Keith Boone created LANG-1355:
---------------------------------
Summary: 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
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)
