Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 56959 invoked from network); 2 Jun 2010 08:54:44 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 2 Jun 2010 08:54:44 -0000 Received: (qmail 29953 invoked by uid 500); 2 Jun 2010 08:54:43 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 29935 invoked by uid 500); 2 Jun 2010 08:54:43 -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 29927 invoked by uid 99); 2 Jun 2010 08:54:43 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 02 Jun 2010 08:54:43 +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; Wed, 02 Jun 2010 08:54:36 +0000 Received: from [192.168.1.113] by supertool.net.cn (MDaemon PRO v9.6.1) with ESMTP id md50000167943.msg for ; Wed, 02 Jun 2010 16:54:15 +0800 Subject: Re: [***SPAM*** ] Re: writing speed test From: Shuai Yuan To: user@cassandra.apache.org In-Reply-To: References: <1275373111.2481.27.camel@supertool-2907-01> Content-Type: text/plain; charset="GB18030" Date: Wed, 02 Jun 2010 16:54:10 +0800 Message-ID: <1275468850.7724.20.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, Wed, 02 Jun 2010 16:54:15 +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 Thanks Peter! In my test application, for each record, rowkey -> rand() * 4, about 64B column * 20 -> rand() * 20, about 320B I use batch_insert(rowkey, col*20) in thrift. Kevin Yuan -------- ԭʼ�ż� -------- ������: Peter Sch��ller �ռ���: user@cassandra.apache.org ����: [***SPAM*** ] Re: writing speed test ����: Wed, 2 Jun 2010 10:44:52 +0200 Since this thread has now gone on for a while... As far as I can tell you never specify the characteristics of your writes. Evaluating expected write throughput in terms of "MB/s to disk" is pretty impossible if one does not know anything about the nature of the writes. If you're expecting 50 MB, is that reasonable? I don't know; if you're writing a gazillion one-byte values with shortish keys, 50 MB/seconds translates to a *huge* amounts of writes per second and you're likely to be CPU bound even in the most efficient implementation reasonably possible. If on the other hand you're writing large values (say slabs of 128k) you might more reasonably be expecting higher disk throughput. I don't have enough hands-on experience with cassandra to have a feel for the CPU vs. disk in terms of bottlenecking, and when we expect to bottleneck on what, but I can say that it's definitely going to matter quite a lot what *kind* of writes you're doing. This tends to be the case regardless of the database system.