Return-Path: X-Original-To: apmail-hbase-issues-archive@www.apache.org Delivered-To: apmail-hbase-issues-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id EBC2CE7AC for ; Mon, 4 Feb 2013 06:04:14 +0000 (UTC) Received: (qmail 41040 invoked by uid 500); 4 Feb 2013 06:04:14 -0000 Delivered-To: apmail-hbase-issues-archive@hbase.apache.org Received: (qmail 40755 invoked by uid 500); 4 Feb 2013 06:04:13 -0000 Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list issues@hbase.apache.org Received: (qmail 40735 invoked by uid 99); 4 Feb 2013 06:04:12 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 04 Feb 2013 06:04:12 +0000 Date: Mon, 4 Feb 2013 06:04:12 +0000 (UTC) From: "Lars Hofhansl (JIRA)" To: issues@hbase.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (HBASE-7755) Experiment with LAB in BlockEndcoding MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HBASE-7755?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13570003#comment-13570003 ] Lars Hofhansl commented on HBASE-7755: -------------------------------------- Making the LAB even smaller (my KVs are small, I'll have more data) I can get this down to 3.7s. > Experiment with LAB in BlockEndcoding > ------------------------------------- > > Key: HBASE-7755 > URL: https://issues.apache.org/jira/browse/HBASE-7755 > Project: HBase > Issue Type: Bug > Reporter: Lars Hofhansl > > I was looking at and profiling the BlockEncoding code to figure out how to make it faster. One issue that jumped out was we call ByteBuffer.allocate(...) for each single KV. > As an experiment I tried using the MemStoreLAB code to allocate those buffers. > Here are some preliminary numbers, all scanning 10m rows (all in cache): > * no encoding: 5.2s > * FAST_DIFF without patch: 7.3s > * FAST_DIFF with patch and small LAB: 4.1s > * FAST_DIFF with patch and large LAB: 11s > So this is very sensitive to the right sizing of the LAB. > Need to do a bit more testing, but it seems that there is a chance to actually make scanning with block encoding faster than without! -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira