VDiff: Add some stats

codecov.yml

@@ -44,7 +44,10 @@ comment: # https://docs.codecov.com/docs/pull-request-comments
 
 coverage:
   status: # https://docs.codecov.com/docs/commit-status
+    patch:
+      default:
+        informational: true # Don't ever fail the codecov/patch test
     project:
       default:
-        informational: true # Don't ever fail the codecov/project or codecov/patch tests
+        informational: true # Don't ever fail the codecov/project test
 

go/test/endtoend/vreplication/vdiff2_test.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"math"
 	"runtime"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -31,6 +32,7 @@ import (
 	"google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/proto"
 
+	"vitess.io/vitess/go/test/endtoend/cluster"
 	"vitess.io/vitess/go/vt/log"
 	"vitess.io/vitess/go/vt/sqlparser"
 	"vitess.io/vitess/go/vt/vttablet"
@@ -56,6 +58,7 @@ type testCase struct {
 	testCLICreateWait   bool // test CLI create and wait until done against this workflow (only needs to be done once)
 	testCLIFlagHandling bool // test vtctldclient flag handling from end-to-end
 	extraVDiffFlags     map[string]string
+	vdiffCount          int64 // Keep track of the number of vdiffs created to test the stats
 }
 
 const (
@@ -119,6 +122,14 @@ var testCases = []*testCase{
 	},
 }
 
+func checkVDiffCountStat(t *testing.T, tablet *cluster.VttabletProcess, expectedCount int64) {
+	countStr, err := getDebugVar(t, tablet.Port, []string{"VDiffCount"})
+	require.NoError(t, err, "failed to get VDiffCount stat from %s-%d tablet: %v", tablet.Cell, tablet.TabletUID, err)
+	count, err := strconv.Atoi(countStr)
+	require.NoError(t, err, "failed to convert VDiffCount stat string to int: %v", err)
+	require.Equal(t, expectedCount, int64(count), "expected VDiffCount stat to be %d but got %d", expectedCount, count)
+}
+
 func TestVDiff2(t *testing.T) {
 	cellNames := "zone5,zone1,zone2,zone3,zone4"
 	sourceKs := "product"
@@ -172,6 +183,21 @@ func TestVDiff2(t *testing.T) {
 			testWorkflow(t, vc, tc, tks, []*Cell{zone3, zone2, zone1})
 		})
 	}
+
+	statsTablet := vc.getPrimaryTablet(t, targetKs, targetShards[0])
+
+	// We diffed X rows so confirm that the global total is > 0.
+	countStr, err := getDebugVar(t, statsTablet.Port, []string{"VDiffRowsComparedTotal"})
+	require.NoError(t, err, "failed to get VDiffRowsComparedTotal stat from %s-%d tablet: %v", statsTablet.Cell, statsTablet.TabletUID, err)
+	count, err := strconv.Atoi(countStr)
+	require.NoError(t, err, "failed to convert VDiffRowsComparedTotal stat string to int: %v", err)
+	require.Greater(t, count, 0, "expected VDiffRowsComparedTotal stat to be greater than 0 but got %d", count)
+
+	// The VDiffs should all be cleaned up so the VDiffRowsCompared value, which
+	// is produced from controller info, should be empty.
+	vdrc, err := getDebugVar(t, statsTablet.Port, []string{"VDiffRowsCompared"})
+	require.NoError(t, err, "failed to get VDiffRowsCompared stat from %s-%d tablet: %v", statsTablet.Cell, statsTablet.TabletUID, err)
+	require.Equal(t, "{}", vdrc, "expected VDiffRowsCompared stat to be empty but got %s", vdrc)
 }
 
 func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, tks *Keyspace, cells []*Cell) {
@@ -183,6 +209,8 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, tks *Keyspace,
 
 	}
 	ksWorkflow := fmt.Sprintf("%s.%s", tc.targetKs, tc.workflow)
+	statsShard := arrTargetShards[0]
+	statsTablet := vc.getPrimaryTablet(t, tc.targetKs, statsShard)
 	var args []string
 	args = append(args, tc.typ, "--")
 	args = append(args, "--source", tc.sourceKs)
@@ -251,9 +279,21 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, tks *Keyspace,
 		}
 		// Wait for the workflow to catch up again on the deletes.
 		waitForShardsToCatchup()
+		tc.vdiffCount++ // We only did vtctldclient vdiff create
 	} else {
 		vdiff(t, tc.targetKs, tc.workflow, allCellNames, true, true, nil)
+		tc.vdiffCount += 2 // We did vtctlclient AND vtctldclient vdiff create
 	}
+	checkVDiffCountStat(t, statsTablet, tc.vdiffCount)
+
+	// Confirm that the VDiffRowsCompared stat -- which is a running count of the rows
+	// compared by vdiff per table at the controller level -- works as expected.
+	vdrc, err := getDebugVar(t, statsTablet.Port, []string{"VDiffRowsCompared"})
+	require.NoError(t, err, "failed to get VDiffRowsCompared stat from %s-%d tablet: %v", statsTablet.Cell, statsTablet.TabletUID, err)
+	uuid, jsout := performVDiff2Action(t, false, ksWorkflow, allCellNames, "show", "last", false, "--verbose")
+	expect := gjson.Get(jsout, fmt.Sprintf("Reports.customer.%s", statsShard)).Int()
+	got := gjson.Get(vdrc, fmt.Sprintf("%s.%s.%s", tc.workflow, uuid, "customer")).Int()
+	require.Equal(t, expect, got, "expected VDiffRowsCompared stat to be %d, but got %d", expect, got)
 
 	if tc.autoRetryError {
 		testAutoRetryError(t, tc, allCellNames)
@@ -263,26 +303,37 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, tks *Keyspace,
 		testResume(t, tc, allCellNames)
 	}
 
+	checkVDiffCountStat(t, statsTablet, tc.vdiffCount)
+
 	// These are done here so that we have a valid workflow to test the commands against.
 	if tc.stop {
 		testStop(t, ksWorkflow, allCellNames)
+		tc.vdiffCount++ // We did either vtctlclient OR vtctldclient vdiff create
 	}
 	if tc.testCLICreateWait {
 		testCLICreateWait(t, ksWorkflow, allCellNames)
+		tc.vdiffCount++ // We did either vtctlclient OR vtctldclient vdiff create
 	}
 	if tc.testCLIErrors {
 		testCLIErrors(t, ksWorkflow, allCellNames)
 	}
 	if tc.testCLIFlagHandling {
 		testCLIFlagHandling(t, tc.targetKs, tc.workflow, cells[0])
+		tc.vdiffCount++ // We did either vtctlclient OR vtctldclient vdiff create
 	}
 
+	checkVDiffCountStat(t, statsTablet, tc.vdiffCount)
+
 	testDelete(t, ksWorkflow, allCellNames)
+	tc.vdiffCount = 0 // All vdiffs are deleted, so reset the count and check
+	checkVDiffCountStat(t, statsTablet, tc.vdiffCount)
 
 	// Create another VDiff record to confirm it gets deleted when the workflow is completed.
 	ts := time.Now()
-	uuid, _ := performVDiff2Action(t, false, ksWorkflow, allCellNames, "create", "", false)
+	uuid, _ = performVDiff2Action(t, false, ksWorkflow, allCellNames, "create", "", false)
 	waitForVDiff2ToComplete(t, false, ksWorkflow, allCellNames, uuid, ts)
+	tc.vdiffCount++
+	checkVDiffCountStat(t, statsTablet, tc.vdiffCount)
 
 	err = vc.VtctlClient.ExecuteCommand(tc.typ, "--", "SwitchTraffic", ksWorkflow)
 	require.NoError(t, err)
@@ -291,6 +342,8 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, tks *Keyspace,
 
 	// Confirm the VDiff data is deleted for the workflow.
 	testNoOrphanedData(t, tc.targetKs, tc.workflow, arrTargetShards)
+	tc.vdiffCount = 0 // All vdiffs are deleted, so reset the count and check
+	checkVDiffCountStat(t, statsTablet, tc.vdiffCount)
 }
 
 func testCLIErrors(t *testing.T, ksWorkflow, cells string) {

go/vt/vttablet/tabletmanager/vdiff/action.go

@@ -63,15 +63,23 @@
 	}
 )
 
-func (vde *Engine) PerformVDiffAction(ctx context.Context, req *tabletmanagerdatapb.VDiffRequest) (*tabletmanagerdatapb.VDiffResponse, error) {
+func (vde *Engine) PerformVDiffAction(ctx context.Context, req *tabletmanagerdatapb.VDiffRequest) (resp *tabletmanagerdatapb.VDiffResponse, err error) {
+	defer func() {
+		if err != nil {
+			globalStats.ErrorCount.Add(1)
+		}
+	}()
+	if req == nil {
+		return nil, vterrors.New(vtrpcpb.Code_INVALID_ARGUMENT, "nil vdiff request")
+	}
 	if !vde.isOpen {
 		return nil, vterrors.New(vtrpcpb.Code_UNAVAILABLE, "vdiff engine is closed")
 	}
 	if vde.cancelRetry != nil {
 		return nil, vterrors.New(vtrpcpb.Code_UNAVAILABLE, "vdiff engine is still trying to open")
 	}
 
-	resp := &tabletmanagerdatapb.VDiffResponse{
+	resp = &tabletmanagerdatapb.VDiffResponse{
 		Id:     0,
 		Output: nil,
 	}
@@ -368,6 +376,9 @@
 		}
 		controller.Stop()
 		delete(vde.controllers, controller.id)
+		globalStats.mu.Lock()
+		defer globalStats.mu.Unlock()
+		delete(globalStats.controllers, controller.id)
 	}
 
 	switch req.ActionArg {

go/vt/vttablet/tabletmanager/vdiff/action_test.go

@@ -56,8 +56,13 @@ func TestPerformVDiffAction(t *testing.T) {
 		expectQueries []queryAndResult
 		wantErr       error
 	}{
+		{
+			name:    "nil request",
+			wantErr: vterrors.New(vtrpcpb.Code_INVALID_ARGUMENT, "nil vdiff request"),
+		},
 		{
 			name:    "engine not open",
+			req:     &tabletmanagerdatapb.VDiffRequest{},
 			vde:     &Engine{isOpen: false},
 			wantErr: vterrors.New(vtrpcpb.Code_UNAVAILABLE, "vdiff engine is closed"),
 		},
@@ -208,6 +213,7 @@ func TestPerformVDiffAction(t *testing.T) {
 			},
 		},
 	}
+	errCount := int64(0)
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			if tt.preFunc != nil {
@@ -224,6 +230,9 @@ func TestPerformVDiffAction(t *testing.T) {
 				vdiffenv.dbClient.ExpectRequest(queryResult.query, queryResult.result, nil)
 			}
 			got, err := tt.vde.PerformVDiffAction(ctx, tt.req)
+			if err != nil {
+				errCount++
+			}
 			vdiffenv.dbClient.Wait()
 			if tt.wantErr != nil && !vterrors.Equals(err, tt.wantErr) {
 				t.Errorf("Engine.PerformVDiffAction() error = %v, wantErr %v", err, tt.wantErr)
@@ -239,6 +248,8 @@ func TestPerformVDiffAction(t *testing.T) {
 			// No VDiffs should be running anymore.
 			require.Equal(t, 0, len(vdiffenv.vde.controllers), "expected no controllers to be running, but found %d",
 				len(vdiffenv.vde.controllers))
+			require.Equal(t, int64(0), globalStats.numControllers(), "expected no controllers, but found %d")
 		})
+		require.Equal(t, errCount, globalStats.ErrorCount.Get(), "expected error count %d, got %d", errCount, globalStats.ErrorCount.Get())
 	}
 }

go/vt/vttablet/tabletmanager/vdiff/controller.go

@@ -27,6 +27,7 @@
 
 	"vitess.io/vitess/go/mysql/replication"
 	"vitess.io/vitess/go/sqltypes"
+	"vitess.io/vitess/go/stats"
 	"vitess.io/vitess/go/vt/binlog/binlogplayer"
 	"vitess.io/vitess/go/vt/log"
 	"vitess.io/vitess/go/vt/proto/tabletmanagerdata"
@@ -75,6 +76,11 @@
 	sourceTimeZone, targetTimeZone string // Named time zones if conversions are necessary for datetime values
 
 	externalCluster string // For Mount+Migrate
+
+	// Information used in vdiff stats/metrics.
+	Errors                *stats.CountersWithMultiLabels
+	TableDiffRowCounts    *stats.CountersWithMultiLabels
+	TableDiffPhaseTimings *stats.Timings
 }
 
 func newController(ctx context.Context, row sqltypes.RowNamedValues, dbClientFactory func() binlogplayer.DBClient,
@@ -84,16 +90,19 @@
 	id, _ := row["id"].ToInt64()
 
 	ct := &controller{
-		id:              id,
-		uuid:            row["vdiff_uuid"].ToString(),
-		workflow:        row["workflow"].ToString(),
-		dbClientFactory: dbClientFactory,
-		ts:              ts,
-		vde:             vde,
-		done:            make(chan struct{}),
-		tmc:             vde.tmClientFactory(),
-		sources:         make(map[string]*migrationSource),
-		options:         options,
+		id:                    id,
+		uuid:                  row["vdiff_uuid"].ToString(),
+		workflow:              row["workflow"].ToString(),
+		dbClientFactory:       dbClientFactory,
+		ts:                    ts,
+		vde:                   vde,
+		done:                  make(chan struct{}),
+		tmc:                   vde.tmClientFactory(),
+		sources:               make(map[string]*migrationSource),
+		options:               options,
+		Errors:                stats.NewCountersWithMultiLabels("", "", []string{"Error"}),
+		TableDiffRowCounts:    stats.NewCountersWithMultiLabels("", "", []string{"Rows"}),
+		TableDiffPhaseTimings: stats.NewTimings("", "", "", "TablePhase"),
 	}
 	ctx, ct.cancel = context.WithCancel(ctx)
 	go ct.run(ctx)

go/vt/vttablet/tabletmanager/vdiff/engine.go

@@ -26,17 +26,16 @@
 
 	"vitess.io/vitess/go/mysql/collations"
 	"vitess.io/vitess/go/mysql/sqlerror"
-	"vitess.io/vitess/go/vt/proto/tabletmanagerdata"
-	"vitess.io/vitess/go/vt/proto/topodata"
-	"vitess.io/vitess/go/vt/sqlparser"
-	"vitess.io/vitess/go/vt/vttablet/tabletmanager/vreplication"
-	"vitess.io/vitess/go/vt/vttablet/tmclient"
-
 	"vitess.io/vitess/go/sqltypes"
 	"vitess.io/vitess/go/vt/binlog/binlogplayer"
 	"vitess.io/vitess/go/vt/dbconfigs"
 	"vitess.io/vitess/go/vt/log"
+	"vitess.io/vitess/go/vt/proto/tabletmanagerdata"
+	"vitess.io/vitess/go/vt/proto/topodata"
+	"vitess.io/vitess/go/vt/sqlparser"
 	"vitess.io/vitess/go/vt/topo"
+	"vitess.io/vitess/go/vt/vttablet/tabletmanager/vreplication"
+	"vitess.io/vitess/go/vt/vttablet/tmclient"
 )
 
 type Engine struct {
@@ -159,6 +158,7 @@
 	if err := vde.initControllers(rows); err != nil {
 		return err
 	}
+	vde.updateStats()
 
 	// At this point we've fully and successfully opened so begin
 	// retrying error'd VDiffs until the engine is closed.
@@ -218,6 +218,9 @@
 			row, vde.thisTablet.Alias)
 	}
 	vde.controllers[ct.id] = ct
+	globalStats.mu.Lock()
+	defer globalStats.mu.Unlock()
+	globalStats.controllers[ct.id] = ct
 	return nil
 }
 
@@ -392,4 +395,16 @@
 		ct.Stop()
 	}
 	vde.controllers = make(map[int64]*controller)
+	vde.updateStats()
+}
+
+// updateStats must only be called while holding the engine lock.
+func (vre *Engine) updateStats() {
+	globalStats.mu.Lock()
+	defer globalStats.mu.Unlock()
+
+	globalStats.controllers = make(map[int64]*controller, len(vre.controllers))
+	for id, ct := range vre.controllers {
+		globalStats.controllers[id] = ct
+	}
 }