PK96684: THREAD HANGING IN JAVA.UTIL.HASHMAP

APAR status

• Closed as program error.

Error description

• When using certain PUMA group attributes in a high load
  situation, several threads may hang in java.util.HashMap due to
  unsynchronized access to the collection class. The following
  stack trace appears in trace.log:
  
  10:09:44:471 CEST] 0000002a ThreadMonitor W WSVR0605W: Thread
  "WebContainer : 10" (00000050) has been active for 702661
  milliseconds
  and may be hung. There is/are 2 thread(s) in total in the server
  that
  may be hung.
  at java.util.HashMap.findNonNullKeyEntry(HashMap.java:526)
  at java.util.HashMap.putImpl(HashMap.java:622)
  at java.util.HashMap.put(HashMap.java:605)
  at
  com.ibm.wps.um.GroupImpl.extractAttributes(GroupImpl.java:228)
  at com.ibm.wps.um.GroupImpl.setVmmPrincipal(GroupImpl.java:181)
  

Local fix

Problem summary

• When using certain PUMA group attributes in a high load
  situation, several threads may hang in java.util.HashMap due to
  unsynchronized access to the collection class. The following
  stack trace appears in trace.log:
  
  10:09:44:471 CEST] 0000002a ThreadMonitor W WSVR0605W: Thread
  "WebContainer : 10" (00000050) has been active for 702661
  milliseconds and may be hung. There is/are 2 thread(s) in total
  in the server that may be hung.
  at java.util.HashMap.findNonNullKeyEntry(HashMap.java:526)
  at java.util.HashMap.putImpl(HashMap.java:622)
  at java.util.HashMap.put(HashMap.java:605)
  at
  com.ibm.wps.um.GroupImpl.extractAttributes(GroupImpl.java:228)
  at com.ibm.wps.um.GroupImpl.setVmmPrincipal(GroupImpl.java:181)
  

Problem conclusion

• Although the PUMA code appears to be read-only code, it does
  access a java collection (HashMap) by writing to it in order to
  perform a lazy initialization. This code path needs to be
  synchronized.
  
  Manual Steps:
     None
  
  Failing Module(s):
     Portal Access Control
  
  Affected Users:
     All end users
  
  Version Information:
      Portal Version(s): 6.1.0.1
       Pre-Requisite(s): PK86483
        Co-Requisite(s): ---
  
      Portal Version(s): 6.1.0.2
       Pre-Requisite(s): PK86483
        Co-Requisite(s): ---
  
  Platform Specific:
     This fix applies to all platforms.
  
  A fix is available from Fix Central:
  
  http://www.ibm.com/eserver/support/fixes/fixcentral/swgquickorde
  ?apar=PK96684&productid=WebSphere%20Portal&brandid=5
  
  You might need to type or paste the complete address into your
  Web browser.
  

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

  WEBSPHERE PORTA

• Fixed component ID

  5724E7600

Applicable component levels

• R61A PSY

     UP

• R61B PSY

     UP