二重化主备切换过程中Postgresql的状态变化

在使用pacemaker部署的主备服务器环境中，由于使用到了postgresql，对其复杂的状态变化做了如下整理。

1.pgsql-status

￭PRI : running as Primary(Master)
￭HS : running as Hot Standby(Slave)
    HS:alone : running as Hot Standby,not connected to Primary
    HS:async : running as Hot Standby in Asynchronous replication mode
    HS:sync : running as Hot Standby in Synchronous replication mode
￭STOP : stopped

2.pgsql-data-status

￭DISCONNECT:
    Master changes other node state into DISCONNECT if Master can't detect connection of replication because of LAN failure or breakdown of Slave and so on.
￭{state}|{sync_state}
    Master changes other node state into {state}|{sync_state} if Master detects connection of replication.
    {state} and {sync_state} means state of replication which is retrieved using "select state and sync_state from pg_stat_replication" on Master.
    For example, INIT, CATCHUP, and STREAMING are displayed in {state} and ASYNC, SYNC are displayed in {sync_state}
￭LATEST:
    It's displayed when it's Master.

3.Pacemaker's status

￭Master : manage PostgreSQL as Master
￭Slave : manage PostgreSQL as Slave
￭Stopped : manage PostgreSQL as Stopped     

4.status change