ddl(dm): make skipped ddl pass SplitDDL() (#4176)

close #4173

dm/syncer/syncer.go

@@ -2163,26 +2163,37 @@ func (s *Syncer) handleQueryEvent(ev *replication.QueryEvent, ec eventContext, o
 		appliedDDLs:  make([]string, 0),
 		sourceTbls:   make(map[string]map[string]struct{}),
 	}
-	qec.p, err = event.GetParserForStatusVars(ev.StatusVars)
-	if err != nil {
-		log.L().Warn("found error when get sql_mode from binlog status_vars", zap.Error(err))
-	}
 
-	stmt, err := parseOneStmt(qec)
-	if err != nil {
-		// return error if parse fail and filter fail
+	defer func() {
+		if err == nil {
+			return
+		}
+		// why not `skipSQLByPattern` at beginning, but at defer?
+		// it is in order to track every ddl except for the one that will cause error.
+		// if `skipSQLByPattern` at beginning, some ddl should be tracked may be skipped.
 		needSkip, err2 := s.skipSQLByPattern(qec.originSQL)
 		if err2 != nil {
-			return err2
+			err = err2
+			return
 		}
 		if !needSkip {
-			return err
+			return
 		}
-		// don't return error if parse fail and filter success
+		// don't return error if filter success
 		metrics.SkipBinlogDurationHistogram.WithLabelValues("query", s.cfg.Name, s.cfg.SourceID).Observe(time.Since(ec.startTime).Seconds())
 		ec.tctx.L().Warn("skip event", zap.String("event", "query"), zap.Stringer("query event context", qec))
 		*ec.lastLocation = *ec.currentLocation // before record skip location, update lastLocation
-		return s.recordSkipSQLsLocation(&ec)
+		err = s.recordSkipSQLsLocation(&ec)
+	}()
+
+	qec.p, err = event.GetParserForStatusVars(ev.StatusVars)
+	if err != nil {
+		log.L().Warn("found error when get sql_mode from binlog status_vars", zap.Error(err))
+	}
+
+	stmt, err := parseOneStmt(qec)
+	if err != nil {
+		return err
 	}
 
 	if node, ok := stmt.(ast.DMLNode); ok {

dm/tests/all_mode/run.sh

@@ -380,6 +380,15 @@ function run() {
 	# use sync_diff_inspector to check full dump loader
 	check_sync_diff $WORK_DIR $cur/conf/diff_config.toml
 
+	# check create view(should be skipped by func `skipSQLByPattern`) will not stop sync task
+	run_sql_source1 "create view all_mode.t1_v as select * from all_mode.t1 where id=0;"
+	sleep 1
+	run_dm_ctl $WORK_DIR "127.0.0.1:$MASTER_PORT" \
+		"query-status -s $SOURCE_ID1" \
+		"\"result\": true" 2 \
+		"\"unit\": \"Sync\"" 1 \
+		"\"stage\": \"Running\"" 2
+
 	run_sql_source1 "SHOW SLAVE HOSTS;"
 	check_contains 'Slave_UUID'
 
@@ -498,7 +507,6 @@ function run() {
 	check_log_not_contains $WORK_DIR/worker2/log/dm-worker.log "Error .* Table .* doesn't exist"
 
 	# test Db not exists should be reported
-
 	run_sql_tidb "drop database all_mode"
 	run_sql_source1 "create table all_mode.db_error (c int primary key);"
 	run_dm_ctl_with_retry $WORK_DIR "127.0.0.1:$MASTER_PORT" \