Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 11599 invoked from network); 24 Feb 2011 08:47:07 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 24 Feb 2011 08:47:07 -0000 Received: (qmail 59595 invoked by uid 500); 24 Feb 2011 08:47:05 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 59197 invoked by uid 500); 24 Feb 2011 08:47:01 -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 59183 invoked by uid 500); 24 Feb 2011 08:47:00 -0000 Delivered-To: apmail-incubator-cassandra-user@incubator.apache.org Received: (qmail 59174 invoked by uid 99); 24 Feb 2011 08:47:00 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 24 Feb 2011 08:47:00 +0000 X-ASF-Spam-Status: No, hits=2.0 required=5.0 tests=FREEMAIL_FROM,SPF_NEUTRAL,T_TO_NO_BRKTS_FREEMAIL,URI_HEX X-Spam-Check-By: apache.org Received-SPF: neutral (nike.apache.org: 216.139.236.26 is neither permitted nor denied by domain of tijoriwala.ritesh@gmail.com) Received: from [216.139.236.26] (HELO sam.nabble.com) (216.139.236.26) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 24 Feb 2011 08:46:53 +0000 Received: from jim.nabble.com ([192.168.236.80]) by sam.nabble.com with esmtp (Exim 4.69) (envelope-from ) id 1PsWqG-0005GZ-LG for cassandra-user@incubator.apache.org; Thu, 24 Feb 2011 00:46:32 -0800 Date: Thu, 24 Feb 2011 00:46:32 -0800 (PST) From: "tijoriwala.ritesh" To: cassandra-user@incubator.apache.org Message-ID: <1298537192652-6059594.post@n2.nabble.com> In-Reply-To: References: Subject: Re: New Chain for : Does Cassandra use vector clocks MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org If it cannot protect against lost updates, isn't that an issue? How is client support to protect against concurrency? I see lot of users mentioning the use of cages (i.e. use ZooKeeper) but involving locks on every writes at the application level is certainly not acceptable. And again, the application will end up using vector clocks anyways. IMHO, this support should be built into cassandra especially when it provides all the knobs to the client to choose the right consistency level. So if client chooses R + W > N, then it should be possible for Cassandra to detect conflicts. -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/New-Chain-for-Does-Cassandra-use-vector-clocks-tp6058892p6059594.html Sent from the cassandra-user@incubator.apache.org mailing list archive at Nabble.com.