便于数据恢复，设置从库延迟主库1个小时
此图借用李磊的 直接上图了 非本人笔记
CHANGE MASTER TO MASTER_DELAY = 1800；单位为秒
[root@backup ~]# mysql -uroot -p123456 -e "show slave status \G"|grep -i sql mysql: [Warning] Using a password on the command line interface can be insecure. Master_Log_File: mysql-bin.000008 Relay_Master_Log_File: mysql-bin.000008 Slave_SQL_Running: Yes Last_SQL_Errno: 0 Last_SQL_Error: Master_Info_File: /home/nflow/data/backup/mysql/data/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates Last_SQL_Error_Timestamp:
[root@backup ~]# mysql -uroot -p123456 -e "show slave status \G"|grep -i sql mysql: [Warning] Using a password on the command line interface can be insecure. Master_Log_File: mysql-bin.000008 Relay_Master_Log_File: mysql-bin.000008 Slave_SQL_Running: Yes Last_SQL_Errno: 0 Last_SQL_Error: Master_Info_File: /home/nflow/data/backup/mysql/data/master.info SQL_Delay: 1800 #代表延迟同步1800s SQL_Remaining_Delay: 1775 #从1800 每秒减一个 Slave_SQL_Running_State: Waiting until MASTER_DELAY seconds after master executed event Last_SQL_Error_Timestamp: [root@backup ~]#
SQL_Delay：正数表明slave有延迟了。
SQL_Remaining_Delay：整数表明延迟时间。
Slave_SQL_Running_State：表明sql线程状态。