog for remote store enabled
+                    // indices as replica would only need to read translog in failover scenario and we always fetch data
+                    // from remote translog at the time of failover.
+                    final SegmentInfos lastCommittedSegmentInfos = store().readLastCommittedSegmentsInfo();
+                    final String translogUUID = lastCommittedSegmentInfos.userData.get(TRANSLOG_UUID_KEY);
+                    final long checkpoint = Long.parseLong(lastCommittedSegmentInfos.userData.get(SequenceNumbers.LOCAL_CHECKPOINT_KEY));
+                    Translog.createEmptyTranslog(
+                        shardPath().resolveTranslog(),
+                        shardId(),
+                        checkpoint,
+                        getPendingPrimaryTerm(),
+                        translogUUID,
+                        FileChannel::open
+                    );
                 }
             }
             // we must create a new engine under mutex (see IndexShard#snapshotStoreMetadata).
@@ -2959,7 +3059,7 @@ public ReplicationStats getReplicationStats() {
             long maxBytesBehind = stats.stream().mapToLong(SegmentReplicationShardStats::getBytesBehindCount).max().orElse(0L);
             long totalBytesBehind = stats.stream().mapToLong(SegmentReplicationShardStats::getBytesBehindCount).sum();
             long maxReplicationLag = stats.stream()
-                .mapToLong(SegmentReplicationShardStats::getCurrentReplicationTimeMillis)
+                .mapToLong(SegmentReplicationShardStats::getCurrentReplicationLagMillis)
                 .max()
                 .orElse(0L);
             return new ReplicationStats(maxBytesBehind, totalBytesBehind, maxReplicationLag);
@@ -3342,6 +3442,20 @@ assert getLocalCheckpoint() == primaryContext.getCheckpointStates().get(routingE
         synchronized (mutex) {
             replicationTracker.activateWithPrimaryContext(primaryContext); // make changes to primaryMode flag only under mutex
         }
+        postActivatePrimaryMode();
+    }
+
+    private void postActivatePrimaryMode() {
+        if (indexSettings.isRemoteStoreEnabled()) {
+            // We make sure to upload translog (even if it does not contain any operations) to remote translog.
+            // This helps to get a consistent state in remote store where both remote segment store and remote
+            // translog contains data.
+            try {
+                getEngine().translogManager().syncTranslog();
+            } catch (IOException e) {
+                logger.error("Failed to sync translog to remote from new primary", e);
+            }
+        }
         ensurePeerRecoveryRetentionLeasesExist();
     }
 
@@ -3486,6 +3600,7 @@ public void startRecovery(
         // }
         // }}
         // }
+        logger.debug("startRecovery type={}", recoveryState.getRecoverySource().getType());
         assert recoveryState.getRecoverySource().equals(shardRouting.recoverySource());
         switch (recoveryState.getRecoverySource().getType()) {
             case EMPTY_STORE:
@@ -3735,9 +3850,9 @@ private EngineConfig newEngineConfig(LongSupplier globalCheckpointSupplier) thro
             );
         }
 
-        /**
-         * With segment replication enabled for primary relocation, recover replica shard initially as read only and
-         * change to a writeable engine during relocation handoff after a round of segment replication.
+        /*
+          With segment replication enabled for primary relocation, recover replica shard initially as read only and
+          change to a writeable engine during relocation handoff after a round of segment replication.
          */
         boolean isReadOnlyReplica = indexSettings.isSegRepEnabled()
             && (shardRouting.primary() == false
@@ -3749,7 +3864,7 @@ private EngineConfig newEngineConfig(LongSupplier globalCheckpointSupplier) thro
             indexSettings,
             warmer,
             store,
-            indexSettings.getMergePolicy(),
+            indexSettings.getMergePolicy(isTimeSeriesIndex),
             mapperService != null ? mapperService.indexAnalyzer() : null,
             similarityService.similarity(mapperService),
             engineConfigFactory.newCodecServiceOrDefault(indexSettings, mapperService, logger, codecService),
@@ -3764,13 +3879,13 @@ private EngineConfig newEngineConfig(LongSupplier globalCheckpointSupplier) thro
             circuitBreakerService,
             globalCheckpointSupplier,
             replicationTracker::getRetentionLeases,
-            () -> getOperationPrimaryTerm(),
+            this::getOperationPrimaryTerm,
             tombstoneDocSupplier(),
             isReadOnlyReplica,
-            replicationTracker::isPrimaryMode,
+            this::isStartedPrimary,
             translogFactorySupplier.apply(indexSettings, shardRouting),
             isTimeSeriesDescSortOptimizationEnabled() ? DataStream.TIMESERIES_LEAF_SORTER : null // DESC @timestamp default order for
-                                                                                                 // timeseries
+            // timeseries
         );
     }
 
@@ -3782,6 +3897,15 @@ public boolean isRemoteTranslogEnabled() {
         return indexSettings() != null && indexSettings().isRemoteTranslogStoreEnabled();
     }
 
+    /**
+     * This checks if we are in state to upload to remote store. Until the cluster-manager informs the shard through
+     * cluster state, the shard will not be in STARTED state. This method is used to prevent pre-emptive segment or
+     * translog uploads.
+     */
+    public boolean isStartedPrimary() {
+        return getReplicationTracker().isPrimaryMode() && state() == IndexShardState.STARTED;
+    }
+
     /**
      * @return true if segment reverse search optimization is enabled for time series based workload.
      */
@@ -4304,8 +4428,9 @@ private RefreshListeners buildRefreshListeners() {
      *
      * @see IndexShard#addShardFailureCallback(Consumer)
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class ShardFailure {
         public final ShardRouting routing;
         public final String reason;
@@ -4373,15 +4498,19 @@ public final boolean isSearchIdle() {
     }
 
     /**
-     *
      * Returns true if this shard supports search idle.
-     *
+     * <p>
      * Indices using Segment Replication will ignore search idle unless there are no replicas.
      * Primary shards push out new segments only
      * after a refresh, so we don't want to wait for a search to trigger that cycle. Replicas will only refresh after receiving
      * a new set of segments.
      */
     public final boolean isSearchIdleSupported() {
+        // If the index is remote store backed, then search idle is not supported. This is to ensure that async refresh
+        // task continues to upload to remote store periodically.
+        if (isRemoteTranslogEnabled()) {
+            return false;
+        }
         return indexSettings.isSegRepEnabled() == false || indexSettings.getNumberOfReplicas() == 0;
     }
 
@@ -4703,11 +4832,23 @@ public void syncTranslogFilesFromRemoteTranslog() throws IOException {
     }
 
     /**
-     * Downloads segments from remote segment store.
-     * @param overrideLocal flag to override local segment files with those in remote store
-     * @throws IOException if exception occurs while reading segments from remote store
+     * Downloads segments from remote segment store
+     * @param overrideLocal flag to override local segment files with those in remote store.
+     * @throws IOException if exception occurs while reading segments from remote store.
      */
     public void syncSegmentsFromRemoteSegmentStore(boolean overrideLocal) throws IOException {
+        syncSegmentsFromRemoteSegmentStore(overrideLocal, () -> {});
+    }
+
+    /**
+     * Downloads segments from remote segment store along with updating the access time of the recovery target.
+     * @param overrideLocal flag to override local segment files with those in remote store.
+     * @param onFileSync runnable that updates the access time when run.
+     * @throws IOException if exception occurs while reading segments from remote store.
+     */
+    public void syncSegmentsFromRemoteSegmentStore(boolean overrideLocal, final Runnable onFileSync) throws IOException {
+        boolean syncSegmentSuccess = false;
+        long startTimeMs = System.currentTimeMillis();
         assert indexSettings.isRemoteStoreEnabled();
         logger.trace("Downloading segments from remote segment store");
         RemoteSegmentStoreDirectory remoteDirectory = getRemoteDirectory();
@@ -4738,7 +4879,7 @@ public void syncSegmentsFromRemoteSegmentStore(boolean overrideLocal) throws IOE
             } else {
                 storeDirectory = store.directory();
             }
-            copySegmentFiles(storeDirectory, remoteDirectory, null, uploadedSegments, overrideLocal);
+            copySegmentFiles(storeDirectory, remoteDirectory, null, uploadedSegments, overrideLocal, onFileSync);
 
             if (remoteSegmentMetadata != null) {
                 final SegmentInfos infosSnapshot = store.buildSegmentInfos(
@@ -4757,9 +4898,15 @@ public void syncSegmentsFromRemoteSegmentStore(boolean overrideLocal) throws IOE
                     : "There should not be any segments file in the dir";
                 store.commitSegmentInfos(infosSnapshot, processedLocalCheckpoint, processedLocalCheckpoint);
             }
+            syncSegmentSuccess = true;
         } catch (IOException e) {
             throw new IndexShardRecoveryException(shardId, "Exception while copying segment files from remote segment store", e);
         } finally {
+            logger.trace(
+                "syncSegmentsFromRemoteSegmentStore success={} elapsedTime={}",
+                syncSegmentSuccess,
+                (System.currentTimeMillis() - startTimeMs)
+            );
             store.decRef();
             remoteStore.decRef();
         }
@@ -4787,8 +4934,7 @@ public void syncSegmentsFromGivenRemoteSegmentStore(
             remoteStore.incRef();
         }
         Map<String, RemoteSegmentStoreDirectory.UploadedSegmentMetadata> uploadedSegments = sourceRemoteDirectory
-            .initializeToSpecificCommit(primaryTerm, commitGeneration)
-            .getMetadata();
+            .getSegmentsUploadedToRemoteStore();
         final Directory storeDirectory = store.directory();
         store.incRef();
 
@@ -4798,7 +4944,8 @@ public void syncSegmentsFromGivenRemoteSegmentStore(
                 sourceRemoteDirectory,
                 remoteDirectory,
                 uploadedSegments,
-                overrideLocal
+                overrideLocal,
+                () -> {}
             );
             if (segmentsNFile != null) {
                 try (
@@ -4831,42 +4978,51 @@ private String copySegmentFiles(
         RemoteSegmentStoreDirectory sourceRemoteDirectory,
         RemoteSegmentStoreDirectory targetRemoteDirectory,
         Map<String, RemoteSegmentStoreDirectory.UploadedSegmentMetadata> uploadedSegments,
-        boolean overrideLocal
+        boolean overrideLocal,
+        final Runnable onFileSync
     ) throws IOException {
-        List<String> downloadedSegments = new ArrayList<>();
-        List<String> skippedSegments = new ArrayList<>();
+        Set<String> toDownloadSegments = new HashSet<>();
+        Set<String> skippedSegments = new HashSet<>();
         String segmentNFile = null;
+
         try {
-            Set<String> localSegmentFiles = Sets.newHashSet(storeDirectory.listAll());
             if (overrideLocal) {
-                for (String file : localSegmentFiles) {
+                for (String file : storeDirectory.listAll()) {
                     storeDirectory.deleteFile(file);
                 }
             }
+
             for (String file : uploadedSegments.keySet()) {
                 long checksum = Long.parseLong(uploadedSegments.get(file).getChecksum());
                 if (overrideLocal || localDirectoryContains(storeDirectory, file, checksum) == false) {
-                    storeDirectory.copyFrom(sourceRemoteDirectory, file, file, IOContext.DEFAULT);
-                    downloadedSegments.add(file);
+                    toDownloadSegments.add(file);
                 } else {
                     skippedSegments.add(file);
                 }
-                if (targetRemoteDirectory != null) {
-                    targetRemoteDirectory.copyFrom(storeDirectory, file, file, IOContext.DEFAULT);
-                }
+
                 if (file.startsWith(IndexFileNames.SEGMENTS)) {
                     assert segmentNFile == null : "There should be only one SegmentInfosSnapshot file";
                     segmentNFile = file;
                 }
             }
+
+            if (toDownloadSegments.isEmpty() == false) {
+                try {
+                    fileDownloader.download(sourceRemoteDirectory, storeDirectory, targetRemoteDirectory, toDownloadSegments, onFileSync);
+                } catch (Exception e) {
+                    throw new IOException("Error occurred when downloading segments from remote store", e);
+                }
+            }
         } finally {
-            logger.trace("Downloaded segments here: {}", downloadedSegments);
+            logger.trace("Downloaded segments here: {}", toDownloadSegments);
             logger.trace("Skipped download for segments here: {}", skippedSegments);
         }
+
         return segmentNFile;
     }
 
-    private boolean localDirectoryContains(Directory localDirectory, String file, long checksum) {
+    // Visible for testing
+    boolean localDirectoryContains(Directory localDirectory, String file, long checksum) throws IOException {
         try (IndexInput indexInput = localDirectory.openInput(file, IOContext.DEFAULT)) {
             if (checksum == CodecUtil.retrieveChecksum(indexInput)) {
                 return true;
@@ -4885,6 +5041,8 @@ private boolean localDirectoryContains(Directory localDirectory, String file, lo
             logger.debug("File {} does not exist in local FS, downloading from remote store", file);
         } catch (IOException e) {
             logger.warn("Exception while reading checksum of file: {}, this can happen if file is corrupted", file);
+            // For any other exception on reading checksum, we delete the file to re-download again
+            localDirectory.deleteFile(file);
         }
         return false;
     }
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShardClosedException.java b/server/src/main/java/org/opensearch/index/shard/IndexShardClosedException.java
index 8b4c9a188e00c..8cc8f0356b775 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShardClosedException.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShardClosedException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -40,8 +41,9 @@
 /**
  * Exception thrown if trying to operate on a closed Index Shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardClosedException extends IllegalIndexShardStateException {
     public IndexShardClosedException(ShardId shardId) {
         super(shardId, IndexShardState.CLOSED, "Closed");
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShardNotRecoveringException.java b/server/src/main/java/org/opensearch/index/shard/IndexShardNotRecoveringException.java
index 75af4ef53e638..d996464f25723 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShardNotRecoveringException.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShardNotRecoveringException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -40,8 +41,9 @@
 /**
  * Exception thrown if an index shard is not recovering
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardNotRecoveringException extends IllegalIndexShardStateException {
 
     public IndexShardNotRecoveringException(ShardId shardId, IndexShardState currentState) {
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShardNotStartedException.java b/server/src/main/java/org/opensearch/index/shard/IndexShardNotStartedException.java
index 7f37ae2a00873..0371e57bfc282 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShardNotStartedException.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShardNotStartedException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -40,8 +41,9 @@
 /**
  * Exception thrown when trying to operate on an Index Shard that hasn't been started
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardNotStartedException extends IllegalIndexShardStateException {
 
     public IndexShardNotStartedException(ShardId shardId, IndexShardState currentState) {
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShardRecoveringException.java b/server/src/main/java/org/opensearch/index/shard/IndexShardRecoveringException.java
index 9372ff222d6f0..eb145803d25ec 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShardRecoveringException.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShardRecoveringException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -40,8 +41,9 @@
 /**
  * Exception thrown when there is an error recovering an Index Shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardRecoveringException extends IllegalIndexShardStateException {
 
     public IndexShardRecoveringException(ShardId shardId) {
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShardRelocatedException.java b/server/src/main/java/org/opensearch/index/shard/IndexShardRelocatedException.java
index 5176b23edcf82..be77a295d7bfc 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShardRelocatedException.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShardRelocatedException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -40,8 +41,9 @@
 /**
  * Exception thrown if there is an error relocating an index shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardRelocatedException extends IllegalIndexShardStateException {
 
     public IndexShardRelocatedException(ShardId shardId) {
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShardStartedException.java b/server/src/main/java/org/opensearch/index/shard/IndexShardStartedException.java
index a724952e37707..f2f3554f6ef12 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShardStartedException.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShardStartedException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -40,8 +41,9 @@
 /**
  * Exception thrown if there is an error starting an index shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardStartedException extends IllegalIndexShardStateException {
 
     public IndexShardStartedException(ShardId shardId) {
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShardState.java b/server/src/main/java/org/opensearch/index/shard/IndexShardState.java
index dc6f2fc3a86d9..deadf1db8314f 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShardState.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShardState.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.index.shard;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Index Shard States
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum IndexShardState {
     CREATED((byte) 0),
     RECOVERING((byte) 1),
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexingOperationListener.java b/server/src/main/java/org/opensearch/index/shard/IndexingOperationListener.java
index ccc4cd336cff7..edce676b7c81e 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexingOperationListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexingOperationListener.java
@@ -33,6 +33,7 @@
 
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.engine.Engine;
 
@@ -41,8 +42,9 @@
 /**
  * An indexing listener for indexing, delete, events.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IndexingOperationListener {
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexingStats.java b/server/src/main/java/org/opensearch/index/shard/IndexingStats.java
index 8953ef38da51b..862962dc5467a 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexingStats.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexingStats.java
@@ -33,10 +33,12 @@
 package org.opensearch.index.shard;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.ToXContentFragment;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -44,21 +46,108 @@
 
 import java.io.IOException;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicLong;
 
 /**
  * Tracks indexing statistics
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexingStats implements Writeable, ToXContentFragment {
 
     /**
      * Internal statistics for indexing
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Stats implements Writeable, ToXContentFragment {
 
+        /**
+         * Tracks item level rest category class codes during indexing
+         *
+         * @opensearch.api
+         */
+        @PublicApi(since = "1.0.0")
+        public static class DocStatusStats implements Writeable, ToXContentFragment {
+
+            final AtomicLong[] docStatusCounter;
+
+            public DocStatusStats() {
+                docStatusCounter = new AtomicLong[5];
+                for (int i = 0; i < docStatusCounter.length; ++i) {
+                    docStatusCounter[i] = new AtomicLong(0);
+                }
+            }
+
+            public DocStatusStats(StreamInput in) throws IOException {
+                docStatusCounter = in.readArray(i -> new AtomicLong(i.readLong()), AtomicLong[]::new);
+
+                assert docStatusCounter.length == 5 : "Length of incoming array should be 5! Got " + docStatusCounter.length;
+            }
+
+            /**
+             * Increment counter for status
+             *
+             * @param status {@link RestStatus}
+             */
+            public void inc(final RestStatus status) {
+                add(status, 1L);
+            }
+
+            /**
+             * Increment counter for status by count
+             *
+             * @param status {@link RestStatus}
+             * @param delta The value to add
+             */
+            void add(final RestStatus status, final long delta) {
+                docStatusCounter[status.getStatusFamilyCode() - 1].addAndGet(delta);
+            }
+
+            /**
+             * Accumulate stats from the passed Object
+             *
+             * @param stats Instance storing {@link DocStatusStats}
+             */
+            public void add(final DocStatusStats stats) {
+                if (null == stats) {
+                    return;
+                }
+
+                for (int i = 0; i < docStatusCounter.length; ++i) {
+                    docStatusCounter[i].addAndGet(stats.docStatusCounter[i].longValue());
+                }
+            }
+
+            public AtomicLong[] getDocStatusCounter() {
+                return docStatusCounter;
+            }
+
+            @Override
+            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+                builder.startObject(Fields.DOC_STATUS);
+
+                for (int i = 0; i < docStatusCounter.length; ++i) {
+                    long value = docStatusCounter[i].longValue();
+
+                    if (value > 0) {
+                        String key = i + 1 + "xx";
+                        builder.field(key, value);
+                    }
+                }
+
+                return builder.endObject();
+            }
+
+            @Override
+            public void writeTo(StreamOutput out) throws IOException {
+                out.writeArray((o, v) -> o.writeLong(v.longValue()), docStatusCounter);
+            }
+
+        }
+
         private long indexCount;
         private long indexTimeInMillis;
         private long indexCurrent;
@@ -69,8 +158,11 @@ public static class Stats implements Writeable, ToXContentFragment {
         private long noopUpdateCount;
         private long throttleTimeInMillis;
         private boolean isThrottled;
+        private final DocStatusStats docStatusStats;
 
-        Stats() {}
+        Stats() {
+            docStatusStats = new DocStatusStats();
+        }
 
         public Stats(StreamInput in) throws IOException {
             indexCount = in.readVLong();
@@ -83,6 +175,12 @@ public Stats(StreamInput in) throws IOException {
             noopUpdateCount = in.readVLong();
             isThrottled = in.readBoolean();
             throttleTimeInMillis = in.readLong();
+
+            if (in.getVersion().onOrAfter(Version.V_2_11_0)) {
+                docStatusStats = in.readOptionalWriteable(DocStatusStats::new);
+            } else {
+                docStatusStats = null;
+            }
         }
 
         public Stats(
@@ -95,7 +193,8 @@ public Stats(
             long deleteCurrent,
             long noopUpdateCount,
             boolean isThrottled,
-            long throttleTimeInMillis
+            long throttleTimeInMillis,
+            DocStatusStats docStatusStats
         ) {
             this.indexCount = indexCount;
             this.indexTimeInMillis = indexTimeInMillis;
@@ -107,6 +206,7 @@ public Stats(
             this.noopUpdateCount = noopUpdateCount;
             this.isThrottled = isThrottled;
             this.throttleTimeInMillis = throttleTimeInMillis;
+            this.docStatusStats = docStatusStats;
         }
 
         public void add(Stats stats) {
@@ -121,8 +221,10 @@ public void add(Stats stats) {
 
             noopUpdateCount += stats.noopUpdateCount;
             throttleTimeInMillis += stats.throttleTimeInMillis;
-            if (isThrottled != stats.isThrottled) {
-                isThrottled = true; // When combining if one is throttled set result to throttled.
+            isThrottled |= stats.isThrottled; // When combining if one is throttled set result to throttled.
+
+            if (getDocStatusStats() != null) {
+                getDocStatusStats().add(stats.getDocStatusStats());
             }
         }
 
@@ -193,6 +295,10 @@ public long getNoopUpdateCount() {
             return noopUpdateCount;
         }
 
+        public DocStatusStats getDocStatusStats() {
+            return docStatusStats;
+        }
+
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             out.writeVLong(indexCount);
@@ -206,6 +312,9 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeBoolean(isThrottled);
             out.writeLong(throttleTimeInMillis);
 
+            if (out.getVersion().onOrAfter(Version.V_2_11_0)) {
+                out.writeOptionalWriteable(docStatusStats);
+            }
         }
 
         @Override
@@ -223,8 +332,14 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
 
             builder.field(Fields.IS_THROTTLED, isThrottled);
             builder.humanReadableField(Fields.THROTTLED_TIME_IN_MILLIS, Fields.THROTTLED_TIME, getThrottleTime());
+
+            if (getDocStatusStats() != null) {
+                getDocStatusStats().toXContent(builder, params);
+            }
+
             return builder;
         }
+
     }
 
     private final Stats totalStats;
@@ -279,7 +394,7 @@ public XContentBuilder toXContent(XContentBuilder builder, ToXContent.Params par
      *
      * @opensearch.internal
      */
-    static final class Fields {
+    private static final class Fields {
         static final String INDEXING = "indexing";
         static final String INDEX_TOTAL = "index_total";
         static final String INDEX_TIME = "index_time";
@@ -294,6 +409,7 @@ static final class Fields {
         static final String IS_THROTTLED = "is_throttled";
         static final String THROTTLED_TIME_IN_MILLIS = "throttle_time_in_millis";
         static final String THROTTLED_TIME = "throttle_time";
+        static final String DOC_STATUS = "doc_status";
     }
 
     @Override
@@ -303,4 +419,5 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeBoolean(false);
         }
     }
+
 }
diff --git a/server/src/main/java/org/opensearch/index/shard/InternalIndexingStats.java b/server/src/main/java/org/opensearch/index/shard/InternalIndexingStats.java
index d7e15dd3e40f5..55b65bb4be6d8 100644
--- a/server/src/main/java/org/opensearch/index/shard/InternalIndexingStats.java
+++ b/server/src/main/java/org/opensearch/index/shard/InternalIndexingStats.java
@@ -154,7 +154,8 @@ IndexingStats.Stats stats(boolean isThrottled, long currentThrottleMillis) {
                 deleteCurrent.count(),
                 noopUpdates.count(),
                 isThrottled,
-                TimeUnit.MILLISECONDS.toMillis(currentThrottleMillis)
+                TimeUnit.MILLISECONDS.toMillis(currentThrottleMillis),
+                new IndexingStats.Stats.DocStatusStats()
             );
         }
     }
diff --git a/server/src/main/java/org/opensearch/index/shard/PrimaryReplicaSyncer.java b/server/src/main/java/org/opensearch/index/shard/PrimaryReplicaSyncer.java
index 875eda5473806..af8220db25fcb 100644
--- a/server/src/main/java/org/opensearch/index/shard/PrimaryReplicaSyncer.java
+++ b/server/src/main/java/org/opensearch/index/shard/PrimaryReplicaSyncer.java
@@ -38,6 +38,7 @@
 import org.opensearch.action.resync.ResyncReplicationRequest;
 import org.opensearch.action.resync.ResyncReplicationResponse;
 import org.opensearch.action.resync.TransportResyncReplicationAction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.util.concurrent.AbstractRunnable;
 import org.opensearch.common.util.io.IOUtils;
@@ -398,8 +399,9 @@ public ActionRequestValidationException validate() {
     /**
      * Task to resync primary and replica
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ResyncTask extends Task {
         private volatile String phase = "starting";
         private volatile int totalOperations;
@@ -465,8 +467,9 @@ public ResyncTask.Status getStatus() {
         /**
          * Status for primary replica syncer
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class Status implements Task.Status {
             public static final String NAME = "resync";
 
diff --git a/server/src/main/java/org/opensearch/index/shard/RefreshListeners.java b/server/src/main/java/org/opensearch/index/shard/RefreshListeners.java
index 7dbbcbb2d7d20..803db773efe6c 100644
--- a/server/src/main/java/org/opensearch/index/shard/RefreshListeners.java
+++ b/server/src/main/java/org/opensearch/index/shard/RefreshListeners.java
@@ -54,7 +54,7 @@
 /**
  * Allows for the registration of listeners that are called when a change becomes visible for search. This functionality is exposed from
  * {@link IndexShard} but kept here so it can be tested without standing up the entire thing.
- *
+ * <p>
  * When {@link Closeable#close()}d it will no longer accept listeners and flush any existing listeners.
  *
  * @opensearch.internal
@@ -86,7 +86,7 @@ public final class RefreshListeners implements ReferenceManager.RefreshListener,
      * List of refresh listeners. Defaults to null and built on demand because most refresh cycles won't need it. Entries are never removed
      * from it, rather, it is nulled and rebuilt when needed again. The (hopefully) rare entries that didn't make the current refresh cycle
      * are just added back to the new list. Both the reference and the contents are always modified while synchronized on {@code this}.
-     *
+     * <p>
      * We never set this to non-null while closed it {@code true}.
      */
     private volatile List<Tuple<Translog.Location, Consumer<Boolean>>> refreshListeners = null;
diff --git a/server/src/main/java/org/opensearch/index/shard/CloseableRetryableRefreshListener.java b/server/src/main/java/org/opensearch/index/shard/ReleasableRetryableRefreshListener.java
similarity index 78%
rename from server/src/main/java/org/opensearch/index/shard/CloseableRetryableRefreshListener.java
rename to server/src/main/java/org/opensearch/index/shard/ReleasableRetryableRefreshListener.java
index 9bc105bf13f0a..757275932c5f1 100644
--- a/server/src/main/java/org/opensearch/index/shard/CloseableRetryableRefreshListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/ReleasableRetryableRefreshListener.java
@@ -10,10 +10,11 @@
 
 import org.apache.logging.log4j.Logger;
 import org.apache.lucene.search.ReferenceManager;
+import org.opensearch.common.lease.Releasable;
+import org.opensearch.common.lease.Releasables;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.threadpool.ThreadPool;
 
-import java.io.Closeable;
 import java.io.IOException;
 import java.util.Objects;
 import java.util.concurrent.Semaphore;
@@ -22,11 +23,11 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
- * RefreshListener that runs afterRefresh method if and only if there is a permit available. Once the listener
- * is closed, all the permits are acquired and there are no available permits to afterRefresh. This abstract class provides
+ * RefreshListener that runs afterRefresh method if and only if there is a permit available. Once the {@code drainRefreshes()}
+ * is called, all the permits are acquired and there are no available permits to afterRefresh. This abstract class provides
  * necessary abstract methods to schedule retry.
  */
-public abstract class CloseableRetryableRefreshListener implements ReferenceManager.RefreshListener, Closeable {
+public abstract class ReleasableRetryableRefreshListener implements ReferenceManager.RefreshListener {
 
     /**
      * Total permits = 1 ensures that there is only single instance of runAfterRefreshWithPermit that is running at a time.
@@ -34,6 +35,8 @@ public abstract class CloseableRetryableRefreshListener implements ReferenceMana
      */
     private static final int TOTAL_PERMITS = 1;
 
+    private static final TimeValue DRAIN_TIMEOUT = TimeValue.timeValueMinutes(10);
+
     private final AtomicBoolean closed = new AtomicBoolean(false);
 
     private final Semaphore semaphore = new Semaphore(TOTAL_PERMITS);
@@ -45,11 +48,11 @@ public abstract class CloseableRetryableRefreshListener implements ReferenceMana
      */
     private final AtomicBoolean retryScheduled = new AtomicBoolean(false);
 
-    public CloseableRetryableRefreshListener() {
+    public ReleasableRetryableRefreshListener() {
         this.threadPool = null;
     }
 
-    public CloseableRetryableRefreshListener(ThreadPool threadPool) {
+    public ReleasableRetryableRefreshListener(ThreadPool threadPool) {
         assert Objects.nonNull(threadPool);
         this.threadPool = threadPool;
     }
@@ -104,6 +107,7 @@ protected TimeValue getNextRetryInterval() {
     private void scheduleRetry(TimeValue interval, String retryThreadPoolName, boolean didRefresh) {
         // If the underlying listener has closed, then we do not allow even the retry to be scheduled
         if (closed.get() || isRetryEnabled() == false) {
+            getLogger().debug("skip retry on closed={} isRetryEnabled={}", closed.get(), isRetryEnabled());
             return;
         }
 
@@ -112,6 +116,7 @@ private void scheduleRetry(TimeValue interval, String retryThreadPoolName, boole
         // If the retryScheduled is already true, then we return from here itself. If not, then we proceed with scheduling
         // the retry.
         if (retryScheduled.getAndSet(true)) {
+            getLogger().debug("skip retry on retryScheduled=true");
             return;
         }
 
@@ -182,25 +187,39 @@ private void scheduleRetry(boolean afterRefreshSuccessful, boolean didRefresh) {
      */
     protected abstract boolean performAfterRefreshWithPermit(boolean didRefresh);
 
-    @Override
-    public final void close() throws IOException {
+    public final Releasable drainRefreshes() {
         try {
-            if (semaphore.tryAcquire(TOTAL_PERMITS, 10, TimeUnit.MINUTES)) {
+            TimeValue timeout = getDrainTimeout();
+            if (semaphore.tryAcquire(TOTAL_PERMITS, timeout.seconds(), TimeUnit.SECONDS)) {
                 boolean result = closed.compareAndSet(false, true);
                 assert result && semaphore.availablePermits() == 0;
-                getLogger().info("Closed");
+                getLogger().info("All permits are acquired and refresh listener is closed");
+                return Releasables.releaseOnce(() -> {
+                    semaphore.release(TOTAL_PERMITS);
+                    boolean wasClosed = closed.getAndSet(false);
+                    assert semaphore.availablePermits() == TOTAL_PERMITS : "Available permits is " + semaphore.availablePermits();
+                    assert wasClosed : "RefreshListener is not closed before reopening it";
+                    getLogger().info("All permits are released and refresh listener is open");
+                });
             } else {
-                throw new TimeoutException("timeout while closing gated refresh listener");
+                throw new TimeoutException("Timeout while acquiring all permits");
             }
         } catch (InterruptedException | TimeoutException e) {
-            throw new RuntimeException("Failed to close the closeable retryable listener", e);
+            throw new RuntimeException("Failed to acquire all permits", e);
         }
     }
 
     protected abstract Logger getLogger();
 
-    // Visible for testing
+    // Made available for unit testing purpose only
+    /**
+     * Returns the timeout which is used while draining refreshes.
+     */
+    TimeValue getDrainTimeout() {
+        return DRAIN_TIMEOUT;
+    }
 
+    // Visible for testing
     /**
      * Returns if the retry is scheduled or not.
      *
@@ -209,4 +228,14 @@ public final void close() throws IOException {
     boolean getRetryScheduledStatus() {
         return retryScheduled.get();
     }
+
+    // Visible for testing
+    int availablePermits() {
+        return semaphore.availablePermits();
+    }
+
+    // Visible for testing
+    boolean isClosed() {
+        return closed.get();
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java b/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
index 4e035af9bbc5e..d96a7e7c95ecf 100644
--- a/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
@@ -20,6 +20,7 @@
 import org.opensearch.action.LatchedActionListener;
 import org.opensearch.action.bulk.BackoffPolicy;
 import org.opensearch.action.support.GroupedActionListener;
+import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.common.concurrent.GatedCloseable;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.unit.TimeValue;
@@ -53,7 +54,7 @@
  *
  * @opensearch.internal
  */
-public final class RemoteStoreRefreshListener extends CloseableRetryableRefreshListener {
+public final class RemoteStoreRefreshListener extends ReleasableRetryableRefreshListener {
 
     private final Logger logger;
 
@@ -78,15 +79,13 @@ public final class RemoteStoreRefreshListener extends CloseableRetryableRefreshL
     );
 
     public static final Set<String> EXCLUDE_FILES = Set.of("write.lock");
-    // Visible for testing
-    public static final int LAST_N_METADATA_FILES_TO_KEEP = 10;
 
     private final IndexShard indexShard;
     private final Directory storeDirectory;
     private final RemoteSegmentStoreDirectory remoteDirectory;
     private final RemoteSegmentTransferTracker segmentTracker;
     private final Map<String, String> localSegmentChecksumMap;
-    private long primaryTerm;
+    private volatile long primaryTerm;
     private volatile Iterator<TimeValue> backoffDelayIterator;
     private final SegmentReplicationCheckpointPublisher checkpointPublisher;
 
@@ -123,13 +122,12 @@ public void beforeRefresh() throws IOException {}
 
     @Override
     protected void runAfterRefreshExactlyOnce(boolean didRefresh) {
-        if (shouldSync(didRefresh)) {
-            segmentTracker.updateLocalRefreshTimeAndSeqNo();
+        // We have 2 separate methods to check if sync needs to be done or not. This is required since we use the return boolean
+        // from isReadyForUpload to schedule refresh retries as the index shard or the primary mode are not in complete
+        // ready state.
+        if (shouldSync(didRefresh, true) && isReadyForUpload()) {
             try {
-                if (this.primaryTerm != indexShard.getOperationPrimaryTerm()) {
-                    this.primaryTerm = indexShard.getOperationPrimaryTerm();
-                    this.remoteDirectory.init();
-                }
+                segmentTracker.updateLocalRefreshTimeAndSeqNo();
                 try (GatedCloseable<SegmentInfos> segmentInfosGatedCloseable = indexShard.getSegmentInfosSnapshot()) {
                     Collection<String> localSegmentsPostRefresh = segmentInfosGatedCloseable.get().files(true);
                     updateLocalSizeMapAndTracker(localSegmentsPostRefresh);
@@ -150,9 +148,7 @@ protected void runAfterRefreshExactlyOnce(boolean didRefresh) {
     @Override
     protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
         boolean successful;
-        // The third condition exists for uploading the zero state segments where the refresh has not changed the reader reference, but it
-        // is important to upload the zero state segments so that the restore does not break.
-        if (shouldSync(didRefresh)) {
+        if (shouldSync(didRefresh, false)) {
             successful = syncSegments();
         } else {
             successful = true;
@@ -160,30 +156,40 @@ protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
         return successful;
     }
 
-    private boolean shouldSync(boolean didRefresh) {
-        return this.primaryTerm != indexShard.getOperationPrimaryTerm()
-            || didRefresh
-            || remoteDirectory.getSegmentsUploadedToRemoteStore().isEmpty();
+    /**
+     * This checks if there is a sync required to remote.
+     *
+     * @param didRefresh             if the readers changed.
+     * @param skipPrimaryTermCheck consider change in primary term or not for should sync
+     * @return true if sync is needed
+     */
+    private boolean shouldSync(boolean didRefresh, boolean skipPrimaryTermCheck) {
+        boolean shouldSync = didRefresh // If the readers change, didRefresh is always true.
+            // The third condition exists for uploading the zero state segments where the refresh has not changed the reader
+            // reference, but it is important to upload the zero state segments so that the restore does not break.
+            || remoteDirectory.getSegmentsUploadedToRemoteStore().isEmpty()
+            // When the shouldSync is called the first time, then 1st condition on primary term is true. But after that
+            // we update the primary term and the same condition would not evaluate to true again in syncSegments.
+            // Below check ensures that if there is commit, then that gets picked up by both 1st and 2nd shouldSync call.
+            || isRefreshAfterCommitSafe();
+        if (shouldSync || skipPrimaryTermCheck) {
+            return shouldSync;
+        }
+        return this.primaryTerm != indexShard.getOperationPrimaryTerm();
     }
 
+    /*
+     @return false if retry is needed
+     */
     private boolean syncSegments() {
-        if (indexShard.getReplicationTracker().isPrimaryMode() == false || indexShard.state() == IndexShardState.CLOSED) {
-            logger.trace(
-                "Skipped syncing segments with primaryMode={} indexShardState={}",
-                indexShard.getReplicationTracker().isPrimaryMode(),
-                indexShard.state()
-            );
+        if (isReadyForUpload() == false) {
             // Following check is required to enable retry and make sure that we do not lose this refresh event
             // When primary shard is restored from remote store, the recovery happens first followed by changing
             // primaryMode to true. Due to this, the refresh that is triggered post replay of translog will not go through
             // if following condition does not exist. The segments created as part of translog replay will not be present
             // in the remote store.
-            if (indexShard.state() == IndexShardState.STARTED && indexShard.getEngine() instanceof InternalEngine) {
-                return false;
-            }
-            return true;
+            return indexShard.state() != IndexShardState.STARTED || !(indexShard.getEngine() instanceof InternalEngine);
         }
-        ReplicationCheckpoint checkpoint = indexShard.getLatestReplicationCheckpoint();
         beforeSegmentsSync();
         long refreshTimeMs = segmentTracker.getLocalRefreshTimeMs(), refreshClockTimeMs = segmentTracker.getLocalRefreshClockTimeMs();
         long refreshSeqNo = segmentTracker.getLocalRefreshSeqNo();
@@ -192,19 +198,17 @@ private boolean syncSegments() {
 
         try {
             try {
+                initializeRemoteDirectoryOnTermUpdate();
                 // if a new segments_N file is present in local that is not uploaded to remote store yet, it
                 // is considered as a first refresh post commit. A cleanup of stale commit files is triggered.
                 // This is done to avoid delete post each refresh.
                 if (isRefreshAfterCommit()) {
-                    remoteDirectory.deleteStaleSegmentsAsync(LAST_N_METADATA_FILES_TO_KEEP);
+                    remoteDirectory.deleteStaleSegmentsAsync(indexShard.getRecoverySettings().getMinRemoteSegmentMetadataFiles());
                 }
 
                 try (GatedCloseable<SegmentInfos> segmentInfosGatedCloseable = indexShard.getSegmentInfosSnapshot()) {
                     SegmentInfos segmentInfos = segmentInfosGatedCloseable.get();
-                    assert segmentInfos.getGeneration() == checkpoint.getSegmentsGen() : "SegmentInfos generation: "
-                        + segmentInfos.getGeneration()
-                        + " does not match metadata generation: "
-                        + checkpoint.getSegmentsGen();
+                    final ReplicationCheckpoint checkpoint = indexShard.computeReplicationCheckpoint(segmentInfos);
                     // Capture replication checkpoint before uploading the segments as upload can take some time and checkpoint can
                     // move.
                     long lastRefreshedCheckpoint = ((InternalEngine) indexShard.getEngine()).lastRefreshedCheckpoint();
@@ -217,8 +221,10 @@ private boolean syncSegments() {
                         @Override
                         public void onResponse(Void unused) {
                             try {
+                                logger.debug("New segments upload successful");
                                 // Start metadata file upload
                                 uploadMetadata(localSegmentsPostRefresh, segmentInfos, checkpoint);
+                                logger.debug("Metadata upload successful");
                                 clearStaleFilesFromLocalSegmentChecksumMap(localSegmentsPostRefresh);
                                 onSuccessfulSegmentsSync(
                                     refreshTimeMs,
@@ -262,6 +268,7 @@ public void onFailure(Exception e) {
         updateFinalStatusInSegmentTracker(successful.get(), bytesBeforeUpload, startTimeInNS);
         // If there are failures in uploading segments, then we should retry as search idle can lead to
         // refresh not occurring until write happens.
+        logger.debug("syncSegments runStatus={}", successful.get());
         return successful.get();
     }
 
@@ -300,6 +307,7 @@ private void onSuccessfulSegmentsSync(
         indexShard.getEngine().translogManager().setMinSeqNoToKeep(lastRefreshedCheckpoint + 1);
         // Publishing the new checkpoint which is used for remote store + segrep indexes
         checkpointPublisher.publish(indexShard, checkpoint);
+        logger.debug("onSuccessfulSegmentsSync lastRefreshedCheckpoint={} checkpoint={}", lastRefreshedCheckpoint, checkpoint);
     }
 
     /**
@@ -325,6 +333,19 @@ private boolean isRefreshAfterCommit() throws IOException {
             && !remoteDirectory.containsFile(lastCommittedLocalSegmentFileName, getChecksumOfLocalFile(lastCommittedLocalSegmentFileName)));
     }
 
+    /**
+     * Returns if the current refresh has happened after a commit.
+     * @return true if this refresh has happened on account of a commit. If otherwise or exception, returns false.
+     */
+    private boolean isRefreshAfterCommitSafe() {
+        try {
+            return isRefreshAfterCommit();
+        } catch (Exception e) {
+            logger.info("Exception occurred in isRefreshAfterCommitSafe", e);
+        }
+        return false;
+    }
+
     void uploadMetadata(Collection<String> localSegmentsPostRefresh, SegmentInfos segmentInfos, ReplicationCheckpoint replicationCheckpoint)
         throws IOException {
         final long maxSeqNo = ((InternalEngine) indexShard.getEngine()).currentOngoingRefreshCheckpoint();
@@ -344,7 +365,8 @@ void uploadMetadata(Collection<String> localSegmentsPostRefresh, SegmentInfos se
                 segmentInfosSnapshot,
                 storeDirectory,
                 translogFileGeneration,
-                replicationCheckpoint
+                replicationCheckpoint,
+                indexShard.getNodeId()
             );
         }
     }
@@ -352,10 +374,12 @@ void uploadMetadata(Collection<String> localSegmentsPostRefresh, SegmentInfos se
     private void uploadNewSegments(Collection<String> localSegmentsPostRefresh, ActionListener<Void> listener) {
         Collection<String> filteredFiles = localSegmentsPostRefresh.stream().filter(file -> !skipUpload(file)).collect(Collectors.toList());
         if (filteredFiles.size() == 0) {
+            logger.debug("No new segments to upload in uploadNewSegments");
             listener.onResponse(null);
             return;
         }
 
+        logger.debug("Effective new segments files to upload {}", filteredFiles);
         ActionListener<Collection<Void>> mappedListener = ActionListener.map(listener, resp -> null);
         GroupedActionListener<Void> batchUploadListener = new GroupedActionListener<>(mappedListener, filteredFiles.size());
 
@@ -438,6 +462,63 @@ private void updateFinalStatusInSegmentTracker(boolean uploadStatus, long bytesB
         }
     }
 
+    /**
+     * On primary term update, we (re)initialise the remote segment directory to reflect the latest metadata file that
+     * has been uploaded to remote store successfully. This method also updates the segment tracker about the latest
+     * uploaded segment files onto remote store.
+     */
+    private void initializeRemoteDirectoryOnTermUpdate() throws IOException {
+        if (this.primaryTerm != indexShard.getOperationPrimaryTerm()) {
+            logger.trace("primaryTerm update from={} to={}", primaryTerm, indexShard.getOperationPrimaryTerm());
+            this.primaryTerm = indexShard.getOperationPrimaryTerm();
+            RemoteSegmentMetadata uploadedMetadata = this.remoteDirectory.init();
+
+            // During failover, the uploaded metadata would have names of files that have been uploaded to remote store.
+            // Here we update the tracker with latest remote uploaded files.
+            if (uploadedMetadata != null) {
+                segmentTracker.setLatestUploadedFiles(uploadedMetadata.getMetadata().keySet());
+            }
+        }
+    }
+
+    /**
+     * This checks for readiness of the index shard and primary mode. This has separated from shouldSync since we use the
+     * returned value of this method for scheduling retries in syncSegments method.
+     * @return true iff the shard is a started with primary mode true or it is local or snapshot recovery.
+     */
+    private boolean isReadyForUpload() {
+        boolean isReady = indexShard.isStartedPrimary() || isLocalOrSnapshotRecovery();
+
+        if (isReady == false) {
+            StringBuilder sb = new StringBuilder("Skipped syncing segments with");
+            if (indexShard.getReplicationTracker() != null) {
+                sb.append(" primaryMode=").append(indexShard.getReplicationTracker().isPrimaryMode());
+            }
+            if (indexShard.state() != null) {
+                sb.append(" indexShardState=").append(indexShard.state());
+            }
+            if (indexShard.getEngineOrNull() != null) {
+                sb.append(" engineType=").append(indexShard.getEngine().getClass().getSimpleName());
+            }
+            if (indexShard.recoveryState() != null) {
+                sb.append(" recoverySourceType=").append(indexShard.recoveryState().getRecoverySource().getType());
+                sb.append(" primary=").append(indexShard.shardRouting.primary());
+            }
+            logger.info(sb.toString());
+        }
+        return isReady;
+    }
+
+    private boolean isLocalOrSnapshotRecovery() {
+        // In this case when the primary mode is false, we need to upload segments to Remote Store
+        // This is required in case of snapshots/shrink/ split/clone where we need to durable persist
+        // all segments to remote before completing the recovery to ensure durability.
+        return (indexShard.state() == IndexShardState.RECOVERING && indexShard.shardRouting.primary())
+            && indexShard.recoveryState() != null
+            && (indexShard.recoveryState().getRecoverySource().getType() == RecoverySource.Type.LOCAL_SHARDS
+                || indexShard.recoveryState().getRecoverySource().getType() == RecoverySource.Type.SNAPSHOT);
+    }
+
     /**
      * Creates an {@link UploadListener} containing the stats population logic which would be triggered before and after segment upload events
      */
diff --git a/server/src/main/java/org/opensearch/index/shard/ReplicationGroup.java b/server/src/main/java/org/opensearch/index/shard/ReplicationGroup.java
index 6d19e9f500411..f585267f21832 100644
--- a/server/src/main/java/org/opensearch/index/shard/ReplicationGroup.java
+++ b/server/src/main/java/org/opensearch/index/shard/ReplicationGroup.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.set.Sets;
 
 import java.util.ArrayList;
@@ -43,8 +44,9 @@
 /**
  * Replication group for a shard. Used by a primary shard to coordinate replication and recoveries.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ReplicationGroup {
     private final IndexShardRoutingTable routingTable;
     private final Set<String> inSyncAllocationIds;
diff --git a/server/src/main/java/org/opensearch/index/shard/SearchOperationListener.java b/server/src/main/java/org/opensearch/index/shard/SearchOperationListener.java
index e9206731058db..849a4f9c15318 100644
--- a/server/src/main/java/org/opensearch/index/shard/SearchOperationListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/SearchOperationListener.java
@@ -34,6 +34,7 @@
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.opensearch.ExceptionsHelper;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.internal.ReaderContext;
 import org.opensearch.search.internal.SearchContext;
 import org.opensearch.transport.TransportRequest;
@@ -43,8 +44,9 @@
 /**
  * An listener for search, fetch and context events.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface SearchOperationListener {
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/shard/ShardPath.java b/server/src/main/java/org/opensearch/index/shard/ShardPath.java
index b7bb4283eca32..d16e5707b2e0e 100644
--- a/server/src/main/java/org/opensearch/index/shard/ShardPath.java
+++ b/server/src/main/java/org/opensearch/index/shard/ShardPath.java
@@ -34,6 +34,7 @@
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.util.Strings;
 import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
@@ -54,8 +55,9 @@
 /**
  * Path for a shard
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ShardPath {
     public static final String INDEX_FOLDER_NAME = "index";
     public static final String TRANSLOG_FOLDER_NAME = "translog";
diff --git a/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java b/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
index 6d675b709e05b..5b1940bb1d9a5 100644
--- a/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
+++ b/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
@@ -191,6 +191,15 @@ void recoverFromLocalShards(
                     // just trigger a merge to do housekeeping on the
                     // copied segments - we will also see them in stats etc.
                     indexShard.getEngine().forceMerge(false, -1, false, false, false, UUIDs.randomBase64UUID());
+                    if (indexShard.isRemoteTranslogEnabled()) {
+                        if (indexShard.isRemoteSegmentStoreInSync() == false) {
+                            throw new IndexShardRecoveryException(
+                                indexShard.shardId(),
+                                "failed to upload to remote",
+                                new IOException("Failed to upload to remote segment store")
+                            );
+                        }
+                    }
                     return true;
                 } catch (IOException ex) {
                     throw new IndexShardRecoveryException(indexShard.shardId(), "failed to recover from local shards", ex);
@@ -399,7 +408,12 @@ void recoverFromSnapshotAndRemoteStore(
                 RemoteSegmentStoreDirectory sourceRemoteDirectory = (RemoteSegmentStoreDirectory) directoryFactory.newDirectory(
                     remoteStoreRepository,
                     indexUUID,
-                    String.valueOf(shardId.id())
+                    shardId
+                );
+                sourceRemoteDirectory.initializeToSpecificCommit(
+                    primaryTerm,
+                    commitGeneration,
+                    recoverySource.snapshot().getSnapshotId().getUUID()
                 );
                 indexShard.syncSegmentsFromGivenRemoteSegmentStore(true, sourceRemoteDirectory, primaryTerm, commitGeneration);
                 final Store store = indexShard.store();
@@ -418,6 +432,12 @@ void recoverFromSnapshotAndRemoteStore(
                 }
                 indexShard.getEngine().fillSeqNoGaps(indexShard.getPendingPrimaryTerm());
                 indexShard.finalizeRecovery();
+                if (indexShard.isRemoteTranslogEnabled()) {
+                    if (indexShard.isRemoteSegmentStoreInSync() == false) {
+                        listener.onFailure(new IndexShardRestoreFailedException(shardId, "Failed to upload to remote segment store"));
+                        return;
+                    }
+                }
                 indexShard.postRecovery("restore done");
 
                 listener.onResponse(true);
@@ -536,7 +556,6 @@ private void recoverFromRemoteStore(IndexShard indexShard) throws IndexShardReco
         try {
             // Download segments from remote segment store
             indexShard.syncSegmentsFromRemoteSegmentStore(true);
-
             indexShard.syncTranslogFilesFromRemoteTranslog();
 
             // On index creation, the only segment file that is created is segments_N. We can safely discard this file
@@ -698,6 +717,12 @@ private void restore(
             }
             indexShard.getEngine().fillSeqNoGaps(indexShard.getPendingPrimaryTerm());
             indexShard.finalizeRecovery();
+            if (indexShard.isRemoteTranslogEnabled()) {
+                if (indexShard.isRemoteSegmentStoreInSync() == false) {
+                    listener.onFailure(new IndexShardRestoreFailedException(shardId, "Failed to upload to remote segment store"));
+                    return;
+                }
+            }
             indexShard.postRecovery("restore done");
             listener.onResponse(true);
         }, e -> listener.onFailure(new IndexShardRestoreFailedException(shardId, "restore failed", e)));
diff --git a/server/src/main/java/org/opensearch/index/similarity/SimilarityProvider.java b/server/src/main/java/org/opensearch/index/similarity/SimilarityProvider.java
index ad64f3a55228f..33065dc1739a3 100644
--- a/server/src/main/java/org/opensearch/index/similarity/SimilarityProvider.java
+++ b/server/src/main/java/org/opensearch/index/similarity/SimilarityProvider.java
@@ -33,14 +33,16 @@
 package org.opensearch.index.similarity;
 
 import org.apache.lucene.search.similarities.Similarity;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Objects;
 
 /**
  * Wrapper around a {@link Similarity} and its name.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SimilarityProvider {
 
     private final String name;
@@ -70,23 +72,23 @@ public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         SimilarityProvider that = (SimilarityProvider) o;
-        /**
-         * We check <code>name</code> only because the <code>similarity</code> is
-         * re-created for each new instance and they don't implement equals.
-         * This is not entirely correct though but we only use equality checks
-         * for similarities inside the same index and names are unique in this case.
-         **/
+        /*
+          We check <code>name</code> only because the <code>similarity</code> is
+          re-created for each new instance and they don't implement equals.
+          This is not entirely correct though but we only use equality checks
+          for similarities inside the same index and names are unique in this case.
+         */
         return Objects.equals(name, that.name);
     }
 
     @Override
     public int hashCode() {
-        /**
-         * We use <code>name</code> only because the <code>similarity</code> is
-         * re-created for each new instance and they don't implement equals.
-         * This is not entirely correct though but we only use equality checks
-         * for similarities a single index and names are unique in this case.
-         **/
+        /*
+          We use <code>name</code> only because the <code>similarity</code> is
+          re-created for each new instance and they don't implement equals.
+          This is not entirely correct though but we only use equality checks
+          for similarities a single index and names are unique in this case.
+         */
         return Objects.hash(name);
     }
 }
diff --git a/server/src/main/java/org/opensearch/index/similarity/SimilarityService.java b/server/src/main/java/org/opensearch/index/similarity/SimilarityService.java
index c3fc7ffbb0fe5..6b4566826cedc 100644
--- a/server/src/main/java/org/opensearch/index/similarity/SimilarityService.java
+++ b/server/src/main/java/org/opensearch/index/similarity/SimilarityService.java
@@ -45,6 +45,7 @@
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.Version;
 import org.opensearch.common.TriFunction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.index.AbstractIndexComponent;
@@ -63,8 +64,9 @@
 /**
  * Service for similarity computations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SimilarityService extends AbstractIndexComponent {
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(SimilarityService.class);
     public static final String DEFAULT_SIMILARITY = "BM25";
diff --git a/server/src/main/java/org/opensearch/index/snapshots/IndexShardSnapshotStatus.java b/server/src/main/java/org/opensearch/index/snapshots/IndexShardSnapshotStatus.java
index d48da6f462502..d844a7d2d25c4 100644
--- a/server/src/main/java/org/opensearch/index/snapshots/IndexShardSnapshotStatus.java
+++ b/server/src/main/java/org/opensearch/index/snapshots/IndexShardSnapshotStatus.java
@@ -32,21 +32,25 @@
 
 package org.opensearch.index.snapshots;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Represent shard snapshot status
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndexShardSnapshotStatus {
 
     /**
      * Snapshot stage
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Stage {
         /**
          * Snapshot hasn't started yet
@@ -248,8 +252,9 @@ public static IndexShardSnapshotStatus newDone(
     /**
      * Returns an immutable state of {@link IndexShardSnapshotStatus} at a given point in time.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Copy {
 
         private final Stage stage;
diff --git a/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java b/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java
index eefc1469a06a0..d54e9686ab951 100644
--- a/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java
+++ b/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.snapshots.blobstore;
 
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.xcontent.ToXContentFragment;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -22,8 +23,9 @@
 /**
  * Remote Store based Shard snapshot metadata
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.9.0")
 public class RemoteStoreShardShallowCopySnapshot implements ToXContentFragment, IndexShardSnapshot {
 
     private final String snapshot;
@@ -322,10 +324,10 @@ public String snapshot() {
         return snapshot;
     }
 
-    /**
-     * Returns list of files in the shard
-     *
-     * @return list of files
+    /*
+      Returns list of files in the shard
+
+      @return list of files
      */
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/stats/IndexingPressurePerShardStats.java b/server/src/main/java/org/opensearch/index/stats/IndexingPressurePerShardStats.java
index d69ae02fa8e34..21e1105422725 100644
--- a/server/src/main/java/org/opensearch/index/stats/IndexingPressurePerShardStats.java
+++ b/server/src/main/java/org/opensearch/index/stats/IndexingPressurePerShardStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.stats;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -22,8 +23,9 @@
 /**
  * Per shard indexing pressure statistics
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.3.0")
 public class IndexingPressurePerShardStats implements Writeable, ToXContentFragment {
 
     private final String shardId;
diff --git a/server/src/main/java/org/opensearch/index/stats/IndexingPressureStats.java b/server/src/main/java/org/opensearch/index/stats/IndexingPressureStats.java
index dcdea8adbbcde..53442a7a04adf 100644
--- a/server/src/main/java/org/opensearch/index/stats/IndexingPressureStats.java
+++ b/server/src/main/java/org/opensearch/index/stats/IndexingPressureStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.stats;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * Base indexing pressure statistics
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.3.0")
 public class IndexingPressureStats implements Writeable, ToXContentFragment {
 
     private final long totalCombinedCoordinatingAndPrimaryBytes;
diff --git a/server/src/main/java/org/opensearch/index/stats/ShardIndexingPressureStats.java b/server/src/main/java/org/opensearch/index/stats/ShardIndexingPressureStats.java
index b7071d883bb4c..0b8cd75a24ded 100644
--- a/server/src/main/java/org/opensearch/index/stats/ShardIndexingPressureStats.java
+++ b/server/src/main/java/org/opensearch/index/stats/ShardIndexingPressureStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.stats;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -23,8 +24,9 @@
 /**
  * Cumulative shard indexing pressure stats
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.3.0")
 public class ShardIndexingPressureStats implements Writeable, ToXContentFragment {
 
     private final Map<ShardId, IndexingPressurePerShardStats> shardIndexingPressureStore;
diff --git a/server/src/main/java/org/opensearch/index/store/DirectoryFileTransferTracker.java b/server/src/main/java/org/opensearch/index/store/DirectoryFileTransferTracker.java
index 7ad48cb56a33b..2ab615677dedb 100644
--- a/server/src/main/java/org/opensearch/index/store/DirectoryFileTransferTracker.java
+++ b/server/src/main/java/org/opensearch/index/store/DirectoryFileTransferTracker.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.store;
 
 import org.apache.lucene.store.Directory;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.MovingAverage;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -22,8 +23,9 @@
 /**
  * Tracks the amount of bytes transferred between two {@link Directory} instances
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class DirectoryFileTransferTracker {
     /**
      * Cumulative size of files (in bytes) attempted to be transferred over from the source {@link Directory}
@@ -166,8 +168,9 @@ public DirectoryFileTransferTracker.Stats stats() {
     /**
      * Represents the tracker's stats presentable to an API.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "2.10.0")
     public static class Stats implements Writeable {
         public final long transferredBytesStarted;
         public final long transferredBytesFailed;
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java b/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java
index 594b7f99cd85a..345583bbbd1be 100644
--- a/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java
+++ b/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java
@@ -39,7 +39,6 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicReference;
@@ -62,9 +61,9 @@ public class RemoteDirectory extends Directory {
     protected final BlobContainer blobContainer;
     private static final Logger logger = LogManager.getLogger(RemoteDirectory.class);
 
-    protected final UnaryOperator<OffsetRangeInputStream> uploadRateLimiter;
+    private final UnaryOperator<OffsetRangeInputStream> uploadRateLimiter;
 
-    protected final UnaryOperator<InputStream> downloadRateLimiter;
+    private final UnaryOperator<InputStream> downloadRateLimiter;
 
     /**
      * Number of bytes in the segment file to store checksum
@@ -193,10 +192,14 @@ public IndexOutput createOutput(String name, IOContext context) {
      */
     @Override
     public IndexInput openInput(String name, IOContext context) throws IOException {
+        return openInput(name, fileLength(name), context);
+    }
+
+    public IndexInput openInput(String name, long fileLength, IOContext context) throws IOException {
         InputStream inputStream = null;
         try {
             inputStream = blobContainer.readBlob(name);
-            return new RemoteIndexInput(name, downloadRateLimiter.apply(inputStream), fileLength(name));
+            return new RemoteIndexInput(name, downloadRateLimiter.apply(inputStream), fileLength);
         } catch (Exception e) {
             // Incase the RemoteIndexInput creation fails, close the input stream to avoid file handler leak.
             if (inputStream != null) {
@@ -230,9 +233,9 @@ public void close() throws IOException {
     @Override
     public long fileLength(String name) throws IOException {
         // ToDo: Instead of calling remote store each time, keep a cache with segment metadata
-        Map<String, BlobMetadata> metadata = blobContainer.listBlobsByPrefix(name);
-        if (metadata.containsKey(name)) {
-            return metadata.get(name).length();
+        List<BlobMetadata> metadata = blobContainer.listBlobsByPrefixInSortedOrder(name, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+        if (metadata.size() == 1 && metadata.get(0).name().equals(name)) {
+            return metadata.get(0).length();
         }
         throw new NoSuchFileException(name);
     }
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
index 266552cea93d9..9c1e902606cab 100644
--- a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
+++ b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
@@ -24,13 +24,18 @@
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.Version;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.io.VersionedCodecStreamWrapper;
+import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.lucene.store.ByteArrayIndexInput;
 import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.remote.RemoteStoreUtils;
 import org.opensearch.index.store.lockmanager.FileLockInfo;
 import org.opensearch.index.store.lockmanager.RemoteStoreCommitLevelLockManager;
 import org.opensearch.index.store.lockmanager.RemoteStoreLockManager;
+import org.opensearch.index.store.lockmanager.RemoteStoreMetadataLockManager;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadata;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadataHandler;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
@@ -46,6 +51,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -61,8 +67,9 @@
  * remote segment store also keeps track of refresh checkpoints as metadata in a separate path which is handled by
  * another instance of {@code RemoteDirectory}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public final class RemoteSegmentStoreDirectory extends FilterDirectory implements RemoteStoreCommitLevelLockManager {
 
     /**
@@ -97,7 +104,9 @@ public final class RemoteSegmentStoreDirectory extends FilterDirectory implement
         RemoteSegmentMetadata.METADATA_CODEC
     );
 
-    private static final Logger logger = LogManager.getLogger(RemoteSegmentStoreDirectory.class);
+    private static final Logger staticLogger = LogManager.getLogger(RemoteSegmentStoreDirectory.class);
+
+    private final Logger logger;
 
     /**
      * AtomicBoolean that ensures only one staleCommitDeletion activity is scheduled at a time.
@@ -107,17 +116,21 @@ public final class RemoteSegmentStoreDirectory extends FilterDirectory implement
 
     private final AtomicLong metadataUploadCounter = new AtomicLong(0);
 
+    public static final int METADATA_FILES_TO_FETCH = 10;
+
     public RemoteSegmentStoreDirectory(
         RemoteDirectory remoteDataDirectory,
         RemoteDirectory remoteMetadataDirectory,
         RemoteStoreLockManager mdLockManager,
-        ThreadPool threadPool
+        ThreadPool threadPool,
+        ShardId shardId
     ) throws IOException {
         super(remoteDataDirectory);
         this.remoteDataDirectory = remoteDataDirectory;
         this.remoteMetadataDirectory = remoteMetadataDirectory;
         this.mdLockManager = mdLockManager;
         this.threadPool = threadPool;
+        this.logger = Loggers.getLogger(getClass(), shardId);
         init();
     }
 
@@ -130,12 +143,14 @@ public RemoteSegmentStoreDirectory(
      * @throws IOException if there were any failures in reading the metadata file
      */
     public RemoteSegmentMetadata init() throws IOException {
+        logger.debug("Start initialisation of remote segment metadata");
         RemoteSegmentMetadata remoteSegmentMetadata = readLatestMetadataFile();
         if (remoteSegmentMetadata != null) {
             this.segmentsUploadedToRemoteStore = new ConcurrentHashMap<>(remoteSegmentMetadata.getMetadata());
         } else {
             this.segmentsUploadedToRemoteStore = new ConcurrentHashMap<>();
         }
+        logger.debug("Initialisation of remote segment metadata completed");
         return remoteSegmentMetadata;
     }
 
@@ -147,8 +162,9 @@ public RemoteSegmentMetadata init() throws IOException {
      *
      * @throws IOException if there were any failures in reading the metadata file
      */
-    public RemoteSegmentMetadata initializeToSpecificCommit(long primaryTerm, long commitGeneration) throws IOException {
-        String metadataFile = getMetadataFileForCommit(primaryTerm, commitGeneration);
+    public RemoteSegmentMetadata initializeToSpecificCommit(long primaryTerm, long commitGeneration, String acquirerId) throws IOException {
+        String metadataFilePrefix = MetadataFilenameUtils.getMetadataFilePrefixForCommit(primaryTerm, commitGeneration);
+        String metadataFile = ((RemoteStoreMetadataLockManager) mdLockManager).fetchLock(metadataFilePrefix, acquirerId);
         RemoteSegmentMetadata remoteSegmentMetadata = readMetadataFile(metadataFile);
         if (remoteSegmentMetadata != null) {
             this.segmentsUploadedToRemoteStore = new ConcurrentHashMap<>(remoteSegmentMetadata.getMetadata());
@@ -176,9 +192,11 @@ public RemoteSegmentMetadata readLatestMetadataFile() throws IOException {
 
         List<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
             MetadataFilenameUtils.METADATA_PREFIX,
-            1
+            METADATA_FILES_TO_FETCH
         );
 
+        RemoteStoreUtils.verifyNoMultipleWriters(metadataFiles, MetadataFilenameUtils::getNodeIdByPrimaryTermAndGen);
+
         if (metadataFiles.isEmpty() == false) {
             String latestMetadataFile = metadataFiles.get(0);
             logger.trace("Reading latest Metadata file {}", latestMetadataFile);
@@ -199,7 +217,10 @@ private RemoteSegmentMetadata readMetadataFile(String metadataFilename) throws I
 
     /**
      * Metadata of a segment that is uploaded to remote segment store.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "2.3.0")
     public static class UploadedSegmentMetadata {
         // Visible for testing
         static final String SEPARATOR = "::";
@@ -248,7 +269,7 @@ public static UploadedSegmentMetadata fromString(String uploadedFilename) {
             String[] values = uploadedFilename.split(SEPARATOR);
             UploadedSegmentMetadata metadata = new UploadedSegmentMetadata(values[0], values[1], values[2], Long.parseLong(values[3]));
             if (values.length < 5) {
-                logger.error("Lucene version is missing for UploadedSegmentMetadata: " + uploadedFilename);
+                staticLogger.error("Lucene version is missing for UploadedSegmentMetadata: " + uploadedFilename);
             }
 
             metadata.setWrittenByMajor(Integer.parseInt(values[4]));
@@ -295,12 +316,13 @@ static String getMetadataFilePrefixForCommit(long primaryTerm, long generation)
         }
 
         // Visible for testing
-        static String getMetadataFilename(
+        public static String getMetadataFilename(
             long primaryTerm,
             long generation,
             long translogGeneration,
             long uploadCounter,
-            int metadataVersion
+            int metadataVersion,
+            String nodeId
         ) {
             return String.join(
                 SEPARATOR,
@@ -309,6 +331,7 @@ static String getMetadataFilename(
                 RemoteStoreUtils.invertLong(generation),
                 RemoteStoreUtils.invertLong(translogGeneration),
                 RemoteStoreUtils.invertLong(uploadCounter),
+                String.valueOf(Objects.hash(nodeId)),
                 RemoteStoreUtils.invertLong(System.currentTimeMillis()),
                 String.valueOf(metadataVersion)
             );
@@ -323,6 +346,19 @@ static long getPrimaryTerm(String[] filenameTokens) {
         static long getGeneration(String[] filenameTokens) {
             return RemoteStoreUtils.invertLong(filenameTokens[2]);
         }
+
+        public static Tuple<String, String> getNodeIdByPrimaryTermAndGen(String filename) {
+            String[] tokens = filename.split(SEPARATOR);
+            if (tokens.length < 8) {
+                // For versions < 2.11, we don't have node id.
+                return null;
+            }
+            String primaryTermAndGen = String.join(SEPARATOR, tokens[1], tokens[2], tokens[3]);
+
+            String nodeId = tokens[5];
+            return new Tuple<>(primaryTermAndGen, nodeId);
+        }
+
     }
 
     /**
@@ -396,8 +432,9 @@ public IndexOutput createOutput(String name, IOContext context) throws IOExcepti
     @Override
     public IndexInput openInput(String name, IOContext context) throws IOException {
         String remoteFilename = getExistingRemoteFilename(name);
+        long fileLength = fileLength(name);
         if (remoteFilename != null) {
-            return remoteDataDirectory.openInput(remoteFilename, context);
+            return remoteDataDirectory.openInput(remoteFilename, fileLength, context);
         } else {
             throw new NoSuchFileException(name);
         }
@@ -547,6 +584,7 @@ public boolean containsFile(String localFilename, String checksum) {
      * @param storeDirectory instance of local directory to temporarily create metadata file before upload
      * @param translogGeneration translog generation
      * @param replicationCheckpoint ReplicationCheckpoint of primary shard
+     * @param nodeId node id
      * @throws IOException in case of I/O error while uploading the metadata file
      */
     public void uploadMetadata(
@@ -554,7 +592,8 @@ public void uploadMetadata(
         SegmentInfos segmentInfosSnapshot,
         Directory storeDirectory,
         long translogGeneration,
-        ReplicationCheckpoint replicationCheckpoint
+        ReplicationCheckpoint replicationCheckpoint,
+        String nodeId
     ) throws IOException {
         synchronized (this) {
             String metadataFilename = MetadataFilenameUtils.getMetadataFilename(
@@ -562,7 +601,8 @@ public void uploadMetadata(
                 segmentInfosSnapshot.getGeneration(),
                 translogGeneration,
                 metadataUploadCounter.incrementAndGet(),
-                RemoteSegmentMetadata.CURRENT_VERSION
+                RemoteSegmentMetadata.CURRENT_VERSION,
+                nodeId
             );
             try {
                 try (IndexOutput indexOutput = storeDirectory.createOutput(metadataFilename, IOContext.DEFAULT)) {
@@ -641,7 +681,7 @@ private Map<String, Integer> getSegmentToLuceneVersion(Collection<String> segmen
      */
     private void tryAndDeleteLocalFile(String filename, Directory directory) {
         try {
-            logger.trace("Deleting file: " + filename);
+            logger.debug("Deleting file: " + filename);
             directory.deleteFile(filename);
         } catch (NoSuchFileException | FileNotFoundException e) {
             logger.trace("Exception while deleting. Missing file : " + filename, e);
@@ -686,12 +726,18 @@ public Map<String, UploadedSegmentMetadata> getSegmentsUploadedToRemoteStore() {
      * @throws IOException in case of I/O error while reading from / writing to remote segment store
      */
     public void deleteStaleSegments(int lastNMetadataFilesToKeep) throws IOException {
+        if (lastNMetadataFilesToKeep == -1) {
+            logger.info(
+                "Stale segment deletion is disabled if cluster.remote_store.index.segment_metadata.retention.max_count is set to -1"
+            );
+            return;
+        }
         List<String> sortedMetadataFileList = remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
             MetadataFilenameUtils.METADATA_PREFIX,
             Integer.MAX_VALUE
         );
         if (sortedMetadataFileList.size() <= lastNMetadataFilesToKeep) {
-            logger.trace(
+            logger.debug(
                 "Number of commits in remote segment store={}, lastNMetadataFilesToKeep={}",
                 sortedMetadataFileList.size(),
                 lastNMetadataFilesToKeep
@@ -719,6 +765,11 @@ public void deleteStaleSegments(int lastNMetadataFilesToKeep) throws IOException
         }).collect(Collectors.toList());
 
         sortedMetadataFileList.removeAll(metadataFilesToBeDeleted);
+        logger.debug(
+            "metadataFilesEligibleToDelete={} metadataFilesToBeDeleted={}",
+            metadataFilesEligibleToDelete,
+            metadataFilesEligibleToDelete
+        );
 
         Map<String, UploadedSegmentMetadata> activeSegmentFilesMetadataMap = new HashMap<>();
         Set<String> activeSegmentRemoteFilenames = new HashSet<>();
@@ -729,6 +780,7 @@ public void deleteStaleSegments(int lastNMetadataFilesToKeep) throws IOException
                 segmentMetadataMap.values().stream().map(metadata -> metadata.uploadedFilename).collect(Collectors.toSet())
             );
         }
+        Set<String> deletedSegmentFiles = new HashSet<>();
         for (String metadataFile : metadataFilesToBeDeleted) {
             Map<String, UploadedSegmentMetadata> staleSegmentFilesMetadataMap = readMetadataFile(metadataFile).getMetadata();
             Set<String> staleSegmentRemoteFilenames = staleSegmentFilesMetadataMap.values()
@@ -736,28 +788,33 @@ public void deleteStaleSegments(int lastNMetadataFilesToKeep) throws IOException
                 .map(metadata -> metadata.uploadedFilename)
                 .collect(Collectors.toSet());
             AtomicBoolean deletionSuccessful = new AtomicBoolean(true);
-            staleSegmentRemoteFilenames.stream().filter(file -> !activeSegmentRemoteFilenames.contains(file)).forEach(file -> {
-                try {
-                    remoteDataDirectory.deleteFile(file);
-                    if (!activeSegmentFilesMetadataMap.containsKey(getLocalSegmentFilename(file))) {
-                        segmentsUploadedToRemoteStore.remove(getLocalSegmentFilename(file));
+            staleSegmentRemoteFilenames.stream()
+                .filter(file -> activeSegmentRemoteFilenames.contains(file) == false)
+                .filter(file -> deletedSegmentFiles.contains(file) == false)
+                .forEach(file -> {
+                    try {
+                        remoteDataDirectory.deleteFile(file);
+                        deletedSegmentFiles.add(file);
+                        if (!activeSegmentFilesMetadataMap.containsKey(getLocalSegmentFilename(file))) {
+                            segmentsUploadedToRemoteStore.remove(getLocalSegmentFilename(file));
+                        }
+                    } catch (NoSuchFileException e) {
+                        logger.info("Segment file {} corresponding to metadata file {} does not exist in remote", file, metadataFile);
+                    } catch (IOException e) {
+                        deletionSuccessful.set(false);
+                        logger.warn(
+                            "Exception while deleting segment file {} corresponding to metadata file {}. Deletion will be re-tried",
+                            file,
+                            metadataFile
+                        );
                     }
-                } catch (NoSuchFileException e) {
-                    logger.info("Segment file {} corresponding to metadata file {} does not exist in remote", file, metadataFile);
-                } catch (IOException e) {
-                    deletionSuccessful.set(false);
-                    logger.info(
-                        "Exception while deleting segment file {} corresponding to metadata file {}. Deletion will be re-tried",
-                        file,
-                        metadataFile
-                    );
-                }
-            });
+                });
             if (deletionSuccessful.get()) {
-                logger.trace("Deleting stale metadata file {} from remote segment store", metadataFile);
+                logger.debug("Deleting stale metadata file {} from remote segment store", metadataFile);
                 remoteMetadataDirectory.deleteFile(metadataFile);
             }
         }
+        logger.debug("deletedSegmentFiles={}", deletedSegmentFiles);
     }
 
     public void deleteStaleSegmentsAsync(int lastNMetadataFilesToKeep) {
@@ -805,7 +862,7 @@ private boolean deleteIfEmpty() throws IOException {
             1
         );
         if (metadataFiles.size() != 0) {
-            logger.info("Remote directory still has files , not deleting the path");
+            logger.info("Remote directory still has files, not deleting the path");
             return false;
         }
 
@@ -821,6 +878,7 @@ private boolean deleteIfEmpty() throws IOException {
         return true;
     }
 
+    @Override
     public void close() throws IOException {
         deleteStaleSegmentsAsync(0, ActionListener.wrap(r -> deleteIfEmpty(), e -> logger.error("Failed to cleanup remote directory")));
     }
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java
index 31b49f6813ad2..a5e89ec6a8327 100644
--- a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java
+++ b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java
@@ -10,6 +10,7 @@
 
 import org.apache.lucene.store.Directory;
 import org.opensearch.common.blobstore.BlobPath;
+import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.shard.ShardPath;
 import org.opensearch.index.store.lockmanager.RemoteStoreLockManager;
@@ -45,17 +46,15 @@ public RemoteSegmentStoreDirectoryFactory(Supplier<RepositoriesService> reposito
     public Directory newDirectory(IndexSettings indexSettings, ShardPath path) throws IOException {
         String repositoryName = indexSettings.getRemoteStoreRepository();
         String indexUUID = indexSettings.getIndex().getUUID();
-        String shardId = String.valueOf(path.getShardId().getId());
-
-        return newDirectory(repositoryName, indexUUID, shardId);
+        return newDirectory(repositoryName, indexUUID, path.getShardId());
     }
 
-    public Directory newDirectory(String repositoryName, String indexUUID, String shardId) throws IOException {
+    public Directory newDirectory(String repositoryName, String indexUUID, ShardId shardId) throws IOException {
         try (Repository repository = repositoriesService.get().repository(repositoryName)) {
             assert repository instanceof BlobStoreRepository : "repository should be instance of BlobStoreRepository";
             BlobStoreRepository blobStoreRepository = ((BlobStoreRepository) repository);
             BlobPath commonBlobPath = blobStoreRepository.basePath();
-            commonBlobPath = commonBlobPath.add(indexUUID).add(shardId).add(SEGMENTS);
+            commonBlobPath = commonBlobPath.add(indexUUID).add(String.valueOf(shardId.id())).add(SEGMENTS);
 
             RemoteDirectory dataDirectory = new RemoteDirectory(
                 blobStoreRepository.blobStore().blobContainer(commonBlobPath.add("data")),
@@ -69,16 +68,12 @@ public Directory newDirectory(String repositoryName, String indexUUID, String sh
                 repositoriesService.get(),
                 repositoryName,
                 indexUUID,
-                shardId
+                String.valueOf(shardId.id())
             );
 
-            return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, mdLockManager, threadPool);
+            return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, mdLockManager, threadPool, shardId);
         } catch (RepositoryMissingException e) {
             throw new IllegalArgumentException("Repository should be created before creating index with remote_store enabled setting", e);
         }
     }
-
-    private RemoteDirectory createRemoteDirectory(BlobStoreRepository repository, BlobPath commonBlobPath, String extension) {
-        return new RemoteDirectory(repository.blobStore().blobContainer(commonBlobPath.add(extension)));
-    }
 }
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteStoreFileDownloader.java b/server/src/main/java/org/opensearch/index/store/RemoteStoreFileDownloader.java
new file mode 100644
index 0000000000000..134994c0ae32c
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/store/RemoteStoreFileDownloader.java
@@ -0,0 +1,167 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.store;
+
+import org.apache.logging.log4j.Logger;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.opensearch.action.support.GroupedActionListener;
+import org.opensearch.action.support.PlainActionFuture;
+import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.common.logging.Loggers;
+import org.opensearch.common.util.CancellableThreads;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.indices.recovery.RecoverySettings;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ExecutionException;
+
+/**
+ * Helper class to downloads files from a {@link RemoteSegmentStoreDirectory}
+ * instance to a local {@link Directory} instance in parallel depending on thread
+ * pool size and recovery settings.
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "2.11.0")
+public final class RemoteStoreFileDownloader {
+    private final Logger logger;
+    private final ThreadPool threadPool;
+    private final RecoverySettings recoverySettings;
+
+    public RemoteStoreFileDownloader(ShardId shardId, ThreadPool threadPool, RecoverySettings recoverySettings) {
+        this.logger = Loggers.getLogger(RemoteStoreFileDownloader.class, shardId);
+        this.threadPool = threadPool;
+        this.recoverySettings = recoverySettings;
+    }
+
+    /**
+     * Copies the given segments from the remote segment store to the given
+     * local directory.
+     * @param source The remote directory to copy segment files from
+     * @param destination The local directory to copy segment files to
+     * @param toDownloadSegments The list of segment files to download
+     * @param listener Callback listener to be notified upon completion
+     */
+    public void downloadAsync(
+        CancellableThreads cancellableThreads,
+        Directory source,
+        Directory destination,
+        Collection<String> toDownloadSegments,
+        ActionListener<Void> listener
+    ) {
+        downloadInternal(cancellableThreads, source, destination, null, toDownloadSegments, () -> {}, listener);
+    }
+
+    /**
+     * Copies the given segments from the remote segment store to the given
+     * local directory, while also copying the segments _to_ another remote directory.
+     * @param source The remote directory to copy segment files from
+     * @param destination The local directory to copy segment files to
+     * @param secondDestination The second remote directory that segment files are
+     *                          copied to after being copied to the local directory
+     * @param toDownloadSegments The list of segment files to download
+     * @param onFileCompletion A generic runnable that is invoked after each file download.
+     *                         Must be thread safe as this may be invoked concurrently from
+     *                         different threads.
+     */
+    public void download(
+        Directory source,
+        Directory destination,
+        Directory secondDestination,
+        Collection<String> toDownloadSegments,
+        Runnable onFileCompletion
+    ) throws InterruptedException, IOException {
+        final CancellableThreads cancellableThreads = new CancellableThreads();
+        final PlainActionFuture<Void> listener = PlainActionFuture.newFuture();
+        downloadInternal(cancellableThreads, source, destination, secondDestination, toDownloadSegments, onFileCompletion, listener);
+        try {
+            listener.get();
+        } catch (ExecutionException e) {
+            if (e.getCause() instanceof RuntimeException) {
+                throw (RuntimeException) e.getCause();
+            } else if (e.getCause() instanceof IOException) {
+                throw (IOException) e.getCause();
+            }
+            throw new RuntimeException(e);
+        } catch (InterruptedException e) {
+            // If the blocking call on the PlainActionFuture itself is interrupted, then we must
+            // cancel the asynchronous work we were waiting on
+            cancellableThreads.cancel(e.getMessage());
+            Thread.currentThread().interrupt();
+            throw e;
+        }
+    }
+
+    private void downloadInternal(
+        CancellableThreads cancellableThreads,
+        Directory source,
+        Directory destination,
+        @Nullable Directory secondDestination,
+        Collection<String> toDownloadSegments,
+        Runnable onFileCompletion,
+        ActionListener<Void> listener
+    ) {
+        final Queue<String> queue = new ConcurrentLinkedQueue<>(toDownloadSegments);
+        // Choose the minimum of:
+        // - number of files to download
+        // - max thread pool size
+        // - "indices.recovery.max_concurrent_remote_store_streams" setting
+        final int threads = Math.min(
+            toDownloadSegments.size(),
+            Math.min(threadPool.info(ThreadPool.Names.REMOTE_RECOVERY).getMax(), recoverySettings.getMaxConcurrentRemoteStoreStreams())
+        );
+        logger.trace("Starting download of {} files with {} threads", queue.size(), threads);
+        final ActionListener<Void> allFilesListener = new GroupedActionListener<>(ActionListener.map(listener, r -> null), threads);
+        for (int i = 0; i < threads; i++) {
+            copyOneFile(cancellableThreads, source, destination, secondDestination, queue, onFileCompletion, allFilesListener);
+        }
+    }
+
+    private void copyOneFile(
+        CancellableThreads cancellableThreads,
+        Directory source,
+        Directory destination,
+        @Nullable Directory secondDestination,
+        Queue<String> queue,
+        Runnable onFileCompletion,
+        ActionListener<Void> listener
+    ) {
+        final String file = queue.poll();
+        if (file == null) {
+            // Queue is empty, so notify listener we are done
+            listener.onResponse(null);
+        } else {
+            threadPool.executor(ThreadPool.Names.REMOTE_RECOVERY).submit(() -> {
+                logger.trace("Downloading file {}", file);
+                try {
+                    cancellableThreads.executeIO(() -> {
+                        destination.copyFrom(source, file, file, IOContext.DEFAULT);
+                        onFileCompletion.run();
+                        if (secondDestination != null) {
+                            secondDestination.copyFrom(destination, file, file, IOContext.DEFAULT);
+                        }
+                    });
+                } catch (Exception e) {
+                    // Clear the queue to stop any future processing, report the failure, then return
+                    queue.clear();
+                    listener.onFailure(e);
+                    return;
+                }
+                copyOneFile(cancellableThreads, source, destination, secondDestination, queue, onFileCompletion, listener);
+            });
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/index/store/Store.java b/server/src/main/java/org/opensearch/index/store/Store.java
index b3ea2cdd02e21..1930a37daa400 100644
--- a/server/src/main/java/org/opensearch/index/store/Store.java
+++ b/server/src/main/java/org/opensearch/index/store/Store.java
@@ -66,6 +66,7 @@
 import org.apache.lucene.util.Version;
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.lucene.Lucene;
@@ -92,6 +93,7 @@
 import org.opensearch.index.seqno.SequenceNumbers;
 import org.opensearch.index.shard.AbstractIndexShardComponent;
 import org.opensearch.index.shard.IndexShard;
+import org.opensearch.index.shard.ShardPath;
 import org.opensearch.index.translog.Translog;
 
 import java.io.Closeable;
@@ -143,8 +145,9 @@
  *      }
  * </pre>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Store extends AbstractIndexShardComponent implements Closeable, RefCounted {
     /**
      * This is an escape hatch for lucenes internal optimization that checks if the IndexInput is an instance of ByteBufferIndexInput
@@ -179,6 +182,7 @@ public class Store extends AbstractIndexShardComponent implements Closeable, Ref
     private final ReentrantReadWriteLock metadataLock = new ReentrantReadWriteLock();
     private final ShardLock shardLock;
     private final OnClose onClose;
+    private final ShardPath shardPath;
 
     // used to ref count files when a new Reader is opened for PIT/Scroll queries
     // prevents segment files deletion until the PIT/Scroll expires or is discarded
@@ -192,10 +196,17 @@ protected void closeInternal() {
     };
 
     public Store(ShardId shardId, IndexSettings indexSettings, Directory directory, ShardLock shardLock) {
-        this(shardId, indexSettings, directory, shardLock, OnClose.EMPTY);
+        this(shardId, indexSettings, directory, shardLock, OnClose.EMPTY, null);
     }
 
-    public Store(ShardId shardId, IndexSettings indexSettings, Directory directory, ShardLock shardLock, OnClose onClose) {
+    public Store(
+        ShardId shardId,
+        IndexSettings indexSettings,
+        Directory directory,
+        ShardLock shardLock,
+        OnClose onClose,
+        ShardPath shardPath
+    ) {
         super(shardId, indexSettings);
         final TimeValue refreshInterval = indexSettings.getValue(INDEX_STORE_STATS_REFRESH_INTERVAL_SETTING);
         logger.debug("store stats are refreshed with refresh_interval [{}]", refreshInterval);
@@ -203,6 +214,7 @@ public Store(ShardId shardId, IndexSettings indexSettings, Directory directory,
         this.directory = new StoreDirectory(sizeCachingDir, Loggers.getLogger("index.store.deletes", shardId));
         this.shardLock = shardLock;
         this.onClose = onClose;
+        this.shardPath = shardPath;
         assert onClose != null;
         assert shardLock != null;
         assert shardLock.getShardId().equals(shardId);
@@ -213,6 +225,10 @@ public Directory directory() {
         return directory;
     }
 
+    public ShardPath shardPath() {
+        return shardPath;
+    }
+
     /**
      * Returns the last committed segments info for this store
      *
@@ -283,14 +299,15 @@ final void ensureOpen() {
     /**
      * Returns a new MetadataSnapshot for the given commit. If the given commit is <code>null</code>
      * the latest commit point is used.
-     *
+     * <p>
      * Note that this method requires the caller verify it has the right to access the store and
      * no concurrent file changes are happening. If in doubt, you probably want to use one of the following:
-     *
+     * <p>
      * {@link #readMetadataSnapshot(Path, ShardId, NodeEnvironment.ShardLocker, Logger)} to read a meta data while locking
      * {@link IndexShard#snapshotStoreMetadata()} to safely read from an existing shard
      * {@link IndexShard#acquireLastIndexCommit(boolean)} to get an {@link IndexCommit} which is safe to use but has to be freed
-     * @param commit the index commit to read the snapshot from or <code>null</code> if the latest snapshot should be read from the
+     *
+     * @param commit the index commit to read the snapshot from or {@code null} if the latest snapshot should be read from the
      *               directory
      * @throws CorruptIndexException      if the lucene index is corrupted. This can be caused by a checksum mismatch or an
      *                                    unexpected exception when opening the index reading the segments file.
@@ -314,10 +331,10 @@ public MetadataSnapshot getMetadata() throws IOException {
     /**
      * Returns a new MetadataSnapshot for the given commit. If the given commit is <code>null</code>
      * the latest commit point is used.
-     *
+     * <p>
      * Note that this method requires the caller verify it has the right to access the store and
      * no concurrent file changes are happening. If in doubt, you probably want to use one of the following:
-     *
+     * <p>
      * {@link #readMetadataSnapshot(Path, ShardId, NodeEnvironment.ShardLocker, Logger)} to read a meta data while locking
      * {@link IndexShard#snapshotStoreMetadata()} to safely read from an existing shard
      * {@link IndexShard#acquireLastIndexCommit(boolean)} to get an {@link IndexCommit} which is safe to use but has to be freed
@@ -369,7 +386,13 @@ public MetadataSnapshot getMetadata(SegmentInfos segmentInfos) throws IOExceptio
      */
     public Map<String, StoreFileMetadata> getSegmentMetadataMap(SegmentInfos segmentInfos) throws IOException {
         assert indexSettings.isSegRepEnabled();
-        return loadMetadata(segmentInfos, directory, logger, true).fileMetadata;
+        failIfCorrupted();
+        try {
+            return loadMetadata(segmentInfos, directory, logger, true).fileMetadata;
+        } catch (NoSuchFileException | CorruptIndexException | IndexFormatTooOldException | IndexFormatTooNewException ex) {
+            markStoreCorrupted(ex);
+            throw ex;
+        }
     }
 
     /**
@@ -784,7 +807,7 @@ public void cleanupAndVerify(String reason, MetadataSnapshot sourceMetadata) thr
 
     /**
      * Segment replication method
-     *
+     * <p>
      * This method takes the segment info bytes to build SegmentInfos. It inc'refs files pointed by passed in SegmentInfos
      * bytes to ensure they are not deleted.
      *
@@ -859,7 +882,7 @@ public void beforeClose() {
      * have the ability to create a writer directly from a SegmentInfos object.  To promote the replica as a primary and avoid reindexing, we must first commit
      * on the replica so that it can be opened with a writeable engine. Further, InternalEngine currently invokes `trimUnsafeCommits` which reverts the engine to a previous safeCommit where the max seqNo is less than or equal
      * to the current global checkpoint. It is likely that the replica has a maxSeqNo that is higher than the global cp and a new commit will be wiped.
-     *
+     * <p>
      * To get around these limitations, this method first creates an IndexCommit directly from SegmentInfos, it then
      * uses an appending IW to create an IndexCommit from the commit created on SegmentInfos.
      * This ensures that 1. All files in the new commit are fsynced and 2. Deletes older commit points so the only commit to start from is our new commit.
@@ -999,8 +1022,9 @@ private void downloadFailed(long fileSize, long startTimeInMs) {
      *
      * @see StoreFileMetadata
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class MetadataSnapshot implements Iterable<StoreFileMetadata>, Writeable {
         private final Map<String, StoreFileMetadata> metadata;
 
@@ -1406,8 +1430,9 @@ public String getSyncId() {
      *
      * @see MetadataSnapshot#recoveryDiff(org.opensearch.index.store.Store.MetadataSnapshot)
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class RecoveryDiff {
         /**
          * Files that exist in both snapshots and they can be considered the same ie. they don't need to be recovered
diff --git a/server/src/main/java/org/opensearch/index/store/StoreFileMetadata.java b/server/src/main/java/org/opensearch/index/store/StoreFileMetadata.java
index f8c4df50afc8f..c286a5bdbd9d8 100644
--- a/server/src/main/java/org/opensearch/index/store/StoreFileMetadata.java
+++ b/server/src/main/java/org/opensearch/index/store/StoreFileMetadata.java
@@ -35,6 +35,7 @@
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.store.ByteArrayIndexInput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * Metadata for the store file
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class StoreFileMetadata implements Writeable {
 
     private final String name;
diff --git a/server/src/main/java/org/opensearch/index/store/StoreStats.java b/server/src/main/java/org/opensearch/index/store/StoreStats.java
index aa73a2c629515..4763b5e5e8a21 100644
--- a/server/src/main/java/org/opensearch/index/store/StoreStats.java
+++ b/server/src/main/java/org/opensearch/index/store/StoreStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.store;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * Statistics about an OpenSearch Store
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class StoreStats implements Writeable, ToXContentFragment {
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java b/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java
index 24f42743e1a04..b6be60c489a6c 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java
@@ -21,6 +21,7 @@
 public class FileLockInfo implements LockInfo {
     private String fileToLock;
     private String acquirerId;
+    private static final int INVALID_INDEX = -1;
 
     public String getAcquirerId() {
         return acquirerId;
@@ -88,21 +89,34 @@ static String generateLockName(String fileToLock, String acquirerId) {
         }
 
         public static String getFileToLockNameFromLock(String lockName) {
-            String[] lockNameTokens = lockName.split(RemoteStoreLockManagerUtils.SEPARATOR);
-
-            if (lockNameTokens.length != 2) {
-                throw new IllegalArgumentException("Provided Lock Name " + lockName + " is not Valid.");
+            // use proper separator for the lock file depending on the version it is created
+            String lockSeparator = lockName.endsWith(RemoteStoreLockManagerUtils.PRE_OS210_LOCK_FILE_EXTENSION)
+                ? RemoteStoreLockManagerUtils.PRE_OS210_LOCK_SEPARATOR
+                : RemoteStoreLockManagerUtils.SEPARATOR;
+            final int indexOfSeparator = lockName.lastIndexOf(lockSeparator);
+            if (indexOfSeparator == INVALID_INDEX) {
+                throw new IllegalArgumentException("Provided lock name: " + lockName + " is invalid with separator: " + lockSeparator);
             }
-            return lockNameTokens[0];
+            return lockName.substring(0, indexOfSeparator);
         }
 
         public static String getAcquirerIdFromLock(String lockName) {
-            String[] lockNameTokens = lockName.split(RemoteStoreLockManagerUtils.SEPARATOR);
+            String lockExtension = RemoteStoreLockManagerUtils.LOCK_FILE_EXTENSION;
+            String lockSeparator = RemoteStoreLockManagerUtils.SEPARATOR;
 
-            if (lockNameTokens.length != 2) {
-                throw new IllegalArgumentException("Provided Lock Name " + lockName + " is not Valid.");
+            // check if lock file is created on version <=2.10
+            if (lockName.endsWith(RemoteStoreLockManagerUtils.PRE_OS210_LOCK_FILE_EXTENSION)) {
+                lockSeparator = RemoteStoreLockManagerUtils.PRE_OS210_LOCK_SEPARATOR;
+                lockExtension = RemoteStoreLockManagerUtils.PRE_OS210_LOCK_FILE_EXTENSION;
+            }
+            final int indexOfSeparator = lockName.lastIndexOf(lockSeparator);
+            final int indexOfExt = lockName.lastIndexOf(lockExtension);
+            if (indexOfSeparator == INVALID_INDEX || indexOfExt == INVALID_INDEX) {
+                throw new IllegalArgumentException(
+                    "Provided lock name: " + lockName + " is invalid with separator: " + lockSeparator + " and extension: " + lockExtension
+                );
             }
-            return lockNameTokens[1].replace(RemoteStoreLockManagerUtils.LOCK_FILE_EXTENSION, "");
+            return lockName.substring(indexOfSeparator + lockSeparator.length(), indexOfExt);
         }
     }
 
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/LockInfo.java b/server/src/main/java/org/opensearch/index/store/lockmanager/LockInfo.java
index 1470969540d36..6aab518808a3f 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/LockInfo.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/LockInfo.java
@@ -8,11 +8,15 @@
 
 package org.opensearch.index.store.lockmanager;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * An Interface that defines Remote Store Lock Information.
  * Individual Implemented Classes of this interface can decide how the lock should look like and its contents.
- * @opensearch.internal
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public interface LockInfo {
     /**
      * A function which generates the lock name on the basis of given information.
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java
index 9eb066d9e955e..4fa23dfe9dc3a 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java
@@ -8,14 +8,18 @@
 
 package org.opensearch.index.store.lockmanager;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 
 /**
  * An Interface that defines Remote Store Lock Manager.
  * This will provide the functionality to acquire lock, release lock or to check if a lock is acquired on a specific
  * file in remote store.
- * @opensearch.internal
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public interface RemoteStoreLockManager {
     /**
      *
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerFactory.java b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerFactory.java
index 1a306f3261094..00666ada11983 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerFactory.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerFactory.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.store.lockmanager;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.blobstore.BlobContainer;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.index.store.RemoteBufferedOutputDirectory;
@@ -22,8 +23,9 @@
 /**
  * Factory for remote store lock manager
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public class RemoteStoreLockManagerFactory {
     private static final String SEGMENTS = "segments";
     private static final String LOCK_FILES = "lock_files";
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerUtils.java b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerUtils.java
index 452dfc329d88b..d5fb2722a64dc 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerUtils.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManagerUtils.java
@@ -15,8 +15,11 @@
  */
 public class RemoteStoreLockManagerUtils {
     static final String FILE_TO_LOCK_NAME = "file_to_lock";
-    static final String SEPARATOR = "___";
-    static final String LOCK_FILE_EXTENSION = ".lock";
+    static final String PRE_OS210_LOCK_SEPARATOR = "___";
+    static final String SEPARATOR = "...";
+    // for versions <= 2.10, we have lock files with this extension.
+    static final String PRE_OS210_LOCK_FILE_EXTENSION = ".lock";
+    static final String LOCK_FILE_EXTENSION = ".v2_lock";
     static final String ACQUIRER_ID = "acquirer_id";
     public static final String NO_TTL = "-1";
     static final String LOCK_EXPIRY_TIME = "lock_expiry_time";
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
index fd7906729e314..5ebd00f59ef49 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
@@ -12,12 +12,16 @@
 import org.apache.logging.log4j.Logger;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.store.RemoteBufferedOutputDirectory;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.NoSuchFileException;
 import java.util.Collection;
+import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 /**
  * A Class that implements Remote Store Lock Manager by creating lock files for the remote store files that needs to
@@ -25,8 +29,9 @@
  * It uses {@code LockFileInfo} instance to get the information about the lock file on which operations need to
  * be executed.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.8.0")
 public class RemoteStoreMetadataLockManager implements RemoteStoreLockManager {
     private static final Logger logger = LogManager.getLogger(RemoteStoreMetadataLockManager.class);
     private final RemoteBufferedOutputDirectory lockDirectory;
@@ -70,6 +75,19 @@ public void release(LockInfo lockInfo) throws IOException {
         }
     }
 
+    public String fetchLock(String filenamePrefix, String acquirerId) throws IOException {
+        Collection<String> lockFiles = lockDirectory.listFilesByPrefix(filenamePrefix);
+        List<String> lockFilesForAcquirer = lockFiles.stream()
+            .filter(lockFile -> acquirerId.equals(FileLockInfo.LockFileUtils.getAcquirerIdFromLock(lockFile)))
+            .map(FileLockInfo.LockFileUtils::getFileToLockNameFromLock)
+            .collect(Collectors.toList());
+        if (lockFilesForAcquirer.size() == 0) {
+            throw new FileNotFoundException("No lock file found for prefix: " + filenamePrefix + " and acquirerId: " + acquirerId);
+        }
+        assert lockFilesForAcquirer.size() == 1;
+        return lockFilesForAcquirer.get(0);
+    }
+
     /**
      * Checks whether a given file have any lock on it or not.
      * @param lockInfo File Lock Info instance for which we need to check if lock is acquired.
diff --git a/server/src/main/java/org/opensearch/index/store/remote/file/OnDemandBlockIndexInput.java b/server/src/main/java/org/opensearch/index/store/remote/file/OnDemandBlockIndexInput.java
index 7319a5324777a..6fd198747570f 100644
--- a/server/src/main/java/org/opensearch/index/store/remote/file/OnDemandBlockIndexInput.java
+++ b/server/src/main/java/org/opensearch/index/store/remote/file/OnDemandBlockIndexInput.java
@@ -27,7 +27,7 @@
  * <br>
  * This class delegate the responsibility of actually fetching the block when demanded to its subclasses using
  * {@link OnDemandBlockIndexInput#fetchBlock(int)}.
- *
+ * <p>
  * Like {@link IndexInput}, this class may only be used from one thread as it is not thread safe.
  * However, a cleaning action may run from another thread triggered by the {@link Cleaner}, but
  * this is okay because at that point the {@link OnDemandBlockIndexInput} instance is phantom
@@ -428,10 +428,10 @@ Builder blockSizeShift(int blockSizeShift) {
      * instance to hold the current underlying IndexInput, while allowing it to
      * be changed out with different instances as {@link OnDemandBlockIndexInput}
      * reads through the data.
-     *
+     * <p>
      * This class implements {@link Runnable} so that it can be passed directly
      * to the cleaner to run its close action.
-     *
+     * <p>
      * [1]: https://github.com/apache/lucene/blob/8340b01c3cc229f33584ce2178b07b8984daa6a9/lucene/core/src/java/org/apache/lucene/store/IndexInput.java#L32-L33
      */
     private static class BlockHolder implements Closeable, Runnable {
diff --git a/server/src/main/java/org/opensearch/index/store/remote/filecache/CachedIndexInput.java b/server/src/main/java/org/opensearch/index/store/remote/filecache/CachedIndexInput.java
index a29598dbee505..b7dacb3761c33 100644
--- a/server/src/main/java/org/opensearch/index/store/remote/filecache/CachedIndexInput.java
+++ b/server/src/main/java/org/opensearch/index/store/remote/filecache/CachedIndexInput.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.store.remote.filecache;
 
 import org.apache.lucene.store.IndexInput;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 
@@ -17,8 +18,9 @@
  * {@link IndexInput}. Exactly how the IndexInput is created is determined by
  * the implementations.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public interface CachedIndexInput extends AutoCloseable {
     /**
      * Gets the {@link IndexInput} this cache entry represents.
diff --git a/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCache.java b/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCache.java
index dbbbbecbc6afd..2029b461674c7 100644
--- a/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCache.java
+++ b/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCache.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.store.remote.filecache;
 
 import org.apache.lucene.store.IndexInput;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.core.common.breaker.CircuitBreaker;
 import org.opensearch.core.common.breaker.CircuitBreakingException;
@@ -43,8 +44,9 @@
  * items from cache tail and triggers a callback to clean up the file from disk. The
  * cleanup process also includes closing file’s descriptor.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class FileCache implements RefCountedCache<Path, CachedIndexInput> {
     private final SegmentedCache<Path, CachedIndexInput> theCache;
 
diff --git a/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCacheStats.java b/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCacheStats.java
index ebb6202c86ec9..070fd663896a3 100644
--- a/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCacheStats.java
+++ b/server/src/main/java/org/opensearch/index/store/remote/filecache/FileCacheStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.store.remote.filecache;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -20,8 +21,9 @@
 /**
  * Statistics on file cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class FileCacheStats implements Writeable, ToXContentFragment {
 
     private final long timestamp;
diff --git a/server/src/main/java/org/opensearch/index/store/remote/metadata/RemoteSegmentMetadata.java b/server/src/main/java/org/opensearch/index/store/remote/metadata/RemoteSegmentMetadata.java
index 1cec20ec3f6cc..41a145273e8ef 100644
--- a/server/src/main/java/org/opensearch/index/store/remote/metadata/RemoteSegmentMetadata.java
+++ b/server/src/main/java/org/opensearch/index/store/remote/metadata/RemoteSegmentMetadata.java
@@ -11,6 +11,7 @@
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.index.Index;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.store.RemoteSegmentStoreDirectory;
@@ -25,8 +26,9 @@
 /**
  * Metadata object for Remote Segment
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.6.0")
 public class RemoteSegmentMetadata {
     /**
      * Latest supported version of metadata
diff --git a/server/src/main/java/org/opensearch/index/store/remote/utils/cache/CacheUsage.java b/server/src/main/java/org/opensearch/index/store/remote/utils/cache/CacheUsage.java
index 1cb9242926046..0b5480d3ca978 100644
--- a/server/src/main/java/org/opensearch/index/store/remote/utils/cache/CacheUsage.java
+++ b/server/src/main/java/org/opensearch/index/store/remote/utils/cache/CacheUsage.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.index.store.remote.utils.cache;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Usage metrics for {@link RefCountedCache}
  *
  * @opensearch.internal
  */
+@PublicApi(since = "2.7.0")
 public class CacheUsage {
     /**
      * Cache usage of the system
diff --git a/server/src/main/java/org/opensearch/index/store/remote/utils/cache/stats/CacheStats.java b/server/src/main/java/org/opensearch/index/store/remote/utils/cache/stats/CacheStats.java
index f0a7154effb1d..55893752669a8 100644
--- a/server/src/main/java/org/opensearch/index/store/remote/utils/cache/stats/CacheStats.java
+++ b/server/src/main/java/org/opensearch/index/store/remote/utils/cache/stats/CacheStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.store.remote.utils.cache.stats;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.store.remote.utils.cache.RefCountedCache;
 
 import java.util.Objects;
@@ -15,8 +16,9 @@
 /**
  * Statistics about the performance of a {@link RefCountedCache}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public final class CacheStats {
     private final long hitCount;
     private final long missCount;
diff --git a/server/src/main/java/org/opensearch/index/translog/BaseTranslogReader.java b/server/src/main/java/org/opensearch/index/translog/BaseTranslogReader.java
index ea817c4b0932a..d6fa2a2e53de3 100644
--- a/server/src/main/java/org/opensearch/index/translog/BaseTranslogReader.java
+++ b/server/src/main/java/org/opensearch/index/translog/BaseTranslogReader.java
@@ -108,7 +108,7 @@ protected final int readSize(ByteBuffer reusableBuffer, long position) throws IO
         return size;
     }
 
-    public TranslogSnapshot newSnapshot() {
+    TranslogSnapshot newSnapshot() {
         return new TranslogSnapshot(this, sizeInBytes());
     }
 
diff --git a/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamInput.java b/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamInput.java
index 8c9ccc3b487df..f75f27b7bcb91 100644
--- a/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamInput.java
+++ b/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamInput.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.translog;
 
 import org.apache.lucene.store.BufferedChecksum;
+import org.apache.lucene.util.BitUtil;
 import org.opensearch.core.common.io.stream.FilterStreamInput;
 import org.opensearch.core.common.io.stream.StreamInput;
 
@@ -92,22 +93,21 @@ public void readBytes(byte[] b, int offset, int len) throws IOException {
     public short readShort() throws IOException {
         final byte[] buf = buffer.get();
         readBytes(buf, 0, 2);
-        return (short) (((buf[0] & 0xFF) << 8) | (buf[1] & 0xFF));
+        return (short) BitUtil.VH_BE_SHORT.get(buf, 0);
     }
 
     @Override
     public int readInt() throws IOException {
         final byte[] buf = buffer.get();
         readBytes(buf, 0, 4);
-        return ((buf[0] & 0xFF) << 24) | ((buf[1] & 0xFF) << 16) | ((buf[2] & 0xFF) << 8) | (buf[3] & 0xFF);
+        return (int) BitUtil.VH_BE_INT.get(buf, 0);
     }
 
     @Override
     public long readLong() throws IOException {
         final byte[] buf = buffer.get();
         readBytes(buf, 0, 8);
-        return (((long) (((buf[0] & 0xFF) << 24) | ((buf[1] & 0xFF) << 16) | ((buf[2] & 0xFF) << 8) | (buf[3] & 0xFF))) << 32) | ((((buf[4]
-            & 0xFF) << 24) | ((buf[5] & 0xFF) << 16) | ((buf[6] & 0xFF) << 8) | (buf[7] & 0xFF)) & 0xFFFFFFFFL);
+        return (long) BitUtil.VH_BE_LONG.get(buf, 0);
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamOutput.java b/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamOutput.java
index eaf9ac0893f1b..9e96664c79cc5 100644
--- a/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamOutput.java
+++ b/server/src/main/java/org/opensearch/index/translog/BufferedChecksumStreamOutput.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.translog;
 
 import org.apache.lucene.store.BufferedChecksum;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamOutput;
 
 import java.io.IOException;
@@ -43,8 +44,9 @@
  * Similar to Lucene's BufferedChecksumIndexOutput, however this wraps a
  * {@link StreamOutput} so anything written will update the checksum
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class BufferedChecksumStreamOutput extends StreamOutput {
     private final StreamOutput out;
     private final Checksum digest;
diff --git a/server/src/main/java/org/opensearch/index/translog/ChannelFactory.java b/server/src/main/java/org/opensearch/index/translog/ChannelFactory.java
index f86b9dea0a5f7..4fba85b9d224d 100644
--- a/server/src/main/java/org/opensearch/index/translog/ChannelFactory.java
+++ b/server/src/main/java/org/opensearch/index/translog/ChannelFactory.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 import java.nio.channels.FileChannel;
 import java.nio.file.OpenOption;
@@ -40,9 +42,10 @@
 /**
  * only for testing until we have a disk-full FileSystem
  *
- * @opensearch.internal
+ * @opensearch.api
  */
 @FunctionalInterface
+@PublicApi(since = "1.0.0")
 public interface ChannelFactory {
     default FileChannel open(Path path) throws IOException {
         return open(path, StandardOpenOption.WRITE, StandardOpenOption.READ, StandardOpenOption.CREATE_NEW);
diff --git a/server/src/main/java/org/opensearch/index/translog/Checkpoint.java b/server/src/main/java/org/opensearch/index/translog/Checkpoint.java
index a9f905f52bc3a..d309564ef5d32 100644
--- a/server/src/main/java/org/opensearch/index/translog/Checkpoint.java
+++ b/server/src/main/java/org/opensearch/index/translog/Checkpoint.java
@@ -44,6 +44,7 @@
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.NIOFSDirectory;
 import org.apache.lucene.store.OutputStreamIndexOutput;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.Channels;
 import org.opensearch.index.seqno.SequenceNumbers;
 
@@ -57,9 +58,10 @@
 /**
  * A checkpoint for OpenSearch operations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
-final public class Checkpoint {
+@PublicApi(since = "1.0.0")
+public final class Checkpoint {
 
     final long offset;
     final int numOps;
diff --git a/server/src/main/java/org/opensearch/index/translog/DefaultTranslogDeletionPolicy.java b/server/src/main/java/org/opensearch/index/translog/DefaultTranslogDeletionPolicy.java
index efc762ef00d52..05049e5d07373 100644
--- a/server/src/main/java/org/opensearch/index/translog/DefaultTranslogDeletionPolicy.java
+++ b/server/src/main/java/org/opensearch/index/translog/DefaultTranslogDeletionPolicy.java
@@ -14,7 +14,7 @@
 /**
  * Default implementation for the {@link TranslogDeletionPolicy}. Plugins can override the default behaviour
  * via the {@link org.opensearch.plugins.EnginePlugin#getCustomTranslogDeletionPolicyFactory()}.
- *
+ * <p>
  * The default policy uses total number, size in bytes and maximum age for files.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/index/translog/InternalTranslogFactory.java b/server/src/main/java/org/opensearch/index/translog/InternalTranslogFactory.java
index d7be1250c0b5b..415d7dc4d1a9d 100644
--- a/server/src/main/java/org/opensearch/index/translog/InternalTranslogFactory.java
+++ b/server/src/main/java/org/opensearch/index/translog/InternalTranslogFactory.java
@@ -28,7 +28,7 @@ public Translog newTranslog(
         LongSupplier globalCheckpointSupplier,
         LongSupplier primaryTermSupplier,
         LongConsumer persistedSequenceNumberConsumer,
-        BooleanSupplier primaryModeSupplier
+        BooleanSupplier startedPrimarySupplier
     ) throws IOException {
 
         return new LocalTranslog(
diff --git a/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java b/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java
index 6b51cb17dcc41..a22c538286a88 100644
--- a/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java
@@ -8,16 +8,18 @@
 
 package org.opensearch.index.translog;
 
-import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.apache.lucene.store.AlreadyClosedException;
+import org.opensearch.common.lease.Releasable;
+import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.util.concurrent.ReleasableLock;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.engine.LifecycleAware;
 import org.opensearch.index.seqno.LocalCheckpointTracker;
 import org.opensearch.index.translog.listener.TranslogEventListener;
+import org.opensearch.index.translog.transfer.TranslogUploadFailedException;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -43,7 +45,7 @@ public class InternalTranslogManager implements TranslogManager, Closeable {
     private final AtomicBoolean pendingTranslogRecovery = new AtomicBoolean(false);
     private final TranslogEventListener translogEventListener;
     private final Supplier<LocalCheckpointTracker> localCheckpointTrackerSupplier;
-    private static final Logger logger = LogManager.getLogger(InternalTranslogManager.class);
+    private final Logger logger;
 
     public InternalTranslogManager(
         TranslogConfig translogConfig,
@@ -57,7 +59,7 @@ public InternalTranslogManager(
         TranslogEventListener translogEventListener,
         LifecycleAware engineLifeCycleAware,
         TranslogFactory translogFactory,
-        BooleanSupplier primaryModeSupplier
+        BooleanSupplier startedPrimarySupplier
     ) throws IOException {
         this.shardId = shardId;
         this.readLock = readLock;
@@ -70,23 +72,27 @@ public InternalTranslogManager(
             if (tracker != null) {
                 tracker.markSeqNoAsPersisted(seqNo);
             }
-        }, translogUUID, translogFactory, primaryModeSupplier);
+        }, translogUUID, translogFactory, startedPrimarySupplier);
         assert translog.getGeneration() != null;
         this.translog = translog;
         assert pendingTranslogRecovery.get() == false : "translog recovery can't be pending before we set it";
         // don't allow commits until we are done with recovering
         pendingTranslogRecovery.set(true);
+        this.logger = Loggers.getLogger(getClass(), shardId);
     }
 
     /**
      * Rolls the translog generation and cleans unneeded.
      */
     @Override
-    public void rollTranslogGeneration() throws TranslogException {
+    public void rollTranslogGeneration() throws TranslogException, IOException {
         try (ReleasableLock ignored = readLock.acquire()) {
             engineLifeCycleAware.ensureOpen();
             translog.rollGeneration();
             translog.trimUnreferencedReaders();
+        } catch (TranslogUploadFailedException e) {
+            // Do not trigger the translogEventListener as it fails the Engine while this is only an issue with remote upload
+            throw e;
         } catch (AlreadyClosedException e) {
             translogEventListener.onFailure("translog roll generation failed", e);
             throw e;
@@ -296,10 +302,16 @@ public void setMinSeqNoToKeep(long seqNo) {
         translog.setMinSeqNoToKeep(seqNo);
     }
 
+    @Override
     public void onDelete() {
         translog.onDelete();
     }
 
+    @Override
+    public Releasable drainSync() {
+        return translog.drainSync();
+    }
+
     @Override
     public Translog.TranslogGeneration getTranslogGeneration() {
         return translog.getGeneration();
@@ -357,7 +369,7 @@ protected Translog openTranslog(
         LongConsumer persistedSequenceNumberConsumer,
         String translogUUID,
         TranslogFactory translogFactory,
-        BooleanSupplier primaryModeSupplier
+        BooleanSupplier startedPrimarySupplier
     ) throws IOException {
         return translogFactory.newTranslog(
             translogConfig,
@@ -366,7 +378,7 @@ protected Translog openTranslog(
             globalCheckpointSupplier,
             primaryTermSupplier,
             persistedSequenceNumberConsumer,
-            primaryModeSupplier
+            startedPrimarySupplier
         );
     }
 
@@ -425,10 +437,10 @@ public String getTranslogUUID() {
      * @return if the translog should be flushed
      */
     public boolean shouldPeriodicallyFlush(long localCheckpointOfLastCommit, long flushThreshold) {
-        final long translogGenerationOfLastCommit = translog.getMinGenerationForSeqNo(
-            localCheckpointOfLastCommit + 1
-        ).translogFileGeneration;
-        if (translog.sizeInBytesByMinGen(translogGenerationOfLastCommit) < flushThreshold) {
+        // This is the minimum seqNo that is referred in translog and considered for calculating translog size
+        long minTranslogRefSeqNo = translog.getMinUnreferencedSeqNoInSegments(localCheckpointOfLastCommit + 1);
+        final long minReferencedTranslogGeneration = translog.getMinGenerationForSeqNo(minTranslogRefSeqNo).translogFileGeneration;
+        if (translog.sizeInBytesByMinGen(minReferencedTranslogGeneration) < flushThreshold) {
             return false;
         }
         /*
@@ -449,7 +461,7 @@ public boolean shouldPeriodicallyFlush(long localCheckpointOfLastCommit, long fl
         final long translogGenerationOfNewCommit = translog.getMinGenerationForSeqNo(
             localCheckpointTrackerSupplier.get().getProcessedCheckpoint() + 1
         ).translogFileGeneration;
-        return translogGenerationOfLastCommit < translogGenerationOfNewCommit
+        return minReferencedTranslogGeneration < translogGenerationOfNewCommit
             || localCheckpointTrackerSupplier.get().getProcessedCheckpoint() == localCheckpointTrackerSupplier.get().getMaxSeqNo();
     }
 
diff --git a/server/src/main/java/org/opensearch/index/translog/LocalTranslog.java b/server/src/main/java/org/opensearch/index/translog/LocalTranslog.java
index 22dba3973cfc1..7664631e0ed07 100644
--- a/server/src/main/java/org/opensearch/index/translog/LocalTranslog.java
+++ b/server/src/main/java/org/opensearch/index/translog/LocalTranslog.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.util.concurrent.ReleasableLock;
 import org.opensearch.common.util.io.IOUtils;
 
@@ -140,6 +141,11 @@ public TranslogStats stats() {
         }
     }
 
+    @Override
+    Releasable drainSync() {
+        return () -> {}; // noop
+    }
+
     @Override
     public void close() throws IOException {
         assert Translog.calledFromOutsideOrViaTragedyClose()
diff --git a/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java b/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java
index 3e6a8e69edfbb..b4aa7865570a6 100644
--- a/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.util.concurrent.ReleasableLock;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -121,8 +122,14 @@ public Translog.Snapshot newChangesSnapshot(long fromSeqNo, long toSeqNo, boolea
         throw new UnsupportedOperationException("Translog snapshot unsupported with no-op translogs");
     }
 
+    @Override
     public void onDelete() {}
 
+    @Override
+    public Releasable drainSync() {
+        return () -> {};
+    }
+
     @Override
     public Translog.TranslogGeneration getTranslogGeneration() {
         return null;
diff --git a/server/src/main/java/org/opensearch/index/translog/RemoteBlobStoreInternalTranslogFactory.java b/server/src/main/java/org/opensearch/index/translog/RemoteBlobStoreInternalTranslogFactory.java
index 1e2cb388e690e..e100ffaabf13d 100644
--- a/server/src/main/java/org/opensearch/index/translog/RemoteBlobStoreInternalTranslogFactory.java
+++ b/server/src/main/java/org/opensearch/index/translog/RemoteBlobStoreInternalTranslogFactory.java
@@ -59,7 +59,7 @@ public Translog newTranslog(
         LongSupplier globalCheckpointSupplier,
         LongSupplier primaryTermSupplier,
         LongConsumer persistedSequenceNumberConsumer,
-        BooleanSupplier primaryModeSupplier
+        BooleanSupplier startedPrimarySupplier
     ) throws IOException {
 
         assert repository instanceof BlobStoreRepository : "repository should be instance of BlobStoreRepository";
@@ -73,7 +73,7 @@ public Translog newTranslog(
             persistedSequenceNumberConsumer,
             blobStoreRepository,
             threadPool,
-            primaryModeSupplier,
+            startedPrimarySupplier,
             remoteTranslogTransferTracker
         );
     }
diff --git a/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java b/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java
index c488127857ed5..7b969a37e4aa6 100644
--- a/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java
+++ b/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.translog;
 
 import org.apache.logging.log4j.Logger;
+import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.SetOnce;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lease.Releasables;
@@ -39,6 +40,9 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.BooleanSupplier;
 import java.util.function.LongConsumer;
 import java.util.function.LongSupplier;
@@ -54,10 +58,9 @@
 public class RemoteFsTranslog extends Translog {
 
     private final Logger logger;
-    private final BlobStoreRepository blobStoreRepository;
     private final TranslogTransferManager translogTransferManager;
     private final FileTransferTracker fileTransferTracker;
-    private final BooleanSupplier primaryModeSupplier;
+    private final BooleanSupplier startedPrimarySupplier;
     private final RemoteTranslogTransferTracker remoteTranslogTransferTracker;
     private volatile long maxRemoteTranslogGenerationUploaded;
 
@@ -76,6 +79,11 @@ public class RemoteFsTranslog extends Translog {
     // Semaphore used to allow only single remote generation to happen at a time
     private final Semaphore remoteGenerationDeletionPermits = new Semaphore(REMOTE_DELETION_PERMITS);
 
+    // These permits exist to allow any inflight background triggered upload.
+    private static final int SYNC_PERMIT = 1;
+    private final Semaphore syncPermit = new Semaphore(SYNC_PERMIT);
+    private final AtomicBoolean pauseSync = new AtomicBoolean(false);
+
     public RemoteFsTranslog(
         TranslogConfig config,
         String translogUUID,
@@ -85,13 +93,12 @@ public RemoteFsTranslog(
         LongConsumer persistedSequenceNumberConsumer,
         BlobStoreRepository blobStoreRepository,
         ThreadPool threadPool,
-        BooleanSupplier primaryModeSupplier,
+        BooleanSupplier startedPrimarySupplier,
         RemoteTranslogTransferTracker remoteTranslogTransferTracker
     ) throws IOException {
         super(config, translogUUID, deletionPolicy, globalCheckpointSupplier, primaryTermSupplier, persistedSequenceNumberConsumer);
         logger = Loggers.getLogger(getClass(), shardId);
-        this.blobStoreRepository = blobStoreRepository;
-        this.primaryModeSupplier = primaryModeSupplier;
+        this.startedPrimarySupplier = startedPrimarySupplier;
         this.remoteTranslogTransferTracker = remoteTranslogTransferTracker;
         fileTransferTracker = new FileTransferTracker(shardId, remoteTranslogTransferTracker);
         this.translogTransferManager = buildTranslogTransferManager(
@@ -104,6 +111,7 @@ public RemoteFsTranslog(
         try {
             download(translogTransferManager, location, logger);
             Checkpoint checkpoint = readCheckpoint(location);
+            logger.info("Downloaded data from remote translog till maxSeqNo = {}", checkpoint.maxSeqNo);
             this.readers.addAll(recoverFromFiles(checkpoint));
             if (readers.isEmpty()) {
                 String errorMsg = String.format(Locale.ROOT, "%s at least one reader must be recovered", shardId);
@@ -162,6 +170,7 @@ public static void download(Repository repository, ShardId shardId, ThreadPool t
             remoteTranslogTransferTracker
         );
         RemoteFsTranslog.download(translogTransferManager, location, logger);
+        logger.trace(remoteTranslogTransferTracker.toString());
     }
 
     static void download(TranslogTransferManager translogTransferManager, Path location, Logger logger) throws IOException {
@@ -174,19 +183,25 @@ static void download(TranslogTransferManager translogTransferManager, Path locat
          */
         IOException ex = null;
         for (int i = 0; i <= DOWNLOAD_RETRIES; i++) {
+            boolean success = false;
+            long startTimeMs = System.currentTimeMillis();
             try {
                 downloadOnce(translogTransferManager, location, logger);
+                success = true;
                 return;
             } catch (FileNotFoundException | NoSuchFileException e) {
                 // continue till download retries
                 ex = e;
+            } finally {
+                logger.trace("downloadOnce success={} timeElapsed={}", success, (System.currentTimeMillis() - startTimeMs));
             }
         }
+        logger.info("Exhausted all download retries during translog/checkpoint file download");
         throw ex;
     }
 
     static private void downloadOnce(TranslogTransferManager translogTransferManager, Path location, Logger logger) throws IOException {
-        logger.trace("Downloading translog files from remote");
+        logger.debug("Downloading translog files from remote");
         RemoteTranslogTransferTracker statsTracker = translogTransferManager.getRemoteTranslogTransferTracker();
         long prevDownloadBytesSucceeded = statsTracker.getDownloadBytesSucceeded();
         long prevDownloadTimeInMillis = statsTracker.getTotalDownloadTimeInMillis();
@@ -206,6 +221,11 @@ static private void downloadOnce(TranslogTransferManager translogTransferManager
                 String generation = Long.toString(i);
                 translogTransferManager.downloadTranslog(generationToPrimaryTermMapper.get(generation), generation, location);
             }
+            logger.info(
+                "Downloaded translog and checkpoint files from={} to={}",
+                translogMetadata.getMinTranslogGeneration(),
+                translogMetadata.getGeneration()
+            );
 
             statsTracker.recordDownloadStats(prevDownloadBytesSucceeded, prevDownloadTimeInMillis);
 
@@ -216,7 +236,7 @@ static private void downloadOnce(TranslogTransferManager translogTransferManager
                 location.resolve(Translog.CHECKPOINT_FILE_NAME)
             );
         }
-        logger.trace("Downloaded translog files from remote");
+        logger.debug("downloadOnce execution completed");
     }
 
     public static TranslogTransferManager buildTranslogTransferManager(
@@ -237,15 +257,10 @@ public static TranslogTransferManager buildTranslogTransferManager(
 
     @Override
     public boolean ensureSynced(Location location) throws IOException {
-        try (ReleasableLock ignored = writeLock.acquire()) {
-            assert location.generation <= current.getGeneration();
-            if (location.generation == current.getGeneration()) {
-                ensureOpen();
-                return prepareAndUpload(primaryTermSupplier.getAsLong(), location.generation);
-            }
-        } catch (final Exception ex) {
-            closeOnTragicEvent(ex);
-            throw ex;
+        assert location.generation <= current.getGeneration();
+        if (location.generation == current.getGeneration()) {
+            ensureOpen();
+            return prepareAndUpload(primaryTermSupplier.getAsLong(), location.generation);
         }
         return false;
     }
@@ -260,9 +275,23 @@ public void rollGeneration() throws IOException {
     }
 
     private boolean prepareAndUpload(Long primaryTerm, Long generation) throws IOException {
+        // During primary relocation, both the old and new primary have engine created with RemoteFsTranslog and having
+        // ReplicationTracker.primaryMode() as true. However, before we perform the `internal:index/shard/replication/segments_sync`
+        // action which re-downloads the segments and translog on the new primary. We are ensuring 2 things here -
+        // 1. Using startedPrimarySupplier, we prevent the new primary to do pre-emptive syncs
+        // 2. Using syncPermits, we prevent syncs at the desired time during primary relocation.
+        if (startedPrimarySupplier.getAsBoolean() == false || syncPermit.tryAcquire(SYNC_PERMIT) == false) {
+            logger.debug("skipped uploading translog for {} {} syncPermits={}", primaryTerm, generation, syncPermit.availablePermits());
+            // NO-OP
+            return false;
+        }
+        long maxSeqNo = -1;
         try (Releasable ignored = writeLock.acquire()) {
             if (generation == null || generation == current.getGeneration()) {
                 try {
+                    if (closed.get() == false) {
+                        maxSeqNo = getMaxSeqNo();
+                    }
                     final TranslogReader reader = current.closeIntoReader();
                     readers.add(reader);
                     copyCheckpointTo(location.resolve(getCommitCheckpointFileName(current.getGeneration())));
@@ -270,6 +299,11 @@ private boolean prepareAndUpload(Long primaryTerm, Long generation) throws IOExc
                         logger.trace("Creating new writer for gen: [{}]", current.getGeneration() + 1);
                         current = createWriter(current.getGeneration() + 1);
                     }
+                    assert writeLock.isHeldByCurrentThread() : "Write lock must be held before we acquire the read lock";
+                    // Here we are downgrading the write lock by acquiring the read lock and releasing the write lock
+                    // This ensures that other threads can still acquire the read locks while also protecting the
+                    // readers and writer to not be mutated any further.
+                    readLock.acquire();
                 } catch (final Exception e) {
                     tragedy.setTragicException(e);
                     closeOnTragicEvent(e);
@@ -278,7 +312,10 @@ private boolean prepareAndUpload(Long primaryTerm, Long generation) throws IOExc
             } else if (generation < current.getGeneration()) {
                 return false;
             }
+        }
 
+        assert readLock.isHeldByCurrentThread() == true;
+        try (Releasable ignored = readLock; Releasable ignoredGenLock = deletionPolicy.acquireTranslogGen(getMinFileGeneration())) {
             // Do we need remote writes in sync fashion ?
             // If we don't , we should swallow FileAlreadyExistsException while writing to remote store
             // and also verify for same during primary-primary relocation
@@ -286,27 +323,17 @@ private boolean prepareAndUpload(Long primaryTerm, Long generation) throws IOExc
             // is not updated in remote translog except in primary to primary recovery.
             if (generation == null) {
                 if (closed.get() == false) {
-                    return upload(primaryTerm, current.getGeneration() - 1);
+                    return upload(primaryTerm, current.getGeneration() - 1, maxSeqNo);
                 } else {
-                    return upload(primaryTerm, current.getGeneration());
+                    return upload(primaryTerm, current.getGeneration(), maxSeqNo);
                 }
             } else {
-                return upload(primaryTerm, generation);
+                return upload(primaryTerm, generation, maxSeqNo);
             }
         }
     }
 
-    private boolean upload(Long primaryTerm, Long generation) throws IOException {
-        // During primary relocation (primary-primary peer recovery), both the old and the new primary have engine
-        // created with the RemoteFsTranslog. Both primaries are equipped to upload the translogs. The primary mode check
-        // below ensures that the real primary only is uploading. Before the primary mode is set as true for the new
-        // primary, the engine is reset to InternalEngine which also initialises the RemoteFsTranslog which in turns
-        // downloads all the translogs from remote store and does a flush before the relocation finishes.
-        if (primaryModeSupplier.getAsBoolean() == false) {
-            logger.trace("skipped uploading translog for {} {}", primaryTerm, generation);
-            // NO-OP
-            return true;
-        }
+    private boolean upload(long primaryTerm, long generation, long maxSeqNo) throws IOException {
         logger.trace("uploading translog for {} {}", primaryTerm, generation);
         try (
             TranslogCheckpointTransferSnapshot transferSnapshotProvider = new TranslogCheckpointTransferSnapshot.Builder(
@@ -314,14 +341,16 @@ private boolean upload(Long primaryTerm, Long generation) throws IOException {
                 generation,
                 location,
                 readers,
-                Translog::getCommitCheckpointFileName
+                Translog::getCommitCheckpointFileName,
+                config.getNodeId()
             ).build()
         ) {
-            Releasable transferReleasable = Releasables.wrap(deletionPolicy.acquireTranslogGen(getMinFileGeneration()));
             return translogTransferManager.transferSnapshot(
                 transferSnapshotProvider,
-                new RemoteFsTranslogTransferListener(transferReleasable, generation, primaryTerm)
+                new RemoteFsTranslogTransferListener(generation, primaryTerm, maxSeqNo)
             );
+        } finally {
+            syncPermit.release(SYNC_PERMIT);
         }
 
     }
@@ -342,14 +371,8 @@ private boolean syncToDisk() throws IOException {
 
     @Override
     public void sync() throws IOException {
-        try {
-            if (syncToDisk() || syncNeeded()) {
-                prepareAndUpload(primaryTermSupplier.getAsLong(), null);
-            }
-        } catch (final Exception e) {
-            tragedy.setTragicException(e);
-            closeOnTragicEvent(e);
-            throw e;
+        if (syncToDisk() || syncNeeded()) {
+            prepareAndUpload(primaryTermSupplier.getAsLong(), null);
         }
     }
 
@@ -367,12 +390,14 @@ public boolean syncNeeded() {
     public void close() throws IOException {
         assert Translog.calledFromOutsideOrViaTragedyClose() : shardId
             + "Translog.close method is called from inside Translog, but not via closeOnTragicEvent method";
-        if (closed.compareAndSet(false, true)) {
-            try (ReleasableLock lock = writeLock.acquire()) {
-                sync();
-            } finally {
-                logger.debug("translog closed");
-                closeFilesIfNoPendingRetentionLocks();
+        try (ReleasableLock lock = writeLock.acquire()) {
+            if (closed.compareAndSet(false, true)) {
+                try {
+                    sync();
+                } finally {
+                    logger.debug("translog closed");
+                    closeFilesIfNoPendingRetentionLocks();
+                }
             }
         }
     }
@@ -408,11 +433,39 @@ protected void setMinSeqNoToKeep(long seqNo) {
         this.minSeqNoToKeep = seqNo;
     }
 
+    @Override
+    protected Releasable drainSync() {
+        try {
+            if (syncPermit.tryAcquire(SYNC_PERMIT, 1, TimeUnit.MINUTES)) {
+                boolean result = pauseSync.compareAndSet(false, true);
+                assert result && syncPermit.availablePermits() == 0;
+                logger.info("All inflight remote translog syncs finished and further syncs paused");
+                return Releasables.releaseOnce(() -> {
+                    syncPermit.release(SYNC_PERMIT);
+                    boolean wasSyncPaused = pauseSync.getAndSet(false);
+                    assert syncPermit.availablePermits() == SYNC_PERMIT : "Available permits is " + syncPermit.availablePermits();
+                    assert wasSyncPaused : "RemoteFsTranslog sync was not paused before re-enabling it";
+                    logger.info("Resumed remote translog sync back on relocation failure");
+                });
+            } else {
+                throw new TimeoutException("Timeout while acquiring all permits");
+            }
+        } catch (TimeoutException | InterruptedException e) {
+            throw new RuntimeException("Failed to acquire all permits", e);
+        }
+    }
+
     @Override
     public void trimUnreferencedReaders() throws IOException {
         // clean up local translog files and updates readers
         super.trimUnreferencedReaders();
 
+        // This is to ensure that after the permits are acquired during primary relocation, there are no further modification on remote
+        // store.
+        if (startedPrimarySupplier.getAsBoolean() == false || pauseSync.get()) {
+            return;
+        }
+
         // Since remote generation deletion is async, this ensures that only one generation deletion happens at a time.
         // Remote generations involves 2 async operations - 1) Delete translog generation files 2) Delete metadata files
         // We try to acquire 2 permits and if we can not, we return from here itself.
@@ -423,7 +476,7 @@ public void trimUnreferencedReaders() throws IOException {
         // cleans up remote translog files not referenced in latest uploaded metadata.
         // This enables us to restore translog from the metadata in case of failover or relocation.
         Set<Long> generationsToDelete = new HashSet<>();
-        for (long generation = minRemoteGenReferenced - 1; generation >= 0; generation--) {
+        for (long generation = minRemoteGenReferenced - 1 - indexSettings().getRemoteTranslogExtraKeep(); generation >= 0; generation--) {
             if (fileTransferTracker.uploaded(Translog.getFilename(generation)) == false) {
                 break;
             }
@@ -490,55 +543,55 @@ public static void cleanup(Repository repository, ShardId shardId, ThreadPool th
     }
 
     protected void onDelete() {
-        if (primaryModeSupplier.getAsBoolean() == false) {
-            logger.trace("skipped delete translog");
-            // NO-OP
-            return;
-        }
+        ClusterService.assertClusterOrClusterManagerStateThread();
         // clean up all remote translog files
         translogTransferManager.delete();
     }
 
+    // Visible for testing
+    boolean isRemoteGenerationDeletionPermitsAvailable() {
+        return remoteGenerationDeletionPermits.availablePermits() == REMOTE_DELETION_PERMITS;
+    }
+
     /**
      * TranslogTransferListener implementation for RemoteFsTranslog
      *
      * @opensearch.internal
      */
     private class RemoteFsTranslogTransferListener implements TranslogTransferListener {
-        /**
-         * Releasable instance for the translog
-         */
-        private final Releasable transferReleasable;
 
         /**
          * Generation for the translog
          */
-        private final Long generation;
+        private final long generation;
 
         /**
          * Primary Term for the translog
          */
-        private final Long primaryTerm;
+        private final long primaryTerm;
+
+        private final long maxSeqNo;
 
-        RemoteFsTranslogTransferListener(Releasable transferReleasable, Long generation, Long primaryTerm) {
-            this.transferReleasable = transferReleasable;
+        RemoteFsTranslogTransferListener(long generation, long primaryTerm, long maxSeqNo) {
             this.generation = generation;
             this.primaryTerm = primaryTerm;
+            this.maxSeqNo = maxSeqNo;
         }
 
         @Override
         public void onUploadComplete(TransferSnapshot transferSnapshot) throws IOException {
-            transferReleasable.close();
-            closeFilesIfNoPendingRetentionLocks();
             maxRemoteTranslogGenerationUploaded = generation;
             minRemoteGenReferenced = getMinFileGeneration();
-            logger.trace("uploaded translog for {} {} ", primaryTerm, generation);
+            logger.debug(
+                "Successfully uploaded translog for primary term = {}, generation = {}, maxSeqNo = {}",
+                primaryTerm,
+                generation,
+                maxSeqNo
+            );
         }
 
         @Override
         public void onUploadFailed(TransferSnapshot transferSnapshot, Exception ex) throws IOException {
-            transferReleasable.close();
-            closeFilesIfNoPendingRetentionLocks();
             if (ex instanceof IOException) {
                 throw (IOException) ex;
             } else {
@@ -546,4 +599,14 @@ public void onUploadFailed(TransferSnapshot transferSnapshot, Exception ex) thro
             }
         }
     }
+
+    @Override
+    public long getMinUnreferencedSeqNoInSegments(long minUnrefCheckpointInLastCommit) {
+        return minSeqNoToKeep;
+    }
+
+    // Visible for testing
+    int availablePermits() {
+        return syncPermit.availablePermits();
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/translog/RemoteTranslogStats.java b/server/src/main/java/org/opensearch/index/translog/RemoteTranslogStats.java
index 966f8ebc2875a..03c15e0ea4752 100644
--- a/server/src/main/java/org/opensearch/index/translog/RemoteTranslogStats.java
+++ b/server/src/main/java/org/opensearch/index/translog/RemoteTranslogStats.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.translog;
 
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStats;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -23,8 +24,9 @@
 /**
  * Encapsulates the stats related to Remote Translog Store operations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class RemoteTranslogStats implements ToXContentFragment, Writeable {
     /**
      * Total number of Remote Translog Store uploads that have been started
diff --git a/server/src/main/java/org/opensearch/index/translog/TragicExceptionHolder.java b/server/src/main/java/org/opensearch/index/translog/TragicExceptionHolder.java
index 818d840cb11fd..023e277edfd6c 100644
--- a/server/src/main/java/org/opensearch/index/translog/TragicExceptionHolder.java
+++ b/server/src/main/java/org/opensearch/index/translog/TragicExceptionHolder.java
@@ -34,14 +34,16 @@
 
 import org.apache.lucene.store.AlreadyClosedException;
 import org.opensearch.ExceptionsHelper;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Exception thrown if there are any massive OpenSearch failures
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TragicExceptionHolder {
     private final AtomicReference<Exception> tragedy = new AtomicReference<>();
 
diff --git a/server/src/main/java/org/opensearch/index/translog/Translog.java b/server/src/main/java/org/opensearch/index/translog/Translog.java
index baa3737d576de..9f877e87415dd 100644
--- a/server/src/main/java/org/opensearch/index/translog/Translog.java
+++ b/server/src/main/java/org/opensearch/index/translog/Translog.java
@@ -37,6 +37,7 @@
 import org.opensearch.Version;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.stream.ReleasableBytesStreamOutput;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lease.Releasables;
@@ -110,8 +111,9 @@
  * operation etc. are still preserved.
  * </p>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class Translog extends AbstractIndexShardComponent implements IndexShardComponent, Closeable {
 
     /*
@@ -840,7 +842,7 @@ public boolean ensureSynced(Stream<Location> locations) throws IOException {
 
     /**
      * Closes the translog if the current translog writer experienced a tragic exception.
-     *
+     * <p>
      * Note that in case this thread closes the translog it must not already be holding a read lock on the translog as it will acquire a
      * write lock in the course of closing the translog
      *
@@ -894,8 +896,9 @@ public TranslogDeletionPolicy getDeletionPolicy() {
     /**
      * Location in the translot
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Location implements Comparable<Location> {
 
         public final long generation;
@@ -953,8 +956,9 @@ public int hashCode() {
     /**
      * A snapshot of the transaction log, allows to iterate over all the transaction log operations.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Snapshot extends Closeable {
 
         /**
@@ -1039,14 +1043,16 @@ public void close() throws IOException {
      * A generic interface representing an operation performed on the transaction log.
      * Each is associated with a type.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Operation {
         /**
          * The type of operation
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         enum Type {
             @Deprecated
             CREATE((byte) 1),
@@ -1137,8 +1143,9 @@ static void writeOperation(final StreamOutput output, final Operation operation)
     /**
      * The source in the translog
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Source {
 
         public final BytesReference source;
@@ -1566,8 +1573,9 @@ public String toString() {
     /**
      * How to sync the translog
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Durability {
 
         /**
@@ -1809,6 +1817,11 @@ protected void setMinSeqNoToKeep(long seqNo) {}
 
     protected void onDelete() {}
 
+    /**
+     * Drains ongoing syncs to the underlying store. It returns a releasable which can be closed to resume the syncs back.
+     */
+    abstract Releasable drainSync();
+
     /**
      * deletes all files associated with a reader. package-private to be able to simulate node failures at this point
      */
@@ -1833,8 +1846,9 @@ void closeFilesIfNoPendingRetentionLocks() throws IOException {
     /**
      * References a transaction log generation
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class TranslogGeneration {
         public final String translogUUID;
         public final long translogFileGeneration;
@@ -1976,7 +1990,7 @@ static String createEmptyTranslog(
     /**
      * Creates a new empty translog within the specified {@code location} that contains the given {@code initialGlobalCheckpoint},
      * {@code primaryTerm} and {@code translogUUID}.
-     *
+     * <p>
      * This method should be used directly under specific circumstances like for shards that will see no indexing. Specifying a non-unique
      * translog UUID could cause a lot of issues and that's why in all (but one) cases the method
      * {@link #createEmptyTranslog(Path, long, ShardId, long)} should be used instead.
@@ -2034,4 +2048,8 @@ public static String createEmptyTranslog(
         writer.close();
         return uuid;
     }
+
+    public long getMinUnreferencedSeqNoInSegments(long minUnrefCheckpointInLastCommit) {
+        return minUnrefCheckpointInLastCommit;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogConfig.java b/server/src/main/java/org/opensearch/index/translog/TranslogConfig.java
index cac88bee82a73..2f00773075d41 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogConfig.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogConfig.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.BigArrays;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.common.unit.ByteSizeValue;
@@ -45,8 +46,9 @@
  * Once {@link Translog} has been created with this object, changes to this
  * object will affect the {@link Translog} instance.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class TranslogConfig {
 
     public static final ByteSizeValue DEFAULT_BUFFER_SIZE = new ByteSizeValue(1, ByteSizeUnit.MB);
@@ -56,6 +58,7 @@ public final class TranslogConfig {
     private final ShardId shardId;
     private final Path translogPath;
     private final ByteSizeValue bufferSize;
+    private final String nodeId;
 
     /**
      * Creates a new TranslogConfig instance
@@ -64,16 +67,24 @@ public final class TranslogConfig {
      * @param indexSettings the index settings used to set internal variables
      * @param bigArrays a bigArrays instance used for temporarily allocating write operations
      */
-    public TranslogConfig(ShardId shardId, Path translogPath, IndexSettings indexSettings, BigArrays bigArrays) {
-        this(shardId, translogPath, indexSettings, bigArrays, DEFAULT_BUFFER_SIZE);
+    public TranslogConfig(ShardId shardId, Path translogPath, IndexSettings indexSettings, BigArrays bigArrays, String nodeId) {
+        this(shardId, translogPath, indexSettings, bigArrays, DEFAULT_BUFFER_SIZE, nodeId);
     }
 
-    TranslogConfig(ShardId shardId, Path translogPath, IndexSettings indexSettings, BigArrays bigArrays, ByteSizeValue bufferSize) {
+    TranslogConfig(
+        ShardId shardId,
+        Path translogPath,
+        IndexSettings indexSettings,
+        BigArrays bigArrays,
+        ByteSizeValue bufferSize,
+        String nodeId
+    ) {
         this.bufferSize = bufferSize;
         this.indexSettings = indexSettings;
         this.shardId = shardId;
         this.translogPath = translogPath;
         this.bigArrays = bigArrays;
+        this.nodeId = nodeId;
     }
 
     /**
@@ -110,4 +121,8 @@ public Path getTranslogPath() {
     public ByteSizeValue getBufferSize() {
         return bufferSize;
     }
+
+    public String getNodeId() {
+        return nodeId;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicy.java b/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicy.java
index 99784b77c61f5..972b19a029a8b 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicy.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicy.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.translog;
 
 import org.apache.lucene.util.Counter;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.core.Assertions;
 import org.opensearch.index.seqno.SequenceNumbers;
@@ -47,8 +48,9 @@
 /**
  * Defines a translog deletion policy
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class TranslogDeletionPolicy {
 
     private final Map<Object, RuntimeException> openTranslogRef;
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicyFactory.java b/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicyFactory.java
index 8f40fdc90368f..dcce8ade12b32 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicyFactory.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogDeletionPolicyFactory.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.seqno.RetentionLeases;
 
@@ -19,6 +20,7 @@
  * @opensearch.api
  */
 @FunctionalInterface
+@PublicApi(since = "1.0.0")
 public interface TranslogDeletionPolicyFactory {
     TranslogDeletionPolicy create(IndexSettings settings, Supplier<RetentionLeases> supplier);
 }
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogException.java b/server/src/main/java/org/opensearch/index/translog/TranslogException.java
index d7a8d649543d6..eb8e77a055752 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogException.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogException.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.translog;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 
@@ -41,8 +42,9 @@
 /**
  * Exception thrown if there are any failures in the translog
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TranslogException extends OpenSearchException {
 
     public TranslogException(ShardId shardId, String msg) {
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogFactory.java b/server/src/main/java/org/opensearch/index/translog/TranslogFactory.java
index ab8e2b7752e66..4300435093b5d 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogFactory.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogFactory.java
@@ -8,6 +8,8 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 import java.util.function.BooleanSupplier;
 import java.util.function.LongConsumer;
@@ -17,9 +19,10 @@
  * Translog Factory to enable creation of various local on-disk
  * and remote store flavors of {@link Translog}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
 @FunctionalInterface
+@PublicApi(since = "1.0.0")
 public interface TranslogFactory {
 
     Translog newTranslog(
@@ -29,6 +32,6 @@ Translog newTranslog(
         final LongSupplier globalCheckpointSupplier,
         final LongSupplier primaryTermSupplier,
         final LongConsumer persistedSequenceNumberConsumer,
-        final BooleanSupplier primaryModeSupplier
+        final BooleanSupplier startedPrimarySupplier
     ) throws IOException;
 }
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogHeader.java b/server/src/main/java/org/opensearch/index/translog/TranslogHeader.java
index 42bda11d75783..7b5be9505f27a 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogHeader.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogHeader.java
@@ -147,7 +147,11 @@ static TranslogHeader read(final String translogUUID, final Path path, final Fil
         if (actualUUID.bytesEquals(expectedUUID) == false) {
             throw new TranslogCorruptedException(
                 path.toString(),
-                "expected shard UUID " + expectedUUID + " but got: " + actualUUID + " this translog file belongs to a different translog"
+                "expected shard UUID "
+                    + translogUUID
+                    + " but got: "
+                    + translogHeader.translogUUID
+                    + " this translog file belongs to a different translog"
             );
         }
         return translogHeader;
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogManager.java b/server/src/main/java/org/opensearch/index/translog/TranslogManager.java
index 78aaa1bc13a00..e1a0b7d1c1293 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogManager.java
@@ -8,20 +8,24 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.common.lease.Releasable;
+
 import java.io.IOException;
 import java.util.stream.Stream;
 
 /**
  * The interface that orchestrates Translog operations and manages the {@link Translog} and interfaces with the Engine
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface TranslogManager {
 
     /**
      * Rolls the translog generation and cleans unneeded.
      */
-    void rollTranslogGeneration() throws TranslogException;
+    void rollTranslogGeneration() throws TranslogException, IOException;
 
     /**
      * Performs recovery from the transaction log up to {@code recoverUpToSeqNo} (inclusive).
@@ -132,5 +136,10 @@ public interface TranslogManager {
      */
     void onDelete();
 
+    /**
+     * Drains ongoing syncs to the underlying store. It returns a releasable which can be closed to resume the syncs back.
+     */
+    Releasable drainSync();
+
     Translog.TranslogGeneration getTranslogGeneration();
 }
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogReader.java b/server/src/main/java/org/opensearch/index/translog/TranslogReader.java
index 9ea3328587645..d590663670b28 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogReader.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogReader.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.store.AlreadyClosedException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.Channels;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.index.seqno.SequenceNumbers;
@@ -52,8 +53,9 @@
 /**
  * an immutable translog filereader
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TranslogReader extends BaseTranslogReader implements Closeable {
     protected final long length;
     private final int totalOperations;
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogRecoveryRunner.java b/server/src/main/java/org/opensearch/index/translog/TranslogRecoveryRunner.java
index 91c9a95b07d58..007c1fb98f398 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogRecoveryRunner.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogRecoveryRunner.java
@@ -8,14 +8,17 @@
 
 package org.opensearch.index.translog;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 
 /**
  * The interface that defines how {@link Translog.Snapshot} will get replayed into the Engine
  *
- * @opensearch.internal
+ * @opensearch.api
  */
 @FunctionalInterface
+@PublicApi(since = "1.0.0")
 public interface TranslogRecoveryRunner {
 
     /**
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogStats.java b/server/src/main/java/org/opensearch/index/translog/TranslogStats.java
index a4699cea671a0..619dd6371c553 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogStats.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogStats.java
@@ -32,6 +32,7 @@
 package org.opensearch.index.translog;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,8 +47,9 @@
 /**
  * Translog statistics
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TranslogStats implements Writeable, ToXContentFragment {
     private static final String TRANSLOG = "translog";
     private long translogSizeInBytes;
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogWriter.java b/server/src/main/java/org/opensearch/index/translog/TranslogWriter.java
index a5f0607431a8b..86f7567f3333d 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogWriter.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogWriter.java
@@ -37,6 +37,7 @@
 import org.apache.lucene.util.BytesRefIterator;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SuppressForbidden;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.bytes.ReleasableBytesReference;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.io.Channels;
@@ -73,8 +74,9 @@
 /**
  * Writer that writes operations to the translog
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TranslogWriter extends BaseTranslogReader implements Closeable {
 
     private final ShardId shardId;
@@ -376,7 +378,7 @@ synchronized boolean assertNoSeqAbove(long belowTerm, long aboveSeqNo) {
 
     /**
      * write all buffered ops to disk and fsync file.
-     *
+     * <p>
      * Note: any exception during the sync process will be interpreted as a tragic exception and the writer will be closed before
      * raising the exception.
      * @return  <code>true</code> if this call caused an actual sync operation
@@ -471,7 +473,7 @@ public TranslogReader closeIntoReader() throws IOException {
     }
 
     @Override
-    public TranslogSnapshot newSnapshot() {
+    TranslogSnapshot newSnapshot() {
         // make sure to acquire the sync lock first, to prevent dead locks with threads calling
         // syncUpTo() , where the sync lock is acquired first, following by the synchronize(this)
         // After the sync lock we acquire the write lock to avoid deadlocks with threads writing where
diff --git a/server/src/main/java/org/opensearch/index/translog/TruncateTranslogAction.java b/server/src/main/java/org/opensearch/index/translog/TruncateTranslogAction.java
index 0d85123b60c75..25fcdc614172a 100644
--- a/server/src/main/java/org/opensearch/index/translog/TruncateTranslogAction.java
+++ b/server/src/main/java/org/opensearch/index/translog/TruncateTranslogAction.java
@@ -194,7 +194,8 @@ private boolean isTranslogClean(ShardPath shardPath, ClusterState clusterState,
                 shardPath.getShardId(),
                 translogPath,
                 indexSettings,
-                BigArrays.NON_RECYCLING_INSTANCE
+                BigArrays.NON_RECYCLING_INSTANCE,
+                ""
             );
             long primaryTerm = indexSettings.getIndexMetadata().primaryTerm(shardPath.getShardId().id());
             // We open translog to check for corruption, do not clean anything.
diff --git a/server/src/main/java/org/opensearch/index/translog/WriteOnlyTranslogManager.java b/server/src/main/java/org/opensearch/index/translog/WriteOnlyTranslogManager.java
index adeeb213b2913..a7a524ad78e95 100644
--- a/server/src/main/java/org/opensearch/index/translog/WriteOnlyTranslogManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/WriteOnlyTranslogManager.java
@@ -38,7 +38,7 @@ public WriteOnlyTranslogManager(
         TranslogEventListener translogEventListener,
         LifecycleAware engineLifecycleAware,
         TranslogFactory translogFactory,
-        BooleanSupplier primaryModeSupplier
+        BooleanSupplier startedPrimarySupplier
     ) throws IOException {
         super(
             translogConfig,
@@ -52,7 +52,7 @@ public WriteOnlyTranslogManager(
             translogEventListener,
             engineLifecycleAware,
             translogFactory,
-            primaryModeSupplier
+            startedPrimarySupplier
         );
     }
 
diff --git a/server/src/main/java/org/opensearch/index/translog/transfer/TranslogCheckpointTransferSnapshot.java b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogCheckpointTransferSnapshot.java
index 10dec13c81e1a..fb78731246a07 100644
--- a/server/src/main/java/org/opensearch/index/translog/transfer/TranslogCheckpointTransferSnapshot.java
+++ b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogCheckpointTransferSnapshot.java
@@ -40,11 +40,14 @@ public class TranslogCheckpointTransferSnapshot implements TransferSnapshot, Clo
     private final long primaryTerm;
     private long minTranslogGeneration;
 
-    TranslogCheckpointTransferSnapshot(long primaryTerm, long generation, int size) {
+    private String nodeId;
+
+    TranslogCheckpointTransferSnapshot(long primaryTerm, long generation, int size, String nodeId) {
         translogCheckpointFileInfoTupleSet = new HashSet<>(size);
         this.size = size;
         this.generation = generation;
         this.primaryTerm = primaryTerm;
+        this.nodeId = nodeId;
     }
 
     private void add(TranslogFileSnapshot translogFileSnapshot, CheckpointFileSnapshot checkPointFileSnapshot) {
@@ -63,7 +66,13 @@ public Set<TransferFileSnapshot> getTranslogFileSnapshots() {
 
     @Override
     public TranslogTransferMetadata getTranslogTransferMetadata() {
-        return new TranslogTransferMetadata(primaryTerm, generation, minTranslogGeneration, translogCheckpointFileInfoTupleSet.size() * 2);
+        return new TranslogTransferMetadata(
+            primaryTerm,
+            generation,
+            minTranslogGeneration,
+            translogCheckpointFileInfoTupleSet.size() * 2,
+            nodeId
+        );
     }
 
     @Override
@@ -110,19 +119,22 @@ public static class Builder {
         private final List<TranslogReader> readers;
         private final Function<Long, String> checkpointGenFileNameMapper;
         private final Path location;
+        private final String nodeId;
 
         public Builder(
             long primaryTerm,
             long generation,
             Path location,
             List<TranslogReader> readers,
-            Function<Long, String> checkpointGenFileNameMapper
+            Function<Long, String> checkpointGenFileNameMapper,
+            String nodeId
         ) {
             this.primaryTerm = primaryTerm;
             this.generation = generation;
             this.readers = readers;
             this.checkpointGenFileNameMapper = checkpointGenFileNameMapper;
             this.location = location;
+            this.nodeId = nodeId;
         }
 
         public TranslogCheckpointTransferSnapshot build() throws IOException {
@@ -134,7 +146,8 @@ public TranslogCheckpointTransferSnapshot build() throws IOException {
             TranslogCheckpointTransferSnapshot translogTransferSnapshot = new TranslogCheckpointTransferSnapshot(
                 primaryTerm,
                 generation,
-                readers.size()
+                readers.size(),
+                nodeId
             );
             for (TranslogReader reader : readers) {
                 final long readerGeneration = reader.getGeneration();
diff --git a/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferManager.java b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferManager.java
index fd4936603671c..2f6055df87804 100644
--- a/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferManager.java
@@ -24,6 +24,7 @@
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.index.remote.RemoteStoreUtils;
 import org.opensearch.index.remote.RemoteTranslogTransferTracker;
 import org.opensearch.index.translog.Translog;
 import org.opensearch.index.translog.transfer.listener.TranslogTransferListener;
@@ -41,7 +42,6 @@
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
 import java.util.stream.Collectors;
 
 import static org.opensearch.index.translog.transfer.FileSnapshot.TransferFileSnapshot;
@@ -64,6 +64,8 @@ public class TranslogTransferManager {
 
     private static final long TRANSFER_TIMEOUT_IN_MILLIS = 30000;
 
+    private static final int METADATA_FILES_TO_FETCH = 10;
+
     private final Logger logger;
     private final static String METADATA_DIR = "metadata";
     private final static String DATA_DIR = "data";
@@ -153,14 +155,17 @@ public boolean transferSnapshot(TransferSnapshot transferSnapshot, TranslogTrans
 
             try {
                 if (latch.await(TRANSFER_TIMEOUT_IN_MILLIS, TimeUnit.MILLISECONDS) == false) {
-                    Exception ex = new TimeoutException("Timed out waiting for transfer of snapshot " + transferSnapshot + " to complete");
+                    Exception ex = new TranslogUploadFailedException(
+                        "Timed out waiting for transfer of snapshot " + transferSnapshot + " to complete"
+                    );
                     exceptionList.forEach(ex::addSuppressed);
                     throw ex;
                 }
             } catch (InterruptedException ex) {
-                exceptionList.forEach(ex::addSuppressed);
+                Exception exception = new TranslogUploadFailedException("Failed to upload " + transferSnapshot, ex);
+                exceptionList.forEach(exception::addSuppressed);
                 Thread.currentThread().interrupt();
-                throw ex;
+                throw exception;
             }
             if (exceptionList.isEmpty()) {
                 TransferFileSnapshot tlogMetadata = prepareMetadata(transferSnapshot);
@@ -173,7 +178,7 @@ public boolean transferSnapshot(TransferSnapshot transferSnapshot, TranslogTrans
                     remoteTranslogTransferTracker.addUploadTimeInMillis((System.nanoTime() - metadataUploadStartTime) / 1_000_000L);
                     remoteTranslogTransferTracker.addUploadBytesFailed(metadataBytesToUpload);
                     // outer catch handles capturing stats on upload failure
-                    throw exception;
+                    throw new TranslogUploadFailedException("Failed to upload " + tlogMetadata.getName(), exception);
                 }
 
                 remoteTranslogTransferTracker.addUploadTimeInMillis((System.nanoTime() - metadataUploadStartTime) / 1_000_000L);
@@ -182,7 +187,7 @@ public boolean transferSnapshot(TransferSnapshot transferSnapshot, TranslogTrans
                 translogTransferListener.onUploadComplete(transferSnapshot);
                 return true;
             } else {
-                Exception ex = new IOException("Failed to upload " + exceptionList.size() + " files during transfer");
+                Exception ex = new TranslogUploadFailedException("Failed to upload " + exceptionList.size() + " files during transfer");
                 exceptionList.forEach(ex::addSuppressed);
                 throw ex;
             }
@@ -227,7 +232,7 @@ private void captureStatsOnUploadFailure() {
     }
 
     public boolean downloadTranslog(String primaryTerm, String generation, Path location) throws IOException {
-        logger.info(
+        logger.trace(
             "Downloading translog files with: Primary Term = {}, Generation = {}, Location = {}",
             primaryTerm,
             generation,
@@ -275,6 +280,10 @@ public TranslogTransferMetadata readMetadata() throws IOException {
         LatchedActionListener<List<BlobMetadata>> latchedActionListener = new LatchedActionListener<>(
             ActionListener.wrap(blobMetadataList -> {
                 if (blobMetadataList.isEmpty()) return;
+                RemoteStoreUtils.verifyNoMultipleWriters(
+                    blobMetadataList.stream().map(BlobMetadata::name).collect(Collectors.toList()),
+                    TranslogTransferMetadata::getNodeIdByPrimaryTermAndGen
+                );
                 String filename = blobMetadataList.get(0).name();
                 boolean downloadStatus = false;
                 long downloadStartTime = System.nanoTime(), bytesToRead = 0;
@@ -289,11 +298,15 @@ public TranslogTransferMetadata readMetadata() throws IOException {
                     exceptionSetOnce.set(e);
                 } finally {
                     remoteTranslogTransferTracker.addDownloadTimeInMillis((System.nanoTime() - downloadStartTime) / 1_000_000L);
+                    logger.debug("translogMetadataDownloadStatus={}", downloadStatus);
                     if (downloadStatus) {
                         remoteTranslogTransferTracker.addDownloadBytesSucceeded(bytesToRead);
                     }
                 }
             }, e -> {
+                if (e instanceof RuntimeException) {
+                    throw (RuntimeException) e;
+                }
                 logger.error(() -> new ParameterizedMessage("Exception while listing metadata files"), e);
                 exceptionSetOnce.set((IOException) e);
             }),
@@ -304,7 +317,7 @@ public TranslogTransferMetadata readMetadata() throws IOException {
             transferService.listAllInSortedOrder(
                 remoteMetadataTransferPath,
                 TranslogTransferMetadata.METADATA_PREFIX,
-                1,
+                METADATA_FILES_TO_FETCH,
                 latchedActionListener
             );
             latch.await();
diff --git a/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferMetadata.java b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferMetadata.java
index a8b3404d3f2ce..052206d807fa6 100644
--- a/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferMetadata.java
+++ b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogTransferMetadata.java
@@ -9,6 +9,7 @@
 package org.opensearch.index.translog.transfer;
 
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.collect.Tuple;
 import org.opensearch.index.remote.RemoteStoreUtils;
 
 import java.util.Arrays;
@@ -30,7 +31,7 @@ public class TranslogTransferMetadata {
 
     private final long minTranslogGeneration;
 
-    private int count;
+    private final int count;
 
     private final SetOnce<Map<String, String>> generationToPrimaryTermMapper = new SetOnce<>();
 
@@ -46,12 +47,22 @@ public class TranslogTransferMetadata {
 
     private final long createdAt;
 
-    public TranslogTransferMetadata(long primaryTerm, long generation, long minTranslogGeneration, int count) {
+    private final String nodeId;
+
+    public TranslogTransferMetadata(long primaryTerm, long generation, long minTranslogGeneration, int count, String nodeId) {
         this.primaryTerm = primaryTerm;
         this.generation = generation;
         this.minTranslogGeneration = minTranslogGeneration;
         this.count = count;
         this.createdAt = System.currentTimeMillis();
+        this.nodeId = nodeId;
+    }
+
+    /*
+    Used only at the time of download . Since details are read from content , nodeId is not available
+     */
+    public TranslogTransferMetadata(long primaryTerm, long generation, long minTranslogGeneration, int count) {
+        this(primaryTerm, generation, minTranslogGeneration, count, "");
     }
 
     public long getPrimaryTerm() {
@@ -89,11 +100,33 @@ public String getFileName() {
                 RemoteStoreUtils.invertLong(primaryTerm),
                 RemoteStoreUtils.invertLong(generation),
                 RemoteStoreUtils.invertLong(createdAt),
+                String.valueOf(Objects.hash(nodeId)),
                 String.valueOf(CURRENT_VERSION)
             )
         );
     }
 
+    public static Tuple<Tuple<Long, Long>, String> getNodeIdByPrimaryTermAndGeneration(String filename) {
+        String[] tokens = filename.split(METADATA_SEPARATOR);
+        if (tokens.length < 6) {
+            // For versions < 2.11, we don't have node id
+            return null;
+        }
+        return new Tuple<>(new Tuple<>(RemoteStoreUtils.invertLong(tokens[1]), RemoteStoreUtils.invertLong(tokens[2])), tokens[4]);
+    }
+
+    public static Tuple<String, String> getNodeIdByPrimaryTermAndGen(String filename) {
+        String[] tokens = filename.split(METADATA_SEPARATOR);
+        if (tokens.length < 6) {
+            // For versions < 2.11, we don't have node id.
+            return null;
+        }
+        String primaryTermAndGen = String.join(METADATA_SEPARATOR, tokens[1], tokens[2]);
+
+        String nodeId = tokens[4];
+        return new Tuple<>(primaryTermAndGen, nodeId);
+    }
+
     @Override
     public int hashCode() {
         return Objects.hash(primaryTerm, generation);
diff --git a/server/src/main/java/org/opensearch/index/translog/transfer/TranslogUploadFailedException.java b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogUploadFailedException.java
new file mode 100644
index 0000000000000..4a9b10ec5a52e
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/translog/transfer/TranslogUploadFailedException.java
@@ -0,0 +1,27 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.translog.transfer;
+
+import java.io.IOException;
+
+/**
+ * Exception is thrown if there are any exceptions while uploading translog to remote store.
+ * @opensearch.internal
+ */
+public class TranslogUploadFailedException extends IOException {
+
+    public TranslogUploadFailedException(String message) {
+        super(message);
+    }
+
+    public TranslogUploadFailedException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+}
diff --git a/server/src/main/java/org/opensearch/index/warmer/ShardIndexWarmerService.java b/server/src/main/java/org/opensearch/index/warmer/ShardIndexWarmerService.java
index cadff0d3838f9..26f29f17b86c0 100644
--- a/server/src/main/java/org/opensearch/index/warmer/ShardIndexWarmerService.java
+++ b/server/src/main/java/org/opensearch/index/warmer/ShardIndexWarmerService.java
@@ -33,6 +33,7 @@
 package org.opensearch.index.warmer;
 
 import org.apache.logging.log4j.Logger;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.common.metrics.MeanMetric;
 import org.opensearch.core.index.shard.ShardId;
@@ -44,8 +45,9 @@
 /**
  * Warms the index into the cache
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardIndexWarmerService extends AbstractIndexShardComponent {
 
     private final CounterMetric current = new CounterMetric();
diff --git a/server/src/main/java/org/opensearch/index/warmer/WarmerStats.java b/server/src/main/java/org/opensearch/index/warmer/WarmerStats.java
index 375dcc029fa70..789baaea20d04 100644
--- a/server/src/main/java/org/opensearch/index/warmer/WarmerStats.java
+++ b/server/src/main/java/org/opensearch/index/warmer/WarmerStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index.warmer;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -44,8 +45,9 @@
 /**
  * Stats collected about the warmer
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class WarmerStats implements Writeable, ToXContentFragment {
 
     private long current;
diff --git a/server/src/main/java/org/opensearch/indices/IndicesQueryCache.java b/server/src/main/java/org/opensearch/indices/IndicesQueryCache.java
index 228723045d8cc..52ed311a1eb92 100644
--- a/server/src/main/java/org/opensearch/indices/IndicesQueryCache.java
+++ b/server/src/main/java/org/opensearch/indices/IndicesQueryCache.java
@@ -44,6 +44,7 @@
 import org.apache.lucene.search.Scorer;
 import org.apache.lucene.search.ScorerSupplier;
 import org.apache.lucene.search.Weight;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.ShardCoreKeyMap;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
@@ -65,8 +66,9 @@
 /**
  * The query cache for indices
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesQueryCache implements QueryCache, Closeable {
 
     private static final Logger logger = LogManager.getLogger(IndicesQueryCache.class);
@@ -186,6 +188,12 @@ public BulkScorer bulkScorer(LeafReaderContext context) throws IOException {
             return in.bulkScorer(context);
         }
 
+        @Override
+        public int count(LeafReaderContext context) throws IOException {
+            shardKeyMap.add(context.reader());
+            return in.count(context);
+        }
+
         @Override
         public boolean isCacheable(LeafReaderContext ctx) {
             return in.isCacheable(ctx);
diff --git a/server/src/main/java/org/opensearch/indices/IndicesService.java b/server/src/main/java/org/opensearch/indices/IndicesService.java
index 2ed3cb8d9e8ea..3d1794f8d3197 100644
--- a/server/src/main/java/org/opensearch/indices/IndicesService.java
+++ b/server/src/main/java/org/opensearch/indices/IndicesService.java
@@ -47,6 +47,7 @@
 import org.opensearch.action.admin.indices.stats.CommonStatsFlags.Flag;
 import org.opensearch.action.admin.indices.stats.IndexShardStats;
 import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.action.search.SearchRequestStats;
 import org.opensearch.action.search.SearchType;
 import org.opensearch.client.Client;
 import org.opensearch.cluster.ClusterState;
@@ -60,6 +61,7 @@
 import org.opensearch.common.CheckedFunction;
 import org.opensearch.common.CheckedSupplier;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
@@ -132,6 +134,7 @@
 import org.opensearch.index.shard.IndexShardState;
 import org.opensearch.index.shard.IndexingOperationListener;
 import org.opensearch.index.shard.IndexingStats;
+import org.opensearch.index.shard.IndexingStats.Stats.DocStatusStats;
 import org.opensearch.index.store.remote.filecache.FileCacheCleaner;
 import org.opensearch.index.translog.InternalTranslogFactory;
 import org.opensearch.index.translog.RemoteBlobStoreInternalTranslogFactory;
@@ -142,6 +145,7 @@
 import org.opensearch.indices.mapper.MapperRegistry;
 import org.opensearch.indices.recovery.PeerRecoveryTargetService;
 import org.opensearch.indices.recovery.RecoveryListener;
+import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.indices.replication.checkpoint.SegmentReplicationCheckpointPublisher;
 import org.opensearch.indices.replication.common.ReplicationType;
@@ -202,8 +206,9 @@
 /**
  * Main OpenSearch indices service
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesService extends AbstractLifecycleComponent
     implements
         IndicesClusterStateService.AllocatedIndices<IndexShard, IndexService>,
@@ -284,6 +289,18 @@ public class IndicesService extends AbstractLifecycleComponent
         Property.Dynamic
     );
 
+    /**
+     * This setting is used to restrict creation or updation of index where the `index.translog.durability` index setting
+     * is set as ASYNC if enabled. If disabled, any of the durability mode can be used and switched at any later time from
+     * one to another.
+     */
+    public static final Setting<Boolean> CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING = Setting.boolSetting(
+        "cluster.remote_store.index.restrict.async-durability",
+        false,
+        Property.NodeScope,
+        Property.Final
+    );
+
     /**
      * The node's settings.
      */
@@ -321,6 +338,7 @@ public class IndicesService extends AbstractLifecycleComponent
     private final CountDownLatch closeLatch = new CountDownLatch(1);
     private volatile boolean idFieldDataEnabled;
     private volatile boolean allowExpensiveQueries;
+    private final RecoverySettings recoverySettings;
 
     @Nullable
     private final OpenSearchThreadPoolExecutor danglingIndicesThreadPoolExecutor;
@@ -333,6 +351,8 @@ public class IndicesService extends AbstractLifecycleComponent
     private volatile TimeValue clusterRemoteTranslogBufferInterval;
     private final FileCacheCleaner fileCacheCleaner;
 
+    private final SearchRequestStats searchRequestStats;
+
     @Override
     protected void doStart() {
         // Start thread that will manage cleaning the field data cache periodically
@@ -363,7 +383,9 @@ public IndicesService(
         IndexStorePlugin.DirectoryFactory remoteDirectoryFactory,
         Supplier<RepositoriesService> repositoriesServiceSupplier,
         FileCacheCleaner fileCacheCleaner,
-        @Nullable RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory
+        SearchRequestStats searchRequestStats,
+        @Nullable RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory,
+        RecoverySettings recoverySettings
     ) {
         this.settings = settings;
         this.threadPool = threadPool;
@@ -453,12 +475,14 @@ protected void closeInternal() {
         clusterService.getClusterSettings().addSettingsUpdateConsumer(ALLOW_EXPENSIVE_QUERIES, this::setAllowExpensiveQueries);
         this.remoteDirectoryFactory = remoteDirectoryFactory;
         this.translogFactorySupplier = getTranslogFactorySupplier(repositoriesServiceSupplier, threadPool, remoteStoreStatsTrackerFactory);
+        this.searchRequestStats = searchRequestStats;
         this.clusterDefaultRefreshInterval = CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING.get(clusterService.getSettings());
         clusterService.getClusterSettings()
             .addSettingsUpdateConsumer(CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING, this::onRefreshIntervalUpdate);
         this.clusterRemoteTranslogBufferInterval = CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.get(clusterService.getSettings());
         clusterService.getClusterSettings()
             .addSettingsUpdateConsumer(CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING, this::setClusterRemoteTranslogBufferInterval);
+        this.recoverySettings = recoverySettings;
     }
 
     /**
@@ -576,7 +600,7 @@ public NodeIndicesStats stats(CommonStatsFlags flags) {
             }
         }
 
-        return new NodeIndicesStats(commonStats, statsByShard(this, flags));
+        return new NodeIndicesStats(commonStats, statsByShard(this, flags), searchRequestStats);
     }
 
     Map<Index, List<IndexShardStats>> statsByShard(final IndicesService indicesService, final CommonStatsFlags flags) {
@@ -856,7 +880,8 @@ private synchronized IndexService createIndexService(
             remoteDirectoryFactory,
             translogFactorySupplier,
             this::getClusterDefaultRefreshInterval,
-            this::getClusterRemoteTranslogBufferInterval
+            this::getClusterRemoteTranslogBufferInterval,
+            this.recoverySettings
         );
     }
 
@@ -903,7 +928,7 @@ private EngineFactory getEngineFactory(final IndexSettings idxSettings) {
     /**
      * creates a new mapper service for the given index, in order to do administrative work like mapping updates.
      * This *should not* be used for document parsing. Doing so will result in an exception.
-     *
+     * <p>
      * Note: the returned {@link MapperService} should be closed when unneeded.
      */
     public synchronized MapperService createIndexMapperService(IndexMetadata indexMetadata) throws IOException {
@@ -1041,6 +1066,15 @@ public IndicesQueryCache getIndicesQueryCache() {
         return indicesQueryCache;
     }
 
+    /**
+     * Accumulate stats from the passed Object
+     *
+     * @param stats Instance storing {@link DocStatusStats}
+     */
+    public void addDocStatusStats(final DocStatusStats stats) {
+        oldShardsStats.indexingStats.getTotal().getDocStatusStats().add(stats);
+    }
+
     /**
      * Statistics for old shards
      *
@@ -1106,7 +1140,7 @@ public void deleteUnassignedIndex(String reason, IndexMetadata metadata, Cluster
     /**
      * Deletes the index store trying to acquire all shards locks for this index.
      * This method will delete the metadata for the index even if the actual shards can't be locked.
-     *
+     * <p>
      * Package private for testing
      */
     void deleteIndexStore(String reason, IndexMetadata metadata) throws IOException {
@@ -1187,7 +1221,7 @@ public void deleteShardStore(String reason, ShardLock lock, IndexSettings indexS
      * This method deletes the shard contents on disk for the given shard ID. This method will fail if the shard deleting
      * is prevented by {@link #canDeleteShardContent(ShardId, IndexSettings)}
      * of if the shards lock can not be acquired.
-     *
+     * <p>
      * On data nodes, if the deleted shard is the last shard folder in its index, the method will attempt to remove
      * the index folder as well.
      *
@@ -1288,7 +1322,10 @@ public IndexMetadata verifyIndexIsDeleted(final Index index, final ClusterState
 
     /**
      * result type returned by {@link #canDeleteShardContent signaling different reasons why a shard can / cannot be deleted}
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum ShardDeletionCheckResult {
         FOLDER_FOUND_CAN_DELETE, // shard data exists and can be deleted
         STILL_ALLOCATED, // the shard is still allocated / active on this node
diff --git a/server/src/main/java/org/opensearch/indices/NodeIndicesStats.java b/server/src/main/java/org/opensearch/indices/NodeIndicesStats.java
index cc3d8193dfa6b..35b6fd395ee12 100644
--- a/server/src/main/java/org/opensearch/indices/NodeIndicesStats.java
+++ b/server/src/main/java/org/opensearch/indices/NodeIndicesStats.java
@@ -35,7 +35,9 @@
 import org.opensearch.action.admin.indices.stats.CommonStats;
 import org.opensearch.action.admin.indices.stats.IndexShardStats;
 import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.action.search.SearchRequestStats;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -68,10 +70,10 @@
 /**
  * Global information on indices stats running on a specific node.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NodeIndicesStats implements Writeable, ToXContentFragment {
-
     private CommonStats stats;
     private Map<Index, List<IndexShardStats>> statsByShard;
 
@@ -92,7 +94,7 @@ public NodeIndicesStats(StreamInput in) throws IOException {
         }
     }
 
-    public NodeIndicesStats(CommonStats oldStats, Map<Index, List<IndexShardStats>> statsByShard) {
+    public NodeIndicesStats(CommonStats oldStats, Map<Index, List<IndexShardStats>> statsByShard, SearchRequestStats searchRequestStats) {
         // this.stats = stats;
         this.statsByShard = statsByShard;
 
@@ -105,6 +107,9 @@ public NodeIndicesStats(CommonStats oldStats, Map<Index, List<IndexShardStats>>
                 }
             }
         }
+        if (this.stats.search != null) {
+            this.stats.search.setSearchRequestStats(searchRequestStats);
+        }
     }
 
     @Nullable
diff --git a/server/src/main/java/org/opensearch/indices/ShardLimitValidator.java b/server/src/main/java/org/opensearch/indices/ShardLimitValidator.java
index d9a64781c3f46..e345b613eebbd 100644
--- a/server/src/main/java/org/opensearch/indices/ShardLimitValidator.java
+++ b/server/src/main/java/org/opensearch/indices/ShardLimitValidator.java
@@ -54,7 +54,7 @@
 /**
  * This class contains the logic used to check the cluster-wide shard limit before shards are created and ensuring that the limit is
  * updated correctly on setting updates, etc.
- *
+ * <p>
  * NOTE: This is the limit applied at *shard creation time*. If you are looking for the limit applied at *allocation* time, which is
  * controlled by a different setting,
  * see {@link org.opensearch.cluster.routing.allocation.decider.ShardsLimitAllocationDecider}.
diff --git a/server/src/main/java/org/opensearch/indices/analysis/PreBuiltCacheFactory.java b/server/src/main/java/org/opensearch/indices/analysis/PreBuiltCacheFactory.java
index 601bd79a24746..13cc78b620b9a 100644
--- a/server/src/main/java/org/opensearch/indices/analysis/PreBuiltCacheFactory.java
+++ b/server/src/main/java/org/opensearch/indices/analysis/PreBuiltCacheFactory.java
@@ -48,11 +48,11 @@ public class PreBuiltCacheFactory {
 
     /**
      * The strategy of caching the analyzer
-     *
-     * ONE               Exactly one version is stored. Useful for analyzers which do not store version information
-     * LUCENE            Exactly one version for each lucene version is stored. Useful to prevent different analyzers with the same version
-     * OPENSEARCH        Exactly one version per opensearch version is stored. Useful if you change an analyzer between opensearch
-     *                   releases, when the lucene version does not change
+     * <ul>
+     * <li>ONE        : Exactly one version is stored. Useful for analyzers which do not store version information</li>
+     * <li>LUCENE     : Exactly one version for each lucene version is stored. Useful to prevent different analyzers with the same version</li>
+     * <li>OPENSEARCH : Exactly one version per opensearch version is stored. Useful if you change an analyzer between opensearch releases, when the lucene version does not change</li>
+     * </ul>
      */
     public enum CachingStrategy {
         ONE,
diff --git a/server/src/main/java/org/opensearch/indices/cluster/IndicesClusterStateService.java b/server/src/main/java/org/opensearch/indices/cluster/IndicesClusterStateService.java
index dc538a03de595..7fb8b172ae352 100644
--- a/server/src/main/java/org/opensearch/indices/cluster/IndicesClusterStateService.java
+++ b/server/src/main/java/org/opensearch/indices/cluster/IndicesClusterStateService.java
@@ -51,6 +51,7 @@
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
 import org.opensearch.common.settings.Settings;
@@ -1059,8 +1060,9 @@ void processPendingDeletes(Index index, IndexSettings indexSettings, TimeValue t
         /**
          * Why the index was removed
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         enum IndexRemovalReason {
             /**
              * Shard of this index were previously assigned to this node but all shards have been relocated.
diff --git a/server/src/main/java/org/opensearch/indices/fielddata/cache/IndicesFieldDataCache.java b/server/src/main/java/org/opensearch/indices/fielddata/cache/IndicesFieldDataCache.java
index e2fac15f44604..e78f05831d7ac 100644
--- a/server/src/main/java/org/opensearch/indices/fielddata/cache/IndicesFieldDataCache.java
+++ b/server/src/main/java/org/opensearch/indices/fielddata/cache/IndicesFieldDataCache.java
@@ -40,6 +40,7 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.util.Accountable;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.cache.Cache;
 import org.opensearch.common.cache.CacheBuilder;
 import org.opensearch.common.cache.RemovalListener;
@@ -67,8 +68,9 @@
 /**
  * The field data cache for multiple indices
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class IndicesFieldDataCache implements RemovalListener<IndicesFieldDataCache.Key, Accountable>, Releasable {
 
     private static final Logger logger = LogManager.getLogger(IndicesFieldDataCache.class);
@@ -252,8 +254,9 @@ public void clear(String fieldName) {
     /**
      * Key for the indices field data cache
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Key {
         public final IndexFieldCache indexCache;
         public final IndexReader.CacheKey readerKey;
diff --git a/server/src/main/java/org/opensearch/indices/mapper/MapperRegistry.java b/server/src/main/java/org/opensearch/indices/mapper/MapperRegistry.java
index c26428309aec5..7974de3514ce3 100644
--- a/server/src/main/java/org/opensearch/indices/mapper/MapperRegistry.java
+++ b/server/src/main/java/org/opensearch/indices/mapper/MapperRegistry.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.indices.mapper;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.mapper.Mapper;
 import org.opensearch.index.mapper.MetadataFieldMapper;
 import org.opensearch.plugins.MapperPlugin;
@@ -45,8 +46,9 @@
 /**
  * A registry for all field mappers.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class MapperRegistry {
 
     private final Map<String, Mapper.TypeParser> mapperParsers;
diff --git a/server/src/main/java/org/opensearch/indices/recovery/LocalStorePeerRecoverySourceHandler.java b/server/src/main/java/org/opensearch/indices/recovery/LocalStorePeerRecoverySourceHandler.java
index a915046c381fc..ac6b2e6b77d18 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/LocalStorePeerRecoverySourceHandler.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/LocalStorePeerRecoverySourceHandler.java
@@ -161,6 +161,7 @@ && isTargetSameHistory()
                 }, shardId + " removing retention lease for [" + request.targetAllocationId() + "]", shard, cancellableThreads, logger);
 
                 deleteRetentionLeaseStep.whenComplete(ignored -> {
+                    logger.debug("deleteRetentionLeaseStep completed");
                     assert Transports.assertNotTransportThread(this + "[phase1]");
                     phase1(wrappedSafeCommit.get(), startingSeqNo, () -> estimateNumOps, sendFileStep, false);
                 }, onFailure);
@@ -172,12 +173,14 @@ && isTargetSameHistory()
         assert startingSeqNo >= 0 : "startingSeqNo must be non negative. got: " + startingSeqNo;
 
         sendFileStep.whenComplete(r -> {
+            logger.debug("sendFileStep completed");
             assert Transports.assertNotTransportThread(this + "[prepareTargetForTranslog]");
             // For a sequence based recovery, the target can keep its local translog
             prepareTargetForTranslog(countNumberOfHistoryOperations(startingSeqNo), prepareEngineStep);
         }, onFailure);
 
         prepareEngineStep.whenComplete(prepareEngineTime -> {
+            logger.debug("prepareEngineStep completed");
             assert Transports.assertNotTransportThread(this + "[phase2]");
             /*
              * add shard to replication group (shard will receive replication requests from this point on) now that engine is open.
diff --git a/server/src/main/java/org/opensearch/indices/recovery/PeerRecoverySourceService.java b/server/src/main/java/org/opensearch/indices/recovery/PeerRecoverySourceService.java
index 6c7632a8a408d..cb2bedf00de99 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/PeerRecoverySourceService.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/PeerRecoverySourceService.java
@@ -376,7 +376,8 @@ private Tuple<RecoverySourceHandler, RemoteRecoveryTargetHandler> createRecovery
                     transportService,
                     request.targetNode(),
                     recoverySettings,
-                    throttleTime -> shard.recoveryStats().addThrottleTime(throttleTime)
+                    throttleTime -> shard.recoveryStats().addThrottleTime(throttleTime),
+                    shard.isRemoteTranslogEnabled()
                 );
                 handler = RecoverySourceHandlerFactory.create(shard, recoveryTarget, request, recoverySettings);
                 return Tuple.tuple(handler, recoveryTarget);
diff --git a/server/src/main/java/org/opensearch/indices/recovery/PeerRecoveryTargetService.java b/server/src/main/java/org/opensearch/indices/recovery/PeerRecoveryTargetService.java
index df1589b3f29b9..4232d32987e86 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/PeerRecoveryTargetService.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/PeerRecoveryTargetService.java
@@ -46,6 +46,7 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.CancellableThreads;
@@ -91,8 +92,9 @@
  * Note, it can be safely assumed that there will only be a single recovery per shard (index+id) and
  * not several of them (since we don't allocate several shard replicas to the same node).
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PeerRecoveryTargetService implements IndexEventListener {
 
     private static final Logger logger = LogManager.getLogger(PeerRecoveryTargetService.class);
@@ -245,7 +247,18 @@ private void doRecovery(final long recoveryId, final StartRecoveryRequest preExi
                     indexShard.prepareForIndexRecovery();
                     final boolean hasRemoteSegmentStore = indexShard.indexSettings().isRemoteStoreEnabled();
                     if (hasRemoteSegmentStore) {
-                        indexShard.syncSegmentsFromRemoteSegmentStore(false);
+                        // ToDo: This is a temporary mitigation to not fail the peer recovery flow in case there is
+                        // an exception while downloading segments from remote store. For remote backed indexes, we
+                        // plan to revamp this flow so that node-node segment copy will not happen.
+                        // GitHub Issue to track the revamp: https://github.com/opensearch-project/OpenSearch/issues/11331
+                        try {
+                            indexShard.syncSegmentsFromRemoteSegmentStore(false, recoveryTarget::setLastAccessTime);
+                        } catch (Exception e) {
+                            logger.error(
+                                "Exception while downloading segment files from remote store, will continue with peer to peer segment copy",
+                                e
+                            );
+                        }
                     }
                     final boolean hasRemoteTranslog = recoveryTarget.state().getPrimary() == false && indexShard.isRemoteTranslogEnabled();
                     final boolean hasNoTranslog = indexShard.indexSettings().isRemoteSnapshot();
@@ -264,7 +277,7 @@ private void doRecovery(final long recoveryId, final StartRecoveryRequest preExi
                     actionName = PeerRecoverySourceService.Actions.START_RECOVERY;
                 } catch (final Exception e) {
                     // this will be logged as warning later on...
-                    logger.trace("unexpected error while preparing shard for peer recovery, failing recovery", e);
+                    logger.debug("unexpected error while preparing shard for peer recovery, failing recovery", e);
                     onGoingRecoveries.fail(
                         recoveryId,
                         new RecoveryFailedException(recoveryTarget.state(), "failed to prepare shard for recovery", e),
@@ -272,12 +285,12 @@ private void doRecovery(final long recoveryId, final StartRecoveryRequest preExi
                     );
                     return;
                 }
-                logger.trace("{} starting recovery from {}", startRequest.shardId(), startRequest.sourceNode());
+                logger.debug("{} starting recovery from {}", startRequest.shardId(), startRequest.sourceNode());
             } else {
                 startRequest = preExistingRequest;
                 requestToSend = new ReestablishRecoveryRequest(recoveryId, startRequest.shardId(), startRequest.targetAllocationId());
                 actionName = PeerRecoverySourceService.Actions.REESTABLISH_RECOVERY;
-                logger.trace("{} reestablishing recovery from {}", startRequest.shardId(), startRequest.sourceNode());
+                logger.debug("{} reestablishing recovery from {}", startRequest.shardId(), startRequest.sourceNode());
             }
         }
         transportService.sendRequest(
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RecoveryListener.java b/server/src/main/java/org/opensearch/indices/recovery/RecoveryListener.java
index c8c2fbfc896eb..c1832515e97de 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RecoveryListener.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RecoveryListener.java
@@ -9,6 +9,7 @@
 package org.opensearch.indices.recovery;
 
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.indices.cluster.IndicesClusterStateService;
 import org.opensearch.indices.replication.common.ReplicationFailedException;
 import org.opensearch.indices.replication.common.ReplicationListener;
@@ -19,6 +20,7 @@
  *
  * @opensearch.internal
  */
+@PublicApi(since = "2.2.0")
 public class RecoveryListener implements ReplicationListener {
 
     /**
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RecoverySettings.java b/server/src/main/java/org/opensearch/indices/recovery/RecoverySettings.java
index e2346ae078339..5351ae7fe08dd 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RecoverySettings.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RecoverySettings.java
@@ -36,19 +36,22 @@
 import org.apache.logging.log4j.Logger;
 import org.apache.lucene.store.RateLimiter;
 import org.apache.lucene.store.RateLimiter.SimpleRateLimiter;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.common.unit.ByteSizeValue;
 
 /**
  * Settings for the recovery mechanism
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RecoverySettings {
 
     private static final Logger logger = LogManager.getLogger(RecoverySettings.class);
@@ -84,6 +87,17 @@ public class RecoverySettings {
         Property.NodeScope
     );
 
+    /**
+     * Controls the maximum number of streams that can be started concurrently per recovery when downloading from the remote store.
+     */
+    public static final Setting<Integer> INDICES_RECOVERY_MAX_CONCURRENT_REMOTE_STORE_STREAMS_SETTING = new Setting<>(
+        "indices.recovery.max_concurrent_remote_store_streams",
+        (s) -> Integer.toString(Math.max(1, OpenSearchExecutors.allocatedProcessors(s) / 2)),
+        (s) -> Setting.parseInt(s, 1, "indices.recovery.max_concurrent_remote_store_streams"),
+        Property.Dynamic,
+        Property.NodeScope
+    );
+
     /**
      * how long to wait before retrying after issues cause by cluster state syncing between nodes
      * i.e., local node is not yet known on remote node, remote shard not yet started etc.
@@ -143,12 +157,32 @@ public class RecoverySettings {
         Property.NodeScope
     );
 
+    /**
+     * Controls minimum number of metadata files to keep in remote segment store.
+     * {@code value < 1} will disable deletion of stale segment metadata files.
+     */
+    public static final Setting<Integer> CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING = Setting.intSetting(
+        "cluster.remote_store.index.segment_metadata.retention.max_count",
+        10,
+        -1,
+        v -> {
+            if (v == 0) {
+                throw new IllegalArgumentException(
+                    "Value 0 is not allowed for this setting as it would delete all the data from remote segment store"
+                );
+            }
+        },
+        Property.NodeScope,
+        Property.Dynamic
+    );
+
     // choose 512KB-16B to ensure that the resulting byte[] is not a humongous allocation in G1.
     public static final ByteSizeValue DEFAULT_CHUNK_SIZE = new ByteSizeValue(512 * 1024 - 16, ByteSizeUnit.BYTES);
 
     private volatile ByteSizeValue maxBytesPerSec;
     private volatile int maxConcurrentFileChunks;
     private volatile int maxConcurrentOperations;
+    private volatile int maxConcurrentRemoteStoreStreams;
     private volatile SimpleRateLimiter rateLimiter;
     private volatile TimeValue retryDelayStateSync;
     private volatile TimeValue retryDelayNetwork;
@@ -156,6 +190,7 @@ public class RecoverySettings {
     private volatile TimeValue internalActionTimeout;
     private volatile TimeValue internalActionRetryTimeout;
     private volatile TimeValue internalActionLongTimeout;
+    private volatile int minRemoteSegmentMetadataFiles;
 
     private volatile ByteSizeValue chunkSize = DEFAULT_CHUNK_SIZE;
 
@@ -163,6 +198,7 @@ public RecoverySettings(Settings settings, ClusterSettings clusterSettings) {
         this.retryDelayStateSync = INDICES_RECOVERY_RETRY_DELAY_STATE_SYNC_SETTING.get(settings);
         this.maxConcurrentFileChunks = INDICES_RECOVERY_MAX_CONCURRENT_FILE_CHUNKS_SETTING.get(settings);
         this.maxConcurrentOperations = INDICES_RECOVERY_MAX_CONCURRENT_OPERATIONS_SETTING.get(settings);
+        this.maxConcurrentRemoteStoreStreams = INDICES_RECOVERY_MAX_CONCURRENT_REMOTE_STORE_STREAMS_SETTING.get(settings);
         // doesn't have to be fast as nodes are reconnected every 10s by default (see InternalClusterService.ReconnectToNodes)
         // and we want to give the cluster-manager time to remove a faulty node
         this.retryDelayNetwork = INDICES_RECOVERY_RETRY_DELAY_NETWORK_SETTING.get(settings);
@@ -184,6 +220,10 @@ public RecoverySettings(Settings settings, ClusterSettings clusterSettings) {
         clusterSettings.addSettingsUpdateConsumer(INDICES_RECOVERY_MAX_BYTES_PER_SEC_SETTING, this::setMaxBytesPerSec);
         clusterSettings.addSettingsUpdateConsumer(INDICES_RECOVERY_MAX_CONCURRENT_FILE_CHUNKS_SETTING, this::setMaxConcurrentFileChunks);
         clusterSettings.addSettingsUpdateConsumer(INDICES_RECOVERY_MAX_CONCURRENT_OPERATIONS_SETTING, this::setMaxConcurrentOperations);
+        clusterSettings.addSettingsUpdateConsumer(
+            INDICES_RECOVERY_MAX_CONCURRENT_REMOTE_STORE_STREAMS_SETTING,
+            this::setMaxConcurrentRemoteStoreStreams
+        );
         clusterSettings.addSettingsUpdateConsumer(INDICES_RECOVERY_RETRY_DELAY_STATE_SYNC_SETTING, this::setRetryDelayStateSync);
         clusterSettings.addSettingsUpdateConsumer(INDICES_RECOVERY_RETRY_DELAY_NETWORK_SETTING, this::setRetryDelayNetwork);
         clusterSettings.addSettingsUpdateConsumer(INDICES_RECOVERY_INTERNAL_ACTION_TIMEOUT_SETTING, this::setInternalActionTimeout);
@@ -192,6 +232,11 @@ public RecoverySettings(Settings settings, ClusterSettings clusterSettings) {
             this::setInternalActionLongTimeout
         );
         clusterSettings.addSettingsUpdateConsumer(INDICES_RECOVERY_ACTIVITY_TIMEOUT_SETTING, this::setActivityTimeout);
+        minRemoteSegmentMetadataFiles = CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.get(settings);
+        clusterSettings.addSettingsUpdateConsumer(
+            CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING,
+            this::setMinRemoteSegmentMetadataFiles
+        );
     }
 
     public RateLimiter rateLimiter() {
@@ -279,4 +324,20 @@ public int getMaxConcurrentOperations() {
     private void setMaxConcurrentOperations(int maxConcurrentOperations) {
         this.maxConcurrentOperations = maxConcurrentOperations;
     }
+
+    public int getMaxConcurrentRemoteStoreStreams() {
+        return this.maxConcurrentRemoteStoreStreams;
+    }
+
+    private void setMaxConcurrentRemoteStoreStreams(int maxConcurrentRemoteStoreStreams) {
+        this.maxConcurrentRemoteStoreStreams = maxConcurrentRemoteStoreStreams;
+    }
+
+    private void setMinRemoteSegmentMetadataFiles(int minRemoteSegmentMetadataFiles) {
+        this.minRemoteSegmentMetadataFiles = minRemoteSegmentMetadataFiles;
+    }
+
+    public int getMinRemoteSegmentMetadataFiles() {
+        return this.minRemoteSegmentMetadataFiles;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RecoverySourceHandler.java b/server/src/main/java/org/opensearch/indices/recovery/RecoverySourceHandler.java
index 6d7972d79a96c..7996c48b2b04b 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RecoverySourceHandler.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RecoverySourceHandler.java
@@ -201,9 +201,13 @@ protected void finalizeStepAndCompleteFuture(
         final StepListener<Void> finalizeStep = new StepListener<>();
         // Recovery target can trim all operations >= startingSeqNo as we have sent all these operations in the phase 2
         final long trimAboveSeqNo = startingSeqNo - 1;
-        sendSnapshotStep.whenComplete(r -> finalizeRecovery(r.targetLocalCheckpoint, trimAboveSeqNo, finalizeStep), onFailure);
+        sendSnapshotStep.whenComplete(r -> {
+            logger.debug("sendSnapshotStep completed");
+            finalizeRecovery(r.targetLocalCheckpoint, trimAboveSeqNo, finalizeStep);
+        }, onFailure);
 
         finalizeStep.whenComplete(r -> {
+            logger.debug("finalizeStep completed");
             final long phase1ThrottlingWaitTime = 0L; // TODO: return the actual throttle time
             final SendSnapshotResult sendSnapshotResult = sendSnapshotStep.result();
             final SendFileResult sendFileResult = sendFileStep.result();
@@ -233,7 +237,10 @@ protected void onSendFileStepComplete(
         GatedCloseable<IndexCommit> wrappedSafeCommit,
         Releasable releaseStore
     ) {
-        sendFileStep.whenComplete(r -> IOUtils.close(wrappedSafeCommit, releaseStore), e -> {
+        sendFileStep.whenComplete(r -> {
+            logger.debug("sendFileStep completed");
+            IOUtils.close(wrappedSafeCommit, releaseStore);
+        }, e -> {
             try {
                 IOUtils.close(wrappedSafeCommit, releaseStore);
             } catch (final IOException ex) {
@@ -445,16 +452,22 @@ void phase1(
                     sendFileInfoStep
                 );
 
-                sendFileInfoStep.whenComplete(
-                    r -> sendFiles(store, phase1Files.toArray(new StoreFileMetadata[0]), translogOps, sendFilesStep),
-                    listener::onFailure
-                );
+                sendFileInfoStep.whenComplete(r -> {
+                    logger.debug("sendFileInfoStep completed");
+                    sendFiles(store, phase1Files.toArray(new StoreFileMetadata[0]), translogOps, sendFilesStep);
+                }, listener::onFailure);
 
                 // When doing peer recovery of remote store enabled replica, retention leases are not required.
                 if (skipCreateRetentionLeaseStep) {
-                    sendFilesStep.whenComplete(r -> createRetentionLeaseStep.onResponse(null), listener::onFailure);
+                    sendFilesStep.whenComplete(r -> {
+                        logger.debug("sendFilesStep completed");
+                        createRetentionLeaseStep.onResponse(null);
+                    }, listener::onFailure);
                 } else {
-                    sendFilesStep.whenComplete(r -> createRetentionLease(startingSeqNo, createRetentionLeaseStep), listener::onFailure);
+                    sendFilesStep.whenComplete(r -> {
+                        logger.debug("sendFilesStep completed");
+                        createRetentionLease(startingSeqNo, createRetentionLeaseStep);
+                    }, listener::onFailure);
                 }
 
                 createRetentionLeaseStep.whenComplete(retentionLease -> {
@@ -471,6 +484,7 @@ void phase1(
                 final long totalSize = totalSizeInBytes;
                 final long existingTotalSize = existingTotalSizeInBytes;
                 cleanFilesStep.whenComplete(r -> {
+                    logger.debug("cleanFilesStep completed");
                     final TimeValue took = stopWatch.totalTime();
                     logger.trace("recovery [phase1]: took [{}]", took);
                     listener.onResponse(
@@ -541,7 +555,10 @@ void createRetentionLease(final long startingSeqNo, ActionListener<RetentionLeas
                     new ThreadedActionListener<>(logger, shard.getThreadPool(), ThreadPool.Names.GENERIC, cloneRetentionLeaseStep, false)
                 );
                 logger.trace("cloned primary's retention lease as [{}]", clonedLease);
-                cloneRetentionLeaseStep.whenComplete(rr -> listener.onResponse(clonedLease), listener::onFailure);
+                cloneRetentionLeaseStep.whenComplete(rr -> {
+                    logger.debug("cloneRetentionLeaseStep completed");
+                    listener.onResponse(clonedLease);
+                }, listener::onFailure);
             } catch (RetentionLeaseNotFoundException e) {
                 // it's possible that the primary has no retention lease yet if we are doing a rolling upgrade from a version before
                 // 7.4, and in that case we just create a lease using the local checkpoint of the safe commit which we're using for
@@ -554,7 +571,10 @@ void createRetentionLease(final long startingSeqNo, ActionListener<RetentionLeas
                     estimatedGlobalCheckpoint,
                     new ThreadedActionListener<>(logger, shard.getThreadPool(), ThreadPool.Names.GENERIC, addRetentionLeaseStep, false)
                 );
-                addRetentionLeaseStep.whenComplete(rr -> listener.onResponse(newLease), listener::onFailure);
+                addRetentionLeaseStep.whenComplete(rr -> {
+                    logger.debug("addRetentionLeaseStep completed");
+                    listener.onResponse(newLease);
+                }, listener::onFailure);
                 logger.trace("created retention lease with estimated checkpoint of [{}]", estimatedGlobalCheckpoint);
             }
         }, shardId + " establishing retention lease for [" + request.targetAllocationId() + "]", shard, cancellableThreads, logger);
@@ -810,6 +830,7 @@ void finalizeRecovery(long targetLocalCheckpoint, long trimAboveSeqNo, ActionLis
         cancellableThreads.checkForCancel();
         recoveryTarget.finalizeRecovery(globalCheckpoint, trimAboveSeqNo, finalizeListener);
         finalizeListener.whenComplete(r -> {
+            logger.debug("finalizeListenerStep completed");
             RunUnderPrimaryPermit.run(
                 () -> shard.updateGlobalCheckpointForShard(request.targetAllocationId(), globalCheckpoint),
                 shardId + " updating " + request.targetAllocationId() + "'s global checkpoint",
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RecoveryState.java b/server/src/main/java/org/opensearch/indices/recovery/RecoveryState.java
index 6733a29c19db3..80c05399df627 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RecoveryState.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RecoveryState.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -54,15 +55,17 @@
 /**
  * Keeps track of state related to shard recovery.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RecoveryState implements ReplicationState, ToXContentFragment, Writeable {
 
     /**
      * The stage of the recovery state
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Stage {
         INIT((byte) 0),
 
@@ -370,8 +373,9 @@ static final class Fields {
     /**
      * Verifys the lucene index
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class VerifyIndex extends ReplicationTimer implements ToXContentFragment, Writeable {
         private volatile long checkIndexTime;
 
@@ -412,8 +416,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * The translog
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Translog extends ReplicationTimer implements ToXContentFragment, Writeable {
         public static final int UNKNOWN = -1;
 
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RecoveryTarget.java b/server/src/main/java/org/opensearch/indices/recovery/RecoveryTarget.java
index 539edd834c8f1..f3b5d0d790f83 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RecoveryTarget.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RecoveryTarget.java
@@ -39,6 +39,7 @@
 import org.opensearch.action.admin.indices.flush.FlushRequest;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.common.util.CancellableThreads;
 import org.opensearch.core.Assertions;
@@ -73,8 +74,9 @@
  * Represents a recovery where the current node is the target node of the recovery. To track recoveries in a central place, instances of
  * this class are created through {@link ReplicationCollection}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RecoveryTarget extends ReplicationTarget implements RecoveryTargetHandler {
 
     private static final String RECOVERY_PREFIX = "recovery.";
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RecoveryTargetHandler.java b/server/src/main/java/org/opensearch/indices/recovery/RecoveryTargetHandler.java
index ac28dabf815a5..707e41c8c27e1 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RecoveryTargetHandler.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RecoveryTargetHandler.java
@@ -55,7 +55,7 @@ public interface RecoveryTargetHandler extends FileChunkWriter {
 
     /**
      * Used with Segment replication only
-     *
+     * <p>
      * This function is used to force a sync target primary node with source (old primary). This is to avoid segment files
      * conflict with replicas when target is promoted as primary.
      */
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RemoteRecoveryTargetHandler.java b/server/src/main/java/org/opensearch/indices/recovery/RemoteRecoveryTargetHandler.java
index 36beabc4a9026..37227596fdfe7 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RemoteRecoveryTargetHandler.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RemoteRecoveryTargetHandler.java
@@ -75,6 +75,7 @@ public class RemoteRecoveryTargetHandler implements RecoveryTargetHandler {
     private final AtomicLong requestSeqNoGenerator = new AtomicLong(0);
     private final RetryableTransportClient retryableTransportClient;
     private final RemoteSegmentFileChunkWriter fileChunkWriter;
+    private final boolean remoteStoreEnabled;
 
     public RemoteRecoveryTargetHandler(
         long recoveryId,
@@ -82,7 +83,8 @@ public RemoteRecoveryTargetHandler(
         TransportService transportService,
         DiscoveryNode targetNode,
         RecoverySettings recoverySettings,
-        Consumer<Long> onSourceThrottle
+        Consumer<Long> onSourceThrottle,
+        boolean remoteStoreEnabled
     ) {
         this.transportService = transportService;
         // It is safe to pass the retry timeout value here because RemoteRecoveryTargetHandler
@@ -111,6 +113,7 @@ public RemoteRecoveryTargetHandler(
             requestSeqNoGenerator,
             onSourceThrottle
         );
+        this.remoteStoreEnabled = remoteStoreEnabled;
     }
 
     public DiscoveryNode targetNode() {
@@ -129,7 +132,13 @@ public void prepareForTranslogOperations(int totalTranslogOps, ActionListener<Vo
         );
         final Writeable.Reader<TransportResponse.Empty> reader = in -> TransportResponse.Empty.INSTANCE;
         final ActionListener<TransportResponse.Empty> responseListener = ActionListener.map(listener, r -> null);
-        retryableTransportClient.executeRetryableAction(action, request, responseListener, reader);
+        if (remoteStoreEnabled) {
+            // If remote store is enabled, during the prepare_translog phase, translog is also downloaded on the
+            // target host along with incremental segments download.
+            retryableTransportClient.executeRetryableAction(action, request, translogOpsRequestOptions, responseListener, reader);
+        } else {
+            retryableTransportClient.executeRetryableAction(action, request, responseListener, reader);
+        }
     }
 
     @Override
@@ -189,7 +198,7 @@ public void indexTranslogOperations(
 
     /**
      * Used with Segment replication only
-     *
+     * <p>
      * This function is used to force a sync target primary node with source (old primary). This is to avoid segment files
      * conflict with replicas when target is promoted as primary.
      */
diff --git a/server/src/main/java/org/opensearch/indices/recovery/RemoteStorePeerRecoverySourceHandler.java b/server/src/main/java/org/opensearch/indices/recovery/RemoteStorePeerRecoverySourceHandler.java
index 5d6c0eb3bae05..66c7a3b48f28f 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/RemoteStorePeerRecoverySourceHandler.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/RemoteStorePeerRecoverySourceHandler.java
@@ -80,12 +80,14 @@ protected void innerRecoveryToTarget(ActionListener<RecoveryResponse> listener,
         assert startingSeqNo >= 0 : "startingSeqNo must be non negative. got: " + startingSeqNo;
 
         sendFileStep.whenComplete(r -> {
+            logger.debug("sendFileStep completed");
             assert Transports.assertNotTransportThread(this + "[prepareTargetForTranslog]");
             // For a sequence based recovery, the target can keep its local translog
             prepareTargetForTranslog(0, prepareEngineStep);
         }, onFailure);
 
         prepareEngineStep.whenComplete(prepareEngineTime -> {
+            logger.debug("prepareEngineStep completed");
             assert Transports.assertNotTransportThread(this + "[phase2]");
             RunUnderPrimaryPermit.run(
                 () -> shard.initiateTracking(request.targetAllocationId()),
diff --git a/server/src/main/java/org/opensearch/indices/recovery/StartRecoveryRequest.java b/server/src/main/java/org/opensearch/indices/recovery/StartRecoveryRequest.java
index 91802448abcae..1df0d3861f686 100644
--- a/server/src/main/java/org/opensearch/indices/recovery/StartRecoveryRequest.java
+++ b/server/src/main/java/org/opensearch/indices/recovery/StartRecoveryRequest.java
@@ -33,6 +33,7 @@
 package org.opensearch.indices.recovery;
 
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.index.shard.ShardId;
@@ -45,8 +46,9 @@
 /**
  * Represents a request for starting a peer recovery.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class StartRecoveryRequest extends TransportRequest {
 
     private long recoveryId;
diff --git a/server/src/main/java/org/opensearch/indices/replication/OngoingSegmentReplications.java b/server/src/main/java/org/opensearch/indices/replication/OngoingSegmentReplications.java
index 268894b1c0af3..33967c0203516 100644
--- a/server/src/main/java/org/opensearch/indices/replication/OngoingSegmentReplications.java
+++ b/server/src/main/java/org/opensearch/indices/replication/OngoingSegmentReplications.java
@@ -61,8 +61,8 @@ class OngoingSegmentReplications {
         this.allocationIdToHandlers = ConcurrentCollections.newConcurrentMap();
     }
 
-    /**
-     * Operations on the {@link #copyStateMap} member.
+    /*
+      Operations on the {@link #copyStateMap} member.
      */
 
     /**
@@ -85,12 +85,12 @@ synchronized CopyState getCachedCopyState(ReplicationCheckpoint checkpoint) thro
             // build the CopyState object and cache it before returning
             final CopyState copyState = new CopyState(checkpoint, indexShard);
 
-            /**
-             * Use the checkpoint from the request as the key in the map, rather than
-             * the checkpoint from the created CopyState. This maximizes cache hits
-             * if replication targets make a request with an older checkpoint.
-             * Replication targets are expected to fetch the checkpoint in the response
-             * CopyState to bring themselves up to date.
+            /*
+              Use the checkpoint from the request as the key in the map, rather than
+              the checkpoint from the created CopyState. This maximizes cache hits
+              if replication targets make a request with an older checkpoint.
+              Replication targets are expected to fetch the checkpoint in the response
+              CopyState to bring themselves up to date.
              */
             addToCopyStateMap(checkpoint, copyState);
             return copyState;
diff --git a/server/src/main/java/org/opensearch/indices/replication/PrimaryShardReplicationSource.java b/server/src/main/java/org/opensearch/indices/replication/PrimaryShardReplicationSource.java
index 9dcd16c53e6f3..02fc8feefd698 100644
--- a/server/src/main/java/org/opensearch/indices/replication/PrimaryShardReplicationSource.java
+++ b/server/src/main/java/org/opensearch/indices/replication/PrimaryShardReplicationSource.java
@@ -22,6 +22,7 @@
 import org.opensearch.transport.TransportService;
 
 import java.util.List;
+import java.util.function.BiConsumer;
 
 import static org.opensearch.indices.replication.SegmentReplicationSourceService.Actions.GET_CHECKPOINT_INFO;
 import static org.opensearch.indices.replication.SegmentReplicationSourceService.Actions.GET_SEGMENT_FILES;
@@ -80,8 +81,13 @@ public void getSegmentFiles(
         ReplicationCheckpoint checkpoint,
         List<StoreFileMetadata> filesToFetch,
         IndexShard indexShard,
+        BiConsumer<String, Long> fileProgressTracker,
         ActionListener<GetSegmentFilesResponse> listener
     ) {
+        // fileProgressTracker is a no-op for node to node recovery
+        // MultiFileWriter takes care of progress tracking for downloads in this scenario
+        // TODO: Move state management and tracking into replication methods and use chunking and data
+        // copy mechanisms only from MultiFileWriter
         final Writeable.Reader<GetSegmentFilesResponse> reader = GetSegmentFilesResponse::new;
         final ActionListener<GetSegmentFilesResponse> responseListener = ActionListener.map(listener, r -> r);
         final GetSegmentFilesRequest request = new GetSegmentFilesRequest(
diff --git a/server/src/main/java/org/opensearch/indices/replication/RemoteStoreReplicationSource.java b/server/src/main/java/org/opensearch/indices/replication/RemoteStoreReplicationSource.java
index 7252fea044a02..b06b3e0497cf7 100644
--- a/server/src/main/java/org/opensearch/indices/replication/RemoteStoreReplicationSource.java
+++ b/server/src/main/java/org/opensearch/indices/replication/RemoteStoreReplicationSource.java
@@ -13,9 +13,9 @@
 import org.apache.lucene.index.SegmentInfos;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FilterDirectory;
-import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.Version;
 import org.opensearch.common.concurrent.GatedCloseable;
+import org.opensearch.common.util.CancellableThreads;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.index.shard.IndexShardState;
@@ -25,11 +25,15 @@
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadata;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.BiConsumer;
 import java.util.stream.Collectors;
 
 /**
@@ -43,6 +47,7 @@ public class RemoteStoreReplicationSource implements SegmentReplicationSource {
 
     private final IndexShard indexShard;
     private final RemoteSegmentStoreDirectory remoteDirectory;
+    private final CancellableThreads cancellableThreads = new CancellableThreads();
 
     public RemoteStoreReplicationSource(IndexShard indexShard) {
         this.indexShard = indexShard;
@@ -61,7 +66,7 @@ public void getCheckpointMetadata(
         // TODO: Need to figure out a way to pass this information for segment metadata via remote store.
         try (final GatedCloseable<SegmentInfos> segmentInfosSnapshot = indexShard.getSegmentInfosSnapshot()) {
             final Version version = segmentInfosSnapshot.get().getCommitLuceneVersion();
-            RemoteSegmentMetadata mdFile = remoteDirectory.init();
+            final RemoteSegmentMetadata mdFile = getRemoteSegmentMetadata();
             // During initial recovery flow, the remote store might not
             // have metadata as primary hasn't uploaded anything yet.
             if (mdFile == null && indexShard.state().equals(IndexShardState.STARTED) == false) {
@@ -96,6 +101,7 @@ public void getSegmentFiles(
         ReplicationCheckpoint checkpoint,
         List<StoreFileMetadata> filesToFetch,
         IndexShard indexShard,
+        BiConsumer<String, Long> fileProgressTracker,
         ActionListener<GetSegmentFilesResponse> listener
     ) {
         try {
@@ -103,36 +109,52 @@ public void getSegmentFiles(
                 listener.onResponse(new GetSegmentFilesResponse(Collections.emptyList()));
                 return;
             }
-            logger.trace("Downloading segments files from remote store {}", filesToFetch);
+            logger.debug("Downloading segment files from remote store {}", filesToFetch);
 
-            RemoteSegmentMetadata remoteSegmentMetadata = remoteDirectory.readLatestMetadataFile();
-            List<StoreFileMetadata> downloadedSegments = new ArrayList<>();
-            Collection<String> directoryFiles = List.of(indexShard.store().directory().listAll());
-            if (remoteSegmentMetadata != null) {
-                try {
-                    indexShard.store().incRef();
-                    indexShard.remoteStore().incRef();
-                    final Directory storeDirectory = indexShard.store().directory();
-                    for (StoreFileMetadata fileMetadata : filesToFetch) {
-                        String file = fileMetadata.name();
-                        assert directoryFiles.contains(file) == false : "Local store already contains the file " + file;
-                        storeDirectory.copyFrom(remoteDirectory, file, file, IOContext.DEFAULT);
-                        downloadedSegments.add(fileMetadata);
-                    }
-                    logger.trace("Downloaded segments from remote store {}", downloadedSegments);
-                } finally {
-                    indexShard.store().decRef();
-                    indexShard.remoteStore().decRef();
+            if (remoteMetadataExists()) {
+                final Directory storeDirectory = indexShard.store().directory();
+                final Collection<String> directoryFiles = List.of(storeDirectory.listAll());
+                final List<String> toDownloadSegmentNames = new ArrayList<>();
+                for (StoreFileMetadata fileMetadata : filesToFetch) {
+                    String file = fileMetadata.name();
+                    assert directoryFiles.contains(file) == false : "Local store already contains the file " + file;
+                    toDownloadSegmentNames.add(file);
                 }
+                indexShard.getFileDownloader()
+                    .downloadAsync(
+                        cancellableThreads,
+                        remoteDirectory,
+                        new ReplicationStatsDirectoryWrapper(storeDirectory, fileProgressTracker),
+                        toDownloadSegmentNames,
+                        ActionListener.map(listener, r -> new GetSegmentFilesResponse(filesToFetch))
+                    );
+            } else {
+                listener.onResponse(new GetSegmentFilesResponse(filesToFetch));
             }
-            listener.onResponse(new GetSegmentFilesResponse(downloadedSegments));
-        } catch (Exception e) {
+        } catch (IOException | RuntimeException e) {
             listener.onFailure(e);
         }
     }
 
+    @Override
+    public void cancel() {
+        this.cancellableThreads.cancel("Canceled by target");
+    }
+
     @Override
     public String getDescription() {
         return "RemoteStoreReplicationSource";
     }
+
+    private boolean remoteMetadataExists() throws IOException {
+        final AtomicBoolean metadataExists = new AtomicBoolean(false);
+        cancellableThreads.executeIO(() -> metadataExists.set(remoteDirectory.readLatestMetadataFile() != null));
+        return metadataExists.get();
+    }
+
+    private RemoteSegmentMetadata getRemoteSegmentMetadata() throws IOException {
+        AtomicReference<RemoteSegmentMetadata> mdFile = new AtomicReference<>();
+        cancellableThreads.executeIO(() -> mdFile.set(remoteDirectory.init()));
+        return mdFile.get();
+    }
 }
diff --git a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSource.java b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSource.java
index 6676b5b667e42..24f0cb15ddb25 100644
--- a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSource.java
+++ b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSource.java
@@ -8,13 +8,19 @@
 
 package org.opensearch.indices.replication;
 
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.FilterDirectory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IndexInput;
 import org.opensearch.common.util.CancellableThreads.ExecutionCancelledException;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.index.store.StoreFileMetadata;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 
+import java.io.IOException;
 import java.util.List;
+import java.util.function.BiConsumer;
 
 /**
  * Represents the source of a replication event.
@@ -39,6 +45,7 @@ public interface SegmentReplicationSource {
      * @param checkpoint    {@link ReplicationCheckpoint} Checkpoint to fetch metadata for.
      * @param filesToFetch  {@link List} List of files to fetch.
      * @param indexShard    {@link IndexShard} Reference to the IndexShard.
+     * @param fileProgressTracker {@link BiConsumer} A consumer that updates the replication progress for shard files.
      * @param listener      {@link ActionListener} Listener that completes with the list of files copied.
      */
     void getSegmentFiles(
@@ -46,6 +53,7 @@ void getSegmentFiles(
         ReplicationCheckpoint checkpoint,
         List<StoreFileMetadata> filesToFetch,
         IndexShard indexShard,
+        BiConsumer<String, Long> fileProgressTracker,
         ActionListener<GetSegmentFilesResponse> listener
     );
 
@@ -58,4 +66,69 @@ void getSegmentFiles(
      * Cancel any ongoing requests, should resolve any ongoing listeners with onFailure with a {@link ExecutionCancelledException}.
      */
     default void cancel() {}
+
+    /**
+     * Directory wrapper that records copy process for replication statistics
+     *
+     * @opensearch.internal
+     */
+    final class ReplicationStatsDirectoryWrapper extends FilterDirectory {
+        private final BiConsumer<String, Long> fileProgressTracker;
+
+        ReplicationStatsDirectoryWrapper(Directory in, BiConsumer<String, Long> fileProgressTracker) {
+            super(in);
+            this.fileProgressTracker = fileProgressTracker;
+        }
+
+        @Override
+        public void copyFrom(Directory from, String src, String dest, IOContext context) throws IOException {
+            // here we wrap the index input form the source directory to report progress of file copy for the recovery stats.
+            // we increment the num bytes recovered in the readBytes method below, if users pull statistics they can see immediately
+            // how much has been recovered.
+            in.copyFrom(new FilterDirectory(from) {
+                @Override
+                public IndexInput openInput(String name, IOContext context) throws IOException {
+                    final IndexInput input = in.openInput(name, context);
+                    return new IndexInput("StatsDirectoryWrapper(" + input.toString() + ")") {
+                        @Override
+                        public void close() throws IOException {
+                            input.close();
+                        }
+
+                        @Override
+                        public long getFilePointer() {
+                            throw new UnsupportedOperationException("only straight copies are supported");
+                        }
+
+                        @Override
+                        public void seek(long pos) throws IOException {
+                            throw new UnsupportedOperationException("seeks are not supported");
+                        }
+
+                        @Override
+                        public long length() {
+                            return input.length();
+                        }
+
+                        @Override
+                        public IndexInput slice(String sliceDescription, long offset, long length) throws IOException {
+                            throw new UnsupportedOperationException("slices are not supported");
+                        }
+
+                        @Override
+                        public byte readByte() throws IOException {
+                            throw new UnsupportedOperationException("use a buffer if you wanna perform well");
+                        }
+
+                        @Override
+                        public void readBytes(byte[] b, int offset, int len) throws IOException {
+                            // we rely on the fact that copyFrom uses a buffer
+                            input.readBytes(b, offset, len);
+                            fileProgressTracker.accept(dest, (long) len);
+                        }
+                    };
+                }
+            }, src, dest, context);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSourceHandler.java b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSourceHandler.java
index e2c47b0fb3159..674c09311c645 100644
--- a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSourceHandler.java
+++ b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSourceHandler.java
@@ -12,8 +12,6 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.action.StepListener;
 import org.opensearch.cluster.node.DiscoveryNode;
-import org.opensearch.cluster.routing.IndexShardRoutingTable;
-import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.util.CancellableThreads;
 import org.opensearch.common.util.concurrent.ListenableFuture;
@@ -22,7 +20,6 @@
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.index.store.StoreFileMetadata;
-import org.opensearch.indices.recovery.DelayRecoveryException;
 import org.opensearch.indices.recovery.FileChunkWriter;
 import org.opensearch.indices.recovery.MultiChunkTransfer;
 import org.opensearch.indices.replication.common.CopyState;
@@ -146,12 +143,6 @@ public synchronized void sendFiles(GetSegmentFilesRequest request, ActionListene
                 );
             };
             cancellableThreads.checkForCancel();
-            final IndexShardRoutingTable routingTable = shard.getReplicationGroup().getRoutingTable();
-            ShardRouting targetShardRouting = routingTable.getByAllocationId(request.getTargetAllocationId());
-            if (targetShardRouting == null) {
-                logger.debug("delaying replication of {} as it is not listed as assigned to target node {}", shard.shardId(), targetNode);
-                throw new DelayRecoveryException("source node does not have the shard listed in its state as allocated on the node");
-            }
 
             final StepListener<Void> sendFileStep = new StepListener<>();
             Set<String> storeFiles = new HashSet<>(Arrays.asList(shard.store().directory().listAll()));
diff --git a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationState.java b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationState.java
index 9b5b1f4a1468e..5fa123948c5ac 100644
--- a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationState.java
+++ b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationState.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -29,15 +30,17 @@
 /**
  * ReplicationState implementation to track Segment Replication events.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public class SegmentReplicationState implements ReplicationState, ToXContentFragment, Writeable {
 
     /**
      * The stage of the recovery state
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "2.2.0")
     public enum Stage {
         DONE((byte) 0),
         INIT((byte) 1),
diff --git a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTarget.java b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTarget.java
index 5ae480b7d63a4..cc71ef816e525 100644
--- a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTarget.java
+++ b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTarget.java
@@ -18,7 +18,6 @@
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.opensearch.OpenSearchCorruptionException;
-import org.opensearch.OpenSearchException;
 import org.opensearch.action.StepListener;
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.lucene.Lucene;
@@ -171,7 +170,14 @@ public void startReplication(ActionListener<Void> listener) {
             final List<StoreFileMetadata> filesToFetch = getFiles(checkpointInfo);
             state.setStage(SegmentReplicationState.Stage.GET_FILES);
             cancellableThreads.checkForCancel();
-            source.getSegmentFiles(getId(), checkpointInfo.getCheckpoint(), filesToFetch, indexShard, getFilesListener);
+            source.getSegmentFiles(
+                getId(),
+                checkpointInfo.getCheckpoint(),
+                filesToFetch,
+                indexShard,
+                this::updateFileRecoveryBytes,
+                getFilesListener
+            );
         }, listener::onFailure);
 
         getFilesListener.whenComplete(response -> {
@@ -226,6 +232,7 @@ private List<StoreFileMetadata> getFiles(CheckpointInfoResponse checkpointInfo)
         return missingFiles;
     }
 
+    // pkg private for tests
     private boolean validateLocalChecksum(StoreFileMetadata file) {
         try (IndexInput indexInput = indexShard.store().directory().openInput(file.name(), IOContext.DEFAULT)) {
             String checksum = Store.digestToString(CodecUtil.retrieveChecksum(indexInput));
@@ -237,8 +244,30 @@ private boolean validateLocalChecksum(StoreFileMetadata file) {
                 return false;
             }
         } catch (IOException e) {
-            throw new UncheckedIOException("Error reading " + file, e);
+            logger.warn("Error reading " + file, e);
+            // Delete file on exceptions so that it can be re-downloaded. This is safe to do as this file is local only
+            // and not referenced by reader.
+            try {
+                indexShard.store().directory().deleteFile(file.name());
+            } catch (IOException ex) {
+                throw new UncheckedIOException("Error reading " + file, e);
+            }
+            return false;
+        }
+    }
+
+    /**
+     * Updates the state to reflect recovery progress for the given file and
+     * updates the last access time for the target.
+     * @param fileName Name of the file being downloaded
+     * @param bytesRecovered Number of bytes recovered
+     */
+    private void updateFileRecoveryBytes(String fileName, long bytesRecovered) {
+        ReplicationLuceneIndex index = state.getIndex();
+        if (index != null) {
+            index.addRecoveredBytesToFile(fileName, bytesRecovered);
         }
+        setLastAccessTime();
     }
 
     private void finalizeReplication(CheckpointInfoResponse checkpointInfoResponse) throws OpenSearchCorruptionException {
@@ -261,9 +290,7 @@ private void finalizeReplication(CheckpointInfoResponse checkpointInfoResponse)
         } catch (CorruptIndexException | IndexFormatTooNewException | IndexFormatTooOldException ex) {
             // this is a fatal exception at this stage.
             // this means we transferred files from the remote that have not be checksummed and they are
-            // broken. We have to clean up this shard entirely, remove all files and bubble it up to the
-            // source shard since this index might be broken there as well? The Source can handle this and checks
-            // its content on disk if possible.
+            // broken. We have to clean up this shard entirely, remove all files and bubble it up.
             try {
                 try {
                     store.removeCorruptionMarker();
@@ -279,14 +306,14 @@ private void finalizeReplication(CheckpointInfoResponse checkpointInfoResponse)
             // In this case the shard is closed at some point while updating the reader.
             // This can happen when the engine is closed in a separate thread.
             logger.warn("Shard is already closed, closing replication");
-        } catch (OpenSearchException ex) {
+        } catch (CancellableThreads.ExecutionCancelledException ex) {
             /*
              Ignore closed replication target as it can happen due to index shard closed event in a separate thread.
              In such scenario, ignore the exception
              */
-            assert cancellableThreads.isCancelled() : "Replication target closed but segment replication not cancelled";
+            assert cancellableThreads.isCancelled() : "Replication target cancelled but cancellable threads not cancelled";
         } catch (Exception ex) {
-            throw new OpenSearchCorruptionException(ex);
+            throw new ReplicationFailedException(ex);
         } finally {
             if (store != null) {
                 store.decRef();
diff --git a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java
index c071b22ba4cba..d6db154a4e0e3 100644
--- a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java
+++ b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java
@@ -11,13 +11,17 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.apache.lucene.index.CorruptIndexException;
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.OpenSearchCorruptionException;
 import org.opensearch.action.support.ChannelActionListener;
+import org.opensearch.cluster.ClusterChangedEvent;
+import org.opensearch.cluster.ClusterStateListener;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.CancellableThreads;
 import org.opensearch.common.util.concurrent.AbstractRunnable;
@@ -25,9 +29,11 @@
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.index.IndexService;
 import org.opensearch.index.shard.IndexEventListener;
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.index.shard.IndexShardState;
+import org.opensearch.index.store.Store;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.recovery.FileChunkRequest;
 import org.opensearch.indices.recovery.ForceSyncRequest;
@@ -46,10 +52,12 @@
 import org.opensearch.transport.TransportRequestOptions;
 import org.opensearch.transport.TransportService;
 
+import java.io.IOException;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicLong;
 
+import static org.opensearch.index.seqno.SequenceNumbers.NO_OPS_PERFORMED;
 import static org.opensearch.indices.replication.SegmentReplicationSourceService.Actions.UPDATE_VISIBLE_CHECKPOINT;
 
 /**
@@ -57,7 +65,7 @@
  *
  * @opensearch.internal
  */
-public class SegmentReplicationTargetService implements IndexEventListener {
+public class SegmentReplicationTargetService extends AbstractLifecycleComponent implements ClusterStateListener, IndexEventListener {
 
     private static final Logger logger = LogManager.getLogger(SegmentReplicationTargetService.class);
 
@@ -66,7 +74,7 @@ public class SegmentReplicationTargetService implements IndexEventListener {
 
     private final ReplicationCollection<SegmentReplicationTarget> onGoingReplications;
 
-    private final Map<ShardId, SegmentReplicationTarget> completedReplications = ConcurrentCollections.newConcurrentMap();
+    private final Map<ShardId, SegmentReplicationState> completedReplications = ConcurrentCollections.newConcurrentMap();
 
     private final SegmentReplicationSourceFactory sourceFactory;
 
@@ -140,6 +148,53 @@ public SegmentReplicationTargetService(
         );
     }
 
+    @Override
+    protected void doStart() {
+        if (DiscoveryNode.isDataNode(clusterService.getSettings())) {
+            clusterService.addListener(this);
+        }
+    }
+
+    @Override
+    protected void doStop() {
+        if (DiscoveryNode.isDataNode(clusterService.getSettings())) {
+            clusterService.removeListener(this);
+        }
+    }
+
+    @Override
+    protected void doClose() throws IOException {
+
+    }
+
+    @Override
+    public void clusterChanged(ClusterChangedEvent event) {
+        if (event.routingTableChanged()) {
+            for (IndexService indexService : indicesService) {
+                if (indexService.getIndexSettings().isSegRepEnabled() && event.indexRoutingTableChanged(indexService.index().getName())) {
+                    for (IndexShard shard : indexService) {
+                        if (shard.routingEntry().primary() == false) {
+                            // for this shard look up its primary routing, if it has completed a relocation trigger replication
+                            final String previousNode = event.previousState()
+                                .routingTable()
+                                .shardRoutingTable(shard.shardId())
+                                .primaryShard()
+                                .currentNodeId();
+                            final String currentNode = event.state()
+                                .routingTable()
+                                .shardRoutingTable(shard.shardId())
+                                .primaryShard()
+                                .currentNodeId();
+                            if (previousNode.equals(currentNode) == false) {
+                                processLatestReceivedCheckpoint(shard, Thread.currentThread());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
     /**
      * Cancel any replications on this node for a replica that is about to be closed.
      */
@@ -188,7 +243,7 @@ public SegmentReplicationState getOngoingEventSegmentReplicationState(ShardId sh
      */
     @Nullable
     public SegmentReplicationState getlatestCompletedEventSegmentReplicationState(ShardId shardId) {
-        return Optional.ofNullable(completedReplications.get(shardId)).map(SegmentReplicationTarget::state).orElse(null);
+        return completedReplications.get(shardId);
     }
 
     /**
@@ -208,7 +263,7 @@ public SegmentReplicationState getSegmentReplicationState(ShardId shardId) {
      * @param replicaShard       replica shard on which checkpoint is received
      */
     public synchronized void onNewCheckpoint(final ReplicationCheckpoint receivedCheckpoint, final IndexShard replicaShard) {
-        logger.trace(() -> new ParameterizedMessage("Replica received new replication checkpoint from primary [{}]", receivedCheckpoint));
+        logger.debug(() -> new ParameterizedMessage("Replica received new replication checkpoint from primary [{}]", receivedCheckpoint));
         // if the shard is in any state
         if (replicaShard.state().equals(IndexShardState.CLOSED)) {
             // ignore if shard is closed
@@ -224,7 +279,7 @@ public synchronized void onNewCheckpoint(final ReplicationCheckpoint receivedChe
             SegmentReplicationTarget ongoingReplicationTarget = onGoingReplications.getOngoingReplicationTarget(replicaShard.shardId());
             if (ongoingReplicationTarget != null) {
                 if (ongoingReplicationTarget.getCheckpoint().getPrimaryTerm() < receivedCheckpoint.getPrimaryTerm()) {
-                    logger.trace(
+                    logger.debug(
                         () -> new ParameterizedMessage(
                             "Cancelling ongoing replication {} from old primary with primary term {}",
                             ongoingReplicationTarget.description(),
@@ -233,7 +288,7 @@ public synchronized void onNewCheckpoint(final ReplicationCheckpoint receivedChe
                     );
                     ongoingReplicationTarget.cancel("Cancelling stuck target after new primary");
                 } else {
-                    logger.trace(
+                    logger.debug(
                         () -> new ParameterizedMessage(
                             "Ignoring new replication checkpoint - shard is currently replicating to checkpoint {}",
                             ongoingReplicationTarget.getCheckpoint()
@@ -247,7 +302,7 @@ public synchronized void onNewCheckpoint(final ReplicationCheckpoint receivedChe
                 startReplication(replicaShard, receivedCheckpoint, new SegmentReplicationListener() {
                     @Override
                     public void onReplicationDone(SegmentReplicationState state) {
-                        logger.trace(
+                        logger.debug(
                             () -> new ParameterizedMessage(
                                 "[shardId {}] [replication id {}] Replication complete to {}, timing data: {}",
                                 replicaShard.shardId().getId(),
@@ -279,6 +334,12 @@ public void onReplicationFailure(
                         }
                     }
                 });
+            } else if (replicaShard.isSegmentReplicationAllowed()) {
+                // if we didn't process the checkpoint because we are up to date,
+                // send our latest checkpoint to the primary to update tracking.
+                // replicationId is not used by the primary set to a default value.
+                final long replicationId = NO_OPS_PERFORMED;
+                updateVisibleCheckpoint(replicationId, replicaShard);
             }
         } else {
             logger.trace(
@@ -385,7 +446,7 @@ private DiscoveryNode getPrimaryNode(ShardRouting primaryShard) {
     // visible to tests
     protected boolean processLatestReceivedCheckpoint(IndexShard replicaShard, Thread thread) {
         final ReplicationCheckpoint latestPublishedCheckpoint = latestReceivedCheckpoint.get(replicaShard.shardId());
-        if (latestPublishedCheckpoint != null && latestPublishedCheckpoint.isAheadOf(replicaShard.getLatestReplicationCheckpoint())) {
+        if (latestPublishedCheckpoint != null) {
             logger.trace(
                 () -> new ParameterizedMessage(
                     "Processing latest received checkpoint for shard {} {}",
@@ -512,16 +573,17 @@ private void start(final long replicationId) {
         target.startReplication(new ActionListener<>() {
             @Override
             public void onResponse(Void o) {
-                logger.trace(() -> new ParameterizedMessage("Finished replicating {} marking as done.", target.description()));
+                logger.debug(() -> new ParameterizedMessage("Finished replicating {} marking as done.", target.description()));
                 onGoingReplications.markAsDone(replicationId);
                 if (target.state().getIndex().recoveredFileCount() != 0 && target.state().getIndex().recoveredBytes() != 0) {
-                    completedReplications.put(target.shardId(), target);
+                    completedReplications.put(target.shardId(), target.state());
                 }
             }
 
             @Override
             public void onFailure(Exception e) {
-                if (e instanceof OpenSearchCorruptionException) {
+                logger.debug("Replication failed {}", target.description());
+                if (isStoreCorrupt(target) || e instanceof CorruptIndexException || e instanceof OpenSearchCorruptionException) {
                     onGoingReplications.fail(replicationId, new ReplicationFailedException("Store corruption during replication", e), true);
                     return;
                 }
@@ -530,6 +592,27 @@ public void onFailure(Exception e) {
         });
     }
 
+    private boolean isStoreCorrupt(SegmentReplicationTarget target) {
+        // ensure target is not already closed. In that case
+        // we can assume the store is not corrupt and that the replication
+        // event completed successfully.
+        if (target.refCount() > 0) {
+            final Store store = target.store();
+            if (store.tryIncRef()) {
+                try {
+                    return store.isMarkedCorrupted();
+                } catch (IOException ex) {
+                    logger.warn("Unable to determine if store is corrupt", ex);
+                    return false;
+                } finally {
+                    store.decRef();
+                }
+            }
+        }
+        // store already closed.
+        return false;
+    }
+
     private class FileChunkTransportRequestHandler implements TransportRequestHandler<FileChunkRequest> {
 
         // How many bytes we've copied since we last called RateLimiter.pause
diff --git a/server/src/main/java/org/opensearch/indices/replication/checkpoint/PublishCheckpointAction.java b/server/src/main/java/org/opensearch/indices/replication/checkpoint/PublishCheckpointAction.java
index 76f0d333db977..821ae42e31881 100644
--- a/server/src/main/java/org/opensearch/indices/replication/checkpoint/PublishCheckpointAction.java
+++ b/server/src/main/java/org/opensearch/indices/replication/checkpoint/PublishCheckpointAction.java
@@ -20,6 +20,7 @@
 import org.opensearch.action.support.replication.TransportReplicationAction;
 import org.opensearch.cluster.action.shard.ShardStateAction;
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.ThreadContext;
@@ -45,9 +46,9 @@
 /**
  * Replication action responsible for publishing checkpoint to a replica shard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
-
+@PublicApi(since = "2.2.0")
 public class PublishCheckpointAction extends TransportReplicationAction<
     PublishCheckpointRequest,
     PublishCheckpointRequest,
@@ -137,7 +138,7 @@ public String executor() {
                     @Override
                     public void handleResponse(ReplicationResponse response) {
                         timer.stop();
-                        logger.trace(
+                        logger.debug(
                             () -> new ParameterizedMessage(
                                 "[shardId {}] Completed publishing checkpoint [{}], timing: {}",
                                 indexShard.shardId().getId(),
@@ -152,7 +153,7 @@ public void handleResponse(ReplicationResponse response) {
                     @Override
                     public void handleException(TransportException e) {
                         timer.stop();
-                        logger.trace("[shardId {}] Failed to publish checkpoint, timing: {}", indexShard.shardId().getId(), timer.time());
+                        logger.debug("[shardId {}] Failed to publish checkpoint, timing: {}", indexShard.shardId().getId(), timer.time());
                         task.setPhase("finished");
                         taskManager.unregister(task);
                         if (ExceptionsHelper.unwrap(
diff --git a/server/src/main/java/org/opensearch/indices/replication/checkpoint/ReplicationCheckpoint.java b/server/src/main/java/org/opensearch/indices/replication/checkpoint/ReplicationCheckpoint.java
index 521522803c726..29410159a4955 100644
--- a/server/src/main/java/org/opensearch/indices/replication/checkpoint/ReplicationCheckpoint.java
+++ b/server/src/main/java/org/opensearch/indices/replication/checkpoint/ReplicationCheckpoint.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -25,8 +26,9 @@
 /**
  * Represents a Replication Checkpoint which is sent to a replica shard.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public class ReplicationCheckpoint implements Writeable, Comparable<ReplicationCheckpoint> {
 
     private final ShardId shardId;
diff --git a/server/src/main/java/org/opensearch/indices/replication/checkpoint/SegmentReplicationCheckpointPublisher.java b/server/src/main/java/org/opensearch/indices/replication/checkpoint/SegmentReplicationCheckpointPublisher.java
index b4bcdc92e539a..a35d6fd103dc0 100644
--- a/server/src/main/java/org/opensearch/indices/replication/checkpoint/SegmentReplicationCheckpointPublisher.java
+++ b/server/src/main/java/org/opensearch/indices/replication/checkpoint/SegmentReplicationCheckpointPublisher.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.indices.replication.checkpoint;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.index.shard.IndexShard;
 
@@ -16,8 +17,9 @@
 /**
  * Publish Segment Replication Checkpoint.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public class SegmentReplicationCheckpointPublisher {
 
     private final PublishAction publishAction;
@@ -39,7 +41,10 @@ public void publish(IndexShard indexShard, ReplicationCheckpoint checkpoint) {
 
     /**
      * Represents an action that is invoked to publish segment replication checkpoint to replica shard
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "2.2.0")
     public interface PublishAction {
         void publish(IndexShard indexShard, ReplicationCheckpoint checkpoint);
     }
diff --git a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationFailedException.java b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationFailedException.java
index 47c327baba303..a039f9b860153 100644
--- a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationFailedException.java
+++ b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationFailedException.java
@@ -10,6 +10,7 @@
 
 import org.opensearch.OpenSearchException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.shard.IndexShard;
@@ -19,8 +20,9 @@
 /**
  * Exception thrown if replication fails
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public class ReplicationFailedException extends OpenSearchException {
 
     public ReplicationFailedException(IndexShard shard, Throwable cause) {
diff --git a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationLuceneIndex.java b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationLuceneIndex.java
index 5793356678715..cc52d2bafc614 100644
--- a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationLuceneIndex.java
+++ b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationLuceneIndex.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.indices.replication.common;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -32,8 +33,9 @@
  * Represents the Lucene Index (set of files on a single shard) involved
  * in the replication process.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ReplicationLuceneIndex extends ReplicationTimer implements ToXContentFragment, Writeable {
     private final FilesDetails filesDetails;
 
@@ -393,8 +395,9 @@ public boolean isComplete() {
     /**
      * Metadata about a file
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class FileMetadata implements ToXContentObject, Writeable {
         private String name;
         private long length;
diff --git a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationRequestTracker.java b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationRequestTracker.java
index 39649727e31d7..3775be7b6da15 100644
--- a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationRequestTracker.java
+++ b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationRequestTracker.java
@@ -58,8 +58,7 @@ public class ReplicationRequestTracker {
      * This method will mark that a request with a unique sequence number has been received. If this is the
      * first time the unique request has been received, this method will return a listener to be completed.
      * The caller should then perform the requested action and complete the returned listener.
-     *
-     *
+     * <p>
      * If the unique request has already been received, this method will either complete the provided listener
      * or attach that listener to the listener returned in the first call. In this case, the method will
      * return null and the caller should not perform the requested action as a prior caller is already
diff --git a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationState.java b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationState.java
index 029fcb6a3b690..e783e72a3c5c3 100644
--- a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationState.java
+++ b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationState.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.indices.replication.common;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Represents a state object used to track copying of segments from an external source
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.2.0")
 public interface ReplicationState {
     ReplicationLuceneIndex getIndex();
 
diff --git a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTarget.java b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTarget.java
index ec6b4d06b32c3..aac59df4f6573 100644
--- a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTarget.java
+++ b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTarget.java
@@ -91,6 +91,9 @@ public ReplicationTarget(String name, IndexShard indexShard, ReplicationLuceneIn
         // make sure the store is not released until we are done.
         this.cancellableThreads = new CancellableThreads();
         store.incRef();
+        if (indexShard.indexSettings().isRemoteStoreEnabled()) {
+            indexShard.remoteStore().incRef();
+        }
     }
 
     public long getId() {
@@ -278,6 +281,12 @@ public abstract void writeFileChunk(
     );
 
     protected void closeInternal() {
-        store.decRef();
+        try {
+            store.decRef();
+        } finally {
+            if (indexShard.indexSettings().isRemoteStoreEnabled()) {
+                indexShard.remoteStore().decRef();
+            }
+        }
     }
 }
diff --git a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTimer.java b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTimer.java
index aeb9ef29f4a52..d884e1676f2be 100644
--- a/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTimer.java
+++ b/server/src/main/java/org/opensearch/indices/replication/common/ReplicationTimer.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.indices.replication.common;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -19,8 +20,9 @@
  * A serializable timer that is used to measure the time taken for
  * file replication operations like recovery.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ReplicationTimer implements Writeable {
     private long startTime = 0;
     private long startNanoTime = 0;
diff --git a/server/src/main/java/org/opensearch/ingest/ConfigurationUtils.java b/server/src/main/java/org/opensearch/ingest/ConfigurationUtils.java
index f97388a8262ff..5185b740d90cb 100644
--- a/server/src/main/java/org/opensearch/ingest/ConfigurationUtils.java
+++ b/server/src/main/java/org/opensearch/ingest/ConfigurationUtils.java
@@ -74,7 +74,7 @@ private ConfigurationUtils() {}
 
     /**
      * Returns and removes the specified optional property from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type string a {@link OpenSearchParseException} is thrown.
      */
     public static String readOptionalStringProperty(
@@ -89,7 +89,7 @@ public static String readOptionalStringProperty(
 
     /**
      * Returns and removes the specified property from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type string an {@link OpenSearchParseException} is thrown.
      * If the property is missing an {@link OpenSearchParseException} is thrown
      */
@@ -104,7 +104,7 @@ public static String readStringProperty(
 
     /**
      * Returns and removes the specified property from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type string a {@link OpenSearchParseException} is thrown.
      * If the property is missing and no default value has been specified a {@link OpenSearchParseException} is thrown
      */
@@ -141,7 +141,7 @@ private static String readString(String processorType, String processorTag, Stri
 
     /**
      * Returns and removes the specified property from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type string or int a {@link OpenSearchParseException} is thrown.
      * If the property is missing and no default value has been specified a {@link OpenSearchParseException} is thrown
      */
@@ -180,7 +180,7 @@ private static String readStringOrInt(String processorType, String processorTag,
 
     /**
      * Returns and removes the specified property from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type string or int a {@link OpenSearchParseException} is thrown.
      */
     public static String readOptionalStringOrIntProperty(
@@ -228,7 +228,7 @@ private static Boolean readBoolean(String processorType, String processorTag, St
 
     /**
      * Returns and removes the specified property from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type int a {@link OpenSearchParseException} is thrown.
      * If the property is missing an {@link OpenSearchParseException} is thrown
      */
@@ -257,7 +257,7 @@ public static Integer readIntProperty(
 
     /**
      * Returns and removes the specified property from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type int a {@link OpenSearchParseException} is thrown.
      * If the property is missing an {@link OpenSearchParseException} is thrown
      */
@@ -285,7 +285,7 @@ public static Double readDoubleProperty(
 
     /**
      * Returns and removes the specified property of type list from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type list an {@link OpenSearchParseException} is thrown.
      */
     public static <T> List<T> readOptionalList(
@@ -303,7 +303,7 @@ public static <T> List<T> readOptionalList(
 
     /**
      * Returns and removes the specified property of type list from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type list an {@link OpenSearchParseException} is thrown.
      * If the property is missing an {@link OpenSearchParseException} is thrown
      */
@@ -333,7 +333,7 @@ private static <T> List<T> readList(String processorType, String processorTag, S
 
     /**
      * Returns and removes the specified property of type map from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type map an {@link OpenSearchParseException} is thrown.
      * If the property is missing an {@link OpenSearchParseException} is thrown
      */
@@ -353,7 +353,7 @@ public static <T> Map<String, T> readMap(
 
     /**
      * Returns and removes the specified property of type map from the specified configuration map.
-     *
+     * <p>
      * If the property value isn't of type map an {@link OpenSearchParseException} is thrown.
      */
     public static <T> Map<String, T> readOptionalMap(
diff --git a/server/src/main/java/org/opensearch/ingest/IngestService.java b/server/src/main/java/org/opensearch/ingest/IngestService.java
index 91003e963e302..2d4439e86461b 100644
--- a/server/src/main/java/org/opensearch/ingest/IngestService.java
+++ b/server/src/main/java/org/opensearch/ingest/IngestService.java
@@ -72,6 +72,7 @@
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.VersionType;
 import org.opensearch.index.analysis.AnalysisRegistry;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.plugins.IngestPlugin;
 import org.opensearch.script.ScriptService;
 import org.opensearch.threadpool.ThreadPool;
@@ -128,7 +129,8 @@ public IngestService(
         ScriptService scriptService,
         AnalysisRegistry analysisRegistry,
         List<IngestPlugin> ingestPlugins,
-        Client client
+        Client client,
+        IndicesService indicesService
     ) {
         this.clusterService = clusterService;
         this.scriptService = scriptService;
@@ -143,7 +145,8 @@ public IngestService(
                 (delay, command) -> threadPool.schedule(command, TimeValue.timeValueMillis(delay), ThreadPool.Names.GENERIC),
                 this,
                 client,
-                threadPool.generic()::execute
+                threadPool.generic()::execute,
+                indicesService
             )
         );
         this.threadPool = threadPool;
@@ -695,7 +698,7 @@ public IngestStats stats() {
     /**
      * Adds a listener that gets invoked with the current cluster state before processor factories
      * get invoked.
-     *
+     * <p>
      * This is useful for components that are used by ingest processors, so that they have the opportunity to update
      * before these components get used by the ingest processor factory.
      */
diff --git a/server/src/main/java/org/opensearch/ingest/Pipeline.java b/server/src/main/java/org/opensearch/ingest/Pipeline.java
index 37643e48ed2be..2541cfbf4af77 100644
--- a/server/src/main/java/org/opensearch/ingest/Pipeline.java
+++ b/server/src/main/java/org/opensearch/ingest/Pipeline.java
@@ -123,8 +123,8 @@ public static Pipeline create(
 
     /**
      * Modifies the data of a document to be indexed based on the processor this pipeline holds
-     *
-     * If <code>null</code> is returned then this document will be dropped and not indexed, otherwise
+     * <p>
+     * If {@code null} is returned then this document will be dropped and not indexed, otherwise
      * this document will be kept and indexed.
      */
     public void execute(IngestDocument ingestDocument, BiConsumer<IngestDocument, Exception> handler) {
diff --git a/server/src/main/java/org/opensearch/ingest/PipelineConfiguration.java b/server/src/main/java/org/opensearch/ingest/PipelineConfiguration.java
index d59d9d6da5717..477be3e74f1c7 100644
--- a/server/src/main/java/org/opensearch/ingest/PipelineConfiguration.java
+++ b/server/src/main/java/org/opensearch/ingest/PipelineConfiguration.java
@@ -35,6 +35,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.Diff;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.ParseField;
@@ -56,8 +57,9 @@
 /**
  * Encapsulates a pipeline's id and configuration as a blob
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class PipelineConfiguration extends AbstractDiffable<PipelineConfiguration> implements ToXContentObject {
 
     private static final ObjectParser<Builder, Void> PARSER = new ObjectParser<>("pipeline_config", true, Builder::new);
diff --git a/server/src/main/java/org/opensearch/ingest/Processor.java b/server/src/main/java/org/opensearch/ingest/Processor.java
index e0f196dfcb115..ecae1c139ea5e 100644
--- a/server/src/main/java/org/opensearch/ingest/Processor.java
+++ b/server/src/main/java/org/opensearch/ingest/Processor.java
@@ -36,6 +36,7 @@
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.env.Environment;
 import org.opensearch.index.analysis.AnalysisRegistry;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.script.ScriptService;
 import org.opensearch.threadpool.Scheduler;
 
@@ -48,7 +49,7 @@
 /**
  * A processor implementation may modify the data belonging to a document.
  * Whether changes are made and what exactly is modified is up to the implementation.
- *
+ * <p>
  * Processors may get called concurrently and thus need to be thread-safe.
  *
  * @opensearch.internal
@@ -57,7 +58,7 @@ public interface Processor {
 
     /**
      * Introspect and potentially modify the incoming data.
-     *
+     * <p>
      * Expert method: only override this method if a processor implementation needs to make an asynchronous call,
      * otherwise just overwrite {@link #execute(IngestDocument)}.
      */
@@ -156,6 +157,8 @@ class Parameters {
          */
         public final Client client;
 
+        public final IndicesService indicesService;
+
         public Parameters(
             Environment env,
             ScriptService scriptService,
@@ -165,7 +168,8 @@ public Parameters(
             BiFunction<Long, Runnable, Scheduler.ScheduledCancellable> scheduler,
             IngestService ingestService,
             Client client,
-            Consumer<Runnable> genericExecutor
+            Consumer<Runnable> genericExecutor,
+            IndicesService indicesService
         ) {
             this.env = env;
             this.scriptService = scriptService;
@@ -176,6 +180,7 @@ public Parameters(
             this.ingestService = ingestService;
             this.client = client;
             this.genericExecutor = genericExecutor;
+            this.indicesService = indicesService;
         }
 
     }
diff --git a/server/src/main/java/org/opensearch/ingest/ValueSource.java b/server/src/main/java/org/opensearch/ingest/ValueSource.java
index 0ef7c3373596d..3463fb0f83b26 100644
--- a/server/src/main/java/org/opensearch/ingest/ValueSource.java
+++ b/server/src/main/java/org/opensearch/ingest/ValueSource.java
@@ -56,7 +56,7 @@ public interface ValueSource {
 
     /**
      * Returns a copy of the value this ValueSource holds and resolves templates if there're any.
-     *
+     * <p>
      * For immutable values only a copy of the reference to the value is made.
      *
      * @param model The model to be used when resolving any templates
diff --git a/server/src/main/java/org/opensearch/monitor/fs/FsInfo.java b/server/src/main/java/org/opensearch/monitor/fs/FsInfo.java
index 114702ff0d351..fc1bb86f2ad3e 100644
--- a/server/src/main/java/org/opensearch/monitor/fs/FsInfo.java
+++ b/server/src/main/java/org/opensearch/monitor/fs/FsInfo.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -51,15 +52,17 @@
 /**
  * FileSystem information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FsInfo implements Iterable<FsInfo.Path>, Writeable, ToXContentFragment {
 
     /**
      * Path for the file system
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Path implements Writeable, ToXContentObject {
 
         String path;
@@ -220,8 +223,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * The device status.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class DeviceStats implements Writeable, ToXContentFragment {
 
         final int majorDeviceNumber;
@@ -235,6 +239,14 @@ public static class DeviceStats implements Writeable, ToXContentFragment {
         final long previousWritesCompleted;
         final long currentSectorsWritten;
         final long previousSectorsWritten;
+        final long currentReadTime;
+        final long previousReadTime;
+        final long currentWriteTime;
+        final long previousWriteTime;
+        final long currentQueueSize;
+        final long previousQueueSize;
+        final long currentIOTime;
+        final long previousIOTime;
 
         public DeviceStats(
             final int majorDeviceNumber,
@@ -244,6 +256,10 @@ public DeviceStats(
             final long currentSectorsRead,
             final long currentWritesCompleted,
             final long currentSectorsWritten,
+            final long currentReadTime,
+            final long currentWriteTime,
+            final long currrentQueueSize,
+            final long currentIOTime,
             final DeviceStats previousDeviceStats
         ) {
             this(
@@ -257,7 +273,15 @@ public DeviceStats(
                 currentSectorsRead,
                 previousDeviceStats != null ? previousDeviceStats.currentSectorsRead : -1,
                 currentWritesCompleted,
-                previousDeviceStats != null ? previousDeviceStats.currentWritesCompleted : -1
+                previousDeviceStats != null ? previousDeviceStats.currentWritesCompleted : -1,
+                currentReadTime,
+                previousDeviceStats != null ? previousDeviceStats.currentReadTime : -1,
+                currentWriteTime,
+                previousDeviceStats != null ? previousDeviceStats.currentWriteTime : -1,
+                currrentQueueSize,
+                previousDeviceStats != null ? previousDeviceStats.currentQueueSize : -1,
+                currentIOTime,
+                previousDeviceStats != null ? previousDeviceStats.currentIOTime : -1
             );
         }
 
@@ -272,7 +296,15 @@ private DeviceStats(
             final long currentSectorsRead,
             final long previousSectorsRead,
             final long currentWritesCompleted,
-            final long previousWritesCompleted
+            final long previousWritesCompleted,
+            final long currentReadTime,
+            final long previousReadTime,
+            final long currentWriteTime,
+            final long previousWriteTime,
+            final long currentQueueSize,
+            final long previousQueueSize,
+            final long currentIOTime,
+            final long previousIOTime
         ) {
             this.majorDeviceNumber = majorDeviceNumber;
             this.minorDeviceNumber = minorDeviceNumber;
@@ -285,6 +317,14 @@ private DeviceStats(
             this.previousSectorsRead = previousSectorsRead;
             this.currentSectorsWritten = currentSectorsWritten;
             this.previousSectorsWritten = previousSectorsWritten;
+            this.currentReadTime = currentReadTime;
+            this.previousReadTime = previousReadTime;
+            this.currentWriteTime = currentWriteTime;
+            this.previousWriteTime = previousWriteTime;
+            this.currentQueueSize = currentQueueSize;
+            this.previousQueueSize = previousQueueSize;
+            this.currentIOTime = currentIOTime;
+            this.previousIOTime = previousIOTime;
         }
 
         public DeviceStats(StreamInput in) throws IOException {
@@ -299,6 +339,25 @@ public DeviceStats(StreamInput in) throws IOException {
             previousSectorsRead = in.readLong();
             currentSectorsWritten = in.readLong();
             previousSectorsWritten = in.readLong();
+            if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+                currentReadTime = in.readLong();
+                previousReadTime = in.readLong();
+                currentWriteTime = in.readLong();
+                previousWriteTime = in.readLong();
+                currentQueueSize = in.readLong();
+                previousQueueSize = in.readLong();
+                currentIOTime = in.readLong();
+                previousIOTime = in.readLong();
+            } else {
+                currentReadTime = 0;
+                previousReadTime = 0;
+                currentWriteTime = 0;
+                previousWriteTime = 0;
+                currentQueueSize = 0;
+                previousQueueSize = 0;
+                currentIOTime = 0;
+                previousIOTime = 0;
+            }
         }
 
         @Override
@@ -314,6 +373,16 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeLong(previousSectorsRead);
             out.writeLong(currentSectorsWritten);
             out.writeLong(previousSectorsWritten);
+            if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+                out.writeLong(currentReadTime);
+                out.writeLong(previousReadTime);
+                out.writeLong(currentWriteTime);
+                out.writeLong(previousWriteTime);
+                out.writeLong(currentQueueSize);
+                out.writeLong(previousQueueSize);
+                out.writeLong(currentIOTime);
+                out.writeLong(previousIOTime);
+            }
         }
 
         public long operations() {
@@ -346,6 +415,39 @@ public long writeKilobytes() {
             return (currentSectorsWritten - previousSectorsWritten) / 2;
         }
 
+        /**
+         * Total time taken for all read operations
+         */
+        public long readTime() {
+            if (previousReadTime == -1) return -1;
+            return currentReadTime - previousReadTime;
+        }
+
+        /**
+         * Total time taken for all write operations
+         */
+        public long writeTime() {
+            if (previousWriteTime == -1) return -1;
+            return currentWriteTime - previousWriteTime;
+        }
+
+        /**
+         * Queue size based on weighted time spent doing I/Os
+         */
+        public long queueSize() {
+            if (previousQueueSize == -1) return -1;
+            return currentQueueSize - previousQueueSize;
+        }
+
+        /**
+         * Total time spent doing I/Os
+         */
+        public long ioTimeInMillis() {
+            if (previousIOTime == -1) return -1;
+
+            return (currentIOTime - previousIOTime);
+        }
+
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
             builder.field("device_name", deviceName);
@@ -354,16 +456,20 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.field(IoStats.WRITE_OPERATIONS, writeOperations());
             builder.field(IoStats.READ_KILOBYTES, readKilobytes());
             builder.field(IoStats.WRITE_KILOBYTES, writeKilobytes());
+            builder.field(IoStats.READ_TIME, readTime());
+            builder.field(IoStats.WRITE_TIME, writeTime());
+            builder.field(IoStats.QUEUE_SIZE, queueSize());
+            builder.field(IoStats.IO_TIME_MS, ioTimeInMillis());
             return builder;
         }
-
     }
 
     /**
      * The I/O statistics.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class IoStats implements Writeable, ToXContentFragment {
 
         private static final String OPERATIONS = "operations";
@@ -371,6 +477,10 @@ public static class IoStats implements Writeable, ToXContentFragment {
         private static final String WRITE_OPERATIONS = "write_operations";
         private static final String READ_KILOBYTES = "read_kilobytes";
         private static final String WRITE_KILOBYTES = "write_kilobytes";
+        private static final String READ_TIME = "read_time";
+        private static final String WRITE_TIME = "write_time";
+        private static final String QUEUE_SIZE = "queue_size";
+        private static final String IO_TIME_MS = "io_time_in_millis";
 
         final DeviceStats[] devicesStats;
         final long totalOperations;
@@ -378,6 +488,10 @@ public static class IoStats implements Writeable, ToXContentFragment {
         final long totalWriteOperations;
         final long totalReadKilobytes;
         final long totalWriteKilobytes;
+        final long totalReadTime;
+        final long totalWriteTime;
+        final long totalQueueSize;
+        final long totalIOTimeInMillis;
 
         public IoStats(final DeviceStats[] devicesStats) {
             this.devicesStats = devicesStats;
@@ -386,18 +500,30 @@ public IoStats(final DeviceStats[] devicesStats) {
             long totalWriteOperations = 0;
             long totalReadKilobytes = 0;
             long totalWriteKilobytes = 0;
+            long totalReadTime = 0;
+            long totalWriteTime = 0;
+            long totalQueueSize = 0;
+            long totalIOTimeInMillis = 0;
             for (DeviceStats deviceStats : devicesStats) {
                 totalOperations += deviceStats.operations() != -1 ? deviceStats.operations() : 0;
                 totalReadOperations += deviceStats.readOperations() != -1 ? deviceStats.readOperations() : 0;
                 totalWriteOperations += deviceStats.writeOperations() != -1 ? deviceStats.writeOperations() : 0;
                 totalReadKilobytes += deviceStats.readKilobytes() != -1 ? deviceStats.readKilobytes() : 0;
                 totalWriteKilobytes += deviceStats.writeKilobytes() != -1 ? deviceStats.writeKilobytes() : 0;
+                totalReadTime += deviceStats.readTime() != -1 ? deviceStats.readTime() : 0;
+                totalWriteTime += deviceStats.writeTime() != -1 ? deviceStats.writeTime() : 0;
+                totalQueueSize += deviceStats.queueSize() != -1 ? deviceStats.queueSize() : 0;
+                totalIOTimeInMillis += deviceStats.ioTimeInMillis() != -1 ? deviceStats.ioTimeInMillis() : 0;
             }
             this.totalOperations = totalOperations;
             this.totalReadOperations = totalReadOperations;
             this.totalWriteOperations = totalWriteOperations;
             this.totalReadKilobytes = totalReadKilobytes;
             this.totalWriteKilobytes = totalWriteKilobytes;
+            this.totalReadTime = totalReadTime;
+            this.totalWriteTime = totalWriteTime;
+            this.totalQueueSize = totalQueueSize;
+            this.totalIOTimeInMillis = totalIOTimeInMillis;
         }
 
         public IoStats(StreamInput in) throws IOException {
@@ -412,6 +538,17 @@ public IoStats(StreamInput in) throws IOException {
             this.totalWriteOperations = in.readLong();
             this.totalReadKilobytes = in.readLong();
             this.totalWriteKilobytes = in.readLong();
+            if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+                this.totalReadTime = in.readLong();
+                this.totalWriteTime = in.readLong();
+                this.totalQueueSize = in.readLong();
+                this.totalIOTimeInMillis = in.readLong();
+            } else {
+                this.totalReadTime = 0;
+                this.totalWriteTime = 0;
+                this.totalQueueSize = 0;
+                this.totalIOTimeInMillis = 0;
+            }
         }
 
         @Override
@@ -425,6 +562,12 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeLong(totalWriteOperations);
             out.writeLong(totalReadKilobytes);
             out.writeLong(totalWriteKilobytes);
+            if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+                out.writeLong(totalReadTime);
+                out.writeLong(totalWriteTime);
+                out.writeLong(totalQueueSize);
+                out.writeLong(totalIOTimeInMillis);
+            }
         }
 
         public DeviceStats[] getDevicesStats() {
@@ -451,6 +594,34 @@ public long getTotalWriteKilobytes() {
             return totalWriteKilobytes;
         }
 
+        /**
+         * Sum of read time across all devices
+         */
+        public long getTotalReadTime() {
+            return totalReadTime;
+        }
+
+        /**
+         * Sum of write time across all devices
+         */
+        public long getTotalWriteTime() {
+            return totalWriteTime;
+        }
+
+        /**
+         * Sum of queue size across all devices
+         */
+        public long getTotalQueueSize() {
+            return totalQueueSize;
+        }
+
+        /**
+         * Sum of IO time across all devices
+         */
+        public long getTotalIOTimeMillis() {
+            return totalIOTimeInMillis;
+        }
+
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
             if (devicesStats.length > 0) {
@@ -468,11 +639,15 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
                 builder.field(WRITE_OPERATIONS, totalWriteOperations);
                 builder.field(READ_KILOBYTES, totalReadKilobytes);
                 builder.field(WRITE_KILOBYTES, totalWriteKilobytes);
+
+                builder.field(READ_TIME, totalReadTime);
+                builder.field(WRITE_TIME, totalWriteTime);
+                builder.field(QUEUE_SIZE, totalQueueSize);
+                builder.field(IO_TIME_MS, totalIOTimeInMillis);
                 builder.endObject();
             }
             return builder;
         }
-
     }
 
     private final long timestamp;
diff --git a/server/src/main/java/org/opensearch/monitor/fs/FsProbe.java b/server/src/main/java/org/opensearch/monitor/fs/FsProbe.java
index e20d84cd9763e..f4731a4a34373 100644
--- a/server/src/main/java/org/opensearch/monitor/fs/FsProbe.java
+++ b/server/src/main/java/org/opensearch/monitor/fs/FsProbe.java
@@ -109,6 +109,25 @@ final FsInfo.IoStats ioStats(final Set<Tuple<Integer, Integer>> devicesNumbers,
 
             List<FsInfo.DeviceStats> devicesStats = new ArrayList<>();
 
+            /**
+             * The /proc/diskstats file displays the I/O statistics of block devices.
+             * Each line contains the following 14 fields: ( + additional fields )
+            *
+            * 1  major number
+            * 2  minor number
+            * 3  device name
+            * 4  reads completed successfully
+            * 5  reads merged
+            * 6  sectors read
+            * 7  time spent reading (ms)
+            * 8  writes completed
+            * 9  writes merged
+            * 10  sectors written
+            * 11  time spent writing (ms)
+            * 12  I/Os currently in progress
+            * 13  time spent doing I/Os (ms) ---- IO use percent
+            * 14  weighted time spent doing I/Os (ms) ---- Queue size
+             */
             List<String> lines = readProcDiskStats();
             if (!lines.isEmpty()) {
                 for (String line : lines) {
@@ -123,6 +142,12 @@ final FsInfo.IoStats ioStats(final Set<Tuple<Integer, Integer>> devicesNumbers,
                     final long sectorsRead = Long.parseLong(fields[5]);
                     final long writesCompleted = Long.parseLong(fields[7]);
                     final long sectorsWritten = Long.parseLong(fields[9]);
+                    // readTime and writeTime calculates the total read/write time taken for each request to complete
+                    // ioTime calculates actual time queue and disks are busy
+                    final long readTime = Long.parseLong(fields[6]);
+                    final long writeTime = Long.parseLong(fields[10]);
+                    final long ioTime = fields.length > 12 ? Long.parseLong(fields[12]) : 0;
+                    final long queueSize = fields.length > 13 ? Long.parseLong(fields[13]) : 0;
                     final FsInfo.DeviceStats deviceStats = new FsInfo.DeviceStats(
                         majorDeviceNumber,
                         minorDeviceNumber,
@@ -131,6 +156,10 @@ final FsInfo.IoStats ioStats(final Set<Tuple<Integer, Integer>> devicesNumbers,
                         sectorsRead,
                         writesCompleted,
                         sectorsWritten,
+                        readTime,
+                        writeTime,
+                        queueSize,
+                        ioTime,
                         deviceMap.get(Tuple.tuple(majorDeviceNumber, minorDeviceNumber))
                     );
                     devicesStats.add(deviceStats);
diff --git a/server/src/main/java/org/opensearch/monitor/os/OsProbe.java b/server/src/main/java/org/opensearch/monitor/os/OsProbe.java
index 98229941252ba..a0a14372aa31a 100644
--- a/server/src/main/java/org/opensearch/monitor/os/OsProbe.java
+++ b/server/src/main/java/org/opensearch/monitor/os/OsProbe.java
@@ -59,13 +59,13 @@
 /**
  * The {@link OsProbe} class retrieves information about the physical and swap size of the machine
  * memory, as well as the system load average and cpu load.
- *
+ * <p>
  * In some exceptional cases, it's possible the underlying native methods used by
  * {@link #getFreePhysicalMemorySize()}, {@link #getTotalPhysicalMemorySize()},
  * {@link #getFreeSwapSpaceSize()}, and {@link #getTotalSwapSpaceSize()} can return a
  * negative value. Because of this, we prevent those methods from returning negative values,
  * returning 0 instead.
- *
+ * <p>
  * The OS can report a negative number in a number of cases:
  * - Non-supported OSes (HP-UX, or AIX)
  * - A failure of macOS to initialize host statistics
@@ -183,11 +183,11 @@ public long getTotalSwapSpaceSize() {
 
     /**
      * The system load averages as an array.
-     *
+     * <p>
      * On Windows, this method returns {@code null}.
-     *
+     * <p>
      * On Linux, this method returns the 1, 5, and 15-minute load averages.
-     *
+     * <p>
      * On macOS, this method should return the 1-minute load average.
      *
      * @return the available system load averages or {@code null}
diff --git a/server/src/main/java/org/opensearch/monitor/os/OsStats.java b/server/src/main/java/org/opensearch/monitor/os/OsStats.java
index 697b86c6ba55c..cdcec733cb086 100644
--- a/server/src/main/java/org/opensearch/monitor/os/OsStats.java
+++ b/server/src/main/java/org/opensearch/monitor/os/OsStats.java
@@ -34,6 +34,7 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -48,8 +49,9 @@
 /**
  * Holds stats for the Operating System
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class OsStats implements Writeable, ToXContentFragment {
 
     private final long timestamp;
@@ -143,8 +145,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * CPU Information.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Cpu implements Writeable, ToXContentFragment {
 
         private final short percent;
@@ -208,8 +211,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Swap information.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Swap implements Writeable, ToXContentFragment {
 
         private static final Logger logger = LogManager.getLogger(Swap.class);
@@ -276,8 +280,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * OS Memory information.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Mem implements Writeable, ToXContentFragment {
 
         private static final Logger logger = LogManager.getLogger(Mem.class);
@@ -353,8 +358,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Encapsulates basic cgroup statistics.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Cgroup implements Writeable, ToXContentFragment {
 
         private final String cpuAcctControlGroup;
@@ -546,8 +552,9 @@ public XContentBuilder toXContent(final XContentBuilder builder, final Params pa
         /**
          * Encapsulates CPU time statistics.
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public static class CpuStat implements Writeable, ToXContentFragment {
 
             private final long numberOfElapsedPeriods;
diff --git a/server/src/main/java/org/opensearch/node/AdaptiveSelectionStats.java b/server/src/main/java/org/opensearch/node/AdaptiveSelectionStats.java
index 0241f5f6191d4..eea3e63830227 100644
--- a/server/src/main/java/org/opensearch/node/AdaptiveSelectionStats.java
+++ b/server/src/main/java/org/opensearch/node/AdaptiveSelectionStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.node;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -52,8 +53,9 @@
  * EWMA of queue size, service time, and response time, as well as outgoing
  * searches to each node and the "rank" based on the ARS formula.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AdaptiveSelectionStats implements Writeable, ToXContentFragment {
 
     private final Map<String, Long> clientOutgoingConnections;
diff --git a/server/src/main/java/org/opensearch/node/Node.java b/server/src/main/java/org/opensearch/node/Node.java
index 1f8f17f8e8d91..4cbf8dc191a9d 100644
--- a/server/src/main/java/org/opensearch/node/Node.java
+++ b/server/src/main/java/org/opensearch/node/Node.java
@@ -46,6 +46,8 @@
 import org.opensearch.action.admin.cluster.snapshots.status.TransportNodesSnapshotsStatus;
 import org.opensearch.action.search.SearchExecutionStatsCollector;
 import org.opensearch.action.search.SearchPhaseController;
+import org.opensearch.action.search.SearchRequestSlowLog;
+import org.opensearch.action.search.SearchRequestStats;
 import org.opensearch.action.search.SearchTransportService;
 import org.opensearch.action.support.TransportAction;
 import org.opensearch.action.update.UpdateHelper;
@@ -135,6 +137,7 @@
 import org.opensearch.index.IndexModule;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.IndexingPressureService;
+import org.opensearch.index.SegmentReplicationStatsTracker;
 import org.opensearch.index.analysis.AnalysisRegistry;
 import org.opensearch.index.engine.EngineFactory;
 import org.opensearch.index.recovery.RemoteStoreRestoreService;
@@ -166,6 +169,7 @@
 import org.opensearch.monitor.fs.FsProbe;
 import org.opensearch.monitor.jvm.JvmInfo;
 import org.opensearch.node.remotestore.RemoteStoreNodeService;
+import org.opensearch.node.resource.tracker.NodeResourceUsageTracker;
 import org.opensearch.persistent.PersistentTasksClusterService;
 import org.opensearch.persistent.PersistentTasksExecutor;
 import org.opensearch.persistent.PersistentTasksExecutorRegistry;
@@ -194,6 +198,8 @@
 import org.opensearch.plugins.SearchPlugin;
 import org.opensearch.plugins.SystemIndexPlugin;
 import org.opensearch.plugins.TelemetryPlugin;
+import org.opensearch.ratelimitting.admissioncontrol.AdmissionControlService;
+import org.opensearch.ratelimitting.admissioncontrol.transport.AdmissionControlTransportInterceptor;
 import org.opensearch.repositories.RepositoriesModule;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.rest.RestController;
@@ -223,6 +229,9 @@
 import org.opensearch.tasks.consumer.TopNSearchTasksLogger;
 import org.opensearch.telemetry.TelemetryModule;
 import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.MetricsRegistry;
+import org.opensearch.telemetry.metrics.MetricsRegistryFactory;
+import org.opensearch.telemetry.metrics.NoopMetricsRegistryFactory;
 import org.opensearch.telemetry.tracing.NoopTracerFactory;
 import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.telemetry.tracing.TracerFactory;
@@ -391,6 +400,8 @@ public static class DiscoverySettings {
     private final LocalNodeFactory localNodeFactory;
     private final NodeService nodeService;
     private final Tracer tracer;
+
+    private final MetricsRegistry metricsRegistry;
     final NamedWriteableRegistry namedWriteableRegistry;
     private final AtomicReference<RunnableTaskExecutionListener> runnableTaskListener;
     private FileCache fileCache;
@@ -494,7 +505,7 @@ protected Node(
                 for (ExtensionAwarePlugin extAwarePlugin : extensionAwarePlugins) {
                     additionalSettings.addAll(extAwarePlugin.getExtensionSettings());
                 }
-                this.extensionsManager = new ExtensionsManager(additionalSettings);
+                this.extensionsManager = new ExtensionsManager(additionalSettings, identityService);
             } else {
                 this.extensionsManager = new NoopExtensionsManager();
             }
@@ -590,26 +601,35 @@ protected Node(
             }
 
             TracerFactory tracerFactory;
+            MetricsRegistryFactory metricsRegistryFactory;
             if (FeatureFlags.isEnabled(TELEMETRY)) {
                 final TelemetrySettings telemetrySettings = new TelemetrySettings(settings, clusterService.getClusterSettings());
-                List<TelemetryPlugin> telemetryPlugins = pluginsService.filterPlugins(TelemetryPlugin.class);
-                TelemetryModule telemetryModule = new TelemetryModule(telemetryPlugins, telemetrySettings);
-                tracerFactory = new TracerFactory(telemetrySettings, telemetryModule.getTelemetry(), threadPool.getThreadContext());
+                if (telemetrySettings.isTracingFeatureEnabled() || telemetrySettings.isMetricsFeatureEnabled()) {
+                    List<TelemetryPlugin> telemetryPlugins = pluginsService.filterPlugins(TelemetryPlugin.class);
+                    TelemetryModule telemetryModule = new TelemetryModule(telemetryPlugins, telemetrySettings);
+                    if (telemetrySettings.isTracingFeatureEnabled()) {
+                        tracerFactory = new TracerFactory(telemetrySettings, telemetryModule.getTelemetry(), threadPool.getThreadContext());
+                    } else {
+                        tracerFactory = new NoopTracerFactory();
+                    }
+                    if (telemetrySettings.isMetricsFeatureEnabled()) {
+                        metricsRegistryFactory = new MetricsRegistryFactory(telemetrySettings, telemetryModule.getTelemetry());
+                    } else {
+                        metricsRegistryFactory = new NoopMetricsRegistryFactory();
+                    }
+                } else {
+                    tracerFactory = new NoopTracerFactory();
+                    metricsRegistryFactory = new NoopMetricsRegistryFactory();
+                }
             } else {
                 tracerFactory = new NoopTracerFactory();
+                metricsRegistryFactory = new NoopMetricsRegistryFactory();
             }
 
             tracer = tracerFactory.getTracer();
+            metricsRegistry = metricsRegistryFactory.getMetricsRegistry();
             resourcesToClose.add(tracer::close);
-            final IngestService ingestService = new IngestService(
-                clusterService,
-                threadPool,
-                this.environment,
-                scriptService,
-                analysisModule.getAnalysisRegistry(),
-                pluginsService.filterPlugins(IngestPlugin.class),
-                client
-            );
+            resourcesToClose.add(metricsRegistry::close);
 
             final ClusterInfoService clusterInfoService = newClusterInfoService(settings, clusterService, threadPool, client);
             final UsageService usageService = new UsageService();
@@ -756,11 +776,16 @@ protected Node(
             rerouteServiceReference.set(rerouteService);
             clusterService.setRerouteService(rerouteService);
 
+            final RecoverySettings recoverySettings = new RecoverySettings(settings, settingsModule.getClusterSettings());
+
             final IndexStorePlugin.DirectoryFactory remoteDirectoryFactory = new RemoteSegmentStoreDirectoryFactory(
                 repositoriesServiceReference::get,
                 threadPool
             );
 
+            final SearchRequestStats searchRequestStats = new SearchRequestStats();
+            final SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService);
+
             remoteStoreStatsTrackerFactory = new RemoteStoreStatsTrackerFactory(clusterService, settings);
             final IndicesService indicesService = new IndicesService(
                 settings,
@@ -786,7 +811,20 @@ protected Node(
                 remoteDirectoryFactory,
                 repositoriesServiceReference::get,
                 fileCacheCleaner,
-                remoteStoreStatsTrackerFactory
+                searchRequestStats,
+                remoteStoreStatsTrackerFactory,
+                recoverySettings
+            );
+
+            final IngestService ingestService = new IngestService(
+                clusterService,
+                threadPool,
+                this.environment,
+                scriptService,
+                analysisModule.getAnalysisRegistry(),
+                pluginsService.filterPlugins(IngestPlugin.class),
+                client,
+                indicesService
             );
 
             final AliasValidator aliasValidator = new AliasValidator();
@@ -860,6 +898,29 @@ protected Node(
 
             final RestController restController = actionModule.getRestController();
 
+            final NodeResourceUsageTracker nodeResourceUsageTracker = new NodeResourceUsageTracker(
+                threadPool,
+                settings,
+                clusterService.getClusterSettings()
+            );
+            final ResourceUsageCollectorService resourceUsageCollectorService = new ResourceUsageCollectorService(
+                nodeResourceUsageTracker,
+                clusterService,
+                threadPool
+            );
+
+            final AdmissionControlService admissionControlService = new AdmissionControlService(
+                settings,
+                clusterService,
+                threadPool,
+                resourceUsageCollectorService
+            );
+
+            AdmissionControlTransportInterceptor admissionControlTransportInterceptor = new AdmissionControlTransportInterceptor(
+                admissionControlService
+            );
+
+            List<TransportInterceptor> transportInterceptors = List.of(admissionControlTransportInterceptor);
             final NetworkModule networkModule = new NetworkModule(
                 settings,
                 pluginsService.filterPlugins(NetworkPlugin.class),
@@ -872,8 +933,10 @@ protected Node(
                 networkService,
                 restController,
                 clusterService.getClusterSettings(),
-                tracer
+                tracer,
+                transportInterceptors
             );
+
             Collection<UnaryOperator<Map<String, IndexTemplateMetadata>>> indexTemplateMetadataUpgraders = pluginsService.filterPlugins(
                 Plugin.class
             ).stream().map(Plugin::getIndexTemplateMetadataUpgrader).collect(Collectors.toList());
@@ -947,7 +1010,7 @@ protected Node(
                 transportService.getTaskManager()
             );
 
-            final RecoverySettings recoverySettings = new RecoverySettings(settings, settingsModule.getClusterSettings());
+            final SegmentReplicationStatsTracker segmentReplicationStatsTracker = new SegmentReplicationStatsTracker(indicesService);
             RepositoriesModule repositoriesModule = new RepositoriesModule(
                 this.environment,
                 pluginsService.filterPlugins(RepositoryPlugin.class),
@@ -1075,7 +1138,11 @@ protected Node(
                 searchBackpressureService,
                 searchPipelineService,
                 fileCache,
-                taskCancellationMonitoringService
+                taskCancellationMonitoringService,
+                resourceUsageCollectorService,
+                segmentReplicationStatsTracker,
+                repositoryService,
+                admissionControlService
             );
 
             final SearchService searchService = newSearchService(
@@ -1137,6 +1204,7 @@ protected Node(
                 b.bind(IndexingPressureService.class).toInstance(indexingPressureService);
                 b.bind(TaskResourceTrackingService.class).toInstance(taskResourceTrackingService);
                 b.bind(SearchBackpressureService.class).toInstance(searchBackpressureService);
+                b.bind(AdmissionControlService.class).toInstance(admissionControlService);
                 b.bind(UsageService.class).toInstance(usageService);
                 b.bind(AggregationUsageService.class).toInstance(searchModule.getValuesSourceRegistry().getUsageService());
                 b.bind(NamedWriteableRegistry.class).toInstance(namedWriteableRegistry);
@@ -1196,11 +1264,17 @@ protected Node(
                 b.bind(RerouteService.class).toInstance(rerouteService);
                 b.bind(ShardLimitValidator.class).toInstance(shardLimitValidator);
                 b.bind(FsHealthService.class).toInstance(fsHealthService);
+                b.bind(NodeResourceUsageTracker.class).toInstance(nodeResourceUsageTracker);
+                b.bind(ResourceUsageCollectorService.class).toInstance(resourceUsageCollectorService);
                 b.bind(SystemIndices.class).toInstance(systemIndices);
                 b.bind(IdentityService.class).toInstance(identityService);
                 b.bind(Tracer.class).toInstance(tracer);
+                b.bind(SearchRequestStats.class).toInstance(searchRequestStats);
+                b.bind(SearchRequestSlowLog.class).toInstance(searchRequestSlowLog);
+                b.bind(MetricsRegistry.class).toInstance(metricsRegistry);
                 b.bind(RemoteClusterStateService.class).toProvider(() -> remoteClusterStateService);
                 b.bind(PersistedStateRegistry.class).toInstance(persistedStateRegistry);
+                b.bind(SegmentReplicationStatsTracker.class).toInstance(segmentReplicationStatsTracker);
             });
             injector = modules.createInjector();
 
@@ -1310,6 +1384,8 @@ public Node start() throws NodeValidationException {
         injector.getInstance(RepositoriesService.class).start();
         injector.getInstance(SearchService.class).start();
         injector.getInstance(FsHealthService.class).start();
+        injector.getInstance(NodeResourceUsageTracker.class).start();
+        injector.getInstance(ResourceUsageCollectorService.class).start();
         nodeService.getMonitorService().start();
         nodeService.getSearchBackpressureService().start();
         nodeService.getTaskCancellationMonitoringService().start();
@@ -1338,6 +1414,7 @@ public Node start() throws NodeValidationException {
         assert transportService.getLocalNode().equals(localNodeFactory.getNode())
             : "transportService has a different local node than the factory provided";
         injector.getInstance(PeerRecoverySourceService.class).start();
+        injector.getInstance(SegmentReplicationTargetService.class).start();
         injector.getInstance(SegmentReplicationSourceService.class).start();
 
         final RemoteClusterStateService remoteClusterStateService = injector.getInstance(RemoteClusterStateService.class);
@@ -1472,6 +1549,8 @@ private Node stop() {
         injector.getInstance(ClusterService.class).stop();
         injector.getInstance(NodeConnectionsService.class).stop();
         injector.getInstance(FsHealthService.class).stop();
+        injector.getInstance(NodeResourceUsageTracker.class).stop();
+        injector.getInstance(ResourceUsageCollectorService.class).stop();
         nodeService.getMonitorService().stop();
         nodeService.getSearchBackpressureService().stop();
         injector.getInstance(GatewayService.class).stop();
@@ -1524,6 +1603,7 @@ public synchronized void close() throws IOException {
         toClose.add(injector.getInstance(IndicesStore.class));
         toClose.add(injector.getInstance(PeerRecoverySourceService.class));
         toClose.add(injector.getInstance(SegmentReplicationSourceService.class));
+        toClose.add(injector.getInstance(SegmentReplicationTargetService.class));
         toClose.add(() -> stopWatch.stop().start("cluster"));
         toClose.add(injector.getInstance(ClusterService.class));
         toClose.add(() -> stopWatch.stop().start("node_connections_service"));
@@ -1535,6 +1615,10 @@ public synchronized void close() throws IOException {
         toClose.add(nodeService.getSearchBackpressureService());
         toClose.add(() -> stopWatch.stop().start("fsHealth"));
         toClose.add(injector.getInstance(FsHealthService.class));
+        toClose.add(() -> stopWatch.stop().start("resource_usage_tracker"));
+        toClose.add(injector.getInstance(NodeResourceUsageTracker.class));
+        toClose.add(() -> stopWatch.stop().start("resource_usage_collector"));
+        toClose.add(injector.getInstance(ResourceUsageCollectorService.class));
         toClose.add(() -> stopWatch.stop().start("gateway"));
         toClose.add(injector.getInstance(GatewayService.class));
         toClose.add(() -> stopWatch.stop().start("search"));
@@ -1566,6 +1650,7 @@ public synchronized void close() throws IOException {
         toClose.add(stopWatch::stop);
         if (FeatureFlags.isEnabled(TELEMETRY)) {
             toClose.add(injector.getInstance(Tracer.class));
+            toClose.add(injector.getInstance(MetricsRegistry.class));
         }
 
         if (logger.isTraceEnabled()) {
@@ -1775,18 +1860,17 @@ private LocalNodeFactory(Settings settings, String persistentNodeId, RemoteStore
 
         @Override
         public DiscoveryNode apply(BoundTransportAddress boundTransportAddress) {
+            final DiscoveryNode discoveryNode = DiscoveryNode.createLocal(
+                settings,
+                boundTransportAddress.publishAddress(),
+                persistentNodeId
+            );
+
             if (isRemoteStoreAttributePresent(settings)) {
-                localNode.set(
-                    DiscoveryNode.createRemoteNodeLocal(
-                        settings,
-                        boundTransportAddress.publishAddress(),
-                        persistentNodeId,
-                        remoteStoreNodeService
-                    )
-                );
-            } else {
-                localNode.set(DiscoveryNode.createLocal(settings, boundTransportAddress.publishAddress(), persistentNodeId));
+                remoteStoreNodeService.createAndVerifyRepositories(discoveryNode);
             }
+
+            localNode.set(discoveryNode);
             return localNode.get();
         }
 
diff --git a/server/src/main/java/org/opensearch/node/NodeResourceUsageStats.java b/server/src/main/java/org/opensearch/node/NodeResourceUsageStats.java
new file mode 100644
index 0000000000000..6ef66d4ac1914
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/NodeResourceUsageStats.java
@@ -0,0 +1,81 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node;
+
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+
+import java.io.IOException;
+import java.util.Locale;
+
+/**
+ * This represents the resource usage stats of a node along with the timestamp at which the stats object was created
+ * in the respective node
+ */
+public class NodeResourceUsageStats implements Writeable {
+    final String nodeId;
+    long timestamp;
+    double cpuUtilizationPercent;
+    double memoryUtilizationPercent;
+
+    public NodeResourceUsageStats(String nodeId, long timestamp, double memoryUtilizationPercent, double cpuUtilizationPercent) {
+        this.nodeId = nodeId;
+        this.timestamp = timestamp;
+        this.cpuUtilizationPercent = cpuUtilizationPercent;
+        this.memoryUtilizationPercent = memoryUtilizationPercent;
+    }
+
+    public NodeResourceUsageStats(StreamInput in) throws IOException {
+        this.nodeId = in.readString();
+        this.timestamp = in.readLong();
+        this.cpuUtilizationPercent = in.readDouble();
+        this.memoryUtilizationPercent = in.readDouble();
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeString(this.nodeId);
+        out.writeLong(this.timestamp);
+        out.writeDouble(this.cpuUtilizationPercent);
+        out.writeDouble(this.memoryUtilizationPercent);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder("NodeResourceUsageStats[");
+        sb.append(nodeId).append("](");
+        sb.append("Timestamp: ").append(timestamp);
+        sb.append(", CPU utilization percent: ").append(String.format(Locale.ROOT, "%.1f", cpuUtilizationPercent));
+        sb.append(", Memory utilization percent: ").append(String.format(Locale.ROOT, "%.1f", memoryUtilizationPercent));
+        sb.append(")");
+        return sb.toString();
+    }
+
+    NodeResourceUsageStats(NodeResourceUsageStats nodeResourceUsageStats) {
+        this(
+            nodeResourceUsageStats.nodeId,
+            nodeResourceUsageStats.timestamp,
+            nodeResourceUsageStats.memoryUtilizationPercent,
+            nodeResourceUsageStats.cpuUtilizationPercent
+        );
+    }
+
+    public double getMemoryUtilizationPercent() {
+        return memoryUtilizationPercent;
+    }
+
+    public double getCpuUtilizationPercent() {
+        return cpuUtilizationPercent;
+    }
+
+    public long getTimestamp() {
+        return timestamp;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/node/NodeService.java b/server/src/main/java/org/opensearch/node/NodeService.java
index 2688b894cb9a7..15cc8f3d20bb3 100644
--- a/server/src/main/java/org/opensearch/node/NodeService.java
+++ b/server/src/main/java/org/opensearch/node/NodeService.java
@@ -48,11 +48,14 @@
 import org.opensearch.discovery.Discovery;
 import org.opensearch.http.HttpServerTransport;
 import org.opensearch.index.IndexingPressureService;
+import org.opensearch.index.SegmentReplicationStatsTracker;
 import org.opensearch.index.store.remote.filecache.FileCache;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.ingest.IngestService;
 import org.opensearch.monitor.MonitorService;
 import org.opensearch.plugins.PluginsService;
+import org.opensearch.ratelimitting.admissioncontrol.AdmissionControlService;
+import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.script.ScriptService;
 import org.opensearch.search.aggregations.support.AggregationUsageService;
 import org.opensearch.search.backpressure.SearchBackpressureService;
@@ -83,6 +86,7 @@ public class NodeService implements Closeable {
     private final ScriptService scriptService;
     private final HttpServerTransport httpServerTransport;
     private final ResponseCollectorService responseCollectorService;
+    private final ResourceUsageCollectorService resourceUsageCollectorService;
     private final SearchTransportService searchTransportService;
     private final IndexingPressureService indexingPressureService;
     private final AggregationUsageService aggregationUsageService;
@@ -92,6 +96,9 @@ public class NodeService implements Closeable {
     private final Discovery discovery;
     private final FileCache fileCache;
     private final TaskCancellationMonitoringService taskCancellationMonitoringService;
+    private final RepositoriesService repositoriesService;
+    private final AdmissionControlService admissionControlService;
+    private final SegmentReplicationStatsTracker segmentReplicationStatsTracker;
 
     NodeService(
         Settings settings,
@@ -114,7 +121,11 @@ public class NodeService implements Closeable {
         SearchBackpressureService searchBackpressureService,
         SearchPipelineService searchPipelineService,
         FileCache fileCache,
-        TaskCancellationMonitoringService taskCancellationMonitoringService
+        TaskCancellationMonitoringService taskCancellationMonitoringService,
+        ResourceUsageCollectorService resourceUsageCollectorService,
+        SegmentReplicationStatsTracker segmentReplicationStatsTracker,
+        RepositoriesService repositoriesService,
+        AdmissionControlService admissionControlService
     ) {
         this.settings = settings;
         this.threadPool = threadPool;
@@ -137,8 +148,12 @@ public class NodeService implements Closeable {
         this.clusterService = clusterService;
         this.fileCache = fileCache;
         this.taskCancellationMonitoringService = taskCancellationMonitoringService;
+        this.resourceUsageCollectorService = resourceUsageCollectorService;
+        this.repositoriesService = repositoriesService;
+        this.admissionControlService = admissionControlService;
         clusterService.addStateApplier(ingestService);
         clusterService.addStateApplier(searchPipelineService);
+        this.segmentReplicationStatsTracker = segmentReplicationStatsTracker;
     }
 
     public NodeInfo info(
@@ -217,7 +232,11 @@ public NodeStats stats(
         boolean weightedRoutingStats,
         boolean fileCacheStats,
         boolean taskCancellation,
-        boolean searchPipelineStats
+        boolean searchPipelineStats,
+        boolean resourceUsageStats,
+        boolean segmentReplicationTrackerStats,
+        boolean repositoriesStats,
+        boolean admissionControl
     ) {
         // for indices stats we want to include previous allocated shards stats as well (it will
         // only be applied to the sensible ones to use, like refresh/merge/flush/indexing stats)
@@ -237,6 +256,7 @@ public NodeStats stats(
             discoveryStats ? discovery.stats() : null,
             ingest ? ingestService.stats() : null,
             adaptiveSelection ? responseCollectorService.getAdaptiveStats(searchTransportService.getPendingSearchRequests()) : null,
+            resourceUsageStats ? resourceUsageCollectorService.stats() : null,
             scriptCache ? scriptService.cacheStats() : null,
             indexingPressure ? this.indexingPressureService.nodeStats() : null,
             shardIndexingPressure ? this.indexingPressureService.shardStats(indices) : null,
@@ -245,7 +265,10 @@ public NodeStats stats(
             weightedRoutingStats ? WeightedRoutingStats.getInstance() : null,
             fileCacheStats && fileCache != null ? fileCache.fileCacheStats() : null,
             taskCancellation ? this.taskCancellationMonitoringService.stats() : null,
-            searchPipelineStats ? this.searchPipelineService.stats() : null
+            searchPipelineStats ? this.searchPipelineService.stats() : null,
+            segmentReplicationTrackerStats ? this.segmentReplicationStatsTracker.getTotalRejectionStats() : null,
+            repositoriesStats ? this.repositoriesService.getRepositoriesStats() : null,
+            admissionControl ? this.admissionControlService.stats() : null
         );
     }
 
diff --git a/server/src/main/java/org/opensearch/node/NodesResourceUsageStats.java b/server/src/main/java/org/opensearch/node/NodesResourceUsageStats.java
new file mode 100644
index 0000000000000..3dff9a27f71a8
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/NodesResourceUsageStats.java
@@ -0,0 +1,69 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node;
+
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.xcontent.ToXContentFragment;
+import org.opensearch.core.xcontent.XContentBuilder;
+
+import java.io.IOException;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * This class represents resource usage stats such as CPU, Memory and IO resource usage of each node along with the
+ * timestamp of the stats recorded.
+ */
+public class NodesResourceUsageStats implements Writeable, ToXContentFragment {
+
+    // Map of node id to resource usage stats of the corresponding node.
+    private final Map<String, NodeResourceUsageStats> nodeIdToResourceUsageStatsMap;
+
+    public NodesResourceUsageStats(Map<String, NodeResourceUsageStats> nodeIdToResourceUsageStatsMap) {
+        this.nodeIdToResourceUsageStatsMap = nodeIdToResourceUsageStatsMap;
+    }
+
+    public NodesResourceUsageStats(StreamInput in) throws IOException {
+        this.nodeIdToResourceUsageStatsMap = in.readMap(StreamInput::readString, NodeResourceUsageStats::new);
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeMap(this.nodeIdToResourceUsageStatsMap, StreamOutput::writeString, (stream, stats) -> stats.writeTo(stream));
+    }
+
+    /**
+     * Returns map of node id to resource usage stats of the corresponding node.
+     */
+    public Map<String, NodeResourceUsageStats> getNodeIdToResourceUsageStatsMap() {
+        return nodeIdToResourceUsageStatsMap;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject("resource_usage_stats");
+        for (String nodeId : nodeIdToResourceUsageStatsMap.keySet()) {
+            builder.startObject(nodeId);
+            NodeResourceUsageStats resourceUsageStats = nodeIdToResourceUsageStatsMap.get(nodeId);
+            if (resourceUsageStats != null) {
+                builder.field("timestamp", resourceUsageStats.timestamp);
+                builder.field("cpu_utilization_percent", String.format(Locale.ROOT, "%.1f", resourceUsageStats.cpuUtilizationPercent));
+                builder.field(
+                    "memory_utilization_percent",
+                    String.format(Locale.ROOT, "%.1f", resourceUsageStats.memoryUtilizationPercent)
+                );
+            }
+            builder.endObject();
+        }
+        builder.endObject();
+        return builder;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/node/ResourceUsageCollectorService.java b/server/src/main/java/org/opensearch/node/ResourceUsageCollectorService.java
new file mode 100644
index 0000000000000..f1c763e09f147
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/ResourceUsageCollectorService.java
@@ -0,0 +1,160 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.cluster.ClusterChangedEvent;
+import org.opensearch.cluster.ClusterStateListener;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.concurrent.ConcurrentCollections;
+import org.opensearch.node.resource.tracker.NodeResourceUsageTracker;
+import org.opensearch.threadpool.Scheduler;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentMap;
+
+/**
+ * This collects node level resource usage statistics such as cpu, memory, IO of each node and makes it available for
+ * coordinator node to aid in throttling, ranking etc
+ */
+public class ResourceUsageCollectorService extends AbstractLifecycleComponent implements ClusterStateListener {
+
+    /**
+     * This refresh interval denotes the polling interval of ResourceUsageCollectorService to refresh the resource usage
+     * stats from local node
+     */
+    private static long REFRESH_INTERVAL_IN_MILLIS = 1000;
+
+    private static final Logger logger = LogManager.getLogger(ResourceUsageCollectorService.class);
+    private final ConcurrentMap<String, NodeResourceUsageStats> nodeIdToResourceUsageStats = ConcurrentCollections.newConcurrentMap();
+
+    private ThreadPool threadPool;
+    private volatile Scheduler.Cancellable scheduledFuture;
+
+    private NodeResourceUsageTracker nodeResourceUsageTracker;
+    private ClusterService clusterService;
+
+    public ResourceUsageCollectorService(
+        NodeResourceUsageTracker nodeResourceUsageTracker,
+        ClusterService clusterService,
+        ThreadPool threadPool
+    ) {
+        this.threadPool = threadPool;
+        this.nodeResourceUsageTracker = nodeResourceUsageTracker;
+        this.clusterService = clusterService;
+        clusterService.addListener(this);
+    }
+
+    @Override
+    public void clusterChanged(ClusterChangedEvent event) {
+        if (event.nodesRemoved()) {
+            for (DiscoveryNode removedNode : event.nodesDelta().removedNodes()) {
+                removeNodeResourceUsageStats(removedNode.getId());
+            }
+        }
+    }
+
+    void removeNodeResourceUsageStats(String nodeId) {
+        nodeIdToResourceUsageStats.remove(nodeId);
+    }
+
+    /**
+     * Collect node resource usage stats along with the timestamp
+     */
+    public void collectNodeResourceUsageStats(
+        String nodeId,
+        long timestamp,
+        double memoryUtilizationPercent,
+        double cpuUtilizationPercent
+    ) {
+        nodeIdToResourceUsageStats.compute(nodeId, (id, resourceUsageStats) -> {
+            if (resourceUsageStats == null) {
+                return new NodeResourceUsageStats(nodeId, timestamp, memoryUtilizationPercent, cpuUtilizationPercent);
+            } else {
+                resourceUsageStats.cpuUtilizationPercent = cpuUtilizationPercent;
+                resourceUsageStats.memoryUtilizationPercent = memoryUtilizationPercent;
+                resourceUsageStats.timestamp = timestamp;
+                return resourceUsageStats;
+            }
+        });
+    }
+
+    /**
+     * Get all node resource usage statistics which will be used for node stats
+     */
+    public Map<String, NodeResourceUsageStats> getAllNodeStatistics() {
+        Map<String, NodeResourceUsageStats> nodeStats = new HashMap<>(nodeIdToResourceUsageStats.size());
+        nodeIdToResourceUsageStats.forEach((nodeId, resourceUsageStats) -> {
+            nodeStats.put(nodeId, new NodeResourceUsageStats(resourceUsageStats));
+        });
+        return nodeStats;
+    }
+
+    /**
+     * Optionally return a {@code NodeResourceUsageStats} for the given nodeid, if
+     * resource usage stats information exists for the given node. Returns an empty
+     * {@code Optional} if the node was not found.
+     */
+    public Optional<NodeResourceUsageStats> getNodeStatistics(final String nodeId) {
+        return Optional.ofNullable(nodeIdToResourceUsageStats.get(nodeId))
+            .map(resourceUsageStats -> new NodeResourceUsageStats(resourceUsageStats));
+    }
+
+    /**
+     * Returns collected resource usage statistics of all nodes
+     */
+    public NodesResourceUsageStats stats() {
+        return new NodesResourceUsageStats(getAllNodeStatistics());
+    }
+
+    /**
+     * Fetch local node resource usage statistics and add it to store along with the current timestamp
+     */
+    private void collectLocalNodeResourceUsageStats() {
+        if (nodeResourceUsageTracker.isReady() && clusterService.state() != null) {
+            collectNodeResourceUsageStats(
+                clusterService.state().nodes().getLocalNodeId(),
+                System.currentTimeMillis(),
+                nodeResourceUsageTracker.getMemoryUtilizationPercent(),
+                nodeResourceUsageTracker.getCpuUtilizationPercent()
+            );
+        }
+    }
+
+    @Override
+    protected void doStart() {
+        /**
+         * Fetch local node resource usage statistics every second
+         */
+        scheduledFuture = threadPool.scheduleWithFixedDelay(() -> {
+            try {
+                collectLocalNodeResourceUsageStats();
+            } catch (Exception e) {
+                logger.warn("failure in ResourceUsageCollectorService", e);
+            }
+        }, new TimeValue(REFRESH_INTERVAL_IN_MILLIS), ThreadPool.Names.GENERIC);
+    }
+
+    @Override
+    protected void doStop() {
+        if (scheduledFuture != null) {
+            scheduledFuture.cancel();
+        }
+    }
+
+    @Override
+    protected void doClose() {}
+}
diff --git a/server/src/main/java/org/opensearch/node/ResponseCollectorService.java b/server/src/main/java/org/opensearch/node/ResponseCollectorService.java
index 3451e50d27b5d..7bd3c2d8d8ec6 100644
--- a/server/src/main/java/org/opensearch/node/ResponseCollectorService.java
+++ b/server/src/main/java/org/opensearch/node/ResponseCollectorService.java
@@ -37,6 +37,7 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.ExponentiallyWeightedMovingAverage;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.concurrent.ConcurrentCollections;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -54,8 +55,9 @@
  * tasks executed on each node, making the EWMA of the values available to the
  * coordinating node.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ResponseCollectorService implements ClusterStateListener {
 
     private static final double ALPHA = 0.3;
@@ -120,7 +122,10 @@ public Optional<ComputedNodeStats> getNodeStatistics(final String nodeId) {
      * Struct-like class encapsulating a point-in-time snapshot of a particular
      * node's statistics. This includes the EWMA of queue size, response time,
      * and service time.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ComputedNodeStats implements Writeable {
         // We store timestamps with nanosecond precision, however, the
         // formula specifies milliseconds, therefore we need to convert
diff --git a/server/src/main/java/org/opensearch/node/remotestore/RemoteStoreNodeService.java b/server/src/main/java/org/opensearch/node/remotestore/RemoteStoreNodeService.java
index 26c078353d12a..ca2413a057a6b 100644
--- a/server/src/main/java/org/opensearch/node/remotestore/RemoteStoreNodeService.java
+++ b/server/src/main/java/org/opensearch/node/remotestore/RemoteStoreNodeService.java
@@ -17,6 +17,7 @@
 import org.opensearch.common.settings.Setting;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.Repository;
+import org.opensearch.repositories.RepositoryException;
 import org.opensearch.threadpool.ThreadPool;
 
 import java.util.ArrayList;
@@ -133,10 +134,19 @@ public RepositoriesMetadata updateRepositoriesMetadata(DiscoveryNode joiningNode
                 boolean repositoryAlreadyPresent = false;
                 for (RepositoryMetadata existingRepositoryMetadata : existingRepositories.repositories()) {
                     if (newRepositoryMetadata.name().equals(existingRepositoryMetadata.name())) {
-                        if (newRepositoryMetadata.equalsIgnoreGenerations(existingRepositoryMetadata)) {
+                        try {
+                            // This will help in handling two scenarios -
+                            // 1. When a fresh cluster is formed and a node tries to join the cluster, the repository
+                            // metadata constructed from the node attributes of the joining node will be validated
+                            // against the repository information provided by existing nodes in cluster state.
+                            // 2. It's possible to update repository settings except the restricted ones post the
+                            // creation of a system repository and if a node drops we will need to allow it to join
+                            // even if the non-restricted system repository settings are now different.
+                            repositoriesService.get().ensureValidSystemRepositoryUpdate(newRepositoryMetadata, existingRepositoryMetadata);
+                            newRepositoryMetadata = existingRepositoryMetadata;
                             repositoryAlreadyPresent = true;
                             break;
-                        } else {
+                        } catch (RepositoryException e) {
                             throw new IllegalStateException(
                                 "new repository metadata ["
                                     + newRepositoryMetadata
diff --git a/server/src/main/java/org/opensearch/node/resource/tracker/AbstractAverageUsageTracker.java b/server/src/main/java/org/opensearch/node/resource/tracker/AbstractAverageUsageTracker.java
new file mode 100644
index 0000000000000..f83a1b7f9fc05
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/resource/tracker/AbstractAverageUsageTracker.java
@@ -0,0 +1,100 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node.resource.tracker;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.MovingAverage;
+import org.opensearch.threadpool.Scheduler;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * Base class for sliding window resource usage trackers
+ */
+public abstract class AbstractAverageUsageTracker extends AbstractLifecycleComponent {
+    private static final Logger LOGGER = LogManager.getLogger(AbstractAverageUsageTracker.class);
+
+    private final ThreadPool threadPool;
+    private final TimeValue pollingInterval;
+    private TimeValue windowDuration;
+    private final AtomicReference<MovingAverage> observations = new AtomicReference<>();
+
+    private volatile Scheduler.Cancellable scheduledFuture;
+
+    public AbstractAverageUsageTracker(ThreadPool threadPool, TimeValue pollingInterval, TimeValue windowDuration) {
+        this.threadPool = threadPool;
+        this.pollingInterval = pollingInterval;
+        this.windowDuration = windowDuration;
+        this.setWindowSize(windowDuration);
+    }
+
+    public abstract long getUsage();
+
+    /**
+     * Returns the moving average of the datapoints
+     */
+    public double getAverage() {
+        return observations.get().getAverage();
+    }
+
+    /**
+     * Checks if we have datapoints more than or equal to the window size
+     */
+    public boolean isReady() {
+        return observations.get().isReady();
+    }
+
+    /**
+     * Creates a new instance of MovingAverage with a new window size based on WindowDuration
+     */
+    public void setWindowSize(TimeValue windowDuration) {
+        this.windowDuration = windowDuration;
+        int windowSize = (int) (windowDuration.nanos() / pollingInterval.nanos());
+        LOGGER.debug("updated window size: {}", windowSize);
+        observations.set(new MovingAverage(windowSize));
+    }
+
+    public TimeValue getPollingInterval() {
+        return pollingInterval;
+    }
+
+    public TimeValue getWindowDuration() {
+        return windowDuration;
+    }
+
+    public long getWindowSize() {
+        return observations.get().getCount();
+    }
+
+    public void recordUsage(long usage) {
+        observations.get().record(usage);
+    }
+
+    @Override
+    protected void doStart() {
+        scheduledFuture = threadPool.scheduleWithFixedDelay(() -> {
+            long usage = getUsage();
+            recordUsage(usage);
+        }, pollingInterval, ThreadPool.Names.GENERIC);
+    }
+
+    @Override
+    protected void doStop() {
+        if (scheduledFuture != null) {
+            scheduledFuture.cancel();
+        }
+    }
+
+    @Override
+    protected void doClose() {}
+}
diff --git a/server/src/main/java/org/opensearch/node/resource/tracker/AverageCpuUsageTracker.java b/server/src/main/java/org/opensearch/node/resource/tracker/AverageCpuUsageTracker.java
new file mode 100644
index 0000000000000..160d385762eb0
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/resource/tracker/AverageCpuUsageTracker.java
@@ -0,0 +1,38 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node.resource.tracker;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.monitor.process.ProcessProbe;
+import org.opensearch.threadpool.ThreadPool;
+
+/**
+ * AverageCpuUsageTracker tracks the average CPU usage by polling the CPU usage every (pollingInterval)
+ * and keeping track of the rolling average over a defined time window (windowDuration).
+ */
+public class AverageCpuUsageTracker extends AbstractAverageUsageTracker {
+    private static final Logger LOGGER = LogManager.getLogger(AverageCpuUsageTracker.class);
+
+    public AverageCpuUsageTracker(ThreadPool threadPool, TimeValue pollingInterval, TimeValue windowDuration) {
+        super(threadPool, pollingInterval, windowDuration);
+    }
+
+    /**
+     * Returns the process CPU usage in percent
+     */
+    @Override
+    public long getUsage() {
+        long usage = ProcessProbe.getInstance().getProcessCpuPercent();
+        LOGGER.debug("Recording cpu usage: {}%", usage);
+        return usage;
+    }
+
+}
diff --git a/server/src/main/java/org/opensearch/node/resource/tracker/AverageMemoryUsageTracker.java b/server/src/main/java/org/opensearch/node/resource/tracker/AverageMemoryUsageTracker.java
new file mode 100644
index 0000000000000..c1d1c83656859
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/resource/tracker/AverageMemoryUsageTracker.java
@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node.resource.tracker;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.lang.management.ManagementFactory;
+import java.lang.management.MemoryMXBean;
+
+/**
+ * AverageMemoryUsageTracker tracks the average JVM usage by polling the JVM usage every (pollingInterval)
+ * and keeping track of the rolling average over a defined time window (windowDuration).
+ */
+public class AverageMemoryUsageTracker extends AbstractAverageUsageTracker {
+
+    private static final Logger LOGGER = LogManager.getLogger(AverageMemoryUsageTracker.class);
+
+    private static final MemoryMXBean MEMORY_MX_BEAN = ManagementFactory.getMemoryMXBean();
+
+    public AverageMemoryUsageTracker(ThreadPool threadPool, TimeValue pollingInterval, TimeValue windowDuration) {
+        super(threadPool, pollingInterval, windowDuration);
+    }
+
+    /**
+     * Get current memory usage percentage calculated against max heap memory
+     */
+    @Override
+    public long getUsage() {
+        long usage = MEMORY_MX_BEAN.getHeapMemoryUsage().getUsed() * 100 / MEMORY_MX_BEAN.getHeapMemoryUsage().getMax();
+        LOGGER.debug("Recording memory usage: {}%", usage);
+        return usage;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/node/resource/tracker/NodeResourceUsageTracker.java b/server/src/main/java/org/opensearch/node/resource/tracker/NodeResourceUsageTracker.java
new file mode 100644
index 0000000000000..cf5f38c1b004c
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/resource/tracker/NodeResourceUsageTracker.java
@@ -0,0 +1,118 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node.resource.tracker;
+
+import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.threadpool.ThreadPool;
+
+/**
+ * This tracks the usage of node resources such as CPU, IO and memory
+ */
+public class NodeResourceUsageTracker extends AbstractLifecycleComponent {
+    private ThreadPool threadPool;
+    private final ClusterSettings clusterSettings;
+    private AverageCpuUsageTracker cpuUsageTracker;
+    private AverageMemoryUsageTracker memoryUsageTracker;
+
+    private ResourceTrackerSettings resourceTrackerSettings;
+
+    public NodeResourceUsageTracker(ThreadPool threadPool, Settings settings, ClusterSettings clusterSettings) {
+        this.threadPool = threadPool;
+        this.clusterSettings = clusterSettings;
+        this.resourceTrackerSettings = new ResourceTrackerSettings(settings);
+        initialize();
+    }
+
+    /**
+     * Return CPU utilization average if we have enough datapoints, otherwise return 0
+     */
+    public double getCpuUtilizationPercent() {
+        if (cpuUsageTracker.isReady()) {
+            return cpuUsageTracker.getAverage();
+        }
+        return 0.0;
+    }
+
+    /**
+     * Return memory utilization average if we have enough datapoints, otherwise return 0
+     */
+    public double getMemoryUtilizationPercent() {
+        if (memoryUsageTracker.isReady()) {
+            return memoryUsageTracker.getAverage();
+        }
+        return 0.0;
+    }
+
+    /**
+     * Checks if all of the resource usage trackers are ready
+     */
+    public boolean isReady() {
+        return memoryUsageTracker.isReady() && cpuUsageTracker.isReady();
+    }
+
+    void initialize() {
+        cpuUsageTracker = new AverageCpuUsageTracker(
+            threadPool,
+            resourceTrackerSettings.getCpuPollingInterval(),
+            resourceTrackerSettings.getCpuWindowDuration()
+        );
+        clusterSettings.addSettingsUpdateConsumer(
+            ResourceTrackerSettings.GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING,
+            this::setCpuWindowDuration
+        );
+
+        memoryUsageTracker = new AverageMemoryUsageTracker(
+            threadPool,
+            resourceTrackerSettings.getMemoryPollingInterval(),
+            resourceTrackerSettings.getMemoryWindowDuration()
+        );
+        clusterSettings.addSettingsUpdateConsumer(
+            ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING,
+            this::setMemoryWindowDuration
+        );
+    }
+
+    private void setMemoryWindowDuration(TimeValue windowDuration) {
+        memoryUsageTracker.setWindowSize(windowDuration);
+        resourceTrackerSettings.setMemoryWindowDuration(windowDuration);
+    }
+
+    private void setCpuWindowDuration(TimeValue windowDuration) {
+        cpuUsageTracker.setWindowSize(windowDuration);
+        resourceTrackerSettings.setCpuWindowDuration(windowDuration);
+    }
+
+    /**
+     * Visible for testing
+     */
+    ResourceTrackerSettings getResourceTrackerSettings() {
+        return resourceTrackerSettings;
+    }
+
+    @Override
+    protected void doStart() {
+        cpuUsageTracker.doStart();
+        memoryUsageTracker.doStart();
+    }
+
+    @Override
+    protected void doStop() {
+        cpuUsageTracker.doStop();
+        memoryUsageTracker.doStop();
+    }
+
+    @Override
+    protected void doClose() {
+        cpuUsageTracker.doClose();
+        memoryUsageTracker.doClose();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/node/resource/tracker/ResourceTrackerSettings.java b/server/src/main/java/org/opensearch/node/resource/tracker/ResourceTrackerSettings.java
new file mode 100644
index 0000000000000..f81b008ba7e8b
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/resource/tracker/ResourceTrackerSettings.java
@@ -0,0 +1,90 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node.resource.tracker;
+
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+
+/**
+ * Settings related to resource usage trackers such as polling interval, window duration etc
+ */
+public class ResourceTrackerSettings {
+
+    private static class Defaults {
+        /**
+         * This is the default polling interval of usage trackers to get the resource utilization data
+         */
+        private static final long POLLING_INTERVAL_IN_MILLIS = 500;
+        /**
+         * This is the default window duration on which the average resource utilization values will be calculated
+         */
+        private static final long WINDOW_DURATION_IN_SECONDS = 30;
+    }
+
+    public static final Setting<TimeValue> GLOBAL_CPU_USAGE_AC_POLLING_INTERVAL_SETTING = Setting.positiveTimeSetting(
+        "node.resource.tracker.global_cpu_usage.polling_interval",
+        TimeValue.timeValueMillis(Defaults.POLLING_INTERVAL_IN_MILLIS),
+        Setting.Property.NodeScope
+    );
+    public static final Setting<TimeValue> GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING = Setting.positiveTimeSetting(
+        "node.resource.tracker.global_cpu_usage.window_duration",
+        TimeValue.timeValueSeconds(Defaults.WINDOW_DURATION_IN_SECONDS),
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    public static final Setting<TimeValue> GLOBAL_JVM_USAGE_AC_POLLING_INTERVAL_SETTING = Setting.positiveTimeSetting(
+        "node.resource.tracker.global_jvmmp.polling_interval",
+        TimeValue.timeValueMillis(Defaults.POLLING_INTERVAL_IN_MILLIS),
+        Setting.Property.NodeScope
+    );
+
+    public static final Setting<TimeValue> GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING = Setting.positiveTimeSetting(
+        "node.resource.tracker.global_jvmmp.window_duration",
+        TimeValue.timeValueSeconds(Defaults.WINDOW_DURATION_IN_SECONDS),
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+    private volatile TimeValue cpuWindowDuration;
+    private volatile TimeValue cpuPollingInterval;
+    private volatile TimeValue memoryWindowDuration;
+    private volatile TimeValue memoryPollingInterval;
+
+    public ResourceTrackerSettings(Settings settings) {
+        this.cpuPollingInterval = GLOBAL_CPU_USAGE_AC_POLLING_INTERVAL_SETTING.get(settings);
+        this.cpuWindowDuration = GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING.get(settings);
+        this.memoryPollingInterval = GLOBAL_JVM_USAGE_AC_POLLING_INTERVAL_SETTING.get(settings);
+        this.memoryWindowDuration = GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING.get(settings);
+    }
+
+    public TimeValue getCpuWindowDuration() {
+        return this.cpuWindowDuration;
+    }
+
+    public TimeValue getCpuPollingInterval() {
+        return cpuPollingInterval;
+    }
+
+    public TimeValue getMemoryPollingInterval() {
+        return memoryPollingInterval;
+    }
+
+    public TimeValue getMemoryWindowDuration() {
+        return memoryWindowDuration;
+    }
+
+    public void setCpuWindowDuration(TimeValue cpuWindowDuration) {
+        this.cpuWindowDuration = cpuWindowDuration;
+    }
+
+    public void setMemoryWindowDuration(TimeValue memoryWindowDuration) {
+        this.memoryWindowDuration = memoryWindowDuration;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/node/resource/tracker/package-info.java b/server/src/main/java/org/opensearch/node/resource/tracker/package-info.java
new file mode 100644
index 0000000000000..aace2a019973e
--- /dev/null
+++ b/server/src/main/java/org/opensearch/node/resource/tracker/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * Node level resource usage stats tracker package
+ */
+package org.opensearch.node.resource.tracker;
diff --git a/server/src/main/java/org/opensearch/persistent/NodePersistentTasksExecutor.java b/server/src/main/java/org/opensearch/persistent/NodePersistentTasksExecutor.java
index 209df1e1f498d..403630b89e42a 100644
--- a/server/src/main/java/org/opensearch/persistent/NodePersistentTasksExecutor.java
+++ b/server/src/main/java/org/opensearch/persistent/NodePersistentTasksExecutor.java
@@ -37,7 +37,7 @@
 
 /**
  * This component is responsible for execution of persistent tasks.
- *
+ * <p>
  * It abstracts away the execution of tasks and greatly simplifies testing of PersistentTasksNodeService
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/persistent/PersistentTasksClusterService.java b/server/src/main/java/org/opensearch/persistent/PersistentTasksClusterService.java
index 89bb23930b063..4e38fb34dbf17 100644
--- a/server/src/main/java/org/opensearch/persistent/PersistentTasksClusterService.java
+++ b/server/src/main/java/org/opensearch/persistent/PersistentTasksClusterService.java
@@ -323,7 +323,7 @@ public void clusterStateProcessed(String source, ClusterState oldState, ClusterS
 
     /**
      * This unassigns a task from any node, i.e. it is assigned to a {@code null} node with the provided reason.
-     *
+     * <p>
      * Since the assignment executor node is null, the {@link PersistentTasksClusterService} will attempt to reassign it to a valid
      * node quickly.
      *
diff --git a/server/src/main/java/org/opensearch/plugins/CircuitBreakerPlugin.java b/server/src/main/java/org/opensearch/plugins/CircuitBreakerPlugin.java
index 7e7345811246f..3552c8286b7a3 100644
--- a/server/src/main/java/org/opensearch/plugins/CircuitBreakerPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/CircuitBreakerPlugin.java
@@ -46,9 +46,9 @@ public interface CircuitBreakerPlugin {
 
     /**
      * Each of the factory functions are passed to the configured {@link CircuitBreakerService}.
-     *
+     * <p>
      * The service then constructs a {@link CircuitBreaker} given the resulting {@link BreakerSettings}.
-     *
+     * <p>
      * Custom circuit breakers settings can be found in {@link BreakerSettings}.
      * See:
      *  - limit (example: `breaker.foo.limit`) {@link BreakerSettings#CIRCUIT_BREAKER_LIMIT_SETTING}
@@ -63,7 +63,7 @@ public interface CircuitBreakerPlugin {
     /**
      * The passed {@link CircuitBreaker} object is the same one that was constructed by the {@link BreakerSettings}
      * provided by {@link CircuitBreakerPlugin#getCircuitBreaker(Settings)}.
-     *
+     * <p>
      * This reference should never change throughout the lifetime of the node.
      *
      * @param circuitBreaker The constructed {@link CircuitBreaker} object from the {@link BreakerSettings}
diff --git a/server/src/main/java/org/opensearch/plugins/ClusterPlugin.java b/server/src/main/java/org/opensearch/plugins/ClusterPlugin.java
index c2e147b86d17f..1edd9f52d97a7 100644
--- a/server/src/main/java/org/opensearch/plugins/ClusterPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/ClusterPlugin.java
@@ -64,7 +64,7 @@ default Collection<AllocationDecider> createAllocationDeciders(Settings settings
 
     /**
      * Return {@link ShardsAllocator} implementations added by this plugin.
-     *
+     * <p>
      * The key of the returned {@link Map} is the name of the allocator, and the value
      * is a function to construct the allocator.
      *
@@ -88,7 +88,7 @@ default Map<String, ExistingShardsAllocator> getExistingShardsAllocators() {
     /**
      * Called when the node is started
      *
-     * DEPRECATED: Use {@link #onNodeStarted(DiscoveryNode)} for newer implementations.
+     * @deprecated Use {@link #onNodeStarted(DiscoveryNode)} for newer implementations.
      */
     @Deprecated
     default void onNodeStarted() {}
diff --git a/server/src/main/java/org/opensearch/plugins/CryptoKeyProviderPlugin.java b/server/src/main/java/org/opensearch/plugins/CryptoKeyProviderPlugin.java
index 47dc75c7c908a..d9b5f0d79ec8c 100644
--- a/server/src/main/java/org/opensearch/plugins/CryptoKeyProviderPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/CryptoKeyProviderPlugin.java
@@ -14,7 +14,8 @@
 
 /**
  * Crypto plugin to provide support for custom key providers.
- * @opensearch.api
+ *
+ * @opensearch.experimental
  */
 @ExperimentalApi
 public interface CryptoKeyProviderPlugin {
diff --git a/server/src/main/java/org/opensearch/plugins/DiscoveryPlugin.java b/server/src/main/java/org/opensearch/plugins/DiscoveryPlugin.java
index bca72942bd70e..63f0d826b592f 100644
--- a/server/src/main/java/org/opensearch/plugins/DiscoveryPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/DiscoveryPlugin.java
@@ -68,13 +68,10 @@ public interface DiscoveryPlugin {
      * This can be handy if you want to provide your own Network interface name like _mycard_
      * and implement by yourself the logic to get an actual IP address/hostname based on this
      * name.
-     *
+     * <p>
      * For example: you could call a third party service (an API) to resolve _mycard_.
      * Then you could define in opensearch.yml settings like:
-     *
-     * <pre>{@code
-     * network.host: _mycard_
-     * }</pre>
+     * {@code network.host: _mycard_ }
      */
     default NetworkService.CustomNameResolver getCustomNameResolver(Settings settings) {
         return null;
@@ -82,7 +79,7 @@ default NetworkService.CustomNameResolver getCustomNameResolver(Settings setting
 
     /**
      * Returns providers of seed hosts for discovery.
-     *
+     * <p>
      * The key of the returned map is the name of the host provider
      * (see {@link org.opensearch.discovery.DiscoveryModule#DISCOVERY_SEED_PROVIDERS_SETTING}), and
      * the value is a supplier to construct the host provider when it is selected for use.
diff --git a/server/src/main/java/org/opensearch/plugins/EnginePlugin.java b/server/src/main/java/org/opensearch/plugins/EnginePlugin.java
index 92ae2ff9cd661..5ea5442d84ffa 100644
--- a/server/src/main/java/org/opensearch/plugins/EnginePlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/EnginePlugin.java
@@ -92,7 +92,7 @@ default Optional<CodecServiceFactory> getCustomCodecServiceFactory(IndexSettings
      * When an index is created this method is invoked for each engine plugin. Engine plugins that need to provide a
      * custom {@link TranslogDeletionPolicy} can override this method to return a function that takes the {@link IndexSettings}
      * and a {@link Supplier} for {@link RetentionLeases} and returns a custom {@link TranslogDeletionPolicy}.
-     *
+     * <p>
      * Only one of the installed Engine plugins can override this otherwise {@link IllegalStateException} will be thrown.
      *
      * @return a function that returns an instance of {@link TranslogDeletionPolicy}
diff --git a/server/src/main/java/org/opensearch/plugins/ExtensiblePlugin.java b/server/src/main/java/org/opensearch/plugins/ExtensiblePlugin.java
index 4dd4010383934..367d335ac4fea 100644
--- a/server/src/main/java/org/opensearch/plugins/ExtensiblePlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/ExtensiblePlugin.java
@@ -36,7 +36,7 @@
 
 /**
  * An extension point for {@link Plugin} implementations to be themselves extensible.
- *
+ * <p>
  * This class provides a callback for extensible plugins to be informed of other plugins
  * which extend them.
  *
@@ -62,7 +62,7 @@ interface ExtensionLoader {
 
     /**
      * Allow this plugin to load extensions from other plugins.
-     *
+     * <p>
      * This method is called once only, after initializing this plugin and all plugins extending this plugin. It is called before
      * any other methods on this Plugin instance are called.
      */
diff --git a/server/src/main/java/org/opensearch/plugins/IdentityPlugin.java b/server/src/main/java/org/opensearch/plugins/IdentityPlugin.java
index 00f3f8aff585c..410535504f0dd 100644
--- a/server/src/main/java/org/opensearch/plugins/IdentityPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/IdentityPlugin.java
@@ -19,16 +19,14 @@
 public interface IdentityPlugin {
 
     /**
-     * Get the current subject
-     *
-     * Should never return null
+     * Get the current subject.
+     * @return Should never return null
      * */
     public Subject getSubject();
 
     /**
      * Get the Identity Plugin's token manager implementation
-     *
-     * Should never return null
+     * @return Should never return null.
      */
     public TokenManager getTokenManager();
 }
diff --git a/server/src/main/java/org/opensearch/plugins/IndexStorePlugin.java b/server/src/main/java/org/opensearch/plugins/IndexStorePlugin.java
index 2f549fec54759..ebd5717a00319 100644
--- a/server/src/main/java/org/opensearch/plugins/IndexStorePlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/IndexStorePlugin.java
@@ -36,6 +36,7 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.shard.ShardPath;
 import org.opensearch.indices.recovery.RecoveryState;
@@ -49,12 +50,16 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface IndexStorePlugin {
 
     /**
      * An interface that describes how to create a new directory instance per shard.
+     *
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     interface DirectoryFactory {
         /**
          * Creates a new directory per shard. This method is called once per shard on shard creation.
@@ -77,8 +82,11 @@ interface DirectoryFactory {
 
     /**
      * An interface that allows to create a new {@link RecoveryState} per shard.
+     *
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     interface RecoveryStateFactory {
         /**
          * Creates a new {@link RecoveryState} per shard. This method is called once per shard on shard creation.
diff --git a/server/src/main/java/org/opensearch/plugins/IngestPlugin.java b/server/src/main/java/org/opensearch/plugins/IngestPlugin.java
index dfc11aa8eea55..dc4f22de71344 100644
--- a/server/src/main/java/org/opensearch/plugins/IngestPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/IngestPlugin.java
@@ -46,7 +46,7 @@ public interface IngestPlugin {
 
     /**
      * Returns additional ingest processor types added by this plugin.
-     *
+     * <p>
      * The key of the returned {@link Map} is the unique name for the processor which is specified
      * in pipeline configurations, and the value is a {@link org.opensearch.ingest.Processor.Factory}
      * to create the processor from a given pipeline configuration.
diff --git a/server/src/main/java/org/opensearch/plugins/NetworkPlugin.java b/server/src/main/java/org/opensearch/plugins/NetworkPlugin.java
index f2f8e84f04e02..07df40bafe6a1 100644
--- a/server/src/main/java/org/opensearch/plugins/NetworkPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/NetworkPlugin.java
@@ -83,7 +83,8 @@ default Map<String, Supplier<Transport>> getTransports(
         PageCacheRecycler pageCacheRecycler,
         CircuitBreakerService circuitBreakerService,
         NamedWriteableRegistry namedWriteableRegistry,
-        NetworkService networkService
+        NetworkService networkService,
+        Tracer tracer
     ) {
         return Collections.emptyMap();
     }
diff --git a/server/src/main/java/org/opensearch/plugins/Plugin.java b/server/src/main/java/org/opensearch/plugins/Plugin.java
index 0743cd3807eff..48486a6b55dfd 100644
--- a/server/src/main/java/org/opensearch/plugins/Plugin.java
+++ b/server/src/main/java/org/opensearch/plugins/Plugin.java
@@ -121,7 +121,7 @@ public Collection<Class<? extends LifecycleComponent>> getGuiceServiceClasses()
 
     /**
      * Returns components added by this plugin.
-     *
+     * <p>
      * Any components returned that implement {@link LifecycleComponent} will have their lifecycle managed.
      * Note: To aid in the migration away from guice, all objects returned as components will be bound in guice
      * to themselves.
diff --git a/server/src/main/java/org/opensearch/plugins/PluginInfo.java b/server/src/main/java/org/opensearch/plugins/PluginInfo.java
index 67c0542943e95..dc8fd6e604d72 100644
--- a/server/src/main/java/org/opensearch/plugins/PluginInfo.java
+++ b/server/src/main/java/org/opensearch/plugins/PluginInfo.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.bootstrap.JarHell;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -59,6 +60,7 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class PluginInfo implements Writeable, ToXContentObject {
 
     public static final String OPENSEARCH_PLUGIN_PROPERTIES = "plugin-descriptor.properties";
diff --git a/server/src/main/java/org/opensearch/plugins/PluginsService.java b/server/src/main/java/org/opensearch/plugins/PluginsService.java
index 47195a0264750..cc9cc5b5b5fbf 100644
--- a/server/src/main/java/org/opensearch/plugins/PluginsService.java
+++ b/server/src/main/java/org/opensearch/plugins/PluginsService.java
@@ -468,7 +468,7 @@ private static Bundle readPluginBundle(final Set<Bundle> bundles, final Path plu
 
     /**
      * Return the given bundles, sorted in dependency loading order.
-     *
+     * <p>
      * This sort is stable, so that if two plugins do not have any interdependency,
      * their relative order from iteration of the provided set will not change.
      *
diff --git a/server/src/main/java/org/opensearch/plugins/RepositoryPlugin.java b/server/src/main/java/org/opensearch/plugins/RepositoryPlugin.java
index 189ba3cfc16ab..09233d49f3aea 100644
--- a/server/src/main/java/org/opensearch/plugins/RepositoryPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/RepositoryPlugin.java
@@ -52,9 +52,8 @@ public interface RepositoryPlugin {
      * Returns repository types added by this plugin.
      *
      * @param env The environment for the local node, which may be used for the local settings and path.repo
-     *
-     * The key of the returned {@link Map} is the type name of the repository and
-     * the value is a factory to construct the {@link Repository} interface.
+     *            The key of the returned {@link Map} is the type name of the repository and
+     *            the value is a factory to construct the {@link Repository} interface.
      */
     default Map<String, Repository.Factory> getRepositories(
         Environment env,
@@ -70,9 +69,8 @@ default Map<String, Repository.Factory> getRepositories(
      * through the external API.
      *
      * @param env The environment for the local node, which may be used for the local settings and path.repo
-     *
-     * The key of the returned {@link Map} is the type name of the repository and
-     * the value is a factory to construct the {@link Repository} interface.
+     *            The key of the returned {@link Map} is the type name of the repository and
+     *            the value is a factory to construct the {@link Repository} interface.
      */
     default Map<String, Repository.Factory> getInternalRepositories(
         Environment env,
diff --git a/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java b/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java
index d2ef2b65c5944..7288a8caaec58 100644
--- a/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java
@@ -35,7 +35,7 @@
 public interface SearchPipelinePlugin {
     /**
      * Returns additional search pipeline request processor types added by this plugin.
-     *
+     * <p>
      * The key of the returned {@link Map} is the unique name for the processor which is specified
      * in pipeline configurations, and the value is a {@link org.opensearch.search.pipeline.Processor.Factory}
      * to create the processor from a given pipeline configuration.
@@ -46,7 +46,7 @@ default Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcess
 
     /**
      * Returns additional search pipeline response processor types added by this plugin.
-     *
+     * <p>
      * The key of the returned {@link Map} is the unique name for the processor which is specified
      * in pipeline configurations, and the value is a {@link org.opensearch.search.pipeline.Processor.Factory}
      * to create the processor from a given pipeline configuration.
@@ -57,7 +57,7 @@ default Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProce
 
     /**
      * Returns additional search pipeline search phase results processor types added by this plugin.
-     *
+     * <p>
      * The key of the returned {@link Map} is the unique name for the processor which is specified
      * in pipeline configurations, and the value is a {@link org.opensearch.search.pipeline.Processor.Factory}
      * to create the processor from a given pipeline configuration.
diff --git a/server/src/main/java/org/opensearch/plugins/SearchPlugin.java b/server/src/main/java/org/opensearch/plugins/SearchPlugin.java
index 8b5920e1f4485..40b4f97cd1897 100644
--- a/server/src/main/java/org/opensearch/plugins/SearchPlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/SearchPlugin.java
@@ -551,8 +551,8 @@ class CompositeAggregationSpec {
         private final Consumer<ValuesSourceRegistry.Builder> aggregatorRegistrar;
         private final Class<?> valueSourceBuilderClass;
         @Deprecated
-        /** This is added for backward compatibility, you don't need to set it, as we use aggregationType instead of
-         * byte code
+        /* This is added for backward compatibility, you don't need to set it, as we use aggregationType instead of
+          byte code
          */
         private Byte byteCode;
         private final CompositeAggregationParsingFunction parsingFunction;
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlService.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlService.java
new file mode 100644
index 0000000000000..adca6992833bd
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlService.java
@@ -0,0 +1,140 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.node.ResourceUsageCollectorService;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.AdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.CpuBasedAdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.stats.AdmissionControlStats;
+import org.opensearch.ratelimitting.admissioncontrol.stats.AdmissionControllerStats;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import static org.opensearch.ratelimitting.admissioncontrol.controllers.CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER;
+
+/**
+ * Admission control Service that bootstraps and manages all the Admission Controllers in OpenSearch.
+ */
+public class AdmissionControlService {
+    private final ThreadPool threadPool;
+    public final AdmissionControlSettings admissionControlSettings;
+    private final ConcurrentMap<String, AdmissionController> admissionControllers;
+    private static final Logger logger = LogManager.getLogger(AdmissionControlService.class);
+    private final ClusterService clusterService;
+    private final Settings settings;
+    private final ResourceUsageCollectorService resourceUsageCollectorService;
+
+    /**
+     *
+     * @param settings Immutable settings instance
+     * @param clusterService ClusterService Instance
+     * @param threadPool ThreadPool Instance
+     * @param resourceUsageCollectorService Instance used to get node resource usage stats
+     */
+    public AdmissionControlService(
+        Settings settings,
+        ClusterService clusterService,
+        ThreadPool threadPool,
+        ResourceUsageCollectorService resourceUsageCollectorService
+    ) {
+        this.threadPool = threadPool;
+        this.admissionControlSettings = new AdmissionControlSettings(clusterService.getClusterSettings(), settings);
+        this.admissionControllers = new ConcurrentHashMap<>();
+        this.clusterService = clusterService;
+        this.settings = settings;
+        this.resourceUsageCollectorService = resourceUsageCollectorService;
+        this.initialise();
+    }
+
+    /**
+     * Initialise and Register all the admissionControllers
+     */
+    private void initialise() {
+        // Initialise different type of admission controllers
+        registerAdmissionController(CPU_BASED_ADMISSION_CONTROLLER);
+    }
+
+    /**
+     *
+     * @param action Transport action name
+     * @param admissionControlActionType admissionControllerActionType value
+     */
+    public void applyTransportAdmissionControl(String action, AdmissionControlActionType admissionControlActionType) {
+        this.admissionControllers.forEach(
+            (name, admissionController) -> { admissionController.apply(action, admissionControlActionType); }
+        );
+    }
+
+    /**
+     *
+     * @param admissionControllerName admissionControllerName to register into the service.
+     */
+    public void registerAdmissionController(String admissionControllerName) {
+        AdmissionController admissionController = this.controllerFactory(admissionControllerName);
+        this.admissionControllers.put(admissionControllerName, admissionController);
+    }
+
+    /**
+     * @return AdmissionController Instance
+     */
+    private AdmissionController controllerFactory(String admissionControllerName) {
+        switch (admissionControllerName) {
+            case CPU_BASED_ADMISSION_CONTROLLER:
+                return new CpuBasedAdmissionController(
+                    admissionControllerName,
+                    this.resourceUsageCollectorService,
+                    this.clusterService,
+                    this.settings
+                );
+            default:
+                throw new IllegalArgumentException("Not Supported AdmissionController : " + admissionControllerName);
+        }
+    }
+
+    /**
+     *
+     * @return list of the registered admissionControllers
+     */
+    public List<AdmissionController> getAdmissionControllers() {
+        return new ArrayList<>(this.admissionControllers.values());
+    }
+
+    /**
+     *
+     * @param controllerName name of the admissionController
+     * @return instance of the AdmissionController Instance
+     */
+    public AdmissionController getAdmissionController(String controllerName) {
+        return this.admissionControllers.getOrDefault(controllerName, null);
+    }
+
+    /**
+     * Return admission control stats
+     */
+    public AdmissionControlStats stats() {
+        List<AdmissionControllerStats> statsList = new ArrayList<>();
+        if (this.admissionControllers.size() > 0) {
+            this.admissionControllers.forEach((controllerName, admissionController) -> {
+                AdmissionControllerStats admissionControllerStats = new AdmissionControllerStats(admissionController);
+                statsList.add(admissionControllerStats);
+            });
+            return new AdmissionControlStats(statsList);
+        }
+        return null;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSettings.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSettings.java
new file mode 100644
index 0000000000000..b557190ab54ac
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSettings.java
@@ -0,0 +1,83 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol;
+
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+
+/**
+ * Settings related to admission control.
+ * @opensearch.internal
+ */
+public final class AdmissionControlSettings {
+
+    /**
+     * Default parameters for the AdmissionControlSettings
+     */
+    public static class Defaults {
+        public static final String MODE = "disabled";
+    }
+
+    /**
+     * Feature level setting to operate in shadow-mode or in enforced-mode. If enforced field is set
+     * rejection will be performed, otherwise only rejection metrics will be populated.
+     */
+    public static final Setting<AdmissionControlMode> ADMISSION_CONTROL_TRANSPORT_LAYER_MODE = new Setting<>(
+        "admission_control.transport.mode",
+        Defaults.MODE,
+        AdmissionControlMode::fromName,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    private volatile AdmissionControlMode transportLayeradmissionControlMode;
+
+    /**
+     * @param clusterSettings clusterSettings Instance
+     * @param settings        settings instance
+     */
+    public AdmissionControlSettings(ClusterSettings clusterSettings, Settings settings) {
+        this.transportLayeradmissionControlMode = ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.get(settings);
+        clusterSettings.addSettingsUpdateConsumer(ADMISSION_CONTROL_TRANSPORT_LAYER_MODE, this::setAdmissionControlTransportLayerMode);
+    }
+
+    /**
+     *
+     * @param admissionControlMode update the mode of admission control feature
+     */
+    private void setAdmissionControlTransportLayerMode(AdmissionControlMode admissionControlMode) {
+        this.transportLayeradmissionControlMode = admissionControlMode;
+    }
+
+    /**
+     *
+     * @return return the default mode of the admissionControl
+     */
+    public AdmissionControlMode getAdmissionControlTransportLayerMode() {
+        return this.transportLayeradmissionControlMode;
+    }
+
+    /**
+     *
+     * @return true based on the admission control feature is enforced else false
+     */
+    public Boolean isTransportLayerAdmissionControlEnforced() {
+        return this.transportLayeradmissionControlMode == AdmissionControlMode.ENFORCED;
+    }
+
+    /**
+     *
+     * @return true based on the admission control feature is enabled else false
+     */
+    public Boolean isTransportLayerAdmissionControlEnabled() {
+        return this.transportLayeradmissionControlMode != AdmissionControlMode.DISABLED;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/AdmissionController.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/AdmissionController.java
new file mode 100644
index 0000000000000..2246ce34dd399
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/AdmissionController.java
@@ -0,0 +1,105 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.controllers;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.util.concurrent.ConcurrentCollections;
+import org.opensearch.node.ResourceUsageCollectorService;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * Abstract class for Admission Controller in OpenSearch, which aims to provide resource based request admission control.
+ * It provides methods for any tracking-object that can be incremented (such as memory size),
+ * and admission control can be applied if configured limit has been reached
+ */
+public abstract class AdmissionController {
+
+    private final String admissionControllerName;
+    final ResourceUsageCollectorService resourceUsageCollectorService;
+    public final Map<String, AtomicLong> rejectionCountMap;
+    public final ClusterService clusterService;
+
+    /**
+     * @param admissionControllerName       name of the admissionController
+     * @param resourceUsageCollectorService instance used to get resource usage stats of the node
+     * @param clusterService instance of the clusterService
+     */
+    public AdmissionController(
+        String admissionControllerName,
+        ResourceUsageCollectorService resourceUsageCollectorService,
+        ClusterService clusterService
+    ) {
+        this.admissionControllerName = admissionControllerName;
+        this.resourceUsageCollectorService = resourceUsageCollectorService;
+        this.clusterService = clusterService;
+        this.rejectionCountMap = ConcurrentCollections.newConcurrentMap();
+    }
+
+    /**
+     * Return the current state of the admission controller
+     * @return true if admissionController is enabled for the transport layer else false
+     */
+    public boolean isEnabledForTransportLayer(AdmissionControlMode admissionControlMode) {
+        return admissionControlMode != AdmissionControlMode.DISABLED;
+    }
+
+    /**
+     *
+     * @return true if admissionController is Enforced Mode else false
+     */
+    public Boolean isAdmissionControllerEnforced(AdmissionControlMode admissionControlMode) {
+        return admissionControlMode == AdmissionControlMode.ENFORCED;
+    }
+
+    /**
+     * Apply admission control based on the resource usage for an action
+     */
+    public abstract void apply(String action, AdmissionControlActionType admissionControlActionType);
+
+    /**
+     * @return name of the admission-controller
+     */
+    public String getName() {
+        return this.admissionControllerName;
+    }
+
+    /**
+     * Add rejection count to the rejection count metric tracked by the admission controller
+     */
+    public void addRejectionCount(String admissionControlActionType, long count) {
+        if (!this.rejectionCountMap.containsKey(admissionControlActionType)) {
+            this.rejectionCountMap.put(admissionControlActionType, new AtomicLong(0));
+        }
+        this.rejectionCountMap.get(admissionControlActionType).getAndAdd(count);
+    }
+
+    /**
+     * @return current value of the rejection count metric tracked by the admission-controller.
+     */
+    public long getRejectionCount(String admissionControlActionType) {
+        if (this.rejectionCountMap.containsKey(admissionControlActionType)) {
+            return this.rejectionCountMap.get(admissionControlActionType).get();
+        }
+        return 0;
+    }
+
+    /**
+     * Get rejection stats of the admission controller
+     */
+    public Map<String, Long> getRejectionStats() {
+        Map<String, Long> rejectionStats = new HashMap<>();
+        rejectionCountMap.forEach((actionType, count) -> rejectionStats.put(actionType, count.get()));
+        return rejectionStats;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/CpuBasedAdmissionController.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/CpuBasedAdmissionController.java
new file mode 100644
index 0000000000000..5c180346c05e1
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/CpuBasedAdmissionController.java
@@ -0,0 +1,125 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.controllers;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.concurrency.OpenSearchRejectedExecutionException;
+import org.opensearch.node.NodeResourceUsageStats;
+import org.opensearch.node.ResourceUsageCollectorService;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings;
+
+import java.util.Locale;
+import java.util.Optional;
+
+/**
+ *  Class for CPU Based Admission Controller in OpenSearch, which aims to provide CPU utilisation admission control.
+ *  It provides methods to apply admission control if configured limit has been reached
+ */
+public class CpuBasedAdmissionController extends AdmissionController {
+    public static final String CPU_BASED_ADMISSION_CONTROLLER = "global_cpu_usage";
+    private static final Logger LOGGER = LogManager.getLogger(CpuBasedAdmissionController.class);
+    public CpuBasedAdmissionControllerSettings settings;
+
+    /**
+     * @param admissionControllerName       Name of the admission controller
+     * @param resourceUsageCollectorService Instance used to get node resource usage stats
+     * @param clusterService                ClusterService Instance
+     * @param settings                      Immutable settings instance
+     */
+    public CpuBasedAdmissionController(
+        String admissionControllerName,
+        ResourceUsageCollectorService resourceUsageCollectorService,
+        ClusterService clusterService,
+        Settings settings
+    ) {
+        super(admissionControllerName, resourceUsageCollectorService, clusterService);
+        this.settings = new CpuBasedAdmissionControllerSettings(clusterService.getClusterSettings(), settings);
+    }
+
+    /**
+     * Apply admission control based on process CPU usage
+     * @param action is the transport action
+     */
+    @Override
+    public void apply(String action, AdmissionControlActionType admissionControlActionType) {
+        if (this.isEnabledForTransportLayer(this.settings.getTransportLayerAdmissionControllerMode())) {
+            this.applyForTransportLayer(action, admissionControlActionType);
+        }
+    }
+
+    /**
+     * Apply transport layer admission control if configured limit has been reached
+     */
+    private void applyForTransportLayer(String actionName, AdmissionControlActionType admissionControlActionType) {
+        if (isLimitsBreached(actionName, admissionControlActionType)) {
+            this.addRejectionCount(admissionControlActionType.getType(), 1);
+            if (this.isAdmissionControllerEnforced(this.settings.getTransportLayerAdmissionControllerMode())) {
+                throw new OpenSearchRejectedExecutionException(
+                    String.format(
+                        Locale.ROOT,
+                        "CPU usage admission controller rejected the request for action [%s] as CPU limit reached",
+                        admissionControlActionType.name()
+                    )
+                );
+            }
+        }
+    }
+
+    /**
+     * Check if the configured resource usage limits are breached for the action
+     */
+    private boolean isLimitsBreached(String actionName, AdmissionControlActionType admissionControlActionType) {
+        // check if cluster state is ready
+        if (clusterService.state() != null && clusterService.state().nodes() != null) {
+            long maxCpuLimit = this.getCpuRejectionThreshold(admissionControlActionType);
+            Optional<NodeResourceUsageStats> nodePerformanceStatistics = this.resourceUsageCollectorService.getNodeStatistics(
+                this.clusterService.state().nodes().getLocalNodeId()
+            );
+            if (nodePerformanceStatistics.isPresent()) {
+                double cpuUsage = nodePerformanceStatistics.get().getCpuUtilizationPercent();
+                if (cpuUsage >= maxCpuLimit) {
+                    LOGGER.warn(
+                        "CpuBasedAdmissionController limit reached as the current CPU "
+                            + "usage [{}] exceeds the allowed limit [{}] for transport action [{}] in admissionControlMode [{}]",
+                        cpuUsage,
+                        maxCpuLimit,
+                        actionName,
+                        this.settings.getTransportLayerAdmissionControllerMode()
+                    );
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Get CPU rejection threshold based on action type
+     */
+    private long getCpuRejectionThreshold(AdmissionControlActionType admissionControlActionType) {
+        switch (admissionControlActionType) {
+            case SEARCH:
+                return this.settings.getSearchCPULimit();
+            case INDEXING:
+                return this.settings.getIndexingCPULimit();
+            default:
+                throw new IllegalArgumentException(
+                    String.format(
+                        Locale.ROOT,
+                        "Admission control not Supported for AdmissionControlActionType: %s",
+                        admissionControlActionType.getType()
+                    )
+                );
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/package-info.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/package-info.java
new file mode 100644
index 0000000000000..23746cc61a203
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/controllers/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains classes related to the different admission controllers
+ */
+package org.opensearch.ratelimitting.admissioncontrol.controllers;
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlActionType.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlActionType.java
new file mode 100644
index 0000000000000..8cf6e973ceb64
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlActionType.java
@@ -0,0 +1,45 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.enums;
+
+import java.util.Locale;
+
+/**
+ * Enums that defines the type of the transport requests
+ */
+public enum AdmissionControlActionType {
+    INDEXING("indexing"),
+    SEARCH("search");
+
+    private final String type;
+
+    AdmissionControlActionType(String uriType) {
+        this.type = uriType;
+    }
+
+    /**
+     *
+     * @return type of the request
+     */
+    public String getType() {
+        return type;
+    }
+
+    public static AdmissionControlActionType fromName(String name) {
+        name = name.toLowerCase(Locale.ROOT);
+        switch (name) {
+            case "indexing":
+                return INDEXING;
+            case "search":
+                return SEARCH;
+            default:
+                throw new IllegalArgumentException("Not Supported TransportAction Type: " + name);
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlMode.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlMode.java
new file mode 100644
index 0000000000000..2ae2436ba84e7
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlMode.java
@@ -0,0 +1,66 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.enums;
+
+import java.util.Locale;
+
+/**
+ * Defines the AdmissionControlMode
+ */
+public enum AdmissionControlMode {
+    /**
+     * AdmissionController is completely disabled.
+     */
+    DISABLED("disabled"),
+
+    /**
+     * AdmissionController only monitors the rejection criteria for the requests.
+     */
+    MONITOR("monitor_only"),
+
+    /**
+     * AdmissionController monitors and rejects tasks that exceed resource usage thresholds.
+     */
+    ENFORCED("enforced");
+
+    private final String mode;
+
+    /**
+     * @param mode update mode of the admission controller
+     */
+    AdmissionControlMode(String mode) {
+        this.mode = mode;
+    }
+
+    /**
+     *
+     * @return mode of the admission controller
+     */
+    public String getMode() {
+        return this.mode;
+    }
+
+    /**
+     *
+     * @param name is the mode of the current
+     * @return Enum of AdmissionControlMode based on the mode
+     */
+    public static AdmissionControlMode fromName(String name) {
+        switch (name.toLowerCase(Locale.ROOT)) {
+            case "disabled":
+                return DISABLED;
+            case "monitor_only":
+                return MONITOR;
+            case "enforced":
+                return ENFORCED;
+            default:
+                throw new IllegalArgumentException("Invalid AdmissionControlMode: " + name);
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/package-info.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/package-info.java
new file mode 100644
index 0000000000000..98b08ebd0a7bf
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/enums/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains enums related to the different admission controller feature
+ */
+package org.opensearch.ratelimitting.admissioncontrol.enums;
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/package-info.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/package-info.java
new file mode 100644
index 0000000000000..b3dc229f86fb6
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains base classes needed for the admissionController Feature
+ */
+package org.opensearch.ratelimitting.admissioncontrol;
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/settings/CpuBasedAdmissionControllerSettings.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/settings/CpuBasedAdmissionControllerSettings.java
new file mode 100644
index 0000000000000..1bddd1446a4c4
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/settings/CpuBasedAdmissionControllerSettings.java
@@ -0,0 +1,98 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.settings;
+
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.ratelimitting.admissioncontrol.AdmissionControlSettings;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+
+/**
+ * Settings related to cpu based admission controller.
+ * @opensearch.internal
+ */
+public class CpuBasedAdmissionControllerSettings {
+
+    /**
+     * Default parameters for the CpuBasedAdmissionControllerSettings
+     */
+    public static class Defaults {
+        public static final long CPU_USAGE_LIMIT = 95;
+    }
+
+    private AdmissionControlMode transportLayerMode;
+    private Long searchCPULimit;
+    private Long indexingCPULimit;
+    /**
+     * Feature level setting to operate in shadow-mode or in enforced-mode. If enforced field is set
+     * rejection will be performed, otherwise only rejection metrics will be populated.
+     */
+    public static final Setting<AdmissionControlMode> CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE = new Setting<>(
+        "admission_control.transport.cpu_usage.mode_override",
+        AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE,
+        AdmissionControlMode::fromName,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    /**
+     * This setting used to set the CPU Limits for the search requests by default it will use default IO usage limit
+     */
+    public static final Setting<Long> SEARCH_CPU_USAGE_LIMIT = Setting.longSetting(
+        "admission_control.search.cpu_usage.limit",
+        Defaults.CPU_USAGE_LIMIT,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    /**
+     * This setting used to set the CPU limits for the indexing requests by default it will use default IO usage limit
+     */
+    public static final Setting<Long> INDEXING_CPU_USAGE_LIMIT = Setting.longSetting(
+        "admission_control.indexing.cpu_usage.limit",
+        Defaults.CPU_USAGE_LIMIT,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
+    // currently limited to one setting will add further more settings in follow-up PR's
+    public CpuBasedAdmissionControllerSettings(ClusterSettings clusterSettings, Settings settings) {
+        this.transportLayerMode = CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.get(settings);
+        clusterSettings.addSettingsUpdateConsumer(CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE, this::setTransportLayerMode);
+        this.searchCPULimit = SEARCH_CPU_USAGE_LIMIT.get(settings);
+        this.indexingCPULimit = INDEXING_CPU_USAGE_LIMIT.get(settings);
+        clusterSettings.addSettingsUpdateConsumer(INDEXING_CPU_USAGE_LIMIT, this::setIndexingCPULimit);
+        clusterSettings.addSettingsUpdateConsumer(SEARCH_CPU_USAGE_LIMIT, this::setSearchCPULimit);
+    }
+
+    private void setTransportLayerMode(AdmissionControlMode admissionControlMode) {
+        this.transportLayerMode = admissionControlMode;
+    }
+
+    public AdmissionControlMode getTransportLayerAdmissionControllerMode() {
+        return transportLayerMode;
+    }
+
+    public Long getSearchCPULimit() {
+        return searchCPULimit;
+    }
+
+    public Long getIndexingCPULimit() {
+        return indexingCPULimit;
+    }
+
+    public void setIndexingCPULimit(Long indexingCPULimit) {
+        this.indexingCPULimit = indexingCPULimit;
+    }
+
+    public void setSearchCPULimit(Long searchCPULimit) {
+        this.searchCPULimit = searchCPULimit;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/settings/package-info.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/settings/package-info.java
new file mode 100644
index 0000000000000..a024ccc756745
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/settings/package-info.java
@@ -0,0 +1,11 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+/**
+ * This package contains settings related classes for the different admission controllers
+ */
+package org.opensearch.ratelimitting.admissioncontrol.settings;
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControlStats.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControlStats.java
new file mode 100644
index 0000000000000..39909c571c63e
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControlStats.java
@@ -0,0 +1,67 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.stats;
+
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.xcontent.ToXContentFragment;
+import org.opensearch.core.xcontent.XContentBuilder;
+
+import java.io.IOException;
+import java.util.List;
+
+/**
+ * Class for admission control stats used as part of node stats
+ * @opensearch.internal
+ */
+public class AdmissionControlStats implements ToXContentFragment, Writeable {
+
+    private final List<AdmissionControllerStats> admissionControllerStatsList;
+
+    /**
+     *
+     * @param admissionControllerStatsList list of admissionControllerStats
+     */
+    public AdmissionControlStats(List<AdmissionControllerStats> admissionControllerStatsList) {
+        this.admissionControllerStatsList = admissionControllerStatsList;
+    }
+
+    /**
+     *
+     * @param in the stream to read from
+     * @throws IOException if an I/O error occurs
+     */
+    public AdmissionControlStats(StreamInput in) throws IOException {
+        this.admissionControllerStatsList = in.readList(AdmissionControllerStats::new);
+    }
+
+    /**
+     * Write this into the {@linkplain StreamOutput}.
+     *
+     * @param out the output stream to write entity content to
+     */
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeList(this.admissionControllerStatsList);
+    }
+
+    public List<AdmissionControllerStats> getAdmissionControllerStatsList() {
+        return admissionControllerStatsList;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject("admission_control");
+        for (AdmissionControllerStats admissionControllerStats : this.admissionControllerStatsList) {
+            builder.field(admissionControllerStats.getAdmissionControllerName(), admissionControllerStats);
+        }
+        return builder.endObject();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControllerStats.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControllerStats.java
new file mode 100644
index 0000000000000..3895cac3eaa07
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControllerStats.java
@@ -0,0 +1,74 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.stats;
+
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.xcontent.ToXContentFragment;
+import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.AdmissionController;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * Class for admission controller ( such as CPU ) stats which includes rejection count for each action type
+ * @opensearch.internal
+ */
+public class AdmissionControllerStats implements Writeable, ToXContentFragment {
+    public Map<String, Long> rejectionCount;
+    public String admissionControllerName;
+
+    public AdmissionControllerStats(AdmissionController admissionController) {
+        this.rejectionCount = admissionController.getRejectionStats();
+        this.admissionControllerName = admissionController.getName();
+    }
+
+    public AdmissionControllerStats(StreamInput in) throws IOException {
+        this.rejectionCount = in.readMap(StreamInput::readString, StreamInput::readLong);
+        this.admissionControllerName = in.readString();
+    }
+
+    public String getAdmissionControllerName() {
+        return admissionControllerName;
+    }
+
+    public Map<String, Long> getRejectionCount() {
+        return rejectionCount;
+    }
+
+    /**
+     * Writes this instance into a {@link StreamOutput}
+     * @param out the {@link StreamOutput} to write to
+     * @throws IOException if an error occurs while writing to the StreamOutput
+     */
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeMap(this.rejectionCount, StreamOutput::writeString, StreamOutput::writeLong);
+        out.writeString(this.admissionControllerName);
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject();
+        builder.startObject("transport");
+        {
+            builder.startObject("rejection_count");
+            {
+                for (Map.Entry<String, Long> rejectionCountEntry : this.rejectionCount.entrySet()) {
+                    builder.field(rejectionCountEntry.getKey(), rejectionCountEntry.getValue());
+                }
+            }
+            builder.endObject();
+        }
+        builder.endObject();
+        return builder.endObject();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/package-info.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/package-info.java
new file mode 100644
index 0000000000000..7c96dcd569d64
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/stats/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains stats related classes for the admissionController Feature
+ */
+package org.opensearch.ratelimitting.admissioncontrol.stats;
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportHandler.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportHandler.java
new file mode 100644
index 0000000000000..1e8f309234f90
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportHandler.java
@@ -0,0 +1,70 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.transport;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.core.concurrency.OpenSearchRejectedExecutionException;
+import org.opensearch.ratelimitting.admissioncontrol.AdmissionControlService;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.tasks.Task;
+import org.opensearch.transport.TransportChannel;
+import org.opensearch.transport.TransportRequest;
+import org.opensearch.transport.TransportRequestHandler;
+
+/**
+ * AdmissionControl Handler to intercept Transport Requests.
+ * @param <T> Transport Request
+ */
+public class AdmissionControlTransportHandler<T extends TransportRequest> implements TransportRequestHandler<T> {
+
+    private final String action;
+    private final TransportRequestHandler<T> actualHandler;
+    protected final Logger log = LogManager.getLogger(this.getClass());
+    AdmissionControlService admissionControlService;
+    boolean forceExecution;
+    AdmissionControlActionType admissionControlActionType;
+
+    public AdmissionControlTransportHandler(
+        String action,
+        TransportRequestHandler<T> actualHandler,
+        AdmissionControlService admissionControlService,
+        boolean forceExecution,
+        AdmissionControlActionType admissionControlActionType
+    ) {
+        super();
+        this.action = action;
+        this.actualHandler = actualHandler;
+        this.admissionControlService = admissionControlService;
+        this.forceExecution = forceExecution;
+        this.admissionControlActionType = admissionControlActionType;
+    }
+
+    /**
+     * @param request Transport Request that landed on the node
+     * @param channel Transport channel allows to send a response to a request
+     * @param task Current task that is executing
+     * @throws Exception when admission control rejected the requests
+     */
+    @Override
+    public void messageReceived(T request, TransportChannel channel, Task task) throws Exception {
+        // skip admission control if force execution is true
+        if (!this.forceExecution) {
+            // intercept the transport requests here and apply admission control
+            try {
+                this.admissionControlService.applyTransportAdmissionControl(this.action, this.admissionControlActionType);
+            } catch (final OpenSearchRejectedExecutionException openSearchRejectedExecutionException) {
+                log.warn(openSearchRejectedExecutionException.getMessage());
+                channel.sendResponse(openSearchRejectedExecutionException);
+                return;
+            }
+        }
+        actualHandler.messageReceived(request, channel, task);
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportInterceptor.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportInterceptor.java
new file mode 100644
index 0000000000000..ae1520bca769d
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportInterceptor.java
@@ -0,0 +1,48 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.transport;
+
+import org.opensearch.ratelimitting.admissioncontrol.AdmissionControlService;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.transport.TransportInterceptor;
+import org.opensearch.transport.TransportRequest;
+import org.opensearch.transport.TransportRequestHandler;
+
+/**
+ * This class allows throttling by intercepting requests on both the sender and the receiver side.
+ */
+public class AdmissionControlTransportInterceptor implements TransportInterceptor {
+
+    AdmissionControlService admissionControlService;
+
+    public AdmissionControlTransportInterceptor(AdmissionControlService admissionControlService) {
+        this.admissionControlService = admissionControlService;
+    }
+
+    /**
+     *
+     * @return admissionController handler to intercept transport requests
+     */
+    @Override
+    public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+        String action,
+        String executor,
+        boolean forceExecution,
+        TransportRequestHandler<T> actualHandler,
+        AdmissionControlActionType admissionControlActionType
+    ) {
+        return new AdmissionControlTransportHandler<>(
+            action,
+            actualHandler,
+            this.admissionControlService,
+            forceExecution,
+            admissionControlActionType
+        );
+    }
+}
diff --git a/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/package-info.java b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/package-info.java
new file mode 100644
index 0000000000000..f97f31bc7b1db
--- /dev/null
+++ b/server/src/main/java/org/opensearch/ratelimitting/admissioncontrol/transport/package-info.java
@@ -0,0 +1,11 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+/**
+ * This package contains transport related classes for the admissionController Feature
+ */
+package org.opensearch.ratelimitting.admissioncontrol.transport;
diff --git a/server/src/main/java/org/opensearch/common/rounding/package-info.java b/server/src/main/java/org/opensearch/ratelimitting/package-info.java
similarity index 70%
rename from server/src/main/java/org/opensearch/common/rounding/package-info.java
rename to server/src/main/java/org/opensearch/ratelimitting/package-info.java
index 5fa3e39c6a786..c04358e14284f 100644
--- a/server/src/main/java/org/opensearch/common/rounding/package-info.java
+++ b/server/src/main/java/org/opensearch/ratelimitting/package-info.java
@@ -6,5 +6,7 @@
  * compatible open source license.
  */
 
-/** Base DateTime rounding package. */
-package org.opensearch.common.rounding;
+/**
+ * Base OpenSearch Throttling package
+ */
+package org.opensearch.ratelimitting;
diff --git a/server/src/main/java/org/opensearch/repositories/IndexId.java b/server/src/main/java/org/opensearch/repositories/IndexId.java
index 0b0644ce932e5..87a0063e8c21b 100644
--- a/server/src/main/java/org/opensearch/repositories/IndexId.java
+++ b/server/src/main/java/org/opensearch/repositories/IndexId.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.repositories;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -46,8 +47,9 @@
 /**
  * Represents a single snapshotted index in the repository.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class IndexId implements Writeable, ToXContentObject {
     protected static final String NAME = "name";
     protected static final String ID = "id";
@@ -80,7 +82,7 @@ public String getName() {
      * The unique ID for the index within the repository.  This is *not* the same as the
      * index's UUID, but merely a unique file/URL friendly identifier that a repository can
      * use to name blobs for the index.
-     *
+     * <p>
      * We could not use the index's actual UUID (See {@link Index#getUUID()}) because in the
      * case of snapshot/restore, the index UUID in the snapshotted index will be different
      * from the index UUID assigned to it when it is restored. Hence, the actual index UUID
diff --git a/server/src/main/java/org/opensearch/repositories/IndexMetaDataGenerations.java b/server/src/main/java/org/opensearch/repositories/IndexMetaDataGenerations.java
index 25cb0eaf43455..41f77e6830f5f 100644
--- a/server/src/main/java/org/opensearch/repositories/IndexMetaDataGenerations.java
+++ b/server/src/main/java/org/opensearch/repositories/IndexMetaDataGenerations.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.snapshots.SnapshotId;
 
 import java.util.Collection;
@@ -50,8 +51,9 @@
  * {@link IndexMetadata} should be computed and then used to check if it already exists in the repository via
  * {@link #getIndexMetaBlobId(String)}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class IndexMetaDataGenerations {
 
     public static final IndexMetaDataGenerations EMPTY = new IndexMetaDataGenerations(Collections.emptyMap(), Collections.emptyMap());
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoriesService.java b/server/src/main/java/org/opensearch/repositories/RepositoriesService.java
index 3d6679b3ef80e..68669feb16abc 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoriesService.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoriesService.java
@@ -84,6 +84,7 @@
 import java.util.stream.Stream;
 
 import static org.opensearch.repositories.blobstore.BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY;
+import static org.opensearch.repositories.blobstore.BlobStoreRepository.SYSTEM_REPOSITORY_SETTING;
 
 /**
  * Service responsible for maintaining and providing access to snapshot repositories on nodes.
@@ -154,7 +155,7 @@ public RepositoriesService(
     }
 
     /**
-     * Registers new repository in the cluster
+     * Registers new repository or updates an existing repository in the cluster
      * <p>
      * This method can be only called on the cluster-manager node. It tries to create a new repository on the master
      * and if it was successful it adds new repository to cluster metadata.
@@ -162,7 +163,7 @@ public RepositoriesService(
      * @param request  register repository request
      * @param listener register repository listener
      */
-    public void registerRepository(final PutRepositoryRequest request, final ActionListener<ClusterStateUpdateResponse> listener) {
+    public void registerOrUpdateRepository(final PutRepositoryRequest request, final ActionListener<ClusterStateUpdateResponse> listener) {
         assert lifecycle.started() : "Trying to register new repository but service is in state [" + lifecycle.state() + "]";
 
         final RepositoryMetadata newRepositoryMetadata = new RepositoryMetadata(
@@ -236,14 +237,30 @@ public ClusterState execute(ClusterState currentState) {
                         List<RepositoryMetadata> repositoriesMetadata = new ArrayList<>(repositories.repositories().size() + 1);
 
                         for (RepositoryMetadata repositoryMetadata : repositories.repositories()) {
-                            if (repositoryMetadata.name().equals(newRepositoryMetadata.name())) {
-                                if (newRepositoryMetadata.equalsIgnoreGenerations(repositoryMetadata)) {
+                            RepositoryMetadata updatedRepositoryMetadata = newRepositoryMetadata;
+                            if (isSystemRepositorySettingPresent(repositoryMetadata.settings())) {
+                                Settings updatedSettings = Settings.builder()
+                                    .put(newRepositoryMetadata.settings())
+                                    .put(SYSTEM_REPOSITORY_SETTING.getKey(), true)
+                                    .build();
+                                updatedRepositoryMetadata = new RepositoryMetadata(
+                                    newRepositoryMetadata.name(),
+                                    newRepositoryMetadata.type(),
+                                    updatedSettings,
+                                    newRepositoryMetadata.cryptoMetadata()
+                                );
+                            }
+                            if (repositoryMetadata.name().equals(updatedRepositoryMetadata.name())) {
+                                if (updatedRepositoryMetadata.equalsIgnoreGenerations(repositoryMetadata)) {
                                     // Previous version is the same as this one no update is needed.
                                     return currentState;
                                 }
                                 ensureCryptoSettingsAreSame(repositoryMetadata, request);
                                 found = true;
-                                repositoriesMetadata.add(newRepositoryMetadata);
+                                if (isSystemRepositorySettingPresent(repositoryMetadata.settings())) {
+                                    ensureValidSystemRepositoryUpdate(updatedRepositoryMetadata, repositoryMetadata);
+                                }
+                                repositoriesMetadata.add(updatedRepositoryMetadata);
                             } else {
                                 repositoriesMetadata.add(repositoryMetadata);
                             }
@@ -315,6 +332,7 @@ public ClusterState execute(ClusterState currentState) {
                         for (RepositoryMetadata repositoryMetadata : repositories.repositories()) {
                             if (Regex.simpleMatch(request.name(), repositoryMetadata.name())) {
                                 ensureRepositoryNotInUse(currentState, repositoryMetadata.name());
+                                ensureNotSystemRepository(repositoryMetadata);
                                 logger.info("delete repository [{}]", repositoryMetadata.name());
                                 changed = true;
                             } else {
@@ -439,7 +457,6 @@ public void applyClusterState(ClusterChangedEvent event) {
                     logger.debug("unregistering repository [{}]", entry.getKey());
                     Repository repository = entry.getValue();
                     closeRepository(repository);
-                    archiveRepositoryStats(repository, state.version());
                 } else {
                     survivors.put(entry.getKey(), entry.getValue());
                 }
@@ -456,19 +473,28 @@ public void applyClusterState(ClusterChangedEvent event) {
                         if (previousMetadata.type().equals(repositoryMetadata.type()) == false
                             || previousMetadata.settings().equals(repositoryMetadata.settings()) == false) {
                             // Previous version is different from the version in settings
-                            logger.debug("updating repository [{}]", repositoryMetadata.name());
-                            closeRepository(repository);
-                            archiveRepositoryStats(repository, state.version());
-                            repository = null;
-                            try {
-                                repository = createRepository(repositoryMetadata, typesRegistry);
-                            } catch (RepositoryException ex) {
-                                // TODO: this catch is bogus, it means the old repo is already closed,
-                                // but we have nothing to replace it
-                                logger.warn(
-                                    () -> new ParameterizedMessage("failed to change repository [{}]", repositoryMetadata.name()),
-                                    ex
+                            if (repository.isSystemRepository() && repository.isReloadable()) {
+                                logger.debug(
+                                    "updating repository [{}] in-place to use new metadata [{}]",
+                                    repositoryMetadata.name(),
+                                    repositoryMetadata
                                 );
+                                repository.validateMetadata(repositoryMetadata);
+                                repository.reload(repositoryMetadata);
+                            } else {
+                                logger.debug("updating repository [{}]", repositoryMetadata.name());
+                                closeRepository(repository);
+                                repository = null;
+                                try {
+                                    repository = createRepository(repositoryMetadata, typesRegistry);
+                                } catch (RepositoryException ex) {
+                                    // TODO: this catch is bogus, it means the old repo is already closed,
+                                    // but we have nothing to replace it
+                                    logger.warn(
+                                        () -> new ParameterizedMessage("failed to change repository [{}]", repositoryMetadata.name()),
+                                        ex
+                                    );
+                                }
                             }
                         }
                     } else {
@@ -547,12 +573,12 @@ public Repository repository(String repositoryName) {
     }
 
     public List<RepositoryStatsSnapshot> repositoriesStats() {
-        List<RepositoryStatsSnapshot> archivedRepoStats = repositoriesStatsArchive.getArchivedStats();
         List<RepositoryStatsSnapshot> activeRepoStats = getRepositoryStatsForActiveRepositories();
+        return activeRepoStats;
+    }
 
-        List<RepositoryStatsSnapshot> repositoriesStats = new ArrayList<>(archivedRepoStats);
-        repositoriesStats.addAll(activeRepoStats);
-        return repositoriesStats;
+    public RepositoriesStats getRepositoriesStats() {
+        return new RepositoriesStats(repositoriesStats());
     }
 
     private List<RepositoryStatsSnapshot> getRepositoryStatsForActiveRepositories() {
@@ -612,15 +638,6 @@ public void closeRepository(Repository repository) {
         repository.close();
     }
 
-    private void archiveRepositoryStats(Repository repository, long clusterStateVersion) {
-        if (repository instanceof MeteredBlobStoreRepository) {
-            RepositoryStatsSnapshot stats = ((MeteredBlobStoreRepository) repository).statsSnapshotForArchival(clusterStateVersion);
-            if (repositoriesStatsArchive.archive(stats) == false) {
-                logger.warn("Unable to archive the repository stats [{}] as the archive is full.", stats);
-            }
-        }
-    }
-
     /**
      * Creates repository holder. This method starts the non-internal repository
      */
@@ -682,6 +699,15 @@ public static void validateRepositoryMetadataSettings(
                     + minVersionInCluster
             );
         }
+        // Validation to not allow users to create system repository via put repository call.
+        if (isSystemRepositorySettingPresent(repositoryMetadataSettings)) {
+            throw new RepositoryException(
+                repositoryName,
+                "setting "
+                    + SYSTEM_REPOSITORY_SETTING.getKey()
+                    + " cannot provide system repository setting; this setting is managed by OpenSearch"
+            );
+        }
     }
 
     private static void ensureRepositoryNotInUse(ClusterState clusterState, String repository) {
@@ -756,6 +782,65 @@ public void updateRepositoriesMap(Map<String, Repository> repos) {
         }
     }
 
+    private static void ensureNotSystemRepository(RepositoryMetadata repositoryMetadata) {
+        if (isSystemRepositorySettingPresent(repositoryMetadata.settings())) {
+            throw new RepositoryException(repositoryMetadata.name(), "cannot delete a system repository");
+        }
+    }
+
+    private static boolean isSystemRepositorySettingPresent(Settings repositoryMetadataSettings) {
+        return SYSTEM_REPOSITORY_SETTING.get(repositoryMetadataSettings);
+    }
+
+    private static boolean isValueEqual(String key, String newValue, String currentValue) {
+        if (newValue == null && currentValue == null) {
+            return true;
+        }
+        if (newValue == null) {
+            throw new IllegalArgumentException("[" + key + "] cannot be empty, " + "current value [" + currentValue + "]");
+        }
+        if (newValue.equals(currentValue) == false) {
+            throw new IllegalArgumentException(
+                "trying to modify an unmodifiable attribute "
+                    + key
+                    + " of system repository from "
+                    + "current value ["
+                    + currentValue
+                    + "] to new value ["
+                    + newValue
+                    + "]"
+            );
+        }
+        return true;
+    }
+
+    public void ensureValidSystemRepositoryUpdate(RepositoryMetadata newRepositoryMetadata, RepositoryMetadata currentRepositoryMetadata) {
+        if (isSystemRepositorySettingPresent(currentRepositoryMetadata.settings())) {
+            try {
+                isValueEqual("type", newRepositoryMetadata.type(), currentRepositoryMetadata.type());
+
+                Repository repository = repositories.get(currentRepositoryMetadata.name());
+                Settings newRepositoryMetadataSettings = newRepositoryMetadata.settings();
+                Settings currentRepositoryMetadataSettings = currentRepositoryMetadata.settings();
+
+                List<String> restrictedSettings = repository.getRestrictedSystemRepositorySettings()
+                    .stream()
+                    .map(setting -> setting.getKey())
+                    .collect(Collectors.toList());
+
+                for (String restrictedSettingKey : restrictedSettings) {
+                    isValueEqual(
+                        restrictedSettingKey,
+                        newRepositoryMetadataSettings.get(restrictedSettingKey),
+                        currentRepositoryMetadataSettings.get(restrictedSettingKey)
+                    );
+                }
+            } catch (IllegalArgumentException e) {
+                throw new RepositoryException(currentRepositoryMetadata.name(), e.getMessage());
+            }
+        }
+    }
+
     @Override
     protected void doStart() {
 
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoriesStats.java b/server/src/main/java/org/opensearch/repositories/RepositoriesStats.java
new file mode 100644
index 0000000000000..cfcbc6bb88e66
--- /dev/null
+++ b/server/src/main/java/org/opensearch/repositories/RepositoriesStats.java
@@ -0,0 +1,56 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.repositories;
+
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.common.util.CollectionUtils;
+import org.opensearch.core.xcontent.ToXContentObject;
+import org.opensearch.core.xcontent.XContentBuilder;
+
+import java.io.IOException;
+import java.util.List;
+
+/**
+ * Encapsulates stats for multiple repositories
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "2.11.0")
+public class RepositoriesStats implements Writeable, ToXContentObject {
+
+    List<RepositoryStatsSnapshot> repositoryStatsSnapshots;
+
+    public RepositoriesStats(List<RepositoryStatsSnapshot> repositoryStatsSnapshots) {
+        this.repositoryStatsSnapshots = repositoryStatsSnapshots;
+    }
+
+    public RepositoriesStats(StreamInput in) throws IOException {
+        this.repositoryStatsSnapshots = in.readList(RepositoryStatsSnapshot::new);
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeList(repositoryStatsSnapshots);
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startArray("repositories");
+        if (CollectionUtils.isEmpty(repositoryStatsSnapshots) == false) {
+            for (RepositoryStatsSnapshot repositoryStatsSnapshot : repositoryStatsSnapshots) {
+                repositoryStatsSnapshot.toXContent(builder, params);
+            }
+        }
+        builder.endArray();
+        return builder;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoriesStatsArchive.java b/server/src/main/java/org/opensearch/repositories/RepositoriesStatsArchive.java
index b8f100706f81e..3d35f75176eaf 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoriesStatsArchive.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoriesStatsArchive.java
@@ -70,11 +70,6 @@ public RepositoriesStatsArchive(TimeValue retentionPeriod, int maxCapacity, Long
      * @return {@code true} if the repository stats were archived, {@code false} otherwise.
      */
     synchronized boolean archive(final RepositoryStatsSnapshot repositoryStats) {
-        assert containsRepositoryStats(repositoryStats) == false : "A repository with ephemeral id "
-            + repositoryStats.getRepositoryInfo().ephemeralId
-            + " is already archived";
-        assert repositoryStats.isArchived();
-
         evict();
 
         if (archive.size() >= maxCapacity) {
@@ -116,15 +111,6 @@ private void evict() {
         }
     }
 
-    private boolean containsRepositoryStats(RepositoryStatsSnapshot repositoryStats) {
-        return archive.stream()
-            .anyMatch(
-                entry -> entry.repositoryStatsSnapshot.getRepositoryInfo().ephemeralId.equals(
-                    repositoryStats.getRepositoryInfo().ephemeralId
-                )
-            );
-    }
-
     private static class ArchiveEntry {
         private final RepositoryStatsSnapshot repositoryStatsSnapshot;
         private final long createdAtMillis;
diff --git a/server/src/main/java/org/opensearch/repositories/Repository.java b/server/src/main/java/org/opensearch/repositories/Repository.java
index 10f3dc2b6b340..b3f1e9ce2eed9 100644
--- a/server/src/main/java/org/opensearch/repositories/Repository.java
+++ b/server/src/main/java/org/opensearch/repositories/Repository.java
@@ -41,7 +41,9 @@
 import org.opensearch.cluster.metadata.RepositoryMetadata;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lifecycle.LifecycleComponent;
+import org.opensearch.common.settings.Setting;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.mapper.MapperService;
@@ -55,6 +57,8 @@
 
 import java.io.IOException;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -72,14 +76,18 @@
  * <li>When all shard calls return cluster-manager calls {@link #finalizeSnapshot} with possible list of failures</li>
  * </ul>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface Repository extends LifecycleComponent {
 
     /**
      * An factory interface for constructing repositories.
      * See {@link org.opensearch.plugins.RepositoryPlugin}.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface Factory {
         /**
          * Constructs a repository.
@@ -342,6 +350,14 @@ void restoreShard(
         ActionListener<Void> listener
     );
 
+    /**
+     * Returns the list of restricted system repository settings that cannot be mutated post repository creation.
+     * @return list of settings
+     */
+    default List<Setting<?>> getRestrictedSystemRepositorySettings() {
+        return Collections.emptyList();
+    }
+
     /**
      * Returns Snapshot Shard Metadata for remote store interop enabled snapshot.
      * <p>
@@ -440,4 +456,22 @@ default void cloneRemoteStoreIndexShardSnapshot(
     default Map<String, Object> adaptUserMetadata(Map<String, Object> userMetadata) {
         return userMetadata;
     }
+
+    /**
+     * Checks if the repository can be reloaded inplace or not
+     * @return true if the repository can be reloaded inplace, false otherwise
+     */
+    default boolean isReloadable() {
+        return false;
+    }
+
+    /**
+     * Reload the repository inplace
+     */
+    default void reload(RepositoryMetadata repositoryMetadata) {}
+
+    /**
+     * Validate the repository metadata
+     */
+    default void validateMetadata(RepositoryMetadata repositoryMetadata) {}
 }
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoryCleanupResult.java b/server/src/main/java/org/opensearch/repositories/RepositoryCleanupResult.java
index f09aae195f0e5..eeddf4bd76659 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoryCleanupResult.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoryCleanupResult.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.repositories;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.blobstore.DeleteResult;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
@@ -47,8 +48,9 @@
 /**
  * Result of a repository cleanup action
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RepositoryCleanupResult implements Writeable, ToXContentObject {
 
     public static final ObjectParser<RepositoryCleanupResult, Void> PARSER = new ObjectParser<>(
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoryData.java b/server/src/main/java/org/opensearch/repositories/RepositoryData.java
index 90d7b404d089a..ea48d9b1a49fe 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoryData.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoryData.java
@@ -37,6 +37,7 @@
 import org.opensearch.Version;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.core.xcontent.XContentParserUtils;
@@ -60,8 +61,9 @@
  * A class that represents the data in a repository, as captured in the
  * repository's index blob.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RepositoryData {
 
     /**
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoryInfo.java b/server/src/main/java/org/opensearch/repositories/RepositoryInfo.java
index 8aa86fc46d591..c947ff19bbca8 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoryInfo.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoryInfo.java
@@ -32,7 +32,7 @@
 
 package org.opensearch.repositories;
 
-import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -48,67 +48,31 @@
 /**
  * Information about a repository
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RepositoryInfo implements Writeable, ToXContentFragment {
-    public final String ephemeralId;
     public final String name;
     public final String type;
     public final Map<String, String> location;
-    public final long startedAt;
-    @Nullable
-    public final Long stoppedAt;
 
-    public RepositoryInfo(String ephemeralId, String name, String type, Map<String, String> location, long startedAt) {
-        this(ephemeralId, name, type, location, startedAt, null);
-    }
-
-    public RepositoryInfo(
-        String ephemeralId,
-        String name,
-        String type,
-        Map<String, String> location,
-        long startedAt,
-        @Nullable Long stoppedAt
-    ) {
-        this.ephemeralId = ephemeralId;
+    public RepositoryInfo(String name, String type, Map<String, String> location) {
         this.name = name;
         this.type = type;
         this.location = location;
-        this.startedAt = startedAt;
-        if (stoppedAt != null && startedAt > stoppedAt) {
-            throw new IllegalArgumentException("createdAt must be before or equal to stoppedAt");
-        }
-        this.stoppedAt = stoppedAt;
     }
 
     public RepositoryInfo(StreamInput in) throws IOException {
-        this.ephemeralId = in.readString();
         this.name = in.readString();
         this.type = in.readString();
         this.location = in.readMap(StreamInput::readString, StreamInput::readString);
-        this.startedAt = in.readLong();
-        this.stoppedAt = in.readOptionalLong();
-    }
-
-    public RepositoryInfo stopped(long stoppedAt) {
-        assert isStopped() == false : "The repository is already stopped";
-
-        return new RepositoryInfo(ephemeralId, name, type, location, startedAt, stoppedAt);
-    }
-
-    public boolean isStopped() {
-        return stoppedAt != null;
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        out.writeString(ephemeralId);
         out.writeString(name);
         out.writeString(type);
         out.writeMap(location, StreamOutput::writeString, StreamOutput::writeString);
-        out.writeLong(startedAt);
-        out.writeOptionalLong(stoppedAt);
     }
 
     @Override
@@ -116,11 +80,6 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         builder.field("repository_name", name);
         builder.field("repository_type", type);
         builder.field("repository_location", location);
-        builder.field("repository_ephemeral_id", ephemeralId);
-        builder.field("repository_started_at", startedAt);
-        if (stoppedAt != null) {
-            builder.field("repository_stopped_at", stoppedAt);
-        }
         return builder;
     }
 
@@ -129,17 +88,12 @@ public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         RepositoryInfo that = (RepositoryInfo) o;
-        return ephemeralId.equals(that.ephemeralId)
-            && name.equals(that.name)
-            && type.equals(that.type)
-            && location.equals(that.location)
-            && startedAt == that.startedAt
-            && Objects.equals(stoppedAt, that.stoppedAt);
+        return name.equals(that.name) && type.equals(that.type) && location.equals(that.location);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(ephemeralId, name, type, location, startedAt, stoppedAt);
+        return Objects.hash(name, type, location);
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoryShardId.java b/server/src/main/java/org/opensearch/repositories/RepositoryShardId.java
index 4799f36156a73..5b16ffcdf83a4 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoryShardId.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoryShardId.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.repositories;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -42,8 +43,9 @@
 /**
  * Represents a shard snapshot in a repository.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RepositoryShardId implements Writeable {
 
     private final IndexId index;
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoryStats.java b/server/src/main/java/org/opensearch/repositories/RepositoryStats.java
index efd5d6f8560b6..a0cc1637af00e 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoryStats.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoryStats.java
@@ -32,9 +32,14 @@
 
 package org.opensearch.repositories;
 
+import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.common.blobstore.BlobStore;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
+import org.opensearch.core.xcontent.ToXContentFragment;
+import org.opensearch.core.xcontent.XContentBuilder;
 
 import java.io.IOException;
 import java.util.Collections;
@@ -45,34 +50,66 @@
 /**
  * Stats about a repository
  *
- * @opensearch.internal
+ * @opensearch.api
  */
-public class RepositoryStats implements Writeable {
+@PublicApi(since = "1.0.0")
+public class RepositoryStats implements Writeable, ToXContentFragment {
 
     public static final RepositoryStats EMPTY_STATS = new RepositoryStats(Collections.emptyMap());
 
+    @Nullable
     public final Map<String, Long> requestCounts;
+    @Nullable
+    public final Map<BlobStore.Metric, Map<String, Long>> extendedStats;
+    public final boolean detailed;
 
     public RepositoryStats(Map<String, Long> requestCounts) {
         this.requestCounts = Collections.unmodifiableMap(requestCounts);
+        this.extendedStats = Collections.emptyMap();
+        this.detailed = false;
+    }
+
+    public RepositoryStats(Map<BlobStore.Metric, Map<String, Long>> extendedStats, boolean detailed) {
+        this.requestCounts = Collections.emptyMap();
+        this.extendedStats = Collections.unmodifiableMap(extendedStats);
+        this.detailed = detailed;
     }
 
     public RepositoryStats(StreamInput in) throws IOException {
         this.requestCounts = in.readMap(StreamInput::readString, StreamInput::readLong);
+        this.extendedStats = in.readMap(
+            e -> e.readEnum(BlobStore.Metric.class),
+            i -> i.readMap(StreamInput::readString, StreamInput::readLong)
+        );
+        this.detailed = in.readBoolean();
     }
 
     public RepositoryStats merge(RepositoryStats otherStats) {
-        final Map<String, Long> result = new HashMap<>();
-        result.putAll(requestCounts);
-        for (Map.Entry<String, Long> entry : otherStats.requestCounts.entrySet()) {
-            result.merge(entry.getKey(), entry.getValue(), Math::addExact);
+        assert this.detailed == otherStats.detailed;
+        if (detailed) {
+            final Map<BlobStore.Metric, Map<String, Long>> result = new HashMap<>();
+            result.putAll(extendedStats);
+            for (Map.Entry<BlobStore.Metric, Map<String, Long>> entry : otherStats.extendedStats.entrySet()) {
+                for (Map.Entry<String, Long> nested : entry.getValue().entrySet()) {
+                    result.get(entry.getKey()).merge(nested.getKey(), nested.getValue(), Math::addExact);
+                }
+            }
+            return new RepositoryStats(result, true);
+        } else {
+            final Map<String, Long> result = new HashMap<>();
+            result.putAll(requestCounts);
+            for (Map.Entry<String, Long> entry : otherStats.requestCounts.entrySet()) {
+                result.merge(entry.getKey(), entry.getValue(), Math::addExact);
+            }
+            return new RepositoryStats(result);
         }
-        return new RepositoryStats(result);
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeMap(requestCounts, StreamOutput::writeString, StreamOutput::writeLong);
+        out.writeMap(extendedStats, StreamOutput::writeEnum, (o, v) -> o.writeMap(v, StreamOutput::writeString, StreamOutput::writeLong));
+        out.writeBoolean(detailed);
     }
 
     @Override
@@ -80,16 +117,32 @@ public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         RepositoryStats that = (RepositoryStats) o;
-        return requestCounts.equals(that.requestCounts);
+        return requestCounts.equals(that.requestCounts) && extendedStats.equals(that.extendedStats) && detailed == that.detailed;
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(requestCounts);
+        return Objects.hash(requestCounts, detailed, extendedStats);
     }
 
     @Override
     public String toString() {
-        return "RepositoryStats{" + "requestCounts=" + requestCounts + '}';
+        return "RepositoryStats{" + "requestCounts=" + requestCounts + "extendedStats=" + extendedStats + "detailed =" + detailed + "}";
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        if (detailed == false) {
+            builder.field("request_counts", requestCounts);
+        } else {
+            extendedStats.forEach((k, v) -> {
+                try {
+                    builder.field(k.metricName(), v);
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            });
+        }
+        return builder;
     }
 }
diff --git a/server/src/main/java/org/opensearch/repositories/RepositoryStatsSnapshot.java b/server/src/main/java/org/opensearch/repositories/RepositoryStatsSnapshot.java
index 2b061cd2c2cc9..3340defffc90f 100644
--- a/server/src/main/java/org/opensearch/repositories/RepositoryStatsSnapshot.java
+++ b/server/src/main/java/org/opensearch/repositories/RepositoryStatsSnapshot.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.repositories;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -46,28 +47,25 @@
 /**
  * Stats snapshot about a repository
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RepositoryStatsSnapshot implements Writeable, ToXContentObject {
     public static final long UNKNOWN_CLUSTER_VERSION = -1;
     private final RepositoryInfo repositoryInfo;
     private final RepositoryStats repositoryStats;
     private final long clusterVersion;
-    private final boolean archived;
 
-    public RepositoryStatsSnapshot(RepositoryInfo repositoryInfo, RepositoryStats repositoryStats, long clusterVersion, boolean archived) {
-        assert archived != (clusterVersion == UNKNOWN_CLUSTER_VERSION);
+    public RepositoryStatsSnapshot(RepositoryInfo repositoryInfo, RepositoryStats repositoryStats, long clusterVersion) {
         this.repositoryInfo = repositoryInfo;
         this.repositoryStats = repositoryStats;
         this.clusterVersion = clusterVersion;
-        this.archived = archived;
     }
 
     public RepositoryStatsSnapshot(StreamInput in) throws IOException {
         this.repositoryInfo = new RepositoryInfo(in);
         this.repositoryStats = new RepositoryStats(in);
         this.clusterVersion = in.readLong();
-        this.archived = in.readBoolean();
     }
 
     public RepositoryInfo getRepositoryInfo() {
@@ -78,10 +76,6 @@ public RepositoryStats getRepositoryStats() {
         return repositoryStats;
     }
 
-    public boolean isArchived() {
-        return archived;
-    }
-
     public long getClusterVersion() {
         return clusterVersion;
     }
@@ -91,18 +85,13 @@ public void writeTo(StreamOutput out) throws IOException {
         repositoryInfo.writeTo(out);
         repositoryStats.writeTo(out);
         out.writeLong(clusterVersion);
-        out.writeBoolean(archived);
     }
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject();
         repositoryInfo.toXContent(builder, params);
-        builder.field("request_counts", repositoryStats.requestCounts);
-        builder.field("archived", archived);
-        if (archived) {
-            builder.field("cluster_version", clusterVersion);
-        }
+        repositoryStats.toXContent(builder, params);
         builder.endObject();
         return builder;
     }
@@ -114,13 +103,12 @@ public boolean equals(Object o) {
         RepositoryStatsSnapshot that = (RepositoryStatsSnapshot) o;
         return repositoryInfo.equals(that.repositoryInfo)
             && repositoryStats.equals(that.repositoryStats)
-            && clusterVersion == that.clusterVersion
-            && archived == that.archived;
+            && clusterVersion == that.clusterVersion;
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(repositoryInfo, repositoryStats, clusterVersion, archived);
+        return Objects.hash(repositoryInfo, repositoryStats, clusterVersion);
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/repositories/ShardGenerations.java b/server/src/main/java/org/opensearch/repositories/ShardGenerations.java
index d918eb7e1e476..3591e683e58c1 100644
--- a/server/src/main/java/org/opensearch/repositories/ShardGenerations.java
+++ b/server/src/main/java/org/opensearch/repositories/ShardGenerations.java
@@ -33,6 +33,7 @@
 package org.opensearch.repositories;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Arrays;
 import java.util.Collection;
@@ -48,8 +49,9 @@
 /**
  * Generations of shards for snapshots
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ShardGenerations {
 
     public static final ShardGenerations EMPTY = new ShardGenerations(Collections.emptyMap());
@@ -177,8 +179,9 @@ public static Builder builder() {
     /**
      * Builder for the shard generations.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class Builder {
 
         private final Map<IndexId, Map<Integer, String>> generations = new HashMap<>();
diff --git a/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java b/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java
index 220d468a03090..8a2260e1f6d90 100644
--- a/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java
+++ b/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java
@@ -100,6 +100,7 @@
 import org.opensearch.core.compress.Compressor;
 import org.opensearch.core.compress.CompressorRegistry;
 import org.opensearch.core.compress.NotXContentException;
+import org.opensearch.core.index.Index;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.index.snapshots.IndexShardSnapshotFailedException;
 import org.opensearch.core.util.BytesRefUtils;
@@ -148,6 +149,7 @@
 import java.io.InputStream;
 import java.nio.file.NoSuchFileException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -171,6 +173,7 @@
 import java.util.stream.Stream;
 
 import static org.opensearch.index.snapshots.blobstore.BlobStoreIndexShardSnapshot.FileInfo.canonicalName;
+import static org.opensearch.repositories.blobstore.ChecksumBlobStoreFormat.SNAPSHOT_ONLY_FORMAT_PARAMS;
 
 /**
  * BlobStore - based implementation of Snapshot Repository
@@ -295,21 +298,21 @@ public abstract class BlobStoreRepository extends AbstractLifecycleComponent imp
         Setting.Property.NodeScope
     );
 
-    protected final boolean supportURLRepo;
+    protected volatile boolean supportURLRepo;
 
-    private final int maxShardBlobDeleteBatch;
+    private volatile int maxShardBlobDeleteBatch;
 
-    private final Compressor compressor;
+    private volatile Compressor compressor;
 
-    private final boolean cacheRepositoryData;
+    private volatile boolean cacheRepositoryData;
 
-    private final RateLimiter snapshotRateLimiter;
+    private volatile RateLimiter snapshotRateLimiter;
 
-    private final RateLimiter restoreRateLimiter;
+    private volatile RateLimiter restoreRateLimiter;
 
-    private final RateLimiter remoteUploadRateLimiter;
+    private volatile RateLimiter remoteUploadRateLimiter;
 
-    private final RateLimiter remoteDownloadRateLimiter;
+    private volatile RateLimiter remoteDownloadRateLimiter;
 
     private final CounterMetric snapshotRateLimitingTimeInNanos = new CounterMetric();
 
@@ -354,7 +357,7 @@ public abstract class BlobStoreRepository extends AbstractLifecycleComponent imp
         BlobStoreIndexShardSnapshots::fromXContent
     );
 
-    private final boolean readOnly;
+    private volatile boolean readOnly;
 
     private final boolean isSystemRepository;
 
@@ -364,7 +367,7 @@ public abstract class BlobStoreRepository extends AbstractLifecycleComponent imp
 
     private final SetOnce<BlobStore> blobStore = new SetOnce<>();
 
-    private final ClusterService clusterService;
+    protected final ClusterService clusterService;
 
     private final RecoverySettings recoverySettings;
 
@@ -398,36 +401,54 @@ public abstract class BlobStoreRepository extends AbstractLifecycleComponent imp
     /**
      * IO buffer size hint for reading and writing to the underlying blob store.
      */
-    protected final int bufferSize;
+    protected volatile int bufferSize;
 
     /**
      * Constructs new BlobStoreRepository
-     * @param metadata   The metadata for this repository including name and settings
+     * @param repositoryMetadata   The metadata for this repository including name and settings
      * @param clusterService ClusterService
      */
     protected BlobStoreRepository(
-        final RepositoryMetadata metadata,
-        final boolean compress,
+        final RepositoryMetadata repositoryMetadata,
         final NamedXContentRegistry namedXContentRegistry,
         final ClusterService clusterService,
         final RecoverySettings recoverySettings
     ) {
-        this.metadata = metadata;
+        // Read RepositoryMetadata as the first step
+        readRepositoryMetadata(repositoryMetadata);
+
+        isSystemRepository = SYSTEM_REPOSITORY_SETTING.get(metadata.settings());
         this.namedXContentRegistry = namedXContentRegistry;
         this.threadPool = clusterService.getClusterApplierService().threadPool();
         this.clusterService = clusterService;
         this.recoverySettings = recoverySettings;
-        this.supportURLRepo = SUPPORT_URL_REPO.get(metadata.settings());
+    }
+
+    @Override
+    public void reload(RepositoryMetadata repositoryMetadata) {
+        readRepositoryMetadata(repositoryMetadata);
+    }
+
+    /**
+     * Reloads the values derived from the Repository Metadata
+     *
+     * @param repositoryMetadata RepositoryMetadata instance to derive the values from
+     */
+    private void readRepositoryMetadata(RepositoryMetadata repositoryMetadata) {
+        this.metadata = repositoryMetadata;
+
+        supportURLRepo = SUPPORT_URL_REPO.get(metadata.settings());
         snapshotRateLimiter = getRateLimiter(metadata.settings(), "max_snapshot_bytes_per_sec", new ByteSizeValue(40, ByteSizeUnit.MB));
         restoreRateLimiter = getRateLimiter(metadata.settings(), "max_restore_bytes_per_sec", ByteSizeValue.ZERO);
         remoteUploadRateLimiter = getRateLimiter(metadata.settings(), "max_remote_upload_bytes_per_sec", ByteSizeValue.ZERO);
         remoteDownloadRateLimiter = getRateLimiter(metadata.settings(), "max_remote_download_bytes_per_sec", ByteSizeValue.ZERO);
         readOnly = READONLY_SETTING.get(metadata.settings());
-        isSystemRepository = SYSTEM_REPOSITORY_SETTING.get(metadata.settings());
         cacheRepositoryData = CACHE_REPOSITORY_DATA.get(metadata.settings());
         bufferSize = Math.toIntExact(BUFFER_SIZE_SETTING.get(metadata.settings()).getBytes());
         maxShardBlobDeleteBatch = MAX_SNAPSHOT_SHARD_BLOB_DELETE_BATCH_SIZE.get(metadata.settings());
-        this.compressor = compress ? COMPRESSION_TYPE_SETTING.get(metadata.settings()) : CompressorRegistry.none();
+        compressor = COMPRESS_SETTING.get(metadata.settings())
+            ? COMPRESSION_TYPE_SETTING.get(metadata.settings())
+            : CompressorRegistry.none();
     }
 
     @Override
@@ -830,6 +851,8 @@ public RepositoryStats stats() {
         final BlobStore store = blobStore.get();
         if (store == null) {
             return RepositoryStats.EMPTY_STATS;
+        } else if (store.extendedStats() != null && store.extendedStats().isEmpty() == false) {
+            return new RepositoryStats(store.extendedStats(), true);
         }
         return new RepositoryStats(store.stats());
     }
@@ -1125,7 +1148,11 @@ private void executeStaleShardDelete(
                                     new RemoteSegmentStoreDirectoryFactory(
                                         remoteStoreLockManagerFactory.getRepositoriesService(),
                                         threadPool
-                                    ).newDirectory(remoteStoreRepoForIndex, indexUUID, shardId).close();
+                                    ).newDirectory(
+                                        remoteStoreRepoForIndex,
+                                        indexUUID,
+                                        new ShardId(Index.UNKNOWN_INDEX_NAME, indexUUID, Integer.valueOf(shardId))
+                                    ).close();
                                 }
                             }
                         }
@@ -1591,7 +1618,11 @@ private void executeOneStaleIndexDelete(
                                             new RemoteSegmentStoreDirectoryFactory(
                                                 remoteStoreLockManagerFactory.getRepositoriesService(),
                                                 threadPool
-                                            ).newDirectory(remoteStoreRepoForIndex, indexUUID, shardBlob.getKey()).close();
+                                            ).newDirectory(
+                                                remoteStoreRepoForIndex,
+                                                indexUUID,
+                                                new ShardId(Index.UNKNOWN_INDEX_NAME, indexUUID, Integer.valueOf(shardBlob.getKey()))
+                                            ).close();
                                         }
                                     }
                                 }
@@ -2519,7 +2550,7 @@ private RepositoryMetadata getRepoMetadata(ClusterState state) {
      * the next version number from when the index blob was written.  Each individual index-N blob is
      * only written once and never overwritten.  The highest numbered index-N blob is the latest one
      * that contains the current snapshots in the repository.
-     *
+     * <p>
      * Package private for testing
      */
     long latestIndexBlobId() throws IOException {
@@ -3129,6 +3160,11 @@ public InputStream maybeRateLimitSnapshots(InputStream stream) {
         return maybeRateLimit(stream, () -> snapshotRateLimiter, snapshotRateLimitingTimeInNanos, BlobStoreTransferContext.SNAPSHOT);
     }
 
+    @Override
+    public List<Setting<?>> getRestrictedSystemRepositorySettings() {
+        return Arrays.asList(SYSTEM_REPOSITORY_SETTING, READONLY_SETTING, REMOTE_STORE_INDEX_SHALLOW_COPY);
+    }
+
     @Override
     public RemoteStoreShardShallowCopySnapshot getRemoteStoreShallowCopyShardMetadata(
         SnapshotId snapshotId,
@@ -3300,7 +3336,12 @@ private void writeShardIndexBlobAtomic(
             () -> new ParameterizedMessage("[{}] Writing shard index [{}] to [{}]", metadata.name(), indexGeneration, shardContainer.path())
         );
         final String blobName = INDEX_SHARD_SNAPSHOTS_FORMAT.blobName(String.valueOf(indexGeneration));
-        writeAtomic(shardContainer, blobName, INDEX_SHARD_SNAPSHOTS_FORMAT.serialize(updatedSnapshots, blobName, compressor), true);
+        writeAtomic(
+            shardContainer,
+            blobName,
+            INDEX_SHARD_SNAPSHOTS_FORMAT.serialize(updatedSnapshots, blobName, compressor, SNAPSHOT_ONLY_FORMAT_PARAMS),
+            true
+        );
     }
 
     // Unused blobs are all previous index-, data- and meta-blobs and that are not referenced by the new index- as well as all
diff --git a/server/src/main/java/org/opensearch/repositories/blobstore/ChecksumBlobStoreFormat.java b/server/src/main/java/org/opensearch/repositories/blobstore/ChecksumBlobStoreFormat.java
index 7e1960171043a..3e6052a5ef820 100644
--- a/server/src/main/java/org/opensearch/repositories/blobstore/ChecksumBlobStoreFormat.java
+++ b/server/src/main/java/org/opensearch/repositories/blobstore/ChecksumBlobStoreFormat.java
@@ -83,7 +83,7 @@
 public final class ChecksumBlobStoreFormat<T extends ToXContent> {
 
     // Serialization parameters to specify correct context for metadata serialization
-    private static final ToXContent.Params SNAPSHOT_ONLY_FORMAT_PARAMS;
+    public static final ToXContent.Params SNAPSHOT_ONLY_FORMAT_PARAMS;
 
     static {
         Map<String, String> snapshotOnlyParams = new HashMap<>();
@@ -170,36 +170,94 @@ public T deserialize(String blobName, NamedXContentRegistry namedXContentRegistr
      * @param compressor          whether to use compression
      */
     public void write(final T obj, final BlobContainer blobContainer, final String name, final Compressor compressor) throws IOException {
+        write(obj, blobContainer, name, compressor, SNAPSHOT_ONLY_FORMAT_PARAMS);
+    }
+
+    /**
+     * Writes blob with resolving the blob name using {@link #blobName} method.
+     * <p>
+     * The blob will optionally by compressed.
+     *
+     * @param obj                 object to be serialized
+     * @param blobContainer       blob container
+     * @param name                blob name
+     * @param compressor          whether to use compression
+     * @param params              ToXContent params
+     */
+    public void write(
+        final T obj,
+        final BlobContainer blobContainer,
+        final String name,
+        final Compressor compressor,
+        final ToXContent.Params params
+    ) throws IOException {
         final String blobName = blobName(name);
-        final BytesReference bytes = serialize(obj, blobName, compressor);
+        final BytesReference bytes = serialize(obj, blobName, compressor, params);
         blobContainer.writeBlob(blobName, bytes.streamInput(), bytes.length(), false);
     }
 
     /**
-     * Writes blob with resolving the blob name using {@link #blobName} method.
-     * Leverages the multipart upload if supported by the blobContainer.
+     * Internally calls {@link #writeAsyncWithPriority} with {@link WritePriority#NORMAL}
+     */
+    public void writeAsync(
+        final T obj,
+        final BlobContainer blobContainer,
+        final String name,
+        final Compressor compressor,
+        ActionListener<Void> listener,
+        final ToXContent.Params params
+    ) throws IOException {
+        // use NORMAL priority by default
+        this.writeAsyncWithPriority(obj, blobContainer, name, compressor, WritePriority.NORMAL, listener, params);
+    }
+
+    /**
+     * Internally calls {@link #writeAsyncWithPriority} with {@link WritePriority#URGENT}
+     * <p>
+     * <b>NOTE:</b> We use this method to upload urgent priority objects like cluster state to remote stores.
+     * Use {@link #writeAsync(ToXContent, BlobContainer, String, Compressor, ActionListener, ToXContent.Params)} for
+     * other use cases.
+     */
+    public void writeAsyncWithUrgentPriority(
+        final T obj,
+        final BlobContainer blobContainer,
+        final String name,
+        final Compressor compressor,
+        ActionListener<Void> listener,
+        final ToXContent.Params params
+    ) throws IOException {
+        this.writeAsyncWithPriority(obj, blobContainer, name, compressor, WritePriority.URGENT, listener, params);
+    }
+
+    /**
+     * Method to writes blob with resolving the blob name using {@link #blobName} method with specified
+     * {@link WritePriority}. Leverages the multipart upload if supported by the blobContainer.
      *
      * @param obj                 object to be serialized
      * @param blobContainer       blob container
      * @param name                blob name
      * @param compressor          whether to use compression
+     * @param priority            write priority to be used
      * @param listener            listener to listen to write result
+     * @param params              ToXContent params
      */
-    public void writeAsync(
+    private void writeAsyncWithPriority(
         final T obj,
         final BlobContainer blobContainer,
         final String name,
         final Compressor compressor,
-        ActionListener<Void> listener
+        final WritePriority priority,
+        ActionListener<Void> listener,
+        final ToXContent.Params params
     ) throws IOException {
         if (blobContainer instanceof AsyncMultiStreamBlobContainer == false) {
-            write(obj, blobContainer, name, compressor);
+            write(obj, blobContainer, name, compressor, params);
             listener.onResponse(null);
             return;
         }
         final String blobName = blobName(name);
-        final BytesReference bytes = serialize(obj, blobName, compressor);
-        final String resourceDescription = "ChecksumBlobStoreFormat.writeAsync(blob=\"" + blobName + "\")";
+        final BytesReference bytes = serialize(obj, blobName, compressor, params);
+        final String resourceDescription = "ChecksumBlobStoreFormat.writeAsyncWithPriority(blob=\"" + blobName + "\")";
         try (IndexInput input = new ByteArrayIndexInput(resourceDescription, BytesReference.toBytes(bytes))) {
             long expectedChecksum;
             try {
@@ -219,7 +277,7 @@ public void writeAsync(
                     blobName,
                     bytes.length(),
                     true,
-                    WritePriority.HIGH,
+                    priority,
                     (size, position) -> new OffsetRangeIndexInputStream(input, size, position),
                     expectedChecksum,
                     ((AsyncMultiStreamBlobContainer) blobContainer).remoteIntegrityCheckSupported()
@@ -230,7 +288,8 @@ public void writeAsync(
         }
     }
 
-    public BytesReference serialize(final T obj, final String blobName, final Compressor compressor) throws IOException {
+    public BytesReference serialize(final T obj, final String blobName, final Compressor compressor, final ToXContent.Params params)
+        throws IOException {
         try (BytesStreamOutput outputStream = new BytesStreamOutput()) {
             try (
                 OutputStreamIndexOutput indexOutput = new OutputStreamIndexOutput(
@@ -254,7 +313,7 @@ public void close() throws IOException {
                     )
                 ) {
                     builder.startObject();
-                    obj.toXContent(builder, SNAPSHOT_ONLY_FORMAT_PARAMS);
+                    obj.toXContent(builder, params);
                     builder.endObject();
                 }
                 CodecUtil.writeFooter(indexOutput);
diff --git a/server/src/main/java/org/opensearch/repositories/blobstore/MeteredBlobStoreRepository.java b/server/src/main/java/org/opensearch/repositories/blobstore/MeteredBlobStoreRepository.java
index 54f226e81025e..0651ff586d412 100644
--- a/server/src/main/java/org/opensearch/repositories/blobstore/MeteredBlobStoreRepository.java
+++ b/server/src/main/java/org/opensearch/repositories/blobstore/MeteredBlobStoreRepository.java
@@ -34,12 +34,10 @@
 
 import org.opensearch.cluster.metadata.RepositoryMetadata;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.UUIDs;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.repositories.RepositoryInfo;
 import org.opensearch.repositories.RepositoryStatsSnapshot;
-import org.opensearch.threadpool.ThreadPool;
 
 import java.util.Map;
 
@@ -53,29 +51,24 @@ public abstract class MeteredBlobStoreRepository extends BlobStoreRepository {
 
     public MeteredBlobStoreRepository(
         RepositoryMetadata metadata,
-        boolean compress,
         NamedXContentRegistry namedXContentRegistry,
         ClusterService clusterService,
         RecoverySettings recoverySettings,
         Map<String, String> location
     ) {
-        super(metadata, compress, namedXContentRegistry, clusterService, recoverySettings);
-        ThreadPool threadPool = clusterService.getClusterApplierService().threadPool();
-        this.repositoryInfo = new RepositoryInfo(
-            UUIDs.randomBase64UUID(),
-            metadata.name(),
-            metadata.type(),
-            location,
-            threadPool.absoluteTimeInMillis()
-        );
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings);
+        this.repositoryInfo = new RepositoryInfo(metadata.name(), metadata.type(), location);
     }
 
-    public RepositoryStatsSnapshot statsSnapshot() {
-        return new RepositoryStatsSnapshot(repositoryInfo, stats(), RepositoryStatsSnapshot.UNKNOWN_CLUSTER_VERSION, false);
+    @Override
+    public void reload(RepositoryMetadata repositoryMetadata) {
+        super.reload(repositoryMetadata);
+
+        // Not adding any additional reload logic here is intentional as the constructor only
+        // initializes the repositoryInfo from the repo metadata, which cannot be changed.
     }
 
-    public RepositoryStatsSnapshot statsSnapshotForArchival(long clusterVersion) {
-        RepositoryInfo stoppedRepoInfo = repositoryInfo.stopped(threadPool.absoluteTimeInMillis());
-        return new RepositoryStatsSnapshot(stoppedRepoInfo, stats(), clusterVersion, true);
+    public RepositoryStatsSnapshot statsSnapshot() {
+        return new RepositoryStatsSnapshot(repositoryInfo, stats(), RepositoryStatsSnapshot.UNKNOWN_CLUSTER_VERSION);
     }
 }
diff --git a/server/src/main/java/org/opensearch/repositories/fs/FsRepository.java b/server/src/main/java/org/opensearch/repositories/fs/FsRepository.java
index 3009466f03635..4a9a91336ec1d 100644
--- a/server/src/main/java/org/opensearch/repositories/fs/FsRepository.java
+++ b/server/src/main/java/org/opensearch/repositories/fs/FsRepository.java
@@ -50,6 +50,8 @@
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
 
 import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.function.Function;
 
 /**
@@ -61,7 +63,6 @@
  * <dt>{@code concurrent_streams}</dt><dd>Number of concurrent read/write stream (per repository on each node). Defaults to 5.</dd>
  * <dt>{@code chunk_size}</dt><dd>Large file can be divided into chunks. This parameter specifies the chunk size.
  *      Defaults to not chucked.</dd>
- * <dt>{@code compress}</dt><dd>If set to true metadata files will be stored compressed. Defaults to false.</dd>
  * </dl>
  *
  * @opensearch.internal
@@ -101,11 +102,11 @@ public class FsRepository extends BlobStoreRepository {
 
     public static final Setting<String> BASE_PATH_SETTING = Setting.simpleString("base_path");
 
-    private final Environment environment;
+    protected final Environment environment;
 
-    private ByteSizeValue chunkSize;
+    protected ByteSizeValue chunkSize;
 
-    private final BlobPath basePath;
+    protected BlobPath basePath;
 
     /**
      * Constructs a shared file system repository.
@@ -117,8 +118,27 @@ public FsRepository(
         ClusterService clusterService,
         RecoverySettings recoverySettings
     ) {
-        super(metadata, calculateCompress(metadata, environment), namedXContentRegistry, clusterService, recoverySettings);
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings);
         this.environment = environment;
+        validateLocation();
+        readMetadata();
+    }
+
+    protected void readMetadata() {
+        if (CHUNK_SIZE_SETTING.exists(metadata.settings())) {
+            this.chunkSize = CHUNK_SIZE_SETTING.get(metadata.settings());
+        } else {
+            this.chunkSize = REPOSITORIES_CHUNK_SIZE_SETTING.get(environment.settings());
+        }
+        final String basePath = BASE_PATH_SETTING.get(metadata.settings());
+        if (Strings.hasLength(basePath)) {
+            this.basePath = new BlobPath().add(basePath);
+        } else {
+            this.basePath = BlobPath.cleanPath();
+        }
+    }
+
+    protected void validateLocation() {
         String location = REPOSITORIES_LOCATION_SETTING.get(metadata.settings());
         if (location.isEmpty()) {
             logger.warn(
@@ -151,24 +171,6 @@ public FsRepository(
                 );
             }
         }
-
-        if (CHUNK_SIZE_SETTING.exists(metadata.settings())) {
-            this.chunkSize = CHUNK_SIZE_SETTING.get(metadata.settings());
-        } else {
-            this.chunkSize = REPOSITORIES_CHUNK_SIZE_SETTING.get(environment.settings());
-        }
-        final String basePath = BASE_PATH_SETTING.get(metadata.settings());
-        if (Strings.hasLength(basePath)) {
-            this.basePath = new BlobPath().add(basePath);
-        } else {
-            this.basePath = BlobPath.cleanPath();
-        }
-    }
-
-    private static boolean calculateCompress(RepositoryMetadata metadata, Environment environment) {
-        return COMPRESS_SETTING.exists(metadata.settings())
-            ? COMPRESS_SETTING.get(metadata.settings())
-            : REPOSITORIES_COMPRESS_SETTING.get(environment.settings());
     }
 
     @Override
@@ -187,4 +189,12 @@ protected ByteSizeValue chunkSize() {
     public BlobPath basePath() {
         return basePath;
     }
+
+    @Override
+    public List<Setting<?>> getRestrictedSystemRepositorySettings() {
+        List<Setting<?>> restrictedSettings = new ArrayList<>();
+        restrictedSettings.addAll(super.getRestrictedSystemRepositorySettings());
+        restrictedSettings.add(LOCATION_SETTING);
+        return restrictedSettings;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/repositories/fs/ReloadableFsRepository.java b/server/src/main/java/org/opensearch/repositories/fs/ReloadableFsRepository.java
new file mode 100644
index 0000000000000..c06c805a39396
--- /dev/null
+++ b/server/src/main/java/org/opensearch/repositories/fs/ReloadableFsRepository.java
@@ -0,0 +1,51 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.repositories.fs;
+
+import org.opensearch.cluster.metadata.RepositoryMetadata;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.env.Environment;
+import org.opensearch.indices.recovery.RecoverySettings;
+
+/**
+ * Extension of {@link FsRepository} that can be reloaded inplace
+ *
+ * @opensearch.internal
+ */
+public class ReloadableFsRepository extends FsRepository {
+    /**
+     * Constructs a shared file system repository that is reloadable in-place.
+     */
+    public ReloadableFsRepository(
+        RepositoryMetadata metadata,
+        Environment environment,
+        NamedXContentRegistry namedXContentRegistry,
+        ClusterService clusterService,
+        RecoverySettings recoverySettings
+    ) {
+        super(metadata, environment, namedXContentRegistry, clusterService, recoverySettings);
+    }
+
+    @Override
+    public boolean isReloadable() {
+        return true;
+    }
+
+    @Override
+    public void reload(RepositoryMetadata repositoryMetadata) {
+        if (isReloadable() == false) {
+            return;
+        }
+
+        super.reload(repositoryMetadata);
+        validateLocation();
+        readMetadata();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/rest/RestController.java b/server/src/main/java/org/opensearch/rest/RestController.java
index ac30f999d0da7..cc48b59699a17 100644
--- a/server/src/main/java/org/opensearch/rest/RestController.java
+++ b/server/src/main/java/org/opensearch/rest/RestController.java
@@ -524,7 +524,7 @@ private void handleBadRequest(String uri, RestRequest.Method method, RestChannel
     /**
      * Attempts to extract auth token and login.
      *
-     * @returns false if there was an error and the request should not continue being dispatched
+     * @return false if there was an error and the request should not continue being dispatched
      * */
     private boolean handleAuthenticateUser(final RestRequest request, final RestChannel channel) {
         try {
diff --git a/server/src/main/java/org/opensearch/rest/RestHandler.java b/server/src/main/java/org/opensearch/rest/RestHandler.java
index 7832649e8ad32..294dc3ffbe329 100644
--- a/server/src/main/java/org/opensearch/rest/RestHandler.java
+++ b/server/src/main/java/org/opensearch/rest/RestHandler.java
@@ -108,7 +108,7 @@ default List<ReplacedRoute> replacedRoutes() {
     }
 
     /**
-     * Controls whether requests handled by this class are allowed to to access system indices by default.
+     * Controls whether requests handled by this class are allowed to access system indices by default.
      * @return {@code true} if requests handled by this class should be allowed to access system indices.
      */
     default boolean allowSystemIndexAccessByDefault() {
diff --git a/server/src/main/java/org/opensearch/rest/RestRequest.java b/server/src/main/java/org/opensearch/rest/RestRequest.java
index f64774686c89d..2c397f7fc6e8e 100644
--- a/server/src/main/java/org/opensearch/rest/RestRequest.java
+++ b/server/src/main/java/org/opensearch/rest/RestRequest.java
@@ -37,6 +37,7 @@
 import org.opensearch.common.CheckedConsumer;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
@@ -72,6 +73,7 @@
  *
  * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RestRequest implements ToXContent.Params {
 
     // tchar pattern as defined by RFC7230 section 3.2.6
@@ -231,8 +233,9 @@ public static RestRequest requestWithoutParameters(
     /**
      * The method used.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Method {
         GET,
         POST,
diff --git a/server/src/main/java/org/opensearch/rest/action/cat/RestThreadPoolAction.java b/server/src/main/java/org/opensearch/rest/action/cat/RestThreadPoolAction.java
index 652bc448144e2..0393dd15c8238 100644
--- a/server/src/main/java/org/opensearch/rest/action/cat/RestThreadPoolAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/cat/RestThreadPoolAction.java
@@ -163,6 +163,10 @@ protected Table getTableWithHeader(final RestRequest request) {
         table.addCell("rejected", "alias:r;default:true;text-align:right;desc:number of rejected tasks");
         table.addCell("largest", "alias:l;default:false;text-align:right;desc:highest number of seen active threads");
         table.addCell("completed", "alias:c;default:false;text-align:right;desc:number of completed tasks");
+        table.addCell(
+            "total_wait_time",
+            "alias:twt;default:false;text-align:right;desc:total time tasks spent waiting in thread_pool queue"
+        );
         table.addCell("core", "alias:cr;default:false;text-align:right;desc:core number of threads in a scaling thread pool");
         table.addCell("max", "alias:mx;default:false;text-align:right;desc:maximum number of threads in a scaling thread pool");
         table.addCell("size", "alias:sz;default:false;text-align:right;desc:number of threads in a fixed thread pool");
@@ -267,6 +271,7 @@ private Table buildTable(RestRequest req, ClusterStateResponse state, NodesInfoR
                 table.addCell(poolStats == null ? null : poolStats.getRejected());
                 table.addCell(poolStats == null ? null : poolStats.getLargest());
                 table.addCell(poolStats == null ? null : poolStats.getCompleted());
+                table.addCell(poolStats == null ? null : poolStats.getWaitTime());
                 table.addCell(core);
                 table.addCell(max);
                 table.addCell(size);
diff --git a/server/src/main/java/org/opensearch/rest/action/search/RestSearchAction.java b/server/src/main/java/org/opensearch/rest/action/search/RestSearchAction.java
index ebfd082d974fd..080366e536da1 100644
--- a/server/src/main/java/org/opensearch/rest/action/search/RestSearchAction.java
+++ b/server/src/main/java/org/opensearch/rest/action/search/RestSearchAction.java
@@ -180,6 +180,12 @@ public static void parseSearchRequest(
             searchRequest.allowPartialSearchResults(request.paramAsBoolean("allow_partial_search_results", null));
         }
 
+        if (request.hasParam("phase_took")) {
+            // only set if we have the parameter passed to override the cluster-level default
+            // else phaseTook = null
+            searchRequest.setPhaseTook(request.paramAsBoolean("phase_took", true));
+        }
+
         // do not allow 'query_and_fetch' or 'dfs_query_and_fetch' search types
         // from the REST layer. these modes are an internal optimization and should
         // not be specified explicitly by the user.
diff --git a/server/src/main/java/org/opensearch/script/AggregationScript.java b/server/src/main/java/org/opensearch/script/AggregationScript.java
index ef300e9473d3e..2e2f4af027e1b 100644
--- a/server/src/main/java/org/opensearch/script/AggregationScript.java
+++ b/server/src/main/java/org/opensearch/script/AggregationScript.java
@@ -34,6 +34,7 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.search.Scorable;
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.lucene.ScorerAware;
 import org.opensearch.index.fielddata.ScriptDocValues;
@@ -49,8 +50,9 @@
 /**
  * Scripts for aggregations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class AggregationScript implements ScorerAware {
 
     public static final String[] PARAMETERS = {};
@@ -168,8 +170,9 @@ public double runAsDouble() {
     /**
      * A factory to construct {@link AggregationScript} instances.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface LeafFactory {
         AggregationScript newInstance(LeafReaderContext ctx) throws IOException;
 
diff --git a/server/src/main/java/org/opensearch/script/FieldScript.java b/server/src/main/java/org/opensearch/script/FieldScript.java
index 82b5c9a088a2c..054b60bbaf3e3 100644
--- a/server/src/main/java/org/opensearch/script/FieldScript.java
+++ b/server/src/main/java/org/opensearch/script/FieldScript.java
@@ -33,6 +33,7 @@
 package org.opensearch.script;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.search.lookup.LeafSearchLookup;
@@ -47,8 +48,9 @@
 /**
  * A script to produce dynamic values for return fields.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class FieldScript {
 
     public static final String[] PARAMETERS = {};
@@ -113,8 +115,9 @@ public void setDocument(int docid) {
     /**
      * A factory to construct {@link FieldScript} instances.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface LeafFactory {
         FieldScript newInstance(LeafReaderContext ctx) throws IOException;
     }
diff --git a/server/src/main/java/org/opensearch/script/ScoreScriptUtils.java b/server/src/main/java/org/opensearch/script/ScoreScriptUtils.java
index 0767c29fa1b31..2396aa369e98d 100644
--- a/server/src/main/java/org/opensearch/script/ScoreScriptUtils.java
+++ b/server/src/main/java/org/opensearch/script/ScoreScriptUtils.java
@@ -50,7 +50,6 @@
 import static org.opensearch.common.util.BitMixer.mix32;
 import static org.opensearch.index.query.functionscore.TermFrequencyFunctionFactory.TermFrequencyFunctionName.SUM_TOTAL_TERM_FREQ;
 import static org.opensearch.index.query.functionscore.TermFrequencyFunctionFactory.TermFrequencyFunctionName.TERM_FREQ;
-import static org.opensearch.index.query.functionscore.TermFrequencyFunctionFactory.TermFrequencyFunctionName.TF;
 import static org.opensearch.index.query.functionscore.TermFrequencyFunctionFactory.TermFrequencyFunctionName.TOTAL_TERM_FREQ;
 
 /**
@@ -95,27 +94,6 @@ public int termFreq(String field, String term) {
         }
     }
 
-    /**
-     * Calculates the term frequency-inverse document frequency (tf-idf) for a specific term within a field.
-     *
-     * @opensearch.internal
-     */
-    public static final class TF {
-        private final ScoreScript scoreScript;
-
-        public TF(ScoreScript scoreScript) {
-            this.scoreScript = scoreScript;
-        }
-
-        public float tf(String field, String term) {
-            try {
-                return (float) scoreScript.getTermFrequency(TF, field, term);
-            } catch (Exception e) {
-                throw ExceptionsHelper.convertToOpenSearchException(e);
-            }
-        }
-    }
-
     /**
      * Retrieves the total term frequency within a field for a specific term.
      *
@@ -365,11 +343,14 @@ public double decayNumericGauss(double docValue) {
     /**
      * Limitations: since script functions don't have access to DateFieldMapper,
      * decay functions on dates are limited to dates in the default format and default time zone,
+     * Further, since script module gets initialized before the featureflags are loaded,
+     * we cannot use the feature flag to gate the usage of the new default date format.
      * Also, using calculations with <code>now</code> are not allowed.
      *
      */
     private static final ZoneId defaultZoneId = ZoneId.of("UTC");
-    private static final DateMathParser dateParser = DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.toDateMathParser();
+    // ToDo: use new default date formatter once feature flag is removed
+    private static final DateMathParser dateParser = DateFieldMapper.LEGACY_DEFAULT_DATE_TIME_FORMATTER.toDateMathParser();
 
     /**
      * Linear date decay
diff --git a/server/src/main/java/org/opensearch/script/Script.java b/server/src/main/java/org/opensearch/script/Script.java
index a611e71c3bf3f..9e74314c281cd 100644
--- a/server/src/main/java/org/opensearch/script/Script.java
+++ b/server/src/main/java/org/opensearch/script/Script.java
@@ -70,9 +70,9 @@
  * {@link Script} represents used-defined input that can be used to
  * compile and execute a script from the {@link ScriptService}
  * based on the {@link ScriptType}.
- *
+ * <p>
  * There are three types of scripts specified by {@link ScriptType}.
- *
+ * <p>
  * The following describes the expected parameters for each type of script:
  *
  * <ul>
@@ -348,16 +348,16 @@ public static Script parse(Settings settings) {
 
     /**
      * This will parse XContent into a {@link Script}.  The following formats can be parsed:
-     *
+     * <p>
      * The simple format defaults to an {@link ScriptType#INLINE} with no compiler options or user-defined params:
-     *
+     * <p>
      * Example:
      * {@code
      * "return Math.log(doc.popularity) * 100;"
      * }
      *
      * The complex format where {@link ScriptType} and idOrCode are required while lang, options and params are not required.
-     *
+     * <p>
      * {@code
      * {
      *     // Exactly one of "id" or "source" must be specified
@@ -391,7 +391,7 @@ public static Script parse(Settings settings) {
      *
      * This also handles templates in a special way.  If a complexly formatted query is specified as another complex
      * JSON object the query is assumed to be a template, and the format will be preserved.
-     *
+     * <p>
      * {@code
      * {
      *     "source" : { "query" : ... },
@@ -605,7 +605,7 @@ public void writeTo(StreamOutput out) throws IOException {
 
     /**
      * This will build scripts into the following XContent structure:
-     *
+     * <p>
      * {@code
      * {
      *     "<(id, source)>" : "<idOrCode>",
@@ -635,10 +635,10 @@ public void writeTo(StreamOutput out) throws IOException {
      * }
      *
      * Note that lang, options, and params will only be included if there have been any specified.
-     *
+     * <p>
      * This also handles templates in a special way.  If the {@link Script#CONTENT_TYPE_OPTION} option
      * is provided and the {@link ScriptType#INLINE} is specified then the template will be preserved as a raw field.
-     *
+     * <p>
      * {@code
      * {
      *     "source" : { "query" : ... },
diff --git a/server/src/main/java/org/opensearch/script/ScriptCache.java b/server/src/main/java/org/opensearch/script/ScriptCache.java
index 3c50fc12dcacb..fb57e7cdfa5bd 100644
--- a/server/src/main/java/org/opensearch/script/ScriptCache.java
+++ b/server/src/main/java/org/opensearch/script/ScriptCache.java
@@ -158,7 +158,7 @@ public ScriptContextStats stats(String context) {
     /**
      * Check whether there have been too many compilations within the last minute, throwing a circuit breaking exception if so.
      * This is a variant of the token bucket algorithm: https://en.wikipedia.org/wiki/Token_bucket
-     *
+     * <p>
      * It can be thought of as a bucket with water, every time the bucket is checked, water is added proportional to the amount of time that
      * elapsed since the last time it was checked. If there is enough water, some is removed and the request is allowed. If there is not
      * enough water the request is denied. Just like a normal bucket, if water is added that overflows the bucket, the extra water/capacity
diff --git a/server/src/main/java/org/opensearch/script/ScriptCacheStats.java b/server/src/main/java/org/opensearch/script/ScriptCacheStats.java
index be7a1c9542a60..d06ffa70235f8 100644
--- a/server/src/main/java/org/opensearch/script/ScriptCacheStats.java
+++ b/server/src/main/java/org/opensearch/script/ScriptCacheStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.script;
 
+import org.opensearch.common.annotation.DeprecatedApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -52,6 +53,7 @@
  *
  * @deprecated This class is deprecated in favor of ScriptStats and ScriptContextStats.  It is removed in OpenSearch 2.0.
  */
+@DeprecatedApi(since = "2.0.0")
 @Deprecated
 public class ScriptCacheStats implements Writeable, ToXContentFragment {
     private final Map<String, ScriptStats> context;
diff --git a/server/src/main/java/org/opensearch/script/ScriptContext.java b/server/src/main/java/org/opensearch/script/ScriptContext.java
index 71ced303b062e..2180b6059dbef 100644
--- a/server/src/main/java/org/opensearch/script/ScriptContext.java
+++ b/server/src/main/java/org/opensearch/script/ScriptContext.java
@@ -40,7 +40,7 @@
 
 /**
  * The information necessary to compile and run a script.
- *
+ * <p>
  * A {@link ScriptContext} contains the information related to a single use case and the interfaces
  * and methods necessary for a {@link ScriptEngine} to implement.
  * <p>
diff --git a/server/src/main/java/org/opensearch/script/ScriptContextInfo.java b/server/src/main/java/org/opensearch/script/ScriptContextInfo.java
index d3a64c207e0ce..ee4c0aa09388e 100644
--- a/server/src/main/java/org/opensearch/script/ScriptContextInfo.java
+++ b/server/src/main/java/org/opensearch/script/ScriptContextInfo.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.script;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -60,8 +61,9 @@
 /**
  * Information about a script context
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ScriptContextInfo implements ToXContentObject, Writeable {
     public final String name;
     public final ScriptMethodInfo execute;
@@ -202,8 +204,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Script method information
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ScriptMethodInfo implements ToXContentObject, Writeable {
         public final String name, returnType;
         public final List<ParameterInfo> parameters;
diff --git a/server/src/main/java/org/opensearch/script/ScriptContextStats.java b/server/src/main/java/org/opensearch/script/ScriptContextStats.java
index 16f4a7e313326..15a5596609586 100644
--- a/server/src/main/java/org/opensearch/script/ScriptContextStats.java
+++ b/server/src/main/java/org/opensearch/script/ScriptContextStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.script;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * Stats for a script context
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ScriptContextStats implements Writeable, ToXContentFragment, Comparable<ScriptContextStats> {
     private final String context;
     private final long compilations;
diff --git a/server/src/main/java/org/opensearch/script/ScriptLanguagesInfo.java b/server/src/main/java/org/opensearch/script/ScriptLanguagesInfo.java
index ef64959f99a3c..1a6626db64811 100644
--- a/server/src/main/java/org/opensearch/script/ScriptLanguagesInfo.java
+++ b/server/src/main/java/org/opensearch/script/ScriptLanguagesInfo.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.script;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -56,11 +57,11 @@
 /**
  * The allowable types, languages and their corresponding contexts.  When serialized there is a top level <code>types_allowed</code> list,
  * meant to reflect the setting <code>script.allowed_types</code> with the allowed types (eg <code>inline</code>, <code>stored</code>).
- *
+ * <p>
  * The top-level <code>language_contexts</code> list of objects have the <code>language</code> (eg. <code>painless</code>,
  * <code>mustache</code>) and a list of <code>contexts</code> available for the language.  It is the responsibility of the caller to ensure
  * these contexts are filtered by the <code>script.allowed_contexts</code> setting.
- *
+ * <p>
  * The json serialization of the object has the form:
  * <code>
  *     {
@@ -91,8 +92,9 @@
  * }
  * </code>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ScriptLanguagesInfo implements ToXContentObject, Writeable {
     private static final ParseField TYPES_ALLOWED = new ParseField("types_allowed");
     private static final ParseField LANGUAGE_CONTEXTS = new ParseField("language_contexts");
diff --git a/server/src/main/java/org/opensearch/script/ScriptMetadata.java b/server/src/main/java/org/opensearch/script/ScriptMetadata.java
index 5f529fccd213c..fd92d8f7f02db 100644
--- a/server/src/main/java/org/opensearch/script/ScriptMetadata.java
+++ b/server/src/main/java/org/opensearch/script/ScriptMetadata.java
@@ -183,9 +183,9 @@ static ScriptMetadata deleteStoredScript(ScriptMetadata previous, String id) {
 
     /**
      * This will parse XContent into {@link ScriptMetadata}.
-     *
+     * <p>
      * The following format will be parsed:
-     *
+     * <p>
      * {@code
      * {
      *     "<id>" : "<{@link StoredScriptSource#fromXContent(XContentParser, boolean)}>",
@@ -356,7 +356,7 @@ public void writeTo(StreamOutput out) throws IOException {
 
     /**
      * This will write XContent from {@link ScriptMetadata}.  The following format will be written:
-     *
+     * <p>
      * {@code
      * {
      *     "<id>" : "<{@link StoredScriptSource#toXContent(XContentBuilder, Params)}>",
diff --git a/server/src/main/java/org/opensearch/script/ScriptStats.java b/server/src/main/java/org/opensearch/script/ScriptStats.java
index aeb3645242799..850f7f9d07070 100644
--- a/server/src/main/java/org/opensearch/script/ScriptStats.java
+++ b/server/src/main/java/org/opensearch/script/ScriptStats.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.script;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -48,8 +49,9 @@
 /**
  * Stats for scripts
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ScriptStats implements Writeable, ToXContentFragment {
     private final List<ScriptContextStats> contextStats;
     private final long compilations;
diff --git a/server/src/main/java/org/opensearch/script/StoredScriptSource.java b/server/src/main/java/org/opensearch/script/StoredScriptSource.java
index 0ff44b3af890a..fc19022657f9e 100644
--- a/server/src/main/java/org/opensearch/script/StoredScriptSource.java
+++ b/server/src/main/java/org/opensearch/script/StoredScriptSource.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.Diff;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.core.ParseField;
@@ -65,8 +66,9 @@
  * {@link StoredScriptSource} represents user-defined parameters for a script
  * saved in the {@link ClusterState}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class StoredScriptSource extends AbstractDiffable<StoredScriptSource> implements Writeable, ToXContentObject {
 
     /**
@@ -308,7 +310,7 @@ public static StoredScriptSource parse(BytesReference content, MediaType mediaTy
 
     /**
      * This will parse XContent into a {@link StoredScriptSource}. The following format is what will be parsed:
-     *
+     * <p>
      * {@code
      * {
      *     "script" : {
@@ -387,7 +389,7 @@ public void writeTo(StreamOutput out) throws IOException {
 
     /**
      * This will write XContent from a {@link StoredScriptSource}. The following format will be written:
-     *
+     * <p>
      * {@code
      * {
      *     "script" : {
diff --git a/server/src/main/java/org/opensearch/search/DefaultSearchContext.java b/server/src/main/java/org/opensearch/search/DefaultSearchContext.java
index 28931bb5a860f..960b46d68977b 100644
--- a/server/src/main/java/org/opensearch/search/DefaultSearchContext.java
+++ b/server/src/main/java/org/opensearch/search/DefaultSearchContext.java
@@ -896,6 +896,8 @@ public void evaluateRequestShouldUseConcurrentSearch() {
             && aggregations().factories() != null
             && !aggregations().factories().allFactoriesSupportConcurrentSearch()) {
                 requestShouldUseConcurrentSearch.set(false);
+            } else if (terminateAfter != DEFAULT_TERMINATE_AFTER) {
+                requestShouldUseConcurrentSearch.set(false);
             } else {
                 requestShouldUseConcurrentSearch.set(true);
             }
diff --git a/server/src/main/java/org/opensearch/search/DocValueFormat.java b/server/src/main/java/org/opensearch/search/DocValueFormat.java
index c6187e5949035..9fae14f69b0af 100644
--- a/server/src/main/java/org/opensearch/search/DocValueFormat.java
+++ b/server/src/main/java/org/opensearch/search/DocValueFormat.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.Version;
 import org.opensearch.common.Numbers;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.network.InetAddresses;
 import org.opensearch.common.network.NetworkAddress;
 import org.opensearch.common.time.DateFormatter;
@@ -64,8 +65,9 @@
 /**
  * A formatter for values as returned by the fielddata/doc-values APIs.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface DocValueFormat extends NamedWriteable {
     long MASK_2_63 = 0x8000000000000000L;
     BigInteger BIGINTEGER_2_64_MINUS_ONE = BigInteger.ONE.shiftLeft(64).subtract(BigInteger.ONE); // 2^64 -1
@@ -243,7 +245,12 @@ public DateTime(DateFormatter formatter, ZoneId timeZone, DateFieldMapper.Resolu
         }
 
         public DateTime(StreamInput in) throws IOException {
-            this.formatter = DateFormatter.forPattern(in.readString());
+            if (in.getVersion().onOrAfter(Version.V_2_12_0)) {
+                this.formatter = DateFormatter.forPattern(in.readString(), in.readOptionalString());
+            } else {
+                this.formatter = DateFormatter.forPattern(in.readString());
+            }
+
             this.parser = formatter.toDateMathParser();
             String zoneId = in.readString();
             this.timeZone = ZoneId.of(zoneId);
@@ -260,7 +267,14 @@ public String getWriteableName() {
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
-            out.writeString(formatter.pattern());
+            if (out.getVersion().before(Version.V_2_12_0) && formatter.equals(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER)) {
+                out.writeString(DateFieldMapper.LEGACY_DEFAULT_DATE_TIME_FORMATTER.pattern()); // required for backwards compatibility
+            } else {
+                out.writeString(formatter.pattern());
+            }
+            if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
+                out.writeOptionalString(formatter.printPattern());
+            }
             out.writeString(timeZone.getId());
             out.writeVInt(resolution.ordinal());
             if (out.getVersion().before(Version.V_3_0_0)) {
diff --git a/server/src/main/java/org/opensearch/search/MultiValueMode.java b/server/src/main/java/org/opensearch/search/MultiValueMode.java
index 0fbd41f062710..ca088203733c6 100644
--- a/server/src/main/java/org/opensearch/search/MultiValueMode.java
+++ b/server/src/main/java/org/opensearch/search/MultiValueMode.java
@@ -42,6 +42,7 @@
 import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefBuilder;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -59,8 +60,9 @@
 /**
  * Defines what values to pick in the case a document contains multiple values for a particular field.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum MultiValueMode implements Writeable {
     /**
      * Pick the sum of all the values.
@@ -542,7 +544,7 @@ public static MultiValueMode fromString(String sortMode) {
      * Return a {@link NumericDocValues} instance that can be used to sort documents
      * with this mode and the provided values. When a document has no value,
      * <code>missingValue</code> is returned.
-     *
+     * <p>
      * Allowed Modes: SUM, AVG, MEDIAN, MIN, MAX
      */
     public NumericDocValues select(final SortedNumericDocValues values) {
@@ -583,12 +585,12 @@ protected long pick(SortedNumericDocValues values) throws IOException {
     /**
      * Return a {@link NumericDocValues} instance that can be used to sort root documents
      * with this mode, the provided values and filters for root/inner documents.
-     *
+     * <p>
      * For every root document, the values of its inner documents will be aggregated.
      * If none of the inner documents has a value, then <code>missingValue</code> is returned.
-     *
+     * <p>
      * Allowed Modes: SUM, AVG, MIN, MAX
-     *
+     * <p>
      * NOTE: Calling the returned instance on docs that are not root docs is illegal
      *       The returned instance can only be evaluate the current and upcoming docs
      */
@@ -658,7 +660,7 @@ protected long pick(
      * Return a {@link NumericDoubleValues} instance that can be used to sort documents
      * with this mode and the provided values. When a document has no value,
      * <code>missingValue</code> is returned.
-     *
+     * <p>
      * Allowed Modes: SUM, AVG, MEDIAN, MIN, MAX
      */
     public NumericDoubleValues select(final SortedNumericDoubleValues values) {
@@ -694,12 +696,12 @@ protected double pick(SortedNumericDoubleValues values) throws IOException {
     /**
      * Return a {@link NumericDoubleValues} instance that can be used to sort root documents
      * with this mode, the provided values and filters for root/inner documents.
-     *
+     * <p>
      * For every root document, the values of its inner documents will be aggregated.
      * If none of the inner documents has a value, then <code>missingValue</code> is returned.
-     *
+     * <p>
      * Allowed Modes: SUM, AVG, MIN, MAX
-     *
+     * <p>
      * NOTE: Calling the returned instance on docs that are not root docs is illegal
      *       The returned instance can only be evaluate the current and upcoming docs
      */
@@ -761,7 +763,7 @@ protected double pick(
      * Return a {@link BinaryDocValues} instance that can be used to sort documents
      * with this mode and the provided values. When a document has no value,
      * <code>missingValue</code> is returned.
-     *
+     * <p>
      * Allowed Modes: MIN, MAX
      */
     public BinaryDocValues select(final SortedBinaryDocValues values, final BytesRef missingValue) {
@@ -816,12 +818,12 @@ protected BytesRef pick(SortedBinaryDocValues values) throws IOException {
     /**
      * Return a {@link BinaryDocValues} instance that can be used to sort root documents
      * with this mode, the provided values and filters for root/inner documents.
-     *
+     * <p>
      * For every root document, the values of its inner documents will be aggregated.
      * If none of the inner documents has a value, then <code>missingValue</code> is returned.
-     *
+     * <p>
      * Allowed Modes: MIN, MAX
-     *
+     * <p>
      * NOTE: Calling the returned instance on docs that are not root docs is illegal
      *       The returned instance can only be evaluate the current and upcoming docs
      */
@@ -889,7 +891,7 @@ protected BytesRef pick(
     /**
      * Return a {@link SortedDocValues} instance that can be used to sort documents
      * with this mode and the provided values.
-     *
+     * <p>
      * Allowed Modes: MIN, MAX
      */
     public SortedDocValues select(final SortedSetDocValues values) {
@@ -949,11 +951,11 @@ protected int pick(SortedSetDocValues values) throws IOException {
     /**
      * Return a {@link SortedDocValues} instance that can be used to sort root documents
      * with this mode, the provided values and filters for root/inner documents.
-     *
+     * <p>
      * For every root document, the values of its inner documents will be aggregated.
-     *
+     * <p>
      * Allowed Modes: MIN, MAX
-     *
+     * <p>
      * NOTE: Calling the returned instance on docs that are not root docs is illegal
      *       The returned instance can only be evaluate the current and upcoming docs
      */
diff --git a/server/src/main/java/org/opensearch/search/RescoreDocIds.java b/server/src/main/java/org/opensearch/search/RescoreDocIds.java
index 880f34a924f2a..a916e96638366 100644
--- a/server/src/main/java/org/opensearch/search/RescoreDocIds.java
+++ b/server/src/main/java/org/opensearch/search/RescoreDocIds.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -46,8 +47,9 @@
  * (i.e., documents that will be rescored by query rescorers) need to be serialized/ deserialized between search phases.
  * A {@link RescoreDocIds} encapsulates the top K results for each rescorer by its ordinal index.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class RescoreDocIds implements Writeable {
     public static final RescoreDocIds EMPTY = new RescoreDocIds(Collections.emptyMap());
 
diff --git a/server/src/main/java/org/opensearch/search/Scroll.java b/server/src/main/java/org/opensearch/search/Scroll.java
index 8003316a57e5e..3e634a378717f 100644
--- a/server/src/main/java/org/opensearch/search/Scroll.java
+++ b/server/src/main/java/org/opensearch/search/Scroll.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -44,8 +45,9 @@
  * A scroll enables scrolling of search request. It holds a {@link #keepAlive()} time that
  * will control how long to keep the scrolling resources open.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class Scroll implements Writeable {
 
     private final TimeValue keepAlive;
diff --git a/server/src/main/java/org/opensearch/search/SearchExtBuilder.java b/server/src/main/java/org/opensearch/search/SearchExtBuilder.java
index 4d86c6c2e2277..557269a1e45b1 100644
--- a/server/src/main/java/org/opensearch/search/SearchExtBuilder.java
+++ b/server/src/main/java/org/opensearch/search/SearchExtBuilder.java
@@ -33,6 +33,7 @@
 package org.opensearch.search;
 
 import org.opensearch.common.CheckedFunction;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.NamedWriteable;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,17 +48,18 @@
  * Any state needs to be serialized as part of the {@link Writeable#writeTo(StreamOutput)} method and
  * read from the incoming stream, usually done adding a constructor that takes {@link StreamInput} as
  * an argument.
- *
+ * <p>
  * Registration happens through {@link SearchPlugin#getSearchExts()}, which also needs a {@link CheckedFunction} that's able to parse
  * the incoming request from the REST layer into the proper {@link SearchExtBuilder} subclass.
- *
+ * <p>
  * {@link #getWriteableName()} must return the same name as the one used for the registration
  * of the {@link SearchExtSpec}.
  *
  * @see SearchExtSpec
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SearchExtBuilder implements NamedWriteable, ToXContentFragment {
 
     public abstract int hashCode();
diff --git a/server/src/main/java/org/opensearch/search/SearchHit.java b/server/src/main/java/org/opensearch/search/SearchHit.java
index 49f1cc585fd80..10e65fca3afb5 100644
--- a/server/src/main/java/org/opensearch/search/SearchHit.java
+++ b/server/src/main/java/org/opensearch/search/SearchHit.java
@@ -37,6 +37,7 @@
 import org.opensearch.Version;
 import org.opensearch.action.OriginalIndices;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.ParseField;
@@ -92,8 +93,9 @@
  *
  * @see SearchHits
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SearchHit implements Writeable, ToXContentObject, Iterable<DocumentField> {
 
     private final transient int docId;
@@ -995,8 +997,9 @@ public int hashCode() {
     /**
      * Encapsulates the nested identity of a hit.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class NestedIdentity implements Writeable, ToXContentFragment {
 
         private static final String _NESTED = "_nested";
@@ -1035,7 +1038,7 @@ public int getOffset() {
 
         /**
          * Returns the next child nested level if there is any, otherwise <code>null</code> is returned.
-         *
+         * <p>
          * In the case of mappings with multiple levels of nested object fields
          */
         public NestedIdentity getChild() {
diff --git a/server/src/main/java/org/opensearch/search/SearchHits.java b/server/src/main/java/org/opensearch/search/SearchHits.java
index 1d497840bd12b..8232643b353f5 100644
--- a/server/src/main/java/org/opensearch/search/SearchHits.java
+++ b/server/src/main/java/org/opensearch/search/SearchHits.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.search.TotalHits;
 import org.apache.lucene.search.TotalHits.Relation;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -57,8 +58,9 @@
 /**
  * Encapsulates the results of a search operation
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SearchHits implements Writeable, ToXContentFragment, Iterable<SearchHit> {
     public static SearchHits empty() {
         return empty(true);
diff --git a/server/src/main/java/org/opensearch/search/SearchModule.java b/server/src/main/java/org/opensearch/search/SearchModule.java
index 0f1030b87c036..62d397de58187 100644
--- a/server/src/main/java/org/opensearch/search/SearchModule.java
+++ b/server/src/main/java/org/opensearch/search/SearchModule.java
@@ -327,7 +327,7 @@ public class SearchModule {
 
     /**
      * Constructs a new SearchModule object
-     *
+     * <p>
      * NOTE: This constructor should not be called in production unless an accurate {@link Settings} object is provided.
      *       When constructed, a static flag is set in Lucene {@link BooleanQuery#setMaxClauseCount} according to the settings.
      * @param settings Current settings
diff --git a/server/src/main/java/org/opensearch/search/SearchPhaseResult.java b/server/src/main/java/org/opensearch/search/SearchPhaseResult.java
index 9eda278a40268..a351b3bd2dda6 100644
--- a/server/src/main/java/org/opensearch/search/SearchPhaseResult.java
+++ b/server/src/main/java/org/opensearch/search/SearchPhaseResult.java
@@ -33,6 +33,7 @@
 package org.opensearch.search;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.transport.TransportResponse;
@@ -51,8 +52,9 @@
  * across search phases to ensure the same point in time snapshot is used for querying and
  * fetching etc.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SearchPhaseResult extends TransportResponse {
 
     private SearchShardTarget searchShardTarget;
diff --git a/server/src/main/java/org/opensearch/search/SearchShardTarget.java b/server/src/main/java/org/opensearch/search/SearchShardTarget.java
index 882ba8e069c2e..80b4feda374c6 100644
--- a/server/src/main/java/org/opensearch/search/SearchShardTarget.java
+++ b/server/src/main/java/org/opensearch/search/SearchShardTarget.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.action.OriginalIndices;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -47,8 +48,9 @@
 /**
  * The target that the search request was executed on.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SearchShardTarget implements Writeable, Comparable<SearchShardTarget> {
 
     private final Text nodeId;
diff --git a/server/src/main/java/org/opensearch/search/SearchSortValues.java b/server/src/main/java/org/opensearch/search/SearchSortValues.java
index c1f6b45ded7a5..cbc3900f72f79 100644
--- a/server/src/main/java/org/opensearch/search/SearchSortValues.java
+++ b/server/src/main/java/org/opensearch/search/SearchSortValues.java
@@ -33,6 +33,7 @@
 package org.opensearch.search;
 
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -50,8 +51,9 @@
 /**
  * Values to sort during search
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchSortValues implements ToXContentFragment, Writeable {
 
     private static final Object[] EMPTY_ARRAY = new Object[0];
diff --git a/server/src/main/java/org/opensearch/search/SearchSortValuesAndFormats.java b/server/src/main/java/org/opensearch/search/SearchSortValuesAndFormats.java
index c2e9ea2a35a3e..f9174e92b79e8 100644
--- a/server/src/main/java/org/opensearch/search/SearchSortValuesAndFormats.java
+++ b/server/src/main/java/org/opensearch/search/SearchSortValuesAndFormats.java
@@ -33,6 +33,7 @@
 package org.opensearch.search;
 
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -45,8 +46,9 @@
 /**
  * Doc value and formats to sort during search
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchSortValuesAndFormats implements Writeable {
     private final Object[] rawSortValues;
     private final Object[] formattedSortValues;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/Aggregation.java b/server/src/main/java/org/opensearch/search/aggregations/Aggregation.java
index b723e14a84cbe..b41da3910030a 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/Aggregation.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/Aggregation.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.aggregations;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.ToXContentFragment;
@@ -40,8 +41,9 @@
 /**
  * An aggregation. Extends {@link ToXContent} as it makes it easier to print out its content.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface Aggregation extends ToXContentFragment {
 
     /**
diff --git a/server/src/main/java/org/opensearch/search/aggregations/AggregationBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/AggregationBuilder.java
index 0d4d4bd7d67b2..878f81001344c 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/AggregationBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/AggregationBuilder.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.aggregations;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.NamedWriteable;
@@ -50,8 +51,9 @@
 /**
  * A factory that knows how to create an {@link Aggregator} of a specific type.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class AggregationBuilder
     implements
         NamedWriteable,
@@ -168,8 +170,9 @@ public PipelineTree buildPipelineTree() {
      * Unlike {@link CardinalityUpperBound} which is <strong>total</strong>
      * instead of <strong>per parent bucket</strong>.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum BucketCardinality {
         NONE,
         ONE,
diff --git a/server/src/main/java/org/opensearch/search/aggregations/AggregationProcessor.java b/server/src/main/java/org/opensearch/search/aggregations/AggregationProcessor.java
index 5b3e2f2542dc2..25fea6ea2c1dc 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/AggregationProcessor.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/AggregationProcessor.java
@@ -8,11 +8,15 @@
 
 package org.opensearch.search.aggregations;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.internal.SearchContext;
 
 /**
  * Interface to define different stages of aggregation processing before and after document collection
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.9.0")
 public interface AggregationProcessor {
 
     /**
diff --git a/server/src/main/java/org/opensearch/search/aggregations/Aggregations.java b/server/src/main/java/org/opensearch/search/aggregations/Aggregations.java
index b75ec7fe531a8..90d77d5516415 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/Aggregations.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/Aggregations.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.aggregations;
 
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.xcontent.ToXContentFragment;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -54,8 +55,9 @@
 /**
  * Represents a set of {@link Aggregation}s
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Aggregations implements Iterable<Aggregation>, ToXContentFragment {
 
     public static final String AGGREGATIONS_FIELD = "aggregations";
diff --git a/server/src/main/java/org/opensearch/search/aggregations/Aggregator.java b/server/src/main/java/org/opensearch/search/aggregations/Aggregator.java
index b2ac0fdef04ef..8744d1f6a07d3 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/Aggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/Aggregator.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.aggregations;
 
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -57,6 +58,7 @@
  *
  * @opensearch.internal
  */
+@PublicApi(since = "1.0.0")
 public abstract class Aggregator extends BucketCollector implements Releasable {
 
     /**
@@ -64,9 +66,10 @@ public abstract class Aggregator extends BucketCollector implements Releasable {
      *
      * @see AggregationBuilder
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     public interface Parser {
         /**
          * Returns the aggregator factory with which this parser is associated, may return {@code null} indicating the
@@ -160,9 +163,10 @@ public BucketComparator bucketComparator(String key, SortOrder order) {
     /**
      * Compare two buckets by their ordinal.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     public interface BucketComparator {
         /**
          * Compare two buckets by their ordinal.
diff --git a/server/src/main/java/org/opensearch/search/aggregations/AggregatorBase.java b/server/src/main/java/org/opensearch/search/aggregations/AggregatorBase.java
index 392c65ce27aea..47e9def094623 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/AggregatorBase.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/AggregatorBase.java
@@ -135,7 +135,7 @@ public ScoreMode scoreMode() {
      * Returns a converter for point values if it's safe to use the indexed data instead of
      * doc values.  Generally, this means that the query has no filters or scripts, the aggregation is
      * top level, and the underlying field is indexed, and the index is sorted in the right order.
-     *
+     * <p>
      * If those conditions aren't met, return <code>null</code> to indicate a point reader cannot
      * be used in this case.
      *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java b/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java
index 9b8ebe0b4e5e4..eeb0c606694b0 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.aggregations;
 
 import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.SuggestingErrorOnUnknown;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.Strings;
@@ -82,8 +83,9 @@
 /**
  * An immutable collection of {@link AggregatorFactories}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AggregatorFactories {
     public static final Pattern VALID_AGG_NAME = Pattern.compile("[^\\[\\]>]+");
 
@@ -340,8 +342,9 @@ public int countAggregators() {
      * A mutable collection of {@link AggregationBuilder}s and
      * {@link PipelineAggregationBuilder}s.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder implements Writeable, ToXContentObject {
         private final Set<String> names = new HashSet<>();
 
diff --git a/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactory.java b/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactory.java
index 759d043743978..6cc3a78fb1e36 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactory.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactory.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.query.QueryShardContext;
 import org.opensearch.search.internal.SearchContext;
 
@@ -43,8 +44,9 @@
 /**
  * Base factory to instantiate an internal aggregator
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class AggregatorFactory {
     protected final String name;
     protected final AggregatorFactory parent;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/BucketCollectorProcessor.java b/server/src/main/java/org/opensearch/search/aggregations/BucketCollectorProcessor.java
index 352ecf8bc94ad..135fda71a757a 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/BucketCollectorProcessor.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/BucketCollectorProcessor.java
@@ -10,6 +10,7 @@
 
 import org.apache.lucene.search.Collector;
 import org.apache.lucene.search.MultiCollector;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.MinimumScoreCollector;
 import org.opensearch.search.internal.SearchContext;
 import org.opensearch.search.profile.query.InternalProfileCollector;
@@ -26,7 +27,10 @@
 /**
  * Processor to perform collector level processing specific to {@link BucketCollector} in different stages like: a) PostCollection
  * after search on each leaf is completed and b) process the collectors to perform reduce after collection is completed
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.10.0")
 public class BucketCollectorProcessor {
 
     /**
diff --git a/server/src/main/java/org/opensearch/search/aggregations/CardinalityUpperBound.java b/server/src/main/java/org/opensearch/search/aggregations/CardinalityUpperBound.java
index 15beeac82930a..8407a5eb6d3c0 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/CardinalityUpperBound.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/CardinalityUpperBound.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.aggregations.bucket.BucketsAggregator;
 import org.opensearch.search.aggregations.bucket.filter.FilterAggregator;
 import org.opensearch.search.aggregations.bucket.range.RangeAggregator;
@@ -42,8 +43,9 @@
  * Upper bound of how many {@code owningBucketOrds} that an {@link Aggregator}
  * will have to collect into.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class CardinalityUpperBound {
     /**
      * {@link Aggregator}s with this cardinality won't collect any data at
diff --git a/server/src/main/java/org/opensearch/search/aggregations/InternalAggregation.java b/server/src/main/java/org/opensearch/search/aggregations/InternalAggregation.java
index 04c300658cb1c..49b85ccaea2a8 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/InternalAggregation.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/InternalAggregation.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.aggregations;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.BigArrays;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.NamedWriteable;
@@ -61,14 +62,16 @@
 /**
  * An internal implementation of {@link Aggregation}. Serves as a base class for all aggregation implementations.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class InternalAggregation implements Aggregation, NamedWriteable {
     /**
      * Builds {@link ReduceContext}.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface ReduceContextBuilder {
         /**
          * Build a {@linkplain ReduceContext} to perform a partial reduction.
@@ -84,8 +87,9 @@ public interface ReduceContextBuilder {
     /**
      * The reduce context
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ReduceContext {
         private final BigArrays bigArrays;
         private final ScriptService scriptService;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/InternalAggregations.java b/server/src/main/java/org/opensearch/search/aggregations/InternalAggregations.java
index e4d64e1e8517c..9d55ee4a04506 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/InternalAggregations.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/InternalAggregations.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.aggregations;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -53,8 +54,9 @@
 /**
  * An internal implementation of {@link Aggregations}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class InternalAggregations extends Aggregations implements Writeable {
 
     public static final InternalAggregations EMPTY = new InternalAggregations(Collections.emptyList());
@@ -125,7 +127,7 @@ public double sortValue(AggregationPath.PathElement head, Iterator<AggregationPa
      * Begin the reduction process.  This should be the entry point for the "first" reduction, e.g. called by
      * SearchPhaseController or anywhere else that wants to initiate a reduction.  It _should not_ be called
      * as an intermediate reduction step (e.g. in the middle of an aggregation tree).
-     *
+     * <p>
      * This method first reduces the aggregations, and if it is the final reduce, then reduce the pipeline
      * aggregations (both embedded parent/sibling as well as top-level sibling pipelines)
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/MultiBucketConsumerService.java b/server/src/main/java/org/opensearch/search/aggregations/MultiBucketConsumerService.java
index 5bd36d0255b91..1461dd3009b44 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/MultiBucketConsumerService.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/MultiBucketConsumerService.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.aggregations;
 
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.breaker.CircuitBreaker;
@@ -123,8 +124,9 @@ protected void metadataToXContent(XContentBuilder builder, Params params) throws
      * It is used by aggregators to limit the number of bucket creation during
      * {@link Aggregator#buildAggregations} and {@link InternalAggregation#reduce}.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class MultiBucketConsumer implements IntConsumer {
         private final int limit;
         private final CircuitBreaker breaker;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/PipelineAggregationBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/PipelineAggregationBuilder.java
index 9754498841159..7ff823dbe57f0 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/PipelineAggregationBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/PipelineAggregationBuilder.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.action.ValidateActions;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.NamedWriteable;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
@@ -54,8 +55,9 @@
  * A factory that knows how to create an {@link PipelineAggregator} of a
  * specific type.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class PipelineAggregationBuilder
     implements
         NamedWriteable,
diff --git a/server/src/main/java/org/opensearch/search/aggregations/SearchContextAggregations.java b/server/src/main/java/org/opensearch/search/aggregations/SearchContextAggregations.java
index 16339713dc83e..1cf054a7450bc 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/SearchContextAggregations.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/SearchContextAggregations.java
@@ -31,13 +31,16 @@
 
 package org.opensearch.search.aggregations;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import static org.opensearch.search.aggregations.MultiBucketConsumerService.MultiBucketConsumer;
 
 /**
  * The aggregation context that is part of the search context.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchContextAggregations {
     private final AggregatorFactories factories;
     private final MultiBucketConsumer multiBucketConsumer;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/BucketsAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/BucketsAggregator.java
index 67af0b13eed3b..eef427754f535 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/BucketsAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/BucketsAggregator.java
@@ -132,7 +132,7 @@ public final void collectExistingBucket(LeafBucketCollector subCollector, int do
     /**
      * This only tidies up doc counts. Call {@link MergingBucketsDeferringCollector#mergeBuckets(long[])}  to merge the actual
      * ordinals and doc ID deltas.
-     *
+     * <p>
      * Refer to that method for documentation about the merge map.
      *
      * @deprecated use {@link mergeBuckets(long, LongUnaryOperator)}
@@ -146,7 +146,7 @@ public final void mergeBuckets(long[] mergeMap, long newNumBuckets) {
      *
      *  @param mergeMap a unary operator which maps a bucket's ordinal to the ordinal it should be merged with.
      *  If a bucket's ordinal is mapped to -1 then the bucket is removed entirely.
-     *
+     * <p>
      * This only tidies up doc counts. Call {@link MergingBucketsDeferringCollector#mergeBuckets(LongUnaryOperator)} to
      * merge the actual ordinals and doc ID deltas.
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/GeoTileUtils.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/GeoTileUtils.java
index de74055bb94f3..dfb8f6be7155d 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/GeoTileUtils.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/GeoTileUtils.java
@@ -101,7 +101,7 @@ private GeoTileUtils() {}
 
     /**
      * Parse an integer precision (zoom level). The {@link ValueType#INT} allows it to be a number or a string.
-     *
+     * <p>
      * The precision is expressed as a zoom level between 0 and {@link #MAX_ZOOM} (inclusive).
      *
      * @param parser {@link XContentParser} to parse the value from
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/LocalBucketCountThresholds.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/LocalBucketCountThresholds.java
index 98dc07cec49ab..9d8654565b391 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/LocalBucketCountThresholds.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/LocalBucketCountThresholds.java
@@ -8,14 +8,16 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.aggregations.bucket.terms.TermsAggregator;
 
 /**
  * BucketCountThresholds type that holds the local (either shard level or request level) bucket count thresholds in minDocCount and requireSize fields.
  * Similar to {@link TermsAggregator.BucketCountThresholds} however only provides getters for the local members and no setters.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class LocalBucketCountThresholds {
 
     private final long minDocCount;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/MergingBucketsDeferringCollector.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/MergingBucketsDeferringCollector.java
index 8d35c1edc8cb0..3e9424eda92a9 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/MergingBucketsDeferringCollector.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/MergingBucketsDeferringCollector.java
@@ -55,16 +55,17 @@ public MergingBucketsDeferringCollector(SearchContext context, boolean isGlobal)
 
     /**
      * Merges/prunes the existing bucket ordinals and docDeltas according to the provided mergeMap.
-     *
+     * <p>
      * The mergeMap is an array where the index position represents the current bucket ordinal, and
      * the value at that position represents the ordinal the bucket should be merged with.  If
      * the value is set to -1 it is removed entirely.
-     *
+     * <p>
      * For example, if the mergeMap [1,1,3,-1,3] is provided:
-     *  - Buckets `0` and `1` will be merged to bucket ordinal `1`
-     *  - Bucket `2` and `4` will be merged to ordinal `3`
-     *  - Bucket `3` will be removed entirely
-     *
+     * <ul>
+     *  <li> Buckets `0` and `1` will be merged to bucket ordinal `1`</li>
+     *  <li> Bucket `2` and `4` will be merged to ordinal `3`</li>
+     *  <li> Bucket `3` will be removed entirely</li>
+     * </ul>
      *  This process rebuilds the ordinals and docDeltas according to the mergeMap, so it should
      *  not be called unless there are actually changes to be made, to avoid unnecessary work.
      *
@@ -80,7 +81,7 @@ public void mergeBuckets(long[] mergeMap) {
      *
      * @param mergeMap a unary operator which maps a bucket's ordinal to the ordinal it should be merged with.
      * If a bucket's ordinal is mapped to -1 then the bucket is removed entirely.
-     *
+     * <p>
      * This process rebuilds the ordinals and docDeltas according to the mergeMap, so it should
      * not be called unless there are actually changes to be made, to avoid unnecessary work.
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/DateHistogramValuesSourceBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/DateHistogramValuesSourceBuilder.java
index 366de8619fd55..fd94ba355238a 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/DateHistogramValuesSourceBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/DateHistogramValuesSourceBuilder.java
@@ -216,7 +216,7 @@ public DateHistogramValuesSourceBuilder dateHistogramInterval(DateHistogramInter
     /**
      * Sets the interval of the DateHistogram using calendar units (`1d`, `1w`, `1M`, etc).  These units
      * are calendar-aware, meaning they respect leap additions, variable days per month, etc.
-     *
+     * <p>
      * This is mutually exclusive with {@link DateHistogramValuesSourceBuilder#fixedInterval(DateHistogramInterval)}
      *
      * @param interval The calendar interval to use with the aggregation
@@ -229,7 +229,7 @@ public DateHistogramValuesSourceBuilder calendarInterval(DateHistogramInterval i
     /**
      * Sets the interval of the DateHistogram using fixed units (`1ms`, `1s`, `10m`, `4h`, etc).  These are
      * not calendar aware and are simply multiples of fixed, SI units.
-     *
+     * <p>
      * This is mutually exclusive with {@link DateHistogramValuesSourceBuilder#calendarInterval(DateHistogramInterval)}
      *
      * @param interval The fixed interval to use with the aggregation
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/InternalComposite.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/InternalComposite.java
index 27619044d8995..9f8a4cff5f3fc 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/InternalComposite.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/InternalComposite.java
@@ -142,10 +142,10 @@ public String getWriteableName() {
 
     @Override
     public InternalComposite create(List<InternalBucket> newBuckets) {
-        /**
-         * This is used by pipeline aggregations to filter/remove buckets so we
-         * keep the <code>afterKey</code> of the original aggregation in order
-         * to be able to retrieve the next page even if all buckets have been filtered.
+        /*
+          This is used by pipeline aggregations to filter/remove buckets so we
+          keep the <code>afterKey</code> of the original aggregation in order
+          to be able to retrieve the next page even if all buckets have been filtered.
          */
         return new InternalComposite(
             name,
@@ -473,8 +473,8 @@ public int compareKey(InternalBucket other) {
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            /**
-             * See {@link CompositeAggregation#bucketToXContent}
+            /*
+              See {@link CompositeAggregation#bucketToXContent}
              */
             throw new UnsupportedOperationException("not implemented");
         }
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/ParsedComposite.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/ParsedComposite.java
index 8382b191025fe..2a1544e218f2c 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/ParsedComposite.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/ParsedComposite.java
@@ -70,9 +70,9 @@ public static ParsedComposite fromXContent(XContentParser parser, String name) t
         ParsedComposite aggregation = PARSER.parse(parser, null);
         aggregation.setName(name);
         if (aggregation.afterKey == null && aggregation.getBuckets().size() > 0) {
-            /**
-             * Previous versions (< 6.3) don't send <code>afterKey</code>
-             * in the response so we set it as the last returned buckets.
+            /*
+              Previous versions (< 6.3) don't send <code>afterKey</code>
+              in the response so we set it as the last returned buckets.
              */
             aggregation.setAfterKey(aggregation.getBuckets().get(aggregation.getBuckets().size() - 1).key);
         }
@@ -130,8 +130,8 @@ void setKey(Map<String, Object> key) {
 
         @Override
         public final XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            /**
-             * See {@link CompositeAggregation#bucketToXContent}
+            /*
+              See {@link CompositeAggregation#bucketToXContent}
              */
             throw new UnsupportedOperationException("not implemented");
         }
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/SortedDocsProducer.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/SortedDocsProducer.java
index bd0a4f13ddf08..9442529bf9342 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/SortedDocsProducer.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/composite/SortedDocsProducer.java
@@ -62,7 +62,7 @@ abstract class SortedDocsProducer {
      * Visits all non-deleted documents in <code>iterator</code> and fills the provided <code>queue</code>
      * with the top composite buckets extracted from the collection.
      * Documents that contain a top composite bucket are added in the provided <code>builder</code> if it is not null.
-     *
+     * <p>
      * Returns true if the queue is full and the current <code>leadSourceBucket</code> did not produce any competitive
      * composite buckets.
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FilterAggregatorFactory.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FilterAggregatorFactory.java
index 55c841f5b9c04..a0a636c121e12 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FilterAggregatorFactory.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FilterAggregatorFactory.java
@@ -75,7 +75,7 @@ public FilterAggregatorFactory(
      * necessary. This is done lazily so that the {@link Weight} is only created
      * if the aggregation collects documents reducing the overhead of the
      * aggregation in the case where no documents are collected.
-     *
+     * <p>
      * Note that as aggregations are initialsed and executed in a serial manner,
      * no concurrency considerations are necessary here.
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FiltersAggregatorFactory.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FiltersAggregatorFactory.java
index 35d968b789a21..a8e157a1cbb79 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FiltersAggregatorFactory.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/filter/FiltersAggregatorFactory.java
@@ -92,7 +92,7 @@ public FiltersAggregatorFactory(
      * necessary. This is done lazily so that the {@link Weight}s are only
      * created if the aggregation collects documents reducing the overhead of
      * the aggregation in the case where no documents are collected.
-     *
+     * <p>
      * Note: With concurrent segment search use case, multiple aggregation collectors executing
      * on different threads will try to fetch the weights. To handle the race condition there is
      * a synchronization block
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
index d7f89225524c0..a71c15d551927 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
@@ -34,6 +34,7 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.SortedNumericDocValues;
 import org.apache.lucene.search.ScoreMode;
+import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.CollectionUtil;
 import org.opensearch.common.Rounding;
 import org.opensearch.common.Rounding.Prepared;
@@ -41,6 +42,7 @@
 import org.opensearch.common.util.IntArray;
 import org.opensearch.common.util.LongArray;
 import org.opensearch.core.common.util.ByteArray;
+import org.opensearch.index.mapper.DateFieldMapper;
 import org.opensearch.search.DocValueFormat;
 import org.opensearch.search.aggregations.Aggregator;
 import org.opensearch.search.aggregations.AggregatorFactories;
@@ -125,9 +127,13 @@ static AutoDateHistogramAggregator build(
      * {@link MergingBucketsDeferringCollector#mergeBuckets(long[])}.
      */
     private MergingBucketsDeferringCollector deferringCollector;
+    private final Weight[] filters;
+    private final DateFieldMapper.DateFieldType fieldType;
 
     protected final RoundingInfo[] roundingInfos;
     protected final int targetBuckets;
+    protected int roundingIdx;
+    protected Rounding.Prepared preparedRounding;
 
     private AutoDateHistogramAggregator(
         String name,
@@ -148,8 +154,51 @@ private AutoDateHistogramAggregator(
         this.formatter = valuesSourceConfig.format();
         this.roundingInfos = roundingInfos;
         this.roundingPreparer = roundingPreparer;
+        this.preparedRounding = prepareRounding(0);
+
+        FilterRewriteHelper.FilterContext filterContext = FilterRewriteHelper.buildFastFilterContext(
+            parent(),
+            subAggregators.length,
+            context,
+            b -> getMinimumRounding(b[0], b[1]),
+            // Passing prepared rounding as supplier to ensure the correct prepared
+            // rounding is set as it is done during getMinimumRounding
+            () -> preparedRounding,
+            valuesSourceConfig,
+            fc -> FilterRewriteHelper.getAggregationBounds(context, fc.field())
+        );
+        if (filterContext != null) {
+            fieldType = filterContext.fieldType;
+            filters = filterContext.filters;
+        } else {
+            fieldType = null;
+            filters = null;
+        }
     }
 
+    private Rounding getMinimumRounding(final long low, final long high) {
+        // max - min / targetBuckets = bestDuration
+        // find the right innerInterval this bestDuration belongs to
+        // since we cannot exceed targetBuckets, bestDuration should go up,
+        // so the right innerInterval should be an upper bound
+        long bestDuration = (high - low) / targetBuckets;
+        while (roundingIdx < roundingInfos.length - 1) {
+            final RoundingInfo curRoundingInfo = roundingInfos[roundingIdx];
+            final int temp = curRoundingInfo.innerIntervals[curRoundingInfo.innerIntervals.length - 1];
+            // If the interval duration is covered by the maximum inner interval,
+            // we can start with this outer interval for creating the buckets
+            if (bestDuration <= temp * curRoundingInfo.roughEstimateDurationMillis) {
+                break;
+            }
+            roundingIdx++;
+        }
+
+        preparedRounding = prepareRounding(roundingIdx);
+        return roundingInfos[roundingIdx].rounding;
+    }
+
+    protected abstract LongKeyedBucketOrds getBucketOrds();
+
     @Override
     public final ScoreMode scoreMode() {
         if (valuesSource != null && valuesSource.needsScores()) {
@@ -176,7 +225,32 @@ public final LeafBucketCollector getLeafCollector(LeafReaderContext ctx, LeafBuc
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
         }
-        return getLeafCollector(valuesSource.longValues(ctx), sub);
+
+        final SortedNumericDocValues values = valuesSource.longValues(ctx);
+        final LeafBucketCollector iteratingCollector = getLeafCollector(values, sub);
+
+        // Need to be declared as final and array for usage within the
+        // LeafBucketCollectorBase subclass below
+        final boolean[] useOpt = new boolean[1];
+        useOpt[0] = filters != null;
+
+        return new LeafBucketCollectorBase(sub, values) {
+            @Override
+            public void collect(int doc, long owningBucketOrd) throws IOException {
+                // Try fast filter aggregation if the filters have been created
+                // Skip if tried before and gave incorrect/incomplete results
+                if (useOpt[0]) {
+                    useOpt[0] = FilterRewriteHelper.tryFastFilterAggregation(ctx, filters, fieldType, (key, count) -> {
+                        incrementBucketDocCount(
+                            FilterRewriteHelper.getBucketOrd(getBucketOrds().add(owningBucketOrd, preparedRounding.round(key))),
+                            count
+                        );
+                    });
+                }
+
+                iteratingCollector.collect(doc, owningBucketOrd);
+            }
+        };
     }
 
     protected final InternalAggregation[] buildAggregations(
@@ -247,8 +321,6 @@ protected final void merge(long[] mergeMap, long newNumBuckets) {
      * @opensearch.internal
      */
     private static class FromSingle extends AutoDateHistogramAggregator {
-        private int roundingIdx;
-        private Rounding.Prepared preparedRounding;
         /**
          * Map from value to bucket ordinals.
          * <p>
@@ -286,10 +358,14 @@ private static class FromSingle extends AutoDateHistogramAggregator {
                 metadata
             );
 
-            preparedRounding = prepareRounding(0);
             bucketOrds = new LongKeyedBucketOrds.FromSingle(context.bigArrays());
         }
 
+        @Override
+        protected LongKeyedBucketOrds getBucketOrds() {
+            return bucketOrds;
+        }
+
         @Override
         protected LeafBucketCollector getLeafCollector(SortedNumericDocValues values, LeafBucketCollector sub) throws IOException {
             return new LeafBucketCollectorBase(sub, values) {
@@ -507,6 +583,11 @@ private static class FromMany extends AutoDateHistogramAggregator {
             liveBucketCountUnderestimate = context.bigArrays().newIntArray(1, true);
         }
 
+        @Override
+        protected LongKeyedBucketOrds getBucketOrds() {
+            return bucketOrds;
+        }
+
         @Override
         protected LeafBucketCollector getLeafCollector(SortedNumericDocValues values, LeafBucketCollector sub) throws IOException {
             return new LeafBucketCollectorBase(sub, values) {
@@ -546,7 +627,7 @@ private int collectValue(long owningBucketOrd, int roundingIdx, int doc, long ro
 
                 /**
                  * Increase the rounding of {@code owningBucketOrd} using
-                 * estimated, bucket counts, {@link #rebucket() rebucketing} the all
+                 * estimated, bucket counts, {@link FromMany#rebucket()} rebucketing} the all
                  * buckets if the estimated number of wasted buckets is too high.
                  */
                 private int increaseRoundingIfNeeded(long owningBucketOrd, int oldEstimatedBucketCount, long newKey, int oldRounding) {
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregationBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregationBuilder.java
index 181fb468f3356..a978b5cfa3e3e 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregationBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregationBuilder.java
@@ -245,7 +245,7 @@ public DateHistogramAggregationBuilder dateHistogramInterval(DateHistogramInterv
     /**
      * Sets the interval of the DateHistogram using calendar units (`1d`, `1w`, `1M`, etc).  These units
      * are calendar-aware, meaning they respect leap additions, variable days per month, etc.
-     *
+     * <p>
      * This is mutually exclusive with {@link DateHistogramAggregationBuilder#fixedInterval(DateHistogramInterval)}
      *
      * @param interval The calendar interval to use with the aggregation
@@ -258,7 +258,7 @@ public DateHistogramAggregationBuilder calendarInterval(DateHistogramInterval in
     /**
      * Sets the interval of the DateHistogram using fixed units (`1ms`, `1s`, `10m`, `4h`, etc).  These are
      * not calendar aware and are simply multiples of fixed, SI units.
-     *
+     * <p>
      * This is mutually exclusive with {@link DateHistogramAggregationBuilder#calendarInterval(DateHistogramInterval)}
      *
      * @param interval The fixed interval to use with the aggregation
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregator.java
index 8233c3d995dda..8437e1dce9fe0 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregator.java
@@ -34,10 +34,12 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.SortedNumericDocValues;
 import org.apache.lucene.search.ScoreMode;
+import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.CollectionUtil;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Rounding;
 import org.opensearch.common.lease.Releasables;
+import org.opensearch.index.mapper.DateFieldMapper;
 import org.opensearch.search.DocValueFormat;
 import org.opensearch.search.aggregations.Aggregator;
 import org.opensearch.search.aggregations.AggregatorFactories;
@@ -48,6 +50,7 @@
 import org.opensearch.search.aggregations.LeafBucketCollectorBase;
 import org.opensearch.search.aggregations.bucket.BucketsAggregator;
 import org.opensearch.search.aggregations.bucket.terms.LongKeyedBucketOrds;
+import org.opensearch.search.aggregations.support.FieldContext;
 import org.opensearch.search.aggregations.support.ValuesSource;
 import org.opensearch.search.aggregations.support.ValuesSourceConfig;
 import org.opensearch.search.internal.SearchContext;
@@ -66,7 +69,6 @@
  * @opensearch.internal
  */
 class DateHistogramAggregator extends BucketsAggregator implements SizedBucketAggregator {
-
     private final ValuesSource.Numeric valuesSource;
     private final DocValueFormat formatter;
     private final Rounding rounding;
@@ -76,12 +78,12 @@ class DateHistogramAggregator extends BucketsAggregator implements SizedBucketAg
     private final Rounding.Prepared preparedRounding;
     private final BucketOrder order;
     private final boolean keyed;
-
     private final long minDocCount;
     private final LongBounds extendedBounds;
     private final LongBounds hardBounds;
-
+    private final Weight[] filters;
     private final LongKeyedBucketOrds bucketOrds;
+    private final DateFieldMapper.DateFieldType fieldType;
 
     DateHistogramAggregator(
         String name,
@@ -99,7 +101,6 @@ class DateHistogramAggregator extends BucketsAggregator implements SizedBucketAg
         CardinalityUpperBound cardinality,
         Map<String, Object> metadata
     ) throws IOException {
-
         super(name, factories, aggregationContext, parent, CardinalityUpperBound.MANY, metadata);
         this.rounding = rounding;
         this.preparedRounding = preparedRounding;
@@ -114,6 +115,35 @@ class DateHistogramAggregator extends BucketsAggregator implements SizedBucketAg
         this.formatter = valuesSourceConfig.format();
 
         bucketOrds = LongKeyedBucketOrds.build(context.bigArrays(), cardinality);
+
+        FilterRewriteHelper.FilterContext filterContext = FilterRewriteHelper.buildFastFilterContext(
+            parent,
+            subAggregators.length,
+            context,
+            x -> rounding,
+            () -> preparedRounding,
+            valuesSourceConfig,
+            this::computeBounds
+        );
+        if (filterContext != null) {
+            fieldType = filterContext.fieldType;
+            filters = filterContext.filters;
+        } else {
+            filters = null;
+            fieldType = null;
+        }
+    }
+
+    private long[] computeBounds(final FieldContext fieldContext) throws IOException {
+        final long[] bounds = FilterRewriteHelper.getAggregationBounds(context, fieldContext.field());
+        if (bounds != null) {
+            // Update min/max limit if user specified any hard bounds
+            if (hardBounds != null) {
+                bounds[0] = Math.max(bounds[0], hardBounds.getMin());
+                bounds[1] = Math.min(bounds[1], hardBounds.getMax() - 1); // hard bounds max is exclusive
+            }
+        }
+        return bounds;
     }
 
     @Override
@@ -129,10 +159,27 @@ public LeafBucketCollector getLeafCollector(LeafReaderContext ctx, LeafBucketCol
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
         }
+
+        // Need to be declared as final and array for usage within the
+        // LeafBucketCollectorBase subclass below
+        final boolean[] useOpt = new boolean[1];
+        useOpt[0] = filters != null;
+
         SortedNumericDocValues values = valuesSource.longValues(ctx);
         return new LeafBucketCollectorBase(sub, values) {
             @Override
             public void collect(int doc, long owningBucketOrd) throws IOException {
+                // Try fast filter aggregation if the filters have been created
+                // Skip if tried before and gave incorrect/incomplete results
+                if (useOpt[0]) {
+                    useOpt[0] = FilterRewriteHelper.tryFastFilterAggregation(ctx, filters, fieldType, (key, count) -> {
+                        incrementBucketDocCount(
+                            FilterRewriteHelper.getBucketOrd(bucketOrds.add(owningBucketOrd, preparedRounding.round(key))),
+                            count
+                        );
+                    });
+                }
+
                 if (values.advanceExact(doc)) {
                     int valuesCount = values.docValueCount();
 
@@ -216,9 +263,7 @@ public void collectDebugInfo(BiConsumer<String, Object> add) {
     }
 
     /**
-     * Returns the size of the bucket in specified units.
-     *
-     * If unitSize is null, returns 1.0
+     * @return the size of the bucket in specified units, or 1.0 if unitSize is null
      */
     @Override
     public double bucketSize(long bucket, Rounding.DateTimeUnit unitSize) {
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramInterval.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramInterval.java
index 8f8e71f3cd685..9f907bcacadf9 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramInterval.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramInterval.java
@@ -129,7 +129,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
      * Converts this DateHistogramInterval into a millisecond representation.  If this is a calendar
      * interval, it is an approximation of milliseconds based on the fixed equivalent (e.g. `1h` is treated as 60
      * fixed minutes, rather than the hour at a specific point in time.
-     *
+     * <p>
      * This is merely a convenience helper for quick comparisons and should not be used for situations that
      * require precise durations.
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalConsumer.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalConsumer.java
index a2c63cf25c0c2..1d21152b6f622 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalConsumer.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalConsumer.java
@@ -34,7 +34,7 @@
 
 /**
  * A shared interface for aggregations that parse and use "interval" parameters.
- *
+ * <p>
  * Provides definitions for the new fixed and calendar intervals, and deprecated
  * defintions for the old interval/dateHisto interval parameters
  *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalWrapper.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalWrapper.java
index 2f8d512b7511f..83c20ba1c1d04 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalWrapper.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DateIntervalWrapper.java
@@ -53,13 +53,13 @@
 
 /**
  * A class that handles all the parsing, bwc and deprecations surrounding date histogram intervals.
- *
+ * <p>
  * - Provides parser helpers for the deprecated interval/dateHistogramInterval parameters.
  * - Provides parser helpers for the new calendar/fixed interval parameters
  * - Can read old intervals from a stream and convert to new intervals
  * - Can write new intervals to old format when streaming out
  * - Provides a variety of helper methods to interpret the intervals as different types, depending on caller's need
- *
+ * <p>
  * After the deprecated parameters are removed, this class can be simplified greatly.  The legacy options
  * will be removed, and the mutual-exclusion checks can be done in the setters directly removing the need
  * for the enum and the complicated "state machine" logic
@@ -220,7 +220,7 @@ public DateHistogramInterval getAsCalendarInterval() {
     /**
      * Sets the interval of the DateHistogram using calendar units (`1d`, `1w`, `1M`, etc).  These units
      * are calendar-aware, meaning they respect leap additions, variable days per month, etc.
-     *
+     * <p>
      * This is mutually exclusive with {@link DateIntervalWrapper#fixedInterval(DateHistogramInterval)}
      *
      * @param interval The fixed interval to use
@@ -250,7 +250,7 @@ public DateHistogramInterval getAsFixedInterval() {
     /**
      * Sets the interval of the DateHistogram using fixed units (`1ms`, `1s`, `10m`, `4h`, etc).  These are
      * not calendar aware and are simply multiples of fixed, SI units.
-     *
+     * <p>
      * This is mutually exclusive with {@link DateIntervalWrapper#calendarInterval(DateHistogramInterval)}
      *
      * @param interval The fixed interval to use
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DoubleBounds.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DoubleBounds.java
index 69c70ed1bf7fd..235ae8fcee6d7 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DoubleBounds.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/DoubleBounds.java
@@ -49,7 +49,7 @@
 
 /**
  * Represent hard_bounds and extended_bounds in histogram aggregations.
- *
+ * <p>
  * This class is similar to {@link LongBounds} used in date histograms, but is using longs to store data. LongBounds and DoubleBounds are
  * not used interchangeably and therefore don't share any common interfaces except for serialization.
  *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/FilterRewriteHelper.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/FilterRewriteHelper.java
new file mode 100644
index 0000000000000..29cecd5b382cd
--- /dev/null
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/FilterRewriteHelper.java
@@ -0,0 +1,259 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.aggregations.bucket.histogram;
+
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.index.PointValues;
+import org.apache.lucene.search.CollectionTerminatedException;
+import org.apache.lucene.search.ConstantScoreQuery;
+import org.apache.lucene.search.IndexOrDocValuesQuery;
+import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.PointRangeQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.ScoreMode;
+import org.apache.lucene.search.Weight;
+import org.apache.lucene.util.NumericUtils;
+import org.opensearch.common.CheckedFunction;
+import org.opensearch.common.Rounding;
+import org.opensearch.common.lucene.search.function.FunctionScoreQuery;
+import org.opensearch.index.mapper.DateFieldMapper;
+import org.opensearch.index.query.DateRangeIncludingNowQuery;
+import org.opensearch.search.aggregations.support.FieldContext;
+import org.opensearch.search.aggregations.support.ValuesSourceConfig;
+import org.opensearch.search.internal.SearchContext;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.OptionalLong;
+import java.util.function.BiConsumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+/**
+ * Helpers functions to rewrite and optimize aggregations using
+ * range filter queries
+ *
+ * @opensearch.internal
+ */
+public class FilterRewriteHelper {
+
+    static class FilterContext {
+        final DateFieldMapper.DateFieldType fieldType;
+        final Weight[] filters;
+
+        public FilterContext(DateFieldMapper.DateFieldType fieldType, Weight[] filters) {
+            this.fieldType = fieldType;
+            this.filters = filters;
+        }
+    }
+
+    private static final int MAX_NUM_FILTER_BUCKETS = 1024;
+    private static final Map<Class<?>, Function<Query, Query>> queryWrappers;
+
+    // Initialize the wrappers map for unwrapping the query
+    static {
+        queryWrappers = new HashMap<>();
+        queryWrappers.put(ConstantScoreQuery.class, q -> ((ConstantScoreQuery) q).getQuery());
+        queryWrappers.put(FunctionScoreQuery.class, q -> ((FunctionScoreQuery) q).getSubQuery());
+        queryWrappers.put(DateRangeIncludingNowQuery.class, q -> ((DateRangeIncludingNowQuery) q).getQuery());
+        queryWrappers.put(IndexOrDocValuesQuery.class, q -> ((IndexOrDocValuesQuery) q).getIndexQuery());
+    }
+
+    /**
+     * Recursively unwraps query into the concrete form
+     * for applying the optimization
+     */
+    private static Query unwrapIntoConcreteQuery(Query query) {
+        while (queryWrappers.containsKey(query.getClass())) {
+            query = queryWrappers.get(query.getClass()).apply(query);
+        }
+
+        return query;
+    }
+
+    /**
+     * Finds the min and max bounds for segments within the passed search context
+     */
+    private static long[] getIndexBoundsFromLeaves(final SearchContext context, final String fieldName) throws IOException {
+        final List<LeafReaderContext> leaves = context.searcher().getIndexReader().leaves();
+        long min = Long.MAX_VALUE, max = Long.MIN_VALUE;
+        // Since the query does not specify bounds for aggregation, we can
+        // build the global min/max from local min/max within each segment
+        for (LeafReaderContext leaf : leaves) {
+            final PointValues values = leaf.reader().getPointValues(fieldName);
+            if (values != null) {
+                min = Math.min(min, NumericUtils.sortableBytesToLong(values.getMinPackedValue(), 0));
+                max = Math.max(max, NumericUtils.sortableBytesToLong(values.getMaxPackedValue(), 0));
+            }
+        }
+
+        if (min == Long.MAX_VALUE || max == Long.MIN_VALUE) return null;
+
+        return new long[] { min, max };
+    }
+
+    static long[] getAggregationBounds(final SearchContext context, final String fieldName) throws IOException {
+        final Query cq = unwrapIntoConcreteQuery(context.query());
+        final long[] indexBounds = getIndexBoundsFromLeaves(context, fieldName);
+        if (cq instanceof PointRangeQuery) {
+            final PointRangeQuery prq = (PointRangeQuery) cq;
+            // Ensure that the query and aggregation are on the same field
+            if (prq.getField().equals(fieldName)) {
+                return new long[] {
+                    // Minimum bound for aggregation is the max between query and global
+                    Math.max(NumericUtils.sortableBytesToLong(prq.getLowerPoint(), 0), indexBounds[0]),
+                    // Maximum bound for aggregation is the min between query and global
+                    Math.min(NumericUtils.sortableBytesToLong(prq.getUpperPoint(), 0), indexBounds[1]) };
+            }
+        } else if (cq instanceof MatchAllDocsQuery) {
+            return indexBounds;
+        }
+
+        return null;
+    }
+
+    /**
+     * Creates the range query filters for aggregations using the interval, min/max
+     * bounds and the rounding values
+     */
+    private static Weight[] createFilterForAggregations(
+        final SearchContext context,
+        final Rounding rounding,
+        final Rounding.Prepared preparedRounding,
+        final String field,
+        final DateFieldMapper.DateFieldType fieldType,
+        final long low,
+        final long high
+    ) throws IOException {
+        final OptionalLong intervalOpt = Rounding.getInterval(rounding);
+        if (intervalOpt.isEmpty()) {
+            return null;
+        }
+
+        final long interval = intervalOpt.getAsLong();
+        // Calculate the number of buckets using range and interval
+        long roundedLow = preparedRounding.round(fieldType.convertNanosToMillis(low));
+        long prevRounded = roundedLow;
+        int bucketCount = 0;
+        while (roundedLow <= fieldType.convertNanosToMillis(high)) {
+            bucketCount++;
+            // Below rounding is needed as the interval could return in
+            // non-rounded values for something like calendar month
+            roundedLow = preparedRounding.round(roundedLow + interval);
+            if (prevRounded == roundedLow) break;
+            prevRounded = roundedLow;
+        }
+
+        Weight[] filters = null;
+        if (bucketCount > 0 && bucketCount <= MAX_NUM_FILTER_BUCKETS) {
+            int i = 0;
+            filters = new Weight[bucketCount];
+            roundedLow = preparedRounding.round(fieldType.convertNanosToMillis(low));
+            while (i < bucketCount) {
+                // Calculate the lower bucket bound
+                final byte[] lower = new byte[8];
+                NumericUtils.longToSortableBytes(i == 0 ? low : fieldType.convertRoundedMillisToNanos(roundedLow), lower, 0);
+                // Calculate the upper bucket bound
+                final byte[] upper = new byte[8];
+                roundedLow = preparedRounding.round(roundedLow + interval);
+                // Subtract -1 if the minimum is roundedLow as roundedLow itself
+                // is included in the next bucket
+                NumericUtils.longToSortableBytes(
+                    i + 1 == bucketCount ? high : fieldType.convertRoundedMillisToNanos(roundedLow) - 1,
+                    upper,
+                    0
+                );
+                filters[i++] = context.searcher().createWeight(new PointRangeQuery(field, lower, upper, 1) {
+                    @Override
+                    protected String toString(int dimension, byte[] value) {
+                        return null;
+                    }
+                }, ScoreMode.COMPLETE_NO_SCORES, 1);
+            }
+        }
+
+        return filters;
+    }
+
+    static FilterContext buildFastFilterContext(
+        final Object parent,
+        final int subAggLength,
+        SearchContext context,
+        Function<long[], Rounding> roundingFunction,
+        Supplier<Rounding.Prepared> preparedRoundingSupplier,
+        ValuesSourceConfig valuesSourceConfig,
+        CheckedFunction<FieldContext, long[], IOException> computeBounds
+    ) throws IOException {
+        // Create the filters for fast aggregation only if the query is instance
+        // of point range query and there aren't any parent/sub aggregations
+        if (parent == null && subAggLength == 0 && valuesSourceConfig.missing() == null && valuesSourceConfig.script() == null) {
+            final FieldContext fieldContext = valuesSourceConfig.fieldContext();
+            if (fieldContext != null) {
+                final String fieldName = fieldContext.field();
+                final long[] bounds = computeBounds.apply(fieldContext);
+                if (bounds != null) {
+                    assert fieldContext.fieldType() instanceof DateFieldMapper.DateFieldType;
+                    final DateFieldMapper.DateFieldType fieldType = (DateFieldMapper.DateFieldType) fieldContext.fieldType();
+                    final Rounding rounding = roundingFunction.apply(bounds);
+                    final Weight[] filters = FilterRewriteHelper.createFilterForAggregations(
+                        context,
+                        rounding,
+                        preparedRoundingSupplier.get(),
+                        fieldName,
+                        fieldType,
+                        bounds[0],
+                        bounds[1]
+                    );
+                    return new FilterContext(fieldType, filters);
+                }
+            }
+        }
+        return null;
+    }
+
+    static long getBucketOrd(long bucketOrd) {
+        if (bucketOrd < 0) { // already seen
+            bucketOrd = -1 - bucketOrd;
+        }
+
+        return bucketOrd;
+    }
+
+    static boolean tryFastFilterAggregation(
+        final LeafReaderContext ctx,
+        final Weight[] filters,
+        final DateFieldMapper.DateFieldType fieldType,
+        final BiConsumer<Long, Integer> incrementDocCount
+    ) throws IOException {
+        final int[] counts = new int[filters.length];
+        int i;
+        for (i = 0; i < filters.length; i++) {
+            counts[i] = filters[i].count(ctx);
+            if (counts[i] == -1) {
+                // Cannot use the optimization if any of the counts
+                // is -1 indicating the segment might have deleted documents
+                return false;
+            }
+        }
+
+        for (i = 0; i < filters.length; i++) {
+            if (counts[i] > 0) {
+                incrementDocCount.accept(
+                    fieldType.convertNanosToMillis(
+                        NumericUtils.sortableBytesToLong(((PointRangeQuery) filters[i].getQuery()).getLowerPoint(), 0)
+                    ),
+                    counts[i]
+                );
+            }
+        }
+        throw new CollectionTerminatedException();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/InternalVariableWidthHistogram.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/InternalVariableWidthHistogram.java
index 52f689eb7c229..8ebd67bc1ebe5 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/InternalVariableWidthHistogram.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/InternalVariableWidthHistogram.java
@@ -491,7 +491,7 @@ private void mergeBucketsWithPlan(List<Bucket> buckets, List<BucketRange> plan,
      * Makes a merge plan by simulating the merging of the two closest buckets, until the target number of buckets is reached.
      * Distance is determined by centroid comparison.
      * Then, this plan is actually executed and the underlying buckets are merged.
-     *
+     * <p>
      * Requires: <code>buckets</code> is sorted by centroid.
      */
     private void mergeBucketsIfNeeded(List<Bucket> buckets, int targetNumBuckets, ReduceContext reduceContext) {
@@ -567,7 +567,7 @@ private void mergeBucketsWithSameMin(List<Bucket> buckets, ReduceContext reduceC
     /**
      * When two adjacent buckets A, B overlap (A.max &gt; B.min) then their boundary is set to
      * the midpoint: (A.max + B.min) / 2.
-     *
+     * <p>
      * After this adjustment, A will contain more values than indicated and B will have less.
      */
     private void adjustBoundsForOverlappingBuckets(List<Bucket> buckets, ReduceContext reduceContext) {
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/LongBounds.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/LongBounds.java
index e138824e7fce8..ad6572916c84a 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/LongBounds.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/LongBounds.java
@@ -54,7 +54,7 @@
 
 /**
  * Represent hard_bounds and extended_bounds in date-histogram aggregations.
- *
+ * <p>
  * This class is similar to {@link DoubleBounds} used in histograms, but is using longs to store data. LongBounds and DoubleBounds are
  *  * not used interchangeably and therefore don't share any common interfaces except for serialization.
  *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/VariableWidthHistogramAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/VariableWidthHistogramAggregator.java
index 11ff7dbc407cb..526945243c786 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/VariableWidthHistogramAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/histogram/VariableWidthHistogramAggregator.java
@@ -76,7 +76,7 @@ public class VariableWidthHistogramAggregator extends DeferableBucketAggregator
     /**
      * This aggregator goes through multiple phases of collection. Each phase has a different CollectionPhase::collectValue
      * implementation
-     *
+     * <p>
      * Running a clustering algorithm like K-Means is unfeasible because large indices don't fit into memory.
      * But having multiple collection phases lets us accurately bucket the docs in one pass.
      */
@@ -231,7 +231,7 @@ protected void swap(int i, int j) {
              * Produces a merge map where `mergeMap[i]` represents the index that <code>values[i]</code>
              * would be moved to <b>if</b> <code>values</code> were sorted
              * In other words, this method produces a merge map that will sort <code>values</code>
-             *
+             * <p>
              * See BucketsAggregator::mergeBuckets to learn more about the merge map
              */
             public long[] generateMergeMap() {
@@ -242,10 +242,10 @@ public long[] generateMergeMap() {
 
         /**
          * Sorting the documents by key lets us bucket the documents into groups with a single linear scan
-         *
+         * <p>
          * But we can't do this by just sorting <code>buffer</code>, because we also need to generate a merge map
          * for every change we make to the list, so that we can apply the changes to the underlying buckets as well.
-         *
+         * <p>
          * By just creating a merge map, we eliminate the need to actually sort <code>buffer</code>. We can just
          * use the merge map to find any doc's sorted index.
          */
@@ -347,7 +347,7 @@ private void createAndAppendNewCluster(double value) {
         /**
          * Move the last cluster to position <code>idx</code>
          * This is expensive because a merge map of size <code>numClusters</code> is created, so don't call this method too often
-         *
+         * <p>
          * TODO: Make this more efficient
          */
         private void moveLastCluster(int index) {
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java
index 5f81c76b69385..0f3c9872353c1 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java
@@ -162,6 +162,6 @@ public InternalAggregation buildEmptyAggregation() {
 
     @Override
     protected boolean supportsConcurrentSegmentSearch() {
-        return true;
+        return false;
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregator.java
index 23e2bc6b3e54b..a886bdb3ae188 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregator.java
@@ -55,7 +55,7 @@
 
 /**
  * Aggregate on only the top-scoring docs on a shard.
- *
+ * <p>
  * TODO currently the diversity feature of this agg offers only 'script' and
  * 'field' as a means of generating a de-dup value. In future it would be nice
  * if users could use any of the "bucket" aggs syntax (geo, date histogram...)
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java
index d3db8a66ee21f..51d9830d3cea0 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java
@@ -75,6 +75,6 @@ public Aggregator createInternal(
 
     @Override
     protected boolean supportsConcurrentSegmentSearch() {
-        return true;
+        return false;
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalMultiTerms.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalMultiTerms.java
index 4d1cbd4ce72f1..5b90163fa3959 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalMultiTerms.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalMultiTerms.java
@@ -407,8 +407,8 @@ public int hashCode() {
 
     /**
      * Copy from InternalComposite
-     *
-     * Format <code>obj</code> using the provided {@link DocValueFormat}.
+     * <p>
+     * Format {@code obj} using the provided {@link DocValueFormat}.
      * If the format is equals to {@link DocValueFormat#RAW}, the object is returned as is
      * for numbers and a string for {@link BytesRef}s.
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalTerms.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalTerms.java
index 341ac021f6e0c..0e773291881cf 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalTerms.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalTerms.java
@@ -436,11 +436,11 @@ public InternalAggregation reduce(List<InternalAggregation> aggregations, Reduce
         }
 
         final List<B> reducedBuckets;
-        /**
-         * Buckets returned by a partial reduce or a shard response are sorted by key.
-         * That allows to perform a merge sort when reducing multiple aggregations together.
-         * For backward compatibility, we disable the merge sort and use ({@link InternalTerms#reduceLegacy} if any of
-         * the provided aggregations use a different {@link InternalTerms#reduceOrder}.
+        /*
+          Buckets returned by a partial reduce or a shard response are sorted by key.
+          That allows to perform a merge sort when reducing multiple aggregations together.
+          For backward compatibility, we disable the merge sort and use ({@link InternalTerms#reduceLegacy} if any of
+          the provided aggregations use a different {@link InternalTerms#reduceOrder}.
          */
         BucketOrder thisReduceOrder = getReduceOrder(aggregations);
         if (isKeyOrder(thisReduceOrder)) {
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/MultiTermsAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/MultiTermsAggregator.java
index 0482ef823818c..59f48bd7fbaba 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/MultiTermsAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/MultiTermsAggregator.java
@@ -94,10 +94,10 @@ public MultiTermsAggregator(
         this.partiallyBuiltBucketComparator = order == null ? null : order.partiallyBuiltBucketComparator(b -> b.bucketOrd, this);
         // Todo, copy from TermsAggregator. need to remove duplicate code.
         if (subAggsNeedScore() && descendsFromNestedAggregator(parent)) {
-            /**
-             * Force the execution to depth_first because we need to access the score of
-             * nested documents in a sub-aggregation and we are not able to generate this score
-             * while replaying deferred documents.
+            /*
+              Force the execution to depth_first because we need to access the score of
+              nested documents in a sub-aggregation and we are not able to generate this score
+              while replaying deferred documents.
              */
             this.collectMode = SubAggCollectionMode.DEPTH_FIRST;
         } else {
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/RareTermsAggregationBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/RareTermsAggregationBuilder.java
index dc616ca7512be..5d83d926ab36f 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/RareTermsAggregationBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/RareTermsAggregationBuilder.java
@@ -196,7 +196,7 @@ public double getPrecision() {
      * Set's the false-positive rate for individual cuckoo filters.  Does not dictate the overall fpp rate
      * since we use a "scaling" cuckoo filter which adds more filters as required, and the overall
      * error rate grows differently than individual filters
-     *
+     * <p>
      * This value does, however, affect the overall space usage of the filter.  Coarser precisions provide
      * more compact filters.  The default is 0.01
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/TermsAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/TermsAggregator.java
index 7cacf1e918380..918cc0276ed13 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/TermsAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/terms/TermsAggregator.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.aggregations.bucket.terms;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -67,8 +68,9 @@ public abstract class TermsAggregator extends DeferableBucketAggregator {
     /**
      * Bucket count thresholds
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class BucketCountThresholds implements Writeable, ToXContentFragment {
         private long minDocCount;
         private long shardMinDocCount;
@@ -244,10 +246,10 @@ public TermsAggregator(
         partiallyBuiltBucketComparator = order == null ? null : order.partiallyBuiltBucketComparator(b -> b.bucketOrd, this);
         this.format = format;
         if (subAggsNeedScore() && descendsFromNestedAggregator(parent)) {
-            /**
-             * Force the execution to depth_first because we need to access the score of
-             * nested documents in a sub-aggregation and we are not able to generate this score
-             * while replaying deferred documents.
+            /*
+              Force the execution to depth_first because we need to access the score of
+              nested documents in a sub-aggregation and we are not able to generate this score
+              while replaying deferred documents.
              */
             this.collectMode = SubAggCollectionMode.DEPTH_FIRST;
         } else {
diff --git a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLog.java b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLog.java
index 6b998fc86361d..902e4d69ed5fa 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLog.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLog.java
@@ -34,9 +34,9 @@
 
 /**
  * Hyperloglog counter, implemented based on pseudo code from
- * http://static.googleusercontent.com/media/research.google.com/fr//pubs/archive/40671.pdf and its appendix
- * https://docs.google.com/document/d/1gyjfMHy43U9OWBXxfaeG-3MjGzejW1dlpyMwEYAAWEI/view?fullscreen
- *
+ * <a href="http://static.googleusercontent.com/media/research.google.com/fr//pubs/archive/40671.pdf">40671.pdf</a> and its
+ * <a href="https://docs.google.com/document/d/1gyjfMHy43U9OWBXxfaeG-3MjGzejW1dlpyMwEYAAWEI/view?fullscreen">appendix</a>
+ * <p>
  * Trying to understand what this class does without having read the paper is considered adventurous.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLogPlusPlus.java b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLogPlusPlus.java
index 4354a23b70f6b..e74179b403e8e 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLogPlusPlus.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractHyperLogLogPlusPlus.java
@@ -46,7 +46,6 @@
 
 /**
  * Base class for HLL++ algorithms.
- *
  * It contains methods for cloning and serializing the data structure.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractLinearCounting.java b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractLinearCounting.java
index 3f5f524c9c2f5..7c00b25ae365f 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractLinearCounting.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractLinearCounting.java
@@ -36,11 +36,11 @@
 
 /**
  * Linear counter, implemented based on pseudo code from
- * http://static.googleusercontent.com/media/research.google.com/fr//pubs/archive/40671.pdf and its appendix
- * https://docs.google.com/document/d/1gyjfMHy43U9OWBXxfaeG-3MjGzejW1dlpyMwEYAAWEI/view?fullscreen
- *
+ * <a href="http://static.googleusercontent.com/media/research.google.com/fr//pubs/archive/40671.pdf">40671.pdf</a> and its
+ * <a href="https://docs.google.com/document/d/1gyjfMHy43U9OWBXxfaeG-3MjGzejW1dlpyMwEYAAWEI/view?fullscreen">appendix</a>
+ * <p>
  * Trying to understand what this class does without having read the paper is considered adventurous.
- *
+ * <p>
  * The algorithm just keep a record of all distinct values provided encoded as an integer.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractPercentilesAggregationBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractPercentilesAggregationBuilder.java
index 762b10fc28fa7..fa8830de5dab9 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractPercentilesAggregationBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/metrics/AbstractPercentilesAggregationBuilder.java
@@ -73,7 +73,7 @@ public static <T extends AbstractPercentilesAggregationBuilder<T>> ConstructingO
         ParseField valuesField
     ) {
 
-        /**
+        /*
          * This is a non-ideal ConstructingObjectParser, because it is a compromise between Percentiles and Ranks.
          * Ranks requires an array of values because there is no sane default, and we want to keep that in the ctor.
          * Percentiles has defaults, which means the API allows the user to either use the default or configure
@@ -86,6 +86,7 @@ public static <T extends AbstractPercentilesAggregationBuilder<T>> ConstructingO
          * out the behavior from there
          *
          * `args` are provided from the ConstructingObjectParser in-order they are defined in the parser.  So:
+         *
          *  - args[0]: values
          *  - args[1]: tdigest config options
          *  - args[2]: hdr config options
@@ -197,7 +198,7 @@ public boolean keyed() {
     /**
      * Expert: set the number of significant digits in the values. Only relevant
      * when using {@link PercentilesMethod#HDR}.
-     *
+     * <p>
      * Deprecated: set numberOfSignificantValueDigits by configuring a {@link PercentilesConfig.Hdr} instead
      * and set via {@link PercentilesAggregationBuilder#percentilesConfig(PercentilesConfig)}
      */
@@ -217,7 +218,7 @@ public T numberOfSignificantValueDigits(int numberOfSignificantValueDigits) {
     /**
      * Expert: get the number of significant digits in the values. Only relevant
      * when using {@link PercentilesMethod#HDR}.
-     *
+     * <p>
      * Deprecated: get numberOfSignificantValueDigits by inspecting the {@link PercentilesConfig} returned from
      * {@link PercentilesAggregationBuilder#percentilesConfig()} instead
      */
@@ -232,7 +233,7 @@ public int numberOfSignificantValueDigits() {
     /**
      * Expert: set the compression. Higher values improve accuracy but also
      * memory usage. Only relevant when using {@link PercentilesMethod#TDIGEST}.
-     *
+     * <p>
      * Deprecated: set compression by configuring a {@link PercentilesConfig.TDigest} instead
      * and set via {@link PercentilesAggregationBuilder#percentilesConfig(PercentilesConfig)}
      */
@@ -249,7 +250,7 @@ public T compression(double compression) {
     /**
      * Expert: get the compression. Higher values improve accuracy but also
      * memory usage. Only relevant when using {@link PercentilesMethod#TDIGEST}.
-     *
+     * <p>
      * Deprecated: get compression by inspecting the {@link PercentilesConfig} returned from
      * {@link PercentilesAggregationBuilder#percentilesConfig()} instead
      */
@@ -317,15 +318,15 @@ public T percentilesConfig(PercentilesConfig percentilesConfig) {
 
     /**
      * Return the current algo configuration, or a default (Tdigest) otherwise
-     *
+     * <p>
      * This is needed because builders don't have a "build" or "finalize" method, but
      * the old API did bake in defaults.  Certain operations like xcontent, equals, hashcode
      * will use the values in the builder at any time and need to be aware of defaults.
-     *
+     * <p>
      * But to maintain BWC behavior as much as possible, we allow the user to set
      * algo settings independent of method.  To keep life simple we use a null to track
      * if any method has been selected yet.
-     *
+     * <p>
      * However, this means we need a way to fetch the default if the user hasn't
      * selected any method and uses a builder-side feature like xcontent
      */
diff --git a/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlus.java b/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlus.java
index 7bd1e1aa22a90..7ab35eaed785c 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlus.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlus.java
@@ -49,16 +49,16 @@
  * Hyperloglog++ counter, implemented based on pseudo code from
  * http://static.googleusercontent.com/media/research.google.com/fr//pubs/archive/40671.pdf and its appendix
  * https://docs.google.com/document/d/1gyjfMHy43U9OWBXxfaeG-3MjGzejW1dlpyMwEYAAWEI/view?fullscreen
- *
+ * <p>
  * This implementation is different from the original implementation in that it uses a hash table instead of a sorted list for linear
  * counting. Although this requires more space and makes hyperloglog (which is less accurate) used sooner, this is also considerably faster.
- *
+ * <p>
  * Trying to understand what this class does without having read the paper is considered adventurous.
- *
+ * <p>
  * The HyperLogLogPlusPlus contains two algorithms, one for linear counting and the HyperLogLog algorithm. Initially hashes added to the
  * data structure are processed using the linear counting until a threshold defined by the precision is reached where the data is replayed
  * to the HyperLogLog algorithm and then this is used.
- *
+ * <p>
  * It supports storing several HyperLogLogPlusPlus structures which are identified by a bucket number.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlusSparse.java b/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlusSparse.java
index 252df7358ddcd..558e9df93c804 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlusSparse.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/metrics/HyperLogLogPlusPlusSparse.java
@@ -40,7 +40,7 @@
 /**
  * AbstractHyperLogLogPlusPlus instance that only supports linear counting. The maximum number of hashes supported
  * by the structure is determined at construction time.
- *
+ * <p>
  * This structure expects all the added values to be distinct and therefore there are no checks
  * if an element has been previously added.
  *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/metrics/ValueCountAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/metrics/ValueCountAggregator.java
index be98df384fc28..6f9be06231819 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/metrics/ValueCountAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/metrics/ValueCountAggregator.java
@@ -52,7 +52,7 @@
 
 /**
  * A field data based aggregator that counts the number of values a specific field has within the aggregation context.
- *
+ * <p>
  * This aggregator works in a multi-bucket mode, that is, when serves as a sub-aggregator, a single aggregator instance aggregates the
  * counts for all buckets owned by the parent aggregator)
  *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/pipeline/BucketHelpers.java b/server/src/main/java/org/opensearch/search/aggregations/pipeline/BucketHelpers.java
index 3015e7ce9f364..c7f2a29793bff 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/pipeline/BucketHelpers.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/pipeline/BucketHelpers.java
@@ -64,7 +64,7 @@ public class BucketHelpers {
      * a date_histogram might have empty buckets due to no data existing for that time interval.
      * This can cause problems for operations like a derivative, which relies on a continuous
      * function.
-     *
+     * <p>
      * "insert_zeros": empty buckets will be filled with zeros for all metrics
      * "skip": empty buckets will simply be ignored
      *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovFnPipelineAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovFnPipelineAggregator.java
index a4c3c14f3365f..3e97eda693b91 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovFnPipelineAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovFnPipelineAggregator.java
@@ -52,18 +52,18 @@
 /**
  * This pipeline aggregation gives the user the ability to script functions that "move" across a window
  * of data, instead of single data points.  It is the scripted version of MovingAvg pipeline agg.
- *
+ * <p>
  * Through custom script contexts, we expose a number of convenience methods:
- *
- *  - max
- *  - min
- *  - sum
- *  - unweightedAvg
- *  - linearWeightedAvg
- *  - ewma
- *  - holt
- *  - holtWintersMovAvg
- *
+ * <ul>
+ *   <li>max</li>
+ *  <li> min</li>
+ *  <li> sum</li>
+ *  <li> unweightedAvg</li>
+ *  <li> linearWeightedAvg</li>
+ *  <li> ewma</li>
+ *  <li> holt</li>
+ *  <li> holtWintersMovAvg</li>
+ * </ul>
  *  The user can also define any arbitrary logic via their own scripting, or combine with the above methods.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovingFunctions.java b/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovingFunctions.java
index bac486576f537..051b9c43f63f5 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovingFunctions.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/pipeline/MovingFunctions.java
@@ -75,7 +75,7 @@ public static double sum(double[] values) {
 
     /**
      * Calculate a simple unweighted (arithmetic) moving average.
-     *
+     * <p>
      * Only finite values are averaged.  NaN or null are ignored.
      * If all values are missing/null/NaN, the return value will be NaN.
      * The average is based on the count of non-null, non-NaN values.
@@ -94,7 +94,7 @@ public static double unweightedAvg(double[] values) {
 
     /**
      * Calculate a standard deviation over the values using the provided average.
-     *
+     * <p>
      * Only finite values are averaged.  NaN or null are ignored.
      * If all values are missing/null/NaN, the return value will be NaN.
      * The average is based on the count of non-null, non-NaN values.
@@ -118,7 +118,7 @@ public static double stdDev(double[] values, double avg) {
     /**
      * Calculate a linearly weighted moving average, such that older values are
      * linearly less important.  "Time" is determined by position in collection
-     *
+     * <p>
      * Only finite values are averaged.  NaN or null are ignored.
      * If all values are missing/null/NaN, the return value will be NaN
      * The average is based on the count of non-null, non-NaN values.
@@ -141,11 +141,11 @@ public static double linearWeightedAvg(double[] values) {
     /**
      *
      * Calculate a exponentially weighted moving average.
-     *
+     * <p>
      * Alpha controls the smoothing of the data.  Alpha = 1 retains no memory of past values
      * (e.g. a random walk), while alpha = 0 retains infinite memory of past values (e.g.
      * the series mean).  Useful values are somewhere in between.  Defaults to 0.5.
-     *
+     * <p>
      * Only finite values are averaged.  NaN or null are ignored.
      * If all values are missing/null/NaN, the return value will be NaN
      * The average is based on the count of non-null, non-NaN values.
@@ -171,13 +171,13 @@ public static double ewma(double[] values, double alpha) {
 
     /**
      * Calculate a doubly exponential weighted moving average
-     *
+     * <p>
      * Alpha controls the smoothing of the data.  Alpha = 1 retains no memory of past values
      * (e.g. a random walk), while alpha = 0 retains infinite memory of past values (e.g.
      * the series mean).  Useful values are somewhere in between.  Defaults to 0.5.
-     *
+     * <p>
      * Beta is equivalent to alpha, but controls the smoothing of the trend instead of the data
-     *
+     * <p>
      * Only finite values are averaged.  NaN or null are ignored.
      * If all values are missing/null/NaN, the return value will be NaN
      * The average is based on the count of non-null, non-NaN values.
@@ -241,14 +241,14 @@ public static double[] holtForecast(double[] values, double alpha, double beta,
 
     /**
      * Calculate a triple exponential weighted moving average
-     *
+     * <p>
      * Alpha controls the smoothing of the data.  Alpha = 1 retains no memory of past values
      * (e.g. a random walk), while alpha = 0 retains infinite memory of past values (e.g.
      * the series mean).  Useful values are somewhere in between.  Defaults to 0.5.
-     *
+     * <p>
      * Beta is equivalent to alpha, but controls the smoothing of the trend instead of the data.
      * Gamma is equivalent to alpha, but controls the smoothing of the seasonality instead of the data
-     *
+     * <p>
      * Only finite values are averaged.  NaN or null are ignored.
      * If all values are missing/null/NaN, the return value will be NaN
      * The average is based on the count of non-null, non-NaN values.
diff --git a/server/src/main/java/org/opensearch/search/aggregations/pipeline/PipelineAggregator.java b/server/src/main/java/org/opensearch/search/aggregations/pipeline/PipelineAggregator.java
index 859eba1f1aaff..151051a21f610 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/pipeline/PipelineAggregator.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/pipeline/PipelineAggregator.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations.pipeline;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.search.aggregations.InternalAggregation;
@@ -48,8 +49,9 @@
 /**
  * Base aggregator for pipline aggs
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class PipelineAggregator {
     /**
      * Parse the {@link PipelineAggregationBuilder} from a {@link XContentParser}.
@@ -80,8 +82,9 @@ public interface Parser {
      * Tree of {@link PipelineAggregator}s to modify a tree of aggregations
      * after their final reduction.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class PipelineTree {
         /**
          * An empty tree of {@link PipelineAggregator}s.
diff --git a/server/src/main/java/org/opensearch/search/aggregations/pipeline/SimulatedAnealingMinimizer.java b/server/src/main/java/org/opensearch/search/aggregations/pipeline/SimulatedAnealingMinimizer.java
index a61a866228161..8427346357b0e 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/pipeline/SimulatedAnealingMinimizer.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/pipeline/SimulatedAnealingMinimizer.java
@@ -36,11 +36,11 @@
 
 /**
  * A cost minimizer which will fit a MovAvgModel to the data.
- *
+ * <p>
  * This optimizer uses naive simulated annealing.  Random solutions in the problem space
  * are generated, compared against the last period of data, and the least absolute deviation
  * is recorded as a cost.
- *
+ * <p>
  * If the new cost is better than the old cost, the new coefficients are chosen.  If the new
  * solution is worse, there is a temperature-dependent probability it will be randomly selected
  * anyway.  This allows the algo to sample the problem space widely.  As iterations progress,
@@ -114,7 +114,7 @@ private static double acceptanceProbability(double oldCost, double newCost, doub
     /**
      * Calculates the "cost" of a model.  E.g. when run on the training data, how closely do the  predictions
      * match the test data
-     *
+     * <p>
      * Uses Least Absolute Differences to calculate error.  Note that this is not scale free, but seems
      * to work fairly well in practice
      *
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInfo.java b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInfo.java
index 7d920ee2e9d56..c0aebb49af5ec 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInfo.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInfo.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.service.ReportingService;
@@ -49,8 +50,9 @@
 /**
  * Data describing an agg
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AggregationInfo implements ReportingService.Info {
 
     private final Map<String, Set<String>> aggs;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInspectionHelper.java b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInspectionHelper.java
index 25cdd76183602..a7de47bed2e6e 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInspectionHelper.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationInspectionHelper.java
@@ -78,9 +78,9 @@
  * Provides a set of static helpers to determine if a particular type of InternalAggregation "has a value"
  * or not.  This can be difficult to determine from an external perspective because each agg uses
  * different internal bookkeeping to determine if it is empty or not (NaN, +/-Inf, 0.0, etc).
- *
+ * <p>
  * This set of helpers aim to ease that task by codifying what "empty" is for each agg.
- *
+ * <p>
  * It is not entirely accurate for all aggs, since some do not expose or track the needed state
  * (e.g. sum doesn't record count, so it's not clear if the sum is 0.0 because it is empty
  * or because of summing to zero).  Pipeline aggs in particular are not well supported
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationPath.java b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationPath.java
index 4cfd2070211d7..78180ff08fea9 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationPath.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationPath.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.search.aggregations.AggregationExecutionException;
 import org.opensearch.search.aggregations.Aggregator;
@@ -131,8 +132,9 @@ public static AggregationPath parse(String path) {
     /**
      * Element in an agg path
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class PathElement {
 
         private final String fullName;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationUsageService.java b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationUsageService.java
index 7685ec5ff876f..41f03bd4da9e2 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/AggregationUsageService.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/AggregationUsageService.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.service.ReportingService;
 
 import java.util.HashMap;
@@ -41,8 +42,9 @@
 /**
  * Service to track telemetry about aggregations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AggregationUsageService implements ReportingService<AggregationInfo> {
     private final Map<String, Map<String, LongAdder>> aggs;
     private final AggregationInfo info;
@@ -52,8 +54,9 @@ public class AggregationUsageService implements ReportingService<AggregationInfo
     /**
      * Builder for the Agg usage service to track telemetry
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
         private final Map<String, Map<String, LongAdder>> aggs;
 
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/CoreValuesSourceType.java b/server/src/main/java/org/opensearch/search/aggregations/support/CoreValuesSourceType.java
index 224f9281705e1..f6d6fe28a56d3 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/CoreValuesSourceType.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/CoreValuesSourceType.java
@@ -274,7 +274,7 @@ public ValuesSource replaceMissing(ValuesSource valuesSource, Object rawMissing,
          * MappedFieldType, it prefers to get the formatter from there. Only when a field can't be
          * resolved (which is to say script cases and unmapped field cases), it will fall back to calling this method on whatever
          * ValuesSourceType it was able to resolve to.
-         *
+         * <p>
          * For geoshape field we may never hit this function till we have aggregations which are only geo_shape
          * specific and not present on geo_points, as we use default CoreValueSource types for Geo based aggregations
          * as GEOPOINT
@@ -411,7 +411,7 @@ public ValuesSource replaceMissing(ValuesSource valuesSource, Object rawMissing,
         @Override
         public DocValueFormat getFormatter(String format, ZoneId tz) {
             return new DocValueFormat.DateTime(
-                format == null ? DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER : DateFormatter.forPattern(format),
+                format == null ? DateFieldMapper.getDefaultDateTimeFormatter() : DateFormatter.forPattern(format),
                 tz == null ? ZoneOffset.UTC : tz,
                 // If we were just looking at fields, we could read the resolution from the field settings, but we need to deal with script
                 // output, which has no way to indicate the resolution, so we need to default to something. Milliseconds is the standard.
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/FieldContext.java b/server/src/main/java/org/opensearch/search/aggregations/support/FieldContext.java
index a6207917d52ea..ec8240a5b6b94 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/FieldContext.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/FieldContext.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.aggregations.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.mapper.MappedFieldType;
 
@@ -38,8 +39,9 @@
  * Used by all field data based aggregators. This determine the context of the field data the aggregators are operating
  * in. It holds both the field names and the index field datas that are associated with them.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FieldContext {
 
     private final String field;
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/MultiValuesSourceAggregationBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/support/MultiValuesSourceAggregationBuilder.java
index e3f914ca259f6..c866238d12fcb 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/MultiValuesSourceAggregationBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/MultiValuesSourceAggregationBuilder.java
@@ -51,7 +51,7 @@
 /**
  * Similar to {@link ValuesSourceAggregationBuilder}, except it references multiple ValuesSources (e.g. so that an aggregation
  * can pull values from multiple fields).
- *
+ * <p>
  * A limitation of this class is that all the ValuesSource's being refereenced must be of the same type.
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/ValueType.java b/server/src/main/java/org/opensearch/search/aggregations/support/ValueType.java
index 59fa2e03f0bc3..ad2ae2a41eec9 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/ValueType.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/ValueType.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * Enum to signal what kind of value type is used in the aggregator
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum ValueType implements Writeable {
 
     STRING((byte) 1, "string", "string", CoreValuesSourceType.BYTES, DocValueFormat.RAW),
@@ -61,7 +63,7 @@ public enum ValueType implements Writeable {
         "date",
         "date",
         CoreValuesSourceType.DATE,
-        new DocValueFormat.DateTime(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER, ZoneOffset.UTC, DateFieldMapper.Resolution.MILLISECONDS)
+        new DocValueFormat.DateTime(DateFieldMapper.getDefaultDateTimeFormatter(), ZoneOffset.UTC, DateFieldMapper.Resolution.MILLISECONDS)
     ),
     IP((byte) 6, "ip", "ip", CoreValuesSourceType.IP, DocValueFormat.IP),
     // TODO: what is the difference between "number" and "numeric"?
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSource.java b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSource.java
index 67d311db964d6..1a76183ac1a2d 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSource.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSource.java
@@ -43,6 +43,7 @@
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.common.Rounding;
 import org.opensearch.common.Rounding.Prepared;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.ScorerAware;
 import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.index.fielddata.AbstractSortingNumericDocValues;
@@ -75,8 +76,9 @@
 /**
  * Base class for a ValuesSource; the primitive data for an agg
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class ValuesSource {
 
     /**
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceAggregationBuilder.java b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceAggregationBuilder.java
index 70382369d5615..7a73fafb4a809 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceAggregationBuilder.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceAggregationBuilder.java
@@ -264,7 +264,7 @@ protected final void doWriteTo(StreamOutput out) throws IOException {
 
     /**
      * DO NOT OVERRIDE THIS!
-     *
+     * <p>
      * This method only exists for legacy support.  No new aggregations need this, nor should they override it.
      *
      * @param version For backwards compatibility, subclasses can change behavior based on the version
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceConfig.java b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceConfig.java
index b5bd355bb5847..d006b15df327c 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceConfig.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceConfig.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.aggregations.support;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.fielddata.IndexGeoPointFieldData;
 import org.opensearch.index.fielddata.IndexNumericFieldData;
@@ -50,8 +51,9 @@
  * A configuration that tells aggregations how to retrieve data from the index
  * in order to run a specific aggregation.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ValuesSourceConfig {
 
     /**
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceRegistry.java b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceRegistry.java
index 0cb5a12bac4af..9f084833f8093 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceRegistry.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceRegistry.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.aggregations.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.query.QueryShardContext;
 import org.opensearch.search.SearchModule;
 import org.opensearch.search.aggregations.AggregationExecutionException;
@@ -49,15 +50,17 @@
  * directly instantiate this class, instead get an already-configured copy from {@link QueryShardContext#getValuesSourceRegistry()}, or (in
  * the case of some test scenarios only) directly from {@link SearchModule#getValuesSourceRegistry()}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ValuesSourceRegistry {
 
     /**
      * The registry key for the values source registry key
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static final class RegistryKey<T> {
         private final String name;
         private final Class<T> supplierType;
@@ -90,8 +93,9 @@ public int hashCode() {
     /**
      * Builder for the values source registry
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
         private final AggregationUsageService.Builder usageServiceBuilder;
         private Map<RegistryKey<?>, List<Map.Entry<ValuesSourceType, ?>>> aggregatorRegistry = new HashMap<>();
diff --git a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceType.java b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceType.java
index 86102e63297d1..ff81c08193a0b 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceType.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/support/ValuesSourceType.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.aggregations.support;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.script.AggregationScript;
 import org.opensearch.search.DocValueFormat;
 
@@ -43,14 +44,14 @@
  * {@link ValuesSourceType} represents a collection of fields that share a common set of operations, for example all numeric fields.
  * Aggregations declare their support for a given ValuesSourceType (via {@link ValuesSourceRegistry.Builder#register}),
  * and should then not need to care about the fields which use that ValuesSourceType.
- *
+ * <p>
  * ValuesSourceTypes provide a set of methods to instantiate concrete {@link ValuesSource} instances, based on the actual source of the
  * data for the aggregations.  In general, aggregations should not call these methods, but rather rely on {@link ValuesSourceConfig} to have
  * selected the correct implementation.
- *
+ * <p>
  * ValuesSourceTypes should be stateless.  We recommend that plugins define an enum for their ValuesSourceTypes, even if the plugin only
  * intends to define one ValuesSourceType.  ValuesSourceTypes are not serialized as part of the aggregations framework.
- *
+ * <p>
  * Prefer reusing an existing ValuesSourceType (ideally from {@link CoreValuesSourceType}) over creating a new type.  There are some cases
  * where creating a new type is necessary however.  In particular, consider a new ValuesSourceType if the field has custom encoding/decoding
  * requirements; if the field needs to expose additional information to the aggregation (e.g. {@link ValuesSource.Range#rangeType()}); or
@@ -58,8 +59,9 @@
  * a sum aggregation).  When adding a new ValuesSourceType, new aggregators should be added and registered at the same time, to add support
  * for the new type to existing aggregations, as appropriate.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ValuesSourceType {
     /**
      * Called when an aggregation is operating over a known empty set (usually because the field isn't specified), this method allows for
diff --git a/server/src/main/java/org/opensearch/search/backpressure/SearchBackpressureService.java b/server/src/main/java/org/opensearch/search/backpressure/SearchBackpressureService.java
index 4f6c2c327509d..ebf9623eb367a 100644
--- a/server/src/main/java/org/opensearch/search/backpressure/SearchBackpressureService.java
+++ b/server/src/main/java/org/opensearch/search/backpressure/SearchBackpressureService.java
@@ -255,8 +255,8 @@ boolean isNodeInDuress() {
         return isNodeInDuress;
     }
 
-    /**
-     * Returns true if the increase in heap usage is due to search requests.
+    /*
+      Returns true if the increase in heap usage is due to search requests.
      */
 
     /**
@@ -399,6 +399,7 @@ public SearchBackpressureStats nodeStats() {
         SearchTaskStats searchTaskStats = new SearchTaskStats(
             searchBackpressureStates.get(SearchTask.class).getCancellationCount(),
             searchBackpressureStates.get(SearchTask.class).getLimitReachedCount(),
+            searchBackpressureStates.get(SearchTask.class).getCompletionCount(),
             taskTrackers.get(SearchTask.class)
                 .stream()
                 .collect(Collectors.toUnmodifiableMap(t -> TaskResourceUsageTrackerType.fromName(t.name()), t -> t.stats(searchTasks)))
@@ -407,6 +408,7 @@ public SearchBackpressureStats nodeStats() {
         SearchShardTaskStats searchShardTaskStats = new SearchShardTaskStats(
             searchBackpressureStates.get(SearchShardTask.class).getCancellationCount(),
             searchBackpressureStates.get(SearchShardTask.class).getLimitReachedCount(),
+            searchBackpressureStates.get(SearchShardTask.class).getCompletionCount(),
             taskTrackers.get(SearchShardTask.class)
                 .stream()
                 .collect(Collectors.toUnmodifiableMap(t -> TaskResourceUsageTrackerType.fromName(t.name()), t -> t.stats(searchShardTasks)))
diff --git a/server/src/main/java/org/opensearch/search/backpressure/settings/SearchBackpressureSettings.java b/server/src/main/java/org/opensearch/search/backpressure/settings/SearchBackpressureSettings.java
index d20e3e50d419f..79494eb0d3c24 100644
--- a/server/src/main/java/org/opensearch/search/backpressure/settings/SearchBackpressureSettings.java
+++ b/server/src/main/java/org/opensearch/search/backpressure/settings/SearchBackpressureSettings.java
@@ -54,8 +54,8 @@ private static class Defaults {
     /**
      * Defines the percentage of tasks to cancel relative to the number of successful task completions.
      * In other words, it is the number of tokens added to the bucket on each successful task completion.
-     *
-     * The setting below is deprecated.
+     * <p>
+     * The setting below is deprecated. The new setting is in {@link SearchShardTaskSettings}.
      * To keep backwards compatibility, the old usage is remained, and it's also used as the fallback for the new usage.
      */
     public static final Setting<Double> SETTING_CANCELLATION_RATIO = Setting.doubleSetting(
@@ -71,8 +71,8 @@ private static class Defaults {
     /**
      * Defines the number of tasks to cancel per unit time (in millis).
      * In other words, it is the number of tokens added to the bucket each millisecond.
-     *
-     * The setting below is deprecated.
+     * <p>
+     * The setting below is deprecated. The new setting is in {@link SearchShardTaskSettings}.
      * To keep backwards compatibility, the old usage is remained, and it's also used as the fallback for the new usage.
      */
     public static final Setting<Double> SETTING_CANCELLATION_RATE = Setting.doubleSetting(
@@ -86,8 +86,8 @@ private static class Defaults {
 
     /**
      * Defines the maximum number of tasks that can be cancelled before being rate-limited.
-     *
-     * The setting below is deprecated.
+     * <p>
+     * The setting below is deprecated. The new setting is in {@link SearchShardTaskSettings}.
      * To keep backwards compatibility, the old usage is remained, and it's also used as the fallback for the new usage.
      */
     public static final Setting<Double> SETTING_CANCELLATION_BURST = Setting.doubleSetting(
diff --git a/server/src/main/java/org/opensearch/search/backpressure/stats/SearchShardTaskStats.java b/server/src/main/java/org/opensearch/search/backpressure/stats/SearchShardTaskStats.java
index 678c19d83fb96..ffe97d125b27a 100644
--- a/server/src/main/java/org/opensearch/search/backpressure/stats/SearchShardTaskStats.java
+++ b/server/src/main/java/org/opensearch/search/backpressure/stats/SearchShardTaskStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.search.backpressure.stats;
 
+import org.opensearch.Version;
 import org.opensearch.common.collect.MapBuilder;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -30,21 +31,29 @@
 public class SearchShardTaskStats implements ToXContentObject, Writeable {
     private final long cancellationCount;
     private final long limitReachedCount;
+    private final long completionCount;
     private final Map<TaskResourceUsageTrackerType, TaskResourceUsageTracker.Stats> resourceUsageTrackerStats;
 
     public SearchShardTaskStats(
         long cancellationCount,
         long limitReachedCount,
+        long completionCount,
         Map<TaskResourceUsageTrackerType, TaskResourceUsageTracker.Stats> resourceUsageTrackerStats
     ) {
         this.cancellationCount = cancellationCount;
         this.limitReachedCount = limitReachedCount;
+        this.completionCount = completionCount;
         this.resourceUsageTrackerStats = resourceUsageTrackerStats;
     }
 
     public SearchShardTaskStats(StreamInput in) throws IOException {
         this.cancellationCount = in.readVLong();
         this.limitReachedCount = in.readVLong();
+        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+            completionCount = in.readVLong();
+        } else {
+            completionCount = -1;
+        }
 
         MapBuilder<TaskResourceUsageTrackerType, TaskResourceUsageTracker.Stats> builder = new MapBuilder<>();
         builder.put(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER, in.readOptionalWriteable(CpuUsageTracker.Stats::new));
@@ -62,6 +71,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.field(entry.getKey().getName(), entry.getValue());
         }
         builder.endObject();
+        if (completionCount != -1) {
+            builder.field("completion_count", completionCount);
+        }
 
         builder.startObject("cancellation_stats")
             .field("cancellation_count", cancellationCount)
@@ -75,6 +87,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(cancellationCount);
         out.writeVLong(limitReachedCount);
+        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+            out.writeVLong(completionCount);
+        }
 
         out.writeOptionalWriteable(resourceUsageTrackerStats.get(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER));
         out.writeOptionalWriteable(resourceUsageTrackerStats.get(TaskResourceUsageTrackerType.HEAP_USAGE_TRACKER));
@@ -88,11 +103,12 @@ public boolean equals(Object o) {
         SearchShardTaskStats that = (SearchShardTaskStats) o;
         return cancellationCount == that.cancellationCount
             && limitReachedCount == that.limitReachedCount
+            && completionCount == that.completionCount
             && resourceUsageTrackerStats.equals(that.resourceUsageTrackerStats);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(cancellationCount, limitReachedCount, resourceUsageTrackerStats);
+        return Objects.hash(cancellationCount, limitReachedCount, resourceUsageTrackerStats, completionCount);
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/backpressure/stats/SearchTaskStats.java b/server/src/main/java/org/opensearch/search/backpressure/stats/SearchTaskStats.java
index 302350104bd3a..a7f9b4e3d004f 100644
--- a/server/src/main/java/org/opensearch/search/backpressure/stats/SearchTaskStats.java
+++ b/server/src/main/java/org/opensearch/search/backpressure/stats/SearchTaskStats.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.search.backpressure.stats;
 
+import org.opensearch.Version;
 import org.opensearch.common.collect.MapBuilder;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -31,21 +32,29 @@
 public class SearchTaskStats implements ToXContentObject, Writeable {
     private final long cancellationCount;
     private final long limitReachedCount;
+    private final long completionCount;
     private final Map<TaskResourceUsageTrackerType, TaskResourceUsageTracker.Stats> resourceUsageTrackerStats;
 
     public SearchTaskStats(
         long cancellationCount,
         long limitReachedCount,
+        long completionCount,
         Map<TaskResourceUsageTrackerType, TaskResourceUsageTracker.Stats> resourceUsageTrackerStats
     ) {
         this.cancellationCount = cancellationCount;
         this.limitReachedCount = limitReachedCount;
+        this.completionCount = completionCount;
         this.resourceUsageTrackerStats = resourceUsageTrackerStats;
     }
 
     public SearchTaskStats(StreamInput in) throws IOException {
         this.cancellationCount = in.readVLong();
         this.limitReachedCount = in.readVLong();
+        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+            this.completionCount = in.readVLong();
+        } else {
+            this.completionCount = -1;
+        }
 
         MapBuilder<TaskResourceUsageTrackerType, TaskResourceUsageTracker.Stats> builder = new MapBuilder<>();
         builder.put(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER, in.readOptionalWriteable(CpuUsageTracker.Stats::new));
@@ -63,6 +72,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.field(entry.getKey().getName(), entry.getValue());
         }
         builder.endObject();
+        if (completionCount != -1) {
+            builder.field("completion_count", completionCount);
+        }
 
         builder.startObject("cancellation_stats")
             .field("cancellation_count", cancellationCount)
@@ -76,6 +88,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(cancellationCount);
         out.writeVLong(limitReachedCount);
+        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+            out.writeVLong(completionCount);
+        }
 
         out.writeOptionalWriteable(resourceUsageTrackerStats.get(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER));
         out.writeOptionalWriteable(resourceUsageTrackerStats.get(TaskResourceUsageTrackerType.HEAP_USAGE_TRACKER));
@@ -89,11 +104,12 @@ public boolean equals(Object o) {
         SearchTaskStats that = (SearchTaskStats) o;
         return cancellationCount == that.cancellationCount
             && limitReachedCount == that.limitReachedCount
+            && completionCount == that.completionCount
             && resourceUsageTrackerStats.equals(that.resourceUsageTrackerStats);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(cancellationCount, limitReachedCount, resourceUsageTrackerStats);
+        return Objects.hash(cancellationCount, limitReachedCount, resourceUsageTrackerStats, completionCount);
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/builder/PointInTimeBuilder.java b/server/src/main/java/org/opensearch/search/builder/PointInTimeBuilder.java
index c50f3c75213dd..20bdb71fd1923 100644
--- a/server/src/main/java/org/opensearch/search/builder/PointInTimeBuilder.java
+++ b/server/src/main/java/org/opensearch/search/builder/PointInTimeBuilder.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.builder;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -50,8 +51,9 @@
  * A search request with a point in time will execute using the reader contexts associated with that point time
  * instead of the latest reader contexts.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.3.0")
 public final class PointInTimeBuilder implements Writeable, ToXContentObject {
     private static final ParseField ID_FIELD = new ParseField("id");
     private static final ParseField KEEP_ALIVE_FIELD = new ParseField("keep_alive");
diff --git a/server/src/main/java/org/opensearch/search/builder/SearchSourceBuilder.java b/server/src/main/java/org/opensearch/search/builder/SearchSourceBuilder.java
index 7a2dc65765b22..434e630893f25 100644
--- a/server/src/main/java/org/opensearch/search/builder/SearchSourceBuilder.java
+++ b/server/src/main/java/org/opensearch/search/builder/SearchSourceBuilder.java
@@ -36,6 +36,7 @@
 import org.opensearch.Version;
 import org.opensearch.common.Booleans;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
@@ -91,8 +92,9 @@
  *
  * @see org.opensearch.action.search.SearchRequest#source(SearchSourceBuilder)
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SearchSourceBuilder implements Writeable, ToXContentObject, Rewriteable<SearchSourceBuilder> {
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(SearchSourceBuilder.class);
 
@@ -1493,8 +1495,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     /**
      * Boosts on an index
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class IndexBoost implements Writeable, ToXContentObject {
         private final String index;
         private final float boost;
@@ -1594,8 +1597,9 @@ public boolean equals(Object obj) {
     /**
      * Script field
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ScriptField implements Writeable, ToXContentFragment {
 
         private final boolean ignoreFailure;
diff --git a/server/src/main/java/org/opensearch/search/collapse/CollapseBuilder.java b/server/src/main/java/org/opensearch/search/collapse/CollapseBuilder.java
index 73802cbd7a849..a9ff55b3a90b1 100644
--- a/server/src/main/java/org/opensearch/search/collapse/CollapseBuilder.java
+++ b/server/src/main/java/org/opensearch/search/collapse/CollapseBuilder.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.collapse;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.Strings;
@@ -57,8 +58,9 @@
 /**
  * A builder that enables field collapsing on search request.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CollapseBuilder implements Writeable, ToXContentObject {
     public static final ParseField FIELD_FIELD = new ParseField("field");
     public static final ParseField INNER_HITS_FIELD = new ParseField("inner_hits");
diff --git a/server/src/main/java/org/opensearch/search/collapse/CollapseContext.java b/server/src/main/java/org/opensearch/search/collapse/CollapseContext.java
index 09a612a15d762..79b90d92f4daa 100644
--- a/server/src/main/java/org/opensearch/search/collapse/CollapseContext.java
+++ b/server/src/main/java/org/opensearch/search/collapse/CollapseContext.java
@@ -33,6 +33,7 @@
 
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.grouping.CollapsingTopDocsCollector;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.mapper.KeywordFieldMapper;
 import org.opensearch.index.mapper.MappedFieldType;
 import org.opensearch.index.mapper.NumberFieldMapper;
@@ -43,8 +44,9 @@
 /**
  * Context used for field collapsing
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CollapseContext {
     private final String fieldName;
     private final MappedFieldType fieldType;
diff --git a/server/src/main/java/org/opensearch/search/dfs/AggregatedDfs.java b/server/src/main/java/org/opensearch/search/dfs/AggregatedDfs.java
index 35ab0c0701b4e..61e465e49be53 100644
--- a/server/src/main/java/org/opensearch/search/dfs/AggregatedDfs.java
+++ b/server/src/main/java/org/opensearch/search/dfs/AggregatedDfs.java
@@ -35,6 +35,7 @@
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.CollectionStatistics;
 import org.apache.lucene.search.TermStatistics;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -47,8 +48,9 @@
 /**
  * Compute global distributed frequency across the index
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AggregatedDfs implements Writeable {
 
     private Map<Term, TermStatistics> termStatistics;
diff --git a/server/src/main/java/org/opensearch/search/dfs/DfsSearchResult.java b/server/src/main/java/org/opensearch/search/dfs/DfsSearchResult.java
index 0209f91f7fa52..2338a47435012 100644
--- a/server/src/main/java/org/opensearch/search/dfs/DfsSearchResult.java
+++ b/server/src/main/java/org/opensearch/search/dfs/DfsSearchResult.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.search.CollectionStatistics;
 import org.apache.lucene.search.TermStatistics;
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.search.SearchPhaseResult;
@@ -51,8 +52,9 @@
 /**
  * Result from a Distributed Frequency Search phase
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DfsSearchResult extends SearchPhaseResult {
 
     private static final Term[] EMPTY_TERMS = new Term[0];
diff --git a/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java b/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java
index 09c407cfc70be..a842c0f1adc6e 100644
--- a/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java
+++ b/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java
@@ -44,6 +44,7 @@
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.BitSet;
 import org.opensearch.common.CheckedBiConsumer;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.common.lucene.index.SequentialStoredFieldsLeafReader;
@@ -92,8 +93,9 @@
  * Fetch phase of a search request, used to fetch the actual top matching documents to be returned to the client, identified
  * after reducing all of the matches returned by the query phase
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FetchPhase {
     private static final Logger LOGGER = LogManager.getLogger(FetchPhase.class);
 
diff --git a/server/src/main/java/org/opensearch/search/fetch/FetchSearchResult.java b/server/src/main/java/org/opensearch/search/fetch/FetchSearchResult.java
index a8560863d8d98..26fa90141c2a9 100644
--- a/server/src/main/java/org/opensearch/search/fetch/FetchSearchResult.java
+++ b/server/src/main/java/org/opensearch/search/fetch/FetchSearchResult.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.fetch;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.search.SearchHit;
@@ -46,8 +47,9 @@
 /**
  * Result from a fetch
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class FetchSearchResult extends SearchPhaseResult {
 
     private SearchHits hits;
diff --git a/server/src/main/java/org/opensearch/search/fetch/FetchSubPhase.java b/server/src/main/java/org/opensearch/search/fetch/FetchSubPhase.java
index fa30b2a5c7450..f3a1d5cafe755 100644
--- a/server/src/main/java/org/opensearch/search/fetch/FetchSubPhase.java
+++ b/server/src/main/java/org/opensearch/search/fetch/FetchSubPhase.java
@@ -88,7 +88,7 @@ public int docId() {
         /**
          * This lookup provides access to the source for the given hit document. Note
          * that it should always be set to the correct doc ID and {@link LeafReaderContext}.
-         *
+         * <p>
          * In most cases, the hit document's source is loaded eagerly at the start of the
          * {@link FetchPhase}. This lookup will contain the preloaded source.
          */
@@ -103,7 +103,7 @@ public IndexReader topLevelReader() {
 
     /**
      * Returns a {@link FetchSubPhaseProcessor} for this sub phase.
-     *
+     * <p>
      * If nothing should be executed for the provided {@code FetchContext}, then the
      * implementation should return {@code null}
      */
diff --git a/server/src/main/java/org/opensearch/search/fetch/StoredFieldsContext.java b/server/src/main/java/org/opensearch/search/fetch/StoredFieldsContext.java
index 8cf70b41009a3..3c22c2f9d29c4 100644
--- a/server/src/main/java/org/opensearch/search/fetch/StoredFieldsContext.java
+++ b/server/src/main/java/org/opensearch/search/fetch/StoredFieldsContext.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.fetch;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -51,8 +52,9 @@
 /**
  * Context used to fetch the {@code stored_fields}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class StoredFieldsContext implements Writeable {
     public static final String _NONE_ = "_none_";
 
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesContext.java b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesContext.java
index ce5bd152cca00..14c1d1cdda5ca 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesContext.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesContext.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.search.fetch.subphase;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.IndexSettings;
 
 import java.util.ArrayList;
@@ -42,8 +43,9 @@
 /**
  * All the required context to pull a field from the doc values.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FetchDocValuesContext {
     private final List<FieldAndFormat> fields;
 
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesPhase.java b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesPhase.java
index a8ab8c0dcb8a8..9b17d9dbcd8de 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesPhase.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchDocValuesPhase.java
@@ -47,7 +47,7 @@
 
 /**
  * Fetch sub phase which pulls data from doc values.
- *
+ * <p>
  * Specifying {@code "docvalue_fields": ["field1", "field2"]}
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchFieldsContext.java b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchFieldsContext.java
index 3803dedae9b57..38d04932c3f46 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchFieldsContext.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchFieldsContext.java
@@ -31,13 +31,16 @@
 
 package org.opensearch.search.fetch.subphase;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.List;
 
 /**
  * The context needed to retrieve fields.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FetchFieldsContext {
     private final List<FieldAndFormat> fields;
 
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchSourceContext.java b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchSourceContext.java
index f0ebfd6ab510a..337576890e663 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/FetchSourceContext.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/FetchSourceContext.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.fetch.subphase;
 
 import org.opensearch.common.Booleans;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.support.XContentMapValues;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -55,8 +56,9 @@
 /**
  * Context used to fetch the {@code _source}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class FetchSourceContext implements Writeable, ToXContentObject {
 
     public static final ParseField INCLUDES_FIELD = new ParseField("includes", "include");
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/FieldAndFormat.java b/server/src/main/java/org/opensearch/search/fetch/subphase/FieldAndFormat.java
index f7e4b06624c76..dbdd7bca6678f 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/FieldAndFormat.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/FieldAndFormat.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.fetch.subphase;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -50,8 +51,9 @@
  * Wrapper around a field name and the format that should be used to
  * display values of this field.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class FieldAndFormat implements Writeable, ToXContentObject {
     private static final ParseField FIELD_FIELD = new ParseField("field");
     private static final ParseField FORMAT_FIELD = new ParseField("format");
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/InnerHitsContext.java b/server/src/main/java/org/opensearch/search/fetch/subphase/InnerHitsContext.java
index f50524244b115..5855a0b3217f3 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/InnerHitsContext.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/InnerHitsContext.java
@@ -44,6 +44,7 @@
 import org.apache.lucene.search.TopDocs;
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.Bits;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.search.TopDocsAndMaxScore;
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.internal.SearchContext;
@@ -59,8 +60,9 @@
 /**
  * Context used for inner hits retrieval
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class InnerHitsContext {
     private final Map<String, InnerHitSubContext> innerHits;
 
@@ -91,7 +93,10 @@ public void addInnerHitDefinition(InnerHitSubContext innerHit) {
     /**
      * A {@link SubSearchContext} that associates {@link TopDocs} to each {@link SearchHit}
      * in the parent search context
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract static class InnerHitSubContext extends SubSearchContext {
 
         private final String name;
@@ -138,7 +143,7 @@ public SearchContext parentSearchContext() {
 
         /**
          * The _id of the root document.
-         *
+         * <p>
          * Since this ID is available on the context, inner hits can avoid re-loading the root _id.
          */
         public String getId() {
@@ -151,7 +156,7 @@ public void setId(String id) {
 
         /**
          * A source lookup for the root document.
-         *
+         * <p>
          * This shared lookup allows inner hits to avoid re-loading the root _source.
          */
         public SourceLookup getRootLookup() {
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/ScriptFieldsContext.java b/server/src/main/java/org/opensearch/search/fetch/subphase/ScriptFieldsContext.java
index 78c35098d9cc4..c37d3b359ded8 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/ScriptFieldsContext.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/ScriptFieldsContext.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.fetch.subphase;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.script.FieldScript;
 
 import java.util.ArrayList;
@@ -40,15 +41,17 @@
 /**
  * Context used for script fields
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ScriptFieldsContext {
 
     /**
      * Script field use in the script fields context
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class ScriptField {
         private final String name;
         private final FieldScript.LeafFactory script;
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java
index d0fb0f6da53c4..89c77b3cd403f 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.fetch.subphase.highlight;
 
 import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.highlight.QueryScorer;
 import org.apache.lucene.search.highlight.WeightedSpanTerm;
@@ -104,6 +105,8 @@ protected void extract(Query query, float boost, Map<String, WeightedSpanTerm> t
                 super.extract(((FunctionScoreQuery) query).getSubQuery(), boost, terms);
             } else if (query instanceof OpenSearchToParentBlockJoinQuery) {
                 super.extract(((OpenSearchToParentBlockJoinQuery) query).getChildQuery(), boost, terms);
+            } else if (query instanceof IndexOrDocValuesQuery) {
+                super.extract(((IndexOrDocValuesQuery) query).getIndexQuery(), boost, terms);
             } else {
                 super.extract(query, boost, terms);
             }
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightBuilder.java b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightBuilder.java
index cc0723ed7a432..0e7c3cf30ccec 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightBuilder.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.vectorhighlight.SimpleBoundaryScanner;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -68,8 +69,9 @@
  *
  * @see org.opensearch.search.builder.SearchSourceBuilder#highlight()
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class HighlightBuilder extends AbstractHighlighterBuilder<HighlightBuilder> {
     /** default for whether to highlight fields based on the source even if stored separately */
     public static final boolean DEFAULT_FORCE_SOURCE = false;
@@ -476,8 +478,9 @@ public HighlightBuilder rewrite(QueryRewriteContext ctx) throws IOException {
     /**
      * Field for highlight builder
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Field extends AbstractHighlighterBuilder<Field> {
         static final NamedObjectParser<Field, Void> PARSER;
         static {
@@ -584,8 +587,9 @@ public Field rewrite(QueryRewriteContext ctx) throws IOException {
     /**
      * Order for highlight builder
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Order implements Writeable {
         NONE,
         SCORE;
@@ -615,8 +619,9 @@ public String toString() {
     /**
      * Boundary scanner type
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum BoundaryScannerType implements Writeable {
         CHARS,
         WORD,
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightField.java b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightField.java
index 7a29a53304dc3..30effe2826d76 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightField.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/HighlightField.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.fetch.subphase.highlight;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -52,8 +53,9 @@
 /**
  * A field highlighted with its highlighted fragments.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class HighlightField implements ToXContentFragment, Writeable {
 
     private String name;
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/SearchHighlightContext.java b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/SearchHighlightContext.java
index 7464ba094b97e..c3d34dbdef56c 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/SearchHighlightContext.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/SearchHighlightContext.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.fetch.subphase.highlight;
 
 import org.apache.lucene.search.Query;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.fetch.subphase.highlight.HighlightBuilder.BoundaryScannerType;
 
 import java.util.Arrays;
@@ -46,8 +47,9 @@
 /**
  * Search context used during highlighting phase
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchHighlightContext {
 
     private final Map<String, Field> fields;
@@ -82,8 +84,9 @@ public boolean forceSource(Field field) {
     /**
      * Field for the search highlight context
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Field {
         private final String field;
         private final FieldOptions fieldOptions;
@@ -107,8 +110,9 @@ public FieldOptions fieldOptions() {
     /**
      * Field options for the search highlight context
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class FieldOptions {
 
         // Field options that default to null or -1 are often set to their real default in HighlighterParseElement#parse
diff --git a/server/src/main/java/org/opensearch/search/internal/AliasFilter.java b/server/src/main/java/org/opensearch/search/internal/AliasFilter.java
index c1d425078049c..1732c0ab0db8a 100644
--- a/server/src/main/java/org/opensearch/search/internal/AliasFilter.java
+++ b/server/src/main/java/org/opensearch/search/internal/AliasFilter.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.internal;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -47,8 +48,9 @@
 /**
  * Represents a {@link QueryBuilder} and a list of alias names that filters the builder is composed of.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class AliasFilter implements Writeable, Rewriteable<AliasFilter> {
 
     private final String[] aliases;
diff --git a/server/src/main/java/org/opensearch/search/internal/ContextIndexSearcher.java b/server/src/main/java/org/opensearch/search/internal/ContextIndexSearcher.java
index aa86ed4e56801..b042f3cf41d61 100644
--- a/server/src/main/java/org/opensearch/search/internal/ContextIndexSearcher.java
+++ b/server/src/main/java/org/opensearch/search/internal/ContextIndexSearcher.java
@@ -64,6 +64,7 @@
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.CombinedBitSet;
 import org.apache.lucene.util.SparseFixedBitSet;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lucene.search.TopDocsAndMaxScore;
 import org.opensearch.search.DocValueFormat;
@@ -91,8 +92,9 @@
 /**
  * Context-aware extension of {@link IndexSearcher}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ContextIndexSearcher extends IndexSearcher implements Releasable {
 
     private static final Logger logger = LogManager.getLogger(ContextIndexSearcher.class);
@@ -285,7 +287,7 @@ protected void search(List<LeafReaderContext> leaves, Weight weight, Collector c
 
     /**
      * Lower-level search API.
-     *
+     * <p>
      * {@link LeafCollector#collect(int)} is called for every matching document in
      * the provided <code>ctx</code>.
      */
@@ -505,14 +507,15 @@ private boolean canMatch(LeafReaderContext ctx) throws IOException {
     }
 
     private boolean canMatchSearchAfter(LeafReaderContext ctx) throws IOException {
-        if (searchContext.request() != null && searchContext.request().source() != null) {
+        if (searchContext.searchAfter() != null && searchContext.request() != null && searchContext.request().source() != null) {
             // Only applied on primary sort field and primary search_after.
             FieldSortBuilder primarySortField = FieldSortBuilder.getPrimaryFieldSortOrNull(searchContext.request().source());
             if (primarySortField != null) {
                 MinAndMax<?> minMax = FieldSortBuilder.getMinMaxOrNullForSegment(
                     this.searchContext.getQueryShardContext(),
                     ctx,
-                    primarySortField
+                    primarySortField,
+                    searchContext.sort()
                 );
                 return SearchService.canMatchSearchAfter(
                     searchContext.searchAfter(),
diff --git a/server/src/main/java/org/opensearch/search/internal/InternalSearchResponse.java b/server/src/main/java/org/opensearch/search/internal/InternalSearchResponse.java
index 3af8fc3854cf1..c9d7b0084c1e1 100644
--- a/server/src/main/java/org/opensearch/search/internal/InternalSearchResponse.java
+++ b/server/src/main/java/org/opensearch/search/internal/InternalSearchResponse.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.action.search.SearchResponseSections;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -51,8 +52,9 @@
 /**
  * {@link SearchResponseSections} subclass that can be serialized over the wire.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class InternalSearchResponse extends SearchResponseSections implements Writeable, ToXContentFragment {
     public static InternalSearchResponse empty() {
         return empty(true);
diff --git a/server/src/main/java/org/opensearch/search/internal/ReaderContext.java b/server/src/main/java/org/opensearch/search/internal/ReaderContext.java
index 898aa2e2c6745..776e92d325ae4 100644
--- a/server/src/main/java/org/opensearch/search/internal/ReaderContext.java
+++ b/server/src/main/java/org/opensearch/search/internal/ReaderContext.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.internal;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lease.Releasables;
 import org.opensearch.common.util.concurrent.AbstractRefCounted;
@@ -57,8 +58,9 @@
  * ie. when an index gets removed. To prevent accessing closed IndexReader / IndexSearcher instances the SearchContext
  * can be guarded by a reference count and fail if it's been closed by an external event.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ReaderContext implements Releasable {
     private final ShardSearchContextId id;
     private final IndexService indexService;
diff --git a/server/src/main/java/org/opensearch/search/internal/ScrollContext.java b/server/src/main/java/org/opensearch/search/internal/ScrollContext.java
index ae4074930e0c0..e3517756ced6e 100644
--- a/server/src/main/java/org/opensearch/search/internal/ScrollContext.java
+++ b/server/src/main/java/org/opensearch/search/internal/ScrollContext.java
@@ -34,13 +34,15 @@
 
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.TotalHits;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.Scroll;
 
 /**
  * Wrapper around information that needs to stay around when scrolling.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ScrollContext {
     public TotalHits totalHits = null;
     public float maxScore = Float.NaN;
diff --git a/server/src/main/java/org/opensearch/search/internal/SearchContext.java b/server/src/main/java/org/opensearch/search/internal/SearchContext.java
index dce6da897a74b..cc43f4e5d79fb 100644
--- a/server/src/main/java/org/opensearch/search/internal/SearchContext.java
+++ b/server/src/main/java/org/opensearch/search/internal/SearchContext.java
@@ -35,10 +35,10 @@
 import org.apache.lucene.search.CollectorManager;
 import org.apache.lucene.search.FieldDoc;
 import org.apache.lucene.search.Query;
-import org.apache.lucene.util.ArrayUtil;
 import org.opensearch.action.search.SearchShardTask;
 import org.opensearch.action.search.SearchType;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lease.Releasables;
 import org.opensearch.common.unit.TimeValue;
@@ -86,13 +86,16 @@
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import static org.opensearch.search.aggregations.bucket.BucketUtils.suggestShardSideQueueSize;
+
 /**
  * This class encapsulates the state needed to execute a search. It holds a reference to the
  * shards point in time snapshot (IndexReader / ContextIndexSearcher) and allows passing on
  * state from one query / fetch phase to another.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SearchContext implements Releasable {
 
     public static final int DEFAULT_TERMINATE_AFTER = 0;
@@ -286,7 +289,7 @@ public final void assignRescoreDocIds(RescoreDocIds rescoreDocIds) {
 
     /**
      * Indicates if the current index should perform frequent low level search cancellation check.
-     *
+     * <p>
      * Enabling low-level checks will make long running searches to react to the cancellation request faster. However,
      * since it will produce more cancellation checks it might slow the search performance down.
      */
@@ -408,7 +411,7 @@ public boolean shouldUseConcurrentSearch() {
      */
     public LocalBucketCountThresholds asLocalBucketCountThresholds(TermsAggregator.BucketCountThresholds bucketCountThresholds) {
         if (shouldUseConcurrentSearch()) {
-            return new LocalBucketCountThresholds(0, ArrayUtil.MAX_ARRAY_LENGTH - 1);
+            return new LocalBucketCountThresholds(0, suggestShardSideQueueSize(bucketCountThresholds.getShardSize()));
         } else {
             return new LocalBucketCountThresholds(bucketCountThresholds.getShardMinDocCount(), bucketCountThresholds.getShardSize());
         }
diff --git a/server/src/main/java/org/opensearch/search/internal/ShardSearchContextId.java b/server/src/main/java/org/opensearch/search/internal/ShardSearchContextId.java
index 3e0d2b1d6c638..c6c09ff54241b 100644
--- a/server/src/main/java/org/opensearch/search/internal/ShardSearchContextId.java
+++ b/server/src/main/java/org/opensearch/search/internal/ShardSearchContextId.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.internal;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -42,8 +43,9 @@
 /**
  * Used to support Point in Time Searching
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ShardSearchContextId implements Writeable {
     private final String sessionId;
     private final long id;
diff --git a/server/src/main/java/org/opensearch/search/internal/ShardSearchRequest.java b/server/src/main/java/org/opensearch/search/internal/ShardSearchRequest.java
index d46cad37e9b71..de1d5fb8b4098 100644
--- a/server/src/main/java/org/opensearch/search/internal/ShardSearchRequest.java
+++ b/server/src/main/java/org/opensearch/search/internal/ShardSearchRequest.java
@@ -43,6 +43,7 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.CheckedFunction;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.Strings;
@@ -82,8 +83,9 @@
  * It provides all the methods that the {@link SearchContext} needs.
  * Provides a cache key based on its content that can be used to cache shard level response.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ShardSearchRequest extends TransportRequest implements IndicesRequest {
     public static final ToXContent.Params FORMAT_PARAMS = new ToXContent.MapParams(Collections.singletonMap("pretty", "false"));
 
diff --git a/server/src/main/java/org/opensearch/search/lookup/DocLookup.java b/server/src/main/java/org/opensearch/search/lookup/DocLookup.java
index 069d9dd02ce2b..8de49e8d026f6 100644
--- a/server/src/main/java/org/opensearch/search/lookup/DocLookup.java
+++ b/server/src/main/java/org/opensearch/search/lookup/DocLookup.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.lookup;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.mapper.MappedFieldType;
 import org.opensearch.index.mapper.MapperService;
@@ -41,8 +42,9 @@
 /**
  * Looks up a document
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class DocLookup {
 
     private final MapperService mapperService;
diff --git a/server/src/main/java/org/opensearch/search/lookup/LeafDocLookup.java b/server/src/main/java/org/opensearch/search/lookup/LeafDocLookup.java
index fe911ed799646..3bd1c5118b5fb 100644
--- a/server/src/main/java/org/opensearch/search/lookup/LeafDocLookup.java
+++ b/server/src/main/java/org/opensearch/search/lookup/LeafDocLookup.java
@@ -33,6 +33,7 @@
 
 import org.apache.lucene.index.LeafReaderContext;
 import org.opensearch.ExceptionsHelper;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.fielddata.ScriptDocValues;
 import org.opensearch.index.mapper.MappedFieldType;
@@ -50,8 +51,9 @@
 /**
  * Looks up a doc from a leaf reader
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class LeafDocLookup implements Map<String, ScriptDocValues<?>> {
 
     private final Map<String, ScriptDocValues<?>> localCacheFieldData = new HashMap<>(4);
diff --git a/server/src/main/java/org/opensearch/search/lookup/LeafFieldsLookup.java b/server/src/main/java/org/opensearch/search/lookup/LeafFieldsLookup.java
index 47bb8754a5803..23b1b311f7d93 100644
--- a/server/src/main/java/org/opensearch/search/lookup/LeafFieldsLookup.java
+++ b/server/src/main/java/org/opensearch/search/lookup/LeafFieldsLookup.java
@@ -33,6 +33,7 @@
 
 import org.apache.lucene.index.LeafReader;
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fieldvisitor.SingleFieldsVisitor;
 import org.opensearch.index.mapper.MappedFieldType;
 import org.opensearch.index.mapper.MapperService;
@@ -50,8 +51,9 @@
 /**
  * looks up multiple leaf fields
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class LeafFieldsLookup implements Map {
 
     private final MapperService mapperService;
diff --git a/server/src/main/java/org/opensearch/search/lookup/LeafSearchLookup.java b/server/src/main/java/org/opensearch/search/lookup/LeafSearchLookup.java
index 1c87f26053060..33fd89a305fe1 100644
--- a/server/src/main/java/org/opensearch/search/lookup/LeafSearchLookup.java
+++ b/server/src/main/java/org/opensearch/search/lookup/LeafSearchLookup.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.lookup;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -42,8 +43,9 @@
 /**
  * Per-segment version of {@link SearchLookup}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class LeafSearchLookup {
 
     final LeafReaderContext ctx;
diff --git a/server/src/main/java/org/opensearch/search/lookup/SearchLookup.java b/server/src/main/java/org/opensearch/search/lookup/SearchLookup.java
index 898d34dc02c01..8813865a657dc 100644
--- a/server/src/main/java/org/opensearch/search/lookup/SearchLookup.java
+++ b/server/src/main/java/org/opensearch/search/lookup/SearchLookup.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.lookup;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.fielddata.IndexFieldData;
 import org.opensearch.index.mapper.MappedFieldType;
 import org.opensearch.index.mapper.MapperService;
@@ -47,8 +48,9 @@
 /**
  * Orchestrator class for search phase lookups
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SearchLookup {
     /**
      * The maximum depth of field dependencies.
diff --git a/server/src/main/java/org/opensearch/search/lookup/SourceLookup.java b/server/src/main/java/org/opensearch/search/lookup/SourceLookup.java
index 812030acb9561..cbac29fde7932 100644
--- a/server/src/main/java/org/opensearch/search/lookup/SourceLookup.java
+++ b/server/src/main/java/org/opensearch/search/lookup/SourceLookup.java
@@ -36,6 +36,7 @@
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.common.CheckedBiConsumer;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.lucene.index.SequentialStoredFieldsLeafReader;
 import org.opensearch.common.xcontent.XContentHelper;
@@ -58,8 +59,9 @@
 /**
  * Orchestrator class for source lookups
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SourceLookup implements Map {
 
     private LeafReader reader;
@@ -180,7 +182,7 @@ public List<Object> extractRawValues(String path) {
 
     /**
      * For the provided path, return its value in the source.
-     *
+     * <p>
      * Note that in contrast with {@link SourceLookup#extractRawValues}, array and object values
      * can be returned.
      *
diff --git a/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java b/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java
index d4292b85b20a5..c88dfb2060393 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java
@@ -16,11 +16,13 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.io.stream.NamedWriteableAwareStreamInput;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.search.SearchPhaseResult;
 
+import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -117,106 +119,161 @@ protected void afterResponseProcessor(Processor processor, long timeInNanos) {}
 
     protected void onResponseProcessorFailed(Processor processor) {}
 
-    SearchRequest transformRequest(SearchRequest request) throws SearchPipelineProcessingException {
-        if (searchRequestProcessors.isEmpty() == false) {
-            long pipelineStart = relativeTimeSupplier.getAsLong();
-            beforeTransformRequest();
-            try {
-                try (BytesStreamOutput bytesStreamOutput = new BytesStreamOutput()) {
-                    request.writeTo(bytesStreamOutput);
-                    try (StreamInput in = bytesStreamOutput.bytes().streamInput()) {
-                        try (StreamInput input = new NamedWriteableAwareStreamInput(in, namedWriteableRegistry)) {
-                            request = new SearchRequest(input);
-                        }
-                    }
-                }
-                for (SearchRequestProcessor processor : searchRequestProcessors) {
-                    beforeRequestProcessor(processor);
-                    long start = relativeTimeSupplier.getAsLong();
-                    try {
-                        request = processor.processRequest(request);
-                    } catch (Exception e) {
-                        onRequestProcessorFailed(processor);
-                        if (processor.isIgnoreFailure()) {
-                            logger.warn(
-                                "The exception from request processor ["
-                                    + processor.getType()
-                                    + "] in the search pipeline ["
-                                    + id
-                                    + "] was ignored",
-                                e
-                            );
-                        } else {
-                            throw e;
-                        }
-                    } finally {
-                        long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
-                        afterRequestProcessor(processor, took);
-                    }
+    void transformRequest(SearchRequest request, ActionListener<SearchRequest> requestListener, PipelineProcessingContext requestContext)
+        throws SearchPipelineProcessingException {
+        if (searchRequestProcessors.isEmpty()) {
+            requestListener.onResponse(request);
+            return;
+        }
+
+        try (BytesStreamOutput bytesStreamOutput = new BytesStreamOutput()) {
+            request.writeTo(bytesStreamOutput);
+            try (StreamInput in = bytesStreamOutput.bytes().streamInput()) {
+                try (StreamInput input = new NamedWriteableAwareStreamInput(in, namedWriteableRegistry)) {
+                    request = new SearchRequest(input);
                 }
-            } catch (Exception e) {
-                onTransformRequestFailure();
-                throw new SearchPipelineProcessingException(e);
-            } finally {
-                long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
-                afterTransformRequest(took);
             }
+        } catch (IOException e) {
+            requestListener.onFailure(new SearchPipelineProcessingException(e));
+            return;
         }
-        return request;
+
+        ActionListener<SearchRequest> finalListener = getTerminalSearchRequestActionListener(requestListener, requestContext);
+
+        // Chain listeners back-to-front
+        ActionListener<SearchRequest> currentListener = finalListener;
+        for (int i = searchRequestProcessors.size() - 1; i >= 0; i--) {
+            final ActionListener<SearchRequest> nextListener = currentListener;
+            SearchRequestProcessor processor = searchRequestProcessors.get(i);
+            currentListener = ActionListener.wrap(r -> {
+                long start = relativeTimeSupplier.getAsLong();
+                beforeRequestProcessor(processor);
+                processor.processRequestAsync(r, requestContext, ActionListener.wrap(rr -> {
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterRequestProcessor(processor, took);
+                    nextListener.onResponse(rr);
+                }, e -> {
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterRequestProcessor(processor, took);
+                    onRequestProcessorFailed(processor);
+                    if (processor.isIgnoreFailure()) {
+                        logger.warn(
+                            "The exception from request processor ["
+                                + processor.getType()
+                                + "] in the search pipeline ["
+                                + id
+                                + "] was ignored",
+                            e
+                        );
+                        nextListener.onResponse(r);
+                    } else {
+                        nextListener.onFailure(new SearchPipelineProcessingException(e));
+                    }
+                }));
+            }, finalListener::onFailure);
+        }
+
+        beforeTransformRequest();
+        currentListener.onResponse(request);
     }
 
-    SearchResponse transformResponse(SearchRequest request, SearchResponse response) throws SearchPipelineProcessingException {
-        if (searchResponseProcessors.isEmpty() == false) {
-            long pipelineStart = relativeTimeSupplier.getAsLong();
-            beforeTransformResponse();
-            try {
-                for (SearchResponseProcessor processor : searchResponseProcessors) {
-                    beforeResponseProcessor(processor);
-                    long start = relativeTimeSupplier.getAsLong();
-                    try {
-                        response = processor.processResponse(request, response);
-                    } catch (Exception e) {
-                        onResponseProcessorFailed(processor);
-                        if (processor.isIgnoreFailure()) {
-                            logger.warn(
-                                "The exception from response processor ["
-                                    + processor.getType()
-                                    + "] in the search pipeline ["
-                                    + id
-                                    + "] was ignored",
-                                e
-                            );
-                        } else {
-                            throw e;
-                        }
-                    } finally {
-                        long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
-                        afterResponseProcessor(processor, took);
+    private ActionListener<SearchRequest> getTerminalSearchRequestActionListener(
+        ActionListener<SearchRequest> requestListener,
+        PipelineProcessingContext requestContext
+    ) {
+        final long pipelineStart = relativeTimeSupplier.getAsLong();
+
+        return ActionListener.wrap(r -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
+            afterTransformRequest(took);
+            requestListener.onResponse(new PipelinedRequest(this, r, requestContext));
+        }, e -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
+            afterTransformRequest(took);
+            onTransformRequestFailure();
+            requestListener.onFailure(new SearchPipelineProcessingException(e));
+        });
+    }
+
+    ActionListener<SearchResponse> transformResponseListener(
+        SearchRequest request,
+        ActionListener<SearchResponse> responseListener,
+        PipelineProcessingContext requestContext
+    ) {
+        if (searchResponseProcessors.isEmpty()) {
+            // No response transformation necessary
+            return responseListener;
+        }
+
+        long[] pipelineStart = new long[1];
+
+        final ActionListener<SearchResponse> originalListener = responseListener;
+        responseListener = ActionListener.wrap(r -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart[0]);
+            afterTransformResponse(took);
+            originalListener.onResponse(r);
+        }, e -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart[0]);
+            afterTransformResponse(took);
+            onTransformResponseFailure();
+            originalListener.onFailure(e);
+        });
+        ActionListener<SearchResponse> finalListener = responseListener; // Jump directly to this one on exception.
+
+        for (int i = searchResponseProcessors.size() - 1; i >= 0; i--) {
+            final ActionListener<SearchResponse> currentFinalListener = responseListener;
+            final SearchResponseProcessor processor = searchResponseProcessors.get(i);
+
+            responseListener = ActionListener.wrap(r -> {
+                beforeResponseProcessor(processor);
+                final long start = relativeTimeSupplier.getAsLong();
+                processor.processResponseAsync(request, r, requestContext, ActionListener.wrap(rr -> {
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterResponseProcessor(processor, took);
+                    currentFinalListener.onResponse(rr);
+                }, e -> {
+                    onResponseProcessorFailed(processor);
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterResponseProcessor(processor, took);
+                    if (processor.isIgnoreFailure()) {
+                        logger.warn(
+                            "The exception from response processor ["
+                                + processor.getType()
+                                + "] in the search pipeline ["
+                                + id
+                                + "] was ignored",
+                            e
+                        );
+                        // Pass the previous response through to the next processor in the chain
+                        currentFinalListener.onResponse(r);
+                    } else {
+                        currentFinalListener.onFailure(new SearchPipelineProcessingException(e));
                     }
-                }
-            } catch (Exception e) {
-                onTransformResponseFailure();
-                throw new SearchPipelineProcessingException(e);
-            } finally {
-                long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
-                afterTransformResponse(took);
-            }
+                }));
+            }, finalListener::onFailure);
         }
-        return response;
+        final ActionListener<SearchResponse> chainListener = responseListener;
+        return ActionListener.wrap(r -> {
+            beforeTransformResponse();
+            pipelineStart[0] = relativeTimeSupplier.getAsLong();
+            chainListener.onResponse(r);
+        }, originalListener::onFailure);
+
     }
 
     <Result extends SearchPhaseResult> void runSearchPhaseResultsTransformer(
         SearchPhaseResults<Result> searchPhaseResult,
         SearchPhaseContext context,
         String currentPhase,
-        String nextPhase
+        String nextPhase,
+        PipelineProcessingContext requestContext
     ) throws SearchPipelineProcessingException {
         try {
             for (SearchPhaseResultsProcessor searchPhaseResultsProcessor : searchPhaseResultsProcessors) {
                 if (currentPhase.equals(searchPhaseResultsProcessor.getBeforePhase().getName())
                     && nextPhase.equals(searchPhaseResultsProcessor.getAfterPhase().getName())) {
                     try {
-                        searchPhaseResultsProcessor.process(searchPhaseResult, context);
+                        searchPhaseResultsProcessor.process(searchPhaseResult, context, requestContext);
                     } catch (Exception e) {
                         if (searchPhaseResultsProcessor.isIgnoreFailure()) {
                             logger.warn(
diff --git a/server/src/main/java/org/opensearch/search/pipeline/PipelineConfiguration.java b/server/src/main/java/org/opensearch/search/pipeline/PipelineConfiguration.java
index 9e5f2fa1592a4..2ed770be60458 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/PipelineConfiguration.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/PipelineConfiguration.java
@@ -11,6 +11,7 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.AbstractDiffable;
 import org.opensearch.cluster.Diff;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.ParseField;
@@ -31,9 +32,12 @@
 
 /**
  * TODO: Copied verbatim from {@link org.opensearch.ingest.PipelineConfiguration}.
- *
+ * <p>
  * See if we can refactor into a common class. I suspect not, just because this one will hold
+ *
+ * @opensearch.api
  */
+@PublicApi(since = "2.7.0")
 public class PipelineConfiguration extends AbstractDiffable<PipelineConfiguration> implements ToXContentObject {
     private static final ObjectParser<Builder, Void> PARSER = new ObjectParser<>(
         "pipeline_config",
diff --git a/server/src/main/java/org/opensearch/search/pipeline/PipelineProcessingContext.java b/server/src/main/java/org/opensearch/search/pipeline/PipelineProcessingContext.java
new file mode 100644
index 0000000000000..a1f2b8b99d958
--- /dev/null
+++ b/server/src/main/java/org/opensearch/search/pipeline/PipelineProcessingContext.java
@@ -0,0 +1,38 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * A holder for state that is passed through each processor in the pipeline.
+ */
+public class PipelineProcessingContext {
+    private final Map<String, Object> attributes = new HashMap<>();
+
+    /**
+     * Set a generic attribute in the state for this request. Overwrites any existing value.
+     *
+     * @param name the name of the attribute to set
+     * @param value the value to set on the attributen
+     */
+    public void setAttribute(String name, Object value) {
+        attributes.put(name, value);
+    }
+
+    /**
+     * Retrieves a generic attribute value from the state for this request.
+     * @param name the name of the attribute
+     * @return the value of the attribute if previously set (and null otherwise)
+     */
+    public Object getAttribute(String name) {
+        return attributes.get(name);
+    }
+}
diff --git a/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java b/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java
index 5a7539808c127..d550fbb768133 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java
@@ -12,6 +12,7 @@
 import org.opensearch.action.search.SearchPhaseResults;
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.core.action.ActionListener;
 import org.opensearch.search.SearchPhaseResult;
 
 /**
@@ -21,14 +22,20 @@
  */
 public final class PipelinedRequest extends SearchRequest {
     private final Pipeline pipeline;
+    private final PipelineProcessingContext requestContext;
 
-    PipelinedRequest(Pipeline pipeline, SearchRequest transformedRequest) {
+    PipelinedRequest(Pipeline pipeline, SearchRequest transformedRequest, PipelineProcessingContext requestContext) {
         super(transformedRequest);
         this.pipeline = pipeline;
+        this.requestContext = requestContext;
     }
 
-    public SearchResponse transformResponse(SearchResponse response) {
-        return pipeline.transformResponse(this, response);
+    public void transformRequest(ActionListener<SearchRequest> requestListener) {
+        pipeline.transformRequest(this, requestListener, requestContext);
+    }
+
+    public ActionListener<SearchResponse> transformResponseListener(ActionListener<SearchResponse> responseListener) {
+        return pipeline.transformResponseListener(this, responseListener, requestContext);
     }
 
     public <Result extends SearchPhaseResult> void transformSearchPhaseResults(
@@ -37,7 +44,7 @@ public <Result extends SearchPhaseResult> void transformSearchPhaseResults(
         final String currentPhase,
         final String nextPhase
     ) {
-        pipeline.runSearchPhaseResultsTransformer(searchPhaseResult, searchPhaseContext, currentPhase, nextPhase);
+        pipeline.runSearchPhaseResultsTransformer(searchPhaseResult, searchPhaseContext, currentPhase, nextPhase, requestContext);
     }
 
     // Visible for testing
diff --git a/server/src/main/java/org/opensearch/search/pipeline/Processor.java b/server/src/main/java/org/opensearch/search/pipeline/Processor.java
index fb33f46acada4..a06383fbe9cef 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/Processor.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/Processor.java
@@ -15,19 +15,12 @@
  * Whether changes are made and what exactly is modified is up to the implementation.
  * <p>
  * Processors may get called concurrently and thus need to be thread-safe.
- *
+ * <p>
  * TODO: Refactor {@link org.opensearch.ingest.Processor} to extend this interface, and specialize to IngestProcessor.
  *
  * @opensearch.internal
  */
 public interface Processor {
-    /**
-     * Processor configuration key to let the factory know the context for pipeline creation.
-     * <p>
-     * See {@link PipelineSource}.
-     */
-    String PIPELINE_SOURCE = "pipeline_source";
-
     /**
      * Gets the type of processor
      */
diff --git a/server/src/main/java/org/opensearch/search/pipeline/ProcessorInfo.java b/server/src/main/java/org/opensearch/search/pipeline/ProcessorInfo.java
index 0206b9b6cf716..0b80cdbef6669 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/ProcessorInfo.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/ProcessorInfo.java
@@ -18,7 +18,7 @@
 
 /**
  * Information about a search pipeline  processor
- *
+ * <p>
  * TODO: This is copy/pasted from the ingest ProcessorInfo.
  * Can/should we share implementation or is this just boilerplate?
  *
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchPhaseResultsProcessor.java b/server/src/main/java/org/opensearch/search/pipeline/SearchPhaseResultsProcessor.java
index 772dc8758bace..a64266cfb2a2b 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchPhaseResultsProcessor.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchPhaseResultsProcessor.java
@@ -32,6 +32,22 @@ <Result extends SearchPhaseResult> void process(
         final SearchPhaseContext searchPhaseContext
     );
 
+    /**
+     * Processes the {@link SearchPhaseResults} obtained from a SearchPhase which will be returned to next
+     * SearchPhase. Receives the {@link PipelineProcessingContext} passed to other processors.
+     * @param searchPhaseResult {@link SearchPhaseResults}
+     * @param searchPhaseContext {@link SearchContext}
+     * @param requestContext {@link PipelineProcessingContext}
+     * @param <Result> {@link SearchPhaseResult}
+     */
+    default <Result extends SearchPhaseResult> void process(
+        final SearchPhaseResults<Result> searchPhaseResult,
+        final SearchPhaseContext searchPhaseContext,
+        final PipelineProcessingContext requestContext
+    ) {
+        process(searchPhaseResult, searchPhaseContext);
+    }
+
     /**
      * The phase which should have run before, this processor can start executing.
      * @return {@link SearchPhaseName}
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java b/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
index 739101519ff98..2175b5d135394 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
@@ -408,8 +408,8 @@ public PipelinedRequest resolvePipeline(SearchRequest searchRequest) {
                 pipeline = pipelineHolder.pipeline;
             }
         }
-        SearchRequest transformedRequest = pipeline.transformRequest(searchRequest);
-        return new PipelinedRequest(pipeline, transformedRequest);
+        PipelineProcessingContext requestContext = new PipelineProcessingContext();
+        return new PipelinedRequest(pipeline, searchRequest, requestContext);
     }
 
     Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessorFactories() {
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java b/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java
index c236cde1a5cc0..30adc9b0afbe8 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java
@@ -9,10 +9,50 @@
 package org.opensearch.search.pipeline;
 
 import org.opensearch.action.search.SearchRequest;
+import org.opensearch.core.action.ActionListener;
 
 /**
  * Interface for a search pipeline processor that modifies a search request.
  */
 public interface SearchRequestProcessor extends Processor {
+    /**
+     * Process a SearchRequest without receiving request-scoped state.
+     * Implement this method if the processor makes no asynchronous calls.
+     * @param request the search request (which may have been modified by an earlier processor)
+     * @return the modified search request
+     * @throws Exception implementation-specific processing exception
+     */
     SearchRequest processRequest(SearchRequest request) throws Exception;
+
+    /**
+     * Process a SearchRequest, with request-scoped state shared across processors in the pipeline
+     * Implement this method if the processor makes no asynchronous calls.
+     * @param request the search request (which may have been modified by an earlier processor)
+     * @param requestContext request-scoped state shared across processors in the pipeline
+     * @return the modified search request
+     * @throws Exception implementation-specific processing exception
+     */
+    default SearchRequest processRequest(SearchRequest request, PipelineProcessingContext requestContext) throws Exception {
+        return processRequest(request);
+    }
+
+    /**
+     * Transform a {@link SearchRequest}. Executed on the coordinator node before any {@link org.opensearch.action.search.SearchPhase}
+     * executes.
+     * <p>
+     * Expert method: Implement this if the processor needs to make asynchronous calls. Otherwise, implement processRequest.
+     * @param request the executed {@link SearchRequest}
+     * @param requestListener callback to be invoked on successful processing or on failure
+     */
+    default void processRequestAsync(
+        SearchRequest request,
+        PipelineProcessingContext requestContext,
+        ActionListener<SearchRequest> requestListener
+    ) {
+        try {
+            requestListener.onResponse(processRequest(request, requestContext));
+        } catch (Exception e) {
+            requestListener.onFailure(e);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java b/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java
index 2f22cedb9b5c0..98591ab9d0def 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java
@@ -10,10 +10,60 @@
 
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.core.action.ActionListener;
 
 /**
  * Interface for a search pipeline processor that modifies a search response.
  */
 public interface SearchResponseProcessor extends Processor {
+
+    /**
+     * Transform a {@link SearchResponse}, possibly based on the executed {@link SearchRequest}.
+     * <p>
+     * Implement this method if the processor makes no asynchronous calls.
+     *
+     * @param request  the executed {@link SearchRequest}
+     * @param response the current {@link SearchResponse}, possibly modified by earlier processors
+     * @return a modified {@link SearchResponse} (or the input {@link SearchResponse} if no changes)
+     * @throws Exception if an error occurs during processing
+     */
     SearchResponse processResponse(SearchRequest request, SearchResponse response) throws Exception;
+
+    /**
+     * Process a SearchResponse, with request-scoped state shared across processors in the pipeline
+     * <p>
+     * Implement this method if the processor makes no asynchronous calls.
+     *
+     * @param request        the (maybe transformed) search request
+     * @param response       the search response (which may have been modified by an earlier processor)
+     * @param requestContext request-scoped state shared across processors in the pipeline
+     * @return the modified search response
+     * @throws Exception implementation-specific processing exception
+     */
+    default SearchResponse processResponse(SearchRequest request, SearchResponse response, PipelineProcessingContext requestContext)
+        throws Exception {
+        return processResponse(request, response);
+    }
+
+    /**
+     * Transform a {@link SearchResponse}, possibly based on the executed {@link SearchRequest}.
+     * <p>
+     * Expert method: Implement this if the processor needs to make asynchronous calls. Otherwise, implement processResponse.
+     *
+     * @param request          the executed {@link SearchRequest}
+     * @param response         the current {@link SearchResponse}, possibly modified by earlier processors
+     * @param responseListener callback to be invoked on successful processing or on failure
+     */
+    default void processResponseAsync(
+        SearchRequest request,
+        SearchResponse response,
+        PipelineProcessingContext requestContext,
+        ActionListener<SearchResponse> responseListener
+    ) {
+        try {
+            responseListener.onResponse(processResponse(request, response, requestContext));
+        } catch (Exception e) {
+            responseListener.onFailure(e);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/search/pipeline/StatefulSearchRequestProcessor.java b/server/src/main/java/org/opensearch/search/pipeline/StatefulSearchRequestProcessor.java
new file mode 100644
index 0000000000000..67e1c1147cb87
--- /dev/null
+++ b/server/src/main/java/org/opensearch/search/pipeline/StatefulSearchRequestProcessor.java
@@ -0,0 +1,25 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline;
+
+import org.opensearch.action.search.SearchRequest;
+
+/**
+ * A specialization of {@link SearchRequestProcessor} that makes use of the request-scoped processor state.
+ * Implementors must implement the processRequest method that accepts request-scoped processor state.
+ */
+public interface StatefulSearchRequestProcessor extends SearchRequestProcessor {
+    @Override
+    default SearchRequest processRequest(SearchRequest request) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    SearchRequest processRequest(SearchRequest request, PipelineProcessingContext requestContext) throws Exception;
+}
diff --git a/server/src/main/java/org/opensearch/search/pipeline/StatefulSearchResponseProcessor.java b/server/src/main/java/org/opensearch/search/pipeline/StatefulSearchResponseProcessor.java
new file mode 100644
index 0000000000000..f0842d24e1b56
--- /dev/null
+++ b/server/src/main/java/org/opensearch/search/pipeline/StatefulSearchResponseProcessor.java
@@ -0,0 +1,27 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.pipeline;
+
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+
+/**
+ * A specialization of {@link SearchResponseProcessor} that makes use of the request-scoped processor state.
+ * Implementors must implement the processResponse method that accepts request-scoped processor state.
+ */
+public interface StatefulSearchResponseProcessor extends SearchResponseProcessor {
+    @Override
+    default SearchResponse processResponse(SearchRequest request, SearchResponse response) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    SearchResponse processResponse(SearchRequest request, SearchResponse response, PipelineProcessingContext requestContext)
+        throws Exception;
+}
diff --git a/server/src/main/java/org/opensearch/search/profile/AbstractInternalProfileTree.java b/server/src/main/java/org/opensearch/search/profile/AbstractInternalProfileTree.java
index d1f525477f25f..904b04b249b1b 100644
--- a/server/src/main/java/org/opensearch/search/profile/AbstractInternalProfileTree.java
+++ b/server/src/main/java/org/opensearch/search/profile/AbstractInternalProfileTree.java
@@ -70,7 +70,7 @@ public AbstractInternalProfileTree() {
      * Returns a {@link QueryProfileBreakdown} for a scoring query.  Scoring queries (e.g. those
      * that are past the rewrite phase and are now being wrapped by createWeight() ) follow
      * a recursive progression.  We can track the dependency tree by a simple stack
-     *
+     * <p>
      * The only hiccup is that the first scoring query will be identical to the last rewritten
      * query, so we need to take special care to fix that
      *
@@ -109,7 +109,7 @@ public PB getProfileBreakdown(E query) {
 
     /**
      * Helper method to add a new node to the dependency tree.
-     *
+     * <p>
      * Initializes a new list in the dependency tree, saves the query and
      * generates a new {@link AbstractProfileBreakdown} to track the timings
      * of this element.
diff --git a/server/src/main/java/org/opensearch/search/profile/NetworkTime.java b/server/src/main/java/org/opensearch/search/profile/NetworkTime.java
index 45d8c2883cb4a..89a8836d807ae 100644
--- a/server/src/main/java/org/opensearch/search/profile/NetworkTime.java
+++ b/server/src/main/java/org/opensearch/search/profile/NetworkTime.java
@@ -9,6 +9,7 @@
 package org.opensearch.search.profile;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -18,8 +19,9 @@
 /**
  * Utility class to track time of network operations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NetworkTime implements Writeable {
     private long inboundNetworkTime;
     private long outboundNetworkTime;
diff --git a/server/src/main/java/org/opensearch/search/profile/ProfileResult.java b/server/src/main/java/org/opensearch/search/profile/ProfileResult.java
index 6019bc0479c21..2c0d2cf3ba78a 100644
--- a/server/src/main/java/org/opensearch/search/profile/ProfileResult.java
+++ b/server/src/main/java/org/opensearch/search/profile/ProfileResult.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.profile;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -64,8 +65,9 @@
  * Each InternalProfileResult has a List of InternalProfileResults, which will contain
  * "children" queries if applicable
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class ProfileResult implements Writeable, ToXContentObject {
     static final ParseField TYPE = new ParseField("type");
     static final ParseField DESCRIPTION = new ParseField("description");
diff --git a/server/src/main/java/org/opensearch/search/profile/ProfileShardResult.java b/server/src/main/java/org/opensearch/search/profile/ProfileShardResult.java
index 502d8e4852588..8ff622152ee70 100644
--- a/server/src/main/java/org/opensearch/search/profile/ProfileShardResult.java
+++ b/server/src/main/java/org/opensearch/search/profile/ProfileShardResult.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.profile;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -46,8 +47,9 @@
 /**
  * Shard level profile results
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ProfileShardResult implements Writeable {
 
     private final List<QueryProfileShardResult> queryProfileResults;
diff --git a/server/src/main/java/org/opensearch/search/profile/Profilers.java b/server/src/main/java/org/opensearch/search/profile/Profilers.java
index 8e87c7ff4acd4..75337f89e67ca 100644
--- a/server/src/main/java/org/opensearch/search/profile/Profilers.java
+++ b/server/src/main/java/org/opensearch/search/profile/Profilers.java
@@ -32,9 +32,13 @@
 
 package org.opensearch.search.profile;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.internal.ContextIndexSearcher;
 import org.opensearch.search.profile.aggregation.AggregationProfiler;
 import org.opensearch.search.profile.aggregation.ConcurrentAggregationProfiler;
+import org.opensearch.search.profile.query.ConcurrentQueryProfileTree;
+import org.opensearch.search.profile.query.ConcurrentQueryProfiler;
+import org.opensearch.search.profile.query.InternalQueryProfileTree;
 import org.opensearch.search.profile.query.QueryProfiler;
 
 import java.util.ArrayList;
@@ -44,8 +48,9 @@
 /**
  * Wrapper around all the profilers that makes management easier.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class Profilers {
 
     private final ContextIndexSearcher searcher;
@@ -64,7 +69,9 @@ public Profilers(ContextIndexSearcher searcher, boolean isConcurrentSegmentSearc
 
     /** Switch to a new profile. */
     public QueryProfiler addQueryProfiler() {
-        QueryProfiler profiler = new QueryProfiler(isConcurrentSegmentSearchEnabled);
+        QueryProfiler profiler = isConcurrentSegmentSearchEnabled
+            ? new ConcurrentQueryProfiler(new ConcurrentQueryProfileTree())
+            : new QueryProfiler(new InternalQueryProfileTree());
         searcher.setProfiler(profiler);
         queryProfilers.add(profiler);
         return profiler;
diff --git a/server/src/main/java/org/opensearch/search/profile/Timer.java b/server/src/main/java/org/opensearch/search/profile/Timer.java
index 172762cabeb6a..864c689cf7fa0 100644
--- a/server/src/main/java/org/opensearch/search/profile/Timer.java
+++ b/server/src/main/java/org/opensearch/search/profile/Timer.java
@@ -53,6 +53,18 @@ public class Timer {
     private boolean doTiming;
     private long timing, count, lastCount, start, earliestTimerStartTime;
 
+    public Timer() {
+        this(0, 0, 0, 0, 0);
+    }
+
+    public Timer(long timing, long count, long lastCount, long start, long earliestTimerStartTime) {
+        this.timing = timing;
+        this.count = count;
+        this.lastCount = lastCount;
+        this.start = start;
+        this.earliestTimerStartTime = earliestTimerStartTime;
+    }
+
     /** pkg-private for testing */
     long nanoTime() {
         return System.nanoTime();
diff --git a/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileBreakdown.java b/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileBreakdown.java
index 9fa628f107f7b..8642f0da4a90b 100644
--- a/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileBreakdown.java
+++ b/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileBreakdown.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.profile.aggregation;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.profile.AbstractProfileBreakdown;
 
 import java.util.HashMap;
@@ -42,8 +43,9 @@
 /**
  * {@linkplain AbstractProfileBreakdown} customized to work with aggregations.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AggregationProfileBreakdown extends AbstractProfileBreakdown<AggregationTimingType> {
     private final Map<String, Object> extra = new HashMap<>();
 
diff --git a/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileShardResult.java b/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileShardResult.java
index 046e929821ab5..6cb92b3efaac3 100644
--- a/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileShardResult.java
+++ b/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfileShardResult.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.profile.aggregation;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -51,8 +52,9 @@
  * A container class to hold the profile results for a single shard in the request.
  * Contains a list of query profiles, a collector tree and a total rewrite tree.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class AggregationProfileShardResult implements Writeable, ToXContentFragment {
 
     public static final String AGGREGATIONS = "aggregations";
diff --git a/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfiler.java b/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfiler.java
index 39620c25dc5a3..cae3ced5ad0c5 100644
--- a/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfiler.java
+++ b/server/src/main/java/org/opensearch/search/profile/aggregation/AggregationProfiler.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.profile.aggregation;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.aggregations.Aggregator;
 import org.opensearch.search.profile.AbstractProfiler;
 
@@ -41,8 +42,9 @@
 /**
  * Main class to profile aggregations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class AggregationProfiler extends AbstractProfiler<AggregationProfileBreakdown, Aggregator> {
 
     private final Map<Aggregator, AggregationProfileBreakdown> profileBreakdownLookup = new HashMap<>();
diff --git a/server/src/main/java/org/opensearch/search/profile/query/AbstractQueryProfileTree.java b/server/src/main/java/org/opensearch/search/profile/query/AbstractQueryProfileTree.java
index 8e825def13f5d..2f5d632ee2d87 100644
--- a/server/src/main/java/org/opensearch/search/profile/query/AbstractQueryProfileTree.java
+++ b/server/src/main/java/org/opensearch/search/profile/query/AbstractQueryProfileTree.java
@@ -54,14 +54,11 @@ public void startRewriteTime() {
      * startRewriteTime() must be called for a particular context prior to calling
      * stopAndAddRewriteTime(), otherwise the elapsed time will be negative and
      * nonsensical
-     *
-     * @return          The elapsed time
      */
-    public long stopAndAddRewriteTime() {
+    public void stopAndAddRewriteTime() {
         long time = Math.max(1, System.nanoTime() - rewriteScratch);
         rewriteTime += time;
         rewriteScratch = 0;
-        return time;
     }
 
     public long getRewriteTime() {
diff --git a/server/src/main/java/org/opensearch/search/profile/query/CollectorResult.java b/server/src/main/java/org/opensearch/search/profile/query/CollectorResult.java
index 59d35ddd1a8d0..5cb6942445638 100644
--- a/server/src/main/java/org/opensearch/search/profile/query/CollectorResult.java
+++ b/server/src/main/java/org/opensearch/search/profile/query/CollectorResult.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.profile.query;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -55,8 +56,9 @@
  * Collectors used in the search.  Children CollectorResult's may be
  * embedded inside of a parent CollectorResult
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CollectorResult implements ToXContentObject, Writeable {
 
     public static final String REASON_SEARCH_COUNT = "search_count";
diff --git a/server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdown.java b/server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdown.java
index f37d53737d52b..99169b42c05f0 100644
--- a/server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdown.java
+++ b/server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdown.java
@@ -10,6 +10,7 @@
 
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.search.Collector;
+import org.opensearch.OpenSearchException;
 import org.opensearch.search.profile.AbstractProfileBreakdown;
 import org.opensearch.search.profile.ContextualProfileBreakdown;
 
@@ -69,18 +70,36 @@ public Map<String, Long> toBreakdownMap() {
         );
         final long createWeightTime = topLevelBreakdownMapWithWeightTime.get(QueryTimingType.CREATE_WEIGHT.toString());
 
-        if (sliceCollectorsToLeaves.isEmpty() || contexts.isEmpty()) {
+        if (contexts.isEmpty()) {
             // If there are no leaf contexts, then return the default concurrent query level breakdown, which will include the
             // create_weight time/count
             queryNodeTime = createWeightTime;
-            maxSliceNodeTime = queryNodeTime;
-            minSliceNodeTime = queryNodeTime;
-            avgSliceNodeTime = queryNodeTime;
+            maxSliceNodeTime = 0L;
+            minSliceNodeTime = 0L;
+            avgSliceNodeTime = 0L;
             return buildDefaultQueryBreakdownMap(createWeightTime);
+        } else if (sliceCollectorsToLeaves.isEmpty()) {
+            // This will happen when each slice executes search leaf for its leaves and query is rewritten for the leaf being searched. It
+            // creates a new weight and breakdown map for each rewritten query. This new breakdown map captures the timing information for
+            // the new rewritten query. The sliceCollectorsToLeaves is empty because this breakdown for rewritten query gets created later
+            // in search leaf path which doesn't have collector. Also, this is not needed since this breakdown is per leaf and there is no
+            // concurrency involved.
+            assert contexts.size() == 1 : "Unexpected size: "
+                + contexts.size()
+                + " of leaves breakdown in ConcurrentQueryProfileBreakdown of rewritten query for a leaf.";
+            AbstractProfileBreakdown<QueryTimingType> breakdown = contexts.values().iterator().next();
+            queryNodeTime = breakdown.toNodeTime() + createWeightTime;
+            maxSliceNodeTime = 0L;
+            minSliceNodeTime = 0L;
+            avgSliceNodeTime = 0L;
+            Map<String, Long> queryBreakdownMap = new HashMap<>(breakdown.toBreakdownMap());
+            queryBreakdownMap.put(QueryTimingType.CREATE_WEIGHT.toString(), createWeightTime);
+            queryBreakdownMap.put(QueryTimingType.CREATE_WEIGHT + TIMING_TYPE_COUNT_SUFFIX, 1L);
+            return queryBreakdownMap;
         }
 
         // first create the slice level breakdowns
-        final Map<Collector, Map<String, Long>> sliceLevelBreakdowns = buildSliceLevelBreakdown(createWeightStartTime);
+        final Map<Collector, Map<String, Long>> sliceLevelBreakdowns = buildSliceLevelBreakdown();
         return buildQueryBreakdownMap(sliceLevelBreakdowns, createWeightTime, createWeightStartTime);
     }
 
@@ -124,18 +143,19 @@ private Map<String, Long> buildDefaultQueryBreakdownMap(long createWeightTime) {
     /**
      * Computes the slice level breakdownMap. It uses sliceCollectorsToLeaves to figure out all the leaves or segments part of a slice.
      * Then use the breakdown timing stats for each of these leaves to calculate the breakdown stats at slice level.
-     * @param createWeightStartTime start time when createWeight is called
+     *
      * @return map of collector (or slice) to breakdown map
      */
-    Map<Collector, Map<String, Long>> buildSliceLevelBreakdown(long createWeightStartTime) {
+    Map<Collector, Map<String, Long>> buildSliceLevelBreakdown() {
         final Map<Collector, Map<String, Long>> sliceLevelBreakdowns = new HashMap<>();
-        long totalSliceNodeTime = 0;
+        long totalSliceNodeTime = 0L;
         for (Map.Entry<Collector, List<LeafReaderContext>> slice : sliceCollectorsToLeaves.entrySet()) {
             final Collector sliceCollector = slice.getKey();
             // initialize each slice level breakdown
             final Map<String, Long> currentSliceBreakdown = sliceLevelBreakdowns.computeIfAbsent(sliceCollector, k -> new HashMap<>());
             // max slice end time across all timing types
             long sliceMaxEndTime = Long.MIN_VALUE;
+            long sliceMinStartTime = Long.MAX_VALUE;
             for (QueryTimingType timingType : QueryTimingType.values()) {
                 if (timingType.equals(QueryTimingType.CREATE_WEIGHT)) {
                     // do nothing for create weight as that is query level time and not slice level
@@ -155,24 +175,32 @@ Map<Collector, Map<String, Long>> buildSliceLevelBreakdown(long createWeightStar
                         // leaf, but the leaf level breakdown will not be created in the contexts map.
                         // This is because before updating the contexts map, the query hits earlyTerminationException.
                         // To handle such case, we will ignore the leaf that is not present.
+                        //
+                        // Other than early termination, it can also happen in other cases. For example: there is a must boolean query
+                        // with 2 boolean clauses. While creating scorer for first clause if no docs are found for the field in a leaf
+                        // context then it will return null scorer. Then for 2nd clause weight as well no scorer will be created for this
+                        // leaf context (as it is a must query). Due to this it will end up missing the leaf context in the contexts map
+                        // for second clause weight.
                         continue;
                     }
                     final Map<String, Long> currentSliceLeafBreakdownMap = contexts.get(sliceLeaf).toBreakdownMap();
                     // get the count for current leaf timing type
+                    final long sliceLeafTimingTypeCount = currentSliceLeafBreakdownMap.get(timingTypeCountKey);
                     currentSliceBreakdown.compute(
                         timingTypeCountKey,
-                        (key, value) -> (value == null)
-                            ? currentSliceLeafBreakdownMap.get(timingTypeCountKey)
-                            : value + currentSliceLeafBreakdownMap.get(timingTypeCountKey)
+                        (key, value) -> (value == null) ? sliceLeafTimingTypeCount : value + sliceLeafTimingTypeCount
                     );
 
-                    // compute the sliceEndTime for timingType using max of endTime across slice leaves
-                    final long sliceLeafTimingTypeEndTime = currentSliceLeafBreakdownMap.get(timingTypeStartKey)
-                        + currentSliceLeafBreakdownMap.get(timingType.toString());
-                    currentSliceBreakdown.compute(
-                        timingTypeSliceEndTimeKey,
-                        (key, value) -> (value == null) ? sliceLeafTimingTypeEndTime : Math.max(value, sliceLeafTimingTypeEndTime)
-                    );
+                    if (sliceLeafTimingTypeCount == 0L) {
+                        // In case where a slice with multiple leaves, it is possible that any one of the leaves has 0 invocations for a
+                        // specific breakdown type. We should skip the slice start/end time computation for any leaf with 0 invocations on a
+                        // timing type, as 0 does not represent an actual timing.
+                        // For example, a slice has 0 invocations for a breakdown type from its leading leaves. Another example, let's
+                        // consider a slice with three leaves: leaf A with a score count of 5, leaf B with a score count of 0,
+                        // and leaf C with a score count of 4. In this situation, we only compute the timing type slice start/end time based
+                        // on leaf A and leaf C. This is because leaf B has a start time of zero.
+                        continue;
+                    }
 
                     // compute the sliceStartTime for timingType using min of startTime across slice leaves
                     final long sliceLeafTimingTypeStartTime = currentSliceLeafBreakdownMap.get(timingTypeStartKey);
@@ -180,17 +208,56 @@ Map<Collector, Map<String, Long>> buildSliceLevelBreakdown(long createWeightStar
                         timingTypeSliceStartTimeKey,
                         (key, value) -> (value == null) ? sliceLeafTimingTypeStartTime : Math.min(value, sliceLeafTimingTypeStartTime)
                     );
+
+                    // compute the sliceEndTime for timingType using max of endTime across slice leaves
+                    final long sliceLeafTimingTypeEndTime = sliceLeafTimingTypeStartTime + currentSliceLeafBreakdownMap.get(
+                        timingType.toString()
+                    );
+                    currentSliceBreakdown.compute(
+                        timingTypeSliceEndTimeKey,
+                        (key, value) -> (value == null) ? sliceLeafTimingTypeEndTime : Math.max(value, sliceLeafTimingTypeEndTime)
+                    );
+                }
+                // Only when we've checked all leaves in a slice and still find no invocations, then we should set the slice start/end time
+                // to the default 0L. This is because buildQueryBreakdownMap expects timingTypeSliceStartTimeKey and
+                // timingTypeSliceEndTimeKey in the slice level breakdowns.
+                if (currentSliceBreakdown.get(timingTypeCountKey) != null && currentSliceBreakdown.get(timingTypeCountKey) == 0L) {
+                    currentSliceBreakdown.put(timingTypeSliceStartTimeKey, 0L);
+                    currentSliceBreakdown.put(timingTypeSliceEndTimeKey, 0L);
                 }
                 // compute sliceMaxEndTime as max of sliceEndTime across all timing types
-                sliceMaxEndTime = Math.max(sliceMaxEndTime, currentSliceBreakdown.get(timingTypeSliceEndTimeKey));
+                sliceMaxEndTime = Math.max(sliceMaxEndTime, currentSliceBreakdown.getOrDefault(timingTypeSliceEndTimeKey, Long.MIN_VALUE));
+                long currentSliceStartTime = currentSliceBreakdown.getOrDefault(timingTypeSliceStartTimeKey, Long.MAX_VALUE);
+                if (currentSliceStartTime == 0L) {
+                    // The timer for the current timing type never starts, so we continue here
+                    continue;
+                }
+                sliceMinStartTime = Math.min(sliceMinStartTime, currentSliceStartTime);
                 // compute total time for each timing type at slice level using sliceEndTime and sliceStartTime
                 currentSliceBreakdown.put(
                     timingType.toString(),
-                    currentSliceBreakdown.get(timingTypeSliceEndTimeKey) - currentSliceBreakdown.get(timingTypeSliceStartTimeKey)
+                    currentSliceBreakdown.getOrDefault(timingTypeSliceEndTimeKey, 0L) - currentSliceBreakdown.getOrDefault(
+                        timingTypeSliceStartTimeKey,
+                        0L
+                    )
+                );
+            }
+            // currentSliceNodeTime does not include the create weight time, as that is computed in non-concurrent part
+            long currentSliceNodeTime;
+            if (sliceMinStartTime == Long.MAX_VALUE && sliceMaxEndTime == Long.MIN_VALUE) {
+                currentSliceNodeTime = 0L;
+            } else if (sliceMinStartTime == Long.MAX_VALUE || sliceMaxEndTime == Long.MIN_VALUE) {
+                throw new OpenSearchException(
+                    "Unexpected value of sliceMinStartTime ["
+                        + sliceMinStartTime
+                        + "] or sliceMaxEndTime ["
+                        + sliceMaxEndTime
+                        + "] while computing the slice level timing profile breakdowns"
                 );
+            } else {
+                currentSliceNodeTime = sliceMaxEndTime - sliceMinStartTime;
             }
-            // currentSliceNodeTime includes the create weight time as well which will be same for all the slices
-            long currentSliceNodeTime = sliceMaxEndTime - createWeightStartTime;
+
             // compute max/min slice times
             maxSliceNodeTime = Math.max(maxSliceNodeTime, currentSliceNodeTime);
             minSliceNodeTime = Math.min(minSliceNodeTime, currentSliceNodeTime);
@@ -245,8 +312,8 @@ public Map<String, Long> buildQueryBreakdownMap(
 
             // for all other timing types, we will compute min/max/avg/total across slices
             for (Map.Entry<Collector, Map<String, Long>> sliceBreakdown : sliceLevelBreakdowns.entrySet()) {
-                Long sliceBreakdownTypeTime = sliceBreakdown.getValue().get(timingTypeKey);
-                Long sliceBreakdownTypeCount = sliceBreakdown.getValue().get(timingTypeCountKey);
+                long sliceBreakdownTypeTime = sliceBreakdown.getValue().getOrDefault(timingTypeKey, 0L);
+                long sliceBreakdownTypeCount = sliceBreakdown.getValue().getOrDefault(timingTypeCountKey, 0L);
                 // compute max/min/avg TimingType time across slices
                 queryBreakdownMap.compute(
                     maxBreakdownTypeTime,
@@ -276,17 +343,38 @@ public Map<String, Long> buildQueryBreakdownMap(
                 );
 
                 // query start/end time for a TimingType is min/max of start/end time across slices for that TimingType
-                queryTimingTypeEndTime = Math.max(queryTimingTypeEndTime, sliceBreakdown.getValue().get(sliceEndTimeForTimingType));
-                queryTimingTypeStartTime = Math.min(queryTimingTypeStartTime, sliceBreakdown.getValue().get(sliceStartTimeForTimingType));
+                queryTimingTypeEndTime = Math.max(
+                    queryTimingTypeEndTime,
+                    sliceBreakdown.getValue().getOrDefault(sliceEndTimeForTimingType, Long.MIN_VALUE)
+                );
+                queryTimingTypeStartTime = Math.min(
+                    queryTimingTypeStartTime,
+                    sliceBreakdown.getValue().getOrDefault(sliceStartTimeForTimingType, Long.MAX_VALUE)
+                );
                 queryTimingTypeCount += sliceBreakdownTypeCount;
             }
+
+            if (queryTimingTypeStartTime == Long.MAX_VALUE || queryTimingTypeEndTime == Long.MIN_VALUE) {
+                throw new OpenSearchException(
+                    "Unexpected timing type ["
+                        + timingTypeKey
+                        + "] start ["
+                        + queryTimingTypeStartTime
+                        + "] or end time ["
+                        + queryTimingTypeEndTime
+                        + "] computed across slices for profile results"
+                );
+            }
             queryBreakdownMap.put(timingTypeKey, queryTimingTypeEndTime - queryTimingTypeStartTime);
             queryBreakdownMap.put(timingTypeCountKey, queryTimingTypeCount);
-            queryBreakdownMap.compute(avgBreakdownTypeTime, (key, value) -> (value == null) ? 0 : value / sliceLevelBreakdowns.size());
-            queryBreakdownMap.compute(avgBreakdownTypeCount, (key, value) -> (value == null) ? 0 : value / sliceLevelBreakdowns.size());
+            queryBreakdownMap.compute(avgBreakdownTypeTime, (key, value) -> (value == null) ? 0L : value / sliceLevelBreakdowns.size());
+            queryBreakdownMap.compute(avgBreakdownTypeCount, (key, value) -> (value == null) ? 0L : value / sliceLevelBreakdowns.size());
             // compute query end time using max of query end time across all timing types
             queryEndTime = Math.max(queryEndTime, queryTimingTypeEndTime);
         }
+        if (queryEndTime == Long.MIN_VALUE) {
+            throw new OpenSearchException("Unexpected error while computing the query end time across slices in profile result");
+        }
         queryNodeTime = queryEndTime - createWeightStartTime;
         return queryBreakdownMap;
     }
diff --git a/server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfiler.java b/server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfiler.java
new file mode 100644
index 0000000000000..42bf23bb13fbe
--- /dev/null
+++ b/server/src/main/java/org/opensearch/search/profile/query/ConcurrentQueryProfiler.java
@@ -0,0 +1,134 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.profile.query;
+
+import org.apache.lucene.search.Query;
+import org.opensearch.search.profile.ContextualProfileBreakdown;
+import org.opensearch.search.profile.ProfileResult;
+import org.opensearch.search.profile.Timer;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.LinkedHashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * This class acts as a thread-local storage for profiling a query with concurrent execution
+ *
+ * @opensearch.internal
+ */
+public final class ConcurrentQueryProfiler extends QueryProfiler {
+
+    private final Map<Long, ConcurrentQueryProfileTree> threadToProfileTree;
+    // The LinkedList does not need to be thread safe, as the map associates thread IDs with LinkedList, and only
+    // one thread will access the LinkedList at a time.
+    private final Map<Long, LinkedList<Timer>> threadToRewriteTimers;
+
+    public ConcurrentQueryProfiler(AbstractQueryProfileTree profileTree) {
+        super(profileTree);
+        long threadId = getCurrentThreadId();
+        // We utilize LinkedHashMap to preserve the insertion order of the profiled queries
+        threadToProfileTree = Collections.synchronizedMap(new LinkedHashMap<>());
+        threadToProfileTree.put(threadId, (ConcurrentQueryProfileTree) profileTree);
+        threadToRewriteTimers = new ConcurrentHashMap<>();
+        threadToRewriteTimers.put(threadId, new LinkedList<>());
+    }
+
+    @Override
+    public ContextualProfileBreakdown<QueryTimingType> getQueryBreakdown(Query query) {
+        ConcurrentQueryProfileTree profileTree = threadToProfileTree.computeIfAbsent(
+            getCurrentThreadId(),
+            k -> new ConcurrentQueryProfileTree()
+        );
+        return profileTree.getProfileBreakdown(query);
+    }
+
+    /**
+     * Removes the last (e.g. most recent) element on ConcurrentQueryProfileTree stack.
+     */
+    @Override
+    public void pollLastElement() {
+        ConcurrentQueryProfileTree concurrentProfileTree = threadToProfileTree.get(getCurrentThreadId());
+        if (concurrentProfileTree != null) {
+            concurrentProfileTree.pollLast();
+        }
+    }
+
+    /**
+     * @return a hierarchical representation of the profiled tree
+     */
+    @Override
+    public List<ProfileResult> getTree() {
+        List<ProfileResult> profileResults = new ArrayList<>();
+        for (Map.Entry<Long, ConcurrentQueryProfileTree> profile : threadToProfileTree.entrySet()) {
+            profileResults.addAll(profile.getValue().getTree());
+        }
+        return profileResults;
+    }
+
+    /**
+     * Begin timing the rewrite phase of a request
+     */
+    @Override
+    public void startRewriteTime() {
+        Timer rewriteTimer = new Timer();
+        threadToRewriteTimers.computeIfAbsent(getCurrentThreadId(), k -> new LinkedList<>()).add(rewriteTimer);
+        rewriteTimer.start();
+    }
+
+    /**
+     * Stop recording the current rewrite timer
+     */
+    public void stopAndAddRewriteTime() {
+        Timer rewriteTimer = threadToRewriteTimers.get(getCurrentThreadId()).getLast();
+        rewriteTimer.stop();
+    }
+
+    /**
+     * @return total time taken to rewrite all queries in this concurrent query profiler
+     */
+    @Override
+    public long getRewriteTime() {
+        long totalRewriteTime = 0L;
+        List<Timer> rewriteTimers = new LinkedList<>();
+        threadToRewriteTimers.values().forEach(rewriteTimers::addAll);
+        LinkedList<long[]> mergedIntervals = mergeRewriteTimeIntervals(rewriteTimers);
+        for (long[] interval : mergedIntervals) {
+            totalRewriteTime += interval[1] - interval[0];
+        }
+        return totalRewriteTime;
+    }
+
+    // package private for unit testing
+    LinkedList<long[]> mergeRewriteTimeIntervals(List<Timer> timers) {
+        LinkedList<long[]> mergedIntervals = new LinkedList<>();
+        timers.sort(Comparator.comparingLong(Timer::getEarliestTimerStartTime));
+        for (Timer timer : timers) {
+            long startTime = timer.getEarliestTimerStartTime();
+            long endTime = startTime + timer.getApproximateTiming();
+            if (mergedIntervals.isEmpty() || mergedIntervals.getLast()[1] < startTime) {
+                long[] interval = new long[2];
+                interval[0] = startTime;
+                interval[1] = endTime;
+                mergedIntervals.add(interval);
+            } else {
+                mergedIntervals.getLast()[1] = Math.max(mergedIntervals.getLast()[1], endTime);
+            }
+        }
+        return mergedIntervals;
+    }
+
+    private long getCurrentThreadId() {
+        return Thread.currentThread().getId();
+    }
+}
diff --git a/server/src/main/java/org/opensearch/search/profile/query/InternalProfileCollector.java b/server/src/main/java/org/opensearch/search/profile/query/InternalProfileCollector.java
index 8b860c3a58cea..024d91a8e2ed2 100644
--- a/server/src/main/java/org/opensearch/search/profile/query/InternalProfileCollector.java
+++ b/server/src/main/java/org/opensearch/search/profile/query/InternalProfileCollector.java
@@ -44,11 +44,12 @@
 
 /**
  * This class wraps a Lucene Collector and times the execution of:
- * - setScorer()
- * - collect()
- * - doSetNextReader()
- * - needsScores()
- *
+ * <ul>
+ * <li> setScorer()</li>
+ * <li> collect()</li>
+ * <li> doSetNextReader()</li>
+ * <li> needsScores()</li>
+ * </ul>
  * InternalProfiler facilitates the linking of the Collector graph
  *
  * @opensearch.internal
@@ -117,7 +118,7 @@ public Collector getCollector() {
 
     /**
      * Creates a human-friendly representation of the Collector name.
-     *
+     * <p>
      * InternalBucket Collectors use the aggregation name in their toString() method,
      * which makes the profiled output a bit nicer.
      *
diff --git a/server/src/main/java/org/opensearch/search/profile/query/InternalProfileComponent.java b/server/src/main/java/org/opensearch/search/profile/query/InternalProfileComponent.java
index 1752d76e27f06..4d8fbcb745a00 100644
--- a/server/src/main/java/org/opensearch/search/profile/query/InternalProfileComponent.java
+++ b/server/src/main/java/org/opensearch/search/profile/query/InternalProfileComponent.java
@@ -8,13 +8,16 @@
 
 package org.opensearch.search.profile.query;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.util.Collection;
 
 /**
  * Container for an agg profiling component
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.9.0")
 public interface InternalProfileComponent {
     /**
      * @return profile component name
diff --git a/server/src/main/java/org/opensearch/search/profile/query/QueryProfileShardResult.java b/server/src/main/java/org/opensearch/search/profile/query/QueryProfileShardResult.java
index a9f3d4aaf7885..76d6229159698 100644
--- a/server/src/main/java/org/opensearch/search/profile/query/QueryProfileShardResult.java
+++ b/server/src/main/java/org/opensearch/search/profile/query/QueryProfileShardResult.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.profile.query;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -51,8 +52,9 @@
  * A container class to hold the profile results for a single shard in the request.
  * Contains a list of query profiles, a collector tree and a total rewrite tree.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class QueryProfileShardResult implements Writeable, ToXContentObject {
 
     public static final String COLLECTOR = "collector";
diff --git a/server/src/main/java/org/opensearch/search/profile/query/QueryProfiler.java b/server/src/main/java/org/opensearch/search/profile/query/QueryProfiler.java
index b1024c2312c50..78e65c5bfa257 100644
--- a/server/src/main/java/org/opensearch/search/profile/query/QueryProfiler.java
+++ b/server/src/main/java/org/opensearch/search/profile/query/QueryProfiler.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.profile.query;
 
 import org.apache.lucene.search.Query;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.profile.AbstractProfiler;
 import org.opensearch.search.profile.ContextualProfileBreakdown;
 
@@ -44,22 +45,23 @@
  * "online" as the weights are wrapped by ContextIndexSearcher.  This allows us
  * to know the relationship between nodes in tree without explicitly
  * walking the tree or pre-wrapping everything
- *
+ * <p>
  * A Profiler is associated with every Search, not per Search-Request. E.g. a
  * request may execute two searches (query + global agg).  A Profiler just
  * represents one of those
  *
- * @opensearch.internal
+ * @opensearch.api
  */
-public final class QueryProfiler extends AbstractProfiler<ContextualProfileBreakdown<QueryTimingType>, Query> {
+@PublicApi(since = "1.0.0")
+public class QueryProfiler extends AbstractProfiler<ContextualProfileBreakdown<QueryTimingType>, Query> {
 
     /**
      * The root Collector used in the search
      */
     private InternalProfileComponent collector;
 
-    public QueryProfiler(boolean concurrent) {
-        super(concurrent ? new ConcurrentQueryProfileTree() : new InternalQueryProfileTree());
+    public QueryProfiler(AbstractQueryProfileTree profileTree) {
+        super(profileTree);
     }
 
     /** Set the collector that is associated with this profiler. */
@@ -81,14 +83,14 @@ public void startRewriteTime() {
     /**
      * Stop recording the current rewrite and add it's time to the total tally, returning the
      * cumulative time so far.
-     *
-     * @return cumulative rewrite time
      */
-    public long stopAndAddRewriteTime() {
-        return ((AbstractQueryProfileTree) profileTree).stopAndAddRewriteTime();
+    public void stopAndAddRewriteTime() {
+        ((AbstractQueryProfileTree) profileTree).stopAndAddRewriteTime();
     }
 
     /**
+     * The rewriting process is complex and hard to display because queries can undergo significant changes.
+     * Instead of showing intermediate results, we display the cumulative time for the non-concurrent search case.
      * @return total time taken to rewrite all queries in this profile
      */
     public long getRewriteTime() {
diff --git a/server/src/main/java/org/opensearch/search/query/QueryCollectorContext.java b/server/src/main/java/org/opensearch/search/query/QueryCollectorContext.java
index 10c070ea7dceb..91762bee2ac08 100644
--- a/server/src/main/java/org/opensearch/search/query/QueryCollectorContext.java
+++ b/server/src/main/java/org/opensearch/search/query/QueryCollectorContext.java
@@ -40,6 +40,7 @@
 import org.apache.lucene.search.ScoreMode;
 import org.apache.lucene.search.SimpleCollector;
 import org.apache.lucene.search.Weight;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.MinimumScoreCollector;
 import org.opensearch.common.lucene.search.FilteredCollector;
 import org.opensearch.search.aggregations.AggregationCollectorManager;
@@ -62,8 +63,9 @@
 /**
  * The context used during query collection
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class QueryCollectorContext {
     private static final Collector EMPTY_COLLECTOR = new SimpleCollector() {
         @Override
diff --git a/server/src/main/java/org/opensearch/search/query/QueryPhase.java b/server/src/main/java/org/opensearch/search/query/QueryPhase.java
index f3cf2c13ecdef..8f98f0d9efbd4 100644
--- a/server/src/main/java/org/opensearch/search/query/QueryPhase.java
+++ b/server/src/main/java/org/opensearch/search/query/QueryPhase.java
@@ -48,6 +48,7 @@
 import org.apache.lucene.search.TotalHits;
 import org.opensearch.action.search.SearchShardTask;
 import org.opensearch.common.Booleans;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.common.lucene.search.TopDocsAndMaxScore;
 import org.opensearch.common.util.concurrent.EWMATrackingThreadPoolExecutor;
@@ -88,8 +89,9 @@
  * Query phase of a search request, used to run the query and get back from each shard information about the matching documents
  * (document ids and score or sort criteria) so that matches can be reduced on the coordinating node
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class QueryPhase {
     private static final Logger LOGGER = LogManager.getLogger(QueryPhase.class);
     // TODO: remove this property
diff --git a/server/src/main/java/org/opensearch/search/query/QueryPhaseExecutionException.java b/server/src/main/java/org/opensearch/search/query/QueryPhaseExecutionException.java
index 43bd87183d0be..072c78c67b977 100644
--- a/server/src/main/java/org/opensearch/search/query/QueryPhaseExecutionException.java
+++ b/server/src/main/java/org/opensearch/search/query/QueryPhaseExecutionException.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.query;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.search.SearchException;
 import org.opensearch.search.SearchShardTarget;
@@ -41,8 +42,9 @@
 /**
  * Thrown if there are any errors in the query phase
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class QueryPhaseExecutionException extends SearchException {
 
     public QueryPhaseExecutionException(SearchShardTarget shardTarget, String msg, Throwable cause) {
diff --git a/server/src/main/java/org/opensearch/search/query/QueryPhaseSearcher.java b/server/src/main/java/org/opensearch/search/query/QueryPhaseSearcher.java
index 4518b5e71bdf3..38e45a5212c81 100644
--- a/server/src/main/java/org/opensearch/search/query/QueryPhaseSearcher.java
+++ b/server/src/main/java/org/opensearch/search/query/QueryPhaseSearcher.java
@@ -10,6 +10,7 @@
 
 import org.apache.lucene.search.CollectorManager;
 import org.apache.lucene.search.Query;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.aggregations.AggregationProcessor;
 import org.opensearch.search.aggregations.DefaultAggregationProcessor;
 import org.opensearch.search.internal.ContextIndexSearcher;
@@ -22,8 +23,9 @@
  * The extension point which allows to plug in custom search implementation to be
  * used at {@link QueryPhase}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.0.0")
 public interface QueryPhaseSearcher {
     /**
      * Perform search using {@link CollectorManager}
diff --git a/server/src/main/java/org/opensearch/search/query/QuerySearchResult.java b/server/src/main/java/org/opensearch/search/query/QuerySearchResult.java
index 7de605a244d09..f3ac953ab9d1d 100644
--- a/server/src/main/java/org/opensearch/search/query/QuerySearchResult.java
+++ b/server/src/main/java/org/opensearch/search/query/QuerySearchResult.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.search.FieldDoc;
 import org.apache.lucene.search.TotalHits;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.io.stream.DelayableWriteable;
 import org.opensearch.common.lucene.search.TopDocsAndMaxScore;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -58,8 +59,9 @@
 /**
  * The result of the query search
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class QuerySearchResult extends SearchPhaseResult {
 
     private int from;
@@ -123,7 +125,7 @@ public static QuerySearchResult nullInstance() {
      * Returns true if the result doesn't contain any useful information.
      * It is used by the search action to avoid creating an empty response on
      * shard request that rewrites to match_no_docs.
-     *
+     * <p>
      * TODO: Currently we need the concrete aggregators to build empty responses. This means that we cannot
      *       build an empty response in the coordinating node so we rely on this hack to ensure that at least one shard
      *       returns a valid empty response. We should move the ability to create empty responses to aggregation builders
diff --git a/server/src/main/java/org/opensearch/search/query/ReduceableSearchResult.java b/server/src/main/java/org/opensearch/search/query/ReduceableSearchResult.java
index dbfaa70e1968f..8f89b5bf5a3a7 100644
--- a/server/src/main/java/org/opensearch/search/query/ReduceableSearchResult.java
+++ b/server/src/main/java/org/opensearch/search/query/ReduceableSearchResult.java
@@ -8,13 +8,16 @@
 
 package org.opensearch.search.query;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 
 /**
  * The search result callback returned by reduce phase of the collector manager.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "2.0.0")
 public interface ReduceableSearchResult {
     /**
      * Apply the reduce operation to the query search results
diff --git a/server/src/main/java/org/opensearch/search/query/TopDocsCollectorContext.java b/server/src/main/java/org/opensearch/search/query/TopDocsCollectorContext.java
index 39c34f7c0d5d5..65d3948c8401e 100644
--- a/server/src/main/java/org/opensearch/search/query/TopDocsCollectorContext.java
+++ b/server/src/main/java/org/opensearch/search/query/TopDocsCollectorContext.java
@@ -183,7 +183,9 @@ CollectorManager<?, ReduceableSearchResult> createManager(CollectorManager<?, Re
                 );
             } else {
                 if (hitCount == -1) {
-                    if (trackTotalHitsUpTo != SearchContext.TRACK_TOTAL_HITS_ACCURATE) {
+                    if (trackTotalHitsUpTo == SearchContext.TRACK_TOTAL_HITS_ACCURATE) {
+                        manager = new TotalHitCountCollectorManager(sort);
+                    } else {
                         manager = new EarlyTerminatingCollectorManager<>(
                             new TotalHitCountCollectorManager(sort),
                             trackTotalHitsUpTo,
@@ -530,7 +532,7 @@ public ReduceableSearchResult reduce(Collection<Collector> collectors) throws IO
                     float score = collector.getMaxScore();
                     if (Float.isNaN(maxScore)) {
                         maxScore = score;
-                    } else {
+                    } else if (!Float.isNaN(score)) {
                         maxScore = Math.max(maxScore, score);
                     }
                 }
diff --git a/server/src/main/java/org/opensearch/search/rescore/RescoreContext.java b/server/src/main/java/org/opensearch/search/rescore/RescoreContext.java
index c0e4bbb874531..d4b87f004b58f 100644
--- a/server/src/main/java/org/opensearch/search/rescore/RescoreContext.java
+++ b/server/src/main/java/org/opensearch/search/rescore/RescoreContext.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.rescore;
 
 import org.apache.lucene.search.Query;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Collections;
 import java.util.List;
@@ -43,8 +44,9 @@
  * implementations should extend this with any additional resources that
  * they will need while rescoring.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RescoreContext {
     private final int windowSize;
     private final Rescorer rescorer;
diff --git a/server/src/main/java/org/opensearch/search/rescore/Rescorer.java b/server/src/main/java/org/opensearch/search/rescore/Rescorer.java
index 33f8e5e7b535d..c7a9b077109cf 100644
--- a/server/src/main/java/org/opensearch/search/rescore/Rescorer.java
+++ b/server/src/main/java/org/opensearch/search/rescore/Rescorer.java
@@ -35,19 +35,21 @@
 import org.apache.lucene.search.Explanation;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.TopDocs;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 
 /**
  * A query rescorer interface used to re-rank the Top-K results of a previously
  * executed search.
- *
+ * <p>
  * Subclasses should borrow heavily from {@link QueryRescorer} because it is
  * fairly well behaved and documents that tradeoffs that it is making. There
  * is also an {@code ExampleRescorer} that is worth looking at.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface Rescorer {
     /**
      * Modifies the result of the previously executed search ({@link TopDocs})
diff --git a/server/src/main/java/org/opensearch/search/rescore/RescorerBuilder.java b/server/src/main/java/org/opensearch/search/rescore/RescorerBuilder.java
index 383771306ba7b..7ac7454f02e3b 100644
--- a/server/src/main/java/org/opensearch/search/rescore/RescorerBuilder.java
+++ b/server/src/main/java/org/opensearch/search/rescore/RescorerBuilder.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.rescore;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.Strings;
@@ -51,8 +52,9 @@
 /**
  * The abstract base builder for instances of {@link RescorerBuilder}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class RescorerBuilder<RB extends RescorerBuilder<RB>>
     implements
         NamedWriteable,
diff --git a/server/src/main/java/org/opensearch/search/slice/DocValuesSliceQuery.java b/server/src/main/java/org/opensearch/search/slice/DocValuesSliceQuery.java
index d7d554c058c37..856e103193463 100644
--- a/server/src/main/java/org/opensearch/search/slice/DocValuesSliceQuery.java
+++ b/server/src/main/java/org/opensearch/search/slice/DocValuesSliceQuery.java
@@ -49,7 +49,7 @@
 
 /**
  * A {@link SliceQuery} that uses the numeric doc values of a field to do the slicing.
- *
+ * <p>
  * <b>NOTE</b>: With deterministic field values this query can be used across different readers safely.
  * If updates are accepted on the field you must ensure that the same reader is used for all `slice` queries.
  *
diff --git a/server/src/main/java/org/opensearch/search/slice/SliceBuilder.java b/server/src/main/java/org/opensearch/search/slice/SliceBuilder.java
index 8df44e3958083..c9b8a896ed525 100644
--- a/server/src/main/java/org/opensearch/search/slice/SliceBuilder.java
+++ b/server/src/main/java/org/opensearch/search/slice/SliceBuilder.java
@@ -40,7 +40,7 @@
 import org.opensearch.cluster.routing.GroupShardsIterator;
 import org.opensearch.cluster.routing.ShardIterator;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.logging.DeprecationLogger;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
@@ -76,12 +76,10 @@
  *  Otherwise the provided field must be a numeric and doc_values must be enabled. In that case a
  *  {@link org.opensearch.search.slice.DocValuesSliceQuery} is used to filter the results.
  *
- *  @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SliceBuilder implements Writeable, ToXContentObject {
-
-    private static final DeprecationLogger DEPRECATION_LOG = DeprecationLogger.getLogger(SliceBuilder.class);
-
     public static final ParseField FIELD_FIELD = new ParseField("field");
     public static final ParseField ID_FIELD = new ParseField("id");
     public static final ParseField MAX_FIELD = new ParseField("max");
diff --git a/server/src/main/java/org/opensearch/search/slice/TermsSliceQuery.java b/server/src/main/java/org/opensearch/search/slice/TermsSliceQuery.java
index 297020fe2fe4d..05f36b0d6f3cf 100644
--- a/server/src/main/java/org/opensearch/search/slice/TermsSliceQuery.java
+++ b/server/src/main/java/org/opensearch/search/slice/TermsSliceQuery.java
@@ -53,7 +53,7 @@
 
 /**
  * A {@link SliceQuery} that uses the terms dictionary of a field to do the slicing.
- *
+ * <p>
  * <b>NOTE</b>: The cost of this filter is O(N*M) where N is the number of unique terms in the dictionary
  * and M is the average number of documents per term.
  * For each segment this filter enumerates the terms dictionary, computes the hash code for each term and fills
diff --git a/server/src/main/java/org/opensearch/search/sort/BucketedSort.java b/server/src/main/java/org/opensearch/search/sort/BucketedSort.java
index 3dd682eb841dc..4a7557740384b 100644
--- a/server/src/main/java/org/opensearch/search/sort/BucketedSort.java
+++ b/server/src/main/java/org/opensearch/search/sort/BucketedSort.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.search.Scorable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.lease.Releasables;
 import org.opensearch.common.lucene.ScorerAware;
@@ -94,14 +95,16 @@
  * of allocations and to play well with our paged arrays.
  * </p>
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class BucketedSort implements Releasable {
     /**
      * Callbacks for storing extra data along with competitive sorts.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface ExtraData {
         /**
          * Swap the position of two bits of extra data.
@@ -121,9 +124,10 @@ public interface ExtraData {
         /**
          * Loader for extra data
          *
-         * @opensearch.internal
+         * @opensearch.api
          */
         @FunctionalInterface
+        @PublicApi(since = "1.0.0")
         interface Loader {
             /**
              * Load extra data from a doc.
@@ -194,9 +198,10 @@ public int getBucketSize() {
      * Used with {@link BucketedSort#getValues(long, ResultBuilder)} to
      * build results from the sorting operation.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
     @FunctionalInterface
+    @PublicApi(since = "1.0.0")
     public interface ResultBuilder<T> {
         T build(long index, SortValue sortValue);
     }
@@ -408,7 +413,10 @@ public final void close() {
 
     /**
      * Performs the actual collection against a {@linkplain LeafReaderContext}.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract class Leaf implements ScorerAware {
         private final LeafReaderContext ctx;
         private ExtraData.Loader loader = null;
diff --git a/server/src/main/java/org/opensearch/search/sort/FieldSortBuilder.java b/server/src/main/java/org/opensearch/search/sort/FieldSortBuilder.java
index 97e1d444d4a0a..5cecda1346b90 100644
--- a/server/src/main/java/org/opensearch/search/sort/FieldSortBuilder.java
+++ b/server/src/main/java/org/opensearch/search/sort/FieldSortBuilder.java
@@ -611,7 +611,8 @@ public static FieldSortBuilder getPrimaryFieldSortOrNull(SearchSourceBuilder sou
      * and configurations return <code>null</code>.
      */
     public static MinAndMax<?> getMinMaxOrNull(QueryShardContext context, FieldSortBuilder sortBuilder) throws IOException {
-        return getMinMaxOrNullInternal(context.getIndexReader(), context, sortBuilder);
+        final SortAndFormats sort = SortBuilder.buildSort(Collections.singletonList(sortBuilder), context).get();
+        return getMinMaxOrNullInternal(context.getIndexReader(), context, sortBuilder, sort);
     }
 
     /**
@@ -619,14 +620,21 @@ public static MinAndMax<?> getMinMaxOrNull(QueryShardContext context, FieldSortB
      * The value can be extracted on non-nested indexed mapped fields of type keyword, numeric or date, other fields
      * and configurations return <code>null</code>.
      */
-    public static MinAndMax<?> getMinMaxOrNullForSegment(QueryShardContext context, LeafReaderContext ctx, FieldSortBuilder sortBuilder)
-        throws IOException {
-        return getMinMaxOrNullInternal(ctx.reader(), context, sortBuilder);
+    public static MinAndMax<?> getMinMaxOrNullForSegment(
+        QueryShardContext context,
+        LeafReaderContext ctx,
+        FieldSortBuilder sortBuilder,
+        SortAndFormats sort
+    ) throws IOException {
+        return getMinMaxOrNullInternal(ctx.reader(), context, sortBuilder, sort);
     }
 
-    private static MinAndMax<?> getMinMaxOrNullInternal(IndexReader reader, QueryShardContext context, FieldSortBuilder sortBuilder)
-        throws IOException {
-        SortAndFormats sort = SortBuilder.buildSort(Collections.singletonList(sortBuilder), context).get();
+    private static MinAndMax<?> getMinMaxOrNullInternal(
+        IndexReader reader,
+        QueryShardContext context,
+        FieldSortBuilder sortBuilder,
+        SortAndFormats sort
+    ) throws IOException {
         SortField sortField = sort.sort.getSort()[0];
         if (sortField.getField() == null) {
             return null;
diff --git a/server/src/main/java/org/opensearch/search/sort/NestedSortBuilder.java b/server/src/main/java/org/opensearch/search/sort/NestedSortBuilder.java
index feabdfce4cd21..d101837b8734b 100644
--- a/server/src/main/java/org/opensearch/search/sort/NestedSortBuilder.java
+++ b/server/src/main/java/org/opensearch/search/sort/NestedSortBuilder.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.sort;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -50,8 +51,9 @@
 /**
  * Builds a sort on nested objects
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class NestedSortBuilder implements Writeable, ToXContentObject {
     public static final ParseField NESTED_FIELD = new ParseField("nested");
     public static final ParseField PATH_FIELD = new ParseField("path");
diff --git a/server/src/main/java/org/opensearch/search/sort/SortAndFormats.java b/server/src/main/java/org/opensearch/search/sort/SortAndFormats.java
index e65187e558aef..046faaa03f91f 100644
--- a/server/src/main/java/org/opensearch/search/sort/SortAndFormats.java
+++ b/server/src/main/java/org/opensearch/search/sort/SortAndFormats.java
@@ -33,13 +33,15 @@
 
 import org.apache.lucene.search.Sort;
 import org.opensearch.cluster.metadata.DataStream;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.search.DocValueFormat;
 
 /**
  * Utility class to hold sort and doc value format instances
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SortAndFormats {
 
     public final Sort sort;
diff --git a/server/src/main/java/org/opensearch/search/sort/SortBuilder.java b/server/src/main/java/org/opensearch/search/sort/SortBuilder.java
index 49d317957cdc3..a8c21e7311061 100644
--- a/server/src/main/java/org/opensearch/search/sort/SortBuilder.java
+++ b/server/src/main/java/org/opensearch/search/sort/SortBuilder.java
@@ -36,6 +36,7 @@
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.join.ToChildBlockJoinQuery;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.search.Queries;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -64,8 +65,9 @@
 /**
  * Base class for sort object builders
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SortBuilder<T extends SortBuilder<T>> implements NamedWriteable, ToXContentObject, Rewriteable<SortBuilder<?>> {
 
     protected SortOrder order = SortOrder.ASC;
diff --git a/server/src/main/java/org/opensearch/search/sort/SortOrder.java b/server/src/main/java/org/opensearch/search/sort/SortOrder.java
index ed83a0667c5e7..f4b6701c91f58 100644
--- a/server/src/main/java/org/opensearch/search/sort/SortOrder.java
+++ b/server/src/main/java/org/opensearch/search/sort/SortOrder.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.sort;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -43,8 +44,9 @@
 /**
  * A sorting order.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum SortOrder implements Writeable {
     /**
      * Ascending order.
diff --git a/server/src/main/java/org/opensearch/search/sort/SortValue.java b/server/src/main/java/org/opensearch/search/sort/SortValue.java
index 0c46428bc02d0..f521925695a0d 100644
--- a/server/src/main/java/org/opensearch/search/sort/SortValue.java
+++ b/server/src/main/java/org/opensearch/search/sort/SortValue.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.search.sort;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.NamedWriteable;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -46,8 +47,9 @@
 /**
  * A {@link Comparable}, {@link DocValueFormat} aware wrapper around a sort value.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SortValue implements NamedWriteable, Comparable<SortValue> {
     /**
      * Get a {@linkplain SortValue} for a double.
diff --git a/server/src/main/java/org/opensearch/search/suggest/Suggest.java b/server/src/main/java/org/opensearch/search/suggest/Suggest.java
index 17e5b44ec89e7..b8f2f9b7279cf 100644
--- a/server/src/main/java/org/opensearch/search/suggest/Suggest.java
+++ b/server/src/main/java/org/opensearch/search/suggest/Suggest.java
@@ -34,6 +34,7 @@
 import org.apache.lucene.util.CollectionUtil;
 import org.opensearch.common.CheckedFunction;
 import org.opensearch.common.SetOnce;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
 import org.opensearch.core.common.Strings;
@@ -70,8 +71,9 @@
 /**
  * Top level suggest result, containing the result for each suggestion.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? extends Option>>>, Writeable, ToXContentFragment {
 
     public static final String NAME = "suggest";
@@ -232,7 +234,9 @@ public int hashCode() {
 
     /**
      * The suggestion responses corresponding with the suggestions in the request.
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract static class Suggestion<T extends Suggestion.Entry> implements Iterable<T>, NamedWriteable, ToXContentFragment {
 
         public static final int TYPE = 0;
@@ -263,7 +267,7 @@ public void addTerm(T entry) {
         /**
          * Returns a integer representing the type of the suggestion. This is used for
          * internal serialization over the network.
-         *
+         * <p>
          * This class is now serialized as a NamedWriteable and this method only remains for backwards compatibility
          */
         @Deprecated
@@ -423,7 +427,10 @@ protected static <E extends Suggestion.Entry<?>> void parseEntries(
 
         /**
          * Represents a part from the suggest text with suggested options.
+         *
+         * @opensearch.api
          */
+        @PublicApi(since = "1.0.0")
         public abstract static class Entry<O extends Option> implements Iterable<O>, Writeable, ToXContentFragment {
 
             private static final String TEXT = "text";
@@ -611,7 +618,10 @@ protected static void declareCommonFields(ObjectParser<? extends Entry<? extends
 
             /**
              * Contains the suggested text with its document frequency and score.
+             *
+             * @opensearch.api
              */
+            @PublicApi(since = "1.0.0")
             public abstract static class Option implements Writeable, ToXContentFragment {
 
                 public static final ParseField TEXT = new ParseField("text");
diff --git a/server/src/main/java/org/opensearch/search/suggest/SuggestBuilder.java b/server/src/main/java/org/opensearch/search/suggest/SuggestBuilder.java
index 0691a82299131..f90280da6ce83 100644
--- a/server/src/main/java/org/opensearch/search/suggest/SuggestBuilder.java
+++ b/server/src/main/java/org/opensearch/search/suggest/SuggestBuilder.java
@@ -32,6 +32,7 @@
 package org.opensearch.search.suggest;
 
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.BytesRefs;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -59,8 +60,9 @@
  * Suggesting works by suggesting terms/phrases that appear in the suggest text that are similar compared
  * to the terms in provided text. These suggestions are based on several options described in this class.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SuggestBuilder implements Writeable, ToXContentObject {
     protected static final ParseField GLOBAL_TEXT_FIELD = new ParseField("text");
 
diff --git a/server/src/main/java/org/opensearch/search/suggest/Suggester.java b/server/src/main/java/org/opensearch/search/suggest/Suggester.java
index 29efc6c4a3a6a..cde491a4966ad 100644
--- a/server/src/main/java/org/opensearch/search/suggest/Suggester.java
+++ b/server/src/main/java/org/opensearch/search/suggest/Suggester.java
@@ -34,14 +34,16 @@
 
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.util.CharsRefBuilder;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.io.IOException;
 
 /**
  * Base class used for all suggester implementations
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class Suggester<T extends SuggestionSearchContext.SuggestionContext> {
 
     protected abstract Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>> innerExecute(
diff --git a/server/src/main/java/org/opensearch/search/suggest/SuggestionBuilder.java b/server/src/main/java/org/opensearch/search/suggest/SuggestionBuilder.java
index 05574bbe06fa6..ee465fc527ea3 100644
--- a/server/src/main/java/org/opensearch/search/suggest/SuggestionBuilder.java
+++ b/server/src/main/java/org/opensearch/search/suggest/SuggestionBuilder.java
@@ -34,6 +34,7 @@
 
 import org.apache.lucene.analysis.Analyzer;
 import org.opensearch.OpenSearchParseException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.lucene.BytesRefs;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -54,8 +55,9 @@
 /**
  * Base class for the different suggestion implementations.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class SuggestionBuilder<T extends SuggestionBuilder<T>> implements NamedWriteable, ToXContentFragment {
 
     protected final String field;
diff --git a/server/src/main/java/org/opensearch/search/suggest/SuggestionSearchContext.java b/server/src/main/java/org/opensearch/search/suggest/SuggestionSearchContext.java
index f0d8efc64b6b3..32f72d1115973 100644
--- a/server/src/main/java/org/opensearch/search/suggest/SuggestionSearchContext.java
+++ b/server/src/main/java/org/opensearch/search/suggest/SuggestionSearchContext.java
@@ -33,6 +33,7 @@
 
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.query.QueryShardContext;
 
 import java.util.LinkedHashMap;
@@ -41,8 +42,9 @@
 /**
  * Context used for suggestion based search
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SuggestionSearchContext {
 
     private final Map<String, SuggestionContext> suggestions = new LinkedHashMap<>(4);
@@ -58,8 +60,9 @@ public Map<String, SuggestionContext> suggestions() {
     /**
      * The suggestion context
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public abstract static class SuggestionContext {
 
         private BytesRef text;
diff --git a/server/src/main/java/org/opensearch/search/suggest/completion/CompletionStats.java b/server/src/main/java/org/opensearch/search/suggest/completion/CompletionStats.java
index b54f988218ac8..ad91e75c591f3 100644
--- a/server/src/main/java/org/opensearch/search/suggest/completion/CompletionStats.java
+++ b/server/src/main/java/org/opensearch/search/suggest/completion/CompletionStats.java
@@ -33,6 +33,7 @@
 
 import org.opensearch.common.FieldMemoryStats;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -45,8 +46,9 @@
 /**
  * Stats for completion suggester
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class CompletionStats implements Writeable, ToXContentFragment {
 
     private static final String COMPLETION = "completion";
diff --git a/server/src/main/java/org/opensearch/search/suggest/completion/CompletionSuggestion.java b/server/src/main/java/org/opensearch/search/suggest/completion/CompletionSuggestion.java
index 96e47cf7c8000..e3e6cad65be62 100644
--- a/server/src/main/java/org/opensearch/search/suggest/completion/CompletionSuggestion.java
+++ b/server/src/main/java/org/opensearch/search/suggest/completion/CompletionSuggestion.java
@@ -63,14 +63,14 @@
 
 /**
  * Suggestion response for {@link CompletionSuggester} results
- *
+ * <p>
  * Response format for each entry:
  * {
  *     "text" : STRING
  *     "score" : FLOAT
  *     "contexts" : CONTEXTS
  * }
- *
+ * <p>
  * CONTEXTS : {
  *     "CONTEXT_NAME" : ARRAY,
  *     ..
diff --git a/server/src/main/java/org/opensearch/search/suggest/completion/FuzzyOptions.java b/server/src/main/java/org/opensearch/search/suggest/completion/FuzzyOptions.java
index 56cc8fbfbcf66..139742f84b80b 100644
--- a/server/src/main/java/org/opensearch/search/suggest/completion/FuzzyOptions.java
+++ b/server/src/main/java/org/opensearch/search/suggest/completion/FuzzyOptions.java
@@ -142,7 +142,7 @@ public int getEditDistance() {
 
     /**
      * Returns if transpositions option is set
-     *
+     * <p>
      * if transpositions is set, then swapping one character for another counts as one edit instead of two.
      */
     public boolean isTranspositions() {
diff --git a/server/src/main/java/org/opensearch/search/suggest/completion/TopSuggestGroupDocsCollector.java b/server/src/main/java/org/opensearch/search/suggest/completion/TopSuggestGroupDocsCollector.java
index 4fbd661037aa9..fbc39536502de 100644
--- a/server/src/main/java/org/opensearch/search/suggest/completion/TopSuggestGroupDocsCollector.java
+++ b/server/src/main/java/org/opensearch/search/suggest/completion/TopSuggestGroupDocsCollector.java
@@ -43,7 +43,7 @@
 /**
  *
  * Extension of the {@link TopSuggestDocsCollector} that returns top documents from the completion suggester.
- *
+ * <p>
  * This collector groups suggestions coming from the same document but matching different contexts
  * or surface form together. When different contexts or surface forms match the same suggestion form only
  * the best one per document (sorted by weight) is kept.
@@ -55,7 +55,7 @@ class TopSuggestGroupDocsCollector extends TopSuggestDocsCollector {
 
     /**
      * Sole constructor
-     *
+     * <p>
      * Collects at most <code>num</code> completions
      * with corresponding document and weight
      */
diff --git a/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMapping.java b/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMapping.java
index 61e60293f4943..94707ff2b4569 100644
--- a/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMapping.java
+++ b/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMapping.java
@@ -54,7 +54,7 @@
 /**
  * A {@link ContextMapping} defines criteria that can be used to
  * filter and/or boost suggestions at query time for {@link CompletionFieldMapper}.
- *
+ * <p>
  * Implementations have to define how contexts are parsed at query/index time
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMappings.java b/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMappings.java
index 0f5781fefcf07..cff5a901a473f 100644
--- a/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMappings.java
+++ b/server/src/main/java/org/opensearch/search/suggest/completion/context/ContextMappings.java
@@ -124,11 +124,11 @@ public Iterator<ContextMapping<?>> iterator() {
      * Field prepends context values with a suggestion
      * Context values are associated with a type, denoted by
      * a type id, which is prepended to the context value.
-     *
+     * <p>
      * Every defined context mapping yields a unique type id (index of the
      * corresponding context mapping in the context mappings list)
      * for all its context values
-     *
+     * <p>
      * The type, context and suggestion values are encoded as follows:
      * <p>
      *     TYPE_ID | CONTEXT_VALUE | CONTEXT_SEP | SUGGESTION_VALUE
@@ -209,7 +209,7 @@ public ContextQuery toContextQuery(CompletionQuery query, Map<String, List<Conte
 
     /**
      * Maps an output context list to a map of context mapping names and their values
-     *
+     * <p>
      * see {@link org.opensearch.search.suggest.completion.context.ContextMappings.TypedContextField}
      * @return a map of context names and their values
      *
@@ -232,7 +232,7 @@ public Map<String, Set<String>> getNamedContexts(List<CharSequence> contexts) {
 
     /**
      * Loads {@link ContextMappings} from configuration
-     *
+     * <p>
      * Expected configuration:
      *  List of maps representing {@link ContextMapping}
      *  [{"name": .., "type": .., ..}, {..}]
@@ -286,7 +286,7 @@ private static String extractRequiredValue(Map<String, Object> contextConfig, St
 
     /**
      * Writes a list of objects specified by the defined {@link ContextMapping}s
-     *
+     * <p>
      * see {@link ContextMapping#toXContent(XContentBuilder, Params)}
      */
     @Override
diff --git a/server/src/main/java/org/opensearch/search/suggest/completion/context/GeoContextMapping.java b/server/src/main/java/org/opensearch/search/suggest/completion/context/GeoContextMapping.java
index 17f858b0b1302..0e29e928df760 100644
--- a/server/src/main/java/org/opensearch/search/suggest/completion/context/GeoContextMapping.java
+++ b/server/src/main/java/org/opensearch/search/suggest/completion/context/GeoContextMapping.java
@@ -71,7 +71,7 @@
  * The suggestions can be boosted and/or filtered depending on
  * whether it falls within an area, represented by a query geo hash
  * with a specified precision
- *
+ * <p>
  * {@link GeoQueryContext} defines the options for constructing
  * a unit of query context for this context type
  *
diff --git a/server/src/main/java/org/opensearch/search/suggest/phrase/DirectCandidateGenerator.java b/server/src/main/java/org/opensearch/search/suggest/phrase/DirectCandidateGenerator.java
index 6335629f61cf1..1a00cb9465771 100644
--- a/server/src/main/java/org/opensearch/search/suggest/phrase/DirectCandidateGenerator.java
+++ b/server/src/main/java/org/opensearch/search/suggest/phrase/DirectCandidateGenerator.java
@@ -147,9 +147,9 @@ public TermStats internalTermStats(BytesRef term) throws IOException {
         if (termsEnum.seekExact(term)) {
             return new TermStats(
                 termsEnum.docFreq(),
-                /**
-                 * We use the {@link TermsEnum#docFreq()} for fields that don't
-                 * record the {@link TermsEnum#totalTermFreq()}.
+                /*
+                  We use the {@link TermsEnum#docFreq()} for fields that don't
+                  record the {@link TermsEnum#totalTermFreq()}.
                  */
                 termsEnum.totalTermFreq() == -1 ? termsEnum.docFreq() : termsEnum.totalTermFreq()
             );
@@ -168,10 +168,10 @@ public CandidateSet drawCandidates(CandidateSet set) throws IOException {
         float origThreshold = spellchecker.getThresholdFrequency();
         try {
             if (suggestMode != SuggestMode.SUGGEST_ALWAYS) {
-                /**
-                 * We use the {@link TermStats#docFreq} to compute the frequency threshold
-                 * because that's what {@link DirectSpellChecker#suggestSimilar} expects
-                 * when filtering terms.
+                /*
+                  We use the {@link TermStats#docFreq} to compute the frequency threshold
+                  because that's what {@link DirectSpellChecker#suggestSimilar} expects
+                  when filtering terms.
                  */
                 int threshold = thresholdTermFrequency(original.termStats.docFreq);
                 if (threshold == Integer.MAX_VALUE) {
diff --git a/server/src/main/java/org/opensearch/search/suggest/phrase/LinearInterpolation.java b/server/src/main/java/org/opensearch/search/suggest/phrase/LinearInterpolation.java
index f1dba9793ba9e..bc942da738c7e 100644
--- a/server/src/main/java/org/opensearch/search/suggest/phrase/LinearInterpolation.java
+++ b/server/src/main/java/org/opensearch/search/suggest/phrase/LinearInterpolation.java
@@ -70,7 +70,7 @@ public final class LinearInterpolation extends SmoothingModel {
 
     /**
      * Creates a linear interpolation smoothing model.
-     *
+     * <p>
      * Note: the lambdas must sum up to one.
      *
      * @param trigramLambda
diff --git a/server/src/main/java/org/opensearch/search/suggest/phrase/PhraseSuggestionBuilder.java b/server/src/main/java/org/opensearch/search/suggest/phrase/PhraseSuggestionBuilder.java
index e37d964cc0424..a6bfb880cf249 100644
--- a/server/src/main/java/org/opensearch/search/suggest/phrase/PhraseSuggestionBuilder.java
+++ b/server/src/main/java/org/opensearch/search/suggest/phrase/PhraseSuggestionBuilder.java
@@ -222,7 +222,7 @@ public Integer gramSize() {
      * misspellings in order to form a correction. This method accepts a float
      * value in the range [0..1) as a fraction of the actual query terms a
      * number {@code &gt;=1} as an absolute number of query terms.
-     *
+     * <p>
      * The default is set to {@code 1.0} which corresponds to that only
      * corrections with at most 1 misspelled term are returned.
      */
diff --git a/server/src/main/java/org/opensearch/snapshots/InternalSnapshotsInfoService.java b/server/src/main/java/org/opensearch/snapshots/InternalSnapshotsInfoService.java
index 3e1f231b513c6..797a58f3b0d9b 100644
--- a/server/src/main/java/org/opensearch/snapshots/InternalSnapshotsInfoService.java
+++ b/server/src/main/java/org/opensearch/snapshots/InternalSnapshotsInfoService.java
@@ -45,6 +45,7 @@
 import org.opensearch.cluster.routing.ShardRoutingState;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Priority;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
@@ -364,9 +365,9 @@ private static Set<SnapshotShard> listOfSnapshotShards(final ClusterState state)
     /**
      * A snapshot of a shard
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
-
+    @PublicApi(since = "1.0.0")
     public static class SnapshotShard {
 
         private final Snapshot snapshot;
diff --git a/server/src/main/java/org/opensearch/snapshots/RestoreInfo.java b/server/src/main/java/org/opensearch/snapshots/RestoreInfo.java
index 5a628eb7f04a0..2ccbf308705bc 100644
--- a/server/src/main/java/org/opensearch/snapshots/RestoreInfo.java
+++ b/server/src/main/java/org/opensearch/snapshots/RestoreInfo.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.snapshots;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -53,8 +54,9 @@
  * <p>
  * Returned as part of {@link org.opensearch.action.admin.cluster.snapshots.restore.RestoreSnapshotResponse}
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class RestoreInfo implements ToXContentObject, Writeable {
 
     private String name;
diff --git a/server/src/main/java/org/opensearch/snapshots/RestoreService.java b/server/src/main/java/org/opensearch/snapshots/RestoreService.java
index 955ec71f30360..9d2c7eb882fa1 100644
--- a/server/src/main/java/org/opensearch/snapshots/RestoreService.java
+++ b/server/src/main/java/org/opensearch/snapshots/RestoreService.java
@@ -429,6 +429,10 @@ public ClusterState execute(ClusterState currentState) {
                                     createIndexService.validateIndexName(renamedIndexName, currentState);
                                     createIndexService.validateDotIndex(renamedIndexName, isHidden);
                                     createIndexService.validateIndexSettings(renamedIndexName, snapshotIndexMetadata.getSettings(), false);
+                                    MetadataCreateIndexService.validateRefreshIntervalSettings(
+                                        snapshotIndexMetadata.getSettings(),
+                                        clusterSettings
+                                    );
                                     IndexMetadata.Builder indexMdBuilder = IndexMetadata.builder(snapshotIndexMetadata)
                                         .state(IndexMetadata.State.OPEN)
                                         .index(renamedIndexName);
@@ -578,6 +582,7 @@ public ClusterState execute(ClusterState currentState) {
                             if (metadata.templates() != null) {
                                 // TODO: Should all existing templates be deleted first?
                                 for (final IndexTemplateMetadata cursor : metadata.templates().values()) {
+                                    MetadataCreateIndexService.validateRefreshIntervalSettings(cursor.settings(), clusterSettings);
                                     mdBuilder.put(cursor);
                                 }
                             }
diff --git a/server/src/main/java/org/opensearch/snapshots/Snapshot.java b/server/src/main/java/org/opensearch/snapshots/Snapshot.java
index e7c92195eff08..4dd930c7b59c0 100644
--- a/server/src/main/java/org/opensearch/snapshots/Snapshot.java
+++ b/server/src/main/java/org/opensearch/snapshots/Snapshot.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.snapshots;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -42,8 +43,9 @@
 /**
  * Basic information about a snapshot - a SnapshotId and the repository that the snapshot belongs to.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class Snapshot implements Writeable {
 
     private final String repository;
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotId.java b/server/src/main/java/org/opensearch/snapshots/SnapshotId.java
index aec3aebd93585..4eeb956a0cb19 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotId.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotId.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.snapshots;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -44,8 +45,9 @@
 /**
  * SnapshotId - snapshot name + snapshot UUID
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SnapshotId implements Comparable<SnapshotId>, Writeable, ToXContentObject {
 
     private static final String NAME = "name";
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java b/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java
index 41452671e6a91..191b872cdd563 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java
@@ -35,6 +35,7 @@
 import org.opensearch.action.admin.cluster.snapshots.get.GetSnapshotsRequest;
 import org.opensearch.cluster.SnapshotsInProgress;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
@@ -64,8 +65,9 @@
 /**
  * Information about a snapshot
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class SnapshotInfo implements Comparable<SnapshotInfo>, ToXContent, Writeable {
 
     public static final String CONTEXT_MODE_PARAM = "context_mode";
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotShardFailure.java b/server/src/main/java/org/opensearch/snapshots/SnapshotShardFailure.java
index 9d47a4edbfa22..5efcd5f12e37b 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotShardFailure.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotShardFailure.java
@@ -35,6 +35,7 @@
 import org.opensearch.OpenSearchParseException;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ShardOperationFailedException;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -52,8 +53,9 @@
 /**
  * Stores information about failures that occurred during shard snapshotting process
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotShardFailure extends ShardOperationFailedException {
 
     @Nullable
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotShardSizeInfo.java b/server/src/main/java/org/opensearch/snapshots/SnapshotShardSizeInfo.java
index b5818c5650b3c..6c456be8ca9e3 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotShardSizeInfo.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotShardSizeInfo.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.annotation.PublicApi;
 
 import java.util.Collections;
 import java.util.Map;
@@ -41,8 +42,9 @@
 /**
  * Information about a snapshot shard size
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class SnapshotShardSizeInfo {
 
     public static final SnapshotShardSizeInfo EMPTY = new SnapshotShardSizeInfo(Map.of());
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotShardsService.java b/server/src/main/java/org/opensearch/snapshots/SnapshotShardsService.java
index af2f925f89726..1c25d8c71f948 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotShardsService.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotShardsService.java
@@ -37,6 +37,7 @@
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.apache.lucene.index.IndexCommit;
 import org.opensearch.Version;
+import org.opensearch.action.admin.indices.flush.FlushRequest;
 import org.opensearch.cluster.ClusterChangedEvent;
 import org.opensearch.cluster.ClusterStateListener;
 import org.opensearch.cluster.SnapshotsInProgress;
@@ -73,6 +74,7 @@
 import org.opensearch.transport.TransportService;
 
 import java.io.IOException;
+import java.nio.file.NoSuchFileException;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
@@ -401,18 +403,32 @@ private void snapshot(
             try {
                 if (remoteStoreIndexShallowCopy && indexShard.indexSettings().isRemoteStoreEnabled()) {
                     long startTime = threadPool.relativeTimeInMillis();
+                    long primaryTerm = indexShard.getOperationPrimaryTerm();
                     // we flush first to make sure we get the latest writes snapshotted
                     wrappedSnapshot = indexShard.acquireLastIndexCommitAndRefresh(true);
-                    long primaryTerm = indexShard.getOperationPrimaryTerm();
-                    final IndexCommit snapshotIndexCommit = wrappedSnapshot.get();
+                    IndexCommit snapshotIndexCommit = wrappedSnapshot.get();
                     long commitGeneration = snapshotIndexCommit.getGeneration();
-                    indexShard.acquireLockOnCommitData(snapshot.getSnapshotId().getUUID(), primaryTerm, commitGeneration);
+                    try {
+                        indexShard.acquireLockOnCommitData(snapshot.getSnapshotId().getUUID(), primaryTerm, commitGeneration);
+                    } catch (NoSuchFileException e) {
+                        wrappedSnapshot.close();
+                        logger.warn(
+                            "Exception while acquiring lock on primaryTerm = {} and generation = {}",
+                            primaryTerm,
+                            commitGeneration
+                        );
+                        indexShard.flush(new FlushRequest(shardId.getIndexName()).force(true));
+                        wrappedSnapshot = indexShard.acquireLastIndexCommit(false);
+                        snapshotIndexCommit = wrappedSnapshot.get();
+                        commitGeneration = snapshotIndexCommit.getGeneration();
+                        indexShard.acquireLockOnCommitData(snapshot.getSnapshotId().getUUID(), primaryTerm, commitGeneration);
+                    }
                     try {
                         repository.snapshotRemoteStoreIndexShard(
                             indexShard.store(),
                             snapshot.getSnapshotId(),
                             indexId,
-                            wrappedSnapshot.get(),
+                            snapshotIndexCommit,
                             getShardStateId(indexShard, snapshotIndexCommit),
                             snapshotStatus,
                             primaryTerm,
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotState.java b/server/src/main/java/org/opensearch/snapshots/SnapshotState.java
index dd1b3ebb8404d..7ad838f741a3f 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotState.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotState.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.snapshots;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Represents the state that a snapshot can be in
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public enum SnapshotState {
     /**
      * Snapshot process has started
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java b/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java
index 1f063bfed8cfe..71918bc73b55a 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java
@@ -1565,7 +1565,7 @@ private void runNextQueuedOperation(RepositoryData repositoryData, String reposi
 
     /**
      * Runs a cluster state update that checks whether we have outstanding snapshot deletions that can be executed and executes them.
-     *
+     * <p>
      * TODO: optimize this to execute in a single CS update together with finalizing the latest snapshot
      */
     private void runReadyDeletions(RepositoryData repositoryData, String repository) {
@@ -2758,7 +2758,7 @@ public boolean assertAllListenersResolved() {
      * Every shard snapshot or clone state update can result in multiple snapshots being updated. In order to determine whether or not a
      * shard update has an effect we use an outer loop over all current executing snapshot operations that iterates over them in the order
      * they were started in and an inner loop over the list of shard update tasks.
-     *
+     * <p>
      * If the inner loop finds that a shard update task applies to a given snapshot and either a shard-snapshot or shard-clone operation in
      * it then it will update the state of the snapshot entry accordingly. If that update was a noop, then the task is removed from the
      * iteration as it was already applied before and likely just arrived on the cluster-manager node again due to retries upstream.
@@ -2768,7 +2768,7 @@ public boolean assertAllListenersResolved() {
      * a task in the executed tasks collection applied to a shard it was waiting for to become available, then the shard snapshot operation
      * will be started for that snapshot entry and the task removed from the collection of tasks that need to be applied to snapshot
      * entries since it can not have any further effects.
-     *
+     * <p>
      * Package private to allow for tests.
      */
     static final ClusterStateTaskExecutor<ShardSnapshotUpdate> SHARD_STATE_EXECUTOR = new ClusterStateTaskExecutor<ShardSnapshotUpdate>() {
@@ -3058,7 +3058,7 @@ private static ShardSnapshotStatus startShardSnapshotAfterClone(ClusterState cur
 
     /**
      * An update to the snapshot state of a shard.
-     *
+     * <p>
      * Package private for testing
      */
     static final class ShardSnapshotUpdate {
diff --git a/server/src/main/java/org/opensearch/tasks/Task.java b/server/src/main/java/org/opensearch/tasks/Task.java
index dcd7fc581a8fd..a21a454a65d0e 100644
--- a/server/src/main/java/org/opensearch/tasks/Task.java
+++ b/server/src/main/java/org/opensearch/tasks/Task.java
@@ -32,9 +32,8 @@
 
 package org.opensearch.tasks;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.opensearch.ExceptionsHelper;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.action.ActionResponse;
 import org.opensearch.core.action.NotifyOnceListener;
 import org.opensearch.core.common.io.stream.NamedWriteable;
@@ -62,12 +61,10 @@
 /**
  * Current task information
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class Task {
-
-    private static final Logger logger = LogManager.getLogger(Task.class);
-
     /**
      * The request header to mark tasks with specific ids
      */
@@ -501,7 +498,10 @@ public boolean supportsResourceTracking() {
      * <b>can</b> change this on version upgrade but we should be careful
      * because some statuses (reindex) have become defacto standardized because
      * they are used by systems like Kibana.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public interface Status extends ToXContentObject, NamedWriteable {}
 
     /**
@@ -550,11 +550,11 @@ public int incrementResourceTrackingThreads() {
      * This method is called when threads finish execution, and also when the task is unregistered (to mark the task's
      * own thread as complete). When the active thread count becomes zero, the onTaskResourceTrackingCompleted method
      * is called exactly once on all registered listeners.
-     *
+     * <p>
      * Since a task is unregistered after the message is processed, it implies that the threads responsible to produce
      * the response must have started prior to it (i.e. startThreadResourceTracking called before unregister).
      * This ensures that the number of active threads doesn't drop to zero pre-maturely.
-     *
+     * <p>
      * Rarely, some threads may even start execution after the task is unregistered. As resource stats are piggy-backed
      * with the response, any thread usage info captured after the task is unregistered may be irrelevant.
      *
diff --git a/server/src/main/java/org/opensearch/tasks/TaskCancellation.java b/server/src/main/java/org/opensearch/tasks/TaskCancellation.java
index 9b61b2454b53c..2d152e513f197 100644
--- a/server/src/main/java/org/opensearch/tasks/TaskCancellation.java
+++ b/server/src/main/java/org/opensearch/tasks/TaskCancellation.java
@@ -18,7 +18,7 @@
 /**
  * TaskCancellation represents a task eligible for cancellation.
  * It doesn't guarantee that the task will actually get cancelled or not; that decision is left to the caller.
- *
+ * <p>
  * It contains a list of cancellation reasons along with callbacks that are invoked when cancel() is called.
  *
  * @opensearch.internal
@@ -87,7 +87,7 @@ private void runOnCancelCallbacks() {
 
     /**
      * Returns the sum of all cancellation scores.
-     *
+     * <p>
      * A zero score indicates no reason to cancel the task.
      * A task with a higher score suggests greater possibility of recovering the node when it is cancelled.
      */
diff --git a/server/src/main/java/org/opensearch/tasks/TaskInfo.java b/server/src/main/java/org/opensearch/tasks/TaskInfo.java
index b51240f234e39..3a04e8e4072b2 100644
--- a/server/src/main/java/org/opensearch/tasks/TaskInfo.java
+++ b/server/src/main/java/org/opensearch/tasks/TaskInfo.java
@@ -33,6 +33,7 @@
 package org.opensearch.tasks;
 
 import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
@@ -66,8 +67,9 @@
  * and use in APIs. Instead, immutable and writeable TaskInfo objects are used to represent
  * snapshot information about currently running tasks.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class TaskInfo implements Writeable, ToXContentFragment {
     private final TaskId taskId;
 
diff --git a/server/src/main/java/org/opensearch/tasks/TaskResult.java b/server/src/main/java/org/opensearch/tasks/TaskResult.java
index f42e833f5ca08..846fbde48ea59 100644
--- a/server/src/main/java/org/opensearch/tasks/TaskResult.java
+++ b/server/src/main/java/org/opensearch/tasks/TaskResult.java
@@ -34,6 +34,7 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.client.Requests;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -63,8 +64,9 @@
  * Information about a running task or a task that stored its result. Running tasks just have a {@link #getTask()} while
  * tasks with stored result will have either a {@link #getError()} or {@link #getResponse()}.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public final class TaskResult implements Writeable, ToXContentObject {
     private final boolean completed;
     private final TaskInfo task;
diff --git a/server/src/main/java/org/opensearch/telemetry/TelemetrySettings.java b/server/src/main/java/org/opensearch/telemetry/TelemetrySettings.java
index dc0b04244296f..24dcab98c8870 100644
--- a/server/src/main/java/org/opensearch/telemetry/TelemetrySettings.java
+++ b/server/src/main/java/org/opensearch/telemetry/TelemetrySettings.java
@@ -12,6 +12,7 @@
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
 
 /**
  * Wrapper class to encapsulate tracing related settings
@@ -27,6 +28,20 @@ public class TelemetrySettings {
         Setting.Property.Dynamic
     );
 
+    public static final Setting<Boolean> TRACER_FEATURE_ENABLED_SETTING = Setting.boolSetting(
+        "telemetry.feature.tracer.enabled",
+        false,
+        Setting.Property.NodeScope,
+        Setting.Property.Final
+    );
+
+    public static final Setting<Boolean> METRICS_FEATURE_ENABLED_SETTING = Setting.boolSetting(
+        "telemetry.feature.metrics.enabled",
+        false,
+        Setting.Property.NodeScope,
+        Setting.Property.Final
+    );
+
     /**
      * Probability of sampler
      */
@@ -39,12 +54,27 @@ public class TelemetrySettings {
         Setting.Property.Dynamic
     );
 
+    /**
+     * metrics publish interval in seconds.
+     */
+    public static final Setting<TimeValue> METRICS_PUBLISH_INTERVAL_SETTING = Setting.timeSetting(
+        "telemetry.otel.metrics.publish.interval",
+        TimeValue.timeValueSeconds(60),
+        Setting.Property.NodeScope,
+        Setting.Property.Final
+    );
+
     private volatile boolean tracingEnabled;
     private volatile double samplingProbability;
 
+    private final boolean tracingFeatureEnabled;
+    private final boolean metricsFeatureEnabled;
+
     public TelemetrySettings(Settings settings, ClusterSettings clusterSettings) {
         this.tracingEnabled = TRACER_ENABLED_SETTING.get(settings);
         this.samplingProbability = TRACER_SAMPLER_PROBABILITY.get(settings);
+        this.tracingFeatureEnabled = TRACER_FEATURE_ENABLED_SETTING.get(settings);
+        this.metricsFeatureEnabled = METRICS_FEATURE_ENABLED_SETTING.get(settings);
 
         clusterSettings.addSettingsUpdateConsumer(TRACER_ENABLED_SETTING, this::setTracingEnabled);
         clusterSettings.addSettingsUpdateConsumer(TRACER_SAMPLER_PROBABILITY, this::setSamplingProbability);
@@ -72,4 +102,12 @@ public void setSamplingProbability(double samplingProbability) {
     public double getSamplingProbability() {
         return samplingProbability;
     }
+
+    public boolean isTracingFeatureEnabled() {
+        return tracingFeatureEnabled;
+    }
+
+    public boolean isMetricsFeatureEnabled() {
+        return metricsFeatureEnabled;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/telemetry/metrics/MetricsRegistryFactory.java b/server/src/main/java/org/opensearch/telemetry/metrics/MetricsRegistryFactory.java
new file mode 100644
index 0000000000000..c7e2229c18437
--- /dev/null
+++ b/server/src/main/java/org/opensearch/telemetry/metrics/MetricsRegistryFactory.java
@@ -0,0 +1,76 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.telemetry.Telemetry;
+import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.noop.NoopMetricsRegistry;
+import org.opensearch.telemetry.tracing.Tracer;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.Optional;
+
+/**
+ * {@link MetricsRegistryFactory} represents a single global class that is used to access {@link MetricsRegistry}s.
+ * <p>
+ * The {@link MetricsRegistry} singleton object can be retrieved using MetricsRegistryFactory::getMetricsRegistry. The {@link MetricsRegistryFactory} object
+ * is created during class initialization and cannot subsequently be changed.
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+public class MetricsRegistryFactory implements Closeable {
+
+    private static final Logger logger = LogManager.getLogger(MetricsRegistryFactory.class);
+
+    private final TelemetrySettings telemetrySettings;
+    private final MetricsRegistry metricsRegistry;
+
+    public MetricsRegistryFactory(TelemetrySettings telemetrySettings, Optional<Telemetry> telemetry) {
+        this.telemetrySettings = telemetrySettings;
+        this.metricsRegistry = metricsRegistry(telemetry);
+    }
+
+    /**
+     * Returns the {@link MetricsRegistry} instance
+     *
+     * @return MetricsRegistry instance
+     */
+    public MetricsRegistry getMetricsRegistry() {
+        return metricsRegistry;
+    }
+
+    /**
+     * Closes the {@link Tracer}
+     */
+    @Override
+    public void close() {
+        try {
+            metricsRegistry.close();
+        } catch (IOException e) {
+            logger.warn("Error closing MetricsRegistry", e);
+        }
+    }
+
+    private MetricsRegistry metricsRegistry(Optional<Telemetry> telemetry) {
+        MetricsRegistry metricsRegistry = telemetry.map(Telemetry::getMetricsTelemetry)
+            .map(metricsTelemetry -> createDefaultMetricsRegistry(metricsTelemetry))
+            .orElse(NoopMetricsRegistry.INSTANCE);
+        return metricsRegistry;
+    }
+
+    private MetricsRegistry createDefaultMetricsRegistry(MetricsTelemetry metricsTelemetry) {
+        return new DefaultMetricsRegistry(metricsTelemetry);
+    }
+
+}
diff --git a/server/src/main/java/org/opensearch/telemetry/metrics/NoopMetricsRegistryFactory.java b/server/src/main/java/org/opensearch/telemetry/metrics/NoopMetricsRegistryFactory.java
new file mode 100644
index 0000000000000..5137cb18e2cc0
--- /dev/null
+++ b/server/src/main/java/org/opensearch/telemetry/metrics/NoopMetricsRegistryFactory.java
@@ -0,0 +1,36 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.annotation.InternalApi;
+import org.opensearch.telemetry.metrics.noop.NoopMetricsRegistry;
+
+import java.util.Optional;
+
+/**
+ * No-op implementation of {@link MetricsRegistryFactory}
+ *
+ * @opensearch.internal
+ */
+@InternalApi
+public class NoopMetricsRegistryFactory extends MetricsRegistryFactory {
+    public NoopMetricsRegistryFactory() {
+        super(null, Optional.empty());
+    }
+
+    @Override
+    public MetricsRegistry getMetricsRegistry() {
+        return NoopMetricsRegistry.INSTANCE;
+    }
+
+    @Override
+    public void close() {
+
+    }
+}
diff --git a/server/src/main/java/org/opensearch/telemetry/metrics/package-info.java b/server/src/main/java/org/opensearch/telemetry/metrics/package-info.java
new file mode 100644
index 0000000000000..ad4564e1d7773
--- /dev/null
+++ b/server/src/main/java/org/opensearch/telemetry/metrics/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains classes needed for telemetry.
+ */
+package org.opensearch.telemetry.metrics;
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/AttributeNames.java b/server/src/main/java/org/opensearch/telemetry/tracing/AttributeNames.java
index e86b21ae0fd3b..b6b2cf360d1c5 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/AttributeNames.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/AttributeNames.java
@@ -60,8 +60,38 @@ private AttributeNames() {
      */
     public static final String TRANSPORT_TARGET_HOST = "target_host";
 
+    /**
+     * Transport Service send request local host.
+     */
+    public static final String TRANSPORT_HOST = "host";
+
     /**
      * Action Name.
      */
     public static final String TRANSPORT_ACTION = "action";
+
+    /**
+     * Index Name
+     */
+    public static final String INDEX = "index";
+
+    /**
+     * Shard ID
+     */
+    public static final String SHARD_ID = "shard_id";
+
+    /**
+     * Number of request items in bulk request
+     */
+    public static final String BULK_REQUEST_ITEMS = "bulk_request_items";
+
+    /**
+     * Node ID
+     */
+    public static final String NODE_ID = "node_id";
+
+    /**
+     * Refresh Policy
+     */
+    public static final String REFRESH_POLICY = "refresh_policy";
 }
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/SpanBuilder.java b/server/src/main/java/org/opensearch/telemetry/tracing/SpanBuilder.java
index d247d48389fc8..1dce422943b7a 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/SpanBuilder.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/SpanBuilder.java
@@ -8,11 +8,14 @@
 
 package org.opensearch.telemetry.tracing;
 
+import org.opensearch.action.bulk.BulkShardRequest;
+import org.opensearch.action.support.replication.ReplicatedWriteRequest;
 import org.opensearch.common.annotation.InternalApi;
 import org.opensearch.core.common.Strings;
 import org.opensearch.http.HttpRequest;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.telemetry.tracing.attributes.Attributes;
+import org.opensearch.transport.TcpChannel;
 import org.opensearch.transport.Transport;
 
 import java.util.Arrays;
@@ -45,7 +48,7 @@ private SpanBuilder() {
      * @return context.
      */
     public static SpanCreationContext from(HttpRequest request) {
-        return new SpanCreationContext(createSpanName(request), buildSpanAttributes(request));
+        return SpanCreationContext.server().name(createSpanName(request)).attributes(buildSpanAttributes(request));
     }
 
     /**
@@ -54,7 +57,7 @@ public static SpanCreationContext from(HttpRequest request) {
      * @return context
      */
     public static SpanCreationContext from(RestRequest request) {
-        return new SpanCreationContext(createSpanName(request), buildSpanAttributes(request));
+        return SpanCreationContext.client().name(createSpanName(request)).attributes(buildSpanAttributes(request));
     }
 
     /**
@@ -64,7 +67,11 @@ public static SpanCreationContext from(RestRequest request) {
      * @return context
      */
     public static SpanCreationContext from(String action, Transport.Connection connection) {
-        return new SpanCreationContext(createSpanName(action, connection), buildSpanAttributes(action, connection));
+        return SpanCreationContext.server().name(createSpanName(action, connection)).attributes(buildSpanAttributes(action, connection));
+    }
+
+    public static SpanCreationContext from(String spanName, String nodeId, ReplicatedWriteRequest request) {
+        return SpanCreationContext.server().name(spanName).attributes(buildSpanAttributes(nodeId, request));
     }
 
     private static String createSpanName(HttpRequest httpRequest) {
@@ -127,4 +134,40 @@ private static Attributes buildSpanAttributes(String action, Transport.Connectio
         return attributes;
     }
 
+    /**
+     * Creates {@link SpanCreationContext} from Inbound Handler.
+     * @param action action.
+     * @param tcpChannel tcp channel.
+     * @return context
+     */
+    public static SpanCreationContext from(String action, TcpChannel tcpChannel) {
+        return SpanCreationContext.server().name(createSpanName(action, tcpChannel)).attributes(buildSpanAttributes(action, tcpChannel));
+    }
+
+    private static String createSpanName(String action, TcpChannel tcpChannel) {
+        return action + SEPARATOR + (tcpChannel.getRemoteAddress() != null
+            ? tcpChannel.getRemoteAddress().getHostString()
+            : tcpChannel.getLocalAddress().getHostString());
+    }
+
+    private static Attributes buildSpanAttributes(String action, TcpChannel tcpChannel) {
+        Attributes attributes = Attributes.create().addAttribute(AttributeNames.TRANSPORT_ACTION, action);
+        attributes.addAttribute(AttributeNames.TRANSPORT_HOST, tcpChannel.getLocalAddress().getHostString());
+        return attributes;
+    }
+
+    private static Attributes buildSpanAttributes(String nodeId, ReplicatedWriteRequest request) {
+        Attributes attributes = Attributes.create()
+            .addAttribute(AttributeNames.NODE_ID, nodeId)
+            .addAttribute(AttributeNames.REFRESH_POLICY, request.getRefreshPolicy().getValue());
+        if (request.shardId() != null) {
+            attributes.addAttribute(AttributeNames.INDEX, request.shardId().getIndexName())
+                .addAttribute(AttributeNames.SHARD_ID, request.shardId().getId());
+        }
+        if (request instanceof BulkShardRequest) {
+            attributes.addAttribute(AttributeNames.BULK_REQUEST_ITEMS, ((BulkShardRequest) request).items().length);
+        }
+        return attributes;
+    }
+
 }
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/ThreadContextBasedTracerContextStorage.java b/server/src/main/java/org/opensearch/telemetry/tracing/ThreadContextBasedTracerContextStorage.java
index 208df90f65d74..863f56d9fbe94 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/ThreadContextBasedTracerContextStorage.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/ThreadContextBasedTracerContextStorage.java
@@ -15,7 +15,6 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 
 /**
  * Core's ThreadContext based TracerContextStorage implementation
@@ -79,17 +78,7 @@ public Map<String, String> headers(Map<String, Object> source) {
     }
 
     Span getCurrentSpan(String key) {
-        Optional<Span> optionalSpanFromContext = spanFromThreadContext(key);
-        return optionalSpanFromContext.orElse(spanFromHeader());
-    }
-
-    private Optional<Span> spanFromThreadContext(String key) {
         SpanReference currentSpanRef = threadContext.getTransient(key);
-        return (currentSpanRef == null) ? Optional.empty() : Optional.ofNullable(currentSpanRef.getSpan());
-    }
-
-    private Span spanFromHeader() {
-        Optional<Span> span = tracingTelemetry.getContextPropagator().extract(threadContext.getHeaders());
-        return span.orElse(null);
+        return (currentSpanRef == null) ? null : currentSpanRef.getSpan();
     }
 }
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/TracerFactory.java b/server/src/main/java/org/opensearch/telemetry/tracing/TracerFactory.java
index 1cb73e0247c3a..b0cecb0ee485d 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/TracerFactory.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/TracerFactory.java
@@ -62,6 +62,13 @@ public void close() {
         }
     }
 
+    protected TracerContextStorage<String, Span> createTracerContextStorage(
+        TracingTelemetry tracingTelemetry,
+        ThreadContext threadContext
+    ) {
+        return new ThreadContextBasedTracerContextStorage(threadContext, tracingTelemetry);
+    }
+
     private Tracer tracer(Optional<Telemetry> telemetry, ThreadContext threadContext) {
         return telemetry.map(Telemetry::getTracingTelemetry)
             .map(tracingTelemetry -> createDefaultTracer(tracingTelemetry, threadContext))
@@ -70,10 +77,7 @@ private Tracer tracer(Optional<Telemetry> telemetry, ThreadContext threadContext
     }
 
     private Tracer createDefaultTracer(TracingTelemetry tracingTelemetry, ThreadContext threadContext) {
-        TracerContextStorage<String, Span> tracerContextStorage = new ThreadContextBasedTracerContextStorage(
-            threadContext,
-            tracingTelemetry
-        );
+        TracerContextStorage<String, Span> tracerContextStorage = createTracerContextStorage(tracingTelemetry, threadContext);
         return new DefaultTracer(tracingTelemetry, tracerContextStorage);
     }
 
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/WrappedTracer.java b/server/src/main/java/org/opensearch/telemetry/tracing/WrappedTracer.java
index d8cf39d4a4d09..dfe456a0a6784 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/WrappedTracer.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/WrappedTracer.java
@@ -10,11 +10,10 @@
 
 import org.opensearch.common.annotation.InternalApi;
 import org.opensearch.telemetry.TelemetrySettings;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
 import org.opensearch.telemetry.tracing.noop.NoopTracer;
 
 import java.io.IOException;
-import java.util.List;
+import java.util.Collection;
 import java.util.Map;
 
 /**
@@ -41,17 +40,7 @@ public WrappedTracer(TelemetrySettings telemetrySettings, Tracer defaultTracer)
 
     @Override
     public Span startSpan(SpanCreationContext context) {
-        return startSpan(context.getSpanName(), context.getAttributes());
-    }
-
-    @Override
-    public Span startSpan(String spanName) {
-        return startSpan(spanName, Attributes.EMPTY);
-    }
-
-    @Override
-    public Span startSpan(String spanName, Attributes attributes) {
-        return startSpan(spanName, (SpanContext) null, attributes);
+        return getDelegateTracer().startSpan(context);
     }
 
     @Override
@@ -62,12 +51,7 @@ public SpanContext getCurrentSpan() {
 
     @Override
     public ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext) {
-        return startScopedSpan(spanCreationContext, null);
-    }
-
-    @Override
-    public ScopedSpan startScopedSpan(SpanCreationContext spanCreationContext, SpanContext parentSpan) {
-        return getDelegateTracer().startScopedSpan(spanCreationContext, parentSpan);
+        return getDelegateTracer().startScopedSpan(spanCreationContext);
     }
 
     @Override
@@ -76,9 +60,8 @@ public SpanScope withSpanInScope(Span span) {
     }
 
     @Override
-    public Span startSpan(String spanName, SpanContext parentSpan, Attributes attributes) {
-        Tracer delegateTracer = getDelegateTracer();
-        return delegateTracer.startSpan(spanName, parentSpan, attributes);
+    public boolean isRecording() {
+        return getDelegateTracer().isRecording();
     }
 
     @Override
@@ -92,7 +75,7 @@ Tracer getDelegateTracer() {
     }
 
     @Override
-    public Span startSpan(SpanCreationContext spanCreationContext, Map<String, List<String>> headers) {
+    public Span startSpan(SpanCreationContext spanCreationContext, Map<String, Collection<String>> headers) {
         return defaultTracer.startSpan(spanCreationContext, headers);
     }
 }
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableHttpChannel.java b/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableHttpChannel.java
index 9229d334dea01..e0fb690bd29be 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableHttpChannel.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableHttpChannel.java
@@ -8,7 +8,6 @@
 
 package org.opensearch.telemetry.tracing.channels;
 
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.http.HttpChannel;
 import org.opensearch.http.HttpResponse;
@@ -18,6 +17,7 @@
 
 import java.net.InetSocketAddress;
 import java.util.Objects;
+import java.util.Optional;
 
 /**
  * Tracer wrapped {@link HttpChannel}
@@ -49,13 +49,20 @@ private TraceableHttpChannel(HttpChannel delegate, Span span, Tracer tracer) {
      * @return http channel
      */
     public static HttpChannel create(HttpChannel delegate, Span span, Tracer tracer) {
-        if (FeatureFlags.isEnabled(FeatureFlags.TELEMETRY) == true) {
+        if (tracer.isRecording() == true) {
             return new TraceableHttpChannel(delegate, span, tracer);
         } else {
             return delegate;
         }
     }
 
+    @Override
+    public void handleException(Exception ex) {
+        span.addEvent("The HttpChannel was closed without sending the response");
+        span.setError(ex);
+        span.endSpan();
+    }
+
     @Override
     public void close() {
         delegate.close();
@@ -85,4 +92,9 @@ public InetSocketAddress getLocalAddress() {
     public InetSocketAddress getRemoteAddress() {
         return delegate.getRemoteAddress();
     }
+
+    @Override
+    public <T> Optional<T> get(String name, Class<T> clazz) {
+        return delegate.get(name, clazz);
+    }
 }
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableRestChannel.java b/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableRestChannel.java
index d256c9d4d0e53..32769dd1d848d 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableRestChannel.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableRestChannel.java
@@ -9,7 +9,6 @@
 package org.opensearch.telemetry.tracing.channels;
 
 import org.opensearch.common.io.stream.BytesStreamOutput;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.MediaType;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.rest.RestChannel;
@@ -53,7 +52,7 @@ private TraceableRestChannel(RestChannel delegate, Span span, Tracer tracer) {
      * @return rest channel
      */
     public static RestChannel create(RestChannel delegate, Span span, Tracer tracer) {
-        if (FeatureFlags.isEnabled(FeatureFlags.TELEMETRY) == true) {
+        if (tracer.isRecording() == true) {
             return new TraceableRestChannel(delegate, span, tracer);
         } else {
             return delegate;
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableTcpTransportChannel.java b/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableTcpTransportChannel.java
new file mode 100644
index 0000000000000..45268b4807cd9
--- /dev/null
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/channels/TraceableTcpTransportChannel.java
@@ -0,0 +1,117 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing.channels;
+
+import org.opensearch.Version;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanScope;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.transport.BaseTcpTransportChannel;
+import org.opensearch.transport.TcpTransportChannel;
+import org.opensearch.transport.TransportChannel;
+
+import java.io.IOException;
+import java.util.Optional;
+
+/**
+ * Tracer wrapped {@link TransportChannel}
+ */
+public class TraceableTcpTransportChannel extends BaseTcpTransportChannel {
+
+    private final TransportChannel delegate;
+    private final Span span;
+    private final Tracer tracer;
+
+    /**
+     * Constructor.
+     * @param delegate delegate
+     * @param span span
+     * @param tracer tracer
+     */
+    public TraceableTcpTransportChannel(TcpTransportChannel delegate, Span span, Tracer tracer) {
+        super(delegate.getChannel());
+        this.delegate = delegate;
+        this.span = span;
+        this.tracer = tracer;
+    }
+
+    /**
+     * Factory method.
+     *
+     * @param delegate delegate
+     * @param span     span
+     * @param tracer tracer
+     * @return transport channel
+     */
+    public static TransportChannel create(TcpTransportChannel delegate, final Span span, final Tracer tracer) {
+        if (tracer.isRecording() == true) {
+            delegate.getChannel().addCloseListener(new ActionListener<Void>() {
+                @Override
+                public void onResponse(Void unused) {
+                    onFailure(null);
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                    span.addEvent("The TransportChannel was closed without sending the response");
+                    span.setError(e);
+                    span.endSpan();
+                }
+            });
+
+            return new TraceableTcpTransportChannel(delegate, span, tracer);
+        } else {
+            return delegate;
+        }
+    }
+
+    @Override
+    public String getProfileName() {
+        return delegate.getProfileName();
+    }
+
+    @Override
+    public String getChannelType() {
+        return delegate.getChannelType();
+    }
+
+    @Override
+    public void sendResponse(TransportResponse response) throws IOException {
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            delegate.sendResponse(response);
+        } catch (final IOException ex) {
+            span.setError(ex);
+            throw ex;
+        } finally {
+            span.endSpan();
+        }
+    }
+
+    @Override
+    public void sendResponse(Exception exception) throws IOException {
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            delegate.sendResponse(exception);
+        } finally {
+            span.setError(exception);
+            span.endSpan();
+        }
+    }
+
+    @Override
+    public Version getVersion() {
+        return delegate.getVersion();
+    }
+
+    @Override
+    public <T> Optional<T> get(String name, Class<T> clazz) {
+        return delegate.get(name, clazz);
+    }
+}
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/handler/TraceableTransportResponseHandler.java b/server/src/main/java/org/opensearch/telemetry/tracing/handler/TraceableTransportResponseHandler.java
new file mode 100644
index 0000000000000..eb9d53d2df51b
--- /dev/null
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/handler/TraceableTransportResponseHandler.java
@@ -0,0 +1,107 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing.handler;
+
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanScope;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.transport.TransportException;
+import org.opensearch.transport.TransportResponseHandler;
+
+import java.io.IOException;
+import java.util.Objects;
+
+/**
+ * Tracer wrapped {@link TransportResponseHandler}
+ * @param <T> TransportResponse
+ */
+public class TraceableTransportResponseHandler<T extends TransportResponse> implements TransportResponseHandler<T> {
+
+    private final Span span;
+    private final TransportResponseHandler<T> delegate;
+    private final Tracer tracer;
+
+    /**
+     * Constructor.
+     *
+     * @param delegate delegate
+     * @param span span
+     * @param tracer tracer
+     */
+    private TraceableTransportResponseHandler(TransportResponseHandler<T> delegate, Span span, Tracer tracer) {
+        this.delegate = Objects.requireNonNull(delegate);
+        this.span = Objects.requireNonNull(span);
+        this.tracer = Objects.requireNonNull(tracer);
+    }
+
+    /**
+     * Factory method.
+     * @param delegate delegate
+     * @param span span
+     * @param tracer tracer
+     * @return transportResponseHandler
+     */
+    public static <S extends TransportResponse> TransportResponseHandler<S> create(
+        TransportResponseHandler<S> delegate,
+        Span span,
+        Tracer tracer
+    ) {
+        if (tracer.isRecording() == true) {
+            return new TraceableTransportResponseHandler<S>(delegate, span, tracer);
+        } else {
+            return delegate;
+        }
+    }
+
+    @Override
+    public T read(StreamInput in) throws IOException {
+        return delegate.read(in);
+    }
+
+    @Override
+    public void handleResponse(T response) {
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            delegate.handleResponse(response);
+        } finally {
+            span.endSpan();
+        }
+    }
+
+    @Override
+    public void handleException(TransportException exp) {
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            delegate.handleException(exp);
+        } finally {
+            span.setError(exp);
+            span.endSpan();
+        }
+    }
+
+    @Override
+    public String executor() {
+        return delegate.executor();
+    }
+
+    @Override
+    public String toString() {
+        return delegate.toString();
+    }
+
+    @Override
+    public void handleRejection(Exception exp) {
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            delegate.handleRejection(exp);
+        } finally {
+            span.setError(exp);
+            span.endSpan();
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/handler/package-info.java b/server/src/main/java/org/opensearch/telemetry/tracing/handler/package-info.java
new file mode 100644
index 0000000000000..ff9f8f57dc07c
--- /dev/null
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/handler/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * This package contains classes needed for tracing requests.
+ */
+package org.opensearch.telemetry.tracing.handler;
diff --git a/server/src/main/java/org/opensearch/telemetry/tracing/listener/TraceableActionListener.java b/server/src/main/java/org/opensearch/telemetry/tracing/listener/TraceableActionListener.java
index 3e201641a529b..0cb4ce71d05f8 100644
--- a/server/src/main/java/org/opensearch/telemetry/tracing/listener/TraceableActionListener.java
+++ b/server/src/main/java/org/opensearch/telemetry/tracing/listener/TraceableActionListener.java
@@ -8,7 +8,6 @@
 
 package org.opensearch.telemetry.tracing.listener;
 
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.telemetry.tracing.Span;
 import org.opensearch.telemetry.tracing.SpanScope;
@@ -47,7 +46,7 @@ private TraceableActionListener(ActionListener<Response> delegate, Span span, Tr
      * @return action listener
      */
     public static <Response> ActionListener<Response> create(ActionListener<Response> delegate, Span span, Tracer tracer) {
-        if (FeatureFlags.isEnabled(FeatureFlags.TELEMETRY) == true) {
+        if (tracer.isRecording() == true) {
             return new TraceableActionListener<Response>(delegate, span, tracer);
         } else {
             return delegate;
diff --git a/server/src/main/java/org/opensearch/threadpool/ExecutorBuilder.java b/server/src/main/java/org/opensearch/threadpool/ExecutorBuilder.java
index d26131484ba71..d57b74b3a45e0 100644
--- a/server/src/main/java/org/opensearch/threadpool/ExecutorBuilder.java
+++ b/server/src/main/java/org/opensearch/threadpool/ExecutorBuilder.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.threadpool;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.OpenSearchExecutors;
@@ -44,8 +45,9 @@
  *
  * @param <U> the underlying type of the executor settings
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class ExecutorBuilder<U extends ExecutorBuilder.ExecutorSettings> {
 
     private final String name;
diff --git a/server/src/main/java/org/opensearch/threadpool/Scheduler.java b/server/src/main/java/org/opensearch/threadpool/Scheduler.java
index 86c322ec89dd7..9733db29f5939 100644
--- a/server/src/main/java/org/opensearch/threadpool/Scheduler.java
+++ b/server/src/main/java/org/opensearch/threadpool/Scheduler.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.common.SuppressForbidden;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.concurrent.AbstractRunnable;
@@ -60,7 +61,7 @@ public interface Scheduler {
 
     /**
      * Create a scheduler that can be used client side. Server side, please use <code>ThreadPool.schedule</code> instead.
-     *
+     * <p>
      * Notice that if any scheduled jobs fail with an exception, these will bubble up to the uncaught exception handler where they will
      * be logged as a warning. This includes jobs started using execute, submit and schedule.
      * @param settings the settings to use
@@ -154,7 +155,10 @@ static ScheduledCancellable wrapAsScheduledCancellable(ScheduledFuture<?> schedu
 
     /**
      * This interface represents an object whose execution may be cancelled during runtime.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface Cancellable {
 
         /**
@@ -171,14 +175,17 @@ interface Cancellable {
 
     /**
      * A scheduled cancellable allow cancelling and reading the remaining delay of a scheduled task.
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface ScheduledCancellable extends Delayed, Cancellable {}
 
     /**
      * This class encapsulates the scheduling of a {@link Runnable} that needs to be repeated on a interval. For example, checking a value
      * for cleanup every second could be done by passing in a Runnable that can perform the check and the specified interval between
      * executions of this runnable. <em>NOTE:</em> the runnable is only rescheduled to run again after completion of the runnable.
-     *
+     * <p>
      * For this class, <i>completion</i> means that the call to {@link Runnable#run()} returned or an exception was thrown and caught. In
      * case of an exception, this class will log the exception and reschedule the runnable for its next execution. This differs from the
      * {@link ScheduledThreadPoolExecutor#scheduleWithFixedDelay(Runnable, long, long, TimeUnit)} semantics as an exception there would
diff --git a/server/src/main/java/org/opensearch/threadpool/TaskAwareRunnable.java b/server/src/main/java/org/opensearch/threadpool/TaskAwareRunnable.java
index 183b9b2f4cf9a..90f50f78d84ad 100644
--- a/server/src/main/java/org/opensearch/threadpool/TaskAwareRunnable.java
+++ b/server/src/main/java/org/opensearch/threadpool/TaskAwareRunnable.java
@@ -25,7 +25,7 @@
 /**
  * Responsible for wrapping the original task's runnable and sending updates on when it starts and finishes to
  * entities listening to the events.
- *
+ * <p>
  * It's able to associate runnable with a task with the help of task Id available in thread context.
  */
 public class TaskAwareRunnable extends AbstractRunnable implements WrappedRunnable {
diff --git a/server/src/main/java/org/opensearch/threadpool/ThreadPool.java b/server/src/main/java/org/opensearch/threadpool/ThreadPool.java
index 6ddf3ff6b2f6a..12052598d3671 100644
--- a/server/src/main/java/org/opensearch/threadpool/ThreadPool.java
+++ b/server/src/main/java/org/opensearch/threadpool/ThreadPool.java
@@ -115,14 +115,16 @@ public static class Names {
         public static final String TRANSLOG_SYNC = "translog_sync";
         public static final String REMOTE_PURGE = "remote_purge";
         public static final String REMOTE_REFRESH_RETRY = "remote_refresh_retry";
+        public static final String REMOTE_RECOVERY = "remote_recovery";
         public static final String INDEX_SEARCHER = "index_searcher";
     }
 
     /**
      * The threadpool type.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum ThreadPoolType {
         DIRECT("direct"),
         FIXED("fixed"),
@@ -184,6 +186,7 @@ public static ThreadPoolType fromType(String type) {
         map.put(Names.TRANSLOG_SYNC, ThreadPoolType.FIXED);
         map.put(Names.REMOTE_PURGE, ThreadPoolType.SCALING);
         map.put(Names.REMOTE_REFRESH_RETRY, ThreadPoolType.SCALING);
+        map.put(Names.REMOTE_RECOVERY, ThreadPoolType.SCALING);
         if (FeatureFlags.isEnabled(FeatureFlags.CONCURRENT_SEGMENT_SEARCH)) {
             map.put(Names.INDEX_SEARCHER, ThreadPoolType.RESIZABLE);
         }
@@ -228,6 +231,7 @@ public ThreadPool(
 
         final Map<String, ExecutorBuilder> builders = new HashMap<>();
         final int allocatedProcessors = OpenSearchExecutors.allocatedProcessors(settings);
+        final int halfProc = halfAllocatedProcessors(allocatedProcessors);
         final int halfProcMaxAt5 = halfAllocatedProcessorsMaxFive(allocatedProcessors);
         final int halfProcMaxAt10 = halfAllocatedProcessorsMaxTen(allocatedProcessors);
         final int genericThreadPoolMax = boundedBy(4 * allocatedProcessors, 128, 512);
@@ -261,13 +265,22 @@ public ThreadPool(
         builders.put(Names.SYSTEM_WRITE, new FixedExecutorBuilder(settings, Names.SYSTEM_WRITE, halfProcMaxAt5, 1000, false));
         builders.put(
             Names.TRANSLOG_TRANSFER,
-            new ScalingExecutorBuilder(Names.TRANSLOG_TRANSFER, 1, halfProcMaxAt10, TimeValue.timeValueMinutes(5))
+            new ScalingExecutorBuilder(Names.TRANSLOG_TRANSFER, 1, halfProc, TimeValue.timeValueMinutes(5))
         );
         builders.put(Names.TRANSLOG_SYNC, new FixedExecutorBuilder(settings, Names.TRANSLOG_SYNC, allocatedProcessors * 4, 10000));
-        builders.put(Names.REMOTE_PURGE, new ScalingExecutorBuilder(Names.REMOTE_PURGE, 1, halfProcMaxAt5, TimeValue.timeValueMinutes(5)));
+        builders.put(Names.REMOTE_PURGE, new ScalingExecutorBuilder(Names.REMOTE_PURGE, 1, halfProc, TimeValue.timeValueMinutes(5)));
         builders.put(
             Names.REMOTE_REFRESH_RETRY,
-            new ScalingExecutorBuilder(Names.REMOTE_REFRESH_RETRY, 1, halfProcMaxAt10, TimeValue.timeValueMinutes(5))
+            new ScalingExecutorBuilder(Names.REMOTE_REFRESH_RETRY, 1, halfProc, TimeValue.timeValueMinutes(5))
+        );
+        builders.put(
+            Names.REMOTE_RECOVERY,
+            new ScalingExecutorBuilder(
+                Names.REMOTE_RECOVERY,
+                1,
+                twiceAllocatedProcessors(allocatedProcessors),
+                TimeValue.timeValueMinutes(5)
+            )
         );
         if (FeatureFlags.isEnabled(FeatureFlags.CONCURRENT_SEGMENT_SEARCH)) {
             builders.put(
@@ -314,7 +327,7 @@ public ThreadPool(
 
     /**
      * Returns a value of milliseconds that may be used for relative time calculations.
-     *
+     * <p>
      * This method should only be used for calculating time deltas. For an epoch based
      * timestamp, see {@link #absoluteTimeInMillis()}.
      */
@@ -324,7 +337,7 @@ public long relativeTimeInMillis() {
 
     /**
      * Returns a value of nanoseconds that may be used for relative time calculations.
-     *
+     * <p>
      * This method should only be used for calculating time deltas. For an epoch based
      * timestamp, see {@link #absoluteTimeInMillis()}.
      */
@@ -337,7 +350,7 @@ public long relativeTimeInNanos() {
      * that require the highest precision possible. Performance critical code must use
      * either {@link #relativeTimeInNanos()} or {@link #relativeTimeInMillis()} which
      * give better performance at the cost of lower precision.
-     *
+     * <p>
      * This method should only be used for calculating time deltas. For an epoch based
      * timestamp, see {@link #absoluteTimeInMillis()}.
      */
@@ -347,7 +360,7 @@ public long preciseRelativeTimeInNanos() {
 
     /**
      * Returns the value of milliseconds since UNIX epoch.
-     *
+     * <p>
      * This method should only be used for exact date/time formatting. For calculating
      * time deltas that should not suffer from negative deltas, which are possible with
      * this method, see {@link #relativeTimeInMillis()}.
@@ -383,19 +396,21 @@ public ThreadPoolStats stats() {
             long rejected = -1;
             int largest = -1;
             long completed = -1;
-            if (holder.executor() instanceof ThreadPoolExecutor) {
-                ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) holder.executor();
+            long waitTimeNanos = -1;
+            if (holder.executor() instanceof OpenSearchThreadPoolExecutor) {
+                OpenSearchThreadPoolExecutor threadPoolExecutor = (OpenSearchThreadPoolExecutor) holder.executor();
                 threads = threadPoolExecutor.getPoolSize();
                 queue = threadPoolExecutor.getQueue().size();
                 active = threadPoolExecutor.getActiveCount();
                 largest = threadPoolExecutor.getLargestPoolSize();
                 completed = threadPoolExecutor.getCompletedTaskCount();
+                waitTimeNanos = threadPoolExecutor.getPoolWaitTimeNanos();
                 RejectedExecutionHandler rejectedExecutionHandler = threadPoolExecutor.getRejectedExecutionHandler();
                 if (rejectedExecutionHandler instanceof XRejectedExecutionHandler) {
                     rejected = ((XRejectedExecutionHandler) rejectedExecutionHandler).rejected();
                 }
             }
-            stats.add(new ThreadPoolStats.Stats(name, threads, queue, active, rejected, largest, completed));
+            stats.add(new ThreadPoolStats.Stats(name, threads, queue, active, rejected, largest, completed, waitTimeNanos));
         }
         return new ThreadPoolStats(stats);
     }
@@ -541,6 +556,10 @@ static int boundedBy(int value, int min, int max) {
         return Math.min(max, Math.max(min, value));
     }
 
+    static int halfAllocatedProcessors(int allocatedProcessors) {
+        return (allocatedProcessors + 1) / 2;
+    }
+
     static int halfAllocatedProcessorsMaxFive(final int allocatedProcessors) {
         return boundedBy((allocatedProcessors + 1) / 2, 1, 5);
     }
@@ -641,7 +660,7 @@ public String toString() {
     /**
      * A thread to cache millisecond time values from
      * {@link System#nanoTime()} and {@link System#currentTimeMillis()}.
-     *
+     * <p>
      * The values are updated at a specified interval.
      */
     static class CachedTimeThread extends Thread {
@@ -721,8 +740,9 @@ ExecutorService executor() {
     /**
      * The thread pool information.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Info implements Writeable, ToXContentFragment {
 
         private final String name;
diff --git a/server/src/main/java/org/opensearch/threadpool/ThreadPoolInfo.java b/server/src/main/java/org/opensearch/threadpool/ThreadPoolInfo.java
index f49ad34e70119..49d961f0b506f 100644
--- a/server/src/main/java/org/opensearch/threadpool/ThreadPoolInfo.java
+++ b/server/src/main/java/org/opensearch/threadpool/ThreadPoolInfo.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.threadpool;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.service.ReportingService;
@@ -45,8 +46,9 @@
 /**
  * Information about a threadpool
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ThreadPoolInfo implements ReportingService.Info, Iterable<ThreadPool.Info> {
 
     private final List<ThreadPool.Info> infos;
diff --git a/server/src/main/java/org/opensearch/threadpool/ThreadPoolStats.java b/server/src/main/java/org/opensearch/threadpool/ThreadPoolStats.java
index b4d7e4a3fbf7a..968c2cc4c4887 100644
--- a/server/src/main/java/org/opensearch/threadpool/ThreadPoolStats.java
+++ b/server/src/main/java/org/opensearch/threadpool/ThreadPoolStats.java
@@ -32,6 +32,9 @@
 
 package org.opensearch.threadpool;
 
+import org.opensearch.Version;
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -47,15 +50,17 @@
 /**
  * Stats for a threadpool
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class ThreadPoolStats implements Writeable, ToXContentFragment, Iterable<ThreadPoolStats.Stats> {
 
     /**
      * The statistics.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Stats implements Writeable, ToXContentFragment, Comparable<Stats> {
 
         private final String name;
@@ -65,8 +70,9 @@ public static class Stats implements Writeable, ToXContentFragment, Comparable<S
         private final long rejected;
         private final int largest;
         private final long completed;
+        private final long waitTimeNanos;
 
-        public Stats(String name, int threads, int queue, int active, long rejected, int largest, long completed) {
+        public Stats(String name, int threads, int queue, int active, long rejected, int largest, long completed, long waitTimeNanos) {
             this.name = name;
             this.threads = threads;
             this.queue = queue;
@@ -74,6 +80,7 @@ public Stats(String name, int threads, int queue, int active, long rejected, int
             this.rejected = rejected;
             this.largest = largest;
             this.completed = completed;
+            this.waitTimeNanos = waitTimeNanos;
         }
 
         public Stats(StreamInput in) throws IOException {
@@ -84,6 +91,7 @@ public Stats(StreamInput in) throws IOException {
             rejected = in.readLong();
             largest = in.readInt();
             completed = in.readLong();
+            waitTimeNanos = in.getVersion().onOrAfter(Version.V_2_11_0) ? in.readLong() : -1;
         }
 
         @Override
@@ -95,6 +103,9 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeLong(rejected);
             out.writeInt(largest);
             out.writeLong(completed);
+            if (out.getVersion().onOrAfter(Version.V_2_11_0)) {
+                out.writeLong(waitTimeNanos);
+            }
         }
 
         public String getName() {
@@ -125,6 +136,14 @@ public long getCompleted() {
             return this.completed;
         }
 
+        public TimeValue getWaitTime() {
+            return TimeValue.timeValueNanos(waitTimeNanos);
+        }
+
+        public long getWaitTimeNanos() {
+            return waitTimeNanos;
+        }
+
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
             builder.startObject(name);
@@ -146,6 +165,12 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             if (completed != -1) {
                 builder.field(Fields.COMPLETED, completed);
             }
+            if (waitTimeNanos != -1) {
+                if (builder.humanReadable()) {
+                    builder.field(Fields.WAIT_TIME, getWaitTime());
+                }
+                builder.field(Fields.WAIT_TIME_NANOS, getWaitTimeNanos());
+            }
             builder.endObject();
             return builder;
         }
@@ -197,6 +222,8 @@ static final class Fields {
         static final String REJECTED = "rejected";
         static final String LARGEST = "largest";
         static final String COMPLETED = "completed";
+        static final String WAIT_TIME = "total_wait_time";
+        static final String WAIT_TIME_NANOS = "total_wait_time_in_nanos";
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/transport/BaseTcpTransportChannel.java b/server/src/main/java/org/opensearch/transport/BaseTcpTransportChannel.java
new file mode 100644
index 0000000000000..14e065d3350c7
--- /dev/null
+++ b/server/src/main/java/org/opensearch/transport/BaseTcpTransportChannel.java
@@ -0,0 +1,33 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.transport;
+
+/**
+ * Base class TcpTransportChannel
+ */
+public abstract class BaseTcpTransportChannel implements TransportChannel {
+    private final TcpChannel channel;
+
+    /**
+     * Constructor.
+     * @param channel tcp channel
+     */
+    public BaseTcpTransportChannel(TcpChannel channel) {
+        this.channel = channel;
+    }
+
+    /**
+     * Returns {@link TcpChannel}
+     * @return TcpChannel
+     */
+    public TcpChannel getChannel() {
+        return channel;
+    }
+
+}
diff --git a/server/src/main/java/org/opensearch/transport/CompressibleBytesOutputStream.java b/server/src/main/java/org/opensearch/transport/CompressibleBytesOutputStream.java
index 5cb169439a14d..57707d3b44477 100644
--- a/server/src/main/java/org/opensearch/transport/CompressibleBytesOutputStream.java
+++ b/server/src/main/java/org/opensearch/transport/CompressibleBytesOutputStream.java
@@ -48,11 +48,11 @@
  * requires that the underlying {@link DeflaterOutputStream} be closed to write EOS bytes. However, the
  * {@link BytesStream} should not be closed yet, as we have not used the bytes. This class handles these
  * intricacies.
- *
+ * <p>
  * {@link CompressibleBytesOutputStream#materializeBytes()} should be called when all the bytes have been
  * written to this stream. If compression is enabled, the proper EOS bytes will be written at that point.
  * The underlying {@link BytesReference} will be returned.
- *
+ * <p>
  * {@link CompressibleBytesOutputStream#close()} will NOT close the underlying stream. The byte stream passed
  * in the constructor must be closed individually.
  *
diff --git a/server/src/main/java/org/opensearch/transport/InboundHandler.java b/server/src/main/java/org/opensearch/transport/InboundHandler.java
index 9f9232c18079a..a8315c3cae4e0 100644
--- a/server/src/main/java/org/opensearch/transport/InboundHandler.java
+++ b/server/src/main/java/org/opensearch/transport/InboundHandler.java
@@ -46,12 +46,21 @@
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanBuilder;
+import org.opensearch.telemetry.tracing.SpanScope;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.telemetry.tracing.channels.TraceableTcpTransportChannel;
 import org.opensearch.threadpool.ThreadPool;
 
 import java.io.EOFException;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.nio.ByteBuffer;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+import java.util.stream.Collectors;
 
 /**
  * Handler for inbound data
@@ -74,6 +83,8 @@ public class InboundHandler {
 
     private volatile long slowLogThresholdMs = Long.MAX_VALUE;
 
+    private final Tracer tracer;
+
     InboundHandler(
         ThreadPool threadPool,
         OutboundHandler outboundHandler,
@@ -81,7 +92,8 @@ public class InboundHandler {
         TransportHandshaker handshaker,
         TransportKeepAlive keepAlive,
         Transport.RequestHandlers requestHandlers,
-        Transport.ResponseHandlers responseHandlers
+        Transport.ResponseHandlers responseHandlers,
+        Tracer tracer
     ) {
         this.threadPool = threadPool;
         this.outboundHandler = outboundHandler;
@@ -90,6 +102,7 @@ public class InboundHandler {
         this.keepAlive = keepAlive;
         this.requestHandlers = requestHandlers;
         this.responseHandlers = responseHandlers;
+        this.tracer = tracer;
     }
 
     void setMessageListener(TransportMessageListener listener) {
@@ -108,7 +121,6 @@ void inboundMessage(TcpChannel channel, InboundMessage message) throws Exception
         final long startTime = threadPool.relativeTimeInMillis();
         channel.getChannelStats().markAccessed(startTime);
         TransportLogger.logInboundMessage(channel, message);
-
         if (message.isPing()) {
             keepAlive.receiveKeepAlive(channel);
         } else {
@@ -123,7 +135,6 @@ private void messageReceived(TcpChannel channel, InboundMessage message, long st
         final InetSocketAddress remoteAddress = channel.getRemoteAddress();
         final Header header = message.getHeader();
         assert header.needsToReadVariableHeader() == false;
-
         ThreadContext threadContext = threadPool.getThreadContext();
         try (ThreadContext.StoredContext existing = threadContext.stashContext()) {
             // Place the context with the headers from the message
@@ -165,6 +176,7 @@ private void messageReceived(TcpChannel channel, InboundMessage message, long st
                         handleResponse(requestId, remoteAddress, EMPTY_STREAM_INPUT, handler);
                     }
                 }
+
             }
         } finally {
             final long took = threadPool.relativeTimeInMillis() - startTime;
@@ -180,84 +192,98 @@ private void messageReceived(TcpChannel channel, InboundMessage message, long st
         }
     }
 
+    private Map<String, Collection<String>> extractHeaders(Map<String, String> headers) {
+        return headers.entrySet().stream().collect(Collectors.toMap(e -> e.getKey(), e -> Collections.singleton(e.getValue())));
+    }
+
     private <T extends TransportRequest> void handleRequest(TcpChannel channel, Header header, InboundMessage message) throws IOException {
         final String action = header.getActionName();
         final long requestId = header.getRequestId();
         final Version version = header.getVersion();
-        if (header.isHandshake()) {
-            messageListener.onRequestReceived(requestId, action);
-            // Cannot short circuit handshakes
-            assert message.isShortCircuit() == false;
-            final StreamInput stream = namedWriteableStream(message.openOrGetStreamInput());
-            assertRemoteVersion(stream, header.getVersion());
-            final TransportChannel transportChannel = new TcpTransportChannel(
-                outboundHandler,
-                channel,
-                action,
-                requestId,
-                version,
-                header.getFeatures(),
-                header.isCompressed(),
-                header.isHandshake(),
-                message.takeBreakerReleaseControl()
-            );
-            try {
-                handshaker.handleHandshake(transportChannel, requestId, stream);
-            } catch (Exception e) {
-                if (Version.CURRENT.isCompatible(header.getVersion())) {
-                    sendErrorResponse(action, transportChannel, e);
-                } else {
-                    logger.warn(
-                        new ParameterizedMessage(
-                            "could not send error response to handshake received on [{}] using wire format version [{}], closing channel",
-                            channel,
-                            header.getVersion()
-                        ),
-                        e
-                    );
-                    channel.close();
-                }
-            }
-        } else {
-            final TransportChannel transportChannel = new TcpTransportChannel(
-                outboundHandler,
-                channel,
-                action,
-                requestId,
-                version,
-                header.getFeatures(),
-                header.isCompressed(),
-                header.isHandshake(),
-                message.takeBreakerReleaseControl()
-            );
-            try {
+        final Map<String, Collection<String>> headers = extractHeaders(header.getHeaders().v1());
+        Span span = tracer.startSpan(SpanBuilder.from(action, channel), headers);
+        try (SpanScope spanScope = tracer.withSpanInScope(span)) {
+            if (header.isHandshake()) {
                 messageListener.onRequestReceived(requestId, action);
-                if (message.isShortCircuit()) {
-                    sendErrorResponse(action, transportChannel, message.getException());
-                } else {
-                    final StreamInput stream = namedWriteableStream(message.openOrGetStreamInput());
-                    assertRemoteVersion(stream, header.getVersion());
-                    final RequestHandlerRegistry<T> reg = requestHandlers.getHandler(action);
-                    assert reg != null;
-
-                    final T request = newRequest(requestId, action, stream, reg);
-                    request.remoteAddress(new TransportAddress(channel.getRemoteAddress()));
-                    checkStreamIsFullyConsumed(requestId, action, stream);
-
-                    final String executor = reg.getExecutor();
-                    if (ThreadPool.Names.SAME.equals(executor)) {
-                        try {
-                            reg.processMessageReceived(request, transportChannel);
-                        } catch (Exception e) {
-                            sendErrorResponse(reg.getAction(), transportChannel, e);
-                        }
+                // Cannot short circuit handshakes
+                assert message.isShortCircuit() == false;
+                final StreamInput stream = namedWriteableStream(message.openOrGetStreamInput());
+                assertRemoteVersion(stream, header.getVersion());
+                final TcpTransportChannel transportChannel = new TcpTransportChannel(
+                    outboundHandler,
+                    channel,
+                    action,
+                    requestId,
+                    version,
+                    header.getFeatures(),
+                    header.isCompressed(),
+                    header.isHandshake(),
+                    message.takeBreakerReleaseControl()
+                );
+                TransportChannel traceableTransportChannel = TraceableTcpTransportChannel.create(transportChannel, span, tracer);
+                try {
+                    handshaker.handleHandshake(traceableTransportChannel, requestId, stream);
+                } catch (Exception e) {
+                    if (Version.CURRENT.isCompatible(header.getVersion())) {
+                        sendErrorResponse(action, traceableTransportChannel, e);
                     } else {
-                        threadPool.executor(executor).execute(new RequestHandler<>(reg, request, transportChannel));
+                        logger.warn(
+                            new ParameterizedMessage(
+                                "could not send error response to handshake received on [{}] using wire format version [{}], closing channel",
+                                channel,
+                                header.getVersion()
+                            ),
+                            e
+                        );
+                        channel.close();
                     }
                 }
-            } catch (Exception e) {
-                sendErrorResponse(action, transportChannel, e);
+            } else {
+                final TcpTransportChannel transportChannel = new TcpTransportChannel(
+                    outboundHandler,
+                    channel,
+                    action,
+                    requestId,
+                    version,
+                    header.getFeatures(),
+                    header.isCompressed(),
+                    header.isHandshake(),
+                    message.takeBreakerReleaseControl()
+                );
+                TransportChannel traceableTransportChannel = TraceableTcpTransportChannel.create(transportChannel, span, tracer);
+                try {
+                    messageListener.onRequestReceived(requestId, action);
+                    if (message.isShortCircuit()) {
+                        sendErrorResponse(action, traceableTransportChannel, message.getException());
+                    } else {
+                        final StreamInput stream = namedWriteableStream(message.openOrGetStreamInput());
+                        assertRemoteVersion(stream, header.getVersion());
+                        final RequestHandlerRegistry<T> reg = requestHandlers.getHandler(action);
+                        assert reg != null;
+
+                        final T request = newRequest(requestId, action, stream, reg);
+                        request.remoteAddress(new TransportAddress(channel.getRemoteAddress()));
+                        checkStreamIsFullyConsumed(requestId, action, stream);
+
+                        final String executor = reg.getExecutor();
+                        if (ThreadPool.Names.SAME.equals(executor)) {
+                            try {
+                                reg.processMessageReceived(request, traceableTransportChannel);
+                            } catch (Exception e) {
+                                sendErrorResponse(reg.getAction(), traceableTransportChannel, e);
+                            }
+                        } else {
+                            threadPool.executor(executor).execute(new RequestHandler<>(reg, request, traceableTransportChannel));
+                        }
+                    }
+                } catch (Exception e) {
+                    sendErrorResponse(action, traceableTransportChannel, e);
+                }
             }
+        } catch (Exception e) {
+            span.setError(e);
+            span.endSpan();
+            throw e;
         }
     }
 
diff --git a/server/src/main/java/org/opensearch/transport/ProxyConnectionStrategy.java b/server/src/main/java/org/opensearch/transport/ProxyConnectionStrategy.java
index e914542023ad9..b4477edaba687 100644
--- a/server/src/main/java/org/opensearch/transport/ProxyConnectionStrategy.java
+++ b/server/src/main/java/org/opensearch/transport/ProxyConnectionStrategy.java
@@ -309,7 +309,7 @@ public void onResponse(Void v) {
 
                     @Override
                     public void onFailure(Exception e) {
-                        logger.debug(
+                        logger.error(
                             new ParameterizedMessage(
                                 "failed to open remote connection [remote cluster: {}, address: {}]",
                                 clusterAlias,
diff --git a/server/src/main/java/org/opensearch/transport/RemoteClusterConnection.java b/server/src/main/java/org/opensearch/transport/RemoteClusterConnection.java
index 1599c4cb75517..8a5f6dfffb036 100644
--- a/server/src/main/java/org/opensearch/transport/RemoteClusterConnection.java
+++ b/server/src/main/java/org/opensearch/transport/RemoteClusterConnection.java
@@ -54,10 +54,10 @@
  * current node is part of the cluster and it won't receive cluster state updates from the remote cluster. Remote clusters are also not
  * fully connected with the current node. From a connection perspective a local cluster forms a bi-directional star network while in the
  * remote case we only connect to a subset of the nodes in the cluster in an uni-directional fashion.
- *
+ * <p>
  * This class also handles the discovery of nodes from the remote cluster. The initial list of seed nodes is only used to discover all nodes
  * in the remote cluster and connects to all eligible nodes, for details see {@link RemoteClusterService#REMOTE_NODE_ATTRIBUTE}.
- *
+ * <p>
  * In the case of a disconnection, this class will issue a re-connect task to establish at most
  * {@link SniffConnectionStrategy#REMOTE_CONNECTIONS_PER_CLUSTER} until either all eligible nodes are exhausted or the maximum number of
  * connections per cluster has been reached.
@@ -123,7 +123,7 @@ void ensureConnected(ActionListener<Void> listener) {
     /**
      * Collects all nodes on the connected cluster and returns / passes a nodeID to {@link DiscoveryNode} lookup function
      * that returns <code>null</code> if the node ID is not found.
-     *
+     * <p>
      * The requests to get cluster state on the connected cluster are made in the system context because logically
      * they are equivalent to checking a single detail in the local cluster state and should not require that the
      * user who made the request that is using this method in its implementation is authorized to view the entire
diff --git a/server/src/main/java/org/opensearch/transport/RemoteClusterService.java b/server/src/main/java/org/opensearch/transport/RemoteClusterService.java
index 35691cc5f8a1e..87786fb22f22e 100644
--- a/server/src/main/java/org/opensearch/transport/RemoteClusterService.java
+++ b/server/src/main/java/org/opensearch/transport/RemoteClusterService.java
@@ -270,7 +270,7 @@ protected void updateRemoteCluster(String clusterAlias, Settings settings) {
             // are on the cluster state thread and our custom future implementation will throw an
             // assertion.
             if (latch.await(10, TimeUnit.SECONDS) == false) {
-                logger.warn("failed to connect to new remote cluster {} within {}", clusterAlias, TimeValue.timeValueSeconds(10));
+                logger.error("failed to connect to new remote cluster {} within {}", clusterAlias, TimeValue.timeValueSeconds(10));
             }
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
diff --git a/server/src/main/java/org/opensearch/transport/RequestHandlerRegistry.java b/server/src/main/java/org/opensearch/transport/RequestHandlerRegistry.java
index 464282730d2b2..98c182c562928 100644
--- a/server/src/main/java/org/opensearch/transport/RequestHandlerRegistry.java
+++ b/server/src/main/java/org/opensearch/transport/RequestHandlerRegistry.java
@@ -91,14 +91,14 @@ public void processMessageReceived(Request request, TransportChannel channel) th
 
         Releasable unregisterTask = () -> taskManager.unregister(task);
         try {
-            if (channel instanceof TcpTransportChannel && task instanceof CancellableTask) {
+            if (channel instanceof BaseTcpTransportChannel && task instanceof CancellableTask) {
                 if (request instanceof ShardSearchRequest) {
                     // on receiving request, update the inbound network time to reflect time spent in transit over the network
                     ((ShardSearchRequest) request).setInboundNetworkTime(
                         Math.max(0, System.currentTimeMillis() - ((ShardSearchRequest) request).getInboundNetworkTime())
                     );
                 }
-                final TcpChannel tcpChannel = ((TcpTransportChannel) channel).getChannel();
+                final TcpChannel tcpChannel = ((BaseTcpTransportChannel) channel).getChannel();
                 final Releasable stopTracking = taskManager.startTrackingCancellableChannelTask(tcpChannel, (CancellableTask) task);
                 unregisterTask = Releasables.wrap(unregisterTask, stopTracking);
             }
diff --git a/server/src/main/java/org/opensearch/transport/TaskTransportChannel.java b/server/src/main/java/org/opensearch/transport/TaskTransportChannel.java
index 052611317f174..4dab0039ec878 100644
--- a/server/src/main/java/org/opensearch/transport/TaskTransportChannel.java
+++ b/server/src/main/java/org/opensearch/transport/TaskTransportChannel.java
@@ -37,6 +37,7 @@
 import org.opensearch.core.transport.TransportResponse;
 
 import java.io.IOException;
+import java.util.Optional;
 
 /**
  * Transport channel for tasks
@@ -89,4 +90,9 @@ public Version getVersion() {
     public TransportChannel getChannel() {
         return channel;
     }
+
+    @Override
+    public <T> Optional<T> get(String name, Class<T> clazz) {
+        return getChannel().get(name, clazz);
+    }
 }
diff --git a/server/src/main/java/org/opensearch/transport/TcpChannel.java b/server/src/main/java/org/opensearch/transport/TcpChannel.java
index eac137ec30f1a..f98b65d0a4df1 100644
--- a/server/src/main/java/org/opensearch/transport/TcpChannel.java
+++ b/server/src/main/java/org/opensearch/transport/TcpChannel.java
@@ -38,6 +38,7 @@
 import org.opensearch.core.common.bytes.BytesReference;
 
 import java.net.InetSocketAddress;
+import java.util.Optional;
 
 /**
  * This is a tcp channel representing a single channel connection to another node. It is the base channel
@@ -96,6 +97,20 @@ public interface TcpChannel extends CloseableChannel {
      */
     ChannelStats getChannelStats();
 
+    /**
+     * Returns the contextual property associated with this specific TCP channel (the
+     * implementation of how such properties are managed depends on the the particular
+     * transport engine).
+     *
+     * @param name the name of the property
+     * @param clazz the expected type of the property
+     *
+     * @return the value of the property
+     */
+    default <T> Optional<T> get(String name, Class<T> clazz) {
+        return Optional.empty();
+    }
+
     /**
      * Channel statistics
      *
diff --git a/server/src/main/java/org/opensearch/transport/TcpTransport.java b/server/src/main/java/org/opensearch/transport/TcpTransport.java
index 7da7dcad13120..d0e6516973382 100644
--- a/server/src/main/java/org/opensearch/transport/TcpTransport.java
+++ b/server/src/main/java/org/opensearch/transport/TcpTransport.java
@@ -68,6 +68,7 @@
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.monitor.jvm.JvmInfo;
 import org.opensearch.node.Node;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
@@ -159,7 +160,8 @@ public TcpTransport(
         PageCacheRecycler pageCacheRecycler,
         CircuitBreakerService circuitBreakerService,
         NamedWriteableRegistry namedWriteableRegistry,
-        NetworkService networkService
+        NetworkService networkService,
+        Tracer tracer
     ) {
         this.settings = settings;
         this.profileSettings = getProfileSettings(settings);
@@ -208,7 +210,8 @@ public TcpTransport(
             handshaker,
             keepAlive,
             requestHandlers,
-            responseHandlers
+            responseHandlers,
+            tracer
         );
     }
 
diff --git a/server/src/main/java/org/opensearch/transport/TcpTransportChannel.java b/server/src/main/java/org/opensearch/transport/TcpTransportChannel.java
index 00702d08902a9..81de0af07ea7c 100644
--- a/server/src/main/java/org/opensearch/transport/TcpTransportChannel.java
+++ b/server/src/main/java/org/opensearch/transport/TcpTransportChannel.java
@@ -38,6 +38,7 @@
 import org.opensearch.search.query.QuerySearchResult;
 
 import java.io.IOException;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -46,11 +47,10 @@
  *
  * @opensearch.internal
  */
-public final class TcpTransportChannel implements TransportChannel {
+public final class TcpTransportChannel extends BaseTcpTransportChannel {
 
     private final AtomicBoolean released = new AtomicBoolean();
     private final OutboundHandler outboundHandler;
-    private final TcpChannel channel;
     private final String action;
     private final long requestId;
     private final Version version;
@@ -70,9 +70,9 @@ public final class TcpTransportChannel implements TransportChannel {
         boolean isHandshake,
         Releasable breakerRelease
     ) {
+        super(channel);
         this.version = version;
         this.features = features;
-        this.channel = channel;
         this.outboundHandler = outboundHandler;
         this.action = action;
         this.requestId = requestId;
@@ -83,7 +83,7 @@ public final class TcpTransportChannel implements TransportChannel {
 
     @Override
     public String getProfileName() {
-        return channel.getProfile();
+        return getChannel().getProfile();
     }
 
     @Override
@@ -93,7 +93,7 @@ public void sendResponse(TransportResponse response) throws IOException {
                 // update outbound network time with current time before sending response over network
                 ((QuerySearchResult) response).getShardSearchRequest().setOutboundNetworkTime(System.currentTimeMillis());
             }
-            outboundHandler.sendResponse(version, features, channel, requestId, action, response, compressResponse, isHandshake);
+            outboundHandler.sendResponse(version, features, getChannel(), requestId, action, response, compressResponse, isHandshake);
         } finally {
             release(false);
         }
@@ -102,7 +102,7 @@ public void sendResponse(TransportResponse response) throws IOException {
     @Override
     public void sendResponse(Exception exception) throws IOException {
         try {
-            outboundHandler.sendErrorResponse(version, features, channel, requestId, action, exception);
+            outboundHandler.sendErrorResponse(version, features, getChannel(), requestId, action, exception);
         } finally {
             release(true);
         }
@@ -131,7 +131,8 @@ public Version getVersion() {
         return version;
     }
 
-    public TcpChannel getChannel() {
-        return channel;
+    @Override
+    public <T> Optional<T> get(String name, Class<T> clazz) {
+        return getChannel().get(name, clazz);
     }
 }
diff --git a/server/src/main/java/org/opensearch/transport/Transport.java b/server/src/main/java/org/opensearch/transport/Transport.java
index f516f64d7ee26..8abedff37db14 100644
--- a/server/src/main/java/org/opensearch/transport/Transport.java
+++ b/server/src/main/java/org/opensearch/transport/Transport.java
@@ -34,6 +34,7 @@
 
 import org.opensearch.Version;
 import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.collect.MapBuilder;
 import org.opensearch.common.lifecycle.LifecycleComponent;
 import org.opensearch.common.unit.TimeValue;
@@ -111,7 +112,10 @@ default boolean isSecure() {
 
     /**
      * A unidirectional connection to a {@link DiscoveryNode}
+     *
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     interface Connection extends Closeable {
         /**
          * The node this connection is associated with
diff --git a/server/src/main/java/org/opensearch/transport/TransportChannel.java b/server/src/main/java/org/opensearch/transport/TransportChannel.java
index 3c582127f28e8..f84ee5dc745c3 100644
--- a/server/src/main/java/org/opensearch/transport/TransportChannel.java
+++ b/server/src/main/java/org/opensearch/transport/TransportChannel.java
@@ -39,6 +39,7 @@
 import org.opensearch.core.transport.TransportResponse;
 
 import java.io.IOException;
+import java.util.Optional;
 
 /**
  * A transport channel allows to send a response to a request on the channel.
@@ -78,4 +79,18 @@ static void sendErrorResponse(TransportChannel channel, String actionName, Trans
             );
         }
     }
+
+    /**
+     * Returns the contextual property associated with this specific transport channel (the
+     * implementation of how such properties are managed depends on the particular
+     * transport engine).
+     *
+     * @param name the name of the property
+     * @param clazz the expected type of the property
+     *
+     * @return the value of the property.
+     */
+    default <T> Optional<T> get(String name, Class<T> clazz) {
+        return Optional.empty();
+    }
 }
diff --git a/server/src/main/java/org/opensearch/transport/TransportException.java b/server/src/main/java/org/opensearch/transport/TransportException.java
index 1522f2378bca3..5e557a77ff704 100644
--- a/server/src/main/java/org/opensearch/transport/TransportException.java
+++ b/server/src/main/java/org/opensearch/transport/TransportException.java
@@ -33,6 +33,7 @@
 package org.opensearch.transport;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 
 import java.io.IOException;
@@ -40,8 +41,9 @@
 /**
  * Thrown for any transport errors
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TransportException extends OpenSearchException {
     public TransportException(Throwable cause) {
         super(cause);
diff --git a/server/src/main/java/org/opensearch/transport/TransportInterceptor.java b/server/src/main/java/org/opensearch/transport/TransportInterceptor.java
index 9ee2db6d39893..e8efbeb7de3f9 100644
--- a/server/src/main/java/org/opensearch/transport/TransportInterceptor.java
+++ b/server/src/main/java/org/opensearch/transport/TransportInterceptor.java
@@ -35,6 +35,7 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.core.common.io.stream.Writeable.Reader;
 import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
 
 /**
  * This interface allows plugins to intercept requests on both the sender and the receiver side.
@@ -57,6 +58,19 @@ default <T extends TransportRequest> TransportRequestHandler<T> interceptHandler
         return actualHandler;
     }
 
+    /**
+     * This is called for handlers that needs admission control support
+     */
+    default <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+        String action,
+        String executor,
+        boolean forceExecution,
+        TransportRequestHandler<T> actualHandler,
+        AdmissionControlActionType admissionControlActionType
+    ) {
+        return interceptHandler(action, executor, forceExecution, actualHandler);
+    }
+
     /**
      * This is called up-front providing the actual low level {@link AsyncSender} that performs the low level send request.
      * The returned sender is used to send all requests that come in via
diff --git a/server/src/main/java/org/opensearch/transport/TransportRequest.java b/server/src/main/java/org/opensearch/transport/TransportRequest.java
index f13b460dfb0c3..c62cf59d3be2f 100644
--- a/server/src/main/java/org/opensearch/transport/TransportRequest.java
+++ b/server/src/main/java/org/opensearch/transport/TransportRequest.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.transport;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.tasks.TaskId;
@@ -43,8 +44,9 @@
 /**
  * A transport request
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public abstract class TransportRequest extends TransportMessage implements TaskAwareRequest {
     /**
      * Empty transport request
diff --git a/server/src/main/java/org/opensearch/transport/TransportRequestOptions.java b/server/src/main/java/org/opensearch/transport/TransportRequestOptions.java
index fe54d8185ea5f..9f44d93f0cd71 100644
--- a/server/src/main/java/org/opensearch/transport/TransportRequestOptions.java
+++ b/server/src/main/java/org/opensearch/transport/TransportRequestOptions.java
@@ -32,13 +32,15 @@
 
 package org.opensearch.transport;
 
+import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.unit.TimeValue;
 
 /**
  * Options for transport requests
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class TransportRequestOptions {
 
     private final TimeValue timeout;
@@ -62,8 +64,9 @@ public Type type() {
     /**
      * Type of transport request
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Type {
         RECOVERY,
         BULK,
@@ -79,8 +82,9 @@ public static Builder builder() {
     /**
      * Builder for transport request options
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public static class Builder {
         private TimeValue timeout;
         private Type type = Type.REG;
diff --git a/server/src/main/java/org/opensearch/transport/TransportResponseHandler.java b/server/src/main/java/org/opensearch/transport/TransportResponseHandler.java
index 0b39983cc3bee..8992af18edb48 100644
--- a/server/src/main/java/org/opensearch/transport/TransportResponseHandler.java
+++ b/server/src/main/java/org/opensearch/transport/TransportResponseHandler.java
@@ -52,6 +52,13 @@ public interface TransportResponseHandler<T extends TransportResponse> extends W
 
     String executor();
 
+    /**
+     * This method should be handling the rejection/failure scenarios where connection to the node is rejected or failed.
+     * It should be used to clear up the resources held by the {@link TransportResponseHandler}.
+     * @param exp exception
+     */
+    default void handleRejection(Exception exp) {}
+
     default <Q extends TransportResponse> TransportResponseHandler<Q> wrap(Function<Q, T> converter, Writeable.Reader<Q> reader) {
         final TransportResponseHandler<T> self = this;
         return new TransportResponseHandler<Q>() {
diff --git a/server/src/main/java/org/opensearch/transport/TransportService.java b/server/src/main/java/org/opensearch/transport/TransportService.java
index 52274872e8cc8..a1697b1898eeb 100644
--- a/server/src/main/java/org/opensearch/transport/TransportService.java
+++ b/server/src/main/java/org/opensearch/transport/TransportService.java
@@ -64,9 +64,14 @@
 import org.opensearch.core.service.ReportingService;
 import org.opensearch.core.transport.TransportResponse;
 import org.opensearch.node.NodeClosedException;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
 import org.opensearch.tasks.Task;
 import org.opensearch.tasks.TaskManager;
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanBuilder;
+import org.opensearch.telemetry.tracing.SpanScope;
 import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.telemetry.tracing.handler.TraceableTransportResponseHandler;
 import org.opensearch.threadpool.Scheduler;
 import org.opensearch.threadpool.ThreadPool;
 
@@ -166,12 +171,12 @@ public void close() {}
     };
 
     static {
-        /**
-         * Registers server specific types as a streamables for serialization
-         * over the {@link StreamOutput} and {@link StreamInput} wire
+        /*
+          Registers server specific types as a streamables for serialization
+          over the {@link StreamOutput} and {@link StreamInput} wire
          */
         Streamables.registerStreamables();
-        /** Registers OpenSearch server specific exceptions (exceptions outside of core library) */
+        /* Registers OpenSearch server specific exceptions (exceptions outside of core library) */
         OpenSearchServerException.registerExceptions();
     }
 
@@ -333,6 +338,7 @@ protected void doStop() {
                 getExecutorService().execute(new AbstractRunnable() {
                     @Override
                     public void onRejection(Exception e) {
+                        holderToNotify.handler().handleRejection(e);
                         // if we get rejected during node shutdown we don't wanna bubble it up
                         logger.debug(
                             () -> new ParameterizedMessage(
@@ -345,6 +351,7 @@ public void onRejection(Exception e) {
 
                     @Override
                     public void onFailure(Exception e) {
+                        holderToNotify.handler().handleRejection(e);
                         logger.warn(
                             () -> new ParameterizedMessage(
                                 "failed to notify response handler on exception, action: {}",
@@ -861,53 +868,19 @@ public final <T extends TransportResponse> void sendRequest(
         final TransportRequestOptions options,
         final TransportResponseHandler<T> handler
     ) {
-        try {
-            logger.debug("Action: " + action);
-            final TransportResponseHandler<T> delegate;
-            if (request.getParentTask().isSet()) {
-                // TODO: capture the connection instead so that we can cancel child tasks on the remote connections.
-                final Releasable unregisterChildNode = taskManager.registerChildNode(request.getParentTask().getId(), connection.getNode());
-                delegate = new TransportResponseHandler<T>() {
-                    @Override
-                    public void handleResponse(T response) {
-                        unregisterChildNode.close();
-                        handler.handleResponse(response);
-                    }
-
-                    @Override
-                    public void handleException(TransportException exp) {
-                        unregisterChildNode.close();
-                        handler.handleException(exp);
-                    }
-
-                    @Override
-                    public String executor() {
-                        return handler.executor();
-                    }
-
-                    @Override
-                    public T read(StreamInput in) throws IOException {
-                        return handler.read(in);
-                    }
-
-                    @Override
-                    public String toString() {
-                        return getClass().getName() + "/[" + action + "]:" + handler.toString();
-                    }
-                };
-            } else {
-                delegate = handler;
-            }
-            asyncSender.sendRequest(connection, action, request, options, delegate);
-        } catch (final Exception ex) {
-            // the caller might not handle this so we invoke the handler
-            final TransportException te;
-            if (ex instanceof TransportException) {
-                te = (TransportException) ex;
-            } else {
-                te = new TransportException("failure to send", ex);
+        if (connection == localNodeConnection) {
+            // See please https://github.com/opensearch-project/OpenSearch/issues/10291
+            sendRequestAsync(connection, action, request, options, handler);
+        } else {
+            final Span span = tracer.startSpan(SpanBuilder.from(action, connection));
+            try (SpanScope spanScope = tracer.withSpanInScope(span)) {
+                TransportResponseHandler<T> traceableTransportResponseHandler = TraceableTransportResponseHandler.create(
+                    handler,
+                    span,
+                    tracer
+                );
+                sendRequestAsync(connection, action, request, options, traceableTransportResponseHandler);
             }
-            handler.handleException(te);
         }
     }
 
@@ -1017,6 +990,7 @@ private <T extends TransportResponse> void sendRequestInternal(
                 threadPool.executor(executor).execute(new AbstractRunnable() {
                     @Override
                     public void onRejection(Exception e) {
+                        contextToNotify.handler().handleRejection(e);
                         // if we get rejected during node shutdown we don't wanna bubble it up
                         logger.debug(
                             () -> new ParameterizedMessage(
@@ -1029,6 +1003,7 @@ public void onRejection(Exception e) {
 
                     @Override
                     public void onFailure(Exception e) {
+                        contextToNotify.handler().handleRejection(e);
                         logger.warn(
                             () -> new ParameterizedMessage(
                                 "failed to notify response handler on exception, action: {}",
@@ -1226,6 +1201,40 @@ public <Request extends TransportRequest> void registerRequestHandler(
         transport.registerRequestHandler(reg);
     }
 
+    /**
+     * Registers a new request handler with admission control support
+     *
+     * @param action                The action the request handler is associated with
+     * @param executor              The executor the request handling will be executed on
+     * @param forceExecution        Force execution on the executor queue and never reject it
+     * @param canTripCircuitBreaker Check the request size and raise an exception in case the limit is breached.
+     * @param admissionControlActionType Admission control based on resource usage limits of provided action type
+     * @param requestReader               The request class that will be used to construct new instances for streaming
+     * @param handler               The handler itself that implements the request handling
+     */
+    public <Request extends TransportRequest> void registerRequestHandler(
+        String action,
+        String executor,
+        boolean forceExecution,
+        boolean canTripCircuitBreaker,
+        AdmissionControlActionType admissionControlActionType,
+        Writeable.Reader<Request> requestReader,
+        TransportRequestHandler<Request> handler
+    ) {
+        validateActionName(action);
+        handler = interceptor.interceptHandler(action, executor, forceExecution, handler, admissionControlActionType);
+        RequestHandlerRegistry<Request> reg = new RequestHandlerRegistry<>(
+            action,
+            requestReader,
+            taskManager,
+            handler,
+            executor,
+            forceExecution,
+            canTripCircuitBreaker
+        );
+        transport.registerRequestHandler(reg);
+    }
+
     /**
      * called by the {@link Transport} implementation when an incoming request arrives but before
      * any parsing of it has happened (with the exception of the requestId and action)
@@ -1675,4 +1684,61 @@ public void onResponseReceived(long requestId, Transport.ResponseContext holder)
             }
         }
     }
+
+    private <T extends TransportResponse> void sendRequestAsync(
+        final Transport.Connection connection,
+        final String action,
+        final TransportRequest request,
+        final TransportRequestOptions options,
+        final TransportResponseHandler<T> handler
+    ) {
+        try {
+            logger.debug("Action: " + action);
+            final TransportResponseHandler<T> delegate;
+            if (request.getParentTask().isSet()) {
+                // TODO: capture the connection instead so that we can cancel child tasks on the remote connections.
+                final Releasable unregisterChildNode = taskManager.registerChildNode(request.getParentTask().getId(), connection.getNode());
+                delegate = new TransportResponseHandler<T>() {
+                    @Override
+                    public void handleResponse(T response) {
+                        unregisterChildNode.close();
+                        handler.handleResponse(response);
+                    }
+
+                    @Override
+                    public void handleException(TransportException exp) {
+                        unregisterChildNode.close();
+                        handler.handleException(exp);
+                    }
+
+                    @Override
+                    public String executor() {
+                        return handler.executor();
+                    }
+
+                    @Override
+                    public T read(StreamInput in) throws IOException {
+                        return handler.read(in);
+                    }
+
+                    @Override
+                    public String toString() {
+                        return getClass().getName() + "/[" + action + "]:" + handler.toString();
+                    }
+                };
+            } else {
+                delegate = handler;
+            }
+            asyncSender.sendRequest(connection, action, request, options, delegate);
+        } catch (final Exception ex) {
+            // the caller might not handle this so we invoke the handler
+            final TransportException te;
+            if (ex instanceof TransportException) {
+                te = (TransportException) ex;
+            } else {
+                te = new TransportException("failure to send", ex);
+            }
+            handler.handleException(te);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/watcher/FileWatcher.java b/server/src/main/java/org/opensearch/watcher/FileWatcher.java
index 82f95d6a1622c..d773e3b5d7c9e 100644
--- a/server/src/main/java/org/opensearch/watcher/FileWatcher.java
+++ b/server/src/main/java/org/opensearch/watcher/FileWatcher.java
@@ -44,7 +44,7 @@
 
 /**
  * File resources watcher
- *
+ * <p>
  * The file watcher checks directory and all its subdirectories for file changes and notifies its listeners accordingly
  *
  * @opensearch.internal
diff --git a/server/src/main/java/org/opensearch/watcher/ResourceWatcher.java b/server/src/main/java/org/opensearch/watcher/ResourceWatcher.java
index 0c656c52388df..a54ba60815883 100644
--- a/server/src/main/java/org/opensearch/watcher/ResourceWatcher.java
+++ b/server/src/main/java/org/opensearch/watcher/ResourceWatcher.java
@@ -31,6 +31,8 @@
 
 package org.opensearch.watcher;
 
+import org.opensearch.common.annotation.PublicApi;
+
 import java.io.IOException;
 
 /**
@@ -39,8 +41,9 @@
  * Different resource watchers can be registered with {@link ResourceWatcherService} to be called
  * periodically in order to check for changes in different external resources.
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public interface ResourceWatcher {
     /**
      * Called once when the resource watcher is added to {@link ResourceWatcherService}
diff --git a/server/src/main/java/org/opensearch/watcher/ResourceWatcherService.java b/server/src/main/java/org/opensearch/watcher/ResourceWatcherService.java
index 9b9c00cd4252f..519d7c6e68a57 100644
--- a/server/src/main/java/org/opensearch/watcher/ResourceWatcherService.java
+++ b/server/src/main/java/org/opensearch/watcher/ResourceWatcherService.java
@@ -49,7 +49,7 @@
 
 /**
  * Generic resource watcher service
- *
+ * <p>
  * Other opensearch services can register their resource watchers with this service using {@link #add(ResourceWatcher)}
  * method. This service will call {@link org.opensearch.watcher.ResourceWatcher#checkAndNotify()} method of all
  * registered watcher periodically. The frequency of checks can be specified using {@code resource.reload.interval} setting, which
@@ -64,8 +64,9 @@ public class ResourceWatcherService implements Closeable {
     /**
      * Frequency level to watch.
      *
-     * @opensearch.internal
+     * @opensearch.api
      */
+    @PublicApi(since = "1.0.0")
     public enum Frequency {
 
         /**
diff --git a/server/src/main/java/org/opensearch/watcher/WatcherHandle.java b/server/src/main/java/org/opensearch/watcher/WatcherHandle.java
index 6890364cd0cd6..dd8f898e11860 100644
--- a/server/src/main/java/org/opensearch/watcher/WatcherHandle.java
+++ b/server/src/main/java/org/opensearch/watcher/WatcherHandle.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.watcher;
 
+import org.opensearch.common.annotation.PublicApi;
+
 /**
  * Handle to a watcher
  *
- * @opensearch.internal
+ * @opensearch.api
  */
+@PublicApi(since = "1.0.0")
 public class WatcherHandle<W extends ResourceWatcher> {
 
     private final ResourceWatcherService.ResourceMonitor monitor;
diff --git a/server/src/test/java/org/opensearch/OpenSearchExceptionTests.java b/server/src/test/java/org/opensearch/OpenSearchExceptionTests.java
index 7546a2d7c898e..d83539a2fef61 100644
--- a/server/src/test/java/org/opensearch/OpenSearchExceptionTests.java
+++ b/server/src/test/java/org/opensearch/OpenSearchExceptionTests.java
@@ -976,7 +976,7 @@ public void testFailureToAndFromXContentWithDetails() throws IOException {
 
     /**
      * Builds a {@link ToXContent} using a JSON XContentBuilder and compares the result to the given json in string format.
-     *
+     * <p>
      * By default, the stack trace of the exception is not rendered. The parameter `errorTrace` forces the stack trace to
      * be rendered like the REST API does when the "error_trace" parameter is set to true.
      */
diff --git a/server/src/test/java/org/opensearch/action/ActionModuleTests.java b/server/src/test/java/org/opensearch/action/ActionModuleTests.java
index deb0bb58a5c4d..8479f011adf48 100644
--- a/server/src/test/java/org/opensearch/action/ActionModuleTests.java
+++ b/server/src/test/java/org/opensearch/action/ActionModuleTests.java
@@ -143,7 +143,7 @@ public void testSetupRestHandlerContainsKnownBuiltin() throws IOException {
             usageService,
             null,
             new IdentityService(Settings.EMPTY, new ArrayList<>()),
-            new ExtensionsManager(Set.of())
+            new ExtensionsManager(Set.of(), new IdentityService(Settings.EMPTY, List.of()))
         );
         actionModule.initRestHandlers(null);
         // At this point the easiest way to confirm that a handler is loaded is to try to register another one on top of it and to fail
diff --git a/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java b/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java
index b50ce17a3d391..b8ab5c935fa34 100644
--- a/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java
+++ b/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java
@@ -34,11 +34,14 @@
 
 import org.opensearch.action.admin.indices.stats.CommonStats;
 import org.opensearch.action.admin.indices.stats.CommonStatsFlags;
+import org.opensearch.action.search.SearchRequestStats;
 import org.opensearch.cluster.coordination.PendingClusterStateStats;
+import org.opensearch.cluster.coordination.PersistedStateStats;
 import org.opensearch.cluster.coordination.PublishClusterStateStats;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.routing.WeightedRoutingStats;
 import org.opensearch.cluster.service.ClusterManagerThrottlingStats;
+import org.opensearch.cluster.service.ClusterStateStats;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.metrics.OperationStats;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -46,8 +49,10 @@
 import org.opensearch.core.indices.breaker.AllCircuitBreakerStats;
 import org.opensearch.core.indices.breaker.CircuitBreakerStats;
 import org.opensearch.discovery.DiscoveryStats;
+import org.opensearch.gateway.remote.RemotePersistenceStats;
 import org.opensearch.http.HttpStats;
 import org.opensearch.index.ReplicationStats;
+import org.opensearch.index.SegmentReplicationRejectionStats;
 import org.opensearch.index.remote.RemoteSegmentStats;
 import org.opensearch.index.remote.RemoteTranslogTransferTracker;
 import org.opensearch.index.translog.RemoteTranslogStats;
@@ -58,7 +63,14 @@
 import org.opensearch.monitor.os.OsStats;
 import org.opensearch.monitor.process.ProcessStats;
 import org.opensearch.node.AdaptiveSelectionStats;
+import org.opensearch.node.NodeResourceUsageStats;
+import org.opensearch.node.NodesResourceUsageStats;
 import org.opensearch.node.ResponseCollectorService;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.AdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.CpuBasedAdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.stats.AdmissionControlStats;
+import org.opensearch.ratelimitting.admissioncontrol.stats.AdmissionControllerStats;
 import org.opensearch.script.ScriptCacheStats;
 import org.opensearch.script.ScriptStats;
 import org.opensearch.test.OpenSearchTestCase;
@@ -68,6 +80,7 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -281,6 +294,10 @@ public void testSerialization() throws IOException {
                     assertEquals(ioStats.getTotalReadOperations(), deserializedIoStats.getTotalReadOperations());
                     assertEquals(ioStats.getTotalWriteKilobytes(), deserializedIoStats.getTotalWriteKilobytes());
                     assertEquals(ioStats.getTotalWriteOperations(), deserializedIoStats.getTotalWriteOperations());
+                    assertEquals(ioStats.getTotalReadTime(), deserializedIoStats.getTotalReadTime());
+                    assertEquals(ioStats.getTotalWriteTime(), deserializedIoStats.getTotalWriteTime());
+                    assertEquals(ioStats.getTotalQueueSize(), deserializedIoStats.getTotalQueueSize());
+                    assertEquals(ioStats.getTotalIOTimeMillis(), deserializedIoStats.getTotalIOTimeMillis());
                     assertEquals(ioStats.getDevicesStats().length, deserializedIoStats.getDevicesStats().length);
                     for (int i = 0; i < ioStats.getDevicesStats().length; i++) {
                         FsInfo.DeviceStats deviceStats = ioStats.getDevicesStats()[i];
@@ -341,6 +358,26 @@ public void testSerialization() throws IOException {
                         assertEquals(queueStats.getTotal(), deserializedDiscoveryStats.getQueueStats().getTotal());
                         assertEquals(queueStats.getPending(), deserializedDiscoveryStats.getQueueStats().getPending());
                     }
+                    ClusterStateStats stateStats = discoveryStats.getClusterStateStats();
+                    if (stateStats == null) {
+                        assertNull(deserializedDiscoveryStats.getClusterStateStats());
+                    } else {
+                        assertEquals(stateStats.getUpdateFailed(), deserializedDiscoveryStats.getClusterStateStats().getUpdateFailed());
+                        assertEquals(stateStats.getUpdateSuccess(), deserializedDiscoveryStats.getClusterStateStats().getUpdateSuccess());
+                        assertEquals(
+                            stateStats.getUpdateTotalTimeInMillis(),
+                            deserializedDiscoveryStats.getClusterStateStats().getUpdateTotalTimeInMillis()
+                        );
+                        assertEquals(1, deserializedDiscoveryStats.getClusterStateStats().getPersistenceStats().size());
+                        PersistedStateStats deserializedRemoteStateStats = deserializedDiscoveryStats.getClusterStateStats()
+                            .getPersistenceStats()
+                            .get(0);
+                        PersistedStateStats remoteStateStats = stateStats.getPersistenceStats().get(0);
+                        assertEquals(remoteStateStats.getStatsName(), deserializedRemoteStateStats.getStatsName());
+                        assertEquals(remoteStateStats.getFailedCount(), deserializedRemoteStateStats.getFailedCount());
+                        assertEquals(remoteStateStats.getSuccessCount(), deserializedRemoteStateStats.getSuccessCount());
+                        assertEquals(remoteStateStats.getTotalTimeInMillis(), deserializedRemoteStateStats.getTotalTimeInMillis());
+                    }
                 }
                 IngestStats ingestStats = nodeStats.getIngestStats();
                 IngestStats deserializedIngestStats = deserializedNodeStats.getIngestStats();
@@ -392,6 +429,35 @@ public void testSerialization() throws IOException {
                         assertEquals(aStats.responseTime, bStats.responseTime, 0.01);
                     });
                 }
+                NodesResourceUsageStats resourceUsageStats = nodeStats.getResourceUsageStats();
+                NodesResourceUsageStats deserializedResourceUsageStats = deserializedNodeStats.getResourceUsageStats();
+                if (resourceUsageStats == null) {
+                    assertNull(deserializedResourceUsageStats);
+                } else {
+                    resourceUsageStats.getNodeIdToResourceUsageStatsMap().forEach((k, v) -> {
+                        NodeResourceUsageStats aResourceUsageStats = resourceUsageStats.getNodeIdToResourceUsageStatsMap().get(k);
+                        NodeResourceUsageStats bResourceUsageStats = deserializedResourceUsageStats.getNodeIdToResourceUsageStatsMap()
+                            .get(k);
+                        assertEquals(
+                            aResourceUsageStats.getMemoryUtilizationPercent(),
+                            bResourceUsageStats.getMemoryUtilizationPercent(),
+                            0.0
+                        );
+                        assertEquals(aResourceUsageStats.getCpuUtilizationPercent(), bResourceUsageStats.getCpuUtilizationPercent(), 0.0);
+                        assertEquals(aResourceUsageStats.getTimestamp(), bResourceUsageStats.getTimestamp());
+                    });
+                }
+                SegmentReplicationRejectionStats segmentReplicationRejectionStats = nodeStats.getSegmentReplicationRejectionStats();
+                SegmentReplicationRejectionStats deserializedSegmentReplicationRejectionStats = deserializedNodeStats
+                    .getSegmentReplicationRejectionStats();
+                if (segmentReplicationRejectionStats == null) {
+                    assertNull(deserializedSegmentReplicationRejectionStats);
+                } else {
+                    assertEquals(
+                        segmentReplicationRejectionStats.getTotalRejectionCount(),
+                        deserializedSegmentReplicationRejectionStats.getTotalRejectionCount()
+                    );
+                }
                 ScriptCacheStats scriptCacheStats = nodeStats.getScriptCacheStats();
                 ScriptCacheStats deserializedScriptCacheStats = deserializedNodeStats.getScriptCacheStats();
                 if (scriptCacheStats == null) {
@@ -479,15 +545,44 @@ public void testSerialization() throws IOException {
                     assertEquals(replicationStats.getTotalBytesBehind(), deserializedReplicationStats.getTotalBytesBehind());
                     assertEquals(replicationStats.getMaxReplicationLag(), deserializedReplicationStats.getMaxReplicationLag());
                 }
+                AdmissionControlStats admissionControlStats = nodeStats.getAdmissionControlStats();
+                AdmissionControlStats deserializedAdmissionControlStats = deserializedNodeStats.getAdmissionControlStats();
+                if (admissionControlStats == null) {
+                    assertNull(deserializedAdmissionControlStats);
+                } else {
+                    assertEquals(
+                        admissionControlStats.getAdmissionControllerStatsList().size(),
+                        deserializedAdmissionControlStats.getAdmissionControllerStatsList().size()
+                    );
+                    AdmissionControllerStats admissionControllerStats = admissionControlStats.getAdmissionControllerStatsList().get(0);
+                    AdmissionControllerStats deserializedAdmissionControllerStats = deserializedAdmissionControlStats
+                        .getAdmissionControllerStatsList()
+                        .get(0);
+                    assertEquals(
+                        admissionControllerStats.getAdmissionControllerName(),
+                        deserializedAdmissionControllerStats.getAdmissionControllerName()
+                    );
+                    assertEquals(1, (long) admissionControllerStats.getRejectionCount().get(AdmissionControlActionType.SEARCH.getType()));
+                    assertEquals(
+                        admissionControllerStats.getRejectionCount().get(AdmissionControlActionType.SEARCH.getType()),
+                        deserializedAdmissionControllerStats.getRejectionCount().get(AdmissionControlActionType.SEARCH.getType())
+                    );
+
+                    assertEquals(2, (long) admissionControllerStats.getRejectionCount().get(AdmissionControlActionType.INDEXING.getType()));
+                    assertEquals(
+                        admissionControllerStats.getRejectionCount().get(AdmissionControlActionType.INDEXING.getType()),
+                        deserializedAdmissionControllerStats.getRejectionCount().get(AdmissionControlActionType.INDEXING.getType())
+                    );
+                }
             }
         }
     }
 
-    public static NodeStats createNodeStats() {
+    public static NodeStats createNodeStats() throws IOException {
         return createNodeStats(false);
     }
 
-    public static NodeStats createNodeStats(boolean remoteStoreStats) {
+    public static NodeStats createNodeStats(boolean remoteStoreStats) throws IOException {
         DiscoveryNode node = new DiscoveryNode(
             "test_node",
             buildNewFakeTransportAddress(),
@@ -602,7 +697,8 @@ public static NodeStats createNodeStats(boolean remoteStoreStats) {
                         randomIntBetween(1, 1000),
                         randomNonNegativeLong(),
                         randomIntBetween(1, 1000),
-                        randomIntBetween(1, 1000)
+                        randomIntBetween(1, 1000),
+                        randomIntBetween(-1, 10)
                     )
                 );
             }
@@ -623,6 +719,10 @@ public static NodeStats createNodeStats(boolean remoteStoreStats) {
                         randomNonNegativeLong(),
                         randomNonNegativeLong(),
                         randomNonNegativeLong(),
+                        randomNonNegativeLong(),
+                        randomNonNegativeLong(),
+                        randomNonNegativeLong(),
+                        randomNonNegativeLong(),
                         null
                     );
                 deviceStatsArray[i] = new FsInfo.DeviceStats(
@@ -633,6 +733,10 @@ public static NodeStats createNodeStats(boolean remoteStoreStats) {
                     randomNonNegativeLong(),
                     randomNonNegativeLong(),
                     randomNonNegativeLong(),
+                    randomNonNegativeLong(),
+                    randomNonNegativeLong(),
+                    randomNonNegativeLong(),
+                    randomNonNegativeLong(),
                     previousDeviceStats
                 );
             }
@@ -679,12 +783,16 @@ public static NodeStats createNodeStats(boolean remoteStoreStats) {
         ScriptStats scriptStats = frequently()
             ? new ScriptStats(randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong())
             : null;
+        ClusterStateStats stateStats = new ClusterStateStats();
+        RemotePersistenceStats remoteStateStats = new RemotePersistenceStats();
+        stateStats.setPersistenceStats(Arrays.asList(remoteStateStats));
         DiscoveryStats discoveryStats = frequently()
             ? new DiscoveryStats(
                 randomBoolean() ? new PendingClusterStateStats(randomInt(), randomInt(), randomInt()) : null,
                 randomBoolean()
                     ? new PublishClusterStateStats(randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong())
-                    : null
+                    : null,
+                randomBoolean() ? stateStats : null
             )
             : null;
         IngestStats ingestStats = null;
@@ -754,11 +862,60 @@ public static NodeStats createNodeStats(boolean remoteStoreStats) {
             }
             adaptiveSelectionStats = new AdaptiveSelectionStats(nodeConnections, nodeStats);
         }
+        NodesResourceUsageStats nodesResourceUsageStats = null;
+        if (frequently()) {
+            int numNodes = randomIntBetween(0, 10);
+            Map<String, Long> nodeConnections = new HashMap<>();
+            Map<String, NodeResourceUsageStats> resourceUsageStatsMap = new HashMap<>();
+            for (int i = 0; i < numNodes; i++) {
+                String nodeId = randomAlphaOfLengthBetween(3, 10);
+                // add outgoing connection info
+                if (frequently()) {
+                    nodeConnections.put(nodeId, randomLongBetween(0, 100));
+                }
+                // add node calculations
+                if (frequently()) {
+                    NodeResourceUsageStats stats = new NodeResourceUsageStats(
+                        nodeId,
+                        System.currentTimeMillis(),
+                        randomDoubleBetween(1.0, 100.0, true),
+                        randomDoubleBetween(1.0, 100.0, true)
+                    );
+                    resourceUsageStatsMap.put(nodeId, stats);
+                }
+            }
+            nodesResourceUsageStats = new NodesResourceUsageStats(resourceUsageStatsMap);
+        }
+        SegmentReplicationRejectionStats segmentReplicationRejectionStats = null;
+        if (frequently()) {
+            segmentReplicationRejectionStats = new SegmentReplicationRejectionStats(randomNonNegativeLong());
+        }
+
         ClusterManagerThrottlingStats clusterManagerThrottlingStats = null;
         if (frequently()) {
             clusterManagerThrottlingStats = new ClusterManagerThrottlingStats();
             clusterManagerThrottlingStats.onThrottle("test-task", randomInt());
         }
+
+        AdmissionControlStats admissionControlStats = null;
+        if (frequently()) {
+            AdmissionController admissionController = new AdmissionController(
+                CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER,
+                null,
+                null
+            ) {
+                @Override
+                public void apply(String action, AdmissionControlActionType admissionControlActionType) {
+                    return;
+                }
+            };
+            admissionController.addRejectionCount(AdmissionControlActionType.SEARCH.getType(), 1);
+            admissionController.addRejectionCount(AdmissionControlActionType.INDEXING.getType(), 2);
+            AdmissionControllerStats stats = new AdmissionControllerStats(admissionController);
+            List<AdmissionControllerStats> statsList = new ArrayList();
+            statsList.add(stats);
+            admissionControlStats = new AdmissionControlStats(statsList);
+        }
         ScriptCacheStats scriptCacheStats = scriptStats != null ? scriptStats.toScriptCacheStats() : null;
 
         WeightedRoutingStats weightedRoutingStats = null;
@@ -785,6 +942,7 @@ public static NodeStats createNodeStats(boolean remoteStoreStats) {
             discoveryStats,
             ingestStats,
             adaptiveSelectionStats,
+            nodesResourceUsageStats,
             scriptCacheStats,
             null,
             null,
@@ -793,15 +951,17 @@ public static NodeStats createNodeStats(boolean remoteStoreStats) {
             weightedRoutingStats,
             null,
             null,
-            null
+            null,
+            segmentReplicationRejectionStats,
+            null,
+            admissionControlStats
         );
     }
 
     private static NodeIndicesStats getNodeIndicesStats(boolean remoteStoreStats) {
         NodeIndicesStats indicesStats = null;
         if (remoteStoreStats) {
-            indicesStats = new NodeIndicesStats(new CommonStats(CommonStatsFlags.ALL), new HashMap<>());
-
+            indicesStats = new NodeIndicesStats(new CommonStats(CommonStatsFlags.ALL), new HashMap<>(), new SearchRequestStats());
             RemoteSegmentStats remoteSegmentStats = indicesStats.getSegments().getRemoteSegmentStats();
             remoteSegmentStats.addUploadBytesStarted(10L);
             remoteSegmentStats.addUploadBytesSucceeded(10L);
@@ -814,6 +974,7 @@ private static NodeIndicesStats getNodeIndicesStats(boolean remoteStoreStats) {
             remoteSegmentStats.setMaxRefreshTimeLag(2L);
             remoteSegmentStats.addTotalUploadTime(20L);
             remoteSegmentStats.addTotalDownloadTime(20L);
+            remoteSegmentStats.addTotalRejections(5L);
 
             RemoteTranslogStats remoteTranslogStats = indicesStats.getTranslog().getRemoteTranslogStats();
             RemoteTranslogStats otherRemoteTranslogStats = new RemoteTranslogStats(getRandomRemoteTranslogTransferTrackerStats());
diff --git a/server/src/test/java/org/opensearch/action/admin/cluster/node/tasks/TaskManagerTestCase.java b/server/src/test/java/org/opensearch/action/admin/cluster/node/tasks/TaskManagerTestCase.java
index 07e149dd72164..a3fa0f9cb16e4 100644
--- a/server/src/test/java/org/opensearch/action/admin/cluster/node/tasks/TaskManagerTestCase.java
+++ b/server/src/test/java/org/opensearch/action/admin/cluster/node/tasks/TaskManagerTestCase.java
@@ -211,7 +211,8 @@ public TestNode(String name, ThreadPool threadPool, Settings settings) {
                     new NetworkService(Collections.emptyList()),
                     PageCacheRecycler.NON_RECYCLING_INSTANCE,
                     new NamedWriteableRegistry(ClusterModule.getNamedWriteables()),
-                    new NoneCircuitBreakerService()
+                    new NoneCircuitBreakerService(),
+                    NoopTracer.INSTANCE
                 ),
                 threadPool,
                 TransportService.NOOP_TRANSPORT_INTERCEPTOR,
diff --git a/server/src/test/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodesTests.java b/server/src/test/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodesTests.java
index a0c45f95ef7c0..40a30342b86b9 100644
--- a/server/src/test/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodesTests.java
+++ b/server/src/test/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodesTests.java
@@ -41,6 +41,7 @@
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.test.OpenSearchTestCase;
 
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Iterator;
@@ -87,7 +88,13 @@ public void testNetworkTypesToXContent() throws Exception {
     }
 
     public void testIngestStats() throws Exception {
-        NodeStats nodeStats = randomValueOtherThanMany(n -> n.getIngestStats() == null, NodeStatsTests::createNodeStats);
+        NodeStats nodeStats = randomValueOtherThanMany(n -> n.getIngestStats() == null, () -> {
+            try {
+                return NodeStatsTests.createNodeStats();
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        });
 
         SortedMap<String, long[]> processorStats = new TreeMap<>();
         nodeStats.getIngestStats().getProcessorStats().values().forEach(stats -> {
diff --git a/server/src/test/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestTests.java b/server/src/test/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestTests.java
index 67846efab2af8..d35c821b41aa0 100644
--- a/server/src/test/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestTests.java
+++ b/server/src/test/java/org/opensearch/action/admin/indices/segments/IndicesSegmentsRequestTests.java
@@ -34,7 +34,7 @@
 
 import org.opensearch.action.support.IndicesOptions;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.indices.IndexClosedException;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.test.InternalSettingsPlugin;
@@ -56,7 +56,7 @@ protected Collection<Class<? extends Plugin>> getPlugins() {
     public void setupIndex() {
         Settings settings = Settings.builder()
             // don't allow any merges so that the num docs is the expected segments
-            .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+            .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
             .build();
         createIndex("test", settings);
 
diff --git a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIndicesThatCannotBeCreatedTests.java b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIndicesThatCannotBeCreatedTests.java
index 9ef0f85893fc8..cf7080ab2fc06 100644
--- a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIndicesThatCannotBeCreatedTests.java
+++ b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIndicesThatCannotBeCreatedTests.java
@@ -54,6 +54,7 @@
 import org.opensearch.index.VersionType;
 import org.opensearch.indices.SystemIndices;
 import org.opensearch.tasks.Task;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.test.VersionUtils;
 import org.opensearch.threadpool.ThreadPool;
@@ -154,7 +155,9 @@ private void indicesThatCannotBeCreatedTestCase(
                 Settings.EMPTY,
                 new ClusterService(Settings.EMPTY, new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS), null)
             ),
-            new SystemIndices(emptyMap())
+            null,
+            new SystemIndices(emptyMap()),
+            NoopTracer.INSTANCE
         ) {
             @Override
             void executeBulk(
diff --git a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIngestTests.java b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIngestTests.java
index 5410d6a88a5b9..141c630b94020 100644
--- a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIngestTests.java
+++ b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionIngestTests.java
@@ -70,6 +70,7 @@
 import org.opensearch.indices.SystemIndices;
 import org.opensearch.ingest.IngestService;
 import org.opensearch.tasks.Task;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.test.VersionUtils;
 import org.opensearch.threadpool.ThreadPool;
@@ -171,7 +172,9 @@ class TestTransportBulkAction extends TransportBulkAction {
                     SETTINGS,
                     new ClusterService(SETTINGS, new ClusterSettings(SETTINGS, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS), null)
                 ),
-                new SystemIndices(emptyMap())
+                null,
+                new SystemIndices(emptyMap()),
+                NoopTracer.INSTANCE
             );
         }
 
diff --git a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTests.java b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTests.java
index 098bd8e8d8cfe..6bbd740df7f9c 100644
--- a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTests.java
+++ b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTests.java
@@ -60,6 +60,7 @@
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.index.IndexingPressureService;
 import org.opensearch.index.VersionType;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.SystemIndexDescriptor;
 import org.opensearch.indices.SystemIndices;
 import org.opensearch.telemetry.tracing.noop.NoopTracer;
@@ -88,6 +89,7 @@
 import static org.opensearch.test.ClusterServiceUtils.createClusterService;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
+import static org.mockito.Mockito.mock;
 
 public class TransportBulkActionTests extends OpenSearchTestCase {
 
@@ -115,7 +117,9 @@ class TestTransportBulkAction extends TransportBulkAction {
                 new Resolver(),
                 new AutoCreateIndex(Settings.EMPTY, clusterService.getClusterSettings(), new Resolver(), new SystemIndices(emptyMap())),
                 new IndexingPressureService(Settings.EMPTY, clusterService),
-                new SystemIndices(emptyMap())
+                mock(IndicesService.class),
+                new SystemIndices(emptyMap()),
+                NoopTracer.INSTANCE
             );
         }
 
diff --git a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTookTests.java b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTookTests.java
index 829eee45cac5b..9d5b4430ea395 100644
--- a/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTookTests.java
+++ b/server/src/test/java/org/opensearch/action/bulk/TransportBulkActionTookTests.java
@@ -280,8 +280,10 @@ static class TestTransportBulkAction extends TransportBulkAction {
                 indexNameExpressionResolver,
                 autoCreateIndex,
                 new IndexingPressureService(Settings.EMPTY, clusterService),
+                null,
                 new SystemIndices(emptyMap()),
-                relativeTimeProvider
+                relativeTimeProvider,
+                NoopTracer.INSTANCE
             );
         }
 
diff --git a/server/src/test/java/org/opensearch/action/bulk/TransportShardBulkActionTests.java b/server/src/test/java/org/opensearch/action/bulk/TransportShardBulkActionTests.java
index fe0fdd07025d9..65b555649b2d0 100644
--- a/server/src/test/java/org/opensearch/action/bulk/TransportShardBulkActionTests.java
+++ b/server/src/test/java/org/opensearch/action/bulk/TransportShardBulkActionTests.java
@@ -88,6 +88,7 @@
 import org.opensearch.index.translog.Translog;
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.SystemIndices;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.threadpool.TestThreadPool;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.threadpool.ThreadPool.Names;
@@ -96,11 +97,15 @@
 import org.opensearch.transport.TransportService;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 import java.util.concurrent.BrokenBarrierException;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.LongSupplier;
 
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -946,6 +951,82 @@ public void testRetries() throws Exception {
         latch.await();
     }
 
+    public void testUpdateWithRetryOnConflict() throws IOException, InterruptedException {
+        IndexSettings indexSettings = new IndexSettings(indexMetadata(), Settings.EMPTY);
+
+        int nItems = randomIntBetween(2, 5);
+        List<BulkItemRequest> items = new ArrayList<>(nItems);
+        for (int i = 0; i < nItems; i++) {
+            int retryOnConflictCount = randomIntBetween(0, 3);
+            logger.debug("Setting retryCount for item {}: {}", i, retryOnConflictCount);
+            UpdateRequest updateRequest = new UpdateRequest("index", "id").doc(Requests.INDEX_CONTENT_TYPE, "field", "value")
+                .retryOnConflict(retryOnConflictCount);
+            items.add(new BulkItemRequest(i, updateRequest));
+        }
+
+        IndexRequest updateResponse = new IndexRequest("index").id("id").source(Requests.INDEX_CONTENT_TYPE, "field", "value");
+
+        Exception err = new VersionConflictEngineException(shardId, "id", "I'm conflicted <(;_;)>");
+        Engine.IndexResult conflictedResult = new Engine.IndexResult(err, 0);
+
+        IndexShard shard = mock(IndexShard.class);
+        when(shard.applyIndexOperationOnPrimary(anyLong(), any(), any(), anyLong(), anyLong(), anyLong(), anyBoolean())).thenAnswer(
+            ir -> conflictedResult
+        );
+        when(shard.indexSettings()).thenReturn(indexSettings);
+        when(shard.shardId()).thenReturn(shardId);
+        when(shard.mapperService()).thenReturn(mock(MapperService.class));
+
+        UpdateHelper updateHelper = mock(UpdateHelper.class);
+        when(updateHelper.prepare(any(), eq(shard), any())).thenReturn(
+            new UpdateHelper.Result(
+                updateResponse,
+                randomBoolean() ? DocWriteResponse.Result.CREATED : DocWriteResponse.Result.UPDATED,
+                Collections.singletonMap("field", "value"),
+                Requests.INDEX_CONTENT_TYPE
+            )
+        );
+
+        BulkShardRequest bulkShardRequest = new BulkShardRequest(shardId, RefreshPolicy.NONE, items.toArray(BulkItemRequest[]::new));
+
+        final CountDownLatch latch = new CountDownLatch(1);
+        Runnable runnable = () -> TransportShardBulkAction.performOnPrimary(
+            bulkShardRequest,
+            shard,
+            updateHelper,
+            threadPool::absoluteTimeInMillis,
+            new NoopMappingUpdatePerformer(),
+            listener -> listener.onResponse(null),
+            new LatchedActionListener<>(ActionTestUtils.assertNoFailureListener(result -> {
+                assertEquals(nItems, result.replicaRequest().items().length);
+                for (BulkItemRequest item : result.replicaRequest().items()) {
+                    assertEquals(VersionConflictEngineException.class, item.getPrimaryResponse().getFailure().getCause().getClass());
+                }
+            }), latch),
+            threadPool,
+            Names.WRITE
+        );
+
+        // execute the runnable on a separate thread so that the infinite loop can be detected
+        new Thread(runnable).start();
+
+        // timeout the request in 10 seconds if there is an infinite loop
+        assertTrue(latch.await(10, TimeUnit.SECONDS));
+
+        items.forEach(item -> {
+            assertEquals(item.getPrimaryResponse().getFailure().getCause().getClass(), VersionConflictEngineException.class);
+
+            // this assertion is based on the assumption that all bulk item requests are updates and are hence calling
+            // UpdateRequest::prepareRequest
+            UpdateRequest updateRequest = (UpdateRequest) item.request();
+            verify(updateHelper, times(updateRequest.retryOnConflict() + 1)).prepare(
+                eq(updateRequest),
+                any(IndexShard.class),
+                any(LongSupplier.class)
+            );
+        });
+    }
+
     public void testForceExecutionOnRejectionAfterMappingUpdate() throws Exception {
         TestThreadPool rejectingThreadPool = new TestThreadPool(
             "TransportShardBulkActionTests#testForceExecutionOnRejectionAfterMappingUpdate",
@@ -1074,7 +1155,8 @@ public void testHandlePrimaryTermValidationRequestWithDifferentAllocationId() {
             mock(IndexingPressureService.class),
             mock(SegmentReplicationPressureService.class),
             mock(RemoteStorePressureService.class),
-            mock(SystemIndices.class)
+            mock(SystemIndices.class),
+            NoopTracer.INSTANCE
         );
         action.handlePrimaryTermValidationRequest(
             new TransportShardBulkAction.PrimaryTermValidationRequest(aId + "-1", 1, shardId),
@@ -1105,7 +1187,8 @@ public void testHandlePrimaryTermValidationRequestWithOlderPrimaryTerm() {
             mock(IndexingPressureService.class),
             mock(SegmentReplicationPressureService.class),
             mock(RemoteStorePressureService.class),
-            mock(SystemIndices.class)
+            mock(SystemIndices.class),
+            NoopTracer.INSTANCE
         );
         action.handlePrimaryTermValidationRequest(
             new TransportShardBulkAction.PrimaryTermValidationRequest(aId, 1, shardId),
@@ -1136,7 +1219,8 @@ public void testHandlePrimaryTermValidationRequestSuccess() {
             mock(IndexingPressureService.class),
             mock(SegmentReplicationPressureService.class),
             mock(RemoteStorePressureService.class),
-            mock(SystemIndices.class)
+            mock(SystemIndices.class),
+            NoopTracer.INSTANCE
         );
         action.handlePrimaryTermValidationRequest(
             new TransportShardBulkAction.PrimaryTermValidationRequest(aId, 1, shardId),
@@ -1178,7 +1262,8 @@ private TransportShardBulkAction createAction() {
             mock(IndexingPressureService.class),
             mock(SegmentReplicationPressureService.class),
             mock(RemoteStorePressureService.class),
-            mock(SystemIndices.class)
+            mock(SystemIndices.class),
+            NoopTracer.INSTANCE
         );
     }
 
diff --git a/server/src/test/java/org/opensearch/action/ingest/SimulatePipelineRequestParsingTests.java b/server/src/test/java/org/opensearch/action/ingest/SimulatePipelineRequestParsingTests.java
index 705fb546a2fed..41f782e308785 100644
--- a/server/src/test/java/org/opensearch/action/ingest/SimulatePipelineRequestParsingTests.java
+++ b/server/src/test/java/org/opensearch/action/ingest/SimulatePipelineRequestParsingTests.java
@@ -85,7 +85,7 @@ public void init() throws IOException {
         when(ingestService.getProcessorFactories()).thenReturn(registry);
     }
 
-    public void testParseUsingPipelineStore(boolean useExplicitType) throws Exception {
+    public void testParseUsingPipelineStore() throws Exception {
         int numDocs = randomIntBetween(1, 10);
 
         Map<String, Object> requestContent = new HashMap<>();
@@ -131,7 +131,7 @@ public void testParseUsingPipelineStore(boolean useExplicitType) throws Exceptio
         assertThat(actualRequest.getPipeline().getProcessors().size(), equalTo(1));
     }
 
-    public void innerTestParseWithProvidedPipeline() throws Exception {
+    public void testParseWithProvidedPipeline() throws Exception {
         int numDocs = randomIntBetween(1, 10);
 
         Map<String, Object> requestContent = new HashMap<>();
@@ -144,17 +144,29 @@ public void innerTestParseWithProvidedPipeline() throws Exception {
             List<IngestDocument.Metadata> fields = Arrays.asList(INDEX, ID, ROUTING, VERSION, VERSION_TYPE, IF_SEQ_NO, IF_PRIMARY_TERM);
             for (IngestDocument.Metadata field : fields) {
                 if (field == VERSION) {
-                    Long value = randomLong();
-                    doc.put(field.getFieldName(), value);
-                    expectedDoc.put(field.getFieldName(), value);
+                    if (randomBoolean()) {
+                        Long value = randomLong();
+                        doc.put(field.getFieldName(), value);
+                        expectedDoc.put(field.getFieldName(), value);
+                    } else {
+                        int value = randomIntBetween(1, 1000000);
+                        doc.put(field.getFieldName(), value);
+                        expectedDoc.put(field.getFieldName(), (long) value);
+                    }
                 } else if (field == VERSION_TYPE) {
                     String value = VersionType.toString(randomFrom(VersionType.INTERNAL, VersionType.EXTERNAL, VersionType.EXTERNAL_GTE));
                     doc.put(field.getFieldName(), value);
                     expectedDoc.put(field.getFieldName(), value);
                 } else if (field == IF_SEQ_NO || field == IF_PRIMARY_TERM) {
-                    Long value = randomNonNegativeLong();
-                    doc.put(field.getFieldName(), value);
-                    expectedDoc.put(field.getFieldName(), value);
+                    if (randomBoolean()) {
+                        Long value = randomNonNegativeLong();
+                        doc.put(field.getFieldName(), value);
+                        expectedDoc.put(field.getFieldName(), value);
+                    } else {
+                        int value = randomIntBetween(1, 1000000);
+                        doc.put(field.getFieldName(), value);
+                        expectedDoc.put(field.getFieldName(), (long) value);
+                    }
                 } else {
                     if (randomBoolean()) {
                         String value = randomAlphaOfLengthBetween(1, 10);
@@ -282,4 +294,40 @@ public void testNotValidDocs() {
         );
         assertThat(e3.getMessage(), containsString("required property is missing"));
     }
+
+    public void testNotValidMetadataFields() {
+        List<IngestDocument.Metadata> fields = Arrays.asList(VERSION, IF_SEQ_NO, IF_PRIMARY_TERM);
+        for (IngestDocument.Metadata field : fields) {
+            String metadataFieldName = field.getFieldName();
+            Map<String, Object> requestContent = new HashMap<>();
+            List<Map<String, Object>> docs = new ArrayList<>();
+            requestContent.put(Fields.DOCS, docs);
+            Map<String, Object> doc = new HashMap<>();
+            doc.put(metadataFieldName, randomAlphaOfLengthBetween(1, 10));
+            doc.put(Fields.SOURCE, Collections.singletonMap(randomAlphaOfLengthBetween(1, 10), randomAlphaOfLengthBetween(1, 10)));
+            docs.add(doc);
+
+            Map<String, Object> pipelineConfig = new HashMap<>();
+            List<Map<String, Object>> processors = new ArrayList<>();
+            Map<String, Object> processorConfig = new HashMap<>();
+            List<Map<String, Object>> onFailureProcessors = new ArrayList<>();
+            int numOnFailureProcessors = randomIntBetween(0, 1);
+            for (int j = 0; j < numOnFailureProcessors; j++) {
+                onFailureProcessors.add(Collections.singletonMap("mock_processor", Collections.emptyMap()));
+            }
+            if (numOnFailureProcessors > 0) {
+                processorConfig.put("on_failure", onFailureProcessors);
+            }
+            processors.add(Collections.singletonMap("mock_processor", processorConfig));
+            pipelineConfig.put("processors", processors);
+
+            requestContent.put(Fields.PIPELINE, pipelineConfig);
+
+            assertThrows(
+                "Failed to parse parameter [" + metadataFieldName + "], only int or long is accepted",
+                IllegalArgumentException.class,
+                () -> SimulatePipelineRequest.parse(requestContent, false, ingestService)
+            );
+        }
+    }
 }
diff --git a/server/src/test/java/org/opensearch/action/resync/TransportResyncReplicationActionTests.java b/server/src/test/java/org/opensearch/action/resync/TransportResyncReplicationActionTests.java
index fbac465f946f4..da87a0a967f53 100644
--- a/server/src/test/java/org/opensearch/action/resync/TransportResyncReplicationActionTests.java
+++ b/server/src/test/java/org/opensearch/action/resync/TransportResyncReplicationActionTests.java
@@ -135,7 +135,8 @@ public void testResyncDoesNotBlockOnPrimaryAction() throws Exception {
                     new NetworkService(emptyList()),
                     PageCacheRecycler.NON_RECYCLING_INSTANCE,
                     new NamedWriteableRegistry(emptyList()),
-                    new NoneCircuitBreakerService()
+                    new NoneCircuitBreakerService(),
+                    NoopTracer.INSTANCE
                 )
             ) {
 
@@ -202,7 +203,8 @@ public void testResyncDoesNotBlockOnPrimaryAction() throws Exception {
                     shardStateAction,
                     new ActionFilters(new HashSet<>()),
                     new IndexingPressureService(Settings.EMPTY, clusterService),
-                    new SystemIndices(emptyMap())
+                    new SystemIndices(emptyMap()),
+                    NoopTracer.INSTANCE
                 );
 
                 assertThat(action.globalBlockLevel(), nullValue());
@@ -255,7 +257,8 @@ private TransportResyncReplicationAction createAction() {
             mock(ShardStateAction.class),
             new ActionFilters(new HashSet<>()),
             mock(IndexingPressureService.class),
-            new SystemIndices(emptyMap())
+            new SystemIndices(emptyMap()),
+            NoopTracer.INSTANCE
         );
     }
 }
diff --git a/server/src/test/java/org/opensearch/action/search/AbstractSearchAsyncActionTests.java b/server/src/test/java/org/opensearch/action/search/AbstractSearchAsyncActionTests.java
index 705479ec21fc1..e17fbab32a12e 100644
--- a/server/src/test/java/org/opensearch/action/search/AbstractSearchAsyncActionTests.java
+++ b/server/src/test/java/org/opensearch/action/search/AbstractSearchAsyncActionTests.java
@@ -38,8 +38,12 @@
 import org.opensearch.cluster.routing.GroupShardsIterator;
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.util.concurrent.AtomicArray;
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.common.breaker.CircuitBreaker;
+import org.opensearch.core.common.breaker.NoopCircuitBreaker;
 import org.opensearch.core.index.Index;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.query.MatchAllQueryBuilder;
@@ -51,7 +55,10 @@
 import org.opensearch.search.internal.ShardSearchContextId;
 import org.opensearch.search.internal.ShardSearchRequest;
 import org.opensearch.search.query.QuerySearchResult;
+import org.opensearch.test.InternalAggregationTestCase;
 import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.Transport;
 import org.junit.After;
 import org.junit.Before;
@@ -65,6 +72,7 @@
 import java.util.UUID;
 import java.util.concurrent.CopyOnWriteArraySet;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
@@ -77,18 +85,21 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 import static org.hamcrest.Matchers.instanceOf;
+import static org.mockito.Mockito.mock;
 
 public class AbstractSearchAsyncActionTests extends OpenSearchTestCase {
 
     private final List<Tuple<String, String>> resolvedNodes = new ArrayList<>();
     private final Set<ShardSearchContextId> releasedContexts = new CopyOnWriteArraySet<>();
     private ExecutorService executor;
+    ThreadPool threadPool;
 
     @Before
     @Override
     public void setUp() throws Exception {
         super.setUp();
         executor = Executors.newFixedThreadPool(1);
+        threadPool = new TestThreadPool(getClass().getName());
     }
 
     @After
@@ -97,6 +108,7 @@ public void tearDown() throws Exception {
         super.tearDown();
         executor.shutdown();
         assertTrue(executor.awaitTermination(1, TimeUnit.SECONDS));
+        ThreadPool.terminate(threadPool, 5, TimeUnit.SECONDS);
     }
 
     private AbstractSearchAsyncAction<SearchPhaseResult> createAction(
@@ -126,6 +138,7 @@ private AbstractSearchAsyncAction<SearchPhaseResult> createAction(
         final AtomicLong expected,
         final SearchShardIterator... shards
     ) {
+
         final Runnable runnable;
         final TransportSearchAction.SearchTimeProvider timeProvider;
         if (controlled) {
@@ -161,7 +174,8 @@ private AbstractSearchAsyncAction<SearchPhaseResult> createAction(
             null,
             results,
             request.getMaxConcurrentShardRequests(),
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         ) {
             @Override
             protected SearchPhase getNextPhase(final SearchPhaseResults<SearchPhaseResult> results, SearchPhaseContext context) {
@@ -313,6 +327,53 @@ public void testSendSearchResponseDisallowPartialFailures() {
         assertEquals(requestIds, releasedContexts);
     }
 
+    public void testOnPhaseFailureAndVerifyListeners() {
+        SearchRequestStats testListener = new SearchRequestStats();
+
+        final List<SearchRequestOperationsListener> requestOperationListeners = new ArrayList<>(List.of(testListener));
+        SearchQueryThenFetchAsyncAction action = createSearchQueryThenFetchAsyncAction(requestOperationListeners);
+        action.start();
+        assertEquals(1, testListener.getPhaseCurrent(action.getSearchPhaseName()));
+        action.onPhaseFailure(new SearchPhase("test") {
+            @Override
+            public void run() {
+
+            }
+        }, "message", null);
+        assertEquals(0, testListener.getPhaseCurrent(action.getSearchPhaseName()));
+        assertEquals(0, testListener.getPhaseTotal(action.getSearchPhaseName()));
+
+        SearchDfsQueryThenFetchAsyncAction searchDfsQueryThenFetchAsyncAction = createSearchDfsQueryThenFetchAsyncAction(
+            requestOperationListeners
+        );
+        searchDfsQueryThenFetchAsyncAction.start();
+        assertEquals(1, testListener.getPhaseCurrent(searchDfsQueryThenFetchAsyncAction.getSearchPhaseName()));
+        searchDfsQueryThenFetchAsyncAction.onPhaseFailure(new SearchPhase("test") {
+            @Override
+            public void run() {
+
+            }
+        }, "message", null);
+        assertEquals(0, testListener.getPhaseCurrent(action.getSearchPhaseName()));
+        assertEquals(0, testListener.getPhaseTotal(action.getSearchPhaseName()));
+
+        FetchSearchPhase fetchPhase = createFetchSearchPhase();
+        ShardId shardId = new ShardId(randomAlphaOfLengthBetween(5, 10), randomAlphaOfLength(10), randomInt());
+        SearchShardIterator searchShardIterator = new SearchShardIterator(null, shardId, Collections.emptyList(), OriginalIndices.NONE);
+        searchShardIterator.resetAndSkip();
+        action.skipShard(searchShardIterator);
+        action.executeNextPhase(action, fetchPhase);
+        assertEquals(1, testListener.getPhaseCurrent(fetchPhase.getSearchPhaseName()));
+        action.onPhaseFailure(new SearchPhase("test") {
+            @Override
+            public void run() {
+
+            }
+        }, "message", null);
+        assertEquals(0, testListener.getPhaseCurrent(fetchPhase.getSearchPhaseName()));
+        assertEquals(0, testListener.getPhaseTotal(fetchPhase.getSearchPhaseName()));
+    }
+
     public void testOnPhaseFailure() {
         SearchRequest searchRequest = new SearchRequest().allowPartialSearchResults(false);
         AtomicReference<Exception> exception = new AtomicReference<>();
@@ -321,6 +382,7 @@ public void testOnPhaseFailure() {
         List<Tuple<String, String>> nodeLookups = new ArrayList<>();
         ArraySearchPhaseResults<SearchPhaseResult> phaseResults = phaseResults(requestIds, nodeLookups, 0);
         AbstractSearchAsyncAction<SearchPhaseResult> action = createAction(searchRequest, phaseResults, listener, false, new AtomicLong());
+
         action.onPhaseFailure(new SearchPhase("test") {
             @Override
             public void run() {
@@ -528,6 +590,224 @@ public void onFailure(Exception e) {
         assertThat(searchResponse.getSuccessfulShards(), equalTo(shards.length));
     }
 
+    public void testOnPhaseListenersWithQueryAndThenFetchType() throws InterruptedException {
+        SearchRequestStats testListener = new SearchRequestStats();
+        final List<SearchRequestOperationsListener> requestOperationListeners = new ArrayList<>(List.of(testListener));
+
+        long delay = (randomIntBetween(1, 5));
+        delay = delay * 10;
+
+        SearchQueryThenFetchAsyncAction action = createSearchQueryThenFetchAsyncAction(requestOperationListeners);
+        action.start();
+
+        // Verify queryPhase current metric
+        assertEquals(1, testListener.getPhaseCurrent(action.getSearchPhaseName()));
+        TimeUnit.MILLISECONDS.sleep(delay);
+
+        FetchSearchPhase fetchPhase = createFetchSearchPhase();
+        ShardId shardId = new ShardId(randomAlphaOfLengthBetween(5, 10), randomAlphaOfLength(10), randomInt());
+        SearchShardIterator searchShardIterator = new SearchShardIterator(null, shardId, Collections.emptyList(), OriginalIndices.NONE);
+        searchShardIterator.resetAndSkip();
+        action.skipShard(searchShardIterator);
+        action.executeNextPhase(action, fetchPhase);
+
+        // Verify queryPhase total, current and latency metrics
+        assertEquals(0, testListener.getPhaseCurrent(action.getSearchPhaseName()));
+        assertThat(testListener.getPhaseMetric(action.getSearchPhaseName()), greaterThanOrEqualTo(delay));
+        assertEquals(1, testListener.getPhaseTotal(action.getSearchPhaseName()));
+
+        // Verify fetchPhase current metric
+        assertEquals(1, testListener.getPhaseCurrent(fetchPhase.getSearchPhaseName()));
+        TimeUnit.MILLISECONDS.sleep(delay);
+
+        ExpandSearchPhase expandPhase = createExpandSearchPhase();
+        action.executeNextPhase(fetchPhase, expandPhase);
+        TimeUnit.MILLISECONDS.sleep(delay);
+
+        // Verify fetchPhase total, current and latency metrics
+        assertThat(testListener.getPhaseMetric(fetchPhase.getSearchPhaseName()), greaterThanOrEqualTo(delay));
+        assertEquals(1, testListener.getPhaseTotal(fetchPhase.getSearchPhaseName()));
+        assertEquals(0, testListener.getPhaseCurrent(fetchPhase.getSearchPhaseName()));
+
+        assertEquals(1, testListener.getPhaseCurrent(expandPhase.getSearchPhaseName()));
+
+        action.executeNextPhase(expandPhase, fetchPhase);
+
+        action.sendSearchResponse(mock(InternalSearchResponse.class), mock(String.valueOf(QuerySearchResult.class)));
+        assertThat(testListener.getPhaseMetric(expandPhase.getSearchPhaseName()), greaterThanOrEqualTo(delay));
+        assertEquals(1, testListener.getPhaseTotal(expandPhase.getSearchPhaseName()));
+        assertEquals(0, testListener.getPhaseCurrent(expandPhase.getSearchPhaseName()));
+    }
+
+    public void testOnPhaseListenersWithDfsType() throws InterruptedException {
+        SearchRequestStats testListener = new SearchRequestStats();
+        final List<SearchRequestOperationsListener> requestOperationListeners = new ArrayList<>(List.of(testListener));
+
+        SearchDfsQueryThenFetchAsyncAction searchDfsQueryThenFetchAsyncAction = createSearchDfsQueryThenFetchAsyncAction(
+            requestOperationListeners
+        );
+        long delay = (randomIntBetween(1, 5));
+
+        FetchSearchPhase fetchPhase = createFetchSearchPhase();
+        searchDfsQueryThenFetchAsyncAction.start();
+        assertEquals(1, testListener.getPhaseCurrent(searchDfsQueryThenFetchAsyncAction.getSearchPhaseName()));
+        TimeUnit.MILLISECONDS.sleep(delay);
+        ShardId shardId = new ShardId(randomAlphaOfLengthBetween(5, 10), randomAlphaOfLength(10), randomInt());
+        SearchShardIterator searchShardIterator = new SearchShardIterator(null, shardId, Collections.emptyList(), OriginalIndices.NONE);
+        searchShardIterator.resetAndSkip();
+
+        searchDfsQueryThenFetchAsyncAction.skipShard(searchShardIterator);
+        searchDfsQueryThenFetchAsyncAction.executeNextPhase(searchDfsQueryThenFetchAsyncAction, fetchPhase);
+
+        assertThat(testListener.getPhaseMetric(searchDfsQueryThenFetchAsyncAction.getSearchPhaseName()), greaterThanOrEqualTo(delay));
+        assertEquals(1, testListener.getPhaseTotal(searchDfsQueryThenFetchAsyncAction.getSearchPhaseName()));
+        assertEquals(0, testListener.getPhaseCurrent(searchDfsQueryThenFetchAsyncAction.getSearchPhaseName()));
+    }
+
+    private SearchDfsQueryThenFetchAsyncAction createSearchDfsQueryThenFetchAsyncAction(
+        List<SearchRequestOperationsListener> searchRequestOperationsListeners
+    ) {
+        SearchPhaseController controller = new SearchPhaseController(
+            writableRegistry(),
+            r -> InternalAggregationTestCase.emptyReduceContextBuilder()
+        );
+        SearchRequest searchRequest = new SearchRequest().allowPartialSearchResults(true);
+        SearchTask task = new SearchTask(0, "n/a", "n/a", () -> "test", null, Collections.emptyMap());
+        Executor executor = OpenSearchExecutors.newDirectExecutorService();
+        SearchShardIterator shards = new SearchShardIterator(null, null, Collections.emptyList(), null);
+        GroupShardsIterator<SearchShardIterator> shardsIter = new GroupShardsIterator<>(List.of(shards));
+        QueryPhaseResultConsumer resultConsumer = new QueryPhaseResultConsumer(
+            searchRequest,
+            executor,
+            new NoopCircuitBreaker(CircuitBreaker.REQUEST),
+            controller,
+            task.getProgressListener(),
+            writableRegistry(),
+            shardsIter.size(),
+            exc -> {}
+        );
+        AtomicReference<Exception> exception = new AtomicReference<>();
+        ActionListener<SearchResponse> listener = ActionListener.wrap(response -> fail("onResponse should not be called"), exception::set);
+        TransportSearchAction.SearchTimeProvider timeProvider = new TransportSearchAction.SearchTimeProvider(
+            0,
+            System.nanoTime(),
+            System::nanoTime
+        );
+        return new SearchDfsQueryThenFetchAsyncAction(
+            logger,
+            null,
+            null,
+            null,
+            null,
+            null,
+            null,
+            executor,
+            resultConsumer,
+            searchRequest,
+            listener,
+            shardsIter,
+            timeProvider,
+            null,
+            task,
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext(new SearchRequestOperationsListener.CompositeListener(searchRequestOperationsListeners, logger))
+        );
+    }
+
+    private SearchQueryThenFetchAsyncAction createSearchQueryThenFetchAsyncAction(
+        List<SearchRequestOperationsListener> searchRequestOperationsListeners
+    ) {
+        SearchPhaseController controller = new SearchPhaseController(
+            writableRegistry(),
+            r -> InternalAggregationTestCase.emptyReduceContextBuilder()
+        );
+        SearchRequest searchRequest = new SearchRequest().allowPartialSearchResults(true);
+        SearchTask task = new SearchTask(0, "n/a", "n/a", () -> "test", null, Collections.emptyMap());
+        Executor executor = OpenSearchExecutors.newDirectExecutorService();
+        SearchShardIterator shards = new SearchShardIterator(null, null, Collections.emptyList(), null);
+        GroupShardsIterator<SearchShardIterator> shardsIter = new GroupShardsIterator<>(List.of(shards));
+        QueryPhaseResultConsumer resultConsumer = new QueryPhaseResultConsumer(
+            searchRequest,
+            executor,
+            new NoopCircuitBreaker(CircuitBreaker.REQUEST),
+            controller,
+            task.getProgressListener(),
+            writableRegistry(),
+            shardsIter.size(),
+            exc -> {}
+        );
+        AtomicReference<Exception> exception = new AtomicReference<>();
+        ActionListener<SearchResponse> listener = ActionListener.wrap(response -> fail("onResponse should not be called"), exception::set);
+        TransportSearchAction.SearchTimeProvider timeProvider = new TransportSearchAction.SearchTimeProvider(
+            0,
+            System.nanoTime(),
+            System::nanoTime
+        );
+        return new SearchQueryThenFetchAsyncAction(
+            logger,
+            null,
+            null,
+            null,
+            null,
+            null,
+            null,
+            executor,
+            resultConsumer,
+            searchRequest,
+            listener,
+            shardsIter,
+            timeProvider,
+            null,
+            task,
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext(new SearchRequestOperationsListener.CompositeListener(searchRequestOperationsListeners, logger))
+        ) {
+            @Override
+            ShardSearchFailure[] buildShardFailures() {
+                return ShardSearchFailure.EMPTY_ARRAY;
+            }
+
+            @Override
+            public void sendSearchResponse(InternalSearchResponse internalSearchResponse, AtomicArray<SearchPhaseResult> queryResults) {
+                start();
+            }
+        };
+    }
+
+    private FetchSearchPhase createFetchSearchPhase() {
+        SearchPhaseController controller = new SearchPhaseController(
+            writableRegistry(),
+            r -> InternalAggregationTestCase.emptyReduceContextBuilder()
+        );
+        MockSearchPhaseContext mockSearchPhaseContext = new MockSearchPhaseContext(1);
+        QueryPhaseResultConsumer results = controller.newSearchPhaseResults(
+            OpenSearchExecutors.newDirectExecutorService(),
+            new NoopCircuitBreaker(CircuitBreaker.REQUEST),
+            SearchProgressListener.NOOP,
+            mockSearchPhaseContext.getRequest(),
+            1,
+            exc -> {}
+        );
+        return new FetchSearchPhase(
+            results,
+            controller,
+            null,
+            mockSearchPhaseContext,
+            (searchResponse, scrollId) -> new SearchPhase("test") {
+                @Override
+                public void run() {
+                    mockSearchPhaseContext.sendSearchResponse(searchResponse, null);
+                }
+            }
+        );
+    }
+
+    private ExpandSearchPhase createExpandSearchPhase() {
+        MockSearchPhaseContext mockSearchPhaseContext = new MockSearchPhaseContext(1);
+        InternalSearchResponse internalSearchResponse = new InternalSearchResponse(null, null, null, null, false, null, 1);
+        return new ExpandSearchPhase(mockSearchPhaseContext, internalSearchResponse, null);
+    }
+
     private static final class PhaseResult extends SearchPhaseResult {
         PhaseResult(ShardSearchContextId contextId) {
             this.contextId = contextId;
diff --git a/server/src/test/java/org/opensearch/action/search/BottomSortValuesCollectorTests.java b/server/src/test/java/org/opensearch/action/search/BottomSortValuesCollectorTests.java
index 3efcadbfb320d..8042a7e296869 100644
--- a/server/src/test/java/org/opensearch/action/search/BottomSortValuesCollectorTests.java
+++ b/server/src/test/java/org/opensearch/action/search/BottomSortValuesCollectorTests.java
@@ -46,7 +46,6 @@
 import java.time.ZoneId;
 import java.util.Arrays;
 
-import static org.opensearch.index.mapper.DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.apache.lucene.search.TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO;
@@ -136,7 +135,11 @@ public void testWithDates() {
         for (boolean reverse : new boolean[] { true, false }) {
             SortField[] sortFields = new SortField[] { new SortField("foo", SortField.Type.LONG, reverse) };
             DocValueFormat[] sortFormats = new DocValueFormat[] {
-                new DocValueFormat.DateTime(DEFAULT_DATE_TIME_FORMATTER, ZoneId.of("UTC"), DateFieldMapper.Resolution.MILLISECONDS) };
+                new DocValueFormat.DateTime(
+                    DateFieldMapper.getDefaultDateTimeFormatter(),
+                    ZoneId.of("UTC"),
+                    DateFieldMapper.Resolution.MILLISECONDS
+                ) };
             BottomSortValuesCollector collector = new BottomSortValuesCollector(3, sortFields);
             collector.consumeTopDocs(
                 createTopDocs(sortFields[0], 100, newDateArray("2017-06-01T12:18:20Z", "2018-04-03T15:10:27Z", "2013-06-01T13:10:20Z")),
@@ -170,7 +173,11 @@ public void testWithDateNanos() {
         for (boolean reverse : new boolean[] { true, false }) {
             SortField[] sortFields = new SortField[] { new SortField("foo", SortField.Type.LONG, reverse) };
             DocValueFormat[] sortFormats = new DocValueFormat[] {
-                new DocValueFormat.DateTime(DEFAULT_DATE_TIME_FORMATTER, ZoneId.of("UTC"), DateFieldMapper.Resolution.NANOSECONDS) };
+                new DocValueFormat.DateTime(
+                    DateFieldMapper.getDefaultDateTimeFormatter(),
+                    ZoneId.of("UTC"),
+                    DateFieldMapper.Resolution.NANOSECONDS
+                ) };
             BottomSortValuesCollector collector = new BottomSortValuesCollector(3, sortFields);
             collector.consumeTopDocs(
                 createTopDocs(sortFields[0], 100, newDateNanoArray("2017-06-01T12:18:20Z", "2018-04-03T15:10:27Z", "2013-06-01T13:10:20Z")),
@@ -242,7 +249,7 @@ private Object[] newBytesArray(String... values) {
     private Object[] newDateArray(String... values) {
         Long[] longs = new Long[values.length];
         for (int i = 0; i < values.length; i++) {
-            longs[i] = DEFAULT_DATE_TIME_FORMATTER.parseMillis(values[i]);
+            longs[i] = DateFieldMapper.getDefaultDateTimeFormatter().parseMillis(values[i]);
         }
         return longs;
     }
@@ -250,7 +257,7 @@ private Object[] newDateArray(String... values) {
     private Object[] newDateNanoArray(String... values) {
         Long[] longs = new Long[values.length];
         for (int i = 0; i < values.length; i++) {
-            longs[i] = DateUtils.toNanoSeconds(DEFAULT_DATE_TIME_FORMATTER.parseMillis(values[i]));
+            longs[i] = DateUtils.toNanoSeconds(DateFieldMapper.getDefaultDateTimeFormatter().parseMillis(values[i]));
         }
         return longs;
     }
diff --git a/server/src/test/java/org/opensearch/action/search/CanMatchPreFilterSearchPhaseTests.java b/server/src/test/java/org/opensearch/action/search/CanMatchPreFilterSearchPhaseTests.java
index 45f00a8418d5c..4ed4797efe604 100644
--- a/server/src/test/java/org/opensearch/action/search/CanMatchPreFilterSearchPhaseTests.java
+++ b/server/src/test/java/org/opensearch/action/search/CanMatchPreFilterSearchPhaseTests.java
@@ -136,7 +136,8 @@ public void run() throws IOException {
                     latch.countDown();
                 }
             },
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         );
 
         canMatchPhase.start();
@@ -227,7 +228,8 @@ public void run() throws IOException {
                     latch.countDown();
                 }
             },
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         );
 
         canMatchPhase.start();
@@ -317,7 +319,8 @@ public void sendCanMatch(
                 null,
                 new ArraySearchPhaseResults<>(iter.size()),
                 randomIntBetween(1, 32),
-                SearchResponse.Clusters.EMPTY
+                SearchResponse.Clusters.EMPTY,
+                new SearchRequestContext()
             ) {
 
                 @Override
@@ -344,7 +347,8 @@ protected void executePhaseOnShard(
                     }
                 }
             },
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         );
 
         canMatchPhase.start();
@@ -428,7 +432,8 @@ public void run() {
                         latch.countDown();
                     }
                 },
-                SearchResponse.Clusters.EMPTY
+                SearchResponse.Clusters.EMPTY,
+                new SearchRequestContext()
             );
 
             canMatchPhase.start();
@@ -527,7 +532,8 @@ public void run() {
                         latch.countDown();
                     }
                 },
-                SearchResponse.Clusters.EMPTY
+                SearchResponse.Clusters.EMPTY,
+                new SearchRequestContext()
             );
 
             canMatchPhase.start();
diff --git a/server/src/test/java/org/opensearch/action/search/CreatePitControllerTests.java b/server/src/test/java/org/opensearch/action/search/CreatePitControllerTests.java
index 2643aa5b6db01..6cbe458a35ef8 100644
--- a/server/src/test/java/org/opensearch/action/search/CreatePitControllerTests.java
+++ b/server/src/test/java/org/opensearch/action/search/CreatePitControllerTests.java
@@ -339,8 +339,8 @@ public void onFailure(Exception e) {
                 createListener.onFailure(new Exception("Exception occurred in phase 1"));
                 latch.await();
                 assertEquals(0, updateNodesInvoked.size());
-                /**
-                 * cleanup is not called on create pit phase one failure
+                /*
+                  cleanup is not called on create pit phase one failure
                  */
                 assertEquals(0, deleteNodesInvoked.size());
             }
@@ -438,8 +438,8 @@ public void onFailure(Exception e) {
                 createListener.onResponse(searchResponse);
                 latch.await();
                 assertEquals(3, updateNodesInvoked.size());
-                /**
-                 * check if cleanup is called for all nodes in case of update pit failure
+                /*
+                  check if cleanup is called for all nodes in case of update pit failure
                  */
                 assertEquals(3, deleteNodesInvoked.size());
             }
@@ -526,8 +526,8 @@ public void onFailure(Exception e) {
                 createListener.onResponse(searchResponse);
                 latch.await();
                 assertEquals(3, updateNodesInvoked.size());
-                /**
-                 * check if cleanup is called for all nodes in case of update pit failure
+                /*
+                  check if cleanup is called for all nodes in case of update pit failure
                  */
                 assertEquals(3, deleteNodesInvoked.size());
             }
diff --git a/server/src/test/java/org/opensearch/action/search/MockSearchPhaseContext.java b/server/src/test/java/org/opensearch/action/search/MockSearchPhaseContext.java
index e078b4a467e91..04a00a09dcbc4 100644
--- a/server/src/test/java/org/opensearch/action/search/MockSearchPhaseContext.java
+++ b/server/src/test/java/org/opensearch/action/search/MockSearchPhaseContext.java
@@ -65,11 +65,16 @@ public final class MockSearchPhaseContext implements SearchPhaseContext {
     final List<ShardSearchFailure> failures = Collections.synchronizedList(new ArrayList<>());
     SearchTransportService searchTransport;
     final Set<ShardSearchContextId> releasedSearchContexts = new HashSet<>();
-    final SearchRequest searchRequest = new SearchRequest();
+    final SearchRequest searchRequest;
     final AtomicReference<SearchResponse> searchResponse = new AtomicReference<>();
 
     public MockSearchPhaseContext(int numShards) {
+        this(numShards, new SearchRequest());
+    }
+
+    public MockSearchPhaseContext(int numShards, SearchRequest searchRequest) {
         this.numShards = numShards;
+        this.searchRequest = searchRequest;
         numSuccess = new AtomicInteger(numShards);
     }
 
@@ -99,6 +104,11 @@ public SearchRequest getRequest() {
         return searchRequest;
     }
 
+    @Override
+    public SearchPhase getCurrentPhase() {
+        return null;
+    }
+
     @Override
     public void sendSearchResponse(InternalSearchResponse internalSearchResponse, AtomicArray<SearchPhaseResult> queryResults) {
         String scrollId = getRequest().scroll() != null ? TransportSearchHelper.buildScrollId(queryResults, Version.CURRENT) : null;
diff --git a/server/src/test/java/org/opensearch/action/search/SearchAsyncActionTests.java b/server/src/test/java/org/opensearch/action/search/SearchAsyncActionTests.java
index 830fa99f90bb9..7b4fa1d8387df 100644
--- a/server/src/test/java/org/opensearch/action/search/SearchAsyncActionTests.java
+++ b/server/src/test/java/org/opensearch/action/search/SearchAsyncActionTests.java
@@ -135,7 +135,8 @@ public void testSkipSearchShards() throws InterruptedException {
             null,
             new ArraySearchPhaseResults<>(shardsIter.size()),
             request.getMaxConcurrentShardRequests(),
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         ) {
 
             @Override
@@ -253,7 +254,8 @@ public void testLimitConcurrentShardRequests() throws InterruptedException {
             null,
             new ArraySearchPhaseResults<>(shardsIter.size()),
             request.getMaxConcurrentShardRequests(),
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         ) {
 
             @Override
@@ -370,7 +372,8 @@ public void sendFreeContext(Transport.Connection connection, ShardSearchContextI
             null,
             new ArraySearchPhaseResults<>(shardsIter.size()),
             request.getMaxConcurrentShardRequests(),
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         ) {
             TestSearchResponse response = new TestSearchResponse();
 
@@ -492,7 +495,8 @@ public void sendFreeContext(Transport.Connection connection, ShardSearchContextI
             null,
             new ArraySearchPhaseResults<>(shardsIter.size()),
             request.getMaxConcurrentShardRequests(),
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         ) {
             TestSearchResponse response = new TestSearchResponse();
 
@@ -605,9 +609,9 @@ public void testAllowPartialResults() throws InterruptedException {
             null,
             new ArraySearchPhaseResults<>(shardsIter.size()),
             request.getMaxConcurrentShardRequests(),
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         ) {
-
             @Override
             protected void executePhaseOnShard(
                 SearchShardIterator shardIt,
diff --git a/server/src/test/java/org/opensearch/action/search/SearchQueryCategorizerTests.java b/server/src/test/java/org/opensearch/action/search/SearchQueryCategorizerTests.java
new file mode 100644
index 0000000000000..a2e301143d694
--- /dev/null
+++ b/server/src/test/java/org/opensearch/action/search/SearchQueryCategorizerTests.java
@@ -0,0 +1,228 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.opensearch.index.query.BoolQueryBuilder;
+import org.opensearch.index.query.BoostingQueryBuilder;
+import org.opensearch.index.query.MatchNoneQueryBuilder;
+import org.opensearch.index.query.MatchQueryBuilder;
+import org.opensearch.index.query.MultiMatchQueryBuilder;
+import org.opensearch.index.query.QueryBuilders;
+import org.opensearch.index.query.QueryStringQueryBuilder;
+import org.opensearch.index.query.RangeQueryBuilder;
+import org.opensearch.index.query.RegexpQueryBuilder;
+import org.opensearch.index.query.TermQueryBuilder;
+import org.opensearch.index.query.WildcardQueryBuilder;
+import org.opensearch.index.query.functionscore.FunctionScoreQueryBuilder;
+import org.opensearch.search.aggregations.bucket.range.RangeAggregationBuilder;
+import org.opensearch.search.aggregations.bucket.terms.MultiTermsAggregationBuilder;
+import org.opensearch.search.aggregations.support.MultiTermsValuesSourceConfig;
+import org.opensearch.search.builder.SearchSourceBuilder;
+import org.opensearch.search.sort.ScoreSortBuilder;
+import org.opensearch.search.sort.SortOrder;
+import org.opensearch.telemetry.metrics.Counter;
+import org.opensearch.telemetry.metrics.MetricsRegistry;
+import org.opensearch.telemetry.metrics.tags.Tags;
+import org.opensearch.test.OpenSearchTestCase;
+import org.junit.Before;
+
+import java.util.Arrays;
+
+import org.mockito.Mockito;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.when;
+
+public final class SearchQueryCategorizerTests extends OpenSearchTestCase {
+
+    private MetricsRegistry metricsRegistry;
+
+    private SearchQueryCategorizer searchQueryCategorizer;
+
+    @Before
+    public void setup() {
+        metricsRegistry = mock(MetricsRegistry.class);
+        when(metricsRegistry.createCounter(any(String.class), any(String.class), any(String.class))).thenAnswer(
+            invocation -> mock(Counter.class)
+        );
+        searchQueryCategorizer = new SearchQueryCategorizer(metricsRegistry);
+    }
+
+    public void testAggregationsQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.aggregation(
+            new MultiTermsAggregationBuilder("agg1").terms(
+                Arrays.asList(
+                    new MultiTermsValuesSourceConfig.Builder().setFieldName("username").build(),
+                    new MultiTermsValuesSourceConfig.Builder().setFieldName("rating").build()
+                )
+            )
+        );
+        sourceBuilder.size(0);
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.aggCounter).add(eq(1.0d));
+    }
+
+    public void testBoolQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        sourceBuilder.query(new BoolQueryBuilder().must(new MatchQueryBuilder("searchText", "fox")));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.boolCounter).add(eq(1.0d), any(Tags.class));
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.matchCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testFunctionScoreQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        sourceBuilder.query(new FunctionScoreQueryBuilder(QueryBuilders.prefixQuery("text", "bro")));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.functionScoreCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testMatchQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        sourceBuilder.query(QueryBuilders.matchQuery("tags", "php"));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.matchCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testMatchPhraseQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        sourceBuilder.query(QueryBuilders.matchPhraseQuery("tags", "php"));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.matchPhrasePrefixCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testMultiMatchQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        sourceBuilder.query(new MultiMatchQueryBuilder("foo bar", "myField"));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.multiMatchCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testOtherQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        BoostingQueryBuilder queryBuilder = new BoostingQueryBuilder(
+            new TermQueryBuilder("unmapped_field", "foo"),
+            new MatchNoneQueryBuilder()
+        );
+        sourceBuilder.query(queryBuilder);
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.otherQueryCounter, times(2)).add(eq(1.0d), any(Tags.class));
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.termCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testQueryStringQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        QueryStringQueryBuilder queryBuilder = new QueryStringQueryBuilder("foo:*");
+        sourceBuilder.query(queryBuilder);
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.queryStringQueryCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testRangeQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        RangeQueryBuilder rangeQuery = new RangeQueryBuilder("date");
+        rangeQuery.gte("1970-01-01");
+        rangeQuery.lt("1982-01-01");
+        sourceBuilder.query(rangeQuery);
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.rangeCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testRegexQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.query(new RegexpQueryBuilder("field", "text"));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.regexCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testSortQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.query(QueryBuilders.matchQuery("tags", "ruby"));
+        sourceBuilder.sort("creationDate", SortOrder.DESC);
+        sourceBuilder.sort(new ScoreSortBuilder());
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.matchCounter).add(eq(1.0d), any(Tags.class));
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.sortCounter, times(2)).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testTermQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        sourceBuilder.query(QueryBuilders.termQuery("field", "value2"));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.termCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testWildcardQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+        sourceBuilder.query(new WildcardQueryBuilder("field", "text"));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.wildcardCounter).add(eq(1.0d), any(Tags.class));
+    }
+
+    public void testComplexQuery() {
+        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+        sourceBuilder.size(50);
+
+        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("field", "value2");
+        MatchQueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("tags", "php");
+        RegexpQueryBuilder regexpQueryBuilder = new RegexpQueryBuilder("field", "text");
+        BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder().must(termQueryBuilder)
+            .filter(matchQueryBuilder)
+            .should(regexpQueryBuilder);
+        sourceBuilder.query(boolQueryBuilder);
+        sourceBuilder.aggregation(new RangeAggregationBuilder("agg1").field("num"));
+
+        searchQueryCategorizer.categorize(sourceBuilder);
+
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.termCounter).add(eq(1.0d), any(Tags.class));
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.matchCounter).add(eq(1.0d), any(Tags.class));
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.regexCounter).add(eq(1.0d), any(Tags.class));
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.boolCounter).add(eq(1.0d), any(Tags.class));
+        Mockito.verify(searchQueryCategorizer.searchQueryCounters.aggCounter).add(eq(1.0d));
+    }
+}
diff --git a/server/src/test/java/org/opensearch/action/search/SearchQueryThenFetchAsyncActionTests.java b/server/src/test/java/org/opensearch/action/search/SearchQueryThenFetchAsyncActionTests.java
index 0e2780c195cb8..a8c0c43ac5080 100644
--- a/server/src/test/java/org/opensearch/action/search/SearchQueryThenFetchAsyncActionTests.java
+++ b/server/src/test/java/org/opensearch/action/search/SearchQueryThenFetchAsyncActionTests.java
@@ -214,7 +214,8 @@ public void sendExecuteQuery(
             timeProvider,
             null,
             task,
-            SearchResponse.Clusters.EMPTY
+            SearchResponse.Clusters.EMPTY,
+            new SearchRequestContext()
         ) {
             @Override
             protected SearchPhase getNextPhase(SearchPhaseResults<SearchPhaseResult> results, SearchPhaseContext context) {
@@ -226,6 +227,7 @@ public void run() {
                 };
             }
         };
+
         action.start();
         latch.await();
         assertThat(successfulOps.get(), equalTo(numShards));
diff --git a/server/src/test/java/org/opensearch/action/search/SearchRequestOperationsListenerSupport.java b/server/src/test/java/org/opensearch/action/search/SearchRequestOperationsListenerSupport.java
new file mode 100644
index 0000000000000..58a4c4a4e555d
--- /dev/null
+++ b/server/src/test/java/org/opensearch/action/search/SearchRequestOperationsListenerSupport.java
@@ -0,0 +1,22 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+/**
+ * Helper interface to access package protected {@link SearchRequestOperationsListener} from test cases.
+ */
+public interface SearchRequestOperationsListenerSupport {
+    default void onPhaseStart(SearchRequestOperationsListener listener, SearchPhaseContext context) {
+        listener.onPhaseStart(context);
+    }
+
+    default void onPhaseEnd(SearchRequestOperationsListener listener, SearchPhaseContext context) {
+        listener.onPhaseEnd(context, new SearchRequestContext());
+    }
+}
diff --git a/server/src/test/java/org/opensearch/action/search/SearchRequestOperationsListenerTests.java b/server/src/test/java/org/opensearch/action/search/SearchRequestOperationsListenerTests.java
new file mode 100644
index 0000000000000..a53c35a8401b3
--- /dev/null
+++ b/server/src/test/java/org/opensearch/action/search/SearchRequestOperationsListenerTests.java
@@ -0,0 +1,69 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class SearchRequestOperationsListenerTests extends OpenSearchTestCase {
+
+    public void testListenersAreExecuted() {
+        Map<SearchPhaseName, SearchRequestStats.StatsHolder> searchPhaseMap = new HashMap<>();
+
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            searchPhaseMap.put(searchPhaseName, new SearchRequestStats.StatsHolder());
+        }
+        SearchRequestOperationsListener testListener = new SearchRequestOperationsListener() {
+
+            @Override
+            public void onPhaseStart(SearchPhaseContext context) {
+                searchPhaseMap.get(context.getCurrentPhase().getSearchPhaseName()).current.inc();
+            }
+
+            @Override
+            public void onPhaseEnd(SearchPhaseContext context, SearchRequestContext searchRequestContext) {
+                searchPhaseMap.get(context.getCurrentPhase().getSearchPhaseName()).current.dec();
+                searchPhaseMap.get(context.getCurrentPhase().getSearchPhaseName()).total.inc();
+            }
+
+            @Override
+            public void onPhaseFailure(SearchPhaseContext context) {
+                searchPhaseMap.get(context.getCurrentPhase().getSearchPhaseName()).current.dec();
+            }
+        };
+
+        int totalListeners = randomIntBetween(1, 10);
+        final List<SearchRequestOperationsListener> requestOperationListeners = new ArrayList<>();
+        for (int i = 0; i < totalListeners; i++) {
+            requestOperationListeners.add(testListener);
+        }
+
+        SearchRequestOperationsListener compositeListener = new SearchRequestOperationsListener.CompositeListener(
+            requestOperationListeners,
+            logger
+        );
+
+        SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+        SearchPhase searchPhase = mock(SearchPhase.class);
+
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            when(ctx.getCurrentPhase()).thenReturn(searchPhase);
+            when(searchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            compositeListener.onPhaseStart(ctx);
+            assertEquals(totalListeners, searchPhaseMap.get(searchPhaseName).current.count());
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/action/search/SearchRequestSlowLogTests.java b/server/src/test/java/org/opensearch/action/search/SearchRequestSlowLogTests.java
new file mode 100644
index 0000000000000..e23f08c9415eb
--- /dev/null
+++ b/server/src/test/java/org/opensearch/action/search/SearchRequestSlowLogTests.java
@@ -0,0 +1,410 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.action.search;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.lucene.search.TotalHits;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.logging.Loggers;
+import org.opensearch.common.logging.MockAppender;
+import org.opensearch.common.logging.SlowLogLevel;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.index.query.QueryBuilders;
+import org.opensearch.search.builder.SearchSourceBuilder;
+import org.opensearch.test.OpenSearchTestCase;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Phaser;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.endsWith;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasToString;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.startsWith;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class SearchRequestSlowLogTests extends OpenSearchTestCase {
+    static MockAppender appender;
+    static Logger logger = LogManager.getLogger(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX + ".SearchRequestSlowLog");
+
+    @BeforeClass
+    public static void init() throws IllegalAccessException {
+        appender = new MockAppender("trace_appender");
+        appender.start();
+        Loggers.addAppender(logger, appender);
+    }
+
+    @AfterClass
+    public static void cleanup() {
+        Loggers.removeAppender(logger, appender);
+        appender.stop();
+    }
+
+    public void testMultipleSlowLoggersUseSingleLog4jLogger() {
+        LoggerContext context = (LoggerContext) LogManager.getContext(false);
+
+        SearchPhaseContext searchPhaseContext1 = new MockSearchPhaseContext(1);
+        ClusterService clusterService1 = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            null
+        );
+        SearchRequestSlowLog searchRequestSlowLog1 = new SearchRequestSlowLog(clusterService1);
+        int numberOfLoggersBefore = context.getLoggers().size();
+
+        SearchPhaseContext searchPhaseContext2 = new MockSearchPhaseContext(1);
+        ClusterService clusterService2 = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            null
+        );
+        SearchRequestSlowLog searchRequestSlowLog2 = new SearchRequestSlowLog(clusterService2);
+
+        int numberOfLoggersAfter = context.getLoggers().size();
+        assertThat(numberOfLoggersAfter, equalTo(numberOfLoggersBefore));
+    }
+
+    public void testOnRequestEnd() throws InterruptedException {
+        final Logger logger = mock(Logger.class);
+        final SearchRequestContext searchRequestContext = mock(SearchRequestContext.class);
+        final SearchPhaseContext searchPhaseContext = mock(SearchPhaseContext.class);
+        final SearchRequest searchRequest = mock(SearchRequest.class);
+        final SearchTask searchTask = mock(SearchTask.class);
+
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING.getKey(), "0ms");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING.getKey(), "0ms");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING.getKey(), "0ms");
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+        SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService, logger);
+        final List<SearchRequestOperationsListener> searchListenersList = new ArrayList<>(List.of(searchRequestSlowLog));
+
+        when(searchRequestContext.getSearchRequestOperationsListener()).thenReturn(
+            new SearchRequestOperationsListener.CompositeListener(searchListenersList, logger)
+        );
+        when(searchRequestContext.getAbsoluteStartNanos()).thenReturn(System.nanoTime() - 1L);
+        when(searchPhaseContext.getRequest()).thenReturn(searchRequest);
+        when(searchPhaseContext.getTask()).thenReturn(searchTask);
+        when(searchRequest.searchType()).thenReturn(SearchType.QUERY_THEN_FETCH);
+
+        searchRequestContext.getSearchRequestOperationsListener().onRequestEnd(searchPhaseContext, searchRequestContext);
+
+        verify(logger, never()).warn(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+        verify(logger, times(1)).info(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+        verify(logger, never()).debug(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+        verify(logger, never()).trace(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+    }
+
+    public void testConcurrentOnRequestEnd() throws InterruptedException {
+        final Logger logger = mock(Logger.class);
+        final SearchPhaseContext searchPhaseContext = mock(SearchPhaseContext.class);
+        final SearchRequest searchRequest = mock(SearchRequest.class);
+        final SearchTask searchTask = mock(SearchTask.class);
+
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING.getKey(), "-1");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING.getKey(), "10s");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING.getKey(), "-1");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING.getKey(), "-1");
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+        SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService, logger);
+        final List<SearchRequestOperationsListener> searchListenersList = new ArrayList<>(List.of(searchRequestSlowLog));
+
+        when(searchPhaseContext.getRequest()).thenReturn(searchRequest);
+        when(searchPhaseContext.getTask()).thenReturn(searchTask);
+        when(searchRequest.searchType()).thenReturn(SearchType.QUERY_THEN_FETCH);
+
+        int numRequests = 50;
+        int numRequestsLogged = randomIntBetween(0, 50);
+        Thread[] threads = new Thread[numRequests];
+        Phaser phaser = new Phaser(numRequests + 1);
+        CountDownLatch countDownLatch = new CountDownLatch(numRequests);
+
+        // create a list of SearchRequestContexts
+        // each SearchRequestContext contains unique composite SearchRequestOperationsListener
+        ArrayList<SearchRequestContext> searchRequestContexts = new ArrayList<>();
+        for (int i = 0; i < numRequests; i++) {
+            SearchRequestContext searchRequestContext = new SearchRequestContext(
+                new SearchRequestOperationsListener.CompositeListener(searchListenersList, logger)
+            );
+            searchRequestContext.setAbsoluteStartNanos((i < numRequestsLogged) ? 0 : System.nanoTime());
+            searchRequestContexts.add(searchRequestContext);
+        }
+
+        for (int i = 0; i < numRequests; i++) {
+            int finalI = i;
+            threads[i] = new Thread(() -> {
+                phaser.arriveAndAwaitAdvance();
+                SearchRequestContext thisContext = searchRequestContexts.get(finalI);
+                thisContext.getSearchRequestOperationsListener().onRequestEnd(searchPhaseContext, thisContext);
+                countDownLatch.countDown();
+            });
+            threads[i].start();
+        }
+        phaser.arriveAndAwaitAdvance();
+        countDownLatch.await();
+
+        verify(logger, never()).warn(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+        verify(logger, times(numRequestsLogged)).info(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+        verify(logger, never()).debug(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+        verify(logger, never()).trace(any(SearchRequestSlowLog.SearchRequestSlowLogMessage.class));
+    }
+
+    public void testSearchRequestSlowLogHasJsonFields_EmptySearchRequestContext() throws IOException {
+        SearchSourceBuilder source = SearchSourceBuilder.searchSource().query(QueryBuilders.matchAllQuery());
+        SearchRequest searchRequest = new SearchRequest().source(source);
+        SearchPhaseContext searchPhaseContext = new MockSearchPhaseContext(1, searchRequest);
+        SearchRequestContext searchRequestContext = new SearchRequestContext();
+        SearchRequestSlowLog.SearchRequestSlowLogMessage p = new SearchRequestSlowLog.SearchRequestSlowLogMessage(
+            searchPhaseContext,
+            10,
+            searchRequestContext
+        );
+
+        assertThat(p.getValueFor("took"), equalTo("10nanos"));
+        assertThat(p.getValueFor("took_millis"), equalTo("0"));
+        assertThat(p.getValueFor("phase_took"), equalTo("{}"));
+        assertThat(p.getValueFor("total_hits"), equalTo("-1"));
+        assertThat(p.getValueFor("search_type"), equalTo("QUERY_THEN_FETCH"));
+        assertThat(p.getValueFor("shards"), equalTo(""));
+        assertThat(p.getValueFor("source"), equalTo("{\\\"query\\\":{\\\"match_all\\\":{\\\"boost\\\":1.0}}}"));
+        assertThat(p.getValueFor("id"), equalTo(null));
+    }
+
+    public void testSearchRequestSlowLogHasJsonFields_NotEmptySearchRequestContext() throws IOException {
+        SearchSourceBuilder source = SearchSourceBuilder.searchSource().query(QueryBuilders.matchAllQuery());
+        SearchRequest searchRequest = new SearchRequest().source(source);
+        SearchPhaseContext searchPhaseContext = new MockSearchPhaseContext(1, searchRequest);
+        SearchRequestContext searchRequestContext = new SearchRequestContext();
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.FETCH.getName(), 10L);
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.QUERY.getName(), 50L);
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.EXPAND.getName(), 5L);
+        searchRequestContext.setTotalHits(new TotalHits(3L, TotalHits.Relation.EQUAL_TO));
+        searchRequestContext.setShardStats(10, 8, 1, 1);
+        SearchRequestSlowLog.SearchRequestSlowLogMessage p = new SearchRequestSlowLog.SearchRequestSlowLogMessage(
+            searchPhaseContext,
+            10,
+            searchRequestContext
+        );
+
+        assertThat(p.getValueFor("took"), equalTo("10nanos"));
+        assertThat(p.getValueFor("took_millis"), equalTo("0"));
+        assertThat(p.getValueFor("phase_took"), equalTo("{expand=5, fetch=10, query=50}"));
+        assertThat(p.getValueFor("total_hits"), equalTo("3 hits"));
+        assertThat(p.getValueFor("search_type"), equalTo("QUERY_THEN_FETCH"));
+        assertThat(p.getValueFor("shards"), equalTo("{total:10, successful:8, skipped:1, failed:1}"));
+        assertThat(p.getValueFor("source"), equalTo("{\\\"query\\\":{\\\"match_all\\\":{\\\"boost\\\":1.0}}}"));
+        assertThat(p.getValueFor("id"), equalTo(null));
+    }
+
+    public void testSearchRequestSlowLogHasJsonFields_PartialContext() throws IOException {
+        SearchSourceBuilder source = SearchSourceBuilder.searchSource().query(QueryBuilders.matchAllQuery());
+        SearchRequest searchRequest = new SearchRequest().source(source);
+        SearchPhaseContext searchPhaseContext = new MockSearchPhaseContext(1, searchRequest);
+        SearchRequestContext searchRequestContext = new SearchRequestContext();
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.FETCH.getName(), 10L);
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.QUERY.getName(), 50L);
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.EXPAND.getName(), 5L);
+        searchRequestContext.setTotalHits(new TotalHits(3L, TotalHits.Relation.EQUAL_TO));
+        searchRequestContext.setShardStats(5, 3, 1, 1);
+        SearchRequestSlowLog.SearchRequestSlowLogMessage p = new SearchRequestSlowLog.SearchRequestSlowLogMessage(
+            searchPhaseContext,
+            10000000000L,
+            searchRequestContext
+        );
+
+        assertThat(p.getValueFor("took"), equalTo("10s"));
+        assertThat(p.getValueFor("took_millis"), equalTo("10000"));
+        assertThat(p.getValueFor("phase_took"), equalTo("{expand=5, fetch=10, query=50}"));
+        assertThat(p.getValueFor("total_hits"), equalTo("3 hits"));
+        assertThat(p.getValueFor("search_type"), equalTo("QUERY_THEN_FETCH"));
+        assertThat(p.getValueFor("shards"), equalTo("{total:5, successful:3, skipped:1, failed:1}"));
+        assertThat(p.getValueFor("source"), equalTo("{\\\"query\\\":{\\\"match_all\\\":{\\\"boost\\\":1.0}}}"));
+        assertThat(p.getValueFor("id"), equalTo(null));
+    }
+
+    public void testSearchRequestSlowLogSearchContextPrinterToLog() throws IOException {
+        SearchSourceBuilder source = SearchSourceBuilder.searchSource().query(QueryBuilders.matchAllQuery());
+        SearchRequest searchRequest = new SearchRequest().source(source);
+        SearchPhaseContext searchPhaseContext = new MockSearchPhaseContext(1, searchRequest);
+        SearchRequestContext searchRequestContext = new SearchRequestContext();
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.FETCH.getName(), 10L);
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.QUERY.getName(), 50L);
+        searchRequestContext.updatePhaseTookMap(SearchPhaseName.EXPAND.getName(), 5L);
+        searchRequestContext.setTotalHits(new TotalHits(3L, TotalHits.Relation.EQUAL_TO));
+        searchRequestContext.setShardStats(10, 8, 1, 1);
+        SearchRequestSlowLog.SearchRequestSlowLogMessage p = new SearchRequestSlowLog.SearchRequestSlowLogMessage(
+            searchPhaseContext,
+            100000,
+            searchRequestContext
+        );
+
+        assertThat(p.getFormattedMessage(), startsWith("took[100micros]"));
+        assertThat(p.getFormattedMessage(), containsString("took_millis[0]"));
+        assertThat(p.getFormattedMessage(), containsString("phase_took_millis[{expand=5, fetch=10, query=50}]"));
+        assertThat(p.getFormattedMessage(), containsString("total_hits[3 hits]"));
+        assertThat(p.getFormattedMessage(), containsString("search_type[QUERY_THEN_FETCH]"));
+        assertThat(p.getFormattedMessage(), containsString("shards[{total:10, successful:8, skipped:1, failed:1}]"));
+        assertThat(p.getFormattedMessage(), containsString("source[{\"query\":{\"match_all\":{\"boost\":1.0}}}]"));
+        // Makes sure that output doesn't contain any new lines
+        assertThat(p.getFormattedMessage(), not(containsString("\n")));
+        assertThat(p.getFormattedMessage(), endsWith("id[]"));
+    }
+
+    public void testLevelSettingWarn() {
+        SlowLogLevel level = SlowLogLevel.WARN;
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_LEVEL.getKey(), level);
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+        SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService);
+        assertEquals(level, searchRequestSlowLog.getLevel());
+    }
+
+    public void testLevelSettingDebug() {
+        String level = "DEBUG";
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_LEVEL.getKey(), level);
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+        SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService);
+        assertEquals(level, searchRequestSlowLog.getLevel().toString());
+    }
+
+    public void testLevelSettingFail() {
+        String level = "NOT A LEVEL";
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_LEVEL.getKey(), level);
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+
+        try {
+            new SearchRequestSlowLog(clusterService);
+            fail();
+        } catch (IllegalArgumentException ex) {
+            final String expected = "No enum constant org.opensearch.common.logging.SlowLogLevel.NOT A LEVEL";
+            assertThat(ex, hasToString(containsString(expected)));
+            assertThat(ex, instanceOf(IllegalArgumentException.class));
+        }
+    }
+
+    public void testSetThresholds() {
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING.getKey(), "400ms");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING.getKey(), "300ms");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING.getKey(), "200ms");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING.getKey(), "100ms");
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+        SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService);
+        assertEquals(TimeValue.timeValueMillis(400).nanos(), searchRequestSlowLog.getWarnThreshold());
+        assertEquals(TimeValue.timeValueMillis(300).nanos(), searchRequestSlowLog.getInfoThreshold());
+        assertEquals(TimeValue.timeValueMillis(200).nanos(), searchRequestSlowLog.getDebugThreshold());
+        assertEquals(TimeValue.timeValueMillis(100).nanos(), searchRequestSlowLog.getTraceThreshold());
+        assertEquals(SlowLogLevel.TRACE, searchRequestSlowLog.getLevel());
+    }
+
+    public void testSetThresholdsUnits() {
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING.getKey(), "400s");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_INFO_SETTING.getKey(), "300ms");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING.getKey(), "200micros");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_TRACE_SETTING.getKey(), "100nanos");
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+        SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService);
+        assertEquals(TimeValue.timeValueSeconds(400).nanos(), searchRequestSlowLog.getWarnThreshold());
+        assertEquals(TimeValue.timeValueMillis(300).nanos(), searchRequestSlowLog.getInfoThreshold());
+        assertEquals(TimeValue.timeValueNanos(200000).nanos(), searchRequestSlowLog.getDebugThreshold());
+        assertEquals(TimeValue.timeValueNanos(100).nanos(), searchRequestSlowLog.getTraceThreshold());
+        assertEquals(SlowLogLevel.TRACE, searchRequestSlowLog.getLevel());
+    }
+
+    public void testSetThresholdsDefaults() {
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING.getKey(), "400ms");
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_DEBUG_SETTING.getKey(), "200ms");
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+        SearchRequestSlowLog searchRequestSlowLog = new SearchRequestSlowLog(clusterService);
+        assertEquals(TimeValue.timeValueMillis(400).nanos(), searchRequestSlowLog.getWarnThreshold());
+        assertEquals(TimeValue.timeValueMillis(-1).nanos(), searchRequestSlowLog.getInfoThreshold());
+        assertEquals(TimeValue.timeValueMillis(200).nanos(), searchRequestSlowLog.getDebugThreshold());
+        assertEquals(TimeValue.timeValueMillis(-1).nanos(), searchRequestSlowLog.getTraceThreshold());
+        assertEquals(SlowLogLevel.TRACE, searchRequestSlowLog.getLevel());
+    }
+
+    public void testSetThresholdsError() {
+        Settings.Builder settingsBuilder = Settings.builder();
+        settingsBuilder.put(SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_THRESHOLD_WARN_SETTING.getKey(), "NOT A TIME VALUE");
+        Settings settings = settingsBuilder.build();
+        ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        ClusterService clusterService = new ClusterService(settings, clusterSettings, null);
+
+        try {
+            new SearchRequestSlowLog(clusterService);
+            fail();
+        } catch (IllegalArgumentException ex) {
+            final String expected =
+                "failed to parse setting [cluster.search.request.slowlog.threshold.warn] with value [NOT A TIME VALUE] as a time value";
+            assertThat(ex, hasToString(containsString(expected)));
+            assertThat(ex, instanceOf(IllegalArgumentException.class));
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/action/search/SearchRequestStatsTests.java b/server/src/test/java/org/opensearch/action/search/SearchRequestStatsTests.java
new file mode 100644
index 0000000000000..93cf77933fdd5
--- /dev/null
+++ b/server/src/test/java/org/opensearch/action/search/SearchRequestStatsTests.java
@@ -0,0 +1,150 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Phaser;
+import java.util.concurrent.TimeUnit;
+
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class SearchRequestStatsTests extends OpenSearchTestCase {
+    public void testSearchRequestPhaseFailure() {
+        SearchRequestStats testRequestStats = new SearchRequestStats();
+        SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+        SearchPhase mockSearchPhase = mock(SearchPhase.class);
+        when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            testRequestStats.onPhaseStart(ctx);
+            assertEquals(1, testRequestStats.getPhaseCurrent(searchPhaseName));
+            testRequestStats.onPhaseFailure(ctx);
+            assertEquals(0, testRequestStats.getPhaseCurrent(searchPhaseName));
+        }
+    }
+
+    public void testSearchRequestStats() {
+        SearchRequestStats testRequestStats = new SearchRequestStats();
+
+        SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+        SearchPhase mockSearchPhase = mock(SearchPhase.class);
+        when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            long tookTimeInMillis = randomIntBetween(1, 10);
+            testRequestStats.onPhaseStart(ctx);
+            long startTime = System.nanoTime() - TimeUnit.MILLISECONDS.toNanos(tookTimeInMillis);
+            when(mockSearchPhase.getStartTimeInNanos()).thenReturn(startTime);
+            assertEquals(1, testRequestStats.getPhaseCurrent(searchPhaseName));
+            testRequestStats.onPhaseEnd(ctx, new SearchRequestContext());
+            assertEquals(0, testRequestStats.getPhaseCurrent(searchPhaseName));
+            assertEquals(1, testRequestStats.getPhaseTotal(searchPhaseName));
+            assertThat(testRequestStats.getPhaseMetric(searchPhaseName), greaterThanOrEqualTo(tookTimeInMillis));
+        }
+    }
+
+    public void testSearchRequestStatsOnPhaseStartConcurrently() throws InterruptedException {
+        SearchRequestStats testRequestStats = new SearchRequestStats();
+        int numTasks = randomIntBetween(5, 50);
+        Thread[] threads = new Thread[numTasks * SearchPhaseName.values().length];
+        Phaser phaser = new Phaser(numTasks * SearchPhaseName.values().length + 1);
+        CountDownLatch countDownLatch = new CountDownLatch(numTasks * SearchPhaseName.values().length);
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+            SearchPhase mockSearchPhase = mock(SearchPhase.class);
+            when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            for (int i = 0; i < numTasks; i++) {
+                threads[i] = new Thread(() -> {
+                    phaser.arriveAndAwaitAdvance();
+                    testRequestStats.onPhaseStart(ctx);
+                    countDownLatch.countDown();
+                });
+                threads[i].start();
+            }
+        }
+        phaser.arriveAndAwaitAdvance();
+        countDownLatch.await();
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            assertEquals(numTasks, testRequestStats.getPhaseCurrent(searchPhaseName));
+        }
+    }
+
+    public void testSearchRequestStatsOnPhaseEndConcurrently() throws InterruptedException {
+        SearchRequestStats testRequestStats = new SearchRequestStats();
+        int numTasks = randomIntBetween(5, 50);
+        Thread[] threads = new Thread[numTasks * SearchPhaseName.values().length];
+        Phaser phaser = new Phaser(numTasks * SearchPhaseName.values().length + 1);
+        CountDownLatch countDownLatch = new CountDownLatch(numTasks * SearchPhaseName.values().length);
+        Map<SearchPhaseName, Long> searchPhaseNameLongMap = new HashMap<>();
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+            SearchPhase mockSearchPhase = mock(SearchPhase.class);
+            when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            long tookTimeInMillis = randomIntBetween(1, 10);
+            long startTime = System.nanoTime() - TimeUnit.MILLISECONDS.toNanos(tookTimeInMillis);
+            when(mockSearchPhase.getStartTimeInNanos()).thenReturn(startTime);
+            for (int i = 0; i < numTasks; i++) {
+                threads[i] = new Thread(() -> {
+                    phaser.arriveAndAwaitAdvance();
+                    testRequestStats.onPhaseEnd(ctx, new SearchRequestContext());
+                    countDownLatch.countDown();
+                });
+                threads[i].start();
+            }
+            searchPhaseNameLongMap.put(searchPhaseName, tookTimeInMillis);
+        }
+        phaser.arriveAndAwaitAdvance();
+        countDownLatch.await();
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            assertEquals(numTasks, testRequestStats.getPhaseTotal(searchPhaseName));
+            assertThat(
+                testRequestStats.getPhaseMetric(searchPhaseName),
+                greaterThanOrEqualTo((searchPhaseNameLongMap.get(searchPhaseName) * numTasks))
+            );
+        }
+    }
+
+    public void testSearchRequestStatsOnPhaseFailureConcurrently() throws InterruptedException {
+        SearchRequestStats testRequestStats = new SearchRequestStats();
+        int numTasks = randomIntBetween(5, 50);
+        Thread[] threads = new Thread[numTasks * SearchPhaseName.values().length];
+        Phaser phaser = new Phaser(numTasks * SearchPhaseName.values().length + 1);
+        CountDownLatch countDownLatch = new CountDownLatch(numTasks * SearchPhaseName.values().length);
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+            SearchPhase mockSearchPhase = mock(SearchPhase.class);
+            when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            for (int i = 0; i < numTasks; i++) {
+                threads[i] = new Thread(() -> {
+                    phaser.arriveAndAwaitAdvance();
+                    testRequestStats.onPhaseStart(ctx);
+                    testRequestStats.onPhaseFailure(ctx);
+                    countDownLatch.countDown();
+                });
+                threads[i].start();
+            }
+        }
+        phaser.arriveAndAwaitAdvance();
+        countDownLatch.await();
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            assertEquals(0, testRequestStats.getPhaseCurrent(searchPhaseName));
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/action/search/SearchRequestTests.java b/server/src/test/java/org/opensearch/action/search/SearchRequestTests.java
index 25d8c5551880f..f025e3a63b9bf 100644
--- a/server/src/test/java/org/opensearch/action/search/SearchRequestTests.java
+++ b/server/src/test/java/org/opensearch/action/search/SearchRequestTests.java
@@ -244,6 +244,9 @@ private SearchRequest mutate(SearchRequest searchRequest) {
         );
         mutators.add(() -> mutation.source(randomValueOtherThan(searchRequest.source(), this::createSearchSourceBuilder)));
         mutators.add(() -> mutation.setCcsMinimizeRoundtrips(searchRequest.isCcsMinimizeRoundtrips() == false));
+        mutators.add(
+            () -> mutation.setPhaseTook(searchRequest.isPhaseTook() == null ? randomBoolean() : searchRequest.isPhaseTook() == false)
+        );
         mutators.add(
             () -> mutation.setCancelAfterTimeInterval(
                 searchRequest.getCancelAfterTimeInterval() != null
diff --git a/server/src/test/java/org/opensearch/action/search/SearchResponseTests.java b/server/src/test/java/org/opensearch/action/search/SearchResponseTests.java
index 097e922147698..c9e59ab4ea04d 100644
--- a/server/src/test/java/org/opensearch/action/search/SearchResponseTests.java
+++ b/server/src/test/java/org/opensearch/action/search/SearchResponseTests.java
@@ -74,7 +74,9 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.UUID;
 
 import static java.util.Collections.singletonMap;
@@ -152,6 +154,11 @@ public SearchResponse createTestItem(
         Boolean terminatedEarly = randomBoolean() ? null : randomBoolean();
         int numReducePhases = randomIntBetween(1, 10);
         long tookInMillis = randomNonNegativeLong();
+        Map<String, Long> phaseTookMap = new HashMap<>();
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            phaseTookMap.put(searchPhaseName.getName(), randomNonNegativeLong());
+        }
+        SearchResponse.PhaseTook phaseTook = new SearchResponse.PhaseTook(phaseTookMap);
         int totalShards = randomIntBetween(1, Integer.MAX_VALUE);
         int successfulShards = randomIntBetween(0, totalShards);
         int skippedShards = randomIntBetween(0, totalShards);
@@ -182,6 +189,7 @@ public SearchResponse createTestItem(
             successfulShards,
             skippedShards,
             tookInMillis,
+            phaseTook,
             shardSearchFailures,
             randomBoolean() ? randomClusters() : SearchResponse.Clusters.EMPTY,
             null
@@ -353,6 +361,14 @@ public void testToXContent() {
             assertEquals(1, searchExtBuilders.size());
         }
         {
+            Map<String, Long> phaseTookMap = new HashMap<>();
+            for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+                phaseTookMap.put(searchPhaseName.getName(), 0L);
+            }
+            phaseTookMap.put(SearchPhaseName.QUERY.getName(), 50L);
+            phaseTookMap.put(SearchPhaseName.FETCH.getName(), 25L);
+            phaseTookMap.put(SearchPhaseName.EXPAND.getName(), 30L);
+            SearchResponse.PhaseTook phaseTook = new SearchResponse.PhaseTook(phaseTookMap);
             SearchResponse response = new SearchResponse(
                 new InternalSearchResponse(
                     new SearchHits(hits, new TotalHits(100, TotalHits.Relation.EQUAL_TO), 1.5f),
@@ -368,13 +384,24 @@ public void testToXContent() {
                 0,
                 0,
                 0,
+                phaseTook,
                 ShardSearchFailure.EMPTY_ARRAY,
-                new SearchResponse.Clusters(5, 3, 2)
+                new SearchResponse.Clusters(5, 3, 2),
+                null
             );
             StringBuilder expectedString = new StringBuilder();
             expectedString.append("{");
             {
                 expectedString.append("\"took\":0,");
+                expectedString.append("\"phase_took\":");
+                {
+                    expectedString.append("{\"dfs_pre_query\":0,");
+                    expectedString.append("\"query\":50,");
+                    expectedString.append("\"fetch\":25,");
+                    expectedString.append("\"dfs_query\":0,");
+                    expectedString.append("\"expand\":30,");
+                    expectedString.append("\"can_match\":0},");
+                }
                 expectedString.append("\"timed_out\":false,");
                 expectedString.append("\"_shards\":");
                 {
@@ -477,6 +504,24 @@ public void testToXContentEmptyClusters() throws IOException {
         assertEquals(0, builder.toString().length());
     }
 
+    public void testSearchResponsePhaseTookEquals() throws IOException {
+        SearchResponse.PhaseTook phaseTookA = new SearchResponse.PhaseTook(Map.of("foo", 0L, "bar", 1L));
+        SearchResponse.PhaseTook phaseTookB = new SearchResponse.PhaseTook(Map.of("foo", 1L, "bar", 1L));
+        SearchResponse.PhaseTook phaseTookC = new SearchResponse.PhaseTook(Map.of("foo", 0L));
+        SearchResponse.PhaseTook phaseTookD = new SearchResponse.PhaseTook(Map.of());
+
+        assertNotEquals(phaseTookA, phaseTookB);
+        assertNotEquals(phaseTookB, phaseTookA);
+        assertNotEquals(phaseTookA, phaseTookC);
+        assertNotEquals(phaseTookC, phaseTookA);
+        assertNotEquals(phaseTookA, phaseTookD);
+        assertNotEquals(phaseTookD, phaseTookA);
+        assertEquals(phaseTookA, phaseTookA);
+        assertEquals(phaseTookB, phaseTookB);
+        assertEquals(phaseTookC, phaseTookC);
+        assertEquals(phaseTookD, phaseTookD);
+    }
+
     static class DummySearchExtBuilder extends SearchExtBuilder {
 
         static ParseField DUMMY_FIELD = new ParseField("dummy");
diff --git a/server/src/test/java/org/opensearch/action/search/SearchTimeProviderTests.java b/server/src/test/java/org/opensearch/action/search/SearchTimeProviderTests.java
new file mode 100644
index 0000000000000..4d8a44417a3ee
--- /dev/null
+++ b/server/src/test/java/org/opensearch/action/search/SearchTimeProviderTests.java
@@ -0,0 +1,54 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.search;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.concurrent.TimeUnit;
+
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class SearchTimeProviderTests extends OpenSearchTestCase {
+
+    public void testSearchTimeProviderPhaseFailure() {
+        TransportSearchAction.SearchTimeProvider testTimeProvider = new TransportSearchAction.SearchTimeProvider(0, 0, () -> 0);
+        SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+        SearchPhase mockSearchPhase = mock(SearchPhase.class);
+        when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            testTimeProvider.onPhaseStart(ctx);
+            assertNull(testTimeProvider.getPhaseTookTime(searchPhaseName));
+            testTimeProvider.onPhaseFailure(ctx);
+            assertNull(testTimeProvider.getPhaseTookTime(searchPhaseName));
+        }
+    }
+
+    public void testSearchTimeProviderPhaseEnd() {
+        TransportSearchAction.SearchTimeProvider testTimeProvider = new TransportSearchAction.SearchTimeProvider(0, 0, () -> 0);
+
+        SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+        SearchPhase mockSearchPhase = mock(SearchPhase.class);
+        when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            long tookTimeInMillis = randomIntBetween(1, 100);
+            testTimeProvider.onPhaseStart(ctx);
+            long startTime = System.nanoTime() - TimeUnit.MILLISECONDS.toNanos(tookTimeInMillis);
+            when(mockSearchPhase.getStartTimeInNanos()).thenReturn(startTime);
+            assertNull(testTimeProvider.getPhaseTookTime(searchPhaseName));
+            testTimeProvider.onPhaseEnd(ctx, new SearchRequestContext());
+            assertThat(testTimeProvider.getPhaseTookTime(searchPhaseName), greaterThanOrEqualTo(tookTimeInMillis));
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/action/support/replication/BroadcastReplicationTests.java b/server/src/test/java/org/opensearch/action/support/replication/BroadcastReplicationTests.java
index 77c9c64ad6611..19a9918fa4561 100644
--- a/server/src/test/java/org/opensearch/action/support/replication/BroadcastReplicationTests.java
+++ b/server/src/test/java/org/opensearch/action/support/replication/BroadcastReplicationTests.java
@@ -116,7 +116,8 @@ public void setUp() throws Exception {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            circuitBreakerService
+            circuitBreakerService,
+            NoopTracer.INSTANCE
         );
         clusterService = createClusterService(threadPool);
         transportService = new TransportService(
diff --git a/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationActionTests.java b/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationActionTests.java
index 0bee99f4d5656..dad0fa0efd3ec 100644
--- a/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationActionTests.java
+++ b/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationActionTests.java
@@ -153,7 +153,7 @@ public class TransportReplicationActionTests extends OpenSearchTestCase {
     /**
      * takes a request that was sent by a {@link TransportReplicationAction} and captured
      * and returns the underlying request if it's wrapped or the original (cast to the expected type).
-     *
+     * <p>
      * This will throw a {@link ClassCastException} if the request is of the wrong type.
      */
     public static <R extends ReplicationRequest> R resolveRequest(TransportRequest requestOrWrappedRequest) {
@@ -1318,7 +1318,8 @@ public void testRetryOnReplicaWithRealTransport() throws Exception {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             namedWriteableRegistry,
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         );
         transportService = new MockTransportService(
             Settings.EMPTY,
diff --git a/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationAllPermitsAcquisitionTests.java b/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationAllPermitsAcquisitionTests.java
index 839ac7ab5bb92..cce8758ef1014 100644
--- a/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationAllPermitsAcquisitionTests.java
+++ b/server/src/test/java/org/opensearch/action/support/replication/TransportReplicationAllPermitsAcquisitionTests.java
@@ -114,7 +114,7 @@
  * This test tests the concurrent execution of several transport replication actions. All of these actions (except one) acquire a single
  * permit during their execution on shards and are expected to fail if a global level or index level block is present in the cluster state.
  * These actions are all started at the same time, but some are delayed until one last action.
- *
+ * <p>
  * This last action is special because it acquires all the permits on shards, adds the block to the cluster state and then "releases" the
  * previously delayed single permit actions. This way, there is a clear transition between the single permit actions executed before the
  * all permit action that sets the block and those executed afterwards that are doomed to fail because of the block.
diff --git a/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionForIndexingPressureTests.java b/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionForIndexingPressureTests.java
index 4a2185d1558f7..7212b1f5efe13 100644
--- a/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionForIndexingPressureTests.java
+++ b/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionForIndexingPressureTests.java
@@ -392,7 +392,8 @@ protected TestAction(
                 ignore -> ThreadPool.Names.SAME,
                 false,
                 TransportWriteActionForIndexingPressureTests.this.indexingPressureService,
-                new SystemIndices(emptyMap())
+                new SystemIndices(emptyMap()),
+                NoopTracer.INSTANCE
             );
         }
 
diff --git a/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionTests.java b/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionTests.java
index 9d2069ac16190..b4549f82230bf 100644
--- a/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionTests.java
+++ b/server/src/test/java/org/opensearch/action/support/replication/TransportWriteActionTests.java
@@ -477,7 +477,8 @@ protected TestAction(boolean withDocumentFailureOnPrimary, boolean withDocumentF
                 ignore -> ThreadPool.Names.SAME,
                 false,
                 new IndexingPressureService(Settings.EMPTY, TransportWriteActionTests.this.clusterService),
-                new SystemIndices(emptyMap())
+                new SystemIndices(emptyMap()),
+                NoopTracer.INSTANCE
             );
             this.withDocumentFailureOnPrimary = withDocumentFailureOnPrimary;
             this.withDocumentFailureOnReplica = withDocumentFailureOnReplica;
@@ -505,7 +506,8 @@ protected TestAction(
                 ignore -> ThreadPool.Names.SAME,
                 false,
                 new IndexingPressureService(settings, clusterService),
-                new SystemIndices(emptyMap())
+                new SystemIndices(emptyMap()),
+                NoopTracer.INSTANCE
             );
             this.withDocumentFailureOnPrimary = false;
             this.withDocumentFailureOnReplica = false;
diff --git a/server/src/test/java/org/opensearch/action/termvectors/AbstractTermVectorsTestCase.java b/server/src/test/java/org/opensearch/action/termvectors/AbstractTermVectorsTestCase.java
index 23153b5a45d4c..4b0bde0984ad1 100644
--- a/server/src/test/java/org/opensearch/action/termvectors/AbstractTermVectorsTestCase.java
+++ b/server/src/test/java/org/opensearch/action/termvectors/AbstractTermVectorsTestCase.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.action.termvectors;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.CharArraySet;
 import org.apache.lucene.analysis.LowerCaseFilter;
@@ -62,22 +64,43 @@
 import org.apache.lucene.store.Directory;
 import org.opensearch.action.admin.indices.alias.Alias;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.xcontent.XContentBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Locale;
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.equalTo;
 
-public abstract class AbstractTermVectorsTestCase extends OpenSearchIntegTestCase {
+public abstract class AbstractTermVectorsTestCase extends ParameterizedOpenSearchIntegTestCase {
+
+    public AbstractTermVectorsTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     protected static class TestFieldSetting {
         public final String name;
         public final boolean storedOffset;
diff --git a/server/src/test/java/org/opensearch/cluster/DiskUsageTests.java b/server/src/test/java/org/opensearch/cluster/DiskUsageTests.java
index 8ba965b3df1ab..ff47ec3015697 100644
--- a/server/src/test/java/org/opensearch/cluster/DiskUsageTests.java
+++ b/server/src/test/java/org/opensearch/cluster/DiskUsageTests.java
@@ -190,6 +190,10 @@ public void testFillDiskUsage() {
                 null,
                 null,
                 null,
+                null,
+                null,
+                null,
+                null,
                 null
             ),
             new NodeStats(
@@ -216,6 +220,10 @@ public void testFillDiskUsage() {
                 null,
                 null,
                 null,
+                null,
+                null,
+                null,
+                null,
                 null
             ),
             new NodeStats(
@@ -242,6 +250,10 @@ public void testFillDiskUsage() {
                 null,
                 null,
                 null,
+                null,
+                null,
+                null,
+                null,
                 null
             )
         );
@@ -299,6 +311,10 @@ public void testFillDiskUsageSomeInvalidValues() {
                 null,
                 null,
                 null,
+                null,
+                null,
+                null,
+                null,
                 null
             ),
             new NodeStats(
@@ -325,6 +341,10 @@ public void testFillDiskUsageSomeInvalidValues() {
                 null,
                 null,
                 null,
+                null,
+                null,
+                null,
+                null,
                 null
             ),
             new NodeStats(
@@ -351,6 +371,10 @@ public void testFillDiskUsageSomeInvalidValues() {
                 null,
                 null,
                 null,
+                null,
+                null,
+                null,
+                null,
                 null
             )
         );
diff --git a/server/src/test/java/org/opensearch/cluster/coordination/CoordinationCheckerSettingsTests.java b/server/src/test/java/org/opensearch/cluster/coordination/CoordinationCheckerSettingsTests.java
new file mode 100644
index 0000000000000..56bd2d94dce84
--- /dev/null
+++ b/server/src/test/java/org/opensearch/cluster/coordination/CoordinationCheckerSettingsTests.java
@@ -0,0 +1,113 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.cluster.coordination;
+
+import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsResponse;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.test.OpenSearchSingleNodeTestCase;
+
+import static org.opensearch.cluster.coordination.FollowersChecker.FOLLOWER_CHECK_TIMEOUT_SETTING;
+import static org.opensearch.cluster.coordination.LeaderChecker.LEADER_CHECK_TIMEOUT_SETTING;
+import static org.opensearch.common.unit.TimeValue.timeValueSeconds;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+
+public class CoordinationCheckerSettingsTests extends OpenSearchSingleNodeTestCase {
+    public void testFollowerCheckTimeoutValueUpdate() {
+        Setting<TimeValue> setting1 = FOLLOWER_CHECK_TIMEOUT_SETTING;
+        Settings timeSettings1 = Settings.builder().put(setting1.getKey(), "60s").build();
+        try {
+            ClusterUpdateSettingsResponse response = client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setPersistentSettings(timeSettings1)
+                .execute()
+                .actionGet();
+
+            assertAcked(response);
+            assertEquals(timeValueSeconds(60), setting1.get(response.getPersistentSettings()));
+        } finally {
+            // cleanup
+            timeSettings1 = Settings.builder().putNull(setting1.getKey()).build();
+            client().admin().cluster().prepareUpdateSettings().setPersistentSettings(timeSettings1).execute().actionGet();
+        }
+    }
+
+    public void testFollowerCheckTimeoutMaxValue() {
+        Setting<TimeValue> setting1 = FOLLOWER_CHECK_TIMEOUT_SETTING;
+        Settings timeSettings1 = Settings.builder().put(setting1.getKey(), "61s").build();
+
+        assertThrows(
+            "failed to parse value [61s] for setting [" + setting1.getKey() + "], must be <= [60000ms]",
+            IllegalArgumentException.class,
+            () -> {
+                client().admin().cluster().prepareUpdateSettings().setPersistentSettings(timeSettings1).execute().actionGet();
+            }
+        );
+    }
+
+    public void testFollowerCheckTimeoutMinValue() {
+        Setting<TimeValue> setting1 = FOLLOWER_CHECK_TIMEOUT_SETTING;
+        Settings timeSettings1 = Settings.builder().put(setting1.getKey(), "0s").build();
+
+        assertThrows(
+            "failed to parse value [0s] for setting [" + setting1.getKey() + "], must be >= [1ms]",
+            IllegalArgumentException.class,
+            () -> {
+                client().admin().cluster().prepareUpdateSettings().setPersistentSettings(timeSettings1).execute().actionGet();
+            }
+        );
+    }
+
+    public void testLeaderCheckTimeoutValueUpdate() {
+        Setting<TimeValue> setting1 = LEADER_CHECK_TIMEOUT_SETTING;
+        Settings timeSettings1 = Settings.builder().put(setting1.getKey(), "60s").build();
+        try {
+            ClusterUpdateSettingsResponse response = client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setPersistentSettings(timeSettings1)
+                .execute()
+                .actionGet();
+            assertAcked(response);
+            assertEquals(timeValueSeconds(60), setting1.get(response.getPersistentSettings()));
+        } finally {
+            // cleanup
+            timeSettings1 = Settings.builder().putNull(setting1.getKey()).build();
+            client().admin().cluster().prepareUpdateSettings().setPersistentSettings(timeSettings1).execute().actionGet();
+        }
+    }
+
+    public void testLeaderCheckTimeoutMaxValue() {
+        Setting<TimeValue> setting1 = LEADER_CHECK_TIMEOUT_SETTING;
+        Settings timeSettings1 = Settings.builder().put(setting1.getKey(), "61s").build();
+
+        assertThrows(
+            "failed to parse value [61s] for setting [" + setting1.getKey() + "], must be <= [60000ms]",
+            IllegalArgumentException.class,
+            () -> {
+                client().admin().cluster().prepareUpdateSettings().setPersistentSettings(timeSettings1).execute().actionGet();
+            }
+        );
+    }
+
+    public void testLeaderCheckTimeoutMinValue() {
+        Setting<TimeValue> setting1 = LEADER_CHECK_TIMEOUT_SETTING;
+        Settings timeSettings1 = Settings.builder().put(setting1.getKey(), "0s").build();
+
+        assertThrows(
+            "failed to parse value [0s] for setting [" + setting1.getKey() + "], must be >= [1ms]",
+            IllegalArgumentException.class,
+            () -> {
+                client().admin().cluster().prepareUpdateSettings().setPersistentSettings(timeSettings1).execute().actionGet();
+            }
+        );
+    }
+}
diff --git a/server/src/test/java/org/opensearch/cluster/coordination/CoordinationStateTests.java b/server/src/test/java/org/opensearch/cluster/coordination/CoordinationStateTests.java
index d1c2dda615992..1c0dc7fc1ca2d 100644
--- a/server/src/test/java/org/opensearch/cluster/coordination/CoordinationStateTests.java
+++ b/server/src/test/java/org/opensearch/cluster/coordination/CoordinationStateTests.java
@@ -60,6 +60,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mockito;
 
 import static java.util.Collections.emptyMap;
@@ -70,6 +71,9 @@
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.nullValue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
 public class CoordinationStateTests extends OpenSearchTestCase {
 
@@ -925,6 +929,7 @@ public void testHandlePrePublishAndCommitWhenRemoteStateEnabled() throws IOExcep
         final RemoteClusterStateService remoteClusterStateService = Mockito.mock(RemoteClusterStateService.class);
         final VotingConfiguration initialConfig = VotingConfiguration.of(node1);
         final ClusterState clusterState = clusterState(0L, 0L, node1, initialConfig, initialConfig, 42L);
+        final String previousClusterUUID = "prev-cluster-uuid";
         final ClusterMetadataManifest manifest = new ClusterMetadataManifest(
             0L,
             0L,
@@ -933,14 +938,20 @@ public void testHandlePrePublishAndCommitWhenRemoteStateEnabled() throws IOExcep
             Version.CURRENT,
             randomAlphaOfLength(10),
             false,
+            1,
+            randomAlphaOfLength(10),
             Collections.emptyList(),
-            randomAlphaOfLength(10)
+            randomAlphaOfLength(10),
+            true
         );
-        Mockito.when(remoteClusterStateService.writeFullMetadata(clusterState)).thenReturn(manifest);
+        Mockito.when(remoteClusterStateService.writeFullMetadata(clusterState, previousClusterUUID)).thenReturn(manifest);
 
         final PersistedStateRegistry persistedStateRegistry = persistedStateRegistry();
         persistedStateRegistry.addPersistedState(PersistedStateType.LOCAL, ps1);
-        persistedStateRegistry.addPersistedState(PersistedStateType.REMOTE, new RemotePersistedState(remoteClusterStateService));
+        persistedStateRegistry.addPersistedState(
+            PersistedStateType.REMOTE,
+            new RemotePersistedState(remoteClusterStateService, previousClusterUUID)
+        );
 
         String randomRepoName = "randomRepoName";
         String stateRepoTypeAttributeKey = String.format(
@@ -963,11 +974,28 @@ public void testHandlePrePublishAndCommitWhenRemoteStateEnabled() throws IOExcep
 
         final CoordinationState coordinationState = createCoordinationState(persistedStateRegistry, node1, settings);
         coordinationState.handlePrePublish(clusterState);
-        Mockito.verify(remoteClusterStateService, Mockito.times(1)).writeFullMetadata(clusterState);
+        Mockito.verify(remoteClusterStateService, Mockito.times(1)).writeFullMetadata(clusterState, previousClusterUUID);
         assertThat(persistedStateRegistry.getPersistedState(PersistedStateType.REMOTE).getLastAcceptedState(), equalTo(clusterState));
 
         coordinationState.handlePreCommit();
-        Mockito.verify(remoteClusterStateService, Mockito.times(1)).markLastStateAsCommitted(clusterState, manifest);
+        ClusterState committedClusterState = ClusterState.builder(clusterState)
+            .metadata(Metadata.builder(clusterState.metadata()).clusterUUIDCommitted(true).build())
+            .build();
+        // Mockito.verify(remoteClusterStateService, Mockito.times(1)).markLastStateAsCommitted(committedClusterState, manifest);
+        ArgumentCaptor<ClusterState> clusterStateCaptor = ArgumentCaptor.forClass(ClusterState.class);
+        verify(remoteClusterStateService, times(1)).markLastStateAsCommitted(clusterStateCaptor.capture(), any());
+        assertThat(clusterStateCaptor.getValue().metadata().indices(), equalTo(committedClusterState.metadata().indices()));
+        assertThat(clusterStateCaptor.getValue().metadata().clusterUUID(), equalTo(committedClusterState.metadata().clusterUUID()));
+        assertThat(clusterStateCaptor.getValue().stateUUID(), equalTo(committedClusterState.stateUUID()));
+        assertThat(
+            clusterStateCaptor.getValue().coordinationMetadata().term(),
+            equalTo(committedClusterState.coordinationMetadata().term())
+        );
+        assertThat(clusterStateCaptor.getValue().version(), equalTo(committedClusterState.version()));
+        assertThat(
+            clusterStateCaptor.getValue().metadata().clusterUUIDCommitted(),
+            equalTo(committedClusterState.metadata().clusterUUIDCommitted())
+        );
     }
 
     public static CoordinationState createCoordinationState(
diff --git a/server/src/test/java/org/opensearch/cluster/coordination/FollowersCheckerTests.java b/server/src/test/java/org/opensearch/cluster/coordination/FollowersCheckerTests.java
index c152a1606681e..a106706c00732 100644
--- a/server/src/test/java/org/opensearch/cluster/coordination/FollowersCheckerTests.java
+++ b/server/src/test/java/org/opensearch/cluster/coordination/FollowersCheckerTests.java
@@ -39,6 +39,7 @@
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodeRole;
 import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.settings.Settings.Builder;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -96,7 +97,7 @@ public class FollowersCheckerTests extends OpenSearchTestCase {
     public void testChecksExpectedNodes() {
         final DiscoveryNode localNode = new DiscoveryNode("local-node", buildNewFakeTransportAddress(), Version.CURRENT);
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), localNode.getName()).build();
-
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DiscoveryNodes[] discoveryNodesHolder = new DiscoveryNodes[] {
             DiscoveryNodes.builder().add(localNode).localNodeId(localNode.getId()).build() };
 
@@ -132,6 +133,7 @@ protected void onSendRequest(long requestId, String action, TransportRequest req
 
         final FollowersChecker followersChecker = new FollowersChecker(
             settings,
+            clusterSettings,
             transportService,
             fcr -> { assert false : fcr; },
             (node, reason) -> {
@@ -257,6 +259,7 @@ public void testFailsNodeThatDisconnects() {
         final DiscoveryNode localNode = new DiscoveryNode("local-node", buildNewFakeTransportAddress(), Version.CURRENT);
         final DiscoveryNode otherNode = new DiscoveryNode("other-node", buildNewFakeTransportAddress(), Version.CURRENT);
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), localNode.getName()).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
 
         final MockTransport mockTransport = new MockTransport() {
@@ -297,6 +300,7 @@ public String toString() {
 
         final FollowersChecker followersChecker = new FollowersChecker(
             settings,
+            clusterSettings,
             transportService,
             fcr -> { assert false : fcr; },
             (node, reason) -> {
@@ -336,6 +340,7 @@ private void testBehaviourOfFailingNode(
         final DiscoveryNode localNode = new DiscoveryNode("local-node", buildNewFakeTransportAddress(), Version.CURRENT);
         final DiscoveryNode otherNode = new DiscoveryNode("other-node", buildNewFakeTransportAddress(), Version.CURRENT);
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), localNode.getName()).put(testSettings).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
 
         final MockTransport mockTransport = new MockTransport() {
@@ -384,6 +389,7 @@ public String toString() {
 
         final FollowersChecker followersChecker = new FollowersChecker(
             settings,
+            clusterSettings,
             transportService,
             fcr -> { assert false : fcr; },
             (node, reason) -> {
@@ -464,6 +470,7 @@ public void testUnhealthyNodeRejectsImmediately() {
         final DiscoveryNode leader = new DiscoveryNode("leader", buildNewFakeTransportAddress(), Version.CURRENT);
         final DiscoveryNode follower = new DiscoveryNode("follower", buildNewFakeTransportAddress(), Version.CURRENT);
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), follower.getName()).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
 
         final MockTransport mockTransport = new MockTransport() {
@@ -488,7 +495,7 @@ protected void onSendRequest(long requestId, String action, TransportRequest req
         final AtomicBoolean calledCoordinator = new AtomicBoolean();
         final AtomicReference<RuntimeException> coordinatorException = new AtomicReference<>();
 
-        final FollowersChecker followersChecker = new FollowersChecker(settings, transportService, fcr -> {
+        final FollowersChecker followersChecker = new FollowersChecker(settings, clusterSettings, transportService, fcr -> {
             assertTrue(calledCoordinator.compareAndSet(false, true));
             final RuntimeException exception = coordinatorException.get();
             if (exception != null) {
@@ -536,6 +543,7 @@ public void testResponder() {
         final DiscoveryNode leader = new DiscoveryNode("leader", buildNewFakeTransportAddress(), Version.CURRENT);
         final DiscoveryNode follower = new DiscoveryNode("follower", buildNewFakeTransportAddress(), Version.CURRENT);
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), follower.getName()).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
 
         final MockTransport mockTransport = new MockTransport() {
@@ -560,7 +568,7 @@ protected void onSendRequest(long requestId, String action, TransportRequest req
         final AtomicBoolean calledCoordinator = new AtomicBoolean();
         final AtomicReference<RuntimeException> coordinatorException = new AtomicReference<>();
 
-        final FollowersChecker followersChecker = new FollowersChecker(settings, transportService, fcr -> {
+        final FollowersChecker followersChecker = new FollowersChecker(settings, clusterSettings, transportService, fcr -> {
             assertTrue(calledCoordinator.compareAndSet(false, true));
             final RuntimeException exception = coordinatorException.get();
             if (exception != null) {
@@ -700,6 +708,7 @@ public void testPreferClusterManagerNodes() {
         DiscoveryNodes discoveryNodes = discoNodesBuilder.localNodeId(nodes.get(0).getId()).build();
         CapturingTransport capturingTransport = new CapturingTransport();
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), nodes.get(0).getName()).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
         TransportService transportService = capturingTransport.createTransportService(
             Settings.EMPTY,
@@ -710,15 +719,9 @@ public void testPreferClusterManagerNodes() {
             emptySet(),
             NoopTracer.INSTANCE
         );
-        final FollowersChecker followersChecker = new FollowersChecker(
-            Settings.EMPTY,
-            transportService,
-            fcr -> { assert false : fcr; },
-            (node, reason) -> {
-                assert false : node;
-            },
-            () -> new StatusInfo(HEALTHY, "healthy-info")
-        );
+        final FollowersChecker followersChecker = new FollowersChecker(Settings.EMPTY, clusterSettings, transportService, fcr -> {
+            assert false : fcr;
+        }, (node, reason) -> { assert false : node; }, () -> new StatusInfo(HEALTHY, "healthy-info"));
         followersChecker.setCurrentNodes(discoveryNodes);
         List<DiscoveryNode> followerTargets = Stream.of(capturingTransport.getCapturedRequestsAndClear())
             .map(cr -> cr.node)
@@ -754,7 +757,7 @@ private static Settings randomSettings() {
             settingsBuilder.put(FOLLOWER_CHECK_INTERVAL_SETTING.getKey(), randomIntBetween(100, 100000) + "ms");
         }
         if (randomBoolean()) {
-            settingsBuilder.put(FOLLOWER_CHECK_TIMEOUT_SETTING.getKey(), randomIntBetween(1, 100000) + "ms");
+            settingsBuilder.put(FOLLOWER_CHECK_TIMEOUT_SETTING.getKey(), randomIntBetween(1, 60000) + "ms");
         }
         return settingsBuilder.build();
     }
diff --git a/server/src/test/java/org/opensearch/cluster/coordination/LeaderCheckerTests.java b/server/src/test/java/org/opensearch/cluster/coordination/LeaderCheckerTests.java
index 8915f4c5c1274..fe65058333116 100644
--- a/server/src/test/java/org/opensearch/cluster/coordination/LeaderCheckerTests.java
+++ b/server/src/test/java/org/opensearch/cluster/coordination/LeaderCheckerTests.java
@@ -38,6 +38,7 @@
 import org.opensearch.cluster.coordination.LeaderChecker.LeaderCheckRequest;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.transport.TransportResponse;
@@ -117,6 +118,7 @@ public void testFollowerBehaviour() {
         final AtomicBoolean allResponsesFail = new AtomicBoolean();
 
         final Settings settings = settingsBuilder.build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         logger.info("--> using {}", settings);
 
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
@@ -174,7 +176,7 @@ public String toString() {
 
         final AtomicBoolean leaderFailed = new AtomicBoolean();
 
-        final LeaderChecker leaderChecker = new LeaderChecker(settings, transportService, e -> {
+        final LeaderChecker leaderChecker = new LeaderChecker(settings, clusterSettings, transportService, e -> {
             assertThat(e.getMessage(), matchesRegex("node \\[.*\\] failed \\[[1-9][0-9]*\\] consecutive checks"));
             assertTrue(leaderFailed.compareAndSet(false, true));
         }, () -> new StatusInfo(StatusInfo.Status.HEALTHY, "healthy-info"));
@@ -242,6 +244,7 @@ public void testFollowerFailsImmediatelyOnDisconnection() {
         final Response[] responseHolder = new Response[] { Response.SUCCESS };
 
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), localNode.getId()).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
         final MockTransport mockTransport = new MockTransport() {
             @Override
@@ -290,7 +293,7 @@ public String toString() {
         transportService.acceptIncomingRequests();
 
         final AtomicBoolean leaderFailed = new AtomicBoolean();
-        final LeaderChecker leaderChecker = new LeaderChecker(settings, transportService, e -> {
+        final LeaderChecker leaderChecker = new LeaderChecker(settings, clusterSettings, transportService, e -> {
             assertThat(e.getMessage(), anyOf(endsWith("disconnected"), endsWith("disconnected during check")));
             assertTrue(leaderFailed.compareAndSet(false, true));
         }, () -> new StatusInfo(StatusInfo.Status.HEALTHY, "healthy-info"));
@@ -357,6 +360,7 @@ public void testFollowerFailsImmediatelyOnHealthCheckFailure() {
         final Response[] responseHolder = new Response[] { Response.SUCCESS };
 
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), localNode.getId()).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
         final MockTransport mockTransport = new MockTransport() {
             @Override
@@ -403,7 +407,7 @@ public String toString() {
         transportService.acceptIncomingRequests();
 
         final AtomicBoolean leaderFailed = new AtomicBoolean();
-        final LeaderChecker leaderChecker = new LeaderChecker(settings, transportService, e -> {
+        final LeaderChecker leaderChecker = new LeaderChecker(settings, clusterSettings, transportService, e -> {
             assertThat(e.getMessage(), endsWith("failed health checks"));
             assertTrue(leaderFailed.compareAndSet(false, true));
         }, () -> new StatusInfo(StatusInfo.Status.HEALTHY, "healthy-info"));
@@ -432,6 +436,7 @@ public void testLeaderBehaviour() {
         final DiscoveryNode localNode = new DiscoveryNode("local-node", buildNewFakeTransportAddress(), Version.CURRENT);
         final DiscoveryNode otherNode = new DiscoveryNode("other-node", buildNewFakeTransportAddress(), Version.CURRENT);
         final Settings settings = Settings.builder().put(NODE_NAME_SETTING.getKey(), localNode.getId()).build();
+        final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         final DeterministicTaskQueue deterministicTaskQueue = new DeterministicTaskQueue(settings, random());
         final CapturingTransport capturingTransport = new CapturingTransport();
         AtomicReference<StatusInfo> nodeHealthServiceStatus = new AtomicReference<>(new StatusInfo(UNHEALTHY, "unhealthy-info"));
@@ -450,6 +455,7 @@ public void testLeaderBehaviour() {
 
         final LeaderChecker leaderChecker = new LeaderChecker(
             settings,
+            clusterSettings,
             transportService,
             e -> fail("shouldn't be checking anything"),
             () -> nodeHealthServiceStatus.get()
diff --git a/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java b/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
index 8adaae6d230cd..c4a782209421b 100644
--- a/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
+++ b/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
@@ -70,6 +70,8 @@
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.mapper.MapperService;
 import org.opensearch.index.query.QueryShardContext;
+import org.opensearch.index.translog.Translog;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.InvalidAliasNameException;
 import org.opensearch.indices.InvalidIndexNameException;
 import org.opensearch.indices.ShardLimitValidator;
@@ -115,6 +117,7 @@
 import static org.opensearch.cluster.metadata.IndexMetadata.INDEX_NUMBER_OF_ROUTING_SHARDS_SETTING;
 import static org.opensearch.cluster.metadata.IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING;
 import static org.opensearch.cluster.metadata.IndexMetadata.INDEX_READ_ONLY_BLOCK;
+import static org.opensearch.cluster.metadata.IndexMetadata.INDEX_REPLICATION_TYPE_SETTING;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_SHARDS;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_READ_ONLY;
@@ -132,8 +135,10 @@
 import static org.opensearch.index.IndexSettings.INDEX_REFRESH_INTERVAL_SETTING;
 import static org.opensearch.index.IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING;
 import static org.opensearch.index.IndexSettings.INDEX_SOFT_DELETES_SETTING;
+import static org.opensearch.index.IndexSettings.INDEX_TRANSLOG_DURABILITY_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_DEFAULT_INDEX_REFRESH_INTERVAL_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING;
+import static org.opensearch.indices.IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_REPLICATION_TYPE_SETTING;
 import static org.opensearch.indices.ShardLimitValidatorTests.createTestShardLimitService;
 import static org.opensearch.node.Node.NODE_ATTRIBUTES;
@@ -1213,6 +1218,27 @@ public void testvalidateIndexSettings() {
         threadPool.shutdown();
     }
 
+    public void testIndexTemplateReplicationType() {
+        Settings templateSettings = Settings.builder().put(INDEX_REPLICATION_TYPE_SETTING.getKey(), ReplicationType.SEGMENT).build();
+
+        request = new CreateIndexClusterStateUpdateRequest("create index", "test", "test");
+        final Settings.Builder requestSettings = Settings.builder();
+        request.settings(requestSettings.build());
+        Settings indexSettings = aggregateIndexSettings(
+            ClusterState.EMPTY_STATE,
+            request,
+            templateSettings,
+            null,
+            Settings.EMPTY,
+            IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
+            randomShardLimitService(),
+            Collections.emptySet(),
+            clusterSettings
+        );
+        assertNotEquals(ReplicationType.SEGMENT, clusterSettings.get(CLUSTER_REPLICATION_TYPE_SETTING));
+        assertEquals(ReplicationType.SEGMENT.toString(), indexSettings.get(INDEX_REPLICATION_TYPE_SETTING.getKey()));
+    }
+
     public void testRemoteStoreNoUserOverrideExceptReplicationTypeSegmentIndexSettings() {
         Settings settings = Settings.builder()
             .put(CLUSTER_REPLICATION_TYPE_SETTING.getKey(), ReplicationType.DOCUMENT)
@@ -1725,6 +1751,87 @@ public void testRefreshIntervalValidationFailureWithIndexSetting() {
         );
     }
 
+    public void testAnyTranslogDurabilityWhenRestrictSettingFalse() {
+        // This checks that aggregateIndexSettings works for the case when the cluster setting
+        // cluster.remote_store.index.restrict.async-durability is false or not set, it allows all types of durability modes
+        request = new CreateIndexClusterStateUpdateRequest("create index", "test", "test");
+        final Settings.Builder requestSettings = Settings.builder();
+        Translog.Durability durability = randomFrom(Translog.Durability.values());
+        requestSettings.put(INDEX_TRANSLOG_DURABILITY_SETTING.getKey(), durability);
+        request.settings(requestSettings.build());
+        if (randomBoolean()) {
+            Settings settings = Settings.builder().put(CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING.getKey(), false).build();
+            clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        }
+        Settings indexSettings = aggregateIndexSettings(
+            ClusterState.EMPTY_STATE,
+            request,
+            Settings.EMPTY,
+            null,
+            Settings.EMPTY,
+            IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
+            randomShardLimitService(),
+            Collections.emptySet(),
+            clusterSettings
+        );
+        assertFalse(clusterSettings.get(IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING));
+        assertEquals(durability, INDEX_TRANSLOG_DURABILITY_SETTING.get(indexSettings));
+    }
+
+    public void testAsyncDurabilityThrowsExceptionWhenRestrictSettingTrue() {
+        // This checks that aggregateIndexSettings works for the case when the cluster setting
+        // cluster.remote_store.index.restrict.async-durability is false or not set, it allows all types of durability modes
+        request = new CreateIndexClusterStateUpdateRequest("create index", "test", "test");
+        final Settings.Builder requestSettings = Settings.builder();
+        requestSettings.put(INDEX_TRANSLOG_DURABILITY_SETTING.getKey(), Translog.Durability.ASYNC);
+        request.settings(requestSettings.build());
+        Settings settings = Settings.builder().put(CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING.getKey(), true).build();
+        clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        IllegalArgumentException exception = assertThrows(
+            IllegalArgumentException.class,
+            () -> aggregateIndexSettings(
+                ClusterState.EMPTY_STATE,
+                request,
+                Settings.EMPTY,
+                null,
+                Settings.builder().put("node.attr.remote_store.setting", "test").build(),
+                IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
+                randomShardLimitService(),
+                Collections.emptySet(),
+                clusterSettings
+            )
+        );
+        // verify that the message is as expected
+        assertEquals(
+            "index setting [index.translog.durability=async] is not allowed as cluster setting [cluster.remote_store.index.restrict.async-durability=true]",
+            exception.getMessage()
+        );
+    }
+
+    public void testRequestDurabilityWhenRestrictSettingTrue() {
+        // This checks that aggregateIndexSettings works for the case when the cluster setting
+        // cluster.remote_store.index.restrict.async-durability is false or not set, it allows all types of durability modes
+        request = new CreateIndexClusterStateUpdateRequest("create index", "test", "test");
+        final Settings.Builder requestSettings = Settings.builder();
+        requestSettings.put(INDEX_TRANSLOG_DURABILITY_SETTING.getKey(), Translog.Durability.REQUEST);
+        request.settings(requestSettings.build());
+        Settings settings = Settings.builder().put(CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING.getKey(), true).build();
+        clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        Settings indexSettings = aggregateIndexSettings(
+            ClusterState.EMPTY_STATE,
+            request,
+            Settings.EMPTY,
+            null,
+            Settings.EMPTY,
+            IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
+            randomShardLimitService(),
+            Collections.emptySet(),
+            clusterSettings
+        );
+        assertTrue(clusterSettings.get(IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING));
+        assertEquals(Translog.Durability.REQUEST, INDEX_TRANSLOG_DURABILITY_SETTING.get(indexSettings));
+    }
+
     private IndexTemplateMetadata addMatchingTemplate(Consumer<IndexTemplateMetadata.Builder> configurator) {
         IndexTemplateMetadata.Builder builder = templateMetadataBuilder("template1", "te*");
         configurator.accept(builder);
diff --git a/server/src/test/java/org/opensearch/cluster/metadata/MetadataTests.java b/server/src/test/java/org/opensearch/cluster/metadata/MetadataTests.java
index 40eefa6cdbf03..618fcb923bc60 100644
--- a/server/src/test/java/org/opensearch/cluster/metadata/MetadataTests.java
+++ b/server/src/test/java/org/opensearch/cluster/metadata/MetadataTests.java
@@ -627,6 +627,39 @@ public void testGlobalStateEqualsCoordinationMetadata() {
         assertFalse(Metadata.isGlobalStateEquals(metadata1, metadata2));
     }
 
+    public void testGlobalResourcesStateEqualsCoordinationMetadata() {
+        CoordinationMetadata coordinationMetadata1 = new CoordinationMetadata(
+            randomNonNegativeLong(),
+            randomVotingConfig(),
+            randomVotingConfig(),
+            randomVotingConfigExclusions()
+        );
+        Metadata metadata1 = Metadata.builder()
+            .coordinationMetadata(coordinationMetadata1)
+            .clusterUUID(randomAlphaOfLength(10))
+            .clusterUUIDCommitted(false)
+            .hashesOfConsistentSettings(Map.of("a", "b"))
+            .persistentSettings(Settings.builder().put(Metadata.SETTING_READ_ONLY_SETTING.getKey(), true).build())
+            .build();
+        CoordinationMetadata coordinationMetadata2 = new CoordinationMetadata(
+            randomNonNegativeLong(),
+            randomVotingConfig(),
+            randomVotingConfig(),
+            randomVotingConfigExclusions()
+        );
+        Metadata metadata2 = Metadata.builder()
+            .coordinationMetadata(coordinationMetadata2)
+            .clusterUUIDCommitted(true)
+            .clusterUUID(randomAlphaOfLength(11))
+            .hashesOfConsistentSettings(Map.of("b", "a"))
+            .persistentSettings(Settings.builder().put(Metadata.SETTING_READ_ONLY_SETTING.getKey(), true).build())
+            .build();
+
+        assertTrue(Metadata.isGlobalStateEquals(metadata1, metadata1));
+        assertFalse(Metadata.isGlobalStateEquals(metadata1, metadata2));
+        assertTrue(Metadata.isGlobalResourcesMetadataEquals(metadata1, metadata2));
+    }
+
     public void testSerializationWithIndexGraveyard() throws IOException {
         final IndexGraveyard graveyard = IndexGraveyardTests.createRandom();
         final Metadata originalMeta = Metadata.builder().indexGraveyard(graveyard).build();
diff --git a/server/src/test/java/org/opensearch/cluster/node/DiscoveryNodeTests.java b/server/src/test/java/org/opensearch/cluster/node/DiscoveryNodeTests.java
index 8b61e8f6d724d..c8a6fc76ce820 100644
--- a/server/src/test/java/org/opensearch/cluster/node/DiscoveryNodeTests.java
+++ b/server/src/test/java/org/opensearch/cluster/node/DiscoveryNodeTests.java
@@ -38,13 +38,16 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.node.remotestore.RemoteStoreNodeAttribute;
 import org.opensearch.test.NodeRoles;
 import org.opensearch.test.OpenSearchTestCase;
 
 import java.net.InetAddress;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -81,6 +84,22 @@ public void testRolesAreSorted() {
 
     }
 
+    public void testRemoteStoreRedactionInToString() {
+        final Set<DiscoveryNodeRole> roles = new HashSet<>(randomSubsetOf(DiscoveryNodeRole.BUILT_IN_ROLES));
+        Map<String, String> attributes = new HashMap<>();
+        attributes.put(RemoteStoreNodeAttribute.REMOTE_STORE_SEGMENT_REPOSITORY_NAME_ATTRIBUTE_KEY, "test-repo");
+        attributes.put(RemoteStoreNodeAttribute.REMOTE_STORE_CLUSTER_STATE_REPOSITORY_NAME_ATTRIBUTE_KEY, "test-repo");
+        final DiscoveryNode node = new DiscoveryNode(
+            "name",
+            "id",
+            new TransportAddress(TransportAddress.META_ADDRESS, 9200),
+            attributes,
+            roles,
+            Version.CURRENT
+        );
+        assertFalse(node.toString().contains(RemoteStoreNodeAttribute.REMOTE_STORE_NODE_ATTRIBUTE_KEY_PREFIX));
+    }
+
     public void testDiscoveryNodeIsCreatedWithHostFromInetAddress() throws Exception {
         InetAddress inetAddress = randomBoolean()
             ? InetAddress.getByName("192.0.2.1")
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/AllocationPriorityTests.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/AllocationPriorityTests.java
index f9f181402da1b..8cd664c8c13fc 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/AllocationPriorityTests.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/AllocationPriorityTests.java
@@ -50,7 +50,7 @@ public class AllocationPriorityTests extends OpenSearchAllocationTestCase {
 
     /**
      * Tests that higher prioritized primaries and replicas are allocated first even on the balanced shard allocator
-     * See https://github.com/elastic/elasticsearch/issues/13249 for details
+     * See <a href="https://github.com/elastic/elasticsearch/issues/13249">elasticsearch issue #13249</a> for details
      */
     public void testPrioritizedIndicesAllocatedFirst() {
         AllocationService allocation = createAllocationService(
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/BalanceConfigurationTests.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/BalanceConfigurationTests.java
index ba1e2d27a3bc5..62dce9c4edeb5 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/BalanceConfigurationTests.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/BalanceConfigurationTests.java
@@ -247,13 +247,13 @@ public void testPrimaryBalanceWithPreferPrimaryBalanceSetting() {
     /**
      * This test verifies the allocation logic when nodes breach multiple constraints and ensure node breaching min
      * constraints chosen for allocation.
-     *
+     * <p>
      * This test mimics a cluster state containing four nodes, where one node breaches two constraints while one breaches
      * only one. In order to have nodes breach constraints, test excludes two nodes (node2, node3) from allocation so
      * that other two nodes (node0, node1) have all shards assignments resulting in constraints breach. Test asserts that
      * the new primary shard assignment lands on the node breaching one constraint(node1), while replica land on the other
      * (node0). Final shard allocation state.
-     *
+     * <p>
      routing_nodes:
      -----node_id[node2][V]
      -----node_id[node3][V]
@@ -384,13 +384,13 @@ public void testGlobalPrimaryBalance() throws Exception {
      * This test mimics a cluster state which can not be rebalanced due to
      * {@link org.opensearch.cluster.routing.allocation.decider.SameShardAllocationDecider}
      * allocation decider which prevents shard relocation, leaving cluster unbalanced on primaries.
-     *
+     * <p>
      * There are two nodes (N1, N2) where all primaries land on N1 while replicas on N2.
      * N1        N2
      * ------  --------
      * P1        R1
      * P2        R2
-     *
+     * <p>
      * -----node_id[node_0][V]
      * --------[test][1], node[node_0], [P], s[STARTED], a[id=xqfZSToVSQaff2xvuxh_yA]
      * --------[test][0], node[node_0], [P], s[STARTED], a[id=VGjOeBGdSmu3pJR6T7v29A]
@@ -454,14 +454,14 @@ public void testPrimaryBalance_NotSolved_1() {
      * This test mimics cluster state where re-balancing is not possible due to existing limitation of re-balancing
      * logic which applies at index level i.e. balance shards single index across all nodes. This will be solved when
      * primary shard count across indices, constraint is added.
-     *
+     * <p>
      * Please note, P1, P2 belongs to different index
-     *
+     * <p>
      * N1        N2
      * ------  --------
      * P1       R1
      * P2       R2
-     *
+     * <p>
      * -----node_id[node_0][V]
      * --------[test1][0], node[node_0], [P], s[STARTED], a[id=u7qtyy5AR42hgEa-JpeArg]
      * --------[test0][0], node[node_0], [P], s[STARTED], a[id=BQrLSo6sQyGlcLdVvGgqLQ]
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/CatAllocationTestCase.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/CatAllocationTestCase.java
index 10271cad33fec..8f90882c21804 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/CatAllocationTestCase.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/CatAllocationTestCase.java
@@ -66,7 +66,7 @@
  * A base testcase that allows to run tests based on the output of the CAT API
  * The input is a line based cat/shards output like:
  *   kibana-int           0 p STARTED       2  24.8kb 10.202.245.2 r5-9-35
- *
+ * <p>
  * the test builds up a clusterstate from the cat input and optionally runs a full balance on it.
  * This can be used to debug cluster allocation decisions.
  */
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardConstraintDeciderOverlapTests.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardConstraintDeciderOverlapTests.java
index cf32d2b3cf00f..7f2f048485318 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardConstraintDeciderOverlapTests.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardConstraintDeciderOverlapTests.java
@@ -30,7 +30,7 @@ public class IndexShardConstraintDeciderOverlapTests extends OpenSearchAllocatio
     /**
      * High watermark breach blocks new shard allocations to affected nodes. If shard count on such
      * nodes is low, this will cause IndexShardPerNodeConstraint to breach.
-     *
+     * <p>
      * This test verifies that this doesn't lead to unassigned shards, and there are no hot spots in eligible
      * nodes.
      */
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardHotSpotTests.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardHotSpotTests.java
index 2efbb256e36bc..617c9b4701722 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardHotSpotTests.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/IndexShardHotSpotTests.java
@@ -58,7 +58,7 @@ public void testUnderReplicatedClusterScaleOut() {
     /**
      * Test cluster scale in scenario, when nodes are gracefully excluded from
      * cluster before termination.
-     *
+     * <p>
      * During moveShards(), shards are picked from across indexes in an interleaved manner.
      * This prevents hot spots by evenly picking up shards. Since shard order can change
      * in subsequent runs.
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsAllocateUnassignedTests.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsAllocateUnassignedTests.java
index ed178ed7e1526..0be1a1f36118d 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsAllocateUnassignedTests.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsAllocateUnassignedTests.java
@@ -13,11 +13,16 @@
 import org.opensearch.cluster.routing.RoutingNodes;
 import org.opensearch.cluster.routing.RoutingPool;
 import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.cluster.routing.UnassignedInfo;
 import org.opensearch.cluster.routing.allocation.allocator.RemoteShardsBalancer;
 
 import java.util.HashMap;
 import java.util.Map;
 
+import static org.opensearch.cluster.routing.UnassignedInfo.AllocationStatus.DECIDERS_NO;
+import static org.opensearch.cluster.routing.UnassignedInfo.AllocationStatus.DECIDERS_THROTTLED;
+import static org.opensearch.cluster.routing.UnassignedInfo.AllocationStatus.NO_ATTEMPT;
+
 public class RemoteShardsAllocateUnassignedTests extends RemoteShardsBalancerBaseTestCase {
 
     /**
@@ -89,6 +94,38 @@ public void testPrimaryAllocation() {
         }
     }
 
+    /**
+     * Test remote unassigned shard allocation when deciders make NO or THROTTLED decision.
+     */
+    public void testNoRemoteAllocation() {
+        final int localOnlyNodes = 10;
+        final int remoteCapableNodes = 5;
+        final int localIndices = 2;
+        final int remoteIndices = 1;
+        final ClusterState oldState = createInitialCluster(localOnlyNodes, remoteCapableNodes, localIndices, remoteIndices);
+        final boolean throttle = randomBoolean();
+        final AllocationService service = this.createRejectRemoteAllocationService(throttle);
+        final ClusterState newState = allocateShardsAndBalance(oldState, service);
+        final RoutingNodes routingNodes = newState.getRoutingNodes();
+        final RoutingAllocation allocation = getRoutingAllocation(newState, routingNodes);
+
+        assertEquals(totalShards(remoteIndices), routingNodes.unassigned().size());
+
+        for (ShardRouting shard : newState.getRoutingTable().allShards()) {
+            if (RoutingPool.getShardPool(shard, allocation) == RoutingPool.REMOTE_CAPABLE) {
+                assertTrue(shard.unassigned());
+                if (shard.primary()) {
+                    final UnassignedInfo.AllocationStatus expect = throttle ? DECIDERS_THROTTLED : DECIDERS_NO;
+                    assertEquals(expect, shard.unassignedInfo().getLastAllocationStatus());
+                } else {
+                    assertEquals(NO_ATTEMPT, shard.unassignedInfo().getLastAllocationStatus());
+                }
+            } else {
+                assertFalse(shard.unassigned());
+            }
+        }
+    }
+
     /**
      * Test remote unassigned shard allocation when remote capable nodes fail to come up.
      */
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsBalancerBaseTestCase.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsBalancerBaseTestCase.java
index dbb08a999877d..a1db6cd83ab6c 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsBalancerBaseTestCase.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsBalancerBaseTestCase.java
@@ -20,7 +20,9 @@
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.cluster.node.DiscoveryNodeRole;
 import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.cluster.routing.RoutingNode;
 import org.opensearch.cluster.routing.RoutingNodes;
+import org.opensearch.cluster.routing.RoutingPool;
 import org.opensearch.cluster.routing.RoutingTable;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.routing.UnassignedInfo;
@@ -28,6 +30,7 @@
 import org.opensearch.cluster.routing.allocation.allocator.ShardsAllocator;
 import org.opensearch.cluster.routing.allocation.decider.AllocationDecider;
 import org.opensearch.cluster.routing.allocation.decider.AllocationDeciders;
+import org.opensearch.cluster.routing.allocation.decider.Decision;
 import org.opensearch.common.SuppressForbidden;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
@@ -201,6 +204,36 @@ public AllocationService createRemoteCapableAllocationService(String excludeNode
         );
     }
 
+    public AllocationService createRejectRemoteAllocationService(boolean throttle) {
+        Settings settings = Settings.Builder.EMPTY_SETTINGS;
+        return new OpenSearchAllocationTestCase.MockAllocationService(
+            createRejectRemoteAllocationDeciders(throttle),
+            new TestGatewayAllocator(),
+            createShardAllocator(settings),
+            EmptyClusterInfoService.INSTANCE,
+            SNAPSHOT_INFO_SERVICE_WITH_NO_SHARD_SIZES
+        );
+    }
+
+    public AllocationDeciders createRejectRemoteAllocationDeciders(boolean throttle) {
+        Settings settings = Settings.Builder.EMPTY_SETTINGS;
+        List<AllocationDecider> deciders = new ArrayList<>(
+            ClusterModule.createAllocationDeciders(settings, EMPTY_CLUSTER_SETTINGS, Collections.emptyList())
+        );
+        deciders.add(new AllocationDecider() {
+            @Override
+            public Decision canAllocate(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation) {
+                if (RoutingPool.REMOTE_CAPABLE.equals(RoutingPool.getShardPool(shardRouting, allocation))) {
+                    return throttle ? Decision.THROTTLE : Decision.NO;
+                } else {
+                    return Decision.ALWAYS;
+                }
+            }
+        });
+        Collections.shuffle(deciders, random());
+        return new AllocationDeciders(deciders);
+    }
+
     public AllocationDeciders createAllocationDeciders() {
         Settings settings = Settings.Builder.EMPTY_SETTINGS;
         return randomAllocationDeciders(settings, EMPTY_CLUSTER_SETTINGS, random());
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsRebalanceShardsTests.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsRebalanceShardsTests.java
index ef9ae90e18bb5..e1c0a7eff1f6e 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsRebalanceShardsTests.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/RemoteShardsRebalanceShardsTests.java
@@ -21,7 +21,7 @@ public class RemoteShardsRebalanceShardsTests extends RemoteShardsBalancerBaseTe
 
     /**
      * Test remote shard allocation and balancing for standard new cluster setup.
-     *
+     * <p>
      * Post rebalance primaries should be balanced across all the nodes.
      */
     public void testShardAllocationAndRebalance() {
@@ -72,7 +72,7 @@ private int getTotalShardCountAcrossNodes(final Map<String, Integer> nodePrimari
 
     /**
      * Asserts that the expected value is within the variance range.
-     *
+     * <p>
      * Being used to assert the average number of shards per node.
      * Variance is required in case of non-absolute mean values;
      * for example, total number of remote capable nodes in a cluster.
diff --git a/server/src/test/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDeciderTests.java b/server/src/test/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDeciderTests.java
index 8f2db5db969d2..052c7877404a8 100644
--- a/server/src/test/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDeciderTests.java
+++ b/server/src/test/java/org/opensearch/cluster/routing/allocation/decider/TargetPoolAllocationDeciderTests.java
@@ -200,4 +200,88 @@ public void testTargetPoolDedicatedSearchNodeAllocationDecisions() {
         assertEquals(Decision.YES.type(), deciders.shouldAutoExpandToNode(localIdx, localOnlyNode.node(), globalAllocation).type());
         assertEquals(Decision.YES.type(), deciders.shouldAutoExpandToNode(remoteIdx, remoteCapableNode.node(), globalAllocation).type());
     }
+
+    public void testDebugMessage() {
+        ClusterState clusterState = createInitialCluster(3, 3, true, 2, 2);
+        AllocationService service = this.createRemoteCapableAllocationService();
+        clusterState = allocateShardsAndBalance(clusterState, service);
+
+        // Add an unassigned primary shard for force allocation checks
+        Metadata metadata = Metadata.builder(clusterState.metadata())
+            .put(IndexMetadata.builder("test_local_unassigned").settings(settings(Version.CURRENT)).numberOfShards(1).numberOfReplicas(1))
+            .build();
+        RoutingTable routingTable = RoutingTable.builder(clusterState.routingTable())
+            .addAsNew(metadata.index("test_local_unassigned"))
+            .build();
+        clusterState = ClusterState.builder(clusterState).metadata(metadata).routingTable(routingTable).build();
+
+        // Add remote index unassigned primary
+        clusterState = createRemoteIndex(clusterState, "test_remote_unassigned");
+
+        RoutingNodes defaultRoutingNodes = clusterState.getRoutingNodes();
+        RoutingAllocation globalAllocation = getRoutingAllocation(clusterState, defaultRoutingNodes);
+        globalAllocation.setDebugMode(RoutingAllocation.DebugMode.ON);
+
+        ShardRouting localShard = clusterState.routingTable()
+            .allShards(getIndexName(0, false))
+            .stream()
+            .filter(ShardRouting::primary)
+            .collect(Collectors.toList())
+            .get(0);
+        ShardRouting remoteShard = clusterState.routingTable()
+            .allShards(getIndexName(0, true))
+            .stream()
+            .filter(ShardRouting::primary)
+            .collect(Collectors.toList())
+            .get(0);
+        ShardRouting unassignedLocalShard = clusterState.routingTable()
+            .allShards("test_local_unassigned")
+            .stream()
+            .filter(ShardRouting::primary)
+            .collect(Collectors.toList())
+            .get(0);
+        ShardRouting unassignedRemoteShard = clusterState.routingTable()
+            .allShards("test_remote_unassigned")
+            .stream()
+            .filter(ShardRouting::primary)
+            .collect(Collectors.toList())
+            .get(0);
+        IndexMetadata localIdx = globalAllocation.metadata().getIndexSafe(localShard.index());
+        IndexMetadata remoteIdx = globalAllocation.metadata().getIndexSafe(remoteShard.index());
+        String localNodeId = LOCAL_NODE_PREFIX;
+        for (RoutingNode routingNode : globalAllocation.routingNodes()) {
+            if (routingNode.nodeId().startsWith(LOCAL_NODE_PREFIX)) {
+                localNodeId = routingNode.nodeId();
+                break;
+            }
+        }
+        String remoteNodeId = remoteShard.currentNodeId();
+        RoutingNode localOnlyNode = defaultRoutingNodes.node(localNodeId);
+        RoutingNode remoteCapableNode = defaultRoutingNodes.node(remoteNodeId);
+
+        TargetPoolAllocationDecider targetPoolAllocationDecider = new TargetPoolAllocationDecider();
+        Decision decision = targetPoolAllocationDecider.canAllocate(localShard, remoteCapableNode, globalAllocation);
+        assertEquals(
+            "Routing pools are incompatible. Shard pool: [LOCAL_ONLY], node pool: [REMOTE_CAPABLE] without [data] role",
+            decision.getExplanation()
+        );
+
+        decision = targetPoolAllocationDecider.canAllocate(remoteShard, localOnlyNode, globalAllocation);
+        assertEquals("Routing pools are incompatible. Shard pool: [REMOTE_CAPABLE], node pool: [LOCAL_ONLY]", decision.getExplanation());
+
+        decision = targetPoolAllocationDecider.canAllocate(remoteShard, remoteCapableNode, globalAllocation);
+        assertEquals("Routing pools are compatible. Shard pool: [REMOTE_CAPABLE], node pool: [REMOTE_CAPABLE]", decision.getExplanation());
+
+        decision = targetPoolAllocationDecider.canAllocate(localIdx, remoteCapableNode, globalAllocation);
+        assertEquals(
+            "Routing pools are incompatible. Index pool: [LOCAL_ONLY], node pool: [REMOTE_CAPABLE] without [data] role",
+            decision.getExplanation()
+        );
+
+        decision = targetPoolAllocationDecider.canAllocate(remoteIdx, localOnlyNode, globalAllocation);
+        assertEquals("Routing pools are incompatible. Index pool: [REMOTE_CAPABLE], node pool: [LOCAL_ONLY]", decision.getExplanation());
+
+        decision = targetPoolAllocationDecider.canAllocate(remoteIdx, remoteCapableNode, globalAllocation);
+        assertEquals("Routing pools are compatible. Index pool: [REMOTE_CAPABLE], node pool: [REMOTE_CAPABLE]", decision.getExplanation());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/cluster/service/MasterServiceTests.java b/server/src/test/java/org/opensearch/cluster/service/MasterServiceTests.java
index 9cdbe04e0a0e4..85f6c129944fa 100644
--- a/server/src/test/java/org/opensearch/cluster/service/MasterServiceTests.java
+++ b/server/src/test/java/org/opensearch/cluster/service/MasterServiceTests.java
@@ -487,6 +487,9 @@ public void onFailure(String source, Exception e) {
                     }
                 });
                 assertBusy(mockAppender::assertAllExpectationsMatched);
+                // verify stats values after state is published
+                assertEquals(1, clusterManagerService.getClusterStateStats().getUpdateSuccess());
+                assertEquals(0, clusterManagerService.getClusterStateStats().getUpdateFailed());
             }
         }
     }
diff --git a/server/src/test/java/org/opensearch/common/RoundingTests.java b/server/src/test/java/org/opensearch/common/RoundingTests.java
index 0ebfe02dc7641..9a6e6a6ac54d0 100644
--- a/server/src/test/java/org/opensearch/common/RoundingTests.java
+++ b/server/src/test/java/org/opensearch/common/RoundingTests.java
@@ -33,7 +33,6 @@
 package org.opensearch.common;
 
 import org.opensearch.common.collect.Tuple;
-import org.opensearch.common.rounding.DateTimeUnit;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.time.DateFormatters;
 import org.opensearch.common.unit.TimeValue;
@@ -236,10 +235,10 @@ public void testOffsetRounding() {
 
     /**
      * Randomized test on TimeUnitRounding. Test uses random
-     * {@link DateTimeUnit} and {@link ZoneId} and often (50% of the time)
+     * {@link org.opensearch.common.Rounding.DateTimeUnit} and {@link ZoneId} and often (50% of the time)
      * chooses test dates that are exactly on or close to offset changes (e.g.
      * DST) in the chosen time zone.
-     *
+     * <p>
      * It rounds the test date down and up and performs various checks on the
      * rounding unit interval that is defined by this. Assumptions tested are
      * described in
@@ -1143,28 +1142,6 @@ public void testNonMillisecondsBasedUnitCalendarRoundingSize() {
         assertThat(prepared.roundingSize(thirdQuarter, Rounding.DateTimeUnit.HOUR_OF_DAY), closeTo(2208.0, 0.000001));
     }
 
-    public void testArrayRoundingImplementations() {
-        int length = randomIntBetween(1, 256);
-        long[] values = new long[length];
-        for (int i = 1; i < values.length; i++) {
-            values[i] = values[i - 1] + (randomNonNegativeLong() % 100);
-        }
-
-        Rounding.Prepared binarySearchImpl = new Rounding.BinarySearchArrayRounding(values, length, null);
-        Rounding.Prepared linearSearchImpl = new Rounding.BidirectionalLinearSearchArrayRounding(values, length, null);
-
-        for (int i = 0; i < 100000; i++) {
-            long key = values[0] + (randomNonNegativeLong() % (100 + values[length - 1] - values[0]));
-            assertEquals(binarySearchImpl.round(key), linearSearchImpl.round(key));
-        }
-
-        AssertionError exception = expectThrows(AssertionError.class, () -> { binarySearchImpl.round(values[0] - 1); });
-        assertEquals("utcMillis must be after " + values[0], exception.getMessage());
-
-        exception = expectThrows(AssertionError.class, () -> { linearSearchImpl.round(values[0] - 1); });
-        assertEquals("utcMillis must be after " + values[0], exception.getMessage());
-    }
-
     private void assertInterval(long rounded, long nextRoundingValue, Rounding rounding, int minutes, ZoneId tz) {
         assertInterval(rounded, dateBetween(rounded, nextRoundingValue), nextRoundingValue, rounding, tz);
         long millisPerMinute = 60_000;
diff --git a/server/src/test/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainerTests.java b/server/src/test/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainerTests.java
new file mode 100644
index 0000000000000..1780819390052
--- /dev/null
+++ b/server/src/test/java/org/opensearch/common/blobstore/AsyncMultiStreamEncryptedBlobContainerTests.java
@@ -0,0 +1,125 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.blobstore;
+
+import org.opensearch.common.Randomness;
+import org.opensearch.common.blobstore.stream.read.ReadContext;
+import org.opensearch.common.blobstore.stream.read.listener.ListenerTestUtils;
+import org.opensearch.common.crypto.CryptoHandler;
+import org.opensearch.common.crypto.DecryptedRangedStreamProvider;
+import org.opensearch.common.io.InputStreamContainer;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.UnaryOperator;
+
+import org.mockito.Mockito;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class AsyncMultiStreamEncryptedBlobContainerTests extends OpenSearchTestCase {
+
+    // Tests the happy path scenario for decrypting a read context
+    @SuppressWarnings("unchecked")
+    public void testReadBlobAsync() throws Exception {
+        String testBlobName = "testBlobName";
+        int size = 100;
+
+        // Mock objects needed for the test
+        AsyncMultiStreamBlobContainer blobContainer = mock(AsyncMultiStreamBlobContainer.class);
+        CryptoHandler<Object, Object> cryptoHandler = mock(CryptoHandler.class);
+        Object cryptoContext = mock(Object.class);
+        when(cryptoHandler.loadEncryptionMetadata(any())).thenReturn(cryptoContext);
+        when(cryptoHandler.estimateDecryptedLength(any(), anyLong())).thenReturn((long) size);
+        long[] adjustedRanges = { 0, size - 1 };
+        DecryptedRangedStreamProvider rangedStreamProvider = new DecryptedRangedStreamProvider(adjustedRanges, UnaryOperator.identity());
+        when(cryptoHandler.createDecryptingStreamOfRange(eq(cryptoContext), anyLong(), anyLong())).thenReturn(rangedStreamProvider);
+
+        // Objects needed for API call
+        final byte[] data = new byte[size];
+        Randomness.get().nextBytes(data);
+
+        final InputStreamContainer inputStreamContainer = new InputStreamContainer(new ByteArrayInputStream(data), data.length, 0);
+        final ListenerTestUtils.CountingCompletionListener<ReadContext> completionListener =
+            new ListenerTestUtils.CountingCompletionListener<>();
+        final CompletableFuture<InputStreamContainer> streamContainerFuture = CompletableFuture.completedFuture(inputStreamContainer);
+        final ReadContext readContext = new ReadContext(size, List.of(() -> streamContainerFuture), null);
+
+        Mockito.doAnswer(invocation -> {
+            ActionListener<ReadContext> readContextActionListener = invocation.getArgument(1);
+            readContextActionListener.onResponse(readContext);
+            return null;
+        }).when(blobContainer).readBlobAsync(eq(testBlobName), any());
+
+        AsyncMultiStreamEncryptedBlobContainer<Object, Object> asyncMultiStreamEncryptedBlobContainer =
+            new AsyncMultiStreamEncryptedBlobContainer<>(blobContainer, cryptoHandler);
+        asyncMultiStreamEncryptedBlobContainer.readBlobAsync(testBlobName, completionListener);
+
+        // Assert results
+        ReadContext response = completionListener.getResponse();
+        assertEquals(0, completionListener.getFailureCount());
+        assertEquals(1, completionListener.getResponseCount());
+        assertNull(completionListener.getException());
+
+        assertTrue(response instanceof AsyncMultiStreamEncryptedBlobContainer.DecryptedReadContext);
+        assertEquals(1, response.getNumberOfParts());
+        assertEquals(size, response.getBlobSize());
+
+        InputStreamContainer responseContainer = response.getPartStreams().get(0).get().join();
+        assertEquals(0, responseContainer.getOffset());
+        assertEquals(size, responseContainer.getContentLength());
+        assertEquals(100, responseContainer.getInputStream().available());
+    }
+
+    // Tests the exception scenario for decrypting a read context
+    @SuppressWarnings("unchecked")
+    public void testReadBlobAsyncException() throws Exception {
+        String testBlobName = "testBlobName";
+        int size = 100;
+
+        // Mock objects needed for the test
+        AsyncMultiStreamBlobContainer blobContainer = mock(AsyncMultiStreamBlobContainer.class);
+        CryptoHandler<Object, Object> cryptoHandler = mock(CryptoHandler.class);
+        when(cryptoHandler.loadEncryptionMetadata(any())).thenThrow(new IOException());
+
+        // Objects needed for API call
+        final byte[] data = new byte[size];
+        Randomness.get().nextBytes(data);
+        final InputStreamContainer inputStreamContainer = new InputStreamContainer(new ByteArrayInputStream(data), data.length, 0);
+        final ListenerTestUtils.CountingCompletionListener<ReadContext> completionListener =
+            new ListenerTestUtils.CountingCompletionListener<>();
+        final CompletableFuture<InputStreamContainer> streamContainerFuture = CompletableFuture.completedFuture(inputStreamContainer);
+        final ReadContext readContext = new ReadContext(size, List.of(() -> streamContainerFuture), null);
+
+        Mockito.doAnswer(invocation -> {
+            ActionListener<ReadContext> readContextActionListener = invocation.getArgument(1);
+            readContextActionListener.onResponse(readContext);
+            return null;
+        }).when(blobContainer).readBlobAsync(eq(testBlobName), any());
+
+        AsyncMultiStreamEncryptedBlobContainer<Object, Object> asyncMultiStreamEncryptedBlobContainer =
+            new AsyncMultiStreamEncryptedBlobContainer<>(blobContainer, cryptoHandler);
+        asyncMultiStreamEncryptedBlobContainer.readBlobAsync(testBlobName, completionListener);
+
+        // Assert results
+        assertEquals(1, completionListener.getFailureCount());
+        assertEquals(0, completionListener.getResponseCount());
+        assertNull(completionListener.getResponse());
+        assertTrue(completionListener.getException() instanceof IOException);
+    }
+
+}
diff --git a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/FileCompletionListenerTests.java b/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/FileCompletionListenerTests.java
deleted file mode 100644
index fa13d90f42fa6..0000000000000
--- a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/FileCompletionListenerTests.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.common.blobstore.stream.read.listener;
-
-import org.opensearch.test.OpenSearchTestCase;
-
-import java.io.IOException;
-
-import static org.opensearch.common.blobstore.stream.read.listener.ListenerTestUtils.CountingCompletionListener;
-
-public class FileCompletionListenerTests extends OpenSearchTestCase {
-
-    public void testFileCompletionListener() {
-        int numStreams = 10;
-        String fileName = "test_segment_file";
-        CountingCompletionListener<String> completionListener = new CountingCompletionListener<String>();
-        FileCompletionListener fileCompletionListener = new FileCompletionListener(numStreams, fileName, completionListener);
-
-        for (int stream = 0; stream < numStreams; stream++) {
-            // Ensure completion listener called only when all streams are completed
-            assertEquals(0, completionListener.getResponseCount());
-            fileCompletionListener.onResponse(null);
-        }
-
-        assertEquals(1, completionListener.getResponseCount());
-        assertEquals(fileName, completionListener.getResponse());
-    }
-
-    public void testFileCompletionListenerFailure() {
-        int numStreams = 10;
-        String fileName = "test_segment_file";
-        CountingCompletionListener<String> completionListener = new CountingCompletionListener<String>();
-        FileCompletionListener fileCompletionListener = new FileCompletionListener(numStreams, fileName, completionListener);
-
-        // Fail the listener initially
-        IOException exception = new IOException();
-        fileCompletionListener.onFailure(exception);
-
-        for (int stream = 0; stream < numStreams - 1; stream++) {
-            assertEquals(0, completionListener.getResponseCount());
-            fileCompletionListener.onResponse(null);
-        }
-
-        assertEquals(1, completionListener.getFailureCount());
-        assertEquals(exception, completionListener.getException());
-        assertEquals(0, completionListener.getResponseCount());
-
-        fileCompletionListener.onFailure(exception);
-        assertEquals(2, completionListener.getFailureCount());
-        assertEquals(exception, completionListener.getException());
-    }
-}
diff --git a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriterTests.java b/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriterTests.java
index 811566eb5767b..f2a758b9bbe10 100644
--- a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriterTests.java
+++ b/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/FilePartWriterTests.java
@@ -13,14 +13,11 @@
 import org.junit.Before;
 
 import java.io.ByteArrayInputStream;
-import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.UUID;
-import java.util.concurrent.atomic.AtomicBoolean;
-
-import static org.opensearch.common.blobstore.stream.read.listener.ListenerTestUtils.CountingCompletionListener;
+import java.util.function.UnaryOperator;
 
 public class FilePartWriterTests extends OpenSearchTestCase {
 
@@ -34,130 +31,37 @@ public void init() throws Exception {
     public void testFilePartWriter() throws Exception {
         Path segmentFilePath = path.resolve(UUID.randomUUID().toString());
         int contentLength = 100;
-        int partNumber = 1;
         InputStream inputStream = new ByteArrayInputStream(randomByteArrayOfLength(contentLength));
         InputStreamContainer inputStreamContainer = new InputStreamContainer(inputStream, inputStream.available(), 0);
-        AtomicBoolean anyStreamFailed = new AtomicBoolean();
-        CountingCompletionListener<Integer> fileCompletionListener = new CountingCompletionListener<>();
 
-        FilePartWriter filePartWriter = new FilePartWriter(
-            partNumber,
-            inputStreamContainer,
-            segmentFilePath,
-            anyStreamFailed,
-            fileCompletionListener
-        );
-        filePartWriter.run();
+        FilePartWriter.write(segmentFilePath, inputStreamContainer, UnaryOperator.identity());
 
         assertTrue(Files.exists(segmentFilePath));
         assertEquals(contentLength, Files.size(segmentFilePath));
-        assertEquals(1, fileCompletionListener.getResponseCount());
-        assertEquals(Integer.valueOf(partNumber), fileCompletionListener.getResponse());
     }
 
     public void testFilePartWriterWithOffset() throws Exception {
         Path segmentFilePath = path.resolve(UUID.randomUUID().toString());
         int contentLength = 100;
         int offset = 10;
-        int partNumber = 1;
         InputStream inputStream = new ByteArrayInputStream(randomByteArrayOfLength(contentLength));
         InputStreamContainer inputStreamContainer = new InputStreamContainer(inputStream, inputStream.available(), offset);
-        AtomicBoolean anyStreamFailed = new AtomicBoolean();
-        CountingCompletionListener<Integer> fileCompletionListener = new CountingCompletionListener<>();
 
-        FilePartWriter filePartWriter = new FilePartWriter(
-            partNumber,
-            inputStreamContainer,
-            segmentFilePath,
-            anyStreamFailed,
-            fileCompletionListener
-        );
-        filePartWriter.run();
+        FilePartWriter.write(segmentFilePath, inputStreamContainer, UnaryOperator.identity());
 
         assertTrue(Files.exists(segmentFilePath));
         assertEquals(contentLength + offset, Files.size(segmentFilePath));
-        assertEquals(1, fileCompletionListener.getResponseCount());
-        assertEquals(Integer.valueOf(partNumber), fileCompletionListener.getResponse());
     }
 
     public void testFilePartWriterLargeInput() throws Exception {
         Path segmentFilePath = path.resolve(UUID.randomUUID().toString());
         int contentLength = 20 * 1024 * 1024;
-        int partNumber = 1;
         InputStream inputStream = new ByteArrayInputStream(randomByteArrayOfLength(contentLength));
         InputStreamContainer inputStreamContainer = new InputStreamContainer(inputStream, contentLength, 0);
-        AtomicBoolean anyStreamFailed = new AtomicBoolean();
-        CountingCompletionListener<Integer> fileCompletionListener = new CountingCompletionListener<>();
 
-        FilePartWriter filePartWriter = new FilePartWriter(
-            partNumber,
-            inputStreamContainer,
-            segmentFilePath,
-            anyStreamFailed,
-            fileCompletionListener
-        );
-        filePartWriter.run();
+        FilePartWriter.write(segmentFilePath, inputStreamContainer, UnaryOperator.identity());
 
         assertTrue(Files.exists(segmentFilePath));
         assertEquals(contentLength, Files.size(segmentFilePath));
-
-        assertEquals(1, fileCompletionListener.getResponseCount());
-        assertEquals(Integer.valueOf(partNumber), fileCompletionListener.getResponse());
-    }
-
-    public void testFilePartWriterException() throws Exception {
-        Path segmentFilePath = path.resolve(UUID.randomUUID().toString());
-        int contentLength = 100;
-        int partNumber = 1;
-        InputStream inputStream = new ByteArrayInputStream(randomByteArrayOfLength(contentLength));
-        InputStreamContainer inputStreamContainer = new InputStreamContainer(inputStream, contentLength, 0);
-        AtomicBoolean anyStreamFailed = new AtomicBoolean();
-        CountingCompletionListener<Integer> fileCompletionListener = new CountingCompletionListener<>();
-
-        IOException ioException = new IOException();
-        FilePartWriter filePartWriter = new FilePartWriter(
-            partNumber,
-            inputStreamContainer,
-            segmentFilePath,
-            anyStreamFailed,
-            fileCompletionListener
-        );
-        assertFalse(anyStreamFailed.get());
-        filePartWriter.processFailure(ioException);
-
-        assertTrue(anyStreamFailed.get());
-        assertFalse(Files.exists(segmentFilePath));
-
-        // Fail stream again to simulate another stream failure for same file
-        filePartWriter.processFailure(ioException);
-
-        assertTrue(anyStreamFailed.get());
-        assertFalse(Files.exists(segmentFilePath));
-
-        assertEquals(0, fileCompletionListener.getResponseCount());
-        assertEquals(1, fileCompletionListener.getFailureCount());
-        assertEquals(ioException, fileCompletionListener.getException());
-    }
-
-    public void testFilePartWriterStreamFailed() throws Exception {
-        Path segmentFilePath = path.resolve(UUID.randomUUID().toString());
-        int contentLength = 100;
-        int partNumber = 1;
-        InputStream inputStream = new ByteArrayInputStream(randomByteArrayOfLength(contentLength));
-        InputStreamContainer inputStreamContainer = new InputStreamContainer(inputStream, inputStream.available(), 0);
-        AtomicBoolean anyStreamFailed = new AtomicBoolean(true);
-        CountingCompletionListener<Integer> fileCompletionListener = new CountingCompletionListener<>();
-
-        FilePartWriter filePartWriter = new FilePartWriter(
-            partNumber,
-            inputStreamContainer,
-            segmentFilePath,
-            anyStreamFailed,
-            fileCompletionListener
-        );
-        filePartWriter.run();
-
-        assertFalse(Files.exists(segmentFilePath));
-        assertEquals(0, fileCompletionListener.getResponseCount());
     }
 }
diff --git a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ListenerTestUtils.java b/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ListenerTestUtils.java
index 1e9450c83e3ab..a3a32f6db2148 100644
--- a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ListenerTestUtils.java
+++ b/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ListenerTestUtils.java
@@ -19,7 +19,7 @@ public class ListenerTestUtils {
      * CountingCompletionListener acts as a verification instance for wrapping listener based calls.
      * Keeps track of the last response, failure and count of response and failure invocations.
      */
-    static class CountingCompletionListener<T> implements ActionListener<T> {
+    public static class CountingCompletionListener<T> implements ActionListener<T> {
         private int responseCount;
         private int failureCount;
         private T response;
diff --git a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListenerTests.java b/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListenerTests.java
index 21b7b47390a9b..0163c2275e7f4 100644
--- a/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListenerTests.java
+++ b/server/src/test/java/org/opensearch/common/blobstore/stream/read/listener/ReadContextListenerTests.java
@@ -29,7 +29,9 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CountDownLatch;
+import java.util.function.UnaryOperator;
 
 import static org.opensearch.common.blobstore.stream.read.listener.ListenerTestUtils.CountingCompletionListener;
 
@@ -46,6 +48,7 @@ public class ReadContextListenerTests extends OpenSearchTestCase {
     private static final int NUMBER_OF_PARTS = 5;
     private static final int PART_SIZE = 10;
     private static final String TEST_SEGMENT_FILE = "test_segment_file";
+    private static final int MAX_CONCURRENT_STREAMS = 10;
 
     @BeforeClass
     public static void setup() {
@@ -64,10 +67,17 @@ public void init() throws Exception {
 
     public void testReadContextListener() throws InterruptedException, IOException {
         Path fileLocation = path.resolve(UUID.randomUUID().toString());
-        List<InputStreamContainer> blobPartStreams = initializeBlobPartStreams();
+        List<ReadContext.StreamPartCreator> blobPartStreams = initializeBlobPartStreams();
         CountDownLatch countDownLatch = new CountDownLatch(1);
         ActionListener<String> completionListener = new LatchedActionListener<>(new PlainActionFuture<>(), countDownLatch);
-        ReadContextListener readContextListener = new ReadContextListener(TEST_SEGMENT_FILE, fileLocation, threadPool, completionListener);
+        ReadContextListener readContextListener = new ReadContextListener(
+            TEST_SEGMENT_FILE,
+            fileLocation,
+            completionListener,
+            threadPool,
+            UnaryOperator.identity(),
+            MAX_CONCURRENT_STREAMS
+        );
         ReadContext readContext = new ReadContext((long) PART_SIZE * NUMBER_OF_PARTS, blobPartStreams, null);
         readContextListener.onResponse(readContext);
 
@@ -79,10 +89,17 @@ public void testReadContextListener() throws InterruptedException, IOException {
 
     public void testReadContextListenerFailure() throws Exception {
         Path fileLocation = path.resolve(UUID.randomUUID().toString());
-        List<InputStreamContainer> blobPartStreams = initializeBlobPartStreams();
+        List<ReadContext.StreamPartCreator> blobPartStreams = initializeBlobPartStreams();
         CountDownLatch countDownLatch = new CountDownLatch(1);
         ActionListener<String> completionListener = new LatchedActionListener<>(new PlainActionFuture<>(), countDownLatch);
-        ReadContextListener readContextListener = new ReadContextListener(TEST_SEGMENT_FILE, fileLocation, threadPool, completionListener);
+        ReadContextListener readContextListener = new ReadContextListener(
+            TEST_SEGMENT_FILE,
+            fileLocation,
+            completionListener,
+            threadPool,
+            UnaryOperator.identity(),
+            MAX_CONCURRENT_STREAMS
+        );
         InputStream badInputStream = new InputStream() {
 
             @Override
@@ -101,29 +118,111 @@ public int available() {
             }
         };
 
-        blobPartStreams.add(NUMBER_OF_PARTS, new InputStreamContainer(badInputStream, PART_SIZE, PART_SIZE * NUMBER_OF_PARTS));
+        blobPartStreams.add(
+            NUMBER_OF_PARTS,
+            () -> CompletableFuture.supplyAsync(
+                () -> new InputStreamContainer(badInputStream, PART_SIZE, PART_SIZE * NUMBER_OF_PARTS),
+                threadPool.generic()
+            )
+        );
         ReadContext readContext = new ReadContext((long) (PART_SIZE + 1) * NUMBER_OF_PARTS, blobPartStreams, null);
         readContextListener.onResponse(readContext);
 
         countDownLatch.await();
         assertFalse(Files.exists(fileLocation));
+        assertFalse(Files.exists(readContextListener.getTmpFileLocation()));
     }
 
     public void testReadContextListenerException() {
         Path fileLocation = path.resolve(UUID.randomUUID().toString());
         CountingCompletionListener<String> listener = new CountingCompletionListener<String>();
-        ReadContextListener readContextListener = new ReadContextListener(TEST_SEGMENT_FILE, fileLocation, threadPool, listener);
+        ReadContextListener readContextListener = new ReadContextListener(
+            TEST_SEGMENT_FILE,
+            fileLocation,
+            listener,
+            threadPool,
+            UnaryOperator.identity(),
+            MAX_CONCURRENT_STREAMS
+        );
         IOException exception = new IOException();
         readContextListener.onFailure(exception);
         assertEquals(1, listener.getFailureCount());
         assertEquals(exception, listener.getException());
     }
 
-    private List<InputStreamContainer> initializeBlobPartStreams() {
-        List<InputStreamContainer> blobPartStreams = new ArrayList<>();
+    public void testWriteToTempFile() throws Exception {
+        final String fileName = UUID.randomUUID().toString();
+        Path fileLocation = path.resolve(fileName);
+        List<ReadContext.StreamPartCreator> blobPartStreams = initializeBlobPartStreams();
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+        ActionListener<String> completionListener = new LatchedActionListener<>(new PlainActionFuture<>(), countDownLatch);
+        ReadContextListener readContextListener = new ReadContextListener(
+            TEST_SEGMENT_FILE,
+            fileLocation,
+            completionListener,
+            threadPool,
+            UnaryOperator.identity(),
+            MAX_CONCURRENT_STREAMS
+        );
+        ByteArrayInputStream assertingStream = new ByteArrayInputStream(randomByteArrayOfLength(PART_SIZE)) {
+            @Override
+            public int read(byte[] b) throws IOException {
+                assertTrue("parts written to temp file location", Files.exists(readContextListener.getTmpFileLocation()));
+                return super.read(b);
+            }
+        };
+        blobPartStreams.add(
+            NUMBER_OF_PARTS,
+            () -> CompletableFuture.supplyAsync(
+                () -> new InputStreamContainer(assertingStream, PART_SIZE, PART_SIZE * NUMBER_OF_PARTS),
+                threadPool.generic()
+            )
+        );
+        ReadContext readContext = new ReadContext((long) (PART_SIZE + 1) * NUMBER_OF_PARTS + 1, blobPartStreams, null);
+        readContextListener.onResponse(readContext);
+
+        countDownLatch.await();
+        assertTrue(Files.exists(fileLocation));
+        assertFalse(Files.exists(readContextListener.getTmpFileLocation()));
+    }
+
+    public void testWriteToTempFile_alreadyExists_replacesFile() throws Exception {
+        final String fileName = UUID.randomUUID().toString();
+        Path fileLocation = path.resolve(fileName);
+        // create an empty file at location.
+        Files.createFile(fileLocation);
+        assertEquals(0, Files.readAllBytes(fileLocation).length);
+        List<ReadContext.StreamPartCreator> blobPartStreams = initializeBlobPartStreams();
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+        ActionListener<String> completionListener = new LatchedActionListener<>(new PlainActionFuture<>(), countDownLatch);
+        ReadContextListener readContextListener = new ReadContextListener(
+            TEST_SEGMENT_FILE,
+            fileLocation,
+            completionListener,
+            threadPool,
+            UnaryOperator.identity(),
+            MAX_CONCURRENT_STREAMS
+        );
+        ReadContext readContext = new ReadContext((long) (PART_SIZE + 1) * NUMBER_OF_PARTS, blobPartStreams, null);
+        readContextListener.onResponse(readContext);
+
+        countDownLatch.await();
+        assertTrue(Files.exists(fileLocation));
+        assertEquals(50, Files.readAllBytes(fileLocation).length);
+        assertFalse(Files.exists(readContextListener.getTmpFileLocation()));
+    }
+
+    private List<ReadContext.StreamPartCreator> initializeBlobPartStreams() {
+        List<ReadContext.StreamPartCreator> blobPartStreams = new ArrayList<>();
         for (int partNumber = 0; partNumber < NUMBER_OF_PARTS; partNumber++) {
             InputStream testStream = new ByteArrayInputStream(randomByteArrayOfLength(PART_SIZE));
-            blobPartStreams.add(new InputStreamContainer(testStream, PART_SIZE, (long) partNumber * PART_SIZE));
+            int finalPartNumber = partNumber;
+            blobPartStreams.add(
+                () -> CompletableFuture.supplyAsync(
+                    () -> new InputStreamContainer(testStream, PART_SIZE, (long) finalPartNumber * PART_SIZE),
+                    threadPool.generic()
+                )
+            );
         }
         return blobPartStreams;
     }
diff --git a/server/src/test/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainerTests.java b/server/src/test/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainerTests.java
index a33e5f453d1e1..074f659850c7b 100644
--- a/server/src/test/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainerTests.java
+++ b/server/src/test/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainerTests.java
@@ -8,21 +8,36 @@
 
 package org.opensearch.common.blobstore.transfer;
 
+import org.apache.lucene.store.AlreadyClosedException;
+import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.RateLimiter;
 import org.opensearch.common.StreamContext;
 import org.opensearch.common.blobstore.stream.write.WriteContext;
 import org.opensearch.common.blobstore.stream.write.WritePriority;
 import org.opensearch.common.blobstore.transfer.stream.OffsetRangeFileInputStream;
+import org.opensearch.common.blobstore.transfer.stream.OffsetRangeIndexInputStream;
 import org.opensearch.common.blobstore.transfer.stream.OffsetRangeInputStream;
+import org.opensearch.common.blobstore.transfer.stream.RateLimitingOffsetRangeInputStream;
 import org.opensearch.common.blobstore.transfer.stream.ResettableCheckedInputStream;
 import org.opensearch.common.io.InputStreamContainer;
 import org.opensearch.test.OpenSearchTestCase;
 import org.junit.Before;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
+import java.util.Arrays;
 import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Supplier;
+
+import org.mockito.Mockito;
+import org.mockito.stubbing.Answer;
 
 public class RemoteTransferContainerTests extends OpenSearchTestCase {
 
@@ -92,25 +107,37 @@ private void testSupplyStreamContext(
         int partCount = streamContext.getNumberOfParts();
         assertEquals(expectedPartCount, partCount);
         Thread[] threads = new Thread[partCount];
+        InputStream[] streams = new InputStream[partCount];
         long totalContentLength = remoteTransferContainer.getContentLength();
         assert partSize * (partCount - 1) + lastPartSize == totalContentLength
             : "part sizes and last part size don't add up to total content length";
         logger.info("partSize: {}, lastPartSize: {}, partCount: {}", partSize, lastPartSize, streamContext.getNumberOfParts());
-        for (int partIdx = 0; partIdx < partCount; partIdx++) {
-            int finalPartIdx = partIdx;
-            long expectedPartSize = (partIdx == partCount - 1) ? lastPartSize : partSize;
-            threads[partIdx] = new Thread(() -> {
+        try {
+            for (int partIdx = 0; partIdx < partCount; partIdx++) {
+                int finalPartIdx = partIdx;
+                long expectedPartSize = (partIdx == partCount - 1) ? lastPartSize : partSize;
+                threads[partIdx] = new Thread(() -> {
+                    try {
+                        InputStreamContainer inputStreamContainer = streamContext.provideStream(finalPartIdx);
+                        streams[finalPartIdx] = inputStreamContainer.getInputStream();
+                        assertEquals(expectedPartSize, inputStreamContainer.getContentLength());
+                    } catch (IOException e) {
+                        fail("IOException during stream creation");
+                    }
+                });
+                threads[partIdx].start();
+            }
+            for (int i = 0; i < partCount; i++) {
+                threads[i].join();
+            }
+        } finally {
+            Arrays.stream(streams).forEach(stream -> {
                 try {
-                    InputStreamContainer inputStreamContainer = streamContext.provideStream(finalPartIdx);
-                    assertEquals(expectedPartSize, inputStreamContainer.getContentLength());
+                    stream.close();
                 } catch (IOException e) {
-                    fail("IOException during stream creation");
+                    throw new RuntimeException(e);
                 }
             });
-            threads[partIdx].start();
-        }
-        for (int i = 0; i < partCount; i++) {
-            threads[i].join();
         }
     }
 
@@ -182,6 +209,7 @@ public OffsetRangeInputStream get(long size, long position) throws IOException {
     }
 
     private void testTypeOfProvidedStreams(boolean isRemoteDataIntegritySupported) throws IOException {
+        InputStream inputStream = null;
         try (
             RemoteTransferContainer remoteTransferContainer = new RemoteTransferContainer(
                 testFile.getFileName().toString(),
@@ -201,12 +229,132 @@ public OffsetRangeInputStream get(long size, long position) throws IOException {
         ) {
             StreamContext streamContext = remoteTransferContainer.supplyStreamContext(16);
             InputStreamContainer inputStreamContainer = streamContext.provideStream(0);
+            inputStream = inputStreamContainer.getInputStream();
             if (shouldOffsetInputStreamsBeChecked(isRemoteDataIntegritySupported)) {
                 assertTrue(inputStreamContainer.getInputStream() instanceof ResettableCheckedInputStream);
             } else {
                 assertTrue(inputStreamContainer.getInputStream() instanceof OffsetRangeInputStream);
             }
             assertThrows(RuntimeException.class, () -> remoteTransferContainer.supplyStreamContext(16));
+        } finally {
+            if (inputStream != null) {
+                inputStream.close();
+            }
+        }
+    }
+
+    public void testCloseDuringOngoingReadOnStream() throws IOException, InterruptedException {
+        Supplier<RateLimiter> rateLimiterSupplier = Mockito.mock(Supplier.class);
+        Mockito.when(rateLimiterSupplier.get()).thenReturn(null);
+        CountDownLatch readInvokedLatch = new CountDownLatch(1);
+        AtomicBoolean readAfterClose = new AtomicBoolean();
+        CountDownLatch streamClosed = new CountDownLatch(1);
+        AtomicBoolean indexInputClosed = new AtomicBoolean();
+        AtomicInteger closedCount = new AtomicInteger();
+        try (
+            RemoteTransferContainer remoteTransferContainer = new RemoteTransferContainer(
+                testFile.getFileName().toString(),
+                testFile.getFileName().toString(),
+                TEST_FILE_SIZE_BYTES,
+                true,
+                WritePriority.NORMAL,
+                new RemoteTransferContainer.OffsetRangeInputStreamSupplier() {
+                    @Override
+                    public OffsetRangeInputStream get(long size, long position) throws IOException {
+                        IndexInput indexInput = Mockito.mock(IndexInput.class);
+                        Mockito.doAnswer(invocation -> {
+                            indexInputClosed.set(true);
+                            closedCount.incrementAndGet();
+                            return null;
+                        }).when(indexInput).close();
+                        Mockito.when(indexInput.getFilePointer()).thenAnswer((Answer<Long>) invocation -> {
+                            if (readAfterClose.get() == false) {
+                                return 0L;
+                            }
+                            readInvokedLatch.countDown();
+                            boolean closedSuccess = streamClosed.await(30, TimeUnit.SECONDS);
+                            assertTrue(closedSuccess);
+                            assertFalse(indexInputClosed.get());
+                            return 0L;
+                        });
+
+                        OffsetRangeIndexInputStream offsetRangeIndexInputStream = new OffsetRangeIndexInputStream(
+                            indexInput,
+                            size,
+                            position
+                        );
+                        return new RateLimitingOffsetRangeInputStream(offsetRangeIndexInputStream, rateLimiterSupplier, null);
+                    }
+                },
+                0,
+                true
+            )
+        ) {
+            StreamContext streamContext = remoteTransferContainer.supplyStreamContext(16);
+            InputStreamContainer inputStreamContainer = streamContext.provideStream(0);
+            assertTrue(inputStreamContainer.getInputStream() instanceof RateLimitingOffsetRangeInputStream);
+            CountDownLatch latch = new CountDownLatch(1);
+            new Thread(() -> {
+                try {
+                    readAfterClose.set(true);
+                    inputStreamContainer.getInputStream().readAllBytes();
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                } finally {
+                    latch.countDown();
+                }
+            }).start();
+            boolean successReadWait = readInvokedLatch.await(30, TimeUnit.SECONDS);
+            assertTrue(successReadWait);
+            // Closing stream here. Test Multiple invocations of close. Shouldn't throw any exception
+            inputStreamContainer.getInputStream().close();
+            inputStreamContainer.getInputStream().close();
+            inputStreamContainer.getInputStream().close();
+            streamClosed.countDown();
+            boolean processed = latch.await(30, TimeUnit.SECONDS);
+            assertTrue(processed);
+            assertTrue(readAfterClose.get());
+            assertTrue(indexInputClosed.get());
+
+            // Test Multiple invocations of close. Close count should always be 1.
+            inputStreamContainer.getInputStream().close();
+            inputStreamContainer.getInputStream().close();
+            inputStreamContainer.getInputStream().close();
+            assertEquals(1, closedCount.get());
+
+        }
+    }
+
+    public void testReadAccessWhenStreamClosed() throws IOException {
+        Supplier<RateLimiter> rateLimiterSupplier = Mockito.mock(Supplier.class);
+        Mockito.when(rateLimiterSupplier.get()).thenReturn(null);
+        try (
+            RemoteTransferContainer remoteTransferContainer = new RemoteTransferContainer(
+                testFile.getFileName().toString(),
+                testFile.getFileName().toString(),
+                TEST_FILE_SIZE_BYTES,
+                true,
+                WritePriority.NORMAL,
+                new RemoteTransferContainer.OffsetRangeInputStreamSupplier() {
+                    @Override
+                    public OffsetRangeInputStream get(long size, long position) throws IOException {
+                        IndexInput indexInput = Mockito.mock(IndexInput.class);
+                        OffsetRangeIndexInputStream offsetRangeIndexInputStream = new OffsetRangeIndexInputStream(
+                            indexInput,
+                            size,
+                            position
+                        );
+                        return new RateLimitingOffsetRangeInputStream(offsetRangeIndexInputStream, rateLimiterSupplier, null);
+                    }
+                },
+                0,
+                true
+            )
+        ) {
+            StreamContext streamContext = remoteTransferContainer.supplyStreamContext(16);
+            InputStreamContainer inputStreamContainer = streamContext.provideStream(0);
+            inputStreamContainer.getInputStream().close();
+            assertThrows(AlreadyClosedException.class, () -> inputStreamContainer.getInputStream().readAllBytes());
         }
     }
 
diff --git a/server/src/test/java/org/opensearch/common/geo/GeoJsonShapeParserTests.java b/server/src/test/java/org/opensearch/common/geo/GeoJsonShapeParserTests.java
index 25140d1ef73d5..e16dd859ec14c 100644
--- a/server/src/test/java/org/opensearch/common/geo/GeoJsonShapeParserTests.java
+++ b/server/src/test/java/org/opensearch/common/geo/GeoJsonShapeParserTests.java
@@ -1169,9 +1169,9 @@ public void testParseOGCPolygonWithHoles() throws IOException, ParseException {
     }
 
     public void testParseInvalidPolygon() throws IOException {
-        /**
-         * The following 3 test cases ensure proper error handling of invalid polygons
-         * per the GeoJSON specification
+        /*
+          The following 3 test cases ensure proper error handling of invalid polygons
+          per the GeoJSON specification
          */
         // test case 1: create an invalid polygon with only 2 points
         String invalidPoly = XContentFactory.jsonBuilder()
diff --git a/server/src/test/java/org/opensearch/common/geo/GeometryIndexerTests.java b/server/src/test/java/org/opensearch/common/geo/GeometryIndexerTests.java
index 297b7d9f65d5f..7fc95c2316aef 100644
--- a/server/src/test/java/org/opensearch/common/geo/GeometryIndexerTests.java
+++ b/server/src/test/java/org/opensearch/common/geo/GeometryIndexerTests.java
@@ -225,7 +225,7 @@ public static MultiPoint remove180s(MultiPoint points) {
     /**
      * A randomized test that generates a random lines crossing anti-merdian and checks that the decomposed segments of this line
      * have the same total length (measured using Euclidean distances between neighboring points) as the original line.
-     *
+     * <p>
      * It also extracts all points from these lines, performs normalization of these points and then compares that the resulting
      * points of line normalization match the points of points normalization with the exception of points that were created on the
      * antimeridian as the result of line decomposition.
diff --git a/server/src/test/java/org/opensearch/common/joda/JavaJodaTimeDuellingTests.java b/server/src/test/java/org/opensearch/common/joda/JavaJodaTimeDuellingTests.java
index 02bc6c58ad233..e8ddfde11f4cc 100644
--- a/server/src/test/java/org/opensearch/common/joda/JavaJodaTimeDuellingTests.java
+++ b/server/src/test/java/org/opensearch/common/joda/JavaJodaTimeDuellingTests.java
@@ -61,8 +61,8 @@ protected boolean enableWarningsCheck() {
     }
 
     public void testTimezoneParsing() {
-        /** this testcase won't work in joda. See comment in {@link #testPartialTimeParsing()}
-         *  assertSameDateAs("2016-11-30T+01", "strict_date_optional_time", "strict_date_optional_time");
+        /* this testcase won't work in joda. See comment in {@link #testPartialTimeParsing()}
+           assertSameDateAs("2016-11-30T+01", "strict_date_optional_time", "strict_date_optional_time");
          */
         assertSameDateAs("2016-11-30T00+01", "strict_date_optional_time", "strict_date_optional_time");
         assertSameDateAs("2016-11-30T00+0100", "strict_date_optional_time", "strict_date_optional_time");
diff --git a/server/src/test/java/org/opensearch/common/network/NetworkModuleTests.java b/server/src/test/java/org/opensearch/common/network/NetworkModuleTests.java
index d28a4a51999e6..de4bdcac6c2b2 100644
--- a/server/src/test/java/org/opensearch/common/network/NetworkModuleTests.java
+++ b/server/src/test/java/org/opensearch/common/network/NetworkModuleTests.java
@@ -57,6 +57,7 @@
 import org.opensearch.transport.TransportRequest;
 import org.opensearch.transport.TransportRequestHandler;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
@@ -118,12 +119,13 @@ public Map<String, Supplier<Transport>> getTransports(
                 PageCacheRecycler pageCacheRecycler,
                 CircuitBreakerService circuitBreakerService,
                 NamedWriteableRegistry namedWriteableRegistry,
-                NetworkService networkService
+                NetworkService networkService,
+                Tracer tracer
             ) {
                 return Collections.singletonMap("custom", custom);
             }
         };
-        NetworkModule module = newNetworkModule(settings, plugin);
+        NetworkModule module = newNetworkModule(settings, null, plugin);
         assertSame(custom, module.getTransportSupplier());
     }
 
@@ -134,7 +136,7 @@ public void testRegisterHttpTransport() {
             .build();
         Supplier<HttpServerTransport> custom = FakeHttpTransport::new;
 
-        NetworkModule module = newNetworkModule(settings, new NetworkPlugin() {
+        NetworkModule module = newNetworkModule(settings, null, new NetworkPlugin() {
             @Override
             public Map<String, Supplier<HttpServerTransport>> getHttpTransports(
                 Settings settings,
@@ -154,7 +156,7 @@ public Map<String, Supplier<HttpServerTransport>> getHttpTransports(
         assertSame(custom, module.getHttpServerTransportSupplier());
 
         settings = Settings.builder().put(NetworkModule.TRANSPORT_TYPE_KEY, "local").build();
-        NetworkModule newModule = newNetworkModule(settings);
+        NetworkModule newModule = newNetworkModule(settings, null);
         expectThrows(IllegalStateException.class, () -> newModule.getHttpServerTransportSupplier());
     }
 
@@ -168,7 +170,7 @@ public void testOverrideDefault() {
         Supplier<Transport> customTransport = () -> null;  // content doesn't matter we check reference equality
         Supplier<HttpServerTransport> custom = FakeHttpTransport::new;
         Supplier<HttpServerTransport> def = FakeHttpTransport::new;
-        NetworkModule module = newNetworkModule(settings, new NetworkPlugin() {
+        NetworkModule module = newNetworkModule(settings, null, new NetworkPlugin() {
             @Override
             public Map<String, Supplier<Transport>> getTransports(
                 Settings settings,
@@ -176,7 +178,8 @@ public Map<String, Supplier<Transport>> getTransports(
                 PageCacheRecycler pageCacheRecycler,
                 CircuitBreakerService circuitBreakerService,
                 NamedWriteableRegistry namedWriteableRegistry,
-                NetworkService networkService
+                NetworkService networkService,
+                Tracer tracer
             ) {
                 return Collections.singletonMap("default_custom", customTransport);
             }
@@ -212,7 +215,7 @@ public void testDefaultKeys() {
         Supplier<HttpServerTransport> custom = FakeHttpTransport::new;
         Supplier<HttpServerTransport> def = FakeHttpTransport::new;
         Supplier<Transport> customTransport = () -> null;
-        NetworkModule module = newNetworkModule(settings, new NetworkPlugin() {
+        NetworkModule module = newNetworkModule(settings, null, new NetworkPlugin() {
             @Override
             public Map<String, Supplier<Transport>> getTransports(
                 Settings settings,
@@ -220,7 +223,8 @@ public Map<String, Supplier<Transport>> getTransports(
                 PageCacheRecycler pageCacheRecycler,
                 CircuitBreakerService circuitBreakerService,
                 NamedWriteableRegistry namedWriteableRegistry,
-                NetworkService networkService
+                NetworkService networkService,
+                Tracer tracer
             ) {
                 return Collections.singletonMap("default_custom", customTransport);
             }
@@ -270,7 +274,7 @@ public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
                 return actualHandler;
             }
         };
-        NetworkModule module = newNetworkModule(settings, new NetworkPlugin() {
+        NetworkModule module = newNetworkModule(settings, null, new NetworkPlugin() {
             @Override
             public List<TransportInterceptor> getTransportInterceptors(
                 NamedWriteableRegistry namedWriteableRegistry,
@@ -292,7 +296,7 @@ public List<TransportInterceptor> getTransportInterceptors(
         assertSame(((NetworkModule.CompositeTransportInterceptor) transportInterceptor).transportInterceptors.get(0), interceptor);
 
         NullPointerException nullPointerException = expectThrows(NullPointerException.class, () -> {
-            newNetworkModule(settings, new NetworkPlugin() {
+            newNetworkModule(settings, null, new NetworkPlugin() {
                 @Override
                 public List<TransportInterceptor> getTransportInterceptors(
                     NamedWriteableRegistry namedWriteableRegistry,
@@ -306,7 +310,202 @@ public List<TransportInterceptor> getTransportInterceptors(
         assertEquals("interceptor must not be null", nullPointerException.getMessage());
     }
 
-    private NetworkModule newNetworkModule(Settings settings, NetworkPlugin... plugins) {
+    public void testRegisterCoreInterceptor() {
+        Settings settings = Settings.builder().put(NetworkModule.TRANSPORT_TYPE_KEY, "local").build();
+        AtomicInteger called = new AtomicInteger(0);
+
+        TransportInterceptor interceptor = new TransportInterceptor() {
+            @Override
+            public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+                String action,
+                String executor,
+                boolean forceExecution,
+                TransportRequestHandler<T> actualHandler
+            ) {
+                called.incrementAndGet();
+                if ("foo/bar/boom".equals(action)) {
+                    assertTrue(forceExecution);
+                } else {
+                    assertFalse(forceExecution);
+                }
+                return actualHandler;
+            }
+        };
+
+        List<TransportInterceptor> coreTransportInterceptors = new ArrayList<>();
+        coreTransportInterceptors.add(interceptor);
+
+        NetworkModule module = newNetworkModule(settings, coreTransportInterceptors);
+
+        TransportInterceptor transportInterceptor = module.getTransportInterceptor();
+        assertEquals(0, called.get());
+        transportInterceptor.interceptHandler("foo/bar/boom", null, true, null);
+        assertEquals(1, called.get());
+        transportInterceptor.interceptHandler("foo/baz/boom", null, false, null);
+        assertEquals(2, called.get());
+        assertTrue(transportInterceptor instanceof NetworkModule.CompositeTransportInterceptor);
+        assertEquals(((NetworkModule.CompositeTransportInterceptor) transportInterceptor).transportInterceptors.size(), 1);
+        assertSame(((NetworkModule.CompositeTransportInterceptor) transportInterceptor).transportInterceptors.get(0), interceptor);
+    }
+
+    public void testInterceptorOrder() {
+        Settings settings = Settings.builder().put(NetworkModule.TRANSPORT_TYPE_KEY, "local").build();
+        AtomicInteger called = new AtomicInteger(0);
+        AtomicInteger called1 = new AtomicInteger(0);
+
+        TransportInterceptor interceptor = new TransportInterceptor() {
+            @Override
+            public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+                String action,
+                String executor,
+                boolean forceExecution,
+                TransportRequestHandler<T> actualHandler
+            ) {
+                called.incrementAndGet();
+                if ("foo/bar/boom".equals(action)) {
+                    assertTrue(forceExecution);
+                } else {
+                    assertFalse(forceExecution);
+                }
+                return actualHandler;
+            }
+        };
+
+        TransportInterceptor interceptor1 = new TransportInterceptor() {
+            @Override
+            public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+                String action,
+                String executor,
+                boolean forceExecution,
+                TransportRequestHandler<T> actualHandler
+            ) {
+                called1.incrementAndGet();
+                if ("foo/bar/boom".equals(action)) {
+                    assertTrue(forceExecution);
+                } else {
+                    assertFalse(forceExecution);
+                }
+                return actualHandler;
+            }
+        };
+
+        List<TransportInterceptor> coreTransportInterceptors = new ArrayList<>();
+        coreTransportInterceptors.add(interceptor1);
+
+        NetworkModule module = newNetworkModule(settings, coreTransportInterceptors, new NetworkPlugin() {
+            @Override
+            public List<TransportInterceptor> getTransportInterceptors(
+                NamedWriteableRegistry namedWriteableRegistry,
+                ThreadContext threadContext
+            ) {
+                assertNotNull(threadContext);
+                return Collections.singletonList(interceptor);
+            }
+        });
+
+        TransportInterceptor transportInterceptor = module.getTransportInterceptor();
+        assertEquals(((NetworkModule.CompositeTransportInterceptor) transportInterceptor).transportInterceptors.size(), 2);
+
+        assertEquals(0, called.get());
+        assertEquals(0, called1.get());
+        transportInterceptor.interceptHandler("foo/bar/boom", null, true, null);
+        assertEquals(1, called.get());
+        assertEquals(1, called1.get());
+        transportInterceptor.interceptHandler("foo/baz/boom", null, false, null);
+        assertEquals(2, called.get());
+        assertEquals(2, called1.get());
+    }
+
+    public void testInterceptorOrderException() {
+        Settings settings = Settings.builder().put(NetworkModule.TRANSPORT_TYPE_KEY, "local").build();
+        AtomicInteger called = new AtomicInteger(0);
+        AtomicInteger called1 = new AtomicInteger(0);
+
+        TransportInterceptor interceptor = new TransportInterceptor() {
+            @Override
+            public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+                String action,
+                String executor,
+                boolean forceExecution,
+                TransportRequestHandler<T> actualHandler
+            ) {
+                called.incrementAndGet();
+                if ("foo/bar/boom".equals(action)) {
+                    assertTrue(forceExecution);
+                } else {
+                    assertFalse(forceExecution);
+                }
+                return actualHandler;
+            }
+        };
+
+        TransportInterceptor interceptor1 = new TransportInterceptor() {
+            @Override
+            public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
+                String action,
+                String executor,
+                boolean forceExecution,
+                TransportRequestHandler<T> actualHandler
+            ) {
+                called1.incrementAndGet();
+                throw new RuntimeException("Handler Invoke Failed");
+            }
+        };
+
+        List<TransportInterceptor> coreTransportInterceptors = new ArrayList<>();
+        coreTransportInterceptors.add(interceptor1);
+
+        NetworkModule module = newNetworkModule(settings, coreTransportInterceptors, new NetworkPlugin() {
+            @Override
+            public List<TransportInterceptor> getTransportInterceptors(
+                NamedWriteableRegistry namedWriteableRegistry,
+                ThreadContext threadContext
+            ) {
+                assertNotNull(threadContext);
+                return Collections.singletonList(interceptor);
+            }
+        });
+
+        TransportInterceptor transportInterceptor = module.getTransportInterceptor();
+        assertEquals(((NetworkModule.CompositeTransportInterceptor) transportInterceptor).transportInterceptors.size(), 2);
+
+        assertEquals(0, called.get());
+        assertEquals(0, called1.get());
+        try {
+            transportInterceptor.interceptHandler("foo/bar/boom", null, true, null);
+        } catch (Exception e) {
+            assertEquals(1, called.get());
+            assertEquals(1, called1.get());
+        }
+
+        coreTransportInterceptors = new ArrayList<>();
+        coreTransportInterceptors.add(interceptor);
+        module = newNetworkModule(settings, coreTransportInterceptors, new NetworkPlugin() {
+            @Override
+            public List<TransportInterceptor> getTransportInterceptors(
+                NamedWriteableRegistry namedWriteableRegistry,
+                ThreadContext threadContext
+            ) {
+                assertNotNull(threadContext);
+                return Collections.singletonList(interceptor1);
+            }
+        });
+
+        transportInterceptor = module.getTransportInterceptor();
+
+        try {
+            transportInterceptor.interceptHandler("foo/baz/boom", null, false, null);
+        } catch (Exception e) {
+            assertEquals(1, called.get());
+            assertEquals(2, called1.get());
+        }
+    }
+
+    private NetworkModule newNetworkModule(
+        Settings settings,
+        List<TransportInterceptor> coreTransportInterceptors,
+        NetworkPlugin... plugins
+    ) {
         return new NetworkModule(
             settings,
             Arrays.asList(plugins),
@@ -319,7 +518,8 @@ private NetworkModule newNetworkModule(Settings settings, NetworkPlugin... plugi
             null,
             new NullDispatcher(),
             new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
-            NoopTracer.INSTANCE
+            NoopTracer.INSTANCE,
+            coreTransportInterceptors
         );
     }
 }
diff --git a/server/src/test/java/org/opensearch/common/regex/RegexTests.java b/server/src/test/java/org/opensearch/common/regex/RegexTests.java
index b92fcdad56d74..21d3cb2df8f61 100644
--- a/server/src/test/java/org/opensearch/common/regex/RegexTests.java
+++ b/server/src/test/java/org/opensearch/common/regex/RegexTests.java
@@ -96,7 +96,22 @@ public void testDoubleWildcardMatch() {
         assertFalse(Regex.simpleMatch("fff**ddd", "fffabcdd"));
         assertTrue(Regex.simpleMatch("fff*******ddd", "fffabcddd"));
         assertTrue(Regex.simpleMatch("fff*******ddd", "FffAbcdDd", true));
+        assertFalse(Regex.simpleMatch("fff*******ddd", "FffAbcdDd", false));
         assertFalse(Regex.simpleMatch("fff******ddd", "fffabcdd"));
+        assertTrue(Regex.simpleMatch("abCDefGH******ddd", "abCDefGHddd", false));
+        assertTrue(Regex.simpleMatch("******", "a"));
+        assertTrue(Regex.simpleMatch("***WILDcard***", "aaaaaaaaWILDcardZZZZZZ", false));
+        assertFalse(Regex.simpleMatch("***xxxxx123456789xxxxxx***", "xxxxxabcdxxxxx", false));
+        assertFalse(Regex.simpleMatch("***xxxxxabcdxxxxx***", "xxxxxABCDxxxxx", false));
+        assertTrue(Regex.simpleMatch("***xxxxxabcdxxxxx***", "xxxxxABCDxxxxx", true));
+        assertTrue(Regex.simpleMatch("**stephenIsSuperCool**", "ItIsTrueThatStephenIsSuperCoolSoYouShouldLetThisIn", true));
+        assertTrue(
+            Regex.simpleMatch(
+                "**w**X**y**Z**",
+                "abcdeFGHIJKLMNOPqrstuvwabcdeFGHIJKLMNOPqrstuvwXabcdeFGHIJKLMNOPqrstuvwXyabcdeFGHIJKLMNOPqrstuvwXyZ",
+                false
+            )
+        );
     }
 
     public void testSimpleMatch() {
diff --git a/server/src/test/java/org/opensearch/common/rounding/DateTimeUnitTests.java b/server/src/test/java/org/opensearch/common/rounding/DateTimeUnitTests.java
deleted file mode 100644
index 7b87e136c5f38..0000000000000
--- a/server/src/test/java/org/opensearch/common/rounding/DateTimeUnitTests.java
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.test.OpenSearchTestCase;
-
-import static org.opensearch.common.rounding.DateTimeUnit.DAY_OF_MONTH;
-import static org.opensearch.common.rounding.DateTimeUnit.HOUR_OF_DAY;
-import static org.opensearch.common.rounding.DateTimeUnit.MINUTES_OF_HOUR;
-import static org.opensearch.common.rounding.DateTimeUnit.MONTH_OF_YEAR;
-import static org.opensearch.common.rounding.DateTimeUnit.QUARTER;
-import static org.opensearch.common.rounding.DateTimeUnit.SECOND_OF_MINUTE;
-import static org.opensearch.common.rounding.DateTimeUnit.WEEK_OF_WEEKYEAR;
-import static org.opensearch.common.rounding.DateTimeUnit.YEAR_OF_CENTURY;
-
-public class DateTimeUnitTests extends OpenSearchTestCase {
-
-    /**
-     * test that we don't accidentally change enum ids
-     */
-    public void testEnumIds() {
-        assertEquals(1, WEEK_OF_WEEKYEAR.id());
-        assertEquals(WEEK_OF_WEEKYEAR, DateTimeUnit.resolve((byte) 1));
-
-        assertEquals(2, YEAR_OF_CENTURY.id());
-        assertEquals(YEAR_OF_CENTURY, DateTimeUnit.resolve((byte) 2));
-
-        assertEquals(3, QUARTER.id());
-        assertEquals(QUARTER, DateTimeUnit.resolve((byte) 3));
-
-        assertEquals(4, MONTH_OF_YEAR.id());
-        assertEquals(MONTH_OF_YEAR, DateTimeUnit.resolve((byte) 4));
-
-        assertEquals(5, DAY_OF_MONTH.id());
-        assertEquals(DAY_OF_MONTH, DateTimeUnit.resolve((byte) 5));
-
-        assertEquals(6, HOUR_OF_DAY.id());
-        assertEquals(HOUR_OF_DAY, DateTimeUnit.resolve((byte) 6));
-
-        assertEquals(7, MINUTES_OF_HOUR.id());
-        assertEquals(MINUTES_OF_HOUR, DateTimeUnit.resolve((byte) 7));
-
-        assertEquals(8, SECOND_OF_MINUTE.id());
-        assertEquals(SECOND_OF_MINUTE, DateTimeUnit.resolve((byte) 8));
-    }
-}
diff --git a/server/src/test/java/org/opensearch/common/rounding/RoundingDuelTests.java b/server/src/test/java/org/opensearch/common/rounding/RoundingDuelTests.java
deleted file mode 100644
index 3088067cd1f84..0000000000000
--- a/server/src/test/java/org/opensearch/common/rounding/RoundingDuelTests.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.common.unit.TimeValue;
-import org.opensearch.test.OpenSearchTestCase;
-import org.joda.time.DateTimeZone;
-
-import java.time.ZoneOffset;
-
-import static org.hamcrest.Matchers.is;
-
-public class RoundingDuelTests extends OpenSearchTestCase {
-
-    // dont include nano/micro seconds as rounding would become zero then and throw an exception
-    private static final String[] ALLOWED_TIME_SUFFIXES = new String[] { "d", "h", "ms", "s", "m" };
-
-    public void testDuellingImplementations() {
-        org.opensearch.common.Rounding.DateTimeUnit randomDateTimeUnit = randomFrom(org.opensearch.common.Rounding.DateTimeUnit.values());
-        org.opensearch.common.Rounding.Prepared rounding;
-        Rounding roundingJoda;
-
-        if (randomBoolean()) {
-            rounding = org.opensearch.common.Rounding.builder(randomDateTimeUnit).timeZone(ZoneOffset.UTC).build().prepareForUnknown();
-            DateTimeUnit dateTimeUnit = DateTimeUnit.resolve(randomDateTimeUnit.getId());
-            roundingJoda = Rounding.builder(dateTimeUnit).timeZone(DateTimeZone.UTC).build();
-        } else {
-            TimeValue interval = timeValue();
-            rounding = org.opensearch.common.Rounding.builder(interval).timeZone(ZoneOffset.UTC).build().prepareForUnknown();
-            roundingJoda = Rounding.builder(interval).timeZone(DateTimeZone.UTC).build();
-        }
-
-        long roundValue = randomLong();
-        assertThat(roundingJoda.round(roundValue), is(rounding.round(roundValue)));
-    }
-
-    static TimeValue timeValue() {
-        return TimeValue.parseTimeValue(randomIntBetween(1, 1000) + randomFrom(ALLOWED_TIME_SUFFIXES), "settingName");
-    }
-}
diff --git a/server/src/test/java/org/opensearch/common/rounding/TimeZoneRoundingTests.java b/server/src/test/java/org/opensearch/common/rounding/TimeZoneRoundingTests.java
deleted file mode 100644
index 8297f8fcf47e2..0000000000000
--- a/server/src/test/java/org/opensearch/common/rounding/TimeZoneRoundingTests.java
+++ /dev/null
@@ -1,822 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.common.collect.Tuple;
-import org.opensearch.common.rounding.Rounding.TimeIntervalRounding;
-import org.opensearch.common.rounding.Rounding.TimeUnitRounding;
-import org.opensearch.common.unit.TimeValue;
-import org.opensearch.test.OpenSearchTestCase;
-import org.joda.time.DateTime;
-import org.joda.time.DateTimeConstants;
-import org.joda.time.DateTimeZone;
-import org.joda.time.format.DateTimeFormat;
-import org.joda.time.format.DateTimeFormatter;
-import org.joda.time.format.ISODateTimeFormat;
-import org.hamcrest.Description;
-import org.hamcrest.Matcher;
-import org.hamcrest.TypeSafeMatcher;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.greaterThan;
-import static org.hamcrest.Matchers.greaterThanOrEqualTo;
-import static org.hamcrest.Matchers.lessThan;
-import static org.hamcrest.Matchers.lessThanOrEqualTo;
-import static org.hamcrest.Matchers.startsWith;
-
-public class TimeZoneRoundingTests extends OpenSearchTestCase {
-
-    public void testUTCTimeUnitRounding() {
-        Rounding tzRounding = Rounding.builder(DateTimeUnit.MONTH_OF_YEAR).build();
-        DateTimeZone tz = DateTimeZone.UTC;
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-01T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-01T00:00:00.000Z")), isDate(time("2009-03-01T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.WEEK_OF_WEEKYEAR).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-09T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-16T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.QUARTER).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-01T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-04-01T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T01:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-09T01:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-10T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.YEAR_OF_CENTURY).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-01T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2013-01-01T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.MINUTES_OF_HOUR).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T01:01:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-09T00:01:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.SECOND_OF_MINUTE).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T01:01:01.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-09T00:00:01.000Z"), tz));
-    }
-
-    public void testUTCIntervalRounding() {
-        Rounding tzRounding = Rounding.builder(TimeValue.timeValueHours(12)).build();
-        DateTimeZone tz = DateTimeZone.UTC;
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-03T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T00:00:00.000Z")), isDate(time("2009-02-03T12:00:00.000Z"), tz));
-        assertThat(tzRounding.round(time("2009-02-03T13:01:01")), isDate(time("2009-02-03T12:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T12:00:00.000Z")), isDate(time("2009-02-04T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(TimeValue.timeValueHours(48)).build();
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-03T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T00:00:00.000Z")), isDate(time("2009-02-05T00:00:00.000Z"), tz));
-        assertThat(tzRounding.round(time("2009-02-05T13:01:01")), isDate(time("2009-02-05T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-05T00:00:00.000Z")), isDate(time("2009-02-07T00:00:00.000Z"), tz));
-    }
-
-    /**
-     * test TimeIntervalRounding, (interval &lt; 12h) with time zone shift
-     */
-    public void testTimeIntervalRounding() {
-        DateTimeZone tz = DateTimeZone.forOffsetHours(-1);
-        Rounding tzRounding = Rounding.builder(TimeValue.timeValueHours(6)).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T00:01:01")), isDate(time("2009-02-02T19:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-02T19:00:00.000Z")), isDate(time("2009-02-03T01:00:00.000Z"), tz));
-
-        assertThat(tzRounding.round(time("2009-02-03T13:01:01")), isDate(time("2009-02-03T13:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T13:00:00.000Z")), isDate(time("2009-02-03T19:00:00.000Z"), tz));
-    }
-
-    /**
-     * test DayIntervalRounding, (interval &gt;= 12h) with time zone shift
-     */
-    public void testDayIntervalRounding() {
-        DateTimeZone tz = DateTimeZone.forOffsetHours(-8);
-        Rounding tzRounding = Rounding.builder(TimeValue.timeValueHours(12)).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T00:01:01")), isDate(time("2009-02-02T20:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-02T20:00:00.000Z")), isDate(time("2009-02-03T08:00:00.000Z"), tz));
-
-        assertThat(tzRounding.round(time("2009-02-03T13:01:01")), isDate(time("2009-02-03T08:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T08:00:00.000Z")), isDate(time("2009-02-03T20:00:00.000Z"), tz));
-    }
-
-    public void testDayRounding() {
-        int timezoneOffset = -2;
-        Rounding tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(DateTimeZone.forOffsetHours(timezoneOffset)).build();
-        assertThat(tzRounding.round(0), equalTo(0L - TimeValue.timeValueHours(24 + timezoneOffset).millis()));
-        assertThat(
-            tzRounding.nextRoundingValue(0L - TimeValue.timeValueHours(24 + timezoneOffset).millis()),
-            equalTo(TimeValue.timeValueHours(-timezoneOffset).millis())
-        );
-
-        DateTimeZone tz = DateTimeZone.forID("-08:00");
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2012-04-01T04:15:30Z")), isDate(time("2012-03-31T08:00:00Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.MONTH_OF_YEAR).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2012-04-01T04:15:30Z")), equalTo(time("2012-03-01T08:00:00Z")));
-
-        // date in Feb-3rd, but still in Feb-2nd in -02:00 timezone
-        tz = DateTimeZone.forID("-02:00");
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-02T02:00:00"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-02T02:00:00")), isDate(time("2009-02-03T02:00:00"), tz));
-
-        // date in Feb-3rd, also in -02:00 timezone
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T02:01:01")), isDate(time("2009-02-03T02:00:00"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T02:00:00")), isDate(time("2009-02-04T02:00:00"), tz));
-    }
-
-    public void testTimeRounding() {
-        // hour unit
-        DateTimeZone tz = DateTimeZone.forOffsetHours(-2);
-        Rounding tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(tz).build();
-        assertThat(tzRounding.round(0), equalTo(0L));
-        assertThat(tzRounding.nextRoundingValue(0L), equalTo(TimeValue.timeValueHours(1L).getMillis()));
-
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-03T01:00:00"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T01:00:00")), isDate(time("2009-02-03T02:00:00"), tz));
-    }
-
-    public void testTimeUnitRoundingDST() {
-        Rounding tzRounding;
-        // testing savings to non savings switch
-        DateTimeZone cet = DateTimeZone.forID("CET");
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(cet).build();
-        assertThat(tzRounding.round(time("2014-10-26T01:01:01", cet)), isDate(time("2014-10-26T01:00:00+02:00"), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-10-26T01:00:00", cet)), isDate(time("2014-10-26T02:00:00+02:00"), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-10-26T02:00:00", cet)), isDate(time("2014-10-26T02:00:00+01:00"), cet));
-
-        // testing non savings to savings switch
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(cet).build();
-        assertThat(tzRounding.round(time("2014-03-30T01:01:01", cet)), isDate(time("2014-03-30T01:00:00+01:00"), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-03-30T01:00:00", cet)), isDate(time("2014-03-30T03:00:00", cet), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-03-30T03:00:00", cet)), isDate(time("2014-03-30T04:00:00", cet), cet));
-
-        // testing non savings to savings switch (America/Chicago)
-        DateTimeZone chg = DateTimeZone.forID("America/Chicago");
-        Rounding tzRounding_utc = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(DateTimeZone.UTC).build();
-        assertThat(tzRounding.round(time("2014-03-09T03:01:01", chg)), isDate(time("2014-03-09T03:00:00", chg), chg));
-
-        Rounding tzRounding_chg = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(chg).build();
-        assertThat(tzRounding_chg.round(time("2014-03-09T03:01:01", chg)), isDate(time("2014-03-09T03:00:00", chg), chg));
-
-        // testing savings to non savings switch 2013 (America/Chicago)
-        assertThat(tzRounding_utc.round(time("2013-11-03T06:01:01", chg)), isDate(time("2013-11-03T06:00:00", chg), chg));
-        assertThat(tzRounding_chg.round(time("2013-11-03T06:01:01", chg)), isDate(time("2013-11-03T06:00:00", chg), chg));
-
-        // testing savings to non savings switch 2014 (America/Chicago)
-        assertThat(tzRounding_utc.round(time("2014-11-02T06:01:01", chg)), isDate(time("2014-11-02T06:00:00", chg), chg));
-        assertThat(tzRounding_chg.round(time("2014-11-02T06:01:01", chg)), isDate(time("2014-11-02T06:00:00", chg), chg));
-    }
-
-    /**
-     * Randomized test on TimeUnitRounding. Test uses random
-     * {@link DateTimeUnit} and {@link DateTimeZone} and often (50% of the time)
-     * chooses test dates that are exactly on or close to offset changes (e.g.
-     * DST) in the chosen time zone.
-     *
-     * It rounds the test date down and up and performs various checks on the
-     * rounding unit interval that is defined by this. Assumptions tested are
-     * described in
-     * {@link #assertInterval(long, long, long, Rounding, DateTimeZone)}
-     */
-    public void testRoundingRandom() {
-        for (int i = 0; i < 1000; ++i) {
-            DateTimeUnit timeUnit = randomTimeUnit();
-            DateTimeZone tz = randomDateTimeZone();
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-            long date = Math.abs(randomLong() % (2 * (long) 10e11)); // 1970-01-01T00:00:00Z - 2033-05-18T05:33:20.000+02:00
-            long unitMillis = timeUnit.field(tz).getDurationField().getUnitMillis();
-            if (randomBoolean()) {
-                nastyDate(date, tz, unitMillis);
-            }
-            final long roundedDate = rounding.round(date);
-            final long nextRoundingValue = rounding.nextRoundingValue(roundedDate);
-
-            assertInterval(roundedDate, date, nextRoundingValue, rounding, tz);
-
-            // check correct unit interval width for units smaller than a day, they should be fixed size except for transitions
-            if (unitMillis <= DateTimeConstants.MILLIS_PER_DAY) {
-                // if the interval defined didn't cross timezone offset transition, it should cover unitMillis width
-                if (tz.getOffset(roundedDate - 1) == tz.getOffset(nextRoundingValue + 1)) {
-                    assertThat(
-                        "unit interval width not as expected for [" + timeUnit + "], [" + tz + "] at " + new DateTime(roundedDate),
-                        nextRoundingValue - roundedDate,
-                        equalTo(unitMillis)
-                    );
-                }
-            }
-        }
-    }
-
-    /**
-     * To be even more nasty, go to a transition in the selected time zone.
-     * In one third of the cases stay there, otherwise go half a unit back or forth
-     */
-    private static long nastyDate(long initialDate, DateTimeZone timezone, long unitMillis) {
-        long date = timezone.nextTransition(initialDate);
-        if (randomBoolean()) {
-            return date + (randomLong() % unitMillis);  // positive and negative offset possible
-        } else {
-            return date;
-        }
-    }
-
-    /**
-     * test DST end with interval rounding
-     * CET: 25 October 2015, 03:00:00 clocks were turned backward 1 hour to 25 October 2015, 02:00:00 local standard time
-     */
-    public void testTimeIntervalCET_DST_End() {
-        long interval = TimeUnit.MINUTES.toMillis(20);
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        Rounding rounding = new TimeIntervalRounding(interval, tz);
-
-        assertThat(rounding.round(time("2015-10-25T01:55:00+02:00")), isDate(time("2015-10-25T01:40:00+02:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:15:00+02:00")), isDate(time("2015-10-25T02:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:35:00+02:00")), isDate(time("2015-10-25T02:20:00+02:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:55:00+02:00")), isDate(time("2015-10-25T02:40:00+02:00"), tz));
-        // after DST shift
-        assertThat(rounding.round(time("2015-10-25T02:15:00+01:00")), isDate(time("2015-10-25T02:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:35:00+01:00")), isDate(time("2015-10-25T02:20:00+01:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:55:00+01:00")), isDate(time("2015-10-25T02:40:00+01:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T03:15:00+01:00")), isDate(time("2015-10-25T03:00:00+01:00"), tz));
-    }
-
-    /**
-     * test DST start with interval rounding
-     * CET: 27 March 2016, 02:00:00 clocks were turned forward 1 hour to 27 March 2016, 03:00:00 local daylight time
-     */
-    public void testTimeIntervalCET_DST_Start() {
-        long interval = TimeUnit.MINUTES.toMillis(20);
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        Rounding rounding = new TimeIntervalRounding(interval, tz);
-        // test DST start
-        assertThat(rounding.round(time("2016-03-27T01:55:00+01:00")), isDate(time("2016-03-27T01:40:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T02:00:00+01:00")), isDate(time("2016-03-27T03:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:15:00+02:00")), isDate(time("2016-03-27T03:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:35:00+02:00")), isDate(time("2016-03-27T03:20:00+02:00"), tz));
-    }
-
-    /**
-     * test DST start with offset not fitting interval, e.g. Asia/Kathmandu
-     * adding 15min on 1986-01-01T00:00:00 the interval from
-     * 1986-01-01T00:15:00+05:45 to 1986-01-01T00:20:00+05:45 to only be 5min
-     * long
-     */
-    public void testTimeInterval_Kathmandu_DST_Start() {
-        long interval = TimeUnit.MINUTES.toMillis(20);
-        DateTimeZone tz = DateTimeZone.forID("Asia/Kathmandu");
-        Rounding rounding = new TimeIntervalRounding(interval, tz);
-        assertThat(rounding.round(time("1985-12-31T23:55:00+05:30")), isDate(time("1985-12-31T23:40:00+05:30"), tz));
-        assertThat(rounding.round(time("1986-01-01T00:16:00+05:45")), isDate(time("1986-01-01T00:15:00+05:45"), tz));
-        assertThat(time("1986-01-01T00:15:00+05:45") - time("1985-12-31T23:40:00+05:30"), equalTo(TimeUnit.MINUTES.toMillis(20)));
-        assertThat(rounding.round(time("1986-01-01T00:26:00+05:45")), isDate(time("1986-01-01T00:20:00+05:45"), tz));
-        assertThat(time("1986-01-01T00:20:00+05:45") - time("1986-01-01T00:15:00+05:45"), equalTo(TimeUnit.MINUTES.toMillis(5)));
-        assertThat(rounding.round(time("1986-01-01T00:46:00+05:45")), isDate(time("1986-01-01T00:40:00+05:45"), tz));
-        assertThat(time("1986-01-01T00:40:00+05:45") - time("1986-01-01T00:20:00+05:45"), equalTo(TimeUnit.MINUTES.toMillis(20)));
-    }
-
-    /**
-     * Special test for intervals that don't fit evenly into rounding interval.
-     * In this case, when interval crosses DST transition point, rounding in local
-     * time can land in a DST gap which results in wrong UTC rounding values.
-     */
-    public void testIntervalRounding_NotDivisibleInteval() {
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        long interval = TimeUnit.MINUTES.toMillis(14);
-        Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-
-        assertThat(rounding.round(time("2016-03-27T01:41:00+01:00")), isDate(time("2016-03-27T01:30:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T01:51:00+01:00")), isDate(time("2016-03-27T01:44:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T01:59:00+01:00")), isDate(time("2016-03-27T01:58:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:05:00+02:00")), isDate(time("2016-03-27T03:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:12:00+02:00")), isDate(time("2016-03-27T03:08:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:25:00+02:00")), isDate(time("2016-03-27T03:22:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:39:00+02:00")), isDate(time("2016-03-27T03:36:00+02:00"), tz));
-    }
-
-    /**
-     * Test for half day rounding intervals scrossing DST.
-     */
-    public void testIntervalRounding_HalfDay_DST() {
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        long interval = TimeUnit.HOURS.toMillis(12);
-        Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-
-        assertThat(rounding.round(time("2016-03-26T01:00:00+01:00")), isDate(time("2016-03-26T00:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-26T13:00:00+01:00")), isDate(time("2016-03-26T12:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T01:00:00+01:00")), isDate(time("2016-03-27T00:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T13:00:00+02:00")), isDate(time("2016-03-27T12:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-28T01:00:00+02:00")), isDate(time("2016-03-28T00:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-28T13:00:00+02:00")), isDate(time("2016-03-28T12:00:00+02:00"), tz));
-    }
-
-    /**
-     * randomized test on {@link TimeIntervalRounding} with random interval and time zone offsets
-     */
-    public void testIntervalRoundingRandom() {
-        for (int i = 0; i < 1000; i++) {
-            TimeUnit unit = randomFrom(new TimeUnit[] { TimeUnit.MINUTES, TimeUnit.HOURS, TimeUnit.DAYS });
-            long interval = unit.toMillis(randomIntBetween(1, 365));
-            DateTimeZone tz = randomDateTimeZone();
-            Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-            long mainDate = Math.abs(randomLong() % (2 * (long) 10e11)); // 1970-01-01T00:00:00Z - 2033-05-18T05:33:20.000+02:00
-            if (randomBoolean()) {
-                mainDate = nastyDate(mainDate, tz, interval);
-            }
-            // check two intervals around date
-            long previousRoundedValue = Long.MIN_VALUE;
-            for (long date = mainDate - 2 * interval; date < mainDate + 2 * interval; date += interval / 2) {
-                try {
-                    final long roundedDate = rounding.round(date);
-                    final long nextRoundingValue = rounding.nextRoundingValue(roundedDate);
-                    assertThat("Rounding should be idempotent", roundedDate, equalTo(rounding.round(roundedDate)));
-                    assertThat("Rounded value smaller or equal than unrounded", roundedDate, lessThanOrEqualTo(date));
-                    assertThat(
-                        "Values smaller than rounded value should round further down",
-                        rounding.round(roundedDate - 1),
-                        lessThan(roundedDate)
-                    );
-                    assertThat("Rounding should be >= previous rounding value", roundedDate, greaterThanOrEqualTo(previousRoundedValue));
-
-                    if (tz.isFixed()) {
-                        assertThat("NextRounding value should be greater than date", nextRoundingValue, greaterThan(roundedDate));
-                        assertThat(
-                            "NextRounding value should be interval from rounded value",
-                            nextRoundingValue - roundedDate,
-                            equalTo(interval)
-                        );
-                        assertThat(
-                            "NextRounding value should be a rounded date",
-                            nextRoundingValue,
-                            equalTo(rounding.round(nextRoundingValue))
-                        );
-                    }
-                    previousRoundedValue = roundedDate;
-                } catch (AssertionError e) {
-                    logger.error("Rounding error at {}, timezone {}, interval: {},", new DateTime(date, tz), tz, interval);
-                    throw e;
-                }
-            }
-        }
-    }
-
-    /**
-     * Test that rounded values are always greater or equal to last rounded value if date is increasing.
-     * The example covers an interval around 2011-10-30T02:10:00+01:00, time zone CET, interval: 2700000ms
-     */
-    public void testIntervalRoundingMonotonic_CET() {
-        long interval = TimeUnit.MINUTES.toMillis(45);
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-        List<Tuple<String, String>> expectedDates = new ArrayList<>();
-        // first date is the date to be rounded, second the expected result
-        expectedDates.add(new Tuple<>("2011-10-30T01:40:00.000+02:00", "2011-10-30T01:30:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:02:30.000+02:00", "2011-10-30T01:30:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:25:00.000+02:00", "2011-10-30T02:15:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:47:30.000+02:00", "2011-10-30T02:15:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:10:00.000+01:00", "2011-10-30T02:15:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:32:30.000+01:00", "2011-10-30T02:15:00.000+01:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:55:00.000+01:00", "2011-10-30T02:15:00.000+01:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T03:17:30.000+01:00", "2011-10-30T03:00:00.000+01:00"));
-
-        long previousDate = Long.MIN_VALUE;
-        for (Tuple<String, String> dates : expectedDates) {
-            final long roundedDate = rounding.round(time(dates.v1()));
-            assertThat(roundedDate, isDate(time(dates.v2()), tz));
-            assertThat(roundedDate, greaterThanOrEqualTo(previousDate));
-            previousDate = roundedDate;
-        }
-        // here's what this means for interval widths
-        assertEquals(TimeUnit.MINUTES.toMillis(45), time("2011-10-30T02:15:00.000+02:00") - time("2011-10-30T01:30:00.000+02:00"));
-        assertEquals(TimeUnit.MINUTES.toMillis(60), time("2011-10-30T02:15:00.000+01:00") - time("2011-10-30T02:15:00.000+02:00"));
-        assertEquals(TimeUnit.MINUTES.toMillis(45), time("2011-10-30T03:00:00.000+01:00") - time("2011-10-30T02:15:00.000+01:00"));
-    }
-
-    /**
-     * special test for DST switch from #9491
-     */
-    public void testAmbiguousHoursAfterDSTSwitch() {
-        Rounding tzRounding;
-        final DateTimeZone tz = DateTimeZone.forID("Asia/Jerusalem");
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-10-26T00:30:00+03:00")), isDate(time("2014-10-26T00:00:00+03:00"), tz));
-        assertThat(tzRounding.round(time("2014-10-26T01:30:00+03:00")), isDate(time("2014-10-26T01:00:00+03:00"), tz));
-        // the utc date for "2014-10-25T03:00:00+03:00" and "2014-10-25T03:00:00+02:00" is the same, local time turns back 1h here
-        assertThat(time("2014-10-26T03:00:00+03:00"), isDate(time("2014-10-26T02:00:00+02:00"), tz));
-        assertThat(tzRounding.round(time("2014-10-26T01:30:00+02:00")), isDate(time("2014-10-26T01:00:00+02:00"), tz));
-        assertThat(tzRounding.round(time("2014-10-26T02:30:00+02:00")), isDate(time("2014-10-26T02:00:00+02:00"), tz));
-
-        // Day interval
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(time("2014-11-11T00:00:00", tz), tz));
-        // DST on
-        assertThat(tzRounding.round(time("2014-08-11T17:00:00", tz)), isDate(time("2014-08-11T00:00:00", tz), tz));
-        // Day of switching DST on -> off
-        assertThat(tzRounding.round(time("2014-10-26T17:00:00", tz)), isDate(time("2014-10-26T00:00:00", tz), tz));
-        // Day of switching DST off -> on
-        assertThat(tzRounding.round(time("2015-03-27T17:00:00", tz)), isDate(time("2015-03-27T00:00:00", tz), tz));
-
-        // Month interval
-        tzRounding = Rounding.builder(DateTimeUnit.MONTH_OF_YEAR).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(time("2014-11-01T00:00:00", tz), tz));
-        // DST on
-        assertThat(tzRounding.round(time("2014-10-10T17:00:00", tz)), isDate(time("2014-10-01T00:00:00", tz), tz));
-
-        // Year interval
-        tzRounding = Rounding.builder(DateTimeUnit.YEAR_OF_CENTURY).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(time("2014-01-01T00:00:00", tz), tz));
-
-        // Two timestamps in same year and different timezone offset ("Double buckets" issue - #9491)
-        tzRounding = Rounding.builder(DateTimeUnit.YEAR_OF_CENTURY).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(tzRounding.round(time("2014-08-11T17:00:00", tz)), tz));
-    }
-
-    /**
-     * test for #10025, strict local to UTC conversion can cause joda exceptions
-     * on DST start
-     */
-    public void testLenientConversionDST() {
-        DateTimeZone tz = DateTimeZone.forID("America/Sao_Paulo");
-        long start = time("2014-10-18T20:50:00.000", tz);
-        long end = time("2014-10-19T01:00:00.000", tz);
-        Rounding tzRounding = new Rounding.TimeUnitRounding(DateTimeUnit.MINUTES_OF_HOUR, tz);
-        Rounding dayTzRounding = new Rounding.TimeIntervalRounding(60000, tz);
-        for (long time = start; time < end; time = time + 60000) {
-            assertThat(tzRounding.nextRoundingValue(time), greaterThan(time));
-            assertThat(dayTzRounding.nextRoundingValue(time), greaterThan(time));
-        }
-    }
-
-    public void testEdgeCasesTransition() {
-        {
-            // standard +/-1 hour DST transition, CET
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("CET");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            // 29 Mar 2015 - Daylight Saving Time Started
-            // at 02:00:00 clocks were turned forward 1 hour to 03:00:00
-            assertInterval(time("2015-03-29T00:00:00.000+01:00"), time("2015-03-29T01:00:00.000+01:00"), rounding, 60, tz);
-            assertInterval(time("2015-03-29T01:00:00.000+01:00"), time("2015-03-29T03:00:00.000+02:00"), rounding, 60, tz);
-            assertInterval(time("2015-03-29T03:00:00.000+02:00"), time("2015-03-29T04:00:00.000+02:00"), rounding, 60, tz);
-
-            // 25 Oct 2015 - Daylight Saving Time Ended
-            // at 03:00:00 clocks were turned backward 1 hour to 02:00:00
-            assertInterval(time("2015-10-25T01:00:00.000+02:00"), time("2015-10-25T02:00:00.000+02:00"), rounding, 60, tz);
-            assertInterval(time("2015-10-25T02:00:00.000+02:00"), time("2015-10-25T02:00:00.000+01:00"), rounding, 60, tz);
-            assertInterval(time("2015-10-25T02:00:00.000+01:00"), time("2015-10-25T03:00:00.000+01:00"), rounding, 60, tz);
-        }
-
-        {
-            // time zone "Asia/Kathmandu"
-            // 1 Jan 1986 - Time Zone Change (IST → NPT), at 00:00:00 clocks were turned forward 00:15 minutes
-            //
-            // hour rounding is stable before 1985-12-31T23:00:00.000 and after 1986-01-01T01:00:00.000+05:45
-            // the interval between is 105 minutes long because the hour after transition starts at 00:15
-            // which is not a round value for hourly rounding
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("Asia/Kathmandu");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            assertInterval(time("1985-12-31T22:00:00.000+05:30"), time("1985-12-31T23:00:00.000+05:30"), rounding, 60, tz);
-            assertInterval(time("1985-12-31T23:00:00.000+05:30"), time("1986-01-01T01:00:00.000+05:45"), rounding, 105, tz);
-            assertInterval(time("1986-01-01T01:00:00.000+05:45"), time("1986-01-01T02:00:00.000+05:45"), rounding, 60, tz);
-        }
-
-        {
-            // time zone "Australia/Lord_Howe"
-            // 3 Mar 1991 - Daylight Saving Time Ended
-            // at 02:00:00 clocks were turned backward 0:30 hours to Sunday, 3 March 1991, 01:30:00
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("Australia/Lord_Howe");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            assertInterval(time("1991-03-03T00:00:00.000+11:00"), time("1991-03-03T01:00:00.000+11:00"), rounding, 60, tz);
-            assertInterval(time("1991-03-03T01:00:00.000+11:00"), time("1991-03-03T02:00:00.000+10:30"), rounding, 90, tz);
-            assertInterval(time("1991-03-03T02:00:00.000+10:30"), time("1991-03-03T03:00:00.000+10:30"), rounding, 60, tz);
-
-            // 27 Oct 1991 - Daylight Saving Time Started
-            // at 02:00:00 clocks were turned forward 0:30 hours to 02:30:00
-            assertInterval(time("1991-10-27T00:00:00.000+10:30"), time("1991-10-27T01:00:00.000+10:30"), rounding, 60, tz);
-            // the interval containing the switch time is 90 minutes long
-            assertInterval(time("1991-10-27T01:00:00.000+10:30"), time("1991-10-27T03:00:00.000+11:00"), rounding, 90, tz);
-            assertInterval(time("1991-10-27T03:00:00.000+11:00"), time("1991-10-27T04:00:00.000+11:00"), rounding, 60, tz);
-        }
-
-        {
-            // time zone "Pacific/Chatham"
-            // 5 Apr 2015 - Daylight Saving Time Ended
-            // at 03:45:00 clocks were turned backward 1 hour to 02:45:00
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("Pacific/Chatham");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            assertInterval(time("2015-04-05T02:00:00.000+13:45"), time("2015-04-05T03:00:00.000+13:45"), rounding, 60, tz);
-            assertInterval(time("2015-04-05T03:00:00.000+13:45"), time("2015-04-05T03:00:00.000+12:45"), rounding, 60, tz);
-            assertInterval(time("2015-04-05T03:00:00.000+12:45"), time("2015-04-05T04:00:00.000+12:45"), rounding, 60, tz);
-
-            // 27 Sep 2015 - Daylight Saving Time Started
-            // at 02:45:00 clocks were turned forward 1 hour to 03:45:00
-
-            assertInterval(time("2015-09-27T01:00:00.000+12:45"), time("2015-09-27T02:00:00.000+12:45"), rounding, 60, tz);
-            assertInterval(time("2015-09-27T02:00:00.000+12:45"), time("2015-09-27T04:00:00.000+13:45"), rounding, 60, tz);
-            assertInterval(time("2015-09-27T04:00:00.000+13:45"), time("2015-09-27T05:00:00.000+13:45"), rounding, 60, tz);
-        }
-    }
-
-    public void testDST_Europe_Rome() {
-        // time zone "Europe/Rome", rounding to days. Rome had two midnights on the day the clocks went back in 1978, and
-        // timeZone.convertLocalToUTC() gives the later of the two because Rome is east of UTC, whereas we want the earlier.
-
-        DateTimeUnit timeUnit = DateTimeUnit.DAY_OF_MONTH;
-        DateTimeZone tz = DateTimeZone.forID("Europe/Rome");
-        Rounding rounding = new TimeUnitRounding(timeUnit, tz);
-
-        {
-            long timeBeforeFirstMidnight = time("1978-09-30T23:59:00+02:00");
-            long floor = rounding.round(timeBeforeFirstMidnight);
-            assertThat(floor, isDate(time("1978-09-30T00:00:00+02:00"), tz));
-        }
-
-        {
-            long timeBetweenMidnights = time("1978-10-01T00:30:00+02:00");
-            long floor = rounding.round(timeBetweenMidnights);
-            assertThat(floor, isDate(time("1978-10-01T00:00:00+02:00"), tz));
-        }
-
-        {
-            long timeAfterSecondMidnight = time("1978-10-01T00:30:00+01:00");
-            long floor = rounding.round(timeAfterSecondMidnight);
-            assertThat(floor, isDate(time("1978-10-01T00:00:00+02:00"), tz));
-
-            long prevFloor = rounding.round(floor - 1);
-            assertThat(prevFloor, lessThan(floor));
-            assertThat(prevFloor, isDate(time("1978-09-30T00:00:00+02:00"), tz));
-        }
-    }
-
-    /**
-     * Test for a time zone whose days overlap because the clocks are set back across midnight at the end of DST.
-     */
-    public void testDST_America_St_Johns() {
-        // time zone "America/St_Johns", rounding to days.
-        DateTimeUnit timeUnit = DateTimeUnit.DAY_OF_MONTH;
-        DateTimeZone tz = DateTimeZone.forID("America/St_Johns");
-        Rounding rounding = new TimeUnitRounding(timeUnit, tz);
-
-        // 29 October 2006 - Daylight Saving Time ended, changing the UTC offset from -02:30 to -03:30.
-        // This happened at 02:31 UTC, 00:01 local time, so the clocks were set back 1 hour to 23:01 on the 28th.
-        // This means that 2006-10-29 has _two_ midnights, one in the -02:30 offset and one in the -03:30 offset.
-        // Only the first of these is considered "rounded". Moreover, the extra time between 23:01 and 23:59
-        // should be considered as part of the 28th even though it comes after midnight on the 29th.
-
-        {
-            // Times before the first midnight should be rounded up to the first midnight.
-            long timeBeforeFirstMidnight = time("2006-10-28T23:30:00.000-02:30");
-            long floor = rounding.round(timeBeforeFirstMidnight);
-            assertThat(floor, isDate(time("2006-10-28T00:00:00.000-02:30"), tz));
-            long ceiling = rounding.nextRoundingValue(timeBeforeFirstMidnight);
-            assertThat(ceiling, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-            assertInterval(floor, timeBeforeFirstMidnight, ceiling, rounding, tz);
-        }
-
-        {
-            // Times between the two midnights which are on the later day should be rounded down to the later day's midnight.
-            long timeBetweenMidnights = time("2006-10-29T00:00:30.000-02:30");
-            // (this is halfway through the last minute before the clocks changed, in which local time was ambiguous)
-
-            long floor = rounding.round(timeBetweenMidnights);
-            assertThat(floor, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-
-            long ceiling = rounding.nextRoundingValue(timeBetweenMidnights);
-            assertThat(ceiling, isDate(time("2006-10-30T00:00:00.000-03:30"), tz));
-
-            assertInterval(floor, timeBetweenMidnights, ceiling, rounding, tz);
-        }
-
-        {
-            // Times between the two midnights which are on the earlier day should be rounded down to the earlier day's midnight.
-            long timeBetweenMidnights = time("2006-10-28T23:30:00.000-03:30");
-            // (this is halfway through the hour after the clocks changed, in which local time was ambiguous)
-
-            long floor = rounding.round(timeBetweenMidnights);
-            assertThat(floor, isDate(time("2006-10-28T00:00:00.000-02:30"), tz));
-
-            long ceiling = rounding.nextRoundingValue(timeBetweenMidnights);
-            assertThat(ceiling, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-
-            assertInterval(floor, timeBetweenMidnights, ceiling, rounding, tz);
-        }
-
-        {
-            // Times after the second midnight should be rounded down to the first midnight.
-            long timeAfterSecondMidnight = time("2006-10-29T06:00:00.000-03:30");
-            long floor = rounding.round(timeAfterSecondMidnight);
-            assertThat(floor, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-            long ceiling = rounding.nextRoundingValue(timeAfterSecondMidnight);
-            assertThat(ceiling, isDate(time("2006-10-30T00:00:00.000-03:30"), tz));
-            assertInterval(floor, timeAfterSecondMidnight, ceiling, rounding, tz);
-        }
-    }
-
-    /**
-     * tests for dst transition with overlaps and day roundings.
-     */
-    public void testDST_END_Edgecases() {
-        // First case, dst happens at 1am local time, switching back one hour.
-        // We want the overlapping hour to count for the next day, making it a 25h interval
-
-        DateTimeUnit timeUnit = DateTimeUnit.DAY_OF_MONTH;
-        DateTimeZone tz = DateTimeZone.forID("Atlantic/Azores");
-        Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-        // Sunday, 29 October 2000, 01:00:00 clocks were turned backward 1 hour
-        // to Sunday, 29 October 2000, 00:00:00 local standard time instead
-        // which means there were two midnights that day.
-
-        long midnightBeforeTransition = time("2000-10-29T00:00:00", tz);
-        long midnightOfTransition = time("2000-10-29T00:00:00-01:00");
-        assertEquals(60L * 60L * 1000L, midnightOfTransition - midnightBeforeTransition);
-        long nextMidnight = time("2000-10-30T00:00:00", tz);
-
-        assertInterval(midnightBeforeTransition, nextMidnight, rounding, 25 * 60, tz);
-
-        assertThat(rounding.round(time("2000-10-29T06:00:00-01:00")), isDate(time("2000-10-29T00:00:00Z"), tz));
-
-        // Second case, dst happens at 0am local time, switching back one hour to 23pm local time.
-        // We want the overlapping hour to count for the previous day here
-
-        tz = DateTimeZone.forID("America/Lima");
-        rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-        // Sunday, 1 April 1990, 00:00:00 clocks were turned backward 1 hour to
-        // Saturday, 31 March 1990, 23:00:00 local standard time instead
-
-        midnightBeforeTransition = time("1990-03-31T00:00:00.000-04:00");
-        nextMidnight = time("1990-04-01T00:00:00.000-05:00");
-        assertInterval(midnightBeforeTransition, nextMidnight, rounding, 25 * 60, tz);
-
-        // make sure the next interval is 24h long again
-        long midnightAfterTransition = time("1990-04-01T00:00:00.000-05:00");
-        nextMidnight = time("1990-04-02T00:00:00.000-05:00");
-        assertInterval(midnightAfterTransition, nextMidnight, rounding, 24 * 60, tz);
-    }
-
-    /**
-     * Test that time zones are correctly parsed. There is a bug with
-     * Joda 2.9.4 (see https://github.com/JodaOrg/joda-time/issues/373)
-     */
-    public void testsTimeZoneParsing() {
-        final DateTime expected = new DateTime(2016, 11, 10, 5, 37, 59, randomDateTimeZone());
-
-        // Formatter used to print and parse the sample date.
-        // Printing the date works but parsing it back fails
-        // with Joda 2.9.4
-        DateTimeFormatter formatter = DateTimeFormat.forPattern("YYYY-MM-dd'T'HH:mm:ss " + randomFrom("ZZZ", "[ZZZ]", "'['ZZZ']'"));
-
-        String dateTimeAsString = formatter.print(expected);
-        assertThat(dateTimeAsString, startsWith("2016-11-10T05:37:59 "));
-
-        DateTime parsedDateTime = formatter.parseDateTime(dateTimeAsString);
-        assertThat(parsedDateTime.getZone(), equalTo(expected.getZone()));
-    }
-
-    private static void assertInterval(long rounded, long nextRoundingValue, Rounding rounding, int minutes, DateTimeZone tz) {
-        assertInterval(rounded, dateBetween(rounded, nextRoundingValue), nextRoundingValue, rounding, tz);
-        assertEquals(DateTimeConstants.MILLIS_PER_MINUTE * minutes, nextRoundingValue - rounded);
-    }
-
-    /**
-     * perform a number on assertions and checks on {@link TimeUnitRounding} intervals
-     * @param rounded the expected low end of the rounding interval
-     * @param unrounded a date in the interval to be checked for rounding
-     * @param nextRoundingValue the expected upper end of the rounding interval
-     * @param rounding the rounding instance
-     */
-    private static void assertInterval(long rounded, long unrounded, long nextRoundingValue, Rounding rounding, DateTimeZone tz) {
-        assertThat("rounding should be idempotent ", rounding.round(rounded), isDate(rounded, tz));
-        assertThat("rounded value smaller or equal than unrounded" + rounding, rounded, lessThanOrEqualTo(unrounded));
-        assertThat("values less than rounded should round further down" + rounding, rounding.round(rounded - 1), lessThan(rounded));
-        assertThat("nextRounding value should be a rounded date", rounding.round(nextRoundingValue), isDate(nextRoundingValue, tz));
-        assertThat(
-            "values above nextRounding should round down there",
-            rounding.round(nextRoundingValue + 1),
-            isDate(nextRoundingValue, tz)
-        );
-
-        if (isTimeWithWellDefinedRounding(tz, unrounded)) {
-            assertThat("nextRounding value should be greater than date" + rounding, nextRoundingValue, greaterThan(unrounded));
-
-            long dateBetween = dateBetween(rounded, nextRoundingValue);
-            assertThat(
-                "dateBetween [" + new DateTime(dateBetween, tz) + "] should round down to roundedDate",
-                rounding.round(dateBetween),
-                isDate(rounded, tz)
-            );
-            assertThat(
-                "dateBetween [" + new DateTime(dateBetween, tz) + "] should round up to nextRoundingValue",
-                rounding.nextRoundingValue(dateBetween),
-                isDate(nextRoundingValue, tz)
-            );
-        }
-    }
-
-    private static boolean isTimeWithWellDefinedRounding(DateTimeZone tz, long t) {
-        if (tz.getID().equals("America/St_Johns")
-            || tz.getID().equals("America/Goose_Bay")
-            || tz.getID().equals("America/Moncton")
-            || tz.getID().equals("Canada/Newfoundland")) {
-
-            // Clocks went back at 00:01 between 1987 and 2010, causing overlapping days.
-            // These timezones are otherwise uninteresting, so just skip this period.
-
-            return t <= time("1987-10-01T00:00:00Z") || t >= time("2010-12-01T00:00:00Z");
-        }
-
-        if (tz.getID().equals("Antarctica/Casey")) {
-
-            // Clocks went back 3 hours at 02:00 on 2010-03-05, causing overlapping days.
-
-            return t <= time("2010-03-03T00:00:00Z") || t >= time("2010-03-07T00:00:00Z");
-        }
-
-        return true;
-    }
-
-    private static long dateBetween(long lower, long upper) {
-        long dateBetween = randomLongBetween(lower, upper - 1);
-        assert lower <= dateBetween && dateBetween < upper;
-        return dateBetween;
-    }
-
-    private static DateTimeUnit randomTimeUnit() {
-        byte id = (byte) randomIntBetween(1, 8);
-        return DateTimeUnit.resolve(id);
-    }
-
-    private static long time(String time) {
-        return time(time, DateTimeZone.UTC);
-    }
-
-    private static long time(String time, DateTimeZone zone) {
-        return ISODateTimeFormat.dateOptionalTimeParser().withZone(zone).parseMillis(time);
-    }
-
-    private static Matcher<Long> isDate(final long expected, DateTimeZone tz) {
-        return new TypeSafeMatcher<Long>() {
-            @Override
-            public boolean matchesSafely(final Long item) {
-                return expected == item.longValue();
-            }
-
-            @Override
-            public void describeTo(Description description) {
-                description.appendText(new DateTime(expected, tz) + " [" + expected + "] ");
-            }
-
-            @Override
-            protected void describeMismatchSafely(final Long actual, final Description mismatchDescription) {
-                mismatchDescription.appendText(" was ").appendValue(new DateTime(actual, tz) + " [" + actual + "]");
-            }
-        };
-    }
-}
diff --git a/server/src/test/java/org/opensearch/common/settings/SettingsTests.java b/server/src/test/java/org/opensearch/common/settings/SettingsTests.java
index af4efabb341ee..669d40f40bb2c 100644
--- a/server/src/test/java/org/opensearch/common/settings/SettingsTests.java
+++ b/server/src/test/java/org/opensearch/common/settings/SettingsTests.java
@@ -50,6 +50,7 @@
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -64,7 +65,9 @@
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.hasToString;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.notNullValue;
@@ -93,6 +96,15 @@ public void testReplacePropertiesPlaceholderSystemPropertyList() {
         assertThat(settings.getAsList("setting1"), contains(hostname, hostip));
     }
 
+    public void testReplacePropertiesPlaceholderSystemPropertyEmptyList() {
+        final Settings settings = Settings.builder()
+            .put("setting1", "${HOSTNAMES}")
+            .replacePropertyPlaceholders(name -> name.equals("HOSTNAMES") ? "[]" : null)
+            .build();
+        assertThat(settings.getAsList("setting1"), empty());
+        assertThat(settings.get("setting1"), equalTo("[]"));
+    }
+
     public void testReplacePropertiesPlaceholderSystemVariablesHaveNoEffect() {
         final String value = System.getProperty("java.home");
         assertNotNull(value);
@@ -603,6 +615,18 @@ public void testSimpleYamlSettings() throws Exception {
         assertThat(settings.getAsList("test1.test3").size(), equalTo(2));
         assertThat(settings.getAsList("test1.test3").get(0), equalTo("test3-1"));
         assertThat(settings.getAsList("test1.test3").get(1), equalTo("test3-2"));
+        assertThat(settings.getAsList("test1.test4"), empty());
+    }
+
+    public void testYamlPlaceholder() throws IOException {
+        try (InputStream in = new ByteArrayInputStream("hosts: ${HOSTNAMES}".getBytes(StandardCharsets.UTF_8))) {
+            Settings settings = Settings.builder()
+                .loadFromStream("foo.yml", in, false)
+                .replacePropertyPlaceholders(name -> name.equals("HOSTNAMES") ? "[\"h1\", \"h2\"]" : null)
+                .build();
+            assertThat(settings.getAsList("hosts"), hasSize(2));
+            assertThat(settings.getAsList("hosts"), containsInAnyOrder("h1", "h2"));
+        }
     }
 
     public void testYamlLegacyList() throws IOException {
diff --git a/server/src/test/java/org/opensearch/core/RestStatusTests.java b/server/src/test/java/org/opensearch/core/RestStatusTests.java
new file mode 100644
index 0000000000000..f8dba99aa8b60
--- /dev/null
+++ b/server/src/test/java/org/opensearch/core/RestStatusTests.java
@@ -0,0 +1,91 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.core;
+
+import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.core.action.ShardOperationFailedException;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.io.IOException;
+import java.util.PriorityQueue;
+
+public class RestStatusTests extends OpenSearchTestCase {
+
+    public void testStatusReturns200ForNoFailures() {
+        int totalShards = randomIntBetween(1, 100);
+        int successfulShards = randomIntBetween(1, totalShards);
+
+        assertEquals(RestStatus.OK, RestStatus.status(successfulShards, totalShards));
+    }
+
+    public void testStatusReturns503ForUnavailableShards() {
+        int totalShards = randomIntBetween(1, 100);
+        int successfulShards = 0;
+
+        assertEquals(RestStatus.SERVICE_UNAVAILABLE, RestStatus.status(successfulShards, totalShards));
+    }
+
+    public void testStatusReturnsFailureStatusWhenFailuresExist() {
+        int totalShards = randomIntBetween(1, 100);
+        int successfulShards = 0;
+
+        TestException[] failures = new TestException[totalShards];
+        PriorityQueue<TestException> heapOfFailures = new PriorityQueue<>((x, y) -> y.status().compareTo(x.status()));
+
+        for (int i = 0; i < totalShards; ++i) {
+            /*
+             * Status here doesn't need to convey failure and is not as per rest
+             * contract. We're not testing the contract, but if status() returns
+             * the greatest rest code from the failures selection
+             */
+            RestStatus status = randomFrom(RestStatus.values());
+            TestException failure = new TestException(status);
+
+            failures[i] = failure;
+            heapOfFailures.add(failure);
+        }
+
+        assertEquals(heapOfFailures.peek().status(), RestStatus.status(successfulShards, totalShards, failures));
+    }
+
+    public void testSerialization() throws IOException {
+        final RestStatus status = randomFrom(RestStatus.values());
+
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            RestStatus.writeTo(out, status);
+
+            try (StreamInput in = out.bytes().streamInput()) {
+                RestStatus deserializedStatus = RestStatus.readFrom(in);
+
+                assertEquals(status, deserializedStatus);
+            }
+        }
+    }
+
+    private static class TestException extends ShardOperationFailedException {
+        TestException(final RestStatus status) {
+            super("super-idx", randomInt(), "gone-fishing", status, new Throwable("cake"));
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            throw new IOException("not implemented");
+        }
+
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            throw new IOException("not implemented");
+        }
+    }
+
+}
diff --git a/server/src/test/java/org/opensearch/discovery/FileBasedSeedHostsProviderTests.java b/server/src/test/java/org/opensearch/discovery/FileBasedSeedHostsProviderTests.java
index 688a532a61c4a..f4515361a89b8 100644
--- a/server/src/test/java/org/opensearch/discovery/FileBasedSeedHostsProviderTests.java
+++ b/server/src/test/java/org/opensearch/discovery/FileBasedSeedHostsProviderTests.java
@@ -100,7 +100,8 @@ private void createTransportSvc() {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
             @Override
             public BoundTransportAddress boundAddress() {
diff --git a/server/src/test/java/org/opensearch/discovery/InitializeExtensionRequestTests.java b/server/src/test/java/org/opensearch/discovery/InitializeExtensionRequestTests.java
index ca94a3b52a56c..daa42d3abbc50 100644
--- a/server/src/test/java/org/opensearch/discovery/InitializeExtensionRequestTests.java
+++ b/server/src/test/java/org/opensearch/discovery/InitializeExtensionRequestTests.java
@@ -27,6 +27,7 @@ public class InitializeExtensionRequestTests extends OpenSearchTestCase {
     public void testInitializeExtensionRequest() throws Exception {
         String expectedUniqueId = "test uniqueid";
         Version expectedVersion = Version.fromString("2.0.0");
+        String expectedServiceAccountHeader = "test";
         ExtensionDependency expectedDependency = new ExtensionDependency(expectedUniqueId, expectedVersion);
         DiscoveryExtensionNode expectedExtensionNode = new DiscoveryExtensionNode(
             "firstExtension",
@@ -46,9 +47,14 @@ public void testInitializeExtensionRequest() throws Exception {
             Version.CURRENT
         );
 
-        InitializeExtensionRequest initializeExtensionRequest = new InitializeExtensionRequest(expectedSourceNode, expectedExtensionNode);
+        InitializeExtensionRequest initializeExtensionRequest = new InitializeExtensionRequest(
+            expectedSourceNode,
+            expectedExtensionNode,
+            expectedServiceAccountHeader
+        );
         assertEquals(expectedExtensionNode, initializeExtensionRequest.getExtension());
         assertEquals(expectedSourceNode, initializeExtensionRequest.getSourceNode());
+        assertEquals(expectedServiceAccountHeader, initializeExtensionRequest.getServiceAccountHeader());
 
         try (BytesStreamOutput out = new BytesStreamOutput()) {
             initializeExtensionRequest.writeTo(out);
@@ -58,6 +64,7 @@ public void testInitializeExtensionRequest() throws Exception {
 
                 assertEquals(expectedExtensionNode, initializeExtensionRequest.getExtension());
                 assertEquals(expectedSourceNode, initializeExtensionRequest.getSourceNode());
+                assertEquals(expectedServiceAccountHeader, initializeExtensionRequest.getServiceAccountHeader());
             }
         }
     }
diff --git a/server/src/test/java/org/opensearch/discovery/SeedHostsResolverTests.java b/server/src/test/java/org/opensearch/discovery/SeedHostsResolverTests.java
index dc0829adac101..421f6c6fe279b 100644
--- a/server/src/test/java/org/opensearch/discovery/SeedHostsResolverTests.java
+++ b/server/src/test/java/org/opensearch/discovery/SeedHostsResolverTests.java
@@ -185,7 +185,8 @@ public void testRemovingLocalAddresses() {
             networkService,
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
 
             @Override
@@ -237,7 +238,8 @@ public void testUnknownHost() {
             networkService,
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
 
             @Override
@@ -292,7 +294,8 @@ public void testResolveTimeout() {
             networkService,
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
 
             @Override
@@ -368,7 +371,8 @@ public void testCancellationOnClose() throws InterruptedException {
             networkService,
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
 
             @Override
@@ -432,7 +436,8 @@ public void testInvalidHosts() throws IllegalAccessException {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
             @Override
             public BoundTransportAddress boundAddress() {
diff --git a/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java b/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java
index 57883f1e5914a..3c25dbdff3342 100644
--- a/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java
+++ b/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java
@@ -36,6 +36,7 @@
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
 import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.discovery.InitializeExtensionRequest;
 import org.opensearch.env.Environment;
 import org.opensearch.env.EnvironmentSettingsResponse;
 import org.opensearch.extensions.ExtensionsSettings.Extension;
@@ -77,6 +78,7 @@
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
@@ -115,7 +117,8 @@ public void setup() throws Exception {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         );
         transportService = new MockTransportService(
             settings,
@@ -184,7 +187,7 @@ public void testLoadExtensions() throws Exception {
 
         Set<Setting<?>> additionalSettings = extAwarePlugin.getExtensionSettings().stream().collect(Collectors.toSet());
         ExtensionScopedSettings extensionScopedSettings = new ExtensionScopedSettings(additionalSettings);
-        ExtensionsManager extensionsManager = new ExtensionsManager(additionalSettings);
+        ExtensionsManager extensionsManager = new ExtensionsManager(additionalSettings, identityService);
         ExtensionDependency dependentExtension = new ExtensionDependency("uniqueid0", Version.fromString("2.0.0"));
 
         Extension firstExtension = new Extension(
@@ -280,7 +283,7 @@ public void testNonUniqueLoadedExtensions() throws Exception {
             null,
             null
         );
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         extensionsManager.loadExtension(firstExtension);
         IOException exception = expectThrows(IOException.class, () -> extensionsManager.loadExtension(secondExtension));
         assertEquals(
@@ -319,7 +322,7 @@ public void testNonUniqueLoadedExtensions() throws Exception {
     public void testMissingRequiredFieldsWhileLoadingExtension() throws Exception {
 
         Extension firstExtension = new Extension("firstExtension", "uniqueid1", "127.0.0.0", "9300", "0.0.7", "3.0.0", "", null, null);
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
 
         IOException exception = expectThrows(IOException.class, () -> extensionsManager.loadExtension(firstExtension));
         assertEquals("Required field [minimum opensearch version] is missing in the request", exception.getMessage());
@@ -376,7 +379,7 @@ public void testExtensionDependency() throws Exception {
     }
 
     public void testInitialize() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
 
         initialize(extensionsManager);
 
@@ -409,19 +412,94 @@ public void testInitialize() throws Exception {
                 )
             );
 
-            // Test needs to be changed to mock the connection between the local node and an extension. Assert statment is commented out for
-            // now.
+            // Test needs to be changed to mock the connection between the local node and an extension.
             // Link to issue: https://github.com/opensearch-project/OpenSearch/issues/4045
             // mockLogAppender.assertAllExpectationsMatched();
         }
     }
 
+    public void testInitializeExtension() throws Exception {
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
+
+        TransportService mockTransportService = spy(
+            new TransportService(
+                Settings.EMPTY,
+                mock(Transport.class),
+                threadPool,
+                TransportService.NOOP_TRANSPORT_INTERCEPTOR,
+                x -> null,
+                null,
+                Collections.emptySet(),
+                NoopTracer.INSTANCE
+            )
+        );
+
+        doNothing().when(mockTransportService).connectToExtensionNode(any(DiscoveryExtensionNode.class));
+
+        doNothing().when(mockTransportService)
+            .sendRequest(any(DiscoveryExtensionNode.class), anyString(), any(InitializeExtensionRequest.class), any());
+
+        extensionsManager.initializeServicesAndRestHandler(
+            actionModule,
+            settingsModule,
+            mockTransportService,
+            clusterService,
+            settings,
+            client,
+            identityService
+        );
+
+        Extension firstExtension = new Extension(
+            "firstExtension",
+            "uniqueid1",
+            "127.0.0.0",
+            "9301",
+            "0.0.7",
+            "2.0.0",
+            "2.0.0",
+            List.of(),
+            null
+        );
+
+        extensionsManager.initializeExtension(firstExtension);
+
+        Extension secondExtension = new Extension(
+            "secondExtension",
+            "uniqueid2",
+            "127.0.0.0",
+            "9301",
+            "0.0.7",
+            "2.0.0",
+            "2.0.0",
+            List.of(),
+            null
+        );
+
+        extensionsManager.initializeExtension(secondExtension);
+
+        ThreadPool.terminate(threadPool, 3, TimeUnit.SECONDS);
+
+        verify(mockTransportService, times(2)).connectToExtensionNode(any(DiscoveryExtensionNode.class));
+
+        verify(mockTransportService, times(2)).sendRequest(
+            any(DiscoveryExtensionNode.class),
+            anyString(),
+            any(InitializeExtensionRequest.class),
+            any()
+        );
+    }
+
     public void testHandleRegisterRestActionsRequest() throws Exception {
 
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         String uniqueIdStr = "uniqueid1";
+
+        extensionsManager.loadExtension(
+            new Extension("firstExtension", uniqueIdStr, "127.0.0.0", "9300", "0.0.7", "3.0.0", "3.0.0", List.of(), null)
+        );
+
         List<String> actionsList = List.of("GET /foo foo", "PUT /bar bar", "POST /baz baz");
         List<String> deprecatedActionsList = List.of("GET /deprecated/foo foo_deprecated", "It's deprecated!");
         RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest(uniqueIdStr, actionsList, deprecatedActionsList);
@@ -431,8 +509,60 @@ public void testHandleRegisterRestActionsRequest() throws Exception {
         assertTrue(((AcknowledgedResponse) response).getStatus());
     }
 
+    public void testHandleRegisterRestActionsRequestRequiresDiscoveryNode() throws Exception {
+
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
+        initialize(extensionsManager);
+
+        RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest("uniqueId1", List.of(), List.of());
+
+        expectThrows(
+            IllegalStateException.class,
+            () -> extensionsManager.getRestActionsRequestHandler()
+                .handleRegisterRestActionsRequest(registerActionsRequest, actionModule.getDynamicActionRegistry())
+        );
+    }
+
+    public void testHandleRegisterRestActionsRequestMultiple() throws Exception {
+
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
+        initialize(extensionsManager);
+
+        List<String> actionsList = List.of("GET /foo foo", "PUT /bar bar", "POST /baz baz");
+        List<String> deprecatedActionsList = List.of("GET /deprecated/foo foo_deprecated", "It's deprecated!");
+        for (int i = 0; i < 2; i++) {
+            String uniqueIdStr = "uniqueid-%d" + i;
+
+            Set<Setting<?>> additionalSettings = extAwarePlugin.getExtensionSettings().stream().collect(Collectors.toSet());
+            ExtensionScopedSettings extensionScopedSettings = new ExtensionScopedSettings(additionalSettings);
+            Extension firstExtension = new Extension(
+                "Extension %s" + i,
+                uniqueIdStr,
+                "127.0.0.0",
+                "9300",
+                "0.0.7",
+                "3.0.0",
+                "3.0.0",
+                List.of(),
+                extensionScopedSettings
+            );
+
+            extensionsManager.loadExtension(firstExtension);
+
+            RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest(
+                uniqueIdStr,
+                actionsList,
+                deprecatedActionsList
+            );
+            TransportResponse response = extensionsManager.getRestActionsRequestHandler()
+                .handleRegisterRestActionsRequest(registerActionsRequest, actionModule.getDynamicActionRegistry());
+            assertEquals(AcknowledgedResponse.class, response.getClass());
+            assertTrue(((AcknowledgedResponse) response).getStatus());
+        }
+    }
+
     public void testHandleRegisterSettingsRequest() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         String uniqueIdStr = "uniqueid1";
@@ -448,10 +578,13 @@ public void testHandleRegisterSettingsRequest() throws Exception {
     }
 
     public void testHandleRegisterRestActionsRequestWithInvalidMethod() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         String uniqueIdStr = "uniqueid1";
+        extensionsManager.loadExtension(
+            new Extension("firstExtension", uniqueIdStr, "127.0.0.0", "9300", "0.0.7", "3.0.0", "3.0.0", List.of(), null)
+        );
         List<String> actionsList = List.of("FOO /foo", "PUT /bar", "POST /baz");
         List<String> deprecatedActionsList = List.of("GET /deprecated/foo", "It's deprecated!");
         RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest(uniqueIdStr, actionsList, deprecatedActionsList);
@@ -463,10 +596,13 @@ public void testHandleRegisterRestActionsRequestWithInvalidMethod() throws Excep
     }
 
     public void testHandleRegisterRestActionsRequestWithInvalidDeprecatedMethod() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         String uniqueIdStr = "uniqueid1";
+        extensionsManager.loadExtension(
+            new Extension("firstExtension", uniqueIdStr, "127.0.0.0", "9300", "0.0.7", "3.0.0", "3.0.0", List.of(), null)
+        );
         List<String> actionsList = List.of("GET /foo", "PUT /bar", "POST /baz");
         List<String> deprecatedActionsList = List.of("FOO /deprecated/foo", "It's deprecated!");
         RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest(uniqueIdStr, actionsList, deprecatedActionsList);
@@ -478,9 +614,12 @@ public void testHandleRegisterRestActionsRequestWithInvalidDeprecatedMethod() th
     }
 
     public void testHandleRegisterRestActionsRequestWithInvalidUri() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
         String uniqueIdStr = "uniqueid1";
+        extensionsManager.loadExtension(
+            new Extension("firstExtension", uniqueIdStr, "127.0.0.0", "9300", "0.0.7", "3.0.0", "3.0.0", List.of(), null)
+        );
         List<String> actionsList = List.of("GET", "PUT /bar", "POST /baz");
         List<String> deprecatedActionsList = List.of("GET /deprecated/foo", "It's deprecated!");
         RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest(uniqueIdStr, actionsList, deprecatedActionsList);
@@ -492,9 +631,12 @@ public void testHandleRegisterRestActionsRequestWithInvalidUri() throws Exceptio
     }
 
     public void testHandleRegisterRestActionsRequestWithInvalidDeprecatedUri() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
         String uniqueIdStr = "uniqueid1";
+        extensionsManager.loadExtension(
+            new Extension("firstExtension", uniqueIdStr, "127.0.0.0", "9300", "0.0.7", "3.0.0", "3.0.0", List.of(), null)
+        );
         List<String> actionsList = List.of("GET /foo", "PUT /bar", "POST /baz");
         List<String> deprecatedActionsList = List.of("GET", "It's deprecated!");
         RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest(uniqueIdStr, actionsList, deprecatedActionsList);
@@ -506,7 +648,7 @@ public void testHandleRegisterRestActionsRequestWithInvalidDeprecatedUri() throw
     }
 
     public void testHandleExtensionRequest() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         ExtensionRequest clusterStateRequest = new ExtensionRequest(ExtensionRequestProto.RequestType.REQUEST_EXTENSION_CLUSTER_STATE);
@@ -660,7 +802,7 @@ public void testEnvironmentSettingsDefaultValue() throws Exception {
     }
 
     public void testAddSettingsUpdateConsumerRequest() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         List<Setting<?>> componentSettings = List.of(
@@ -704,7 +846,7 @@ public void testAddSettingsUpdateConsumerRequest() throws Exception {
     }
 
     public void testHandleAddSettingsUpdateConsumerRequest() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         List<Setting<?>> componentSettings = List.of(
@@ -724,7 +866,7 @@ public void testHandleAddSettingsUpdateConsumerRequest() throws Exception {
     }
 
     public void testUpdateSettingsRequest() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         initialize(extensionsManager);
 
         Setting<?> componentSetting = Setting.boolSetting("falseSetting", false, Property.Dynamic);
@@ -753,7 +895,7 @@ public void testUpdateSettingsRequest() throws Exception {
 
     public void testRegisterHandler() throws Exception {
 
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
 
         TransportService mockTransportService = spy(
             new TransportService(
@@ -781,7 +923,7 @@ public void testRegisterHandler() throws Exception {
     }
 
     public void testIncompatibleExtensionRegistration() throws IOException {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), identityService);
         Extension firstExtension = new Extension(
             "firstExtension",
             "uniqueid1",
@@ -822,7 +964,7 @@ public List<Setting<?>> getExtensionSettings() {
             extensionScopedSettings
         );
 
-        ExtensionsManager extensionsManager = new ExtensionsManager(additionalSettings);
+        ExtensionsManager extensionsManager = new ExtensionsManager(additionalSettings, identityService);
         extensionsManager.loadExtension(firstExtension);
 
         DiscoveryExtensionNode extension = new DiscoveryExtensionNode(
@@ -860,7 +1002,7 @@ public void testAdditionalExtensionSettingsForExtensionWithoutCustomSettingSet()
             extensionScopedSettings
         );
 
-        ExtensionsManager extensionsManager = new ExtensionsManager(additionalSettings);
+        ExtensionsManager extensionsManager = new ExtensionsManager(additionalSettings, identityService);
         extensionsManager.loadExtension(firstExtension);
 
         DiscoveryExtensionNode extension = new DiscoveryExtensionNode(
diff --git a/server/src/test/java/org/opensearch/extensions/action/ExtensionTransportActionsHandlerTests.java b/server/src/test/java/org/opensearch/extensions/action/ExtensionTransportActionsHandlerTests.java
index 1dede94c68208..c4d2f81f7cf79 100644
--- a/server/src/test/java/org/opensearch/extensions/action/ExtensionTransportActionsHandlerTests.java
+++ b/server/src/test/java/org/opensearch/extensions/action/ExtensionTransportActionsHandlerTests.java
@@ -68,7 +68,8 @@ public void setup() throws Exception {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         );
         transportService = new MockTransportService(
             settings,
diff --git a/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java b/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java
index 87767978147cd..0dae0ae1b4e0b 100644
--- a/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java
+++ b/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java
@@ -19,8 +19,10 @@
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.extensions.DiscoveryExtensionNode;
 import org.opensearch.extensions.ExtensionsManager;
-import org.opensearch.extensions.ExtensionsSettings;
+import org.opensearch.extensions.ExtensionsSettings.Extension;
+import org.opensearch.identity.IdentityService;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.OpenSearchTestCase;
@@ -66,7 +68,8 @@ public void setup() throws Exception {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         );
         transportService = new MockTransportService(
             settings,
@@ -118,7 +121,7 @@ public void testRestInitializeExtensionActionResponse() throws Exception {
     }
 
     public void testRestInitializeExtensionActionFailure() throws Exception {
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(), new IdentityService(Settings.EMPTY, List.of()));
         RestInitializeExtensionAction restInitializeExtensionAction = new RestInitializeExtensionAction(extensionsManager);
 
         final String content = "{\"name\":\"ad-extension\",\"uniqueId\":\"\",\"hostAddress\":\"127.0.0.1\","
@@ -151,13 +154,16 @@ public void testRestInitializeExtensionActionResponseWithAdditionalSettings() th
             Function.identity(),
             Setting.Property.ExtensionScope
         );
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(boolSetting, stringSetting, intSetting, listSetting));
+        ExtensionsManager extensionsManager = new ExtensionsManager(
+            Set.of(boolSetting, stringSetting, intSetting, listSetting),
+            new IdentityService(Settings.EMPTY, List.of())
+        );
         ExtensionsManager spy = spy(extensionsManager);
 
         // optionally, you can stub out some methods:
         when(spy.getAdditionalSettings()).thenCallRealMethod();
-        Mockito.doCallRealMethod().when(spy).loadExtension(any(ExtensionsSettings.Extension.class));
-        Mockito.doNothing().when(spy).initialize();
+        Mockito.doCallRealMethod().when(spy).loadExtension(any(Extension.class));
+        Mockito.doNothing().when(spy).initializeExtensionNode(any(DiscoveryExtensionNode.class));
         RestInitializeExtensionAction restInitializeExtensionAction = new RestInitializeExtensionAction(spy);
         final String content = "{\"name\":\"ad-extension\",\"uniqueId\":\"ad-extension\",\"hostAddress\":\"127.0.0.1\","
             + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\""
@@ -173,10 +179,10 @@ public void testRestInitializeExtensionActionResponseWithAdditionalSettings() th
         FakeRestChannel channel = new FakeRestChannel(request, false, 0);
         restInitializeExtensionAction.handleRequest(request, channel, null);
 
-        assertEquals(channel.capturedResponse().status(), RestStatus.ACCEPTED);
+        assertEquals(RestStatus.ACCEPTED, channel.capturedResponse().status());
         assertTrue(channel.capturedResponse().content().utf8ToString().contains("A request to initialize an extension has been sent."));
 
-        Optional<ExtensionsSettings.Extension> extension = spy.lookupExtensionSettingsById("ad-extension");
+        Optional<Extension> extension = spy.lookupExtensionSettingsById("ad-extension");
         assertTrue(extension.isPresent());
         assertEquals(true, extension.get().getAdditionalSettings().get(boolSetting));
         assertEquals("customSetting", extension.get().getAdditionalSettings().get(stringSetting));
@@ -198,13 +204,16 @@ public void testRestInitializeExtensionActionResponseWithAdditionalSettingsUsing
             Function.identity(),
             Setting.Property.ExtensionScope
         );
-        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(boolSetting, stringSetting, intSetting, listSetting));
+        ExtensionsManager extensionsManager = new ExtensionsManager(
+            Set.of(boolSetting, stringSetting, intSetting, listSetting),
+            new IdentityService(Settings.EMPTY, List.of())
+        );
         ExtensionsManager spy = spy(extensionsManager);
 
         // optionally, you can stub out some methods:
         when(spy.getAdditionalSettings()).thenCallRealMethod();
-        Mockito.doCallRealMethod().when(spy).loadExtension(any(ExtensionsSettings.Extension.class));
-        Mockito.doNothing().when(spy).initialize();
+        Mockito.doCallRealMethod().when(spy).loadExtension(any(Extension.class));
+        Mockito.doNothing().when(spy).initializeExtensionNode(any(DiscoveryExtensionNode.class));
         RestInitializeExtensionAction restInitializeExtensionAction = new RestInitializeExtensionAction(spy);
         final String content = "{\"name\":\"ad-extension\",\"uniqueId\":\"ad-extension\",\"hostAddress\":\"127.0.0.1\","
             + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\""
@@ -220,10 +229,10 @@ public void testRestInitializeExtensionActionResponseWithAdditionalSettingsUsing
         FakeRestChannel channel = new FakeRestChannel(request, false, 0);
         restInitializeExtensionAction.handleRequest(request, channel, null);
 
-        assertEquals(channel.capturedResponse().status(), RestStatus.ACCEPTED);
+        assertEquals(RestStatus.ACCEPTED, channel.capturedResponse().status());
         assertTrue(channel.capturedResponse().content().utf8ToString().contains("A request to initialize an extension has been sent."));
 
-        Optional<ExtensionsSettings.Extension> extension = spy.lookupExtensionSettingsById("ad-extension");
+        Optional<Extension> extension = spy.lookupExtensionSettingsById("ad-extension");
         assertTrue(extension.isPresent());
         assertEquals(false, extension.get().getAdditionalSettings().get(boolSetting));
         assertEquals("default", extension.get().getAdditionalSettings().get(stringSetting));
diff --git a/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java b/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java
index 992e37b3f120a..9da976de7d7f6 100644
--- a/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java
+++ b/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java
@@ -79,7 +79,8 @@ public void setup() throws Exception {
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         );
         transportService = new MockTransportService(
             settings,
@@ -122,7 +123,7 @@ public void setup() throws Exception {
             usageService,
             null,
             new IdentityService(Settings.EMPTY, new ArrayList<>()),
-            new ExtensionsManager(Set.of())
+            new ExtensionsManager(Set.of(), new IdentityService(Settings.EMPTY, List.of()))
         );
         identityService = new IdentityService(Settings.EMPTY, new ArrayList<>());
         dynamicActionRegistry = actionModule.getDynamicActionRegistry();
@@ -150,7 +151,7 @@ public void testRestSendToExtensionAction() throws Exception {
             identityService
         );
 
-        assertEquals("send_to_extension_action", restSendToExtensionAction.getName());
+        assertEquals("uniqueid1:send_to_extension_action", restSendToExtensionAction.getName());
         List<Route> expected = new ArrayList<>();
         String uriPrefix = "/_extensions/_uniqueid1";
         expected.add(new Route(Method.GET, uriPrefix + "/foo"));
@@ -183,7 +184,7 @@ public void testRestSendToExtensionActionWithNamedRoute() throws Exception {
             identityService
         );
 
-        assertEquals("send_to_extension_action", restSendToExtensionAction.getName());
+        assertEquals("uniqueid1:send_to_extension_action", restSendToExtensionAction.getName());
         List<NamedRoute> expected = new ArrayList<>();
         String uriPrefix = "/_extensions/_uniqueid1";
         NamedRoute nr1 = new NamedRoute.Builder().method(Method.GET).path(uriPrefix + "/foo").uniqueName("foo").build();
@@ -229,7 +230,7 @@ public void testRestSendToExtensionActionWithNamedRouteAndLegacyActionName() thr
             identityService
         );
 
-        assertEquals("send_to_extension_action", restSendToExtensionAction.getName());
+        assertEquals("uniqueid1:send_to_extension_action", restSendToExtensionAction.getName());
         List<NamedRoute> expected = new ArrayList<>();
         String uriPrefix = "/_extensions/_uniqueid1";
         NamedRoute nr1 = new NamedRoute.Builder().method(Method.GET)
diff --git a/server/src/test/java/org/opensearch/gateway/ClusterStateUpdatersTests.java b/server/src/test/java/org/opensearch/gateway/ClusterStateUpdatersTests.java
index c83da46b23fb1..1c43bb565ef69 100644
--- a/server/src/test/java/org/opensearch/gateway/ClusterStateUpdatersTests.java
+++ b/server/src/test/java/org/opensearch/gateway/ClusterStateUpdatersTests.java
@@ -40,6 +40,11 @@
 import org.opensearch.cluster.metadata.MetadataIndexStateService;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodeRole;
+import org.opensearch.cluster.routing.IndexRoutingTable;
+import org.opensearch.cluster.routing.IndexShardRoutingTable;
+import org.opensearch.cluster.routing.RecoverySource;
+import org.opensearch.cluster.routing.RoutingTable;
+import org.opensearch.cluster.routing.UnassignedInfo;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.settings.ClusterSettings;
@@ -48,10 +53,14 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.index.Index;
+import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.repositories.IndexId;
 import org.opensearch.test.OpenSearchTestCase;
 
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Set;
 import java.util.function.BiConsumer;
 import java.util.function.Function;
@@ -269,6 +278,108 @@ public void testUpdateRoutingTable() {
         }
     }
 
+    public void testRoutingTableUpdateWhenRemoteStateRecovery() {
+        final int numOfShards = randomIntBetween(1, 10);
+
+        final IndexMetadata remoteMetadata = createIndexMetadata(
+            "test-remote",
+            Settings.builder()
+                .put(IndexMetadata.SETTING_REMOTE_STORE_ENABLED, true)
+                .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, numOfShards)
+                .build()
+        );
+
+        // Test remote index routing table is generated with ExistingStoreRecoverySource
+        {
+            final Index index = remoteMetadata.getIndex();
+            final ClusterState initialState = ClusterState.builder(ClusterState.EMPTY_STATE)
+                .metadata(Metadata.builder().put(remoteMetadata, false).build())
+                .build();
+            final ClusterState newState = updateRoutingTable(initialState);
+            IndexRoutingTable newRemoteIndexRoutingTable = newState.routingTable().index(remoteMetadata.getIndex());
+            assertTrue(newState.routingTable().hasIndex(index));
+            assertEquals(
+                0,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.unassignedInfo().getReason().equals(UnassignedInfo.Reason.INDEX_CREATED)
+                )
+            );
+            assertEquals(
+                numOfShards,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.unassignedInfo().getReason().equals(UnassignedInfo.Reason.CLUSTER_RECOVERED)
+                )
+            );
+            assertEquals(
+                0,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.recoverySource() instanceof RecoverySource.RemoteStoreRecoverySource
+                )
+            );
+            assertEquals(
+                numOfShards,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.recoverySource() instanceof RecoverySource.EmptyStoreRecoverySource
+                )
+            );
+
+        }
+
+        // Test remote index routing table is overridden if recovery source is RemoteStoreRecoverySource
+        {
+            final Index index = remoteMetadata.getIndex();
+            Map<ShardId, IndexShardRoutingTable> routingTableMap = new HashMap<>();
+            for (int shardNumber = 0; shardNumber < remoteMetadata.getNumberOfShards(); shardNumber++) {
+                ShardId shardId = new ShardId(index, shardNumber);
+                routingTableMap.put(shardId, new IndexShardRoutingTable.Builder(new ShardId(remoteMetadata.getIndex(), 1)).build());
+            }
+            IndexRoutingTable.Builder remoteBuilderWithRemoteRecovery = new IndexRoutingTable.Builder(remoteMetadata.getIndex())
+                .initializeAsRemoteStoreRestore(
+                    remoteMetadata,
+                    new RecoverySource.RemoteStoreRecoverySource(
+                        UUIDs.randomBase64UUID(),
+                        remoteMetadata.getCreationVersion(),
+                        new IndexId(remoteMetadata.getIndex().getName(), remoteMetadata.getIndexUUID())
+                    ),
+                    routingTableMap,
+                    true
+                );
+            final ClusterState initialState = ClusterState.builder(ClusterState.EMPTY_STATE)
+                .metadata(Metadata.builder().put(remoteMetadata, false).build())
+                .routingTable(new RoutingTable.Builder().add(remoteBuilderWithRemoteRecovery.build()).build())
+                .build();
+            assertTrue(initialState.routingTable().hasIndex(index));
+            final ClusterState newState = updateRoutingTable(initialState);
+            IndexRoutingTable newRemoteIndexRoutingTable = newState.routingTable().index(remoteMetadata.getIndex());
+            assertTrue(newState.routingTable().hasIndex(index));
+            assertEquals(
+                0,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.unassignedInfo().getReason().equals(UnassignedInfo.Reason.INDEX_CREATED)
+                )
+            );
+            assertEquals(
+                numOfShards,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.unassignedInfo().getReason().equals(UnassignedInfo.Reason.CLUSTER_RECOVERED)
+                )
+            );
+            assertEquals(
+                0,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.recoverySource() instanceof RecoverySource.RemoteStoreRecoverySource
+                )
+            );
+            assertEquals(
+                numOfShards,
+                newRemoteIndexRoutingTable.shardsMatchingPredicateCount(
+                    shardRouting -> shardRouting.recoverySource() instanceof RecoverySource.EmptyStoreRecoverySource
+                )
+            );
+
+        }
+    }
+
     public void testMixCurrentAndRecoveredState() {
         final ClusterState currentState = ClusterState.builder(ClusterState.EMPTY_STATE)
             .blocks(ClusterBlocks.builder().addGlobalBlock(STATE_NOT_RECOVERED_BLOCK).build())
diff --git a/server/src/test/java/org/opensearch/gateway/GatewayMetaStatePersistedStateTests.java b/server/src/test/java/org/opensearch/gateway/GatewayMetaStatePersistedStateTests.java
index 486717faaf864..74bae7b5eb7cf 100644
--- a/server/src/test/java/org/opensearch/gateway/GatewayMetaStatePersistedStateTests.java
+++ b/server/src/test/java/org/opensearch/gateway/GatewayMetaStatePersistedStateTests.java
@@ -68,6 +68,7 @@
 import org.opensearch.gateway.PersistedClusterStateService.Writer;
 import org.opensearch.gateway.remote.ClusterMetadataManifest;
 import org.opensearch.gateway.remote.RemoteClusterStateService;
+import org.opensearch.gateway.remote.RemotePersistenceStats;
 import org.opensearch.index.recovery.RemoteStoreRestoreService;
 import org.opensearch.index.recovery.RemoteStoreRestoreService.RemoteRestoreResult;
 import org.opensearch.node.Node;
@@ -86,10 +87,12 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mockito;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_INDEX_UUID;
@@ -104,6 +107,7 @@
 import static org.hamcrest.Matchers.nullValue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.Mockito.doCallRealMethod;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -716,10 +720,11 @@ Directory createDirectory(Path path) {
     public void testRemotePersistedState() throws IOException {
         final RemoteClusterStateService remoteClusterStateService = Mockito.mock(RemoteClusterStateService.class);
         final ClusterMetadataManifest manifest = ClusterMetadataManifest.builder().clusterTerm(1L).stateVersion(5L).build();
-        Mockito.when(remoteClusterStateService.writeFullMetadata(Mockito.any())).thenReturn(manifest);
+        final String previousClusterUUID = "prev-cluster-uuid";
+        Mockito.when(remoteClusterStateService.writeFullMetadata(Mockito.any(), Mockito.any())).thenReturn(manifest);
 
         Mockito.when(remoteClusterStateService.writeIncrementalMetadata(Mockito.any(), Mockito.any(), Mockito.any())).thenReturn(manifest);
-        CoordinationState.PersistedState remotePersistedState = new RemotePersistedState(remoteClusterStateService);
+        CoordinationState.PersistedState remotePersistedState = new RemotePersistedState(remoteClusterStateService, previousClusterUUID);
 
         assertThat(remotePersistedState.getLastAcceptedState(), nullValue());
         assertThat(remotePersistedState.getCurrentTerm(), equalTo(0L));
@@ -731,7 +736,7 @@ public void testRemotePersistedState() throws IOException {
         );
 
         remotePersistedState.setLastAcceptedState(clusterState);
-        Mockito.verify(remoteClusterStateService).writeFullMetadata(clusterState);
+        Mockito.verify(remoteClusterStateService).writeFullMetadata(clusterState, previousClusterUUID);
 
         assertThat(remotePersistedState.getLastAcceptedState(), equalTo(clusterState));
         assertThat(remotePersistedState.getCurrentTerm(), equalTo(clusterTerm));
@@ -742,7 +747,7 @@ public void testRemotePersistedState() throws IOException {
         );
 
         remotePersistedState.setLastAcceptedState(secondClusterState);
-        Mockito.verify(remoteClusterStateService, times(1)).writeFullMetadata(secondClusterState);
+        Mockito.verify(remoteClusterStateService, times(1)).writeFullMetadata(secondClusterState, previousClusterUUID);
 
         assertThat(remotePersistedState.getLastAcceptedState(), equalTo(secondClusterState));
         assertThat(remotePersistedState.getCurrentTerm(), equalTo(clusterTerm));
@@ -752,14 +757,59 @@ public void testRemotePersistedState() throws IOException {
 
         assertThat(remotePersistedState.getLastAcceptedState(), equalTo(secondClusterState));
         assertThat(remotePersistedState.getCurrentTerm(), equalTo(clusterTerm));
+        assertThat(remotePersistedState.getLastAcceptedState().metadata().clusterUUIDCommitted(), equalTo(false));
 
+        final ClusterState thirdClusterState = ClusterState.builder(secondClusterState)
+            .metadata(Metadata.builder(secondClusterState.getMetadata()).clusterUUID(randomAlphaOfLength(10)).build())
+            .build();
+        remotePersistedState.setLastAcceptedState(thirdClusterState);
+        remotePersistedState.markLastAcceptedStateAsCommitted();
+        assertThat(remotePersistedState.getLastAcceptedState().metadata().clusterUUIDCommitted(), equalTo(true));
+    }
+
+    public void testRemotePersistedStateNotCommitted() throws IOException {
+        final RemoteClusterStateService remoteClusterStateService = Mockito.mock(RemoteClusterStateService.class);
+        final String previousClusterUUID = "prev-cluster-uuid";
+        final ClusterMetadataManifest manifest = ClusterMetadataManifest.builder()
+            .previousClusterUUID(previousClusterUUID)
+            .clusterTerm(1L)
+            .stateVersion(5L)
+            .build();
+        Mockito.when(remoteClusterStateService.getLatestClusterMetadataManifest(Mockito.any(), Mockito.any()))
+            .thenReturn(Optional.of(manifest));
+        Mockito.when(remoteClusterStateService.writeFullMetadata(Mockito.any(), Mockito.any())).thenReturn(manifest);
+
+        Mockito.when(remoteClusterStateService.writeIncrementalMetadata(Mockito.any(), Mockito.any(), Mockito.any())).thenReturn(manifest);
+        CoordinationState.PersistedState remotePersistedState = new RemotePersistedState(
+            remoteClusterStateService,
+            ClusterState.UNKNOWN_UUID
+        );
+
+        assertThat(remotePersistedState.getLastAcceptedState(), nullValue());
+        assertThat(remotePersistedState.getCurrentTerm(), equalTo(0L));
+
+        final long clusterTerm = randomNonNegativeLong();
+        ClusterState clusterState = createClusterState(
+            randomNonNegativeLong(),
+            Metadata.builder().coordinationMetadata(CoordinationMetadata.builder().term(clusterTerm).build()).build()
+        );
+        clusterState = ClusterState.builder(clusterState)
+            .metadata(Metadata.builder(clusterState.getMetadata()).clusterUUID(randomAlphaOfLength(10)).clusterUUIDCommitted(false).build())
+            .build();
+
+        remotePersistedState.setLastAcceptedState(clusterState);
+        ArgumentCaptor<String> previousClusterUUIDCaptor = ArgumentCaptor.forClass(String.class);
+        ArgumentCaptor<ClusterState> clusterStateCaptor = ArgumentCaptor.forClass(ClusterState.class);
+        Mockito.verify(remoteClusterStateService).writeFullMetadata(clusterStateCaptor.capture(), previousClusterUUIDCaptor.capture());
+        assertEquals(previousClusterUUID, previousClusterUUIDCaptor.getValue());
     }
 
     public void testRemotePersistedStateExceptionOnFullStateUpload() throws IOException {
         final RemoteClusterStateService remoteClusterStateService = Mockito.mock(RemoteClusterStateService.class);
-        Mockito.doThrow(IOException.class).when(remoteClusterStateService).writeFullMetadata(Mockito.any());
+        final String previousClusterUUID = "prev-cluster-uuid";
+        Mockito.doThrow(IOException.class).when(remoteClusterStateService).writeFullMetadata(Mockito.any(), Mockito.any());
 
-        CoordinationState.PersistedState remotePersistedState = new RemotePersistedState(remoteClusterStateService);
+        CoordinationState.PersistedState remotePersistedState = new RemotePersistedState(remoteClusterStateService, previousClusterUUID);
 
         final long clusterTerm = randomNonNegativeLong();
         final ClusterState clusterState = createClusterState(
@@ -770,6 +820,26 @@ public void testRemotePersistedStateExceptionOnFullStateUpload() throws IOExcept
         assertThrows(OpenSearchException.class, () -> remotePersistedState.setLastAcceptedState(clusterState));
     }
 
+    public void testRemotePersistedStateFailureStats() throws IOException {
+        RemotePersistenceStats remoteStateStats = new RemotePersistenceStats();
+        final RemoteClusterStateService remoteClusterStateService = Mockito.mock(RemoteClusterStateService.class);
+        final String previousClusterUUID = "prev-cluster-uuid";
+        Mockito.doThrow(IOException.class).when(remoteClusterStateService).writeFullMetadata(Mockito.any(), Mockito.any());
+        when(remoteClusterStateService.getStats()).thenReturn(remoteStateStats);
+        doCallRealMethod().when(remoteClusterStateService).writeMetadataFailed();
+        CoordinationState.PersistedState remotePersistedState = new RemotePersistedState(remoteClusterStateService, previousClusterUUID);
+
+        final long clusterTerm = randomNonNegativeLong();
+        final ClusterState clusterState = createClusterState(
+            randomNonNegativeLong(),
+            Metadata.builder().coordinationMetadata(CoordinationMetadata.builder().term(clusterTerm).build()).build()
+        );
+
+        assertThrows(OpenSearchException.class, () -> remotePersistedState.setLastAcceptedState(clusterState));
+        assertEquals(1, remoteClusterStateService.getStats().getFailedCount());
+        assertEquals(0, remoteClusterStateService.getStats().getSuccessCount());
+    }
+
     public void testGatewayForRemoteState() throws IOException {
         MockGatewayMetaState gateway = null;
         try {
@@ -831,7 +901,8 @@ public void testGatewayForRemoteStateForInitialBootstrap() throws IOException {
                 remoteClusterStateService,
                 remoteStoreRestoreService,
                 persistedStateRegistry,
-                ClusterState.EMPTY_STATE
+                ClusterState.EMPTY_STATE,
+                false
             );
             final CoordinationState.PersistedState lucenePersistedState = gateway.getPersistedState();
             PersistedState remotePersistedState = persistedStateRegistry.getPersistedState(PersistedStateType.REMOTE);
@@ -877,7 +948,8 @@ public void testGatewayForRemoteStateForNodeReplacement() throws IOException {
                 remoteClusterStateService,
                 remoteStoreRestoreService,
                 persistedStateRegistry,
-                ClusterState.EMPTY_STATE
+                ClusterState.EMPTY_STATE,
+                false
             );
             final CoordinationState.PersistedState lucenePersistedState = gateway.getPersistedState();
             PersistedState remotePersistedState = persistedStateRegistry.getPersistedState(PersistedStateType.REMOTE);
@@ -909,7 +981,13 @@ public void testGatewayForRemoteStateForNodeReboot() throws IOException {
                     .clusterUUID(randomAlphaOfLength(10))
                     .build()
             );
-            gateway = newGatewayForRemoteState(remoteClusterStateService, remoteStoreRestoreService, persistedStateRegistry, clusterState);
+            gateway = newGatewayForRemoteState(
+                remoteClusterStateService,
+                remoteStoreRestoreService,
+                persistedStateRegistry,
+                clusterState,
+                false
+            );
             final CoordinationState.PersistedState lucenePersistedState = gateway.getPersistedState();
             PersistedState remotePersistedState = persistedStateRegistry.getPersistedState(PersistedStateType.REMOTE);
             verifyNoInteractions(remoteClusterStateService);
@@ -924,13 +1002,77 @@ public void testGatewayForRemoteStateForNodeReboot() throws IOException {
         }
     }
 
+    public void testGatewayForRemoteStateForInitialBootstrapBlocksApplied() throws IOException {
+        MockGatewayMetaState gateway = null;
+        try {
+            final RemoteClusterStateService remoteClusterStateService = mock(RemoteClusterStateService.class);
+            when(remoteClusterStateService.getLastKnownUUIDFromRemote(clusterName.value())).thenReturn("test-cluster-uuid");
+
+            final IndexMetadata indexMetadata = IndexMetadata.builder("test-index1")
+                .settings(
+                    settings(Version.CURRENT).put(SETTING_INDEX_UUID, randomAlphaOfLength(10))
+                        .put(IndexMetadata.INDEX_READ_ONLY_SETTING.getKey(), true)
+                )
+                .numberOfShards(5)
+                .numberOfReplicas(1)
+                .build();
+
+            final ClusterState clusterState = ClusterState.builder(
+                createClusterState(
+                    randomNonNegativeLong(),
+                    Metadata.builder()
+                        .coordinationMetadata(CoordinationMetadata.builder().term(randomLong()).build())
+                        .put(indexMetadata, false)
+                        .clusterUUID(ClusterState.UNKNOWN_UUID)
+                        .persistentSettings(Settings.builder().put(Metadata.SETTING_READ_ONLY_SETTING.getKey(), true).build())
+                        .build()
+                )
+            ).nodes(DiscoveryNodes.EMPTY_NODES).build();
+
+            final RemoteStoreRestoreService remoteStoreRestoreService = mock(RemoteStoreRestoreService.class);
+            when(remoteStoreRestoreService.restore(any(), any(), anyBoolean(), any())).thenReturn(
+                RemoteRestoreResult.build("test-cluster-uuid", null, clusterState)
+            );
+            final PersistedStateRegistry persistedStateRegistry = persistedStateRegistry();
+            gateway = newGatewayForRemoteState(
+                remoteClusterStateService,
+                remoteStoreRestoreService,
+                persistedStateRegistry,
+                ClusterState.EMPTY_STATE,
+                true
+            );
+            PersistedState remotePersistedState = persistedStateRegistry.getPersistedState(PersistedStateType.REMOTE);
+            PersistedState lucenePersistedState = persistedStateRegistry.getPersistedState(PersistedStateType.LOCAL);
+            verify(remoteClusterStateService).getLastKnownUUIDFromRemote(clusterName.value()); // change this
+            verify(remoteStoreRestoreService).restore(any(ClusterState.class), any(String.class), anyBoolean(), any(String[].class));
+            assertThat(remotePersistedState.getLastAcceptedState(), nullValue());
+            assertThat(
+                Metadata.isGlobalStateEquals(lucenePersistedState.getLastAcceptedState().metadata(), clusterState.metadata()),
+                equalTo(true)
+            );
+            assertThat(
+                lucenePersistedState.getLastAcceptedState().blocks().hasGlobalBlock(Metadata.CLUSTER_READ_ONLY_BLOCK),
+                equalTo(true)
+            );
+            assertThat(
+                IndexMetadata.INDEX_READ_ONLY_SETTING.get(
+                    lucenePersistedState.getLastAcceptedState().metadata().index("test-index1").getSettings()
+                ),
+                equalTo(true)
+            );
+        } finally {
+            IOUtils.close(gateway);
+        }
+    }
+
     private MockGatewayMetaState newGatewayForRemoteState(
         RemoteClusterStateService remoteClusterStateService,
         RemoteStoreRestoreService remoteStoreRestoreService,
         PersistedStateRegistry persistedStateRegistry,
-        ClusterState currentState
+        ClusterState currentState,
+        boolean prepareFullState
     ) throws IOException {
-        MockGatewayMetaState gateway = new MockGatewayMetaState(localNode, bigArrays);
+        MockGatewayMetaState gateway = new MockGatewayMetaState(localNode, bigArrays, prepareFullState);
         String randomRepoName = "randomRepoName";
         String stateRepoTypeAttributeKey = String.format(
             Locale.getDefault(),
@@ -954,6 +1096,7 @@ private MockGatewayMetaState newGatewayForRemoteState(
         when(clusterService.getClusterSettings()).thenReturn(
             new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)
         );
+        when(transportService.getLocalNode()).thenReturn(mock(DiscoveryNode.class));
         final PersistedClusterStateService persistedClusterStateService = new PersistedClusterStateService(
             nodeEnvironment,
             xContentRegistry(),
diff --git a/server/src/test/java/org/opensearch/gateway/remote/ClusterMetadataManifestTests.java b/server/src/test/java/org/opensearch/gateway/remote/ClusterMetadataManifestTests.java
index 9f8dde5ba9d45..6c9a3201656d7 100644
--- a/server/src/test/java/org/opensearch/gateway/remote/ClusterMetadataManifestTests.java
+++ b/server/src/test/java/org/opensearch/gateway/remote/ClusterMetadataManifestTests.java
@@ -26,6 +26,33 @@
 
 public class ClusterMetadataManifestTests extends OpenSearchTestCase {
 
+    public void testClusterMetadataManifestXContentV0() throws IOException {
+        UploadedIndexMetadata uploadedIndexMetadata = new UploadedIndexMetadata("test-index", "test-uuid", "/test/upload/path");
+        ClusterMetadataManifest originalManifest = new ClusterMetadataManifest(
+            1L,
+            1L,
+            "test-cluster-uuid",
+            "test-state-uuid",
+            Version.CURRENT,
+            "test-node-id",
+            false,
+            ClusterMetadataManifest.CODEC_V0,
+            null,
+            Collections.singletonList(uploadedIndexMetadata),
+            "prev-cluster-uuid",
+            true
+        );
+        final XContentBuilder builder = JsonXContent.contentBuilder();
+        builder.startObject();
+        originalManifest.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        builder.endObject();
+
+        try (XContentParser parser = createParser(JsonXContent.jsonXContent, BytesReference.bytes(builder))) {
+            final ClusterMetadataManifest fromXContentManifest = ClusterMetadataManifest.fromXContentV0(parser);
+            assertEquals(originalManifest, fromXContentManifest);
+        }
+    }
+
     public void testClusterMetadataManifestXContent() throws IOException {
         UploadedIndexMetadata uploadedIndexMetadata = new UploadedIndexMetadata("test-index", "test-uuid", "/test/upload/path");
         ClusterMetadataManifest originalManifest = new ClusterMetadataManifest(
@@ -36,8 +63,11 @@ public void testClusterMetadataManifestXContent() throws IOException {
             Version.CURRENT,
             "test-node-id",
             false,
+            ClusterMetadataManifest.CODEC_V1,
+            "test-global-metadata-file",
             Collections.singletonList(uploadedIndexMetadata),
-            "prev-cluster-uuid"
+            "prev-cluster-uuid",
+            true
         );
         final XContentBuilder builder = JsonXContent.contentBuilder();
         builder.startObject();
@@ -59,8 +89,11 @@ public void testClusterMetadataManifestSerializationEqualsHashCode() {
             Version.CURRENT,
             "B10RX1f5RJenMQvYccCgSQ",
             true,
+            1,
+            "test-global-metadata-file",
             randomUploadedIndexMetadataList(),
-            "yfObdx8KSMKKrXf8UyHhM"
+            "yfObdx8KSMKKrXf8UyHhM",
+            true
         );
         {  // Mutate Cluster Term
             EqualsHashCodeTestUtils.checkEqualsAndHashCode(
@@ -183,6 +216,21 @@ public void testClusterMetadataManifestSerializationEqualsHashCode() {
             );
 
         }
+        { // Mutate cluster uuid committed
+            EqualsHashCodeTestUtils.checkEqualsAndHashCode(
+                initialManifest,
+                orig -> OpenSearchTestCase.copyWriteable(
+                    orig,
+                    new NamedWriteableRegistry(Collections.emptyList()),
+                    ClusterMetadataManifest::new
+                ),
+                manifest -> {
+                    ClusterMetadataManifest.Builder builder = ClusterMetadataManifest.builder(manifest);
+                    builder.clusterUUIDCommitted(false);
+                    return builder.build();
+                }
+            );
+        }
     }
 
     private List<UploadedIndexMetadata> randomUploadedIndexMetadataList() {
diff --git a/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java b/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java
index 9f5067420aab1..65477051cdb30 100644
--- a/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java
+++ b/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java
@@ -9,9 +9,11 @@
 package org.opensearch.gateway.remote;
 
 import org.opensearch.Version;
+import org.opensearch.cluster.ClusterModule;
 import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.coordination.CoordinationMetadata;
+import org.opensearch.cluster.metadata.IndexGraveyard;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.cluster.node.DiscoveryNodes;
@@ -26,14 +28,18 @@
 import org.opensearch.common.blobstore.transfer.RemoteTransferContainer;
 import org.opensearch.common.compress.DeflateCompressor;
 import org.opensearch.common.lucene.store.ByteArrayIndexInput;
+import org.opensearch.common.network.NetworkModule;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.core.ParseField;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.index.Index;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.gateway.remote.ClusterMetadataManifest.UploadedIndexMetadata;
+import org.opensearch.index.remote.RemoteStoreUtils;
+import org.opensearch.indices.IndicesModule;
 import org.opensearch.repositories.FilterRepository;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.RepositoryMissingException;
@@ -59,11 +65,25 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Function;
 import java.util.function.Supplier;
+import java.util.stream.Stream;
 
 import org.mockito.ArgumentCaptor;
 import org.mockito.ArgumentMatchers;
 
+import static java.util.stream.Collectors.toList;
+import static org.opensearch.gateway.remote.RemoteClusterStateService.DELIMITER;
+import static org.opensearch.gateway.remote.RemoteClusterStateService.FORMAT_PARAMS;
+import static org.opensearch.gateway.remote.RemoteClusterStateService.INDEX_METADATA_CURRENT_CODEC_VERSION;
+import static org.opensearch.gateway.remote.RemoteClusterStateService.MANIFEST_CURRENT_CODEC_VERSION;
+import static org.opensearch.gateway.remote.RemoteClusterStateService.MANIFEST_FILE_PREFIX;
+import static org.opensearch.gateway.remote.RemoteClusterStateService.METADATA_FILE_PREFIX;
+import static org.opensearch.gateway.remote.RemoteClusterStateService.RETAINED_MANIFESTS;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_CLUSTER_STATE_REPOSITORY_NAME_ATTRIBUTE_KEY;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_REPOSITORY_SETTINGS_ATTRIBUTE_KEY_PREFIX;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_REPOSITORY_TYPE_ATTRIBUTE_KEY_FORMAT;
@@ -76,11 +96,14 @@
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class RemoteClusterStateServiceTests extends OpenSearchTestCase {
 
     private RemoteClusterStateService remoteClusterStateService;
+    private ClusterSettings clusterSettings;
     private Supplier<RepositoriesService> repositoriesServiceSupplier;
     private RepositoriesService repositoriesService;
     private BlobStoreRepository blobStoreRepository;
@@ -111,16 +134,25 @@ public void setup() {
             .put(RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING.getKey(), true)
             .build();
 
+        clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+        NamedXContentRegistry xContentRegistry = new NamedXContentRegistry(
+            Stream.of(
+                NetworkModule.getNamedXContents().stream(),
+                IndicesModule.getNamedXContents().stream(),
+                ClusterModule.getNamedXWriteables().stream()
+            ).flatMap(Function.identity()).collect(toList())
+        );
+
         blobStoreRepository = mock(BlobStoreRepository.class);
         blobStore = mock(BlobStore.class);
         when(blobStoreRepository.blobStore()).thenReturn(blobStore);
         when(repositoriesService.repository("remote_store_repository")).thenReturn(blobStoreRepository);
-        when(blobStoreRepository.getNamedXContentRegistry()).thenReturn(new NamedXContentRegistry(new ArrayList<>()));
+        when(blobStoreRepository.getNamedXContentRegistry()).thenReturn(xContentRegistry);
         remoteClusterStateService = new RemoteClusterStateService(
             "test-node-id",
             repositoriesServiceSupplier,
             settings,
-            new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            clusterSettings,
             () -> 0L,
             threadPool
         );
@@ -135,7 +167,7 @@ public void teardown() throws Exception {
 
     public void testFailWriteFullMetadataNonClusterManagerNode() throws IOException {
         final ClusterState clusterState = generateClusterStateWithOneIndex().build();
-        final ClusterMetadataManifest manifest = remoteClusterStateService.writeFullMetadata(clusterState);
+        final ClusterMetadataManifest manifest = remoteClusterStateService.writeFullMetadata(clusterState, randomAlphaOfLength(10));
         Assert.assertThat(manifest, nullValue());
     }
 
@@ -169,7 +201,7 @@ public void testWriteFullMetadataSuccess() throws IOException {
         final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
         mockBlobStoreObjects();
         remoteClusterStateService.start();
-        final ClusterMetadataManifest manifest = remoteClusterStateService.writeFullMetadata(clusterState);
+        final ClusterMetadataManifest manifest = remoteClusterStateService.writeFullMetadata(clusterState, "prev-cluster-uuid");
         final UploadedIndexMetadata uploadedIndexMetadata = new UploadedIndexMetadata("test-index", "index-uuid", "metadata-filename");
         List<UploadedIndexMetadata> indices = List.of(uploadedIndexMetadata);
 
@@ -190,6 +222,7 @@ public void testWriteFullMetadataSuccess() throws IOException {
         assertThat(manifest.getStateVersion(), is(expectedManifest.getStateVersion()));
         assertThat(manifest.getClusterUUID(), is(expectedManifest.getClusterUUID()));
         assertThat(manifest.getStateUUID(), is(expectedManifest.getStateUUID()));
+        assertThat(manifest.getPreviousClusterUUID(), is(expectedManifest.getPreviousClusterUUID()));
     }
 
     public void testWriteFullMetadataInParallelSuccess() throws IOException {
@@ -198,14 +231,21 @@ public void testWriteFullMetadataInParallelSuccess() throws IOException {
 
         ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
         ArgumentCaptor<WriteContext> writeContextArgumentCaptor = ArgumentCaptor.forClass(WriteContext.class);
-
+        AtomicReference<WriteContext> capturedWriteContext = new AtomicReference<>();
         doAnswer((i) -> {
             actionListenerArgumentCaptor.getValue().onResponse(null);
             return null;
+        }).doAnswer((i) -> {
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            capturedWriteContext.set(writeContextArgumentCaptor.getValue());
+            return null;
+        }).doAnswer((i) -> {
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            return null;
         }).when(container).asyncBlobUpload(writeContextArgumentCaptor.capture(), actionListenerArgumentCaptor.capture());
 
         remoteClusterStateService.start();
-        final ClusterMetadataManifest manifest = remoteClusterStateService.writeFullMetadata(clusterState);
+        final ClusterMetadataManifest manifest = remoteClusterStateService.writeFullMetadata(clusterState, "prev-cluster-uuid");
 
         final UploadedIndexMetadata uploadedIndexMetadata = new UploadedIndexMetadata("test-index", "index-uuid", "metadata-filename");
         List<UploadedIndexMetadata> indices = List.of(uploadedIndexMetadata);
@@ -216,58 +256,125 @@ public void testWriteFullMetadataInParallelSuccess() throws IOException {
             .stateVersion(1L)
             .stateUUID("state-uuid")
             .clusterUUID("cluster-uuid")
+            .previousClusterUUID("prev-cluster-uuid")
             .build();
 
         assertThat(manifest.getIndices().size(), is(1));
         assertThat(manifest.getIndices().get(0).getIndexName(), is(uploadedIndexMetadata.getIndexName()));
         assertThat(manifest.getIndices().get(0).getIndexUUID(), is(uploadedIndexMetadata.getIndexUUID()));
         assertThat(manifest.getIndices().get(0).getUploadedFilename(), notNullValue());
+        assertThat(manifest.getGlobalMetadataFileName(), notNullValue());
         assertThat(manifest.getClusterTerm(), is(expectedManifest.getClusterTerm()));
         assertThat(manifest.getStateVersion(), is(expectedManifest.getStateVersion()));
         assertThat(manifest.getClusterUUID(), is(expectedManifest.getClusterUUID()));
         assertThat(manifest.getStateUUID(), is(expectedManifest.getStateUUID()));
+        assertThat(manifest.getPreviousClusterUUID(), is(expectedManifest.getPreviousClusterUUID()));
 
-        assertEquals(actionListenerArgumentCaptor.getAllValues().size(), 1);
-        assertEquals(writeContextArgumentCaptor.getAllValues().size(), 1);
+        assertEquals(actionListenerArgumentCaptor.getAllValues().size(), 3);
+        assertEquals(writeContextArgumentCaptor.getAllValues().size(), 3);
 
-        WriteContext capturedWriteContext = writeContextArgumentCaptor.getValue();
-        byte[] writtenBytes = capturedWriteContext.getStreamProvider(Integer.MAX_VALUE).provideStream(0).getInputStream().readAllBytes();
+        byte[] writtenBytes = capturedWriteContext.get()
+            .getStreamProvider(Integer.MAX_VALUE)
+            .provideStream(0)
+            .getInputStream()
+            .readAllBytes();
         IndexMetadata writtenIndexMetadata = RemoteClusterStateService.INDEX_METADATA_FORMAT.deserialize(
-            capturedWriteContext.getFileName(),
+            capturedWriteContext.get().getFileName(),
             blobStoreRepository.getNamedXContentRegistry(),
             new BytesArray(writtenBytes)
         );
 
-        assertEquals(capturedWriteContext.getWritePriority(), WritePriority.HIGH);
+        assertEquals(capturedWriteContext.get().getWritePriority(), WritePriority.URGENT);
         assertEquals(writtenIndexMetadata.getNumberOfShards(), 1);
         assertEquals(writtenIndexMetadata.getNumberOfReplicas(), 0);
         assertEquals(writtenIndexMetadata.getIndex().getName(), "test-index");
         assertEquals(writtenIndexMetadata.getIndex().getUUID(), "index-uuid");
         long expectedChecksum = RemoteTransferContainer.checksumOfChecksum(new ByteArrayIndexInput("metadata-filename", writtenBytes), 8);
-        if (capturedWriteContext.doRemoteDataIntegrityCheck()) {
-            assertEquals(capturedWriteContext.getExpectedChecksum().longValue(), expectedChecksum);
+        if (capturedWriteContext.get().doRemoteDataIntegrityCheck()) {
+            assertEquals(capturedWriteContext.get().getExpectedChecksum().longValue(), expectedChecksum);
         } else {
-            assertEquals(capturedWriteContext.getExpectedChecksum(), null);
+            assertEquals(capturedWriteContext.get().getExpectedChecksum(), null);
         }
 
     }
 
-    public void testWriteFullMetadataInParallelFailure() throws IOException {
+    public void testWriteFullMetadataFailureForGlobalMetadata() throws IOException {
         final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
         AsyncMultiStreamBlobContainer container = (AsyncMultiStreamBlobContainer) mockBlobStoreObjects(AsyncMultiStreamBlobContainer.class);
 
         ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
 
         doAnswer((i) -> {
+            // For async write action listener will be called from different thread, replicating same behaviour here.
+            new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    actionListenerArgumentCaptor.getValue().onFailure(new RuntimeException("Cannot upload to remote"));
+                }
+            }).start();
+            return null;
+        }).when(container).asyncBlobUpload(any(WriteContext.class), actionListenerArgumentCaptor.capture());
+
+        remoteClusterStateService.start();
+        assertThrows(
+            RemoteClusterStateService.RemoteStateTransferException.class,
+            () -> remoteClusterStateService.writeFullMetadata(clusterState, randomAlphaOfLength(10))
+        );
+    }
+
+    public void testTimeoutWhileWritingManifestFile() throws IOException {
+        // verify update metadata manifest upload timeout
+        int metadataManifestUploadTimeout = 2;
+        Settings newSettings = Settings.builder()
+            .put("cluster.remote_store.state.metadata_manifest.upload_timeout", metadataManifestUploadTimeout + "s")
+            .build();
+        clusterSettings.applySettings(newSettings);
+
+        final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
+        AsyncMultiStreamBlobContainer container = (AsyncMultiStreamBlobContainer) mockBlobStoreObjects(AsyncMultiStreamBlobContainer.class);
+
+        ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
+
+        doAnswer((i) -> { // For Global Metadata
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            return null;
+        }).doAnswer((i) -> { // For Index Metadata
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            return null;
+        }).doAnswer((i) -> {
+            // For Manifest file perform No Op, so latch in code will timeout
+            return null;
+        }).when(container).asyncBlobUpload(any(WriteContext.class), actionListenerArgumentCaptor.capture());
+
+        remoteClusterStateService.start();
+        try {
+            remoteClusterStateService.writeFullMetadata(clusterState, randomAlphaOfLength(10));
+        } catch (Exception e) {
+            assertTrue(e instanceof RemoteClusterStateService.RemoteStateTransferException);
+            assertTrue(e.getMessage().contains("Timed out waiting for transfer of manifest file to complete"));
+        }
+    }
+
+    public void testWriteFullMetadataInParallelFailureForIndexMetadata() throws IOException {
+        final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
+        AsyncMultiStreamBlobContainer container = (AsyncMultiStreamBlobContainer) mockBlobStoreObjects(AsyncMultiStreamBlobContainer.class);
+
+        ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
+
+        doAnswer((i) -> {
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            return null;
+        }).doAnswer((i) -> {
             actionListenerArgumentCaptor.getValue().onFailure(new RuntimeException("Cannot upload to remote"));
             return null;
         }).when(container).asyncBlobUpload(any(WriteContext.class), actionListenerArgumentCaptor.capture());
 
         remoteClusterStateService.start();
         assertThrows(
-            RemoteClusterStateService.IndexMetadataTransferException.class,
-            () -> remoteClusterStateService.writeFullMetadata(clusterState)
+            RemoteClusterStateService.RemoteStateTransferException.class,
+            () -> remoteClusterStateService.writeFullMetadata(clusterState, randomAlphaOfLength(10))
         );
+        assertEquals(0, remoteClusterStateService.getStats().getSuccessCount());
     }
 
     public void testFailWriteIncrementalMetadataNonClusterManagerNode() throws IOException {
@@ -275,6 +382,7 @@ public void testFailWriteIncrementalMetadataNonClusterManagerNode() throws IOExc
         remoteClusterStateService.start();
         final ClusterMetadataManifest manifest = remoteClusterStateService.writeIncrementalMetadata(clusterState, clusterState, null);
         Assert.assertThat(manifest, nullValue());
+        assertEquals(0, remoteClusterStateService.getStats().getSuccessCount());
     }
 
     public void testFailWriteIncrementalMetadataWhenTermChanged() {
@@ -327,17 +435,214 @@ public void testWriteIncrementalMetadataSuccess() throws IOException {
         assertThat(manifest.getStateUUID(), is(expectedManifest.getStateUUID()));
     }
 
+    /*
+     * Here we will verify the migration of manifest file from codec V0 and V1.
+     *
+     * Initially codec version is 0 and global metadata is also null, we will perform index metadata update.
+     * In final manifest codec version should be 1 and
+     * global metadata should be updated, even if it was not changed in this cluster state update
+     */
+    public void testMigrationFromCodecV0ManifestToCodecV1Manifest() throws IOException {
+        mockBlobStoreObjects();
+        final CoordinationMetadata coordinationMetadata = CoordinationMetadata.builder().term(1L).build();
+        final ClusterState previousClusterState = ClusterState.builder(ClusterName.DEFAULT)
+            .metadata(Metadata.builder().coordinationMetadata(coordinationMetadata))
+            .nodes(nodesWithLocalNodeClusterManager())
+            .build();
+
+        // Update only index metadata
+        final IndexMetadata indexMetadata = new IndexMetadata.Builder("test").settings(
+            Settings.builder()
+                .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
+                .put(IndexMetadata.SETTING_INDEX_UUID, "uuid")
+                .build()
+        ).numberOfShards(1).numberOfReplicas(0).build();
+        Metadata newMetadata = Metadata.builder(previousClusterState.metadata()).put(indexMetadata, true).build();
+        ClusterState newClusterState = ClusterState.builder(previousClusterState).metadata(newMetadata).build();
+
+        // previous manifest with codec 0 and null global metadata
+        final ClusterMetadataManifest previousManifest = ClusterMetadataManifest.builder()
+            .codecVersion(ClusterMetadataManifest.CODEC_V0)
+            .globalMetadataFileName(null)
+            .indices(Collections.emptyList())
+            .build();
+
+        remoteClusterStateService.start();
+        final ClusterMetadataManifest manifestAfterUpdate = remoteClusterStateService.writeIncrementalMetadata(
+            previousClusterState,
+            newClusterState,
+            previousManifest
+        );
+
+        // global metadata is updated
+        assertThat(manifestAfterUpdate.getGlobalMetadataFileName(), notNullValue());
+        // Manifest file with codec version with 1 is updated.
+        assertThat(manifestAfterUpdate.getCodecVersion(), is(ClusterMetadataManifest.CODEC_V1));
+    }
+
+    public void testWriteIncrementalGlobalMetadataSuccess() throws IOException {
+        final ClusterState clusterState = generateClusterStateWithGlobalMetadata().nodes(nodesWithLocalNodeClusterManager()).build();
+        mockBlobStoreObjects();
+        final CoordinationMetadata coordinationMetadata = CoordinationMetadata.builder().term(1L).build();
+        final ClusterState previousClusterState = ClusterState.builder(ClusterName.DEFAULT)
+            .metadata(Metadata.builder().coordinationMetadata(coordinationMetadata))
+            .build();
+
+        final ClusterMetadataManifest previousManifest = ClusterMetadataManifest.builder()
+            .codecVersion(2)
+            .globalMetadataFileName("global-metadata-file")
+            .indices(Collections.emptyList())
+            .build();
+
+        remoteClusterStateService.start();
+        final ClusterMetadataManifest manifest = remoteClusterStateService.writeIncrementalMetadata(
+            previousClusterState,
+            clusterState,
+            previousManifest
+        );
+
+        final ClusterMetadataManifest expectedManifest = ClusterMetadataManifest.builder()
+            .indices(Collections.emptyList())
+            .globalMetadataFileName("mock-filename")
+            .clusterTerm(1L)
+            .stateVersion(1L)
+            .stateUUID("state-uuid")
+            .clusterUUID("cluster-uuid")
+            .previousClusterUUID("prev-cluster-uuid")
+            .build();
+
+        assertThat(manifest.getGlobalMetadataFileName(), notNullValue());
+        assertThat(manifest.getClusterTerm(), is(expectedManifest.getClusterTerm()));
+        assertThat(manifest.getStateVersion(), is(expectedManifest.getStateVersion()));
+        assertThat(manifest.getClusterUUID(), is(expectedManifest.getClusterUUID()));
+        assertThat(manifest.getStateUUID(), is(expectedManifest.getStateUUID()));
+    }
+
+    /*
+     * Here we will verify index metadata is not uploaded again if change is only in global metadata
+     */
+    public void testGlobalMetadataOnlyUpdated() throws IOException {
+        // setup
+        mockBlobStoreObjects();
+        final CoordinationMetadata coordinationMetadata = CoordinationMetadata.builder().term(1L).build();
+        final ClusterState initialClusterState = ClusterState.builder(ClusterName.DEFAULT)
+            .metadata(Metadata.builder().coordinationMetadata(coordinationMetadata).version(randomNonNegativeLong()))
+            .build();
+        final ClusterMetadataManifest initialManifest = ClusterMetadataManifest.builder()
+            .codecVersion(2)
+            .globalMetadataFileName("global-metadata-file")
+            .indices(Collections.emptyList())
+            .build();
+        remoteClusterStateService.start();
+
+        // Initial cluster state with index.
+        final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
+        // Updating remote cluster state with changing index metadata
+        final ClusterMetadataManifest manifestAfterIndexMetadataUpdate = remoteClusterStateService.writeIncrementalMetadata(
+            initialClusterState,
+            clusterState,
+            initialManifest
+        );
+
+        // new cluster state where only global metadata is different
+        Metadata newMetadata = Metadata.builder(clusterState.metadata())
+            .persistentSettings(Settings.builder().put("cluster.blocks.read_only", true).build())
+            .version(randomNonNegativeLong())
+            .build();
+        ClusterState newClusterState = ClusterState.builder(clusterState).metadata(newMetadata).build();
+
+        // updating remote cluster state with global metadata
+        final ClusterMetadataManifest manifestAfterGlobalMetadataUpdate = remoteClusterStateService.writeIncrementalMetadata(
+            clusterState,
+            newClusterState,
+            manifestAfterIndexMetadataUpdate
+        );
+
+        // Verify that index metadata information is same in manifest files
+        assertThat(manifestAfterIndexMetadataUpdate.getIndices().size(), is(manifestAfterGlobalMetadataUpdate.getIndices().size()));
+        assertThat(
+            manifestAfterIndexMetadataUpdate.getIndices().get(0).getIndexName(),
+            is(manifestAfterGlobalMetadataUpdate.getIndices().get(0).getIndexName())
+        );
+        assertThat(
+            manifestAfterIndexMetadataUpdate.getIndices().get(0).getIndexUUID(),
+            is(manifestAfterGlobalMetadataUpdate.getIndices().get(0).getIndexUUID())
+        );
+
+        // since timestamp is part of file name, if file name is same we can confirm that file is not update in global metadata update
+        assertThat(
+            manifestAfterIndexMetadataUpdate.getIndices().get(0).getUploadedFilename(),
+            is(manifestAfterGlobalMetadataUpdate.getIndices().get(0).getUploadedFilename())
+        );
+
+        // global metadata file would have changed
+        assertFalse(
+            manifestAfterIndexMetadataUpdate.getGlobalMetadataFileName()
+                .equalsIgnoreCase(manifestAfterGlobalMetadataUpdate.getGlobalMetadataFileName())
+        );
+    }
+
+    /*
+     * Here we will verify global metadata is not uploaded again if change is only in index metadata
+     */
+    public void testIndexMetadataOnlyUpdated() throws IOException {
+        // setup
+        mockBlobStoreObjects();
+        final CoordinationMetadata coordinationMetadata = CoordinationMetadata.builder().term(1L).build();
+        final ClusterState initialClusterState = ClusterState.builder(ClusterName.DEFAULT)
+            .metadata(Metadata.builder().coordinationMetadata(coordinationMetadata))
+            .build();
+        final ClusterMetadataManifest initialManifest = ClusterMetadataManifest.builder()
+            .codecVersion(2)
+            .indices(Collections.emptyList())
+            .build();
+        remoteClusterStateService.start();
+
+        // Initial cluster state with global metadata.
+        final ClusterState clusterState = generateClusterStateWithGlobalMetadata().nodes(nodesWithLocalNodeClusterManager()).build();
+
+        // Updating remote cluster state with changing global metadata
+        final ClusterMetadataManifest manifestAfterGlobalMetadataUpdate = remoteClusterStateService.writeIncrementalMetadata(
+            initialClusterState,
+            clusterState,
+            initialManifest
+        );
+
+        // new cluster state where only Index metadata is different
+        final IndexMetadata indexMetadata = new IndexMetadata.Builder("test").settings(
+            Settings.builder()
+                .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
+                .put(IndexMetadata.SETTING_INDEX_UUID, "uuid")
+                .build()
+        ).numberOfShards(1).numberOfReplicas(0).build();
+        Metadata newMetadata = Metadata.builder(clusterState.metadata()).put(indexMetadata, true).build();
+        ClusterState newClusterState = ClusterState.builder(clusterState).metadata(newMetadata).build();
+
+        // updating remote cluster state with index metadata
+        final ClusterMetadataManifest manifestAfterIndexMetadataUpdate = remoteClusterStateService.writeIncrementalMetadata(
+            clusterState,
+            newClusterState,
+            manifestAfterGlobalMetadataUpdate
+        );
+
+        // Verify that global metadata information is same in manifest files after updating index Metadata
+        // since timestamp is part of file name, if file name is same we can confirm that file is not update in index metadata update
+        assertThat(
+            manifestAfterIndexMetadataUpdate.getGlobalMetadataFileName(),
+            is(manifestAfterGlobalMetadataUpdate.getGlobalMetadataFileName())
+        );
+
+        // Index metadata would have changed
+        assertThat(manifestAfterGlobalMetadataUpdate.getIndices().size(), is(0));
+        assertThat(manifestAfterIndexMetadataUpdate.getIndices().size(), is(1));
+    }
+
     public void testReadLatestMetadataManifestFailedIOException() throws IOException {
         final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
 
         BlobContainer blobContainer = mockBlobStoreObjects();
-        when(
-            blobContainer.listBlobsByPrefixInSortedOrder(
-                "manifest" + RemoteClusterStateService.DELIMITER,
-                1,
-                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
-            )
-        ).thenThrow(IOException.class);
+        when(blobContainer.listBlobsByPrefixInSortedOrder("manifest" + DELIMITER, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC))
+            .thenThrow(IOException.class);
 
         remoteClusterStateService.start();
         Exception e = assertThrows(
@@ -354,13 +659,8 @@ public void testReadLatestMetadataManifestFailedNoManifestFileInRemote() throws
         final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
 
         BlobContainer blobContainer = mockBlobStoreObjects();
-        when(
-            blobContainer.listBlobsByPrefixInSortedOrder(
-                "manifest" + RemoteClusterStateService.DELIMITER,
-                1,
-                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
-            )
-        ).thenReturn(List.of());
+        when(blobContainer.listBlobsByPrefixInSortedOrder("manifest" + DELIMITER, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC))
+            .thenReturn(List.of());
 
         remoteClusterStateService.start();
         Optional<ClusterMetadataManifest> manifest = remoteClusterStateService.getLatestClusterMetadataManifest(
@@ -375,13 +675,8 @@ public void testReadLatestMetadataManifestFailedManifestFileRemoveAfterFetchInRe
 
         BlobContainer blobContainer = mockBlobStoreObjects();
         BlobMetadata blobMetadata = new PlainBlobMetadata("manifestFileName", 1);
-        when(
-            blobContainer.listBlobsByPrefixInSortedOrder(
-                "manifest" + RemoteClusterStateService.DELIMITER,
-                1,
-                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
-            )
-        ).thenReturn(Arrays.asList(blobMetadata));
+        when(blobContainer.listBlobsByPrefixInSortedOrder("manifest" + DELIMITER, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC))
+            .thenReturn(Arrays.asList(blobMetadata));
         when(blobContainer.readBlob("manifestFileName")).thenThrow(FileNotFoundException.class);
 
         remoteClusterStateService.start();
@@ -406,6 +701,7 @@ public void testReadLatestMetadataManifestSuccessButNoIndexMetadata() throws IOE
             .nodeId("nodeA")
             .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
             .previousClusterUUID("prev-cluster-uuid")
+            .codecVersion(ClusterMetadataManifest.CODEC_V0)
             .build();
 
         BlobContainer blobContainer = mockBlobStoreObjects();
@@ -413,7 +709,9 @@ public void testReadLatestMetadataManifestSuccessButNoIndexMetadata() throws IOE
 
         remoteClusterStateService.start();
         assertEquals(
-            remoteClusterStateService.getLatestIndexMetadata(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID())
+            remoteClusterStateService.getLatestClusterState(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID())
+                .getMetadata()
+                .getIndices()
                 .size(),
             0
         );
@@ -441,10 +739,10 @@ public void testReadLatestMetadataManifestSuccessButIndexMetadataFetchIOExceptio
         remoteClusterStateService.start();
         Exception e = assertThrows(
             IllegalStateException.class,
-            () -> remoteClusterStateService.getLatestIndexMetadata(
+            () -> remoteClusterStateService.getLatestClusterState(
                 clusterState.getClusterName().value(),
                 clusterState.metadata().clusterUUID()
-            )
+            ).getMetadata().getIndices()
         );
         assertEquals(e.getMessage(), "Error while downloading IndexMetadata - " + uploadedIndexMetadata.getUploadedFilename());
     }
@@ -462,6 +760,7 @@ public void testReadLatestMetadataManifestSuccess() throws IOException {
             .clusterUUID("cluster-uuid")
             .nodeId("nodeA")
             .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
+            .codecVersion(ClusterMetadataManifest.CODEC_V0)
             .previousClusterUUID("prev-cluster-uuid")
             .build();
 
@@ -482,6 +781,82 @@ public void testReadLatestMetadataManifestSuccess() throws IOException {
         assertThat(manifest.getStateUUID(), is(expectedManifest.getStateUUID()));
     }
 
+    public void testReadGlobalMetadata() throws IOException {
+        when(blobStoreRepository.getNamedXContentRegistry()).thenReturn(new NamedXContentRegistry(
+            List.of(new NamedXContentRegistry.Entry(Metadata.Custom.class, new ParseField(IndexGraveyard.TYPE), IndexGraveyard::fromXContent))));
+        final ClusterState clusterState = generateClusterStateWithGlobalMetadata().nodes(nodesWithLocalNodeClusterManager()).build();
+        remoteClusterStateService.start();
+
+        long prevClusterStateVersion = 13L;
+        final ClusterMetadataManifest expectedManifest = ClusterMetadataManifest.builder()
+            .indices(List.of())
+            .clusterTerm(1L)
+            .stateVersion(prevClusterStateVersion)
+            .stateUUID("state-uuid")
+            .clusterUUID("cluster-uuid")
+            .codecVersion(MANIFEST_CURRENT_CODEC_VERSION)
+            .globalMetadataFileName("global-metadata-file")
+            .nodeId("nodeA")
+            .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
+            .previousClusterUUID("prev-cluster-uuid")
+            .build();
+
+        Metadata expactedMetadata = Metadata.builder().persistentSettings(Settings.builder().put("readonly", true).build()).build();
+        mockBlobContainerForGlobalMetadata(mockBlobStoreObjects(), expectedManifest, expactedMetadata);
+
+        ClusterState newClusterState = remoteClusterStateService.getLatestClusterState(
+            clusterState.getClusterName().value(),
+            clusterState.metadata().clusterUUID()
+        );
+
+        assertTrue(Metadata.isGlobalStateEquals(newClusterState.getMetadata(), expactedMetadata));
+
+        long newClusterStateVersion = newClusterState.getVersion();
+        assert prevClusterStateVersion == newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is not equal to current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
+    }
+
+    public void testReadGlobalMetadataIOException() throws IOException {
+        final ClusterState clusterState = generateClusterStateWithGlobalMetadata().nodes(nodesWithLocalNodeClusterManager()).build();
+        remoteClusterStateService.start();
+        String globalIndexMetadataName = "global-metadata-file";
+        final ClusterMetadataManifest expectedManifest = ClusterMetadataManifest.builder()
+            .indices(List.of())
+            .clusterTerm(1L)
+            .stateVersion(1L)
+            .stateUUID("state-uuid")
+            .clusterUUID("cluster-uuid")
+            .codecVersion(MANIFEST_CURRENT_CODEC_VERSION)
+            .globalMetadataFileName(globalIndexMetadataName)
+            .nodeId("nodeA")
+            .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
+            .previousClusterUUID("prev-cluster-uuid")
+            .build();
+
+        Metadata expactedMetadata = Metadata.builder().persistentSettings(Settings.builder().put("readonly", true).build()).build();
+
+        BlobContainer blobContainer = mockBlobStoreObjects();
+        mockBlobContainerForGlobalMetadata(blobContainer, expectedManifest, expactedMetadata);
+
+        when(blobContainer.readBlob(RemoteClusterStateService.GLOBAL_METADATA_FORMAT.blobName(globalIndexMetadataName))).thenThrow(
+            FileNotFoundException.class
+        );
+
+        remoteClusterStateService.start();
+        Exception e = assertThrows(
+            IllegalStateException.class,
+            () -> remoteClusterStateService.getLatestClusterState(
+                clusterState.getClusterName().value(),
+                clusterState.metadata().clusterUUID()
+            )
+        );
+        assertEquals(e.getMessage(), "Error while downloading Global Metadata - " + globalIndexMetadataName);
+    }
+
     public void testReadLatestIndexMetadataSuccess() throws IOException {
         final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
         remoteClusterStateService.start();
@@ -508,19 +883,20 @@ public void testReadLatestIndexMetadataSuccess() throws IOException {
             .nodeId("nodeA")
             .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
             .previousClusterUUID("prev-cluster-uuid")
+            .codecVersion(ClusterMetadataManifest.CODEC_V0)
             .build();
 
         mockBlobContainer(mockBlobStoreObjects(), expectedManifest, Map.of(index.getUUID(), indexMetadata));
 
-        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestIndexMetadata(
+        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestClusterState(
             clusterState.getClusterName().value(),
             clusterState.metadata().clusterUUID()
-        );
+        ).getMetadata().getIndices();
 
         assertEquals(indexMetadataMap.size(), 1);
-        assertEquals(indexMetadataMap.get(index.getUUID()).getIndex().getName(), index.getName());
-        assertEquals(indexMetadataMap.get(index.getUUID()).getNumberOfShards(), indexMetadata.getNumberOfShards());
-        assertEquals(indexMetadataMap.get(index.getUUID()).getNumberOfReplicas(), indexMetadata.getNumberOfReplicas());
+        assertEquals(indexMetadataMap.get(index.getName()).getIndex().getName(), index.getName());
+        assertEquals(indexMetadataMap.get(index.getName()).getNumberOfShards(), indexMetadata.getNumberOfShards());
+        assertEquals(indexMetadataMap.get(index.getName()).getNumberOfReplicas(), indexMetadata.getNumberOfReplicas());
     }
 
     public void testMarkLastStateAsCommittedSuccess() throws IOException {
@@ -571,12 +947,43 @@ public void testGetValidPreviousClusterUUID() throws IOException {
 
     public void testGetValidPreviousClusterUUIDForInvalidChain() throws IOException {
         Map<String, String> clusterUUIDsPointers = Map.of(
+            "cluster-uuid2",
             "cluster-uuid1",
-            ClusterState.UNKNOWN_UUID,
+            "cluster-uuid3",
             "cluster-uuid2",
+            "cluster-uuid5",
+            "cluster-uuid4"
+        );
+        mockObjectsForGettingPreviousClusterUUID(clusterUUIDsPointers);
+
+        remoteClusterStateService.start();
+        assertThrows(IllegalStateException.class, () -> remoteClusterStateService.getLastKnownUUIDFromRemote("test-cluster"));
+    }
+
+    public void testGetValidPreviousClusterUUIDWithMultipleChains() throws IOException {
+        Map<String, String> clusterUUIDsPointers = Map.of(
+            "cluster-uuid2",
+            "cluster-uuid1",
+            "cluster-uuid1",
             ClusterState.UNKNOWN_UUID,
             "cluster-uuid3",
-            "cluster-uuid2"
+            "cluster-uuid1"
+        );
+        mockObjectsForGettingPreviousClusterUUID(clusterUUIDsPointers, randomBoolean(), Collections.emptyMap());
+
+        remoteClusterStateService.start();
+        String previousClusterUUID = remoteClusterStateService.getLastKnownUUIDFromRemote("test-cluster");
+        assertThat(previousClusterUUID, equalTo("cluster-uuid3"));
+    }
+
+    public void testGetValidPreviousClusterUUIDWithInvalidMultipleChains() throws IOException {
+        Map<String, String> clusterUUIDsPointers = Map.of(
+            "cluster-uuid1",
+            ClusterState.UNKNOWN_UUID,
+            "cluster-uuid2",
+            "cluster-uuid1",
+            "cluster-uuid3",
+            ClusterState.UNKNOWN_UUID
         );
         mockObjectsForGettingPreviousClusterUUID(clusterUUIDsPointers);
 
@@ -584,7 +991,249 @@ public void testGetValidPreviousClusterUUIDForInvalidChain() throws IOException
         assertThrows(IllegalStateException.class, () -> remoteClusterStateService.getLastKnownUUIDFromRemote("test-cluster"));
     }
 
+    public void testGetValidPreviousClusterUUIDWhenLastUUIDUncommitted() throws IOException {
+        Map<String, String> clusterUUIDsPointers = Map.of(
+            "cluster-uuid1",
+            ClusterState.UNKNOWN_UUID,
+            "cluster-uuid2",
+            "cluster-uuid1",
+            "cluster-uuid3",
+            "cluster-uuid2"
+        );
+        Map<String, Boolean> clusterUUIDCommitted = Map.of("cluster-uuid1", true, "cluster-uuid2", true, "cluster-uuid3", false);
+        mockObjectsForGettingPreviousClusterUUID(clusterUUIDsPointers, clusterUUIDCommitted);
+
+        remoteClusterStateService.start();
+        String previousClusterUUID = remoteClusterStateService.getLastKnownUUIDFromRemote("test-cluster");
+        assertThat(previousClusterUUID, equalTo("cluster-uuid2"));
+    }
+
+    public void testDeleteStaleClusterUUIDs() throws IOException {
+        final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
+        ClusterMetadataManifest clusterMetadataManifest = ClusterMetadataManifest.builder()
+            .indices(List.of())
+            .clusterTerm(1L)
+            .stateVersion(1L)
+            .stateUUID(randomAlphaOfLength(10))
+            .clusterUUID("cluster-uuid1")
+            .nodeId("nodeA")
+            .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
+            .previousClusterUUID(ClusterState.UNKNOWN_UUID)
+            .committed(true)
+            .build();
+
+        BlobPath blobPath = new BlobPath().add("random-path");
+        when((blobStoreRepository.basePath())).thenReturn(blobPath);
+        BlobContainer uuidContainerContainer = mock(BlobContainer.class);
+        BlobContainer manifest2Container = mock(BlobContainer.class);
+        BlobContainer manifest3Container = mock(BlobContainer.class);
+        when(blobStore.blobContainer(any())).then(invocation -> {
+            BlobPath blobPath1 = invocation.getArgument(0);
+            if (blobPath1.buildAsString().endsWith("cluster-state/")) {
+                return uuidContainerContainer;
+            } else if (blobPath1.buildAsString().contains("cluster-state/cluster-uuid2/")) {
+                return manifest2Container;
+            } else if (blobPath1.buildAsString().contains("cluster-state/cluster-uuid3/")) {
+                return manifest3Container;
+            } else {
+                throw new IllegalArgumentException("Unexpected blob path " + blobPath1);
+            }
+        });
+        Map<String, BlobContainer> blobMetadataMap = Map.of(
+            "cluster-uuid1",
+            mock(BlobContainer.class),
+            "cluster-uuid2",
+            mock(BlobContainer.class),
+            "cluster-uuid3",
+            mock(BlobContainer.class)
+        );
+        when(uuidContainerContainer.children()).thenReturn(blobMetadataMap);
+        when(
+            manifest2Container.listBlobsByPrefixInSortedOrder(
+                MANIFEST_FILE_PREFIX + DELIMITER,
+                Integer.MAX_VALUE,
+                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
+            )
+        ).thenReturn(List.of(new PlainBlobMetadata("mainfest2", 1L)));
+        when(
+            manifest3Container.listBlobsByPrefixInSortedOrder(
+                MANIFEST_FILE_PREFIX + DELIMITER,
+                Integer.MAX_VALUE,
+                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
+            )
+        ).thenReturn(List.of(new PlainBlobMetadata("mainfest3", 1L)));
+        remoteClusterStateService.start();
+        remoteClusterStateService.deleteStaleClusterUUIDs(clusterState, clusterMetadataManifest);
+        try {
+            assertBusy(() -> {
+                verify(manifest2Container, times(1)).delete();
+                verify(manifest3Container, times(1)).delete();
+            });
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public void testRemoteStateStats() throws IOException {
+        final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
+        mockBlobStoreObjects();
+        remoteClusterStateService.start();
+        final ClusterMetadataManifest manifest = remoteClusterStateService.writeFullMetadata(clusterState, "prev-cluster-uuid");
+
+        assertTrue(remoteClusterStateService.getStats() != null);
+        assertEquals(1, remoteClusterStateService.getStats().getSuccessCount());
+        assertEquals(0, remoteClusterStateService.getStats().getCleanupAttemptFailedCount());
+        assertEquals(0, remoteClusterStateService.getStats().getFailedCount());
+    }
+
+    public void testRemoteStateCleanupFailureStats() throws IOException {
+        BlobContainer blobContainer = mock(BlobContainer.class);
+        doThrow(IOException.class).when(blobContainer).delete();
+        when(blobStore.blobContainer(any())).thenReturn(blobContainer);
+        BlobPath blobPath = new BlobPath().add("random-path");
+        when((blobStoreRepository.basePath())).thenReturn(blobPath);
+        remoteClusterStateService.start();
+        remoteClusterStateService.deleteStaleUUIDsClusterMetadata("cluster1", Arrays.asList("cluster-uuid1"));
+        try {
+            assertBusy(() -> {
+                // wait for stats to get updated
+                assertTrue(remoteClusterStateService.getStats() != null);
+                assertEquals(0, remoteClusterStateService.getStats().getSuccessCount());
+                assertEquals(1, remoteClusterStateService.getStats().getCleanupAttemptFailedCount());
+            });
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public void testFileNames() {
+        final Index index = new Index("test-index", "index-uuid");
+        final Settings idxSettings = Settings.builder()
+            .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
+            .put(IndexMetadata.SETTING_INDEX_UUID, index.getUUID())
+            .build();
+        final IndexMetadata indexMetadata = new IndexMetadata.Builder(index.getName()).settings(idxSettings)
+            .numberOfShards(1)
+            .numberOfReplicas(0)
+            .build();
+
+        String indexMetadataFileName = RemoteClusterStateService.indexMetadataFileName(indexMetadata);
+        String[] splittedIndexMetadataFileName = indexMetadataFileName.split(DELIMITER);
+        assertThat(indexMetadataFileName.split(DELIMITER).length, is(4));
+        assertThat(splittedIndexMetadataFileName[0], is(METADATA_FILE_PREFIX));
+        assertThat(splittedIndexMetadataFileName[1], is(RemoteStoreUtils.invertLong(indexMetadata.getVersion())));
+        assertThat(splittedIndexMetadataFileName[3], is(String.valueOf(INDEX_METADATA_CURRENT_CODEC_VERSION)));
+
+        int term = randomIntBetween(5, 10);
+        int version = randomIntBetween(5, 10);
+        String manifestFileName = RemoteClusterStateService.getManifestFileName(term, version, true);
+        assertThat(manifestFileName.split(DELIMITER).length, is(6));
+        String[] splittedName = manifestFileName.split(DELIMITER);
+        assertThat(splittedName[0], is(MANIFEST_FILE_PREFIX));
+        assertThat(splittedName[1], is(RemoteStoreUtils.invertLong(term)));
+        assertThat(splittedName[2], is(RemoteStoreUtils.invertLong(version)));
+        assertThat(splittedName[3], is("C"));
+        assertThat(splittedName[5], is(String.valueOf(MANIFEST_CURRENT_CODEC_VERSION)));
+
+        manifestFileName = RemoteClusterStateService.getManifestFileName(term, version, false);
+        splittedName = manifestFileName.split(DELIMITER);
+        assertThat(splittedName[3], is("P"));
+    }
+
+    public void testSingleConcurrentExecutionOfStaleManifestCleanup() throws Exception {
+        BlobContainer blobContainer = mock(BlobContainer.class);
+        BlobPath blobPath = new BlobPath().add("random-path");
+        when((blobStoreRepository.basePath())).thenReturn(blobPath);
+        when(blobStore.blobContainer(any())).thenReturn(blobContainer);
+
+        CountDownLatch latch = new CountDownLatch(1);
+        AtomicInteger callCount = new AtomicInteger(0);
+        doAnswer(invocation -> {
+            callCount.incrementAndGet();
+            if (latch.await(5000, TimeUnit.SECONDS) == false) {
+                throw new Exception("Timed out waiting for delete task queuing to complete");
+            }
+            return null;
+        }).when(blobContainer)
+            .listBlobsByPrefixInSortedOrder(
+                any(String.class),
+                any(int.class),
+                any(BlobContainer.BlobNameSortOrder.class),
+                any(ActionListener.class)
+            );
+
+        remoteClusterStateService.start();
+        remoteClusterStateService.deleteStaleClusterMetadata("cluster-name", "cluster-uuid", RETAINED_MANIFESTS);
+        remoteClusterStateService.deleteStaleClusterMetadata("cluster-name", "cluster-uuid", RETAINED_MANIFESTS);
+
+        latch.countDown();
+        assertBusy(() -> assertEquals(1, callCount.get()));
+    }
+
+    public void testIndexMetadataUploadWaitTimeSetting() {
+        // verify default value
+        assertEquals(
+            RemoteClusterStateService.INDEX_METADATA_UPLOAD_TIMEOUT_DEFAULT,
+            remoteClusterStateService.getIndexMetadataUploadTimeout()
+        );
+
+        // verify update index metadata upload timeout
+        int indexMetadataUploadTimeout = randomIntBetween(1, 10);
+        Settings newSettings = Settings.builder()
+            .put("cluster.remote_store.state.index_metadata.upload_timeout", indexMetadataUploadTimeout + "s")
+            .build();
+        clusterSettings.applySettings(newSettings);
+        assertEquals(indexMetadataUploadTimeout, remoteClusterStateService.getIndexMetadataUploadTimeout().seconds());
+    }
+
+    public void testMetadataManifestUploadWaitTimeSetting() {
+        // verify default value
+        assertEquals(
+            RemoteClusterStateService.METADATA_MANIFEST_UPLOAD_TIMEOUT_DEFAULT,
+            remoteClusterStateService.getMetadataManifestUploadTimeout()
+        );
+
+        // verify update metadata manifest upload timeout
+        int metadataManifestUploadTimeout = randomIntBetween(1, 10);
+        Settings newSettings = Settings.builder()
+            .put("cluster.remote_store.state.metadata_manifest.upload_timeout", metadataManifestUploadTimeout + "s")
+            .build();
+        clusterSettings.applySettings(newSettings);
+        assertEquals(metadataManifestUploadTimeout, remoteClusterStateService.getMetadataManifestUploadTimeout().seconds());
+    }
+
+    public void testGlobalMetadataUploadWaitTimeSetting() {
+        // verify default value
+        assertEquals(
+            RemoteClusterStateService.GLOBAL_METADATA_UPLOAD_TIMEOUT_DEFAULT,
+            remoteClusterStateService.getGlobalMetadataUploadTimeout()
+        );
+
+        // verify update global metadata upload timeout
+        int globalMetadataUploadTimeout = randomIntBetween(1, 10);
+        Settings newSettings = Settings.builder()
+            .put("cluster.remote_store.state.global_metadata.upload_timeout", globalMetadataUploadTimeout + "s")
+            .build();
+        clusterSettings.applySettings(newSettings);
+        assertEquals(globalMetadataUploadTimeout, remoteClusterStateService.getGlobalMetadataUploadTimeout().seconds());
+    }
+
     private void mockObjectsForGettingPreviousClusterUUID(Map<String, String> clusterUUIDsPointers) throws IOException {
+        mockObjectsForGettingPreviousClusterUUID(clusterUUIDsPointers, false, Collections.emptyMap());
+    }
+
+    private void mockObjectsForGettingPreviousClusterUUID(
+        Map<String, String> clusterUUIDsPointers,
+        Map<String, Boolean> clusterUUIDCommitted
+    ) throws IOException {
+        mockObjectsForGettingPreviousClusterUUID(clusterUUIDsPointers, false, clusterUUIDCommitted);
+    }
+
+    private void mockObjectsForGettingPreviousClusterUUID(
+        Map<String, String> clusterUUIDsPointers,
+        boolean differGlobalMetadata,
+        Map<String, Boolean> clusterUUIDCommitted
+    ) throws IOException {
         final BlobPath blobPath = mock(BlobPath.class);
         when((blobStoreRepository.basePath())).thenReturn(blobPath);
         when(blobPath.add(anyString())).thenReturn(blobPath);
@@ -598,42 +1247,125 @@ private void mockObjectsForGettingPreviousClusterUUID(Map<String, String> cluste
         when(blobContainer3.path()).thenReturn(blobPath);
 
         mockBlobContainerForClusterUUIDs(uuidBlobContainer, clusterUUIDsPointers.keySet());
+        List<UploadedIndexMetadata> uploadedIndexMetadataList1 = List.of(
+            new UploadedIndexMetadata("index1", "index-uuid1", "key1"),
+            new UploadedIndexMetadata("index2", "index-uuid2", "key2")
+        );
         final ClusterMetadataManifest clusterManifest1 = generateClusterMetadataManifest(
             "cluster-uuid1",
             clusterUUIDsPointers.get("cluster-uuid1"),
-            randomAlphaOfLength(10)
+            randomAlphaOfLength(10),
+            uploadedIndexMetadataList1,
+            "test-metadata1",
+            clusterUUIDCommitted.getOrDefault("cluster-uuid1", true)
         );
-        mockBlobContainer(blobContainer1, clusterManifest1, Map.of());
+        Settings indexSettings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build();
+        IndexMetadata indexMetadata1 = IndexMetadata.builder("index1")
+            .settings(indexSettings)
+            .numberOfShards(1)
+            .numberOfReplicas(1)
+            .build();
+        IndexMetadata indexMetadata2 = IndexMetadata.builder("index2")
+            .settings(indexSettings)
+            .numberOfShards(1)
+            .numberOfReplicas(1)
+            .build();
+        Metadata metadata1 = Metadata.builder()
+            .persistentSettings(Settings.builder().put(Metadata.SETTING_READ_ONLY_SETTING.getKey(), true).build())
+            .build();
+        Map<String, IndexMetadata> indexMetadataMap1 = Map.of("index-uuid1", indexMetadata1, "index-uuid2", indexMetadata2);
+        mockBlobContainerForGlobalMetadata(blobContainer1, clusterManifest1, metadata1);
+        mockBlobContainer(blobContainer1, clusterManifest1, indexMetadataMap1, ClusterMetadataManifest.CODEC_V1);
 
+        List<UploadedIndexMetadata> uploadedIndexMetadataList2 = List.of(
+            new UploadedIndexMetadata("index1", "index-uuid1", "key1"),
+            new UploadedIndexMetadata("index2", "index-uuid2", "key2")
+        );
         final ClusterMetadataManifest clusterManifest2 = generateClusterMetadataManifest(
             "cluster-uuid2",
             clusterUUIDsPointers.get("cluster-uuid2"),
-            randomAlphaOfLength(10)
+            randomAlphaOfLength(10),
+            uploadedIndexMetadataList2,
+            "test-metadata2",
+            clusterUUIDCommitted.getOrDefault("cluster-uuid2", true)
         );
-        mockBlobContainer(blobContainer2, clusterManifest2, Map.of());
+        IndexMetadata indexMetadata3 = IndexMetadata.builder("index1")
+            .settings(indexSettings)
+            .numberOfShards(1)
+            .numberOfReplicas(1)
+            .build();
+        IndexMetadata indexMetadata4 = IndexMetadata.builder("index2")
+            .settings(indexSettings)
+            .numberOfShards(1)
+            .numberOfReplicas(1)
+            .build();
+        Metadata metadata2 = Metadata.builder()
+            .persistentSettings(Settings.builder().put(Metadata.SETTING_READ_ONLY_SETTING.getKey(), true).build())
+            .build();
+        Map<String, IndexMetadata> indexMetadataMap2 = Map.of("index-uuid1", indexMetadata3, "index-uuid2", indexMetadata4);
+        mockBlobContainerForGlobalMetadata(blobContainer2, clusterManifest2, metadata2);
+        mockBlobContainer(blobContainer2, clusterManifest2, indexMetadataMap2, ClusterMetadataManifest.CODEC_V1);
+
+        // differGlobalMetadata controls which one of IndexMetadata or Metadata object would be different
+        // when comparing cluster-uuid3 and cluster-uuid1 state.
+        // if set true, only Metadata will differ b/w cluster uuid1 and cluster uuid3.
+        // If set to false, only IndexMetadata would be different
+        // Adding difference in EXACTLY on of these randomly will help us test if our uuid trimming logic compares both
+        // IndexMetadata and Metadata when deciding if the remote state b/w two different cluster uuids is same.
+        List<UploadedIndexMetadata> uploadedIndexMetadataList3 = differGlobalMetadata
+            ? new ArrayList<>(uploadedIndexMetadataList1)
+            : List.of(new UploadedIndexMetadata("index1", "index-uuid1", "key1"));
+        IndexMetadata indexMetadata5 = IndexMetadata.builder("index1")
+            .settings(indexSettings)
+            .numberOfShards(1)
+            .numberOfReplicas(1)
+            .build();
+        Map<String, IndexMetadata> indexMetadataMap3 = differGlobalMetadata
+            ? new HashMap<>(indexMetadataMap1)
+            : Map.of("index-uuid1", indexMetadata5);
+        Metadata metadata3 = Metadata.builder()
+            .persistentSettings(Settings.builder().put(Metadata.SETTING_READ_ONLY_SETTING.getKey(), !differGlobalMetadata).build())
+            .build();
 
         final ClusterMetadataManifest clusterManifest3 = generateClusterMetadataManifest(
             "cluster-uuid3",
             clusterUUIDsPointers.get("cluster-uuid3"),
-            randomAlphaOfLength(10)
+            randomAlphaOfLength(10),
+            uploadedIndexMetadataList3,
+            "test-metadata3",
+            clusterUUIDCommitted.getOrDefault("cluster-uuid3", true)
+        );
+        mockBlobContainerForGlobalMetadata(blobContainer3, clusterManifest3, metadata3);
+        mockBlobContainer(blobContainer3, clusterManifest3, indexMetadataMap3, ClusterMetadataManifest.CODEC_V1);
+
+        ArrayList<BlobContainer> mockBlobContainerOrderedList = new ArrayList<>(
+            List.of(blobContainer1, blobContainer1, blobContainer3, blobContainer3, blobContainer2, blobContainer2)
         );
-        mockBlobContainer(blobContainer3, clusterManifest3, Map.of());
 
-        when(blobStore.blobContainer(ArgumentMatchers.any())).thenReturn(
-            uuidBlobContainer,
-            blobContainer1,
-            blobContainer1,
-            blobContainer2,
-            blobContainer2,
-            blobContainer3,
-            blobContainer3
+        if (differGlobalMetadata) {
+            mockBlobContainerOrderedList.addAll(
+                List.of(blobContainer3, blobContainer1, blobContainer3, blobContainer1, blobContainer1, blobContainer3)
+            );
+        }
+        mockBlobContainerOrderedList.addAll(
+            List.of(blobContainer2, blobContainer1, blobContainer2, blobContainer1, blobContainer1, blobContainer2)
         );
+        BlobContainer[] mockBlobContainerOrderedArray = new BlobContainer[mockBlobContainerOrderedList.size()];
+        mockBlobContainerOrderedList.toArray(mockBlobContainerOrderedArray);
+        when(blobStore.blobContainer(ArgumentMatchers.any())).thenReturn(uuidBlobContainer, mockBlobContainerOrderedArray);
         when(blobStoreRepository.getCompressor()).thenReturn(new DeflateCompressor());
     }
 
-    private ClusterMetadataManifest generateClusterMetadataManifest(String clusterUUID, String previousClusterUUID, String stateUUID) {
+    private ClusterMetadataManifest generateClusterMetadataManifest(
+        String clusterUUID,
+        String previousClusterUUID,
+        String stateUUID,
+        List<UploadedIndexMetadata> uploadedIndexMetadata,
+        String globalMetadataFileName,
+        Boolean isUUIDCommitted
+    ) {
         return ClusterMetadataManifest.builder()
-            .indices(List.of())
+            .indices(uploadedIndexMetadata)
             .clusterTerm(1L)
             .stateVersion(1L)
             .stateUUID(stateUUID)
@@ -642,6 +1374,9 @@ private ClusterMetadataManifest generateClusterMetadataManifest(String clusterUU
             .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
             .previousClusterUUID(previousClusterUUID)
             .committed(true)
+            .clusterUUIDCommitted(isUUIDCommitted)
+            .globalMetadataFileName(globalMetadataFileName)
+            .codecVersion(ClusterMetadataManifest.CODEC_V1)
             .build();
     }
 
@@ -674,21 +1409,29 @@ private void mockBlobContainer(
         ClusterMetadataManifest clusterMetadataManifest,
         Map<String, IndexMetadata> indexMetadataMap
     ) throws IOException {
-        BlobMetadata blobMetadata = new PlainBlobMetadata("manifestFileName", 1);
-        when(
-            blobContainer.listBlobsByPrefixInSortedOrder(
-                "manifest" + RemoteClusterStateService.DELIMITER,
-                1,
-                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
-            )
-        ).thenReturn(Arrays.asList(blobMetadata));
+        mockBlobContainer(blobContainer, clusterMetadataManifest, indexMetadataMap, ClusterMetadataManifest.CODEC_V0);
+    }
+
+    private void mockBlobContainer(
+        BlobContainer blobContainer,
+        ClusterMetadataManifest clusterMetadataManifest,
+        Map<String, IndexMetadata> indexMetadataMap,
+        int codecVersion
+    ) throws IOException {
+        String manifestFileName = codecVersion >= ClusterMetadataManifest.CODEC_V1
+            ? "manifest__manifestFileName__abcd__abcd__abcd__1"
+            : "manifestFileName";
+        BlobMetadata blobMetadata = new PlainBlobMetadata(manifestFileName, 1);
+        when(blobContainer.listBlobsByPrefixInSortedOrder("manifest" + DELIMITER, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC))
+            .thenReturn(Arrays.asList(blobMetadata));
 
         BytesReference bytes = RemoteClusterStateService.CLUSTER_METADATA_MANIFEST_FORMAT.serialize(
             clusterMetadataManifest,
-            "manifestFileName",
-            blobStoreRepository.getCompressor()
+            manifestFileName,
+            blobStoreRepository.getCompressor(),
+            FORMAT_PARAMS
         );
-        when(blobContainer.readBlob("manifestFileName")).thenReturn(new ByteArrayInputStream(bytes.streamInput().readAllBytes()));
+        when(blobContainer.readBlob(manifestFileName)).thenReturn(new ByteArrayInputStream(bytes.streamInput().readAllBytes()));
 
         clusterMetadataManifest.getIndices().forEach(uploadedIndexMetadata -> {
             try {
@@ -697,20 +1440,74 @@ private void mockBlobContainer(
                     return;
                 }
                 String fileName = uploadedIndexMetadata.getUploadedFilename();
-                BytesReference bytesIndexMetadata = RemoteClusterStateService.INDEX_METADATA_FORMAT.serialize(
-                    indexMetadata,
-                    fileName,
-                    blobStoreRepository.getCompressor()
-                );
-                when(blobContainer.readBlob(fileName + ".dat")).thenReturn(
-                    new ByteArrayInputStream(bytesIndexMetadata.streamInput().readAllBytes())
-                );
+                when(blobContainer.readBlob(fileName + ".dat")).thenAnswer((invocationOnMock) -> {
+                    BytesReference bytesIndexMetadata = RemoteClusterStateService.INDEX_METADATA_FORMAT.serialize(
+                        indexMetadata,
+                        fileName,
+                        blobStoreRepository.getCompressor(),
+                        FORMAT_PARAMS
+                    );
+                    return new ByteArrayInputStream(bytesIndexMetadata.streamInput().readAllBytes());
+                });
             } catch (IOException e) {
                 throw new RuntimeException(e);
             }
         });
     }
 
+    private void mockBlobContainerForGlobalMetadata(
+        BlobContainer blobContainer,
+        ClusterMetadataManifest clusterMetadataManifest,
+        Metadata metadata
+    ) throws IOException {
+        String mockManifestFileName = "manifest__1__2__C__456__1";
+        BlobMetadata blobMetadata = new PlainBlobMetadata(mockManifestFileName, 1);
+        when(
+            blobContainer.listBlobsByPrefixInSortedOrder(
+                "manifest" + RemoteClusterStateService.DELIMITER,
+                1,
+                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC
+            )
+        ).thenReturn(Arrays.asList(blobMetadata));
+
+        BytesReference bytes = RemoteClusterStateService.CLUSTER_METADATA_MANIFEST_FORMAT.serialize(
+            clusterMetadataManifest,
+            mockManifestFileName,
+            blobStoreRepository.getCompressor(),
+            FORMAT_PARAMS
+        );
+        when(blobContainer.readBlob(mockManifestFileName)).thenReturn(new ByteArrayInputStream(bytes.streamInput().readAllBytes()));
+
+        String[] splitPath = clusterMetadataManifest.getGlobalMetadataFileName().split("/");
+        when(blobContainer.readBlob(RemoteClusterStateService.GLOBAL_METADATA_FORMAT.blobName(splitPath[splitPath.length - 1]))).thenAnswer(
+            (invocationOnMock) -> {
+                BytesReference bytesGlobalMetadata = RemoteClusterStateService.GLOBAL_METADATA_FORMAT.serialize(
+                    metadata,
+                    "global-metadata-file",
+                    blobStoreRepository.getCompressor(),
+                    FORMAT_PARAMS
+                );
+                return new ByteArrayInputStream(bytesGlobalMetadata.streamInput().readAllBytes());
+            }
+        );
+    }
+
+    private static ClusterState.Builder generateClusterStateWithGlobalMetadata() {
+        final Settings clusterSettings = Settings.builder().put("cluster.blocks.read_only", true).build();
+        final CoordinationMetadata coordinationMetadata = CoordinationMetadata.builder().term(1L).build();
+
+        return ClusterState.builder(ClusterName.DEFAULT)
+            .version(1L)
+            .stateUUID("state-uuid")
+            .metadata(
+                Metadata.builder()
+                    .persistentSettings(clusterSettings)
+                    .clusterUUID("cluster-uuid")
+                    .coordinationMetadata(coordinationMetadata)
+                    .build()
+            );
+    }
+
     private static ClusterState.Builder generateClusterStateWithOneIndex() {
         final Index index = new Index("test-index", "index-uuid");
         final Settings idxSettings = Settings.builder()
@@ -727,7 +1524,12 @@ private static ClusterState.Builder generateClusterStateWithOneIndex() {
             .version(1L)
             .stateUUID("state-uuid")
             .metadata(
-                Metadata.builder().put(indexMetadata, true).clusterUUID("cluster-uuid").coordinationMetadata(coordinationMetadata).build()
+                Metadata.builder()
+                    .version(randomNonNegativeLong())
+                    .put(indexMetadata, true)
+                    .clusterUUID("cluster-uuid")
+                    .coordinationMetadata(coordinationMetadata)
+                    .build()
             );
     }
 
diff --git a/server/src/test/java/org/opensearch/index/IndexModuleTests.java b/server/src/test/java/org/opensearch/index/IndexModuleTests.java
index a1d6be84c9926..97bc822be7d51 100644
--- a/server/src/test/java/org/opensearch/index/IndexModuleTests.java
+++ b/server/src/test/java/org/opensearch/index/IndexModuleTests.java
@@ -105,6 +105,7 @@
 import org.opensearch.indices.cluster.IndicesClusterStateService.AllocatedIndices.IndexRemovalReason;
 import org.opensearch.indices.fielddata.cache.IndicesFieldDataCache;
 import org.opensearch.indices.mapper.MapperRegistry;
+import org.opensearch.indices.recovery.DefaultRecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.plugins.IndexStorePlugin;
 import org.opensearch.repositories.RepositoriesService;
@@ -260,7 +261,8 @@ private IndexService newIndexService(IndexModule module) throws IOException {
             new RemoteSegmentStoreDirectoryFactory(() -> repositoriesService, threadPool),
             translogFactorySupplier,
             () -> IndexSettings.DEFAULT_REFRESH_INTERVAL,
-            () -> IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL
+            () -> IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL,
+            DefaultRecoverySettings.INSTANCE
         );
     }
 
diff --git a/server/src/test/java/org/opensearch/index/IndexServiceTestUtils.java b/server/src/test/java/org/opensearch/index/IndexServiceTestUtils.java
new file mode 100644
index 0000000000000..736c0c0786fe9
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/IndexServiceTestUtils.java
@@ -0,0 +1,20 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index;
+
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.concurrent.AbstractAsyncTask;
+
+public final class IndexServiceTestUtils {
+    private IndexServiceTestUtils() {}
+
+    public static void setTrimTranslogTaskInterval(IndexService indexService, TimeValue interval) {
+        ((AbstractAsyncTask) indexService.getTrimTranslogTask()).setInterval(interval);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/index/IndexServiceTests.java b/server/src/test/java/org/opensearch/index/IndexServiceTests.java
index 1b8e1abb1bf1b..14451ef21726e 100644
--- a/server/src/test/java/org/opensearch/index/IndexServiceTests.java
+++ b/server/src/test/java/org/opensearch/index/IndexServiceTests.java
@@ -33,7 +33,9 @@
 package org.opensearch.index;
 
 import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.TopDocs;
+import org.opensearch.Version;
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.compress.CompressedXContent;
@@ -450,12 +452,7 @@ public void testAsyncTranslogTrimTaskOnClosedIndex() throws Exception {
         assertTrue(indexService.getTrimTranslogTask().mustReschedule());
 
         final Engine readOnlyEngine = getEngine(indexService.getShard(0));
-        assertBusy(
-            () -> assertThat(
-                readOnlyEngine.translogManager().getTranslogStats().getTranslogSizeInBytes(),
-                equalTo((long) Translog.DEFAULT_HEADER_SIZE_IN_BYTES)
-            )
-        );
+        assertBusy(() -> assertTrue(isTranslogEmpty(readOnlyEngine)));
 
         assertAcked(client().admin().indices().prepareOpen("test").setWaitForActiveShards(ActiveShardCount.DEFAULT));
 
@@ -465,6 +462,12 @@ public void testAsyncTranslogTrimTaskOnClosedIndex() throws Exception {
         assertThat(translog.stats().estimatedNumberOfOperations(), equalTo(0));
     }
 
+    boolean isTranslogEmpty(Engine engine) {
+        long tlogSize = engine.translogManager().getTranslogStats().getTranslogSizeInBytes();
+        // translog contains 1(or 2 in some corner cases) empty readers.
+        return tlogSize == Translog.DEFAULT_HEADER_SIZE_IN_BYTES || tlogSize == 2 * Translog.DEFAULT_HEADER_SIZE_IN_BYTES;
+    }
+
     public void testIllegalFsyncInterval() {
         Settings settings = Settings.builder()
             .put(IndexSettings.INDEX_TRANSLOG_SYNC_INTERVAL_SETTING.getKey(), "0ms") // disable
@@ -526,4 +529,76 @@ public void testUpdateRemoteTranslogBufferIntervalDynamically() {
         indexMetadata = client().admin().cluster().prepareState().execute().actionGet().getState().metadata().index("test");
         assertEquals("20s", indexMetadata.getSettings().get(IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey()));
     }
+
+    public void testIndexSort() {
+        Settings settings = Settings.builder()
+            .put(IndexSettings.INDEX_TRANSLOG_SYNC_INTERVAL_SETTING.getKey(), "0ms") // disable
+            .putList("index.sort.field", "sortfield")
+            .build();
+        try {
+            // Integer index sort should be remained to int sort type
+            IndexService index = createIndex("test", settings, createTestMapping("integer"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.INT);
+
+            // Long index sort should be remained to long sort type
+            index = createIndex("test", settings, createTestMapping("long"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.LONG);
+
+            // Float index sort should be remained to float sort type
+            index = createIndex("test", settings, createTestMapping("float"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.FLOAT);
+
+            // Double index sort should be remained to double sort type
+            index = createIndex("test", settings, createTestMapping("double"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.DOUBLE);
+
+            // String index sort should be remained to string sort type
+            index = createIndex("test", settings, createTestMapping("string"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.STRING);
+        } catch (IllegalArgumentException ex) {
+            assertEquals("failed to parse value [0ms] for setting [index.translog.sync_interval], must be >= [100ms]", ex.getMessage());
+        }
+    }
+
+    public void testIndexSortBackwardCompatible() {
+        Settings settings = Settings.builder()
+            .put(IndexSettings.INDEX_TRANSLOG_SYNC_INTERVAL_SETTING.getKey(), "0ms") // disable
+            .put(IndexMetadata.SETTING_INDEX_VERSION_CREATED.getKey(), Version.V_2_6_1)
+            .putList("index.sort.field", "sortfield")
+            .build();
+        try {
+            // Integer index sort should be converted to long sort type
+            IndexService index = createIndex("test", settings, createTestMapping("integer"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.LONG);
+
+            // Long index sort should be remained to long sort type
+            index = createIndex("test", settings, createTestMapping("long"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.LONG);
+
+            // Float index sort should be remained to float sort type
+            index = createIndex("test", settings, createTestMapping("float"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.FLOAT);
+
+            // Double index sort should be remained to double sort type
+            index = createIndex("test", settings, createTestMapping("double"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.DOUBLE);
+
+            // String index sort should be remained to string sort type
+            index = createIndex("test", settings, createTestMapping("string"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.STRING);
+        } catch (IllegalArgumentException ex) {
+            assertEquals("failed to parse value [0ms] for setting [index.translog.sync_interval], must be >= [100ms]", ex.getMessage());
+        }
+    }
+
+    private static String createTestMapping(String type) {
+        return "  \"properties\": {\n"
+            + "    \"test\": {\n"
+            + "      \"type\": \"text\"\n"
+            + "    },\n"
+            + "    \"sortfield\": {\n"
+            + "      \"type\": \" + type + \"\n"
+            + "    }\n"
+            + "  }";
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/IndexingSlowLogTests.java b/server/src/test/java/org/opensearch/index/IndexingSlowLogTests.java
index b2df78b473785..2d1c633f95ccb 100644
--- a/server/src/test/java/org/opensearch/index/IndexingSlowLogTests.java
+++ b/server/src/test/java/org/opensearch/index/IndexingSlowLogTests.java
@@ -44,6 +44,7 @@
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.logging.MockAppender;
+import org.opensearch.common.logging.SlowLogLevel;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.json.JsonXContent;
@@ -412,7 +413,7 @@ public void testLevelSetting() {
             assertNotNull(ex.getCause());
             assertThat(ex.getCause(), instanceOf(IllegalArgumentException.class));
             final IllegalArgumentException cause = (IllegalArgumentException) ex.getCause();
-            assertThat(cause, hasToString(containsString("No enum constant org.opensearch.index.SlowLogLevel.NOT A LEVEL")));
+            assertThat(cause, hasToString(containsString("No enum constant org.opensearch.common.logging.SlowLogLevel.NOT A LEVEL")));
         }
         assertEquals(SlowLogLevel.TRACE, log.getLevel());
 
diff --git a/server/src/test/java/org/opensearch/index/MergePolicySettingsTests.java b/server/src/test/java/org/opensearch/index/MergePolicySettingsTests.java
index 387997892ee30..32c4c048d77ba 100644
--- a/server/src/test/java/org/opensearch/index/MergePolicySettingsTests.java
+++ b/server/src/test/java/org/opensearch/index/MergePolicySettingsTests.java
@@ -31,6 +31,7 @@
 
 package org.opensearch.index;
 
+import org.apache.lucene.index.LogByteSizeMergePolicy;
 import org.apache.lucene.index.NoMergePolicy;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.unit.ByteSizeUnit;
@@ -49,17 +50,17 @@ public class MergePolicySettingsTests extends OpenSearchTestCase {
     protected final ShardId shardId = new ShardId("index", "_na_", 1);
 
     public void testCompoundFileSettings() throws IOException {
-        assertThat(new MergePolicyConfig(logger, indexSettings(Settings.EMPTY)).getMergePolicy().getNoCFSRatio(), equalTo(0.1));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build(true))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build(0.5))).getMergePolicy().getNoCFSRatio(), equalTo(0.5));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build(1.0))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build("true"))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build("True"))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build("False"))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build("false"))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build(false))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build(0))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
-        assertThat(new MergePolicyConfig(logger, indexSettings(build(0.0))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(Settings.EMPTY)).getMergePolicy().getNoCFSRatio(), equalTo(0.1));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build(true))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build(0.5))).getMergePolicy().getNoCFSRatio(), equalTo(0.5));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build(1.0))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build("true"))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build("True"))).getMergePolicy().getNoCFSRatio(), equalTo(1.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build("False"))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build("false"))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build(false))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build(0))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
+        assertThat(new TieredMergePolicyProvider(logger, indexSettings(build(0.0))).getMergePolicy().getNoCFSRatio(), equalTo(0.0));
     }
 
     private static IndexSettings indexSettings(Settings settings) {
@@ -67,33 +68,197 @@ private static IndexSettings indexSettings(Settings settings) {
     }
 
     public void testNoMerges() {
-        MergePolicyConfig mp = new MergePolicyConfig(
+        TieredMergePolicyProvider tmp = new TieredMergePolicyProvider(
             logger,
-            indexSettings(Settings.builder().put(MergePolicyConfig.INDEX_MERGE_ENABLED, false).build())
+            indexSettings(Settings.builder().put(MergePolicyProvider.INDEX_MERGE_ENABLED, false).build())
         );
-        assertTrue(mp.getMergePolicy() instanceof NoMergePolicy);
+        LogByteSizeMergePolicyProvider lbsmp = new LogByteSizeMergePolicyProvider(
+            logger,
+            indexSettings(Settings.builder().put(MergePolicyProvider.INDEX_MERGE_ENABLED, false).build())
+        );
+        assertTrue(tmp.getMergePolicy() instanceof NoMergePolicy);
+        assertTrue(lbsmp.getMergePolicy() instanceof NoMergePolicy);
     }
 
     public void testUpdateSettings() throws IOException {
-        IndexSettings indexSettings = indexSettings(EMPTY_SETTINGS);
-        assertThat(indexSettings.getMergePolicy().getNoCFSRatio(), equalTo(0.1));
+        Settings settings = Settings.builder()
+            .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.TIERED.getValue())
+            .build();
+        IndexSettings indexSettings = indexSettings(settings);
+        assertThat(indexSettings.getMergePolicy(false).getNoCFSRatio(), equalTo(0.1));
         indexSettings = indexSettings(build(0.9));
-        assertThat((indexSettings.getMergePolicy()).getNoCFSRatio(), equalTo(0.9));
+        assertThat((indexSettings.getMergePolicy(false)).getNoCFSRatio(), equalTo(0.9));
         indexSettings.updateIndexMetadata(newIndexMeta("index", build(0.1)));
-        assertThat((indexSettings.getMergePolicy()).getNoCFSRatio(), equalTo(0.1));
+        assertThat((indexSettings.getMergePolicy(false)).getNoCFSRatio(), equalTo(0.1));
         indexSettings.updateIndexMetadata(newIndexMeta("index", build(0.0)));
-        assertThat((indexSettings.getMergePolicy()).getNoCFSRatio(), equalTo(0.0));
+        assertThat((indexSettings.getMergePolicy(false)).getNoCFSRatio(), equalTo(0.0));
         indexSettings.updateIndexMetadata(newIndexMeta("index", build("true")));
-        assertThat((indexSettings.getMergePolicy()).getNoCFSRatio(), equalTo(1.0));
+        assertThat((indexSettings.getMergePolicy(false)).getNoCFSRatio(), equalTo(1.0));
         indexSettings.updateIndexMetadata(newIndexMeta("index", build("false")));
-        assertThat((indexSettings.getMergePolicy()).getNoCFSRatio(), equalTo(0.0));
+        assertThat((indexSettings.getMergePolicy(false)).getNoCFSRatio(), equalTo(0.0));
+    }
+
+    public void testDefaultMergePolicy() throws IOException {
+        IndexSettings indexSettings = indexSettings(EMPTY_SETTINGS);
+        assertTrue(indexSettings.getMergePolicy(false) instanceof OpenSearchTieredMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof OpenSearchTieredMergePolicy);
+    }
+
+    public void testMergePolicyPrecedence() throws IOException {
+        // 1. INDEX_MERGE_POLICY is not set
+        // assert defaults
+        IndexSettings indexSettings = indexSettings(EMPTY_SETTINGS);
+        assertTrue(indexSettings.getMergePolicy(false) instanceof OpenSearchTieredMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof OpenSearchTieredMergePolicy);
+
+        // 1.1 node setting TIME_SERIES_INDEX_MERGE_POLICY is set as log_byte_size
+        // assert index policy is tiered whereas time series index policy is log_byte_size
+        Settings nodeSettings = Settings.builder()
+            .put(IndexSettings.TIME_SERIES_INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.LOG_BYTE_SIZE.getValue())
+            .build();
+        indexSettings = new IndexSettings(newIndexMeta("test", Settings.EMPTY), nodeSettings);
+        assertTrue(indexSettings.getMergePolicy(false) instanceof OpenSearchTieredMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof LogByteSizeMergePolicy);
+
+        // 1.2 node setting TIME_SERIES_INDEX_MERGE_POLICY is set as tiered
+        // assert both index and time series index policy is tiered
+        nodeSettings = Settings.builder()
+            .put(IndexSettings.TIME_SERIES_INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.TIERED.getValue())
+            .build();
+        indexSettings = new IndexSettings(newIndexMeta("test", Settings.EMPTY), nodeSettings);
+        assertTrue(indexSettings.getMergePolicy(false) instanceof OpenSearchTieredMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof OpenSearchTieredMergePolicy);
+
+        // 2. INDEX_MERGE_POLICY set as tiered
+        // assert both index and time-series-index merge policy is set as tiered
+        indexSettings = indexSettings(
+            Settings.builder().put(IndexSettings.INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.TIERED.getValue()).build()
+        );
+        assertTrue(indexSettings.getMergePolicy(false) instanceof OpenSearchTieredMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof OpenSearchTieredMergePolicy);
+
+        // 2.1 node setting TIME_SERIES_INDEX_MERGE_POLICY is set as log_byte_size
+        // assert both index and time-series-index merge policy is set as tiered
+        nodeSettings = Settings.builder()
+            .put(IndexSettings.TIME_SERIES_INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.LOG_BYTE_SIZE.getValue())
+            .build();
+        indexSettings = new IndexSettings(
+            newIndexMeta(
+                "test",
+                Settings.builder().put(IndexSettings.INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.TIERED.getValue()).build()
+            ),
+            nodeSettings
+        );
+        assertTrue(indexSettings.getMergePolicy(false) instanceof OpenSearchTieredMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof OpenSearchTieredMergePolicy);
+
+        // 3. INDEX_MERGE_POLICY set as log_byte_size
+        // assert both index and time-series-index merge policy is set as log_byte_size
+        indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.LOG_BYTE_SIZE.getValue())
+                .build()
+        );
+        assertTrue(indexSettings.getMergePolicy(false) instanceof LogByteSizeMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof LogByteSizeMergePolicy);
+
+        // 3.1 node setting TIME_SERIES_INDEX_MERGE_POLICY is set as tiered
+        // assert both index and time-series-index merge policy is set as log_byte_size
+        nodeSettings = Settings.builder()
+            .put(IndexSettings.TIME_SERIES_INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.TIERED.getValue())
+            .build();
+        indexSettings = new IndexSettings(
+            newIndexMeta(
+                "test",
+                Settings.builder()
+                    .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.LOG_BYTE_SIZE.getValue())
+                    .build()
+            ),
+            nodeSettings
+        );
+        assertTrue(indexSettings.getMergePolicy(false) instanceof LogByteSizeMergePolicy);
+        assertTrue(indexSettings.getMergePolicy(true) instanceof LogByteSizeMergePolicy);
+
+    }
+
+    public void testInvalidMergePolicy() throws IOException {
+
+        final Settings invalidSettings = Settings.builder().put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "invalid").build();
+        IllegalArgumentException exc1 = expectThrows(
+            IllegalArgumentException.class,
+            () -> IndexSettings.INDEX_MERGE_POLICY.get(invalidSettings)
+        );
+        assertThat(exc1.getMessage(), containsString(" has unsupported policy specified: "));
+        IllegalArgumentException exc2 = expectThrows(
+            IllegalArgumentException.class,
+            () -> indexSettings(invalidSettings).getMergePolicy(false)
+        );
+        assertThat(exc2.getMessage(), containsString(" has unsupported policy specified: "));
+
+        final Settings invalidSettings2 = Settings.builder().put(IndexSettings.TIME_SERIES_INDEX_MERGE_POLICY.getKey(), "invalid").build();
+        IllegalArgumentException exc3 = expectThrows(
+            IllegalArgumentException.class,
+            () -> IndexSettings.TIME_SERIES_INDEX_MERGE_POLICY.get(invalidSettings2)
+        );
+        assertThat(exc3.getMessage(), containsString(" has unsupported policy specified: "));
+
+        IllegalArgumentException exc4 = expectThrows(
+            IllegalArgumentException.class,
+            () -> new IndexSettings(newIndexMeta("test", Settings.EMPTY), invalidSettings2).getMergePolicy(true)
+        );
+        assertThat(exc4.getMessage(), containsString(" has unsupported policy specified: "));
+    }
+
+    public void testUpdateSettingsForLogByteSizeMergePolicy() throws IOException {
+        IndexSettings indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.LOG_BYTE_SIZE.getValue())
+                .build()
+        );
+        assertTrue(indexSettings.getMergePolicy(true) instanceof LogByteSizeMergePolicy);
+        assertThat(indexSettings.getMergePolicy(true).getNoCFSRatio(), equalTo(0.1));
+        indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                .put(LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING.getKey(), 0.9)
+                .build()
+        );
+        assertThat((indexSettings.getMergePolicy(true)).getNoCFSRatio(), equalTo(0.9));
+        indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                .put(LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING.getKey(), 0.1)
+                .build()
+        );
+        assertThat((indexSettings.getMergePolicy(true)).getNoCFSRatio(), equalTo(0.1));
+        indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                .put(LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING.getKey(), 0.0)
+                .build()
+        );
+        assertThat((indexSettings.getMergePolicy(true)).getNoCFSRatio(), equalTo(0.0));
+        indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                .put(LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING.getKey(), "true")
+                .build()
+        );
+        assertThat((indexSettings.getMergePolicy(true)).getNoCFSRatio(), equalTo(1.0));
+        indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                .put(LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING.getKey(), "false")
+                .build()
+        );
+        assertThat((indexSettings.getMergePolicy(true)).getNoCFSRatio(), equalTo(0.0));
     }
 
     public void testTieredMergePolicySettingsUpdate() throws IOException {
         IndexSettings indexSettings = indexSettings(Settings.EMPTY);
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getForceMergeDeletesPctAllowed(),
-            MergePolicyConfig.DEFAULT_EXPUNGE_DELETES_ALLOWED,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getForceMergeDeletesPctAllowed(),
+            TieredMergePolicyProvider.DEFAULT_EXPUNGE_DELETES_ALLOWED,
             0.0d
         );
 
@@ -102,21 +267,21 @@ public void testTieredMergePolicySettingsUpdate() throws IOException {
                 "index",
                 Settings.builder()
                     .put(
-                        MergePolicyConfig.INDEX_MERGE_POLICY_EXPUNGE_DELETES_ALLOWED_SETTING.getKey(),
-                        MergePolicyConfig.DEFAULT_EXPUNGE_DELETES_ALLOWED + 1.0d
+                        TieredMergePolicyProvider.INDEX_MERGE_POLICY_EXPUNGE_DELETES_ALLOWED_SETTING.getKey(),
+                        TieredMergePolicyProvider.DEFAULT_EXPUNGE_DELETES_ALLOWED + 1.0d
                     )
                     .build()
             )
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getForceMergeDeletesPctAllowed(),
-            MergePolicyConfig.DEFAULT_EXPUNGE_DELETES_ALLOWED + 1.0d,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getForceMergeDeletesPctAllowed(),
+            TieredMergePolicyProvider.DEFAULT_EXPUNGE_DELETES_ALLOWED + 1.0d,
             0.0d
         );
 
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getFloorSegmentMB(),
-            MergePolicyConfig.DEFAULT_FLOOR_SEGMENT.getMbFrac(),
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getFloorSegmentMB(),
+            TieredMergePolicyProvider.DEFAULT_FLOOR_SEGMENT.getMbFrac(),
             0
         );
         indexSettings.updateIndexMetadata(
@@ -124,41 +289,41 @@ public void testTieredMergePolicySettingsUpdate() throws IOException {
                 "index",
                 Settings.builder()
                     .put(
-                        MergePolicyConfig.INDEX_MERGE_POLICY_FLOOR_SEGMENT_SETTING.getKey(),
-                        new ByteSizeValue(MergePolicyConfig.DEFAULT_FLOOR_SEGMENT.getMb() + 1, ByteSizeUnit.MB)
+                        TieredMergePolicyProvider.INDEX_MERGE_POLICY_FLOOR_SEGMENT_SETTING.getKey(),
+                        new ByteSizeValue(TieredMergePolicyProvider.DEFAULT_FLOOR_SEGMENT.getMb() + 1, ByteSizeUnit.MB)
                     )
                     .build()
             )
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getFloorSegmentMB(),
-            new ByteSizeValue(MergePolicyConfig.DEFAULT_FLOOR_SEGMENT.getMb() + 1, ByteSizeUnit.MB).getMbFrac(),
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getFloorSegmentMB(),
+            new ByteSizeValue(TieredMergePolicyProvider.DEFAULT_FLOOR_SEGMENT.getMb() + 1, ByteSizeUnit.MB).getMbFrac(),
             0.001
         );
 
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getMaxMergeAtOnce(),
-            MergePolicyConfig.DEFAULT_MAX_MERGE_AT_ONCE
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getMaxMergeAtOnce(),
+            TieredMergePolicyProvider.DEFAULT_MAX_MERGE_AT_ONCE
         );
         indexSettings.updateIndexMetadata(
             newIndexMeta(
                 "index",
                 Settings.builder()
                     .put(
-                        MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(),
-                        MergePolicyConfig.DEFAULT_MAX_MERGE_AT_ONCE - 1
+                        TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(),
+                        TieredMergePolicyProvider.DEFAULT_MAX_MERGE_AT_ONCE - 1
                     )
                     .build()
             )
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getMaxMergeAtOnce(),
-            MergePolicyConfig.DEFAULT_MAX_MERGE_AT_ONCE - 1
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getMaxMergeAtOnce(),
+            TieredMergePolicyProvider.DEFAULT_MAX_MERGE_AT_ONCE - 1
         );
 
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getMaxMergedSegmentMB(),
-            MergePolicyConfig.DEFAULT_MAX_MERGED_SEGMENT.getMbFrac(),
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getMaxMergedSegmentMB(),
+            TieredMergePolicyProvider.DEFAULT_MAX_MERGED_SEGMENT.getMbFrac(),
             0.0001
         );
         indexSettings.updateIndexMetadata(
@@ -166,21 +331,21 @@ public void testTieredMergePolicySettingsUpdate() throws IOException {
                 "index",
                 Settings.builder()
                     .put(
-                        MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGED_SEGMENT_SETTING.getKey(),
-                        new ByteSizeValue(MergePolicyConfig.DEFAULT_MAX_MERGED_SEGMENT.getBytes() + 1)
+                        TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGED_SEGMENT_SETTING.getKey(),
+                        new ByteSizeValue(TieredMergePolicyProvider.DEFAULT_MAX_MERGED_SEGMENT.getBytes() + 1)
                     )
                     .build()
             )
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getMaxMergedSegmentMB(),
-            new ByteSizeValue(MergePolicyConfig.DEFAULT_MAX_MERGED_SEGMENT.getBytes() + 1).getMbFrac(),
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getMaxMergedSegmentMB(),
+            new ByteSizeValue(TieredMergePolicyProvider.DEFAULT_MAX_MERGED_SEGMENT.getBytes() + 1).getMbFrac(),
             0.0001
         );
 
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getSegmentsPerTier(),
-            MergePolicyConfig.DEFAULT_SEGMENTS_PER_TIER,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getSegmentsPerTier(),
+            TieredMergePolicyProvider.DEFAULT_SEGMENTS_PER_TIER,
             0
         );
         indexSettings.updateIndexMetadata(
@@ -188,37 +353,37 @@ public void testTieredMergePolicySettingsUpdate() throws IOException {
                 "index",
                 Settings.builder()
                     .put(
-                        MergePolicyConfig.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(),
-                        MergePolicyConfig.DEFAULT_SEGMENTS_PER_TIER + 1
+                        TieredMergePolicyProvider.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(),
+                        TieredMergePolicyProvider.DEFAULT_SEGMENTS_PER_TIER + 1
                     )
                     .build()
             )
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getSegmentsPerTier(),
-            MergePolicyConfig.DEFAULT_SEGMENTS_PER_TIER + 1,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getSegmentsPerTier(),
+            TieredMergePolicyProvider.DEFAULT_SEGMENTS_PER_TIER + 1,
             0
         );
 
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getDeletesPctAllowed(),
-            MergePolicyConfig.DEFAULT_DELETES_PCT_ALLOWED,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getDeletesPctAllowed(),
+            TieredMergePolicyProvider.DEFAULT_DELETES_PCT_ALLOWED,
             0
         );
         indexSettings.updateIndexMetadata(
             newIndexMeta(
                 "index",
-                Settings.builder().put(MergePolicyConfig.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING.getKey(), 22).build()
+                Settings.builder().put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING.getKey(), 22).build()
             )
         );
-        assertEquals(((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getDeletesPctAllowed(), 22, 0);
+        assertEquals(((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getDeletesPctAllowed(), 22, 0);
 
         IllegalArgumentException exc = expectThrows(
             IllegalArgumentException.class,
             () -> indexSettings.updateIndexMetadata(
                 newIndexMeta(
                     "index",
-                    Settings.builder().put(MergePolicyConfig.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING.getKey(), 53).build()
+                    Settings.builder().put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_DELETES_PCT_ALLOWED_SETTING.getKey(), 53).build()
                 )
             )
         );
@@ -226,50 +391,162 @@ public void testTieredMergePolicySettingsUpdate() throws IOException {
         assertThat(cause.getMessage(), containsString("must be <= 50.0"));
         indexSettings.updateIndexMetadata(newIndexMeta("index", EMPTY_SETTINGS)); // see if defaults are restored
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getForceMergeDeletesPctAllowed(),
-            MergePolicyConfig.DEFAULT_EXPUNGE_DELETES_ALLOWED,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getForceMergeDeletesPctAllowed(),
+            TieredMergePolicyProvider.DEFAULT_EXPUNGE_DELETES_ALLOWED,
             0.0d
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getFloorSegmentMB(),
-            new ByteSizeValue(MergePolicyConfig.DEFAULT_FLOOR_SEGMENT.getMb(), ByteSizeUnit.MB).getMbFrac(),
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getFloorSegmentMB(),
+            new ByteSizeValue(TieredMergePolicyProvider.DEFAULT_FLOOR_SEGMENT.getMb(), ByteSizeUnit.MB).getMbFrac(),
             0.00
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getMaxMergeAtOnce(),
-            MergePolicyConfig.DEFAULT_MAX_MERGE_AT_ONCE
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getMaxMergeAtOnce(),
+            TieredMergePolicyProvider.DEFAULT_MAX_MERGE_AT_ONCE
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getMaxMergedSegmentMB(),
-            new ByteSizeValue(MergePolicyConfig.DEFAULT_MAX_MERGED_SEGMENT.getBytes() + 1).getMbFrac(),
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getMaxMergedSegmentMB(),
+            new ByteSizeValue(TieredMergePolicyProvider.DEFAULT_MAX_MERGED_SEGMENT.getBytes() + 1).getMbFrac(),
             0.0001
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getSegmentsPerTier(),
-            MergePolicyConfig.DEFAULT_SEGMENTS_PER_TIER,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getSegmentsPerTier(),
+            TieredMergePolicyProvider.DEFAULT_SEGMENTS_PER_TIER,
             0
         );
         assertEquals(
-            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy()).getDeletesPctAllowed(),
-            MergePolicyConfig.DEFAULT_DELETES_PCT_ALLOWED,
+            ((OpenSearchTieredMergePolicy) indexSettings.getMergePolicy(false)).getDeletesPctAllowed(),
+            TieredMergePolicyProvider.DEFAULT_DELETES_PCT_ALLOWED,
             0
         );
     }
 
+    public void testLogByteSizeMergePolicySettingsUpdate() throws IOException {
+
+        IndexSettings indexSettings = indexSettings(
+            Settings.builder()
+                .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), IndexSettings.IndexMergePolicy.LOG_BYTE_SIZE.getValue())
+                .build()
+        );
+        assertEquals(
+            ((LogByteSizeMergePolicy) indexSettings.getMergePolicy(true)).getMergeFactor(),
+            LogByteSizeMergePolicyProvider.DEFAULT_MERGE_FACTOR
+        );
+
+        indexSettings.updateIndexMetadata(
+            newIndexMeta(
+                "index",
+                Settings.builder()
+                    .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                    .put(
+                        LogByteSizeMergePolicyProvider.INDEX_LBS_MERGE_POLICY_MERGE_FACTOR_SETTING.getKey(),
+                        LogByteSizeMergePolicyProvider.DEFAULT_MERGE_FACTOR + 1
+                    )
+                    .build()
+            )
+        );
+        assertEquals(
+            ((LogByteSizeMergePolicy) indexSettings.getMergePolicy(true)).getMergeFactor(),
+            LogByteSizeMergePolicyProvider.DEFAULT_MERGE_FACTOR + 1
+        );
+
+        indexSettings.updateIndexMetadata(
+            newIndexMeta(
+                "index",
+                Settings.builder()
+                    .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                    .put(
+                        LogByteSizeMergePolicyProvider.INDEX_LBS_MERGE_POLICY_MIN_MERGE_SETTING.getKey(),
+                        new ByteSizeValue(LogByteSizeMergePolicyProvider.DEFAULT_MIN_MERGE.getMb() + 1, ByteSizeUnit.MB)
+                    )
+                    .build()
+            )
+        );
+
+        assertEquals(
+            ((LogByteSizeMergePolicy) indexSettings.getMergePolicy(true)).getMinMergeMB(),
+            new ByteSizeValue(LogByteSizeMergePolicyProvider.DEFAULT_MIN_MERGE.getMb() + 1, ByteSizeUnit.MB).getMbFrac(),
+            0.001
+        );
+
+        indexSettings.updateIndexMetadata(
+            newIndexMeta(
+                "index",
+                Settings.builder()
+                    .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                    .put(
+                        LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGE_SEGMENT_SETTING.getKey(),
+                        new ByteSizeValue(LogByteSizeMergePolicyProvider.DEFAULT_MAX_MERGED_SEGMENT.getMb() + 100, ByteSizeUnit.MB)
+                    )
+                    .build()
+            )
+        );
+
+        assertEquals(
+            ((LogByteSizeMergePolicy) indexSettings.getMergePolicy(true)).getMaxMergeMB(),
+            new ByteSizeValue(TieredMergePolicyProvider.DEFAULT_MAX_MERGED_SEGMENT.getMb() + 100, ByteSizeUnit.MB).getMbFrac(),
+            0.001
+        );
+
+        indexSettings.updateIndexMetadata(
+            newIndexMeta(
+                "index",
+                Settings.builder()
+                    .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                    .put(
+                        LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGE_SEGMENT_FOR_FORCED_MERGE_SETTING.getKey(),
+                        new ByteSizeValue(
+                            LogByteSizeMergePolicyProvider.DEFAULT_MAX_MERGE_SEGMENT_FORCE_MERGE.getMb() - 100,
+                            ByteSizeUnit.MB
+                        )
+                    )
+                    .build()
+            )
+        );
+        assertEquals(
+            ((LogByteSizeMergePolicy) indexSettings.getMergePolicy(true)).getMaxMergeMBForForcedMerge(),
+            new ByteSizeValue(LogByteSizeMergePolicyProvider.DEFAULT_MAX_MERGE_SEGMENT_FORCE_MERGE.getMb() - 100, ByteSizeUnit.MB)
+                .getMbFrac(),
+            0.001
+        );
+
+        indexSettings.updateIndexMetadata(
+            newIndexMeta(
+                "index",
+                Settings.builder()
+                    .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                    .put(LogByteSizeMergePolicyProvider.INDEX_LBS_MAX_MERGED_DOCS_SETTING.getKey(), 10000000)
+                    .build()
+            )
+        );
+        assertEquals(((LogByteSizeMergePolicy) indexSettings.getMergePolicy(true)).getMaxMergeDocs(), 10000000);
+
+        indexSettings.updateIndexMetadata(
+            newIndexMeta(
+                "index",
+                Settings.builder()
+                    .put(IndexSettings.INDEX_MERGE_POLICY.getKey(), "log_byte_size")
+                    .put(LogByteSizeMergePolicyProvider.INDEX_LBS_NO_CFS_RATIO_SETTING.getKey(), 0.1)
+                    .build()
+            )
+        );
+        assertEquals(indexSettings.getMergePolicy(true).getNoCFSRatio(), 0.1, 0.0);
+    }
+
     public Settings build(String value) {
-        return Settings.builder().put(MergePolicyConfig.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
+        return Settings.builder().put(TieredMergePolicyProvider.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
     }
 
     public Settings build(double value) {
-        return Settings.builder().put(MergePolicyConfig.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
+        return Settings.builder().put(TieredMergePolicyProvider.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
     }
 
     public Settings build(int value) {
-        return Settings.builder().put(MergePolicyConfig.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
+        return Settings.builder().put(TieredMergePolicyProvider.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
     }
 
     public Settings build(boolean value) {
-        return Settings.builder().put(MergePolicyConfig.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
+        return Settings.builder().put(TieredMergePolicyProvider.INDEX_COMPOUND_FORMAT_SETTING.getKey(), value).build();
     }
 
 }
diff --git a/server/src/test/java/org/opensearch/index/MergeSchedulerSettingsTests.java b/server/src/test/java/org/opensearch/index/MergeSchedulerSettingsTests.java
index 2443ee1ab40be..baaf584702f78 100644
--- a/server/src/test/java/org/opensearch/index/MergeSchedulerSettingsTests.java
+++ b/server/src/test/java/org/opensearch/index/MergeSchedulerSettingsTests.java
@@ -92,8 +92,8 @@ public void testUpdateAutoThrottleSettings() throws Exception {
                 .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
                 .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, "1")
                 .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "0")
-                .put(MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
-                .put(MergePolicyConfig.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
+                .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
+                .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
                 .put(MergeSchedulerConfig.MAX_THREAD_COUNT_SETTING.getKey(), "1")
                 .put(MergeSchedulerConfig.MAX_MERGE_COUNT_SETTING.getKey(), "2")
                 .put(MergeSchedulerConfig.AUTO_THROTTLE_SETTING.getKey(), "true");
@@ -123,8 +123,8 @@ public void testUpdateMergeMaxThreadCount() throws Exception {
                 .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
                 .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, "1")
                 .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "0")
-                .put(MergePolicyConfig.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
-                .put(MergePolicyConfig.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
+                .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_AT_ONCE_SETTING.getKey(), "2")
+                .put(TieredMergePolicyProvider.INDEX_MERGE_POLICY_SEGMENTS_PER_TIER_SETTING.getKey(), "2")
                 .put(MergeSchedulerConfig.MAX_THREAD_COUNT_SETTING.getKey(), "10000")
                 .put(MergeSchedulerConfig.MAX_MERGE_COUNT_SETTING.getKey(), "10000");
             IndexSettings settings = new IndexSettings(newIndexMeta("index", builder.build()), Settings.EMPTY);
diff --git a/server/src/test/java/org/opensearch/index/OpenSearchTieredMergePolicyTests.java b/server/src/test/java/org/opensearch/index/OpenSearchTieredMergePolicyTests.java
index cbc439041666f..614dacd457782 100644
--- a/server/src/test/java/org/opensearch/index/OpenSearchTieredMergePolicyTests.java
+++ b/server/src/test/java/org/opensearch/index/OpenSearchTieredMergePolicyTests.java
@@ -32,9 +32,18 @@
 
 package org.opensearch.index;
 
+import org.apache.lucene.index.MergePolicy;
+import org.apache.lucene.index.SegmentCommitInfo;
+import org.apache.lucene.index.SegmentInfos;
 import org.apache.lucene.index.TieredMergePolicy;
+import org.apache.lucene.util.InfoStream;
+import org.apache.lucene.util.Version;
 import org.opensearch.test.OpenSearchTestCase;
 
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Set;
+
 public class OpenSearchTieredMergePolicyTests extends OpenSearchTestCase {
 
     public void testDefaults() {
@@ -80,4 +89,32 @@ public void testSetDeletesPctAllowed() {
         policy.setDeletesPctAllowed(42);
         assertEquals(42, policy.regularMergePolicy.getDeletesPctAllowed(), 0);
     }
+
+    public void testFindDeleteMergesReturnsNullOnEmptySegmentInfos() throws IOException {
+        MergePolicy.MergeSpecification mergeSpecification = new OpenSearchTieredMergePolicy().findForcedDeletesMerges(
+            new SegmentInfos(Version.LATEST.major),
+            new MergePolicy.MergeContext() {
+                @Override
+                public int numDeletesToMerge(SegmentCommitInfo info) {
+                    return 0;
+                }
+
+                @Override
+                public int numDeletedDocs(SegmentCommitInfo info) {
+                    return 0;
+                }
+
+                @Override
+                public InfoStream getInfoStream() {
+                    return InfoStream.NO_OUTPUT;
+                }
+
+                @Override
+                public Set<SegmentCommitInfo> getMergingSegments() {
+                    return Collections.emptySet();
+                }
+            }
+        );
+        assertNull(mergeSpecification);
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/SearchSlowLogTests.java b/server/src/test/java/org/opensearch/index/SearchSlowLogTests.java
index 7835916e14581..0c0dec29c9dbf 100644
--- a/server/src/test/java/org/opensearch/index/SearchSlowLogTests.java
+++ b/server/src/test/java/org/opensearch/index/SearchSlowLogTests.java
@@ -41,6 +41,7 @@
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.logging.MockAppender;
+import org.opensearch.common.logging.SlowLogLevel;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.BigArrays;
@@ -337,7 +338,7 @@ public void testLevelSetting() {
             assertNotNull(ex.getCause());
             assertThat(ex.getCause(), instanceOf(IllegalArgumentException.class));
             final IllegalArgumentException cause = (IllegalArgumentException) ex.getCause();
-            assertThat(cause, hasToString(containsString("No enum constant org.opensearch.index.SlowLogLevel.NOT A LEVEL")));
+            assertThat(cause, hasToString(containsString("No enum constant org.opensearch.common.logging.SlowLogLevel.NOT A LEVEL")));
         }
         assertEquals(SlowLogLevel.TRACE, log.getLevel());
 
diff --git a/server/src/test/java/org/opensearch/index/SegmentReplicationPressureServiceTests.java b/server/src/test/java/org/opensearch/index/SegmentReplicationPressureServiceTests.java
index 34fa13f0ba62c..a9725f638cc53 100644
--- a/server/src/test/java/org/opensearch/index/SegmentReplicationPressureServiceTests.java
+++ b/server/src/test/java/org/opensearch/index/SegmentReplicationPressureServiceTests.java
@@ -217,6 +217,8 @@ public void testFailStaleReplicaTask() throws Exception {
             assertEquals(5, shardStats.getCheckpointsBehindCount());
 
             // call the background task
+            assertTrue(service.getFailStaleReplicaTask().mustReschedule());
+            assertTrue(service.getFailStaleReplicaTask().isScheduled());
             service.getFailStaleReplicaTask().runInternal();
 
             // verify that remote shard failed method is called which fails the replica shards falling behind.
@@ -257,6 +259,41 @@ public void testFailStaleReplicaTaskDisabled() throws Exception {
         }
     }
 
+    public void testFailStaleReplicaTaskToggleOnOff() throws Exception {
+        final Settings settings = Settings.builder()
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .put(SEGMENT_REPLICATION_INDEXING_PRESSURE_ENABLED.getKey(), true)
+            .put(MAX_REPLICATION_TIME_BACKPRESSURE_SETTING.getKey(), TimeValue.timeValueMillis(10))
+            .put(MAX_REPLICATION_LIMIT_STALE_REPLICA_SETTING.getKey(), TimeValue.timeValueMillis(1))
+            .build();
+
+        try (ReplicationGroup shards = createGroup(1, settings, new NRTReplicationEngineFactory())) {
+            shards.startAll();
+            final IndexShard primaryShard = shards.getPrimary();
+            SegmentReplicationPressureService service = buildPressureService(settings, primaryShard);
+
+            // index docs in batches without refreshing
+            indexInBatches(5, shards, primaryShard);
+
+            // assert that replica shard is few checkpoints behind primary
+            Set<SegmentReplicationShardStats> replicationStats = primaryShard.getReplicationStatsForTrackedReplicas();
+            assertEquals(1, replicationStats.size());
+            SegmentReplicationShardStats shardStats = replicationStats.stream().findFirst().get();
+            assertEquals(5, shardStats.getCheckpointsBehindCount());
+
+            assertTrue(service.getFailStaleReplicaTask().mustReschedule());
+            assertTrue(service.getFailStaleReplicaTask().isScheduled());
+            replicateSegments(primaryShard, shards.getReplicas());
+
+            service.setReplicationTimeLimitFailReplica(TimeValue.ZERO);
+            assertFalse(service.getFailStaleReplicaTask().mustReschedule());
+            assertFalse(service.getFailStaleReplicaTask().isScheduled());
+            service.setReplicationTimeLimitFailReplica(TimeValue.timeValueMillis(1));
+            assertTrue(service.getFailStaleReplicaTask().mustReschedule());
+            assertTrue(service.getFailStaleReplicaTask().isScheduled());
+        }
+    }
+
     private int indexInBatches(int count, ReplicationGroup shards, IndexShard primaryShard) throws Exception {
         int totalDocs = 0;
         for (int i = 0; i < count; i++) {
@@ -278,6 +315,13 @@ private SegmentReplicationPressureService buildPressureService(Settings settings
         ClusterService clusterService = mock(ClusterService.class);
         when(clusterService.getClusterSettings()).thenReturn(new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS));
 
-        return new SegmentReplicationPressureService(settings, clusterService, indicesService, shardStateAction, mock(ThreadPool.class));
+        return new SegmentReplicationPressureService(
+            settings,
+            clusterService,
+            indicesService,
+            shardStateAction,
+            new SegmentReplicationStatsTracker(indicesService),
+            mock(ThreadPool.class)
+        );
     }
 }
diff --git a/server/src/test/java/org/opensearch/index/SegmentReplicationStatsTrackerTests.java b/server/src/test/java/org/opensearch/index/SegmentReplicationStatsTrackerTests.java
new file mode 100644
index 0000000000000..04423d583e8f9
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/SegmentReplicationStatsTrackerTests.java
@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index;
+
+import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.indices.IndicesService;
+import org.opensearch.test.OpenSearchTestCase;
+
+import org.mockito.Mockito;
+
+import static org.mockito.Mockito.mock;
+
+public class SegmentReplicationStatsTrackerTests extends OpenSearchTestCase {
+
+    private IndicesService indicesService = mock(IndicesService.class);
+
+    public void testRejectedCount() {
+        SegmentReplicationStatsTracker segmentReplicationStatsTracker = new SegmentReplicationStatsTracker(indicesService);
+
+        // Verify that total rejection count is 0 on an empty rejectionCount map in statsTracker.
+        assertTrue(segmentReplicationStatsTracker.getRejectionCount().isEmpty());
+        assertEquals(segmentReplicationStatsTracker.getTotalRejectionStats().getTotalRejectionCount(), 0L);
+
+        // Verify that total rejection count is 1 after incrementing rejectionCount.
+        segmentReplicationStatsTracker.incrementRejectionCount(Mockito.mock(ShardId.class));
+        assertEquals(segmentReplicationStatsTracker.getTotalRejectionStats().getTotalRejectionCount(), 1L);
+    }
+
+}
diff --git a/server/src/test/java/org/opensearch/index/SlowLogLevelTests.java b/server/src/test/java/org/opensearch/index/SlowLogLevelTests.java
index 290af7360ce52..d0da07f7a7018 100644
--- a/server/src/test/java/org/opensearch/index/SlowLogLevelTests.java
+++ b/server/src/test/java/org/opensearch/index/SlowLogLevelTests.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.index;
 
+import org.opensearch.common.logging.SlowLogLevel;
 import org.opensearch.test.OpenSearchTestCase;
 
 public class SlowLogLevelTests extends OpenSearchTestCase {
diff --git a/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java b/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java
index e3d77d45861ac..5b586524d0bfc 100644
--- a/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java
+++ b/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java
@@ -40,7 +40,6 @@
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.appender.AbstractAppender;
 import org.apache.logging.log4j.core.filter.RegexFilter;
-import org.apache.lucene.codecs.LiveDocsFormat;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.KeywordField;
 import org.apache.lucene.document.LongPoint;
@@ -233,7 +232,6 @@
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -3238,22 +3236,10 @@ public void testUnreferencedFileCleanUpOnSegmentMergeFailureWithCleanUpEnabled()
         MockDirectoryWrapper wrapper = newMockDirectory();
         final CountDownLatch cleanupCompleted = new CountDownLatch(1);
         MockDirectoryWrapper.Failure fail = new MockDirectoryWrapper.Failure() {
-            public boolean didFail1;
-            public boolean didFail2;
-
             @Override
             public void eval(MockDirectoryWrapper dir) throws IOException {
-                if (!doFail) {
-                    return;
-                }
-
-                // Fail segment merge with diskfull during merging terms.
-                if (callStackContainsAnyOf("mergeTerms") && !didFail1) {
-                    didFail1 = true;
-                    throw new IOException("No space left on device");
-                }
-                if (callStackContains(LiveDocsFormat.class, "writeLiveDocs") && !didFail2) {
-                    didFail2 = true;
+                // Fail segment merge with diskfull during merging terms
+                if (callStackContainsAnyOf("mergeTerms")) {
                     throw new IOException("No space left on device");
                 }
             }
@@ -3326,7 +3312,6 @@ public void onFailedEngine(String reason, Exception e) {
             segments = engine.segments(false);
             assertThat(segments.size(), equalTo(2));
 
-            fail.setDoFail();
             // IndexWriter can throw either IOException or IllegalStateException depending on whether tragedy is set or not.
             expectThrowsAnyOf(
                 Arrays.asList(IOException.class, IllegalStateException.class),
@@ -3334,6 +3319,9 @@ public void onFailedEngine(String reason, Exception e) {
             );
 
             assertTrue(cleanupCompleted.await(10, TimeUnit.SECONDS));
+            // Cleanup count will be incremented whenever cleanup is performed correctly.
+            long unreferencedFileCleanUpsPerformed = engine.unreferencedFileCleanUpsPerformed();
+            assertThat(unreferencedFileCleanUpsPerformed, equalTo(1L));
         } catch (Exception ex) {
             throw new AssertionError(ex);
         }
@@ -3343,20 +3331,10 @@ public void testUnreferencedFileCleanUpOnSegmentMergeFailureWithCleanUpDisabled(
         MockDirectoryWrapper wrapper = newMockDirectory();
         final CountDownLatch cleanupCompleted = new CountDownLatch(1);
         MockDirectoryWrapper.Failure fail = new MockDirectoryWrapper.Failure() {
-            public boolean didFail1;
-            public boolean didFail2;
 
             @Override
             public void eval(MockDirectoryWrapper dir) throws IOException {
-                if (!doFail) {
-                    return;
-                }
-                if (callStackContainsAnyOf("mergeTerms") && !didFail1) {
-                    didFail1 = true;
-                    throw new IOException("No space left on device");
-                }
-                if (callStackContains(LiveDocsFormat.class, "writeLiveDocs") && !didFail2) {
-                    didFail2 = true;
+                if (callStackContainsAnyOf("mergeTerms")) {
                     throw new IOException("No space left on device");
                 }
             }
@@ -3437,7 +3415,6 @@ public void onFailedEngine(String reason, Exception e) {
             segments = engine.segments(false);
             assertThat(segments.size(), equalTo(2));
 
-            fail.setDoFail();
             // IndexWriter can throw either IOException or IllegalStateException depending on whether tragedy is set or not.
             expectThrowsAnyOf(
                 Arrays.asList(IOException.class, IllegalStateException.class),
@@ -3445,6 +3422,9 @@ public void onFailedEngine(String reason, Exception e) {
             );
 
             assertTrue(cleanupCompleted.await(10, TimeUnit.SECONDS));
+            // Cleanup count will not be incremented whenever cleanup is disabled.
+            long unreferencedFileCleanUpsPerformed = engine.unreferencedFileCleanUpsPerformed();
+            assertThat(unreferencedFileCleanUpsPerformed, equalTo(0L));
         } catch (Exception ex) {
             throw new AssertionError(ex);
         }
@@ -3454,20 +3434,10 @@ public void testUnreferencedFileCleanUpFailsOnSegmentMergeFailureWhenDirectoryCl
         MockDirectoryWrapper wrapper = newMockDirectory();
         final CountDownLatch cleanupCompleted = new CountDownLatch(1);
         MockDirectoryWrapper.Failure fail = new MockDirectoryWrapper.Failure() {
-            public boolean didFail1;
-            public boolean didFail2;
 
             @Override
             public void eval(MockDirectoryWrapper dir) throws IOException {
-                if (!doFail) {
-                    return;
-                }
-                if (callStackContainsAnyOf("mergeTerms") && !didFail1) {
-                    didFail1 = true;
-                    throw new IOException("No space left on device");
-                }
-                if (callStackContains(LiveDocsFormat.class, "writeLiveDocs") && !didFail2) {
-                    didFail2 = true;
+                if (callStackContainsAnyOf("mergeTerms")) {
                     throw new IOException("No space left on device");
                 }
             }
@@ -3532,7 +3502,6 @@ public void onFailedEngine(String reason, Exception e) {
             segments = engine.segments(false);
             assertThat(segments.size(), equalTo(2));
 
-            fail.setDoFail();
             // Close the store so that unreferenced file cleanup will fail.
             store.close();
 
@@ -3549,6 +3518,9 @@ public void onFailedEngine(String reason, Exception e) {
             );
 
             assertTrue(cleanupCompleted.await(10, TimeUnit.SECONDS));
+            // Cleanup count will not be incremented whenever there is some issue with cleanup.
+            long unreferencedFileCleanUpsPerformed = engine.unreferencedFileCleanUpsPerformed();
+            assertThat(unreferencedFileCleanUpsPerformed, equalTo(0L));
         } catch (Exception ex) {
             throw new AssertionError(ex);
         }
@@ -3997,7 +3969,7 @@ public void testRecoverFromForeignTranslog() throws IOException {
         final Path badTranslogLog = createTempDir();
         final String badUUID = Translog.createEmptyTranslog(badTranslogLog, SequenceNumbers.NO_OPS_PERFORMED, shardId, primaryTerm.get());
         Translog translog = new LocalTranslog(
-            new TranslogConfig(shardId, badTranslogLog, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+            new TranslogConfig(shardId, badTranslogLog, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
             badUUID,
             createTranslogDeletionPolicy(INDEX_SETTINGS),
             () -> SequenceNumbers.NO_OPS_PERFORMED,
@@ -4014,7 +3986,8 @@ public void testRecoverFromForeignTranslog() throws IOException {
             shardId,
             translog.location(),
             config.getIndexSettings(),
-            BigArrays.NON_RECYCLING_INSTANCE
+            BigArrays.NON_RECYCLING_INSTANCE,
+            ""
         );
 
         EngineConfig brokenConfig = new EngineConfig.Builder().shardId(shardId)
@@ -7247,7 +7220,11 @@ public void testMaxSeqNoInCommitUserData() throws Exception {
             engine.ensureOpen();
             while (running.get()
                 && assertAndGetInternalTranslogManager(engine.translogManager()).getTranslog().currentFileGeneration() < 500) {
-                engine.translogManager().rollTranslogGeneration(); // make adding operations to translog slower
+                try {
+                    engine.translogManager().rollTranslogGeneration(); // make adding operations to translog slower
+                } catch (IOException e) {
+                    fail("io exception not expected");
+                }
             }
         });
         rollTranslog.start();
@@ -7703,7 +7680,8 @@ public void testNotWarmUpSearcherInEngineCtor() throws Exception {
                 config.getTranslogConfig().getShardId(),
                 createTempDir(),
                 config.getTranslogConfig().getIndexSettings(),
-                config.getTranslogConfig().getBigArrays()
+                config.getTranslogConfig().getBigArrays(),
+                ""
             );
             EngineConfig configWithWarmer = new EngineConfig.Builder().shardId(config.getShardId())
                 .threadPool(config.getThreadPool())
@@ -7823,7 +7801,9 @@ public void testMaxDocsOnPrimary() throws Exception {
                     assertNotNull(result.getFailure());
                     assertThat(
                         result.getFailure().getMessage(),
-                        containsString("Number of documents in the index can't exceed [" + maxDocs + "]")
+                        containsString(
+                            "Number of documents in shard " + shardId + " exceeds the limit of [" + maxDocs + "] documents per shard"
+                        )
                     );
                     assertThat(result.getSeqNo(), equalTo(UNASSIGNED_SEQ_NO));
                     assertThat(engine.getLocalCheckpointTracker().getMaxSeqNo(), equalTo(maxSeqNo));
diff --git a/server/src/test/java/org/opensearch/index/engine/NRTReplicationEngineTests.java b/server/src/test/java/org/opensearch/index/engine/NRTReplicationEngineTests.java
index 7b587e9a83d2d..57509c5daa2b1 100644
--- a/server/src/test/java/org/opensearch/index/engine/NRTReplicationEngineTests.java
+++ b/server/src/test/java/org/opensearch/index/engine/NRTReplicationEngineTests.java
@@ -35,6 +35,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicLong;
@@ -577,6 +578,59 @@ public void testDecrefToZeroRemovesFile() throws IOException {
         }
     }
 
+    public void testCommitOnCloseThrowsException_decRefStore() throws Exception {
+        final AtomicLong globalCheckpoint = new AtomicLong(SequenceNumbers.NO_OPS_PERFORMED);
+
+        final Store nrtEngineStore = createStore(INDEX_SETTINGS, newDirectory());
+        final NRTReplicationEngine nrtEngine = buildNrtReplicaEngine(globalCheckpoint, nrtEngineStore, INDEX_SETTINGS);
+        List<Engine.Operation> operations = generateHistoryOnReplica(
+            randomIntBetween(1, 10),
+            randomBoolean(),
+            randomBoolean(),
+            randomBoolean()
+        );
+        indexOperations(nrtEngine, operations);
+        // wipe the nrt directory initially so we can sync with primary.
+        cleanAndCopySegmentsFromPrimary(nrtEngine);
+        final Optional<String> toDelete = Set.of(nrtEngineStore.directory().listAll()).stream().filter(f -> f.endsWith(".si")).findAny();
+        assertTrue(toDelete.isPresent());
+        nrtEngineStore.directory().deleteFile(toDelete.get());
+        assertEquals(2, nrtEngineStore.refCount());
+        nrtEngine.close();
+        assertEquals(1, nrtEngineStore.refCount());
+        assertTrue(nrtEngineStore.isMarkedCorrupted());
+        // store will throw when eventually closed, not handled here.
+        assertThrows(RuntimeException.class, nrtEngineStore::close);
+    }
+
+    public void testFlushThrowsFlushFailedExceptionOnCorruption() throws Exception {
+        final AtomicLong globalCheckpoint = new AtomicLong(SequenceNumbers.NO_OPS_PERFORMED);
+
+        final Store nrtEngineStore = createStore(INDEX_SETTINGS, newDirectory());
+        final NRTReplicationEngine nrtEngine = buildNrtReplicaEngine(globalCheckpoint, nrtEngineStore, INDEX_SETTINGS);
+        List<Engine.Operation> operations = generateHistoryOnReplica(
+            randomIntBetween(1, 10),
+            randomBoolean(),
+            randomBoolean(),
+            randomBoolean()
+        );
+        indexOperations(nrtEngine, operations);
+        // wipe the nrt directory initially so we can sync with primary.
+        cleanAndCopySegmentsFromPrimary(nrtEngine);
+        final Optional<String> toDelete = Set.of(nrtEngineStore.directory().listAll()).stream().filter(f -> f.endsWith(".si")).findAny();
+        assertTrue(toDelete.isPresent());
+        nrtEngineStore.directory().deleteFile(toDelete.get());
+        assertThrows(FlushFailedEngineException.class, nrtEngine::flush);
+        nrtEngine.close();
+        if (nrtEngineStore.isMarkedCorrupted()) {
+            assertThrows(RuntimeException.class, nrtEngineStore::close);
+        } else {
+            // With certain mock directories a NoSuchFileException is thrown which is not treated as a
+            // corruption Exception. In these cases we don't expect any issue on store close.
+            nrtEngineStore.close();
+        }
+    }
+
     private void copySegments(Collection<String> latestPrimaryFiles, Engine nrtEngine) throws IOException {
         final Store store = nrtEngine.store;
         final List<String> replicaFiles = List.of(store.directory().listAll());
diff --git a/server/src/test/java/org/opensearch/index/fielddata/AbstractFieldDataImplTestCase.java b/server/src/test/java/org/opensearch/index/fielddata/AbstractFieldDataImplTestCase.java
index 1ffacf98a6836..2b44e759f4ff9 100644
--- a/server/src/test/java/org/opensearch/index/fielddata/AbstractFieldDataImplTestCase.java
+++ b/server/src/test/java/org/opensearch/index/fielddata/AbstractFieldDataImplTestCase.java
@@ -39,6 +39,7 @@
 import org.apache.lucene.search.MatchAllDocsQuery;
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.SortField;
+import org.apache.lucene.search.SortedNumericSortField;
 import org.apache.lucene.search.TopFieldDocs;
 import org.apache.lucene.util.BytesRef;
 import org.opensearch.core.common.Strings;
@@ -144,6 +145,27 @@ public void testSingleValueAllSet() throws Exception {
         }
     }
 
+    public void testWideSortField() throws Exception {
+        if (this instanceof NoOrdinalsStringFieldDataTests || this instanceof PagedBytesStringFieldDataTests) {
+            return; // Numeric types are not supported there.
+        }
+        // integer to long widening should happen
+        IndexFieldData<?> indexFieldData = getForField("int", "value");
+        SortField sortField = indexFieldData.wideSortField(null, MultiValueMode.MIN, null, false);
+        assertTrue(((SortedNumericSortField) sortField).getNumericType() == SortField.Type.LONG);
+
+        // long to long no widening should happen
+        indexFieldData = getForField("long", "value");
+        sortField = indexFieldData.wideSortField(null, MultiValueMode.MIN, null, false);
+        assertTrue(((SortedNumericSortField) sortField).getNumericType() == SortField.Type.LONG);
+
+        // float to float no widening should happen
+        indexFieldData = getForField("float", "value");
+        sortField = indexFieldData.wideSortField(null, MultiValueMode.MIN, null, false);
+        assertTrue(((SortedNumericSortField) sortField).getNumericType() == SortField.Type.FLOAT);
+
+    }
+
     protected abstract void fillSingleValueWithMissing() throws Exception;
 
     public void assertValues(SortedBinaryDocValues values, int docId, BytesRef... actualValues) throws IOException {
diff --git a/server/src/test/java/org/opensearch/index/mapper/DateFieldMapperTests.java b/server/src/test/java/org/opensearch/index/mapper/DateFieldMapperTests.java
index 2afd6773b15d4..054d3956596af 100644
--- a/server/src/test/java/org/opensearch/index/mapper/DateFieldMapperTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/DateFieldMapperTests.java
@@ -66,6 +66,7 @@ protected void registerParameters(ParameterChecker checker) throws IOException {
         checker.registerConflictCheck("index", b -> b.field("index", false));
         checker.registerConflictCheck("store", b -> b.field("store", true));
         checker.registerConflictCheck("format", b -> b.field("format", "yyyy-MM-dd"));
+        checker.registerConflictCheck("print_format", b -> b.field("print_format", "yyyy-MM-dd"));
         checker.registerConflictCheck("locale", b -> b.field("locale", "es"));
         checker.registerConflictCheck("null_value", b -> b.field("null_value", "34500000"));
         checker.registerUpdateCheck(b -> b.field("ignore_malformed", true), m -> assertTrue(((DateFieldMapper) m).getIgnoreMalformed()));
@@ -148,7 +149,7 @@ public void testStore() throws Exception {
     public void testIgnoreMalformed() throws IOException {
         testIgnoreMalformedForValue(
             "2016-03-99",
-            "failed to parse date field [2016-03-99] with format [strict_date_optional_time||epoch_millis]"
+            "failed to parse date field [2016-03-99] with format [strict_date_time_no_millis||strict_date_optional_time||epoch_millis]"
         );
         testIgnoreMalformedForValue("-2147483648", "Invalid value for Year (valid values -999999999 - 999999999): -2147483648");
         testIgnoreMalformedForValue("-522000000", "long overflow");
diff --git a/server/src/test/java/org/opensearch/index/mapper/DateFieldTypeTests.java b/server/src/test/java/org/opensearch/index/mapper/DateFieldTypeTests.java
index 37d4a53f36878..ab53ae81ab0ce 100644
--- a/server/src/test/java/org/opensearch/index/mapper/DateFieldTypeTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/DateFieldTypeTests.java
@@ -107,7 +107,7 @@ public void isFieldWithinRangeTestCase(DateFieldType ft) throws IOException {
         w.addDocument(doc);
         DirectoryReader reader = DirectoryReader.open(w);
 
-        DateMathParser alternateFormat = DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.toDateMathParser();
+        DateMathParser alternateFormat = DateFieldMapper.getDefaultDateTimeFormatter().toDateMathParser();
         doTestIsFieldWithinQuery(ft, reader, null, null);
         doTestIsFieldWithinQuery(ft, reader, null, alternateFormat);
         doTestIsFieldWithinQuery(ft, reader, DateTimeZone.UTC, null);
@@ -158,7 +158,7 @@ private void doTestIsFieldWithinQuery(DateFieldType ft, DirectoryReader reader,
 
     public void testValueFormat() {
         MappedFieldType ft = new DateFieldType("field");
-        long instant = DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse("2015-10-12T14:10:55"))
+        long instant = DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse("2015-10-12T14:10:55"))
             .toInstant()
             .toEpochMilli();
 
@@ -167,14 +167,14 @@ public void testValueFormat() {
         assertEquals("2015", new DateFieldType("field").docValueFormat("YYYY", ZoneOffset.UTC).format(instant));
         assertEquals(instant, ft.docValueFormat(null, ZoneOffset.UTC).parseLong("2015-10-12T14:10:55", false, null));
         assertEquals(instant + 999, ft.docValueFormat(null, ZoneOffset.UTC).parseLong("2015-10-12T14:10:55", true, null));
-        long i = DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse("2015-10-13")).toInstant().toEpochMilli();
+        long i = DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse("2015-10-13")).toInstant().toEpochMilli();
         assertEquals(i - 1, ft.docValueFormat(null, ZoneOffset.UTC).parseLong("2015-10-12||/d", true, null));
     }
 
     public void testValueForSearch() {
         MappedFieldType ft = new DateFieldType("field");
         String date = "2015-10-12T12:09:55.000Z";
-        long instant = DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parseMillis(date);
+        long instant = DateFieldMapper.getDefaultDateTimeFormatter().parseMillis(date);
         assertEquals(date, ft.valueForDisplay(instant));
     }
 
@@ -205,7 +205,7 @@ public void testTermQuery() {
         );
         MappedFieldType ft = new DateFieldType("field");
         String date = "2015-10-12T14:10:55";
-        long instant = DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(date)).toInstant().toEpochMilli();
+        long instant = DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(date)).toInstant().toEpochMilli();
         Query expected = new IndexOrDocValuesQuery(
             LongPoint.newRangeQuery("field", instant, instant + 999),
             SortedNumericDocValuesField.newSlowRangeQuery("field", instant, instant + 999)
@@ -217,7 +217,7 @@ public void testTermQuery() {
             false,
             false,
             true,
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             Resolution.MILLISECONDS,
             null,
             Collections.emptyMap()
@@ -254,8 +254,8 @@ public void testRangeQuery() throws IOException {
         MappedFieldType ft = new DateFieldType("field");
         String date1 = "2015-10-12T14:10:55";
         String date2 = "2016-04-28T11:33:52";
-        long instant1 = DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(date1)).toInstant().toEpochMilli();
-        long instant2 = DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(date2)).toInstant().toEpochMilli() + 999;
+        long instant1 = DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(date1)).toInstant().toEpochMilli();
+        long instant2 = DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(date2)).toInstant().toEpochMilli() + 999;
         Query expected = new IndexOrDocValuesQuery(
             LongPoint.newRangeQuery("field", instant1, instant2),
             SortedNumericDocValuesField.newSlowRangeQuery("field", instant1, instant2)
@@ -280,7 +280,7 @@ public void testRangeQuery() throws IOException {
             false,
             false,
             true,
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             Resolution.MILLISECONDS,
             null,
             Collections.emptyMap()
@@ -326,8 +326,8 @@ public void testRangeQueryWithIndexSort() {
         MappedFieldType ft = new DateFieldType("field");
         String date1 = "2015-10-12T14:10:55";
         String date2 = "2016-04-28T11:33:52";
-        long instant1 = DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(date1)).toInstant().toEpochMilli();
-        long instant2 = DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(date2)).toInstant().toEpochMilli() + 999;
+        long instant1 = DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(date1)).toInstant().toEpochMilli();
+        long instant2 = DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(date2)).toInstant().toEpochMilli() + 999;
 
         Query pointQuery = LongPoint.newRangeQuery("field", instant1, instant2);
         Query dvQuery = SortedNumericDocValuesField.newSlowRangeQuery("field", instant1, instant2);
diff --git a/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java b/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java
index 0d8ef6784a28c..393c448330142 100644
--- a/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java
@@ -44,13 +44,17 @@
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.DocValuesFieldExistsQuery;
 import org.apache.lucene.search.FuzzyQuery;
+import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.MultiTermQuery;
 import org.apache.lucene.search.NormsFieldExistsQuery;
+import org.apache.lucene.search.Query;
 import org.apache.lucene.search.RegexpQuery;
 import org.apache.lucene.search.TermInSetQuery;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.TermRangeQuery;
+import org.apache.lucene.search.WildcardQuery;
 import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.automaton.Operations;
 import org.opensearch.OpenSearchException;
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.IndexMetadata;
@@ -128,14 +132,29 @@ public void testTermsQuery() {
         List<BytesRef> terms = new ArrayList<>();
         terms.add(new BytesRef("foo"));
         terms.add(new BytesRef("bar"));
-        assertEquals(new TermInSetQuery("field", terms), ft.termsQuery(Arrays.asList("foo", "bar"), null));
+        Query expected = new IndexOrDocValuesQuery(
+            new TermInSetQuery("field", terms),
+            new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, "field", terms)
+        );
+        assertEquals(expected, ft.termsQuery(Arrays.asList("foo", "bar"), null));
 
-        MappedFieldType unsearchable = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        Query expectedIndex = new TermInSetQuery("field", terms);
+        assertEquals(expectedIndex, onlyIndexed.termsQuery(Arrays.asList("foo", "bar"), null));
+
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        Query expectedDocValues = new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, "field", terms);
+        assertEquals(expectedDocValues, onlyDocValues.termsQuery(Arrays.asList("foo", "bar"), null));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
         IllegalArgumentException e = expectThrows(
             IllegalArgumentException.class,
             () -> unsearchable.termsQuery(Arrays.asList("foo", "bar"), null)
         );
-        assertEquals("Cannot search on field [field] since it is not indexed.", e.getMessage());
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
+        );
     }
 
     public void testExistsQuery() {
@@ -157,9 +176,36 @@ public void testExistsQuery() {
 
     public void testRangeQuery() {
         MappedFieldType ft = new KeywordFieldType("field");
+
+        Query indexExpected = new TermRangeQuery("field", BytesRefs.toBytesRef("foo"), BytesRefs.toBytesRef("bar"), true, false);
+        Query dvExpected = new TermRangeQuery(
+            "field",
+            BytesRefs.toBytesRef("foo"),
+            BytesRefs.toBytesRef("bar"),
+            true,
+            false,
+            MultiTermQuery.DOC_VALUES_REWRITE
+        );
+
+        Query expected = new IndexOrDocValuesQuery(indexExpected, dvExpected);
+        Query actual = ft.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC);
+        assertEquals(expected, actual);
+
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC));
+
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(dvExpected, onlyDocValues.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
+        IllegalArgumentException e = expectThrows(
+            IllegalArgumentException.class,
+            () -> unsearchable.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC)
+        );
+
         assertEquals(
-            new TermRangeQuery("field", BytesRefs.toBytesRef("foo"), BytesRefs.toBytesRef("bar"), true, false),
-            ft.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC)
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
         );
 
         OpenSearchException ee = expectThrows(
@@ -175,16 +221,37 @@ public void testRangeQuery() {
     public void testRegexpQuery() {
         MappedFieldType ft = new KeywordFieldType("field");
         assertEquals(
-            new RegexpQuery(new Term("field", "foo.*")),
+            new IndexOrDocValuesQuery(
+                new RegexpQuery(new Term("field", "foo.*")),
+                new RegexpQuery(new Term("field", "foo.*"), 0, 0, RegexpQuery.DEFAULT_PROVIDER, 10, MultiTermQuery.DOC_VALUES_REWRITE)
+            ),
             ft.regexpQuery("foo.*", 0, 0, 10, MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC)
         );
 
-        MappedFieldType unsearchable = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        Query indexExpected = new RegexpQuery(new Term("field", "foo.*"));
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.regexpQuery("foo.*", 0, 0, 10, MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC));
+
+        Query dvExpected = new RegexpQuery(
+            new Term("field", "foo.*"),
+            0,
+            0,
+            RegexpQuery.DEFAULT_PROVIDER,
+            10,
+            MultiTermQuery.DOC_VALUES_REWRITE
+        );
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(dvExpected, onlyDocValues.regexpQuery("foo.*", 0, 0, 10, MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
         IllegalArgumentException e = expectThrows(
             IllegalArgumentException.class,
             () -> unsearchable.regexpQuery("foo.*", 0, 0, 10, null, MOCK_QSC)
         );
-        assertEquals("Cannot search on field [field] since it is not indexed.", e.getMessage());
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
+        );
 
         OpenSearchException ee = expectThrows(
             OpenSearchException.class,
@@ -200,12 +267,26 @@ public void testFuzzyQuery() {
             ft.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MOCK_QSC)
         );
 
-        MappedFieldType unsearchable = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        Query indexExpected = new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true);
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MOCK_QSC));
+
+        Query dvExpected = new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true, MultiTermQuery.DOC_VALUES_REWRITE);
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(
+            dvExpected,
+            onlyDocValues.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC)
+        );
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
         IllegalArgumentException e = expectThrows(
             IllegalArgumentException.class,
-            () -> unsearchable.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MOCK_QSC)
+            () -> unsearchable.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC)
+        );
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
         );
-        assertEquals("Cannot search on field [field] since it is not indexed.", e.getMessage());
 
         OpenSearchException ee = expectThrows(
             OpenSearchException.class,
@@ -214,6 +295,47 @@ public void testFuzzyQuery() {
         assertEquals("[fuzzy] queries cannot be executed when 'search.allow_expensive_queries' is set to false.", ee.getMessage());
     }
 
+    public void testWildCardQuery() {
+        MappedFieldType ft = new KeywordFieldType("field");
+        Query expected = new IndexOrDocValuesQuery(
+            new WildcardQuery(new Term("field", new BytesRef("foo*"))),
+            new WildcardQuery(
+                new Term("field", new BytesRef("foo*")),
+                Operations.DEFAULT_DETERMINIZE_WORK_LIMIT,
+                MultiTermQuery.DOC_VALUES_REWRITE
+            )
+        );
+        assertEquals(expected, ft.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC));
+
+        Query indexExpected = new WildcardQuery(new Term("field", new BytesRef("foo*")));
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC));
+
+        Query dvExpected = new WildcardQuery(
+            new Term("field", new BytesRef("foo*")),
+            Operations.DEFAULT_DETERMINIZE_WORK_LIMIT,
+            MultiTermQuery.DOC_VALUES_REWRITE
+        );
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(dvExpected, onlyDocValues.wildcardQuery("foo*", MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
+        IllegalArgumentException e = expectThrows(
+            IllegalArgumentException.class,
+            () -> unsearchable.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC)
+        );
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
+        );
+
+        OpenSearchException ee = expectThrows(
+            OpenSearchException.class,
+            () -> ft.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC_DISALLOW_EXPENSIVE)
+        );
+        assertEquals("[wildcard] queries cannot be executed when 'search.allow_expensive_queries' is set to false.", ee.getMessage());
+    }
+
     public void testNormalizeQueries() {
         MappedFieldType ft = new KeywordFieldType("field");
         assertEquals(new TermQuery(new Term("field", new BytesRef("FOO"))), ft.termQuery("FOO", null));
diff --git a/server/src/test/java/org/opensearch/index/mapper/NestedObjectMapperTests.java b/server/src/test/java/org/opensearch/index/mapper/NestedObjectMapperTests.java
index f3f682697a930..9a0d34c916f5c 100644
--- a/server/src/test/java/org/opensearch/index/mapper/NestedObjectMapperTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/NestedObjectMapperTests.java
@@ -1097,8 +1097,8 @@ public void testLimitNestedDocsMultipleNestedFields() throws Exception {
 
     @Override
     protected boolean forbidPrivateIndexSettings() {
-        /**
-         * This is needed to force the index version with {@link IndexMetadata.SETTING_INDEX_VERSION_CREATED}.
+        /*
+          This is needed to force the index version with {@link IndexMetadata.SETTING_INDEX_VERSION_CREATED}.
          */
         return false;
     }
diff --git a/server/src/test/java/org/opensearch/index/mapper/RangeFieldMapperTests.java b/server/src/test/java/org/opensearch/index/mapper/RangeFieldMapperTests.java
index 4ebb160c07c8e..331bfb7b2ddf4 100644
--- a/server/src/test/java/org/opensearch/index/mapper/RangeFieldMapperTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/RangeFieldMapperTests.java
@@ -361,7 +361,12 @@ public void testSerializeDefaults() throws Exception {
 
             // if type is date_range we check that the mapper contains the default format and locale
             // otherwise it should not contain a locale or format
-            assertTrue(got, got.contains("\"format\":\"strict_date_optional_time||epoch_millis\"") == type.equals("date_range"));
+            assertTrue(
+                got,
+                got.contains("\"format\":\"strict_date_time_no_millis||strict_date_optional_time||epoch_millis\"") == type.equals(
+                    "date_range"
+                )
+            );
             assertTrue(got, got.contains("\"locale\":" + "\"" + Locale.ROOT + "\"") == type.equals("date_range"));
         }
     }
diff --git a/server/src/test/java/org/opensearch/index/mapper/RangeFieldTypeTests.java b/server/src/test/java/org/opensearch/index/mapper/RangeFieldTypeTests.java
index 668666a53cd7c..755d77c6ae392 100644
--- a/server/src/test/java/org/opensearch/index/mapper/RangeFieldTypeTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/RangeFieldTypeTests.java
@@ -265,7 +265,9 @@ public void testDateRangeQueryUsingMappingFormat() {
         );
         assertThat(
             ex.getMessage(),
-            containsString("failed to parse date field [2016-15-06T15:29:50+08:00] with format [strict_date_optional_time||epoch_millis]")
+            containsString(
+                "failed to parse date field [2016-15-06T15:29:50+08:00] with format [strict_date_time_no_millis||strict_date_optional_time||epoch_millis]"
+            )
         );
 
         // setting mapping format which is compatible with those dates
diff --git a/server/src/test/java/org/opensearch/index/query/BoolQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/BoolQueryBuilderTests.java
index 2160ab6220866..d0f26f3026789 100644
--- a/server/src/test/java/org/opensearch/index/query/BoolQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/BoolQueryBuilderTests.java
@@ -47,10 +47,13 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import static org.opensearch.index.query.QueryBuilders.boolQuery;
 import static org.opensearch.index.query.QueryBuilders.termQuery;
@@ -456,4 +459,26 @@ public void testMustRewrite() throws IOException {
         IllegalStateException e = expectThrows(IllegalStateException.class, () -> boolQuery.toQuery(context));
         assertEquals("Rewrite first", e.getMessage());
     }
+
+    public void testVisit() {
+        BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder();
+        boolQueryBuilder.should(new TermQueryBuilder(TEXT_FIELD_NAME, "should"));
+        boolQueryBuilder.must(new TermQueryBuilder(TEXT_FIELD_NAME, "must1"));
+        boolQueryBuilder.must(new TermQueryBuilder(TEXT_FIELD_NAME, "must2")); // Add a second one to confirm that they both get visited
+        boolQueryBuilder.mustNot(new TermQueryBuilder(TEXT_FIELD_NAME, "mustNot"));
+        boolQueryBuilder.filter(new TermQueryBuilder(TEXT_FIELD_NAME, "filter"));
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        boolQueryBuilder.visit(createTestVisitor(visitedQueries));
+        assertEquals(6, visitedQueries.size());
+        Set<Object> set = new HashSet<>(Arrays.asList("should", "must1", "must2", "mustNot", "filter"));
+
+        for (QueryBuilder qb : visitedQueries) {
+            if (qb instanceof TermQueryBuilder) {
+                set.remove(((TermQueryBuilder) qb).value());
+            }
+        }
+
+        assertEquals(0, set.size());
+
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/BoostingQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/BoostingQueryBuilderTests.java
index 94ded24975be4..66a02a02d4e5b 100644
--- a/server/src/test/java/org/opensearch/index/query/BoostingQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/BoostingQueryBuilderTests.java
@@ -38,6 +38,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.nullValue;
@@ -153,4 +155,16 @@ public void testMustRewrite() throws IOException {
         e = expectThrows(IllegalStateException.class, () -> queryBuilder2.toQuery(context));
         assertEquals("Rewrite first", e.getMessage());
     }
+
+    public void testVisit() {
+        BoostingQueryBuilder builder = new BoostingQueryBuilder(
+            new TermQueryBuilder("unmapped_field", "value"),
+            new TermQueryBuilder(KEYWORD_FIELD_NAME, "other_value")
+        );
+
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        builder.visit(createTestVisitor(visitedQueries));
+
+        assertEquals(3, visitedQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/ConstantScoreQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/ConstantScoreQueryBuilderTests.java
index 2bfe964ce7259..527413d2513d0 100644
--- a/server/src/test/java/org/opensearch/index/query/ConstantScoreQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/ConstantScoreQueryBuilderTests.java
@@ -39,6 +39,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.nullValue;
@@ -133,4 +135,12 @@ public void testMustRewrite() throws IOException {
         IllegalStateException e = expectThrows(IllegalStateException.class, () -> queryBuilder.toQuery(context));
         assertEquals("Rewrite first", e.getMessage());
     }
+
+    public void testVisit() {
+        ConstantScoreQueryBuilder queryBuilder = new ConstantScoreQueryBuilder(new TermQueryBuilder("unmapped_field", "foo"));
+        List<QueryBuilder> visitorQueries = new ArrayList<>();
+        queryBuilder.visit(createTestVisitor(visitorQueries));
+
+        assertEquals(2, visitorQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/DisMaxQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/DisMaxQueryBuilderTests.java
index 8d589bd76f2bb..cb0df38de5c02 100644
--- a/server/src/test/java/org/opensearch/index/query/DisMaxQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/DisMaxQueryBuilderTests.java
@@ -41,6 +41,7 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
@@ -156,4 +157,14 @@ public void testRewriteMultipleTimes() throws IOException {
         assertEquals(rewrittenAgain, expected);
         assertEquals(Rewriteable.rewrite(dismax, createShardContext()), expected);
     }
+
+    public void testVisit() {
+        DisMaxQueryBuilder dismax = new DisMaxQueryBuilder();
+        dismax.add(new WrapperQueryBuilder(new WrapperQueryBuilder(new MatchAllQueryBuilder().toString()).toString()));
+
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        dismax.visit(createTestVisitor(visitedQueries));
+
+        assertEquals(2, visitedQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilderTests.java
index 7e893a0947531..db0a7bf1795ff 100644
--- a/server/src/test/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/FieldMaskingSpanQueryBuilderTests.java
@@ -41,6 +41,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.opensearch.index.query.FieldMaskingSpanQueryBuilder.SPAN_FIELD_MASKING_FIELD;
 import static org.hamcrest.CoreMatchers.equalTo;
@@ -147,4 +149,10 @@ public void testDeprecatedName() throws IOException {
             "Deprecated field [field_masking_span] used, expected [" + SPAN_FIELD_MASKING_FIELD.getPreferredName() + "] instead"
         );
     }
+
+    public void testVisit() {
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        doCreateTestQueryBuilder().visit(createTestVisitor(visitedQueries));
+        assertEquals(2, visitedQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/InnerHitBuilderTests.java b/server/src/test/java/org/opensearch/index/query/InnerHitBuilderTests.java
index 729205c9775b4..7c7598e5dc3c4 100644
--- a/server/src/test/java/org/opensearch/index/query/InnerHitBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/InnerHitBuilderTests.java
@@ -109,7 +109,7 @@ public void testSerialization() throws Exception {
     /**
      * Test that if we serialize and deserialize an object, further
      * serialization leads to identical bytes representation.
-     *
+     * <p>
      * This is necessary to ensure because we use the serialized BytesReference
      * of this builder as part of the cacheKey in
      * {@link ShardSearchRequest} (via
diff --git a/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java
index e1391393f44fa..39f5bb313fe9e 100644
--- a/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java
@@ -304,10 +304,16 @@ public void testToQueryBooleanPrefixMultipleFields() throws IOException {
                 } else if (disjunct instanceof PrefixQuery) {
                     final PrefixQuery secondDisjunct = (PrefixQuery) disjunct;
                     assertThat(secondDisjunct.getPrefix(), equalTo(new Term(KEYWORD_FIELD_NAME, "foo bar")));
+                } else if (disjunct instanceof IndexOrDocValuesQuery) {
+                    final IndexOrDocValuesQuery iodvqDisjunct = (IndexOrDocValuesQuery) disjunct;
+                    assertThat(iodvqDisjunct.getIndexQuery().toString(), equalTo("mapped_string_2:foo bar*"));
                 } else {
                     throw new AssertionError();
                 }
-                assertThat(disjunct, either(instanceOf(BooleanQuery.class)).or(instanceOf(PrefixQuery.class)));
+                assertThat(
+                    disjunct,
+                    either(instanceOf(BooleanQuery.class)).or(instanceOf(PrefixQuery.class)).or(instanceOf(IndexOrDocValuesQuery.class))
+                );
             }
         }
     }
diff --git a/server/src/test/java/org/opensearch/index/query/NestedQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/NestedQueryBuilderTests.java
index 0d66654a70f08..62337264bc0b1 100644
--- a/server/src/test/java/org/opensearch/index/query/NestedQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/NestedQueryBuilderTests.java
@@ -66,6 +66,8 @@
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.notNullValue;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class NestedQueryBuilderTests extends AbstractQueryTestCase<NestedQueryBuilder> {
@@ -411,4 +413,22 @@ public void testDisallowExpensiveQueries() {
         OpenSearchException e = expectThrows(OpenSearchException.class, () -> queryBuilder.toQuery(queryShardContext));
         assertEquals("[joining] queries cannot be executed when 'search.allow_expensive_queries' is set to false.", e.getMessage());
     }
+
+    public void testSetParentFilterInContext() throws Exception {
+        QueryShardContext queryShardContext = createShardContext();
+        QueryBuilder innerQueryBuilder = spy(new MatchAllQueryBuilderTests().createTestQueryBuilder());
+        when(innerQueryBuilder.toQuery(queryShardContext)).thenAnswer(invoke -> {
+            QueryShardContext context = invoke.getArgument(0);
+            if (context.getParentFilter() == null) {
+                throw new Exception("Expect parent filter to be non-null");
+            }
+            return invoke.callRealMethod();
+        });
+        NestedQueryBuilder nqb = new NestedQueryBuilder("nested1", innerQueryBuilder, RandomPicks.randomFrom(random(), ScoreMode.values()));
+
+        assertNull(queryShardContext.getParentFilter());
+        nqb.rewrite(queryShardContext).toQuery(queryShardContext);
+        assertNull(queryShardContext.getParentFilter());
+        verify(innerQueryBuilder).toQuery(queryShardContext);
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/QueryBuilderVisitorTests.java b/server/src/test/java/org/opensearch/index/query/QueryBuilderVisitorTests.java
new file mode 100644
index 0000000000000..7849d3985ca59
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/query/QueryBuilderVisitorTests.java
@@ -0,0 +1,33 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.query;
+
+import org.apache.lucene.search.BooleanClause;
+import org.opensearch.test.AbstractBuilderTestCase;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class QueryBuilderVisitorTests extends AbstractBuilderTestCase {
+
+    public void testNoOpsVisitor() {
+        BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder();
+
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        QueryBuilderVisitor qbv = createTestVisitor(visitedQueries);
+        boolQueryBuilder.visit(qbv);
+        QueryBuilderVisitor subQbv = qbv.getChildVisitor(BooleanClause.Occur.MUST_NOT);
+        assertEquals(0, visitedQueries.size());
+        assertEquals(qbv, subQbv);
+    }
+
+    protected static QueryBuilderVisitor createTestVisitor(List<QueryBuilder> visitedQueries) {
+        return QueryBuilderVisitor.NO_OP_VISITOR;
+    }
+}
diff --git a/server/src/test/java/org/opensearch/index/query/QueryShapeVisitorTests.java b/server/src/test/java/org/opensearch/index/query/QueryShapeVisitorTests.java
new file mode 100644
index 0000000000000..18b814aec61c2
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/query/QueryShapeVisitorTests.java
@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.query;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+import static org.junit.Assert.assertEquals;
+
+public final class QueryShapeVisitorTests extends OpenSearchTestCase {
+    public void testQueryShapeVisitor() {
+        QueryBuilder builder = new BoolQueryBuilder().must(new TermQueryBuilder("foo", "bar"))
+            .filter(new ConstantScoreQueryBuilder(new RangeQueryBuilder("timestamp").from("12345677").to("2345678")))
+            .should(
+                new BoolQueryBuilder().must(new MatchQueryBuilder("text", "this is some text"))
+                    .mustNot(new RegexpQueryBuilder("color", "red.*"))
+            )
+            .must(new TermsQueryBuilder("genre", "action", "drama", "romance"));
+        QueryShapeVisitor shapeVisitor = new QueryShapeVisitor();
+        builder.visit(shapeVisitor);
+        assertEquals(
+            "{\"type\":\"bool\",\"must\"[{\"type\":\"term\"},{\"type\":\"terms\"}],\"filter\"[{\"type\":\"constant_score\",\"filter\"[{\"type\":\"range\"}]}],\"should\"[{\"type\":\"bool\",\"must\"[{\"type\":\"match\"}],\"must_not\"[{\"type\":\"regexp\"}]}]}",
+            shapeVisitor.toJson()
+        );
+    }
+}
diff --git a/server/src/test/java/org/opensearch/index/query/RangeQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/RangeQueryBuilderTests.java
index 50f785bdf4a34..e72be29b85b63 100644
--- a/server/src/test/java/org/opensearch/index/query/RangeQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/RangeQueryBuilderTests.java
@@ -87,8 +87,8 @@ protected RangeQueryBuilder doCreateTestQueryBuilder() {
                 ZonedDateTime start = now.minusMillis(randomIntBetween(0, 1000000)).atZone(ZoneOffset.UTC);
                 ZonedDateTime end = now.plusMillis(randomIntBetween(0, 1000000)).atZone(ZoneOffset.UTC);
                 query = new RangeQueryBuilder(randomFrom(DATE_FIELD_NAME, DATE_RANGE_FIELD_NAME, DATE_ALIAS_FIELD_NAME));
-                query.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.format(start));
-                query.to(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.format(end));
+                query.from(DateFieldMapper.getDefaultDateTimeFormatter().format(start));
+                query.to(DateFieldMapper.getDefaultDateTimeFormatter().format(end));
                 // Create timestamp option only then we have a date mapper,
                 // otherwise we could trigger exception.
                 if (createShardContext().getMapperService().fieldType(DATE_FIELD_NAME) != null) {
diff --git a/server/src/test/java/org/opensearch/index/query/ScriptScoreQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/ScriptScoreQueryBuilderTests.java
index 320ff20b2ef5d..29d45fb42ffcc 100644
--- a/server/src/test/java/org/opensearch/index/query/ScriptScoreQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/ScriptScoreQueryBuilderTests.java
@@ -43,7 +43,9 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -140,4 +142,11 @@ public void testDisallowExpensiveQueries() {
         OpenSearchException e = expectThrows(OpenSearchException.class, () -> queryBuilder.toQuery(queryShardContext));
         assertEquals("[script score] queries cannot be executed when 'search.allow_expensive_queries' is set to false.", e.getMessage());
     }
+
+    public void testVisit() {
+        ScriptScoreQueryBuilder scriptQueryBuilder = doCreateTestQueryBuilder();
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        scriptQueryBuilder.visit(createTestVisitor(visitedQueries));
+        assertEquals(2, visitedQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/SpanContainingQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/SpanContainingQueryBuilderTests.java
index fff4369e155b3..2a5441b0ea932 100644
--- a/server/src/test/java/org/opensearch/index/query/SpanContainingQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/SpanContainingQueryBuilderTests.java
@@ -38,6 +38,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -192,4 +194,10 @@ public void testFromJsonWithNonDefaultBoostInLittleQuery() {
             equalTo("span_containing [little] as a nested span clause can't have non-default boost value [2.0]")
         );
     }
+
+    public void testVisit() {
+        List<QueryBuilder> visitorQueries = new ArrayList<>();
+        doCreateTestQueryBuilder().visit(createTestVisitor(visitorQueries));
+        assertEquals(3, visitorQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/SpanFirstQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/SpanFirstQueryBuilderTests.java
index 781d2defcfd37..82bb77726b037 100644
--- a/server/src/test/java/org/opensearch/index/query/SpanFirstQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/SpanFirstQueryBuilderTests.java
@@ -40,6 +40,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.opensearch.index.query.QueryBuilders.spanTermQuery;
 import static org.hamcrest.CoreMatchers.equalTo;
@@ -128,4 +130,10 @@ public void testFromJsonWithNonDefaultBoostInMatchQuery() {
         Exception exception = expectThrows(ParsingException.class, () -> parseQuery(json));
         assertThat(exception.getMessage(), equalTo("span_first [match] as a nested span clause can't have non-default boost value [2.0]"));
     }
+
+    public void testVisit() {
+        List<QueryBuilder> visitorQueries = new ArrayList<>();
+        doCreateTestQueryBuilder().visit(createTestVisitor(visitorQueries));
+        assertEquals(2, visitorQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/SpanMultiTermQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/SpanMultiTermQueryBuilderTests.java
index e20d56c6aff2a..b4abff118802e 100644
--- a/server/src/test/java/org/opensearch/index/query/SpanMultiTermQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/SpanMultiTermQueryBuilderTests.java
@@ -60,6 +60,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static java.util.Collections.singleton;
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
@@ -306,4 +308,12 @@ public void testTopNMultiTermsRewriteInsideSpan() throws Exception {
         }
 
     }
+
+    public void testVisit() {
+        MultiTermQueryBuilder multiTermQueryBuilder = new PrefixQueryBuilderTests().createTestQueryBuilder();
+        SpanMultiTermQueryBuilder spanMultiTermQueryBuilder = new SpanMultiTermQueryBuilder(multiTermQueryBuilder);
+        List<QueryBuilder> visitorQueries = new ArrayList<>();
+        spanMultiTermQueryBuilder.visit(createTestVisitor(visitorQueries));
+        assertEquals(2, visitorQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/SpanNearQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/SpanNearQueryBuilderTests.java
index 8c9130d4b7bbd..c97b541da2199 100644
--- a/server/src/test/java/org/opensearch/index/query/SpanNearQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/SpanNearQueryBuilderTests.java
@@ -41,7 +41,9 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Iterator;
+import java.util.List;
 
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.either;
@@ -231,4 +233,12 @@ public void testFromJsonWithNonDefaultBoostInInnerQuery() {
         Exception exception = expectThrows(ParsingException.class, () -> parseQuery(json));
         assertThat(exception.getMessage(), equalTo("span_near [clauses] as a nested span clause can't have non-default boost value [2.0]"));
     }
+
+    public void testVisit() {
+        SpanTermQueryBuilder[] spanTermQueries = new SpanTermQueryBuilderTests().createSpanTermQueryBuilders(1);
+        SpanNearQueryBuilder spanNearQueryBuilder = new SpanNearQueryBuilder(spanTermQueries[0], 1);
+        List<QueryBuilder> visitorQueries = new ArrayList<>();
+        spanNearQueryBuilder.visit(createTestVisitor(visitorQueries));
+        assertEquals(2, visitorQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/SpanNotQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/SpanNotQueryBuilderTests.java
index b85c7cf81b0e1..ff42b271ffca5 100644
--- a/server/src/test/java/org/opensearch/index/query/SpanNotQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/SpanNotQueryBuilderTests.java
@@ -40,6 +40,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.opensearch.index.query.QueryBuilders.spanNearQuery;
 import static org.opensearch.index.query.QueryBuilders.spanTermQuery;
@@ -316,4 +318,10 @@ public void testFromJsonWithNonDefaultBoostInExcludeQuery() {
         Exception exception = expectThrows(ParsingException.class, () -> parseQuery(json));
         assertThat(exception.getMessage(), equalTo("span_not [exclude] as a nested span clause can't have non-default boost value [2.0]"));
     }
+
+    public void testVisit() {
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        doCreateTestQueryBuilder().visit(createTestVisitor(visitedQueries));
+        assertEquals(3, visitedQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/SpanOrQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/SpanOrQueryBuilderTests.java
index 45323b5df74df..eb4b8fd486cb0 100644
--- a/server/src/test/java/org/opensearch/index/query/SpanOrQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/SpanOrQueryBuilderTests.java
@@ -39,7 +39,9 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Iterator;
+import java.util.List;
 
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -137,4 +139,12 @@ public void testFromJsonWithNonDefaultBoostInInnerQuery() {
         Exception exception = expectThrows(ParsingException.class, () -> parseQuery(json));
         assertThat(exception.getMessage(), equalTo("span_or [clauses] as a nested span clause can't have non-default boost value [2.0]"));
     }
+
+    public void testVisit() {
+        SpanTermQueryBuilder spanTermQueryBuilder = new SpanTermQueryBuilder("demo", "demo");
+        SpanOrQueryBuilder spanOrQueryBuilder = new SpanOrQueryBuilder(spanTermQueryBuilder);
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        spanOrQueryBuilder.visit(createTestVisitor(visitedQueries));
+        assertEquals(2, visitedQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/query/SpanWithinQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/SpanWithinQueryBuilderTests.java
index e8b6a21254ff8..74b955e872d51 100644
--- a/server/src/test/java/org/opensearch/index/query/SpanWithinQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/SpanWithinQueryBuilderTests.java
@@ -38,6 +38,8 @@
 import org.opensearch.test.AbstractQueryTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -189,4 +191,10 @@ public void testFromJsonWithNonDefaultBoostInLittleQuery() {
             equalTo("span_within [little] as a nested span clause can't have non-default boost value [2.0]")
         );
     }
+
+    public void testVisit() {
+        List<QueryBuilder> visitedQueries = new ArrayList<>();
+        doCreateTestQueryBuilder().visit(createTestVisitor(visitedQueries));
+        assertEquals(3, visitedQueries.size());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/remote/RemoteSegmentTransferTrackerTests.java b/server/src/test/java/org/opensearch/index/remote/RemoteSegmentTransferTrackerTests.java
index 0bf00f9e48137..c87cdfcc8f1a1 100644
--- a/server/src/test/java/org/opensearch/index/remote/RemoteSegmentTransferTrackerTests.java
+++ b/server/src/test/java/org/opensearch/index/remote/RemoteSegmentTransferTrackerTests.java
@@ -23,6 +23,8 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static org.opensearch.index.remote.RemoteSegmentTransferTracker.currentTimeMsUsingSystemNanos;
+
 public class RemoteSegmentTransferTrackerTests extends OpenSearchTestCase {
     private RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory;
     private ClusterService clusterService;
@@ -92,7 +94,7 @@ public void testUpdateLocalRefreshTimeMs() {
             directoryFileTransferTracker,
             remoteStoreStatsTrackerFactory.getMovingAverageWindowSize()
         );
-        long refreshTimeMs = System.nanoTime() / 1_000_000L + randomIntBetween(10, 100);
+        long refreshTimeMs = currentTimeMsUsingSystemNanos() + randomIntBetween(10, 100);
         transferTracker.updateLocalRefreshTimeMs(refreshTimeMs);
         assertEquals(refreshTimeMs, transferTracker.getLocalRefreshTimeMs());
     }
@@ -103,7 +105,7 @@ public void testUpdateRemoteRefreshTimeMs() {
             directoryFileTransferTracker,
             remoteStoreStatsTrackerFactory.getMovingAverageWindowSize()
         );
-        long refreshTimeMs = System.nanoTime() / 1_000_000 + randomIntBetween(10, 100);
+        long refreshTimeMs = currentTimeMsUsingSystemNanos() + randomIntBetween(10, 100);
         transferTracker.updateRemoteRefreshTimeMs(refreshTimeMs);
         assertEquals(refreshTimeMs, transferTracker.getRemoteRefreshTimeMs());
     }
@@ -133,20 +135,29 @@ public void testComputeSeqNoLagOnUpdate() {
         assertEquals(localRefreshSeqNo - remoteRefreshSeqNo, transferTracker.getRefreshSeqNoLag());
     }
 
-    public void testComputeTimeLagOnUpdate() {
+    public void testComputeTimeLagOnUpdate() throws InterruptedException {
         transferTracker = new RemoteSegmentTransferTracker(
             shardId,
             directoryFileTransferTracker,
             remoteStoreStatsTrackerFactory.getMovingAverageWindowSize()
         );
-        long currentLocalRefreshTimeMs = transferTracker.getLocalRefreshTimeMs();
-        long currentTimeMs = System.nanoTime() / 1_000_000L;
-        long localRefreshTimeMs = currentTimeMs + randomIntBetween(100, 500);
-        long remoteRefreshTimeMs = currentTimeMs + randomIntBetween(50, 99);
-        transferTracker.updateLocalRefreshTimeMs(localRefreshTimeMs);
-        assertEquals(localRefreshTimeMs - currentLocalRefreshTimeMs, transferTracker.getTimeMsLag());
-        transferTracker.updateRemoteRefreshTimeMs(remoteRefreshTimeMs);
-        assertEquals(localRefreshTimeMs - remoteRefreshTimeMs, transferTracker.getTimeMsLag());
+
+        // No lag if there is a remote upload corresponding to a local refresh
+        assertEquals(0, transferTracker.getTimeMsLag());
+
+        // Set a local refresh time that is higher than remote refresh time
+        Thread.sleep(1);
+        transferTracker.updateLocalRefreshTimeMs(currentTimeMsUsingSystemNanos());
+
+        // Sleep for 100ms and then the lag should be within 100ms +/- 20ms
+        Thread.sleep(100);
+        assertTrue(Math.abs(transferTracker.getTimeMsLag() - 100) <= 20);
+
+        transferTracker.updateRemoteRefreshTimeMs(transferTracker.getLocalRefreshTimeMs());
+        transferTracker.updateLocalRefreshTimeMs(currentTimeMsUsingSystemNanos());
+        long random = randomIntBetween(50, 200);
+        Thread.sleep(random);
+        assertTrue(Math.abs(transferTracker.getTimeMsLag() - random) <= 20);
     }
 
     public void testAddUploadBytesStarted() {
@@ -519,7 +530,7 @@ public void testStatsObjectCreation() {
         transferTracker = constructTracker();
         RemoteSegmentTransferTracker.Stats transferTrackerStats = transferTracker.stats();
         assertEquals(transferTracker.getShardId(), transferTrackerStats.shardId);
-        assertEquals(transferTracker.getTimeMsLag(), (int) transferTrackerStats.refreshTimeLagMs);
+        assertTrue(Math.abs(transferTracker.getTimeMsLag() - transferTrackerStats.refreshTimeLagMs) <= 20);
         assertEquals(transferTracker.getLocalRefreshSeqNo(), (int) transferTrackerStats.localRefreshNumber);
         assertEquals(transferTracker.getRemoteRefreshSeqNo(), (int) transferTrackerStats.remoteRefreshNumber);
         assertEquals(transferTracker.getBytesLag(), (int) transferTrackerStats.bytesLag);
@@ -591,9 +602,9 @@ private RemoteSegmentTransferTracker constructTracker() {
         );
         transferTracker.incrementTotalUploadsStarted();
         transferTracker.incrementTotalUploadsFailed();
-        transferTracker.updateUploadTimeMovingAverage(System.nanoTime() / 1_000_000L + randomIntBetween(10, 100));
+        transferTracker.updateUploadTimeMovingAverage(currentTimeMsUsingSystemNanos() + randomIntBetween(10, 100));
         transferTracker.updateUploadBytesMovingAverage(99);
-        transferTracker.updateRemoteRefreshTimeMs(System.nanoTime() / 1_000_000L + randomIntBetween(10, 100));
+        transferTracker.updateRemoteRefreshTimeMs(currentTimeMsUsingSystemNanos() + randomIntBetween(10, 100));
         transferTracker.incrementRejectionCount();
         transferTracker.getDirectoryFileTransferTracker().addTransferredBytesStarted(10);
         transferTracker.getDirectoryFileTransferTracker().addTransferredBytesSucceeded(10, System.currentTimeMillis());
diff --git a/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureServiceTests.java b/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureServiceTests.java
index ada8d9983aa3d..cb77174e612fd 100644
--- a/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureServiceTests.java
+++ b/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureServiceTests.java
@@ -21,8 +21,11 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import java.util.stream.IntStream;
 
+import static org.opensearch.index.remote.RemoteSegmentTransferTracker.currentTimeMsUsingSystemNanos;
 import static org.opensearch.index.remote.RemoteStoreTestsHelper.createIndexShard;
 
 public class RemoteStorePressureServiceTests extends OpenSearchTestCase {
@@ -58,7 +61,7 @@ public void tearDown() throws Exception {
     public void testIsSegmentsUploadBackpressureEnabled() {
         remoteStoreStatsTrackerFactory = new RemoteStoreStatsTrackerFactory(clusterService, Settings.EMPTY);
         pressureService = new RemoteStorePressureService(clusterService, Settings.EMPTY, remoteStoreStatsTrackerFactory);
-        assertFalse(pressureService.isSegmentsUploadBackpressureEnabled());
+        assertTrue(pressureService.isSegmentsUploadBackpressureEnabled());
 
         Settings newSettings = Settings.builder()
             .put(RemoteStorePressureSettings.REMOTE_REFRESH_SEGMENT_PRESSURE_ENABLED.getKey(), "true")
@@ -68,7 +71,7 @@ public void testIsSegmentsUploadBackpressureEnabled() {
         assertTrue(pressureService.isSegmentsUploadBackpressureEnabled());
     }
 
-    public void testValidateSegmentUploadLag() {
+    public void testValidateSegmentUploadLag() throws InterruptedException {
         // Create the pressure tracker
         IndexShard indexShard = createIndexShard(shardId, true);
         remoteStoreStatsTrackerFactory = new RemoteStoreStatsTrackerFactory(clusterService, Settings.EMPTY);
@@ -86,14 +89,27 @@ public void testValidateSegmentUploadLag() {
             sum.addAndGet(i);
         });
         double avg = (double) sum.get() / 20;
-        long currentMs = System.nanoTime() / 1_000_000;
-        pressureTracker.updateLocalRefreshTimeMs((long) (currentMs + 12 * avg));
-        pressureTracker.updateRemoteRefreshTimeMs(currentMs);
-        Exception e = assertThrows(OpenSearchRejectedExecutionException.class, () -> pressureService.validateSegmentsUploadLag(shardId));
-        assertTrue(e.getMessage().contains("due to remote segments lagging behind local segments"));
-        assertTrue(e.getMessage().contains("time_lag:114 ms dynamic_time_lag_threshold:95.0 ms"));
 
-        pressureTracker.updateRemoteRefreshTimeMs((long) (currentMs + 2 * avg));
+        // We run this to ensure that the local and remote refresh time are not same anymore
+        while (pressureTracker.getLocalRefreshTimeMs() == currentTimeMsUsingSystemNanos()) {
+            Thread.sleep(10);
+        }
+        long localRefreshTimeMs = currentTimeMsUsingSystemNanos();
+        pressureTracker.updateLocalRefreshTimeMs(localRefreshTimeMs);
+
+        while (currentTimeMsUsingSystemNanos() - localRefreshTimeMs <= 20 * avg) {
+            Thread.sleep((long) (4 * avg));
+        }
+        Exception e = assertThrows(OpenSearchRejectedExecutionException.class, () -> pressureService.validateSegmentsUploadLag(shardId));
+        String regex = "^rejected execution on primary shard:\\[index]\\[0] due to remote segments lagging behind "
+            + "local segments.time_lag:[0-9]{2,3} ms dynamic_time_lag_threshold:95\\.0 ms$";
+        Pattern pattern = Pattern.compile(regex);
+        Matcher matcher = pattern.matcher(e.getMessage());
+        assertTrue(matcher.matches());
+
+        pressureTracker.updateRemoteRefreshTimeMs(pressureTracker.getLocalRefreshTimeMs());
+        pressureTracker.updateLocalRefreshTimeMs(currentTimeMsUsingSystemNanos());
+        Thread.sleep((long) (2 * avg));
         pressureService.validateSegmentsUploadLag(shardId);
 
         // 2. bytes lag more than dynamic threshold
diff --git a/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureSettingsTests.java b/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureSettingsTests.java
index f5514b8936a2f..064c6c10eba02 100644
--- a/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureSettingsTests.java
+++ b/server/src/test/java/org/opensearch/index/remote/RemoteStorePressureSettingsTests.java
@@ -48,7 +48,7 @@ public void testGetDefaultSettings() {
         );
 
         // Check remote refresh segment pressure enabled is false
-        assertFalse(pressureSettings.isRemoteRefreshSegmentPressureEnabled());
+        assertTrue(pressureSettings.isRemoteRefreshSegmentPressureEnabled());
 
         // Check bytes lag variance threshold default value
         assertEquals(10.0, pressureSettings.getBytesLagVarianceFactor(), 0.0d);
diff --git a/server/src/test/java/org/opensearch/index/remote/RemoteStoreUtilsTests.java b/server/src/test/java/org/opensearch/index/remote/RemoteStoreUtilsTests.java
index 9afa75dd601b2..d3c7d754d6b61 100644
--- a/server/src/test/java/org/opensearch/index/remote/RemoteStoreUtilsTests.java
+++ b/server/src/test/java/org/opensearch/index/remote/RemoteStoreUtilsTests.java
@@ -8,10 +8,85 @@
 
 package org.opensearch.index.remote;
 
+import org.opensearch.common.blobstore.BlobMetadata;
+import org.opensearch.common.blobstore.support.PlainBlobMetadata;
+import org.opensearch.index.store.RemoteSegmentStoreDirectory;
+import org.opensearch.index.translog.transfer.TranslogTransferMetadata;
 import org.opensearch.test.OpenSearchTestCase;
 
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.opensearch.index.remote.RemoteStoreUtils.verifyNoMultipleWriters;
+import static org.opensearch.index.store.RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX;
+import static org.opensearch.index.store.RemoteSegmentStoreDirectory.MetadataFilenameUtils.SEPARATOR;
+import static org.opensearch.index.translog.transfer.TranslogTransferMetadata.METADATA_SEPARATOR;
+
 public class RemoteStoreUtilsTests extends OpenSearchTestCase {
 
+    private final String metadataFilename = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        12,
+        23,
+        34,
+        1,
+        1,
+        "node-1"
+    );
+
+    private final String metadataFilenameDup = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        12,
+        23,
+        34,
+        2,
+        1,
+        "node-2"
+    );
+    private final String metadataFilename2 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        12,
+        13,
+        34,
+        1,
+        1,
+        "node-1"
+    );
+
+    private final String oldMetadataFilename = getOldSegmentMetadataFilename(12, 23, 34, 1, 1);
+
+    /*
+    Gives segment metadata filename for <2.11 version
+     */
+    public static String getOldSegmentMetadataFilename(
+        long primaryTerm,
+        long generation,
+        long translogGeneration,
+        long uploadCounter,
+        int metadataVersion
+    ) {
+        return String.join(
+            SEPARATOR,
+            METADATA_PREFIX,
+            RemoteStoreUtils.invertLong(primaryTerm),
+            RemoteStoreUtils.invertLong(generation),
+            RemoteStoreUtils.invertLong(translogGeneration),
+            RemoteStoreUtils.invertLong(uploadCounter),
+            RemoteStoreUtils.invertLong(System.currentTimeMillis()),
+            String.valueOf(metadataVersion)
+        );
+    }
+
+    public static String getOldTranslogMetadataFilename(long primaryTerm, long generation, int metadataVersion) {
+        return String.join(
+            METADATA_SEPARATOR,
+            METADATA_PREFIX,
+            RemoteStoreUtils.invertLong(primaryTerm),
+            RemoteStoreUtils.invertLong(generation),
+            RemoteStoreUtils.invertLong(System.currentTimeMillis()),
+            String.valueOf(metadataVersion)
+        );
+    }
+
     public void testInvertToStrInvalid() {
         assertThrows(IllegalArgumentException.class, () -> RemoteStoreUtils.invertLong(-1));
     }
@@ -60,4 +135,48 @@ public void testGetSegmentNameUnderscoreDelimiterOverrides() {
     public void testGetSegmentNameException() {
         assertThrows(IllegalArgumentException.class, () -> RemoteStoreUtils.getSegmentName("dvd"));
     }
+
+    public void testVerifyMultipleWriters_Segment() {
+        List<String> mdFiles = new ArrayList<>();
+        mdFiles.add(metadataFilename);
+        mdFiles.add(metadataFilename2);
+        mdFiles.add(oldMetadataFilename);
+        verifyNoMultipleWriters(mdFiles, RemoteSegmentStoreDirectory.MetadataFilenameUtils::getNodeIdByPrimaryTermAndGen);
+
+        mdFiles.add(metadataFilenameDup);
+        assertThrows(
+            IllegalStateException.class,
+            () -> verifyNoMultipleWriters(mdFiles, RemoteSegmentStoreDirectory.MetadataFilenameUtils::getNodeIdByPrimaryTermAndGen)
+        );
+    }
+
+    public void testVerifyMultipleWriters_Translog() throws InterruptedException {
+        TranslogTransferMetadata tm = new TranslogTransferMetadata(1, 1, 1, 2, "node--1");
+        String mdFilename = tm.getFileName();
+        Thread.sleep(1);
+        TranslogTransferMetadata tm2 = new TranslogTransferMetadata(1, 1, 1, 2, "node--1");
+        String mdFilename2 = tm2.getFileName();
+        List<BlobMetadata> bmList = new LinkedList<>();
+        bmList.add(new PlainBlobMetadata(mdFilename, 1));
+        bmList.add(new PlainBlobMetadata(mdFilename2, 1));
+        bmList.add(new PlainBlobMetadata(getOldTranslogMetadataFilename(1, 1, 1), 1));
+        RemoteStoreUtils.verifyNoMultipleWriters(
+            bmList.stream().map(BlobMetadata::name).collect(Collectors.toList()),
+            TranslogTransferMetadata::getNodeIdByPrimaryTermAndGen
+        );
+
+        bmList = new LinkedList<>();
+        bmList.add(new PlainBlobMetadata(mdFilename, 1));
+        TranslogTransferMetadata tm3 = new TranslogTransferMetadata(1, 1, 1, 2, "node--2");
+        bmList.add(new PlainBlobMetadata(tm3.getFileName(), 1));
+        List<BlobMetadata> finalBmList = bmList;
+        assertThrows(
+            IllegalStateException.class,
+            () -> RemoteStoreUtils.verifyNoMultipleWriters(
+                finalBmList.stream().map(BlobMetadata::name).collect(Collectors.toList()),
+                TranslogTransferMetadata::getNodeIdByPrimaryTermAndGen
+            )
+        );
+    }
+
 }
diff --git a/server/src/test/java/org/opensearch/index/search/stats/SearchStatsTests.java b/server/src/test/java/org/opensearch/index/search/stats/SearchStatsTests.java
index f65b0e231b1dd..52b272094cd86 100644
--- a/server/src/test/java/org/opensearch/index/search/stats/SearchStatsTests.java
+++ b/server/src/test/java/org/opensearch/index/search/stats/SearchStatsTests.java
@@ -32,13 +32,23 @@
 
 package org.opensearch.index.search.stats;
 
+import org.opensearch.action.search.SearchPhase;
+import org.opensearch.action.search.SearchPhaseContext;
+import org.opensearch.action.search.SearchPhaseName;
+import org.opensearch.action.search.SearchRequestOperationsListenerSupport;
+import org.opensearch.action.search.SearchRequestStats;
 import org.opensearch.index.search.stats.SearchStats.Stats;
 import org.opensearch.test.OpenSearchTestCase;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 
-public class SearchStatsTests extends OpenSearchTestCase {
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class SearchStatsTests extends OpenSearchTestCase implements SearchRequestOperationsListenerSupport {
 
     // https://github.com/elastic/elasticsearch/issues/7644
     public void testShardLevelSearchGroupStats() throws Exception {
@@ -63,6 +73,37 @@ public void testShardLevelSearchGroupStats() throws Exception {
         // adding again would then return wrong search stats (would return 4! instead of 3)
         searchStats1.add(searchStats2);
         assertStats(groupStats1.get("group1"), 3);
+
+        long paramValue = randomIntBetween(2, 50);
+
+        // Testing for request stats
+        SearchRequestStats testRequestStats = new SearchRequestStats();
+        SearchPhaseContext ctx = mock(SearchPhaseContext.class);
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            SearchPhase mockSearchPhase = mock(SearchPhase.class);
+            when(ctx.getCurrentPhase()).thenReturn(mockSearchPhase);
+            when(mockSearchPhase.getStartTimeInNanos()).thenReturn(System.nanoTime() - TimeUnit.SECONDS.toNanos(paramValue));
+            when(mockSearchPhase.getSearchPhaseName()).thenReturn(searchPhaseName);
+            for (int iterator = 0; iterator < paramValue; iterator++) {
+                onPhaseStart(testRequestStats, ctx);
+                onPhaseEnd(testRequestStats, ctx);
+            }
+        }
+        searchStats1.setSearchRequestStats(testRequestStats);
+        for (SearchPhaseName searchPhaseName : SearchPhaseName.values()) {
+            assertEquals(
+                0,
+                searchStats1.getTotal().getRequestStatsLongHolder().getRequestStatsHolder().get(searchPhaseName.getName()).current
+            );
+            assertEquals(
+                paramValue,
+                searchStats1.getTotal().getRequestStatsLongHolder().getRequestStatsHolder().get(searchPhaseName.getName()).total
+            );
+            assertThat(
+                searchStats1.getTotal().getRequestStatsLongHolder().getRequestStatsHolder().get(searchPhaseName.getName()).timeInMillis,
+                greaterThanOrEqualTo(paramValue)
+            );
+        }
     }
 
     private static void assertStats(Stats stats, long equalTo) {
@@ -87,5 +128,4 @@ private static void assertStats(Stats stats, long equalTo) {
         // avg_concurrency is not summed up across stats
         assertEquals(1, stats.getConcurrentAvgSliceCount(), 0);
     }
-
 }
diff --git a/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java b/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java
index 28c95ddf13fc4..7971591e82bab 100644
--- a/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java
+++ b/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java
@@ -1907,6 +1907,86 @@ public void testSegmentReplicationCheckpointTracking() {
         }
     }
 
+    public void testSegmentReplicationCheckpointForRelocatingPrimary() {
+        Settings settings = Settings.builder().put(SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT).build();
+        final long initialClusterStateVersion = randomNonNegativeLong();
+        final int numberOfActiveAllocationsIds = randomIntBetween(2, 2);
+        final int numberOfInitializingIds = randomIntBetween(2, 2);
+        final Tuple<Set<AllocationId>, Set<AllocationId>> activeAndInitializingAllocationIds = randomActiveAndInitializingAllocationIds(
+            numberOfActiveAllocationsIds,
+            numberOfInitializingIds
+        );
+        final Set<AllocationId> activeAllocationIds = activeAndInitializingAllocationIds.v1();
+        final Set<AllocationId> initializingIds = activeAndInitializingAllocationIds.v2();
+
+        AllocationId targetAllocationId = initializingIds.iterator().next();
+        AllocationId primaryId = activeAllocationIds.iterator().next();
+        String relocatingToNodeId = nodeIdFromAllocationId(targetAllocationId);
+
+        logger.info("--> activeAllocationIds {} Primary {}", activeAllocationIds, primaryId.getId());
+        logger.info("--> initializingIds {} Target {}", initializingIds, targetAllocationId);
+
+        final ShardId shardId = new ShardId("test", "_na_", 0);
+        final IndexShardRoutingTable.Builder builder = new IndexShardRoutingTable.Builder(shardId);
+        for (final AllocationId initializingId : initializingIds) {
+            boolean primaryRelocationTarget = initializingId.equals(targetAllocationId);
+            builder.addShard(
+                TestShardRouting.newShardRouting(
+                    shardId,
+                    nodeIdFromAllocationId(initializingId),
+                    null,
+                    primaryRelocationTarget,
+                    ShardRoutingState.INITIALIZING,
+                    initializingId
+                )
+            );
+        }
+        builder.addShard(
+            TestShardRouting.newShardRouting(
+                shardId,
+                nodeIdFromAllocationId(primaryId),
+                relocatingToNodeId,
+                true,
+                ShardRoutingState.STARTED,
+                primaryId
+            )
+        );
+        IndexShardRoutingTable routingTable = builder.build();
+        final ReplicationTracker tracker = newTracker(primaryId, settings);
+        tracker.updateFromClusterManager(initialClusterStateVersion, ids(activeAllocationIds), routingTable);
+        tracker.activatePrimaryMode(NO_OPS_PERFORMED);
+        assertThat(tracker.getReplicationGroup().getInSyncAllocationIds(), equalTo(ids(activeAllocationIds)));
+        assertThat(tracker.getReplicationGroup().getRoutingTable(), equalTo(routingTable));
+        assertTrue(activeAllocationIds.stream().allMatch(a -> tracker.getTrackedLocalCheckpointForShard(a.getId()).inSync));
+        initializingIds.forEach(aId -> markAsTrackingAndInSyncQuietly(tracker, aId.getId(), NO_OPS_PERFORMED));
+
+        final StoreFileMetadata segment_1 = new StoreFileMetadata("segment_1", 5L, "abcd", Version.LATEST);
+        final ReplicationCheckpoint initialCheckpoint = new ReplicationCheckpoint(
+            tracker.shardId(),
+            0L,
+            1,
+            1,
+            5L,
+            Codec.getDefault().getName(),
+            Map.of("segment_1", segment_1)
+        );
+        tracker.setLatestReplicationCheckpoint(initialCheckpoint);
+        tracker.startReplicationLagTimers(initialCheckpoint);
+
+        final Set<String> expectedIds = initializingIds.stream()
+            .filter(id -> id.equals(targetAllocationId))
+            .map(AllocationId::getId)
+            .collect(Collectors.toSet());
+
+        Set<SegmentReplicationShardStats> groupStats = tracker.getSegmentReplicationStats();
+        assertEquals(expectedIds.size(), groupStats.size());
+        for (SegmentReplicationShardStats shardStat : groupStats) {
+            assertEquals(1, shardStat.getCheckpointsBehindCount());
+            assertEquals(5L, shardStat.getBytesBehindCount());
+            assertTrue(shardStat.getCurrentReplicationLagMillis() >= shardStat.getCurrentReplicationTimeMillis());
+        }
+    }
+
     public void testSegmentReplicationCheckpointTrackingInvalidAllocationIDs() {
         Settings settings = Settings.builder().put(SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT).build();
         final long initialClusterStateVersion = randomNonNegativeLong();
diff --git a/server/src/test/java/org/opensearch/index/seqno/RetentionLeaseSyncActionTests.java b/server/src/test/java/org/opensearch/index/seqno/RetentionLeaseSyncActionTests.java
index d9bca55a208c2..63a9ac2f2e8ec 100644
--- a/server/src/test/java/org/opensearch/index/seqno/RetentionLeaseSyncActionTests.java
+++ b/server/src/test/java/org/opensearch/index/seqno/RetentionLeaseSyncActionTests.java
@@ -125,7 +125,8 @@ public void testRetentionLeaseSyncActionOnPrimary() {
             shardStateAction,
             new ActionFilters(Collections.emptySet()),
             new IndexingPressureService(Settings.EMPTY, clusterService),
-            new SystemIndices(emptyMap())
+            new SystemIndices(emptyMap()),
+            NoopTracer.INSTANCE
         );
         final RetentionLeases retentionLeases = mock(RetentionLeases.class);
         final RetentionLeaseSyncAction.Request request = new RetentionLeaseSyncAction.Request(indexShard.shardId(), retentionLeases);
@@ -162,7 +163,8 @@ public void testRetentionLeaseSyncActionOnReplica() throws Exception {
             shardStateAction,
             new ActionFilters(Collections.emptySet()),
             new IndexingPressureService(Settings.EMPTY, clusterService),
-            new SystemIndices(emptyMap())
+            new SystemIndices(emptyMap()),
+            NoopTracer.INSTANCE
         );
         final RetentionLeases retentionLeases = mock(RetentionLeases.class);
         final RetentionLeaseSyncAction.Request request = new RetentionLeaseSyncAction.Request(indexShard.shardId(), retentionLeases);
@@ -203,7 +205,8 @@ public void testBlocks() {
             shardStateAction,
             new ActionFilters(Collections.emptySet()),
             new IndexingPressureService(Settings.EMPTY, clusterService),
-            new SystemIndices(emptyMap())
+            new SystemIndices(emptyMap()),
+            NoopTracer.INSTANCE
         );
 
         assertNull(action.indexBlockLevel());
@@ -233,7 +236,8 @@ private RetentionLeaseSyncAction createAction() {
             shardStateAction,
             new ActionFilters(Collections.emptySet()),
             new IndexingPressureService(Settings.EMPTY, clusterService),
-            new SystemIndices(emptyMap())
+            new SystemIndices(emptyMap()),
+            NoopTracer.INSTANCE
         );
     }
 
diff --git a/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java b/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java
index cd272d8f626d0..46be10ce62840 100644
--- a/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java
@@ -1416,7 +1416,7 @@ public void testRestoreLocalHistoryFromTranslogOnPromotion() throws IOException,
             indexShard,
             indexShard.getPendingPrimaryTerm() + 1,
             globalCheckpoint,
-            randomLongBetween(SequenceNumbers.NO_OPS_PERFORMED, maxSeqNo),
+            randomLongBetween(SequenceNumbers.NO_OPS_PERFORMED, maxSeqNoOfUpdatesOrDeletesBeforeRollback),
             new ActionListener<Releasable>() {
                 @Override
                 public void onResponse(Releasable releasable) {
@@ -1780,7 +1780,7 @@ public Set<String> getPendingDeletions() throws IOException {
             }
         };
 
-        try (Store store = createStore(shardId, new IndexSettings(metadata, Settings.EMPTY), directory)) {
+        try (Store store = createStore(shardId, new IndexSettings(metadata, Settings.EMPTY), directory, shardPath)) {
             IndexShard shard = newShard(
                 shardRouting,
                 shardPath,
@@ -2745,6 +2745,7 @@ public void testRelocatedForRemoteTranslogBackedIndexWithAsyncDurability() throw
             AllocationId.newRelocation(routing.allocationId())
         );
         IndexShardTestCase.updateRoutingEntry(indexShard, routing);
+        indexDoc(indexShard, "_doc", "0");
         assertTrue(indexShard.isSyncNeeded());
         try {
             indexShard.relocated(routing.getTargetRelocatingShard().allocationId().getId(), primaryContext -> {}, () -> {});
@@ -2849,6 +2850,7 @@ public void testSyncSegmentsFromGivenRemoteSegmentStore() throws IOException {
         indexDoc(source, "_doc", "1");
         indexDoc(source, "_doc", "2");
         source.refresh("test");
+        assertTrue("At lease one remote sync should have been completed", source.isRemoteSegmentStoreInSync());
         assertDocs(source, "1", "2");
         indexDoc(source, "_doc", "3");
         source.refresh("test");
@@ -4910,6 +4912,8 @@ private void populateSampleRemoteSegmentStats(RemoteSegmentTransferTracker track
         tracker.addUploadBytesStarted(30L);
         tracker.addUploadBytesSucceeded(10L);
         tracker.addUploadBytesFailed(10L);
+        tracker.incrementRejectionCount();
+        tracker.incrementRejectionCount();
     }
 
     private void populateSampleRemoteTranslogStats(RemoteTranslogTransferTracker tracker) {
@@ -4943,5 +4947,7 @@ private static void assertRemoteSegmentStats(
         assertEquals(remoteSegmentTransferTracker.getUploadBytesStarted(), remoteSegmentStats.getUploadBytesStarted());
         assertEquals(remoteSegmentTransferTracker.getUploadBytesSucceeded(), remoteSegmentStats.getUploadBytesSucceeded());
         assertEquals(remoteSegmentTransferTracker.getUploadBytesFailed(), remoteSegmentStats.getUploadBytesFailed());
+        assertTrue(remoteSegmentStats.getTotalRejections() > 0);
+        assertEquals(remoteSegmentTransferTracker.getRejectionCount(), remoteSegmentStats.getTotalRejections());
     }
 }
diff --git a/server/src/test/java/org/opensearch/index/shard/IndexingStatsTests.java b/server/src/test/java/org/opensearch/index/shard/IndexingStatsTests.java
new file mode 100644
index 0000000000000..acf482552c260
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/shard/IndexingStatsTests.java
@@ -0,0 +1,141 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.shard;
+
+import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.concurrent.atomic.AtomicLong;
+
+public class IndexingStatsTests extends OpenSearchTestCase {
+
+    public void testSerialization() throws IOException {
+        IndexingStats stats = createTestInstance();
+
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            stats.writeTo(out);
+
+            try (StreamInput in = out.bytes().streamInput()) {
+                IndexingStats deserializedStats = new IndexingStats(in);
+
+                if (stats.getTotal() == null) {
+                    assertNull(deserializedStats.getTotal());
+                    return;
+                }
+
+                IndexingStats.Stats totalStats = stats.getTotal();
+                IndexingStats.Stats deserializedTotalStats = deserializedStats.getTotal();
+
+                assertEquals(totalStats.getIndexCount(), deserializedTotalStats.getIndexCount());
+                assertEquals(totalStats.getIndexTime(), deserializedTotalStats.getIndexTime());
+                assertEquals(totalStats.getIndexCurrent(), deserializedTotalStats.getIndexCurrent());
+                assertEquals(totalStats.getIndexFailedCount(), deserializedTotalStats.getIndexFailedCount());
+                assertEquals(totalStats.getDeleteCount(), deserializedTotalStats.getDeleteCount());
+                assertEquals(totalStats.getDeleteTime(), deserializedTotalStats.getDeleteTime());
+                assertEquals(totalStats.getDeleteCurrent(), deserializedTotalStats.getDeleteCurrent());
+                assertEquals(totalStats.getNoopUpdateCount(), deserializedTotalStats.getNoopUpdateCount());
+                assertEquals(totalStats.isThrottled(), deserializedTotalStats.isThrottled());
+                assertEquals(totalStats.getThrottleTime(), deserializedTotalStats.getThrottleTime());
+
+                if (totalStats.getDocStatusStats() == null) {
+                    assertNull(deserializedTotalStats.getDocStatusStats());
+                    return;
+                }
+
+                IndexingStats.Stats.DocStatusStats docStatusStats = totalStats.getDocStatusStats();
+                IndexingStats.Stats.DocStatusStats deserializedDocStatusStats = deserializedTotalStats.getDocStatusStats();
+
+                assertTrue(
+                    Arrays.equals(
+                        docStatusStats.getDocStatusCounter(),
+                        deserializedDocStatusStats.getDocStatusCounter(),
+                        Comparator.comparingLong(AtomicLong::longValue)
+                    )
+                );
+            }
+        }
+    }
+
+    public void testToXContentForIndexingStats() throws IOException {
+        IndexingStats stats = createTestInstance();
+        IndexingStats.Stats totalStats = stats.getTotal();
+        AtomicLong[] counter = totalStats.getDocStatusStats().getDocStatusCounter();
+
+        String expected = "{\"indexing\":{\"index_total\":"
+            + totalStats.getIndexCount()
+            + ",\"index_time_in_millis\":"
+            + totalStats.getIndexTime().getMillis()
+            + ",\"index_current\":"
+            + totalStats.getIndexCurrent()
+            + ",\"index_failed\":"
+            + totalStats.getIndexFailedCount()
+            + ",\"delete_total\":"
+            + totalStats.getDeleteCount()
+            + ",\"delete_time_in_millis\":"
+            + totalStats.getDeleteTime().getMillis()
+            + ",\"delete_current\":"
+            + totalStats.getDeleteCurrent()
+            + ",\"noop_update_total\":"
+            + totalStats.getNoopUpdateCount()
+            + ",\"is_throttled\":"
+            + totalStats.isThrottled()
+            + ",\"throttle_time_in_millis\":"
+            + totalStats.getThrottleTime().getMillis()
+            + ",\"doc_status\":{\"1xx\":"
+            + counter[0]
+            + ",\"2xx\":"
+            + counter[1]
+            + ",\"3xx\":"
+            + counter[2]
+            + ",\"4xx\":"
+            + counter[3]
+            + ",\"5xx\":"
+            + counter[4]
+            + "}}}";
+
+        XContentBuilder xContentBuilder = MediaTypeRegistry.contentBuilder(MediaTypeRegistry.JSON);
+        xContentBuilder.startObject();
+        xContentBuilder = stats.toXContent(xContentBuilder, ToXContent.EMPTY_PARAMS);
+        xContentBuilder.endObject();
+
+        assertEquals(expected, xContentBuilder.toString());
+    }
+
+    private IndexingStats createTestInstance() {
+        IndexingStats.Stats.DocStatusStats docStatusStats = new IndexingStats.Stats.DocStatusStats();
+        for (int i = 1; i < 6; ++i) {
+            docStatusStats.add(RestStatus.fromCode(i * 100), randomNonNegativeLong());
+        }
+
+        IndexingStats.Stats stats = new IndexingStats.Stats(
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomBoolean(),
+            randomNonNegativeLong(),
+            docStatusStats
+        );
+
+        return new IndexingStats(stats);
+    }
+
+}
diff --git a/server/src/test/java/org/opensearch/index/shard/RefreshListenersTests.java b/server/src/test/java/org/opensearch/index/shard/RefreshListenersTests.java
index afe6e47bec7b2..a45b25f04060b 100644
--- a/server/src/test/java/org/opensearch/index/shard/RefreshListenersTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/RefreshListenersTests.java
@@ -133,7 +133,8 @@ public void setupListeners() throws Exception {
             shardId,
             createTempDir("translog"),
             indexSettings,
-            BigArrays.NON_RECYCLING_INSTANCE
+            BigArrays.NON_RECYCLING_INSTANCE,
+            ""
         );
         Engine.EventListener eventListener = new Engine.EventListener() {
             @Override
diff --git a/server/src/test/java/org/opensearch/index/shard/CloseableRetryableRefreshListenerTests.java b/server/src/test/java/org/opensearch/index/shard/ReleasableRetryableRefreshListenerTests.java
similarity index 66%
rename from server/src/test/java/org/opensearch/index/shard/CloseableRetryableRefreshListenerTests.java
rename to server/src/test/java/org/opensearch/index/shard/ReleasableRetryableRefreshListenerTests.java
index 01242063caa77..a0641c365a2a1 100644
--- a/server/src/test/java/org/opensearch/index/shard/CloseableRetryableRefreshListenerTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/ReleasableRetryableRefreshListenerTests.java
@@ -10,6 +10,7 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.opensearch.common.lease.Releasable;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.threadpool.TestThreadPool;
@@ -26,9 +27,9 @@
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-public class CloseableRetryableRefreshListenerTests extends OpenSearchTestCase {
+public class ReleasableRetryableRefreshListenerTests extends OpenSearchTestCase {
 
-    private static final Logger logger = LogManager.getLogger(CloseableRetryableRefreshListenerTests.class);
+    private static final Logger logger = LogManager.getLogger(ReleasableRetryableRefreshListenerTests.class);
 
     private ThreadPool threadPool;
 
@@ -43,7 +44,7 @@ public void init() {
     public void testPerformAfterRefresh() throws IOException {
 
         CountDownLatch countDownLatch = new CountDownLatch(2);
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(mock(ThreadPool.class)) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(mock(ThreadPool.class)) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -66,7 +67,7 @@ protected Logger getLogger() {
         // Second invocation of afterRefresh method
         testRefreshListener.afterRefresh(true);
         assertEquals(0, countDownLatch.getCount());
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
     }
 
     /**
@@ -75,7 +76,7 @@ protected Logger getLogger() {
     public void testCloseAfterRefresh() throws IOException {
         final int initialCount = randomIntBetween(10, 100);
         final CountDownLatch countDownLatch = new CountDownLatch(initialCount);
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(mock(ThreadPool.class)) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(mock(ThreadPool.class)) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -98,7 +99,7 @@ protected Logger getLogger() {
         assertEquals(initialCount - refreshCount, countDownLatch.getCount());
 
         // Closing the refresh listener so that no further afterRefreshes are executed going forward
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
 
         for (int i = 0; i < initialCount - refreshCount; i++) {
             testRefreshListener.afterRefresh(true);
@@ -112,7 +113,7 @@ protected Logger getLogger() {
     public void testNoRetry() throws IOException {
         int initialCount = randomIntBetween(10, 100);
         final CountDownLatch countDownLatch = new CountDownLatch(initialCount);
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(mock(ThreadPool.class)) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(mock(ThreadPool.class)) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -129,9 +130,9 @@ protected Logger getLogger() {
         };
         testRefreshListener.afterRefresh(true);
         assertEquals(initialCount - 1, countDownLatch.getCount());
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
 
-        testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -148,9 +149,9 @@ protected Logger getLogger() {
         };
         testRefreshListener.afterRefresh(true);
         assertEquals(initialCount - 2, countDownLatch.getCount());
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
 
-        testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -172,9 +173,9 @@ protected Logger getLogger() {
         };
         testRefreshListener.afterRefresh(true);
         assertEquals(initialCount - 3, countDownLatch.getCount());
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
 
-        testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -196,7 +197,7 @@ protected Logger getLogger() {
         };
         testRefreshListener.afterRefresh(true);
         assertEquals(initialCount - 4, countDownLatch.getCount());
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
     }
 
     /**
@@ -205,7 +206,7 @@ protected Logger getLogger() {
     public void testRetry() throws Exception {
         int initialCount = randomIntBetween(10, 20);
         final CountDownLatch countDownLatch = new CountDownLatch(initialCount);
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -237,7 +238,7 @@ protected boolean isRetryEnabled() {
         };
         testRefreshListener.afterRefresh(true);
         assertBusy(() -> assertEquals(0, countDownLatch.getCount()));
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
     }
 
     /**
@@ -246,7 +247,7 @@ protected boolean isRetryEnabled() {
     public void testCloseWithRetryPending() throws IOException {
         int initialCount = randomIntBetween(10, 20);
         final CountDownLatch countDownLatch = new CountDownLatch(initialCount);
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 countDownLatch.countDown();
@@ -272,13 +273,14 @@ protected Logger getLogger() {
             }
         };
         testRefreshListener.afterRefresh(randomBoolean());
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
         assertNotEquals(0, countDownLatch.getCount());
+        assertRefreshListenerClosed(testRefreshListener);
     }
 
     public void testCloseWaitsForAcquiringAllPermits() throws Exception {
         final CountDownLatch countDownLatch = new CountDownLatch(1);
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 try {
@@ -307,13 +309,14 @@ protected Logger getLogger() {
         });
         thread.start();
         assertBusy(() -> assertEquals(0, countDownLatch.getCount()));
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
+        assertRefreshListenerClosed(testRefreshListener);
     }
 
     public void testScheduleRetryAfterClose() throws Exception {
         // This tests that once the listener has been closed, even the retries would not be scheduled.
         final AtomicLong runCount = new AtomicLong();
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 try {
@@ -358,8 +361,8 @@ protected TimeValue getNextRetryInterval() {
         Thread thread2 = new Thread(() -> {
             try {
                 Thread.sleep(500);
-                testRefreshListener.close();
-            } catch (IOException | InterruptedException e) {
+                testRefreshListener.drainRefreshes();
+            } catch (InterruptedException e) {
                 throw new AssertionError(e);
             }
         });
@@ -368,13 +371,14 @@ protected TimeValue getNextRetryInterval() {
         thread1.join();
         thread2.join();
         assertBusy(() -> assertEquals(1, runCount.get()));
+        assertRefreshListenerClosed(testRefreshListener);
     }
 
     public void testConcurrentScheduleRetry() throws Exception {
         // This tests that there can be only 1 retry that can be scheduled at a time.
         final AtomicLong runCount = new AtomicLong();
         final AtomicInteger retryCount = new AtomicInteger(0);
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(threadPool) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(threadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 retryCount.incrementAndGet();
@@ -408,7 +412,8 @@ protected boolean isRetryEnabled() {
         testRefreshListener.afterRefresh(true);
         testRefreshListener.afterRefresh(true);
         assertBusy(() -> assertEquals(3, runCount.get()));
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
+        assertRefreshListenerClosed(testRefreshListener);
     }
 
     public void testExceptionDuringThreadPoolSchedule() throws Exception {
@@ -417,7 +422,7 @@ public void testExceptionDuringThreadPoolSchedule() throws Exception {
         AtomicInteger runCount = new AtomicInteger();
         ThreadPool mockThreadPool = mock(ThreadPool.class);
         when(mockThreadPool.schedule(any(), any(), any())).thenThrow(new RuntimeException());
-        CloseableRetryableRefreshListener testRefreshListener = new CloseableRetryableRefreshListener(mockThreadPool) {
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(mockThreadPool) {
             @Override
             protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
                 runCount.incrementAndGet();
@@ -450,7 +455,121 @@ protected boolean isRetryEnabled() {
         assertThrows(RuntimeException.class, () -> testRefreshListener.afterRefresh(true));
         assertBusy(() -> assertFalse(testRefreshListener.getRetryScheduledStatus()));
         assertEquals(1, runCount.get());
-        testRefreshListener.close();
+        testRefreshListener.drainRefreshes();
+        assertRefreshListenerClosed(testRefreshListener);
+    }
+
+    public void testTimeoutDuringClose() throws Exception {
+        // This test checks the expected behaviour when the drainRefreshes times out.
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(mock(ThreadPool.class)) {
+            @Override
+            protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
+                try {
+                    Thread.sleep(TimeValue.timeValueSeconds(2).millis());
+                } catch (InterruptedException e) {
+                    throw new AssertionError(e);
+                }
+                return true;
+            }
+
+            @Override
+            public void beforeRefresh() {}
+
+            @Override
+            protected Logger getLogger() {
+                return logger;
+            }
+
+            @Override
+            TimeValue getDrainTimeout() {
+                return TimeValue.timeValueSeconds(1);
+            }
+        };
+        Thread thread1 = new Thread(() -> {
+            try {
+                testRefreshListener.afterRefresh(true);
+            } catch (IOException e) {
+                throw new AssertionError(e);
+            }
+        });
+        thread1.start();
+        assertBusy(() -> assertEquals(0, testRefreshListener.availablePermits()));
+        RuntimeException ex = assertThrows(RuntimeException.class, testRefreshListener::drainRefreshes);
+        assertEquals("Failed to acquire all permits", ex.getMessage());
+        thread1.join();
+    }
+
+    public void testThreadInterruptDuringClose() throws Exception {
+        // This test checks the expected behaviour when the thread performing the drainRefresh is interrupted.
+        CountDownLatch latch = new CountDownLatch(2);
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(mock(ThreadPool.class)) {
+            @Override
+            protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
+                try {
+                    Thread.sleep(TimeValue.timeValueSeconds(2).millis());
+                } catch (InterruptedException e) {
+                    throw new AssertionError(e);
+                }
+                return true;
+            }
+
+            @Override
+            public void beforeRefresh() {}
+
+            @Override
+            protected Logger getLogger() {
+                return logger;
+            }
+
+            @Override
+            TimeValue getDrainTimeout() {
+                return TimeValue.timeValueSeconds(2);
+            }
+        };
+        Thread thread1 = new Thread(() -> {
+            try {
+                testRefreshListener.afterRefresh(true);
+                latch.countDown();
+            } catch (IOException e) {
+                throw new AssertionError(e);
+            }
+        });
+        Thread thread2 = new Thread(() -> {
+            RuntimeException ex = assertThrows(RuntimeException.class, testRefreshListener::drainRefreshes);
+            assertEquals("Failed to acquire all permits", ex.getMessage());
+            latch.countDown();
+        });
+        thread1.start();
+        assertBusy(() -> assertEquals(0, testRefreshListener.availablePermits()));
+        thread2.start();
+        thread2.interrupt();
+        thread1.join();
+        thread2.join();
+        assertEquals(0, latch.getCount());
+    }
+
+    public void testResumeRefreshesAfterDrainRefreshes() {
+        // This test checks the expected behaviour when the refresh listener is drained, but then refreshes are resumed again
+        // by closing the releasables acquired by calling the drainRefreshes method.
+        ReleasableRetryableRefreshListener testRefreshListener = new ReleasableRetryableRefreshListener(mock(ThreadPool.class)) {
+            @Override
+            protected boolean performAfterRefreshWithPermit(boolean didRefresh) {
+                return true;
+            }
+
+            @Override
+            public void beforeRefresh() {}
+
+            @Override
+            protected Logger getLogger() {
+                return logger;
+            }
+        };
+        assertRefreshListenerOpen(testRefreshListener);
+        Releasable releasable = testRefreshListener.drainRefreshes();
+        assertRefreshListenerClosed(testRefreshListener);
+        releasable.close();
+        assertRefreshListenerOpen(testRefreshListener);
     }
 
     @After
@@ -458,4 +577,14 @@ public void tearDown() throws Exception {
         super.tearDown();
         terminate(threadPool);
     }
+
+    private void assertRefreshListenerClosed(ReleasableRetryableRefreshListener testRefreshListener) {
+        assertTrue(testRefreshListener.isClosed());
+        assertEquals(0, testRefreshListener.availablePermits());
+    }
+
+    private void assertRefreshListenerOpen(ReleasableRetryableRefreshListener testRefreshListener) {
+        assertFalse(testRefreshListener.isClosed());
+        assertEquals(1, testRefreshListener.availablePermits());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/index/shard/RemoteIndexShardCorruptionTests.java b/server/src/test/java/org/opensearch/index/shard/RemoteIndexShardCorruptionTests.java
new file mode 100644
index 0000000000000..21bf580712761
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/shard/RemoteIndexShardCorruptionTests.java
@@ -0,0 +1,75 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.shard;
+
+import org.apache.lucene.codecs.CodecUtil;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.tests.util.LuceneTestCase;
+import org.opensearch.core.util.FileSystemUtils;
+import org.opensearch.test.CorruptionUtils;
+
+import java.io.IOException;
+import java.nio.channels.FileChannel;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.stream.Stream;
+
+@LuceneTestCase.SuppressFileSystems("WindowsFS")
+public class RemoteIndexShardCorruptionTests extends IndexShardTestCase {
+
+    public void testLocalDirectoryContains() throws IOException {
+        IndexShard indexShard = newStartedShard(true);
+        int numDocs = between(1, 10);
+        for (int i = 0; i < numDocs; i++) {
+            indexDoc(indexShard, "_doc", Integer.toString(i));
+        }
+        flushShard(indexShard);
+        indexShard.store().incRef();
+        Directory localDirectory = indexShard.store().directory();
+        Path shardPath = indexShard.shardPath().getDataPath().resolve(ShardPath.INDEX_FOLDER_NAME);
+        Path tempDir = createTempDir();
+        for (String file : localDirectory.listAll()) {
+            if (file.equals("write.lock") || file.startsWith("extra")) {
+                continue;
+            }
+            boolean corrupted = randomBoolean();
+            long checksum = 0;
+            try (IndexInput indexInput = localDirectory.openInput(file, IOContext.DEFAULT)) {
+                checksum = CodecUtil.retrieveChecksum(indexInput);
+            }
+            if (corrupted) {
+                Files.copy(shardPath.resolve(file), tempDir.resolve(file));
+                try (FileChannel raf = FileChannel.open(shardPath.resolve(file), StandardOpenOption.READ, StandardOpenOption.WRITE)) {
+                    CorruptionUtils.corruptAt(shardPath.resolve(file), raf, (int) (raf.size() - 8));
+                }
+            }
+            if (corrupted == false) {
+                assertTrue(indexShard.localDirectoryContains(localDirectory, file, checksum));
+            } else {
+                assertFalse(indexShard.localDirectoryContains(localDirectory, file, checksum));
+                assertFalse(Files.exists(shardPath.resolve(file)));
+            }
+        }
+        try (Stream<Path> files = Files.list(tempDir)) {
+            files.forEach(p -> {
+                try {
+                    Files.copy(p, shardPath.resolve(p.getFileName()));
+                } catch (IOException e) {
+                    // Ignore
+                }
+            });
+        }
+        FileSystemUtils.deleteSubDirectories(tempDir);
+        indexShard.store().decRef();
+        closeShards(indexShard);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/index/shard/RemoteIndexShardTests.java b/server/src/test/java/org/opensearch/index/shard/RemoteIndexShardTests.java
index 6a99063d11353..dd92bfb47afdb 100644
--- a/server/src/test/java/org/opensearch/index/shard/RemoteIndexShardTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/RemoteIndexShardTests.java
@@ -31,18 +31,22 @@
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 import org.opensearch.indices.replication.common.ReplicationFailedException;
 import org.opensearch.indices.replication.common.ReplicationType;
+import org.opensearch.test.CorruptionUtils;
+import org.opensearch.test.junit.annotations.TestLogging;
 import org.hamcrest.MatcherAssert;
 import org.junit.Assert;
 
 import java.io.IOException;
+import java.nio.channels.FileChannel;
 import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.BiConsumer;
 import java.util.stream.Collectors;
 
 import static org.opensearch.index.engine.EngineTestCase.assertAtMostOneLuceneDocumentPerSequenceNumber;
@@ -294,31 +298,39 @@ public void testPrimaryRestart_PrimaryHasExtraCommits() throws Exception {
         }
     }
 
+    @TestLogging(reason = "Getting trace logs from replication package", value = "org.opensearch.indices.replication:TRACE")
     public void testRepicaCleansUpOldCommitsWhenReceivingNew() throws Exception {
         final Path remotePath = createTempDir();
         try (ReplicationGroup shards = createGroup(1, getIndexSettings(), indexMapping, new NRTReplicationEngineFactory(), remotePath)) {
             shards.startAll();
             final IndexShard primary = shards.getPrimary();
             final IndexShard replica = shards.getReplicas().get(0);
+            final Store store = replica.store();
+            final SegmentInfos initialCommit = store.readLastCommittedSegmentsInfo();
             shards.indexDocs(1);
             flushShard(primary);
             replicateSegments(primary, shards.getReplicas());
+
             assertDocCount(primary, 1);
             assertDocCount(replica, 1);
-            assertEquals("segments_5", replica.store().readLastCommittedSegmentsInfo().getSegmentsFileName());
-            assertSingleSegmentFile(replica, "segments_5");
+            assertSingleSegmentFile(replica);
+            final SegmentInfos secondCommit = store.readLastCommittedSegmentsInfo();
+            assertTrue(secondCommit.getGeneration() > initialCommit.getGeneration());
 
             shards.indexDocs(1);
             primary.refresh("test");
             replicateSegments(primary, shards.getReplicas());
             assertDocCount(replica, 2);
-            assertSingleSegmentFile(replica, "segments_5");
+            assertSingleSegmentFile(replica);
+            assertEquals(store.readLastCommittedSegmentsInfo().getGeneration(), secondCommit.getGeneration());
 
             shards.indexDocs(1);
             flushShard(primary);
             replicateSegments(primary, shards.getReplicas());
             assertDocCount(replica, 3);
-            assertSingleSegmentFile(replica, "segments_6");
+            assertSingleSegmentFile(replica);
+            final SegmentInfos thirdCommit = store.readLastCommittedSegmentsInfo();
+            assertTrue(thirdCommit.getGeneration() > secondCommit.getGeneration());
 
             final Store.RecoveryDiff diff = Store.segmentReplicationDiff(primary.getSegmentMetadataMap(), replica.getSegmentMetadataMap());
             assertTrue(diff.missing.isEmpty());
@@ -359,6 +371,7 @@ public void testPrimaryRestart() throws Exception {
      * prevent FileAlreadyExistsException. It does so by only copying files in first round of segment replication without
      * committing locally so that in next round of segment replication those files are not considered for download again
      */
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/10885")
     public void testSegRepSucceedsOnPreviousCopiedFiles() throws Exception {
         try (ReplicationGroup shards = createGroup(1, getIndexSettings(), new NRTReplicationEngineFactory())) {
             shards.startAll();
@@ -370,36 +383,9 @@ public void testSegRepSucceedsOnPreviousCopiedFiles() throws Exception {
 
             final SegmentReplicationSourceFactory sourceFactory = mock(SegmentReplicationSourceFactory.class);
             final SegmentReplicationTargetService targetService = newTargetService(sourceFactory);
-            Runnable[] runAfterGetFiles = { () -> { throw new RuntimeException("Simulated"); }, () -> {} };
-            AtomicInteger index = new AtomicInteger(0);
-            RemoteStoreReplicationSource testRSReplicationSource = new RemoteStoreReplicationSource(replica) {
-                @Override
-                public void getCheckpointMetadata(
-                    long replicationId,
-                    ReplicationCheckpoint checkpoint,
-                    ActionListener<CheckpointInfoResponse> listener
-                ) {
-                    super.getCheckpointMetadata(replicationId, checkpoint, listener);
-                }
-
-                @Override
-                public void getSegmentFiles(
-                    long replicationId,
-                    ReplicationCheckpoint checkpoint,
-                    List<StoreFileMetadata> filesToFetch,
-                    IndexShard indexShard,
-                    ActionListener<GetSegmentFilesResponse> listener
-                ) {
-                    super.getSegmentFiles(replicationId, checkpoint, filesToFetch, indexShard, listener);
-                    runAfterGetFiles[index.getAndIncrement()].run();
-                }
-
-                @Override
-                public String getDescription() {
-                    return "TestRemoteStoreReplicationSource";
-                }
-            };
-            when(sourceFactory.get(any())).thenReturn(testRSReplicationSource);
+            when(sourceFactory.get(any())).thenReturn(
+                getRemoteStoreReplicationSource(replica, () -> { throw new RuntimeException("Simulated"); })
+            );
             CountDownLatch latch = new CountDownLatch(1);
 
             // Start first round of segment replication. This should fail with simulated error but with replica having
@@ -410,6 +396,7 @@ public String getDescription() {
                 new SegmentReplicationTargetService.SegmentReplicationListener() {
                     @Override
                     public void onReplicationDone(SegmentReplicationState state) {
+                        latch.countDown();
                         Assert.fail("Replication should fail with simulated error");
                     }
 
@@ -419,9 +406,9 @@ public void onReplicationFailure(
                         ReplicationFailedException e,
                         boolean sendShardFailure
                     ) {
+                        latch.countDown();
                         assertFalse(sendShardFailure);
                         logger.error("Replication error", e);
-                        latch.countDown();
                     }
                 }
             );
@@ -437,7 +424,8 @@ public void onReplicationFailure(
             assertEquals("Files should be copied to disk", false, onDiskFiles.isEmpty());
             assertEquals(target.state().getStage(), SegmentReplicationState.Stage.GET_FILES);
 
-            // Start next round of segment replication
+            // Start next round of segment replication and not throwing exception resulting in commit on replica
+            when(sourceFactory.get(any())).thenReturn(getRemoteStoreReplicationSource(replica, () -> {}));
             CountDownLatch waitForSecondRound = new CountDownLatch(1);
             final SegmentReplicationTarget newTarget = targetService.startReplication(
                 replica,
@@ -454,9 +442,9 @@ public void onReplicationFailure(
                         ReplicationFailedException e,
                         boolean sendShardFailure
                     ) {
+                        waitForSecondRound.countDown();
                         logger.error("Replication error", e);
                         Assert.fail("Replication should not fail");
-                        waitForSecondRound.countDown();
                     }
                 }
             );
@@ -469,11 +457,133 @@ public void onReplicationFailure(
         }
     }
 
-    private void assertSingleSegmentFile(IndexShard shard, String fileName) throws IOException {
+    /**
+     * This test validates that local non-readable (corrupt, partially) on disk are deleted vs failing the
+     * replication event. This test mimics local files (not referenced by reader) by throwing exception post file copy and
+     * blocking update of reader. Once this is done, it corrupts one segment file and ensure that file is deleted in next
+     * round of segment replication by ensuring doc count.
+     */
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/10885")
+    public void testNoFailuresOnFileReads() throws Exception {
+        try (ReplicationGroup shards = createGroup(1, getIndexSettings(), new NRTReplicationEngineFactory())) {
+            shards.startAll();
+            IndexShard primary = shards.getPrimary();
+            final IndexShard replica = shards.getReplicas().get(0);
+
+            final int docCount = 10;
+            shards.indexDocs(docCount);
+            primary.refresh("Test");
+
+            final SegmentReplicationSourceFactory sourceFactory = mock(SegmentReplicationSourceFactory.class);
+            final SegmentReplicationTargetService targetService = newTargetService(sourceFactory);
+            when(sourceFactory.get(any())).thenReturn(
+                getRemoteStoreReplicationSource(replica, () -> { throw new RuntimeException("Simulated"); })
+            );
+            CountDownLatch waitOnReplicationCompletion = new CountDownLatch(1);
+
+            // Start first round of segment replication. This should fail with simulated error but with replica having
+            // files in its local store but not in active reader.
+            SegmentReplicationTarget segmentReplicationTarget = targetService.startReplication(
+                replica,
+                primary.getLatestReplicationCheckpoint(),
+                new SegmentReplicationTargetService.SegmentReplicationListener() {
+                    @Override
+                    public void onReplicationDone(SegmentReplicationState state) {
+                        waitOnReplicationCompletion.countDown();
+                        Assert.fail("Replication should fail with simulated error");
+                    }
+
+                    @Override
+                    public void onReplicationFailure(
+                        SegmentReplicationState state,
+                        ReplicationFailedException e,
+                        boolean sendShardFailure
+                    ) {
+                        waitOnReplicationCompletion.countDown();
+                        assertFalse(sendShardFailure);
+                    }
+                }
+            );
+            waitOnReplicationCompletion.await();
+            assertBusy(() -> { assertEquals("Target should be closed", 0, segmentReplicationTarget.refCount()); });
+            String fileToCorrupt = null;
+            // Corrupt one data file
+            Path shardPath = replica.shardPath().getDataPath().resolve(ShardPath.INDEX_FOLDER_NAME);
+            for (String file : replica.store().directory().listAll()) {
+                if (file.equals("write.lock") || file.startsWith("extra") || file.startsWith("segment")) {
+                    continue;
+                }
+                fileToCorrupt = file;
+                logger.info("--> Corrupting file {}", fileToCorrupt);
+                try (FileChannel raf = FileChannel.open(shardPath.resolve(file), StandardOpenOption.READ, StandardOpenOption.WRITE)) {
+                    CorruptionUtils.corruptAt(shardPath.resolve(file), raf, (int) (raf.size() - 8));
+                }
+                break;
+            }
+            Assert.assertNotNull(fileToCorrupt);
+
+            // Ingest more data and start next round of segment replication
+            shards.indexDocs(docCount);
+            primary.refresh("Post corruption");
+            replicateSegments(primary, List.of(replica));
+
+            assertDocCount(primary, 2 * docCount);
+            assertDocCount(replica, 2 * docCount);
+
+            final Store.RecoveryDiff diff = Store.segmentReplicationDiff(primary.getSegmentMetadataMap(), replica.getSegmentMetadataMap());
+            assertTrue(diff.missing.isEmpty());
+            assertTrue(diff.different.isEmpty());
+
+            // clean up
+            shards.removeReplica(replica);
+            closeShards(replica);
+        }
+    }
+
+    private RemoteStoreReplicationSource getRemoteStoreReplicationSource(IndexShard shard, Runnable postGetFilesRunnable) {
+        return new RemoteStoreReplicationSource(shard) {
+            @Override
+            public void getCheckpointMetadata(
+                long replicationId,
+                ReplicationCheckpoint checkpoint,
+                ActionListener<CheckpointInfoResponse> listener
+            ) {
+                super.getCheckpointMetadata(replicationId, checkpoint, listener);
+            }
+
+            @Override
+            public void getSegmentFiles(
+                long replicationId,
+                ReplicationCheckpoint checkpoint,
+                List<StoreFileMetadata> filesToFetch,
+                IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
+                ActionListener<GetSegmentFilesResponse> listener
+            ) {
+                super.getSegmentFiles(replicationId, checkpoint, filesToFetch, indexShard, (fileName, bytesRecovered) -> {}, listener);
+                postGetFilesRunnable.run();
+            }
+
+            @Override
+            public String getDescription() {
+                return "TestRemoteStoreReplicationSource";
+            }
+        };
+    }
+
+    @Override
+    protected void validateShardIdleWithNoReplicas(IndexShard primary) {
+        // ensure search idle conditions are met.
+        assertFalse(primary.isSearchIdleSupported());
+        assertTrue(primary.isSearchIdle());
+        assertTrue(primary.scheduledRefresh());
+        assertFalse(primary.hasRefreshPending());
+    }
+
+    private void assertSingleSegmentFile(IndexShard shard) throws IOException {
         final Set<String> segmentsFileNames = Arrays.stream(shard.store().directory().listAll())
             .filter(file -> file.startsWith(IndexFileNames.SEGMENTS))
             .collect(Collectors.toSet());
         assertEquals("Expected a single segment file", 1, segmentsFileNames.size());
-        assertEquals(segmentsFileNames.stream().findFirst().get(), fileName);
     }
 }
diff --git a/server/src/test/java/org/opensearch/index/shard/RemoteStoreRefreshListenerTests.java b/server/src/test/java/org/opensearch/index/shard/RemoteStoreRefreshListenerTests.java
index c713ccdddd66a..811d6a722d0f6 100644
--- a/server/src/test/java/org/opensearch/index/shard/RemoteStoreRefreshListenerTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/RemoteStoreRefreshListenerTests.java
@@ -33,6 +33,7 @@
 import org.opensearch.index.store.RemoteSegmentStoreDirectory.MetadataFilenameUtils;
 import org.opensearch.index.store.Store;
 import org.opensearch.index.store.lockmanager.RemoteStoreLockManager;
+import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.replication.checkpoint.SegmentReplicationCheckpointPublisher;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.threadpool.ThreadPool;
@@ -46,6 +47,7 @@
 import java.util.concurrent.atomic.AtomicLong;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REPLICATION_TYPE;
+import static org.opensearch.index.store.RemoteSegmentStoreDirectory.METADATA_FILES_TO_FETCH;
 import static org.opensearch.test.RemoteStoreTestUtils.createMetadataFileBytes;
 import static org.opensearch.test.RemoteStoreTestUtils.getDummyMetadata;
 import static org.mockito.ArgumentMatchers.any;
@@ -138,7 +140,8 @@ public void testRemoteDirectoryInitThrowsException() throws IOException {
                 return Collections.singletonList("dummy string");
             }
             throw new IOException();
-        }).when(remoteMetadataDirectory).listFilesByPrefixInLexicographicOrder(MetadataFilenameUtils.METADATA_PREFIX, 1);
+        }).when(remoteMetadataDirectory)
+            .listFilesByPrefixInLexicographicOrder(MetadataFilenameUtils.METADATA_PREFIX, METADATA_FILES_TO_FETCH);
 
         SegmentInfos segmentInfos;
         try (Store indexShardStore = indexShard.store()) {
@@ -152,7 +155,8 @@ public void testRemoteDirectoryInitThrowsException() throws IOException {
             mock(RemoteDirectory.class),
             remoteMetadataDirectory,
             mock(RemoteStoreLockManager.class),
-            mock(ThreadPool.class)
+            mock(ThreadPool.class),
+            shardId
         );
         FilterDirectory remoteStoreFilterDirectory = new RemoteStoreRefreshListenerTests.TestFilterDirectory(
             new RemoteStoreRefreshListenerTests.TestFilterDirectory(remoteSegmentStoreDirectory)
@@ -165,7 +169,10 @@ public void testRemoteDirectoryInitThrowsException() throws IOException {
         // Validate that the stream of metadata file of remoteMetadataDirectory has been opened only once and the
         // listFilesByPrefixInLexicographicOrder has been called twice.
         verify(remoteMetadataDirectory, times(1)).getBlobStream(any());
-        verify(remoteMetadataDirectory, times(2)).listFilesByPrefixInLexicographicOrder(MetadataFilenameUtils.METADATA_PREFIX, 1);
+        verify(remoteMetadataDirectory, times(2)).listFilesByPrefixInLexicographicOrder(
+            MetadataFilenameUtils.METADATA_PREFIX,
+            METADATA_FILES_TO_FETCH
+        );
     }
 
     public void testAfterRefresh() throws IOException {
@@ -231,7 +238,7 @@ public void testAfterMultipleCommits() throws IOException {
         setup(true, 3);
         assertDocs(indexShard, "1", "2", "3");
 
-        for (int i = 0; i < RemoteStoreRefreshListener.LAST_N_METADATA_FILES_TO_KEEP + 3; i++) {
+        for (int i = 0; i < indexShard.getRecoverySettings().getMinRemoteSegmentMetadataFiles() + 3; i++) {
             indexDocs(4 * (i + 1), 4);
             flushShard(indexShard);
         }
@@ -313,7 +320,7 @@ public void testRefreshSuccessOnFirstAttempt() throws Exception {
         // This is the case of isRetry=false, shouldRetry=false
         // Succeed on 1st attempt
         int succeedOnAttempt = 1;
-        // We spy on IndexShard.getReplicationTracker() to validate that we have tried running remote time as per the expectation.
+        // We spy on IndexShard.isPrimaryStarted() to validate that we have tried running remote time as per the expectation.
         CountDownLatch refreshCountLatch = new CountDownLatch(succeedOnAttempt);
         // We spy on IndexShard.getEngine() to validate that we have successfully hit the terminal code for ascertaining successful upload.
         // Value has been set as 3 as during a successful upload IndexShard.getEngine() is hit thrice and with mockito we are counting down
@@ -334,7 +341,7 @@ public void testRefreshSuccessOnSecondAttempt() throws Exception {
         // This covers 2 cases - 1) isRetry=false, shouldRetry=true 2) isRetry=true, shouldRetry=false
         // Succeed on 2nd attempt
         int succeedOnAttempt = 2;
-        // We spy on IndexShard.getReplicationTracker() to validate that we have tried running remote time as per the expectation.
+        // We spy on IndexShard.isPrimaryStarted() to validate that we have tried running remote time as per the expectation.
         CountDownLatch refreshCountLatch = new CountDownLatch(succeedOnAttempt);
         // We spy on IndexShard.getEngine() to validate that we have successfully hit the terminal code for ascertaining successful upload.
         // Value has been set as 3 as during a successful upload IndexShard.getEngine() is hit thrice and with mockito we are counting down
@@ -358,7 +365,7 @@ public void testRefreshSuccessOnSecondAttempt() throws Exception {
     public void testRefreshSuccessAfterFailureInFirstAttemptAfterSnapshotAndMetadataUpload() throws Exception {
         int succeedOnAttempt = 1;
         int checkpointPublishSucceedOnAttempt = 2;
-        // We spy on IndexShard.getReplicationTracker() to validate that we have tried running remote time as per the expectation.
+        // We spy on IndexShard.isPrimaryStarted() to validate that we have tried running remote time as per the expectation.
         CountDownLatch refreshCountLatch = new CountDownLatch(succeedOnAttempt);
         // We spy on IndexShard.getEngine() to validate that we have successfully hit the terminal code for ascertaining successful upload.
         // Value has been set as 6 as during a successful upload IndexShard.getEngine() is hit thrice and here we are running the flow twice
@@ -380,7 +387,7 @@ public void testRefreshSuccessOnThirdAttempt() throws Exception {
         // This covers 3 cases - 1) isRetry=false, shouldRetry=true 2) isRetry=true, shouldRetry=false 3) isRetry=True, shouldRetry=true
         // Succeed on 3rd attempt
         int succeedOnAttempt = 3;
-        // We spy on IndexShard.getReplicationTracker() to validate that we have tried running remote time as per the expectation.
+        // We spy on IndexShard.isPrimaryStarted() to validate that we have tried running remote time as per the expectation.
         CountDownLatch refreshCountLatch = new CountDownLatch(succeedOnAttempt);
         // We spy on IndexShard.getEngine() to validate that we have successfully hit the terminal code for ascertaining successful upload.
         // Value has been set as 3 as during a successful upload IndexShard.getEngine() is hit thrice and with mockito we are counting down
@@ -472,6 +479,7 @@ private Tuple<RemoteStoreRefreshListener, RemoteStoreStatsTrackerFactory> mockIn
         IndexShard shard = mock(IndexShard.class);
         Store store = mock(Store.class);
         when(shard.store()).thenReturn(store);
+        when(shard.state()).thenReturn(IndexShardState.STARTED);
         when(store.directory()).thenReturn(indexShard.store().directory());
 
         // Mock (RemoteSegmentStoreDirectory) ((FilterDirectory) ((FilterDirectory) indexShard.remoteStore().directory())
@@ -493,13 +501,12 @@ private Tuple<RemoteStoreRefreshListener, RemoteStoreStatsTrackerFactory> mockIn
         when(shard.getThreadPool()).thenReturn(threadPool);
 
         // Mock indexShard.getReplicationTracker().isPrimaryMode()
-
         doAnswer(invocation -> {
             if (Objects.nonNull(refreshCountLatch)) {
                 refreshCountLatch.countDown();
             }
-            return indexShard.getReplicationTracker();
-        }).when(shard).getReplicationTracker();
+            return true;
+        }).when(shard).isStartedPrimary();
 
         AtomicLong counter = new AtomicLong();
         // Mock indexShard.getSegmentInfosSnapshot()
@@ -514,8 +521,8 @@ private Tuple<RemoteStoreRefreshListener, RemoteStoreStatsTrackerFactory> mockIn
             if (counter.incrementAndGet() <= succeedOnAttempt) {
                 throw new RuntimeException("Inducing failure in upload");
             }
-            return indexShard.getLatestSegmentInfosAndCheckpoint();
-        })).when(shard).getLatestSegmentInfosAndCheckpoint();
+            return indexShard.getLatestReplicationCheckpoint();
+        })).when(shard).computeReplicationCheckpoint(any());
 
         doAnswer(invocation -> {
             if (Objects.nonNull(successLatch)) {
@@ -544,6 +551,9 @@ private Tuple<RemoteStoreRefreshListener, RemoteStoreStatsTrackerFactory> mockIn
         RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory = indexShard.getRemoteStoreStatsTrackerFactory();
         when(shard.indexSettings()).thenReturn(indexShard.indexSettings());
         when(shard.shardId()).thenReturn(indexShard.shardId());
+        RecoverySettings recoverySettings = mock(RecoverySettings.class);
+        when(recoverySettings.getMinRemoteSegmentMetadataFiles()).thenReturn(10);
+        when(shard.getRecoverySettings()).thenReturn(recoverySettings);
         RemoteSegmentTransferTracker tracker = remoteStoreStatsTrackerFactory.getRemoteSegmentTransferTracker(indexShard.shardId());
         RemoteStoreRefreshListener refreshListener = new RemoteStoreRefreshListener(shard, emptyCheckpointPublisher, tracker);
         refreshListener.afterRefresh(true);
@@ -578,4 +588,5 @@ private void verifyUploadedSegments(RemoteSegmentStoreDirectory remoteSegmentSto
             }
         }
     }
+
 }
diff --git a/server/src/test/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandTests.java b/server/src/test/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandTests.java
index 9c8f9896850c6..c88c86d51be08 100644
--- a/server/src/test/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/RemoveCorruptedShardDataCommandTests.java
@@ -58,7 +58,7 @@
 import org.opensearch.env.TestEnvironment;
 import org.opensearch.gateway.PersistedClusterStateService;
 import org.opensearch.index.IndexSettings;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.index.engine.EngineConfigFactory;
 import org.opensearch.index.engine.EngineCreationFailureException;
 import org.opensearch.index.engine.InternalEngineFactory;
@@ -134,7 +134,7 @@ public void setup() throws IOException {
         final Settings settings = Settings.builder()
             .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
             .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
-            .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+            .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
             .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
             .put(IndexMetadata.SETTING_INDEX_UUID, shardId.getIndex().getUUID())
             .build();
diff --git a/server/src/test/java/org/opensearch/index/shard/SegmentReplicationIndexShardTests.java b/server/src/test/java/org/opensearch/index/shard/SegmentReplicationIndexShardTests.java
index 528402d48658a..7caff3e5f5479 100644
--- a/server/src/test/java/org/opensearch/index/shard/SegmentReplicationIndexShardTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/SegmentReplicationIndexShardTests.java
@@ -91,6 +91,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.BiConsumer;
 import java.util.function.Function;
 
 import static org.opensearch.index.engine.EngineTestCase.assertAtMostOneLuceneDocumentPerSequenceNumber;
@@ -435,13 +436,17 @@ public void testShardIdleWithNoReplicas() throws Exception {
             shards.startAll();
             final IndexShard primary = shards.getPrimary();
             shards.indexDocs(randomIntBetween(1, 10));
-            // ensure search idle conditions are met.
-            assertTrue(primary.isSearchIdle());
-            assertFalse(primary.scheduledRefresh());
-            assertTrue(primary.hasRefreshPending());
+            validateShardIdleWithNoReplicas(primary);
         }
     }
 
+    protected void validateShardIdleWithNoReplicas(IndexShard primary) {
+        // ensure search idle conditions are met.
+        assertTrue(primary.isSearchIdle());
+        assertFalse(primary.scheduledRefresh());
+        assertTrue(primary.hasRefreshPending());
+    }
+
     /**
      * here we are starting a new primary shard in PrimaryMode and testing if the shard publishes checkpoint after refresh.
      */
@@ -725,6 +730,7 @@ public void getSegmentFiles(
                     ReplicationCheckpoint checkpoint,
                     List<StoreFileMetadata> filesToFetch,
                     IndexShard indexShard,
+                    BiConsumer<String, Long> fileProgressTracker,
                     ActionListener<GetSegmentFilesResponse> listener
                 ) {
                     // set the listener, we will only fail it once we cancel the source.
@@ -923,6 +929,33 @@ public void testSnapshotWhileFailoverIncomplete() throws Exception {
         }
     }
 
+    public void testReuseReplicationCheckpointWhenLatestInfosIsUnChanged() throws Exception {
+        try (ReplicationGroup shards = createGroup(1, settings, indexMapping, new NRTReplicationEngineFactory(), createTempDir())) {
+            final IndexShard primaryShard = shards.getPrimary();
+            shards.startAll();
+            shards.indexDocs(10);
+            shards.refresh("test");
+            replicateSegments(primaryShard, shards.getReplicas());
+            shards.assertAllEqual(10);
+            final ReplicationCheckpoint latestReplicationCheckpoint = primaryShard.getLatestReplicationCheckpoint();
+            try (GatedCloseable<SegmentInfos> segmentInfosSnapshot = primaryShard.getSegmentInfosSnapshot()) {
+                assertEquals(latestReplicationCheckpoint, primaryShard.computeReplicationCheckpoint(segmentInfosSnapshot.get()));
+            }
+            final Tuple<GatedCloseable<SegmentInfos>, ReplicationCheckpoint> latestSegmentInfosAndCheckpoint = primaryShard
+                .getLatestSegmentInfosAndCheckpoint();
+            try (final GatedCloseable<SegmentInfos> closeable = latestSegmentInfosAndCheckpoint.v1()) {
+                assertEquals(latestReplicationCheckpoint, primaryShard.computeReplicationCheckpoint(closeable.get()));
+            }
+        }
+    }
+
+    public void testComputeReplicationCheckpointNullInfosReturnsEmptyCheckpoint() throws Exception {
+        try (ReplicationGroup shards = createGroup(1, settings, indexMapping, new NRTReplicationEngineFactory(), createTempDir())) {
+            final IndexShard primaryShard = shards.getPrimary();
+            assertEquals(ReplicationCheckpoint.empty(primaryShard.shardId), primaryShard.computeReplicationCheckpoint(null));
+        }
+    }
+
     private SnapshotShardsService getSnapshotShardsService(IndexShard replicaShard) {
         final TransportService transportService = mock(TransportService.class);
         when(transportService.getThreadPool()).thenReturn(threadPool);
diff --git a/server/src/test/java/org/opensearch/index/shard/SegmentReplicationWithNodeToNodeIndexShardTests.java b/server/src/test/java/org/opensearch/index/shard/SegmentReplicationWithNodeToNodeIndexShardTests.java
index c394101697b47..f0950fe5392de 100644
--- a/server/src/test/java/org/opensearch/index/shard/SegmentReplicationWithNodeToNodeIndexShardTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/SegmentReplicationWithNodeToNodeIndexShardTests.java
@@ -47,6 +47,7 @@
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.stream.Collectors;
@@ -87,6 +88,7 @@ public void getSegmentFiles(
                     ReplicationCheckpoint checkpoint,
                     List<StoreFileMetadata> filesToFetch,
                     IndexShard indexShard,
+                    BiConsumer<String, Long> fileProgressTracker,
                     ActionListener<GetSegmentFilesResponse> listener
                 ) {
                     // randomly resolve the listener, indicating the source has resolved.
@@ -131,6 +133,7 @@ public void getSegmentFiles(
                     ReplicationCheckpoint checkpoint,
                     List<StoreFileMetadata> filesToFetch,
                     IndexShard indexShard,
+                    BiConsumer<String, Long> fileProgressTracker,
                     ActionListener<GetSegmentFilesResponse> listener
                 ) {
                     Assert.fail("Should not be reached");
@@ -176,6 +179,7 @@ public void getSegmentFiles(
                     ReplicationCheckpoint checkpoint,
                     List<StoreFileMetadata> filesToFetch,
                     IndexShard indexShard,
+                    BiConsumer<String, Long> fileProgressTracker,
                     ActionListener<GetSegmentFilesResponse> listener
                 ) {
                     Assert.fail("Unreachable");
@@ -223,6 +227,7 @@ public void getSegmentFiles(
                     ReplicationCheckpoint checkpoint,
                     List<StoreFileMetadata> filesToFetch,
                     IndexShard indexShard,
+                    BiConsumer<String, Long> fileProgressTracker,
                     ActionListener<GetSegmentFilesResponse> listener
                 ) {}
             };
@@ -269,6 +274,7 @@ public void getSegmentFiles(
                     ReplicationCheckpoint checkpoint,
                     List<StoreFileMetadata> filesToFetch,
                     IndexShard indexShard,
+                    BiConsumer<String, Long> fileProgressTracker,
                     ActionListener<GetSegmentFilesResponse> listener
                 ) {
                     listener.onResponse(new GetSegmentFilesResponse(Collections.emptyList()));
diff --git a/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java b/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java
index 3740abc57b02d..9e38e1749d434 100644
--- a/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java
+++ b/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java
@@ -29,7 +29,6 @@
 import java.nio.file.NoSuchFileException;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -41,11 +40,13 @@
 
 import org.mockito.Mockito;
 
+import static org.opensearch.common.blobstore.BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -204,13 +205,29 @@ public void testCreateOutput() {
     public void testOpenInput() throws IOException {
         InputStream mockInputStream = mock(InputStream.class);
         when(blobContainer.readBlob("segment_1")).thenReturn(mockInputStream);
-        Map<String, BlobMetadata> fileInfo = new HashMap<>();
-        fileInfo.put("segment_1", new PlainBlobMetadata("segment_1", 100));
-        when(blobContainer.listBlobsByPrefix("segment_1")).thenReturn(fileInfo);
+
+        BlobMetadata blobMetadata = new PlainBlobMetadata("segment_1", 100);
+
+        when(blobContainer.listBlobsByPrefixInSortedOrder("segment_1", 1, LEXICOGRAPHIC)).thenReturn(List.of(blobMetadata));
 
         IndexInput indexInput = remoteDirectory.openInput("segment_1", IOContext.DEFAULT);
         assertTrue(indexInput instanceof RemoteIndexInput);
         assertEquals(100, indexInput.length());
+        verify(blobContainer).listBlobsByPrefixInSortedOrder("segment_1", 1, LEXICOGRAPHIC);
+    }
+
+    public void testOpenInputWithLength() throws IOException {
+        InputStream mockInputStream = mock(InputStream.class);
+        when(blobContainer.readBlob("segment_1")).thenReturn(mockInputStream);
+
+        BlobMetadata blobMetadata = new PlainBlobMetadata("segment_1", 100);
+
+        when(blobContainer.listBlobsByPrefixInSortedOrder("segment_1", 1, LEXICOGRAPHIC)).thenReturn(List.of(blobMetadata));
+
+        IndexInput indexInput = remoteDirectory.openInput("segment_1", 100, IOContext.DEFAULT);
+        assertTrue(indexInput instanceof RemoteIndexInput);
+        assertEquals(100, indexInput.length());
+        verify(blobContainer, times(0)).listBlobsByPrefixInSortedOrder("segment_1", 1, LEXICOGRAPHIC);
     }
 
     public void testOpenInputIOException() throws IOException {
@@ -228,9 +245,8 @@ public void testOpenInputNoSuchFileException() throws IOException {
     }
 
     public void testFileLength() throws IOException {
-        Map<String, BlobMetadata> fileInfo = new HashMap<>();
-        fileInfo.put("segment_1", new PlainBlobMetadata("segment_1", 100));
-        when(blobContainer.listBlobsByPrefix("segment_1")).thenReturn(fileInfo);
+        BlobMetadata blobMetadata = new PlainBlobMetadata("segment_1", 100);
+        when(blobContainer.listBlobsByPrefixInSortedOrder("segment_1", 1, LEXICOGRAPHIC)).thenReturn(List.of(blobMetadata));
 
         assertEquals(100, remoteDirectory.fileLength("segment_1"));
     }
@@ -246,13 +262,7 @@ public void testListFilesByPrefixInLexicographicOrder() throws IOException {
             LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
             latchedActionListener.onResponse(List.of(new PlainBlobMetadata("metadata_1", 1)));
             return null;
-        }).when(blobContainer)
-            .listBlobsByPrefixInSortedOrder(
-                eq("metadata"),
-                eq(1),
-                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
-                any(ActionListener.class)
-            );
+        }).when(blobContainer).listBlobsByPrefixInSortedOrder(eq("metadata"), eq(1), eq(LEXICOGRAPHIC), any(ActionListener.class));
 
         assertEquals(List.of("metadata_1"), remoteDirectory.listFilesByPrefixInLexicographicOrder("metadata", 1));
     }
@@ -262,13 +272,7 @@ public void testListFilesByPrefixInLexicographicOrderEmpty() throws IOException
             LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
             latchedActionListener.onResponse(List.of());
             return null;
-        }).when(blobContainer)
-            .listBlobsByPrefixInSortedOrder(
-                eq("metadata"),
-                eq(1),
-                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
-                any(ActionListener.class)
-            );
+        }).when(blobContainer).listBlobsByPrefixInSortedOrder(eq("metadata"), eq(1), eq(LEXICOGRAPHIC), any(ActionListener.class));
 
         assertEquals(List.of(), remoteDirectory.listFilesByPrefixInLexicographicOrder("metadata", 1));
     }
@@ -278,13 +282,7 @@ public void testListFilesByPrefixInLexicographicOrderException() {
             LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
             latchedActionListener.onFailure(new IOException("Error"));
             return null;
-        }).when(blobContainer)
-            .listBlobsByPrefixInSortedOrder(
-                eq("metadata"),
-                eq(1),
-                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
-                any(ActionListener.class)
-            );
+        }).when(blobContainer).listBlobsByPrefixInSortedOrder(eq("metadata"), eq(1), eq(LEXICOGRAPHIC), any(ActionListener.class));
 
         assertThrows(IOException.class, () -> remoteDirectory.listFilesByPrefixInLexicographicOrder("metadata", 1));
     }
diff --git a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java
index d7bbe52aa3905..cad5e47531cc6 100644
--- a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java
+++ b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java
@@ -35,6 +35,7 @@
 
 import org.mockito.ArgumentCaptor;
 
+import static org.opensearch.index.store.RemoteSegmentStoreDirectory.METADATA_FILES_TO_FETCH;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doAnswer;
@@ -78,7 +79,12 @@ public void testNewDirectory() throws IOException {
             latchedActionListener.onResponse(List.of());
             return null;
         }).when(blobContainer)
-            .listBlobsByPrefixInSortedOrder(any(), eq(1), eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC), any(ActionListener.class));
+            .listBlobsByPrefixInSortedOrder(
+                any(),
+                eq(METADATA_FILES_TO_FETCH),
+                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
+                any(ActionListener.class)
+            );
 
         when(repositoriesService.repository("remote_store_repository")).thenReturn(repository);
 
@@ -93,7 +99,7 @@ public void testNewDirectory() throws IOException {
 
             verify(blobContainer).listBlobsByPrefixInSortedOrder(
                 eq(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX),
-                eq(1),
+                eq(METADATA_FILES_TO_FETCH),
                 eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
                 any()
             );
diff --git a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java
index 2948528ad82e1..2c6c4afed69fd 100644
--- a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java
+++ b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java
@@ -8,6 +8,8 @@
 
 package org.opensearch.index.store;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.IndexFormatTooNewException;
@@ -49,6 +51,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -58,9 +61,12 @@
 
 import org.mockito.Mockito;
 
+import static org.opensearch.index.store.RemoteSegmentStoreDirectory.METADATA_FILES_TO_FETCH;
+import static org.opensearch.index.store.RemoteSegmentStoreDirectory.MetadataFilenameUtils.SEPARATOR;
 import static org.opensearch.test.RemoteStoreTestUtils.createMetadataFileBytes;
 import static org.opensearch.test.RemoteStoreTestUtils.getDummyMetadata;
 import static org.hamcrest.CoreMatchers.is;
+import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
@@ -73,6 +79,7 @@
 import static org.mockito.Mockito.when;
 
 public class RemoteSegmentStoreDirectoryTests extends IndexShardTestCase {
+    private static final Logger logger = LogManager.getLogger(RemoteSegmentStoreDirectoryTests.class);
     private RemoteDirectory remoteDataDirectory;
     private RemoteDirectory remoteMetadataDirectory;
     private RemoteStoreMetadataLockManager mdLockManager;
@@ -83,9 +90,47 @@ public class RemoteSegmentStoreDirectoryTests extends IndexShardTestCase {
     private SegmentInfos segmentInfos;
     private ThreadPool threadPool;
 
-    private final String metadataFilename = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(12, 23, 34, 1, 1);
-    private final String metadataFilename2 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(12, 13, 34, 1, 1);
-    private final String metadataFilename3 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(10, 38, 34, 1, 1);
+    private final String metadataFilename = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        12,
+        23,
+        34,
+        1,
+        1,
+        "node-1"
+    );
+
+    private final String metadataFilenameDup = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        12,
+        23,
+        34,
+        2,
+        1,
+        "node-2"
+    );
+    private final String metadataFilename2 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        12,
+        13,
+        34,
+        1,
+        1,
+        "node-1"
+    );
+    private final String metadataFilename3 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        10,
+        38,
+        34,
+        1,
+        1,
+        "node-1"
+    );
+    private final String metadataFilename4 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(
+        10,
+        36,
+        34,
+        1,
+        1,
+        "node-1"
+    );
 
     @Before
     public void setup() throws IOException {
@@ -93,13 +138,6 @@ public void setup() throws IOException {
         remoteMetadataDirectory = mock(RemoteDirectory.class);
         mdLockManager = mock(RemoteStoreMetadataLockManager.class);
         threadPool = mock(ThreadPool.class);
-
-        remoteSegmentStoreDirectory = new RemoteSegmentStoreDirectory(
-            remoteDataDirectory,
-            remoteMetadataDirectory,
-            mdLockManager,
-            threadPool
-        );
         testUploadTracker = new TestUploadListener();
 
         Settings indexSettings = Settings.builder()
@@ -109,11 +147,19 @@ public void setup() throws IOException {
         ExecutorService executorService = OpenSearchExecutors.newDirectExecutorService();
 
         indexShard = newStartedShard(false, indexSettings, new NRTReplicationEngineFactory());
+        remoteSegmentStoreDirectory = new RemoteSegmentStoreDirectory(
+            remoteDataDirectory,
+            remoteMetadataDirectory,
+            mdLockManager,
+            threadPool,
+            indexShard.shardId()
+        );
         try (Store store = indexShard.store()) {
             segmentInfos = store.readLastCommittedSegmentsInfo();
         }
 
         when(threadPool.executor(ThreadPool.Names.REMOTE_PURGE)).thenReturn(executorService);
+        when(threadPool.executor(ThreadPool.Names.REMOTE_RECOVERY)).thenReturn(executorService);
     }
 
     @After
@@ -168,15 +214,13 @@ public void testUploadedSegmentMetadataFromStringException() {
     }
 
     public void testGetPrimaryTermGenerationUuid() {
-        String[] filenameTokens = "abc__9223372036854775795__9223372036854775784__uuid_xyz".split(
-            RemoteSegmentStoreDirectory.MetadataFilenameUtils.SEPARATOR
-        );
+        String[] filenameTokens = "abc__9223372036854775795__9223372036854775784__uuid_xyz".split(SEPARATOR);
         assertEquals(12, RemoteSegmentStoreDirectory.MetadataFilenameUtils.getPrimaryTerm(filenameTokens));
         assertEquals(23, RemoteSegmentStoreDirectory.MetadataFilenameUtils.getGeneration(filenameTokens));
     }
 
     public void testInitException() throws IOException {
-        when(remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX, 1)).thenThrow(
+        when(remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX, METADATA_FILES_TO_FETCH)).thenThrow(
             new IOException("Error")
         );
 
@@ -195,6 +239,13 @@ public void testInitNoMetadataFile() throws IOException {
         assertEquals(Set.of(), actualCache.keySet());
     }
 
+    public void testInitMultipleMetadataFile() throws IOException {
+        when(remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX, METADATA_FILES_TO_FETCH)).thenReturn(
+            List.of(metadataFilename, metadataFilenameDup)
+        );
+        assertThrows(IllegalStateException.class, () -> remoteSegmentStoreDirectory.init());
+    }
+
     private Map<String, Map<String, String>> populateMetadata() throws IOException {
         List<String> metadataFiles = new ArrayList<>();
 
@@ -205,7 +256,7 @@ private Map<String, Map<String, String>> populateMetadata() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(List.of(metadataFilename));
         when(
@@ -255,7 +306,7 @@ public void testInit() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(List.of(metadataFilename));
 
@@ -311,7 +362,7 @@ public void testFileLength() throws IOException {
         assertEquals(uploadedSegments.get("_0.si").getLength(), remoteSegmentStoreDirectory.fileLength("_0.si"));
     }
 
-    public void testFileLenghtNoSuchFile() throws IOException {
+    public void testFileLengthNoSuchFile() throws IOException {
         populateMetadata();
         remoteSegmentStoreDirectory.init();
 
@@ -340,7 +391,7 @@ public void testOpenInput() throws IOException {
         remoteSegmentStoreDirectory.init();
 
         IndexInput indexInput = mock(IndexInput.class);
-        when(remoteDataDirectory.openInput(startsWith("_0.si"), eq(IOContext.DEFAULT))).thenReturn(indexInput);
+        when(remoteDataDirectory.openInput(startsWith("_0.si"), anyLong(), eq(IOContext.DEFAULT))).thenReturn(indexInput);
 
         assertEquals(indexInput, remoteSegmentStoreDirectory.openInput("_0.si", IOContext.DEFAULT));
     }
@@ -353,7 +404,7 @@ public void testOpenInputException() throws IOException {
         populateMetadata();
         remoteSegmentStoreDirectory.init();
 
-        when(remoteDataDirectory.openInput(startsWith("_0.si"), eq(IOContext.DEFAULT))).thenThrow(new IOException("Error"));
+        when(remoteDataDirectory.openInput(startsWith("_0.si"), anyLong(), eq(IOContext.DEFAULT))).thenThrow(new IOException("Error"));
 
         assertThrows(IOException.class, () -> remoteSegmentStoreDirectory.openInput("_0.si", IOContext.DEFAULT));
     }
@@ -524,7 +575,8 @@ public void testCopyFilesFromMultipartIOException() throws Exception {
             remoteDataDirectory,
             remoteMetadataDirectory,
             mdLockManager,
-            threadPool
+            threadPool,
+            indexShard.shardId()
         );
 
         populateMetadata();
@@ -577,7 +629,7 @@ public void testContainsFile() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(metadataFiles);
 
@@ -623,7 +675,8 @@ public void testUploadMetadataEmpty() throws IOException {
                 segmentInfos,
                 storeDirectory,
                 34L,
-                indexShard.getLatestReplicationCheckpoint()
+                indexShard.getLatestReplicationCheckpoint(),
+                ""
             )
         );
     }
@@ -641,7 +694,7 @@ public void testUploadMetadataNonEmpty() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(metadataFiles);
         Map<String, Map<String, String>> metadataFilenameContentMapping = Map.of(
@@ -669,7 +722,8 @@ public void testUploadMetadataNonEmpty() throws IOException {
             segInfos,
             storeDirectory,
             generation,
-            indexShard.getLatestReplicationCheckpoint()
+            indexShard.getLatestReplicationCheckpoint(),
+            ""
         );
 
         verify(remoteMetadataDirectory).copyFrom(
@@ -716,7 +770,8 @@ public void testUploadMetadataMissingSegment() throws IOException {
                 segmentInfos,
                 storeDirectory,
                 12L,
-                indexShard.getLatestReplicationCheckpoint()
+                indexShard.getLatestReplicationCheckpoint(),
+                ""
             )
         );
         verify(indexOutput).close();
@@ -739,7 +794,7 @@ public void testNoMetadataHeaderCorruptIndexException() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(metadataFiles);
 
@@ -762,7 +817,7 @@ public void testInvalidCodecHeaderCorruptIndexException() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(metadataFiles);
 
@@ -787,7 +842,7 @@ public void testHeaderMinVersionCorruptIndexException() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(metadataFiles);
 
@@ -812,7 +867,7 @@ public void testHeaderMaxVersionCorruptIndexException() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(metadataFiles);
 
@@ -837,7 +892,7 @@ public void testIncorrectChecksumCorruptIndexException() throws IOException {
         when(
             remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
                 RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
-                1
+                METADATA_FILES_TO_FETCH
             )
         ).thenReturn(metadataFiles);
 
@@ -933,6 +988,51 @@ public void testDeleteStaleCommitsActualDelete() throws Exception {
         verify(remoteMetadataDirectory).deleteFile(metadataFilename3);
     }
 
+    public void testDeleteStaleCommitsDeleteDedup() throws Exception {
+        Map<String, Map<String, String>> metadataFilenameContentMapping = new HashMap<>(populateMetadata());
+        metadataFilenameContentMapping.put(metadataFilename4, metadataFilenameContentMapping.get(metadataFilename3));
+
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                Integer.MAX_VALUE
+            )
+        ).thenReturn(new ArrayList<>(List.of(metadataFilename, metadataFilename2, metadataFilename3, metadataFilename4)));
+
+        when(remoteMetadataDirectory.getBlobStream(metadataFilename4)).thenAnswer(
+            I -> createMetadataFileBytes(
+                metadataFilenameContentMapping.get(metadataFilename4),
+                indexShard.getLatestReplicationCheckpoint(),
+                segmentInfos
+            )
+        );
+
+        remoteSegmentStoreDirectory.init();
+
+        // popluateMetadata() adds stub to return 4 metadata files
+        // We are passing lastNMetadataFilesToKeep=2 here so that oldest 2 metadata files will be deleted
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(2);
+
+        Set<String> staleSegmentFiles = new HashSet<>();
+        for (String metadata : metadataFilenameContentMapping.get(metadataFilename3).values()) {
+            staleSegmentFiles.add(metadata.split(RemoteSegmentStoreDirectory.UploadedSegmentMetadata.SEPARATOR)[1]);
+        }
+        for (String metadata : metadataFilenameContentMapping.get(metadataFilename4).values()) {
+            staleSegmentFiles.add(metadata.split(RemoteSegmentStoreDirectory.UploadedSegmentMetadata.SEPARATOR)[1]);
+        }
+        staleSegmentFiles.forEach(file -> {
+            try {
+                // Even with the same files in 2 stale metadata files, delete should be called only once.
+                verify(remoteDataDirectory, times(1)).deleteFile(file);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        });
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(true)));
+        verify(remoteMetadataDirectory).deleteFile(metadataFilename3);
+        verify(remoteMetadataDirectory).deleteFile(metadataFilename4);
+    }
+
     public void testDeleteStaleCommitsActualDeleteIOException() throws Exception {
         Map<String, Map<String, String>> metadataFilenameContentMapping = populateMetadata();
         remoteSegmentStoreDirectory.init();
@@ -998,17 +1098,21 @@ private void indexDocs(int startDocId, int numberOfDocs) throws IOException {
     }
 
     public void testMetadataFileNameOrder() {
-        String file1 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 21, 23, 1, 1);
-        String file2 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 38, 1, 1);
-        String file3 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(18, 12, 26, 1, 1);
-        String file4 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 10, 1);
-        String file5 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 1, 1);
-        String file6 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 5, 1);
+        String file1 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 21, 23, 1, 1, "");
+        String file2 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 38, 1, 1, "");
+        String file3 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(18, 12, 26, 1, 1, "");
+        String file4 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 10, 1, "");
+        String file5 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 1, 1, "");
+        String file6 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 5, 1, "");
 
         List<String> actualList = new ArrayList<>(List.of(file1, file2, file3, file4, file5, file6));
         actualList.sort(String::compareTo);
 
         assertEquals(List.of(file3, file2, file4, file6, file5, file1), actualList);
+
+        long count = file1.chars().filter(ch -> ch == SEPARATOR.charAt(0)).count();
+        // There should not be any `_` in mdFile name as it is used a separator .
+        assertEquals(14, count);
     }
 
     private static class WrapperIndexOutput extends IndexOutput {
diff --git a/server/src/test/java/org/opensearch/index/store/RemoteStoreFileDownloaderTests.java b/server/src/test/java/org/opensearch/index/store/RemoteStoreFileDownloaderTests.java
new file mode 100644
index 0000000000000..6d8b3fe4d69fb
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/store/RemoteStoreFileDownloaderTests.java
@@ -0,0 +1,228 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.store;
+
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.FilterDirectory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.NIOFSDirectory;
+import org.opensearch.OpenSearchTimeoutException;
+import org.opensearch.action.support.PlainActionFuture;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.CancellableThreads;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.indices.recovery.RecoverySettings;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.junit.After;
+import org.junit.Before;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.nio.file.NoSuchFileException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+public class RemoteStoreFileDownloaderTests extends OpenSearchTestCase {
+
+    private ThreadPool threadPool;
+    private Directory source;
+    private Directory destination;
+    private Directory secondDestination;
+    private RemoteStoreFileDownloader fileDownloader;
+    private Map<String, Integer> files = new HashMap<>();
+
+    @Before
+    public void setup() throws IOException {
+        final int streamLimit = randomIntBetween(1, 20);
+        final RecoverySettings recoverySettings = new RecoverySettings(
+            Settings.builder().put("indices.recovery.max_concurrent_remote_store_streams", streamLimit).build(),
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)
+        );
+        threadPool = new TestThreadPool(getTestName());
+        source = new NIOFSDirectory(createTempDir());
+        destination = new NIOFSDirectory(createTempDir());
+        secondDestination = new NIOFSDirectory(createTempDir());
+        for (int i = 0; i < 10; i++) {
+            final String filename = "file_" + i;
+            final int content = randomInt();
+            try (IndexOutput output = source.createOutput(filename, IOContext.DEFAULT)) {
+                output.writeInt(content);
+            }
+            files.put(filename, content);
+        }
+        fileDownloader = new RemoteStoreFileDownloader(
+            ShardId.fromString("[RemoteStoreFileDownloaderTests][0]"),
+            threadPool,
+            recoverySettings
+        );
+    }
+
+    @After
+    public void stopThreadPool() throws Exception {
+        threadPool.shutdown();
+        assertTrue(threadPool.awaitTermination(5, TimeUnit.SECONDS));
+    }
+
+    public void testDownload() throws IOException {
+        final PlainActionFuture<Void> l = new PlainActionFuture<>();
+        fileDownloader.downloadAsync(new CancellableThreads(), source, destination, files.keySet(), l);
+        l.actionGet();
+        assertContent(files, destination);
+    }
+
+    public void testDownloadWithSecondDestination() throws IOException, InterruptedException {
+        fileDownloader.download(source, destination, secondDestination, files.keySet(), () -> {});
+        assertContent(files, destination);
+        assertContent(files, secondDestination);
+    }
+
+    public void testDownloadWithFileCompletionHandler() throws IOException, InterruptedException {
+        final AtomicInteger counter = new AtomicInteger(0);
+        fileDownloader.download(source, destination, null, files.keySet(), counter::incrementAndGet);
+        assertContent(files, destination);
+        assertEquals(files.size(), counter.get());
+    }
+
+    public void testDownloadNonExistentFile() throws InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        fileDownloader.downloadAsync(new CancellableThreads(), source, destination, Set.of("not real"), new ActionListener<>() {
+            @Override
+            public void onResponse(Void unused) {}
+
+            @Override
+            public void onFailure(Exception e) {
+                assertEquals(NoSuchFileException.class, e.getClass());
+                latch.countDown();
+            }
+        });
+        assertTrue(latch.await(10, TimeUnit.SECONDS));
+    }
+
+    public void testDownloadExtraNonExistentFile() throws InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        final List<String> filesWithExtra = new ArrayList<>(files.keySet());
+        filesWithExtra.add("not real");
+        fileDownloader.downloadAsync(new CancellableThreads(), source, destination, filesWithExtra, new ActionListener<>() {
+            @Override
+            public void onResponse(Void unused) {}
+
+            @Override
+            public void onFailure(Exception e) {
+                assertEquals(NoSuchFileException.class, e.getClass());
+                latch.countDown();
+            }
+        });
+        assertTrue(latch.await(10, TimeUnit.SECONDS));
+    }
+
+    public void testCancellable() {
+        final CancellableThreads cancellableThreads = new CancellableThreads();
+        final PlainActionFuture<Void> blockingListener = new PlainActionFuture<>();
+        final Directory blockingDestination = new FilterDirectory(destination) {
+            @Override
+            public void copyFrom(Directory from, String src, String dest, IOContext context) {
+                try {
+                    Thread.sleep(60_000); // Will be interrupted
+                    fail("Expected to be interrupted");
+                } catch (InterruptedException e) {
+                    throw new RuntimeException("Failed due to interrupt", e);
+                }
+            }
+        };
+        fileDownloader.downloadAsync(cancellableThreads, source, blockingDestination, files.keySet(), blockingListener);
+        assertThrows(
+            "Expected to timeout due to blocking directory",
+            OpenSearchTimeoutException.class,
+            () -> blockingListener.actionGet(TimeValue.timeValueMillis(500))
+        );
+        cancellableThreads.cancel("test");
+        assertThrows(
+            "Expected to complete with cancellation failure",
+            CancellableThreads.ExecutionCancelledException.class,
+            blockingListener::actionGet
+        );
+    }
+
+    public void testBlockingCallCanBeInterrupted() throws Exception {
+        final Directory blockingDestination = new FilterDirectory(destination) {
+            @Override
+            public void copyFrom(Directory from, String src, String dest, IOContext context) {
+                try {
+                    Thread.sleep(60_000); // Will be interrupted
+                    fail("Expected to be interrupted");
+                } catch (InterruptedException e) {
+                    throw new RuntimeException("Failed due to interrupt", e);
+                }
+            }
+        };
+        final AtomicReference<Exception> capturedException = new AtomicReference<>();
+        final Thread thread = new Thread(() -> {
+            try {
+                fileDownloader.download(source, blockingDestination, null, files.keySet(), () -> {});
+            } catch (Exception e) {
+                capturedException.set(e);
+            }
+        });
+        thread.start();
+        thread.interrupt();
+        thread.join();
+        assertEquals(InterruptedException.class, capturedException.get().getClass());
+    }
+
+    public void testIOException() throws IOException, InterruptedException {
+        final Directory failureDirectory = new FilterDirectory(destination) {
+            @Override
+            public void copyFrom(Directory from, String src, String dest, IOContext context) throws IOException {
+                throw new IOException("test");
+            }
+        };
+        assertThrows(IOException.class, () -> fileDownloader.download(source, failureDirectory, null, files.keySet(), () -> {}));
+
+        final CountDownLatch latch = new CountDownLatch(1);
+        fileDownloader.downloadAsync(new CancellableThreads(), source, failureDirectory, files.keySet(), new ActionListener<>() {
+            @Override
+            public void onResponse(Void unused) {}
+
+            @Override
+            public void onFailure(Exception e) {
+                assertEquals(IOException.class, e.getClass());
+                latch.countDown();
+            }
+        });
+        assertTrue(latch.await(10, TimeUnit.SECONDS));
+    }
+
+    private static void assertContent(Map<String, Integer> expected, Directory destination) throws IOException {
+        // Note that Lucene will randomly write extra files (see org.apache.lucene.tests.mockfile.ExtraFS)
+        // so we just need to check that all the expected files are present but not that _only_ the expected
+        // files are present
+        final Set<String> actualFiles = Set.of(destination.listAll());
+        for (String file : expected.keySet()) {
+            assertTrue(actualFiles.contains(file));
+            try (IndexInput input = destination.openInput(file, IOContext.DEFAULT)) {
+                assertEquals(expected.get(file), Integer.valueOf(input.readInt()));
+                assertThrows(EOFException.class, input::readByte);
+            }
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/index/store/StoreTests.java b/server/src/test/java/org/opensearch/index/store/StoreTests.java
index 8395b3e8ac08e..d7d326b325cc6 100644
--- a/server/src/test/java/org/opensearch/index/store/StoreTests.java
+++ b/server/src/test/java/org/opensearch/index/store/StoreTests.java
@@ -84,6 +84,7 @@
 import org.opensearch.index.seqno.ReplicationTracker;
 import org.opensearch.index.seqno.RetentionLease;
 import org.opensearch.index.seqno.SequenceNumbers;
+import org.opensearch.index.shard.ShardPath;
 import org.opensearch.index.translog.Translog;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.indices.store.TransportNodesListShardStoreMetadata;
@@ -798,7 +799,7 @@ public void testOnCloseCallback() throws IOException {
             assertEquals(shardId, theLock.getShardId());
             assertEquals(lock, theLock);
             count.incrementAndGet();
-        });
+        }, null);
         assertEquals(count.get(), 0);
 
         final int iters = randomIntBetween(1, 10);
@@ -809,6 +810,26 @@ public void testOnCloseCallback() throws IOException {
         assertEquals(count.get(), 1);
     }
 
+    public void testStoreShardPath() {
+        final ShardId shardId = new ShardId("index", "_na_", 1);
+        final Settings settings = Settings.builder()
+            .put(IndexMetadata.SETTING_VERSION_CREATED, org.opensearch.Version.CURRENT)
+            .put(Store.INDEX_STORE_STATS_REFRESH_INTERVAL_SETTING.getKey(), TimeValue.timeValueMinutes(0))
+            .build();
+        final Path path = createTempDir().resolve(shardId.getIndex().getUUID()).resolve(String.valueOf(shardId.id()));
+        final ShardPath shardPath = new ShardPath(false, path, path, shardId);
+        final Store store = new Store(
+            shardId,
+            IndexSettingsModule.newIndexSettings("index", settings),
+            StoreTests.newDirectory(random()),
+            new DummyShardLock(shardId),
+            Store.OnClose.EMPTY,
+            shardPath
+        );
+        assertEquals(shardPath, store.shardPath());
+        store.close();
+    }
+
     public void testStoreStats() throws IOException {
         final ShardId shardId = new ShardId("index", "_na_", 1);
         Settings settings = Settings.builder()
diff --git a/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java b/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java
index f3a2f1859923e..80413d4cb6612 100644
--- a/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java
+++ b/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java
@@ -15,10 +15,24 @@
 public class FileLockInfoTests extends OpenSearchTestCase {
     String testMetadata = "testMetadata";
     String testAcquirerId = "testAcquirerId";
+    String testAcquirerId2 = "ZxZ4Wh89SXyEPmSYAHrIrQ";
+    String testAcquirerId3 = "ZxZ4Wh89SXyEPmSYAHrItS";
+    String testMetadata1 = "metadata__9223372036854775806__9223372036854775803__9223372036854775790"
+        + "__9223372036854775800___Hf3Dbw2QQagfGLlVBOUrg__9223370340398865071__1";
+
+    String oldLock = testMetadata1 + RemoteStoreLockManagerUtils.PRE_OS210_LOCK_SEPARATOR + testAcquirerId2
+        + RemoteStoreLockManagerUtils.PRE_OS210_LOCK_FILE_EXTENSION;
+    String newLock = testMetadata1 + RemoteStoreLockManagerUtils.SEPARATOR + testAcquirerId3
+        + RemoteStoreLockManagerUtils.LOCK_FILE_EXTENSION;
 
     public void testGenerateLockName() {
         FileLockInfo fileLockInfo = FileLockInfo.getLockInfoBuilder().withFileToLock(testMetadata).withAcquirerId(testAcquirerId).build();
         assertEquals(fileLockInfo.generateLockName(), FileLockInfo.LockFileUtils.generateLockName(testMetadata, testAcquirerId));
+
+        // validate that lock generated will be the new version lock
+        fileLockInfo = FileLockInfo.getLockInfoBuilder().withFileToLock(testMetadata1).withAcquirerId(testAcquirerId3).build();
+        assertEquals(fileLockInfo.generateLockName(), newLock);
+
     }
 
     public void testGenerateLockNameFailureCase1() {
@@ -41,13 +55,33 @@ public void testGetLockPrefixFailureCase() {
         assertThrows(IllegalArgumentException.class, fileLockInfo::getLockPrefix);
     }
 
+    public void testGetFileToLockNameFromLock() {
+        assertEquals(testMetadata1, FileLockInfo.LockFileUtils.getFileToLockNameFromLock(oldLock));
+        assertEquals(testMetadata1, FileLockInfo.LockFileUtils.getFileToLockNameFromLock(newLock));
+    }
+
+    public void testGetAcquirerIdFromLock() {
+        assertEquals(testAcquirerId2, FileLockInfo.LockFileUtils.getAcquirerIdFromLock(oldLock));
+        assertEquals(testAcquirerId3, FileLockInfo.LockFileUtils.getAcquirerIdFromLock(newLock));
+    }
+
     public void testGetLocksForAcquirer() throws NoSuchFileException {
+
         String[] locks = new String[] {
             FileLockInfo.LockFileUtils.generateLockName(testMetadata, testAcquirerId),
-            FileLockInfo.LockFileUtils.generateLockName(testMetadata, "acquirerId2") };
+            FileLockInfo.LockFileUtils.generateLockName(testMetadata, "acquirerId2"),
+            oldLock,
+            newLock };
         FileLockInfo fileLockInfo = FileLockInfo.getLockInfoBuilder().withAcquirerId(testAcquirerId).build();
-
         assertEquals(fileLockInfo.getLockForAcquirer(locks), FileLockInfo.LockFileUtils.generateLockName(testMetadata, testAcquirerId));
+
+        // validate old lock
+        fileLockInfo = FileLockInfo.getLockInfoBuilder().withAcquirerId(testAcquirerId2).build();
+        assertEquals(fileLockInfo.getLockForAcquirer(locks), oldLock);
+
+        // validate new lock
+        fileLockInfo = FileLockInfo.getLockInfoBuilder().withAcquirerId(testAcquirerId3).build();
+        assertEquals(fileLockInfo.getLockForAcquirer(locks), newLock);
     }
 
 }
diff --git a/server/src/test/java/org/opensearch/index/translog/InternalTranslogManagerTests.java b/server/src/test/java/org/opensearch/index/translog/InternalTranslogManagerTests.java
index 2de36574064cb..c098d11a3487f 100644
--- a/server/src/test/java/org/opensearch/index/translog/InternalTranslogManagerTests.java
+++ b/server/src/test/java/org/opensearch/index/translog/InternalTranslogManagerTests.java
@@ -38,7 +38,7 @@ public void testRecoveryFromTranslog() throws IOException {
         LocalCheckpointTracker tracker = new LocalCheckpointTracker(NO_OPS_PERFORMED, NO_OPS_PERFORMED);
         try {
             translogManager = new InternalTranslogManager(
-                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
                 primaryTerm,
                 globalCheckpoint::get,
                 createTranslogDeletionPolicy(INDEX_SETTINGS),
@@ -68,7 +68,7 @@ public void testRecoveryFromTranslog() throws IOException {
             translogManager.syncTranslog();
             translogManager.close();
             translogManager = new InternalTranslogManager(
-                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
                 primaryTerm,
                 globalCheckpoint::get,
                 createTranslogDeletionPolicy(INDEX_SETTINGS),
@@ -117,7 +117,7 @@ public void testTranslogRollsGeneration() throws IOException {
         LocalCheckpointTracker tracker = new LocalCheckpointTracker(NO_OPS_PERFORMED, NO_OPS_PERFORMED);
         try {
             translogManager = new InternalTranslogManager(
-                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
                 primaryTerm,
                 globalCheckpoint::get,
                 createTranslogDeletionPolicy(INDEX_SETTINGS),
@@ -147,7 +147,7 @@ public void testTranslogRollsGeneration() throws IOException {
             translogManager.syncTranslog();
             translogManager.close();
             translogManager = new InternalTranslogManager(
-                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
                 primaryTerm,
                 globalCheckpoint::get,
                 createTranslogDeletionPolicy(INDEX_SETTINGS),
@@ -182,7 +182,7 @@ public void testTrimOperationsFromTranslog() throws IOException {
         LocalCheckpointTracker tracker = new LocalCheckpointTracker(NO_OPS_PERFORMED, NO_OPS_PERFORMED);
         try {
             translogManager = new InternalTranslogManager(
-                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
                 primaryTerm,
                 globalCheckpoint::get,
                 createTranslogDeletionPolicy(INDEX_SETTINGS),
@@ -214,7 +214,7 @@ public void testTrimOperationsFromTranslog() throws IOException {
 
             translogManager.close();
             translogManager = new InternalTranslogManager(
-                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
                 primaryTerm,
                 globalCheckpoint::get,
                 createTranslogDeletionPolicy(INDEX_SETTINGS),
@@ -253,7 +253,7 @@ public void testTranslogSync() throws IOException {
             ParsedDocument doc = testParsedDocument("1", null, testDocumentWithTextField(), B_1, null);
             AtomicReference<InternalTranslogManager> translogManagerAtomicReference = new AtomicReference<>();
             translogManager = new InternalTranslogManager(
-                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE),
+                new TranslogConfig(shardId, primaryTranslogDir, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, ""),
                 primaryTerm,
                 globalCheckpoint::get,
                 createTranslogDeletionPolicy(INDEX_SETTINGS),
diff --git a/server/src/test/java/org/opensearch/index/translog/LocalTranslogTests.java b/server/src/test/java/org/opensearch/index/translog/LocalTranslogTests.java
index dbfc66d6de4b3..4997067b75198 100644
--- a/server/src/test/java/org/opensearch/index/translog/LocalTranslogTests.java
+++ b/server/src/test/java/org/opensearch/index/translog/LocalTranslogTests.java
@@ -291,7 +291,7 @@ private TranslogConfig getTranslogConfig(final Path path, final Settings setting
         );
 
         final IndexSettings indexSettings = IndexSettingsModule.newIndexSettings(shardId.getIndex(), settings);
-        return new TranslogConfig(shardId, path, indexSettings, NON_RECYCLING_INSTANCE, bufferSize);
+        return new TranslogConfig(shardId, path, indexSettings, NON_RECYCLING_INSTANCE, bufferSize, "");
     }
 
     private Location addToTranslogAndList(Translog translog, List<Translog.Operation> list, Translog.Operation op) throws IOException {
@@ -1452,7 +1452,8 @@ public void testTranslogWriterCanFlushInAddOrReadCall() throws IOException {
             temp.getTranslogPath(),
             temp.getIndexSettings(),
             temp.getBigArrays(),
-            new ByteSizeValue(1, ByteSizeUnit.KB)
+            new ByteSizeValue(1, ByteSizeUnit.KB),
+            ""
         );
 
         final Set<Long> persistedSeqNos = new HashSet<>();
@@ -1550,7 +1551,8 @@ public void testTranslogWriterFsyncedWithLocalTranslog() throws IOException {
             temp.getTranslogPath(),
             temp.getIndexSettings(),
             temp.getBigArrays(),
-            new ByteSizeValue(1, ByteSizeUnit.KB)
+            new ByteSizeValue(1, ByteSizeUnit.KB),
+            ""
         );
 
         final Set<Long> persistedSeqNos = new HashSet<>();
diff --git a/server/src/test/java/org/opensearch/index/translog/RemoteFsTranslogTests.java b/server/src/test/java/org/opensearch/index/translog/RemoteFsTranslogTests.java
index de1b2990f0a50..6bfab278993ed 100644
--- a/server/src/test/java/org/opensearch/index/translog/RemoteFsTranslogTests.java
+++ b/server/src/test/java/org/opensearch/index/translog/RemoteFsTranslogTests.java
@@ -25,6 +25,8 @@
 import org.opensearch.common.blobstore.fs.FsBlobContainer;
 import org.opensearch.common.blobstore.fs.FsBlobStore;
 import org.opensearch.common.bytes.ReleasableBytesReference;
+import org.opensearch.common.lease.Releasable;
+import org.opensearch.common.lease.Releasables;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.AbstractRunnable;
@@ -47,6 +49,7 @@
 import org.opensearch.index.translog.transfer.BlobStoreTransferService;
 import org.opensearch.index.translog.transfer.TranslogTransferManager;
 import org.opensearch.index.translog.transfer.TranslogTransferMetadata;
+import org.opensearch.index.translog.transfer.TranslogUploadFailedException;
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
@@ -67,6 +70,7 @@
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
@@ -95,6 +99,7 @@
 import java.util.zip.CheckedInputStream;
 
 import static org.opensearch.common.util.BigArrays.NON_RECYCLING_INSTANCE;
+import static org.opensearch.index.IndexSettings.INDEX_REMOTE_TRANSLOG_KEEP_EXTRA_GEN_SETTING;
 import static org.opensearch.index.translog.RemoteFsTranslog.TRANSLOG;
 import static org.opensearch.index.translog.SnapshotMatchers.containsOperationsInAnyOrder;
 import static org.opensearch.index.translog.TranslogDeletionPolicies.createTranslogDeletionPolicy;
@@ -108,7 +113,6 @@
 import static org.mockito.Mockito.when;
 
 @LuceneTestCase.SuppressFileSystems("ExtrasFS")
-
 public class RemoteFsTranslogTests extends OpenSearchTestCase {
 
     protected final ShardId shardId = new ShardId("index", "_na_", 1);
@@ -123,12 +127,15 @@ public class RemoteFsTranslogTests extends OpenSearchTestCase {
     private ThreadPool threadPool;
     private final static String METADATA_DIR = "metadata";
     private final static String DATA_DIR = "data";
+    AtomicInteger writeCalls = new AtomicInteger();
     BlobStoreRepository repository;
 
     BlobStoreTransferService blobStoreTransferService;
 
     TestTranslog.FailSwitch fail;
 
+    TestTranslog.SlowDownWriteSwitch slowDown;
+
     private LongConsumer getPersistedSeqNoConsumer() {
         return seqNo -> {
             final LongConsumer consumer = persistedSeqNoConsumer.get();
@@ -162,13 +169,13 @@ public void tearDown() throws Exception {
 
     private RemoteFsTranslog create(Path path) throws IOException {
         final String translogUUID = Translog.createEmptyTranslog(path, SequenceNumbers.NO_OPS_PERFORMED, shardId, primaryTerm.get());
-        return create(path, createRepository(), translogUUID);
+        return create(path, createRepository(), translogUUID, 0);
     }
 
-    private RemoteFsTranslog create(Path path, BlobStoreRepository repository, String translogUUID) throws IOException {
+    private RemoteFsTranslog create(Path path, BlobStoreRepository repository, String translogUUID, int extraGenToKeep) throws IOException {
         this.repository = repository;
         globalCheckpoint = new AtomicLong(SequenceNumbers.NO_OPS_PERFORMED);
-        final TranslogConfig translogConfig = getTranslogConfig(path);
+        final TranslogConfig translogConfig = getTranslogConfig(path, extraGenToKeep);
         final TranslogDeletionPolicy deletionPolicy = createTranslogDeletionPolicy(translogConfig.getIndexSettings());
         threadPool = new TestThreadPool(getClass().getName());
         blobStoreTransferService = new BlobStoreTransferService(repository.blobStore(), threadPool);
@@ -184,10 +191,17 @@ private RemoteFsTranslog create(Path path, BlobStoreRepository repository, Strin
             primaryMode::get,
             new RemoteTranslogTransferTracker(shardId, 10)
         );
+    }
 
+    private RemoteFsTranslog create(Path path, BlobStoreRepository repository, String translogUUID) throws IOException {
+        return create(path, repository, translogUUID, 0);
     }
 
     private TranslogConfig getTranslogConfig(final Path path) {
+        return getTranslogConfig(path, 0);
+    }
+
+    private TranslogConfig getTranslogConfig(final Path path, int gensToKeep) {
         final Settings settings = Settings.builder()
             .put(IndexMetadata.SETTING_VERSION_CREATED, org.opensearch.Version.CURRENT)
             // only randomize between nog age retention and a long one, so failures will have a chance of reproducing
@@ -195,6 +209,7 @@ private TranslogConfig getTranslogConfig(final Path path) {
             .put(IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING.getKey(), randomIntBetween(-1, 2048) + "b")
             .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
             .put(IndexMetadata.SETTING_REMOTE_STORE_ENABLED, true)
+            .put(INDEX_REMOTE_TRANSLOG_KEEP_EXTRA_GEN_SETTING.getKey(), gensToKeep)
             .build();
         return getTranslogConfig(path, settings);
     }
@@ -207,7 +222,7 @@ private TranslogConfig getTranslogConfig(final Path path, final Settings setting
         );
 
         final IndexSettings indexSettings = IndexSettingsModule.newIndexSettings(shardId.getIndex(), settings);
-        return new TranslogConfig(shardId, path, indexSettings, NON_RECYCLING_INSTANCE, bufferSize);
+        return new TranslogConfig(shardId, path, indexSettings, NON_RECYCLING_INSTANCE, bufferSize, "");
     }
 
     private BlobStoreRepository createRepository() {
@@ -216,13 +231,15 @@ private BlobStoreRepository createRepository() {
         final ClusterService clusterService = BlobStoreTestUtil.mockClusterService(repositoryMetadata);
         fail = new TestTranslog.FailSwitch();
         fail.failNever();
+        slowDown = new TestTranslog.SlowDownWriteSwitch();
         final FsRepository repository = new ThrowingBlobRepository(
             repositoryMetadata,
             createEnvironment(),
             xContentRegistry(),
             clusterService,
             new RecoverySettings(Settings.EMPTY, new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)),
-            fail
+            fail,
+            slowDown
         ) {
             @Override
             protected void assertSnapshotOrGenericThread() {
@@ -371,6 +388,111 @@ public void testSimpleOperations() throws IOException {
 
     }
 
+    private TranslogConfig getConfig(int gensToKeep) {
+        Path tempDir = createTempDir();
+        final TranslogConfig temp = getTranslogConfig(tempDir, gensToKeep);
+        final TranslogConfig config = new TranslogConfig(
+            temp.getShardId(),
+            temp.getTranslogPath(),
+            temp.getIndexSettings(),
+            temp.getBigArrays(),
+            new ByteSizeValue(1, ByteSizeUnit.KB),
+            ""
+        );
+        return config;
+    }
+
+    private ChannelFactory getChannelFactory() {
+        writeCalls = new AtomicInteger();
+        final ChannelFactory channelFactory = (file, openOption) -> {
+            FileChannel delegate = FileChannel.open(file, openOption);
+            boolean success = false;
+            try {
+                // don't do partial writes for checkpoints we rely on the fact that the bytes are written as an atomic operation
+                final boolean isCkpFile = file.getFileName().toString().endsWith(".ckp");
+
+                final FileChannel channel;
+                if (isCkpFile) {
+                    channel = delegate;
+                } else {
+                    channel = new FilterFileChannel(delegate) {
+
+                        @Override
+                        public int write(ByteBuffer src) throws IOException {
+                            writeCalls.incrementAndGet();
+                            return super.write(src);
+                        }
+                    };
+                }
+                success = true;
+                return channel;
+            } finally {
+                if (success == false) {
+                    IOUtils.closeWhileHandlingException(delegate);
+                }
+            }
+        };
+        return channelFactory;
+    }
+
+    public void testExtraGenToKeep() throws Exception {
+        TranslogConfig config = getConfig(1);
+        ChannelFactory channelFactory = getChannelFactory();
+        final Set<Long> persistedSeqNos = new HashSet<>();
+        String translogUUID = Translog.createEmptyTranslog(
+            config.getTranslogPath(),
+            SequenceNumbers.NO_OPS_PERFORMED,
+            shardId,
+            channelFactory,
+            primaryTerm.get()
+        );
+        TranslogDeletionPolicy deletionPolicy = createTranslogDeletionPolicy(config.getIndexSettings());
+        ArrayList<Translog.Operation> ops = new ArrayList<>();
+        try (
+            RemoteFsTranslog translog = new RemoteFsTranslog(
+                config,
+                translogUUID,
+                deletionPolicy,
+                () -> SequenceNumbers.NO_OPS_PERFORMED,
+                primaryTerm::get,
+                persistedSeqNos::add,
+                repository,
+                threadPool,
+                () -> Boolean.TRUE,
+                new RemoteTranslogTransferTracker(shardId, 10)
+            ) {
+                @Override
+                ChannelFactory getChannelFactory() {
+                    return channelFactory;
+                }
+            }
+        ) {
+            addToTranslogAndListAndUpload(translog, ops, new Translog.Index("1", 0, primaryTerm.get(), new byte[] { 1 }));
+
+            addToTranslogAndListAndUpload(translog, ops, new Translog.Index("2", 1, primaryTerm.get(), new byte[] { 1 }));
+
+            addToTranslogAndListAndUpload(translog, ops, new Translog.Index("3", 2, primaryTerm.get(), new byte[] { 1 }));
+
+            // expose the new checkpoint (simulating a commit), before we trim the translog
+            translog.setMinSeqNoToKeep(2);
+
+            // Trims from local
+            translog.trimUnreferencedReaders();
+            assertBusy(() -> assertTrue(translog.isRemoteGenerationDeletionPermitsAvailable()));
+
+            addToTranslogAndListAndUpload(translog, ops, new Translog.Index("4", 3, primaryTerm.get(), new byte[] { 1 }));
+
+            // Trims from remote now
+            translog.trimUnreferencedReaders();
+            assertBusy(() -> assertTrue(translog.isRemoteGenerationDeletionPermitsAvailable()));
+            assertEquals(
+                6,
+                blobStoreTransferService.listAll(getTranslogDirectory().add(DATA_DIR).add(String.valueOf(primaryTerm.get()))).size()
+            );
+
+        }
+    }
+
     public void testReadLocation() throws IOException {
         ArrayList<Translog.Operation> ops = new ArrayList<>();
         ArrayList<Translog.Location> locs = new ArrayList<>();
@@ -618,13 +740,22 @@ public void testSimpleOperationsUpload() throws Exception {
         // this should now trim as tlog-2 files from remote, but not tlog-3 and tlog-4
         addToTranslogAndListAndUpload(translog, ops, new Translog.Index("2", 2, primaryTerm.get(), new byte[] { 1 }));
         assertEquals(2, translog.stats().estimatedNumberOfOperations());
+        assertBusy(() -> assertTrue(translog.isRemoteGenerationDeletionPermitsAvailable()));
 
         translog.setMinSeqNoToKeep(2);
-
+        // this should now trim as tlog-2 files from remote, but not tlog-3 and tlog-4
         translog.trimUnreferencedReaders();
+        assertBusy(() -> assertTrue(translog.isRemoteGenerationDeletionPermitsAvailable()));
         assertEquals(1, translog.readers.size());
         assertEquals(1, translog.stats().estimatedNumberOfOperations());
-        assertBusy(() -> assertEquals(4, translog.allUploaded().size()));
+        assertBusy(() -> {
+            assertEquals(4, translog.allUploaded().size());
+            assertEquals(
+                4,
+                blobStoreTransferService.listAll(getTranslogDirectory().add(DATA_DIR).add(String.valueOf(primaryTerm.get()))).size()
+            );
+        });
+
     }
 
     public void testMetadataFileDeletion() throws Exception {
@@ -693,6 +824,79 @@ public void testMetadataFileDeletion() throws Exception {
         }
     }
 
+    public void testDrainSync() throws Exception {
+        // This test checks following scenarios -
+        // 1. During ongoing uploads, the available permits are 0.
+        // 2. During an upload, if drainSync is called, it will wait for it to acquire and available permits are 0.
+        // 3. After drainSync, if trimUnreferencedReaders is attempted, we do not delete from remote store.
+        // 4. After drainSync, if an upload is an attempted, we do not upload to remote store.
+        ArrayList<Translog.Operation> ops = new ArrayList<>();
+        assertEquals(0, translog.allUploaded().size());
+        assertEquals(1, translog.readers.size());
+
+        addToTranslogAndListAndUpload(translog, ops, new Translog.Index(String.valueOf(0), 0, primaryTerm.get(), new byte[] { 1 }));
+        assertEquals(4, translog.allUploaded().size());
+        assertEquals(2, translog.readers.size());
+        assertBusy(() -> assertEquals(1, blobStoreTransferService.listAll(getTranslogDirectory().add(METADATA_DIR)).size()));
+
+        translog.setMinSeqNoToKeep(0);
+        translog.trimUnreferencedReaders();
+        assertEquals(1, translog.readers.size());
+
+        // Case 1 - During ongoing uploads, the available permits are 0.
+        slowDown.setSleepSeconds(2);
+        CountDownLatch latch = new CountDownLatch(1);
+        Thread thread1 = new Thread(() -> {
+            try {
+                addToTranslogAndListAndUpload(translog, ops, new Translog.Index(String.valueOf(1), 1, primaryTerm.get(), new byte[] { 1 }));
+                assertEquals(2, blobStoreTransferService.listAll(getTranslogDirectory().add(METADATA_DIR)).size());
+                latch.countDown();
+            } catch (IOException e) {
+                throw new AssertionError(e);
+            }
+        });
+        thread1.start();
+        assertBusy(() -> assertEquals(0, translog.availablePermits()));
+        // Case 2 - During an upload, if drainSync is called, it will wait for it to acquire and available permits are 0.
+        Releasable releasable = translog.drainSync();
+        assertBusy(() -> assertEquals(0, latch.getCount()));
+        assertEquals(0, translog.availablePermits());
+        slowDown.setSleepSeconds(0);
+        assertEquals(6, translog.allUploaded().size());
+        assertEquals(2, translog.readers.size());
+        Set<String> mdFiles = blobStoreTransferService.listAll(getTranslogDirectory().add(METADATA_DIR));
+
+        // Case 3 - After drainSync, if trimUnreferencedReaders is attempted, we do not delete from remote store.
+        translog.setMinSeqNoToKeep(1);
+        translog.trimUnreferencedReaders();
+        assertEquals(1, translog.readers.size());
+        assertEquals(6, translog.allUploaded().size());
+        assertEquals(mdFiles, blobStoreTransferService.listAll(getTranslogDirectory().add(METADATA_DIR)));
+
+        // Case 4 - After drainSync, if an upload is an attempted, we do not upload to remote store.
+        Translog.Location loc = addToTranslogAndListAndUpload(
+            translog,
+            ops,
+            new Translog.Index(String.valueOf(2), 2, primaryTerm.get(), new byte[] { 1 })
+        );
+        assertEquals(1, translog.readers.size());
+        assertEquals(6, translog.allUploaded().size());
+        assertEquals(mdFiles, blobStoreTransferService.listAll(getTranslogDirectory().add(METADATA_DIR)));
+
+        // Refill the permits back
+        Releasables.close(releasable);
+        addToTranslogAndListAndUpload(translog, ops, new Translog.Index(String.valueOf(3), 3, primaryTerm.get(), new byte[] { 1 }));
+        assertEquals(2, translog.readers.size());
+        assertEquals(8, translog.allUploaded().size());
+        assertEquals(3, blobStoreTransferService.listAll(getTranslogDirectory().add(METADATA_DIR)).size());
+
+        translog.setMinSeqNoToKeep(3);
+        translog.trimUnreferencedReaders();
+        assertEquals(1, translog.readers.size());
+        assertBusy(() -> assertEquals(4, translog.allUploaded().size()));
+        assertBusy(() -> assertEquals(1, blobStoreTransferService.listAll(getTranslogDirectory().add(METADATA_DIR)).size()));
+    }
+
     private BlobPath getTranslogDirectory() {
         return repository.basePath().add(shardId.getIndex().getUUID()).add(String.valueOf(shardId.id())).add(TRANSLOG);
     }
@@ -1049,7 +1253,7 @@ public void testSyncUpTo() throws IOException {
         }
     }
 
-    public void testSyncUpFailure() throws IOException {
+    public void testSyncUpLocationFailure() throws IOException {
         int translogOperations = randomIntBetween(1, 20);
         int count = 0;
         fail.failAlways();
@@ -1101,6 +1305,26 @@ public void testSyncUpFailure() throws IOException {
         assertDownloadStatsNoDownloads(statsTracker);
     }
 
+    public void testSyncUpAlwaysFailure() throws IOException {
+        int translogOperations = randomIntBetween(1, 20);
+        int count = 0;
+        fail.failAlways();
+        for (int op = 0; op < translogOperations; op++) {
+            translog.add(
+                new Translog.Index(String.valueOf(op), count, primaryTerm.get(), Integer.toString(count).getBytes(StandardCharsets.UTF_8))
+            );
+            try {
+                translog.sync();
+                fail("io exception expected");
+            } catch (TranslogUploadFailedException e) {
+                assertTrue("at least one operation pending", translog.syncNeeded());
+            }
+        }
+        assertTrue(translog.isOpen());
+        fail.failNever();
+        translog.sync();
+    }
+
     public void testSyncUpToStream() throws IOException {
         int iters = randomIntBetween(5, 10);
         for (int i = 0; i < iters; i++) {
@@ -1251,48 +1475,10 @@ public void testTranslogWriter() throws IOException {
     }
 
     public void testTranslogWriterCanFlushInAddOrReadCall() throws IOException {
-        Path tempDir = createTempDir();
-        final TranslogConfig temp = getTranslogConfig(tempDir);
-        final TranslogConfig config = new TranslogConfig(
-            temp.getShardId(),
-            temp.getTranslogPath(),
-            temp.getIndexSettings(),
-            temp.getBigArrays(),
-            new ByteSizeValue(1, ByteSizeUnit.KB)
-        );
-
+        final TranslogConfig config = getConfig(1);
         final Set<Long> persistedSeqNos = new HashSet<>();
-        final AtomicInteger writeCalls = new AtomicInteger();
-
-        final ChannelFactory channelFactory = (file, openOption) -> {
-            FileChannel delegate = FileChannel.open(file, openOption);
-            boolean success = false;
-            try {
-                // don't do partial writes for checkpoints we rely on the fact that the bytes are written as an atomic operation
-                final boolean isCkpFile = file.getFileName().toString().endsWith(".ckp");
-
-                final FileChannel channel;
-                if (isCkpFile) {
-                    channel = delegate;
-                } else {
-                    channel = new FilterFileChannel(delegate) {
-
-                        @Override
-                        public int write(ByteBuffer src) throws IOException {
-                            writeCalls.incrementAndGet();
-                            return super.write(src);
-                        }
-                    };
-                }
-                success = true;
-                return channel;
-            } finally {
-                if (success == false) {
-                    IOUtils.closeWhileHandlingException(delegate);
-                }
-            }
-        };
-
+        writeCalls = new AtomicInteger();
+        final ChannelFactory channelFactory = getChannelFactory();
         String translogUUID = Translog.createEmptyTranslog(
             config.getTranslogPath(),
             SequenceNumbers.NO_OPS_PERFORMED,
@@ -1360,7 +1546,8 @@ public void testTranslogWriterFsyncDisabledInRemoteFsTranslog() throws IOExcepti
             temp.getTranslogPath(),
             temp.getIndexSettings(),
             temp.getBigArrays(),
-            new ByteSizeValue(1, ByteSizeUnit.KB)
+            new ByteSizeValue(1, ByteSizeUnit.KB),
+            ""
         );
 
         final Set<Long> persistedSeqNos = new HashSet<>();
@@ -1515,9 +1702,10 @@ public void testDownloadWithRetries() throws IOException {
     }
 
     public class ThrowingBlobRepository extends FsRepository {
-        private final Environment environment;
 
-        private TestTranslog.FailSwitch fail;
+        private final Environment environment;
+        private final TestTranslog.FailSwitch fail;
+        private final TestTranslog.SlowDownWriteSwitch slowDown;
 
         public ThrowingBlobRepository(
             RepositoryMetadata metadata,
@@ -1525,33 +1713,43 @@ public ThrowingBlobRepository(
             NamedXContentRegistry namedXContentRegistry,
             ClusterService clusterService,
             RecoverySettings recoverySettings,
-            TestTranslog.FailSwitch fail
+            TestTranslog.FailSwitch fail,
+            TestTranslog.SlowDownWriteSwitch slowDown
         ) {
             super(metadata, environment, namedXContentRegistry, clusterService, recoverySettings);
             this.environment = environment;
             this.fail = fail;
+            this.slowDown = slowDown;
         }
 
         protected BlobStore createBlobStore() throws Exception {
             final String location = REPOSITORIES_LOCATION_SETTING.get(getMetadata().settings());
             final Path locationFile = environment.resolveRepoFile(location);
-            return new ThrowingBlobStore(bufferSize, locationFile, isReadOnly(), fail);
+            return new ThrowingBlobStore(bufferSize, locationFile, isReadOnly(), fail, slowDown);
         }
     }
 
     private class ThrowingBlobStore extends FsBlobStore {
 
-        private TestTranslog.FailSwitch fail;
+        private final TestTranslog.FailSwitch fail;
+        private final TestTranslog.SlowDownWriteSwitch slowDown;
 
-        public ThrowingBlobStore(int bufferSizeInBytes, Path path, boolean readonly, TestTranslog.FailSwitch fail) throws IOException {
+        public ThrowingBlobStore(
+            int bufferSizeInBytes,
+            Path path,
+            boolean readonly,
+            TestTranslog.FailSwitch fail,
+            TestTranslog.SlowDownWriteSwitch slowDown
+        ) throws IOException {
             super(bufferSizeInBytes, path, readonly);
             this.fail = fail;
+            this.slowDown = slowDown;
         }
 
         @Override
         public BlobContainer blobContainer(BlobPath path) {
             try {
-                return new ThrowingBlobContainer(this, path, buildAndCreate(path), fail);
+                return new ThrowingBlobContainer(this, path, buildAndCreate(path), fail, slowDown);
             } catch (IOException ex) {
                 throw new OpenSearchException("failed to create blob container", ex);
             }
@@ -1561,17 +1759,33 @@ public BlobContainer blobContainer(BlobPath path) {
     private class ThrowingBlobContainer extends FsBlobContainer {
 
         private TestTranslog.FailSwitch fail;
-
-        public ThrowingBlobContainer(FsBlobStore blobStore, BlobPath blobPath, Path path, TestTranslog.FailSwitch fail) {
+        private final TestTranslog.SlowDownWriteSwitch slowDown;
+
+        public ThrowingBlobContainer(
+            FsBlobStore blobStore,
+            BlobPath blobPath,
+            Path path,
+            TestTranslog.FailSwitch fail,
+            TestTranslog.SlowDownWriteSwitch slowDown
+        ) {
             super(blobStore, blobPath, path);
             this.fail = fail;
+            this.slowDown = slowDown;
         }
 
+        @Override
         public void writeBlobAtomic(final String blobName, final InputStream inputStream, final long blobSize, boolean failIfAlreadyExists)
             throws IOException {
             if (fail.fail()) {
                 throw new IOException("blob container throwing error");
             }
+            if (slowDown.getSleepSeconds() > 0) {
+                try {
+                    Thread.sleep(slowDown.getSleepSeconds() * 1000L);
+                } catch (InterruptedException e) {
+                    throw new RuntimeException(e);
+                }
+            }
             super.writeBlobAtomic(blobName, inputStream, blobSize, failIfAlreadyExists);
         }
     }
diff --git a/server/src/test/java/org/opensearch/index/translog/TestTranslog.java b/server/src/test/java/org/opensearch/index/translog/TestTranslog.java
index fd4be1d7a8635..01c8844b51b02 100644
--- a/server/src/test/java/org/opensearch/index/translog/TestTranslog.java
+++ b/server/src/test/java/org/opensearch/index/translog/TestTranslog.java
@@ -335,6 +335,18 @@ public void onceFailedFailAlways() {
         }
     }
 
+    static class SlowDownWriteSwitch {
+        private volatile int sleepSeconds;
+
+        public void setSleepSeconds(int sleepSeconds) {
+            this.sleepSeconds = sleepSeconds;
+        }
+
+        public int getSleepSeconds() {
+            return sleepSeconds;
+        }
+    }
+
     static class SortedSnapshot implements Translog.Snapshot {
         private final Translog.Snapshot snapshot;
         private List<Translog.Operation> operations = null;
diff --git a/server/src/test/java/org/opensearch/index/translog/TranslogManagerTestCase.java b/server/src/test/java/org/opensearch/index/translog/TranslogManagerTestCase.java
index 43b4d2c9847ab..e17d2770f014a 100644
--- a/server/src/test/java/org/opensearch/index/translog/TranslogManagerTestCase.java
+++ b/server/src/test/java/org/opensearch/index/translog/TranslogManagerTestCase.java
@@ -74,7 +74,7 @@ protected Translog createTranslog(LongSupplier primaryTermSupplier) throws IOExc
     }
 
     protected Translog createTranslog(Path translogPath, LongSupplier primaryTermSupplier) throws IOException {
-        TranslogConfig translogConfig = new TranslogConfig(shardId, translogPath, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE);
+        TranslogConfig translogConfig = new TranslogConfig(shardId, translogPath, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, "");
         String translogUUID = Translog.createEmptyTranslog(
             translogPath,
             SequenceNumbers.NO_OPS_PERFORMED,
diff --git a/server/src/test/java/org/opensearch/index/translog/transfer/TranslogTransferManagerTests.java b/server/src/test/java/org/opensearch/index/translog/transfer/TranslogTransferManagerTests.java
index 6fc4557a75675..e34bc078896f9 100644
--- a/server/src/test/java/org/opensearch/index/translog/transfer/TranslogTransferManagerTests.java
+++ b/server/src/test/java/org/opensearch/index/translog/transfer/TranslogTransferManagerTests.java
@@ -10,12 +10,14 @@
 
 import org.apache.lucene.tests.util.LuceneTestCase;
 import org.opensearch.action.LatchedActionListener;
+import org.opensearch.common.SetOnce;
 import org.opensearch.common.blobstore.BlobContainer;
 import org.opensearch.common.blobstore.BlobMetadata;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.blobstore.BlobStore;
 import org.opensearch.common.blobstore.stream.write.WritePriority;
 import org.opensearch.common.blobstore.support.PlainBlobMetadata;
+import org.opensearch.common.collect.Tuple;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.Index;
 import org.opensearch.core.index.shard.ShardId;
@@ -34,15 +36,19 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
+import java.util.UUID;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.mockito.Mockito;
 
+import static org.opensearch.index.translog.transfer.TranslogTransferMetadata.METADATA_SEPARATOR;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.anyMap;
 import static org.mockito.ArgumentMatchers.anySet;
@@ -176,6 +182,93 @@ public void onUploadFailed(TransferSnapshot transferSnapshot, Exception ex) {
         assertEquals(4, fileTransferTracker.allUploaded().size());
     }
 
+    public void testTransferSnapshotOnUploadTimeout() throws Exception {
+        doAnswer(invocationOnMock -> {
+            Thread.sleep(31 * 1000);
+            return null;
+        }).when(transferService).uploadBlobs(anySet(), anyMap(), any(ActionListener.class), any(WritePriority.class));
+        FileTransferTracker fileTransferTracker = new FileTransferTracker(
+            new ShardId("index", "indexUUid", 0),
+            remoteTranslogTransferTracker
+        );
+        TranslogTransferManager translogTransferManager = new TranslogTransferManager(
+            shardId,
+            transferService,
+            remoteBaseTransferPath,
+            fileTransferTracker,
+            remoteTranslogTransferTracker
+        );
+        SetOnce<Exception> exception = new SetOnce<>();
+        translogTransferManager.transferSnapshot(createTransferSnapshot(), new TranslogTransferListener() {
+            @Override
+            public void onUploadComplete(TransferSnapshot transferSnapshot) {}
+
+            @Override
+            public void onUploadFailed(TransferSnapshot transferSnapshot, Exception ex) {
+                exception.set(ex);
+            }
+        });
+        assertNotNull(exception.get());
+        assertTrue(exception.get() instanceof TranslogUploadFailedException);
+        assertEquals("Timed out waiting for transfer of snapshot test-to-string to complete", exception.get().getMessage());
+    }
+
+    public void testTransferSnapshotOnThreadInterrupt() throws Exception {
+        SetOnce<Thread> uploadThread = new SetOnce<>();
+        doAnswer(invocationOnMock -> {
+            uploadThread.set(new Thread(() -> {
+                ActionListener<TransferFileSnapshot> listener = invocationOnMock.getArgument(2);
+                try {
+                    Thread.sleep(31 * 1000);
+                } catch (InterruptedException ignore) {
+                    List<TransferFileSnapshot> list = new ArrayList<>(invocationOnMock.getArgument(0));
+                    listener.onFailure(new FileTransferException(list.get(0), ignore));
+                }
+            }));
+            uploadThread.get().start();
+            return null;
+        }).when(transferService).uploadBlobs(anySet(), anyMap(), any(ActionListener.class), any(WritePriority.class));
+        FileTransferTracker fileTransferTracker = new FileTransferTracker(
+            new ShardId("index", "indexUUid", 0),
+            remoteTranslogTransferTracker
+        );
+        TranslogTransferManager translogTransferManager = new TranslogTransferManager(
+            shardId,
+            transferService,
+            remoteBaseTransferPath,
+            fileTransferTracker,
+            remoteTranslogTransferTracker
+        );
+        SetOnce<Exception> exception = new SetOnce<>();
+
+        Thread thread = new Thread(() -> {
+            try {
+                translogTransferManager.transferSnapshot(createTransferSnapshot(), new TranslogTransferListener() {
+                    @Override
+                    public void onUploadComplete(TransferSnapshot transferSnapshot) {}
+
+                    @Override
+                    public void onUploadFailed(TransferSnapshot transferSnapshot, Exception ex) {
+                        exception.set(ex);
+                    }
+                });
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        });
+        thread.start();
+
+        Thread.sleep(1000);
+        // Interrupt the thread
+        thread.interrupt();
+        assertBusy(() -> {
+            assertNotNull(exception.get());
+            assertTrue(exception.get() instanceof TranslogUploadFailedException);
+            assertEquals("Failed to upload test-to-string", exception.get().getMessage());
+        });
+        uploadThread.get().interrupt();
+    }
+
     private TransferSnapshot createTransferSnapshot() {
         return new TransferSnapshot() {
             @Override
@@ -228,6 +321,11 @@ public Set<TransferFileSnapshot> getTranslogFileSnapshots() {
             public TranslogTransferMetadata getTranslogTransferMetadata() {
                 return new TranslogTransferMetadata(primaryTerm, generation, minTranslogGeneration, randomInt(5));
             }
+
+            @Override
+            public String toString() {
+                return "test-to-string";
+            }
         };
     }
 
@@ -251,8 +349,8 @@ public void testReadMetadataNoFile() throws IOException {
         assertNoDownloadStats(false);
     }
 
-    // This should happen most of the time - Just a single metadata file
-    public void testReadMetadataSingleFile() throws IOException {
+    // This should happen most of the time -
+    public void testReadMetadataFile() throws IOException {
         TranslogTransferManager translogTransferManager = new TranslogTransferManager(
             shardId,
             transferService,
@@ -260,12 +358,16 @@ public void testReadMetadataSingleFile() throws IOException {
             null,
             remoteTranslogTransferTracker
         );
-        TranslogTransferMetadata tm = new TranslogTransferMetadata(1, 1, 1, 2);
-        String mdFilename = tm.getFileName();
+        TranslogTransferMetadata metadata1 = new TranslogTransferMetadata(1, 1, 1, 2);
+        String mdFilename1 = metadata1.getFileName();
+
+        TranslogTransferMetadata metadata2 = new TranslogTransferMetadata(1, 0, 1, 2);
+        String mdFilename2 = metadata2.getFileName();
         doAnswer(invocation -> {
             LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
             List<BlobMetadata> bmList = new LinkedList<>();
-            bmList.add(new PlainBlobMetadata(mdFilename, 1));
+            bmList.add(new PlainBlobMetadata(mdFilename1, 1));
+            bmList.add(new PlainBlobMetadata(mdFilename2, 1));
             latchedActionListener.onResponse(bmList);
             return null;
         }).when(transferService)
@@ -273,7 +375,7 @@ public void testReadMetadataSingleFile() throws IOException {
 
         TranslogTransferMetadata metadata = createTransferSnapshot().getTranslogTransferMetadata();
         long delayForMdDownload = 1;
-        when(transferService.downloadBlob(any(BlobPath.class), eq(mdFilename))).thenAnswer(invocation -> {
+        when(transferService.downloadBlob(any(BlobPath.class), eq(mdFilename1))).thenAnswer(invocation -> {
             Thread.sleep(delayForMdDownload);
             return new ByteArrayInputStream(translogTransferManager.getMetadataBytes(metadata));
         });
@@ -496,4 +598,43 @@ private void assertTlogCkpDownloadStats() {
         // Expect delay for both tlog and ckp file
         assertTrue(remoteTranslogTransferTracker.getTotalDownloadTimeInMillis() >= 2 * delayForBlobDownload);
     }
+
+    public void testGetPrimaryTermAndGeneration() {
+        String nodeId = UUID.randomUUID().toString();
+        String tm = new TranslogTransferMetadata(1, 2, 1, 2, nodeId).getFileName();
+        Tuple<Tuple<Long, Long>, String> actualOutput = TranslogTransferMetadata.getNodeIdByPrimaryTermAndGeneration(tm);
+        assertEquals(1L, (long) (actualOutput.v1().v1()));
+        assertEquals(2L, (long) (actualOutput.v1().v2()));
+        assertEquals(String.valueOf(Objects.hash(nodeId)), actualOutput.v2());
+    }
+
+    public void testMetadataConflict() throws InterruptedException {
+        TranslogTransferManager translogTransferManager = new TranslogTransferManager(
+            shardId,
+            transferService,
+            remoteBaseTransferPath,
+            null,
+            remoteTranslogTransferTracker
+        );
+        TranslogTransferMetadata tm = new TranslogTransferMetadata(1, 1, 1, 2, "node--1");
+        String mdFilename = tm.getFileName();
+        long count = mdFilename.chars().filter(ch -> ch == METADATA_SEPARATOR.charAt(0)).count();
+        // There should not be any `_` in mdFile name as it is used a separator .
+        assertEquals(10, count);
+        Thread.sleep(1);
+        TranslogTransferMetadata tm2 = new TranslogTransferMetadata(1, 1, 1, 2, "node--2");
+        String mdFilename2 = tm2.getFileName();
+
+        doAnswer(invocation -> {
+            LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
+            List<BlobMetadata> bmList = new LinkedList<>();
+            bmList.add(new PlainBlobMetadata(mdFilename, 1));
+            bmList.add(new PlainBlobMetadata(mdFilename2, 1));
+            latchedActionListener.onResponse(bmList);
+            return null;
+        }).when(transferService)
+            .listAllInSortedOrder(any(BlobPath.class), eq(TranslogTransferMetadata.METADATA_PREFIX), anyInt(), any(ActionListener.class));
+
+        assertThrows(RuntimeException.class, translogTransferManager::readMetadata);
+    }
 }
diff --git a/server/src/test/java/org/opensearch/indices/IndicesQueryCacheTests.java b/server/src/test/java/org/opensearch/indices/IndicesQueryCacheTests.java
index 58113f0123c8e..ba40343fb2130 100644
--- a/server/src/test/java/org/opensearch/indices/IndicesQueryCacheTests.java
+++ b/server/src/test/java/org/opensearch/indices/IndicesQueryCacheTests.java
@@ -151,7 +151,7 @@ public void testBasics() throws IOException {
         assertEquals(1L, stats.getCacheSize());
         assertEquals(1L, stats.getCacheCount());
         assertEquals(0L, stats.getHitCount());
-        assertEquals(1L, stats.getMissCount());
+        assertEquals(2L, stats.getMissCount());
         assertTrue(stats.getMemorySizeInBytes() > 0L && stats.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         for (int i = 1; i < 20; ++i) {
@@ -162,7 +162,7 @@ public void testBasics() throws IOException {
         assertEquals(10L, stats.getCacheSize());
         assertEquals(20L, stats.getCacheCount());
         assertEquals(0L, stats.getHitCount());
-        assertEquals(20L, stats.getMissCount());
+        assertEquals(40L, stats.getMissCount());
         assertTrue(stats.getMemorySizeInBytes() > 0L && stats.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         s.count(new DummyQuery(10));
@@ -171,7 +171,7 @@ public void testBasics() throws IOException {
         assertEquals(10L, stats.getCacheSize());
         assertEquals(20L, stats.getCacheCount());
         assertEquals(1L, stats.getHitCount());
-        assertEquals(20L, stats.getMissCount());
+        assertEquals(40L, stats.getMissCount());
         assertTrue(stats.getMemorySizeInBytes() > 0L && stats.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         IOUtils.close(r, dir);
@@ -181,7 +181,7 @@ public void testBasics() throws IOException {
         assertEquals(0L, stats.getCacheSize());
         assertEquals(20L, stats.getCacheCount());
         assertEquals(1L, stats.getHitCount());
-        assertEquals(20L, stats.getMissCount());
+        assertEquals(40L, stats.getMissCount());
         assertTrue(stats.getMemorySizeInBytes() > 0L && stats.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         cache.onClose(shard);
@@ -232,7 +232,7 @@ public void testTwoShards() throws IOException {
         assertEquals(1L, stats1.getCacheSize());
         assertEquals(1L, stats1.getCacheCount());
         assertEquals(0L, stats1.getHitCount());
-        assertEquals(1L, stats1.getMissCount());
+        assertEquals(2L, stats1.getMissCount());
         assertTrue(stats1.getMemorySizeInBytes() >= 0L && stats1.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         QueryCacheStats stats2 = cache.getStats(shard2);
@@ -248,14 +248,14 @@ public void testTwoShards() throws IOException {
         assertEquals(1L, stats1.getCacheSize());
         assertEquals(1L, stats1.getCacheCount());
         assertEquals(0L, stats1.getHitCount());
-        assertEquals(1L, stats1.getMissCount());
+        assertEquals(2L, stats1.getMissCount());
         assertTrue(stats1.getMemorySizeInBytes() >= 0L && stats1.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         stats2 = cache.getStats(shard2);
         assertEquals(1L, stats2.getCacheSize());
         assertEquals(1L, stats2.getCacheCount());
         assertEquals(0L, stats2.getHitCount());
-        assertEquals(1L, stats2.getMissCount());
+        assertEquals(2L, stats2.getMissCount());
         assertTrue(stats2.getMemorySizeInBytes() >= 0L && stats2.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         for (int i = 0; i < 20; ++i) {
@@ -266,14 +266,14 @@ public void testTwoShards() throws IOException {
         assertEquals(0L, stats1.getCacheSize()); // evicted
         assertEquals(1L, stats1.getCacheCount());
         assertEquals(0L, stats1.getHitCount());
-        assertEquals(1L, stats1.getMissCount());
+        assertEquals(2L, stats1.getMissCount());
         assertTrue(stats1.getMemorySizeInBytes() >= 0L && stats1.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         stats2 = cache.getStats(shard2);
         assertEquals(10L, stats2.getCacheSize());
         assertEquals(20L, stats2.getCacheCount());
         assertEquals(1L, stats2.getHitCount());
-        assertEquals(20L, stats2.getMissCount());
+        assertEquals(40L, stats2.getMissCount());
         assertTrue(stats2.getMemorySizeInBytes() >= 0L && stats2.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         IOUtils.close(r1, dir1);
@@ -283,14 +283,14 @@ public void testTwoShards() throws IOException {
         assertEquals(0L, stats1.getCacheSize());
         assertEquals(1L, stats1.getCacheCount());
         assertEquals(0L, stats1.getHitCount());
-        assertEquals(1L, stats1.getMissCount());
+        assertEquals(2L, stats1.getMissCount());
         assertTrue(stats1.getMemorySizeInBytes() >= 0L && stats1.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         stats2 = cache.getStats(shard2);
         assertEquals(10L, stats2.getCacheSize());
         assertEquals(20L, stats2.getCacheCount());
         assertEquals(1L, stats2.getHitCount());
-        assertEquals(20L, stats2.getMissCount());
+        assertEquals(40L, stats2.getMissCount());
         assertTrue(stats2.getMemorySizeInBytes() >= 0L && stats2.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         cache.onClose(shard1);
@@ -307,7 +307,7 @@ public void testTwoShards() throws IOException {
         assertEquals(10L, stats2.getCacheSize());
         assertEquals(20L, stats2.getCacheCount());
         assertEquals(1L, stats2.getHitCount());
-        assertEquals(20L, stats2.getMissCount());
+        assertEquals(40L, stats2.getMissCount());
         assertTrue(stats2.getMemorySizeInBytes() >= 0L && stats2.getMemorySizeInBytes() < Long.MAX_VALUE);
 
         IOUtils.close(r2, dir2);
@@ -388,8 +388,10 @@ public void testStatsOnEviction() throws IOException {
     private static class DummyWeight extends Weight {
 
         private final Weight weight;
+        private final int randCount = randomIntBetween(0, Integer.MAX_VALUE);
         private boolean scorerCalled;
         private boolean scorerSupplierCalled;
+        private boolean countCalled;
 
         DummyWeight(Weight weight) {
             super(weight.getQuery());
@@ -413,6 +415,12 @@ public ScorerSupplier scorerSupplier(LeafReaderContext context) throws IOExcepti
             return weight.scorerSupplier(context);
         }
 
+        @Override
+        public int count(LeafReaderContext context) throws IOException {
+            countCalled = true;
+            return randCount;
+        }
+
         @Override
         public boolean isCacheable(LeafReaderContext ctx) {
             return true;
@@ -458,4 +466,26 @@ public void onUse(Query query) {}
         cache.onClose(shard);
         cache.close();
     }
+
+    public void testDelegatesCount() throws Exception {
+        Directory dir = newDirectory();
+        IndexWriter w = new IndexWriter(dir, newIndexWriterConfig());
+        w.addDocument(new Document());
+        DirectoryReader r = DirectoryReader.open(w);
+        w.close();
+        ShardId shard = new ShardId("index", "_na_", 0);
+        r = OpenSearchDirectoryReader.wrap(r, shard);
+        IndexSearcher s = new IndexSearcher(r);
+        IndicesQueryCache cache = new IndicesQueryCache(Settings.EMPTY);
+        s.setQueryCache(cache);
+        Query query = new MatchAllDocsQuery();
+        final DummyWeight weight = new DummyWeight(s.createWeight(s.rewrite(query), ScoreMode.COMPLETE_NO_SCORES, 1f));
+        final Weight cached = cache.doCache(weight, s.getQueryCachingPolicy());
+        assertFalse(weight.countCalled);
+        assertEquals(weight.randCount, cached.count(s.getIndexReader().leaves().get(0)));
+        assertTrue(weight.countCalled);
+        IOUtils.close(r, dir);
+        cache.onClose(shard);
+        cache.close();
+    }
 }
diff --git a/server/src/test/java/org/opensearch/indices/IndicesServiceCloseTests.java b/server/src/test/java/org/opensearch/indices/IndicesServiceCloseTests.java
index 415844dccb611..add1dfc348a8b 100644
--- a/server/src/test/java/org/opensearch/indices/IndicesServiceCloseTests.java
+++ b/server/src/test/java/org/opensearch/indices/IndicesServiceCloseTests.java
@@ -32,8 +32,16 @@
 
 package org.opensearch.indices;
 
-import org.apache.lucene.document.LongPoint;
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.search.ConstantScoreScorer;
+import org.apache.lucene.search.ConstantScoreWeight;
+import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.Query;
+import org.apache.lucene.search.QueryVisitor;
+import org.apache.lucene.search.ScoreMode;
+import org.apache.lucene.search.Scorer;
+import org.apache.lucene.search.Weight;
 import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.routing.allocation.DiskThresholdSettings;
 import org.opensearch.common.cache.RemovalNotification;
@@ -59,6 +67,7 @@
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 import org.opensearch.transport.nio.MockNioTransportPlugin;
 
+import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Collections;
@@ -73,6 +82,56 @@
 
 public class IndicesServiceCloseTests extends OpenSearchTestCase {
 
+    private static class DummyQuery extends Query {
+
+        private final int id;
+
+        DummyQuery(int id) {
+            this.id = id;
+        }
+
+        @Override
+        public void visit(QueryVisitor visitor) {
+            visitor.visitLeaf(this);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            return sameClassAs(obj) && id == ((IndicesServiceCloseTests.DummyQuery) obj).id;
+        }
+
+        @Override
+        public int hashCode() {
+            return 31 * classHash() + id;
+        }
+
+        @Override
+        public String toString(String field) {
+            return "dummy";
+        }
+
+        @Override
+        public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
+            return new ConstantScoreWeight(this, boost) {
+                @Override
+                public Scorer scorer(LeafReaderContext context) throws IOException {
+                    return new ConstantScoreScorer(this, score(), scoreMode, DocIdSetIterator.all(context.reader().maxDoc()));
+                }
+
+                @Override
+                public int count(LeafReaderContext context) {
+                    return -1;
+                }
+
+                @Override
+                public boolean isCacheable(LeafReaderContext ctx) {
+                    return true;
+                }
+            };
+        }
+
+    }
+
     private Node startNode() throws NodeValidationException {
         final Path tempDir = createTempDir();
         String nodeName = "node_s_0";
@@ -225,7 +284,7 @@ public void testCloseAfterRequestHasUsedQueryCache() throws Exception {
         Engine.Searcher searcher = shard.acquireSearcher("test");
         assertEquals(1, searcher.getIndexReader().maxDoc());
 
-        Query query = LongPoint.newRangeQuery("foo", 0, 5);
+        Query query = new DummyQuery(1);
         assertEquals(0L, cache.getStats(shard.shardId()).getCacheSize());
         searcher.count(query);
         assertEquals(1L, cache.getStats(shard.shardId()).getCacheSize());
@@ -271,7 +330,7 @@ public void testCloseWhileOngoingRequestUsesQueryCache() throws Exception {
         node.close();
         assertEquals(1, indicesService.indicesRefCount.refCount());
 
-        Query query = LongPoint.newRangeQuery("foo", 0, 5);
+        Query query = new DummyQuery(1);
         assertEquals(0L, cache.getStats(shard.shardId()).getCacheSize());
         searcher.count(query);
         assertEquals(1L, cache.getStats(shard.shardId()).getCacheSize());
diff --git a/server/src/test/java/org/opensearch/indices/NodeIndicesStatsTests.java b/server/src/test/java/org/opensearch/indices/NodeIndicesStatsTests.java
index 9be45d4e77940..6f36d22b7e17b 100644
--- a/server/src/test/java/org/opensearch/indices/NodeIndicesStatsTests.java
+++ b/server/src/test/java/org/opensearch/indices/NodeIndicesStatsTests.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.indices;
 
+import org.opensearch.action.admin.indices.stats.CommonStats;
+import org.opensearch.action.search.SearchRequestStats;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.test.OpenSearchTestCase;
 
@@ -43,7 +45,9 @@
 public class NodeIndicesStatsTests extends OpenSearchTestCase {
 
     public void testInvalidLevel() {
-        final NodeIndicesStats stats = new NodeIndicesStats(null, Collections.emptyMap());
+        CommonStats oldStats = new CommonStats();
+        SearchRequestStats requestStats = new SearchRequestStats();
+        final NodeIndicesStats stats = new NodeIndicesStats(oldStats, Collections.emptyMap(), requestStats);
         final String level = randomAlphaOfLength(16);
         final ToXContent.Params params = new ToXContent.MapParams(Collections.singletonMap("level", level));
         final IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> stats.toXContent(null, params));
diff --git a/server/src/test/java/org/opensearch/indices/recovery/RecoverySettingsDynamicUpdateTests.java b/server/src/test/java/org/opensearch/indices/recovery/RecoverySettingsDynamicUpdateTests.java
index 75639661f539d..18e7dfb375132 100644
--- a/server/src/test/java/org/opensearch/indices/recovery/RecoverySettingsDynamicUpdateTests.java
+++ b/server/src/test/java/org/opensearch/indices/recovery/RecoverySettingsDynamicUpdateTests.java
@@ -96,4 +96,49 @@ public void testInternalLongActionTimeout() {
         );
         assertEquals(new TimeValue(duration, timeUnit), recoverySettings.internalActionLongTimeout());
     }
+
+    public void testSegmentMetadataRetention() {
+        // Default value
+        assertEquals(10, recoverySettings.getMinRemoteSegmentMetadataFiles());
+
+        // Setting value < default (10)
+        clusterSettings.applySettings(
+            Settings.builder().put(RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.getKey(), 5).build()
+        );
+        assertEquals(5, recoverySettings.getMinRemoteSegmentMetadataFiles());
+
+        // Setting min value
+        clusterSettings.applySettings(
+            Settings.builder().put(RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.getKey(), -1).build()
+        );
+        assertEquals(-1, recoverySettings.getMinRemoteSegmentMetadataFiles());
+
+        // Setting value > default (10)
+        clusterSettings.applySettings(
+            Settings.builder().put(RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.getKey(), 15).build()
+        );
+        assertEquals(15, recoverySettings.getMinRemoteSegmentMetadataFiles());
+
+        // Setting value to 0 should fail and retain the existing value
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> clusterSettings.applySettings(
+                Settings.builder()
+                    .put(RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.getKey(), 0)
+                    .build()
+            )
+        );
+        assertEquals(15, recoverySettings.getMinRemoteSegmentMetadataFiles());
+
+        // Setting value < -1 should fail and retain the existing value
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> clusterSettings.applySettings(
+                Settings.builder()
+                    .put(RecoverySettings.CLUSTER_REMOTE_INDEX_SEGMENT_METADATA_RETENTION_MAX_COUNT_SETTING.getKey(), -5)
+                    .build()
+            )
+        );
+        assertEquals(15, recoverySettings.getMinRemoteSegmentMetadataFiles());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/indices/recovery/RecoveryTests.java b/server/src/test/java/org/opensearch/indices/recovery/RecoveryTests.java
index 11d916616578d..ad90255a3cc3f 100644
--- a/server/src/test/java/org/opensearch/indices/recovery/RecoveryTests.java
+++ b/server/src/test/java/org/opensearch/indices/recovery/RecoveryTests.java
@@ -54,7 +54,7 @@
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.xcontent.MediaTypeRegistry;
 import org.opensearch.index.IndexSettings;
-import org.opensearch.index.MergePolicyConfig;
+import org.opensearch.index.MergePolicyProvider;
 import org.opensearch.index.VersionType;
 import org.opensearch.index.engine.DocIdSeqNoAndSource;
 import org.opensearch.index.engine.Engine;
@@ -168,7 +168,7 @@ public void testRecoveryWithOutOfOrderDeleteWithSoftDeletes() throws Exception {
             .put(IndexSettings.INDEX_SOFT_DELETES_RETENTION_OPERATIONS_SETTING.getKey(), 10)
             // If soft-deletes is enabled, delete#1 will be reclaimed because its segment (segment_1) is fully deleted
             // index#0 will be retained if merge is disabled; otherwise it will be reclaimed because gcp=3 and retained_ops=0
-            .put(MergePolicyConfig.INDEX_MERGE_ENABLED, false)
+            .put(MergePolicyProvider.INDEX_MERGE_ENABLED, false)
             .build();
         try (ReplicationGroup shards = createGroup(1, settings)) {
             shards.startAll();
diff --git a/server/src/test/java/org/opensearch/indices/replication/PrimaryShardReplicationSourceTests.java b/server/src/test/java/org/opensearch/indices/replication/PrimaryShardReplicationSourceTests.java
index bcacef83d190a..e4dd32e5c6f70 100644
--- a/server/src/test/java/org/opensearch/indices/replication/PrimaryShardReplicationSourceTests.java
+++ b/server/src/test/java/org/opensearch/indices/replication/PrimaryShardReplicationSourceTests.java
@@ -125,6 +125,7 @@ public void testGetSegmentFiles() {
             checkpoint,
             Arrays.asList(testMetadata),
             mock(IndexShard.class),
+            (fileName, bytesRecovered) -> {},
             mock(ActionListener.class)
         );
         CapturingTransport.CapturedRequest[] requestList = transport.getCapturedRequestsAndClear();
@@ -153,6 +154,7 @@ public void testTransportTimeoutForGetSegmentFilesAction() {
             checkpoint,
             Arrays.asList(testMetadata),
             mock(IndexShard.class),
+            (fileName, bytesRecovered) -> {},
             mock(ActionListener.class)
         );
         CapturingTransport.CapturedRequest[] requestList = transport.getCapturedRequestsAndClear();
@@ -178,6 +180,7 @@ public void testGetSegmentFiles_CancelWhileRequestOpen() throws InterruptedExcep
             checkpoint,
             Arrays.asList(testMetadata),
             mock(IndexShard.class),
+            (fileName, bytesRecovered) -> {},
             new ActionListener<>() {
                 @Override
                 public void onResponse(GetSegmentFilesResponse getSegmentFilesResponse) {
diff --git a/server/src/test/java/org/opensearch/indices/replication/RemoteStoreReplicationSourceTests.java b/server/src/test/java/org/opensearch/indices/replication/RemoteStoreReplicationSourceTests.java
index 9204f48ba5bdd..287962b158c79 100644
--- a/server/src/test/java/org/opensearch/indices/replication/RemoteStoreReplicationSourceTests.java
+++ b/server/src/test/java/org/opensearch/indices/replication/RemoteStoreReplicationSourceTests.java
@@ -90,7 +90,7 @@ public void testGetSegmentFiles() throws ExecutionException, InterruptedExceptio
         List<StoreFileMetadata> filesToFetch = primaryShard.getSegmentMetadataMap().values().stream().collect(Collectors.toList());
         final PlainActionFuture<GetSegmentFilesResponse> res = PlainActionFuture.newFuture();
         replicationSource = new RemoteStoreReplicationSource(primaryShard);
-        replicationSource.getSegmentFiles(REPLICATION_ID, checkpoint, filesToFetch, replicaShard, res);
+        replicationSource.getSegmentFiles(REPLICATION_ID, checkpoint, filesToFetch, replicaShard, (fileName, bytesRecovered) -> {}, res);
         GetSegmentFilesResponse response = res.get();
         assertEquals(response.files.size(), filesToFetch.size());
         assertTrue(response.files.containsAll(filesToFetch));
@@ -104,7 +104,14 @@ public void testGetSegmentFilesAlreadyExists() throws IOException, InterruptedEx
         try {
             final PlainActionFuture<GetSegmentFilesResponse> res = PlainActionFuture.newFuture();
             replicationSource = new RemoteStoreReplicationSource(primaryShard);
-            replicationSource.getSegmentFiles(REPLICATION_ID, checkpoint, filesToFetch, primaryShard, res);
+            replicationSource.getSegmentFiles(
+                REPLICATION_ID,
+                checkpoint,
+                filesToFetch,
+                primaryShard,
+                (fileName, bytesRecovered) -> {},
+                res
+            );
             res.get();
         } catch (AssertionError | ExecutionException ex) {
             latch.countDown();
@@ -118,7 +125,14 @@ public void testGetSegmentFilesReturnEmptyResponse() throws ExecutionException,
         final ReplicationCheckpoint checkpoint = primaryShard.getLatestReplicationCheckpoint();
         final PlainActionFuture<GetSegmentFilesResponse> res = PlainActionFuture.newFuture();
         replicationSource = new RemoteStoreReplicationSource(primaryShard);
-        replicationSource.getSegmentFiles(REPLICATION_ID, checkpoint, Collections.emptyList(), primaryShard, res);
+        replicationSource.getSegmentFiles(
+            REPLICATION_ID,
+            checkpoint,
+            Collections.emptyList(),
+            primaryShard,
+            (fileName, bytesRecovered) -> {},
+            res
+        );
         GetSegmentFilesResponse response = res.get();
         assert (response.files.isEmpty());
     }
diff --git a/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java b/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java
index c1f88a6938d33..f284a425a417b 100644
--- a/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java
+++ b/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java
@@ -9,13 +9,21 @@
 package org.opensearch.indices.replication;
 
 import org.apache.lucene.store.AlreadyClosedException;
+import org.opensearch.ExceptionsHelper;
 import org.opensearch.OpenSearchException;
 import org.opensearch.Version;
+import org.opensearch.cluster.ClusterChangedEvent;
+import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.cluster.routing.IndexRoutingTable;
+import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.cluster.routing.RoutingTable;
+import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.cluster.routing.ShardRoutingState;
+import org.opensearch.cluster.routing.UnassignedInfo;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
@@ -23,6 +31,7 @@
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.transport.TransportResponse;
+import org.opensearch.index.IndexService;
 import org.opensearch.index.engine.NRTReplicationEngineFactory;
 import org.opensearch.index.replication.TestReplicationSource;
 import org.opensearch.index.shard.IndexShard;
@@ -38,6 +47,7 @@
 import org.opensearch.indices.replication.common.ReplicationLuceneIndex;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.telemetry.tracing.noop.NoopTracer;
+import org.opensearch.test.junit.annotations.TestLogging;
 import org.opensearch.test.transport.CapturingTransport;
 import org.opensearch.threadpool.TestThreadPool;
 import org.opensearch.threadpool.ThreadPool;
@@ -49,10 +59,12 @@
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.function.BiConsumer;
 
-import static org.junit.Assert.assertEquals;
+import static org.opensearch.index.seqno.SequenceNumbers.NO_OPS_PERFORMED;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.Mockito.atLeastOnce;
@@ -88,6 +100,8 @@ public class SegmentReplicationTargetServiceTests extends IndexShardTestCase {
     private SegmentReplicationState state;
     private ReplicationCheckpoint initialCheckpoint;
 
+    private ClusterState clusterState;
+
     private static final long TRANSPORT_TIMEOUT = 30000;// 30sec
 
     @Override
@@ -126,7 +140,7 @@ public void setUp() throws Exception {
 
         indicesService = mock(IndicesService.class);
         ClusterService clusterService = mock(ClusterService.class);
-        ClusterState clusterState = mock(ClusterState.class);
+        clusterState = mock(ClusterState.class);
         RoutingTable mockRoutingTable = mock(RoutingTable.class);
         when(clusterService.state()).thenReturn(clusterState);
         when(clusterState.routingTable()).thenReturn(mockRoutingTable);
@@ -210,6 +224,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 Assert.fail("Should not be called");
@@ -243,9 +258,10 @@ public void testAlreadyOnNewCheckpoint() {
         SegmentReplicationTargetService spy = spy(sut);
         spy.onNewCheckpoint(replicaShard.getLatestReplicationCheckpoint(), replicaShard);
         verify(spy, times(0)).startReplication(any(), any(), any());
+        verify(spy, times(1)).updateVisibleCheckpoint(NO_OPS_PERFORMED, replicaShard);
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/8928")
+    @TestLogging(reason = "Getting trace logs from replication package", value = "org.opensearch.indices.replication:TRACE")
     public void testShardAlreadyReplicating() {
         CountDownLatch blockGetCheckpointMetadata = new CountDownLatch(1);
         SegmentReplicationSource source = new TestReplicationSource() {
@@ -275,6 +291,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 listener.onResponse(new GetSegmentFilesResponse(Collections.emptyList()));
@@ -332,6 +349,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 Assert.fail("Unreachable");
@@ -458,9 +476,22 @@ public void testStartReplicationListenerFailure() throws InterruptedException {
         verify(spy, (never())).updateVisibleCheckpoint(eq(0L), eq(replicaShard));
     }
 
-    public void testDoNotProcessLatestCheckpointIfItIsbehind() {
-        sut.updateLatestReceivedCheckpoint(replicaShard.getLatestReplicationCheckpoint(), replicaShard);
-        assertFalse(sut.processLatestReceivedCheckpoint(replicaShard, null));
+    public void testDoNotProcessLatestCheckpointIfCheckpointIsBehind() {
+        SegmentReplicationTargetService service = spy(sut);
+        doReturn(mock(SegmentReplicationTarget.class)).when(service).startReplication(any(), any(), any());
+        ReplicationCheckpoint checkpoint = replicaShard.getLatestReplicationCheckpoint();
+        service.updateLatestReceivedCheckpoint(checkpoint, replicaShard);
+        service.processLatestReceivedCheckpoint(replicaShard, null);
+        verify(service, times(0)).startReplication(eq(replicaShard), eq(checkpoint), any());
+    }
+
+    public void testProcessLatestCheckpointIfCheckpointAhead() {
+        SegmentReplicationTargetService service = spy(sut);
+        doNothing().when(service).startReplication(any());
+        doReturn(mock(SegmentReplicationTarget.class)).when(service).startReplication(any(), any(), any());
+        service.updateLatestReceivedCheckpoint(aheadCheckpoint, replicaShard);
+        service.processLatestReceivedCheckpoint(replicaShard, null);
+        verify(service, times(1)).startReplication(eq(replicaShard), eq(aheadCheckpoint), any());
     }
 
     public void testOnNewCheckpointInvokedOnClosedShardDoesNothing() throws IOException {
@@ -553,7 +584,7 @@ public void testForceSegmentSyncHandlerWithFailure() throws Exception {
             ).txGet();
         });
         Throwable nestedException = finalizeException.getCause().getCause();
-        assertTrue(nestedException instanceof IOException);
+        assertNotNull(ExceptionsHelper.unwrap(finalizeException, IOException.class));
         assertTrue(nestedException.getMessage().contains("dummy failure"));
     }
 
@@ -610,4 +641,46 @@ public void onReplicationFailure(SegmentReplicationState state, ReplicationFaile
         target.cancel("test");
         sut.startReplication(target);
     }
+
+    public void testProcessCheckpointOnClusterStateUpdate() {
+        // set up mocks on indicies & index service to return our replica's index & shard.
+        IndexService indexService = mock(IndexService.class);
+        when(indexService.iterator()).thenReturn(Set.of(replicaShard).iterator());
+        when(indexService.getIndexSettings()).thenReturn(replicaShard.indexSettings());
+        when(indexService.index()).thenReturn(replicaShard.routingEntry().index());
+        when(indicesService.iterator()).thenReturn(Set.of(indexService).iterator());
+
+        // create old & new cluster states
+        final String targetNodeId = "targetNodeId";
+        ShardRouting initialRouting = primaryShard.routingEntry().relocate(targetNodeId, 0L);
+        assertEquals(ShardRoutingState.RELOCATING, initialRouting.state());
+
+        ShardRouting targetRouting = ShardRouting.newUnassigned(
+            primaryShard.shardId(),
+            true,
+            RecoverySource.PeerRecoverySource.INSTANCE,
+            new UnassignedInfo(UnassignedInfo.Reason.REINITIALIZED, "test")
+        ).initialize(targetNodeId, initialRouting.allocationId().getId(), 0L).moveToStarted();
+        assertEquals(targetNodeId, targetRouting.currentNodeId());
+        assertEquals(ShardRoutingState.STARTED, targetRouting.state());
+        ClusterState oldState = ClusterState.builder(ClusterName.DEFAULT)
+            .routingTable(
+                RoutingTable.builder()
+                    .add(IndexRoutingTable.builder(primaryShard.shardId().getIndex()).addShard(initialRouting).build())
+                    .build()
+            )
+            .build();
+        ClusterState newState = ClusterState.builder(ClusterName.DEFAULT)
+            .routingTable(
+                RoutingTable.builder()
+                    .add(IndexRoutingTable.builder(primaryShard.shardId().getIndex()).addShard(targetRouting).build())
+                    .build()
+            )
+            .build();
+
+        // spy so we can verify process is invoked
+        SegmentReplicationTargetService spy = spy(sut);
+        spy.clusterChanged(new ClusterChangedEvent("ignored", oldState, newState));
+        verify(spy, times(1)).processLatestReceivedCheckpoint(eq(replicaShard), any());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetTests.java b/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetTests.java
index 2596dd6e62026..8b4b3aff701b4 100644
--- a/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetTests.java
+++ b/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetTests.java
@@ -40,6 +40,7 @@
 import org.opensearch.index.store.StoreTests;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 import org.opensearch.indices.replication.common.ReplicationFailedException;
+import org.opensearch.indices.replication.common.ReplicationLuceneIndex;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.test.DummyShardLock;
 import org.opensearch.test.IndexSettingsModule;
@@ -53,6 +54,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
+import java.util.function.BiConsumer;
 
 import org.mockito.Mockito;
 
@@ -131,10 +133,12 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 assertEquals(1, filesToFetch.size());
                 assert (filesToFetch.contains(SEGMENT_FILE));
+                filesToFetch.forEach(storeFileMetadata -> fileProgressTracker.accept(storeFileMetadata.name(), storeFileMetadata.length()));
                 listener.onResponse(new GetSegmentFilesResponse(filesToFetch));
             }
         };
@@ -149,6 +153,19 @@ public void getSegmentFiles(
             public void onResponse(Void replicationResponse) {
                 try {
                     verify(spyIndexShard, times(1)).finalizeReplication(any());
+                    assertEquals(
+                        1,
+                        segrepTarget.state()
+                            .getIndex()
+                            .fileDetails()
+                            .stream()
+                            .filter(ReplicationLuceneIndex.FileMetadata::fullyRecovered)
+                            .count()
+                    );
+                    assertEquals(
+                        0,
+                        segrepTarget.state().getIndex().fileDetails().stream().filter(file -> file.fullyRecovered() == false).count()
+                    );
                     segrepTarget.markAsDone();
                 } catch (IOException ex) {
                     Assert.fail();
@@ -182,6 +199,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 listener.onResponse(new GetSegmentFilesResponse(filesToFetch));
@@ -200,6 +218,15 @@ public void onResponse(Void replicationResponse) {
 
             @Override
             public void onFailure(Exception e) {
+                assertEquals(
+                    0,
+                    segrepTarget.state()
+                        .getIndex()
+                        .fileDetails()
+                        .stream()
+                        .filter(ReplicationLuceneIndex.FileMetadata::fullyRecovered)
+                        .count()
+                );
                 assertEquals(exception, e.getCause().getCause());
                 segrepTarget.fail(new ReplicationFailedException(e), false);
             }
@@ -225,6 +252,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 listener.onFailure(exception);
@@ -243,13 +271,22 @@ public void onResponse(Void replicationResponse) {
 
             @Override
             public void onFailure(Exception e) {
+                assertEquals(
+                    0,
+                    segrepTarget.state()
+                        .getIndex()
+                        .fileDetails()
+                        .stream()
+                        .filter(ReplicationLuceneIndex.FileMetadata::fullyRecovered)
+                        .count()
+                );
                 assertEquals(exception, e.getCause().getCause());
                 segrepTarget.fail(new ReplicationFailedException(e), false);
             }
         });
     }
 
-    public void testFailure_finalizeReplication_IOException() throws IOException {
+    public void testFailure_finalizeReplication_NonCorruptionException() throws IOException {
 
         IOException exception = new IOException("dummy failure");
         SegmentReplicationSource segrepSource = new TestReplicationSource() {
@@ -268,6 +305,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 listener.onResponse(new GetSegmentFilesResponse(filesToFetch));
@@ -288,6 +326,7 @@ public void onResponse(Void replicationResponse) {
 
             @Override
             public void onFailure(Exception e) {
+                assertEquals(ReplicationFailedException.class, e.getClass());
                 assertEquals(exception, e.getCause());
                 segrepTarget.fail(new ReplicationFailedException(e), false);
             }
@@ -313,6 +352,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 listener.onResponse(new GetSegmentFilesResponse(filesToFetch));
@@ -357,6 +397,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 listener.onResponse(new GetSegmentFilesResponse(filesToFetch));
@@ -375,6 +416,15 @@ public void onResponse(Void replicationResponse) {
 
             @Override
             public void onFailure(Exception e) {
+                assertEquals(
+                    0,
+                    segrepTarget.state()
+                        .getIndex()
+                        .fileDetails()
+                        .stream()
+                        .filter(ReplicationLuceneIndex.FileMetadata::fullyRecovered)
+                        .count()
+                );
                 assertTrue(e instanceof OpenSearchCorruptionException);
                 assertTrue(e.getMessage().contains("has local copies of segments that differ from the primary"));
                 segrepTarget.fail(new ReplicationFailedException(e), false);
@@ -409,6 +459,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 listener.onResponse(new GetSegmentFilesResponse(filesToFetch));
diff --git a/server/src/test/java/org/opensearch/ingest/IngestServiceTests.java b/server/src/test/java/org/opensearch/ingest/IngestServiceTests.java
index 1dfd41e96817e..2edfe87387c92 100644
--- a/server/src/test/java/org/opensearch/ingest/IngestServiceTests.java
+++ b/server/src/test/java/org/opensearch/ingest/IngestServiceTests.java
@@ -67,6 +67,7 @@
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.VersionType;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.plugins.IngestPlugin;
 import org.opensearch.script.MockScriptEngine;
 import org.opensearch.script.Script;
@@ -149,7 +150,8 @@ public void testIngestPlugin() {
             null,
             null,
             Collections.singletonList(DUMMY_PLUGIN),
-            client
+            client,
+            mock(IndicesService.class)
         );
         Map<String, Processor.Factory> factories = ingestService.getProcessorFactories();
         assertTrue(factories.containsKey("foo"));
@@ -167,7 +169,8 @@ public void testIngestPluginDuplicate() {
                 null,
                 null,
                 Arrays.asList(DUMMY_PLUGIN, DUMMY_PLUGIN),
-                client
+                client,
+                mock(IndicesService.class)
             )
         );
         assertTrue(e.getMessage(), e.getMessage().contains("already registered"));
@@ -182,7 +185,8 @@ public void testExecuteIndexPipelineDoesNotExist() {
             null,
             null,
             Collections.singletonList(DUMMY_PLUGIN),
-            client
+            client,
+            mock(IndicesService.class)
         );
         final IndexRequest indexRequest = new IndexRequest("_index").id("_id")
             .source(emptyMap())
@@ -1485,7 +1489,8 @@ public Map<String, Processor.Factory> getProcessors(Processor.Parameters paramet
             null,
             null,
             Arrays.asList(testPlugin),
-            client
+            client,
+            mock(IndicesService.class)
         );
         ingestService.addIngestClusterStateListener(ingestClusterStateListener);
 
@@ -1702,7 +1707,7 @@ private static IngestService createWithProcessors(Map<String, Processor.Factory>
             public Map<String, Processor.Factory> getProcessors(final Processor.Parameters parameters) {
                 return processors;
             }
-        }), client);
+        }), client, mock(IndicesService.class));
     }
 
     private CompoundProcessor mockCompoundProcessor() {
diff --git a/server/src/test/java/org/opensearch/monitor/fs/DeviceStatsTests.java b/server/src/test/java/org/opensearch/monitor/fs/DeviceStatsTests.java
index 0fd039b84e887..0059f8e215f2e 100644
--- a/server/src/test/java/org/opensearch/monitor/fs/DeviceStatsTests.java
+++ b/server/src/test/java/org/opensearch/monitor/fs/DeviceStatsTests.java
@@ -46,7 +46,12 @@ public void testDeviceStats() {
         final int sectorsRead = randomIntBetween(8 * readsCompleted, 16 * readsCompleted);
         final int writesCompleted = randomIntBetween(1, 1 << 16);
         final int sectorsWritten = randomIntBetween(8 * writesCompleted, 16 * writesCompleted);
-
+        final int readTime = randomIntBetween(1, 1 << 16);
+        ;
+        final int writeTime = randomIntBetween(1, 1 << 16);
+        ;
+        final int queueSize = randomIntBetween(1, 1 << 16);
+        final int ioTime = randomIntBetween(1, 1 << 16);
         FsInfo.DeviceStats previous = new FsInfo.DeviceStats(
             majorDeviceNumber,
             minorDeviceNumber,
@@ -55,6 +60,10 @@ public void testDeviceStats() {
             sectorsRead,
             writesCompleted,
             sectorsWritten,
+            readTime,
+            writeTime,
+            queueSize,
+            ioTime,
             null
         );
         FsInfo.DeviceStats current = new FsInfo.DeviceStats(
@@ -65,6 +74,10 @@ public void testDeviceStats() {
             sectorsRead + 16384,
             writesCompleted + 2048,
             sectorsWritten + 32768,
+            readTime + 500,
+            writeTime + 100,
+            queueSize + 20,
+            ioTime + 8192,
             previous
         );
         assertThat(current.operations(), equalTo(1024L + 2048L));
@@ -72,6 +85,10 @@ public void testDeviceStats() {
         assertThat(current.writeOperations(), equalTo(2048L));
         assertThat(current.readKilobytes(), equalTo(16384L / 2));
         assertThat(current.writeKilobytes(), equalTo(32768L / 2));
+        assertEquals(500, current.readTime());
+        assertEquals(100, current.writeTime());
+        assertEquals(20, current.queueSize());
+        assertEquals(8192, current.ioTimeInMillis());
     }
 
 }
diff --git a/server/src/test/java/org/opensearch/monitor/fs/FsProbeTests.java b/server/src/test/java/org/opensearch/monitor/fs/FsProbeTests.java
index 686a624d988d7..59a888c665be7 100644
--- a/server/src/test/java/org/opensearch/monitor/fs/FsProbeTests.java
+++ b/server/src/test/java/org/opensearch/monitor/fs/FsProbeTests.java
@@ -91,6 +91,14 @@ public void testFsInfo() throws IOException {
                     assertThat(deviceStats.previousWritesCompleted, equalTo(-1L));
                     assertThat(deviceStats.currentSectorsWritten, greaterThanOrEqualTo(0L));
                     assertThat(deviceStats.previousSectorsWritten, equalTo(-1L));
+                    assertThat(deviceStats.currentReadTime, greaterThanOrEqualTo(0L));
+                    assertThat(deviceStats.previousReadTime, greaterThanOrEqualTo(-1L));
+                    assertThat(deviceStats.currentWriteTime, greaterThanOrEqualTo(0L));
+                    assertThat(deviceStats.previousWriteTime, greaterThanOrEqualTo(-1L));
+                    assertThat(deviceStats.currentQueueSize, greaterThanOrEqualTo(0L));
+                    assertThat(deviceStats.previousQueueSize, greaterThanOrEqualTo(-1L));
+                    assertThat(deviceStats.currentIOTime, greaterThanOrEqualTo(0L));
+                    assertThat(deviceStats.previousIOTime, greaterThanOrEqualTo(-1L));
                 }
             } else {
                 assertNull(stats.getIoStats());
@@ -243,6 +251,16 @@ List<String> readProcDiskStats() throws IOException {
         assertThat(first.devicesStats[0].previousWritesCompleted, equalTo(-1L));
         assertThat(first.devicesStats[0].currentSectorsWritten, equalTo(118857776L));
         assertThat(first.devicesStats[0].previousSectorsWritten, equalTo(-1L));
+
+        assertEquals(33457, first.devicesStats[0].currentReadTime);
+        assertEquals(-1, first.devicesStats[0].previousReadTime);
+        assertEquals(18730966, first.devicesStats[0].currentWriteTime);
+        assertEquals(-1, first.devicesStats[0].previousWriteTime);
+        assertEquals(18767169, first.devicesStats[0].currentQueueSize);
+        assertEquals(-1, first.devicesStats[0].previousQueueSize);
+        assertEquals(1918440, first.devicesStats[0].currentIOTime);
+        assertEquals(-1, first.devicesStats[0].previousIOTime);
+
         assertThat(first.devicesStats[1].majorDeviceNumber, equalTo(253));
         assertThat(first.devicesStats[1].minorDeviceNumber, equalTo(2));
         assertThat(first.devicesStats[1].deviceName, equalTo("dm-2"));
@@ -255,6 +273,15 @@ List<String> readProcDiskStats() throws IOException {
         assertThat(first.devicesStats[1].currentSectorsWritten, equalTo(64126096L));
         assertThat(first.devicesStats[1].previousSectorsWritten, equalTo(-1L));
 
+        assertEquals(49312, first.devicesStats[1].currentReadTime);
+        assertEquals(-1, first.devicesStats[1].previousReadTime);
+        assertEquals(33730596, first.devicesStats[1].currentWriteTime);
+        assertEquals(-1, first.devicesStats[1].previousWriteTime);
+        assertEquals(33781827, first.devicesStats[1].currentQueueSize);
+        assertEquals(-1, first.devicesStats[1].previousQueueSize);
+        assertEquals(1058193, first.devicesStats[1].currentIOTime);
+        assertEquals(-1, first.devicesStats[1].previousIOTime);
+
         diskStats.set(
             Arrays.asList(
                 " 259       0 nvme0n1 336870 0 7928397 82876 10264393 0 182986405 52451610 0 2971042 52536492",
@@ -281,6 +308,16 @@ List<String> readProcDiskStats() throws IOException {
         assertThat(second.devicesStats[0].previousWritesCompleted, equalTo(8398869L));
         assertThat(second.devicesStats[0].currentSectorsWritten, equalTo(118857776L));
         assertThat(second.devicesStats[0].previousSectorsWritten, equalTo(118857776L));
+
+        assertEquals(33464, second.devicesStats[0].currentReadTime);
+        assertEquals(33457, second.devicesStats[0].previousReadTime);
+        assertEquals(18730966, second.devicesStats[0].currentWriteTime);
+        assertEquals(18730966, second.devicesStats[0].previousWriteTime);
+        assertEquals(18767176, second.devicesStats[0].currentQueueSize);
+        assertEquals(18767169, second.devicesStats[0].previousQueueSize);
+        assertEquals(1918444, second.devicesStats[0].currentIOTime);
+        assertEquals(1918440, second.devicesStats[0].previousIOTime);
+
         assertThat(second.devicesStats[1].majorDeviceNumber, equalTo(253));
         assertThat(second.devicesStats[1].minorDeviceNumber, equalTo(2));
         assertThat(second.devicesStats[1].deviceName, equalTo("dm-2"));
@@ -293,11 +330,25 @@ List<String> readProcDiskStats() throws IOException {
         assertThat(second.devicesStats[1].currentSectorsWritten, equalTo(64128568L));
         assertThat(second.devicesStats[1].previousSectorsWritten, equalTo(64126096L));
 
+        assertEquals(49369, second.devicesStats[1].currentReadTime);
+        assertEquals(49312, second.devicesStats[1].previousReadTime);
+        assertEquals(33730766, second.devicesStats[1].currentWriteTime);
+        assertEquals(33730596, second.devicesStats[1].previousWriteTime);
+        assertEquals(33781827, first.devicesStats[1].currentQueueSize);
+        assertEquals(-1L, first.devicesStats[1].previousQueueSize);
+        assertEquals(1058193, first.devicesStats[1].currentIOTime);
+        assertEquals(-1L, first.devicesStats[1].previousIOTime);
+
         assertThat(second.totalOperations, equalTo(575L));
         assertThat(second.totalReadOperations, equalTo(261L));
         assertThat(second.totalWriteOperations, equalTo(314L));
         assertThat(second.totalReadKilobytes, equalTo(2392L));
         assertThat(second.totalWriteKilobytes, equalTo(1236L));
+
+        assertEquals(64, second.totalReadTime);
+        assertEquals(170, second.totalWriteTime);
+        assertEquals(236, second.totalQueueSize);
+        assertEquals(158, second.totalIOTimeInMillis);
     }
 
     public void testAdjustForHugeFilesystems() throws Exception {
diff --git a/server/src/test/java/org/opensearch/node/NodeRoleSettingsTests.java b/server/src/test/java/org/opensearch/node/NodeRoleSettingsTests.java
index 0a3af34bc12f4..b2bb6897fe164 100644
--- a/server/src/test/java/org/opensearch/node/NodeRoleSettingsTests.java
+++ b/server/src/test/java/org/opensearch/node/NodeRoleSettingsTests.java
@@ -18,6 +18,7 @@
 import java.util.List;
 
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.empty;
 
 public class NodeRoleSettingsTests extends OpenSearchTestCase {
 
@@ -72,4 +73,13 @@ public void testUnknownNodeRoleOnly() {
         assertEquals(testRole, nodeRoles.get(0).roleName());
         assertEquals(testRole, nodeRoles.get(0).roleNameAbbreviation());
     }
+
+    public void testNodeRolesFromEnvironmentVariables() {
+        Settings roleSettings = Settings.builder()
+            .put(NodeRoleSettings.NODE_ROLES_SETTING.getKey(), "${node.roles.test}")
+            .replacePropertyPlaceholders()
+            .build();
+        List<DiscoveryNodeRole> nodeRoles = NodeRoleSettings.NODE_ROLES_SETTING.get(roleSettings);
+        assertThat(nodeRoles, empty());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/node/ResourceUsageCollectorServiceTests.java b/server/src/test/java/org/opensearch/node/ResourceUsageCollectorServiceTests.java
new file mode 100644
index 0000000000000..b2fa884afab69
--- /dev/null
+++ b/server/src/test/java/org/opensearch/node/ResourceUsageCollectorServiceTests.java
@@ -0,0 +1,190 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node;
+
+import org.opensearch.cluster.ClusterChangedEvent;
+import org.opensearch.cluster.ClusterName;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.node.resource.tracker.NodeResourceUsageTracker;
+import org.opensearch.node.resource.tracker.ResourceTrackerSettings;
+import org.opensearch.test.OpenSearchSingleNodeTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.junit.After;
+import org.junit.Before;
+
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import static org.opensearch.test.ClusterServiceUtils.createClusterService;
+import static org.hamcrest.Matchers.greaterThan;
+
+/**
+ * Tests for ResourceUsageCollectorService where we test collect method, get method and whether schedulers
+ * are working as expected
+ */
+public class ResourceUsageCollectorServiceTests extends OpenSearchSingleNodeTestCase {
+
+    private ClusterService clusterService;
+    private ResourceUsageCollectorService collector;
+    private ThreadPool threadpool;
+    NodeResourceUsageTracker tracker;
+
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+
+        threadpool = new TestThreadPool("resource_usage_collector_tests");
+
+        clusterService = createClusterService(threadpool);
+
+        Settings settings = Settings.builder()
+            .put(ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), new TimeValue(500, TimeUnit.MILLISECONDS))
+            .build();
+        tracker = new NodeResourceUsageTracker(
+            threadpool,
+            settings,
+            new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)
+        );
+        collector = new ResourceUsageCollectorService(tracker, clusterService, threadpool);
+        tracker.start();
+        collector.start();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+        threadpool.shutdownNow();
+        clusterService.close();
+        collector.stop();
+        tracker.stop();
+        collector.close();
+        tracker.close();
+    }
+
+    public void testResourceUsageStats() {
+        collector.collectNodeResourceUsageStats("node1", System.currentTimeMillis(), 97, 99);
+        Map<String, NodeResourceUsageStats> nodeStats = collector.getAllNodeStatistics();
+        assertTrue(nodeStats.containsKey("node1"));
+        assertEquals(99.0, nodeStats.get("node1").cpuUtilizationPercent, 0.0);
+        assertEquals(97.0, nodeStats.get("node1").memoryUtilizationPercent, 0.0);
+
+        Optional<NodeResourceUsageStats> nodeResourceUsageStatsOptional = collector.getNodeStatistics("node1");
+
+        assertNotNull(nodeResourceUsageStatsOptional.get());
+        assertEquals(99.0, nodeResourceUsageStatsOptional.get().cpuUtilizationPercent, 0.0);
+        assertEquals(97.0, nodeResourceUsageStatsOptional.get().memoryUtilizationPercent, 0.0);
+
+        nodeResourceUsageStatsOptional = collector.getNodeStatistics("node2");
+        assertTrue(nodeResourceUsageStatsOptional.isEmpty());
+    }
+
+    public void testScheduler() throws Exception {
+        /**
+         * Wait for cluster state to be ready so that localNode().getId() is ready and we add the values to the map
+         */
+        assertBusy(() -> assertTrue(collector.getNodeStatistics(clusterService.localNode().getId()).isPresent()), 1, TimeUnit.MINUTES);
+        assertTrue(collector.getNodeStatistics(clusterService.localNode().getId()).isPresent());
+        /**
+         * Wait for memory utilization to be reported greater than 0
+         */
+        assertBusy(
+            () -> assertThat(
+                collector.getNodeStatistics(clusterService.localNode().getId()).get().getMemoryUtilizationPercent(),
+                greaterThan(0.0)
+            ),
+            5,
+            TimeUnit.SECONDS
+        );
+        assertTrue(collector.getNodeStatistics("Invalid").isEmpty());
+    }
+
+    /*
+     * Test that concurrently adding values and removing nodes does not cause exceptions
+     */
+    public void testConcurrentAddingAndRemovingNodes() throws Exception {
+        String[] nodes = new String[] { "a", "b", "c", "d" };
+
+        final CountDownLatch latch = new CountDownLatch(5);
+
+        Runnable f = () -> {
+            latch.countDown();
+            try {
+                latch.await();
+            } catch (InterruptedException e) {
+                fail("should not be interrupted");
+            }
+            for (int i = 0; i < randomIntBetween(100, 200); i++) {
+                if (randomBoolean()) {
+                    collector.removeNodeResourceUsageStats(randomFrom(nodes));
+                }
+                collector.collectNodeResourceUsageStats(
+                    randomFrom(nodes),
+                    System.currentTimeMillis(),
+                    randomIntBetween(1, 100),
+                    randomIntBetween(1, 100)
+                );
+            }
+        };
+
+        Thread t1 = new Thread(f);
+        Thread t2 = new Thread(f);
+        Thread t3 = new Thread(f);
+        Thread t4 = new Thread(f);
+
+        t1.start();
+        t2.start();
+        t3.start();
+        t4.start();
+        latch.countDown();
+        t1.join();
+        t2.join();
+        t3.join();
+        t4.join();
+
+        final Map<String, NodeResourceUsageStats> nodeStats = collector.getAllNodeStatistics();
+        for (String nodeId : nodes) {
+            if (nodeStats.containsKey(nodeId)) {
+                assertThat(nodeStats.get(nodeId).memoryUtilizationPercent, greaterThan(0.0));
+                assertThat(nodeStats.get(nodeId).cpuUtilizationPercent, greaterThan(0.0));
+            }
+        }
+    }
+
+    public void testNodeRemoval() {
+        collector.collectNodeResourceUsageStats("node1", System.currentTimeMillis(), randomIntBetween(1, 100), randomIntBetween(1, 100));
+        collector.collectNodeResourceUsageStats("node2", System.currentTimeMillis(), randomIntBetween(1, 100), randomIntBetween(1, 100));
+
+        ClusterState previousState = ClusterState.builder(new ClusterName("cluster"))
+            .nodes(
+                DiscoveryNodes.builder()
+                    .add(DiscoveryNode.createLocal(Settings.EMPTY, new TransportAddress(TransportAddress.META_ADDRESS, 9200), "node1"))
+                    .add(DiscoveryNode.createLocal(Settings.EMPTY, new TransportAddress(TransportAddress.META_ADDRESS, 9201), "node2"))
+            )
+            .build();
+        ClusterState newState = ClusterState.builder(previousState)
+            .nodes(DiscoveryNodes.builder(previousState.nodes()).remove("node2"))
+            .build();
+        ClusterChangedEvent event = new ClusterChangedEvent("test", newState, previousState);
+
+        collector.clusterChanged(event);
+        final Map<String, NodeResourceUsageStats> nodeStats = collector.getAllNodeStatistics();
+        assertTrue(nodeStats.containsKey("node1"));
+        assertFalse(nodeStats.containsKey("node2"));
+    }
+}
diff --git a/server/src/test/java/org/opensearch/node/resource/tracker/AverageUsageTrackerTests.java b/server/src/test/java/org/opensearch/node/resource/tracker/AverageUsageTrackerTests.java
new file mode 100644
index 0000000000000..374c993a264d4
--- /dev/null
+++ b/server/src/test/java/org/opensearch/node/resource/tracker/AverageUsageTrackerTests.java
@@ -0,0 +1,99 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node.resource.tracker;
+
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.junit.After;
+import org.junit.Before;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Tests to validate AverageMemoryUsageTracker and AverageCpuUsageTracker implementation
+ */
+public class AverageUsageTrackerTests extends OpenSearchTestCase {
+    ThreadPool threadPool;
+    AverageMemoryUsageTracker averageMemoryUsageTracker;
+    AverageCpuUsageTracker averageCpuUsageTracker;
+
+    @Before
+    public void setup() {
+        threadPool = new TestThreadPool(getClass().getName());
+        averageMemoryUsageTracker = new AverageMemoryUsageTracker(
+            threadPool,
+            new TimeValue(500, TimeUnit.MILLISECONDS),
+            new TimeValue(1000, TimeUnit.MILLISECONDS)
+        );
+        averageCpuUsageTracker = new AverageCpuUsageTracker(
+            threadPool,
+            new TimeValue(500, TimeUnit.MILLISECONDS),
+            new TimeValue(1000, TimeUnit.MILLISECONDS)
+        );
+    }
+
+    @After
+    public void cleanup() {
+        ThreadPool.terminate(threadPool, 5, TimeUnit.SECONDS);
+    }
+
+    public void testBasicUsage() {
+
+        assertAverageUsageStats(averageMemoryUsageTracker);
+        assertAverageUsageStats(averageCpuUsageTracker);
+    }
+
+    public void testUpdateWindowSize() {
+        assertUpdateWindowSize(averageMemoryUsageTracker);
+        assertUpdateWindowSize(averageCpuUsageTracker);
+    }
+
+    private void assertAverageUsageStats(AbstractAverageUsageTracker usageTracker) {
+        usageTracker.recordUsage(1);
+        assertFalse(usageTracker.isReady());
+        usageTracker.recordUsage(2);
+        assertTrue(usageTracker.isReady());
+        assertEquals(2, usageTracker.getWindowSize());
+        assertEquals(1.5, usageTracker.getAverage(), 0.0);
+        usageTracker.recordUsage(5);
+        // ( 2 + 5 ) / 2 = 3.5
+        assertEquals(3.5, usageTracker.getAverage(), 0.0);
+    }
+
+    private void assertUpdateWindowSize(AbstractAverageUsageTracker usageTracker) {
+        usageTracker.recordUsage(1);
+        usageTracker.recordUsage(2);
+
+        assertEquals(2, usageTracker.getWindowSize());
+        assertEquals(1.5, usageTracker.getAverage(), 0.0);
+        usageTracker.recordUsage(5);
+        // ( 2 + 5 ) / 2 = 3.5
+        assertEquals(3.5, usageTracker.getAverage(), 0.0);
+
+        usageTracker.setWindowSize(new TimeValue(2000, TimeUnit.MILLISECONDS));
+        assertEquals(0, usageTracker.getWindowSize());
+        assertEquals(0.0, usageTracker.getAverage(), 0.0);
+        // verify 2000/500 = 4 is the window size and average is calculated on window size of 4
+        usageTracker.recordUsage(1);
+        usageTracker.recordUsage(2);
+        usageTracker.recordUsage(1);
+        assertFalse(usageTracker.isReady());
+        usageTracker.recordUsage(2);
+        assertTrue(usageTracker.isReady());
+        assertEquals(4, usageTracker.getWindowSize());
+        // (1 + 2 + 1 + 2 ) / 4 = 1.5
+        assertEquals(1.5, usageTracker.getAverage(), 0.0);
+        usageTracker.recordUsage(2);
+        assertTrue(usageTracker.isReady());
+        // ( 2 + 1 + 2 + 2 ) / 4 = 1.75
+        assertEquals(1.75, usageTracker.getAverage(), 0.0);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/node/resource/tracker/NodeResourceUsageTrackerTests.java b/server/src/test/java/org/opensearch/node/resource/tracker/NodeResourceUsageTrackerTests.java
new file mode 100644
index 0000000000000..1ce68b9f29062
--- /dev/null
+++ b/server/src/test/java/org/opensearch/node/resource/tracker/NodeResourceUsageTrackerTests.java
@@ -0,0 +1,96 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.node.resource.tracker;
+
+import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsResponse;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.test.OpenSearchSingleNodeTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.junit.After;
+import org.junit.Before;
+
+import java.util.concurrent.TimeUnit;
+
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.hamcrest.Matchers.greaterThan;
+
+/**
+ * Tests to assert resource usage trackers retrieving resource utilization averages
+ */
+public class NodeResourceUsageTrackerTests extends OpenSearchSingleNodeTestCase {
+    ThreadPool threadPool;
+
+    @Before
+    public void setup() {
+        threadPool = new TestThreadPool(getClass().getName());
+    }
+
+    @After
+    public void cleanup() {
+        ThreadPool.terminate(threadPool, 5, TimeUnit.SECONDS);
+        assertAcked(
+            client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setPersistentSettings(Settings.builder().putNull("*"))
+                .setTransientSettings(Settings.builder().putNull("*"))
+        );
+    }
+
+    public void testStats() throws Exception {
+        Settings settings = Settings.builder()
+            .put(ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), new TimeValue(500, TimeUnit.MILLISECONDS))
+            .build();
+        NodeResourceUsageTracker tracker = new NodeResourceUsageTracker(
+            threadPool,
+            settings,
+            new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)
+        );
+        tracker.start();
+        /**
+         * Asserting memory utilization to be greater than 0
+         * cpu percent used is mostly 0, so skipping assertion for that
+         */
+        assertBusy(() -> assertThat(tracker.getMemoryUtilizationPercent(), greaterThan(0.0)), 5, TimeUnit.SECONDS);
+        tracker.stop();
+        tracker.close();
+    }
+
+    public void testUpdateSettings() {
+        NodeResourceUsageTracker tracker = new NodeResourceUsageTracker(
+            threadPool,
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)
+        );
+
+        assertEquals(tracker.getResourceTrackerSettings().getCpuWindowDuration().getSeconds(), 30);
+        assertEquals(tracker.getResourceTrackerSettings().getMemoryWindowDuration().getSeconds(), 30);
+
+        Settings settings = Settings.builder()
+            .put(ResourceTrackerSettings.GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), "10s")
+            .build();
+        ClusterUpdateSettingsResponse response = client().admin().cluster().prepareUpdateSettings().setPersistentSettings(settings).get();
+        assertEquals(
+            "10s",
+            response.getPersistentSettings().get(ResourceTrackerSettings.GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING.getKey())
+        );
+
+        Settings jvmsettings = Settings.builder()
+            .put(ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), "5s")
+            .build();
+        response = client().admin().cluster().prepareUpdateSettings().setPersistentSettings(jvmsettings).get();
+        assertEquals(
+            "5s",
+            response.getPersistentSettings().get(ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING.getKey())
+        );
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlServiceTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlServiceTests.java
new file mode 100644
index 0000000000000..7a67ffc8c7c5d
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlServiceTests.java
@@ -0,0 +1,158 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.AdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.CpuBasedAdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.List;
+
+public class AdmissionControlServiceTests extends OpenSearchTestCase {
+    private ClusterService clusterService;
+    private ThreadPool threadPool;
+    private AdmissionControlService admissionControlService;
+    private String action = "";
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        threadPool = new TestThreadPool("admission_controller_settings_test");
+        clusterService = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            threadPool
+        );
+        action = "indexing";
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+        super.tearDown();
+        threadPool.shutdownNow();
+    }
+
+    public void testWhenAdmissionControllerRegistered() {
+        admissionControlService = new AdmissionControlService(Settings.EMPTY, clusterService, threadPool, null);
+        assertEquals(admissionControlService.getAdmissionControllers().size(), 1);
+    }
+
+    public void testRegisterInvalidAdmissionController() {
+        String test = "TEST";
+        admissionControlService = new AdmissionControlService(Settings.EMPTY, clusterService, threadPool, null);
+        assertEquals(admissionControlService.getAdmissionControllers().size(), 1);
+        IllegalArgumentException ex = expectThrows(
+            IllegalArgumentException.class,
+            () -> admissionControlService.registerAdmissionController(test)
+        );
+        assertEquals(ex.getMessage(), "Not Supported AdmissionController : " + test);
+    }
+
+    public void testAdmissionControllerSettings() {
+        admissionControlService = new AdmissionControlService(Settings.EMPTY, clusterService, threadPool, null);
+        AdmissionControlSettings admissionControlSettings = admissionControlService.admissionControlSettings;
+        List<AdmissionController> admissionControllerList = admissionControlService.getAdmissionControllers();
+        assertEquals(admissionControllerList.size(), 1);
+        CpuBasedAdmissionController cpuBasedAdmissionController = (CpuBasedAdmissionController) admissionControlService
+            .getAdmissionController(CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER);
+        assertEquals(
+            admissionControlSettings.isTransportLayerAdmissionControlEnabled(),
+            cpuBasedAdmissionController.isEnabledForTransportLayer(
+                cpuBasedAdmissionController.settings.getTransportLayerAdmissionControllerMode()
+            )
+        );
+
+        Settings settings = Settings.builder()
+            .put(AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.DISABLED.getMode())
+            .build();
+        clusterService.getClusterSettings().applySettings(settings);
+        assertEquals(
+            admissionControlSettings.isTransportLayerAdmissionControlEnabled(),
+            cpuBasedAdmissionController.isEnabledForTransportLayer(
+                cpuBasedAdmissionController.settings.getTransportLayerAdmissionControllerMode()
+            )
+        );
+        assertFalse(admissionControlSettings.isTransportLayerAdmissionControlEnabled());
+
+        Settings newSettings = Settings.builder()
+            .put(settings)
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .build();
+        clusterService.getClusterSettings().applySettings(newSettings);
+        assertFalse(admissionControlSettings.isTransportLayerAdmissionControlEnabled());
+        assertTrue(
+            cpuBasedAdmissionController.isEnabledForTransportLayer(
+                cpuBasedAdmissionController.settings.getTransportLayerAdmissionControllerMode()
+            )
+        );
+    }
+
+    public void testApplyAdmissionControllerDisabled() {
+        this.action = "indices:data/write/bulk[s][p]";
+        admissionControlService = new AdmissionControlService(Settings.EMPTY, clusterService, threadPool, null);
+        admissionControlService.applyTransportAdmissionControl(this.action, null);
+        List<AdmissionController> admissionControllerList = admissionControlService.getAdmissionControllers();
+        admissionControllerList.forEach(admissionController -> {
+            assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 0);
+        });
+    }
+
+    public void testApplyAdmissionControllerEnabled() {
+        this.action = "indices:data/write/bulk[s][p]";
+        admissionControlService = new AdmissionControlService(Settings.EMPTY, clusterService, threadPool, null);
+        admissionControlService.applyTransportAdmissionControl(this.action, null);
+        assertEquals(
+            admissionControlService.getAdmissionController(CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER)
+                .getRejectionCount(AdmissionControlActionType.INDEXING.getType()),
+            0
+        );
+
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.MONITOR.getMode()
+            )
+            .build();
+        clusterService.getClusterSettings().applySettings(settings);
+        List<AdmissionController> admissionControllerList = admissionControlService.getAdmissionControllers();
+        assertEquals(admissionControllerList.size(), 1);
+    }
+
+    public void testApplyAdmissionControllerEnforced() {
+        this.action = "indices:data/write/bulk[s][p]";
+        admissionControlService = new AdmissionControlService(Settings.EMPTY, clusterService, threadPool, null);
+        admissionControlService.applyTransportAdmissionControl(this.action, null);
+        assertEquals(
+            admissionControlService.getAdmissionController(CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER)
+                .getRejectionCount(AdmissionControlActionType.INDEXING.getType()),
+            0
+        );
+
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.MONITOR.getMode()
+            )
+            .build();
+        clusterService.getClusterSettings().applySettings(settings);
+        List<AdmissionController> admissionControllerList = admissionControlService.getAdmissionControllers();
+        assertEquals(admissionControllerList.size(), 1);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSettingsTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSettingsTests.java
new file mode 100644
index 0000000000000..c11ee1cc608f6
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSettingsTests.java
@@ -0,0 +1,103 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.List;
+import java.util.Set;
+
+public class AdmissionControlSettingsTests extends OpenSearchTestCase {
+    private ClusterService clusterService;
+    private ThreadPool threadPool;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        threadPool = new TestThreadPool("admission_controller_settings_test");
+        clusterService = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            threadPool
+        );
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+        super.tearDown();
+        threadPool.shutdownNow();
+    }
+
+    public void testSettingsExists() {
+        Set<Setting<?>> settings = ClusterSettings.BUILT_IN_CLUSTER_SETTINGS;
+        assertTrue(
+            "All the admission controller settings should be supported built in settings",
+            settings.containsAll(List.of(AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE))
+        );
+    }
+
+    public void testDefaultSettings() {
+        AdmissionControlSettings admissionControlSettings = new AdmissionControlSettings(
+            clusterService.getClusterSettings(),
+            Settings.EMPTY
+        );
+
+        assertFalse(admissionControlSettings.isTransportLayerAdmissionControlEnabled());
+        assertFalse(admissionControlSettings.isTransportLayerAdmissionControlEnforced());
+        assertEquals(admissionControlSettings.getAdmissionControlTransportLayerMode().getMode(), AdmissionControlSettings.Defaults.MODE);
+    }
+
+    public void testGetConfiguredSettings() {
+        Settings settings = Settings.builder()
+            .put(AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.ENFORCED.getMode())
+            .build();
+
+        AdmissionControlSettings admissionControlSettings = new AdmissionControlSettings(clusterService.getClusterSettings(), settings);
+
+        assertTrue(admissionControlSettings.isTransportLayerAdmissionControlEnabled());
+        assertTrue(admissionControlSettings.isTransportLayerAdmissionControlEnforced());
+    }
+
+    public void testUpdateAfterGetDefaultSettings() {
+        AdmissionControlSettings admissionControlSettings = new AdmissionControlSettings(
+            clusterService.getClusterSettings(),
+            Settings.EMPTY
+        );
+        Settings settings = Settings.builder()
+            .put(AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.MONITOR.getMode())
+            .build();
+        clusterService.getClusterSettings().applySettings(settings);
+        assertTrue(admissionControlSettings.isTransportLayerAdmissionControlEnabled());
+        assertFalse(admissionControlSettings.isTransportLayerAdmissionControlEnforced());
+    }
+
+    public void testUpdateAfterGetConfiguredSettings() {
+        Settings settings = Settings.builder()
+            .put(AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.MONITOR.getMode())
+            .build();
+
+        AdmissionControlSettings admissionControlSettings = new AdmissionControlSettings(clusterService.getClusterSettings(), settings);
+
+        Settings newSettings = Settings.builder()
+            .put(AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.ENFORCED.getMode())
+            .build();
+
+        clusterService.getClusterSettings().applySettings(newSettings);
+
+        assertTrue(admissionControlSettings.isTransportLayerAdmissionControlEnabled());
+        assertTrue(admissionControlSettings.isTransportLayerAdmissionControlEnforced());
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSingleNodeTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSingleNodeTests.java
new file mode 100644
index 0000000000000..a1694b2c3cee2
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/AdmissionControlSingleNodeTests.java
@@ -0,0 +1,203 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol;
+
+import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
+import org.opensearch.action.admin.cluster.state.ClusterStateRequest;
+import org.opensearch.action.admin.cluster.state.ClusterStateResponse;
+import org.opensearch.action.bulk.BulkRequestBuilder;
+import org.opensearch.action.bulk.BulkResponse;
+import org.opensearch.action.search.SearchPhaseExecutionException;
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.action.ActionFuture;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.node.ResourceUsageCollectorService;
+import org.opensearch.node.resource.tracker.ResourceTrackerSettings;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.ratelimitting.admissioncontrol.stats.AdmissionControllerStats;
+import org.opensearch.test.OpenSearchSingleNodeTestCase;
+import org.junit.After;
+
+import static org.opensearch.ratelimitting.admissioncontrol.AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE;
+import static org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings.INDEXING_CPU_USAGE_LIMIT;
+import static org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.hamcrest.Matchers.is;
+
+/**
+ * Single node integration tests for admission control
+ */
+public class AdmissionControlSingleNodeTests extends OpenSearchSingleNodeTestCase {
+
+    @Override
+    protected boolean resetNodeAfterTest() {
+        return true;
+    }
+
+    @After
+    public void cleanup() {
+        assertAcked(
+            client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setPersistentSettings(Settings.builder().putNull("*"))
+                .setTransientSettings(Settings.builder().putNull("*"))
+        );
+    }
+
+    @Override
+    protected Settings nodeSettings() {
+        return Settings.builder()
+            .put(super.nodeSettings())
+            .put(ResourceTrackerSettings.GLOBAL_CPU_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), TimeValue.timeValueMillis(500))
+            .put(ResourceTrackerSettings.GLOBAL_JVM_USAGE_AC_WINDOW_DURATION_SETTING.getKey(), TimeValue.timeValueMillis(500))
+            .put(ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.ENFORCED)
+            .put(SEARCH_CPU_USAGE_LIMIT.getKey(), 0)
+            .put(INDEXING_CPU_USAGE_LIMIT.getKey(), 0)
+            .build();
+    }
+
+    public void testAdmissionControlRejectionEnforcedMode() throws Exception {
+        ensureGreen();
+        assertBusy(() -> assertEquals(1, getInstanceFromNode(ResourceUsageCollectorService.class).getAllNodeStatistics().size()));
+        // Thread.sleep(700);
+        client().admin().indices().prepareCreate("index").execute().actionGet();
+        BulkRequestBuilder bulk = client().prepareBulk();
+        for (int i = 0; i < 3; i++) {
+            bulk.add(client().prepareIndex("index").setSource("foo", "bar " + i));
+        }
+        // Verify that cluster state is updated
+        ActionFuture<ClusterStateResponse> future2 = client().admin().cluster().state(new ClusterStateRequest());
+        assertThat(future2.isDone(), is(true));
+
+        // verify bulk request hits 429
+        BulkResponse res = client().bulk(bulk.request()).actionGet();
+        assertEquals(429, res.getItems()[0].getFailure().getStatus().getStatus());
+        AdmissionControlService admissionControlService = getInstanceFromNode(AdmissionControlService.class);
+        AdmissionControllerStats acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(1, (long) acStats.getRejectionCount().get(AdmissionControlActionType.INDEXING.getType()));
+        client().admin().indices().prepareRefresh("index").get();
+
+        // verify search request hits 429
+        SearchRequest searchRequest = new SearchRequest("index");
+        try {
+            client().search(searchRequest).actionGet();
+        } catch (Exception e) {
+            assertTrue(((SearchPhaseExecutionException) e).getDetailedMessage().contains("OpenSearchRejectedExecutionException"));
+        }
+        acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(1, (long) acStats.getRejectionCount().get(AdmissionControlActionType.SEARCH.getType()));
+    }
+
+    public void testAdmissionControlRejectionMonitorOnlyMode() throws Exception {
+        assertBusy(() -> assertEquals(1, getInstanceFromNode(ResourceUsageCollectorService.class).getAllNodeStatistics().size()));
+        // Verify that cluster state is updated
+        ActionFuture<ClusterStateResponse> future2 = client().admin().cluster().state(new ClusterStateRequest());
+        assertThat(future2.isDone(), is(true));
+
+        ClusterUpdateSettingsRequest updateSettingsRequest = new ClusterUpdateSettingsRequest();
+        updateSettingsRequest.transientSettings(
+            Settings.builder()
+                .put(super.nodeSettings())
+                .put(ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.MONITOR.getMode())
+        );
+        assertAcked(client().admin().cluster().updateSettings(updateSettingsRequest).actionGet());
+
+        BulkRequestBuilder bulk = client().prepareBulk();
+        for (int i = 0; i < 3; i++) {
+            bulk.add(client().prepareIndex("index").setSource("foo", "bar " + i));
+        }
+        // verify bulk request success but admission control having rejections stats
+        BulkResponse res = client().bulk(bulk.request()).actionGet();
+        assertFalse(res.hasFailures());
+        AdmissionControlService admissionControlService = getInstanceFromNode(AdmissionControlService.class);
+        AdmissionControllerStats acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(1, (long) acStats.getRejectionCount().get(AdmissionControlActionType.INDEXING.getType()));
+        client().admin().indices().prepareRefresh("index").get();
+
+        // verify search request success but admission control having rejections stats
+        SearchRequest searchRequest = new SearchRequest("index");
+        SearchResponse searchResponse = client().search(searchRequest).actionGet();
+        assertEquals(3, searchResponse.getHits().getHits().length);
+        acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(1, (long) acStats.getRejectionCount().get(AdmissionControlActionType.SEARCH.getType()));
+    }
+
+    public void testAdmissionControlRejectionDisabledMode() throws Exception {
+        assertBusy(() -> assertEquals(1, getInstanceFromNode(ResourceUsageCollectorService.class).getAllNodeStatistics().size()));
+        // Verify that cluster state is updated
+        ActionFuture<ClusterStateResponse> future2 = client().admin().cluster().state(new ClusterStateRequest());
+        assertThat(future2.isDone(), is(true));
+
+        ClusterUpdateSettingsRequest updateSettingsRequest = new ClusterUpdateSettingsRequest();
+        updateSettingsRequest.transientSettings(
+            Settings.builder().put(super.nodeSettings()).put(ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.DISABLED)
+        );
+        assertAcked(client().admin().cluster().updateSettings(updateSettingsRequest).actionGet());
+
+        BulkRequestBuilder bulk = client().prepareBulk();
+        for (int i = 0; i < 3; i++) {
+            bulk.add(client().prepareIndex("index").setSource("foo", "bar " + i));
+        }
+        // verify bulk request success and no rejections
+        BulkResponse res = client().bulk(bulk.request()).actionGet();
+        assertFalse(res.hasFailures());
+        AdmissionControlService admissionControlService = getInstanceFromNode(AdmissionControlService.class);
+        AdmissionControllerStats acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(0, acStats.getRejectionCount().size());
+        client().admin().indices().prepareRefresh("index").get();
+
+        // verify search request success and no rejections
+        SearchRequest searchRequest = new SearchRequest("index");
+        SearchResponse searchResponse = client().search(searchRequest).actionGet();
+        assertEquals(3, searchResponse.getHits().getHits().length);
+        acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(0, acStats.getRejectionCount().size());
+
+    }
+
+    public void testAdmissionControlWithinLimits() throws Exception {
+        assertBusy(() -> assertEquals(1, getInstanceFromNode(ResourceUsageCollectorService.class).getAllNodeStatistics().size()));
+        // Verify that cluster state is updated
+        ActionFuture<ClusterStateResponse> future2 = client().admin().cluster().state(new ClusterStateRequest());
+        assertThat(future2.isDone(), is(true));
+
+        ClusterUpdateSettingsRequest updateSettingsRequest = new ClusterUpdateSettingsRequest();
+        updateSettingsRequest.transientSettings(
+            Settings.builder()
+                .put(super.nodeSettings())
+                .put(ADMISSION_CONTROL_TRANSPORT_LAYER_MODE.getKey(), AdmissionControlMode.ENFORCED)
+                .put(SEARCH_CPU_USAGE_LIMIT.getKey(), 101)
+                .put(INDEXING_CPU_USAGE_LIMIT.getKey(), 101)
+        );
+        assertAcked(client().admin().cluster().updateSettings(updateSettingsRequest).actionGet());
+
+        BulkRequestBuilder bulk = client().prepareBulk();
+        for (int i = 0; i < 3; i++) {
+            bulk.add(client().prepareIndex("index").setSource("foo", "bar " + i));
+        }
+        // verify bulk request success and no rejections
+        BulkResponse res = client().bulk(bulk.request()).actionGet();
+        assertFalse(res.hasFailures());
+        AdmissionControlService admissionControlService = getInstanceFromNode(AdmissionControlService.class);
+        AdmissionControllerStats acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(0, acStats.getRejectionCount().size());
+        client().admin().indices().prepareRefresh("index").get();
+
+        // verify search request success and no rejections
+        SearchRequest searchRequest = new SearchRequest("index");
+        SearchResponse searchResponse = client().search(searchRequest).actionGet();
+        assertEquals(3, searchResponse.getHits().getHits().length);
+        acStats = admissionControlService.stats().getAdmissionControllerStatsList().get(0);
+        assertEquals(0, acStats.getRejectionCount().size());
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/controllers/CpuBasedAdmissionControllerTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/controllers/CpuBasedAdmissionControllerTests.java
new file mode 100644
index 0000000000000..e72c0cd58ed64
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/controllers/CpuBasedAdmissionControllerTests.java
@@ -0,0 +1,143 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.controllers;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.node.ResourceUsageCollectorService;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+
+import org.mockito.Mockito;
+
+public class CpuBasedAdmissionControllerTests extends OpenSearchTestCase {
+    private ClusterService clusterService;
+    private ThreadPool threadPool;
+    CpuBasedAdmissionController admissionController = null;
+    String action = "TEST_ACTION";
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        threadPool = new TestThreadPool("admission_controller_settings_test");
+        clusterService = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            threadPool
+        );
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+        super.tearDown();
+        threadPool.shutdownNow();
+    }
+
+    public void testCheckDefaultParameters() {
+        admissionController = new CpuBasedAdmissionController(
+            CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER,
+            null,
+            clusterService,
+            Settings.EMPTY
+        );
+        assertEquals(admissionController.getName(), CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER);
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 0);
+        assertEquals(admissionController.settings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.DISABLED);
+        assertFalse(
+            admissionController.isEnabledForTransportLayer(admissionController.settings.getTransportLayerAdmissionControllerMode())
+        );
+    }
+
+    public void testCheckUpdateSettings() {
+        admissionController = new CpuBasedAdmissionController(
+            CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER,
+            null,
+            clusterService,
+            Settings.EMPTY
+        );
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .build();
+        clusterService.getClusterSettings().applySettings(settings);
+
+        assertEquals(admissionController.getName(), CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER);
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 0);
+        assertEquals(admissionController.settings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.ENFORCED);
+        assertTrue(admissionController.isEnabledForTransportLayer(admissionController.settings.getTransportLayerAdmissionControllerMode()));
+    }
+
+    public void testApplyControllerWithDefaultSettings() {
+        ResourceUsageCollectorService rs = Mockito.mock(ResourceUsageCollectorService.class);
+        admissionController = new CpuBasedAdmissionController(
+            CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER,
+            rs,
+            clusterService,
+            Settings.EMPTY
+        );
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 0);
+        assertEquals(admissionController.settings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.DISABLED);
+        action = "indices:data/write/bulk[s][p]";
+        admissionController.apply(action, AdmissionControlActionType.INDEXING);
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 0);
+    }
+
+    public void testApplyControllerWhenSettingsEnabled() throws Exception {
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .build();
+        ResourceUsageCollectorService rs = Mockito.mock(ResourceUsageCollectorService.class);
+        admissionController = new CpuBasedAdmissionController(
+            CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER,
+            rs,
+            clusterService,
+            settings
+        );
+        assertTrue(admissionController.isEnabledForTransportLayer(admissionController.settings.getTransportLayerAdmissionControllerMode()));
+        assertTrue(
+            admissionController.isAdmissionControllerEnforced(admissionController.settings.getTransportLayerAdmissionControllerMode())
+        );
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 0);
+        // we can assert admission control and rejections as part of ITs
+    }
+
+    public void testRejectionCount() {
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .build();
+        ResourceUsageCollectorService rs = Mockito.mock(ResourceUsageCollectorService.class);
+        admissionController = new CpuBasedAdmissionController(
+            CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER,
+            rs,
+            clusterService,
+            settings
+        );
+        admissionController.addRejectionCount(AdmissionControlActionType.SEARCH.getType(), 1);
+        admissionController.addRejectionCount(AdmissionControlActionType.INDEXING.getType(), 3);
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.SEARCH.getType()), 1);
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 3);
+        admissionController.addRejectionCount(AdmissionControlActionType.SEARCH.getType(), 1);
+        admissionController.addRejectionCount(AdmissionControlActionType.INDEXING.getType(), 2);
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.SEARCH.getType()), 2);
+        assertEquals(admissionController.getRejectionCount(AdmissionControlActionType.INDEXING.getType()), 5);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlActionTypeTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlActionTypeTests.java
new file mode 100644
index 0000000000000..15a25e6cbca1c
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlActionTypeTests.java
@@ -0,0 +1,27 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.enums;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+public class AdmissionControlActionTypeTests extends OpenSearchTestCase {
+
+    public void testValidActionType() {
+        assertEquals(AdmissionControlActionType.SEARCH.getType(), "search");
+        assertEquals(AdmissionControlActionType.INDEXING.getType(), "indexing");
+        assertEquals(AdmissionControlActionType.fromName("search"), AdmissionControlActionType.SEARCH);
+        assertEquals(AdmissionControlActionType.fromName("indexing"), AdmissionControlActionType.INDEXING);
+    }
+
+    public void testInValidActionType() {
+        String name = "test";
+        IllegalArgumentException ex = expectThrows(IllegalArgumentException.class, () -> AdmissionControlActionType.fromName(name));
+        assertEquals(ex.getMessage(), "Not Supported TransportAction Type: " + name);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlModeTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlModeTests.java
new file mode 100644
index 0000000000000..98c0f3c7cf24c
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/enums/AdmissionControlModeTests.java
@@ -0,0 +1,29 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.enums;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+public class AdmissionControlModeTests extends OpenSearchTestCase {
+
+    public void testValidActionType() {
+        assertEquals(AdmissionControlMode.DISABLED.getMode(), "disabled");
+        assertEquals(AdmissionControlMode.ENFORCED.getMode(), "enforced");
+        assertEquals(AdmissionControlMode.MONITOR.getMode(), "monitor_only");
+        assertEquals(AdmissionControlMode.fromName("disabled"), AdmissionControlMode.DISABLED);
+        assertEquals(AdmissionControlMode.fromName("enforced"), AdmissionControlMode.ENFORCED);
+        assertEquals(AdmissionControlMode.fromName("monitor_only"), AdmissionControlMode.MONITOR);
+    }
+
+    public void testInValidActionType() {
+        String name = "TEST";
+        IllegalArgumentException ex = expectThrows(IllegalArgumentException.class, () -> AdmissionControlMode.fromName(name));
+        assertEquals(ex.getMessage(), "Invalid AdmissionControlMode: " + name);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/settings/CPUBasedAdmissionControlSettingsTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/settings/CPUBasedAdmissionControlSettingsTests.java
new file mode 100644
index 0000000000000..11688e2f30d4b
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/settings/CPUBasedAdmissionControlSettingsTests.java
@@ -0,0 +1,152 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.settings;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.Arrays;
+import java.util.Set;
+
+public class CPUBasedAdmissionControlSettingsTests extends OpenSearchTestCase {
+    private ClusterService clusterService;
+    private ThreadPool threadPool;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        threadPool = new TestThreadPool("admission_controller_settings_test");
+        clusterService = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            threadPool
+        );
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+        super.tearDown();
+        threadPool.shutdownNow();
+    }
+
+    public void testSettingsExists() {
+        Set<Setting<?>> settings = ClusterSettings.BUILT_IN_CLUSTER_SETTINGS;
+        assertTrue(
+            "All the cpu based admission controller settings should be supported built in settings",
+            settings.containsAll(
+                Arrays.asList(
+                    CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE,
+                    CpuBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT,
+                    CpuBasedAdmissionControllerSettings.INDEXING_CPU_USAGE_LIMIT
+                )
+            )
+        );
+    }
+
+    public void testDefaultSettings() {
+        CpuBasedAdmissionControllerSettings cpuBasedAdmissionControllerSettings = new CpuBasedAdmissionControllerSettings(
+            clusterService.getClusterSettings(),
+            Settings.EMPTY
+        );
+        long percent = 95;
+        assertEquals(cpuBasedAdmissionControllerSettings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.DISABLED);
+        assertEquals(cpuBasedAdmissionControllerSettings.getIndexingCPULimit().longValue(), percent);
+        assertEquals(cpuBasedAdmissionControllerSettings.getSearchCPULimit().longValue(), percent);
+    }
+
+    public void testGetConfiguredSettings() {
+        long percent = 95;
+        long indexingPercent = 85;
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .put(CpuBasedAdmissionControllerSettings.INDEXING_CPU_USAGE_LIMIT.getKey(), indexingPercent)
+            .build();
+
+        CpuBasedAdmissionControllerSettings cpuBasedAdmissionControllerSettings = new CpuBasedAdmissionControllerSettings(
+            clusterService.getClusterSettings(),
+            settings
+        );
+        assertEquals(cpuBasedAdmissionControllerSettings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.ENFORCED);
+        assertEquals(cpuBasedAdmissionControllerSettings.getSearchCPULimit().longValue(), percent);
+        assertEquals(cpuBasedAdmissionControllerSettings.getIndexingCPULimit().longValue(), indexingPercent);
+    }
+
+    public void testUpdateAfterGetDefaultSettings() {
+        long percent = 95;
+        long searchPercent = 80;
+        CpuBasedAdmissionControllerSettings cpuBasedAdmissionControllerSettings = new CpuBasedAdmissionControllerSettings(
+            clusterService.getClusterSettings(),
+            Settings.EMPTY
+        );
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .put(CpuBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT.getKey(), searchPercent)
+            .build();
+        clusterService.getClusterSettings().applySettings(settings);
+        assertEquals(cpuBasedAdmissionControllerSettings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.ENFORCED);
+        assertEquals(cpuBasedAdmissionControllerSettings.getSearchCPULimit().longValue(), searchPercent);
+        assertEquals(cpuBasedAdmissionControllerSettings.getIndexingCPULimit().longValue(), percent);
+    }
+
+    public void testUpdateAfterGetConfiguredSettings() {
+        long percent = 95;
+        long indexingPercent = 85;
+        long searchPercent = 80;
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .put(CpuBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT.getKey(), searchPercent)
+            .build();
+
+        CpuBasedAdmissionControllerSettings cpuBasedAdmissionControllerSettings = new CpuBasedAdmissionControllerSettings(
+            clusterService.getClusterSettings(),
+            settings
+        );
+        assertEquals(cpuBasedAdmissionControllerSettings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.ENFORCED);
+        assertEquals(cpuBasedAdmissionControllerSettings.getSearchCPULimit().longValue(), searchPercent);
+        assertEquals(cpuBasedAdmissionControllerSettings.getIndexingCPULimit().longValue(), percent);
+
+        Settings updatedSettings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.MONITOR.getMode()
+            )
+            .put(CpuBasedAdmissionControllerSettings.INDEXING_CPU_USAGE_LIMIT.getKey(), indexingPercent)
+            .build();
+        clusterService.getClusterSettings().applySettings(updatedSettings);
+        assertEquals(cpuBasedAdmissionControllerSettings.getTransportLayerAdmissionControllerMode(), AdmissionControlMode.MONITOR);
+        assertEquals(cpuBasedAdmissionControllerSettings.getSearchCPULimit().longValue(), searchPercent);
+        assertEquals(cpuBasedAdmissionControllerSettings.getIndexingCPULimit().longValue(), indexingPercent);
+
+        searchPercent = 70;
+
+        updatedSettings = Settings.builder()
+            .put(updatedSettings)
+            .put(CpuBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT.getKey(), searchPercent)
+            .build();
+        clusterService.getClusterSettings().applySettings(updatedSettings);
+
+        assertEquals(cpuBasedAdmissionControllerSettings.getSearchCPULimit().longValue(), searchPercent);
+        assertEquals(cpuBasedAdmissionControllerSettings.getIndexingCPULimit().longValue(), indexingPercent);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControlStatsTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControlStatsTests.java
new file mode 100644
index 0000000000000..7b4db5f787d6e
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControlStatsTests.java
@@ -0,0 +1,92 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.stats;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.xcontent.json.JsonXContent;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.node.ResourceUsageCollectorService;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.AdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.CpuBasedAdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.mockito.Mockito.mock;
+
+public class AdmissionControlStatsTests extends OpenSearchTestCase {
+    AdmissionController admissionController;
+    AdmissionControllerStats admissionControllerStats;
+    AdmissionControlStats admissionControlStats;
+    private ThreadPool threadPool;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .build();
+        threadPool = new TestThreadPool("admission_controller_settings_test");
+        ClusterService clusterService = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            threadPool
+        );
+        admissionController = new CpuBasedAdmissionController(
+            CpuBasedAdmissionController.CPU_BASED_ADMISSION_CONTROLLER,
+            mock(ResourceUsageCollectorService.class),
+            clusterService,
+            settings
+        );
+        admissionControllerStats = new AdmissionControllerStats(admissionController);
+        List<AdmissionControllerStats> admissionControllerStats = new ArrayList<>();
+        admissionControlStats = new AdmissionControlStats(admissionControllerStats);
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+        super.tearDown();
+        threadPool.shutdownNow();
+    }
+
+    public void testDefaults() throws IOException {
+        assertEquals(admissionControlStats.getAdmissionControllerStatsList().size(), 0);
+    }
+
+    public void testRejectionCount() throws IOException {
+        admissionController.addRejectionCount(AdmissionControlActionType.SEARCH.getType(), 11);
+        admissionController.addRejectionCount(AdmissionControlActionType.INDEXING.getType(), 1);
+        admissionControllerStats = new AdmissionControllerStats(admissionController);
+        admissionControlStats = new AdmissionControlStats(List.of(admissionControllerStats));
+        XContentBuilder builder = JsonXContent.contentBuilder();
+        builder.startObject();
+        builder = admissionControlStats.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        builder.endObject();
+        String response = builder.toString();
+        assertEquals(
+            response,
+            "{\"admission_control\":{\"global_cpu_usage\":{\"transport\":{\"rejection_count\":{\"search\":11,\"indexing\":1}}}}}"
+        );
+        AdmissionControlStats admissionControlStats1 = admissionControlStats;
+        assertEquals(admissionControlStats.hashCode(), admissionControlStats1.hashCode());
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControllerStatsTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControllerStatsTests.java
new file mode 100644
index 0000000000000..fe0399e79a5f4
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/stats/AdmissionControllerStatsTests.java
@@ -0,0 +1,82 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.stats;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.xcontent.json.JsonXContent;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.node.ResourceUsageCollectorService;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.AdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.controllers.CpuBasedAdmissionController;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlActionType;
+import org.opensearch.ratelimitting.admissioncontrol.enums.AdmissionControlMode;
+import org.opensearch.ratelimitting.admissioncontrol.settings.CpuBasedAdmissionControllerSettings;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.io.IOException;
+
+import static org.mockito.Mockito.mock;
+
+public class AdmissionControllerStatsTests extends OpenSearchTestCase {
+    AdmissionController admissionController;
+    AdmissionControllerStats admissionControllerStats;
+    private ThreadPool threadPool;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        Settings settings = Settings.builder()
+            .put(
+                CpuBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE.getKey(),
+                AdmissionControlMode.ENFORCED.getMode()
+            )
+            .build();
+        threadPool = new TestThreadPool("admission_controller_settings_test");
+        ClusterService clusterService = new ClusterService(
+            Settings.EMPTY,
+            new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+            threadPool
+        );
+        admissionController = new CpuBasedAdmissionController("TEST", mock(ResourceUsageCollectorService.class), clusterService, settings);
+        admissionControllerStats = new AdmissionControllerStats(admissionController);
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+        super.tearDown();
+        threadPool.shutdownNow();
+    }
+
+    public void testDefaults() throws IOException {
+        assertEquals(admissionControllerStats.getRejectionCount().size(), 0);
+        assertEquals(admissionControllerStats.getAdmissionControllerName(), "TEST");
+    }
+
+    public void testRejectionCount() throws IOException {
+        admissionController.addRejectionCount(AdmissionControlActionType.SEARCH.getType(), 11);
+        admissionController.addRejectionCount(AdmissionControlActionType.INDEXING.getType(), 1);
+        admissionControllerStats = new AdmissionControllerStats(admissionController);
+        long searchRejection = admissionControllerStats.getRejectionCount().getOrDefault(AdmissionControlActionType.SEARCH.getType(), 0L);
+        long indexingRejection = admissionControllerStats.getRejectionCount()
+            .getOrDefault(AdmissionControlActionType.INDEXING.getType(), 0L);
+        assertEquals(searchRejection, 11);
+        assertEquals(indexingRejection, 1);
+        XContentBuilder builder = JsonXContent.contentBuilder();
+        builder = admissionControllerStats.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        String response = builder.toString();
+        assertEquals(response, "{\"transport\":{\"rejection_count\":{\"search\":11,\"indexing\":1}}}");
+        AdmissionControllerStats admissionControllerStats1 = admissionControllerStats;
+        assertEquals(admissionControllerStats.hashCode(), admissionControllerStats1.hashCode());
+    }
+}
diff --git a/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportHandlerTests.java b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportHandlerTests.java
new file mode 100644
index 0000000000000..0c95769e19489
--- /dev/null
+++ b/server/src/test/java/org/opensearch/ratelimitting/admissioncontrol/transport/AdmissionControlTransportHandlerTests.java
@@ -0,0 +1,92 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ratelimitting.admissioncontrol.transport;
+
+import org.opensearch.core.concurrency.OpenSearchRejectedExecutionException;
+import org.opensearch.ratelimitting.admissioncontrol.AdmissionControlService;
+import org.opensearch.tasks.Task;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.transport.TransportChannel;
+import org.opensearch.transport.TransportRequest;
+import org.opensearch.transport.TransportRequestHandler;
+
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+
+public class AdmissionControlTransportHandlerTests extends OpenSearchTestCase {
+    AdmissionControlTransportHandler<TransportRequest> admissionControlTransportHandler;
+
+    public void testHandlerInvoked() throws Exception {
+        String action = "TEST";
+        InterceptingRequestHandler<TransportRequest> handler = new InterceptingRequestHandler<>(action);
+        admissionControlTransportHandler = new AdmissionControlTransportHandler<TransportRequest>(
+            action,
+            handler,
+            mock(AdmissionControlService.class),
+            false,
+            null
+        );
+        admissionControlTransportHandler.messageReceived(mock(TransportRequest.class), mock(TransportChannel.class), mock(Task.class));
+        assertEquals(1, handler.count);
+    }
+
+    public void testHandlerInvokedRejectedException() throws Exception {
+        String action = "TEST";
+        AdmissionControlService admissionControlService = mock(AdmissionControlService.class);
+        doThrow(new OpenSearchRejectedExecutionException()).when(admissionControlService).applyTransportAdmissionControl(action, null);
+        InterceptingRequestHandler<TransportRequest> handler = new InterceptingRequestHandler<>(action);
+        admissionControlTransportHandler = new AdmissionControlTransportHandler<TransportRequest>(
+            action,
+            handler,
+            admissionControlService,
+            false,
+            null
+        );
+        admissionControlTransportHandler.messageReceived(mock(TransportRequest.class), mock(TransportChannel.class), mock(Task.class));
+        assertEquals(0, handler.count);
+        handler.messageReceived(mock(TransportRequest.class), mock(TransportChannel.class), mock(Task.class));
+        assertEquals(1, handler.count);
+    }
+
+    public void testHandlerInvokedRandomException() throws Exception {
+        String action = "TEST";
+        AdmissionControlService admissionControlService = mock(AdmissionControlService.class);
+        doThrow(new NullPointerException()).when(admissionControlService).applyTransportAdmissionControl(action, null);
+        InterceptingRequestHandler<TransportRequest> handler = new InterceptingRequestHandler<>(action);
+        admissionControlTransportHandler = new AdmissionControlTransportHandler<TransportRequest>(
+            action,
+            handler,
+            admissionControlService,
+            false,
+            null
+        );
+        try {
+            admissionControlTransportHandler.messageReceived(mock(TransportRequest.class), mock(TransportChannel.class), mock(Task.class));
+        } catch (Exception exception) {
+            assertEquals(0, handler.count);
+            handler.messageReceived(mock(TransportRequest.class), mock(TransportChannel.class), mock(Task.class));
+        }
+        assertEquals(1, handler.count);
+    }
+
+    private class InterceptingRequestHandler<T extends TransportRequest> implements TransportRequestHandler<T> {
+        private final String action;
+        public int count;
+
+        public InterceptingRequestHandler(String action) {
+            this.action = action;
+            this.count = 0;
+        }
+
+        @Override
+        public void messageReceived(T request, TransportChannel channel, Task task) throws Exception {
+            this.count = this.count + 1;
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java b/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java
index 889d0dc6ddb14..43ebb86fd5342 100644
--- a/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java
+++ b/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java
@@ -94,6 +94,7 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 
+import static org.opensearch.repositories.blobstore.BlobStoreRepository.SYSTEM_REPOSITORY_SETTING;
 import static org.hamcrest.Matchers.equalTo;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doAnswer;
@@ -201,6 +202,13 @@ public void testRegisterRejectsInvalidRepositoryNames() {
         }
     }
 
+    public void testUpdateOrRegisterRejectsForSystemRepository() {
+        String repoName = "name";
+        PutRepositoryRequest request = new PutRepositoryRequest(repoName);
+        request.settings(Settings.builder().put(SYSTEM_REPOSITORY_SETTING.getKey(), true).build());
+        expectThrows(RepositoryException.class, () -> repositoriesService.registerOrUpdateRepository(request, null));
+    }
+
     public void testRepositoriesStatsCanHaveTheSameNameAndDifferentTypeOverTime() {
         String repoName = "name";
         expectThrows(RepositoryMissingException.class, () -> repositoriesService.repository(repoName));
@@ -211,20 +219,17 @@ public void testRepositoriesStatsCanHaveTheSameNameAndDifferentTypeOverTime() {
         assertThat(repositoriesService.repositoriesStats().size(), equalTo(1));
 
         repositoriesService.applyClusterState(new ClusterChangedEvent("new repo", emptyState(), clusterStateWithRepoTypeA));
-        assertThat(repositoriesService.repositoriesStats().size(), equalTo(1));
+        assertThat(repositoriesService.repositoriesStats().size(), equalTo(0));
 
         ClusterState clusterStateWithRepoTypeB = createClusterStateWithRepo(repoName, MeteredRepositoryTypeB.TYPE);
         repositoriesService.applyClusterState(new ClusterChangedEvent("new repo", clusterStateWithRepoTypeB, emptyState()));
 
         List<RepositoryStatsSnapshot> repositoriesStats = repositoriesService.repositoriesStats();
-        assertThat(repositoriesStats.size(), equalTo(2));
+        assertThat(repositoriesStats.size(), equalTo(1));
         RepositoryStatsSnapshot repositoryStatsTypeA = repositoriesStats.get(0);
-        assertThat(repositoryStatsTypeA.getRepositoryInfo().type, equalTo(MeteredRepositoryTypeA.TYPE));
-        assertThat(repositoryStatsTypeA.getRepositoryStats(), equalTo(MeteredRepositoryTypeA.STATS));
+        assertThat(repositoryStatsTypeA.getRepositoryInfo().type, equalTo(MeteredRepositoryTypeB.TYPE));
+        assertThat(repositoryStatsTypeA.getRepositoryStats(), equalTo(MeteredRepositoryTypeB.STATS));
 
-        RepositoryStatsSnapshot repositoryStatsTypeB = repositoriesStats.get(1);
-        assertThat(repositoryStatsTypeB.getRepositoryInfo().type, equalTo(MeteredRepositoryTypeB.TYPE));
-        assertThat(repositoryStatsTypeB.getRepositoryStats(), equalTo(MeteredRepositoryTypeB.STATS));
     }
 
     public void testWithSameKeyProviderNames() {
@@ -250,7 +255,7 @@ public void testWithSameKeyProviderNames() {
             kpTypeA
         );
         repositoriesService.applyClusterState(new ClusterChangedEvent("new repo", clusterStateWithRepoTypeB, emptyState()));
-        assertThat(repositoriesService.repositoriesStats().size(), equalTo(2));
+        assertThat(repositoriesService.repositoriesStats().size(), equalTo(1));
         MeteredRepositoryTypeB repositoryB = (MeteredRepositoryTypeB) repositoriesService.repository("repoName");
         assertNotNull(repositoryB);
         assertNotNull(repository.cryptoHandler);
@@ -310,22 +315,22 @@ public void testRepositoryUpdateWithDifferentCryptoMetadata() {
         assertNotNull(repository.cryptoHandler);
         assertEquals(kpTypeA, repository.cryptoHandler.kpType);
 
-        expectThrows(IllegalArgumentException.class, () -> repositoriesService.registerRepository(request, null));
+        expectThrows(IllegalArgumentException.class, () -> repositoriesService.registerOrUpdateRepository(request, null));
 
         CryptoSettings cryptoSettings = new CryptoSettings(keyProviderName);
         cryptoSettings.keyProviderType(kpTypeA);
         cryptoSettings.settings(Settings.builder().put("key-1", "val-1"));
         request.cryptoSettings(cryptoSettings);
-        expectThrows(IllegalArgumentException.class, () -> repositoriesService.registerRepository(request, null));
+        expectThrows(IllegalArgumentException.class, () -> repositoriesService.registerOrUpdateRepository(request, null));
 
         cryptoSettings.settings(Settings.builder());
         cryptoSettings.keyProviderName("random");
-        expectThrows(IllegalArgumentException.class, () -> repositoriesService.registerRepository(request, null));
+        expectThrows(IllegalArgumentException.class, () -> repositoriesService.registerOrUpdateRepository(request, null));
 
         cryptoSettings.keyProviderName(keyProviderName);
 
         assertEquals(kpTypeA, repository.cryptoHandler.kpType);
-        repositoriesService.registerRepository(request, null);
+        repositoriesService.registerOrUpdateRepository(request, null);
     }
 
     public void testCryptoManagerClusterStateChanges() {
@@ -355,7 +360,7 @@ public void testCryptoManagerClusterStateChanges() {
             verified,
             repositoryMetadata
         );
-        repositoriesService.registerRepository(request, null);
+        repositoriesService.registerOrUpdateRepository(request, null);
         MeteredRepositoryTypeA repository = (MeteredRepositoryTypeA) repositoriesService.repository(repoName);
         assertNotNull(repository.cryptoHandler);
         assertEquals(kpTypeA, repository.cryptoHandler.kpType);
@@ -375,7 +380,7 @@ public void testCryptoManagerClusterStateChanges() {
             verified,
             repositoryMetadata
         );
-        repositoriesService.registerRepository(request, null);
+        repositoriesService.registerOrUpdateRepository(request, null);
 
         repository = (MeteredRepositoryTypeA) repositoriesService.repository(repoName);
         assertNotNull(repository.cryptoHandler);
@@ -397,7 +402,7 @@ public void testCryptoManagerClusterStateChanges() {
             verified,
             repositoryMetadata
         );
-        repositoriesService.registerRepository(request, null);
+        repositoriesService.registerOrUpdateRepository(request, null);
         repository = (MeteredRepositoryTypeA) repositoriesService.repository(repoName);
         assertNotNull(repository.cryptoHandler);
         assertEquals(kpTypeA, repository.cryptoHandler.kpType);
@@ -418,7 +423,7 @@ public void testCryptoManagerClusterStateChanges() {
             verified,
             repositoryMetadata
         );
-        repositoriesService.registerRepository(request, null);
+        repositoriesService.registerOrUpdateRepository(request, null);
         repository = (MeteredRepositoryTypeA) repositoriesService.repository(repoName);
         assertNotNull(repository.cryptoHandler);
         assertEquals(kpTypeB, repository.cryptoHandler.kpType);
@@ -530,7 +535,7 @@ private ClusterState emptyState() {
 
     private void assertThrowsOnRegister(String repoName) {
         PutRepositoryRequest request = new PutRepositoryRequest(repoName);
-        expectThrows(RepositoryException.class, () -> repositoriesService.registerRepository(request, null));
+        expectThrows(RepositoryException.class, () -> repositoriesService.registerOrUpdateRepository(request, null));
     }
 
     private static class TestCryptoProvider implements CryptoHandler<Object, Object> {
@@ -851,14 +856,7 @@ private static class MeteredRepositoryTypeA extends MeteredBlobStoreRepository {
         private final TestCryptoProvider cryptoHandler;
 
         private MeteredRepositoryTypeA(RepositoryMetadata metadata, ClusterService clusterService) {
-            super(
-                metadata,
-                false,
-                mock(NamedXContentRegistry.class),
-                clusterService,
-                mock(RecoverySettings.class),
-                Map.of("bucket", "bucket-a")
-            );
+            super(metadata, mock(NamedXContentRegistry.class), clusterService, mock(RecoverySettings.class), Map.of("bucket", "bucket-a"));
 
             if (metadata.cryptoMetadata() != null) {
                 cryptoHandler = new TestCryptoProvider(
@@ -892,14 +890,7 @@ private static class MeteredRepositoryTypeB extends MeteredBlobStoreRepository {
         private final TestCryptoProvider cryptoHandler;
 
         private MeteredRepositoryTypeB(RepositoryMetadata metadata, ClusterService clusterService) {
-            super(
-                metadata,
-                false,
-                mock(NamedXContentRegistry.class),
-                clusterService,
-                mock(RecoverySettings.class),
-                Map.of("bucket", "bucket-b")
-            );
+            super(metadata, mock(NamedXContentRegistry.class), clusterService, mock(RecoverySettings.class), Map.of("bucket", "bucket-b"));
 
             if (metadata.cryptoMetadata() != null) {
                 cryptoHandler = new TestCryptoProvider(
diff --git a/server/src/test/java/org/opensearch/repositories/RepositoriesStatsArchiveTests.java b/server/src/test/java/org/opensearch/repositories/RepositoriesStatsArchiveTests.java
index cf0b06a3f7d16..da0cbcb1d4b17 100644
--- a/server/src/test/java/org/opensearch/repositories/RepositoriesStatsArchiveTests.java
+++ b/server/src/test/java/org/opensearch/repositories/RepositoriesStatsArchiveTests.java
@@ -32,7 +32,6 @@
 
 package org.opensearch.repositories;
 
-import org.opensearch.common.UUIDs;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.test.OpenSearchTestCase;
 
@@ -122,14 +121,11 @@ private RepositoryStatsSnapshot createRepositoryStats(RepositoryStats repository
 
     private RepositoryStatsSnapshot createRepositoryStats(RepositoryStats repositoryStats, long clusterVersion) {
         RepositoryInfo repositoryInfo = new RepositoryInfo(
-            UUIDs.randomBase64UUID(),
             randomAlphaOfLength(10),
             randomAlphaOfLength(10),
-            Map.of("bucket", randomAlphaOfLength(10)),
-            System.currentTimeMillis(),
-            null
+            Map.of("bucket", randomAlphaOfLength(10))
         );
-        return new RepositoryStatsSnapshot(repositoryInfo, repositoryStats, clusterVersion, true);
+        return new RepositoryStatsSnapshot(repositoryInfo, repositoryStats, clusterVersion);
     }
 
 }
diff --git a/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryHelperTests.java b/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryHelperTests.java
index 4e60cddd14d73..57c126b85ff70 100644
--- a/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryHelperTests.java
+++ b/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryHelperTests.java
@@ -66,7 +66,9 @@ protected String[] getLockFilesInRemoteStore(String remoteStoreIndex, String rem
         BlobPath shardLevelBlobPath = remoteStorerepository.basePath().add(indexUUID).add("0").add("segments").add("lock_files");
         BlobContainer blobContainer = remoteStorerepository.blobStore().blobContainer(shardLevelBlobPath);
         try (RemoteBufferedOutputDirectory lockDirectory = new RemoteBufferedOutputDirectory(blobContainer)) {
-            return Arrays.stream(lockDirectory.listAll()).filter(lock -> lock.endsWith(".lock")).toArray(String[]::new);
+            return Arrays.stream(lockDirectory.listAll())
+                .filter(lock -> lock.endsWith(".lock") || lock.endsWith(".v2_lock"))
+                .toArray(String[]::new);
         }
     }
 
diff --git a/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryRemoteIndexTests.java b/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryRemoteIndexTests.java
index e3e1bf31e82dc..9cca495cced72 100644
--- a/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryRemoteIndexTests.java
+++ b/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryRemoteIndexTests.java
@@ -145,7 +145,7 @@ public void testRetrieveShallowCopySnapshotCase1() throws IOException {
         final SnapshotId snapshotId1 = snapshotInfo.snapshotId();
 
         String[] lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 0) : "there should be no lock files present in directory, but found " + Arrays.toString(lockFiles);
+        assertEquals("there should be no lock files present in directory, but found " + Arrays.toString(lockFiles), 0, lockFiles.length);
         logger.info("--> create remote index shallow snapshot");
         Settings snapshotRepoSettingsForShallowCopy = Settings.builder()
             .put(snapshotRepoSettings)
@@ -161,8 +161,8 @@ public void testRetrieveShallowCopySnapshotCase1() throws IOException {
         final SnapshotId snapshotId2 = snapshotInfo.snapshotId();
 
         lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 1) : "there should be only one lock file, but found " + Arrays.toString(lockFiles);
-        assert lockFiles[0].endsWith(snapshotId2.getUUID() + ".lock");
+        assertEquals("there should be only one lock file, but found " + Arrays.toString(lockFiles), 1, lockFiles.length);
+        assertTrue(lockFiles[0].endsWith(snapshotId2.getUUID() + ".v2_lock"));
 
         logger.info("--> create another normal snapshot");
         updateRepository(client, snapshotRepositoryName, snapshotRepoSettings);
@@ -174,8 +174,8 @@ public void testRetrieveShallowCopySnapshotCase1() throws IOException {
         final SnapshotId snapshotId3 = snapshotInfo.snapshotId();
 
         lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 1) : "there should be only one lock file, but found " + Arrays.toString(lockFiles);
-        assert lockFiles[0].endsWith(snapshotId2.getUUID() + ".lock");
+        assertEquals("there should be only one lock file, but found " + Arrays.toString(lockFiles), 1, lockFiles.length);
+        assertTrue(lockFiles[0].endsWith(snapshotId2.getUUID() + ".v2_lock"));
 
         logger.info("--> make sure the node's repository can resolve the snapshots");
         final List<SnapshotId> originalSnapshots = Arrays.asList(snapshotId1, snapshotId2, snapshotId3);
@@ -230,8 +230,8 @@ public void testGetRemoteStoreShallowCopyShardMetadata() throws IOException {
         final SnapshotId snapshotId = snapshotInfo.snapshotId();
 
         String[] lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 1) : "there should be only one lock file, but found " + Arrays.toString(lockFiles);
-        assert lockFiles[0].endsWith(snapshotId.getUUID() + ".lock");
+        assertEquals("there should be only one lock file, but found " + Arrays.toString(lockFiles), 1, lockFiles.length);
+        assertTrue(lockFiles[0].endsWith(snapshotId.getUUID() + ".v2_lock"));
 
         final RepositoriesService repositoriesService = getInstanceFromNode(RepositoriesService.class);
         final BlobStoreRepository repository = (BlobStoreRepository) repositoriesService.repository(snapshotRepositoryName);
@@ -305,8 +305,8 @@ public void testRetrieveShallowCopySnapshotCase2() throws IOException {
         final SnapshotId snapshotId1 = snapshotInfo.snapshotId();
 
         String[] lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 1) : "lock files are " + Arrays.toString(lockFiles);
-        assert lockFiles[0].endsWith(snapshotId1.getUUID() + ".lock");
+        assertEquals("lock files are " + Arrays.toString(lockFiles), 1, lockFiles.length);
+        assertTrue(lockFiles[0].endsWith(snapshotId1.getUUID() + ".v2_lock"));
 
         logger.info("--> create second remote index shallow snapshot");
         snapshotInfo = createSnapshot(
@@ -317,10 +317,10 @@ public void testRetrieveShallowCopySnapshotCase2() throws IOException {
         final SnapshotId snapshotId2 = snapshotInfo.snapshotId();
 
         lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 2) : "lock files are " + Arrays.toString(lockFiles);
+        assertEquals("lock files are " + Arrays.toString(lockFiles), 2, lockFiles.length);
         List<SnapshotId> shallowCopySnapshotIDs = Arrays.asList(snapshotId1, snapshotId2);
         for (SnapshotId snapshotId : shallowCopySnapshotIDs) {
-            assert lockFiles[0].contains(snapshotId.getUUID()) || lockFiles[1].contains(snapshotId.getUUID());
+            assertTrue(lockFiles[0].contains(snapshotId.getUUID()) || lockFiles[1].contains(snapshotId.getUUID()));
         }
         logger.info("--> create third remote index shallow snapshot");
         snapshotInfo = createSnapshot(
@@ -331,12 +331,14 @@ public void testRetrieveShallowCopySnapshotCase2() throws IOException {
         final SnapshotId snapshotId3 = snapshotInfo.snapshotId();
 
         lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 3);
+        assertEquals(3, lockFiles.length);
         shallowCopySnapshotIDs = Arrays.asList(snapshotId1, snapshotId2, snapshotId3);
         for (SnapshotId snapshotId : shallowCopySnapshotIDs) {
-            assert lockFiles[0].contains(snapshotId.getUUID())
-                || lockFiles[1].contains(snapshotId.getUUID())
-                || lockFiles[2].contains(snapshotId.getUUID());
+            assertTrue(
+                lockFiles[0].contains(snapshotId.getUUID())
+                    || lockFiles[1].contains(snapshotId.getUUID())
+                    || lockFiles[2].contains(snapshotId.getUUID())
+            );
         }
         logger.info("--> create normal snapshot");
         createRepository(client, snapshotRepositoryName, snapshotRepoSettings);
@@ -348,12 +350,14 @@ public void testRetrieveShallowCopySnapshotCase2() throws IOException {
         final SnapshotId snapshotId4 = snapshotInfo.snapshotId();
 
         lockFiles = getLockFilesInRemoteStore(remoteStoreIndexName, remoteStoreRepositoryName);
-        assert (lockFiles.length == 3) : "lock files are " + Arrays.toString(lockFiles);
+        assertEquals("lock files are " + Arrays.toString(lockFiles), 3, lockFiles.length);
         shallowCopySnapshotIDs = Arrays.asList(snapshotId1, snapshotId2, snapshotId3);
         for (SnapshotId snapshotId : shallowCopySnapshotIDs) {
-            assert lockFiles[0].contains(snapshotId.getUUID())
-                || lockFiles[1].contains(snapshotId.getUUID())
-                || lockFiles[2].contains(snapshotId.getUUID());
+            assertTrue(
+                lockFiles[0].contains(snapshotId.getUUID())
+                    || lockFiles[1].contains(snapshotId.getUUID())
+                    || lockFiles[2].contains(snapshotId.getUUID())
+            );
         }
 
         logger.info("--> make sure the node's repository can resolve the snapshots");
diff --git a/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryTests.java b/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryTests.java
index e097c7025e4fe..9c65ad32fa6a6 100644
--- a/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryTests.java
+++ b/server/src/test/java/org/opensearch/repositories/blobstore/BlobStoreRepositoryTests.java
@@ -252,7 +252,7 @@ public void testBadChunksize() throws Exception {
         );
     }
 
-    public void testFsRepositoryCompressDeprecated() {
+    public void testFsRepositoryCompressDeprecatedIgnored() {
         final Path location = OpenSearchIntegTestCase.randomRepoPath(node().settings());
         final Settings settings = Settings.builder().put(node().settings()).put("location", location).build();
         final RepositoryMetadata metadata = new RepositoryMetadata("test-repo", REPO_TYPE, settings);
@@ -265,10 +265,7 @@ public void testFsRepositoryCompressDeprecated() {
 
         new FsRepository(metadata, useCompressEnvironment, null, BlobStoreTestUtil.mockClusterService(), null);
 
-        assertWarnings(
-            "[repositories.fs.compress] setting was deprecated in OpenSearch and will be removed in a future release!"
-                + " See the breaking changes documentation for the next major version."
-        );
+        assertNoDeprecationWarnings();
     }
 
     private static void writeIndexGen(BlobStoreRepository repository, RepositoryData repositoryData, long generation) throws Exception {
diff --git a/server/src/test/java/org/opensearch/repositories/fs/FsRepositoryTests.java b/server/src/test/java/org/opensearch/repositories/fs/FsRepositoryTests.java
index 303f60283f69f..d9f599714805b 100644
--- a/server/src/test/java/org/opensearch/repositories/fs/FsRepositoryTests.java
+++ b/server/src/test/java/org/opensearch/repositories/fs/FsRepositoryTests.java
@@ -58,6 +58,7 @@
 import org.opensearch.cluster.routing.UnassignedInfo;
 import org.opensearch.common.lucene.Lucene;
 import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.core.common.unit.ByteSizeUnit;
 import org.opensearch.core.index.shard.ShardId;
@@ -70,6 +71,7 @@
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.indices.replication.common.ReplicationLuceneIndex;
 import org.opensearch.repositories.IndexId;
+import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.repositories.blobstore.BlobStoreTestUtil;
 import org.opensearch.snapshots.Snapshot;
 import org.opensearch.snapshots.SnapshotId;
@@ -90,6 +92,7 @@
 
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.emptySet;
+import static org.hamcrest.Matchers.is;
 
 public class FsRepositoryTests extends OpenSearchTestCase {
 
@@ -218,6 +221,31 @@ public void testSnapshotAndRestore() throws IOException, InterruptedException {
         }
     }
 
+    public void testRestrictedSettingsDefault() {
+        Path repo = createTempDir();
+        Settings settings = Settings.builder()
+            .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toAbsolutePath())
+            .put(Environment.PATH_REPO_SETTING.getKey(), repo.toAbsolutePath())
+            .put("location", repo)
+            .put(FsRepository.BASE_PATH_SETTING.getKey(), "my_base_path")
+            .build();
+        RepositoryMetadata metadata = new RepositoryMetadata("test", "fs", settings);
+        FsRepository repository = new FsRepository(
+            metadata,
+            new Environment(settings, null),
+            NamedXContentRegistry.EMPTY,
+            BlobStoreTestUtil.mockClusterService(),
+            new RecoverySettings(settings, new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS))
+        );
+
+        List<Setting<?>> restrictedSettings = repository.getRestrictedSystemRepositorySettings();
+        assertThat(restrictedSettings.size(), is(4));
+        assertTrue(restrictedSettings.contains(BlobStoreRepository.SYSTEM_REPOSITORY_SETTING));
+        assertTrue(restrictedSettings.contains(BlobStoreRepository.READONLY_SETTING));
+        assertTrue(restrictedSettings.contains(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY));
+        assertTrue(restrictedSettings.contains(FsRepository.LOCATION_SETTING));
+    }
+
     private void runGeneric(ThreadPool threadPool, Runnable runnable) throws InterruptedException {
         CountDownLatch latch = new CountDownLatch(1);
         threadPool.generic().submit(() -> {
diff --git a/server/src/test/java/org/opensearch/repositories/fs/ReloadableFsRepositoryTests.java b/server/src/test/java/org/opensearch/repositories/fs/ReloadableFsRepositoryTests.java
new file mode 100644
index 0000000000000..db2cf9c3e9582
--- /dev/null
+++ b/server/src/test/java/org/opensearch/repositories/fs/ReloadableFsRepositoryTests.java
@@ -0,0 +1,119 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.repositories.fs;
+
+import org.opensearch.cluster.metadata.RepositoryMetadata;
+import org.opensearch.common.compress.DeflateCompressor;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.compress.ZstdCompressor;
+import org.opensearch.core.common.unit.ByteSizeUnit;
+import org.opensearch.core.compress.CompressorRegistry;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.env.Environment;
+import org.opensearch.indices.recovery.RecoverySettings;
+import org.opensearch.repositories.blobstore.BlobStoreTestUtil;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.nio.file.Path;
+import java.util.Locale;
+
+public class ReloadableFsRepositoryTests extends OpenSearchTestCase {
+    ReloadableFsRepository repository;
+    RepositoryMetadata metadata;
+    Settings settings;
+    Path repo;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+
+        repo = createTempDir();
+        settings = Settings.builder()
+            .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toAbsolutePath())
+            .put(Environment.PATH_REPO_SETTING.getKey(), repo.toAbsolutePath())
+            .putList(Environment.PATH_DATA_SETTING.getKey(), tmpPaths())
+            .put("location", repo)
+            .put("compress", false)
+            .put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES)
+            .put(FsRepository.BASE_PATH_SETTING.getKey(), "my_base_path")
+            .build();
+        metadata = new RepositoryMetadata("test", "fs", settings);
+        repository = new ReloadableFsRepository(
+            metadata,
+            new Environment(settings, null),
+            NamedXContentRegistry.EMPTY,
+            BlobStoreTestUtil.mockClusterService(),
+            new RecoverySettings(settings, new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS))
+        );
+    }
+
+    /**
+     * Validates that {@link ReloadableFsRepository} supports inplace reloading
+     */
+    public void testIsReloadable() {
+        assertTrue(repository.isReloadable());
+    }
+
+    /**
+     * Updates repository metadata of an existing repository to enable default compressor
+     */
+    public void testCompressReload() {
+        assertEquals(CompressorRegistry.none(), repository.getCompressor());
+        updateCompressionTypeToDefault();
+        repository.validateMetadata(metadata);
+        repository.reload(metadata);
+        assertEquals(CompressorRegistry.defaultCompressor(), repository.getCompressor());
+    }
+
+    /**
+     * Updates repository metadata of an existing repository to change compressor type from default to Zstd
+     */
+    public void testCompressionTypeReload() {
+        assertEquals(CompressorRegistry.none(), repository.getCompressor());
+        updateCompressionTypeToDefault();
+        repository = new ReloadableFsRepository(
+            metadata,
+            new Environment(settings, null),
+            NamedXContentRegistry.EMPTY,
+            BlobStoreTestUtil.mockClusterService(),
+            new RecoverySettings(settings, new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS))
+        );
+        assertEquals(CompressorRegistry.defaultCompressor(), repository.getCompressor());
+
+        settings = Settings.builder()
+            .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toAbsolutePath())
+            .put(Environment.PATH_REPO_SETTING.getKey(), repo.toAbsolutePath())
+            .putList(Environment.PATH_DATA_SETTING.getKey(), tmpPaths())
+            .put("location", repo)
+            .put("compress", true)
+            .put("compression_type", ZstdCompressor.NAME.toLowerCase(Locale.ROOT))
+            .put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES)
+            .put(FsRepository.BASE_PATH_SETTING.getKey(), "my_base_path")
+            .build();
+        metadata = new RepositoryMetadata("test", "fs", settings);
+        repository.validateMetadata(metadata);
+        repository.reload(metadata);
+        assertEquals(CompressorRegistry.getCompressor(ZstdCompressor.NAME.toUpperCase(Locale.ROOT)), repository.getCompressor());
+    }
+
+    private void updateCompressionTypeToDefault() {
+        settings = Settings.builder()
+            .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toAbsolutePath())
+            .put(Environment.PATH_REPO_SETTING.getKey(), repo.toAbsolutePath())
+            .putList(Environment.PATH_DATA_SETTING.getKey(), tmpPaths())
+            .put("location", repo)
+            .put("compress", true)
+            .put("compression_type", DeflateCompressor.NAME.toLowerCase(Locale.ROOT))
+            .put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES)
+            .put(FsRepository.BASE_PATH_SETTING.getKey(), "my_base_path")
+            .build();
+        metadata = new RepositoryMetadata("test", "fs", settings);
+    }
+}
diff --git a/server/src/test/java/org/opensearch/search/CreatePitSingleNodeTests.java b/server/src/test/java/org/opensearch/search/CreatePitSingleNodeTests.java
index 4bbb03322b1f8..2661873d9498f 100644
--- a/server/src/test/java/org/opensearch/search/CreatePitSingleNodeTests.java
+++ b/server/src/test/java/org/opensearch/search/CreatePitSingleNodeTests.java
@@ -321,9 +321,9 @@ public void testCreatePitMoreThanMaxOpenPitContexts() throws Exception {
         // deleteall
         DeletePitRequest deletePITRequest = new DeletePitRequest(pitIds.toArray(new String[0]));
 
-        /**
-         * When we invoke delete again, returns success after clearing the remaining readers. Asserting reader context
-         * not found exceptions don't result in failures ( as deletion in one node is successful )
+        /*
+          When we invoke delete again, returns success after clearing the remaining readers. Asserting reader context
+          not found exceptions don't result in failures ( as deletion in one node is successful )
          */
         ActionFuture<DeletePitResponse> execute = client().execute(DeletePitAction.INSTANCE, deletePITRequest);
         DeletePitResponse deletePITResponse = execute.get();
@@ -489,8 +489,8 @@ public void testPitAfterUpdateIndex() throws Exception {
                 client().prepareSearch().setSize(0).setQuery(matchAllQuery()).get().getHits().getTotalHits().value,
                 Matchers.equalTo(50L)
             );
-            /**
-             * assert without point in time
+            /*
+              assert without point in time
              */
 
             assertThat(
@@ -509,8 +509,8 @@ public void testPitAfterUpdateIndex() throws Exception {
                 client().prepareSearch().setSize(0).setQuery(termQuery("message", "update")).get().getHits().getTotalHits().value,
                 Matchers.equalTo(50L)
             );
-            /**
-             * using point in time id will have the same search results as ones before update
+            /*
+              using point in time id will have the same search results as ones before update
              */
             assertThat(
                 client().prepareSearch()
diff --git a/server/src/test/java/org/opensearch/search/aggregations/AggregatorBaseTests.java b/server/src/test/java/org/opensearch/search/aggregations/AggregatorBaseTests.java
index 728b7162bf478..ce96623ea06df 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/AggregatorBaseTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/AggregatorBaseTests.java
@@ -135,7 +135,7 @@ private ValuesSourceConfig getVSConfig(
             indexed,
             false,
             true,
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             resolution,
             null,
             Collections.emptyMap()
@@ -184,7 +184,7 @@ public void testShortcutIsApplicable() throws IOException {
                 assertNull(pointReaderShim(mockSearchContext(null), null, getVSConfig("number", resolution, false, context)));
             }
             // Check that we decode a dates "just like" the doc values instance.
-            Instant expected = Instant.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse("2020-01-01T00:00:00Z"));
+            Instant expected = Instant.from(DateFieldMapper.getDefaultDateTimeFormatter().parse("2020-01-01T00:00:00Z"));
             byte[] scratch = new byte[8];
             LongPoint.encodeDimension(DateFieldMapper.Resolution.MILLISECONDS.convert(expected), scratch, 0);
             assertThat(
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/DateScriptMocksPlugin.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/DateScriptMocksPlugin.java
index 5a9a9e2b6cb51..d6ba4eedd3a19 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/DateScriptMocksPlugin.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/DateScriptMocksPlugin.java
@@ -43,7 +43,7 @@
 
 /**
  * Mock scripts shared by DateRangeIT and DateHistogramIT.
- *
+ * <p>
  * Provides {@link DateScriptMocksPlugin#EXTRACT_FIELD}, {@link DateScriptMocksPlugin#DOUBLE_PLUS_ONE_MONTH},
  * and {@link DateScriptMocksPlugin#LONG_PLUS_ONE_MONTH} scripts.
  */
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/ShardSizeTestCase.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/ShardSizeTestCase.java
index d6981d1c34652..21d05305eed1b 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/ShardSizeTestCase.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/ShardSizeTestCase.java
@@ -32,21 +32,44 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.opensearch.index.query.QueryBuilders.matchAllQuery;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 import static org.hamcrest.Matchers.is;
 
-public abstract class ShardSizeTestCase extends OpenSearchIntegTestCase {
+public abstract class ShardSizeTestCase extends ParameterizedOpenSearchIntegTestCase {
+
+    public ShardSizeTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected int numberOfShards() {
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/composite/LegacyIntervalCompositeAggBuilderTests.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/composite/LegacyIntervalCompositeAggBuilderTests.java
index aa51f9b11ea19..39054f15826f0 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/composite/LegacyIntervalCompositeAggBuilderTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/composite/LegacyIntervalCompositeAggBuilderTests.java
@@ -44,7 +44,7 @@
 /**
  * Duplicates the tests from {@link CompositeAggregationBuilderTests}, except using the deprecated
  * interval on date histo.  Separated to make testing the warnings easier.
- *
+ * <p>
  * Can be removed in when the legacy interval options are gone
  */
 public class LegacyIntervalCompositeAggBuilderTests extends BaseAggregationTestCase<CompositeAggregationBuilder> {
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
index 37cd7a42c7cdf..dda053af78b30 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
@@ -969,6 +969,7 @@ private void indexSampleData(List<ZonedDateTime> dataset, RandomIndexWriter inde
         for (final ZonedDateTime date : dataset) {
             final long instant = date.toInstant().toEpochMilli();
             document.add(new SortedNumericDocValuesField(DATE_FIELD, instant));
+            document.add(new LongPoint(DATE_FIELD, instant));
             document.add(new LongPoint(INSTANT_FIELD, instant));
             document.add(new SortedNumericDocValuesField(NUMERIC_FIELD, i));
             indexWriter.addDocument(document);
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTestCase.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTestCase.java
index f5f4f3d4b0723..fdbc0160e51a3 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTestCase.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTestCase.java
@@ -125,7 +125,7 @@ protected final DateFieldMapper.DateFieldType aggregableDateFieldType(boolean us
             isSearchable,
             false,
             true,
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             useNanosecondResolution ? DateFieldMapper.Resolution.NANOSECONDS : DateFieldMapper.Resolution.MILLISECONDS,
             null,
             Collections.emptyMap()
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java
index 4e8dc20c465a9..bca6623e66104 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java
@@ -1245,7 +1245,7 @@ private void testSearchCase(
     }
 
     private static long asLong(String dateTime) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(dateTime)).toInstant().toEpochMilli();
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(dateTime)).toInstant().toEpochMilli();
     }
 
     private static long asLong(String dateTime, DateFieldMapper.DateFieldType fieldType) {
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateRangeHistogramAggregatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateRangeHistogramAggregatorTests.java
index 08adc6e3d550a..5c12d070824f2 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateRangeHistogramAggregatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/histogram/DateRangeHistogramAggregatorTests.java
@@ -1086,7 +1086,7 @@ private void testCase(
     }
 
     private static long asLong(String dateTime) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(dateTime)).toInstant().toEpochMilli();
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(dateTime)).toInstant().toEpochMilli();
     }
 
     private static ZonedDateTime asZDT(String dateTime) {
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/range/DateRangeAggregatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/range/DateRangeAggregatorTests.java
index 26ccc1075220b..96c8be1a25cc3 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/range/DateRangeAggregatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/range/DateRangeAggregatorTests.java
@@ -273,7 +273,7 @@ private void testCase(
             true,
             false,
             true,
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             resolution,
             null,
             Collections.emptyMap()
diff --git a/server/src/test/java/org/opensearch/search/aggregations/bucket/range/RangeAggregatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/bucket/range/RangeAggregatorTests.java
index 761615ad1d7eb..dd7ae915c3b45 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/bucket/range/RangeAggregatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/bucket/range/RangeAggregatorTests.java
@@ -136,7 +136,7 @@ public void testDateFieldNanosecondResolution() throws IOException {
             true,
             false,
             true,
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             DateFieldMapper.Resolution.NANOSECONDS,
             null,
             Collections.emptyMap()
@@ -167,7 +167,7 @@ public void testMissingDateWithDateField() throws IOException {
             true,
             false,
             true,
-            DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER,
+            DateFieldMapper.getDefaultDateTimeFormatter(),
             DateFieldMapper.Resolution.NANOSECONDS,
             null,
             Collections.emptyMap()
diff --git a/server/src/test/java/org/opensearch/search/aggregations/metrics/AbstractGeoTestCase.java b/server/src/test/java/org/opensearch/search/aggregations/metrics/AbstractGeoTestCase.java
index 21453bbd17375..e02c00005df9b 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/metrics/AbstractGeoTestCase.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/metrics/AbstractGeoTestCase.java
@@ -32,11 +32,14 @@
 
 package org.opensearch.search.aggregations.metrics;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.common.geo.GeoPoint;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -45,20 +48,24 @@
 import org.opensearch.search.sort.SortBuilders;
 import org.opensearch.search.sort.SortOrder;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 import org.opensearch.test.geo.RandomGeoGenerator;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 import static org.hamcrest.Matchers.equalTo;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public abstract class AbstractGeoTestCase extends OpenSearchIntegTestCase {
+public abstract class AbstractGeoTestCase extends ParameterizedOpenSearchIntegTestCase {
 
     protected static final String SINGLE_VALUED_FIELD_NAME = "geo_value";
     protected static final String MULTI_VALUED_FIELD_NAME = "geo_values";
@@ -69,7 +76,6 @@ public abstract class AbstractGeoTestCase extends OpenSearchIntegTestCase {
     protected static final String DATELINE_IDX_NAME = "dateline_idx";
     protected static final String HIGH_CARD_IDX_NAME = "high_card_idx";
     protected static final String IDX_ZERO_NAME = "idx_zero";
-
     protected static int numDocs;
     protected static int numUniqueGeoPoints;
     protected static GeoPoint[] singleValues, multiValues;
@@ -79,6 +85,23 @@ public abstract class AbstractGeoTestCase extends OpenSearchIntegTestCase {
     protected static Map<String, GeoPoint> expectedCentroidsForGeoHash = null;
     protected static final double GEOHASH_TOLERANCE = 1E-5D;
 
+    public AbstractGeoTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex(UNMAPPED_IDX_NAME);
diff --git a/server/src/test/java/org/opensearch/search/aggregations/metrics/MetricAggScriptPlugin.java b/server/src/test/java/org/opensearch/search/aggregations/metrics/MetricAggScriptPlugin.java
index e29eb95a52cd7..b4dbc8017bc3b 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/metrics/MetricAggScriptPlugin.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/metrics/MetricAggScriptPlugin.java
@@ -45,7 +45,7 @@
 
 /**
  * Provides a number of dummy scripts for tests.
- *
+ * <p>
  * Each script provided allows for an {@code inc} parameter which will
  * be added to each value read from a document.
  */
diff --git a/server/src/test/java/org/opensearch/search/aggregations/pipeline/AvgBucketAggregatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/pipeline/AvgBucketAggregatorTests.java
index 3073cb6d35ddf..de213a154c3c5 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/pipeline/AvgBucketAggregatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/pipeline/AvgBucketAggregatorTests.java
@@ -80,15 +80,15 @@ public class AvgBucketAggregatorTests extends AggregatorTestCase {
 
     /**
      * Test for issue #30608.  Under the following circumstances:
-     *
+     * <p>
      * A. Multi-bucket agg in the first entry of our internal list
      * B. Regular agg as the immediate child of the multi-bucket in A
      * C. Regular agg with the same name as B at the top level, listed as the second entry in our internal list
      * D. Finally, a pipeline agg with the path down to B
-     *
+     * <p>
      * BucketMetrics reduction would throw a class cast exception due to bad subpathing.  This test ensures
      * it is fixed.
-     *
+     * <p>
      * Note: we have this test inside of the `avg_bucket` package so that we can get access to the package-private
      * `reduce()` needed for testing this
      */
@@ -144,6 +144,6 @@ public void testSameAggNames() throws IOException {
     }
 
     private static long asLong(String dateTime) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(dateTime)).toInstant().toEpochMilli();
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(dateTime)).toInstant().toEpochMilli();
     }
 }
diff --git a/server/src/test/java/org/opensearch/search/aggregations/pipeline/CumulativeSumAggregatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/pipeline/CumulativeSumAggregatorTests.java
index 17846234a09d1..5d7636208bd70 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/pipeline/CumulativeSumAggregatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/pipeline/CumulativeSumAggregatorTests.java
@@ -344,6 +344,6 @@ private void executeTestCase(
     }
 
     private static long asLong(String dateTime) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(dateTime)).toInstant().toEpochMilli();
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(dateTime)).toInstant().toEpochMilli();
     }
 }
diff --git a/server/src/test/java/org/opensearch/search/aggregations/pipeline/MovFnAggrgatorTests.java b/server/src/test/java/org/opensearch/search/aggregations/pipeline/MovFnAggrgatorTests.java
index 3ae00efaa6da3..d6abe50ea5201 100644
--- a/server/src/test/java/org/opensearch/search/aggregations/pipeline/MovFnAggrgatorTests.java
+++ b/server/src/test/java/org/opensearch/search/aggregations/pipeline/MovFnAggrgatorTests.java
@@ -169,6 +169,6 @@ private void executeTestCase(Query query, DateHistogramAggregationBuilder aggBui
     }
 
     private static long asLong(String dateTime) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(dateTime)).toInstant().toEpochMilli();
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(dateTime)).toInstant().toEpochMilli();
     }
 }
diff --git a/server/src/test/java/org/opensearch/search/backpressure/SearchBackpressureServiceTests.java b/server/src/test/java/org/opensearch/search/backpressure/SearchBackpressureServiceTests.java
index f0d930c4c3acb..9778798b706f4 100644
--- a/server/src/test/java/org/opensearch/search/backpressure/SearchBackpressureServiceTests.java
+++ b/server/src/test/java/org/opensearch/search/backpressure/SearchBackpressureServiceTests.java
@@ -249,10 +249,11 @@ public void testSearchTaskInFlightCancellation() {
         verify(mockTaskManager, times(10)).cancelTaskAndDescendants(any(), anyString(), anyBoolean(), any());
         assertEquals(3, service.getSearchBackpressureState(SearchTask.class).getLimitReachedCount());
 
-        // Verify search backpressure stats.
+        // Verify search backpressure stats. Since we are not marking any task as completed the completionCount will be 0
+        // for SearchTaskStats here.
         SearchBackpressureStats expectedStats = new SearchBackpressureStats(
-            new SearchTaskStats(10, 3, Map.of(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER, new MockStats(10))),
-            new SearchShardTaskStats(0, 0, Collections.emptyMap()),
+            new SearchTaskStats(10, 3, 0, Map.of(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER, new MockStats(10))),
+            new SearchShardTaskStats(0, 0, 0, Collections.emptyMap()),
             SearchBackpressureMode.ENFORCED
         );
         SearchBackpressureStats actualStats = service.nodeStats();
@@ -323,10 +324,11 @@ public void testSearchShardTaskInFlightCancellation() {
         verify(mockTaskManager, times(12)).cancelTaskAndDescendants(any(), anyString(), anyBoolean(), any());
         assertEquals(3, service.getSearchBackpressureState(SearchShardTask.class).getLimitReachedCount());
 
-        // Verify search backpressure stats.
+        // Verify search backpressure stats. We are marking 20 SearchShardTasks as completed this should get
+        // reflected in SearchShardTaskStats.
         SearchBackpressureStats expectedStats = new SearchBackpressureStats(
-            new SearchTaskStats(0, 0, Collections.emptyMap()),
-            new SearchShardTaskStats(12, 3, Map.of(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER, new MockStats(12))),
+            new SearchTaskStats(0, 0, 0, Collections.emptyMap()),
+            new SearchShardTaskStats(12, 3, 20, Map.of(TaskResourceUsageTrackerType.CPU_USAGE_TRACKER, new MockStats(12))),
             SearchBackpressureMode.ENFORCED
         );
         SearchBackpressureStats actualStats = service.nodeStats();
diff --git a/server/src/test/java/org/opensearch/search/backpressure/stats/SearchShardTaskStatsTests.java b/server/src/test/java/org/opensearch/search/backpressure/stats/SearchShardTaskStatsTests.java
index 6478fdfff61d4..f28b82cad30d3 100644
--- a/server/src/test/java/org/opensearch/search/backpressure/stats/SearchShardTaskStatsTests.java
+++ b/server/src/test/java/org/opensearch/search/backpressure/stats/SearchShardTaskStatsTests.java
@@ -39,6 +39,11 @@ public static SearchShardTaskStats randomInstance() {
             new ElapsedTimeTracker.Stats(randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong())
         );
 
-        return new SearchShardTaskStats(randomNonNegativeLong(), randomNonNegativeLong(), resourceUsageTrackerStats);
+        return new SearchShardTaskStats(
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            randomNonNegativeLong(),
+            resourceUsageTrackerStats
+        );
     }
 }
diff --git a/server/src/test/java/org/opensearch/search/backpressure/stats/SearchTaskStatsTests.java b/server/src/test/java/org/opensearch/search/backpressure/stats/SearchTaskStatsTests.java
index eb33bc1c37b7e..cc7aa92826b41 100644
--- a/server/src/test/java/org/opensearch/search/backpressure/stats/SearchTaskStatsTests.java
+++ b/server/src/test/java/org/opensearch/search/backpressure/stats/SearchTaskStatsTests.java
@@ -40,6 +40,6 @@ public static SearchTaskStats randomInstance() {
             new ElapsedTimeTracker.Stats(randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong())
         );
 
-        return new SearchTaskStats(randomNonNegativeLong(), randomNonNegativeLong(), resourceUsageTrackerStats);
+        return new SearchTaskStats(randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong(), resourceUsageTrackerStats);
     }
 }
diff --git a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineInfoTests.java b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineInfoTests.java
index c19c1ebcb5c26..ce7344fa0d2d6 100644
--- a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineInfoTests.java
+++ b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineInfoTests.java
@@ -46,7 +46,7 @@ public void testSerializationRoundtrip() throws IOException {
 
     /**
      * When serializing / deserializing to / from old versions, processor type info is lost.
-     *
+     * <p>
      * Also, we only supported request/response processors.
      */
     public void testSerializationRoundtripBackcompat() throws IOException {
diff --git a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
index d44bd3831281f..f5851e669a2da 100644
--- a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
+++ b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
@@ -41,6 +41,8 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.AtomicArray;
 import org.opensearch.common.util.concurrent.OpenSearchExecutors;
+import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.breaker.CircuitBreaker;
 import org.opensearch.core.common.breaker.NoopCircuitBreaker;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -67,6 +69,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 
 import static org.mockito.ArgumentMatchers.anyString;
@@ -194,7 +197,7 @@ public void testResolveIndexDefaultPipeline() throws Exception {
         service.applyClusterState(cce);
 
         SearchRequest searchRequest = new SearchRequest("my_index").source(SearchSourceBuilder.searchSource().size(5));
-        PipelinedRequest pipelinedRequest = service.resolvePipeline(searchRequest);
+        PipelinedRequest pipelinedRequest = syncTransformRequest(service.resolvePipeline(searchRequest));
         assertEquals("p1", pipelinedRequest.getPipeline().getId());
         assertEquals(10, pipelinedRequest.source().size());
 
@@ -597,7 +600,7 @@ public void testTransformRequest() throws Exception {
         SearchSourceBuilder sourceBuilder = new SearchSourceBuilder().query(new TermQueryBuilder("foo", "bar")).size(size);
         SearchRequest request = new SearchRequest("_index").source(sourceBuilder).pipeline("p1");
 
-        PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(request);
+        PipelinedRequest pipelinedRequest = syncTransformRequest(searchPipelineService.resolvePipeline(request));
 
         assertEquals(2 * size, pipelinedRequest.source().size());
         assertEquals(size, request.source().size());
@@ -641,19 +644,57 @@ public void testTransformResponse() throws Exception {
         // First try without specifying a pipeline, which should be a no-op.
         SearchRequest searchRequest = new SearchRequest();
         PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
-        SearchResponse notTransformedResponse = pipelinedRequest.transformResponse(searchResponse);
+        SearchResponse notTransformedResponse = syncTransformResponse(pipelinedRequest, searchResponse);
         assertSame(searchResponse, notTransformedResponse);
 
         // Now apply a pipeline
         searchRequest = new SearchRequest().pipeline("p1");
         pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
-        SearchResponse transformedResponse = pipelinedRequest.transformResponse(searchResponse);
+        SearchResponse transformedResponse = syncTransformResponse(pipelinedRequest, searchResponse);
         assertEquals(size, transformedResponse.getHits().getHits().length);
         for (int i = 0; i < size; i++) {
             assertEquals(2.0, transformedResponse.getHits().getHits()[i].getScore(), 0.0001f);
         }
     }
 
+    /**
+     * Helper to synchronously apply a response pipeline, returning the transformed response.
+     */
+    private static SearchResponse syncTransformResponse(PipelinedRequest pipelinedRequest, SearchResponse searchResponse) throws Exception {
+        SearchResponse[] responseBox = new SearchResponse[1];
+        Exception[] exceptionBox = new Exception[1];
+        ActionListener<SearchResponse> responseListener = pipelinedRequest.transformResponseListener(ActionListener.wrap(r -> {
+            responseBox[0] = r;
+        }, e -> { exceptionBox[0] = e; }));
+        responseListener.onResponse(searchResponse);
+
+        if (exceptionBox[0] != null) {
+            throw exceptionBox[0];
+        }
+        return responseBox[0];
+    }
+
+    /**
+     * Helper to synchronously apply a request pipeline, returning the transformed request.
+     */
+    private static PipelinedRequest syncTransformRequest(PipelinedRequest request) throws Exception {
+        PipelinedRequest[] requestBox = new PipelinedRequest[1];
+        Exception[] exceptionBox = new Exception[1];
+
+        request.transformRequest(ActionListener.wrap(r -> requestBox[0] = (PipelinedRequest) r, e -> exceptionBox[0] = e));
+        if (exceptionBox[0] != null) {
+            throw exceptionBox[0];
+        }
+        return requestBox[0];
+    }
+
+    /**
+     * Helper to synchronously apply a request pipeline and response pipeline, returning the transformed response.
+     */
+    private static SearchResponse syncExecutePipeline(PipelinedRequest request, SearchResponse response) throws Exception {
+        return syncTransformResponse(syncTransformRequest(request), response);
+    }
+
     public void testTransformSearchPhase() {
         SearchPipelineService searchPipelineService = createWithProcessors();
         SearchPipelineMetadata metadata = new SearchPipelineMetadata(
@@ -875,7 +916,7 @@ public void testInlinePipeline() throws Exception {
         SearchRequest searchRequest = new SearchRequest().source(sourceBuilder);
 
         // Verify pipeline
-        PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
+        PipelinedRequest pipelinedRequest = syncTransformRequest(searchPipelineService.resolvePipeline(searchRequest));
         Pipeline pipeline = pipelinedRequest.getPipeline();
         assertEquals(SearchPipelineService.AD_HOC_PIPELINE_ID, pipeline.getId());
         assertEquals(1, pipeline.getSearchRequestProcessors().size());
@@ -894,7 +935,7 @@ public void testInlinePipeline() throws Exception {
         SearchResponseSections searchResponseSections = new SearchResponseSections(searchHits, null, null, false, false, null, 0);
         SearchResponse searchResponse = new SearchResponse(searchResponseSections, null, 1, 1, 0, 10, null, null);
 
-        SearchResponse transformedResponse = pipeline.transformResponse(searchRequest, searchResponse);
+        SearchResponse transformedResponse = syncTransformResponse(pipelinedRequest, searchResponse);
         for (int i = 0; i < size; i++) {
             assertEquals(2.0, transformedResponse.getHits().getHits()[i].getScore(), 0.0001);
         }
@@ -946,7 +987,10 @@ public void testExceptionOnRequestProcessing() {
         SearchRequest searchRequest = new SearchRequest().source(sourceBuilder);
 
         // Exception thrown when processing the request
-        expectThrows(SearchPipelineProcessingException.class, () -> searchPipelineService.resolvePipeline(searchRequest));
+        expectThrows(
+            SearchPipelineProcessingException.class,
+            () -> syncTransformRequest(searchPipelineService.resolvePipeline(searchRequest))
+        );
     }
 
     public void testExceptionOnResponseProcessing() throws Exception {
@@ -974,10 +1018,10 @@ public void testExceptionOnResponseProcessing() throws Exception {
 
         SearchResponse response = new SearchResponse(null, null, 0, 0, 0, 0, null, null);
         // Exception thrown when processing response
-        expectThrows(SearchPipelineProcessingException.class, () -> pipelinedRequest.transformResponse(response));
+        expectThrows(SearchPipelineProcessingException.class, () -> syncTransformResponse(pipelinedRequest, response));
     }
 
-    public void testCatchExceptionOnRequestProcessing() throws IllegalAccessException {
+    public void testCatchExceptionOnRequestProcessing() throws Exception {
         SearchRequestProcessor throwingRequestProcessor = new FakeRequestProcessor("throwing_request", null, null, true, r -> {
             throw new RuntimeException();
         });
@@ -1008,7 +1052,7 @@ public void testCatchExceptionOnRequestProcessing() throws IllegalAccessExceptio
                     "The exception from request processor [throwing_request] in the search pipeline [_ad_hoc_pipeline] was ignored"
                 )
             );
-            PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
+            syncTransformRequest(searchPipelineService.resolvePipeline(searchRequest));
             mockAppender.assertAllExpectationsMatched();
         }
     }
@@ -1048,7 +1092,7 @@ public void testCatchExceptionOnResponseProcessing() throws Exception {
                     "The exception from response processor [throwing_response] in the search pipeline [_ad_hoc_pipeline] was ignored"
                 )
             );
-            pipelinedRequest.transformResponse(response);
+            syncTransformResponse(pipelinedRequest, response);
             mockAppender.assertAllExpectationsMatched();
         }
     }
@@ -1078,15 +1122,15 @@ public void testStats() throws Exception {
         SearchRequest request = new SearchRequest();
         SearchResponse response = new SearchResponse(null, null, 0, 0, 0, 0, null, null);
 
-        searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")), response);
         expectThrows(
             SearchPipelineProcessingException.class,
-            () -> searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")).transformResponse(response)
+            () -> syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")), response)
         );
-        searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")), response);
         expectThrows(
             SearchPipelineProcessingException.class,
-            () -> searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")).transformResponse(response)
+            () -> syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")), response)
         );
 
         SearchPipelineStats stats = searchPipelineService.stats();
@@ -1164,12 +1208,12 @@ public void testStatsEnabledIgnoreFailure() throws Exception {
         SearchRequest request = new SearchRequest();
         SearchResponse response = new SearchResponse(null, null, 0, 0, 0, 0, null, null);
 
-        searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")), response);
         // Caught Exception here
-        searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")).transformResponse(response);
-        searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")), response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")), response);
         // Caught Exception here
-        searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")), response);
 
         // when ignoreFailure enabled, the search pipelines will all succeed.
         SearchPipelineStats stats = searchPipelineService.stats();
@@ -1273,8 +1317,8 @@ private SearchPipelineService getSearchPipelineService(
     }
 
     private static void assertPipelineStats(OperationStats stats, long count, long failed) {
-        assertEquals(stats.getCount(), count);
-        assertEquals(stats.getFailedCount(), failed);
+        assertEquals(count, stats.getCount());
+        assertEquals(failed, stats.getFailedCount());
     }
 
     public void testAdHocRejectingProcessor() {
@@ -1336,4 +1380,92 @@ public void testExtraParameterInProcessorConfig() {
             fail("Wrong exception type: " + e.getClass());
         }
     }
+
+    private static class FakeStatefulRequestProcessor extends AbstractProcessor implements StatefulSearchRequestProcessor {
+        private final String type;
+        private final Consumer<PipelineProcessingContext> stateConsumer;
+
+        public FakeStatefulRequestProcessor(String type, Consumer<PipelineProcessingContext> stateConsumer) {
+            super(null, null, false);
+            this.type = type;
+            this.stateConsumer = stateConsumer;
+        }
+
+        @Override
+        public String getType() {
+            return type;
+        }
+
+        @Override
+        public SearchRequest processRequest(SearchRequest request, PipelineProcessingContext requestContext) throws Exception {
+            stateConsumer.accept(requestContext);
+            return request;
+        }
+    }
+
+    private static class FakeStatefulResponseProcessor extends AbstractProcessor implements StatefulSearchResponseProcessor {
+        private final String type;
+        private final Consumer<PipelineProcessingContext> stateConsumer;
+
+        public FakeStatefulResponseProcessor(String type, Consumer<PipelineProcessingContext> stateConsumer) {
+            super(null, null, false);
+            this.type = type;
+            this.stateConsumer = stateConsumer;
+        }
+
+        @Override
+        public String getType() {
+            return type;
+        }
+
+        @Override
+        public SearchResponse processResponse(SearchRequest request, SearchResponse response, PipelineProcessingContext requestContext)
+            throws Exception {
+            stateConsumer.accept(requestContext);
+            return response;
+        }
+    }
+
+    public void testStatefulProcessors() throws Exception {
+        AtomicReference<String> contextHolder = new AtomicReference<>();
+        SearchPipelineService searchPipelineService = createWithProcessors(
+            Map.of(
+                "write_context",
+                (pf, t, d, igf, cfg, ctx) -> new FakeStatefulRequestProcessor("write_context", (c) -> c.setAttribute("a", "b"))
+            ),
+            Map.of(
+                "read_context",
+                (pf, t, d, igf, cfg, ctx) -> new FakeStatefulResponseProcessor(
+                    "read_context",
+                    (c) -> contextHolder.set((String) c.getAttribute("a"))
+                )
+            ),
+            Collections.emptyMap()
+        );
+
+        SearchPipelineMetadata metadata = new SearchPipelineMetadata(
+            Map.of(
+                "p1",
+                new PipelineConfiguration(
+                    "p1",
+                    new BytesArray(
+                        "{\"request_processors\" : [ { \"write_context\": {} } ], \"response_processors\": [ { \"read_context\": {} }] }"
+                    ),
+                    XContentType.JSON
+                )
+            )
+        );
+        ClusterState clusterState = ClusterState.builder(new ClusterName("_name")).build();
+        ClusterState previousState = clusterState;
+        clusterState = ClusterState.builder(clusterState)
+            .metadata(Metadata.builder().putCustom(SearchPipelineMetadata.TYPE, metadata))
+            .build();
+        searchPipelineService.applyClusterState(new ClusterChangedEvent("", clusterState, previousState));
+
+        PipelinedRequest request = searchPipelineService.resolvePipeline(new SearchRequest().pipeline("p1"));
+        assertNull(contextHolder.get());
+        syncExecutePipeline(request, new SearchResponse(null, null, 0, 0, 0, 0, null, null));
+        assertNotNull(contextHolder.get());
+        assertEquals("b", contextHolder.get());
+    }
 }
diff --git a/server/src/test/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdownTests.java b/server/src/test/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdownTests.java
index 065c90b262e11..db14eb90ef839 100644
--- a/server/src/test/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdownTests.java
+++ b/server/src/test/java/org/opensearch/search/profile/query/ConcurrentQueryProfileBreakdownTests.java
@@ -81,9 +81,9 @@ public void testBreakdownMapWithNoLeafContext() throws Exception {
                 );
                 // verify total/min/max/avg node time is same as weight time
                 assertEquals(createWeightTime, testQueryProfileBreakdown.toNodeTime());
-                assertEquals(createWeightTime, testQueryProfileBreakdown.getMaxSliceNodeTime());
-                assertEquals(createWeightTime, testQueryProfileBreakdown.getMinSliceNodeTime());
-                assertEquals(createWeightTime, testQueryProfileBreakdown.getAvgSliceNodeTime());
+                assertEquals(0, testQueryProfileBreakdown.getMaxSliceNodeTime());
+                assertEquals(0, testQueryProfileBreakdown.getMinSliceNodeTime());
+                assertEquals(0, testQueryProfileBreakdown.getAvgSliceNodeTime());
                 continue;
             }
             assertEquals(0, (long) queryBreakDownMap.get(timingTypeKey));
@@ -103,16 +103,15 @@ public void testBuildSliceLevelBreakdownWithSingleSlice() throws Exception {
         final LeafReaderContext sliceLeaf = directoryReader.leaves().get(0);
         final Collector sliceCollector = mock(Collector.class);
         final long createWeightEarliestStartTime = createWeightTimer.getEarliestTimerStartTime();
-        final Map<String, Long> leafProfileBreakdownMap = getLeafBreakdownMap(createWeightEarliestStartTime + 10, 10, 1);
+        final long createWeightEndTime = createWeightEarliestStartTime + createWeightTimer.getApproximateTiming();
+        final Map<String, Long> leafProfileBreakdownMap = getLeafBreakdownMap(createWeightEndTime + 10, 10, 1);
         final AbstractProfileBreakdown<QueryTimingType> leafProfileBreakdown = new TestQueryProfileBreakdown(
             QueryTimingType.class,
             leafProfileBreakdownMap
         );
         testQueryProfileBreakdown.associateCollectorToLeaves(sliceCollector, sliceLeaf);
         testQueryProfileBreakdown.getContexts().put(sliceLeaf, leafProfileBreakdown);
-        final Map<Collector, Map<String, Long>> sliceBreakdownMap = testQueryProfileBreakdown.buildSliceLevelBreakdown(
-            createWeightEarliestStartTime
-        );
+        final Map<Collector, Map<String, Long>> sliceBreakdownMap = testQueryProfileBreakdown.buildSliceLevelBreakdown();
         assertFalse(sliceBreakdownMap == null || sliceBreakdownMap.isEmpty());
         assertEquals(1, sliceBreakdownMap.size());
         assertTrue(sliceBreakdownMap.containsKey(sliceCollector));
@@ -141,9 +140,9 @@ public void testBuildSliceLevelBreakdownWithSingleSlice() throws Exception {
                 (long) sliceBreakdown.get(timingTypeKey + SLICE_END_TIME_SUFFIX)
             );
         }
-        assertEquals(20, testQueryProfileBreakdown.getMaxSliceNodeTime());
-        assertEquals(20, testQueryProfileBreakdown.getMinSliceNodeTime());
-        assertEquals(20, testQueryProfileBreakdown.getAvgSliceNodeTime());
+        assertEquals(10, testQueryProfileBreakdown.getMaxSliceNodeTime());
+        assertEquals(10, testQueryProfileBreakdown.getMinSliceNodeTime());
+        assertEquals(10, testQueryProfileBreakdown.getAvgSliceNodeTime());
         directoryReader.close();
         directory.close();
     }
@@ -154,8 +153,9 @@ public void testBuildSliceLevelBreakdownWithMultipleSlices() throws Exception {
         final Collector sliceCollector_1 = mock(Collector.class);
         final Collector sliceCollector_2 = mock(Collector.class);
         final long createWeightEarliestStartTime = createWeightTimer.getEarliestTimerStartTime();
-        final Map<String, Long> leafProfileBreakdownMap_1 = getLeafBreakdownMap(createWeightEarliestStartTime + 10, 10, 1);
-        final Map<String, Long> leafProfileBreakdownMap_2 = getLeafBreakdownMap(createWeightEarliestStartTime + 40, 10, 1);
+        final long createWeightEndTime = createWeightEarliestStartTime + createWeightTimer.getApproximateTiming();
+        final Map<String, Long> leafProfileBreakdownMap_1 = getLeafBreakdownMap(createWeightEndTime + 10, 10, 1);
+        final Map<String, Long> leafProfileBreakdownMap_2 = getLeafBreakdownMap(createWeightEndTime + 40, 10, 1);
         final AbstractProfileBreakdown<QueryTimingType> leafProfileBreakdown_1 = new TestQueryProfileBreakdown(
             QueryTimingType.class,
             leafProfileBreakdownMap_1
@@ -168,9 +168,7 @@ public void testBuildSliceLevelBreakdownWithMultipleSlices() throws Exception {
         testQueryProfileBreakdown.associateCollectorToLeaves(sliceCollector_2, directoryReader.leaves().get(1));
         testQueryProfileBreakdown.getContexts().put(directoryReader.leaves().get(0), leafProfileBreakdown_1);
         testQueryProfileBreakdown.getContexts().put(directoryReader.leaves().get(1), leafProfileBreakdown_2);
-        final Map<Collector, Map<String, Long>> sliceBreakdownMap = testQueryProfileBreakdown.buildSliceLevelBreakdown(
-            createWeightEarliestStartTime
-        );
+        final Map<Collector, Map<String, Long>> sliceBreakdownMap = testQueryProfileBreakdown.buildSliceLevelBreakdown();
         assertFalse(sliceBreakdownMap == null || sliceBreakdownMap.isEmpty());
         assertEquals(2, sliceBreakdownMap.size());
 
@@ -208,9 +206,9 @@ public void testBuildSliceLevelBreakdownWithMultipleSlices() throws Exception {
             }
         }
 
-        assertEquals(50, testQueryProfileBreakdown.getMaxSliceNodeTime());
-        assertEquals(20, testQueryProfileBreakdown.getMinSliceNodeTime());
-        assertEquals(35, testQueryProfileBreakdown.getAvgSliceNodeTime());
+        assertEquals(10, testQueryProfileBreakdown.getMaxSliceNodeTime());
+        assertEquals(10, testQueryProfileBreakdown.getMinSliceNodeTime());
+        assertEquals(10, testQueryProfileBreakdown.getAvgSliceNodeTime());
         directoryReader.close();
         directory.close();
     }
@@ -221,8 +219,9 @@ public void testBreakDownMapWithMultipleSlices() throws Exception {
         final Collector sliceCollector_1 = mock(Collector.class);
         final Collector sliceCollector_2 = mock(Collector.class);
         final long createWeightEarliestStartTime = createWeightTimer.getEarliestTimerStartTime();
-        final Map<String, Long> leafProfileBreakdownMap_1 = getLeafBreakdownMap(createWeightEarliestStartTime + 10, 10, 1);
-        final Map<String, Long> leafProfileBreakdownMap_2 = getLeafBreakdownMap(createWeightEarliestStartTime + 40, 20, 1);
+        final long createWeightEndTime = createWeightEarliestStartTime + createWeightTimer.getApproximateTiming();
+        final Map<String, Long> leafProfileBreakdownMap_1 = getLeafBreakdownMap(createWeightEndTime + 10, 10, 1);
+        final Map<String, Long> leafProfileBreakdownMap_2 = getLeafBreakdownMap(createWeightEndTime + 40, 20, 1);
         final AbstractProfileBreakdown<QueryTimingType> leafProfileBreakdown_1 = new TestQueryProfileBreakdown(
             QueryTimingType.class,
             leafProfileBreakdownMap_1
@@ -269,9 +268,119 @@ public void testBreakDownMapWithMultipleSlices() throws Exception {
             assertEquals(1, (long) queryBreakDownMap.get(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeCountKey));
         }
 
-        assertEquals(60, testQueryProfileBreakdown.getMaxSliceNodeTime());
-        assertEquals(20, testQueryProfileBreakdown.getMinSliceNodeTime());
-        assertEquals(40, testQueryProfileBreakdown.getAvgSliceNodeTime());
+        assertEquals(20, testQueryProfileBreakdown.getMaxSliceNodeTime());
+        assertEquals(10, testQueryProfileBreakdown.getMinSliceNodeTime());
+        assertEquals(15, testQueryProfileBreakdown.getAvgSliceNodeTime());
+        directoryReader.close();
+        directory.close();
+    }
+
+    public void testBreakDownMapWithMultipleSlicesAndOneSliceWithNoLeafContext() throws Exception {
+        final DirectoryReader directoryReader = getDirectoryReader(2);
+        final Directory directory = directoryReader.directory();
+        final Collector sliceCollector_1 = mock(Collector.class);
+        final Collector sliceCollector_2 = mock(Collector.class);
+        final long createWeightEarliestStartTime = createWeightTimer.getEarliestTimerStartTime();
+        final long createWeightEndTime = createWeightEarliestStartTime + createWeightTimer.getApproximateTiming();
+        final Map<String, Long> leafProfileBreakdownMap_1 = getLeafBreakdownMap(createWeightEndTime + 10, 10, 1);
+        final AbstractProfileBreakdown<QueryTimingType> leafProfileBreakdown_1 = new TestQueryProfileBreakdown(
+            QueryTimingType.class,
+            leafProfileBreakdownMap_1
+        );
+        testQueryProfileBreakdown.associateCollectorToLeaves(sliceCollector_1, directoryReader.leaves().get(0));
+        testQueryProfileBreakdown.associateCollectorToLeaves(sliceCollector_2, directoryReader.leaves().get(1));
+        testQueryProfileBreakdown.getContexts().put(directoryReader.leaves().get(0), leafProfileBreakdown_1);
+        // leaf2 profile breakdown is not present in contexts map
+
+        Map<String, Long> queryBreakDownMap = testQueryProfileBreakdown.toBreakdownMap();
+        assertFalse(queryBreakDownMap == null || queryBreakDownMap.isEmpty());
+        assertEquals(66, queryBreakDownMap.size());
+
+        for (QueryTimingType queryTimingType : QueryTimingType.values()) {
+            String timingTypeKey = queryTimingType.toString();
+            String timingTypeCountKey = queryTimingType + TIMING_TYPE_COUNT_SUFFIX;
+
+            if (queryTimingType.equals(QueryTimingType.CREATE_WEIGHT)) {
+                final long createWeightTime = queryBreakDownMap.get(timingTypeKey);
+                assertEquals(createWeightTimer.getApproximateTiming(), createWeightTime);
+                assertEquals(1, (long) queryBreakDownMap.get(timingTypeCountKey));
+                // verify there is no min/max/avg for weight type stats
+                assertFalse(
+                    queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeKey)
+                        || queryBreakDownMap.containsKey(MIN_PREFIX + timingTypeKey)
+                        || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeKey)
+                        || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeCountKey)
+                        || queryBreakDownMap.containsKey(MIN_PREFIX + timingTypeCountKey)
+                        || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeCountKey)
+                );
+                continue;
+            }
+            assertEquals(10, (long) queryBreakDownMap.get(timingTypeKey));
+            assertEquals(10, (long) queryBreakDownMap.get(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeKey));
+            assertEquals(5, (long) queryBreakDownMap.get(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeKey));
+            assertEquals(0, (long) queryBreakDownMap.get(MIN_PREFIX + timingTypeKey));
+            assertEquals(1, (long) queryBreakDownMap.get(timingTypeCountKey));
+            assertEquals(1, (long) queryBreakDownMap.get(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeCountKey));
+            // min of 0 means one of the slice didn't worked on any leaf context
+            assertEquals(0, (long) queryBreakDownMap.get(MIN_PREFIX + timingTypeCountKey));
+            assertEquals(0, (long) queryBreakDownMap.get(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeCountKey));
+        }
+
+        assertEquals(10, testQueryProfileBreakdown.getMaxSliceNodeTime());
+        assertEquals(0, testQueryProfileBreakdown.getMinSliceNodeTime());
+        assertEquals(5, testQueryProfileBreakdown.getAvgSliceNodeTime());
+        directoryReader.close();
+        directory.close();
+    }
+
+    public void testOneLeafContextWithEmptySliceCollectorsToLeaves() throws Exception {
+        final DirectoryReader directoryReader = getDirectoryReader(1);
+        final Directory directory = directoryReader.directory();
+        final long createWeightEarliestStartTime = createWeightTimer.getEarliestTimerStartTime();
+        final long createWeightEndTime = createWeightEarliestStartTime + createWeightTimer.getApproximateTiming();
+        final Map<String, Long> leafProfileBreakdownMap_1 = getLeafBreakdownMap(createWeightEndTime + 10, 10, 1);
+        final AbstractProfileBreakdown<QueryTimingType> leafProfileBreakdown_1 = new TestQueryProfileBreakdown(
+            QueryTimingType.class,
+            leafProfileBreakdownMap_1
+        );
+        testQueryProfileBreakdown.getContexts().put(directoryReader.leaves().get(0), leafProfileBreakdown_1);
+        final Map<String, Long> queryBreakDownMap = testQueryProfileBreakdown.toBreakdownMap();
+        assertFalse(queryBreakDownMap == null || queryBreakDownMap.isEmpty());
+        assertEquals(26, queryBreakDownMap.size());
+        for (QueryTimingType queryTimingType : QueryTimingType.values()) {
+            String timingTypeKey = queryTimingType.toString();
+            String timingTypeCountKey = queryTimingType + TIMING_TYPE_COUNT_SUFFIX;
+
+            if (queryTimingType.equals(QueryTimingType.CREATE_WEIGHT)) {
+                final long createWeightTime = queryBreakDownMap.get(timingTypeKey);
+                assertEquals(createWeightTimer.getApproximateTiming(), createWeightTime);
+                assertEquals(1, (long) queryBreakDownMap.get(timingTypeCountKey));
+                // verify there is no min/max/avg for weight type stats
+                assertFalse(
+                    queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeKey)
+                        || queryBreakDownMap.containsKey(MIN_PREFIX + timingTypeKey)
+                        || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeKey)
+                        || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeCountKey)
+                        || queryBreakDownMap.containsKey(MIN_PREFIX + timingTypeCountKey)
+                        || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeCountKey)
+                );
+                continue;
+            }
+            assertNotNull(queryBreakDownMap.get(timingTypeKey));
+            assertNotNull(queryBreakDownMap.get(timingTypeCountKey));
+            // verify there is no min/max/avg for current breakdown type stats
+            assertFalse(
+                queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeKey)
+                    || queryBreakDownMap.containsKey(MIN_PREFIX + timingTypeKey)
+                    || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeKey)
+                    || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.MAX_PREFIX + timingTypeCountKey)
+                    || queryBreakDownMap.containsKey(MIN_PREFIX + timingTypeCountKey)
+                    || queryBreakDownMap.containsKey(ConcurrentQueryProfileBreakdown.AVG_PREFIX + timingTypeCountKey)
+            );
+        }
+        assertEquals(0, testQueryProfileBreakdown.getMaxSliceNodeTime());
+        assertEquals(0, testQueryProfileBreakdown.getMinSliceNodeTime());
+        assertEquals(0, testQueryProfileBreakdown.getAvgSliceNodeTime());
         directoryReader.close();
         directory.close();
     }
diff --git a/server/src/test/java/org/opensearch/search/profile/query/ConcurrentQueryProfilerTests.java b/server/src/test/java/org/opensearch/search/profile/query/ConcurrentQueryProfilerTests.java
new file mode 100644
index 0000000000000..736bbcdd9e8dd
--- /dev/null
+++ b/server/src/test/java/org/opensearch/search/profile/query/ConcurrentQueryProfilerTests.java
@@ -0,0 +1,36 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.profile.query;
+
+import org.opensearch.search.profile.Timer;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.hamcrest.Matchers.equalTo;
+
+public class ConcurrentQueryProfilerTests extends OpenSearchTestCase {
+
+    public void testMergeRewriteTimeIntervals() {
+        ConcurrentQueryProfiler profiler = new ConcurrentQueryProfiler(new ConcurrentQueryProfileTree());
+        List<Timer> timers = new LinkedList<>();
+        timers.add(new Timer(217134L, 1L, 1L, 0L, 553074511206907L));
+        timers.add(new Timer(228954L, 1L, 1L, 0L, 553074509287335L));
+        timers.add(new Timer(228954L, 1L, 1L, 0L, 553074509287336L));
+        LinkedList<long[]> mergedIntervals = profiler.mergeRewriteTimeIntervals(timers);
+        assertThat(mergedIntervals.size(), equalTo(2));
+        long[] interval = mergedIntervals.get(0);
+        assertThat(interval[0], equalTo(553074509287335L));
+        assertThat(interval[1], equalTo(553074509516290L));
+        interval = mergedIntervals.get(1);
+        assertThat(interval[0], equalTo(553074511206907L));
+        assertThat(interval[1], equalTo(553074511424041L));
+    }
+}
diff --git a/server/src/test/java/org/opensearch/search/profile/query/QueryProfilerTests.java b/server/src/test/java/org/opensearch/search/profile/query/QueryProfilerTests.java
index 64a440b85eb10..481a224f2ff0e 100644
--- a/server/src/test/java/org/opensearch/search/profile/query/QueryProfilerTests.java
+++ b/server/src/test/java/org/opensearch/search/profile/query/QueryProfilerTests.java
@@ -161,7 +161,9 @@ public void tearDown() throws Exception {
     }
 
     public void testBasic() throws IOException {
-        QueryProfiler profiler = new QueryProfiler(executor != null);
+        QueryProfiler profiler = executor != null
+            ? new ConcurrentQueryProfiler(new ConcurrentQueryProfileTree())
+            : new QueryProfiler(new InternalQueryProfileTree());
         searcher.setProfiler(profiler);
         Query query = new TermQuery(new Term("foo", "bar"));
         searcher.search(query, 1);
@@ -228,7 +230,9 @@ public void testBasic() throws IOException {
     }
 
     public void testNoScoring() throws IOException {
-        QueryProfiler profiler = new QueryProfiler(executor != null);
+        QueryProfiler profiler = executor != null
+            ? new ConcurrentQueryProfiler(new ConcurrentQueryProfileTree())
+            : new QueryProfiler(new InternalQueryProfileTree());
         searcher.setProfiler(profiler);
         Query query = new TermQuery(new Term("foo", "bar"));
         searcher.search(query, 1, Sort.INDEXORDER); // scores are not needed
@@ -295,7 +299,9 @@ public void testNoScoring() throws IOException {
     }
 
     public void testUseIndexStats() throws IOException {
-        QueryProfiler profiler = new QueryProfiler(executor != null);
+        QueryProfiler profiler = executor != null
+            ? new ConcurrentQueryProfiler(new ConcurrentQueryProfileTree())
+            : new QueryProfiler(new InternalQueryProfileTree());
         searcher.setProfiler(profiler);
         Query query = new TermQuery(new Term("foo", "bar"));
         searcher.count(query); // will use index stats
@@ -309,7 +315,9 @@ public void testUseIndexStats() throws IOException {
     }
 
     public void testApproximations() throws IOException {
-        QueryProfiler profiler = new QueryProfiler(executor != null);
+        QueryProfiler profiler = executor != null
+            ? new ConcurrentQueryProfiler(new ConcurrentQueryProfileTree())
+            : new QueryProfiler(new InternalQueryProfileTree());
         searcher.setProfiler(profiler);
         Query query = new RandomApproximationQuery(new TermQuery(new Term("foo", "bar")), random());
         searcher.count(query);
diff --git a/server/src/test/java/org/opensearch/search/query/QueryProfilePhaseTests.java b/server/src/test/java/org/opensearch/search/query/QueryProfilePhaseTests.java
index fc77c1b356124..62dcf54e25578 100644
--- a/server/src/test/java/org/opensearch/search/query/QueryProfilePhaseTests.java
+++ b/server/src/test/java/org/opensearch/search/query/QueryProfilePhaseTests.java
@@ -336,12 +336,17 @@ public void testMinScoreDisablesCountOptimization() throws Exception {
         assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
         assertProfileData(context, "MatchAllDocsQuery", query -> {
             assertThat(query.getTimeBreakdown().keySet(), not(empty()));
-            assertThat(query.getTimeBreakdown().get("score"), greaterThanOrEqualTo(100L));
+            assertThat(query.getTimeBreakdown().get("score"), greaterThanOrEqualTo(1L));
             assertThat(query.getTimeBreakdown().get("score_count"), equalTo(1L));
             if (executor != null) {
-                assertThat(query.getTimeBreakdown().get("max_score"), greaterThanOrEqualTo(100L));
-                assertThat(query.getTimeBreakdown().get("min_score"), greaterThanOrEqualTo(100L));
-                assertThat(query.getTimeBreakdown().get("avg_score"), greaterThanOrEqualTo(100L));
+                long maxScore = query.getTimeBreakdown().get("max_score");
+                long minScore = query.getTimeBreakdown().get("min_score");
+                long avgScore = query.getTimeBreakdown().get("avg_score");
+                assertThat(maxScore, greaterThanOrEqualTo(1L));
+                assertThat(minScore, greaterThanOrEqualTo(1L));
+                assertThat(avgScore, greaterThanOrEqualTo(1L));
+                assertThat(maxScore, greaterThanOrEqualTo(avgScore));
+                assertThat(avgScore, greaterThanOrEqualTo(minScore));
                 assertThat(query.getTimeBreakdown().get("max_score_count"), equalTo(1L));
                 assertThat(query.getTimeBreakdown().get("min_score_count"), equalTo(1L));
                 assertThat(query.getTimeBreakdown().get("avg_score_count"), equalTo(1L));
@@ -1104,10 +1109,10 @@ public void testDisableTopScoreCollection() throws Exception {
             assertThat(query.getTimeBreakdown().get("score_count"), greaterThan(0L));
             if (executor != null) {
                 assertThat(query.getTimeBreakdown().get("max_score"), greaterThan(0L));
-                assertThat(query.getTimeBreakdown().get("min_score"), greaterThan(0L));
+                assertThat(query.getTimeBreakdown().get("min_score"), greaterThanOrEqualTo(0L));
                 assertThat(query.getTimeBreakdown().get("avg_score"), greaterThan(0L));
                 assertThat(query.getTimeBreakdown().get("max_score_count"), greaterThan(0L));
-                assertThat(query.getTimeBreakdown().get("min_score_count"), greaterThan(0L));
+                assertThat(query.getTimeBreakdown().get("min_score_count"), greaterThanOrEqualTo(0L));
                 assertThat(query.getTimeBreakdown().get("avg_score_count"), greaterThan(0L));
             }
             assertThat(query.getTimeBreakdown().get("create_weight"), greaterThan(0L));
@@ -1278,7 +1283,7 @@ public void testMaxScore() throws Exception {
                 assertThat(query.getTimeBreakdown().get("max_score"), greaterThan(0L));
                 assertThat(query.getTimeBreakdown().get("min_score"), greaterThanOrEqualTo(0L));
                 assertThat(query.getTimeBreakdown().get("avg_score"), greaterThan(0L));
-                assertThat(query.getTimeBreakdown().get("max_score_count"), greaterThanOrEqualTo(6L));
+                assertThat(query.getTimeBreakdown().get("max_score_count"), greaterThanOrEqualTo(4L));
                 assertThat(query.getTimeBreakdown().get("min_score_count"), greaterThanOrEqualTo(0L));
                 assertThat(query.getTimeBreakdown().get("avg_score_count"), greaterThanOrEqualTo(1L));
             }
@@ -1400,7 +1405,7 @@ public void testCollapseQuerySearchResults() throws Exception {
                 assertThat(query.getTimeBreakdown().get("min_score"), greaterThan(0L));
                 assertThat(query.getTimeBreakdown().get("avg_score"), greaterThan(0L));
                 assertThat(query.getTimeBreakdown().get("max_score_count"), greaterThanOrEqualTo(6L));
-                assertThat(query.getTimeBreakdown().get("min_score_count"), greaterThanOrEqualTo(6L));
+                assertThat(query.getTimeBreakdown().get("min_score_count"), greaterThanOrEqualTo(2L));
                 assertThat(query.getTimeBreakdown().get("avg_score_count"), greaterThanOrEqualTo(6L));
             }
             assertThat(query.getTimeBreakdown().get("create_weight"), greaterThan(0L));
@@ -1435,7 +1440,7 @@ public void testCollapseQuerySearchResults() throws Exception {
                 assertThat(query.getTimeBreakdown().get("min_score"), greaterThan(0L));
                 assertThat(query.getTimeBreakdown().get("avg_score"), greaterThan(0L));
                 assertThat(query.getTimeBreakdown().get("max_score_count"), greaterThanOrEqualTo(6L));
-                assertThat(query.getTimeBreakdown().get("min_score_count"), greaterThanOrEqualTo(6L));
+                assertThat(query.getTimeBreakdown().get("min_score_count"), greaterThanOrEqualTo(2L));
                 assertThat(query.getTimeBreakdown().get("avg_score_count"), greaterThanOrEqualTo(6L));
             }
             assertThat(query.getTimeBreakdown().get("create_weight"), greaterThan(0L));
diff --git a/server/src/test/java/org/opensearch/snapshots/BlobStoreFormatTests.java b/server/src/test/java/org/opensearch/snapshots/BlobStoreFormatTests.java
index 03f0d27188027..c5f36fcc01983 100644
--- a/server/src/test/java/org/opensearch/snapshots/BlobStoreFormatTests.java
+++ b/server/src/test/java/org/opensearch/snapshots/BlobStoreFormatTests.java
@@ -43,6 +43,7 @@
 import org.opensearch.common.blobstore.fs.FsBlobStore;
 import org.opensearch.common.blobstore.stream.read.ReadContext;
 import org.opensearch.common.blobstore.stream.write.WriteContext;
+import org.opensearch.common.blobstore.stream.write.WritePriority;
 import org.opensearch.common.compress.DeflateCompressor;
 import org.opensearch.common.io.Streams;
 import org.opensearch.common.io.stream.BytesStreamOutput;
@@ -65,8 +66,13 @@
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 
+import org.mockito.ArgumentCaptor;
+
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.greaterThan;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
 public class BlobStoreFormatTests extends OpenSearchTestCase {
 
@@ -128,42 +134,36 @@ public void testBlobStoreAsyncOperations() throws IOException, InterruptedExcept
             BlobPath.cleanPath(),
             null
         );
+        MockFsVerifyingBlobContainer spyContainer = spy(mockBlobContainer);
         ChecksumBlobStoreFormat<BlobObj> checksumSMILE = new ChecksumBlobStoreFormat<>(BLOB_CODEC, "%s", BlobObj::fromXContent);
-
+        ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
+        ArgumentCaptor<WriteContext> writeContextArgumentCaptor = ArgumentCaptor.forClass(WriteContext.class);
         CountDownLatch latch = new CountDownLatch(2);
 
-        ActionListener<Void> actionListener = new ActionListener<>() {
-            @Override
-            public void onResponse(Void unused) {
-                logger.info("---> Async write succeeded");
-                latch.countDown();
-            }
-
-            @Override
-            public void onFailure(Exception e) {
-                logger.info("---> Failure in async write");
-                throw new RuntimeException("async write should not fail");
-            }
-        };
-
         // Write blobs in different formats
         checksumSMILE.writeAsync(
             new BlobObj("checksum smile"),
-            mockBlobContainer,
+            spyContainer,
             "check-smile",
             CompressorRegistry.none(),
-            actionListener
+            getVoidActionListener(latch),
+            ChecksumBlobStoreFormat.SNAPSHOT_ONLY_FORMAT_PARAMS
         );
         checksumSMILE.writeAsync(
             new BlobObj("checksum smile compressed"),
-            mockBlobContainer,
+            spyContainer,
             "check-smile-comp",
             CompressorRegistry.getCompressor(DeflateCompressor.NAME),
-            actionListener
+            getVoidActionListener(latch),
+            ChecksumBlobStoreFormat.SNAPSHOT_ONLY_FORMAT_PARAMS
         );
 
         latch.await();
 
+        verify(spyContainer, times(2)).asyncBlobUpload(writeContextArgumentCaptor.capture(), actionListenerArgumentCaptor.capture());
+        assertEquals(2, writeContextArgumentCaptor.getAllValues().size());
+        writeContextArgumentCaptor.getAllValues()
+            .forEach(writeContext -> assertEquals(WritePriority.NORMAL, writeContext.getWritePriority()));
         // Assert that all checksum blobs can be read
         assertEquals(checksumSMILE.read(mockBlobContainer.getDelegate(), "check-smile", xContentRegistry()).getText(), "checksum smile");
         assertEquals(
@@ -172,6 +172,39 @@ public void onFailure(Exception e) {
         );
     }
 
+    public void testBlobStorePriorityAsyncOperation() throws IOException, InterruptedException {
+        BlobStore blobStore = createTestBlobStore();
+        MockFsVerifyingBlobContainer mockBlobContainer = new MockFsVerifyingBlobContainer(
+            (FsBlobStore) blobStore,
+            BlobPath.cleanPath(),
+            null
+        );
+        MockFsVerifyingBlobContainer spyContainer = spy(mockBlobContainer);
+        ChecksumBlobStoreFormat<BlobObj> checksumSMILE = new ChecksumBlobStoreFormat<>(BLOB_CODEC, "%s", BlobObj::fromXContent);
+
+        ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
+        ArgumentCaptor<WriteContext> writeContextArgumentCaptor = ArgumentCaptor.forClass(WriteContext.class);
+        CountDownLatch latch = new CountDownLatch(1);
+
+        // Write blobs in different formats
+        checksumSMILE.writeAsyncWithUrgentPriority(
+            new BlobObj("cluster state diff"),
+            spyContainer,
+            "cluster-state-diff",
+            CompressorRegistry.none(),
+            getVoidActionListener(latch),
+            ChecksumBlobStoreFormat.SNAPSHOT_ONLY_FORMAT_PARAMS
+        );
+        latch.await();
+
+        verify(spyContainer).asyncBlobUpload(writeContextArgumentCaptor.capture(), actionListenerArgumentCaptor.capture());
+        assertEquals(WritePriority.URGENT, writeContextArgumentCaptor.getValue().getWritePriority());
+        assertEquals(
+            checksumSMILE.read(mockBlobContainer.getDelegate(), "cluster-state-diff", xContentRegistry()).getText(),
+            "cluster state diff"
+        );
+    }
+
     public void testBlobStoreOperations() throws IOException {
         BlobStore blobStore = createTestBlobStore();
         BlobContainer blobContainer = blobStore.blobContainer(BlobPath.cleanPath());
@@ -226,6 +259,24 @@ public void testBlobCorruption() throws IOException {
         }
     }
 
+    private ActionListener<Void> getVoidActionListener(CountDownLatch latch) {
+        ActionListener<Void> actionListener = new ActionListener<>() {
+            @Override
+            public void onResponse(Void unused) {
+                logger.info("---> Async write succeeded");
+                latch.countDown();
+            }
+
+            @Override
+            public void onFailure(Exception e) {
+                logger.info("---> Failure in async write");
+                throw new RuntimeException("async write should not fail");
+            }
+        };
+
+        return actionListener;
+    }
+
     protected BlobStore createTestBlobStore() throws IOException {
         return new FsBlobStore(randomIntBetween(1, 8) * 1024, createTempDir(), false);
     }
diff --git a/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java b/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java
index 3c31c979ce856..9fe1f8294fc74 100644
--- a/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java
+++ b/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java
@@ -90,6 +90,7 @@
 import org.opensearch.action.search.SearchExecutionStatsCollector;
 import org.opensearch.action.search.SearchPhaseController;
 import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchRequestSlowLog;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchTransportService;
 import org.opensearch.action.search.TransportSearchAction;
@@ -178,6 +179,7 @@
 import org.opensearch.gateway.TransportNodesListGatewayStartedShards;
 import org.opensearch.index.IndexingPressureService;
 import org.opensearch.index.SegmentReplicationPressureService;
+import org.opensearch.index.SegmentReplicationStatsTracker;
 import org.opensearch.index.analysis.AnalysisRegistry;
 import org.opensearch.index.remote.RemoteStorePressureService;
 import org.opensearch.index.remote.RemoteStoreStatsTrackerFactory;
@@ -195,6 +197,7 @@
 import org.opensearch.indices.analysis.AnalysisModule;
 import org.opensearch.indices.cluster.IndicesClusterStateService;
 import org.opensearch.indices.mapper.MapperRegistry;
+import org.opensearch.indices.recovery.DefaultRecoverySettings;
 import org.opensearch.indices.recovery.PeerRecoverySourceService;
 import org.opensearch.indices.recovery.PeerRecoveryTargetService;
 import org.opensearch.indices.recovery.RecoverySettings;
@@ -221,6 +224,7 @@
 import org.opensearch.search.query.QueryPhase;
 import org.opensearch.snapshots.mockstore.MockEventuallyConsistentRepository;
 import org.opensearch.tasks.TaskResourceTrackingService;
+import org.opensearch.telemetry.metrics.noop.NoopMetricsRegistry;
 import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.test.disruption.DisruptableMockTransport;
@@ -2069,7 +2073,9 @@ public void onFailure(final Exception e) {
                     new RemoteSegmentStoreDirectoryFactory(() -> repositoriesService, threadPool),
                     repositoriesServiceReference::get,
                     fileCacheCleaner,
-                    new RemoteStoreStatsTrackerFactory(clusterService, settings)
+                    null,
+                    new RemoteStoreStatsTrackerFactory(clusterService, settings),
+                    DefaultRecoverySettings.INSTANCE
                 );
                 final RecoverySettings recoverySettings = new RecoverySettings(settings, clusterSettings);
                 snapshotShardsService = new SnapshotShardsService(
@@ -2120,7 +2126,8 @@ public void onFailure(final Exception e) {
                             shardStateAction,
                             actionFilters,
                             new IndexingPressureService(settings, clusterService),
-                            new SystemIndices(emptyMap())
+                            new SystemIndices(emptyMap()),
+                            NoopTracer.INSTANCE
                         )
                     ),
                     new GlobalCheckpointSyncAction(
@@ -2183,10 +2190,12 @@ public void onFailure(final Exception e) {
                         clusterService,
                         mock(IndicesService.class),
                         mock(ShardStateAction.class),
+                        mock(SegmentReplicationStatsTracker.class),
                         mock(ThreadPool.class)
                     ),
                     mock(RemoteStorePressureService.class),
-                    new SystemIndices(emptyMap())
+                    new SystemIndices(emptyMap()),
+                    NoopTracer.INSTANCE
                 );
                 actions.put(
                     BulkAction.INSTANCE,
@@ -2201,7 +2210,8 @@ public void onFailure(final Exception e) {
                             scriptService,
                             new AnalysisModule(environment, Collections.emptyList()).getAnalysisRegistry(),
                             Collections.emptyList(),
-                            client
+                            client,
+                            indicesService
                         ),
                         transportShardBulkAction,
                         client,
@@ -2209,7 +2219,9 @@ public void onFailure(final Exception e) {
                         indexNameExpressionResolver,
                         new AutoCreateIndex(settings, clusterSettings, indexNameExpressionResolver, new SystemIndices(emptyMap())),
                         new IndexingPressureService(settings, clusterService),
-                        new SystemIndices(emptyMap())
+                        mock(IndicesService.class),
+                        new SystemIndices(emptyMap()),
+                        NoopTracer.INSTANCE
                     )
                 );
                 final RestoreService restoreService = new RestoreService(
@@ -2297,7 +2309,10 @@ public void onFailure(final Exception e) {
                             namedWriteableRegistry,
                             List.of(),
                             client
-                        )
+                        ),
+                        null,
+                        new SearchRequestSlowLog(clusterService),
+                        NoopMetricsRegistry.INSTANCE
                     )
                 );
                 actions.put(
diff --git a/server/src/test/java/org/opensearch/snapshots/mockstore/MockEventuallyConsistentRepository.java b/server/src/test/java/org/opensearch/snapshots/mockstore/MockEventuallyConsistentRepository.java
index ca8bec469f3bc..f9388c9e4b86e 100644
--- a/server/src/test/java/org/opensearch/snapshots/mockstore/MockEventuallyConsistentRepository.java
+++ b/server/src/test/java/org/opensearch/snapshots/mockstore/MockEventuallyConsistentRepository.java
@@ -90,7 +90,7 @@ public MockEventuallyConsistentRepository(
         final Context context,
         final Random random
     ) {
-        super(metadata, false, namedXContentRegistry, clusterService, recoverySettings);
+        super(metadata, namedXContentRegistry, clusterService, recoverySettings);
         this.context = context;
         this.namedXContentRegistry = namedXContentRegistry;
         this.random = random;
diff --git a/server/src/test/java/org/opensearch/telemetry/metrics/MetricsRegistryFactoryTests.java b/server/src/test/java/org/opensearch/telemetry/metrics/MetricsRegistryFactoryTests.java
new file mode 100644
index 0000000000000..80942123fd4fd
--- /dev/null
+++ b/server/src/test/java/org/opensearch/telemetry/metrics/MetricsRegistryFactoryTests.java
@@ -0,0 +1,83 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.metrics;
+
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
+import org.opensearch.telemetry.Telemetry;
+import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.noop.NoopCounter;
+import org.opensearch.telemetry.metrics.noop.NoopMetricsRegistry;
+import org.opensearch.telemetry.tracing.TracingTelemetry;
+import org.opensearch.test.OpenSearchTestCase;
+import org.junit.After;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class MetricsRegistryFactoryTests extends OpenSearchTestCase {
+
+    private MetricsRegistryFactory metricsRegistryFactory;
+
+    @After
+    public void close() {
+        metricsRegistryFactory.close();
+    }
+
+    public void testGetMeterRegistryWithUnavailableMetricsTelemetry() {
+        Settings settings = Settings.builder().put(TelemetrySettings.TRACER_ENABLED_SETTING.getKey(), false).build();
+        TelemetrySettings telemetrySettings = new TelemetrySettings(settings, new ClusterSettings(settings, getClusterSettings()));
+        Telemetry mockTelemetry = mock(Telemetry.class);
+        when(mockTelemetry.getTracingTelemetry()).thenReturn(mock(TracingTelemetry.class));
+        metricsRegistryFactory = new MetricsRegistryFactory(telemetrySettings, Optional.empty());
+
+        MetricsRegistry metricsRegistry = metricsRegistryFactory.getMetricsRegistry();
+
+        assertTrue(metricsRegistry instanceof NoopMetricsRegistry);
+        assertTrue(metricsRegistry.createCounter("test", "test", "test") == NoopCounter.INSTANCE);
+        assertTrue(metricsRegistry.createUpDownCounter("test", "test", "test") == NoopCounter.INSTANCE);
+    }
+
+    public void testGetMetricsWithAvailableMetricsTelemetry() {
+        Settings settings = Settings.builder().put(TelemetrySettings.TRACER_ENABLED_SETTING.getKey(), true).build();
+        TelemetrySettings telemetrySettings = new TelemetrySettings(settings, new ClusterSettings(settings, getClusterSettings()));
+        Telemetry mockTelemetry = mock(Telemetry.class);
+        when(mockTelemetry.getMetricsTelemetry()).thenReturn(mock(MetricsTelemetry.class));
+        metricsRegistryFactory = new MetricsRegistryFactory(telemetrySettings, Optional.of(mockTelemetry));
+
+        MetricsRegistry metricsRegistry = metricsRegistryFactory.getMetricsRegistry();
+        assertTrue(metricsRegistry instanceof DefaultMetricsRegistry);
+
+    }
+
+    public void testNullMetricsTelemetry() {
+        Settings settings = Settings.builder().put(TelemetrySettings.METRICS_FEATURE_ENABLED_SETTING.getKey(), false).build();
+        TelemetrySettings telemetrySettings = new TelemetrySettings(settings, new ClusterSettings(settings, getClusterSettings()));
+        Telemetry mockTelemetry = mock(Telemetry.class);
+        when(mockTelemetry.getMetricsTelemetry()).thenReturn(null);
+        metricsRegistryFactory = new MetricsRegistryFactory(telemetrySettings, Optional.of(mockTelemetry));
+
+        MetricsRegistry metricsRegistry = metricsRegistryFactory.getMetricsRegistry();
+        assertTrue(metricsRegistry instanceof NoopMetricsRegistry);
+
+    }
+
+    private Set<Setting<?>> getClusterSettings() {
+        Set<Setting<?>> allTracerSettings = new HashSet<>();
+        ClusterSettings.FEATURE_FLAGGED_CLUSTER_SETTINGS.get(List.of(FeatureFlags.TELEMETRY)).stream().forEach((allTracerSettings::add));
+        return allTracerSettings;
+    }
+}
diff --git a/server/src/test/java/org/opensearch/telemetry/tracing/ThreadContextBasedTracerContextStorageTests.java b/server/src/test/java/org/opensearch/telemetry/tracing/ThreadContextBasedTracerContextStorageTests.java
new file mode 100644
index 0000000000000..ee816aa5f596d
--- /dev/null
+++ b/server/src/test/java/org/opensearch/telemetry/tracing/ThreadContextBasedTracerContextStorageTests.java
@@ -0,0 +1,255 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing;
+
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.common.util.concurrent.ThreadContext.StoredContext;
+import org.opensearch.telemetry.Telemetry;
+import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.MetricsTelemetry;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.test.telemetry.tracing.MockTracingTelemetry;
+import org.junit.After;
+import org.junit.Before;
+
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import static org.opensearch.telemetry.TelemetrySettings.TRACER_ENABLED_SETTING;
+import static org.opensearch.telemetry.TelemetrySettings.TRACER_FEATURE_ENABLED_SETTING;
+import static org.opensearch.telemetry.TelemetrySettings.TRACER_SAMPLER_PROBABILITY;
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.CoreMatchers.nullValue;
+
+public class ThreadContextBasedTracerContextStorageTests extends OpenSearchTestCase {
+    private Tracer tracer;
+    private ThreadContext threadContext;
+    private TracerContextStorage<String, Span> threadContextStorage;
+    private ExecutorService executorService;
+
+    @SuppressWarnings("resource")
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+
+        final Settings settings = Settings.builder()
+            .put(TRACER_ENABLED_SETTING.getKey(), true)
+            .put(TRACER_SAMPLER_PROBABILITY.getKey(), 1d)
+            .put(TRACER_FEATURE_ENABLED_SETTING.getKey(), true)
+            .build();
+
+        final TelemetrySettings telemetrySettings = new TelemetrySettings(
+            settings,
+            new ClusterSettings(Settings.EMPTY, Set.of(TRACER_ENABLED_SETTING, TRACER_SAMPLER_PROBABILITY))
+        );
+
+        final TracingTelemetry tracingTelemetry = new MockTracingTelemetry();
+
+        threadContext = new ThreadContext(Settings.EMPTY);
+        threadContextStorage = new ThreadContextBasedTracerContextStorage(threadContext, tracingTelemetry);
+
+        tracer = new TracerFactory(telemetrySettings, Optional.of(new Telemetry() {
+            @Override
+            public MetricsTelemetry getMetricsTelemetry() {
+                return null;
+            }
+
+            @Override
+            public TracingTelemetry getTracingTelemetry() {
+                return tracingTelemetry;
+            }
+        }), threadContext) {
+            @Override
+            protected TracerContextStorage<String, Span> createTracerContextStorage(
+                TracingTelemetry tracingTelemetry,
+                ThreadContext threadContext
+            ) {
+                return threadContextStorage;
+            }
+        }.getTracer();
+
+        executorService = Executors.newSingleThreadExecutor();
+        assertThat(tracer, not(instanceOf(NoopTracer.class)));
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+        executorService.shutdown();
+        tracer.close();
+    }
+
+    public void testStartingSpanDoesNotChangeThreadContext() {
+        final Span span = tracer.startSpan(SpanCreationContext.internal().name("test"));
+        assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+    }
+
+    public void testSpanInScopeChangesThreadContext() {
+        final Span span = tracer.startSpan(SpanCreationContext.internal().name("test"));
+
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+            assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(span));
+        }
+
+        assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+    }
+
+    public void testStashingPropagatesThreadContext() {
+        final Span span = tracer.startSpan(SpanCreationContext.internal().name("test"));
+
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            try (StoredContext ignored = threadContext.stashContext()) {
+                assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+                assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(span));
+            }
+        }
+
+        assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+    }
+
+    public void testPreservingContextThreadContext() throws InterruptedException, ExecutionException, TimeoutException {
+        final Span span = tracer.startSpan(SpanCreationContext.internal().name("test"));
+
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            final Runnable r = new Runnable() {
+                @Override
+                public void run() {
+                    assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+                    assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(span));
+                }
+            };
+
+            executorService.submit(threadContext.preserveContext(r)).get(1, TimeUnit.SECONDS);
+        }
+
+        assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+    }
+
+    public void testNoThreadContextToPreserve() throws InterruptedException, ExecutionException, TimeoutException {
+        final Runnable r = new Runnable() {
+            @Override
+            public void run() {
+                assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+                assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+
+                final Span local1 = tracer.startSpan(SpanCreationContext.internal().name("test-local-1"));
+                try (SpanScope localScope = tracer.withSpanInScope(local1)) {
+                    try (StoredContext ignored = threadContext.stashContext()) {
+                        assertThat(local1.getParentSpan(), is(nullValue()));
+                        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(local1));
+                    }
+                }
+
+                final Span local2 = tracer.startSpan(SpanCreationContext.internal().name("test-local-2"));
+                try (SpanScope localScope = tracer.withSpanInScope(local2)) {
+                    try (StoredContext ignored = threadContext.stashContext()) {
+                        assertThat(local2.getParentSpan(), is(nullValue()));
+                        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(local2));
+                    }
+                }
+
+                final Span local3 = tracer.startSpan(SpanCreationContext.internal().name("test-local-3"));
+                try (SpanScope localScope = tracer.withSpanInScope(local3)) {
+                    try (StoredContext ignored = threadContext.stashContext()) {
+                        assertThat(local3.getParentSpan(), is(nullValue()));
+                        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(local3));
+                    }
+                }
+            }
+        };
+
+        executorService.submit(threadContext.preserveContext(r)).get(1, TimeUnit.SECONDS);
+
+        assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+    }
+
+    public void testPreservingContextThreadContextMultipleSpans() throws InterruptedException, ExecutionException, TimeoutException {
+        final Span span = tracer.startSpan(SpanCreationContext.internal().name("test"));
+
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            final Runnable r = new Runnable() {
+                @Override
+                public void run() {
+                    assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+                    assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(span));
+
+                    final Span local1 = tracer.startSpan(SpanCreationContext.internal().name("test-local-1"));
+                    try (SpanScope localScope = tracer.withSpanInScope(local1)) {
+                        try (StoredContext ignored = threadContext.stashContext()) {
+                            assertThat(local1.getParentSpan(), is(span));
+                            assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(local1));
+                        }
+                    }
+
+                    final Span local2 = tracer.startSpan(SpanCreationContext.internal().name("test-local-2"));
+                    try (SpanScope localScope = tracer.withSpanInScope(local2)) {
+                        try (StoredContext ignored = threadContext.stashContext()) {
+                            assertThat(local2.getParentSpan(), is(span));
+                            assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(local2));
+                        }
+                    }
+
+                    final Span local3 = tracer.startSpan(SpanCreationContext.internal().name("test-local-3"));
+                    try (SpanScope localScope = tracer.withSpanInScope(local3)) {
+                        try (StoredContext ignored = threadContext.stashContext()) {
+                            assertThat(local3.getParentSpan(), is(span));
+                            assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(local3));
+                        }
+                    }
+                }
+            };
+
+            executorService.submit(threadContext.preserveContext(r)).get(1, TimeUnit.SECONDS);
+        }
+
+        assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+    }
+
+    public void testPreservingContextAndStashingThreadContext() throws InterruptedException, ExecutionException, TimeoutException {
+        final Span span = tracer.startSpan(SpanCreationContext.internal().name("test"));
+
+        try (SpanScope scope = tracer.withSpanInScope(span)) {
+            final Runnable r = new Runnable() {
+                @Override
+                public void run() {
+                    final Span local = tracer.startSpan(SpanCreationContext.internal().name("test-local"));
+                    try (SpanScope localScope = tracer.withSpanInScope(local)) {
+                        try (StoredContext ignored = threadContext.stashContext()) {
+                            assertThat(
+                                threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN),
+                                is(not(nullValue()))
+                            );
+                            assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(local));
+                        }
+                    }
+                }
+            };
+
+            executorService.submit(threadContext.preserveContext(r)).get(1, TimeUnit.SECONDS);
+        }
+
+        assertThat(threadContext.getTransient(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(not(nullValue())));
+        assertThat(threadContextStorage.get(ThreadContextBasedTracerContextStorage.CURRENT_SPAN), is(nullValue()));
+    }
+}
diff --git a/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java b/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java
index f202be70c9425..3a388be22445e 100644
--- a/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java
+++ b/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java
@@ -48,10 +48,14 @@ public void testGetTracerWithUnavailableTracingTelemetryReturnsNoopTracer() {
         Tracer tracer = tracerFactory.getTracer();
 
         assertTrue(tracer instanceof NoopTracer);
-        assertTrue(tracer.startSpan("foo") == NoopSpan.INSTANCE);
-        assertTrue(tracer.startScopedSpan(new SpanCreationContext("foo", Attributes.EMPTY)) == ScopedSpan.NO_OP);
-        assertTrue(tracer.startScopedSpan(new SpanCreationContext("foo", Attributes.EMPTY)) == ScopedSpan.NO_OP);
-        assertTrue(tracer.withSpanInScope(tracer.startSpan("foo")) == SpanScope.NO_OP);
+        assertTrue(tracer.startSpan(SpanCreationContext.internal().name("foo").attributes(Attributes.EMPTY)) == NoopSpan.INSTANCE);
+        assertTrue(tracer.startScopedSpan(SpanCreationContext.internal().name("foo").attributes(Attributes.EMPTY)) == ScopedSpan.NO_OP);
+        assertTrue(tracer.startScopedSpan(SpanCreationContext.internal().name("foo").attributes(Attributes.EMPTY)) == ScopedSpan.NO_OP);
+        assertTrue(
+            tracer.withSpanInScope(
+                tracer.startSpan(SpanCreationContext.internal().name("foo").attributes(Attributes.EMPTY))
+            ) == SpanScope.NO_OP
+        );
     }
 
     public void testGetTracerWithUnavailableTracingTelemetry() {
@@ -64,7 +68,7 @@ public void testGetTracerWithUnavailableTracingTelemetry() {
         Tracer tracer = tracerFactory.getTracer();
 
         assertTrue(tracer instanceof NoopTracer);
-        assertTrue(tracer.startScopedSpan(new SpanCreationContext("foo", Attributes.EMPTY)) == ScopedSpan.NO_OP);
+        assertTrue(tracer.startScopedSpan(SpanCreationContext.internal().name("foo").attributes(Attributes.EMPTY)) == ScopedSpan.NO_OP);
     }
 
     public void testGetTracerWithAvailableTracingTelemetryReturnsWrappedTracer() {
@@ -79,6 +83,18 @@ public void testGetTracerWithAvailableTracingTelemetryReturnsWrappedTracer() {
 
     }
 
+    public void testNullTracer() {
+        Settings settings = Settings.builder().put(TelemetrySettings.TRACER_FEATURE_ENABLED_SETTING.getKey(), false).build();
+        TelemetrySettings telemetrySettings = new TelemetrySettings(settings, new ClusterSettings(settings, getClusterSettings()));
+        Telemetry mockTelemetry = mock(Telemetry.class);
+        when(mockTelemetry.getTracingTelemetry()).thenReturn(null);
+        tracerFactory = new TracerFactory(telemetrySettings, Optional.of(mockTelemetry), new ThreadContext(Settings.EMPTY));
+
+        Tracer tracer = tracerFactory.getTracer();
+        assertTrue(tracer instanceof NoopTracer);
+
+    }
+
     private Set<Setting<?>> getClusterSettings() {
         Set<Setting<?>> allTracerSettings = new HashSet<>();
         ClusterSettings.FEATURE_FLAGGED_CLUSTER_SETTINGS.get(List.of(FeatureFlags.TELEMETRY)).stream().forEach((allTracerSettings::add));
diff --git a/server/src/test/java/org/opensearch/telemetry/tracing/WrappedTracerTests.java b/server/src/test/java/org/opensearch/telemetry/tracing/WrappedTracerTests.java
index b70fe81d5f9c4..8606104d26103 100644
--- a/server/src/test/java/org/opensearch/telemetry/tracing/WrappedTracerTests.java
+++ b/server/src/test/java/org/opensearch/telemetry/tracing/WrappedTracerTests.java
@@ -22,11 +22,11 @@
 import java.util.List;
 import java.util.Set;
 
-import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class WrappedTracerTests extends OpenSearchTestCase {
 
@@ -36,9 +36,11 @@ public void testStartSpanWithTracingDisabledInvokesNoopTracer() throws Exception
         DefaultTracer mockDefaultTracer = mock(DefaultTracer.class);
 
         try (WrappedTracer wrappedTracer = new WrappedTracer(telemetrySettings, mockDefaultTracer)) {
-            wrappedTracer.startSpan("foo");
+            SpanCreationContext spanCreationContext = SpanCreationContext.internal().name("foo");
+            wrappedTracer.startSpan(spanCreationContext);
             assertTrue(wrappedTracer.getDelegateTracer() instanceof NoopTracer);
-            verify(mockDefaultTracer, never()).startSpan("foo");
+            assertFalse(wrappedTracer.isRecording());
+            verify(mockDefaultTracer, never()).startSpan(SpanCreationContext.internal().name("foo"));
         }
     }
 
@@ -46,12 +48,14 @@ public void testStartSpanWithTracingEnabledInvokesDefaultTracer() throws Excepti
         Settings settings = Settings.builder().put(TelemetrySettings.TRACER_ENABLED_SETTING.getKey(), true).build();
         TelemetrySettings telemetrySettings = new TelemetrySettings(settings, new ClusterSettings(settings, getClusterSettings()));
         DefaultTracer mockDefaultTracer = mock(DefaultTracer.class);
-
+        when(mockDefaultTracer.isRecording()).thenReturn(true);
         try (WrappedTracer wrappedTracer = new WrappedTracer(telemetrySettings, mockDefaultTracer)) {
-            wrappedTracer.startSpan("foo");
+            SpanCreationContext spanCreationContext = SpanCreationContext.internal().name("foo");
+            wrappedTracer.startSpan(spanCreationContext);
 
             assertTrue(wrappedTracer.getDelegateTracer() instanceof DefaultTracer);
-            verify(mockDefaultTracer).startSpan(eq("foo"), eq((SpanContext) null), any(Attributes.class));
+            assertTrue(wrappedTracer.isRecording());
+            verify(mockDefaultTracer).startSpan(eq(spanCreationContext));
         }
     }
 
@@ -61,10 +65,11 @@ public void testStartSpanWithTracingEnabledInvokesDefaultTracerWithAttr() throws
         DefaultTracer mockDefaultTracer = mock(DefaultTracer.class);
         Attributes attributes = Attributes.create().addAttribute("key", "value");
         try (WrappedTracer wrappedTracer = new WrappedTracer(telemetrySettings, mockDefaultTracer)) {
-            wrappedTracer.startSpan("foo", attributes);
+            SpanCreationContext spanCreationContext = SpanCreationContext.internal().name("foo");
+            wrappedTracer.startSpan(spanCreationContext);
 
             assertTrue(wrappedTracer.getDelegateTracer() instanceof DefaultTracer);
-            verify(mockDefaultTracer).startSpan("foo", (SpanContext) null, attributes);
+            verify(mockDefaultTracer).startSpan(spanCreationContext);
         }
     }
 
diff --git a/server/src/test/java/org/opensearch/threadpool/ScalingThreadPoolTests.java b/server/src/test/java/org/opensearch/threadpool/ScalingThreadPoolTests.java
index 92bd15d818bca..97326377ce245 100644
--- a/server/src/test/java/org/opensearch/threadpool/ScalingThreadPoolTests.java
+++ b/server/src/test/java/org/opensearch/threadpool/ScalingThreadPoolTests.java
@@ -32,10 +32,13 @@
 
 package org.opensearch.threadpool;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.OpenSearchThreadPoolExecutor;
 
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
@@ -43,14 +46,29 @@
 import java.util.concurrent.TimeUnit;
 import java.util.function.BiConsumer;
 import java.util.function.Function;
+import java.util.stream.Collectors;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.Matchers.equalTo;
 
 public class ScalingThreadPoolTests extends OpenSearchThreadPoolTestCase {
 
+    @ParametersFactory
+    public static Collection<Object[]> scalingThreadPools() {
+        return ThreadPool.THREAD_POOL_TYPES.entrySet()
+            .stream()
+            .filter(t -> t.getValue().equals(ThreadPool.ThreadPoolType.SCALING))
+            .map(e -> new String[] { e.getKey() })
+            .collect(Collectors.toList());
+    }
+
+    private final String threadPoolName;
+
+    public ScalingThreadPoolTests(String threadPoolName) {
+        this.threadPoolName = threadPoolName;
+    }
+
     public void testScalingThreadPoolConfiguration() throws InterruptedException {
-        final String threadPoolName = randomThreadPool(ThreadPool.ThreadPoolType.SCALING);
         final Settings.Builder builder = Settings.builder();
 
         final int core;
@@ -132,15 +150,15 @@ private int expectedSize(final String threadPoolName, final int numberOfProcesso
         sizes.put(ThreadPool.Names.SNAPSHOT, ThreadPool::halfAllocatedProcessorsMaxFive);
         sizes.put(ThreadPool.Names.FETCH_SHARD_STARTED, ThreadPool::twiceAllocatedProcessors);
         sizes.put(ThreadPool.Names.FETCH_SHARD_STORE, ThreadPool::twiceAllocatedProcessors);
-        sizes.put(ThreadPool.Names.TRANSLOG_TRANSFER, ThreadPool::halfAllocatedProcessorsMaxTen);
+        sizes.put(ThreadPool.Names.TRANSLOG_TRANSFER, ThreadPool::halfAllocatedProcessors);
         sizes.put(ThreadPool.Names.TRANSLOG_SYNC, n -> 4 * n);
-        sizes.put(ThreadPool.Names.REMOTE_PURGE, ThreadPool::halfAllocatedProcessorsMaxFive);
-        sizes.put(ThreadPool.Names.REMOTE_REFRESH_RETRY, ThreadPool::halfAllocatedProcessorsMaxTen);
+        sizes.put(ThreadPool.Names.REMOTE_PURGE, ThreadPool::halfAllocatedProcessors);
+        sizes.put(ThreadPool.Names.REMOTE_REFRESH_RETRY, ThreadPool::halfAllocatedProcessors);
+        sizes.put(ThreadPool.Names.REMOTE_RECOVERY, ThreadPool::twiceAllocatedProcessors);
         return sizes.get(threadPoolName).apply(numberOfProcessors);
     }
 
     public void testScalingThreadPoolIsBounded() throws InterruptedException {
-        final String threadPoolName = randomThreadPool(ThreadPool.ThreadPoolType.SCALING);
         final int size = randomIntBetween(32, 512);
         final Settings settings = Settings.builder().put("thread_pool." + threadPoolName + ".max", size).build();
         runScalingThreadPoolTest(settings, (clusterSettings, threadPool) -> {
@@ -170,7 +188,6 @@ public void testScalingThreadPoolIsBounded() throws InterruptedException {
     }
 
     public void testScalingThreadPoolThreadsAreTerminatedAfterKeepAlive() throws InterruptedException {
-        final String threadPoolName = randomThreadPool(ThreadPool.ThreadPoolType.SCALING);
         final int min = "generic".equals(threadPoolName) ? 4 : 1;
         final Settings settings = Settings.builder()
             .put("thread_pool." + threadPoolName + ".max", 128)
diff --git a/server/src/test/java/org/opensearch/threadpool/ThreadPoolStatsTests.java b/server/src/test/java/org/opensearch/threadpool/ThreadPoolStatsTests.java
index 0965f17ba5c70..869d7ec59b081 100644
--- a/server/src/test/java/org/opensearch/threadpool/ThreadPoolStatsTests.java
+++ b/server/src/test/java/org/opensearch/threadpool/ThreadPoolStatsTests.java
@@ -51,13 +51,13 @@
 public class ThreadPoolStatsTests extends OpenSearchTestCase {
     public void testThreadPoolStatsSort() throws IOException {
         List<ThreadPoolStats.Stats> stats = new ArrayList<>();
-        stats.add(new ThreadPoolStats.Stats("z", -1, 0, 0, 0, 0, 0L));
-        stats.add(new ThreadPoolStats.Stats("m", 3, 0, 0, 0, 0, 0L));
-        stats.add(new ThreadPoolStats.Stats("m", 1, 0, 0, 0, 0, 0L));
-        stats.add(new ThreadPoolStats.Stats("d", -1, 0, 0, 0, 0, 0L));
-        stats.add(new ThreadPoolStats.Stats("m", 2, 0, 0, 0, 0, 0L));
-        stats.add(new ThreadPoolStats.Stats("t", -1, 0, 0, 0, 0, 0L));
-        stats.add(new ThreadPoolStats.Stats("a", -1, 0, 0, 0, 0, 0L));
+        stats.add(new ThreadPoolStats.Stats("z", -1, 0, 0, 0, 0, 0L, 0L));
+        stats.add(new ThreadPoolStats.Stats("m", 3, 0, 0, 0, 0, 0L, 0L));
+        stats.add(new ThreadPoolStats.Stats("m", 1, 0, 0, 0, 0, 0L, 0L));
+        stats.add(new ThreadPoolStats.Stats("d", -1, 0, 0, 0, 0, 0L, 0L));
+        stats.add(new ThreadPoolStats.Stats("m", 2, 0, 0, 0, 0, 0L, 0L));
+        stats.add(new ThreadPoolStats.Stats("t", -1, 0, 0, 0, 0, 0L, 0L));
+        stats.add(new ThreadPoolStats.Stats("a", -1, 0, 0, 0, 0, 0L, 0L));
 
         List<ThreadPoolStats.Stats> copy = new ArrayList<>(stats);
         Collections.sort(copy);
@@ -79,11 +79,11 @@ public void testThreadPoolStatsToXContent() throws IOException {
         try (BytesStreamOutput os = new BytesStreamOutput()) {
 
             List<ThreadPoolStats.Stats> stats = new ArrayList<>();
-            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.SEARCH, -1, 0, 0, 0, 0, 0L));
-            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.WARMER, -1, 0, 0, 0, 0, 0L));
-            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.GENERIC, -1, 0, 0, 0, 0, 0L));
-            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.FORCE_MERGE, -1, 0, 0, 0, 0, 0L));
-            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.SAME, -1, 0, 0, 0, 0, 0L));
+            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.SEARCH, -1, 0, 0, 0, 0, 0L, 0L));
+            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.WARMER, -1, 0, 0, 0, 0, 0L, -1L));
+            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.GENERIC, -1, 0, 0, 0, 0, 0L, -1L));
+            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.FORCE_MERGE, -1, 0, 0, 0, 0, 0L, -1L));
+            stats.add(new ThreadPoolStats.Stats(ThreadPool.Names.SAME, -1, 0, 0, 0, 0, 0L, -1L));
 
             ThreadPoolStats threadPoolStats = new ThreadPoolStats(stats);
             try (XContentBuilder builder = new XContentBuilder(MediaTypeRegistry.JSON.xContent(), os)) {
diff --git a/server/src/test/java/org/opensearch/transport/InboundHandlerTests.java b/server/src/test/java/org/opensearch/transport/InboundHandlerTests.java
index 9a261c5745bc2..e002297911788 100644
--- a/server/src/test/java/org/opensearch/transport/InboundHandlerTests.java
+++ b/server/src/test/java/org/opensearch/transport/InboundHandlerTests.java
@@ -50,6 +50,7 @@
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.tasks.TaskManager;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.MockLogAppender;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.test.VersionUtils;
@@ -117,7 +118,8 @@ public void sendMessage(BytesReference reference, ActionListener<Void> listener)
             handshaker,
             keepAlive,
             requestHandlers,
-            responseHandlers
+            responseHandlers,
+            NoopTracer.INSTANCE
         );
     }
 
diff --git a/server/src/test/java/org/opensearch/transport/TcpTransportTests.java b/server/src/test/java/org/opensearch/transport/TcpTransportTests.java
index 06545b77c6d76..7ab78cca7d615 100644
--- a/server/src/test/java/org/opensearch/transport/TcpTransportTests.java
+++ b/server/src/test/java/org/opensearch/transport/TcpTransportTests.java
@@ -47,6 +47,7 @@
 import org.opensearch.common.util.MockPageCacheRecycler;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.MockLogAppender;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.test.junit.annotations.TestLogging;
@@ -255,7 +256,8 @@ private void testDefaultSeedAddresses(final Settings settings, Matcher<Iterable<
                 new MockPageCacheRecycler(settings),
                 new NoneCircuitBreakerService(),
                 writableRegistry(),
-                new NetworkService(Collections.emptyList())
+                new NetworkService(Collections.emptyList()),
+                NoopTracer.INSTANCE
             ) {
 
                 @Override
diff --git a/server/src/test/java/org/opensearch/transport/TransportServiceHandshakeTests.java b/server/src/test/java/org/opensearch/transport/TransportServiceHandshakeTests.java
index 67db155779ec6..9a884fd29d109 100644
--- a/server/src/test/java/org/opensearch/transport/TransportServiceHandshakeTests.java
+++ b/server/src/test/java/org/opensearch/transport/TransportServiceHandshakeTests.java
@@ -85,7 +85,8 @@ private NetworkHandle startServices(String nodeNameAndId, Settings settings, Ver
             new NetworkService(Collections.emptyList()),
             PageCacheRecycler.NON_RECYCLING_INSTANCE,
             new NamedWriteableRegistry(Collections.emptyList()),
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         );
         TransportService transportService = new MockTransportService(
             settings,
diff --git a/server/src/test/resources/org/opensearch/common/settings/loader/test-settings.yml b/server/src/test/resources/org/opensearch/common/settings/loader/test-settings.yml
index b533ae036e758..1bffbc18e83e6 100644
--- a/server/src/test/resources/org/opensearch/common/settings/loader/test-settings.yml
+++ b/server/src/test/resources/org/opensearch/common/settings/loader/test-settings.yml
@@ -6,3 +6,4 @@ test1:
   test3:
     - test3-1
     - test3-2
+  test4: []
diff --git a/settings.gradle b/settings.gradle
index c04b5997d49b1..24ab4a7a22237 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -10,12 +10,14 @@
  */
 
 plugins {
-  id "com.gradle.enterprise" version "3.14.1"
+  id "com.gradle.enterprise" version "3.16.1"
 }
 
+ext.disableBuildCache = hasProperty('DISABLE_BUILD_CACHE') || System.getenv().containsKey('DISABLE_BUILD_CACHE')
+
 buildCache {
   local {
-    enabled = true
+    enabled = !disableBuildCache
     removeUnusedEntriesAfterDays = 14
   }
 }
diff --git a/test/external-modules/delayed-aggs/src/internalClusterTest/java/org/opensearch/search/aggregations/DelayedShardAggregationIT.java b/test/external-modules/delayed-aggs/src/internalClusterTest/java/org/opensearch/search/aggregations/DelayedShardAggregationIT.java
index e850ae9dcc859..90f4f1ba2ceb2 100644
--- a/test/external-modules/delayed-aggs/src/internalClusterTest/java/org/opensearch/search/aggregations/DelayedShardAggregationIT.java
+++ b/test/external-modules/delayed-aggs/src/internalClusterTest/java/org/opensearch/search/aggregations/DelayedShardAggregationIT.java
@@ -31,25 +31,43 @@
 
 package org.opensearch.search.aggregations;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.search.aggregations.bucket.filter.InternalFilter;
 import org.opensearch.search.aggregations.metrics.InternalMax;
 import org.opensearch.search.aggregations.metrics.MaxAggregationBuilder;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 
-public class DelayedShardAggregationIT extends OpenSearchIntegTestCase {
+public class DelayedShardAggregationIT extends ParameterizedOpenSearchIntegTestCase {
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
diff --git a/test/fixtures/hdfs-fixture/build.gradle b/test/fixtures/hdfs-fixture/build.gradle
index 79841ca70b53a..7adf29792f27d 100644
--- a/test/fixtures/hdfs-fixture/build.gradle
+++ b/test/fixtures/hdfs-fixture/build.gradle
@@ -33,7 +33,7 @@ apply plugin: 'opensearch.java'
 group = 'hdfs'
 
 versions << [
-  'jetty': '9.4.51.v20230217'
+  'jetty': '9.4.53.v20231009'
 ]
 
 dependencies {
@@ -48,9 +48,12 @@ dependencies {
     exclude group: "com.squareup.okhttp3"
     exclude group: "org.xerial.snappy"
     exclude module: "json-io"
+    exclude module: "logback-core"
+    exclude module: "logback-classic"
+    exclude module: "avro"
   }
   api "org.codehaus.jettison:jettison:${versions.jettison}"
-  api "org.apache.commons:commons-compress:1.23.0"
+  api "org.apache.commons:commons-compress:${versions.commonscompress}"
   api "commons-codec:commons-codec:${versions.commonscodec}"
   api "org.apache.logging.log4j:log4j-core:${versions.log4j}"
   api "io.netty:netty-all:${versions.netty}"
@@ -64,13 +67,15 @@ dependencies {
   api "org.jetbrains.kotlin:kotlin-stdlib:${versions.kotlin}"
   api "org.eclipse.jetty:jetty-server:${versions.jetty}"
   api "org.eclipse.jetty.websocket:javax-websocket-server-impl:${versions.jetty}"
-  api 'org.apache.zookeeper:zookeeper:3.9.0'
-  api "org.apache.commons:commons-text:1.10.0"
-  api "commons-net:commons-net:3.9.0"
+  api 'org.apache.zookeeper:zookeeper:3.9.1'
+  api "org.apache.commons:commons-text:1.11.0"
+  api "commons-net:commons-net:3.10.0"
+  api "ch.qos.logback:logback-core:1.2.13"
+  api "ch.qos.logback:logback-classic:1.2.13"
   runtimeOnly "com.google.guava:guava:${versions.guava}"
-  runtimeOnly("com.squareup.okhttp3:okhttp:4.11.0") {
+  runtimeOnly("com.squareup.okhttp3:okhttp:4.12.0") {
     exclude group: "com.squareup.okio"
   }
-  runtimeOnly "com.squareup.okio:okio:3.5.0"
-  runtimeOnly "org.xerial.snappy:snappy-java:1.1.10.3"
+  runtimeOnly "com.squareup.okio:okio:3.7.0"
+  runtimeOnly "org.xerial.snappy:snappy-java:1.1.10.5"
 }
diff --git a/test/framework/src/main/java/org/opensearch/action/support/ActionTestUtils.java b/test/framework/src/main/java/org/opensearch/action/support/ActionTestUtils.java
index 00fd5a5bcf815..52496c331c25e 100644
--- a/test/framework/src/main/java/org/opensearch/action/support/ActionTestUtils.java
+++ b/test/framework/src/main/java/org/opensearch/action/support/ActionTestUtils.java
@@ -55,7 +55,7 @@ public static <Request extends ActionRequest, Response extends ActionResponse> R
 
     /**
      * Executes the given action.
-     *
+     * <p>
      * This is a shim method to make execution publicly available in tests.
      */
     public static <Request extends ActionRequest, Response extends ActionResponse> void execute(
diff --git a/test/framework/src/main/java/org/opensearch/bootstrap/BootstrapForTesting.java b/test/framework/src/main/java/org/opensearch/bootstrap/BootstrapForTesting.java
index 8f065de35aa8b..43881d0660e04 100644
--- a/test/framework/src/main/java/org/opensearch/bootstrap/BootstrapForTesting.java
+++ b/test/framework/src/main/java/org/opensearch/bootstrap/BootstrapForTesting.java
@@ -69,6 +69,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Properties;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -161,12 +162,17 @@ public class BootstrapForTesting {
                     addClassCodebase(codebases, "opensearch-rest-client", "org.opensearch.client.RestClient");
                 }
                 final Policy testFramework = Security.readPolicy(Bootstrap.class.getResource("test-framework.policy"), codebases);
+                // Allow modules to define own test policy in ad-hoc fashion (if needed) that is not really applicable to other modules
+                final Optional<Policy> testPolicy = Optional.ofNullable(Bootstrap.class.getResource("test.policy"))
+                    .map(policy -> Security.readPolicy(policy, codebases));
                 final Policy opensearchPolicy = new OpenSearchPolicy(codebases, perms, getPluginPermissions(), true, new Permissions());
                 Policy.setPolicy(new Policy() {
                     @Override
                     public boolean implies(ProtectionDomain domain, Permission permission) {
                         // implements union
-                        return opensearchPolicy.implies(domain, permission) || testFramework.implies(domain, permission);
+                        return opensearchPolicy.implies(domain, permission)
+                            || testFramework.implies(domain, permission)
+                            || testPolicy.map(policy -> policy.implies(domain, permission)).orElse(false /* no policy */);
                     }
                 });
                 // Create access control context for mocking
diff --git a/test/framework/src/main/java/org/opensearch/cli/CommandTestCase.java b/test/framework/src/main/java/org/opensearch/cli/CommandTestCase.java
index 4ee1314d27fe1..5566b493adc7d 100644
--- a/test/framework/src/main/java/org/opensearch/cli/CommandTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/cli/CommandTestCase.java
@@ -54,7 +54,7 @@ public void resetTerminal() {
 
     /**
      * Runs a command with the given args.
-     *
+     * <p>
      * Output can be found in {@link #terminal}.
      */
     public String execute(String... args) throws Exception {
diff --git a/test/framework/src/main/java/org/opensearch/cluster/MockInternalClusterInfoService.java b/test/framework/src/main/java/org/opensearch/cluster/MockInternalClusterInfoService.java
index 6354cf18e8b62..1ad6083074025 100644
--- a/test/framework/src/main/java/org/opensearch/cluster/MockInternalClusterInfoService.java
+++ b/test/framework/src/main/java/org/opensearch/cluster/MockInternalClusterInfoService.java
@@ -112,6 +112,7 @@ List<NodeStats> adjustNodesStats(List<NodeStats> nodesStats) {
                 nodeStats.getDiscoveryStats(),
                 nodeStats.getIngestStats(),
                 nodeStats.getAdaptiveSelectionStats(),
+                nodeStats.getResourceUsageStats(),
                 nodeStats.getScriptCacheStats(),
                 nodeStats.getIndexingPressureStats(),
                 nodeStats.getShardIndexingPressureStats(),
@@ -120,7 +121,10 @@ List<NodeStats> adjustNodesStats(List<NodeStats> nodesStats) {
                 nodeStats.getWeightedRoutingStats(),
                 nodeStats.getFileCacheStats(),
                 nodeStats.getTaskCancellationStats(),
-                nodeStats.getSearchPipelineStats()
+                nodeStats.getSearchPipelineStats(),
+                nodeStats.getSegmentReplicationRejectionStats(),
+                nodeStats.getRepositoriesStats(),
+                nodeStats.getAdmissionControlStats()
             );
         }).collect(Collectors.toList());
     }
diff --git a/test/framework/src/main/java/org/opensearch/cluster/OpenSearchAllocationWithConstraintsTestCase.java b/test/framework/src/main/java/org/opensearch/cluster/OpenSearchAllocationWithConstraintsTestCase.java
index 7f1d1d3381751..0c08de252e4cd 100644
--- a/test/framework/src/main/java/org/opensearch/cluster/OpenSearchAllocationWithConstraintsTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/cluster/OpenSearchAllocationWithConstraintsTestCase.java
@@ -209,28 +209,28 @@ public int allocateAndCheckIndexShardHotSpots(boolean expected, int nodes, Strin
                     continue;
                 }
 
-                /**
-                 * Hot spots can occur due to the order in which shards get allocated to nodes.
-                 * A node with fewer shards may not be able to accept current shard due to
-                 * SameShardAllocationDecider, causing it to breach allocation constraint on
-                 * another node. We need to differentiate between such hot spots v/s actual hot
-                 * spots.
-                 *
-                 * A simple check could be to ensure there is no node with shards less than
-                 * allocation limit, that can accept current shard. However, in current
-                 * allocation algorithm, when nodes get throttled, shards are added to
-                 * ModelNodes without adding them to actual cluster (RoutingNodes). As a result,
-                 * the shards per node we see here, are different from the ones observed by
-                 * weight function in balancer. RoutingNodes with {@link count} < {@link limit}
-                 * may not have had the same count in the corresponding ModelNode seen by weight
-                 * function. We hence use the following alternate check --
-                 *
-                 * Given the way {@link limit} is defined, we should not have hot spots if *all*
-                 * nodes are eligible to accept the shard. A hot spot is acceptable, if either
-                 * all peer nodes have {@link count} > {@link limit}, or if even one node is
-                 * ineligible to accept the shard due to SameShardAllocationDecider, as this
-                 * leads to a chain of events that breach IndexShardsPerNode constraint on all
-                 * other nodes.
+                /*
+                  Hot spots can occur due to the order in which shards get allocated to nodes.
+                  A node with fewer shards may not be able to accept current shard due to
+                  SameShardAllocationDecider, causing it to breach allocation constraint on
+                  another node. We need to differentiate between such hot spots v/s actual hot
+                  spots.
+
+                  A simple check could be to ensure there is no node with shards less than
+                  allocation limit, that can accept current shard. However, in current
+                  allocation algorithm, when nodes get throttled, shards are added to
+                  ModelNodes without adding them to actual cluster (RoutingNodes). As a result,
+                  the shards per node we see here, are different from the ones observed by
+                  weight function in balancer. RoutingNodes with {@link count} < {@link limit}
+                  may not have had the same count in the corresponding ModelNode seen by weight
+                  function. We hence use the following alternate check --
+
+                  Given the way {@link limit} is defined, we should not have hot spots if *all*
+                  nodes are eligible to accept the shard. A hot spot is acceptable, if either
+                  all peer nodes have {@link count} > {@link limit}, or if even one node is
+                  ineligible to accept the shard due to SameShardAllocationDecider, as this
+                  leads to a chain of events that breach IndexShardsPerNode constraint on all
+                  other nodes.
                  */
 
                 // If all peer nodes have count >= limit, hotspot is acceptable
diff --git a/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java b/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java
index d24cc24d28579..28d7706fb1493 100644
--- a/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java
@@ -1016,6 +1016,11 @@ public void setLastAcceptedState(ClusterState clusterState) {
                 delegate.setLastAcceptedState(clusterState);
             }
 
+            @Override
+            public PersistedStateStats getStats() {
+                return null;
+            }
+
             @Override
             public void close() {
                 assertTrue(openPersistedStates.remove(this));
diff --git a/test/framework/src/main/java/org/opensearch/cluster/coordination/LinearizabilityChecker.java b/test/framework/src/main/java/org/opensearch/cluster/coordination/LinearizabilityChecker.java
index 60aacb83e0dc1..946b980bfb62f 100644
--- a/test/framework/src/main/java/org/opensearch/cluster/coordination/LinearizabilityChecker.java
+++ b/test/framework/src/main/java/org/opensearch/cluster/coordination/LinearizabilityChecker.java
@@ -476,22 +476,22 @@ void unlift() {
 
     /**
      * A cache optimized for small bit-counts (less than 64) and small number of unique permutations of state objects.
-     *
+     * <p>
      * Each combination of states is kept once only, building on the
      * assumption that the number of permutations is small compared to the
      * number of bits permutations. For those histories that are difficult to check
      * we will have many bits combinations that use the same state permutations.
-     *
+     * <p>
      * The smallMap optimization allows us to avoid object overheads for bit-sets up to 64 bit large.
-     *
+     * <p>
      * Comparing set of (bits, state) to smallMap:
      * (bits, state) : 24 (tuple) + 24 (FixedBitSet) + 24 (bits) + 5 (hash buckets) + 24 (hashmap node).
      * smallMap bits to {state} : 10 (bits) + 5 (hash buckets) + avg-size of unique permutations.
-     *
+     * <p>
      * The avg-size of the unique permutations part is very small compared to the
      * sometimes large number of bits combinations (which are the cases where
      * we run into trouble).
-     *
+     * <p>
      * set of (bits, state) totals 101 bytes compared to smallMap bits to { state }
      * which totals 15 bytes, ie. a 6x improvement in memory usage.
      */
diff --git a/test/framework/src/main/java/org/opensearch/common/logging/JsonLogsIntegTestCase.java b/test/framework/src/main/java/org/opensearch/common/logging/JsonLogsIntegTestCase.java
index e4774030f21cb..5f4d92d65548b 100644
--- a/test/framework/src/main/java/org/opensearch/common/logging/JsonLogsIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/common/logging/JsonLogsIntegTestCase.java
@@ -52,11 +52,11 @@
  * Fields available upon process startup: <code>type</code>, <code>timestamp</code>, <code>level</code>, <code>component</code>,
  * <code>message</code>, <code>node.name</code>, <code>cluster.name</code>.
  * Whereas <code>node.id</code> and <code>cluster.uuid</code> are available later once the first clusterState has been received.
- *
+ * <p>
  *
  * <code>node.name</code>, <code>cluster.name</code>, <code>node.id</code>, <code>cluster.uuid</code>
  * should not change across all log lines
- *
+ * <p>
  * Note that this won't pass for nodes in clusters that don't have the node name defined in opensearch.yml <strong>and</strong> start
  * with DEBUG or TRACE level logging. Those nodes log a few lines before the node.name is set by <code>LogConfigurator.setNodeName</code>.
  */
diff --git a/test/framework/src/main/java/org/opensearch/gateway/MockGatewayMetaState.java b/test/framework/src/main/java/org/opensearch/gateway/MockGatewayMetaState.java
index d77596cf5cdd1..2f006a5519d69 100644
--- a/test/framework/src/main/java/org/opensearch/gateway/MockGatewayMetaState.java
+++ b/test/framework/src/main/java/org/opensearch/gateway/MockGatewayMetaState.java
@@ -67,6 +67,12 @@ public class MockGatewayMetaState extends GatewayMetaState {
     private final BigArrays bigArrays;
     private final RemoteClusterStateService remoteClusterStateService;
     private final RemoteStoreRestoreService remoteStoreRestoreService;
+    private boolean prepareFullState = false;
+
+    public MockGatewayMetaState(DiscoveryNode localNode, BigArrays bigArrays, boolean prepareFullState) {
+        this(localNode, bigArrays);
+        this.prepareFullState = prepareFullState;
+    }
 
     public MockGatewayMetaState(DiscoveryNode localNode, BigArrays bigArrays) {
         this.localNode = localNode;
@@ -99,8 +105,12 @@ Metadata upgradeMetadataForNode(
 
     @Override
     ClusterState prepareInitialClusterState(TransportService transportService, ClusterService clusterService, ClusterState clusterState) {
-        // Just set localNode here, not to mess with ClusterService and IndicesService mocking
-        return ClusterStateUpdaters.setLocalNode(clusterState, localNode);
+        if (prepareFullState) {
+            return super.prepareInitialClusterState(transportService, clusterService, clusterState);
+        } else {
+            // Just set localNode here, not to mess with ClusterService and IndicesService mocking
+            return ClusterStateUpdaters.setLocalNode(clusterState, localNode);
+        }
     }
 
     @Override
@@ -113,6 +123,16 @@ public void start(
         NodeEnvironment nodeEnvironment,
         NamedXContentRegistry xContentRegistry,
         PersistedStateRegistry persistedStateRegistry
+    ) {
+        start(settings, nodeEnvironment, xContentRegistry, persistedStateRegistry, false);
+    }
+
+    public void start(
+        Settings settings,
+        NodeEnvironment nodeEnvironment,
+        NamedXContentRegistry xContentRegistry,
+        PersistedStateRegistry persistedStateRegistry,
+        boolean prepareFullState
     ) {
         final TransportService transportService = mock(TransportService.class);
         when(transportService.getThreadPool()).thenReturn(mock(ThreadPool.class));
@@ -126,6 +146,7 @@ public void start(
         } catch (IOException e) {
             throw new AssertionError(e);
         }
+        this.prepareFullState = prepareFullState;
         start(
             settings,
             transportService,
diff --git a/test/framework/src/main/java/org/opensearch/index/MockEngineFactoryPlugin.java b/test/framework/src/main/java/org/opensearch/index/MockEngineFactoryPlugin.java
index 72d34676850b9..0a47db4c740d6 100644
--- a/test/framework/src/main/java/org/opensearch/index/MockEngineFactoryPlugin.java
+++ b/test/framework/src/main/java/org/opensearch/index/MockEngineFactoryPlugin.java
@@ -46,7 +46,7 @@
 
 /**
  * A plugin to use {@link MockEngineFactory}.
- *
+ * <p>
  * Subclasses may override the reader wrapper used.
  */
 public class MockEngineFactoryPlugin extends Plugin implements EnginePlugin {
diff --git a/test/framework/src/main/java/org/opensearch/index/RandomCreateIndexGenerator.java b/test/framework/src/main/java/org/opensearch/index/RandomCreateIndexGenerator.java
index f016d9450425d..5ab77783b2bac 100644
--- a/test/framework/src/main/java/org/opensearch/index/RandomCreateIndexGenerator.java
+++ b/test/framework/src/main/java/org/opensearch/index/RandomCreateIndexGenerator.java
@@ -56,7 +56,7 @@ private RandomCreateIndexGenerator() {}
 
     /**
      * Returns a random {@link CreateIndexRequest}.
-     *
+     * <p>
      * Randomizes the index name, the aliases, mappings and settings associated with the
      * index. If present, the mapping definition will be nested under a type name.
      */
diff --git a/test/framework/src/main/java/org/opensearch/index/engine/EngineTestCase.java b/test/framework/src/main/java/org/opensearch/index/engine/EngineTestCase.java
index 15f9ee546fe6b..43289a7c89524 100644
--- a/test/framework/src/main/java/org/opensearch/index/engine/EngineTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/index/engine/EngineTestCase.java
@@ -527,7 +527,7 @@ protected Translog createTranslog(LongSupplier primaryTermSupplier) throws IOExc
     }
 
     protected Translog createTranslog(Path translogPath, LongSupplier primaryTermSupplier) throws IOException {
-        TranslogConfig translogConfig = new TranslogConfig(shardId, translogPath, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE);
+        TranslogConfig translogConfig = new TranslogConfig(shardId, translogPath, INDEX_SETTINGS, BigArrays.NON_RECYCLING_INSTANCE, "");
         String translogUUID = Translog.createEmptyTranslog(
             translogPath,
             SequenceNumbers.NO_OPS_PERFORMED,
@@ -872,7 +872,13 @@ public EngineConfig config(
         final Engine.EventListener eventListener
     ) {
         final IndexWriterConfig iwc = newIndexWriterConfig();
-        final TranslogConfig translogConfig = new TranslogConfig(shardId, translogPath, indexSettings, BigArrays.NON_RECYCLING_INSTANCE);
+        final TranslogConfig translogConfig = new TranslogConfig(
+            shardId,
+            translogPath,
+            indexSettings,
+            BigArrays.NON_RECYCLING_INSTANCE,
+            ""
+        );
         final List<ReferenceManager.RefreshListener> extRefreshListenerList = externalRefreshListener == null
             ? emptyList()
             : Collections.singletonList(externalRefreshListener);
@@ -939,7 +945,7 @@ protected EngineConfig config(
                 .put(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), true)
                 .build()
         );
-        TranslogConfig translogConfig = new TranslogConfig(shardId, translogPath, indexSettings, BigArrays.NON_RECYCLING_INSTANCE);
+        TranslogConfig translogConfig = new TranslogConfig(shardId, translogPath, indexSettings, BigArrays.NON_RECYCLING_INSTANCE, "");
         return new EngineConfig.Builder().shardId(config.getShardId())
             .threadPool(config.getThreadPool())
             .indexSettings(indexSettings)
diff --git a/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase.java b/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase.java
index 83bb2f1ee7d65..77137073aa30f 100644
--- a/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase.java
@@ -149,7 +149,7 @@ protected Set<String> unsupportedProperties() {
 
     /**
      * Add type-specific modifiers for consistency checking.
-     *
+     * <p>
      * This should be called in a {@code @Before} method
      */
     protected void addModifier(String property, boolean updateable, BiConsumer<T, T> method) {
@@ -158,7 +158,7 @@ protected void addModifier(String property, boolean updateable, BiConsumer<T, T>
 
     /**
      * Add type-specific modifiers for consistency checking.
-     *
+     * <p>
      * This should be called in a {@code @Before} method
      */
     protected void addBooleanModifier(String property, boolean updateable, BiConsumer<T, Boolean> method) {
diff --git a/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase2.java b/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase2.java
index 1987a49431bf9..5dfb2f16a1aae 100644
--- a/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase2.java
+++ b/test/framework/src/main/java/org/opensearch/index/mapper/FieldMapperTestCase2.java
@@ -139,7 +139,7 @@ protected Set<String> unsupportedProperties() {
 
     /**
      * Add type-specific modifiers for consistency checking.
-     *
+     * <p>
      * This should be called in a {@code @Before} method
      */
     protected void addModifier(String property, boolean updateable, BiConsumer<T, T> method) {
@@ -148,7 +148,7 @@ protected void addModifier(String property, boolean updateable, BiConsumer<T, T>
 
     /**
      * Add type-specific modifiers for consistency checking.
-     *
+     * <p>
      * This should be called in a {@code @Before} method
      */
     protected void addBooleanModifier(String property, boolean updateable, BiConsumer<T, Boolean> method) {
diff --git a/test/framework/src/main/java/org/opensearch/index/replication/TestReplicationSource.java b/test/framework/src/main/java/org/opensearch/index/replication/TestReplicationSource.java
index b29e25a0bff2c..bcd47e3d578ee 100644
--- a/test/framework/src/main/java/org/opensearch/index/replication/TestReplicationSource.java
+++ b/test/framework/src/main/java/org/opensearch/index/replication/TestReplicationSource.java
@@ -17,6 +17,7 @@
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 
 import java.util.List;
+import java.util.function.BiConsumer;
 
 /**
  * This class is used by unit tests implementing SegmentReplicationSource
@@ -36,6 +37,7 @@ public abstract void getSegmentFiles(
         ReplicationCheckpoint checkpoint,
         List<StoreFileMetadata> filesToFetch,
         IndexShard indexShard,
+        BiConsumer<String, Long> fileProgressTracker,
         ActionListener<GetSegmentFilesResponse> listener
     );
 
diff --git a/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java b/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java
index 43f2cce668e81..412d5235fe462 100644
--- a/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java
@@ -119,6 +119,7 @@
 import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.breaker.HierarchyCircuitBreakerService;
 import org.opensearch.indices.recovery.AsyncRecoveryTarget;
+import org.opensearch.indices.recovery.DefaultRecoverySettings;
 import org.opensearch.indices.recovery.PeerRecoveryTargetService;
 import org.opensearch.indices.recovery.RecoveryFailedException;
 import org.opensearch.indices.recovery.RecoveryResponse;
@@ -173,6 +174,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -272,11 +274,11 @@ public Settings threadPoolSettings() {
     }
 
     protected Store createStore(IndexSettings indexSettings, ShardPath shardPath) throws IOException {
-        return createStore(shardPath.getShardId(), indexSettings, newFSDirectory(shardPath.resolveIndex()));
+        return createStore(shardPath.getShardId(), indexSettings, newFSDirectory(shardPath.resolveIndex()), shardPath);
     }
 
-    protected Store createStore(ShardId shardId, IndexSettings indexSettings, Directory directory) throws IOException {
-        return new Store(shardId, indexSettings, directory, new DummyShardLock(shardId));
+    protected Store createStore(ShardId shardId, IndexSettings indexSettings, Directory directory, ShardPath shardPath) throws IOException {
+        return new Store(shardId, indexSettings, directory, new DummyShardLock(shardId), Store.OnClose.EMPTY, shardPath);
     }
 
     protected Releasable acquirePrimaryOperationPermitBlockingly(IndexShard indexShard) throws ExecutionException, InterruptedException {
@@ -640,7 +642,7 @@ protected IndexShard newShard(
                 Collections.emptyList(),
                 clusterSettings
             );
-            Store remoteStore = null;
+            Store remoteStore;
             RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory = null;
             RepositoriesService mockRepoSvc = mock(RepositoriesService.class);
 
@@ -654,11 +656,13 @@ protected IndexShard newShard(
                     remotePath = createTempDir();
                 }
 
-                remoteStore = createRemoteStore(remotePath, routing, indexMetadata);
+                remoteStore = createRemoteStore(remotePath, routing, indexMetadata, shardPath);
 
                 remoteStoreStatsTrackerFactory = new RemoteStoreStatsTrackerFactory(clusterService, indexSettings.getSettings());
                 BlobStoreRepository repo = createRepository(remotePath);
                 when(mockRepoSvc.repository(any())).thenAnswer(invocationOnMock -> repo);
+            } else {
+                remoteStore = null;
             }
 
             final BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier = (settings, shardRouting) -> {
@@ -697,7 +701,9 @@ protected IndexShard newShard(
                 checkpointPublisher,
                 remoteStore,
                 remoteStoreStatsTrackerFactory,
-                () -> IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL
+                () -> IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL,
+                "dummy-node",
+                DefaultRecoverySettings.INSTANCE
             );
             indexShard.addShardFailureCallback(DEFAULT_SHARD_FAILURE_HANDLER);
             if (remoteStoreStatsTrackerFactory != null) {
@@ -768,11 +774,12 @@ protected RepositoriesService createRepositoriesService() {
         return repositoriesService;
     }
 
-    protected Store createRemoteStore(Path path, ShardRouting shardRouting, IndexMetadata metadata) throws IOException {
+    protected Store createRemoteStore(Path path, ShardRouting shardRouting, IndexMetadata metadata, ShardPath shardPath)
+        throws IOException {
         Settings nodeSettings = Settings.builder().put("node.name", shardRouting.currentNodeId()).build();
         ShardId shardId = shardRouting.shardId();
         RemoteSegmentStoreDirectory remoteSegmentStoreDirectory = createRemoteSegmentStoreDirectory(shardId, path);
-        return createStore(shardId, new IndexSettings(metadata, nodeSettings), remoteSegmentStoreDirectory);
+        return createStore(shardId, new IndexSettings(metadata, nodeSettings), remoteSegmentStoreDirectory, shardPath);
     }
 
     protected RemoteSegmentStoreDirectory createRemoteSegmentStoreDirectory(ShardId shardId, Path path) throws IOException {
@@ -783,7 +790,7 @@ protected RemoteSegmentStoreDirectory createRemoteSegmentStoreDirectory(ShardId
         RemoteStoreLockManager remoteStoreLockManager = new RemoteStoreMetadataLockManager(
             new RemoteBufferedOutputDirectory(getBlobContainer(remoteShardPath.resolveIndex()))
         );
-        return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, remoteStoreLockManager, threadPool);
+        return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, remoteStoreLockManager, threadPool, shardId);
     }
 
     private RemoteDirectory newRemoteDirectory(Path f) throws IOException {
@@ -1080,7 +1087,7 @@ protected void recoverReplica(
     /**
      * Recovers a replica from the give primary, allow the user to supply a custom recovery target. A typical usage of a custom recovery
      * target is to assert things in the various stages of recovery.
-     *
+     * <p>
      * Note: this method keeps the shard in {@link IndexShardState#POST_RECOVERY} and doesn't start it.
      *
      * @param replica                the recovery target shard
@@ -1614,6 +1621,7 @@ public void getSegmentFiles(
                 ReplicationCheckpoint checkpoint,
                 List<StoreFileMetadata> filesToFetch,
                 IndexShard indexShard,
+                BiConsumer<String, Long> fileProgressTracker,
                 ActionListener<GetSegmentFilesResponse> listener
             ) {
                 try (
diff --git a/test/framework/src/main/java/org/opensearch/indices/recovery/DefaultRecoverySettings.java b/test/framework/src/main/java/org/opensearch/indices/recovery/DefaultRecoverySettings.java
new file mode 100644
index 0000000000000..359668f5dad71
--- /dev/null
+++ b/test/framework/src/main/java/org/opensearch/indices/recovery/DefaultRecoverySettings.java
@@ -0,0 +1,24 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.indices.recovery;
+
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+
+/**
+ * Utility to provide a {@link RecoverySettings} instance containing all defaults
+ */
+public final class DefaultRecoverySettings {
+    private DefaultRecoverySettings() {}
+
+    public static final RecoverySettings INSTANCE = new RecoverySettings(
+        Settings.EMPTY,
+        new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)
+    );
+}
diff --git a/test/framework/src/main/java/org/opensearch/mockito/plugin/PriviledgedMockMaker.java b/test/framework/src/main/java/org/opensearch/mockito/plugin/PriviledgedMockMaker.java
index ef13e065968df..0f5e043ee1135 100644
--- a/test/framework/src/main/java/org/opensearch/mockito/plugin/PriviledgedMockMaker.java
+++ b/test/framework/src/main/java/org/opensearch/mockito/plugin/PriviledgedMockMaker.java
@@ -43,7 +43,7 @@ public class PriviledgedMockMaker implements MockMaker {
      * since Mockito does not support SecurityManager out of the box. The method has to be called by
      * test framework before the SecurityManager is being set, otherwise additional permissions have
      * to be granted to the caller:
-     *
+     * <p>
      *     permission java.security.Permission "createAccessControlContext"
      *
      */
diff --git a/test/framework/src/main/java/org/opensearch/repositories/blobstore/OpenSearchMockAPIBasedRepositoryIntegTestCase.java b/test/framework/src/main/java/org/opensearch/repositories/blobstore/OpenSearchMockAPIBasedRepositoryIntegTestCase.java
index bf020b1bc292d..faa9d52b105b2 100644
--- a/test/framework/src/main/java/org/opensearch/repositories/blobstore/OpenSearchMockAPIBasedRepositoryIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/repositories/blobstore/OpenSearchMockAPIBasedRepositoryIntegTestCase.java
@@ -238,7 +238,7 @@ public void testRequestStats() throws Exception {
         assertEquals(assertionErrorMsg, mockCalls, sdkRequestCounts);
     }
 
-    private Map<String, Long> getMockRequestCounts() {
+    protected Map<String, Long> getMockRequestCounts() {
         for (HttpHandler h : handlers.values()) {
             while (h instanceof DelegatingHttpHandler) {
                 if (h instanceof HttpStatsCollectorHandler) {
@@ -265,7 +265,7 @@ protected static void drainInputStream(final InputStream inputStream) throws IOE
 
     /**
      * HTTP handler that injects random service errors
-     *
+     * <p>
      * Note: it is not a good idea to allow this handler to simulate too many errors as it would
      * slow down the test suite.
      */
@@ -339,7 +339,7 @@ public interface DelegatingHttpHandler extends HttpHandler {
 
     /**
      * HTTP handler that allows collect request stats per request type.
-     *
+     * <p>
      * Implementors should keep track of the desired requests on {@link #maybeTrack(String, Headers)}.
      */
     @SuppressForbidden(reason = "this test uses a HttpServer to emulate a cloud-based storage service")
@@ -377,7 +377,7 @@ public void handle(HttpExchange exchange) throws IOException {
 
         /**
          * Tracks the given request if it matches the criteria.
-         *
+         * <p>
          * The request is represented as:
          * Request = Method SP Request-URI
          *
diff --git a/test/framework/src/main/java/org/opensearch/script/MockScriptEngine.java b/test/framework/src/main/java/org/opensearch/script/MockScriptEngine.java
index cb0614ddeb808..83b245a1bcecb 100644
--- a/test/framework/src/main/java/org/opensearch/script/MockScriptEngine.java
+++ b/test/framework/src/main/java/org/opensearch/script/MockScriptEngine.java
@@ -58,14 +58,14 @@
 
 /**
  * A mocked script engine that can be used for testing purpose.
- *
+ * <p>
  * This script engine allows to define a set of predefined scripts that basically a combination of a key and a
  * function:
- *
+ * <p>
  * The key can be anything as long as it is a {@link String} and is used to resolve the scripts
  * at compilation time. For inline scripts, the key can be a description of the script. For stored and file scripts,
  * the source must match a key in the predefined set of scripts.
- *
+ * <p>
  * The function is used to provide the result of the script execution and can return anything.
  */
 public class MockScriptEngine implements ScriptEngine {
diff --git a/test/framework/src/main/java/org/opensearch/script/ScoreAccessor.java b/test/framework/src/main/java/org/opensearch/script/ScoreAccessor.java
index 26b439fa6438f..9cf2141555957 100644
--- a/test/framework/src/main/java/org/opensearch/script/ScoreAccessor.java
+++ b/test/framework/src/main/java/org/opensearch/script/ScoreAccessor.java
@@ -39,7 +39,7 @@
 
 /**
  * A float encapsulation that dynamically accesses the score of a document.
- *
+ * <p>
  * The provided {@link DocLookup} is used to retrieve the score
  * for the current document.
  */
diff --git a/test/framework/src/main/java/org/opensearch/search/RandomSearchRequestGenerator.java b/test/framework/src/main/java/org/opensearch/search/RandomSearchRequestGenerator.java
index b942136e1f1e2..74de1e6d96d93 100644
--- a/test/framework/src/main/java/org/opensearch/search/RandomSearchRequestGenerator.java
+++ b/test/framework/src/main/java/org/opensearch/search/RandomSearchRequestGenerator.java
@@ -131,6 +131,9 @@ public static SearchRequest randomSearchRequest(Supplier<SearchSourceBuilder> ra
         if (randomBoolean()) {
             searchRequest.setCancelAfterTimeInterval(TimeValue.parseTimeValue(randomTimeValue(), null, "cancel_after_time_interval"));
         }
+        if (randomBoolean()) {
+            searchRequest.setPhaseTook(randomBoolean());
+        }
         return searchRequest;
     }
 
diff --git a/test/framework/src/main/java/org/opensearch/search/aggregations/AggregatorTestCase.java b/test/framework/src/main/java/org/opensearch/search/aggregations/AggregatorTestCase.java
index 5c649f1dc832d..82f15a590bea6 100644
--- a/test/framework/src/main/java/org/opensearch/search/aggregations/AggregatorTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/search/aggregations/AggregatorTestCase.java
@@ -685,7 +685,7 @@ protected static IndexReader maybeWrapReaderEs(DirectoryReader reader) throws IO
      * Implementors should return a list of {@link ValuesSourceType} that the aggregator supports.
      * This is used to test the matrix of supported/unsupported field types against the aggregator
      * and verify it works (or doesn't) as expected.
-     *
+     * <p>
      * If this method is implemented, {@link AggregatorTestCase#createAggBuilderForTypeTest(MappedFieldType, String)}
      * should be implemented as well.
      *
@@ -702,7 +702,7 @@ protected List<ValuesSourceType> getSupportedValuesSourceTypes() {
      * The field type and name are provided, and the implementor is expected to return an AggBuilder accordingly.
      * The AggBuilder should be returned even if the aggregation does not support the field type, because
      * the test will check if an exception is thrown in that case.
-     *
+     * <p>
      * The list of supported types are provided by {@link AggregatorTestCase#getSupportedValuesSourceTypes()},
      * which must also be implemented.
      *
@@ -720,7 +720,7 @@ protected AggregationBuilder createAggBuilderForTypeTest(MappedFieldType fieldTy
      * A method that allows implementors to specifically denylist particular field types (based on their content_name).
      * This is needed in some areas where the ValuesSourceType is not granular enough, for example integer values
      * vs floating points, or `keyword` bytes vs `binary` bytes (which are not searchable)
-     *
+     * <p>
      * This is a denylist instead of an allowlist because there are vastly more field types than ValuesSourceTypes,
      * and it's expected that these unsupported cases are exceptional rather than common
      */
@@ -734,7 +734,7 @@ protected List<String> unsupportedMappedFieldTypes() {
      * is provided by the implementor class, and it is executed against each field type in turn.  If
      * an exception is thrown when the field is supported, that will fail the test.  Similarly, if
      * an exception _is not_ thrown when a field is unsupported, that will also fail the test.
-     *
+     * <p>
      * Exception types/messages are not currently checked, just presence/absence of an exception.
      */
     public void testSupportedFieldTypes() throws IOException {
@@ -825,7 +825,7 @@ private ValuesSourceType fieldToVST(MappedFieldType fieldType) {
 
     /**
      * Helper method to write a single document with a single value specific to the requested fieldType.
-     *
+     * <p>
      * Throws an exception if it encounters an unknown field type, to prevent new ones from sneaking in without
      * being tested.
      */
diff --git a/test/framework/src/main/java/org/opensearch/search/aggregations/bucket/AbstractTermsTestCase.java b/test/framework/src/main/java/org/opensearch/search/aggregations/bucket/AbstractTermsTestCase.java
index 75192e276982e..8e94f2cacf070 100644
--- a/test/framework/src/main/java/org/opensearch/search/aggregations/bucket/AbstractTermsTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/search/aggregations/bucket/AbstractTermsTestCase.java
@@ -32,16 +32,41 @@
 
 package org.opensearch.search.aggregations.bucket;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.opensearch.search.aggregations.bucket.terms.Terms;
 import org.opensearch.search.aggregations.bucket.terms.TermsAggregatorFactory.ExecutionMode;
-import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
+
+import java.util.Arrays;
+import java.util.Collection;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 import static org.opensearch.search.aggregations.AggregationBuilders.terms;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
 
-public abstract class AbstractTermsTestCase extends OpenSearchIntegTestCase {
+public abstract class AbstractTermsTestCase extends ParameterizedOpenSearchIntegTestCase {
+
+    public AbstractTermsTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
 
     public String randomExecutionHint() {
         return randomBoolean() ? null : randomFrom(ExecutionMode.values()).toString();
diff --git a/test/framework/src/main/java/org/opensearch/search/aggregations/composite/BaseCompositeAggregatorTestCase.java b/test/framework/src/main/java/org/opensearch/search/aggregations/composite/BaseCompositeAggregatorTestCase.java
index 1b348dc7d41a7..6b5ec838f401d 100644
--- a/test/framework/src/main/java/org/opensearch/search/aggregations/composite/BaseCompositeAggregatorTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/search/aggregations/composite/BaseCompositeAggregatorTestCase.java
@@ -305,6 +305,6 @@ protected static Map<String, Object> createAfterKey(Object... fields) {
     }
 
     protected static long asLong(String dateTime) {
-        return DateFormatters.from(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.parse(dateTime)).toInstant().toEpochMilli();
+        return DateFormatters.from(DateFieldMapper.getDefaultDateTimeFormatter().parse(dateTime)).toInstant().toEpochMilli();
     }
 }
diff --git a/test/framework/src/main/java/org/opensearch/search/aggregations/metrics/AbstractNumericTestCase.java b/test/framework/src/main/java/org/opensearch/search/aggregations/metrics/AbstractNumericTestCase.java
index a4f6b97115bb0..103b67e2782de 100644
--- a/test/framework/src/main/java/org/opensearch/search/aggregations/metrics/AbstractNumericTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/search/aggregations/metrics/AbstractNumericTestCase.java
@@ -31,18 +31,43 @@
 
 package org.opensearch.search.aggregations.metrics;
 
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+
 import org.opensearch.action.index.IndexRequestBuilder;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
 
 @OpenSearchIntegTestCase.SuiteScopeTestCase
-public abstract class AbstractNumericTestCase extends OpenSearchIntegTestCase {
+public abstract class AbstractNumericTestCase extends ParameterizedOpenSearchIntegTestCase {
     protected static long minValue, maxValue, minValues, maxValues;
 
+    public AbstractNumericTestCase(Settings dynamicSettings) {
+        super(dynamicSettings);
+    }
+
+    @ParametersFactory
+    public static Collection<Object[]> parameters() {
+        return Arrays.asList(
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), false).build() },
+            new Object[] { Settings.builder().put(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey(), true).build() }
+        );
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.CONCURRENT_SEGMENT_SEARCH, "true").build();
+    }
+
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
diff --git a/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java b/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java
index 1bb1e44a8a600..0ee889af5ce1a 100644
--- a/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java
@@ -331,6 +331,12 @@ public static void blockNodeOnAnyFiles(String repository, String nodeName) {
         );
     }
 
+    public static void blockNodeOnAnySegmentFile(String repository, String nodeName) {
+        ((MockRepository) internalCluster().getInstance(RepositoriesService.class, nodeName).repository(repository)).blockOnSegmentFiles(
+            true
+        );
+    }
+
     public static void blockDataNode(String repository, String nodeName) {
         ((MockRepository) internalCluster().getInstance(RepositoriesService.class, nodeName).repository(repository)).blockOnDataFiles(true);
     }
diff --git a/test/framework/src/main/java/org/opensearch/snapshots/mockstore/MockRepository.java b/test/framework/src/main/java/org/opensearch/snapshots/mockstore/MockRepository.java
index 7db71c4be0968..72c4ba44d0a31 100644
--- a/test/framework/src/main/java/org/opensearch/snapshots/mockstore/MockRepository.java
+++ b/test/framework/src/main/java/org/opensearch/snapshots/mockstore/MockRepository.java
@@ -139,6 +139,8 @@ public long getFailureCount() {
 
     private volatile boolean blockOnDataFiles;
 
+    private volatile boolean blockOnSegmentFiles;
+
     private volatile boolean blockOnDeleteIndexN;
 
     /**
@@ -190,6 +192,7 @@ public MockRepository(
         maximumNumberOfFailures = metadata.settings().getAsLong("max_failure_number", 100L);
         blockOnAnyFiles = metadata.settings().getAsBoolean("block_on_control", false);
         blockOnDataFiles = metadata.settings().getAsBoolean("block_on_data", false);
+        blockOnSegmentFiles = metadata.settings().getAsBoolean("block_on_segment", false);
         blockAndFailOnWriteSnapFile = metadata.settings().getAsBoolean("block_on_snap", false);
         randomPrefix = metadata.settings().get("random", "default");
         waitAfterUnblock = metadata.settings().getAsLong("wait_after_unblock", 0L);
@@ -237,6 +240,7 @@ public synchronized void unblock() {
         blocked = false;
         // Clean blocking flags, so we wouldn't try to block again
         blockOnDataFiles = false;
+        blockOnSegmentFiles = false;
         blockOnAnyFiles = false;
         blockAndFailOnWriteIndexFile = false;
         blockOnWriteIndexFile = false;
@@ -259,6 +263,14 @@ public void setBlockOnAnyFiles(boolean blocked) {
         blockOnAnyFiles = blocked;
     }
 
+    public void blockOnSegmentFiles(boolean blocked) {
+        blockOnSegmentFiles = blocked;
+    }
+
+    public void setBlockOnSegmentFiles(boolean blocked) {
+        blockOnSegmentFiles = blocked;
+    }
+
     public void setBlockAndFailOnWriteSnapFiles(boolean blocked) {
         blockAndFailOnWriteSnapFile = blocked;
     }
@@ -306,6 +318,7 @@ private synchronized boolean blockExecution() {
         boolean wasBlocked = false;
         try {
             while (blockOnDataFiles
+                || blockOnSegmentFiles
                 || blockOnAnyFiles
                 || blockAndFailOnWriteIndexFile
                 || blockOnWriteIndexFile
@@ -407,6 +420,8 @@ private void maybeIOExceptionOrBlock(String blobName) throws IOException {
                         blockExecutionAndMaybeWait(blobName);
                     } else if (blobName.startsWith("snap-") && blockAndFailOnWriteSnapFile) {
                         blockExecutionAndFail(blobName);
+                    } else if (blockOnSegmentFiles && blobName.contains(".si__")) {
+                        blockExecutionAndMaybeWait(blobName);
                     }
                 }
             }
diff --git a/test/framework/src/main/java/org/opensearch/test/AbstractBuilderTestCase.java b/test/framework/src/main/java/org/opensearch/test/AbstractBuilderTestCase.java
index 0cfa64df55659..7a8cf4963c4f1 100644
--- a/test/framework/src/main/java/org/opensearch/test/AbstractBuilderTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/AbstractBuilderTestCase.java
@@ -35,6 +35,7 @@
 import com.carrotsearch.randomizedtesting.RandomizedTest;
 import com.carrotsearch.randomizedtesting.SeedUtils;
 
+import org.apache.lucene.search.BooleanClause;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.util.Accountable;
 import org.opensearch.Version;
@@ -69,6 +70,8 @@
 import org.opensearch.index.fielddata.IndexFieldDataService;
 import org.opensearch.index.mapper.MappedFieldType;
 import org.opensearch.index.mapper.MapperService;
+import org.opensearch.index.query.QueryBuilder;
+import org.opensearch.index.query.QueryBuilderVisitor;
 import org.opensearch.index.query.QueryShardContext;
 import org.opensearch.index.similarity.SimilarityService;
 import org.opensearch.indices.IndicesModule;
@@ -316,6 +319,20 @@ protected static QueryShardContext createShardContext() {
         return createShardContext(null);
     }
 
+    protected static QueryBuilderVisitor createTestVisitor(List<QueryBuilder> visitedQueries) {
+        return new QueryBuilderVisitor() {
+            @Override
+            public void accept(QueryBuilder qb) {
+                visitedQueries.add(qb);
+            }
+
+            @Override
+            public QueryBuilderVisitor getChildVisitor(BooleanClause.Occur occur) {
+                return this;
+            }
+        };
+    }
+
     private static class ClientInvocationHandler implements InvocationHandler {
         AbstractBuilderTestCase delegate;
 
diff --git a/test/framework/src/main/java/org/opensearch/test/AbstractDiffableSerializationTestCase.java b/test/framework/src/main/java/org/opensearch/test/AbstractDiffableSerializationTestCase.java
index f5d358a162bd1..10e782e6af8da 100644
--- a/test/framework/src/main/java/org/opensearch/test/AbstractDiffableSerializationTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/AbstractDiffableSerializationTestCase.java
@@ -41,8 +41,8 @@
 
 /**
  * An abstract test case to ensure correct behavior of Diffable.
- *
- * This class can be used as a based class for tests of Metadata.Custom classes and other classes that support,
+ * <p>
+ * This class can be used as a based class for tests of Metadata.Custom classes and other classes that support {@link org.opensearch.core.common.io.stream.Writeable } serialization, XContent-based serialization and is diffable.
  * Writable serialization, XContent-based serialization and is diffable.
  */
 public abstract class AbstractDiffableSerializationTestCase<T extends Diffable<T> & ToXContent> extends AbstractSerializingTestCase<T> {
diff --git a/test/framework/src/main/java/org/opensearch/test/AbstractDiffableWireSerializationTestCase.java b/test/framework/src/main/java/org/opensearch/test/AbstractDiffableWireSerializationTestCase.java
index ff7c39cd8f102..3f97f0704d733 100644
--- a/test/framework/src/main/java/org/opensearch/test/AbstractDiffableWireSerializationTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/AbstractDiffableWireSerializationTestCase.java
@@ -40,8 +40,8 @@
 
 /**
  * An abstract test case to ensure correct behavior of Diffable.
- *
- * This class can be used as a based class for tests of ClusterState.Custom classes and other classes that support,
+ * <p>
+ * This class can be used as a based class for tests of ClusterState.Custom classes and other classes that support {@link org.opensearch.core.common.io.stream.Writeable } serialization and is diffable.
  * Writable serialization and is diffable.
  */
 public abstract class AbstractDiffableWireSerializationTestCase<T extends Diffable<T>> extends AbstractWireSerializingTestCase<T> {
diff --git a/test/framework/src/main/java/org/opensearch/test/AbstractQueryTestCase.java b/test/framework/src/main/java/org/opensearch/test/AbstractQueryTestCase.java
index 47fe85d28975f..afd93e1b72fbb 100644
--- a/test/framework/src/main/java/org/opensearch/test/AbstractQueryTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/AbstractQueryTestCase.java
@@ -213,7 +213,7 @@ public void testUnknownObjectException() throws IOException {
     /**
      * Traverses the json tree of the valid query provided as argument and mutates it one or more times by adding one object within each
      * object encountered.
-     *
+     * <p>
      * For instance given the following valid term query:
      * {
      *     "term" : {
@@ -222,7 +222,7 @@ public void testUnknownObjectException() throws IOException {
      *         }
      *     }
      * }
-     *
+     * <p>
      * The following two mutations will be generated, and an exception is expected when trying to parse them:
      * {
      *     "term" : {
@@ -233,7 +233,7 @@ public void testUnknownObjectException() throws IOException {
      *         }
      *     }
      * }
-     *
+     * <p>
      * {
      *     "term" : {
      *         "field" : {
@@ -243,7 +243,7 @@ public void testUnknownObjectException() throws IOException {
      *         }
      *     }
      * }
-     *
+     * <p>
      * Every mutation is then added to the list of results with a boolean flag indicating if a parsing exception is expected or not
      * for the mutation. Some specific objects do not cause any exception as they can hold arbitrary content; they are passed using the
      * arbitraryMarkers parameter.
@@ -768,7 +768,7 @@ protected static String randomMinimumShouldMatch() {
     /**
      * Call this method to check a valid json string representing the query under test against
      * it's generated json.
-     *
+     * <p>
      * Note: By the time of this writing (Nov 2015) all queries are taken from the query dsl
      * reference docs mirroring examples there. Here's how the queries were generated:
      *
diff --git a/test/framework/src/main/java/org/opensearch/test/AbstractWireTestCase.java b/test/framework/src/main/java/org/opensearch/test/AbstractWireTestCase.java
index 9a4363dc4d946..64c5d916d55d2 100644
--- a/test/framework/src/main/java/org/opensearch/test/AbstractWireTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/AbstractWireTestCase.java
@@ -124,9 +124,9 @@ protected final T copyInstance(T instance) throws IOException {
 
     /**
      * Get the {@link NamedWriteableRegistry} to use when de-serializing the object.
-     *
+     * <p>
      * Override this method if you need to register {@link NamedWriteable}s for the test object to de-serialize.
-     *
+     * <p>
      * By default this will return a {@link NamedWriteableRegistry} with no registered {@link NamedWriteable}s
      */
     protected NamedWriteableRegistry getNamedWriteableRegistry() {
diff --git a/test/framework/src/main/java/org/opensearch/test/CorruptionUtils.java b/test/framework/src/main/java/org/opensearch/test/CorruptionUtils.java
index 0dce5e78bf91f..67522bb618cf1 100644
--- a/test/framework/src/main/java/org/opensearch/test/CorruptionUtils.java
+++ b/test/framework/src/main/java/org/opensearch/test/CorruptionUtils.java
@@ -121,7 +121,7 @@ public static void corruptFile(Random random, Path... files) throws IOException
         }
     }
 
-    static void corruptAt(Path path, FileChannel channel, int position) throws IOException {
+    public static void corruptAt(Path path, FileChannel channel, int position) throws IOException {
         // read
         channel.position(position);
         long filePointer = channel.position();
diff --git a/test/framework/src/main/java/org/opensearch/test/InternalTestCluster.java b/test/framework/src/main/java/org/opensearch/test/InternalTestCluster.java
index d3e24ccd90500..c2b964aa96212 100644
--- a/test/framework/src/main/java/org/opensearch/test/InternalTestCluster.java
+++ b/test/framework/src/main/java/org/opensearch/test/InternalTestCluster.java
@@ -1816,7 +1816,7 @@ public synchronized void stopCurrentClusterManagerNode() throws IOException {
     /**
      * Stops any of the current nodes but not the cluster-manager node.
      */
-    public synchronized void stopRandomNonClusterManagerNode() throws IOException {
+    public synchronized void stopRandomNodeNotCurrentClusterManager() throws IOException {
         NodeAndClient nodeAndClient = getRandomNodeAndClient(new NodeNamePredicate(getClusterManagerName()).negate());
         if (nodeAndClient != null) {
             logger.info(
@@ -1841,11 +1841,11 @@ public synchronized void stopCurrentMasterNode() throws IOException {
     /**
      * Stops any of the current nodes but not the cluster-manager node.
      *
-     * @deprecated As of 2.2, because supporting inclusive language, replaced by {@link #stopRandomNonClusterManagerNode()}
+     * @deprecated As of 2.2, because supporting inclusive language, replaced by {@link #stopRandomNodeNotCurrentClusterManager()}
      */
     @Deprecated
-    public synchronized void stopRandomNonMasterNode() throws IOException {
-        stopRandomNonClusterManagerNode();
+    public synchronized void stopRandomNodeNotCurrentMaster() throws IOException {
+        stopRandomNodeNotCurrentClusterManager();
     }
 
     /**
@@ -1853,14 +1853,16 @@ public synchronized void stopRandomNonMasterNode() throws IOException {
      */
     public void stopAllNodes() {
         try {
-            int totalDataNodes = numDataNodes();
-            while (totalDataNodes > 0) {
-                stopRandomDataNode();
-                totalDataNodes -= 1;
+            if (numDataAndClusterManagerNodes() != numClusterManagerNodes()) {
+                int totalDataNodes = numDataNodes();
+                while (totalDataNodes > 0) {
+                    stopRandomDataNode();
+                    totalDataNodes -= 1;
+                }
             }
             int totalClusterManagerNodes = numClusterManagerNodes();
             while (totalClusterManagerNodes > 1) {
-                stopRandomNonClusterManagerNode();
+                stopRandomNodeNotCurrentClusterManager();
                 totalClusterManagerNodes -= 1;
             }
             stopCurrentClusterManagerNode();
@@ -1869,6 +1871,18 @@ public void stopAllNodes() {
         }
     }
 
+    /**
+     * Replace all nodes by stopping all current node and starting new node.
+     * Used for remote store test cases, where remote state is restored.
+     */
+    public void resetCluster() {
+        int totalClusterManagerNodes = numClusterManagerNodes();
+        int totalDataNodes = numDataNodes();
+        stopAllNodes();
+        startClusterManagerOnlyNodes(totalClusterManagerNodes);
+        startDataOnlyNodes(totalDataNodes);
+    }
+
     private synchronized void startAndPublishNodesAndClients(List<NodeAndClient> nodeAndClients) {
         if (nodeAndClients.size() > 0) {
             final int newClusterManagers = (int) nodeAndClients.stream()
@@ -2718,6 +2732,10 @@ public void ensureEstimatedStats() {
                     false,
                     false,
                     false,
+                    false,
+                    false,
+                    false,
+                    false,
                     false
                 );
                 assertThat(
diff --git a/test/framework/src/main/java/org/opensearch/test/MockKeywordPlugin.java b/test/framework/src/main/java/org/opensearch/test/MockKeywordPlugin.java
index c27f3f169fbae..3d829d77dd323 100644
--- a/test/framework/src/main/java/org/opensearch/test/MockKeywordPlugin.java
+++ b/test/framework/src/main/java/org/opensearch/test/MockKeywordPlugin.java
@@ -44,7 +44,7 @@
 /**
  * Some tests rely on the keyword tokenizer, but this tokenizer isn't part of lucene-core and therefor not available
  * in some modules. What this test plugin does, is use the mock tokenizer and advertise that as the keyword tokenizer.
- *
+ * <p>
  * Most tests that need this test plugin use normalizers. When normalizers are constructed they try to resolve the
  * keyword tokenizer, but if the keyword tokenizer isn't available then constructing normalizers will fail.
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
index 95cf78d3fba79..7e29c43ddc824 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
@@ -71,6 +71,7 @@
 import org.opensearch.action.search.ClearScrollResponse;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.action.support.WriteRequest;
 import org.opensearch.client.AdminClient;
 import org.opensearch.client.Client;
 import org.opensearch.client.ClusterAdminClient;
@@ -130,9 +131,9 @@
 import org.opensearch.http.HttpInfo;
 import org.opensearch.index.IndexModule;
 import org.opensearch.index.IndexSettings;
-import org.opensearch.index.MergePolicyConfig;
 import org.opensearch.index.MergeSchedulerConfig;
 import org.opensearch.index.MockEngineFactoryPlugin;
+import org.opensearch.index.TieredMergePolicyProvider;
 import org.opensearch.index.codec.CodecService;
 import org.opensearch.index.engine.Segment;
 import org.opensearch.index.mapper.CompletionFieldMapper;
@@ -503,7 +504,7 @@ protected Settings.Builder setRandomIndexSettings(Random random, Settings.Builde
     private static Settings.Builder setRandomIndexMergeSettings(Random random, Settings.Builder builder) {
         if (random.nextBoolean()) {
             builder.put(
-                MergePolicyConfig.INDEX_COMPOUND_FORMAT_SETTING.getKey(),
+                TieredMergePolicyProvider.INDEX_COMPOUND_FORMAT_SETTING.getKey(),
                 (random.nextBoolean() ? random.nextDouble() : random.nextBoolean()).toString()
             );
         }
@@ -800,6 +801,30 @@ protected Settings featureFlagSettings() {
         return featureSettings.build();
     }
 
+    /**
+     * Represent if it needs to trigger remote state restore or not.
+     * For tests with remote store enabled domain, it will be overridden to true.
+     *
+     * @return if needs to perform remote state restore or not
+     */
+    protected boolean triggerRemoteStateRestore() {
+        return false;
+    }
+
+    /**
+     * For tests with remote cluster state, it will reset the cluster and cluster state will be
+     * restored from remote.
+     */
+    protected void performRemoteStoreTestAction() {
+        if (triggerRemoteStateRestore()) {
+            String clusterUUIDBefore = clusterService().state().metadata().clusterUUID();
+            internalCluster().resetCluster();
+            String clusterUUIDAfter = clusterService().state().metadata().clusterUUID();
+            // assertion that UUID is changed post restore.
+            assertFalse(clusterUUIDBefore.equals(clusterUUIDAfter));
+        }
+    }
+
     /**
      * Creates one or more indices and asserts that the indices are acknowledged. If one of the indices
      * already exists this method will fail and wipe all the indices created so far.
@@ -1354,7 +1379,7 @@ protected void ensureStableCluster(int nodeCount, TimeValue timeValue, boolean l
 
     /**
      * Ensures that all nodes in the cluster are connected to each other.
-     *
+     * <p>
      * Some network disruptions may leave nodes that are not the cluster-manager disconnected from each other.
      * {@link org.opensearch.cluster.NodeConnectionsService} will eventually reconnect but it's
      * handy to be able to ensure this happens faster
@@ -1633,6 +1658,7 @@ public void indexRandom(boolean forceRefresh, boolean dummyDocuments, boolean ma
             for (List<IndexRequestBuilder> segmented : partition) {
                 BulkRequestBuilder bulkBuilder = client().prepareBulk();
                 for (IndexRequestBuilder indexRequestBuilder : segmented) {
+                    indexRequestBuilder.setRefreshPolicy(WriteRequest.RefreshPolicy.NONE);
                     bulkBuilder.add(indexRequestBuilder);
                 }
                 BulkResponse actionGet = bulkBuilder.execute().actionGet();
@@ -1653,6 +1679,7 @@ public void indexRandom(boolean forceRefresh, boolean dummyDocuments, boolean ma
             }
         }
         assertThat(actualErrors, emptyIterable());
+
         if (!bogusIds.isEmpty()) {
             // delete the bogus types again - it might trigger merges or at least holes in the segments and enforces deleted docs!
             for (List<String> doc : bogusIds) {
@@ -1668,6 +1695,63 @@ public void indexRandom(boolean forceRefresh, boolean dummyDocuments, boolean ma
                 client().admin().indices().prepareRefresh(indicesArray).setIndicesOptions(IndicesOptions.lenientExpandOpen()).get()
             );
         }
+        if (dummyDocuments) {
+            indexRandomForMultipleSlices(indicesArray);
+        }
+    }
+
+    /*
+    * This method ingests bogus documents for the given indices such that multiple slices
+    * are formed. This is useful for testing with the concurrent search use-case as it creates
+    * multiple slices based on segment count.
+    * @param indices         the indices in which bogus documents should be ingested
+    * */
+    protected void indexRandomForMultipleSlices(String... indices) throws InterruptedException {
+        Set<List<String>> bogusIds = new HashSet<>();
+        int refreshCount = randomIntBetween(2, 3);
+        for (String index : indices) {
+            int numDocs = getNumShards(index).totalNumShards * randomIntBetween(2, 10);
+            while (refreshCount-- > 0) {
+                final CopyOnWriteArrayList<Tuple<IndexRequestBuilder, Exception>> errors = new CopyOnWriteArrayList<>();
+                List<CountDownLatch> inFlightAsyncOperations = new ArrayList<>();
+                for (int i = 0; i < numDocs; i++) {
+                    String id = "bogus_doc_" + randomRealisticUnicodeOfLength(between(1, 10)) + dummmyDocIdGenerator.incrementAndGet();
+                    IndexRequestBuilder indexRequestBuilder = client().prepareIndex()
+                        .setIndex(index)
+                        .setId(id)
+                        .setSource("{}", MediaTypeRegistry.JSON)
+                        .setRouting(id);
+                    indexRequestBuilder.execute(
+                        new PayloadLatchedActionListener<>(indexRequestBuilder, newLatch(inFlightAsyncOperations), errors)
+                    );
+                    bogusIds.add(Arrays.asList(index, id));
+                }
+                for (CountDownLatch operation : inFlightAsyncOperations) {
+                    operation.await();
+                }
+                final List<Exception> actualErrors = new ArrayList<>();
+                for (Tuple<IndexRequestBuilder, Exception> tuple : errors) {
+                    Throwable t = ExceptionsHelper.unwrapCause(tuple.v2());
+                    if (t instanceof OpenSearchRejectedExecutionException) {
+                        logger.debug("Error indexing doc: " + t.getMessage() + ", reindexing.");
+                        tuple.v1().execute().actionGet(); // re-index if rejected
+                    } else {
+                        actualErrors.add(tuple.v2());
+                    }
+                }
+                assertThat(actualErrors, emptyIterable());
+                refresh(index);
+            }
+        }
+        for (List<String> doc : bogusIds) {
+            assertEquals(
+                "failed to delete a dummy doc [" + doc.get(0) + "][" + doc.get(1) + "]",
+                DocWriteResponse.Result.DELETED,
+                client().prepareDelete(doc.get(0), doc.get(1)).setRouting(doc.get(1)).get().getResult()
+            );
+        }
+        // refresh is called to make sure the bogus docs doesn't affect the search results
+        refresh();
     }
 
     private final AtomicInteger dummmyDocIdGenerator = new AtomicInteger();
@@ -1942,6 +2026,7 @@ protected Settings nodeSettings(int nodeOrdinal) {
         }
         // Enable tracer only when Telemetry Setting is enabled
         if (featureFlagSettings().getAsBoolean(FeatureFlags.TELEMETRY_SETTING.getKey(), false)) {
+            builder.put(TelemetrySettings.TRACER_FEATURE_ENABLED_SETTING.getKey(), true);
             builder.put(TelemetrySettings.TRACER_ENABLED_SETTING.getKey(), true);
         }
         if (FeatureFlags.CONCURRENT_SEGMENT_SEARCH_SETTING.get(featureFlagSettings)) {
@@ -2317,9 +2402,8 @@ public static void afterClass() throws Exception {
                 INSTANCE.printTestMessage("cleaning up after");
                 INSTANCE.afterInternal(true);
                 checkStaticState(true);
-                StrictCheckSpanProcessor.validateTracingStateOnShutdown();
             }
-
+            StrictCheckSpanProcessor.validateTracingStateOnShutdown();
         } finally {
             SUITE_SEED = null;
             currentCluster = null;
@@ -2329,11 +2413,11 @@ public static void afterClass() throws Exception {
 
     private static void initializeSuiteScope() throws Exception {
         Class<?> targetClass = getTestClass();
-        /**
-         * Note we create these test class instance via reflection
-         * since JUnit creates a new instance per test and that is also
-         * the reason why INSTANCE is static since this entire method
-         * must be executed in a static context.
+        /*
+          Note we create these test class instance via reflection
+          since JUnit creates a new instance per test and that is also
+          the reason why INSTANCE is static since this entire method
+          must be executed in a static context.
          */
         assert INSTANCE == null;
         if (isSuiteScopedTest(targetClass)) {
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java
index f14fe3bf3961c..efc29d1c254e6 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java
@@ -254,6 +254,7 @@ private Node newNode() {
             .putList(INITIAL_CLUSTER_MANAGER_NODES_SETTING.getKey(), nodeName)
             .put(FeatureFlags.TELEMETRY_SETTING.getKey(), true)
             .put(TelemetrySettings.TRACER_ENABLED_SETTING.getKey(), true)
+            .put(TelemetrySettings.TRACER_FEATURE_ENABLED_SETTING.getKey(), true)
             .put(nodeSettings()) // allow test cases to provide their own settings or override these
             .put(featureFlagSettings);
         if (FeatureFlags.CONCURRENT_SEGMENT_SEARCH_SETTING.get(featureFlagSettings)) {
@@ -271,6 +272,7 @@ private Node newNode() {
             plugins.add(MockHttpTransport.TestPlugin.class);
         }
         plugins.add(MockScriptService.TestPlugin.class);
+
         plugins.add(MockTelemetryPlugin.class);
         Node node = new MockNode(settingsBuilder.build(), plugins, forbidPrivateIndexSettings());
         try {
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java
index 8490ee4fc39bc..b5ff30deecf5c 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java
@@ -175,6 +175,8 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import reactor.core.scheduler.Schedulers;
+
 import static java.util.Collections.emptyMap;
 import static org.opensearch.core.common.util.CollectionUtils.arrayAsArrayList;
 import static org.hamcrest.Matchers.empty;
@@ -225,6 +227,7 @@ public static void resetPortCounter() {
 
     @Override
     public void tearDown() throws Exception {
+        Schedulers.shutdownNow();
         FeatureFlagSetter.clear();
         super.tearDown();
     }
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchTokenStreamTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchTokenStreamTestCase.java
index e853c1e6314e1..9f7f33b351be3 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchTokenStreamTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchTokenStreamTestCase.java
@@ -48,9 +48,9 @@
 @TimeoutSuite(millis = TimeUnits.HOUR)
 @LuceneTestCase.SuppressReproduceLine
 @LuceneTestCase.SuppressSysoutChecks(bugUrl = "we log a lot on purpose")
-/**
- * Basic test case for token streams. the assertion methods in this class will
- * run basic checks to enforce correct behavior of the token streams.
+/*
+  Basic test case for token streams. the assertion methods in this class will
+  run basic checks to enforce correct behavior of the token streams.
  */
 public abstract class OpenSearchTokenStreamTestCase extends BaseTokenStreamTestCase {
 
diff --git a/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java b/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java
index 636064d8e4f9d..edda6bf5603f7 100644
--- a/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java
@@ -13,6 +13,8 @@
 import org.junit.After;
 import org.junit.Before;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
+
 /**
  * Base class for running the tests with parameterization of the dynamic settings
  * For any class that wants to use parameterization, use @ParametersFactory to generate
@@ -44,4 +46,11 @@ public void afterTests() {
         dynamicSettings.keySet().forEach(settingsToUnset::putNull);
         client().admin().cluster().prepareUpdateSettings().setPersistentSettings(settingsToUnset).get();
     }
+
+    // This method shouldn't be called in setupSuiteScopeCluster(). Only call this method inside single test.
+    public void indexRandomForConcurrentSearch(String... indices) throws InterruptedException {
+        if (dynamicSettings.get(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey()).equals("true")) {
+            indexRandomForMultipleSlices(indices);
+        }
+    }
 }
diff --git a/test/framework/src/main/java/org/opensearch/test/TestCluster.java b/test/framework/src/main/java/org/opensearch/test/TestCluster.java
index 61742cd4fb827..8c41e6e5d5b38 100644
--- a/test/framework/src/main/java/org/opensearch/test/TestCluster.java
+++ b/test/framework/src/main/java/org/opensearch/test/TestCluster.java
@@ -42,10 +42,12 @@
 import org.opensearch.client.Client;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.IndexTemplateMetadata;
+import org.opensearch.cluster.metadata.RepositoryMetadata;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.indices.IndexTemplateMissingException;
 import org.opensearch.repositories.RepositoryMissingException;
+import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.test.hamcrest.OpenSearchAssertions;
 
 import java.io.Closeable;
@@ -253,7 +255,18 @@ public void wipeRepositories(String... repositories) {
             }
             for (String repository : repositories) {
                 try {
-                    client().admin().cluster().prepareDeleteRepository(repository).execute().actionGet();
+                    List<RepositoryMetadata> repositoryMetadata = client().admin()
+                        .cluster()
+                        .prepareGetRepositories(repository)
+                        .execute()
+                        .actionGet()
+                        .repositories();
+                    if (repositoryMetadata.isEmpty() == false
+                        && BlobStoreRepository.SYSTEM_REPOSITORY_SETTING.get(repositoryMetadata.get(0).settings()) == true) {
+                        client().admin().cluster().prepareCleanupRepository(repository).execute().actionGet();
+                    } else {
+                        client().admin().cluster().prepareDeleteRepository(repository).execute().actionGet();
+                    }
                 } catch (RepositoryMissingException ex) {
                     // ignore
                 }
@@ -263,7 +276,7 @@ public void wipeRepositories(String... repositories) {
 
     /**
      * Ensures that any breaker statistics are reset to 0.
-     *
+     * <p>
      * The implementation is specific to the test cluster, because the act of
      * checking some breaker stats can increase them.
      */
diff --git a/test/framework/src/main/java/org/opensearch/test/XContentTestUtils.java b/test/framework/src/main/java/org/opensearch/test/XContentTestUtils.java
index 0cb39a29e8159..2c535211ca456 100644
--- a/test/framework/src/main/java/org/opensearch/test/XContentTestUtils.java
+++ b/test/framework/src/main/java/org/opensearch/test/XContentTestUtils.java
@@ -164,10 +164,10 @@ private static String differenceBetweenObjectsIgnoringArrayOrder(String path, Ob
      * This method takes the input xContent data and adds a random field value, inner object or array into each
      * json object. This can e.g. be used to test if parsers that handle the resulting xContent can handle the
      * augmented xContent correctly, for example when testing lenient parsing.
-     *
+     * <p>
      * If the xContent output contains objects that should be skipped of such treatment, an optional filtering
      * {@link Predicate} can be supplied that checks xContent paths that should be excluded from this treatment.
-     *
+     * <p>
      * This predicate should check the xContent path that we want to insert to and return {@code true} if the
      * path should be excluded. Paths are string concatenating field names and array indices, so e.g. in:
      *
@@ -188,7 +188,7 @@ private static String differenceBetweenObjectsIgnoringArrayOrder(String path, Ob
      * </pre>
      *
      * "foo1.bar.2.baz" would point to the desired insert location.
-     *
+     * <p>
      * To exclude inserting into the "foo1" object we would user a {@link Predicate} like
      * <pre>
      * {@code
@@ -257,12 +257,12 @@ public static BytesReference insertRandomFields(
      * This utility method takes an XContentParser and walks the xContent structure to find all
      * possible paths to where a new object or array starts. This can be used in tests that add random
      * xContent values to test parsing code for errors or to check their robustness against new fields.
-     *
+     * <p>
      * The path uses dot separated fieldnames and numbers for array indices, similar to what we do in
      * {@link ObjectPath}.
-     *
+     * <p>
      * The {@link Stack} passed in should initially be empty, it gets pushed to by recursive calls
-     *
+     * <p>
      * As an example, the following json xContent:
      * <pre>
      *     {
diff --git a/test/framework/src/main/java/org/opensearch/test/client/NoOpClient.java b/test/framework/src/main/java/org/opensearch/test/client/NoOpClient.java
index a0e87d5fd7189..45d779b3e8697 100644
--- a/test/framework/src/main/java/org/opensearch/test/client/NoOpClient.java
+++ b/test/framework/src/main/java/org/opensearch/test/client/NoOpClient.java
@@ -47,7 +47,7 @@
 /**
  * Client that always responds with {@code null} to every request. Override {@link #doExecute(ActionType, ActionRequest, ActionListener)}
  * for testing.
- *
+ * <p>
  * See also {@link NoOpNodeClient} if you need to mock a {@link org.opensearch.client.node.NodeClient}.
  */
 public class NoOpClient extends AbstractClient {
diff --git a/test/framework/src/main/java/org/opensearch/test/client/NoOpNodeClient.java b/test/framework/src/main/java/org/opensearch/test/client/NoOpNodeClient.java
index 7dfe9298e9a92..4e84fe3b91d15 100644
--- a/test/framework/src/main/java/org/opensearch/test/client/NoOpNodeClient.java
+++ b/test/framework/src/main/java/org/opensearch/test/client/NoOpNodeClient.java
@@ -55,7 +55,7 @@
  * Client that always response with {@code null} to every request. Override {@link #doExecute(ActionType, ActionRequest, ActionListener)},
  * {@link #executeLocally(ActionType, ActionRequest, ActionListener)}, or {@link #executeLocally(ActionType, ActionRequest, TaskListener)}
  * for testing.
- *
+ * <p>
  * See also {@link NoOpClient} if you do not specifically need a {@link NodeClient}.
  */
 public class NoOpNodeClient extends NodeClient {
diff --git a/test/framework/src/main/java/org/opensearch/test/disruption/LongGCDisruption.java b/test/framework/src/main/java/org/opensearch/test/disruption/LongGCDisruption.java
index 690e15dd80873..44837c37962b4 100644
--- a/test/framework/src/main/java/org/opensearch/test/disruption/LongGCDisruption.java
+++ b/test/framework/src/main/java/org/opensearch/test/disruption/LongGCDisruption.java
@@ -248,7 +248,7 @@ public TimeValue expectedTimeToHeal() {
     /**
      * resolves all threads belonging to given node and suspends them if their current stack trace
      * is "safe". Threads are added to nodeThreads if suspended.
-     *
+     * <p>
      * returns true if some live threads were found. The caller is expected to call this method
      * until no more "live" are found.
      */
diff --git a/test/framework/src/main/java/org/opensearch/test/disruption/NetworkDisruption.java b/test/framework/src/main/java/org/opensearch/test/disruption/NetworkDisruption.java
index e77b8f5b24897..62e19750a363b 100644
--- a/test/framework/src/main/java/org/opensearch/test/disruption/NetworkDisruption.java
+++ b/test/framework/src/main/java/org/opensearch/test/disruption/NetworkDisruption.java
@@ -109,7 +109,7 @@ public void ensureHealthy(InternalTestCluster cluster) {
 
     /**
      * Ensures that all nodes in the cluster are connected to each other.
-     *
+     * <p>
      * Some network disruptions may leave nodes that are not the cluster-manager disconnected from each other.
      * {@link org.opensearch.cluster.NodeConnectionsService} will eventually reconnect but it's
      * handy to be able to ensure this happens faster
diff --git a/test/framework/src/main/java/org/opensearch/test/gateway/TestGatewayAllocator.java b/test/framework/src/main/java/org/opensearch/test/gateway/TestGatewayAllocator.java
index 107e42ce43487..7462062a0cd46 100644
--- a/test/framework/src/main/java/org/opensearch/test/gateway/TestGatewayAllocator.java
+++ b/test/framework/src/main/java/org/opensearch/test/gateway/TestGatewayAllocator.java
@@ -57,13 +57,13 @@
  * A gateway allocator implementation that keeps an in memory list of started shard allocation
  * that are used as replies to the, normally async, fetch data requests. The in memory list
  * is adapted when shards are started and failed.
- *
+ * <p>
  * Nodes leaving and joining the cluster do not change the list of shards the class tracks but
  * rather serves as a filter to what is returned by fetch data. Concretely - fetch data will
  * only return shards that were started on nodes that are currently part of the cluster.
- *
+ * <p>
  * For now only primary shard related data is fetched. Replica request always get an empty response.
- *
+ * <p>
  *
  * This class is useful to use in unit tests that require the functionality of {@link GatewayAllocator} but do
  * not have all the infrastructure required to use it.
diff --git a/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestIssueLogging.java b/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestIssueLogging.java
index f81c47b6a0a08..97fdcb796f195 100644
--- a/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestIssueLogging.java
+++ b/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestIssueLogging.java
@@ -43,7 +43,7 @@
 /**
  * Annotation used to set a custom log level when investigating test failures. Do not use this annotation to explicitly
  * control the logging level in tests; instead, use {@link TestLogging}.
- *
+ * <p>
  * It supports multiple logger:level comma-separated key-value pairs of logger:level (e.g.,
  * org.opensearch.cluster.metadata:TRACE). Use the _root keyword to set the root logger level.
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestLogging.java b/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestLogging.java
index d440fae409897..6c0b87ac67354 100644
--- a/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestLogging.java
+++ b/test/framework/src/main/java/org/opensearch/test/junit/annotations/TestLogging.java
@@ -43,7 +43,7 @@
 /**
  * Annotation used to set a custom log level for controlling logging behavior in tests. Do not use this annotation when
  * investigating test failures; instead, use {@link TestIssueLogging}.
- *
+ * <p>
  * It supports multiple logger:level comma-separated key-value pairs of logger:level (e.g.,
  * org.opensearch.cluster.metadata:TRACE). Use the _root keyword to set the root logger level.
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/junit/listeners/LoggingListener.java b/test/framework/src/main/java/org/opensearch/test/junit/listeners/LoggingListener.java
index 7c94c16b77471..ea2c5d055ed8b 100644
--- a/test/framework/src/main/java/org/opensearch/test/junit/listeners/LoggingListener.java
+++ b/test/framework/src/main/java/org/opensearch/test/junit/listeners/LoggingListener.java
@@ -53,7 +53,7 @@
  * A {@link RunListener} that allows changing the log level for a specific test method. When a test method is annotated with the
  * {@link TestLogging} annotation, the level for the specified loggers will be internally saved before the test method execution and
  * overridden with the specified ones. At the end of the test method execution the original loggers levels will be restored.
- *
+ * <p>
  * This class is not thread-safe. Given the static nature of the logging API, it assumes that tests are never run concurrently in the same
  * JVM. For the very same reason no synchronization has been implemented regarding the save/restore process of the original loggers
  * levels.
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/RestActionTestCase.java b/test/framework/src/main/java/org/opensearch/test/rest/RestActionTestCase.java
index dc13924195254..a77865579f3b3 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/RestActionTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/RestActionTestCase.java
@@ -103,7 +103,7 @@ protected void dispatchRequest(RestRequest request) {
     /**
      * A mocked {@link NodeClient} which can be easily reconfigured to verify arbitrary verification
      * functions, and can be reset to allow reconfiguration partway through a test without having to construct a new object.
-     *
+     * <p>
      * By default, will throw {@link AssertionError} when any execution method is called, unless configured otherwise using
      * {@link #setExecuteVerifier(BiFunction)} or {@link #setExecuteLocallyVerifier(BiFunction)}.
      */
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/DenylistedPathPatternMatcher.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/DenylistedPathPatternMatcher.java
index eeaa76b6ca1b3..3a80f25c5d4ab 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/DenylistedPathPatternMatcher.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/DenylistedPathPatternMatcher.java
@@ -35,7 +35,7 @@
 
 /**
  * Matches denylist patterns.
- *
+ * <p>
  * Currently the following syntax is supported:
  *
  * <ul>
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/Features.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/Features.java
index 10fb1e52259a9..8e0bc03b08442 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/Features.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/Features.java
@@ -41,7 +41,7 @@
  * Allows to register additional features supported by the tests runner.
  * This way any runner can add extra features and use proper skip sections to avoid
  * breaking others runners till they have implemented the new feature as well.
- *
+ * <p>
  * Once all runners have implemented the feature, it can be removed from the list
  * and the related skip sections can be removed from the tests as well.
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/OpenSearchClientYamlSuiteTestCase.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/OpenSearchClientYamlSuiteTestCase.java
index c3289e7651056..12599f003077d 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/OpenSearchClientYamlSuiteTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/OpenSearchClientYamlSuiteTestCase.java
@@ -78,7 +78,7 @@
 /**
  * Runs a suite of yaml tests shared with all the official OpenSearch
  * clients against an opensearch cluster.
- *
+ * <p>
  * The suite timeout is extended to account for projects with a large number of tests.
  */
 @TimeoutSuite(millis = 30 * TimeUnits.MINUTE)
@@ -110,9 +110,9 @@ public abstract class OpenSearchClientYamlSuiteTestCase extends OpenSearchRestTe
     /**
      * This separator pattern matches ',' except it is preceded by a '\'.
      * This allows us to support ',' within paths when it is escaped with a slash.
-     *
+     * <p>
      * For example, the path string "/a/b/c\,d/e/f,/foo/bar,/baz" is separated to "/a/b/c\,d/e/f", "/foo/bar" and "/baz".
-     *
+     * <p>
      * For reference, this regular expression feature is known as zero-width negative look-behind.
      *
      */
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/DoSection.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/DoSection.java
index ef8bf37d88227..ae1c33b1eb47f 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/DoSection.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/DoSection.java
@@ -81,7 +81,7 @@
 
 /**
  * Represents a do section:
- *
+ * <p>
  *   - do:
  *      catch:      missing
  *      headers:
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/GreaterThanEqualToAssertion.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/GreaterThanEqualToAssertion.java
index 2132c2ebab51c..8e929eff44348 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/GreaterThanEqualToAssertion.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/GreaterThanEqualToAssertion.java
@@ -47,7 +47,7 @@
 
 /**
  * Represents a gte assert section:
- *
+ * <p>
  *   - gte:     { fields._ttl: 0 }
  */
 public class GreaterThanEqualToAssertion extends Assertion {
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsFalseAssertion.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsFalseAssertion.java
index 6cfbbfc5df8d5..999486ad04455 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsFalseAssertion.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsFalseAssertion.java
@@ -45,7 +45,7 @@
 
 /**
  * Represents an is_false assert section:
- *
+ * <p>
  *   - is_false:  get.fields.bar
  *
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsTrueAssertion.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsTrueAssertion.java
index e746542d89126..bf5822406f014 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsTrueAssertion.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/IsTrueAssertion.java
@@ -46,7 +46,7 @@
 
 /**
  * Represents an is_true assert section:
- *
+ * <p>
  *   - is_true:  get.fields.bar
  *
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanAssertion.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanAssertion.java
index 263e0c8fb9c42..d6e2ae1e23996 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanAssertion.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanAssertion.java
@@ -46,7 +46,7 @@
 
 /**
  * Represents a lt assert section:
- *
+ * <p>
  *  - lt:    { fields._ttl: 20000}
  *
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanOrEqualToAssertion.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanOrEqualToAssertion.java
index f0e7d0c01b8f0..ee46c04496f32 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanOrEqualToAssertion.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/LessThanOrEqualToAssertion.java
@@ -47,7 +47,7 @@
 
 /**
  * Represents a lte assert section:
- *
+ * <p>
  *   - lte:     { fields._ttl: 0 }
  */
 public class LessThanOrEqualToAssertion extends Assertion {
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/MatchAssertion.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/MatchAssertion.java
index a97e3e4cb77ed..77d8f3154729e 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/MatchAssertion.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/MatchAssertion.java
@@ -50,7 +50,7 @@
 
 /**
  * Represents a match assert section:
- *
+ * <p>
  *   - match:   { get.fields._routing: "5" }
  *
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/SetSection.java b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/SetSection.java
index a561a53119a96..c8004d9807cb9 100644
--- a/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/SetSection.java
+++ b/test/framework/src/main/java/org/opensearch/test/rest/yaml/section/SetSection.java
@@ -42,7 +42,7 @@
 
 /**
  * Represents a set section:
- *
+ * <p>
  *   - set: {_scroll_id: scroll_id}
  *
  */
diff --git a/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetry.java b/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetry.java
index 6b428a7f65594..dda413ce2818e 100644
--- a/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetry.java
+++ b/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetry.java
@@ -10,7 +10,9 @@
 
 import org.opensearch.telemetry.Telemetry;
 import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.Counter;
 import org.opensearch.telemetry.metrics.MetricsTelemetry;
+import org.opensearch.telemetry.metrics.noop.NoopCounter;
 import org.opensearch.telemetry.tracing.TracingTelemetry;
 import org.opensearch.test.telemetry.tracing.MockTracingTelemetry;
 
@@ -34,6 +36,20 @@ public TracingTelemetry getTracingTelemetry() {
     @Override
     public MetricsTelemetry getMetricsTelemetry() {
         return new MetricsTelemetry() {
+            @Override
+            public Counter createCounter(String name, String description, String unit) {
+                return NoopCounter.INSTANCE;
+            }
+
+            @Override
+            public Counter createUpDownCounter(String name, String description, String unit) {
+                return NoopCounter.INSTANCE;
+            }
+
+            @Override
+            public void close() {
+
+            }
         };
     }
 }
diff --git a/test/framework/src/main/java/org/opensearch/test/transport/MockTransportService.java b/test/framework/src/main/java/org/opensearch/test/transport/MockTransportService.java
index c1795e61096ac..6bf5381b62cc9 100644
--- a/test/framework/src/main/java/org/opensearch/test/transport/MockTransportService.java
+++ b/test/framework/src/main/java/org/opensearch/test/transport/MockTransportService.java
@@ -58,6 +58,7 @@
 import org.opensearch.plugins.Plugin;
 import org.opensearch.tasks.TaskManager;
 import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.test.tasks.MockTaskManager;
 import org.opensearch.threadpool.ThreadPool;
@@ -140,7 +141,8 @@ public static MockNioTransport newMockTransport(Settings settings, Version versi
             new NetworkService(Collections.emptyList()),
             new MockPageCacheRecycler(settings),
             namedWriteableRegistry,
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         );
     }
 
diff --git a/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransport.java b/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransport.java
index 5795f860efa7e..cd6bf02efef6f 100644
--- a/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransport.java
+++ b/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransport.java
@@ -65,6 +65,7 @@
 import org.opensearch.nio.NioSocketChannel;
 import org.opensearch.nio.Page;
 import org.opensearch.nio.ServerChannelContext;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.ConnectionProfile;
 import org.opensearch.transport.InboundPipeline;
@@ -110,9 +111,10 @@ public MockNioTransport(
         NetworkService networkService,
         PageCacheRecycler pageCacheRecycler,
         NamedWriteableRegistry namedWriteableRegistry,
-        CircuitBreakerService circuitBreakerService
+        CircuitBreakerService circuitBreakerService,
+        Tracer tracer
     ) {
-        super(settings, version, threadPool, pageCacheRecycler, circuitBreakerService, namedWriteableRegistry, networkService);
+        super(settings, version, threadPool, pageCacheRecycler, circuitBreakerService, namedWriteableRegistry, networkService, tracer);
         this.transportThreadWatchdog = new TransportThreadWatchdog(threadPool, settings);
     }
 
diff --git a/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransportPlugin.java b/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransportPlugin.java
index a596bdd5e419f..deb489614be26 100644
--- a/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransportPlugin.java
+++ b/test/framework/src/main/java/org/opensearch/transport/nio/MockNioTransportPlugin.java
@@ -39,6 +39,7 @@
 import org.opensearch.core.indices.breaker.CircuitBreakerService;
 import org.opensearch.plugins.NetworkPlugin;
 import org.opensearch.plugins.Plugin;
+import org.opensearch.telemetry.tracing.Tracer;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.Transport;
 
@@ -57,7 +58,8 @@ public Map<String, Supplier<Transport>> getTransports(
         PageCacheRecycler pageCacheRecycler,
         CircuitBreakerService circuitBreakerService,
         NamedWriteableRegistry namedWriteableRegistry,
-        NetworkService networkService
+        NetworkService networkService,
+        Tracer tracer
     ) {
         return Collections.singletonMap(
             MOCK_NIO_TRANSPORT_NAME,
@@ -68,7 +70,8 @@ public Map<String, Supplier<Transport>> getTransports(
                 networkService,
                 pageCacheRecycler,
                 namedWriteableRegistry,
-                circuitBreakerService
+                circuitBreakerService,
+                tracer
             )
         );
     }
diff --git a/test/framework/src/test/java/org/opensearch/transport/nio/SimpleMockNioTransportTests.java b/test/framework/src/test/java/org/opensearch/transport/nio/SimpleMockNioTransportTests.java
index fb77161a02aef..ce401ad99fad7 100644
--- a/test/framework/src/test/java/org/opensearch/transport/nio/SimpleMockNioTransportTests.java
+++ b/test/framework/src/test/java/org/opensearch/transport/nio/SimpleMockNioTransportTests.java
@@ -42,6 +42,7 @@
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
 import org.opensearch.transport.AbstractSimpleTransportTestCase;
 import org.opensearch.transport.ConnectTransportException;
 import org.opensearch.transport.ConnectionProfile;
@@ -71,7 +72,8 @@ protected Transport build(Settings settings, final Version version, ClusterSetti
             networkService,
             new MockPageCacheRecycler(settings),
             namedWriteableRegistry,
-            new NoneCircuitBreakerService()
+            new NoneCircuitBreakerService(),
+            NoopTracer.INSTANCE
         ) {
 
             @Override
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockSpan.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockSpan.java
index 694a6a2b9e45b..c5d179f6412a8 100644
--- a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockSpan.java
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockSpan.java
@@ -10,6 +10,8 @@
 
 import org.opensearch.telemetry.tracing.AbstractSpan;
 import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanCreationContext;
+import org.opensearch.telemetry.tracing.SpanKind;
 import org.opensearch.telemetry.tracing.attributes.Attributes;
 
 import java.util.HashMap;
@@ -29,6 +31,7 @@ public class MockSpan extends AbstractSpan {
     private boolean hasEnded;
     private final Long startTime;
     private Long endTime;
+    private final SpanKind spanKind;
 
     private final Object lock = new Object();
 
@@ -36,49 +39,43 @@ public class MockSpan extends AbstractSpan {
 
     /**
      * Base Constructor.
-     * @param spanName  Span Name
-     * @param parentSpan  Parent Span
-     * @param spanProcessor  Span Processor
-     * @param attributes attributes
+     *
+     * @param spanCreationContext      Span Creation context.
+     * @param parentSpan    Parent Span
+     * @param spanProcessor Span Processor
      */
-    public MockSpan(String spanName, Span parentSpan, SpanProcessor spanProcessor, Attributes attributes) {
+    public MockSpan(SpanCreationContext spanCreationContext, Span parentSpan, SpanProcessor spanProcessor) {
         this(
-            spanName,
+            spanCreationContext.getSpanName(),
             parentSpan,
             parentSpan != null ? parentSpan.getTraceId() : IdGenerator.generateTraceId(),
             IdGenerator.generateSpanId(),
             spanProcessor,
-            attributes
-        );
-    }
-
-    /**
-     * Constructor.
-     * @param spanName span name.
-     * @param parentSpan parent span name
-     * @param spanProcessor span processor.
-     */
-    public MockSpan(String spanName, Span parentSpan, SpanProcessor spanProcessor) {
-        this(
-            spanName,
-            parentSpan,
-            parentSpan != null ? parentSpan.getTraceId() : IdGenerator.generateTraceId(),
-            IdGenerator.generateSpanId(),
-            spanProcessor,
-            Attributes.EMPTY
+            spanCreationContext.getAttributes(),
+            SpanKind.INTERNAL
         );
     }
 
     /**
      * Constructor with traceId and SpanIds
-     * @param spanName  Span Name
-     * @param parentSpan  Parent Span
-     * @param traceId  Trace ID
-     * @param spanId  Span ID
-     * @param spanProcessor  Span Processor
-     * @param attributes attributes
+     *
+     * @param spanName      Span Name
+     * @param parentSpan    Parent Span
+     * @param traceId       Trace ID
+     * @param spanId        Span ID
+     * @param spanProcessor Span Processor
+     * @param attributes    attributes
+     * @param spanKind      type of span.
      */
-    public MockSpan(String spanName, Span parentSpan, String traceId, String spanId, SpanProcessor spanProcessor, Attributes attributes) {
+    public MockSpan(
+        String spanName,
+        Span parentSpan,
+        String traceId,
+        String spanId,
+        SpanProcessor spanProcessor,
+        Attributes attributes,
+        SpanKind spanKind
+    ) {
         super(spanName, parentSpan);
         this.spanProcessor = spanProcessor;
         this.metadata = new HashMap<>();
@@ -88,6 +85,7 @@ public MockSpan(String spanName, Span parentSpan, String traceId, String spanId,
         if (attributes != null) {
             this.metadata.putAll(attributes.getAttributesMap());
         }
+        this.spanKind = spanKind;
     }
 
     @Override
@@ -168,7 +166,9 @@ public Long getEndTime() {
     }
 
     public void setError(Exception exception) {
-        putMetadata("ERROR", exception.getMessage());
+        if (exception != null) {
+            putMetadata("ERROR", exception.getMessage());
+        }
     }
 
     private static class IdGenerator {
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingContextPropagator.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingContextPropagator.java
index 7525b4424c243..4c58352531ca8 100644
--- a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingContextPropagator.java
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingContextPropagator.java
@@ -10,10 +10,11 @@
 
 import org.opensearch.core.common.Strings;
 import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanKind;
 import org.opensearch.telemetry.tracing.TracingContextPropagator;
 import org.opensearch.telemetry.tracing.attributes.Attributes;
 
-import java.util.List;
+import java.util.Collection;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Optional;
@@ -44,14 +45,14 @@ public Optional<Span> extract(Map<String, String> props) {
             String[] values = value.split(SEPARATOR);
             String traceId = values[0];
             String spanId = values[1];
-            return Optional.of(new MockSpan(null, null, traceId, spanId, spanProcessor, Attributes.EMPTY));
+            return Optional.of(new MockSpan(null, null, traceId, spanId, spanProcessor, Attributes.EMPTY, SpanKind.INTERNAL));
         } else {
             return Optional.empty();
         }
     }
 
     @Override
-    public Optional<Span> extractFromHeaders(Map<String, List<String>> headers) {
+    public Optional<Span> extractFromHeaders(Map<String, Collection<String>> headers) {
         if (headers != null) {
             Map<String, String> convertedHeader = headers.entrySet()
                 .stream()
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingTelemetry.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingTelemetry.java
index c7f5943719230..39817a208bd18 100644
--- a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingTelemetry.java
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingTelemetry.java
@@ -9,9 +9,9 @@
 package org.opensearch.test.telemetry.tracing;
 
 import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.SpanCreationContext;
 import org.opensearch.telemetry.tracing.TracingContextPropagator;
 import org.opensearch.telemetry.tracing.TracingTelemetry;
-import org.opensearch.telemetry.tracing.attributes.Attributes;
 
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -29,8 +29,8 @@ public class MockTracingTelemetry implements TracingTelemetry {
     public MockTracingTelemetry() {}
 
     @Override
-    public Span createSpan(String spanName, Span parentSpan, Attributes attributes) {
-        Span span = new MockSpan(spanName, parentSpan, spanProcessor, attributes);
+    public Span createSpan(SpanCreationContext spanCreationContext, Span parentSpan) {
+        Span span = new MockSpan(spanCreationContext, parentSpan, spanProcessor);
         if (shutdown.get() == false) {
             spanProcessor.onStart(span);
         }
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/TelemetryValidators.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/TelemetryValidators.java
index 8d8c18fb9ef6b..9b5d84954908b 100644
--- a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/TelemetryValidators.java
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/TelemetryValidators.java
@@ -49,7 +49,7 @@ private String printProblematicSpansMap(Map<String, List<MockSpanData>> spanMap)
         StringBuilder sb = new StringBuilder();
         for (var entry : spanMap.entrySet()) {
             sb.append("SpanData validation failed for validator " + entry.getKey());
-            sb.append("/n");
+            sb.append("\n");
             for (MockSpanData span : entry.getValue()) {
                 sb.append(span.toString());
             }
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/validators/NumberOfTraceIDsEqualToRequests.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/validators/NumberOfTraceIDsEqualToRequests.java
index 5fe268a8f0581..045d3a85e21e7 100644
--- a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/validators/NumberOfTraceIDsEqualToRequests.java
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/validators/NumberOfTraceIDsEqualToRequests.java
@@ -13,9 +13,9 @@
 import org.opensearch.test.telemetry.tracing.TracingValidator;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
-import java.util.Set;
 import java.util.stream.Collectors;
 
 /**
@@ -41,13 +41,10 @@ public NumberOfTraceIDsEqualToRequests(Attributes attributes) {
      */
     @Override
     public List<MockSpanData> validate(List<MockSpanData> spans, int requests) {
-        Set<String> totalTraceIDs = spans.stream()
-            .filter(span -> isMatchingSpan(span))
-            .map(MockSpanData::getTraceID)
-            .collect(Collectors.toSet());
+        final Collection<MockSpanData> totalTraceIDs = spans.stream().filter(span -> isMatchingSpan(span)).collect(Collectors.toList());
         List<MockSpanData> problematicSpans = new ArrayList<>();
-        if (totalTraceIDs.size() != requests) {
-            problematicSpans.addAll(spans);
+        if (totalTraceIDs.stream().map(MockSpanData::getTraceID).distinct().count() != requests) {
+            problematicSpans.addAll(totalTraceIDs);
         }
         return problematicSpans;
     }