PM56368: WEBSPHERE ADJUNCT AND SERVANT REGIONS LEAK MEMORY WHEN ANY XARESOURCE FAILS TO RECOVER

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When running WebSphere Application Server zOS, the adjunct and
  the servant regions' JVM heap grows consistently, possibly
  leading to OutOfMemoryError.
  
  A Java heap dump will have many of the following objects:
  com.ibm.ws.sib.jfapchannel.impl.ConversationImpl
  com.ibm.ws.sib.processor.impl.ConnectionImpl
  com.ibm.ws.sib.jfapchannel.impl.OutboundConnection
  
  Also, eventually the following messages are output to the log:
  
  CWSIJ0055E: A resource shortage stopped a new connection from
  being established.
  
  During this time, a single unrelated XAResouce will be
  continuously failing to recover successfully.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM WebSphere Application       *
  *                 Server V6.1                                  *
  ****************************************************************
  * PROBLEM DESCRIPTION: JVM heap growth eventually leading to   *
  *                      OutOfMemoryError and or CWSIJ0055E      *
  *                      messages.                               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  On WebSphere Application Server for zOS, if a single
  XAResource fails to recover successfully, all XAResources in
  the partner log are retried.  This exposes a Connection leak in
  one of the Service Integration Bus XAResources which occurs
  because of the lack of code to ensure that the Connection is
  closed when the transaction service is finished with the
  XAResource.
  This leak in turn causes a memory leak in both the servant and
  adjunct regions as each connection has an in memory
  representation in both of these regions.
  Eventually, SIB is unable to create more conversations and the
  CWSIJ0055E message is output.
  Distributed platforms will also experience this leak, but it
  will only ever be a single Connection as recover is only
  called once per XAResource.
  

Problem conclusion

• This APAR resolves the problem by ensuring that the Connection
  is closed whenever the transaction service is finished with
  the XAResource.
  
  APAR PM56368 is currently targeted for inclusion in Fix Pack
  6.1.0.45 of WebSphere Application Server.
  
  Please refer to URL:
  //www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
  for Fix Pack availability.
  

Temporary fix

Comments

APAR Information

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

  PM39070

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

Modules/Macros

• BBGUBINF BBOUBINF
  

Fix information

• Fixed component name

  WEBSPHERE FOR Z

• Fixed component ID

  5655I3500

Applicable component levels

• R610 PSY UK81646

     UP12/09/23 P F209

Fix is available

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