From user-return-25357-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Thu Apr 5 16:31:15 2012 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 1B35B9647 for ; Thu, 5 Apr 2012 16:31:15 +0000 (UTC) Received: (qmail 64278 invoked by uid 500); 5 Apr 2012 16:31:12 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 64251 invoked by uid 500); 5 Apr 2012 16:31:12 -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 64243 invoked by uid 99); 5 Apr 2012 16:31:12 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 05 Apr 2012 16:31:12 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=5.0 tests=RCVD_IN_DNSWL_LOW,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (athena.apache.org: local policy) Received: from [209.85.160.44] (HELO mail-pb0-f44.google.com) (209.85.160.44) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 05 Apr 2012 16:31:07 +0000 Received: by pbbrq13 with SMTP id rq13so1645846pbb.31 for ; Thu, 05 Apr 2012 09:30:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:x-gm-message-state; bh=22GN67+nYoggHirqV+CwWjGkUECQaDblKsgEPBkfvA8=; b=gMvVUTZ5++GMEzPLANn4efjqJ7jY9QUV+fH8rywSJAPJ5JZhI7ezJP4rHZt//zCXx1 8Ddf86oz+o3ry+xTrzATOGl4mLl17GYkeU0iq2U6DWeFOX7xmhjO0/j9eoWKXqmNKIz0 FjbQU9Mt0oIlKkx+zoqjA4IuE5EW6i5Z7AeNOH88admee8NiXYomi4wcY2PdcF6aWc7/ eeJ7wibRwUUoBsyX+eD/KBFg+TrqM5n80azHj9Itdx2G/tp7GLPOhM+U9UmIQwYLiW9N c/Qakg4Irp7Hct7iqn2mwcSgd9BrL2P/3i7CjzzzjOKobux6jN/dQ8KtCV/Ucy24HOP6 3M0A== MIME-Version: 1.0 Received: by 10.68.216.6 with SMTP id om6mr8326604pbc.117.1333643446495; Thu, 05 Apr 2012 09:30:46 -0700 (PDT) Received: by 10.68.231.228 with HTTP; Thu, 5 Apr 2012 09:30:46 -0700 (PDT) In-Reply-To: References: <641DA0D7-9C8D-4F64-8A18-A895936A200C@gmail.com> Date: Thu, 5 Apr 2012 09:30:46 -0700 Message-ID: Subject: Re: Will Cassandra balance load across replicas? From: Rob Coli To: user@cassandra.apache.org Content-Type: text/plain; charset=ISO-8859-1 X-Gm-Message-State: ALoCoQngBiMDbBOdqnHJ4cKcMGoKa3o4pwITBhiH4Q3VIPWZRgN5Lx+isuq8zmPP8552INF+kkcz X-Virus-Checked: Checked by ClamAV on apache.org On Thu, Apr 5, 2012 at 9:22 AM, zhiming shen wrote: > Thanks for your reply. My question is about the impact of replication on > load balancing. Say we have nodes ABCD... in the ring. ReplicationFactor is > 3 so the data on A will also have replicas on B and C. If we are reading > data own by A, and A is already very busy, will the requests be forwarded to > B and C? How about update requests? Google "cassandra dynamic snitch". -- =Robert Coli AIM>ALK - rcoli@palominodb.com YAHOO - rcoli.palominob SKYPE - rcoli_palominodb