From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Ariel Tejera <artejera@gmail.com>
To: pgsql-bugs@lists.postgresql.org
Subject: Re: Linux OOM killer
Date: Wed, 02 Oct 2024 06:16:31 +0200
Message-ID: <bfffb132207733e9fbf5fdabe5e36f4f37f39932.camel@cybertec.at> (raw)
In-Reply-To: <CAEO-Fc6dPK+oLeaqYbYf8Pjtfrvh+nwtmyOGyWNv83ZQRocfiA@mail.gmail.com>
References: <CAEO-Fc6dPK+oLeaqYbYf8Pjtfrvh+nwtmyOGyWNv83ZQRocfiA@mail.gmail.com>
On Tue, 2024-10-01 at 12:17 -0600, Ariel Tejera wrote:
> Hi. I hope this message finds you well.
>
> The issue is that one of our Postgres servers hit a bug and was killed by linux OOM, as
> shown in the lines below, showing two events:
>
> We were able to fix this problem adjusting the server configuration with:
> enable_memoize = off
>
> Our Postgres version is 14.5
> Linux AWS linux2 (with diverse concurrent workloads)
> Ram 32GB
> Database size 200 GB
>
> This is the first reproducible bug I've found in 20 years using postgres, heavily (!)
>
> As this bug is associated with large databases, it is impractical to offer a reproducible example for it.
> We hope, however, that this report will be of some use for the Postgres project.
First of all, update to 14.latest. I find at least one bug fixed in this area:
https://postgr.es/c/e4b95b9b02, discussed in https://postgr.es/m/83281eed63c74e4f940317186372abfd%40cft.ru
Then, disable memory overcommit, so that you don't get killed by the OOM killer.
Then you will get an "out of memory" error and a memory context dump in the log.
We'd need to see that to figure out if it really is a bug.
It need not be a bug if you run out of memory. It might as well be that you
configured PostgreSQL too generously.
Yours,
Laurenz Albe
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To: pgsql-bugs@postgresql.org
Cc: laurenz.albe@cybertec.at, artejera@gmail.com, pgsql-bugs@lists.postgresql.org
Subject: Re: Linux OOM killer
In-Reply-To: <bfffb132207733e9fbf5fdabe5e36f4f37f39932.camel@cybertec.at>
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