Reads:
- https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-replication.html
- https://www.elastic.co/blog/found-elasticsearch-top-down
- https://www.elastic.co/blog/found-elasticsearch-from-the-bottom-up
- https://blog.insightdatascience.com/anatomy-of-an-elasticsearch-cluster-part-ii-6db4e821b571
- https://medium.com/geekculture/elasticsearch-internals-4c4c9ec077fa
- https://joshua-robinson.medium.com/thawing-the-elasticsearch-frozen-tier-31a19959dfc4
Dedicated master nodes:
- Track all nodes in the cluster.
- Track the number of indexes in the cluster.
- Track the number of shards belonging to each index.
- Maintain routing information for nodes in the cluster.
- Update the cluster state after state changes, such as creating an index and adding or removing nodes in the cluster.
- Replicate changes to the cluster state across all nodes in the cluster.
- Monitor the health of all cluster nodes by sending heartbeat signals, periodic signals that monitor the availability of the data nodes in the cluster.
http://elasticsearch-cheatsheet.jolicode.com
- Index statistics. The API is only intended for human use
GET _cat/indices?h=health,status,index,id,pri,rep,docs.count,docs.deleted,store.size,creation.date.string&v=- Get unhealthy indices
GET _cat/indices?v&health=red&h=index,status,health- Show shards recovery activities
GET _cat/recovery?v&active_only=true- Explain cluster shard allocation
GET /_cluster/allocation/explain- Get setting of an index
GET <INDEX>?features=settings&flat_settings- Set max scroll
PUT _cluster/settings
{
"persistent" : {
"search.max_open_scroll_context": 2048
},
"transient": {
"search.max_open_scroll_context": 2048
}
}