Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cj7su-0002tv-Id for pgsql-hackers@arkaria.postgresql.org; Wed, 01 Mar 2017 17:17:52 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84_2) (envelope-from ) id 1cj7st-0000dp-Ou for pgsql-hackers@arkaria.postgresql.org; Wed, 01 Mar 2017 17:17:51 +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 4.84_2) (envelope-from ) id 1cj7sr-0000bB-U6 for pgsql-hackers@postgresql.org; Wed, 01 Mar 2017 17:17:49 +0000 Received: from out4-smtp.messagingengine.com ([66.111.4.28]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1cj7so-0000bk-7X for pgsql-hackers@postgresql.org; Wed, 01 Mar 2017 17:17:49 +0000 Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id 8496120807; Wed, 1 Mar 2017 12:17:44 -0500 (EST) Received: from frontend2 ([10.202.2.161]) by compute7.internal (MEProxy); Wed, 01 Mar 2017 12:17:44 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= smtpout; bh=Z3j1JPJ8JpM1MUE/4nOGL74Z4Yw=; b=mUso7i2t+i32DsS8+yy0 BjDrj4VfP2PoYJW6Um/5Ww1ECsahbSx8jWr/Zrk1tj0uuakKmSxNhnWajl35tqjv kMq7t6SAxR1UP3pvPTZ2tnC9tuk5hmxvalVN738eplGiklTTjECfda3gR9BxdntC AyPAqGKsL15x46AnE3lbkc8= X-ME-Sender: X-Sasl-enc: RfrlmSG8oj2Glw4Qy0oGcnlhLnjkAUSMUJidhTMgJ7My 1488388664 Received: from april.local (c-73-13-66-39.hsd1.pa.comcast.net [73.13.66.39]) by mail.messagingengine.com (Postfix) with ESMTPA id 388BD24132; Wed, 1 Mar 2017 12:17:44 -0500 (EST) Subject: Re: Restricting maximum keep segments by repslots To: Petr Jelinek , Kyotaro HORIGUCHI , pgsql-hackers@postgresql.org References: <20170228.122736.123383594.horiguchi.kyotaro@lab.ntt.co.jp> <33bcf803-4aa8-27b6-b6bd-4fb3ae950b19@2ndquadrant.com> From: Peter Eisentraut Organization: 2ndQuadrant Message-ID: Date: Wed, 1 Mar 2017 12:17:43 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <33bcf803-4aa8-27b6-b6bd-4fb3ae950b19@2ndquadrant.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -2.6 (--) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-hackers Precedence: bulk Sender: pgsql-hackers-owner@postgresql.org On 2/27/17 23:27, Petr Jelinek wrote: >>> WARNING: restart LSN of replication slots is ignored by checkpoint >>> DETAIL: Some replication slots lose required WAL segnents to continue. > However this is dangerous as logical replication slot does not consider > it error when too old LSN is requested so we'd continue replication, > hiding data loss. In general, we would need a much more evident and strict way to discover when this condition is hit. Like a "full" column in pg_stat_replication_slot, and refusing connections to the slot until it is cleared. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers