vreplication: SplitClone & VerticalSplitClone

examples/local/vttablet-up.sh

@@ -38,7 +38,7 @@ source $script_root/env.sh
 
 init_db_sql_file="$VTROOT/config/init_db.sql"
 
-export  EXTRA_MY_CNF=$VTROOT/config/mycnf/default-fast.cnf
+export EXTRA_MY_CNF=$VTROOT/config/mycnf/default-fast.cnf:$VTROOT/config/mycnf/rbr.cnf
 
 case "$MYSQL_FLAVOR" in
   "MySQL56")

go/vt/key/key.go

@@ -144,7 +144,7 @@ func ParseKeyRangeParts(start, end string) (*topodatapb.KeyRange, error) {
 // KeyRangeString prints a topodatapb.KeyRange
 func KeyRangeString(k *topodatapb.KeyRange) string {
 	if k == nil {
-		return "<nil>"
+		return "-"
 	}
 	return hex.EncodeToString(k.Start) + "-" + hex.EncodeToString(k.End)
 }

go/vt/topo/keyspace.go

@@ -255,6 +255,20 @@ func (ts *Server) FindAllShardsInKeyspace(ctx context.Context, keyspace string)
 	return result, nil
 }
 
+// GetOnlyShard returns the single ShardInfo of an unsharded keyspace.
+func (ts *Server) GetOnlyShard(ctx context.Context, keyspace string) (*ShardInfo, error) {
+	allShards, err := ts.FindAllShardsInKeyspace(ctx, keyspace)
+	if err != nil {
+		return nil, err
+	}
+	if len(allShards) == 1 {
+		for _, s := range allShards {
+			return s, nil
+		}
+	}
+	return nil, vterrors.Errorf(vtrpc.Code_INVALID_ARGUMENT, "keyspace %s must have one and only one shard: %v", keyspace, allShards)
+}
+
 // DeleteKeyspace wraps the underlying Conn.Delete
 // and dispatches the event.
 func (ts *Server) DeleteKeyspace(ctx context.Context, keyspace string) error {

go/vt/vtctl/vtctl.go

@@ -307,6 +307,12 @@ var commands = []commandGroup{
 			{"ValidateKeyspace", commandValidateKeyspace,
 				"[-ping-tablets] <keyspace name>",
 				"Validates that all nodes reachable from the specified keyspace are consistent."},
+			{"SplitClone", commandSplitClone,
+				"<keyspace> <from_shards> <to_shards>",
+				"Start the SplitClone process to perform horizontal resharding. Example: SplitClone ks '0' '-80,80-'"},
+			{"VerticalSplitClone", commandVerticalSplitClone,
+				"<from_keyspace> <to_keyspace> <tables>",
+				"Start the VerticalSplitClone process to perform vertical resharding. Example: SplitClone from_ks to_ks 'a,/b.*/'"},
 			{"MigrateServedTypes", commandMigrateServedTypes,
 				"[-cells=c1,c2,...] [-reverse] [-skip-refresh-state] <keyspace/shard> <served tablet type>",
 				"Migrates a serving type from the source shard to the shards that it replicates to. This command also rebuilds the serving graph. The <keyspace/shard> argument can specify any of the shards involved in the migration."},
@@ -1718,6 +1724,32 @@ func commandValidateKeyspace(ctx context.Context, wr *wrangler.Wrangler, subFlag
 	return wr.ValidateKeyspace(ctx, keyspace, *pingTablets)
 }
 
+func commandSplitClone(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
+	if err := subFlags.Parse(args); err != nil {
+		return err
+	}
+	if subFlags.NArg() != 3 {
+		return fmt.Errorf("three arguments are required: keyspace, from_shards, to_shards")
+	}
+	keyspace := subFlags.Arg(0)
+	from := strings.Split(subFlags.Arg(1), ",")
+	to := strings.Split(subFlags.Arg(2), ",")
+	return wr.SplitClone(ctx, keyspace, from, to)
+}
+
+func commandVerticalSplitClone(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
+	if err := subFlags.Parse(args); err != nil {
+		return err
+	}
+	if subFlags.NArg() != 3 {
+		return fmt.Errorf("three arguments are required: from_keyspace, to_keyspace, tables")
+	}
+	fromKeyspace := subFlags.Arg(0)
+	toKeyspace := subFlags.Arg(1)
+	tables := strings.Split(subFlags.Arg(2), ",")
+	return wr.VerticalSplitClone(ctx, fromKeyspace, toKeyspace, tables)
+}
+
 func commandMigrateServedTypes(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
 	cellsStr := subFlags.String("cells", "", "Specifies a comma-separated list of cells to update")
 	reverse := subFlags.Bool("reverse", false, "Moves the served tablet type backward instead of forward. Use in case of trouble")

go/vt/vttablet/tabletmanager/vreplication/table_plan_builder.go

@@ -147,7 +147,13 @@ func buildQuery(tableName, filter string) string {
 }
 
 func buildTablePlan(rule *binlogdatapb.Rule, tableKeys map[string][]string, lastpk *sqltypes.Result) (*TablePlan, error) {
-	sel, fromTable, err := analyzeSelectFrom(rule.Filter)
+	query := rule.Filter
+	if query == "" {
+		buf := sqlparser.NewTrackedBuffer(nil)
+		buf.Myprintf("select * from %v", sqlparser.NewTableIdent(rule.Match))
+		query = buf.String()
+	}
+	sel, fromTable, err := analyzeSelectFrom(query)
 	if err != nil {
 		return nil, err
 	}
@@ -162,7 +168,7 @@ func buildTablePlan(rule *binlogdatapb.Rule, tableKeys map[string][]string, last
 		if !expr.TableName.IsEmpty() {
 			return nil, fmt.Errorf("unsupported qualifier for '*' expression: %v", sqlparser.String(expr))
 		}
-		sendRule.Filter = rule.Filter
+		sendRule.Filter = query
 		tablePlan := &TablePlan{
 			TargetName: rule.Match,
 			SendRule:   sendRule,

go/vt/vttablet/tabletmanager/vreplication/vplayer.go

@@ -78,7 +78,10 @@ func newVPlayer(vr *vreplicator, settings binlogplayer.VRSettings, copyState map
 // play is not resumable. If pausePos is set, play returns without updating the vreplication state.
 func (vp *vplayer) play(ctx context.Context) error {
 	if !vp.stopPos.IsZero() && vp.startPos.AtLeast(vp.stopPos) {
-		return vp.vr.setState(binlogplayer.BlpStopped, fmt.Sprintf("Stop position %v already reached: %v", vp.startPos, vp.stopPos))
+		if vp.saveStop {
+			return vp.vr.setState(binlogplayer.BlpStopped, fmt.Sprintf("Stop position %v already reached: %v", vp.startPos, vp.stopPos))
+		}
+		return nil
 	}
 
 	plan, err := buildReplicatorPlan(vp.vr.source.Filter, vp.vr.tableKeys, vp.copyState)
@@ -324,8 +327,10 @@ func (vp *vplayer) applyEvent(ctx context.Context, event *binlogdatapb.VEvent, m
 		}
 		if !vp.pos.Equal(vp.stopPos) && vp.pos.AtLeast(vp.stopPos) {
 			// Code is unreachable, but bad data can cause this to happen.
-			if err := vp.vr.setState(binlogplayer.BlpStopped, fmt.Sprintf("next event position %v exceeds stop pos %v, exiting without applying", vp.pos, vp.stopPos)); err != nil {
-				return err
+			if vp.saveStop {
+				if err := vp.vr.setState(binlogplayer.BlpStopped, fmt.Sprintf("next event position %v exceeds stop pos %v, exiting without applying", vp.pos, vp.stopPos)); err != nil {
+					return err
+				}
 			}
 			return io.EOF
 		}

go/vt/wrangler/keyspace.go

@@ -38,6 +38,7 @@ import (
 	"vitess.io/vitess/go/vt/topo/topoproto"
 	"vitess.io/vitess/go/vt/topotools"
 	"vitess.io/vitess/go/vt/topotools/events"
+	"vitess.io/vitess/go/vt/vterrors"
 )
 
 const (
@@ -90,6 +91,107 @@ func (wr *Wrangler) SetKeyspaceShardingInfo(ctx context.Context, keyspace, shard
 	return wr.ts.UpdateKeyspace(ctx, ki)
 }
 
+// SplitClone initiates a SplitClone workflow.
+func (wr *Wrangler) SplitClone(ctx context.Context, keyspace string, from, to []string) error {
+	var fromShards, toShards []*topo.ShardInfo
+	for _, shard := range from {
+		si, err := wr.ts.GetShard(ctx, keyspace, shard)
+		if err != nil {
+			return vterrors.Wrapf(err, "GetShard(%s) failed", shard)
+		}
+		fromShards = append(fromShards, si)
+	}
+	for _, shard := range to {
+		si, err := wr.ts.GetShard(ctx, keyspace, shard)
+		if err != nil {
+			return vterrors.Wrapf(err, "GetShard(%s) failed", shard)
+		}
+		toShards = append(toShards, si)
+	}
+	// TODO(sougou): validate from and to shards.
+
+	for _, dest := range toShards {
+		master, err := wr.ts.GetTablet(ctx, dest.MasterAlias)
+		if err != nil {
+			return vterrors.Wrapf(err, "GetTablet(%v) failed", dest.MasterAlias)
+		}
+		var ids []uint64
+		for _, source := range fromShards {
+			filter := &binlogdatapb.Filter{
+				Rules: []*binlogdatapb.Rule{{
+					Match:  "/.*",
+					Filter: key.KeyRangeString(dest.KeyRange),
+				}},
+			}
+			bls := &binlogdatapb.BinlogSource{
+				Keyspace: keyspace,
+				Shard:    source.ShardName(),
+				Filter:   filter,
+			}
+			cmd := binlogplayer.CreateVReplicationState("VSplitClone", bls, "", binlogplayer.BlpStopped, master.DbName())
+			qr, err := wr.TabletManagerClient().VReplicationExec(ctx, master.Tablet, cmd)
+			if err != nil {
+				return vterrors.Wrapf(err, "VReplicationExec(%v, %s) failed", dest.MasterAlias, cmd)
+			}
+			if err := wr.SourceShardAdd(ctx, keyspace, dest.ShardName(), uint32(qr.InsertId), keyspace, source.ShardName(), source.Shard.KeyRange, nil); err != nil {
+				return vterrors.Wrapf(err, "SourceShardAdd(%s, %s) failed", dest.ShardName(), source.ShardName())
+			}
+			ids = append(ids, qr.InsertId)
+		}
+		// Start vreplication only if all metadata was successfully created.
+		for _, id := range ids {
+			cmd := fmt.Sprintf("update _vt.vreplication set state='%s' where id=%d", binlogplayer.VReplicationInit, id)
+			if _, err = wr.TabletManagerClient().VReplicationExec(ctx, master.Tablet, cmd); err != nil {
+				return vterrors.Wrapf(err, "VReplicationExec(%v, %s) failed", dest.MasterAlias, cmd)
+			}
+		}
+	}
+	return wr.refreshMasters(ctx, toShards)
+}
+
+// VerticalSplitClone initiates a VerticalSplitClone workflow.
+func (wr *Wrangler) VerticalSplitClone(ctx context.Context, fromKeyspace, toKeyspace string, tables []string) error {
+	source, err := wr.ts.GetOnlyShard(ctx, fromKeyspace)
+	if err != nil {
+		return vterrors.Wrapf(err, "GetOnlyShard(%s) failed", fromKeyspace)
+	}
+	dest, err := wr.ts.GetOnlyShard(ctx, toKeyspace)
+	if err != nil {
+		return vterrors.Wrapf(err, "GetOnlyShard(%s) failed", toKeyspace)
+	}
+	// TODO(sougou): validate from and to shards.
+
+	master, err := wr.ts.GetTablet(ctx, dest.MasterAlias)
+	if err != nil {
+		return vterrors.Wrapf(err, "GetTablet(%v) failed", dest.MasterAlias)
+	}
+	filter := &binlogdatapb.Filter{}
+	for _, table := range tables {
+		filter.Rules = append(filter.Rules, &binlogdatapb.Rule{
+			Match: table,
+		})
+	}
+	bls := &binlogdatapb.BinlogSource{
+		Keyspace: fromKeyspace,
+		Shard:    source.ShardName(),
+		Filter:   filter,
+	}
+	cmd := binlogplayer.CreateVReplicationState("VSplitClone", bls, "", binlogplayer.BlpStopped, master.DbName())
+	qr, err := wr.TabletManagerClient().VReplicationExec(ctx, master.Tablet, cmd)
+	if err != nil {
+		return vterrors.Wrapf(err, "VReplicationExec(%v, %s) failed", dest.MasterAlias, cmd)
+	}
+	if err := wr.SourceShardAdd(ctx, toKeyspace, dest.ShardName(), uint32(qr.InsertId), fromKeyspace, source.ShardName(), nil, tables); err != nil {
+		return vterrors.Wrapf(err, "SourceShardAdd(%s, %s) failed", dest.ShardName(), source.ShardName())
+	}
+	// Start vreplication only if metadata was successfully created.
+	cmd = fmt.Sprintf("update _vt.vreplication set state='%s' where id=%d", binlogplayer.VReplicationInit, qr.InsertId)
+	if _, err = wr.TabletManagerClient().VReplicationExec(ctx, master.Tablet, cmd); err != nil {
+		return vterrors.Wrapf(err, "VReplicationExec(%v, %s) failed", dest.MasterAlias, cmd)
+	}
+	return wr.refreshMasters(ctx, []*topo.ShardInfo{dest})
+}
+
 // ShowResharding shows all resharding related metadata for the keyspace/shard.
 func (wr *Wrangler) ShowResharding(ctx context.Context, keyspace, shard string) (err error) {
 	ki, err := wr.ts.GetKeyspace(ctx, keyspace)