Return-Path: Delivered-To: apmail-cassandra-commits-archive@www.apache.org Received: (qmail 10962 invoked from network); 5 Jan 2011 02:03:29 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 5 Jan 2011 02:03:29 -0000 Received: (qmail 40937 invoked by uid 500); 5 Jan 2011 02:03:29 -0000 Delivered-To: apmail-cassandra-commits-archive@cassandra.apache.org Received: (qmail 40889 invoked by uid 500); 5 Jan 2011 02:03:29 -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 40881 invoked by uid 500); 5 Jan 2011 02:03:29 -0000 Delivered-To: apmail-incubator-cassandra-commits@incubator.apache.org Received: (qmail 40876 invoked by uid 99); 5 Jan 2011 02:03:29 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 Jan 2011 02:03:29 +0000 X-ASF-Spam-Status: No, hits=-2000.0 required=10.0 tests=ALL_TRUSTED X-Spam-Check-By: apache.org Received: from [140.211.11.131] (HELO eos.apache.org) (140.211.11.131) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 Jan 2011 02:03:29 +0000 Received: from eosnew.apache.org (localhost [127.0.0.1]) by eos.apache.org (Postfix) with ESMTP id 66B865CF for ; Wed, 5 Jan 2011 02:03:04 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Apache Wiki To: Apache Wiki Date: Wed, 05 Jan 2011 02:03:04 -0000 Message-ID: <20110105020304.16765.91627@eosnew.apache.org> Subject: =?utf-8?q?=5BCassandra_Wiki=5D_Trivial_Update_of_=22Counters=22_by_johano?= =?utf-8?q?skarsson?= Dear Wiki user, You have subscribed to a wiki page or wiki category on "Cassandra Wiki" for= change notification. The "Counters" page has been changed by johanoskarsson. http://wiki.apache.org/cassandra/Counters?action=3Ddiff&rev1=3D6&rev2=3D7 -------------------------------------------------- = Writes require CL.ONE. * The commutative design requires partitionability and idempotence betw= een partitions. + * If a write fails unexpectedly (timeout for example) the client will n= ot know if the operation has been performed. A retry can result in an over = count. = =3D=3D Operational considerations =3D=3D + * Reusing IP addresses will cause problems. Since the current version o= f the patch uses machine ip addresses in the on disk data format as an iden= tifier a reuse of an old address will result in incorrect counts. + = =3D=3D Further reading =3D=3D See [[https://issues.apache.org/jira/browse/CASSANDRA-1072|CASSANDRA-1072= ]] and especially the [[https://issues.apache.org/jira/secure/attachment/12= 459754/Partitionedcountersdesigndoc.pdf|design doc]] for further informatio= n about how this works. =20