enable tx for ob by default

session/core.go

@@ -490,11 +490,6 @@ func (s *session) checkOptions() error {
 		return fmt.Errorf("con:%d %v", s.sessionVars.ConnectionID, err)
 	}
 
-	if s.opt.tranBatch > 1 {
-		s.ddlDB, _ = gorm.Open("mysql", fmt.Sprintf("%s&autocommit=1", addr))
-		s.ddlDB.LogMode(false)
-	}
-
 	// 禁用日志记录器，不显示任何日志
 	db.LogMode(false)
 
@@ -513,13 +508,13 @@ func (s *session) checkOptions() error {
 		if s.inc.BackupHost == "" || s.inc.BackupPort == 0 || s.inc.BackupUser == "" {
 			return errors.New(s.getErrorMessage(ER_INVALID_BACKUP_HOST_INFO))
 		}
-		addr = fmt.Sprintf("%s:%s@tcp(%s:%d)/?charset=%s&parseTime=True&loc=Local&autocommit=1",
+		backupAddr := fmt.Sprintf("%s:%s@tcp(%s:%d)/?charset=%s&parseTime=True&loc=Local&autocommit=1",
 			s.inc.BackupUser, s.inc.BackupPassword, s.inc.BackupHost, s.inc.BackupPort,
 			s.inc.DefaultCharset)
 		if s.inc.BackupTLS != "" {
 			addr += "&tls=" + s.inc.BackupTLS
 		}
-		backupdb, err := gorm.Open("mysql", addr)
+		backupdb, err := gorm.Open("mysql", backupAddr)
 
 		if err != nil {
 			return fmt.Errorf("con:%d %v", s.sessionVars.ConnectionID, err)
@@ -552,6 +547,16 @@ func (s *session) checkOptions() error {
 		s.appendErrorMsg("TiDB暂不支持备份功能.")
 	}
 
+	if s.opt.Backup && s.needTransactionMark() && s.opt.tranBatch <= 1 {
+		s.opt.tranBatch = 50
+		log.Infof("enable transaction with batch size %d to backup with transaction mark", 50)
+	}
+
+	if s.opt.tranBatch > 1 {
+		s.ddlDB, _ = gorm.Open("mysql", fmt.Sprintf("%s&autocommit=1", addr))
+		s.ddlDB.LogMode(false)
+	}
+
 	return nil
 }