Mailing-List: contact issues-help@commons.apache.org; run by ezmlm
Precedence: bulk
Reply-To: issues@commons.apache.org
Date: Tue, 10 Oct 2017 14:42:00 +0000 (UTC)
From: "ASF GitHub Bot (JIRA)" <jira@apache.org>
To: issues@commons.apache.org
Message-ID: <JIRA.13105890.1506637945000.18195.1507646520197@Atlassian.JIRA>
In-Reply-To: <JIRA.13105890.1506637945000@Atlassian.JIRA>
References: <JIRA.13105890.1506637945000@Atlassian.JIRA> <JIRA.13105890.1506637945472@jira-lw-us.apache.org>
Subject: [jira] [Commented] (LANG-1355) TimeZone.getTimeZone() in
 FastDateParser causes resource contention
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
archived-at: Tue, 10 Oct 2017 14:42:07 -0000


    [ https://issues.apache.org/jira/browse/LANG-1355?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16198750#comment-16198750 ] 

ASF GitHub Bot commented on LANG-1355:
--------------------------------------

Github user chonton commented on a diff in the pull request:

    https://github.com/apache/commons-lang/pull/296#discussion_r143748954
  
    --- Diff: src/main/java/org/apache/commons/lang3/time/GmtTimeZone.java ---
    @@ -0,0 +1,103 @@
    +/*
    + * Licensed to the Apache Software Foundation (ASF) under one or more
    + * contributor license agreements.  See the NOTICE file distributed with
    + * this work for additional information regarding copyright ownership.
    + * The ASF licenses this file to You under the Apache License, Version 2.0
    + * (the "License"); you may not use this file except in compliance with
    + * the License.  You may obtain a copy of the License at
    + *
    + *      http://www.apache.org/licenses/LICENSE-2.0
    + *
    + * Unless required by applicable law or agreed to in writing, software
    + * distributed under the License is distributed on an "AS IS" BASIS,
    + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    + * See the License for the specific language governing permissions and
    + * limitations under the License.
    + */
    +package org.apache.commons.lang3.time;
    +
    +import java.util.Date;
    +import java.util.TimeZone;
    +
    +/**
    + * Custom timezone that contains offset from GMT.
    + *
    + * @since 3.7
    + */
    +class GmtTimeZone extends TimeZone {
    --- End diff --
    
    great catch! done


> TimeZone.getTimeZone() in FastDateParser causes resource contention
> -------------------------------------------------------------------
>
>                 Key: LANG-1355
>                 URL: https://issues.apache.org/jira/browse/LANG-1355
>             Project: Commons Lang
>          Issue Type: Bug
>          Components: lang.time.*
>    Affects Versions: 3.6
>         Environment: Windows
>            Reporter: Keith Boone
>            Assignee: Charles Honton
>   Original Estimate: 48h
>  Remaining Estimate: 48h
>
> Under heavy load we are seeing contention in FastDateParser.parse() on calls to TimeZone.getTimeZone().  TimeZone.getTimeZone() is a synchronized static in the Oracle JVM.
> Our proposed solution is to add a class TimeZoneCache containing a single method getTimeZone() which gets the requested time zone from a ConcurrentMap, and if not present, looks it up via TimeZone.getTimeZone() and caches it before returning it.
> Then replace calls to TimeZone.getTimeZone() in FastDateParser ( and whereever else) to calls to TimeZoneCache.getTimeZone().  
> The reason to add a separate class is because it can also be used by other applications which heavily parse or format or do other things where TimeZone is repeatedly needed.
> Under extreme load we have seen an 50:1 improvement in calls to FastDateParser.parse().  This saves about a ms/call in our test environment, and reduces contention.


--
This message was sent by Atlassian JIRA
(v6.4.14#64029)