Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 7FB939FFB for ; Sun, 19 Feb 2012 17:10:57 +0000 (UTC) Received: (qmail 27338 invoked by uid 500); 19 Feb 2012 17:10:55 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 27303 invoked by uid 500); 19 Feb 2012 17:10:55 -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 27294 invoked by uid 99); 19 Feb 2012 17:10:55 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 19 Feb 2012 17:10:55 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=FSL_RCVD_USER,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of watcherfr@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; Sun, 19 Feb 2012 17:10:49 +0000 Received: by wgbdt10 with SMTP id dt10so3225407wgb.25 for ; Sun, 19 Feb 2012 09:10:27 -0800 (PST) Received-SPF: pass (google.com: domain of watcherfr@gmail.com designates 10.180.82.39 as permitted sender) client-ip=10.180.82.39; Authentication-Results: mr.google.com; spf=pass (google.com: domain of watcherfr@gmail.com designates 10.180.82.39 as permitted sender) smtp.mail=watcherfr@gmail.com; dkim=pass header.i=watcherfr@gmail.com Received: from mr.google.com ([10.180.82.39]) by 10.180.82.39 with SMTP id f7mr10771048wiy.19.1329671427314 (num_hops = 1); Sun, 19 Feb 2012 09:10:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=9RgKPqBXGiOUtOuxTt1Xp2Jh05+pFfUkqYkWqoTi600=; b=J7SabanRoz9L1c2nhiD5IpPdcVn4ey/HeT1iwf/GVh49L/2fzrOqaN1sVJOr/SP/c3 EFYWnqE8dBgAK0sknCC2Mh9tdb+BDjCj52HInngpHhaOFA9/g5WFW/koDqIWC3JCsYgv ixuozpC4wYnPHzxkBIyfedqwSOflBWpgXjJ44= MIME-Version: 1.0 Received: by 10.180.82.39 with SMTP id f7mr9026087wiy.19.1329671424872; Sun, 19 Feb 2012 09:10:24 -0800 (PST) Received: by 10.180.4.137 with HTTP; Sun, 19 Feb 2012 09:10:24 -0800 (PST) Received: by 10.180.4.137 with HTTP; Sun, 19 Feb 2012 09:10:24 -0800 (PST) In-Reply-To: References: Date: Sun, 19 Feb 2012 18:10:24 +0100 Message-ID: Subject: Re: reads/s suddenly dropped From: Philippe To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=f46d041826eaf2929004b954406f --f46d041826eaf2929004b954406f Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Perhaps your dataset can no longer be held in memory. Check iostats Le 19 f=E9vr. 2012 11:24, "Franc Carter" a =E9c= rit : > > I've been testing Cassandra - primarily looking at reads/second for our > fairly data model - one unique key with a row of columns that we always > request. I've now setup the cluster with with m1.large (2 cpus 8GB) > > I had loaded a months worth of data in and was doing random requests as a > torture test - and getting very nice results. I then loaded another days > worth of day and repeated the tests while the load was running - still go= od. > > I then started loading more days and at some point the performance droppe= d > by close to an order of magnitude ;-( > > Any ideas on what to look for ? > > thanks > > -- > > *Franc Carter* | Systems architect | Sirca Ltd > > > franc.carter@sirca.org.au | www.sirca.org.au > > Tel: +61 2 9236 9118 > > Level 9, 80 Clarence St, Sydney NSW 2000 > > PO Box H58, Australia Square, Sydney NSW 1215 > > --f46d041826eaf2929004b954406f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

Perhaps your dataset can no longer be held in memory. Check iostats

Le 19 f=E9vr. 2012 11:24, "Franc Carter&quo= t; <franc.carter@sirca.org.= au> a =E9crit=A0:

I've been testing Cassandra - primarily looking at reads= /second for our fairly data model - one unique key with a row of columns th= at we always request. I've now setup the cluster with with m1.large (2 = cpus 8GB)

I had loaded a months worth of data in and was doing random = requests as a torture test - and getting very nice results. I then loaded a= nother days worth of day and repeated the tests while the load was running = - still good.

I then started loading more days and at some point the = performance dropped by close to an order of magnitude ;-(

Any ideas on what to look for ?

thanks

--

Franc Carter<= /b> |<= /span> Systems architect | Sirca Ltd

franc.carter@sirca.org.au=A0|=A0www.sirca.org.au

Tel:= =A0+61 2 9236 9118

Level 9, 80 Clarence St, Sydney=A0NSW 2000

PO Box H58, Australia Square, Sydney NSW 1215<= /span>


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