From user-return-23888-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Wed Feb 1 20:33:35 2012 Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 5B6F39694 for ; Wed, 1 Feb 2012 20:33:35 +0000 (UTC) Received: (qmail 97614 invoked by uid 500); 1 Feb 2012 20:33:32 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 96944 invoked by uid 500); 1 Feb 2012 20:33:31 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 96676 invoked by uid 99); 1 Feb 2012 20:33:31 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Feb 2012 20:33:31 +0000 X-ASF-Spam-Status: No, hits=-0.5 required=5.0 tests=FREEMAIL_ENVFROM_END_DIGIT,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of dnd1066@gmail.com designates 74.125.82.44 as permitted sender) Received: from [74.125.82.44] (HELO mail-ww0-f44.google.com) (74.125.82.44) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Feb 2012 20:33:23 +0000 Received: by wgbdt10 with SMTP id dt10so1434252wgb.25 for ; Wed, 01 Feb 2012 12:33:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject :content-type:content-transfer-encoding; bh=muonYwrBLk73336/WbHWabAqudWBGhehiMISa/zoHxw=; b=QJj3hk+ImPTvjmWUScBGtg8mYj+E9QS7t/lyjvDU6k+YzgBAgB6SGJ+Od8mfwcQJCW cQRsFoXrBCc5wxfElhIFxxB3JDVc6s/CPieadi0LkUfN1hRVEwMyeGpLteVpeYidl/zs ENMcsbaEYGu480vr8hd6+oIM3bplRgOf+hNmg= Received: by 10.180.8.103 with SMTP id q7mr177441wia.1.1328128382295; Wed, 01 Feb 2012 12:33:02 -0800 (PST) Received: from [192.168.1.2] (93-96-159-41.zone4.bethere.co.uk. [93.96.159.41]) by mx.google.com with ESMTPS id j16sm346532wie.4.2012.02.01.12.33.01 (version=SSLv3 cipher=OTHER); Wed, 01 Feb 2012 12:33:01 -0800 (PST) Message-ID: <4F29A188.6010703@gmail.com> Date: Wed, 01 Feb 2012 20:33:12 +0000 From: Guy Incognito User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0) Gecko/20111222 Thunderbird/9.0.1 MIME-Version: 1.0 To: user Subject: read-repair? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit how does read repair work in the following scenario? i have RF=3, my row/column lives on 3 nodes right? if (for some reason, eg a timed-out write at quorum) node 1 has a 'new' version of the row/column (eg clock = 10), but node 2 and 3 have 'old' versions (clock = 5), when i try to read my row/column at quorum, what do i get back? do i get the clock 5 version because that is what the quorum agrees on, and then read-repair kicks in and nodes 2 and 3 are updated to clock 10 so a subsequent read returns clock 10? or are nodes 2 and 3 updated to clock 10 first, and i get the clock 10 version on the initial read?