dm: revert dm#2047

dm/pkg/streamer/reader.go

@@ -39,10 +39,6 @@ import (
 	"github.com/pingcap/ticdc/dm/pkg/utils"
 )
 
-// ErrorMaybeDuplicateEvent indicates that there may be duplicate event in next binlog file
-// this is mainly happened when upstream master changed when relay log not finish reading a transaction.
-var ErrorMaybeDuplicateEvent = errors.New("truncate binlog file found, event may be duplicated")
-
 // Meta represents binlog meta information in relay.meta.
 type Meta struct {
 	BinLogName string `toml:"binlog-name" json:"binlog-name"`
@@ -560,15 +556,6 @@ func (r *BinlogReader) parseFile(
 	if err != nil {
 		if possibleLast && isIgnorableParseError(err) {
 			r.tctx.L().Warn("fail to parse relay log file, meet some ignorable error", zap.String("file", fullPath), zap.Int64("offset", offset), zap.Error(err))
-			// the file is truncated, we send a mock event with `IGNORABLE_EVENT` to notify the the consumer
-			// TODO: should add a integration test for this
-			e := &replication.BinlogEvent{
-				RawData: []byte(ErrorMaybeDuplicateEvent.Error()),
-				Header: &replication.EventHeader{
-					EventType: replication.IGNORABLE_EVENT,
-				},
-			}
-			s.ch <- e
 		} else {
 			r.tctx.L().Error("parse relay log file", zap.String("file", fullPath), zap.Int64("offset", offset), zap.Error(err))
 			return false, false, 0, "", "", false, terror.ErrParserParseRelayLog.Delegate(err, fullPath)

dm/pkg/streamer/streamer.go

@@ -14,7 +14,6 @@
 package streamer
 
 import (
-	"bytes"
 	"context"
 	"time"
 
@@ -67,12 +66,6 @@ func (s *LocalStreamer) GetEvent(ctx context.Context) (*replication.BinlogEvent,
 		heartbeatHeader := &replication.EventHeader{}
 		return event.GenHeartbeatEvent(heartbeatHeader), nil
 	case c := <-s.ch:
-		// special check for maybe truncated relay log
-		if c.Header.EventType == replication.IGNORABLE_EVENT {
-			if bytes.Equal(c.RawData, []byte(ErrorMaybeDuplicateEvent.Error())) {
-				return nil, ErrorMaybeDuplicateEvent
-			}
-		}
 		return c, nil
 	case s.err = <-s.ech:
 		return nil, s.err

dm/relay/relay.go

@@ -307,8 +307,7 @@ func (r *Relay) process(ctx context.Context) error {
 	// handles binlog events with retry mechanism.
 	// it only do the retry for some binlog reader error now.
 	for {
-		eventIdx, err := r.handleEvents(ctx, reader2, transformer2, writer2)
-	checkError:
+		err := r.handleEvents(ctx, reader2, transformer2, writer2)
 		if err == nil {
 			return nil
 		} else if !readerRetry.Check(ctx, err) {
@@ -325,33 +324,6 @@ func (r *Relay) process(ctx context.Context) error {
 			return err
 		}
 		r.logger.Info("retrying to read binlog")
-		if r.cfg.EnableGTID && eventIdx > 0 {
-			// check if server has switched
-			isNew, err2 := isNewServer(ctx, r.meta.UUID(), r.db.DB, r.cfg.Flavor)
-			// should start from the transaction beginning when switch to a new server
-			if err2 != nil {
-				r.logger.Warn("check new server failed, continue outer loop", log.ShortError(err2))
-				err = err2
-				goto checkError
-			}
-			if !isNew {
-				for i := 0; i < eventIdx; {
-					res, err2 := reader2.GetEvent(ctx)
-					if err2 != nil {
-						err = err2
-						goto checkError
-					}
-					tResult := transformer2.Transform(res.Event)
-					// do not count skip event
-					if !tResult.Ignore {
-						i++
-					}
-				}
-				if eventIdx > 0 {
-					r.logger.Info("discard duplicate event", zap.Int("count", eventIdx))
-				}
-			}
-		}
 	}
 }
 
@@ -465,16 +437,15 @@ func (r *Relay) handleEvents(
 	reader2 reader.Reader,
 	transformer2 transformer.Transformer,
 	writer2 writer.Writer,
-) (int, error) {
+) error {
 	var (
 		_, lastPos  = r.meta.Pos()
 		_, lastGTID = r.meta.GTID()
 		err         error
-		eventIndex  int
 	)
 	if lastGTID == nil {
 		if lastGTID, err = gtid.ParserGTID(r.cfg.Flavor, ""); err != nil {
-			return 0, err
+			return err
 		}
 	}
 
@@ -483,20 +454,10 @@ func (r *Relay) handleEvents(
 		// 1. read events from upstream server
 		readTimer := time.Now()
 		rResult, err := reader2.GetEvent(ctx)
-		failpoint.Inject("RelayGetEventFailed", func(v failpoint.Value) {
-			if intVal, ok := v.(int); ok && intVal == eventIndex {
-				err = errors.New("fail point triggered")
-				_, gtid := r.meta.GTID()
-				r.logger.Warn("failed to get event", zap.Int("event_index", eventIndex),
-					zap.Any("gtid", gtid), log.ShortError(err))
-				// wait backoff retry interval
-				time.Sleep(1 * time.Second)
-			}
-		})
 		if err != nil {
 			switch errors.Cause(err) {
 			case context.Canceled:
-				return 0, nil
+				return nil
 			case replication.ErrChecksumMismatch:
 				relayLogDataCorruptionCounter.Inc()
 			case replication.ErrSyncClosed, replication.ErrNeedSyncAgain:
@@ -515,7 +476,7 @@ func (r *Relay) handleEvents(
 				}
 				binlogReadErrorCounter.Inc()
 			}
-			return eventIndex, err
+			return err
 		}
 
 		binlogReadDurationHistogram.Observe(time.Since(readTimer).Seconds())
@@ -547,15 +508,13 @@ func (r *Relay) handleEvents(
 
 		if _, ok := e.Event.(*replication.RotateEvent); ok && utils.IsFakeRotateEvent(e.Header) {
 			isNew, err2 := isNewServer(ctx, r.meta.UUID(), r.db.DB, r.cfg.Flavor)
-			// should start from the transaction beginning when switch to a new server
 			if err2 != nil {
-				return 0, err2
+				return err2
 			}
 			// upstream database switch
 			// report an error, let outer logic handle it
-			// should start from the transaction beginning when switch to a new server
 			if isNew {
-				return 0, terror.ErrRotateEventWithDifferentServerID.Generate()
+				return terror.ErrRotateEventWithDifferentServerID.Generate()
 			}
 		}
 
@@ -566,7 +525,7 @@ func (r *Relay) handleEvents(
 			// and meta file is not created when relay resumed.
 			firstEvent = false
 			if err2 := r.saveAndFlushMeta(lastPos, lastGTID); err2 != nil {
-				return 0, err2
+				return err2
 			}
 		}
 
@@ -576,7 +535,7 @@ func (r *Relay) handleEvents(
 		wResult, err := writer2.WriteEvent(e)
 		if err != nil {
 			relayLogWriteErrorCounter.Inc()
-			return eventIndex, err
+			return err
 		} else if wResult.Ignore {
 			r.logger.Info("ignore event by writer",
 				zap.Reflect("header", e.Header),
@@ -595,7 +554,7 @@ func (r *Relay) handleEvents(
 		lastPos.Pos = tResult.LogPos
 		err = lastGTID.Set(tResult.GTIDSet)
 		if err != nil {
-			return 0, terror.ErrRelayUpdateGTID.Delegate(err, lastGTID, tResult.GTIDSet)
+			return terror.ErrRelayUpdateGTID.Delegate(err, lastGTID, tResult.GTIDSet)
 		}
 		if !r.cfg.EnableGTID {
 			// if go-mysql set RawModeEnabled to true
@@ -620,17 +579,14 @@ func (r *Relay) handleEvents(
 		if needSavePos {
 			err = r.SaveMeta(lastPos, lastGTID)
 			if err != nil {
-				return 0, terror.Annotatef(err, "save position %s, GTID sets %v into meta", lastPos, lastGTID)
+				return terror.Annotatef(err, "save position %s, GTID sets %v into meta", lastPos, lastGTID)
 			}
-			eventIndex = 0
-		} else {
-			eventIndex++
 		}
 		if tResult.NextLogName != "" && !utils.IsFakeRotateEvent(e.Header) {
 			// if the binlog is rotated, we need to save and flush the next binlog filename to meta
 			lastPos.Name = tResult.NextLogName
 			if err := r.saveAndFlushMeta(lastPos, lastGTID); err != nil {
-				return 0, err
+				return err
 			}
 		}
 	}

dm/relay/relay_test.go

@@ -448,7 +448,7 @@ func (t *testRelaySuite) TestHandleEvent(c *C) {
 		replication.ErrSyncClosed,
 		replication.ErrNeedSyncAgain,
 	} {
-		_, handleErr := r.handleEvents(context.Background(), reader2, transformer2, writer2)
+		handleErr := r.handleEvents(context.Background(), reader2, transformer2, writer2)
 		c.Assert(errors.Cause(handleErr), Equals, reader2.err)
 	}
 
@@ -458,7 +458,7 @@ func (t *testRelaySuite) TestHandleEvent(c *C) {
 	// writer return error to force handleEvents return
 	writer2.err = errors.New("writer error for testing")
 	// return with the annotated writer error
-	_, err = r.handleEvents(context.Background(), reader2, transformer2, writer2)
+	err = r.handleEvents(context.Background(), reader2, transformer2, writer2)
 	c.Assert(errors.Cause(err), Equals, writer2.err)
 	// after handle rotate event, we save and flush the meta immediately
 	c.Assert(r.meta.Dirty(), Equals, false)
@@ -477,7 +477,7 @@ func (t *testRelaySuite) TestHandleEvent(c *C) {
 		lm := r.meta.(*LocalMeta)
 		backupUUID := lm.currentUUID
 		lm.currentUUID = "not exist"
-		_, err = r.handleEvents(context.Background(), reader2, transformer2, writer2)
+		err = r.handleEvents(context.Background(), reader2, transformer2, writer2)
 		c.Assert(os.IsNotExist(errors.Cause(err)), Equals, true)
 		lm.currentUUID = backupUUID
 	}
@@ -489,15 +489,15 @@ func (t *testRelaySuite) TestHandleEvent(c *C) {
 	// writer return error
 	writer2.err = errors.New("writer error for testing")
 	// return with the annotated writer error
-	_, err = r.handleEvents(context.Background(), reader2, transformer2, writer2)
+	err = r.handleEvents(context.Background(), reader2, transformer2, writer2)
 	c.Assert(errors.Cause(err), Equals, writer2.err)
 	c.Assert(r.meta.Dirty(), Equals, false)
 
 	// writer without error
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Millisecond)
 	defer cancel()
 	writer2.err = nil
-	_, err = r.handleEvents(ctx, reader2, transformer2, writer2) // returned when ctx timeout
+	err = r.handleEvents(ctx, reader2, transformer2, writer2) // returned when ctx timeout
 	c.Assert(errors.Cause(err), Equals, ctx.Err())
 	// check written event
 	c.Assert(writer2.latestEvent, Equals, reader2.result.Event)
@@ -512,7 +512,7 @@ func (t *testRelaySuite) TestHandleEvent(c *C) {
 
 	// write a QueryEvent with GTID sets
 	reader2.result.Event = queryEv
-	_, err = r.handleEvents(ctx2, reader2, transformer2, writer2)
+	err = r.handleEvents(ctx2, reader2, transformer2, writer2)
 	c.Assert(errors.Cause(err), Equals, ctx.Err())
 	// check written event
 	c.Assert(writer2.latestEvent, Equals, reader2.result.Event)
@@ -531,7 +531,7 @@ func (t *testRelaySuite) TestHandleEvent(c *C) {
 	}
 	ctx4, cancel4 := context.WithTimeout(context.Background(), 10*time.Millisecond)
 	defer cancel4()
-	_, err = r.handleEvents(ctx4, reader2, transformer2, writer2)
+	err = r.handleEvents(ctx4, reader2, transformer2, writer2)
 	c.Assert(errors.Cause(err), Equals, ctx.Err())
 	select {
 	case <-ctx4.Done():
@@ -544,7 +544,7 @@ func (t *testRelaySuite) TestHandleEvent(c *C) {
 	writer2.result.Ignore = true
 	ctx5, cancel5 := context.WithTimeout(context.Background(), 10*time.Millisecond)
 	defer cancel5()
-	_, err = r.handleEvents(ctx5, reader2, transformer2, writer2)
+	err = r.handleEvents(ctx5, reader2, transformer2, writer2)
 	c.Assert(errors.Cause(err), Equals, ctx.Err())
 	select {
 	case <-ctx5.Done():

dm/relay/retry/reader.go

@@ -17,8 +17,6 @@ import (
 	"context"
 	"time"
 
-	"github.com/pingcap/failpoint"
-
 	"github.com/pingcap/ticdc/dm/pkg/backoff"
 	"github.com/pingcap/ticdc/dm/pkg/retry"
 	"github.com/pingcap/ticdc/dm/pkg/terror"
@@ -58,9 +56,6 @@ func NewReaderRetry(cfg ReaderRetryConfig) (*ReaderRetry, error) {
 
 // Check checks whether should retry for the error.
 func (rr *ReaderRetry) Check(ctx context.Context, err error) bool {
-	failpoint.Inject("RelayAllowRetry", func() {
-		failpoint.Return(true)
-	})
 	if !retry.IsConnectionError(err) {
 		return false
 	}

dm/syncer/syncer.go

@@ -1554,28 +1554,6 @@ func (s *Syncer) Run(ctx context.Context) (err error) {
 		return nil
 	}
 
-	maybeSkipNRowsEvent := func(n int) error {
-		if s.cfg.EnableGTID && n > 0 {
-			for i := 0; i < n; {
-				e, err1 := s.getEvent(tctx, currentLocation)
-				if err1 != nil {
-					return err
-				}
-				if _, ok := e.Event.(*replication.RowsEvent); ok {
-					i++
-				}
-			}
-			log.L().Info("discard event already consumed", zap.Int("count", n),
-				zap.Any("cur_loc", currentLocation))
-		}
-		return nil
-	}
-
-	// eventIndex is the rows event index in this transaction, it's used to avoiding read duplicate event in gtid mode
-	eventIndex := 0
-	// the relay log file may be truncated(not end with an RotateEvent), in this situation, we may read some rows events
-	// and then read from the gtid again, so we force enter safe-mode for one more transaction to avoid failure due to
-	// conflict
 	for {
 		if s.execError.Load() != nil {
 			return nil
@@ -1617,14 +1595,6 @@ func (s *Syncer) Run(ctx context.Context) (err error) {
 				err = errors.New("connect: connection refused")
 			}
 		})
-		failpoint.Inject("GetEventErrorInTxn", func(val failpoint.Value) {
-			if intVal, ok := val.(int); ok && intVal == eventIndex {
-				err = errors.New("failpoint triggered")
-				s.tctx.L().Warn("failed to get event", zap.Int("event_index", eventIndex),
-					zap.Any("cur_pos", currentLocation), zap.Any("las_pos", lastLocation),
-					zap.Any("pos", e.Header.LogPos), log.ShortError(err))
-			}
-		})
 		switch {
 		case err == context.Canceled:
 			tctx.L().Info("binlog replication main routine quit(context canceled)!", zap.Stringer("last location", lastLocation))
@@ -1640,13 +1610,6 @@ func (s *Syncer) Run(ctx context.Context) (err error) {
 				return err1
 			}
 			continue
-		case err == streamer.ErrorMaybeDuplicateEvent:
-			tctx.L().Warn("read binlog met a truncated file, need to open safe-mode until the next transaction")
-			err = maybeSkipNRowsEvent(eventIndex)
-			if err == nil {
-				continue
-			}
-			log.L().Warn("skip duplicate rows event failed", zap.Error(err))
 		}
 
 		if err != nil {
@@ -1663,9 +1626,6 @@ func (s *Syncer) Run(ctx context.Context) (err error) {
 					return err
 				}
 				log.L().Info("reset replication binlog puller", zap.Any("pos", s.checkpoint.GlobalPoint()))
-				if err = maybeSkipNRowsEvent(eventIndex); err != nil {
-					return err
-				}
 				continue
 			}
 
@@ -1817,15 +1777,12 @@ func (s *Syncer) Run(ctx context.Context) (err error) {
 		case *replication.RotateEvent:
 			err2 = s.handleRotateEvent(ev, ec)
 		case *replication.RowsEvent:
-			eventIndex++
 			metrics.BinlogEventRowHistogram.WithLabelValues(s.cfg.WorkerName, s.cfg.Name, s.cfg.SourceID).Observe(float64(len(ev.Rows)))
 			err2 = s.handleRowsEvent(ev, ec)
 		case *replication.QueryEvent:
 			originSQL = strings.TrimSpace(string(ev.Query))
 			err2 = s.handleQueryEvent(ev, ec, originSQL)
 		case *replication.XIDEvent:
-			// reset eventIndex and force safeMode flag here.
-			eventIndex = 0
 			if shardingReSync != nil {
 				shardingReSync.currLocation.Position.Pos = e.Header.LogPos
 				shardingReSync.currLocation.Suffix = currentLocation.Suffix

dm/tests/others_integration_2.txt

@@ -7,5 +7,4 @@ case_sensitive
 sql_mode
 http_proxies
 openapi
-duplicate_event
 tracker_ignored_ddl