Master_Log_File: mysql-bin.000283          Read_Master_Log_Pos: 715296037               Relay_Log_File: relay-log.000294                Relay_Log_Pos: 245347818        Relay_Master_Log_File: mysql-bin.000283             Slave_IO_Running: No            Slave_SQL_Running: No              Replicate_Do_DB:           Replicate_Ignore_DB:            Replicate_Do_Table:        Replicate_Ignore_Table:       Replicate_Wild_Do_Table:   Replicate_Wild_Ignore_Table: mysql.%,test.%                   Last_Errno: 1755                   Last_Error: Cannot execute the current event group in the parallel mode. Encountered event Stop, relay-log name ./relay-log.000294, position 245347905 which prevents execution of this event group in parallel mode. Reason: possible malformed group of events from an old master.                 Skip_Counter: 0          Exec_Master_Log_Pos: 245347659              Relay_Log_Space: 715297197              Until_Condition: None               Until_Log_File:                 Until_Log_Pos: 0           Master_SSL_Allowed: No           Master_SSL_CA_File:            Master_SSL_CA_Path:               Master_SSL_Cert:             Master_SSL_Cipher:                Master_SSL_Key:         Seconds_Behind_Master: NULLMaster_SSL_Verify_Server_Cert: No                Last_IO_Errno: 0                Last_IO_Error:                Last_SQL_Errno: 1755               Last_SQL_Error: Cannot execute the current event group in the parallel mode. Encountered event Stop, relay-log name ./relay-log.000294, position 245347905 which prevents execution of this event group in parallel mode. Reason: possible malformed group of events from an old master.  Replicate_Ignore_Server_Ids:              Master_Server_Id: 2331597761                  Master_UUID: 75f94423-e1c1-11e5-8da4-70e2840af125             Master_Info_File: /ssd/mysql/mysql_48284/var/master.info                    SQL_Delay: 0          SQL_Remaining_Delay: NULL      Slave_SQL_Running_State:               Semi_Sync_Group:            Master_Retry_Count: 86400                  Master_Bind:       Last_IO_Error_Timestamp:      Last_SQL_Error_Timestamp: 160311 15:54:17               Master_SSL_Crl:            Master_SSL_Crlpath:            Retrieved_Gtid_Set:             Executed_Gtid_Set:                 Auto_Position: 0

如上报错后，可stop slave后，将slave_parallel_workers设置为0，关闭并行复制,然后再start slave后，重新开启并行复制就没有问题。