Received: from malur.postgresql.org ([2a02:16a8:dc51::56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1fyLPO-0002Tu-Ah for pgsql-performance@arkaria.postgresql.org; Fri, 07 Sep 2018 18:23:06 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1fyLPL-0003ii-Tn for pgsql-performance@arkaria.postgresql.org; Fri, 07 Sep 2018 18:23:03 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1fyLPL-0003ib-Ma for pgsql-performance@lists.postgresql.org; Fri, 07 Sep 2018 18:23:03 +0000 Received: from lists.commandprompt.com ([2604:da00:2:2:5054:ff:fe07:7618]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1fyLPG-0001Mb-It for pgsql-performance@lists.postgresql.org; Fri, 07 Sep 2018 18:23:02 +0000 Received: from [192.168.50.9] (spinlock.commandprompt.com [69.168.55.30]) by lists.commandprompt.com (Postfix) with ESMTPA id 271B975E; Fri, 7 Sep 2018 11:22:53 -0700 (PDT) Received: from c-73-97-49-9.hsd1.wa.comcast.net ([73.97.49.9] helo=[192.168.50.9]) by assp.commandprompt.com with SMTPSA(TLSv1_2 ECDHE-RSA-AES128-GCM-SHA256) (2.5.1); 7 Sep 2018 11:22:52 -0700 Subject: Re: Multi-second pauses blocking even trivial activity To: Andreas Kretschmer , pgsql-performance@lists.postgresql.org, Patrick Molgaard References: From: "Joshua D. Drake" Organization: Command Prompt, Inc. Message-ID: <486ce67e-f1d3-0a11-ce4b-8c422f8f3c46@commandprompt.com> Date: Fri, 7 Sep 2018 11:22:52 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Assp-Version: 2.5.1(16177) on assp.commandprompt.com X-Assp-ID: assp.commandprompt.com m1-44573-13446 X-Assp-Session: 7FF9B49E8338 (mail 1) X-Assp-Original-Subject: Re: Multi-second pauses blocking even trivial activity X-Assp-Client-SSL: yes List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 09/07/2018 11:12 AM, Andreas Kretschmer wrote: >> Intermittently (one or two times a week), all queries on that host are >> simultaneously blocked for extended periods (10s of seconds). >> >> The blocked queries are trivial & not related to locking - I'm seeing >> slowlogs of the form: >> > > please check if THP are enabled. Just to help out those who don't know I believe that Andreas is referring to Transparent Huge Pages. JD > > > Regards, Andreas > > > -- Command Prompt, Inc. || http://the.postgres.company/ || @cmdpromptinc *** A fault and talent of mine is to tell it exactly how it is. *** PostgreSQL centered full stack support, consulting and development. Advocate: @amplifypostgres || Learn: https://postgresconf.org ***** Unless otherwise stated, opinions are my own. *****