Received: from malur.postgresql.org ([217.196.149.56])
	by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from
	<pgsql-performance-owner+M49332=pgsql-performance-ar@postgresql.org>)
	id 1U9cq4-0006sZ-0o for pgsql-performance@arkaria.postgresql.org;
	Sun, 24 Feb 2013 14:46:04 +0000
Received: from localhost ([127.0.0.1] helo=postgresql.org)
	by malur.postgresql.org with smtp (Exim 4.72) (envelope-from
	<pgsql-performance-owner+M49332=pgsql-performance-ar@postgresql.org>)
	id 1U9cq3-0005q4-Ac for pgsql-performance@arkaria.postgresql.org;
	Sun, 24 Feb 2013 14:46:03 +0000
Received: from makus.postgresql.org ([2001:4800:7903:4::125])
	by malur.postgresql.org with esmtp (Exim 4.72)
	(envelope-from <tgl@sss.pgh.pa.us>) id 1U9cq2-0005py-7d
	for pgsql-performance@postgresql.org; Sun, 24 Feb 2013 14:46:02 +0000
Received: from sss.pgh.pa.us ([66.207.139.130])
	by makus.postgresql.org with esmtp (Exim 4.72)
	(envelope-from <tgl@sss.pgh.pa.us>) id 1U9cq1-0003X2-3E
	for pgsql-performance@postgresql.org; Sun, 24 Feb 2013 14:46:01 +0000
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
	by sss.pgh.pa.us (8.14.5/8.14.5) with ESMTP id r1OEjxOZ015089;
	Sun, 24 Feb 2013 09:45:59 -0500 (EST)
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andre <pg@darix.de>
cc: pgsql-performance@postgresql.org
Subject: Re: Server stalls, all CPU 100% system time
In-reply-to: <512A1EC3.4020806@darix.de>
References: <512A1EC3.4020806@darix.de>
Comments: In-reply-to Andre <pg@darix.de>
	message dated "Mon, 25 Feb 2013 00:08:03 +1000"
Date: Sun, 24 Feb 2013 09:45:59 -0500
Message-ID: <15088.1361717159@sss.pgh.pa.us>
X-Pg-Spam-Score: -2.6 (--)
List-Archive: <http://archives.postgresql.org/pgsql-performance>
List-Help: <mailto:majordomo@postgresql.org?body=help>
List-ID: <pgsql-performance.postgresql.org>
List-Owner: <mailto:pgsql-performance-owner@postgresql.org>
List-Post: <mailto:pgsql-performance@postgresql.org>
List-Subscribe: <mailto:majordomo@postgresql.org?body=sub%20pgsql-performance>
List-Unsubscribe: 
 <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>
X-Mailing-List: pgsql-performance
Precedence: bulk
Sender: pgsql-performance-owner@postgresql.org

Andre <pg@darix.de> writes:
> Since our upgrade of hardware, OS and Postgres we experience server stalls under certain conditions, during that time (up to 2 minutes) all CPUs show 100% system time. All Postgres processes show BIND in top.

Odd.  I wonder if you are seeing some variant of the old context swap
storm problem.  The "99.8% system time" reading is suggestive but hardly
conclusive.  Does top's report of context swap rate go to the moon?

It would be interesting to strace a few of the server processes while
one of these events is happening, too.

			regards, tom lane


-- 
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance