From: mark <dvlhntr@gmail.com>
To: 'Bill MacArthur' <webmaster@dhs-club.com>
Cc: pgsql-admin@postgresql.org
Subject: Re: how to tell if a replication server has stopped replicating
Date: Fri, 26 Aug 2011 21:05:01 -0600
Message-ID: <005601cc6466$1d7e73d0$587b5b70$@com> (raw)
In-Reply-To: <4E57C7DC.7020508@dhs-club.com>
References: <4E57C7DC.7020508@dhs-club.com>
> -----Original Message-----
> From: pgsql-admin-owner@postgresql.org [mailto:pgsql-admin-
> owner@postgresql.org] On Behalf Of Bill MacArthur
> Sent: Friday, August 26, 2011 10:21 AM
> To: pgsql-admin@postgresql.org
> Subject: [ADMIN] how to tell if a replication server has stopped
> replicating
>
> Hello,
>
> We recently discovered, quite by accident, that our streaming
> replication server was no longer replicating. We noticed this in our
> master server log file:
> 2011-08-26 00:00:05 PDT postgres 192.168.17.4 [unknown]LOG:
> replication connection authorized: user=postgres host=192.168.17.4
> port=53542
> 2011-08-26 00:00:05 PDT postgres 192.168.17.4 [unknown]FATAL:
> requested WAL segment 00000001000001D10000006B has already been removed
>
> As it turned out this has been going on for at least a week as
> everyday's log files were crammed with these messages. Whatever caused
> the replication server to end up needing the WAL file is a mystery for
> another day. What I would like to do is setup a simple method of
> alerting us if replication stops. We could do a simple grep of log
> files on the replication side, but I am guessing that there is some SQL
> command that could be run against the postgres internals that would be
> cleaner. Is there such an animal?
>
> Thank you,
> Bill MacArthur
>
* http://archives.postgresql.org/pgsql-hackers/2010-11/msg00198.php
* http://archives.postgresql.org/pgsql-hackers/2010-11/msg00252.php
Those two posts should cover the basics. There are other ways some people use to do it, but this seems to be the generally accepted way.
I think 9.1 has some stuff in the works that should make it far easier to monitor.
-Mark
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To: pgsql-admin@postgresql.org
Cc: dvlhntr@gmail.com, webmaster@dhs-club.com
Subject: Re: how to tell if a replication server has stopped replicating
In-Reply-To: <005601cc6466$1d7e73d0$587b5b70$@com>
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