From oracle-l-bounce@freelists.org Wed Sep 7 18:06:15 2005 Return-Path: Received: from air891.startdedicated.com (root@localhost) by orafaq.com (8.12.10/8.12.10) with ESMTP id j87N6FOh014081 for ; Wed, 7 Sep 2005 18:06:15 -0500 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air891.startdedicated.com (8.12.10/8.12.10) with ESMTP id j87N6CIP014069 for ; Wed, 7 Sep 2005 18:06:12 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 8D49D1E9B3B; Wed, 7 Sep 2005 18:06:07 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 02090-10; Wed, 7 Sep 2005 18:06:07 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 10E451E984C; Wed, 7 Sep 2005 18:06:07 -0500 (EST) Date: Wed, 07 Sep 2005 23:04:14 +0000 From: Mladen Gogala Subject: Re: High "global cache blocks lost" statistics on one RAC node To: Amir.Hameed@xerox.com Cc: racdba@freelists.org, oracle-l@freelists.org In-Reply-To: <77A4D80DB2ADD74EB5D7F1D31626F0C0024182D4@usa0300ms03.na.xerox.net> (from Amir.Hameed@xerox.com on Wed Sep 7 16:38:26 2005) Message-Id: <1126134254l.4425l.1l@medo.noip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by Ecartis X-archive-position: 25136 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: gogala@sbcglobal.net Precedence: normal Reply-To: gogala@sbcglobal.net X-list: oracle-l X-Virus-Scanned: by amavisd-new-20030616-p9 (Debian) at avenirtech.net X-mailscan-MailScanner-Information: Please contact the ISP for more information X-mailscan-MailScanner: Found to be clean X-MailScanner-From: oracle-l-bounce@freelists.org X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on air891.startdedicated.com X-Spam-Status: No, hits=-3.8 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=2.63 On 09/07/2005 04:38:26 PM, Hameed, Amir wrote: > I have a two-node RAC running an 11i-ebusiness suite (11.5.9/9.2.0.6 > 64-bit). I am seeing the following from Statspack: > > Inst Statistic Total > per Second per Trans > ----- ---------------------------------------- ------------------ > -------------- ------------ > 1. global cache blocks lost 28 > 0.0 0.0 > 2. global cache blocks lost 4,410 > 2.7 0.9 > > We are using three giga-bit private interconnects going through a > switch. This does not see like an interconnect issue otherwise, I think, > I would have seen a higher number on the 1 node as well. > > Any idea what might be causing it? Pretty good idea. The statistics about the lost blocks is a TCP statistics. Oracle counts, somewhat misleadingly, TCP packets as blocks. I don't know what is your OS (almost anything is 64 bit these days), but if that is Linux, goverment's Department of Enron has a pretty decent Linux/TCP tuning page at: http://www-didc.lbl.gov/TCP-tuning/linux.html -- Mladen Gogala http://www.mgogala.com -- http://www.freelists.org/webpage/oracle-l