From: Bill Moran <wmoran@collaborativefusion.com>
To: Greg Smith <gsmith@gregsmith.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: select on 22 GB table causes "An I/O error occured while sending to the backend." exception
Date: Fri, 29 Aug 2008 07:08:52 -0400
Message-ID: <20080829070852.0000022f.wmoran@collaborativefusion.com> (raw)
In-Reply-To: <Pine.GSO.4.64.0808290039180.23621@westnet.com>
References: <BAY124-W57D3654AF1159CAF8EAC19F5660@phx.gbl>
<82bpze3ou8.fsf@mid.bfk.de>
<alpine.DEB.1.10.0808271436210.907@asgard.lang.hm>
<alpine.DEB.1.10.0808281411220.4454@aragorn.flymine.org>
<20080828095325.3c95f867.wmoran@collaborativefusion.com>
<Pine.GSO.4.64.0808290039180.23621@westnet.com>
In response to Greg Smith <gsmith@gregsmith.com>:
> On Thu, 28 Aug 2008, Bill Moran wrote:
>
> > In linux, it's possible to tell the OOM killer never to consider
> > certain processes for the axe, using /proc magic. See this page:
> > http://linux-mm.org/OOM_Killer
> >
> > Perhaps this should be in the PostgreSQL docs somewhere?
>
> The fact that
> http://www.postgresql.org/docs/current/static/kernel-resources.html#AEN22218
> tells you to flat-out turn off overcommit is the right conservative thing
> to be in the documentation as I see it. Sure, it's possible to keep it on
> but disable the worst side-effect in some kernels (looks like 2.6.11+, so
> no RHEL4 for example). Trying to get into all in the manual is kind of
> pushing what's appropriate for the PostgreSQL docs I think.
I don't know, Greg. First off, the solution of making the postmaster
immune to the OOM killer seems better than disabling overcommit to me
anyway; and secondly, I don't understand why we should avoid making
the PG documentation as comprehensive as possible, which seems to be
what you are saying: "we shouldn't make the PG documentation too
comprehensive, because then it will get very big"
--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/
wmoran@collaborativefusion.com
Phone: 412-422-3463x4023
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To: pgsql-performance@postgresql.org
Cc: wmoran@collaborativefusion.com, gsmith@gregsmith.com
Subject: Re: select on 22 GB table causes "An I/O error occured while sending to the backend." exception
In-Reply-To: <20080829070852.0000022f.wmoran@collaborativefusion.com>
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