[pgpool-general: 3456] Re: Questions about getting pgpool to handle failover more smoothly
Reuven M. Lerner
reuven at lerner.co.il
Wed Feb 4 21:51:57 JST 2015
Hi, Tatsuo. First and foremost, thanks so much for your work on
pgpool-II. I'm appreciative and impressed!
> I am not familiar with repmgr but I guess pgpool-II is confused by
> being taken over the task of failover and promotion by repmgr.
That's quite possible.
> To let pgpool-II properly work, you need to let pgpool-II handle
> faiover and promotion.
Ignoring the use of repmgr (since I don't think that it's connected),
I'm wondering whether it's normal for pgpool-II to reset existing
connections when one of the nodes fails. From the documentation, this
would appear to be the case:
> When a failover is performed, pgpool kills all its child processes,
> which will in turn terminate all active sessions to pgpool. Then
> pgpool invokes the failover_command and waits for its
> completion. After this, pgpool starts new child processes and is
> ready again to accept connections from clients.
So it sounds like no matter how I do the replication, pgpool will reset
all incoming sessions. Is this the case? And if so, why?
I know that most clients can handle a reset like this, but I'm just
curious to know why pgpool can't continue to service the incoming
connections, and shield the failover from the outside world.
Reuven M. Lerner, PhD -- Web development, consulting, and training
Mobile: +972-54-496-8405 * US phone: 847-230-9795
http://lerner.co.il * Skype / WeChat: ReuvenLerner * @reuvenmlerner
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