Return-Path: Delivered-To: apmail-incubator-cassandra-commits-archive@minotaur.apache.org Received: (qmail 17858 invoked from network); 26 May 2009 20:43:56 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 26 May 2009 20:43:56 -0000 Received: (qmail 41145 invoked by uid 500); 26 May 2009 20:44:08 -0000 Delivered-To: apmail-incubator-cassandra-commits-archive@incubator.apache.org Received: (qmail 41032 invoked by uid 500); 26 May 2009 20:44:08 -0000 Mailing-List: contact cassandra-commits-help@incubator.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: cassandra-dev@incubator.apache.org Delivered-To: mailing list cassandra-commits@incubator.apache.org Received: (qmail 40990 invoked by uid 99); 26 May 2009 20:44:08 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 26 May 2009 20:44:08 +0000 X-ASF-Spam-Status: No, hits=-2000.0 required=10.0 tests=ALL_TRUSTED X-Spam-Check-By: apache.org Received: from [140.211.11.140] (HELO brutus.apache.org) (140.211.11.140) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 26 May 2009 20:44:06 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id AC021234C1EF for ; Tue, 26 May 2009 13:43:45 -0700 (PDT) Message-ID: <1242198459.1243370625703.JavaMail.jira@brutus> Date: Tue, 26 May 2009 13:43:45 -0700 (PDT) From: "Jonathan Ellis (JIRA)" To: cassandra-commits@incubator.apache.org Subject: [jira] Commented: (CASSANDRA-48) test-and-set In-Reply-To: <1830224690.1238712914902.JavaMail.jira@brutus> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 X-Virus-Checked: Checked by ClamAV on apache.org [ https://issues.apache.org/jira/browse/CASSANDRA-48?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12713242#action_12713242 ] Jonathan Ellis commented on CASSANDRA-48: ----------------------------------------- ... actually, thinking about it a little more, if you are using ZK locks for consistency I don't really see the point of T&S at all. Read/write locks are described under shared locks here: http://zookeeper.wiki.sourceforge.net/ZooKeeperRecipes. > test-and-set > ------------ > > Key: CASSANDRA-48 > URL: https://issues.apache.org/jira/browse/CASSANDRA-48 > Project: Cassandra > Issue Type: Improvement > Reporter: Jonathan Ellis > > Atomic test-and-set insert operation would be nice: "set value to X but only if the current value is still Y." This allows a sort of optimistic consistency: perform a GET, then perform test-and-set with the value of that GET as Y. > I do not think that this requires strong consistency to be useful. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.