Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1U7ejq-0001Xm-4x for pgsql-performance@arkaria.postgresql.org; Tue, 19 Feb 2013 04:23:30 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.72) (envelope-from ) id 1U7ejp-0002xc-Hp for pgsql-performance@arkaria.postgresql.org; Tue, 19 Feb 2013 04:23:29 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1U7ejn-0002xU-Hn for pgsql-performance@postgresql.org; Tue, 19 Feb 2013 04:23:27 +0000 Received: from [2404:130:0:10::40:2] (helo=mail.catalyst.net.nz) by magus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1U7eji-0003ux-Hx for pgsql-performance@postgresql.org; Tue, 19 Feb 2013 04:23:25 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.catalyst.net.nz (Postfix) with ESMTP id 8B49F32BCD; Tue, 19 Feb 2013 17:23:16 +1300 (NZDT) X-Virus-Scanned: Debian amavisd-new at catalyst.net.nz Received: from mail.catalyst.net.nz ([127.0.0.1]) by localhost (bertrand.catalyst.net.nz [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YkWJz8D+Bz1m; Tue, 19 Feb 2013 17:23:15 +1300 (NZDT) Received: from [IPv6:2404:130:0:1000:a9c4:39c4:b484:92f8] (unknown [IPv6:2404:130:0:1000:a9c4:39c4:b484:92f8]) (Authenticated sender: mark.kirkwood) by mail.catalyst.net.nz (Postfix) with ESMTPSA id D014F3273E; Tue, 19 Feb 2013 17:23:15 +1300 (NZDT) Message-ID: <5122FF50.8030903@catalyst.net.nz> Date: Tue, 19 Feb 2013 17:28:00 +1300 From: Mark Kirkwood User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Josh Berkus CC: Scott Marlowe , postgres performance list Subject: Re: High CPU usage / load average after upgrading to Ubuntu 12.04 References: <60B572D9298D944580F7D51195DD30804357FA4ABF@VMBX125.ihostexchange.net> <60B572D9298D944580F7D51195DD30804357FA4B60@VMBX125.ihostexchange.net> <60B572D9298D944580F7D51195DD30804357FA4C11@VMBX125.ihostexchange.net> <511BE879.8080706@agliodbs.com> <511C2F10.3080409@agliodbs.com> <60B572D9298D944580F7D51195DD30804357FA4DE2@VMBX125.ihostexchange.net> <511D2F11.6040706@agliodbs.com> <60B572D9298D944580F7D51195DD308043580CAA0B@VMBX125.ihostexchange.net> <511D79FE.7060705@agliodbs.com> <60B572D9298D944580F7D51195DD308043580CAA87@VMBX125.ihostexchange.net> <511E7DC0.4090506@agliodbs.com> <5122C507.7060303@agliodbs.com> <5122C9D9.9040909@agliodb s.com> In-Reply-To: <5122C9D9.9040909@agliodbs.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 2404:130:0:10::40:2 (failed) X-Pg-Spam-Score: -1.1 (-) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org On 19/02/13 13:39, Josh Berkus wrote: > Scott, > >> So do you have generally slow IO, or is it fsync behavior etc? > All tests except pgBench show this system as superfast. Bonnie++ and DD > tests are good (200 to 300mb/s), and test_fsync shows 14K/second. > Basically it has no issues until checkpoint kicks in, at which time the > entire system basically halts for the duration of the checkpoint. > > For that matter, if I run a pgbench and halt it just before checkpoint > kicks in, I get around 12000TPS, which is what I'd expect on this system. > > At this point, we've tried 3.2.0.26, 3.2.0.27, 3.4.0, and tried updating > the RAID driver, and changing the IO scheduler. Nothing seems to affect > the behavior. Testing using Ext4 (instead of XFS) next. > > Might be worth looking at your vm.dirty_ratio, vm.dirty_background_ratio and friends settings. We managed to choke up a system with 16x SSD by leaving them at their defaults... Cheers Mark -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance