From user-return-7293-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Wed Jul 07 09:15:47 2010 Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 19921 invoked from network); 7 Jul 2010 09:15:46 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 7 Jul 2010 09:15:46 -0000 Received: (qmail 88550 invoked by uid 500); 7 Jul 2010 09:15:45 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 88310 invoked by uid 500); 7 Jul 2010 09:15:40 -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 88302 invoked by uid 99); 7 Jul 2010 09:15:40 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 07 Jul 2010 09:15:39 +0000 X-ASF-Spam-Status: No, hits=2.2 required=10.0 tests=HTML_MESSAGE,MIME_QP_LONG_LINE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: local policy) Received: from [208.113.200.5] (HELO blingymail-a1.g.dreamhost.com) (208.113.200.5) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 07 Jul 2010 09:15:31 +0000 Received: from localhost (webms.mac.com [17.148.16.116]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by blingymail-a1.g.dreamhost.com (Postfix) with ESMTP id CBB035CD57; Wed, 7 Jul 2010 02:15:02 -0700 (PDT) To: user@cassandra.apache.org Cc: user@cassandra.apache.org From: Aaron Morton Subject: Re: Which node is coordinator node? X-Mailer: MobileMe Mail (1C262606) Message-id: <2b221516-60ef-444e-ee5f-8819022d4066@me.com> Content-Type: multipart/alternative; boundary=Apple-Webmail-42--50b2f79a-fc7d-e7bf-f397-d42185c3a900 MIME-Version: 1.0 In-Reply-To: Date: Wed, 7 Jul 2010 02:15:02 -0700 (PDT) X-Virus-Checked: Checked by ClamAV on apache.org --Apple-Webmail-42--50b2f79a-fc7d-e7bf-f397-d42185c3a900 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1; format=flowed The first option, the coordinator node takes care of sending the work to t= he other nodes. It will return to you when the write has been acknowledged= by the number of nodes you specify in the consistency level.=A0=0A=0AAaro= n=0A=0AOn 07 Jul, 2010,at 06:06 PM, ChingShen wr= ote:=0A=0AThanks aaron morton,=0A=0A=A0=A0 I have an another question abou= t replication. if I run a write operation on A node and how does the repli= cation work?=A0 A node dispatches three request to B, C and D nodes respec= tively to do write operation? or A node dispatches a request to B node, th= en B node forwards it to C node, finally, C node forwards it to D node?=0A= =0AThanks.=0A=0AShen=0A=0AOn Tue, Jul 6, 2010 at 8:04 PM, aaron morton wrote:=0AWhich ever node the client connects to is = the coordinator node. It will take care of sending the messages to the nod= es who will do the actual work.=0A=0AIf you have multiple nodes try a DNS = round robin to distribute client connections around.=0AAaron=0A=0AOn 6 Jul= 2010, at 22:10, ChingShen wrote:=0A=0A> Hi all,=0A>=0A> =A0 I'm newbie in= Cassandra, I have a question about which node is coordinator node in my c= luster.=0A>=0A> I have A, B, C, D, E, F and G nodes. if I run a write oper= ation on "A" node, and key range between A and B, so the A node is respons= ible to write the key to B, C and D nodes(RF=3D3) ? and does it mean A nod= e is coordinator node?=0A>=0A> Thanks.=0A>=0A> Shen=0A=0A=0A --Apple-Webmail-42--50b2f79a-fc7d-e7bf-f397-d42185c3a900 Content-Type: multipart/related; type="text/html"; boundary=Apple-Webmail-86--50b2f79a-fc7d-e7bf-f397-d42185c3a900 --Apple-Webmail-86--50b2f79a-fc7d-e7bf-f397-d42185c3a900 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1;
The first option, the coordinator node tak= es care of sending the work to the other nodes. It will return to you when= the write has been acknowledged by the number of nodes you specify in the= consistency level. 

Aaron

O= n 07 Jul, 2010,at 06:06 PM, ChingShen <chingshenchen@gmail.com> wrot= e:

Thanks aaron morton,
   I have an another question about replication. if I run = a write operation on A node and how does the replication work?  A nod= e dispatches three request to B, C and D nodes respectively to do write op= eration? or A node dispatches a request to B node, then B node forwards it= to C node, finally, C node forwards it to D node?
=0A
Thanks.
Shen

On Tue, Jul 6, 2010 at 8:04 PM, a= aron morton <aaron@thelastpickle.com> wrote:
=0AWhich ever node the client connects to is th= e coordinator node. It will take care of sending the messages to the nodes= who will do the actual work.
=0A
=0AIf you have multiple nodes try = a DNS round robin to distribute client connections around.
=0AAaron
=0A

On= 6 Jul 2010, at 22:10, ChingShen wrote:
=0A
=0A> Hi all,
=0A&g= t;
=0A>   I'm newbie in Cassandra, I have a question about whic= h node is coordinator node in my cluster.
=0A>
=0A> I have A, = B, C, D, E, F and G nodes. if I run a write operation on "A" node, and key= range between A and B, so the A node is responsible to write the key to B= , C and D nodes(RF=3D3) ? and does it mean A node is coordinator node?
= =0A=0A>
=0A> Thanks.
=0A>
=0A> Shen
=0A
=0A

=0A
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