Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 13512 invoked from network); 3 May 2010 21:30:06 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 3 May 2010 21:30:06 -0000 Received: (qmail 47870 invoked by uid 500); 3 May 2010 21:30:05 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 47811 invoked by uid 500); 3 May 2010 21:30:05 -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 47803 invoked by uid 99); 3 May 2010 21:30:05 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 03 May 2010 21:30:05 +0000 X-ASF-Spam-Status: No, hits=4.7 required=10.0 tests=AWL,FS_REPLICA,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (athena.apache.org: local policy) Received: from [209.85.212.172] (HELO mail-px0-f172.google.com) (209.85.212.172) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 03 May 2010 21:29:58 +0000 Received: by pxi19 with SMTP id 19so1523535pxi.31 for ; Mon, 03 May 2010 14:29:37 -0700 (PDT) Received: by 10.114.164.39 with SMTP id m39mr15321074wae.56.1272922177593; Mon, 03 May 2010 14:29:37 -0700 (PDT) Received: from mail-yx0-f194.google.com (mail-yx0-f194.google.com [209.85.210.194]) by mx.google.com with ESMTPS id c1sm26215172wam.19.2010.05.03.14.29.33 (version=SSLv3 cipher=RC4-MD5); Mon, 03 May 2010 14:29:36 -0700 (PDT) Received: by yxe32 with SMTP id 32so1231003yxe.11 for ; Mon, 03 May 2010 14:29:32 -0700 (PDT) MIME-Version: 1.0 Received: by 10.150.249.24 with SMTP id w24mr10495297ybh.180.1272922172709; Mon, 03 May 2010 14:29:32 -0700 (PDT) Received: by 10.150.201.5 with HTTP; Mon, 3 May 2010 14:29:32 -0700 (PDT) Date: Mon, 3 May 2010 16:29:32 -0500 Message-ID: Subject: replication and memtable flush From: Lee Parker To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=000e0cd5a38eee5d3f0485b7498f --000e0cd5a38eee5d3f0485b7498f Content-Type: text/plain; charset=ISO-8859-1 i have a cluster which contains two CFs. One is a bunch of rows with 10-15 columns per row. the other is an index of those items with only a few rows, but thousands of columns per row. i am noticing that the replication of data between the nodes in the cluster is causing a lot of memtable flushing for the index CF. is this normal? my memtable thresholds are 128M or 1.5m objects. Some of the rows in the index CF have 500k+ columns. Also, this doesn't seem to happen in my dev environment which has a single cassandra node. It also slows down the rate of flush/compact cycles when there is only one node up in the prod cluster. Lee Parker --000e0cd5a38eee5d3f0485b7498f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable i have a cluster which contains two CFs. =A0One is a bunch of rows with 10-= 15 columns per row. =A0the other is an index of those items with only a few= rows, but thousands of columns per row. =A0i am noticing that the replicat= ion of data between the nodes in the cluster is causing a lot of memtable f= lushing for the index CF. =A0is this normal? =A0my memtable thresholds are = 128M or 1.5m objects. =A0Some of the rows in the index CF have 500k+ column= s. =A0Also, this doesn't seem to happen in my dev environment which has= a single cassandra node. =A0It also slows down the rate of flush/compact c= ycles when there is only one node up in the prod cluster.

Lee Parker

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