Return-Path: X-Original-To: apmail-hbase-user-archive@www.apache.org Delivered-To: apmail-hbase-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 4D84410347 for ; Tue, 7 Jan 2014 07:07:08 +0000 (UTC) Received: (qmail 51393 invoked by uid 500); 7 Jan 2014 07:07:05 -0000 Delivered-To: apmail-hbase-user-archive@hbase.apache.org Received: (qmail 50705 invoked by uid 500); 7 Jan 2014 07:07:00 -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 50694 invoked by uid 99); 7 Jan 2014 07:06:57 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 07 Jan 2014 07:06:57 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=5.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: local policy) Received: from [202.38.128.6] (HELO ihep.ac.cn) (202.38.128.6) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 07 Jan 2014 07:06:50 +0000 Received: by ajax-webmail-ihep (Coremail) ; Tue, 7 Jan 2014 15:06:28 +0800 (GMT+08:00) Date: Tue, 7 Jan 2014 15:06:28 +0800 (GMT+08:00) From: "LEI Xiaofeng" To: user@hbase.apache.org Message-ID: <3db73bcb.3b78c.1436b862088.Coremail.leixf@ihep.ac.cn> Subject: hbase read performance tuning failed MIME-Version: 1.0 Content-Type: text/plain; charset=GBK Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.32.34] X-Priority: 3 X-Mailer: Coremail Webmail Server Version XT2.1.9 build 20121203(20875.5107.5063) Copyright (c) 2002-2014 www.mailtech.cn ihep X-SendMailWithSms: false X-CM-TRANSID: AQAAf0D5ikJ0p8tSiIZhAA--.13981W X-CM-SenderInfo: hohl5wo6lkv1wodfhubq/1tbiAQQRA1Dmq2FHJQABsI X-Coremail-Antispam: 1Ur529EdanIXcx71UUUUU7IcSsGvfJ3iIAIbVAYjsxI4VWxJw CS07vEb4IE77IF4wCS07vE1I0E4x80FVAKz4kxMIAIbVAFxVCaYxvI4VCIwcAKzIAtYxBI daVFxhVjvjDU= X-Virus-Checked: Checked by ClamAV on apache.org Hi, I am running hbase-0.94.6-cdh4.5.0 and set up a cluster of 5 nodes. The random read performance is ok, but the scan performance is poor. I tried to increase "hbase.client.scanner.caching" to 100 to promote the scan performance but it made no difference. And when I tried to make smaller blocks by setting "BLOCKSIZE" when created tables to get better random read performance it made no difference too. So, I am wondering if anyone could give some advice to solve this problem. Thanks