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https://issues.apache.org/jira/browse/LANG-1355?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16196436#comment-16196436
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ASF GitHub Bot commented on LANG-1355:
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GitHub user chonton opened a pull request:
https://github.com/apache/commons-lang/pull/296
LANG-1355: Add FastTimeZone to decrease TimeZone.getTimezone latency
Adding FastTimeZone to decrease latency of timezone lookups. I'll hold
this PR open for 48 hours for commons committers' comments. Thanks!
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/chonton/commons-lang LANG-1355
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/commons-lang/pull/296.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #296
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commit a703646e949c277c5249c87e08486d2b7a69cb34
Author: Chas Honton <[email protected]>
Date: 2017-10-09T01:54:17Z
LANG-1355: Add FasTimeZone to decrease TimeZone.getTimezone latency
commit 7670979033076f354af7e4cf852709d5403ffbd4
Author: Chas Honton <[email protected]>
Date: 2017-10-09T02:18:01Z
Replace all TimeZone.getTimeZone(UTC) wiht FastTimeZone.getGmtTimeZone()
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> 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
> 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.
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