From user-return-15432-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Tue Apr 05 13:55:41 2011 Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 89015 invoked from network); 5 Apr 2011 13:55:41 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 5 Apr 2011 13:55:41 -0000 Received: (qmail 99969 invoked by uid 500); 5 Apr 2011 13:55:39 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 99942 invoked by uid 500); 5 Apr 2011 13:55:39 -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 99934 invoked by uid 99); 5 Apr 2011 13:55:38 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 05 Apr 2011 13:55:38 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,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 209.85.212.44 as permitted sender) Received: from [209.85.212.44] (HELO mail-vw0-f44.google.com) (209.85.212.44) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 05 Apr 2011 13:55:33 +0000 Received: by vws12 with SMTP id 12so353565vws.31 for ; Tue, 05 Apr 2011 06:55:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type:content-transfer-encoding; bh=liWeCAsVR99igUq5izo7NADK4Rw5N/3Jg089H3dWlOU=; b=noA5tEOW4Y/Ln6ZfEXLmRMQm+5NSGHYeiG4Fjgiog9KsllwElQyw6AwpILS9PiR1Zm mu6dtBgZfiOFLFAjwk+InxtisoXwKfD2ft1igQ3+4TF/QbpHxtsiASxphnGPMpEG8tZM wz1U3pMjmGtlfWridlbd24ZO3BjYqM27o/FQ8= 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 :cc:content-type:content-transfer-encoding; b=WJoCXw80RiUnRY7jnNpvrXrVVt1ztlv2mb8ZJ5oAnpcsodG8uJjmWwGXa/la3Ii0Sj cqXAzJHMF1HsXBwaXLWuy0aJFEiSZFK/ojqs1vtXuALNFL4FoKwv39gRfG0SWuQQ8Rdd IpsCsVAe/SNcpuZN5ZQP9buV26Sujmhuoyomw= Received: by 10.52.100.2 with SMTP id eu2mr5246215vdb.20.1302011712066; Tue, 05 Apr 2011 06:55:12 -0700 (PDT) MIME-Version: 1.0 Received: by 10.52.169.228 with HTTP; Tue, 5 Apr 2011 06:54:52 -0700 (PDT) In-Reply-To: <4D9A7291.3040208@gmail.com> References: <4D9A7291.3040208@gmail.com> From: Jonathan Ellis Date: Tue, 5 Apr 2011 08:54:52 -0500 Message-ID: Subject: Re: IndexInterval Tuning To: user@cassandra.apache.org Cc: Chris Burroughs Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Adjusting indexinterval is unlikely to be useful on very narrow rows. (Its purpose is to make random access to _large_ rows doable.) On Mon, Apr 4, 2011 at 8:38 PM, Chris Burroughs wrote: > I have a case with very narrow rows. =A0As such I have a large row cache > that does nicely handles > 50% of requests. =A0I think it's likely that > the current tradeoff between page cache and row cache is reasonable. > Using a key cache doesn't make sense in this instance. =A0However, a thir= d > option is to adjust the IndexInterval [1] [2]. > > It would theoretically be reasonable to: > =A0- Increase the IndexInterval to make more memory available for row or > page cache. > =A0- Decrease the IndexInterval for more effective sampling. > > When the knob could be turned either direction it's hard to know which > way to start. > > Does anyone have any experince succesfully adjusting the IndexInterval > for improved performance with narrow rows? > > > [1] https://issues.apache.org/jira/browse/CASSANDRA-1488 > > [2] http://www.datastax.com/dev/blog/whats-new-cassandra-066 > --=20 Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com