PK57072: MEMORY LEAK IN ELEVALUATOR

Java SDK 1.5 SR8 Cumulative Fix for WebSphere Application Server
Java SDK 1.5 SR8 Cumulative Fix for WebSphere Application Server
Java SDK 1.5 SR10 Cumulative Fix for WebSphere Application Server
6.1.0.31: Java SDK 1.5 SR11 FP1 Cumulative Fix for WebSphere Application Server
6.1.0.33: Java SDK 1.5 SR12 FP1 Cumulative Fix for WebSphere
6.1.0.29: Java SDK 1.5 SR11 Cumulative Fix for WebSphere Application Server
6.1.0.35: Java SDK 1.5 SR12 FP2 Cumulative Fix for WebSphere
6.1.0.37: Java SDK 1.5 SR12 FP3 Cumulative Fix for WebSphere
6.1.0.39: Java SDK 1.5 SR12 FP4 Cumulative Fix for WebSphere Application Server
6.1.0.41: Java SDK 1.5 SR12 FP5 Cumulative Fix for WebSphere Application Server
6.1.0.43: Java SDK 1.5 SR13 Cumulative Fix for WebSphere Application Server
6.1.0.45: Java SDK 1.5 SR14 Cumulative Fix for WebSphere Application Server
6.1.0.47: WebSphere Application Server V6.1 Fix Pack 47
6.1.0.47: Java SDK 1.5 SR16 Cumulative Fix for WebSphere Application Server

APAR status

• Closed as program error.

Error description

• Memory leak in standard taglib ELEvaluator class.  A fix has
  been publicly posted and see below link for more information.
  
  http://issues.apache.org/bugzilla/show_bug.cgi?id=31789
  
  
  
  This is actually a bug for version 1.0.6 (but I couldn't select
  that version because it wasn't listed).
  
  WHAT IS IT?:
       All evaluated expressions are added to the ELEvaluator's
  sCachedExpressionStrings map and never removed. This causes a
  memory leak which can eventually cause running programs to crash
  due to an OutOfMemoryError.
  
  
  WHERE IS IT?:
  
  org.apache.taglibs.standard.lang.jstl.ELEvaluator.parseExpressio
  nString(String)
  
  TO REPRODUCE:
       Write a simple page that uses a JSTL tag, give it a
  different dynamically-generated expression as an attribute value
  and refresh the page several times. Eventually you will see the
  memory climb (through profiling, system logs or by your process
  exiting with an OutOfMemoryError).
  
  A POSSIBLE FIX:
       A possible fix would be to use a last-recently-used cache
  (such as Java 1.4's LinkedHashMap) to ensure that items do not
  remain in this cache indefinitely.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: IBM WebSphere Application Server Version     *
  *                 6.0.2 and 6.1 users of Java Server Pages     *
  *                 (JSP).                                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: The Java Standard Tag Library (JSTL)    *
  *                      shipped with Application Server caches  *
  *                      expressions in a hash map that grows    *
  *                      in size with the number of expressions. *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  JSTL's expression evaluator is used for applications with a
  web.xml that defines the servlet specification as 2.3 or
  lower. The hash map that this evaluator caches expressions in
  is not bounded in size and grows with the number of unique
  expressions it evaluates. For applications with a very large
  number of unique expressions this can use a lot of memory.
  

Problem conclusion

• Included fix for Apache Bugzilla Bug 31789
  (http://issues.apache.org/bugzilla/show_bug.cgi?id=31789) in
  the version of JSTL shipped with WebSphere 6.0.2 and 6.1.
  
  The fix for this APAR is currently targeted for inclusion in
  fix packs 6.0.2.27 and 6.1.0.17. 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:

Modules/Macros

• JSP
  

Fix information

• Fixed component name

  WEBSPH APP SERV

• Fixed component ID

  5724J0800

Applicable component levels

• R60A PSY

     UP

• R60H PSY

     UP

• R60I PSY

     UP

• R60P PSY

     UP

• R60S PSY

     UP

• R60W PSY

     UP

• R60Z PSY

     UP

• R61A PSY

     UP

• R61H PSY

     UP

• R61I PSY

     UP

• R61P PSY

     UP

• R61S PSY

     UP

• R61W PSY

     UP

• R61Z PSY

     UP