Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 61437 invoked from network); 26 Apr 2010 21:55:57 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 26 Apr 2010 21:55:57 -0000 Received: (qmail 82232 invoked by uid 500); 26 Apr 2010 21:55:56 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 82202 invoked by uid 500); 26 Apr 2010 21:55:56 -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 82194 invoked by uid 99); 26 Apr 2010 21:55:56 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 26 Apr 2010 21:55:56 +0000 X-ASF-Spam-Status: No, hits=0.7 required=10.0 tests=RCVD_IN_DNSWL_NONE,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (nike.apache.org: local policy) Received: from [74.125.82.172] (HELO mail-wy0-f172.google.com) (74.125.82.172) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 26 Apr 2010 21:55:46 +0000 Received: by wyb35 with SMTP id 35so3191063wyb.31 for ; Mon, 26 Apr 2010 14:55:24 -0700 (PDT) MIME-Version: 1.0 Received: by 10.216.88.15 with SMTP id z15mr677975wee.92.1272318924275; Mon, 26 Apr 2010 14:55:24 -0700 (PDT) Sender: scode@scode.org Received: by 10.216.50.11 with HTTP; Mon, 26 Apr 2010 14:55:24 -0700 (PDT) X-Originating-IP: [213.114.159.69] Date: Mon, 26 Apr 2010 23:55:24 +0200 X-Google-Sender-Auth: 4212b57daf8120aa Message-ID: Subject: Quorom consistency in a changing ring From: Peter Schuller To: user@cassandra.apache.org Content-Type: text/plain; charset=UTF-8 X-Virus-Checked: Checked by ClamAV on apache.org Hello, Is my interpretation correct that Cassandra is intended to guarantee quorom consistency (overlapping read/write sets) at all times, including a ring that is actively changing? I.e., there are no (intended) cases where qurom consistency is defeated due to writes or reads going to nodes that are actively participating in token:s moving? If yes, is there any material on how this is accomplished and/or pointers to roughly which parts of the implementation is responsible for ensuring this works? Thanks! -- / Peter Schuller