MySQL 5.7延迟复制是通过设置复制参数MASTER_DELAY实现(单位为秒，就是从库延迟多少秒后执行这条SQL)

例如：

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
               Master_Host: 10.10.1.101
               .....
              Slave_IO_Running: Yes
                Slave_SQL_Running: Yes
                ......
                Seconds_Behind_Master: 0
                .....
        SQL_Delay: 0
        SQL_Remaining_Delay: 0
                ......
        Channel_Name: master
        Master_TLS_Version: 
1 row in set (0.00 sec)

配置复制master延迟14400秒

mysql> stop slave;
Query OK, 0 rows affected (0.00 sec)

mysql> CHANGE MASTER TO MASTER_DELAY=14400 for channel 'master';
    Query OK, 0 rows affected (0.01 sec)`1q

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

查看结果

mysql> show slave status\G
*************************** 1. row ***************************
 Slave_IO_State: Opening tables
 Master_Host: 10.10.1.101
 .....
 Slave_IO_Running: Yes
 Slave_SQL_Running: Yes
 .....
 Seconds_Behind_Master: 12
.......
 SQL_Delay: 14400
 SQL_Remaining_Delay: 12
 ........
 Channel_Name: master
 Master_TLS_Version: 
1 row in set (0.00 sec)