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 C89C319CC3 for ; Tue, 26 Apr 2016 21:12:13 +0000 (UTC) Received: (qmail 70640 invoked by uid 500); 26 Apr 2016 21:12:13 -0000 Delivered-To: apmail-hbase-issues-archive@hbase.apache.org Received: (qmail 70545 invoked by uid 500); 26 Apr 2016 21:12:13 -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 70416 invoked by uid 99); 26 Apr 2016 21:12:13 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 26 Apr 2016 21:12:13 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id F2D642C1F6A for ; Tue, 26 Apr 2016 21:12:12 +0000 (UTC) Date: Tue, 26 Apr 2016 21:12:12 +0000 (UTC) From: "stack (JIRA)" To: issues@hbase.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (HBASE-15716) HRegion#RegionScannerImpl scannerReadPoints synchronization costs 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-15716?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] stack updated HBASE-15716: -------------------------- Attachment: Screen Shot 2016-04-26 at 2.07.06 PM.png Screen Shot 2016-04-26 at 2.05.45 PM.png Screen Shot 2016-04-26 at 2.06.14 PM.png Here are flight recordings of before and after. The before is current state of branch-1. The workload is ycsb c -- pure random read -- and the hit rate is about 220k/second. The after is my eliding the synchronization. See how our lock instances drops radically from 200k per thread per minute of my sample down to nothing (miscelllenous locking allocating BBs out of BucketCache). The speed up seen is not that much but nothing to sneer at... from 220k to 240k. > HRegion#RegionScannerImpl scannerReadPoints synchronization costs > ----------------------------------------------------------------- > > Key: HBASE-15716 > URL: https://issues.apache.org/jira/browse/HBASE-15716 > Project: HBase > Issue Type: Bug > Components: Performance > Reporter: stack > Attachments: Screen Shot 2016-04-26 at 2.05.45 PM.png, Screen Shot 2016-04-26 at 2.06.14 PM.png, Screen Shot 2016-04-26 at 2.07.06 PM.png > > > Here is a [~lhofhansl] special. > When we construct the region scanner, we get our read point and then store it with the scanner instance in a Region scoped CSLM. This is done under a synchronize on the CSLM. > This synchronize on a region-scoped Map creating region scanners is the outstanding point of lock contention according to flight recorder (My work load is workload c, random reads). -- This message was sent by Atlassian JIRA (v6.3.4#6332)