Return-Path: X-Original-To: apmail-cassandra-commits-archive@www.apache.org Delivered-To: apmail-cassandra-commits-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 367E5105B7 for ; Fri, 20 Sep 2013 20:34:53 +0000 (UTC) Received: (qmail 69179 invoked by uid 500); 20 Sep 2013 20:34:52 -0000 Delivered-To: apmail-cassandra-commits-archive@cassandra.apache.org Received: (qmail 68984 invoked by uid 500); 20 Sep 2013 20:34:52 -0000 Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@cassandra.apache.org Delivered-To: mailing list commits@cassandra.apache.org Received: (qmail 68960 invoked by uid 99); 20 Sep 2013 20:34:52 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 20 Sep 2013 20:34:52 +0000 Date: Fri, 20 Sep 2013 20:34:52 +0000 (UTC) From: "Jonathan Ellis (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (CASSANDRA-2609) Repair multi-DC awareness MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/CASSANDRA-2609?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13773387#comment-13773387 ] Jonathan Ellis commented on CASSANDRA-2609: ------------------------------------------- I'm going to predict that this is unnecessary complexity once CASSANDRA-5351 and possibly CASSANDRA-3362 are done. > Repair multi-DC awareness > ------------------------- > > Key: CASSANDRA-2609 > URL: https://issues.apache.org/jira/browse/CASSANDRA-2609 > Project: Cassandra > Issue Type: Improvement > Components: Core > Reporter: Sylvain Lebresne > Priority: Minor > Labels: ponies > > Repair has no multi-DC awareness in that if you have 2 DC with 3 replica in each, a repair of a node will transit 3 merkle tree cross-DC and potentially initiate as many cross-DC streaming (with likely a non null intersection between those). In theory, we could repair separately in each DC, then repair between only two node cross-DC (that we know are up to date in their respective DC) and finally re-repair in the separate DC (to pass the cross-DC changes to all nodes of the DC). > It is yet unclear to me if we can make that efficient enough that it is worth the added complexity, so this is really meant as an exploratory ticket. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira