From user-return-37051-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Thu Oct 10 10:41:03 2013 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 84BCA10D2D for ; Thu, 10 Oct 2013 10:41:03 +0000 (UTC) Received: (qmail 51825 invoked by uid 500); 10 Oct 2013 10:40:56 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 51784 invoked by uid 500); 10 Oct 2013 10:40:54 -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 51676 invoked by uid 99); 10 Oct 2013 10:40:52 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 10 Oct 2013 10:40:52 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_MESSAGE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of artur.kronenberg@openmarket.com designates 81.187.36.3 as permitted sender) Received: from [81.187.36.3] (HELO puma.mxtelecom.com) (81.187.36.3) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 10 Oct 2013 10:40:47 +0000 Received: from glide.lon.openmarket.com ([10.9.64.115]) by puma.mxtelecom.com with esmtpsa (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.80.1) (envelope-from ) id 1VUDfN-0003Y7-KY for user@cassandra.apache.org; Thu, 10 Oct 2013 11:40:25 +0100 Message-ID: <52568418.3010304@openmarket.com> Date: Thu, 10 Oct 2013 11:40:24 +0100 From: Artur Kronenberg User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: user@cassandra.apache.org Subject: Rowcache and quorum reads cassandra Content-Type: multipart/alternative; boundary="------------070407070300040806030709" X-Virus-Checked: Checked by ClamAV on apache.org This is a multi-part message in MIME format. --------------070407070300040806030709 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit I was reading through configuration tips for cassandra and decided to use row-cache in order to optimize the read performance on my cluster. I have a cluster of 10 nodes, each of them opeartion with 3 GB off-heap using cassandra 2.4.1. I am doing local quorum reads, which means that I will hit 3 nodes out of 5 because I split my 10 nodes into two data-centres. I was under the impression that since each node gets a certain range of reads my total amount of off-heap would be 10 * 3 GB = 30 GB. However is this still correct with quorum reads? How does cassandra handle row-cache hits in combination with quorum reads? Thanks! -- artur --------------070407070300040806030709 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit

I was reading through configuration tips for cassandra and decided to use row-cache in order to optimize the read performance on my cluster.

I have a cluster of 10 nodes, each of them opeartion with 3 GB off-heap using cassandra 2.4.1. I am doing local quorum reads, which means that I will hit 3 nodes out of 5 because I split my 10 nodes into two data-centres.

I was under the impression that since each node gets a certain range of reads my total amount of off-heap would be 10 * 3 GB = 30 GB. However is this still correct with quorum reads? How does cassandra handle row-cache hits in combination with quorum reads?

Thanks!
-- artur

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