Postgres Pro
Downloads
Home   >   mailing lists

Re: Setting up HA postgresql - Mailing list pgsql-general

From William Dunn
Subject Re: Setting up HA postgresql
Date
Msg-id CAEva=VnMZnwfuXoZ45uOKuXGftpPkHtFQUo4MHLJNUKZurs6kw@mail.gmail.com
Whole thread Raw
In response to Re: Setting up HA postgresql  ("Joshua D. Drake" <jd@commandprompt.com>)
Responses Re: Setting up HA postgresql
Re: Setting up HA postgresql
List pgsql-general
Tree view
But it appears that the fail condition for "watchdog" is the failure of a pgpool-II instance. In the configuration described in the wiki you would put a pgpool-II instance on each Postgres node, and if one of the pgpool-II instances fails it executes a script (which can create the trigger file to promote the standby to master). However, if the fail condition for watchdog is a failure of the pgpool-II instance what happens if the DBMS has availability issues but the pgpool-II process on that server is ok? The fail condition would never be triggered, right?

Will J. Dunn

On Tue, Jul 21, 2015 at 4:27 PM, Joshua D. Drake <jd@commandprompt.com> wrote:

On 07/21/2015 01:21 PM, William Dunn wrote:
That's pretty cool! But the intended use of watchdog is so you can have
multiple pgpool-II instances and failover among them
(http://www.pgpool.net/docs/latest/pgpool-en.html#watchdog) rather than
failure of Postgres. In the configuration described in that wiki what
happens when the DBMS goes down but pgpool-II is fine? The watchdog
appears to be monitoring the pgpool-II process, not the
postgres/postmaster process.

 From what I see, it has the ability to execute a command/script based on a failed condition which could include but not be limited to a command to fail over a standby.


JD

--
Command Prompt, Inc. - http://www.commandprompt.com/  503-667-4564
PostgreSQL Centered full stack support, consulting and development.
Announcing "I'm offended" is basically telling the world you can't
control your own emotions, so everyone else should do it for you.

pgsql-general by date:

Previous
From: "Joshua D. Drake"
Date:
Subject: Re: Setting up HA postgresql
Next
From: Fritz Meissner
Date:
Subject: Re: Cannot reach pg server using -h localhost