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 EB50A10A02 for ; Sat, 26 Oct 2013 01:55:11 +0000 (UTC) Received: (qmail 62289 invoked by uid 500); 26 Oct 2013 01:55:09 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 62257 invoked by uid 500); 26 Oct 2013 01:55:09 -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 62249 invoked by uid 99); 26 Oct 2013 01:55:09 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 26 Oct 2013 01:55:09 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of baskar.duraikannu@outlook.com designates 65.54.190.166 as permitted sender) Received: from [65.54.190.166] (HELO bay0-omc3-s28.bay0.hotmail.com) (65.54.190.166) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 26 Oct 2013 01:55:03 +0000 Received: from BAY404-EAS337 ([65.54.190.188]) by bay0-omc3-s28.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Fri, 25 Oct 2013 18:54:42 -0700 X-TMN: [L4b1rqQD/X5I8WOrpl/MCIxPQOVwhoe2] X-Originating-Email: [baskar.duraikannu@outlook.com] Message-ID: MIME-Version: 1.0 To: "user@cassandra.apache.org" From: Baskar Duraikannu Subject: Read repair Date: Fri, 25 Oct 2013 21:54:35 -0400 Content-Type: multipart/alternative; boundary="_4E54F4DA-0515-491F-BD1A-7DB489748F04_" X-OriginalArrivalTime: 26 Oct 2013 01:54:42.0414 (UTC) FILETIME=[568288E0:01CED1EE] X-Virus-Checked: Checked by ClamAV on apache.org --_4E54F4DA-0515-491F-BD1A-7DB489748F04_ Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="Windows-1252" We are thinking through the deployment architecture for our Cassandra clust= er. Let us say that we choose to deploy data across three racks.=20 If let us say that one rack power went down for 10 mins and then it came ba= ck. As soon as it came back up, due to some human error, rack1 goes down. N= ow for some rows it is possible that Quorum cannot be established. Just to = minimize the issues, we are thinking of running read repair manually every = night.=20 Is this a good idea? How often do you perform read repair on your cluster? --_4E54F4DA-0515-491F-BD1A-7DB489748F04_ Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="Windows-1252"

We are thin= king through the deployment architecture for our Cassandra cluster. L= et us say that we choose to deploy data across three racks.

If let = us say that one rack power went down for 10 mins and then it came back. As = soon as it came back up, due to some human error, rack1 goes down. Now for = some rows it is possible that Quorum cannot be established. Just to minimiz= e the issues, we are thinking of running read repair manually every night. =

Is this a good idea? How often do you perform read repair on your c= luster?

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