Return-Path: Delivered-To: apmail-hbase-user-archive@www.apache.org Received: (qmail 93564 invoked from network); 18 Jan 2011 02:46:29 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 18 Jan 2011 02:46:29 -0000 Received: (qmail 44166 invoked by uid 500); 18 Jan 2011 02:46:28 -0000 Delivered-To: apmail-hbase-user-archive@hbase.apache.org Received: (qmail 43876 invoked by uid 500); 18 Jan 2011 02:46:27 -0000 Mailing-List: contact user-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hbase.apache.org Delivered-To: mailing list user@hbase.apache.org Received: (qmail 43868 invoked by uid 99); 18 Jan 2011 02:46:26 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 18 Jan 2011 02:46:26 +0000 X-ASF-Spam-Status: No, hits=1.5 required=10.0 tests=FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,MIME_QP_LONG_LINE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of tatsuya6502@gmail.com designates 74.125.83.41 as permitted sender) Received: from [74.125.83.41] (HELO mail-gw0-f41.google.com) (74.125.83.41) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 18 Jan 2011 02:46:17 +0000 Received: by gwj22 with SMTP id 22so2381488gwj.14 for ; Mon, 17 Jan 2011 18:45:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:subject:references:from:content-type:x-mailer :in-reply-to:message-id:date:to:content-transfer-encoding :mime-version; bh=wb4RiJqU1BmFTB562w9CRPDxQHooVFICb2lgq+rCbso=; b=KA9/tq1xIWBJ9Zps7JQ7eF9Eeex0ZfC5znEI2WKgs0+2vbjc4/ILlDcECoWBSwreEw QzUYFhAWK0MchrkZjpos9HJk9cJd/GIke9kCcf3815XIIKsAhN4rAlP5SalEPbc4FUkS pvwxKw0VWPPCQJBjtqOgfs7wb8pZOUo1XkCkI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; b=gSiJhrvs0rk4z5v9dXnb8o2ugqbubd8Ek8huFgvffd7SX8YDyLsHnsL7cPTmJGEo4f 0DOb4e5FH9wClB9Z/1pwjvodZ0quABOfHSiEwLf2tjpHkZNEN7VjEohuX9tYXNbahNnf RspnNpCr9jmwn4ZhXFo5V2AtKIWKZbAp+lrpI= Received: by 10.147.124.1 with SMTP id b1mr6978293yan.22.1295318756562; Mon, 17 Jan 2011 18:45:56 -0800 (PST) Received: from [126.253.146.124] (pw126253146124.13.tss.panda-world.ne.jp [126.253.146.124]) by mx.google.com with ESMTPS id q4sm2592146yba.14.2011.01.17.18.45.53 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 17 Jan 2011 18:45:55 -0800 (PST) Subject: Re: impact of total region numbers? References: From: Tatsuya Kawano Content-Type: text/plain; charset=us-ascii X-Mailer: iPhone Mail (8C148) In-Reply-To: Message-Id: Date: Tue, 18 Jan 2011 11:45:18 +0900 To: "user@hbase.apache.org" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (iPhone Mail 8C148) X-Virus-Checked: Checked by ClamAV on apache.org Hi Tao,=20 I think the number of regions won't have much impact to random read throughp= ut and latency. But the number of generations (HFiles) per region will do.=20= If this is the case, try to run major compaction on the table. This will mer= ge HFile generations so the read throughput and latency will be recovered. Y= ou can do this from the hbase shell.=20 Also, you might want to increase hbase.region.mstore.flush.size to keep the= number of HFile generations smaller. Thanks,=20 -- Tatsuya Kawano (Mr.) Tokyo, Japan On Jan 18, 2011, at 11:20 AM, Tao Xie wrote: > For example, I have total some data and I can tune > hbase.hregion.max.filesize to increase/decrease total region number, rite?= > I want to know if the region number has performance impact to random read > tests. I observed that in my ycsb test, with larger hfile size, I got > better tput and smaller latency. > Anybody can give me hints. Thanks. >=20 > Tao