Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1YR0jX-0001ke-N1 for pgsql-admin@arkaria.postgresql.org; Thu, 26 Feb 2015 15:52:15 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1YR0jW-00006C-Uw for pgsql-admin@arkaria.postgresql.org; Thu, 26 Feb 2015 15:52:15 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1YR0jO-0008KV-T7 for pgsql-admin@postgresql.org; Thu, 26 Feb 2015 15:52:06 +0000 Received: from mail-yk0-x230.google.com ([2607:f8b0:4002:c07::230]) by magus.postgresql.org with esmtps (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1YR0jK-0005TU-Jc for pgsql-admin@postgresql.org; Thu, 26 Feb 2015 15:52:04 +0000 Received: by ykp9 with SMTP id 9so4434258ykp.10 for ; Thu, 26 Feb 2015 07:52:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=KCgY4H3wUQIZAqWt213/zfU5tk3ob/W1P5S7Hg5P7kw=; b=hr5D8U+xcWtWpTLAOhPkFSpMLIZ1wKoY7mdipz/9NRARzYAXLEF8Ob9En8M78QObev MgyYBaozsCQFvfEZFPb0d/77ogF+4vYvRxsM6RApe72mqw8ygC/xIy5g1dJGCZl27mww NS8BZrb4MeyQ4hOuubvioGC7QqI4uW/BFqEkeonrXnRWKhmhU5fUJY+n+Xtc44rPouyF 0w1Ao4HnFJSwAAjS5+VEFOh0FcWpUgwgV8CqlIUgSGtrnvp0SUDygkfegT8Krtgmq3/i B0bh+Uk1NDn4G2yVW8OUJaf8WZ3bbDjHsGJlBhISuVSN+G/uV+UipJu9+oB+552pQ+Dy NCEQ== X-Received: by 10.236.19.133 with SMTP id n5mr8624546yhn.135.1424965920791; Thu, 26 Feb 2015 07:52:00 -0800 (PST) Received: from [192.168.254.3] (h77.89.102.166.static.ip.windstream.net. [166.102.89.77]) by mx.google.com with ESMTPSA id h71sm812174yha.45.2015.02.26.07.51.59 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 26 Feb 2015 07:52:00 -0800 (PST) Message-ID: <54EF411B.80202@gmail.com> Date: Thu, 26 Feb 2015 10:51:55 -0500 From: John Scalia User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: "David F. Skoll" , pgsql-admin@postgresql.org Subject: Re: Weird spikes in delay for async streaming replication on 9.1 References: <20150214110050.2f032f05@ollie.roaringpenguin.com> <20150226094428.34531376@hydrogen.roaringpenguin.com> <54EF3E6F.60403@gmail.com> <20150226104433.1b0df1db@hydrogen.roaringpenguin.com> In-Reply-To: <20150226104433.1b0df1db@hydrogen.roaringpenguin.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -2.7 (--) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-admin Precedence: bulk Sender: pgsql-admin-owner@postgresql.org On 2/26/2015 10:44 AM, David F. Skoll wrote: > On Thu, 26 Feb 2015 10:40:31 -0500 > John Scalia wrote: > >> Apologies, David, but as I don't check this list very often, I >> thought you should have received an answer. Have you tried watching >> the transaction with tcpdump or wireshark? > Yes. Haven't observed anything unusual. > >> To me this sounds like either a network problem or like you're >> thinking a contention problem. > It is not a network problem; we monitor the link between sites. And it > happens absolutely regularly, like clockwork, when we run our nightly > pg_dump on the master. > >> Also, are you running streaming replication? If so, there >> shouldn't be ANY delay as the standby gets the commit before the >> primary. Otherwise, how are you replicating? -- Jay > We are running asynchronous streaming replication. > OK, if it's asynchronous, is your script checking that primary isn't holding up closing out and transmitting the latest WAL segment during these times? And if the Standby really needs to be up to date, why not try synchronous replication? -- Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin