MySQL主从同步故障

故障现象： 进入slave服务器，运行： mysql show slave status\G ....... Relay_Log_File: localhost-relay-bin.000535 Relay_Log_Pos: 21795072 Relay_Master_Log_File: localhost-bin.000094 Slave_IO_Running: Yes Slave_SQL_Running: No Replicate_Do_DB

故障现象：

进入slave服务器，运行：

mysql> show slave status\G

         .......
             Relay_Log_File: localhost-relay-bin.000535
              Relay_Log_Pos: 21795072
      Relay_Master_Log_File: localhost-bin.000094
          Slave_IO_Running: Yes
          Slave_SQL_Running: No
            Replicate_Do_DB: 
        Replicate_Ignore_DB: 
       ......

解决办法一、

Slave_SQL_Running: No
1.程序可能在slave上进行了写操作

2.也可能是slave机器重起后，事务回滚造成的.

一般是事务回滚造成的：
解决办法：
mysql> slave stop;
mysql> set GLOBAL SQL_SLAVE_SKIP_COUNTER=1;
mysql> slave start;

解决办法二、

首先停掉Slave服务：slave stop
到主服务器上查看主机状态：
记录File和Position对应的值

进入master

mysql> show master status;
+----------------------+----------+--------------+------------------+
| File                 | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+----------------------+----------+--------------+------------------+
| localhost-bin.000094 | 33622483 |              |                  | 
+----------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

然后到slave服务器上执行手动同步：

mysql> change master to 
> master_host='master_ip',
> master_user='user', 
> master_password='pwd', 
> master_port=3306, 
> master_log_file=localhost-bin.000094', 
> master_log_pos=33622483 ;
1 row in set (0.00 sec)
mysql> slave start;
1 row in set (0.00 sec)

mysql> show slave status\G
*************************** 1. row ***************************
........
            Master_Log_File: localhost-bin.000094
        Read_Master_Log_Pos: 33768775
             Relay_Log_File: localhost-relay-bin.000537
              Relay_Log_Pos: 1094034
      Relay_Master_Log_File: localhost-bin.000094
           Slave_IO_Running: Yes
          Slave_SQL_Running: Yes
            Replicate_Do_DB:

手动同步需要停止master的写操作！