MySQL双主热备问题处理

1. Slave_IO_Running: No

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State:
                  Master_Host: 172.16.1.21
                  Master_User: cahms
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 20398
               Relay_Log_File: mysqld-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: mysql-bin.000003
             Slave_IO_Running: No
            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: 20398
              Relay_Log_Space: 106
              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: 1593
                Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server ids; these ids must be different for replication to work (or the --replicate-same-server-id option must be used on slave but this does not always make sense; please check the manual before using it).
               Last_SQL_Errno: 0
               Last_SQL_Error:
1 row in set (0.00 sec)

(1) master and slave have equal MySQL server ids
【解决办法】
修改/etc/my.cnf 下的server-id的值，确保master和slave的server-id不一样即可；

(2) Error reading packet from server:

Access denied; you need the REPLICATION SLAVE privilege for this operation ( server_errno=1227)

【解决办法】主服务器给的复制权限不够，重新赋予权限。

```
> grant replication slave on *.* to ‘uname‘@‘对端ip‘ identified by ‘password‘；
> flush privileges；

== e.g ==

> grant replication slave on *.* to ‘root‘@‘172.16.1.21‘ identified by ‘amtium‘;

grant replication slave on . to ‘root’@’172.16.1.23’ identified by ‘amtium’;

**2. Slave_IO_State:** 

Waiting to reconnect after a failed master event read
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting to reconnect after a failed master event read
                  Master_Host: 172.16.1.231
                  Master_User: cahms
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 106
               Relay_Log_File: mysqld-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: mysql-bin.000003
             Slave_IO_Running: No
            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: 106
              Relay_Log_Space: 106
              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: 0
               Last_SQL_Error:
1 row in set (0.00 sec)

【解决办法】

> grant replication slave on *.* to
   ‘root‘@‘172.16.1.228‘ identified by ‘amtium‘;

> grant replication slave on *.* to
  ‘root‘@‘172.16.1.231‘ identified by ‘amtium‘;

> flush privileges;