The slave I/O thread stops because master and slave have equal MySQL server UUIDs；

最近在部署MySQL主从复制架构的时候，碰到了"Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs;  these UUIDs must be different for replication to work." 这个错误提示。即主从架构中使用了相同的UUID。检查server_id系统变量，已经是不同的设置，那原因是？接下来为具体描述。

1、错误消息
mysql> show slave staus;
 
Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; 
these UUIDs must be different for replication to work.
 
2、查看主从的server_id变量
master_mysql> show variables like 'server_id';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id    | 33    |
+---------------+-------+

slave_mysql> show variables like 'server_id';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id    | 11    |
+---------------+-------+
-- 从上面的情形可知，主从mysql已经使用了不同的server_id

3、解决故障
###查看auto.cnf文件    -----find / -name auto.cnf 查找auto.cnf的路径
[root@dbsrv1 ~] cat /data/mysqldata/auto.cnf  ### 主上的uuid
[auto]
server-uuid=62ee10aa-b1f7-11e4-90ae-080027615026

[root@dbsrv2 ~]# more /data/mysqldata/auto.cnf ###从上的uuid，果然出现了重复，原因是克隆了虚拟机，只改server_id不行
[auto]
server-uuid=62ee10aa-b1f7-11e4-90ae-080027615026

[root@dbsrv2 ~]# mv /data/mysqldata/auto.cnf  /data/mysqldata/auto.cnf.bk  ###重命名该文件或直接删除该文件然后重启
[root@dbsrv2 ~]# service mysql restart          ###重启mysql
Shutting down MySQL.[  OK  ]
Starting MySQL.[  OK  ]
[root@dbsrv2 ~]# more /data/mysqldata/auto.cnf  ###重启后自动生成新的auto.cnf文件，即新的UUID
[auto]
server-uuid=6ac0fdae-b5d7-11e4-a9f3-0800278ce5c9

###再次查看slave的状态已经正常
[root@dbsrv1 ~]# mysql -uroot -pxxx -e "show slave status\G"|grep Running
Warning: Using a password on the command line interface can be insecure.
            Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
      Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it

 

###主库端查看自身的uuid
master_mysql> show variables like 'server_uuid';
+---------------+--------------------------------------+
| Variable_name | Value                                |
+---------------+--------------------------------------+
| server_uuid  | 62ee10aa-b1f7-11e4-90ae-080027615026 |
+---------------+--------------------------------------+
1 row in set (0.00 sec)

###主库端查看从库的uuid
master_mysql> show slave hosts;
+-----------+------+------+-----------+--------------------------------------+
| Server_id | Host | Port | Master_id | Slave_UUID                          |
+-----------+------+------+-----------+--------------------------------------+
|        33 |      | 3306 |        11 | 62ee10aa-b1f7-11e4-90ae-080027615030 |
|        22 |      | 3306 |        11 | 6ac0fdae-b5d7-11e4-a9f3-0800278ce5c9 |
+-----------+------+------+-----------+--------------------------------------+