Slave failed to initialize relay log info structure from the repository问题的

郑全

启动备库时，报以下错误：

mysql> start slave;
ERROR 1872 (HY000): Slave failed to initialize relay log info structure from the repository

 

查看slave状态，发现以下情况：Relay_Log_File: sztech1-relay-bin.000001
Relay_Log_File:按理应该为mysql3db-relay-bin才对，

 

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State:
                  Master_Host: 127.0.0.1
                  Master_User: xx
                  Master_Port: 3307
                Connect_Retry: 60
              Master_Log_File: mysql1db-bin.000006
          Read_Master_Log_Pos: 120
               Relay_Log_File: sztech1-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: sztech1-bin.000004
             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:
                   Last_Errno: 1872
                   Last_Error: Slave failed to initialize relay log info structure from the repository
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 327
              Relay_Log_Space: 0
              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: 1872
               Last_SQL_Error: Slave failed to initialize relay log info structure from the repository
  Replicate_Ignore_Server_Ids:
             Master_Server_Id: 0
                  Master_UUID:
             Master_Info_File: /var/lib/mysql3309/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State:
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp: 141219 17:26:10
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position: 0
1 row in set (0.00 sec)

 

估计 由于新的slave改变了服务端口和文件路径，分析应该是由于mysql-relay-bin.index中仍然保存着旧relay日志文件的路径，而这些路径下又找不到合适的文件，因此报错。对于这类问题解决起来是比较简单的，重置slave的参照即可，执行命令如下：
mysql> reset slave；

 

之后，再stop slave,再 start slave之后，就好了：

 

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 127.0.0.1
                  Master_User: xx
                  Master_Port: 3307
                Connect_Retry: 60
              Master_Log_File: mysql1db-bin.000007
          Read_Master_Log_Pos: 120
               Relay_Log_File: mysql3db-relay-bin.000010
                Relay_Log_Pos: 286
        Relay_Master_Log_File: mysql1db-bin.000007
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB:
           Replicate_Do_Table:
       Replicate_Ignore_Table:
      Replicate_Wild_Do_Table:
  Replicate_Wild_Ignore_Table:
                   Last_Errno: 0
                   Last_Error:
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 120
              Relay_Log_Space: 628
              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: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error:
               Last_SQL_Errno: 0
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Master_Server_Id: 1
                  Master_UUID: 238ddde3-879c-11e4-bc7a-000c293e4707
             Master_Info_File: /var/lib/mysql3309/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position: 0
1 row in set (0.00 sec)