ddlManager (ticdc): add bootstrap sending function

cdc/owner/changefeed_test.go

@@ -140,6 +140,10 @@ func (m *mockDDLSink) emitCheckpointTs(ts uint64, tables []*model.TableInfo) {
 	m.mu.currentTables = tables
 }
 
+func (m *mockDDLSink) emitBootstrapEvent(ctx context.Context, ddl *model.DDLEvent) error {
+	return nil
+}
+
 func (m *mockDDLSink) getCheckpointTsAndTableNames() (uint64, []*model.TableInfo) {
 	m.mu.Lock()
 	defer m.mu.Unlock()

cdc/owner/ddl_manager.go

@@ -17,6 +17,7 @@ import (
 	"context"
 	"math/rand"
 	"sort"
+	"sync/atomic"
 	"time"
 
 	"github.com/pingcap/errors"
@@ -93,6 +94,14 @@ var redoBarrierDDLs = map[timodel.ActionType]struct{}{
 	timodel.ActionRemovePartitioning:     {},
 }
 
+type bootstrapState int32
+
+const (
+	bootstrapStateNone bootstrapState = iota
+	bootstrapStateRunning
+	bootstrapStateCompleted
+)
+
 // ddlManager holds the pending DDL events of all tables and responsible for
 // executing them to downstream.
 // It also provides the ability to calculate the barrier of a changefeed.
@@ -130,6 +139,10 @@ type ddlManager struct {
 	BDRMode       bool
 	sinkType      model.DownstreamType
 	ddlResolvedTs model.Ts
+
+	needBootstrap  bool
+	errCh          chan error
+	bootstrapState int32
 }
 
 func newDDLManager(
@@ -167,6 +180,7 @@ func newDDLManager(
 		sinkType:        model.DB,
 		tableCheckpoint: make(map[model.TableName]model.Ts),
 		pendingDDLs:     make(map[model.TableName][]*model.DDLEvent),
+		errCh:           make(chan error, 1),
 	}
 }
 
@@ -184,6 +198,18 @@ func (m *ddlManager) tick(
 	checkpointTs model.Ts,
 	tableCheckpoint map[model.TableName]model.Ts,
 ) ([]model.TableID, *schedulepb.BarrierWithMinTs, error) {
+	// needBootstrap is true when the downstream is kafka
+	// and the protocol is simple protocol.
+	if m.needBootstrap {
+		ok, err := m.checkAndBootstrap(ctx)
+		if err != nil {
+			return nil, nil, err
+		}
+		if !ok {
+			return nil, nil, nil
+		}
+	}
+
 	m.justSentDDL = nil
 	m.updateCheckpointTs(checkpointTs, tableCheckpoint)
 
@@ -598,6 +624,53 @@ func (m *ddlManager) cleanCache() {
 	m.physicalTablesCache = nil
 }
 
+func (m *ddlManager) checkAndBootstrap(ctx context.Context) (bool, error) {
+	if atomic.LoadInt32(&m.bootstrapState) == int32(bootstrapStateCompleted) {
+		return true, nil
+	}
+
+	select {
+	case err := <-m.errCh:
+		return false, err
+	default:
+	}
+
+	if atomic.LoadInt32(&m.bootstrapState) == int32(bootstrapStateRunning) {
+		return false, nil
+	}
+	// begin bootstrap
+	atomic.StoreInt32(&m.bootstrapState, int32(bootstrapStateRunning))
+	tables, err := m.allTables(ctx)
+	if err != nil {
+		return false, err
+	}
+	bootstrapEvents := make([]*model.DDLEvent, 0, len(tables))
+	for _, table := range tables {
+		ddlEvent := &model.DDLEvent{
+			StartTs:     m.startTs,
+			CommitTs:    m.startTs,
+			TableInfo:   table,
+			IsBootstrap: true,
+		}
+		bootstrapEvents = append(bootstrapEvents, ddlEvent)
+	}
+	// send bootstrap events
+	go func() {
+		for _, event := range bootstrapEvents {
+			err := m.ddlSink.emitBootstrapEvent(ctx, event)
+			if err != nil {
+				log.Error("emit bootstrap event failed",
+					zap.Any("bootstrapEvent", event), zap.Error(err))
+				atomic.StoreInt32(&m.bootstrapState, int32(bootstrapStateNone))
+				m.errCh <- err
+				return
+			}
+		}
+		atomic.StoreInt32(&m.bootstrapState, int32(bootstrapStateCompleted))
+	}()
+	return false, nil
+}
+
 // getRelatedPhysicalTableIDs get all related physical table ids of a ddl event.
 // It is a helper function to calculate tableBarrier.
 func getRelatedPhysicalTableIDs(ddl *model.DDLEvent) []model.TableID {

cdc/owner/ddl_sink.go

@@ -54,6 +54,7 @@ type DDLSink interface {
 	// the DDL event will be sent to another goroutine and execute to downstream
 	// the caller of this function can call again and again until a true returned
 	emitDDLEvent(ctx context.Context, ddl *model.DDLEvent) (bool, error)
+	emitBootstrapEvent(ctx context.Context, ddl *model.DDLEvent) error
 	emitSyncPoint(ctx context.Context, checkpointTs uint64) error
 	// close the ddlsink, cancel running goroutine.
 	close(ctx context.Context) error
@@ -384,6 +385,22 @@ func (s *ddlSinkImpl) emitDDLEvent(ctx context.Context, ddl *model.DDLEvent) (bo
 	return false, nil
 }
 
+// emitBootstrapEvent sent bootstrap event to downstream.
+// It is a synchronous operation.
+func (s *ddlSinkImpl) emitBootstrapEvent(ctx context.Context, ddl *model.DDLEvent) error {
+	if !ddl.IsBootstrap {
+		return nil
+	}
+	err := s.sink.WriteDDLEvent(ctx, ddl)
+	if err != nil {
+		return errors.Trace(err)
+	}
+	// TODO: change this log to debug level after testing complete.
+	log.Info("emit bootstrap event", zap.String("namespace", s.changefeedID.Namespace),
+		zap.String("changefeed", s.changefeedID.ID), zap.Any("bootstrapEvent", ddl))
+	return nil
+}
+
 func (s *ddlSinkImpl) emitSyncPoint(ctx context.Context, checkpointTs uint64) (err error) {
 	if checkpointTs == s.lastSyncPoint {
 		return nil