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 ECFB710C96 for ; Fri, 13 Sep 2013 04:08:07 +0000 (UTC) Received: (qmail 14492 invoked by uid 500); 12 Sep 2013 21:46:29 -0000 Delivered-To: apmail-cassandra-commits-archive@cassandra.apache.org Received: (qmail 13788 invoked by uid 500); 12 Sep 2013 21:46:07 -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 13059 invoked by uid 99); 12 Sep 2013 21:45:53 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 12 Sep 2013 21:45:53 +0000 Date: Thu, 12 Sep 2013 21:45:53 +0000 (UTC) From: "Jonathan Ellis (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (CASSANDRA-6012) CAS does not always correctly replay inProgress rounds 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-6012?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13765928#comment-13765928 ] Jonathan Ellis commented on CASSANDRA-6012: ------------------------------------------- +1 > CAS does not always correctly replay inProgress rounds > ------------------------------------------------------ > > Key: CASSANDRA-6012 > URL: https://issues.apache.org/jira/browse/CASSANDRA-6012 > Project: Cassandra > Issue Type: Bug > Reporter: Sylvain Lebresne > Assignee: Sylvain Lebresne > Fix For: 2.0.1 > > Attachments: 0001-Don-t-skip-paxos-old-round-replay-if-there-is-a-value-.txt > > > Paxos says that on receiving the result of a prepare from a quorum of acceptors, the proposer should propose the value of the higher-number proposal accepted amongst the ones returned by the acceptors, and only propose his own value if no acceptor has send us back a previously accepted value. > But in PrepareCallback we only keep the more recent inProgress commit regardless of whether is has an update. Which means we could ignore a value already accepted by some acceptors if any of the acceptor send us a more recent ballot than the other acceptor but with no values. The net effect is that we can mistakenly accept two different values for the same round. -- 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