Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id BE08A9FA085 for ; Wed, 1 Nov 2006 01:23:53 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 35291-02 for ; Wed, 1 Nov 2006 05:23:17 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from server.linux27.com (server.linux27.com [72.232.77.42]) by postgresql.org (Postfix) with ESMTP id 0C4929FA354 for ; Wed, 1 Nov 2006 01:23:17 -0400 (AST) Received: from 201-35-199-75.bnut3703.dsl.brasiltelecom.net.br ([201.35.199.75]:11119 helo=PC1) by server.linux27.com with esmtpa (Exim 4.52) id 1Gf8ZH-00089J-3M for pgsql-performance@postgresql.org; Wed, 01 Nov 2006 03:23:15 -0200 Reply-To: From: "Carlos H. Reimer" To: Subject: Context switching Date: Wed, 1 Nov 2006 03:23:17 -0200 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0004_01C6FD65.12C85180" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 Importance: Normal X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - server.linux27.com X-AntiAbuse: Original Domain - postgresql.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - opendb.com.br X-Source: X-Source-Args: X-Source-Dir: X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200611/69 X-Sequence-Number: 21839 This is a multi-part message in MIME format. ------=_NextPart_000_0004_01C6FD65.12C85180 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Hi, We've migrated one of our servers from pg 7.4 to 8.1 and from times to times (4 hours) the server start doing a lot of context switching and all transactions become very slow. The average context switching for this server as vmstat shows is 1 but when the problem occurs it goes to 250000. CPU and memory usage are ok. What can produce this context switching storms? It is a box with 12GB RAM and 4 processors running RedHat Enterprise Linux AS. Thank you in advance! Reimer carlos.reimer@opendb.com.br OpenDB Serviços e Treinamentos PostgreSQL e DB2 Fone: 47 3327-0878 Cel: 47 9602-0151 www.opendb.com.br ------=_NextPart_000_0004_01C6FD65.12C85180 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi,
 
We've = migrated one=20 of our servers from pg 7.4 to 8.1 and from times to times (4 hours) the = server=20 start doing a lot of context switching and all transactions become very=20 slow.
 
The = average context=20 switching for this server as vmstat shows is 1 but when the problem = occurs it=20 goes to 250000.
 
CPU = and memory=20 usage are ok.
 
What = can produce=20 this context switching storms?
 
It is = a box with=20 12GB RAM and 4 processors running RedHat Enterprise Linux=20 AS.
 
Thank = you in=20 advance!

Reimer
carlos.reimer@opendb.com.brOpenDB=20 Servi=E7os e Treinamentos PostgreSQL e DB2
Fone: 47 3327-0878 Cel: 47 = 9602-0151
www.opendb.com.br

 
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