From: Dmitry Potapov <fortune.fish@gmail.com>
To: Joshua D. Drake <jd@commandprompt.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: io storm on checkpoints, postgresql 8.2.4, linux
Date: Wed, 22 Aug 2007 20:22:59 +0400
Message-ID: <878c83960708220922n747c8485r30584d3ef793ec2e@mail.gmail.com> (raw)
In-Reply-To: <46CC5DE7.9010201@commandprompt.com>
References: <878c83960708220833l72dbd461k827aea77ec7d6c32@mail.gmail.com>
<46CC5DE7.9010201@commandprompt.com>
2007/8/22, Joshua D. Drake <jd@commandprompt.com>:
> > We've run into an issue of IO storms on checkpoints. Once in 20min
> > (which is checkpoint_interval) the database becomes unresponsive for
> about
> > 4-8 seconds. Query processing is suspended, server does nothing but
> writing
>
> What are your background writer settings?
>
>
bgwriter_delay=100ms
bgwriter_lru_percent=20.0
bgwriter_lru_maxpages=100
bgwriter_all_percent=3
bgwriter_all_maxpages=600
In fact, with dirty_background_ratio > 0 bgwriter even make things a tiny
bit worse.
--
Regards,
Dmitry
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To: pgsql-performance@postgresql.org
Cc: fortune.fish@gmail.com, jd@commandprompt.com
Subject: Re: io storm on checkpoints, postgresql 8.2.4, linux
In-Reply-To: <878c83960708220922n747c8485r30584d3ef793ec2e@mail.gmail.com>
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