MySQL5.7主从同步Slave I/O错误解决方法

MySQL5.7主从同步出现以下error：
[ERROR] Slave I/O for channel ‘’: Master command COM_REGISTER_SLAVE failed: Access denied for user ‘sync’@’%’ (using password: YES) (Errno: 1045), Error_code: 1597

解决方法：修改主的授权→GRANT REPLICATION SLAVE ON . TO ‘sync’@’%’ identified by ‘S’;

show grants for ‘sync’@’%’;