Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 53897 invoked from network); 1 Apr 2011 17:15:53 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 1 Apr 2011 17:15:53 -0000 Received: (qmail 52204 invoked by uid 500); 1 Apr 2011 17:15:49 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 52146 invoked by uid 500); 1 Apr 2011 17:15:48 -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 52024 invoked by uid 500); 1 Apr 2011 17:15:48 -0000 Delivered-To: apmail-incubator-cassandra-user@incubator.apache.org Received: (qmail 51969 invoked by uid 99); 1 Apr 2011 17:15:48 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 01 Apr 2011 17:15:48 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=5.0 tests=RCVD_IN_DNSWL_LOW,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (athena.apache.org: local policy) Received: from [74.125.83.47] (HELO mail-gw0-f47.google.com) (74.125.83.47) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 01 Apr 2011 17:15:42 +0000 Received: by gwb11 with SMTP id 11so1517448gwb.6 for ; Fri, 01 Apr 2011 10:15:21 -0700 (PDT) MIME-Version: 1.0 Received: by 10.150.213.18 with SMTP id l18mr1295852ybg.329.1301678121020; Fri, 01 Apr 2011 10:15:21 -0700 (PDT) Sender: scode@scode.org Received: by 10.150.204.17 with HTTP; Fri, 1 Apr 2011 10:15:20 -0700 (PDT) X-Originating-IP: [90.233.79.15] In-Reply-To: <1301627265785-6229564.post@n2.nabble.com> References: <1301609209534-6228872.post@n2.nabble.com> <1301627265785-6229564.post@n2.nabble.com> Date: Fri, 1 Apr 2011 19:15:20 +0200 X-Google-Sender-Auth: wHpfY4EWWBtiXt4bWDo2sByikPA Message-ID: Subject: Re: Node added, no performance boost -- are the tokens correct? From: Peter Schuller To: user@cassandra.apache.org Cc: buddhasystem , cassandra-user@incubator.apache.org Content-Type: text/plain; charset=UTF-8 > Now, I moved the tokens. I still observe that read latency deteriorated with > 3 machines vs original one. Replication factor is 1, Cassandra version 0.7.2 > (didn't have time to upgrade as I need results by this weekend). Read *latency* is fully expected to increase if you just add a node. *Throughput* should increase, unless you have a workload that manages to be more expensive on RPC than actual reads/writes. Latency would only be improved by additional nodes under some significant load. How are you benchmarking? Are you concurrently submitting requests to all nodes at the same time? Try using stress.py from the Cassandra tree as a comparison. If you're sending one request at a time, there is no expectation at all of a performance improvement - just a decrease in performance. -- / Peter Schuller