From: Scott Marlowe <scott.marlowe@gmail.com>
To: Adrian Moisey <adrian@careerjunction.co.za>
Cc: Greg Smith <gsmith@gregsmith.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: strange pauses
Date: Thu, 17 Jan 2008 07:44:28 -0600
Message-ID: <dcc563d10801170544n445433f6m958c9b2ca83558d5@mail.gmail.com> (raw)
In-Reply-To: <478EFAB0.30205@careerjunction.co.za>
References: <478DDF83.8070106@careerjunction.co.za>
<478DE16F.50308@archonet.com>
<Pine.GSO.4.64.0801161030260.16621@westnet.com>
<478EFAB0.30205@careerjunction.co.za>
On Jan 17, 2008 12:50 AM, Adrian Moisey <adrian@careerjunction.co.za> wrote:
> Hi
>
> >> Search this list for references to "checkpoints". If you run
> >> vmstat/iostat for a bit you should see bursts of disk activity at
> >> those times.
> >
> > The most straightforward way to prove or disprove that the slow queries
> > line up with checkpoints is to set to checkpoint_warning to a high value
> > (3600 should work), which should log every checkpoint, and then see if
> > they show up at the same time in the logs.
>
> You guys were spot on. During these pauses the IO goes up high.
You need to tune your background writer process. See this link:
http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm
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To: pgsql-performance@postgresql.org
Cc: scott.marlowe@gmail.com, adrian@careerjunction.co.za, gsmith@gregsmith.com
Subject: Re: strange pauses
In-Reply-To: <dcc563d10801170544n445433f6m958c9b2ca83558d5@mail.gmail.com>
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