Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1YbAx3-0006P1-8H for pgsql-admin@arkaria.postgresql.org; Thu, 26 Mar 2015 16:48:13 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1YbAx2-0007rW-Gt for pgsql-admin@arkaria.postgresql.org; Thu, 26 Mar 2015 16:48:12 +0000 Received: from makus.postgresql.org ([2001:4800:1501:1::229]) by malur.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1YbAx1-0007rG-At for pgsql-admin@postgresql.org; Thu, 26 Mar 2015 16:48:11 +0000 Received: from mailout.easymail.ca ([64.68.201.169]) by makus.postgresql.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1YbAwx-0004Mu-MF for pgsql-admin@postgresql.org; Thu, 26 Mar 2015 16:48:09 +0000 Received: from localhost (localhost [127.0.0.1]) by mailout.easymail.ca (Postfix) with ESMTP id 6D623E51E; Thu, 26 Mar 2015 12:48:06 -0400 (EDT) X-Virus-Scanned: Debian amavisd-new at mailout.easymail.ca X-Spam-Flag: NO X-Spam-Score: -3.934 X-Spam-Level: X-Spam-Status: No, score=-3.934 required=5 tests=[ALL_TRUSTED=-1.8, AWL=-0.227, BAYES_00=-2.599, DNS_FROM_AHBL_RHSBL=0.692] Received: from mailout.easymail.ca ([127.0.0.1]) by localhost (easymail-mailout.easydns.vpn [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id j8xWtu4mcHKu; Thu, 26 Mar 2015 12:48:06 -0400 (EDT) Received: from [192.168.2.16] (unknown [8.39.228.5]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mailout.easymail.ca (Postfix) with ESMTPSA id ECBCCE527; Thu, 26 Mar 2015 12:48:05 -0400 (EDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2070.6\)) Subject: Re: postgres hot-standby questions. From: Scott Ribe In-Reply-To: Date: Thu, 26 Mar 2015 10:48:03 -0600 Cc: Postgres Maillist Content-Transfer-Encoding: quoted-printable Message-Id: References: <848F3721-4A21-4260-9640-8F698E3EE376@skogoglandskap.no> <3C08D5DD-0702-4136-BBE3-21CBE064ADDE@elevated-dev.com> <604F46E7-7F6C-485B-BB72-21378D341F94@elevated-dev.com> <7EE11DF8-A813-4B65-BFD2-B258C5A9D666@elevated-dev.com> To: "Graeme B. Bell" X-Mailer: Apple Mail (2.2070.6) X-Pg-Spam-Score: -2.6 (--) 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 Mar 26, 2015, at 10:40 AM, Graeme B. Bell wrote: >=20 > I could be missing something obvious, but how does this stop e.g. checkpo= ints, autovacuum etc from occuring and generating new wal that the standby = might like? It seems like stopping services accessing the DB is likely to c= ause a lengthy autovacuum to begin, for example.=20 OK, fair point. But do you care?=20 I care that all committed transactions are on the replica. I don't care if = they're still in WAL or written to the backing files. Actually, think about= that question, you don't either--WAL gets copied to the replica, then move= d to the backing files. Checkpoints don't affect replication as far as I kn= ow. And autovacuum? Couldn't care less if its effects are replicated yet; w= hen the replica becomes master, autovacuum will run on it. --=20 Scott Ribe scott_ribe@elevated-dev.com http://www.elevated-dev.com/ https://www.linkedin.com/in/scottribe/ (303) 722-0567 voice --=20 Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin