fix(cdc): skip foreign key tables in scanner

Author: jiangxinmeng1

pkg/cdc/sql_builder.go

@@ -248,19 +248,20 @@ const (
 		"table_name = '%s'"
 
 	CDCCollectTableInfoSqlTemplate = "SELECT " +
-		" rel_id, " +
-		" relname, " +
-		" reldatabase_id, " +
-		" reldatabase, " +
-		" rel_createsql, " +
-		" account_id " +
-		"FROM `mo_catalog`.`mo_tables` " +
+		" tbl.rel_id, " +
+		" tbl.relname, " +
+		" tbl.reldatabase_id, " +
+		" tbl.reldatabase, " +
+		" tbl.rel_createsql, " +
+		" tbl.account_id, " +
+		" tbl.`constraint` " +
+		"FROM `mo_catalog`.`mo_tables` tbl " +
 		"WHERE " +
-		" account_id IN (%s) " +
+		" tbl.account_id IN (%s) " +
 		"%s" +
 		"%s" +
-		" AND relkind = '%s' " +
-		" AND reldatabase NOT IN (%s)"
+		" AND tbl.relkind = '%s' " +
+		" AND tbl.reldatabase NOT IN (%s)"
 	CDCInsertMOISCPLogSqlTemplate = `REPLACE INTO mo_catalog.mo_iscp_log (` +
 		`account_id,` +
 		`table_id,` +
@@ -475,6 +476,7 @@ var CDCSQLTemplates = [CDCSqlTemplateCount]struct {
 			"reldatabase",
 			"rel_createsql",
 			"account_id",
+			"constraint",
 		},
 	},
 	CDCGetWatermarkWhereSqlTemplate_Idx: {
@@ -1071,13 +1073,13 @@ func (b cdcSQLBuilder) CollectTableInfoSQL(accountIDs string, dbNames string, ta
 			if dbNames == "*" {
 				return ""
 			}
-			return " AND reldatabase IN (" + dbNames + ") "
+			return " AND tbl.reldatabase IN (" + dbNames + ") "
 		}(),
 		func() string {
 			if tableNames == "*" {
 				return ""
 			}
-			return " AND relname IN (" + tableNames + ") "
+			return " AND tbl.relname IN (" + tableNames + ") "
 		}(),
 		catalog.SystemOrdinaryRel,
 		AddSingleQuotesJoin(catalog.SystemDatabases),

pkg/cdc/table_change_stream.go

@@ -603,8 +603,8 @@ func (s *TableChangeStream) cleanup(ctx context.Context) {
 		)
 	}()
 
-	// Remove from running readers
-	s.runningReaders.Delete(s.runningReaderKey)
+	// Remove from running readers only if this stream still owns the entry.
+	s.runningReaders.CompareAndDelete(s.runningReaderKey, s)
 
 	// Remove watermark cache
 	removeStart := time.Now()

pkg/cdc/table_change_stream_test.go

@@ -378,6 +378,43 @@ func TestTableChangeStream_Run_DuplicateReader(t *testing.T) {
 	}
 }
 
+func TestTableChangeStreamCleanupDoesNotDeleteReplacedReader(t *testing.T) {
+	runningReaders := &sync.Map{}
+
+	key := "db1.t1"
+	oldStream := &TableChangeStream{
+		accountId:               1,
+		taskId:                  "task1",
+		tableInfo:               &DbTableInfo{SourceDbName: "db1", SourceTblName: "t1", SourceTblId: 1},
+		sinker:                  newTableStreamRecordingSinker(),
+		watermarkUpdater:        newWatermarkUpdaterStub(),
+		watermarkKey:            &WatermarkKey{AccountId: 1, TaskId: "task1", DBName: "db1", TableName: "t1"},
+		runningReaders:          runningReaders,
+		runningReaderKey:        key,
+		progressTracker:         nil,
+		watermarkStallThreshold: defaultWatermarkStallThreshold,
+	}
+	newStream := &TableChangeStream{
+		accountId:        1,
+		taskId:           "task1",
+		tableInfo:        &DbTableInfo{SourceDbName: "db1", SourceTblName: "t1", SourceTblId: 1},
+		sinker:           newTableStreamRecordingSinker(),
+		watermarkUpdater: newWatermarkUpdaterStub(),
+		watermarkKey:     &WatermarkKey{AccountId: 1, TaskId: "task1", DBName: "db1", TableName: "t1"},
+		runningReaders:   runningReaders,
+		runningReaderKey: key,
+	}
+	runningReaders.Store(key, oldStream)
+	runningReaders.Store(key, newStream)
+
+	oldStream.wg.Add(1)
+	oldStream.cleanup(context.Background())
+
+	stored, ok := runningReaders.Load(key)
+	require.True(t, ok, "replaced reader ownership should remain")
+	require.Same(t, newStream, stored, "old cleanup must not delete a newer reader")
+}
+
 // Integration: commit failure triggers EnsureCleanup rollback, then recovery succeeds
 func TestTableChangeStream_CommitFailure_EnsureCleanup_ThenRecover(t *testing.T) {
 	updaterStub := newWatermarkUpdaterStub()

pkg/cdc/table_scanner.go

@@ -19,7 +19,6 @@ import (
 	"fmt"
 	"runtime/debug"
 	"slices"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -37,6 +36,7 @@ import (
 	"github.com/matrixorigin/matrixone/pkg/defines"
 	"github.com/matrixorigin/matrixone/pkg/logutil"
 	"github.com/matrixorigin/matrixone/pkg/util/executor"
+	"github.com/matrixorigin/matrixone/pkg/vm/engine"
 )
 
 const (
@@ -744,6 +744,7 @@ func (s *TableDetector) scanTable() error {
 	}
 	defer result.Close()
 
+	var scanErr error
 	result.ReadRows(func(rows int, cols []*vector.Vector) bool {
 		for i := 0; i < rows; i++ {
 			tblId := vector.MustFixedColWithTypeCheck[uint64](cols[0])[i]
@@ -752,9 +753,21 @@ func (s *TableDetector) scanTable() error {
 			dbName := cols[3].GetStringAt(i)
 			createSql := cols[4].GetStringAt(i)
 			accountId := vector.MustFixedColWithTypeCheck[uint32](cols[5])[i]
+			hasForeignKey, decodeErr := tableHasForeignKeyConstraint(cols[6].GetBytesAt(i))
+			if decodeErr != nil {
+				scanErr = decodeErr
+				logutil.Warn(
+					"cdc.table_detector.scan_constraint_failed",
+					zap.Uint32("account-id", accountId),
+					zap.String("db", dbName),
+					zap.String("table", tblName),
+					zap.Error(decodeErr),
+				)
+				return false
+			}
 
 			// skip table with foreign key
-			if strings.Contains(strings.ToLower("createSql"), "foreign key") {
+			if hasForeignKey {
 				continue
 			}
 
@@ -776,21 +789,48 @@ func (s *TableDetector) scanTable() error {
 				mp[accountId][key] = newInfo
 			} else {
 				idChanged := oldInfo.OnlyDiffinTblId(newInfo)
-				oldInfo.SourceDbId = dbId
-				oldInfo.SourceDbName = dbName
-				oldInfo.SourceTblId = tblId
-				oldInfo.SourceTblName = tblName
-				oldInfo.SourceCreateSql = createSql
-				oldInfo.IdChanged = oldInfo.IdChanged || idChanged
-				mp[accountId][key] = oldInfo
+				updatedInfo := oldInfo.Clone()
+				updatedInfo.SourceDbId = dbId
+				updatedInfo.SourceDbName = dbName
+				updatedInfo.SourceTblId = tblId
+				updatedInfo.SourceTblName = tblName
+				updatedInfo.SourceCreateSql = createSql
+				updatedInfo.IdChanged = updatedInfo.IdChanged || idChanged
+				mp[accountId][key] = updatedInfo
 			}
 		}
 		return true
 	})
+	if scanErr != nil {
+		return scanErr
+	}
 
 	// replace the old table map
 	s.mu.Lock()
 	s.Mp = mp
 	s.mu.Unlock()
 	return nil
 }
+
+func tableHasForeignKeyConstraint(data []byte) (hasForeignKey bool, err error) {
+	if len(data) == 0 {
+		return false, nil
+	}
+
+	defer func() {
+		if r := recover(); r != nil {
+			err = moerr.NewInternalErrorNoCtxf("unmarshal table constraint failed: %v", r)
+		}
+	}()
+
+	constraintDef := &engine.ConstraintDef{}
+	if err := constraintDef.UnmarshalBinary(data); err != nil {
+		return false, err
+	}
+	for _, constraint := range constraintDef.Cts {
+		if foreignKeyDef, ok := constraint.(*engine.ForeignKeyDef); ok && len(foreignKeyDef.Fkeys) > 0 {
+			return true, nil
+		}
+	}
+	return false, nil
+}