PI29977: EXCESSIVE THREADS FROM COM/IBM/ICU/UTIL/CALENDAR CODE CAUSES RUNTIME DELAY

7.0.0.39: WebSphere Application Server V7.0 Fix Pack 39
7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.39: Java SDK 1.6 SR16 FP7 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server

APAR status

• Closed as program error.

Error description

• Client is using Commerce and getting slow-moving threads in what
  appears to be com/ibm/icu/util/Calendar code.  No gc or high CPU
  issues. The following threads are seen from javacores:
  
  ---------
  "WebContianer : 8" has 8 threads waiting for it to complete with
  the
  top of its thread stack being:
  at com/dynatrace/diagnostics/agent/introspection/
  ExceptionIntrospection.a(Bytecode PC:48(Compiled Code))
  at com/dynatrace/diagnostics/agent/introspection/
  ExceptionIntrospection.ExceptionEvent(Bytecode PC:4(Compiled
  Code))
  at java/util/MissingResourceException.
  (MissingResourceException.java:52
  (Compiled Code))
  at com/ibm/icu/impl/ICUResourceBundle.handleGetObjectImpl
  (ICUResourceBundle.java:852(Compiled Code))
  at com/ibm/icu/impl/ICUResourceBundle.handleGetObjectImpl
  (ICUResourceBundle.java:849(Compiled Code))
  at com/ibm/icu/impl/ICUResourceBundle.handleGetObject
  (ICUResourceBundle.java:835(Compiled Code))
  at java/util/ResourceBundle.getObject(ResourceBundle.java:421
  (Compiled Code))
  --------------
  
  It appears that in this version of ICU4J, the Calendar
  constructor walked through ICU resource bundles to resolve an
  appropriate calendar type for a given locale, which is  almost
  always Gregorian calendar except for a few locales. The
  resource bundle implementation in ICU4J 3.4.5 did not utilize
  resource bundle cache, therefore, it repeatedly fetch the
  same contents from resource which involves synchronization
  here and there.
  
  
  Environment:
  WebSphere Network Deployment version 7.0.0.x
  
  Operating System:
  Distributed
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server V7.0                                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: The application server exhibits slow    *
  *                      response and all of the webcontainer    *
  *                      threads are in use.                     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The constructor for com.ibm.icu.util.Calendar.class invokes
  the Calendar.getCalendarType(locale) to retrieve the proper
  calendar type for the locale. This process walks through the
  ICU resource bundles, searching for a match. Since parts of
  this codepath are synchronized this can lead to delays when
  multiple threads are instantiating the Calendar.class at the
  same time.
  When this problem is encountered, the stalled webcontainer
  threads will show the stack trace entries:
  at com/ibm/icu/impl/ICUResourceBundle.getFunctionalEquivalent
  (ICUResourceBundle.java:499(Compiled Code))
  at com/ibm/icu/util/Calendar.getCalendarType(Calendar.java:1719
  (Compiled Code))
  

Problem conclusion

• The resource bundle implementation in ICU4J 3.4.5 does not
  utilize the resource bundle cache, therefore, it repeatedly
  fetches the same contents.
  
  Calendar.class has been updated to cache a calendar type for a
  locale and avoid calling
  ICUResourceBundle.getFunctionalEquivalent(...) repeatedly.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 7.0.0.39.  Please refer to the Recommended Updates
  page for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels

• R700 PSY

     UP