From user-return-6262-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Tue Jun 01 06:19:08 2010 Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 9308 invoked from network); 1 Jun 2010 06:19:08 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 1 Jun 2010 06:19:08 -0000 Received: (qmail 62886 invoked by uid 500); 1 Jun 2010 06:19:07 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 62820 invoked by uid 500); 1 Jun 2010 06:19:06 -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 62810 invoked by uid 99); 1 Jun 2010 06:19:06 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 01 Jun 2010 06:19:06 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: local policy) Received: from [111.67.198.66] (HELO supertool.net.cn) (111.67.198.66) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 01 Jun 2010 06:18:59 +0000 Received: from [192.168.1.113] by supertool.net.cn (MDaemon PRO v9.6.1) with ESMTP id md50000167153.msg for ; Tue, 01 Jun 2010 14:18:37 +0800 Subject: writing speed test From: Shuai Yuan To: user@cassandra.apache.org Content-Type: text/plain; charset="GB18030" Date: Tue, 01 Jun 2010 14:18:31 +0800 Message-ID: <1275373111.2481.27.camel@supertool-2907-01> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 8bit X-Authenticated-Sender: yuanshuai@supertool.net.cn X-Spam-Processed: supertool.net.cn, Tue, 01 Jun 2010 14:18:37 +0800 (not processed: message from valid local sender) X-Lookup-Warning: EHLO lookup on [192.168.1.113] does not match 219.142.138.203 X-Lookup-Warning: SMTP connection lookup on 219.142.138.203 does not match 219.142.138.203 X-MDRemoteIP: 219.142.138.203 X-Return-Path: yuanshuai@supertool.net.cn X-Envelope-From: yuanshuai@supertool.net.cn X-MDaemon-Deliver-To: user@cassandra.apache.org X-Virus-Checked: Checked by ClamAV on apache.org Hi all, I'm testing writing speed of cassandra with 4 servers. I'm confused by the behavior of cassandra. ---env--- load-data app written in c++, using libcassandra (w/ modified batch insert) 20 writing threads in 2 processes running on 2 servers ---optimization--- 1.turn log level to INFO 2.JVM has 8G heap 3.32 concurrent read & 128 write in storage-conf.xml, other cache enlarged as well. ---result--- 1-monitoring by `date;nodetool -h host ring` I add all load together and measure the writing speed by (load_difference / time_difference), and I get about 15MB/s for the whole cluster. 2-monitoring by `iostat -m 10` I can watch the disk_io from the system level and have about 10MB/s - 65MB/s for a single machine. Very big variance over time. 3-monitoring by `iptraf -g` In this way I watch the communication between servers and get about 10MB/s for a single machine. ---opinion--- So, have you checked the writing speed of cassandra? I feel it's quite slow currently. Could anyone confirm this is the normal writing speed of cassandra, or please provide someway of improving it? -- Shuai Yuan 袁帅 Supertool Corp. 北京学之途网络科技有限公司 13810436859 yuan-shuai@yuan-shuai.info