Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 7001 invoked from network); 1 Apr 2010 02:16:39 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 1 Apr 2010 02:16:39 -0000 Received: (qmail 75695 invoked by uid 500); 1 Apr 2010 02:16:39 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 75678 invoked by uid 500); 1 Apr 2010 02:16:38 -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 75670 invoked by uid 99); 1 Apr 2010 02:16:38 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 01 Apr 2010 02:16:38 +0000 X-ASF-Spam-Status: No, hits=-0.5 required=10.0 tests=AWL,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of jbellis@gmail.com designates 74.125.82.44 as permitted sender) Received: from [74.125.82.44] (HELO mail-ww0-f44.google.com) (74.125.82.44) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 01 Apr 2010 02:16:32 +0000 Received: by wwb31 with SMTP id 31so485472wwb.31 for ; Wed, 31 Mar 2010 19:16:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :from:date:received:message-id:subject:to:content-type :content-transfer-encoding; bh=e2X2Anl8sVJw27pZtl+YR+T5nKzRnC0eKIchxH1beZI=; b=UlGWoTC6MnP4oo2hrXm/wFtnBje0WZtrgQT3IElzrqBKKTbkhbZw0akU6QQeRBBqme 3eRuv0sCgw0rB92XcFuO2DXhmlFc5tJ3tAoG9innkMnmzDQQ1urNDyduJ9nvXp164mkk ThnO6tASILtldllDhhTfT5JB3jLnI/PEqEZpE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type:content-transfer-encoding; b=tVjpnaBkopIyHYRzdTsHTX6sy6zLBAqNd3bmXUFNHiTNCt9B7aC0M5RTzOMYiw2nhH jN5RMBRLDORTdlvzr0fJ0MVpG8sRcpGKhVkRzehi7kqaknsrgJxbwykBzeiU+iBWWO5C vn3Ws13M0dlxdTlbD8K0ZujLhT3Dmp3uTzkk0= MIME-Version: 1.0 Received: by 10.216.25.204 with HTTP; Wed, 31 Mar 2010 19:15:51 -0700 (PDT) In-Reply-To: References: <1ab2da821003302047h128aaed9g1a65f3972836b086@mail.gmail.com> <1270060358.18338.3.camel@barium> From: Jonathan Ellis Date: Wed, 31 Mar 2010 21:15:51 -0500 Received: by 10.216.93.79 with SMTP id k57mr68814wef.161.1270088171130; Wed, 31 Mar 2010 19:16:11 -0700 (PDT) Message-ID: Subject: Re: Read Performance To: user@cassandra.apache.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Wed, Mar 31, 2010 at 6:21 PM, James Golick wrote= : > Keyspace: ActivityFeed > =A0=A0 =A0 =A0 =A0Read Count: 699443 > =A0=A0 =A0 =A0 =A0Read Latency: 16.11017477192566 ms. > =A0=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Column Family: Events > =A0=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Read Count: 232378 > =A0=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Read Latency: 0.396 ms. > =A0=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Row cache capacity: 500000 > =A0=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Row cache size: 62768 > =A0=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Row cache hit rate: 0.00771604938271604= 9 This says that - recent queries to Events are much faster than the lifetime average for your Keyspace - even though you have almost no row cache hits (~1700 out of 232000 reads= ) Not sure what to make of that, tbh. If it were me I would try to reproduce on a test machine w/o all that pesky live traffic confusing things. -Jonathan