報錯：
1）
change master導致的：
Last_IO_Error: error connecting to master 'repl1@IP:3306' - retry-time: 60 retries
2）
在沒有解鎖的情況下停止slave進程：
mysql> stop slave;
ERROR 1192 (HY000): Can't execute the given command because you have active locked tables or an active transaction
3）
change master語法錯誤，落下逗號
mysql> change master to
-> master_host='IP'
-> master_user='USER',
-> master_password='PASSWD',
-> master_log_file='mysql-bin.000002',
-> master_log_pos=106;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'master_user='USER',
master_password='PASSWD',
master_log_file='mysql-bin.000002' at line 3
4）
在沒有停止slave進程的情況下change master
mysql> change master to master_host=‘IP', master_user='USER', master_password='PASSWD', master_log_file='mysql-bin.000001',master_log_pos=106;
ERROR 1198 (HY000): This operation cannot be performed with a running slave; run STOP SLAVE first
5）
A B的server-id相同：
Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server ids;
these ids must be different for replication to work (or the --replicate-same-server-id option must be used on
slave but this does not always make sense; please check the manual before using it).
查看server-id
mysql> show variables like 'server_id';
手動修改server-id
mysql> set global server_id=2; #此處的數值和my.cnf裡設置的一樣就行
mysql> slave start;
6）change master之後，查看slave的狀態，發現slave_IO_running 為NO
需要注意的是，做完上述操作之後最後重啟mysql進程
摘自：ANLJF的專欄
