Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 13458 invoked from network); 11 Jun 2010 17:34:40 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 11 Jun 2010 17:34:40 -0000 Received: (qmail 4053 invoked by uid 500); 11 Jun 2010 17:34:39 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 4018 invoked by uid 500); 11 Jun 2010 17:34:39 -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 4010 invoked by uid 99); 11 Jun 2010 17:34:39 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 11 Jun 2010 17:34:39 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of aaron.blew@iovation.com designates 74.121.28.15 as permitted sender) Received: from [74.121.28.15] (HELO mail.iovation.com) (74.121.28.15) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 11 Jun 2010 17:34:33 +0000 Received: from cpexch01.iovation.com ([10.12.2.21]) by cpexch01.iovation.com ([10.12.2.21]) with mapi; Fri, 11 Jun 2010 10:34:12 -0700 From: "Blew, Aaron" To: "user@cassandra.apache.org" Content-Class: urn:content-classes:message Date: Fri, 11 Jun 2010 10:34:10 -0700 Subject: RackAwareStrategy Documentation Disparity Thread-Topic: RackAwareStrategy Documentation Disparity Thread-Index: AcsJjE2+4n9javu1RZqD42se0z450A== Message-ID: <172DA46F-043A-46F9-8333-F835EAE4A52A@iovation.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Virus-Checked: Checked by ClamAV on apache.org Hello, I was browsing the docs for the RackAware replication strategy and saw this= on the wiki: "RackAwareStrategy: replica 2 is placed in the first node along the ring th= e belongs in another data center than the first; the remaining N-2 replicas= , if any, are placed on the first nodes along the ring in the *same* rack a= s the first" However the storage.conf comments say the following: "Strategy: Setting this to the class that implements IReplicaPlacementStrat= egy will change the way the node picker works. Out of the box, Cassandra p= rovides org.apache.cassandra.locator.RackUnawareStrategy and org.apache.cas= sandra.locator.RackAwareStrategy (place one replica in a different datacent= er, and the others on different racks in the same one.)" To me the comments in storage.conf make more sense since you'd want datacen= ter diversity for the data as well as rack level diversity within the local= datacenter. Which one is accurate? Is the disparity a result of the wiki= page not being updated after the behavior changed with a release? Thanks all, -Aaron --- Aaron Blew - Sr. Infrastructure Engineer | The Automator iovation - The Power of Reputation=99 aaron.blew@iovation.com iovation 111 SW Fifth Avenue Suite 3200 Portland, OR 97204 http://www.iovation.com/ The information contained in this email message may be privileged, confiden= tial and protected from disclosure. If you are not the intended recipient, = any dissemination, distribution or copying is strictly prohibited. If you t= hink that you have received this email message in error, please notify the = sender by reply email and delete the message and any attachments.