Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 29FEC1337B8B for ; Thu, 30 Dec 2010 11:04:02 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 44864-04 for ; Thu, 30 Dec 2010 15:03:54 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mx.openit.de (mx.openit.de [217.69.65.200]) by mail.postgresql.org (Postfix) with ESMTP id 86D071337B88 for ; Thu, 30 Dec 2010 11:03:54 -0400 (AST) Received: from warpcore.openit.de (unknown [IPv6:2001:aa8:fffd::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx.openit.de (Postfix) with ESMTP id 415DF1000DC for ; Thu, 30 Dec 2010 16:03:53 +0100 (CET) Received: from warpcore.openit.de (localhost.localdomain [127.0.0.1]) by warpcore.openit.de (8.13.8/8.13.8) with ESMTP id oBUF3rTI029392 for ; Thu, 30 Dec 2010 16:03:53 +0100 Received: (from julian@localhost) by warpcore.openit.de (8.13.8/8.13.8/Submit) id oBUF3rJc029391; Thu, 30 Dec 2010 16:03:53 +0100 X-Authentication-Warning: warpcore.i.openit.de: julian set sender to bock@openit.de using -f From: bock@openit.de (Julian v. Bock) To: pgsql-performance@postgresql.org Subject: Re: long wait times in ProcessCatchupEvent() In-Reply-To: <10249.1293635921@sss.pgh.pa.us> (Tom Lane's message of "Wed, 29 Dec 2010 10:18:41 -0500") Organization: OpenIT GmbH References: <10249.1293635921@sss.pgh.pa.us> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1.50 (gnu/linux) X-Face: $~?g2!-On|QWPz8qkxU3V^DL7_Tli#/R8{t\$SYTT,/`5"; d|]YB@q/9_|NP; |:tK&kx:n7f=%y:G)b0$[Y{}F_@"gb6WsI_LV8"%F7-|Kd="x6g18{t|/Gan9"&C!t_$6(HTf-1.}t/]RUW4k-; O6j5+FEyG29jrf,f?hKqa*l]*DVr; nhJN)+~H5&Xm&M\m_&rX/+WL Date: Thu, 30 Dec 2010 16:03:53 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.61 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201012/334 X-Sequence-Number: 41786 Hi >>>>> "TL" =3D=3D Tom Lane writes: TL> bock@openit.de (Julian v. Bock) writes: >> I have the problem that on our servers it happens regularly under a >> certain workload (several times per minute) that all backend >> processes get a SIGUSR1 and spend several seconds in >> ProcessCatchupEvent(). TL> This is fixed in 8.4 and up. TL> http://archives.postgresql.org/pgsql-committers/2008-06/msg00227.php Thanks for the quick reply. TL> If you aren't willing to move off 8.3 you might be able to TL> ameliorate the problem by reducing the volume of catalog changes, TL> but that can be pretty hard if you're dependent on temp tables. Upgrading to 8.4 or 9.0 is not possible at the moment but if it is only catalog changes I can probably work around that. Regards, Julian v. Bock --=20 Julian v. Bock Projektleitung Software-Entwicklung OpenIT GmbH Tel +49 211 239 577-0 In der Steele 33a-41 Fax +49 211 239 577-10 D-40599 D=C3=BCsseldorf http://www.openit.de ________________________________________________________________ HRB 38815 Amtsgericht D=C3=BCsseldorf USt-Id DE 812951861 Gesch=C3=A4ftsf=C3=BChrer: Oliver Haakert, Maurice Kemmann