From common-issues-return-154649-archive-asf-public=cust-asf.ponee.io@hadoop.apache.org Wed Jul 11 10:57:04 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id 70A0F18077A for ; Wed, 11 Jul 2018 10:57:03 +0200 (CEST) Received: (qmail 6140 invoked by uid 500); 11 Jul 2018 08:57:02 -0000 Mailing-List: contact common-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list common-issues@hadoop.apache.org Received: (qmail 5956 invoked by uid 99); 11 Jul 2018 08:57:02 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd1-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 11 Jul 2018 08:57:02 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd1-us-west.apache.org (ASF Mail Server at spamd1-us-west.apache.org) with ESMTP id F007ECBD68 for ; Wed, 11 Jul 2018 08:57:01 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -109.501 X-Spam-Level: X-Spam-Status: No, score=-109.501 tagged_above=-999 required=6.31 tests=[ENV_AND_HDR_SPF_MATCH=-0.5, KAM_ASCII_DIVIDERS=0.8, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, USER_IN_DEF_SPF_WL=-7.5, USER_IN_WHITELIST=-100] autolearn=disabled Received: from mx1-lw-us.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id Gf6GpJgtljq1 for ; Wed, 11 Jul 2018 08:57:01 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-us.apache.org (ASF Mail Server at mx1-lw-us.apache.org) with ESMTP id 0CEF05F502 for ; Wed, 11 Jul 2018 08:57:01 +0000 (UTC) Received: from jira-lw-us.apache.org (unknown [207.244.88.139]) by mailrelay1-us-west.apache.org (ASF Mail Server at mailrelay1-us-west.apache.org) with ESMTP id 7AD0EE1067 for ; Wed, 11 Jul 2018 08:57:00 +0000 (UTC) Received: from jira-lw-us.apache.org (localhost [127.0.0.1]) by jira-lw-us.apache.org (ASF Mail Server at jira-lw-us.apache.org) with ESMTP id 3363A2713F for ; Wed, 11 Jul 2018 08:57:00 +0000 (UTC) Date: Wed, 11 Jul 2018 08:57:00 +0000 (UTC) From: "Prasanth Jayachandran (JIRA)" To: common-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (HADOOP-15598) DataChecksum calculate checksum is contented on hashtable synchronization MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HADOOP-15598?page=3Dcom.atlassi= an.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D16= 539750#comment-16539750 ]=20 Prasanth Jayachandran commented on HADOOP-15598: ------------------------------------------------ Results from JMH microbenchmark. As we can see for bytebuffers of size >128= there is no significant benefit as most of the time is spent on the chunk = looping. But for smaller size, the synchronization has significant impact.= =C2=A0 {noformat} Benchmark (size) Mode Cnt = Score Error Units ComputeChecksumBenchmark.benchmarkChecksumWithoutPatch 8 avgt 10 = 66.970 =C2=B1 1.247 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithoutPatch 16 avgt 10 = 91.524 =C2=B1 2.141 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithoutPatch 32 avgt 10 = 127.155 =C2=B1 8.037 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithoutPatch 64 avgt 10 = 233.941 =C2=B1 14.327 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithoutPatch 128 avgt 10 = 382.898 =C2=B1 4.316 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithoutPatch 1024 avgt 10 = 2707.026 =C2=B1 53.266 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithoutPatch 4096 avgt 10 = 11411.330 =C2=B1 181.900 ns/op Benchmark (size) Mode Cnt = Score Error Units ComputeChecksumBenchmark.benchmarkChecksumWithPatch 8 avgt 10 = 27.948 =C2=B1 0.507 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithPatch 16 avgt 10 = 49.336 =C2=B1 1.212 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithPatch 32 avgt 10 = 96.344 =C2=B1 1.360 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithPatch 64 avgt 10 1= 82.513 =C2=B1 2.553 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithPatch 128 avgt 10 3= 56.205 =C2=B1 4.282 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithPatch 1024 avgt 10 28= 25.526 =C2=B1 31.177 ns/op ComputeChecksumBenchmark.benchmarkChecksumWithPatch 4096 avgt 10 120= 78.055 =C2=B1 262.343 ns/op {noformat} > DataChecksum calculate checksum is contented on hashtable synchronization > ------------------------------------------------------------------------- > > Key: HADOOP-15598 > URL: https://issues.apache.org/jira/browse/HADOOP-15598 > Project: Hadoop Common > Issue Type: Bug > Components: common > Affects Versions: 3.2.0 > Reporter: Prasanth Jayachandran > Priority: Major > Attachments: HADOOP-15598.1.patch, Screen Shot 2018-07-11 at 1.45= .06 AM.png > > > When profiling a multi-threaded hive streaming ingest, observed lock cont= ention on java.util.Properties getProperty() to check if os is "sparc". jav= a.util.Properties internally uses HashTable. HashTable.get() is synchronize= d method. In the test application, on a 30s profile with 64 threads ~40% CP= U time is spent on getProperty() contention. See attached snapshot. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscribe@hadoop.apache.org For additional commands, e-mail: common-issues-help@hadoop.apache.org