VDiff: properly split cell values in record when using TabletPicker

go/cmd/vtctldclient/command/vreplication/vdiff/vdiff.go

@@ -861,6 +861,7 @@ func registerVDiffCommands(root *cobra.Command) {
 	create.Flags().StringSliceVar(&createOptions.SourceCells, "source-cells", nil, "The source cell(s) to compare from; default is any available cell.")
 	create.Flags().StringSliceVar(&createOptions.TargetCells, "target-cells", nil, "The target cell(s) to compare with; default is any available cell.")
 	create.Flags().Var((*topoprotopb.TabletTypeListFlag)(&createOptions.TabletTypes), "tablet-types", "Tablet types to use on the source and target.")
+	create.Flags().BoolVar(&common.CreateOptions.TabletTypesInPreferenceOrder, "tablet-types-in-preference-order", true, "When performing source tablet selection, look for candidates in the type order as they are listed in the tablet-types flag.")
 	create.Flags().DurationVar(&createOptions.FilteredReplicationWaitTime, "filtered-replication-wait-time", 30*time.Second, "Specifies the maximum time to wait, in seconds, for replication to catch up when syncing tablet streams.")
 	create.Flags().Uint32Var(&createOptions.Limit, "limit", math.MaxUint32, "Max rows to stop comparing after.")
 	create.Flags().BoolVar(&createOptions.DebugQuery, "debug-query", false, "Adds a mysql query to the report that can be used for further debugging.")

go/test/endtoend/vreplication/vdiff2_test.go

@@ -104,23 +104,27 @@ var testCases = []*testCase{
 }
 
 func TestVDiff2(t *testing.T) {
-	allCellNames = "zone1"
-	defaultCellName := "zone1"
+	allCellNames = "zone5,zone1,zone2,zone3,zone4"
 	sourceKs := "product"
 	sourceShards := []string{"0"}
 	targetKs := "customer"
 	targetShards := []string{"-80", "80-"}
 	// This forces us to use multiple vstream packets even with small test tables
 	extraVTTabletArgs = []string{"--vstream_packet_size=1"}
 
-	vc = NewVitessCluster(t, "TestVDiff2", []string{allCellNames}, mainClusterConfig)
+	vc = NewVitessCluster(t, "TestVDiff2", strings.Split(allCellNames, ","), mainClusterConfig)
 	require.NotNil(t, vc)
-	defaultCell = vc.Cells[defaultCellName]
-	cells := []*Cell{defaultCell}
+	zone1 := vc.Cells["zone1"]
+	zone2 := vc.Cells["zone2"]
+	zone3 := vc.Cells["zone3"]
+	defaultCell = zone1
 
 	defer vc.TearDown(t)
 
-	vc.AddKeyspace(t, cells, sourceKs, strings.Join(sourceShards, ","), initialProductVSchema, initialProductSchema, 0, 0, 100, sourceKsOpts)
+	// The primary tablet is only added in the first cell.
+	// We ONLY add primary tablets in this test.
+	_, err := vc.AddKeyspace(t, []*Cell{zone2, zone1, zone3}, sourceKs, strings.Join(sourceShards, ","), initialProductVSchema, initialProductSchema, 0, 0, 100, sourceKsOpts)
+	require.NoError(t, err)
 
 	vtgate = defaultCell.Vtgates[0]
 	require.NotNil(t, vtgate)
@@ -140,23 +144,25 @@ func TestVDiff2(t *testing.T) {
 
 	generateMoreCustomers(t, sourceKs, 100)
 
-	_, err := vc.AddKeyspace(t, cells, targetKs, strings.Join(targetShards, ","), customerVSchema, customerSchema, 0, 0, 200, targetKsOpts)
+	// The primary tablet is only added in the first cell.
+	// We ONLY add primary tablets in this test.
+	tks, err := vc.AddKeyspace(t, []*Cell{zone3, zone1, zone2}, targetKs, strings.Join(targetShards, ","), customerVSchema, customerSchema, 0, 0, 200, targetKsOpts)
 	require.NoError(t, err)
 	for _, shard := range targetShards {
 		require.NoError(t, cluster.WaitForHealthyShard(vc.VtctldClient, targetKs, shard))
 	}
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			testWorkflow(t, vc, tc, cells)
+			// Primary tablets for any new shards are added in the first cell.
+			testWorkflow(t, vc, tc, tks, []*Cell{zone3, zone2, zone1})
 		})
 	}
 }
 
-func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, cells []*Cell) {
+func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, tks *Keyspace, cells []*Cell) {
 	arrTargetShards := strings.Split(tc.targetShards, ",")
 	if tc.typ == "Reshard" {
-		tks := vc.Cells[cells[0].Name].Keyspaces[tc.targetKs]
 		require.NoError(t, vc.AddShards(t, cells, tks, tc.targetShards, 0, 0, tc.tabletBaseID, targetKsOpts))
 		for _, shard := range arrTargetShards {
 			require.NoError(t, cluster.WaitForHealthyShard(vc.VtctldClient, tc.targetKs, shard))
@@ -169,6 +175,7 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, cells []*Cell)
 	if tc.typ == "Reshard" {
 		args = append(args, "--source_shards", tc.sourceShards, "--target_shards", tc.targetShards)
 	}
+	args = append(args, "--cells", allCellNames)
 	args = append(args, "--tables", tc.tables)
 	args = append(args, "Create")
 	args = append(args, ksWorkflow)
@@ -180,7 +187,7 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, cells []*Cell)
 		catchup(t, tab, tc.workflow, tc.typ)
 	}
 
-	vdiff(t, tc.targetKs, tc.workflow, cells[0].Name, true, true, nil)
+	vdiff(t, tc.targetKs, tc.workflow, allCellNames, true, true, nil)
 
 	if tc.autoRetryError {
 		testAutoRetryError(t, tc, cells[0].Name)

go/test/endtoend/vreplication/vdiff_helper_test.go

@@ -177,7 +177,11 @@ func performVDiff2Action(t *testing.T, useVtctlclient bool, ksWorkflow, cells, a
 	require.True(t, ok, "invalid keyspace.workflow value: %s", ksWorkflow)
 
 	if useVtctlclient {
-		args := []string{"VDiff", "--", "--tablet_types=primary", "--source_cell=" + cells, "--format=json"}
+		// This will always result in us using a PRIMARY tablet, which is all
+		// we start in many e2e tests, but it avoids the tablet picker logic
+		// where when you ONLY specify the PRIMARY type it then picks the
+		// shard's primary and ignores any cell settings.
+		args := []string{"VDiff", "--", "--tablet_types=in_order:primary,replica", "--source_cell=" + cells, "--format=json"}
 		if len(extraFlags) > 0 {
 			args = append(args, extraFlags...)
 		}
@@ -195,7 +199,11 @@ func performVDiff2Action(t *testing.T, useVtctlclient bool, ksWorkflow, cells, a
 	} else {
 		args := []string{"VDiff", "--target-keyspace", targetKeyspace, "--workflow", workflowName, "--format=json", action}
 		if strings.ToLower(action) == string(vdiff2.CreateAction) {
-			args = append(args, "--tablet-types=primary", "--source-cells="+cells)
+			// This will always result in us using a PRIMARY tablet, which is all
+			// we start in many e2e tests, but it avoids the tablet picker logic
+			// where when you ONLY specify the PRIMARY type it then picks the
+			// shard's primary and ignores any cell settings.
+			args = append(args, "--tablet-types=primary,replica", "--tablet-types-in-preference-order", "--source-cells="+cells)
 		}
 		if len(extraFlags) > 0 {
 			args = append(args, extraFlags...)

go/vt/vttablet/tabletmanager/vdiff/engine_test.go

@@ -19,6 +19,7 @@ package vdiff
 import (
 	"context"
 	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/google/uuid"
@@ -107,8 +108,8 @@ func TestVDiff(t *testing.T) {
 			MaxRows:        100,
 		},
 		PickerOptions: &tabletmanagerdatapb.VDiffPickerOptions{
-			SourceCell:  tstenv.Cells[0],
-			TargetCell:  tstenv.Cells[0],
+			SourceCell:  strings.Join(tstenv.Cells, ","),
+			TargetCell:  strings.Join(tstenv.Cells, ","),
 			TabletTypes: "primary",
 		},
 		ReportOptions: &tabletmanagerdatapb.VDiffReportOptions{

go/vt/vttablet/tabletmanager/vdiff/table_differ.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -120,7 +121,7 @@ func (td *tableDiffer) initialize(ctx context.Context) error {
 		}
 	}()
 
-	if err := td.selectTablets(ctx, td.wd.opts.PickerOptions.SourceCell, td.wd.opts.PickerOptions.TabletTypes); err != nil {
+	if err := td.selectTablets(ctx); err != nil {
 		return err
 	}
 	if err := td.syncSourceStreams(ctx); err != nil {
@@ -198,16 +199,22 @@ func (td *tableDiffer) forEachSource(cb func(source *migrationSource) error) err
 	return allErrors.AggrError(vterrors.Aggregate)
 }
 
-func (td *tableDiffer) selectTablets(ctx context.Context, cell, tabletTypes string) error {
-	var wg sync.WaitGroup
-	ct := td.wd.ct
-	var err1, err2 error
+func (td *tableDiffer) selectTablets(ctx context.Context) error {
+	var (
+		wg                   sync.WaitGroup
+		sourceErr, targetErr error
+		targetTablet         *topodata.Tablet
+	)
+
+	// The cells from the vdiff record are a comma separated list.
+	sourceCells := strings.Split(td.wd.opts.PickerOptions.SourceCell, ",")
+	targetCells := strings.Split(td.wd.opts.PickerOptions.TargetCell, ",")
 
 	// For Mount+Migrate, the source tablets will be in a different
 	// Vitess cluster with its own TopoServer.
-	sourceTopoServer := ct.ts
-	if ct.externalCluster != "" {
-		extTS, err := ct.ts.OpenExternalVitessClusterServer(ctx, ct.externalCluster)
+	sourceTopoServer := td.wd.ct.ts
+	if td.wd.ct.externalCluster != "" {
+		extTS, err := td.wd.ct.ts.OpenExternalVitessClusterServer(ctx, td.wd.ct.externalCluster)
 		if err != nil {
 			return err
 		}
@@ -216,39 +223,39 @@ func (td *tableDiffer) selectTablets(ctx context.Context, cell, tabletTypes stri
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
-		err1 = td.forEachSource(func(source *migrationSource) error {
-			tablet, err := pickTablet(ctx, sourceTopoServer, cell, ct.vde.thisTablet.Alias.Cell, ct.sourceKeyspace, source.shard, tabletTypes)
+		sourceErr = td.forEachSource(func(source *migrationSource) error {
+			sourceTablet, err := pickTablet(ctx, sourceTopoServer, sourceCells, td.wd.ct.vde.thisTablet.Alias.Cell, td.wd.ct.sourceKeyspace, source.shard, td.wd.opts.PickerOptions.TabletTypes)
 			if err != nil {
 				return err
 			}
-			source.tablet = tablet
+			source.tablet = sourceTablet
 			return nil
 		})
 	}()
 
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
-		tablet, err2 := pickTablet(ctx, ct.ts, td.wd.opts.PickerOptions.TargetCell, ct.vde.thisTablet.Alias.Cell, ct.vde.thisTablet.Keyspace,
-			ct.vde.thisTablet.Shard, td.wd.opts.PickerOptions.TabletTypes)
-		if err2 != nil {
+		targetTablet, targetErr = pickTablet(ctx, td.wd.ct.ts, targetCells, td.wd.ct.vde.thisTablet.Alias.Cell, td.wd.ct.vde.thisTablet.Keyspace,
+			td.wd.ct.vde.thisTablet.Shard, td.wd.opts.PickerOptions.TabletTypes)
+		if targetErr != nil {
 			return
 		}
-		ct.targetShardStreamer = &shardStreamer{
-			tablet: tablet,
-			shard:  tablet.Shard,
+		td.wd.ct.targetShardStreamer = &shardStreamer{
+			tablet: targetTablet,
+			shard:  targetTablet.Shard,
 		}
 	}()
 
 	wg.Wait()
-	if err1 != nil {
-		return err1
+	if sourceErr != nil {
+		return sourceErr
 	}
-	return err2
+	return targetErr
 }
 
-func pickTablet(ctx context.Context, ts *topo.Server, cell, localCell, keyspace, shard, tabletTypes string) (*topodata.Tablet, error) {
-	tp, err := discovery.NewTabletPicker(ctx, ts, []string{cell}, localCell, keyspace, shard, tabletTypes, discovery.TabletPickerOptions{})
+func pickTablet(ctx context.Context, ts *topo.Server, cells []string, localCell, keyspace, shard, tabletTypes string) (*topodata.Tablet, error) {
+	tp, err := discovery.NewTabletPicker(ctx, ts, cells, localCell, keyspace, shard, tabletTypes, discovery.TabletPickerOptions{})
 	if err != nil {
 		return nil, err
 	}