From: Guillaume Smet <guillaume.smet@gmail.com>
To: Jérôme BENOIS <benois@argia-engineering.fr>
Cc: Scott Marlowe <smarlowe@g2switchworks.com>
Cc: Dave Dutcher <dave@tridecap.com>
Cc: pgsql-performance@postgresql.org, "Xavier Milliard" <milliard@argia.fr>
Subject: Re: High CPU Load
Date: Fri, 15 Sep 2006 00:24:43 +0200
Message-ID: <1d4e0c10609141524j3532e140i308111908c1ab437@mail.gmail.com> (raw)
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On 9/14/06, Jérôme BENOIS <benois@argia-engineering.fr> wrote:
> Yes i have a lot of users ;-)
So your work_mem is probably far too high (that's what I told you in
my first message) and you probably swap when you have too many users.
Remember that work_mem can be used several times per query (and it's
especially the case when you have a lot of sorts).
When your load is high, check your swap activity and your io/wait. top
gives you these information. If you swap, lower your work_mem to 32 MB
for example then see if it's enough for your queries to run fast (you
can check if there are files created in the $PGDATA/base/<your
database oid>/pg_tmp) and if it doesn't swap. Retry with a
lower/higher value to find the one that fits best to your queries and
load.
> I agree but by moment DB Server is so slow.
Yep, that's the information that was missing :).
> what's means "HT" please ?
Hyper threading. It's usually not recommended to enable it on
PostgreSQL servers. On most servers, you can disable it directly in
the BIOS.
--
Guillaume
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To: pgsql-performance@postgresql.org
Cc: guillaume.smet@gmail.com, benois@argia-engineering.fr, smarlowe@g2switchworks.com, dave@tridecap.com, milliard@argia.fr
Subject: Re: High CPU Load
In-Reply-To: <1d4e0c10609141524j3532e140i308111908c1ab437@mail.gmail.com>
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