PK56545: NULLPOINTEREXCEPTION WITH READAHEADHINT ACCESS INTENT AND EMPTY CHILD TABLES

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

• With ReadAheadHint access intent enabled and empty child tables
  linked to parent with primary key, a NullPointerException can
  occur. This APAR is to improve EJB caching behavior to avoid the
  exception. Exception will look something like:
  java.lang.NullPointerException
   at
  sample.SampleMwKey.hashCode(SampleMwKey.java:40
  )
   at java.util.HashMap.hash(HashMap.java:343)
   at java.util.HashMap.get(HashMap.java:399)
   at
  com.ibm.ws.ejbpersistence.cache.TransactionScopedCache.getEntry(
  Unkn
  own
  Source)
   at
  com.ibm.ws.ejbpersistence.cache.CacheManagerImpl.peekEntry(Unkno
  wn
  Source)
   at
  com.ibm.ws.ejbpersistence.dataaccess.ResultCollectionImpl.proces
  sSin
  gleRow(Unknown
  Source)
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: WebSphere Application Server v5.1, v6.0.2 &  *
  *                 v6.1 Persistence Manager users with          *
  *                 ReadAhead hint defined on their CMP CMP      *
  *                 beans                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: When the ReadAhead hint access intent   *
  *                      with CMR on CMP beans is defined and    *
  *                      no valid row in child table is linked   *
  *                      back to the parent table, a             *
  *                      NullPointerException is thrown which    *
  *                      triggers a javax.ejb.EJBException.      *
  *                      The transcation is rolled back due to   *
  *                      this EJBException.                      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The problem occurs in situations involving two beans bound by
  a CMR relationship with ReadAheadHint access intent enabled.
  
  
  When the parent bean is activated with ReadAheadhint access
  intent enabled, all related beans in the child table will also
  be retrieved from the database and persisted to Persistent
  Manager cache.  In the case an empty child table is retrieved
  from the database and EJB caching manager processes the data of
  the empty child table, if any or the primary key fields is of
  a non-primitive type and the corresponding table column value
  is null, then the hashCode of the primary key class
  throws a NullPointerException which results in transaction
  rollback.
  

Problem conclusion

• The NullPointerException is caught in proper manner and a
  warning message is issued to log the exception.
  
  This APAR will be included in fixpacks 5.1.1.18, 6.0.2.27 and
  6.1.0.15
  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

• PM
  

Fix information

• Fixed component name

  WEBS APP SERV N

• Fixed component ID

  5724H8800

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