Return-Path: Delivered-To: apmail-incubator-cassandra-user-archive@minotaur.apache.org Received: (qmail 82560 invoked from network); 20 Aug 2009 00:32:30 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 20 Aug 2009 00:32:30 -0000 Received: (qmail 70622 invoked by uid 500); 20 Aug 2009 00:32:48 -0000 Delivered-To: apmail-incubator-cassandra-user-archive@incubator.apache.org Received: (qmail 70598 invoked by uid 500); 20 Aug 2009 00:32:48 -0000 Mailing-List: contact cassandra-user-help@incubator.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: cassandra-user@incubator.apache.org Delivered-To: mailing list cassandra-user@incubator.apache.org Received: (qmail 70589 invoked by uid 99); 20 Aug 2009 00:32:48 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 20 Aug 2009 00:32:48 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of huming.wu@gmail.com designates 209.85.223.203 as permitted sender) Received: from [209.85.223.203] (HELO mail-iw0-f203.google.com) (209.85.223.203) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 20 Aug 2009 00:32:38 +0000 Received: by iwn41 with SMTP id 41so239156iwn.32 for ; Wed, 19 Aug 2009 17:32:18 -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 :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=NBGlTknfvVobLUud/nlm73oQmtB3RrbClC5jE8XKmro=; b=p8mjhWEArgMxUFSgQ3e+77wGUxiS36g85IRv9+IrLICThZxjaDrBfr2gakyIpYVsRd utQIcBQvzJgvyFLhbeosxjxECIX7wblKuFI59eIWDMk13fB52Tbc69fY4i4828y0/st4 9X89RsFY5hCu0Sh3poKyeYhL4aXUbTSHhDBGY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=S0ZoUW5AsItsNJF+hs8eRIY0pjNdpXov9lUJvrXxfp+z/a9iqoac8IZ1j96+ixX6Uf 2/b0wpBLlAlQcBYF2bVNzxjkixspk1CBxe71VgXnYE1n/ddF8yRrPWpiyf5jijpdIsu1 toDjVx2xTLq/xiBf0Qn1mhSi1Aem+WxBOeL+g= MIME-Version: 1.0 Received: by 10.231.13.201 with SMTP id d9mr4357523iba.35.1250728338043; Wed, 19 Aug 2009 17:32:18 -0700 (PDT) In-Reply-To: References: Date: Wed, 19 Aug 2009 17:32:18 -0700 Message-ID: Subject: Re: Cassandra performance From: Huming Wu To: cassandra-user@incubator.apache.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Virus-Checked: Checked by ClamAV on apache.org On Tue, Aug 18, 2009 at 12:02 PM, Michael Greene wrote: > According to the HBase guys and confirmed by > http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#icms, > on an 8-core machine you are not going to want to enable > -XX:+CMSIncrementalMode -- it is for 1 or 2 core machines that are > using the CMS GC. =A0This should affect your latency numbers positively, > but I wouldn't see it changing the CPU usage much. Looks I do need to use the incremental GC though otherwise the memory growth is very fast... On the get_slice CPU, I tried the profiling (on single node and low load 1 get_slice call per second) and it looks org.apache.thrift.transport.TIOStreamTransport.read sucks up all CPU. Here is the snapshot http://farm3.static.flickr.com/2595/3838562412_8ffb42ea8c_o.png (sounds an issue in thrift). Any idea? Thanks, Huming