syncer: fix syncer gtid auto switch from off to on

dm/worker/server.go

@@ -254,8 +254,10 @@ func (s *Server) doStartKeepAlive() {
 }
 
 func (s *Server) stopKeepAlive() {
-	s.kaCancel()
-	s.kaWg.Wait()
+	if s.kaCancel != nil {
+		s.kaCancel()
+		s.kaWg.Wait()
+	}
 }
 
 func (s *Server) restartKeepAlive() {

pkg/binlog/position.go

@@ -316,6 +316,34 @@ func CompareLocation(location1, location2 Location, cmpGTID bool) int {
 	return compareIndex(location1.Suffix, location2.Suffix)
 }
 
+// IsFreshPosition returns true when location1 is a fresh location without any info.
+func IsFreshPosition(location1 Location, flavor string, cmpGTID bool) bool {
+	location2 := NewLocation(flavor)
+	if cmpGTID {
+		cmp, canCmp := CompareGTID(location1.gtidSet, location2.gtidSet)
+		if canCmp {
+			if cmp != 0 {
+				return cmp <= 0
+			}
+			// not supposed to happen, for safety here.
+			if location1.gtidSet != nil && location1.gtidSet.String() != "" {
+				return false
+			}
+			// empty GTIDSet, then compare by position
+			log.L().Warn("both gtidSets are empty, will compare by position", zap.Stringer("location1", location1), zap.Stringer("location2", location2))
+		} else {
+			// if can't compare by GTIDSet, then compare by position
+			log.L().Warn("gtidSet can't be compared, will compare by position", zap.Stringer("location1", location1), zap.Stringer("location2", location2))
+		}
+	}
+
+	cmp := ComparePosition(location1.Position, location2.Position)
+	if cmp != 0 {
+		return cmp <= 0
+	}
+	return compareIndex(location1.Suffix, location2.Suffix) <= 0
+}
+
 // CompareGTID returns:
 //   1, true if gSet1 is bigger than gSet2
 //   0, true if gSet1 is equal to gSet2

pkg/binlog/position_test.go

@@ -794,3 +794,89 @@ func (t *testPositionSuite) TestExtractSuffix(c *C) {
 		c.Assert(suffix, Equals, tc.suffix)
 	}
 }
+
+func (t *testPositionSuite) TestIsFreshPosition(c *C) {
+	mysqlPos := gmysql.Position{
+		Name: "mysql-binlog.00001",
+		Pos:  123,
+	}
+	mysqlGTIDSet, err := gtid.ParserGTID(gmysql.MySQLFlavor, "e8e592a6-7a59-11eb-8da1-0242ac110002:1-36")
+	c.Assert(err, IsNil)
+	mariaGTIDSet, err := gtid.ParserGTID(gmysql.MariaDBFlavor, "0-1001-233")
+	c.Assert(err, IsNil)
+	testCases := []struct {
+		loc     Location
+		flavor  string
+		cmpGTID bool
+		fresh   bool
+	}{
+		{
+			InitLocation(mysqlPos, mysqlGTIDSet),
+			gmysql.MySQLFlavor,
+			true,
+			false,
+		},
+		{
+			InitLocation(mysqlPos, gtid.MinGTIDSet(gmysql.MySQLFlavor)),
+			gmysql.MySQLFlavor,
+			true,
+			false,
+		},
+		{
+
+			InitLocation(MinPosition, mysqlGTIDSet),
+			gmysql.MySQLFlavor,
+			true,
+			false,
+		},
+		{
+			InitLocation(MinPosition, mysqlGTIDSet),
+			gmysql.MySQLFlavor,
+			false,
+			true,
+		},
+		{
+			InitLocation(MinPosition, gtid.MinGTIDSet(gmysql.MySQLFlavor)),
+			gmysql.MySQLFlavor,
+			true,
+			true,
+		},
+
+		{
+			InitLocation(mysqlPos, mariaGTIDSet),
+			gmysql.MariaDBFlavor,
+			true,
+			false,
+		},
+		{
+			InitLocation(mysqlPos, gtid.MinGTIDSet(gmysql.MariaDBFlavor)),
+			gmysql.MariaDBFlavor,
+			true,
+			false,
+		},
+		{
+
+			InitLocation(MinPosition, mariaGTIDSet),
+			gmysql.MariaDBFlavor,
+			true,
+			false,
+		},
+		{
+			InitLocation(MinPosition, mariaGTIDSet),
+			gmysql.MariaDBFlavor,
+			false,
+			true,
+		},
+		{
+			InitLocation(MinPosition, gtid.MinGTIDSet(gmysql.MariaDBFlavor)),
+			gmysql.MariaDBFlavor,
+			true,
+			true,
+		},
+	}
+
+	for _, tc := range testCases {
+		fresh := IsFreshPosition(tc.loc, tc.flavor, tc.cmpGTID)
+		c.Assert(fresh, Equals, tc.fresh)
+	}
+}

pkg/binlog/reader/reader.go

@@ -42,3 +42,9 @@ type Reader interface {
 	// Status returns the status of the reader.
 	Status() interface{}
 }
+
+// Streamer provides the ability to get binlog event from remote server or local file.
+type Streamer interface {
+	// GetEvent returns binlog event
+	GetEvent(ctx context.Context) (*replication.BinlogEvent, error)
+}

pkg/binlog/reader/util.go

@@ -30,26 +30,14 @@ import (
 	"github.com/pingcap/dm/relay/common"
 )
 
-// GetGTIDsForPos tries to get GTID sets for the specified binlog position (for the corresponding txn).
-// NOTE: this method is very similar with `relay/writer/file_util.go/getTxnPosGTIDs`, unify them if needed later.
-// NOTE: this method is not well tested directly, but more tests have already been done for `relay/writer/file_util.go/getTxnPosGTIDs`.
-func GetGTIDsForPos(ctx context.Context, r Reader, endPos gmysql.Position) (gtid.Set, error) {
-	// start to get and parse binlog event from the beginning of the file.
-	startPos := gmysql.Position{
-		Name: endPos.Name,
-		Pos:  0,
-	}
-	err := r.StartSyncByPos(startPos)
-	if err != nil {
-		return nil, err
-	}
-	defer r.Close()
-
+// GetGTIDsForPosFromStreamer tries to get GTID sets for the specified binlog position (for the corresponding txn) from a Streamer.
+func GetGTIDsForPosFromStreamer(ctx context.Context, r Streamer, endPos gmysql.Position) (gtid.Set, error) {
 	var (
 		flavor      string
 		latestPos   uint32
 		latestGSet  gmysql.GTIDSet
 		nextGTIDStr string // can be recorded if the coming transaction completed
+		err         error
 	)
 	for {
 		var e *replication.BinlogEvent
@@ -141,6 +129,24 @@ func GetGTIDsForPos(ctx context.Context, r Reader, endPos gmysql.Position) (gtid
 	}
 }
 
+// GetGTIDsForPos tries to get GTID sets for the specified binlog position (for the corresponding txn).
+// NOTE: this method is very similar with `relay/writer/file_util.go/getTxnPosGTIDs`, unify them if needed later.
+// NOTE: this method is not well tested directly, but more tests have already been done for `relay/writer/file_util.go/getTxnPosGTIDs`.
+func GetGTIDsForPos(ctx context.Context, r Reader, endPos gmysql.Position) (gtid.Set, error) {
+	// start to get and parse binlog event from the beginning of the file.
+	startPos := gmysql.Position{
+		Name: endPos.Name,
+		Pos:  0,
+	}
+	err := r.StartSyncByPos(startPos)
+	if err != nil {
+		return nil, err
+	}
+	defer r.Close()
+
+	return GetGTIDsForPosFromStreamer(ctx, r, endPos)
+}
+
 // GetPreviousGTIDFromGTIDSet tries to get previous GTID sets from Previous_GTID_EVENT GTID for the specified GITD Set.
 // events should be [fake_rotate_event,format_description_event,previous_gtids_event/mariadb_gtid_list_event].
 func GetPreviousGTIDFromGTIDSet(ctx context.Context, r Reader, gset gtid.Set) (gtid.Set, error) {

pkg/streamer/streamer.go

@@ -19,6 +19,7 @@ import (
 
 	"github.com/pingcap/dm/pkg/binlog/common"
 	"github.com/pingcap/dm/pkg/binlog/event"
+	"github.com/pingcap/dm/pkg/binlog/reader"
 	"github.com/pingcap/dm/pkg/log"
 	"github.com/pingcap/dm/pkg/terror"
 
@@ -32,10 +33,7 @@ var heartbeatInterval = common.MasterHeartbeatPeriod
 // TODO: maybe one day we can make a pull request to go-mysql to support LocalStreamer.
 
 // Streamer provides the ability to get binlog event from remote server or local file.
-type Streamer interface {
-	// GetEvent returns binlog event
-	GetEvent(ctx context.Context) (*replication.BinlogEvent, error)
-}
+type Streamer reader.Streamer
 
 // LocalStreamer reads and parses binlog events from local binlog file.
 type LocalStreamer struct {

syncer/checkpoint.go

@@ -781,7 +781,8 @@ func (cp *RemoteCheckPoint) Load(tctx *tcontext.Context) error {
 			gset,
 		)
 		if isGlobal {
-			if binlog.CompareLocation(location, binlog.NewLocation(cp.cfg.Flavor), cp.cfg.EnableGTID) > 0 {
+			// Use IsFreshPosition here to make sure checkpoint can be updated if gset is empty
+			if !binlog.IsFreshPosition(location, cp.cfg.Flavor, cp.cfg.EnableGTID) {
 				cp.globalPoint = newBinlogPoint(location, location, nil, nil, cp.cfg.EnableGTID)
 				cp.logCtx.L().Info("fetch global checkpoint from DB", log.WrapStringerField("global checkpoint", cp.globalPoint))
 			}

syncer/syncer.go

@@ -49,6 +49,7 @@ import (
 	"github.com/pingcap/dm/pkg/binlog"
 	"github.com/pingcap/dm/pkg/binlog/common"
 	"github.com/pingcap/dm/pkg/binlog/event"
+	"github.com/pingcap/dm/pkg/binlog/reader"
 	"github.com/pingcap/dm/pkg/conn"
 	tcontext "github.com/pingcap/dm/pkg/context"
 	fr "github.com/pingcap/dm/pkg/func-rollback"
@@ -427,7 +428,8 @@ func (s *Syncer) initShardingGroups(ctx context.Context) error {
 func (s *Syncer) IsFreshTask(ctx context.Context) (bool, error) {
 	globalPoint := s.checkpoint.GlobalPoint()
 	tablePoint := s.checkpoint.TablePoint()
-	return binlog.CompareLocation(globalPoint, binlog.NewLocation(s.cfg.Flavor), s.cfg.EnableGTID) <= 0 && len(tablePoint) == 0, nil
+	// doesn't have neither GTID nor binlog pos
+	return binlog.IsFreshPosition(globalPoint, s.cfg.Flavor, s.cfg.EnableGTID) && len(tablePoint) == 0, nil
 }
 
 func (s *Syncer) reset() {
@@ -1128,23 +1130,30 @@ func (s *Syncer) Run(ctx context.Context) (err error) {
 		if err != nil {
 			return err
 		}
-
-		// for fresh and all-mode task, flush checkpoint so we could delete metadata file
-		if s.cfg.Mode == config.ModeAll {
-			if err = s.flushCheckPoints(); err != nil {
-				tctx.L().Warn("fail to flush checkpoints when starting task", zap.Error(err))
-			} else if s.cfg.CleanDumpFile {
-				tctx.L().Info("try to remove loaded files")
-				metadataFile := path.Join(s.cfg.Dir, "metadata")
-				if err = os.Remove(metadataFile); err != nil {
-					tctx.L().Warn("error when remove loaded dump file", zap.String("data file", metadataFile), zap.Error(err))
-				}
-				if err = os.Remove(s.cfg.Dir); err != nil {
-					tctx.L().Warn("error when remove loaded dump folder", zap.String("data folder", s.cfg.Dir), zap.Error(err))
-				}
+	}
+	needFlushCheckpoint, err := s.adjustGlobalPointGTID(tctx)
+	if err != nil {
+		return err
+	}
+	if needFlushCheckpoint || s.cfg.Mode == config.ModeAll {
+		if err = s.flushCheckPoints(); err != nil {
+			tctx.L().Warn("fail to flush checkpoints when starting task", zap.Error(err))
+		} else if s.cfg.Mode == config.ModeAll && s.cfg.CleanDumpFile {
+			tctx.L().Info("try to remove loaded files")
+			metadataFile := path.Join(s.cfg.Dir, "metadata")
+			if err = os.Remove(metadataFile); err != nil {
+				tctx.L().Warn("error when remove loaded dump file", zap.String("data file", metadataFile), zap.Error(err))
+			}
+			if err = os.Remove(s.cfg.Dir); err != nil {
+				tctx.L().Warn("error when remove loaded dump folder", zap.String("data folder", s.cfg.Dir), zap.Error(err))
 			}
 		}
 	}
+	failpoint.Inject("AdjustGTIDExit", func() {
+		tctx.L().Warn("exit triggered", zap.String("failpoint", "AdjustGTIDExit"))
+		s.streamerController.Close(tctx)
+		utils.OsExit(1)
+	})
 
 	// startLocation is the start location for current received event
 	// currentLocation is the end location for current received event (End_log_pos in `show binlog events` for mysql)
@@ -2855,3 +2864,51 @@ func (s *Syncer) getEvent(tctx *tcontext.Context, startLocation binlog.Location)
 
 	return s.streamerController.GetEvent(tctx)
 }
+
+func (s *Syncer) adjustGlobalPointGTID(tctx *tcontext.Context) (bool, error) {
+	location := s.checkpoint.GlobalPoint()
+	// situations that don't need to adjust
+	// 1. GTID is not enabled
+	// 2. location already has GTID position
+	// 3. location is totally new, has no position info
+	if !s.cfg.EnableGTID || location.GTIDSetStr() != "" || location.Position.Name == "" {
+		return false, nil
+	}
+	// set enableGTID to false for new streamerController
+	streamerController := NewStreamerController(s.syncCfg, false, s.fromDB, s.binlogType, s.cfg.RelayDir, s.timezone)
+
+	endPos := binlog.AdjustPosition(location.Position)
+	startPos := mysql.Position{
+		Name: endPos.Name,
+		Pos:  0,
+	}
+	startLocation := location.Clone()
+	startLocation.Position = startPos
+
+	err := streamerController.Start(tctx, startLocation)
+	if err != nil {
+		return false, err
+	}
+	defer streamerController.Close(tctx)
+
+	gs, err := reader.GetGTIDsForPosFromStreamer(tctx.Context(), streamerController.streamer, endPos)
+	if err != nil {
+		s.tctx.L().Warn("fail to get gtids for global location", zap.Stringer("pos", location), zap.Error(err))
+		return false, err
+	}
+	err = location.SetGTID(gs.Origin())
+	if err != nil {
+		s.tctx.L().Warn("fail to set gtid for global location", zap.Stringer("pos", location),
+			zap.String("adjusted_gtid", gs.String()), zap.Error(err))
+		return false, err
+	}
+	s.checkpoint.SaveGlobalPoint(location)
+	// redirect streamer for new gtid set location
+	err = s.streamerController.RedirectStreamer(tctx, location)
+	if err != nil {
+		s.tctx.L().Warn("fail to redirect streamer for global location", zap.Stringer("pos", location),
+			zap.String("adjusted_gtid", gs.String()), zap.Error(err))
+		return false, err
+	}
+	return true, nil
+}