Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 2D5CF37C3B7 for ; Wed, 8 Oct 2008 15:09:04 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 00433-04 for ; Wed, 8 Oct 2008 15:08:58 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from gwmta.wicourts.gov (gwmta.wicourts.gov [165.219.244.99]) by postgresql.org (Postfix) with ESMTP id 7338837C096 for ; Wed, 8 Oct 2008 15:08:55 -0300 (ADT) Received: from Courts-MTA by gwmta.wicourts.gov with Novell_GroupWise; Wed, 08 Oct 2008 13:08:53 -0500 Message-Id: <48ECB0DD.EE98.0025.0@wicourts.gov> X-Mailer: Novell GroupWise Internet Agent 7.0.3 Date: Wed, 08 Oct 2008 13:08:46 -0500 From: "Kevin Grittner" To: "Rafael Domiciano" Cc: "Julio Leyva" , "pgsql-admin@postgresql.org" Subject: Re: checkpoint_timeout References: <3a0028490810071321j32b4f450m95123d02b9fe6f49@mail.gmail.com> <3a0028490810080531y155edffi7ff7c68b965a834a@mail.gmail.com> <1223475780.6070.10.camel@bnicholson-desktop> <3a0028490810080734r26912c72n94d6f509dfb55b6e@mail.gmail.com> <3a0028490810080919v3762f924je688a56210558e95@mail.gmail.com> <3a0028490810080934l211d137uc9dde69cad7879d9@mail.gmail.com> <48EC9D9F.EE98.0025.0@wicourts.gov> <3a0028490810081054o2100b2bci7bde6b7213712c58@mail.gmail.com> In-Reply-To: <3a0028490810081054o2100b2bci7bde6b7213712c58@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200810/60 X-Sequence-Number: 30516 >>> "Rafael Domiciano" wrote: > Right...I going to restart my server only tonight, the access along the day > is too much to do now...! > Maybe increasing a little bit could do difference? > I thougth to increase to around 256 Kb! > I have a doubt... what's the chance to my server get instable? Changing wal_buffers to that isn't at all likely to cause problems, unless you are teetering right on the edge of exceeding your shmmax setting. It's also unlikely to help much, in my opinion. If the problem is checkpoints (which seems likely but far from a sure thing based on the information provided), aggressive background writer setting might be your best bet under 8.2.X. To solve similar problems we had to go to the following, although many on these lists feel that settings this aggressive are rarely needed, so use at your own risk. #bgwriter_delay = 200ms bgwriter_lru_percent = 20.0 bgwriter_lru_maxpages = 200 bgwriter_all_percent = 10.0 bgwriter_all_maxpages = 600 Even better would be to go to the latest revision of the 8.3 release, which at this writing is 8.3.4. In that release PostgreSQL spreads out the work of a checkpoint to minimize this problem. -Kevin