报错信息：
在搭建Mysql主从架构过程中，由于从服务器是克隆的主服务器系统，导致主从Mysql uuid相同， Slave_IO无法启动，报错如下：
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.
解决方法：
找到auto.cnf文件，修改里面的uuid值，保证各个db的uuid不一样，重启db即可。
1.查看主库与从库UUID
[root@localhost ~]# find / -name auto.cnf /var/lib/mysql/auto.cnf [root@localhost ~]# cat /var/lib/mysql/auto.cnf //查看主数据库auto.cnf文件中的UUID信息 [auto] server-uuid=e46c9961-5780-11ea-bf2f-000c291a8b6b [root@localhost ~]# mysql -uroot -p123qqq...A ... mysql> show variables like '%server_uuid%'; //查看主数据库UUID +---------------+--------------------------------------+ | Variable_name | Value | +---------------+--------------------------------------+ | server_uuid | e46c9961-5780-11ea-bf2f-000c291a8b6b | +---------------+--------------------------------------+
[root@test2 ~]# find / -name auto.cnf /var/lib/mysql/auto.cnf [root@test2 ~]# cat /var/lib/mysql/auto.cnf //查看从数据库auto.cnf中的UUID信息 [auto] server-uuid=e46c9961-5780-11ea-bf2f-000c291a8b6b [root@test2 ~]# mysql -uroot -p123qqq...A ... mysql> show variables like '%server_uuid%'; //查看从数据库UUID +---------------+--------------------------------------+ | Variable_name | Value | +---------------+--------------------------------------+ | server_uuid | e46c9961-5780-11ea-bf2f-000c291a8b6b | +---------------+--------------------------------------+
2.修改主库或者从库auto.cnf文件的UUID
[root@localhost ~]# vim /var/lib/mysql/auto.cnf //修改主库的auto.cnf文件的UUID [auto] server-uuid=e46c9961-5780-11ea-bf2f-000c128a8b6b [root@localhost ~]# systemctl restart mysqld
3.从库重启slave进程，查看slave状态
[root@test2 ~]# mysql -uroot -p123qqq...A ... mysql> stop slave; mysql> start slave; mysql> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.2.128 Master_User: mysqluser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: db128.000002 Read_Master_Log_Pos: 452757169 Relay_Log_File: test2-relay-bin.000002 Relay_Log_Pos: 3205508 Relay_Master_Log_File: db128.000002 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: 452757169 Relay_Log_Space: 3205715 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: 128 Master_UUID: e46c9961-5780-11ea-bf2f-000c128a8b6b Master_Info_File: /var/lib/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates 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 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)
可以看到IO线程、SQL线程都是Yes状态。
