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 5634D92BA for ; Mon, 13 Feb 2012 09:30:24 +0000 (UTC) Received: (qmail 54608 invoked by uid 500); 13 Feb 2012 09:30:21 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 54531 invoked by uid 500); 13 Feb 2012 09:30:13 -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 54519 invoked by uid 99); 13 Feb 2012 09:30:12 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 13 Feb 2012 09:30:12 +0000 X-ASF-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_MED,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (athena.apache.org: local policy) Received: from [74.125.149.155] (HELO na3sys009aog126.obsmtp.com) (74.125.149.155) by apache.org (qpsmtpd/0.29) with SMTP; Mon, 13 Feb 2012 09:30:06 +0000 Received: from mail-lpp01m010-f44.google.com ([209.85.215.44]) (using TLSv1) by na3sys009aob126.postini.com ([74.125.148.12]) with SMTP ID DSNKTzjX75HfDZ5h7RB/LjWcVNx3MG0UvOBm@postini.com; Mon, 13 Feb 2012 01:29:45 PST Received: by mail-lpp01m010-f44.google.com with SMTP id l5so6053757lah.17 for ; Mon, 13 Feb 2012 01:29:19 -0800 (PST) Received: by 10.152.134.200 with SMTP id pm8mr10733478lab.34.1329125359155; Mon, 13 Feb 2012 01:29:19 -0800 (PST) MIME-Version: 1.0 Received: by 10.112.26.199 with HTTP; Mon, 13 Feb 2012 01:28:59 -0800 (PST) In-Reply-To: References: <201202131403484201571@jike.com> From: Franc Carter Date: Mon, 13 Feb 2012 20:28:59 +1100 Message-ID: Subject: Re: keycache persisted to disk ? To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=f46d042fde2ee4f99f04b8d51c9b X-Gm-Message-State: ALoCoQlhkE4iICosmSPMMqLZ7zVeawxpfrtsdqzSpZiDfJTK3DQnFYhkIqey2ez9A/SgmCtPN6PR --f46d042fde2ee4f99f04b8d51c9b Content-Type: text/plain; charset=ISO-8859-1 On Mon, Feb 13, 2012 at 8:15 PM, Peter Schuller wrote: > > 2 Node cluster, 7.9GB of ram (ec2 m1.large) > > RF=2 > > 11GB per node > > Quorum reads > > 122 million keys > > heap size is 1867M (default from the AMI I am running) > > I'm reading about 900k keys > > Ok, so basically a very significant portion of the data fits in page > cache, but not all. > yep > > > As I was just going through cfstats - I noticed something I don't > understand > > > > Key cache capacity: 906897 > > Key cache size: 906897 > > > > I set the key cache to 2million, it's somehow got to a rather odd number > > You're on 1.0 +? yep 1.07 > Nowadays there is code to actively make caches > smaller if Cassandra detects that you seem to be running low on heap. > Watch cassandra.log for messages to that effect (don't remember the > exact message right now). > > I just grep'd the logs and couldn't see anything that looked like that > -- > / Peter Schuller (@scode, http://worldmodscode.wordpress.com) > -- *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 --f46d042fde2ee4f99f04b8d51c9b Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Mon, Feb 13, 2012 at 8:15 PM, Peter Schuller <peter.schuller@infidyne.com&g= t; wrote:
> 2 Node cluster, 7.9GB of ram (ec2 m1.large)
> RF=3D2
> 11GB per node
> Quorum reads
> 122 million keys
> heap size is 1867M (default from the AMI I am running)
> I'm reading about 900k keys

Ok, so basically a very significant portion of the data fits in page<= br> cache, but not all.

yep
=A0

> As I was just going through cfstats - I noticed something I don't = understand
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Key cache capacity: 906897
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Key cache size: 906897
>
> I set the key cache to 2million, it's somehow got to a rather odd = number

You're on 1.0 +?

yep 1.07
=A0
Nowadays there is code to activ= ely make caches
smaller if Cassandra detects that you seem to be running low on heap.
Watch cassandra.log for messages to that effect (don't remember the
exact message right now).


I just grep'd the logs and couldn't see anything that looke= d like that
=A0
--
/ Peter Schuller (@scode, http://worldmodscode.wordpress.com)



--

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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