slave have equal MySQL server UUIDs

港控/mmm° 2022-08-07 01:46 10阅读 0赞

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
    [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
    [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 |
    +-----------+------+------+-----------+--------------------------------------+
    ### Author : Leshami
    ### Blog   : http://blog.csdn.net/leshami

4、延生参考  
a、有关server\_id的描述  
The server ID, used in replication to give each master and slave a unique identity. This variable is set  
by the --server-id option. For each server participating in replication, you should pick a  
positive integer in the range from 1 to 232– 1(2的32次方减1) to act as that server's ID.

b、有关 server\_uuid的描述  
Beginning with MySQL 5.6, the server generates a true UUID in addition to the --server-id  
supplied by the user. **This is available as the global, read-only variable server\_uuid**(全局只读变量)

When starting, the MySQL server automatically obtains a UUID as follows:  
a).  Attempt to read and use the UUID written in the file data\_dir/auto.cnf (where data\_dir is  
the server's data directory); exit on success.  
b). Otherwise, generate a new UUID and save it to this file, creating the file if necessary.  
The auto.cnf file has a format similar to that used for my.cnf or my.ini files. In MySQL 5.6,  
auto.cnf has only a single \[auto\] section containing a single server\_uuid \[1992\] setting and  
value;

**Important  
The auto.cnf file is automatically generated; you should not attempt to write  
or modify this file**

Also beginning with MySQL 5.6, when using MySQL replication, masters and slaves know one  
another's UUIDs. The value of a slave's UUID can be seen in the output of SHOW SLAVE HOSTS. Once  
START SLAVE has been executed (but not before), the value of the master's UUID is available on the  
slave in the output of SHOW SLAVE STATUS.

In MySQL 5.6.5 and later, a server's server\_uuid is also used in GTIDs for transactions originating  
on that server. For more information, see Section 16.1.3, “Replication with Global Transaction