环境：

redhat7.5 

mysql5.7

老IP ：192.168.1.1， 192.168.1.2

新IP ：192.168.3.3， 192.168.3.4

--备库停机

mysql> stop slave;

systemctl stop mysqld

--主库停机

systemctl stop mysqld

--修改主库备库服务器IP

--起主库

systemctl start mysqld

--主库增加新同步用户授权到新IP
grant replication slave on *.* to 'repl'@'192.168.3.4' identified by 'xxx';

--删除老的同步用户

delete from mysql.user where user='repl' and host='192.168.1.2';

flush privileges;

show grants for 'repl'@'192.168.3.4';

--查看主库当前的偏移量（如果使用gtid可以不用记录）
show master status \G
        
        
        
--起从库

systemctl start mysqld

stop slave;

change master to master_host='192.168.3.3', master_user='repl',master_password='xxx',master_port=3306,master_auto_position=1;

start slave;

grant replication slave on *.* to 'repl'@'192.168.3.3' identified by 'xxx';

flush privileges;

--删除老的同步用户

delete from mysql.user where user='repl' and host='192.168.1.1';

--确认同步状态

show slave status\G