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 441D19C27 for ; Wed, 12 Oct 2011 02:19:00 +0000 (UTC) Received: (qmail 53774 invoked by uid 500); 12 Oct 2011 02:18:58 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 53730 invoked by uid 500); 12 Oct 2011 02:18:58 -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 53722 invoked by uid 99); 12 Oct 2011 02:18:58 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 12 Oct 2011 02:18:58 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of tyler@datastax.com designates 209.85.214.44 as permitted sender) Received: from [209.85.214.44] (HELO mail-bw0-f44.google.com) (209.85.214.44) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 12 Oct 2011 02:18:51 +0000 Received: by bkbzv3 with SMTP id zv3so70684bkb.31 for ; Tue, 11 Oct 2011 19:18:30 -0700 (PDT) MIME-Version: 1.0 Received: by 10.223.16.76 with SMTP id n12mr23839358faa.25.1318385909676; Tue, 11 Oct 2011 19:18:29 -0700 (PDT) Received: by 10.152.1.195 with HTTP; Tue, 11 Oct 2011 19:18:29 -0700 (PDT) X-Originating-IP: [70.124.83.21] In-Reply-To: <49C6D558-09B1-49E9-A53C-F53B2335C94C@thelastpickle.com> References: <49C6D558-09B1-49E9-A53C-F53B2335C94C@thelastpickle.com> Date: Tue, 11 Oct 2011 21:18:29 -0500 Message-ID: Subject: Re: CompletedTasks attribute exposed via JMX From: Tyler Hobbs To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=00151747b9aad2bc1704af10a33e X-Virus-Checked: Checked by ClamAV on apache.org --00151747b9aad2bc1704af10a33e Content-Type: text/plain; charset=ISO-8859-1 The OpsCenter graph you're referring to basically does the following: 1. For each node, find out how much the WriteOperations attribute of the StorageProxy increased during the last minute. 2. Sum these values to get a total for the cluster. 3. Divide by 60 to get an average number of WriteOperations per second for the cluster. On Tue, Oct 11, 2011 at 3:55 PM, aaron morton wrote: > Its the number of mutations, a mutation is a collection of changes for a > single row across one or more column families. > > Take a look at the nodetool cfstats, this is where I assume Ops Centre is > getting it's data from. > > Cheers > > ----------------- > Aaron Morton > Freelance Cassandra Developer > @aaronmorton > http://www.thelastpickle.com > > On 12/10/2011, at 3:44 AM, Alexandru Dan Sicoe wrote: > > Hello everyone, > I was trying to get some cluster wide statistics of the total insertions > performed in my 3 node Cassandra 0.8.6 cluster. So I wrote a nice little > program that gets the CompletedTasks attribute of > org.apache.cassandra.db:type=Commitlog from every node, sums up the values > and records them in a .csv every 10 sec or so. Everything works and I get my > stats but later I found out that I am not really sure what this measure > means. I think it is the individual column insertions performed! Am I > correct? > In the meantime I installed the trial version of the DataStax Operations > Center. The cluster wide dashboard, showing Writes performed as a function > of time, gives me much smaller values of the rates, compared to the > measurement I described before. The Datastax writes/sec are of the same > order of magnitude as the batch writes I perform on the cluster. But somehow > I cannot relate between this rate and the rate of my CompletedTasks > measurement. > > How do people usually measure insertion rates for their custers ? Per > batch, per single columns or is actual data rate more important to know? > > Cheers, > Alexandru > > > -- Tyler Hobbs Software Engineer, DataStax Maintainer of the pycassa Cassandra Python client library --00151747b9aad2bc1704af10a33e Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable The OpsCenter graph you're referring to basically does the following:
1. For each node, find out how much the WriteOperations attribute of = the StorageProxy increased during the last minute.
2. Sum these values t= o get a total for the cluster.
3. Divide by 60 to get an average number of WriteOperations per second for = the cluster.

On Tue, Oct 11, 2011 at 3:55= PM, aaron morton <aaron@thelastpickle.com> wrote:
Its the= number of mutations, a mutation is a collection of changes for a single ro= w across one or more column families.=A0

Take a look at the nodetool cfstats, this is where I assume = Ops Centre is getting it's data from.=A0

Cheer= s
=A0
-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelast= pickle.com

On 12/10/2011, at 3:44 AM, Alexandru Dan Sicoe wrote:
Hello everyone,
=A0I was trying to get some cluster wide statistics of = the total insertions performed in my 3 node Cassandra 0.8.6 cluster. So I w= rote a nice little program that gets the CompletedTasks attribute of org.ap= ache.cassandra.db:type=3DCommitlog from every node, sums up the values and = records them in a .csv every 10 sec or so. Everything works and I get my st= ats but later I found out that I am not really sure what this measure means= . I think it is the individual column insertions performed! Am I correct? =A0In the meantime I installed the trial version of the DataStax Operations= Center. The cluster wide dashboard, showing Writes performed as a function= of time, gives me much smaller values of the rates, compared to the measur= ement I described before. The Datastax writes/sec are of the same order of = magnitude as the batch writes I perform on the cluster. But somehow I canno= t relate between this rate and the rate of my CompletedTasks measurement.

How do people usually measure insertion rates for their custers ? Per b= atch, per single columns or is actual data rate more important to know?
=
Cheers,
Alexandru





--
Tyler Hobbs Software Engineer, DataS= tax
Maintainer of the pycassa Cassandra Python client library
 --00151747b9aad2bc1704af10a33e--