Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 8559F9FB358 for ; Thu, 19 Jul 2007 22:18:27 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 15935-09 for ; Thu, 19 Jul 2007 22:18:18 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from davinci.ethosmedia.com (server227.ethosmedia.com [209.128.84.227]) by postgresql.org (Postfix) with ESMTP id 292D19FB354 for ; Thu, 19 Jul 2007 22:18:23 -0300 (ADT) X-EthosMedia-Virus-Scanned: no infections found Received: from [63.195.55.98] (account josh@agliodbs.com HELO [192.168.2.3]) by davinci.ethosmedia.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 12700118; Thu, 19 Jul 2007 18:22:32 -0700 From: Josh Berkus Organization: PostgreSQL @ Sun To: pgsql-performance@postgresql.org Subject: Re: User concurrency thresholding: where do I look? Date: Thu, 19 Jul 2007 18:19:13 -0700 User-Agent: KMail/1.8.2 Cc: Tom Lane , Alvaro Herrera References: <200707190828.59088.josh@agliodbs.com> <20070719173704.GA12084@alvh.no-ip.org> <14009.1184867115@sss.pgh.pa.us> In-Reply-To: <14009.1184867115@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707191819.13899.josh@agliodbs.com> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200707/252 X-Sequence-Number: 25936 Tom, all: > Also, have you tried watching vmstat or local equivalent to confirm that > the machine's not starting to swap? We're not swapping. > Josh, what sort of workload is being tested here --- read-mostly, > write-mostly, a mixture? It's a TPCC-like workload, so heavy single-row updates, and the updates/inserts are what's being measured. For that matter, when I've seen this before it was with heavy-write workloads and we were measuring the number of updates/inserts and not the number of reads. -- Josh Berkus PostgreSQL @ Sun San Francisco