> 5.6.23在开启并行复制的时候，进行冷迁移后，start slave报错，set global slave_parallel_workers =0后可正常进行复制。
#### **说明**
已有从库并行复制配置：slave_parallel_workers = 4；通过停库拷贝datadir目录到目标机器，实现冷迁移，完成后目录机器start slave时报如下错误。
#### **具体的报错信息**
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: NULL
Master_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。
可以参考下：http://bugs.mysql.com/bug.php?id=71495 ，之前的版本直接在日志里报的error。
文章最后更新时间：
2016年03月11日 14:43:33
Plaesing to find someone who can think like that
Plaesing to find someone who can think like that
Hey all, anyone try the new Skype app? I have Fresh 3.5, and Skype do;s&n#8217et recognize my phone as the EVO, so it limits the camera to the back facing camera. Does 4.2 get recognized as the EVO?