報錯信息：
在搭建Mysql主從架構過程中，由於從服務器是克隆的主服務器系統，導致主從Mysql uuid相同， Slave_IO無法啓動，報錯如下：
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.
解決方法：
找到auto.cnf文件，修改裏面的uuid值，保證各個db的uuid不一樣，重啓db即可。
1.查看主庫與從庫UUID
[root@localhost ~]# find / -name auto.cnf
/var/lib/mysql/auto.cnf
[root@localhost ~]# cat /var/lib/mysql/auto.cnf //查看主數據庫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%'; //查看主數據庫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 //查看從數據庫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%'; //查看從數據庫UUID
+---------------+--------------------------------------+
| Variable_name | Value |
+---------------+--------------------------------------+
| server_uuid | e46c9961-5780-11ea-bf2f-000c291a8b6b |
+---------------+--------------------------------------+
2.修改主庫或者從庫auto.cnf文件的UUID
[root@localhost ~]# vim /var/lib/mysql/auto.cnf //修改主庫的auto.cnf文件的UUID
[auto]
server-uuid=e46c9961-5780-11ea-bf2f-000c128a8b6b
[root@localhost ~]# systemctl restart mysqld
3.從庫重啓slave進程，查看slave狀態
[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線程、SQL線程都是Yes狀態。