了解mysql-mmm的6种状态及转变原因

mysql-mmm有6种状态

1.online

2.admin_offline

3.hard_offline

4.awaiting_recovery

5.replication_delay

6.replication_fail

 

各种状态的转换如下:

1.online状态是正常的状态,可以充当各种角色.

2.admin_offline是手动下线的状态

3.复制延迟会导致replication_delay状态

4.复制中断(sql_thread,io_thread)会导致replication_fail状态

5.从replication_delay或者replication_fail状态可以直接恢复到online状态,除非主机被设置为抖动.

6.ping不通并且(或者)mysql连接中断,会导致hard_offline状态.

7.如果能ping通,并且mysql连接状态正常,则会变成为awaiting_recovery状态.

8.两种情况可以从awaiting_recovery状态转变为online状态:

a.故障时间少于60秒并且没有重启过.

b.设置了auto_set_online > 0(抖动状态除外)

 

 

参考:

ONLINE	Host is running without any problems.
ADMIN_OFFLINE	host was set to offline manually.
HARD_OFFLINE	Host is offline (Check ping and/or mysql failed)
AWAITING_RECOVERY	Host is awaiting recovery
REPLICATION_DELAY	replication backlog is too big (Check rep_backlog failed)
REPLICATION_FAIL	replication threads are not running (Check rep_threads failed)

Only hosts with state ONLINE may have roles. When a host switches from ONLINE to any other state, all roles will be removed from it.

A host that was in state REPLICATION_DELAY or REPLICATION_FAIL will be switched back to ONLINE if everything is OK again, unless it is flapping (see ).

A host that was in state HARD_OFFLINE will be switched to AWAITING_RECOVERY if everything is OK again. If its downtime was shorter than 60 seconds and it wasn't rebooted or auto_set_online is > 0 it will be switched back to ONLINE automatically, unless it is flapping (see  again).

Replication backlog or failure on the active master isn't considered to be a problem, so the active master will never be in state REPLICATION_DELAY or REPLICATION_FAIL.

Replication backlog or failure will be ignored on hosts whos peers got ONLINE less than 60 seconds ago (That's the default value of master-connect-retry).

If both checks rep_backlog and rep_threads fail, the state will change to REPLICATION_FAIL.

 

If auto_set_online is > 0, flapping hosts will automatically be set to ONLINE after flap_duration seconds.

 

 

源文档 <>