IT19024: NullPointerException in ServerWorker thread and Telemetry service ends

APAR status

• Closed as program error.

Error description

• NullPointerException causes the IBM MQ Telemetry service to end,
  disconnecting
  all connected clients. An FDC is generated with following
  symptom:
  
  Thread          :- name=ServerWorker0 priority=5 group=main
                     ccl=sun.misc.Launcher$AppClassLoader@ca2651dc
  Source Class    :- com.ibm.mq.communications.NonBlockingWorker
  Source Method   :- run
  Probe Id        :- XR014005
  FileInformation :- C:\ProgramData\IBM\MQ\errors\MQXRxxx.FDC
  Suppressed Count:- 0
  JavaDump file   :- null
  Thread          :- ServerWorker0
  Mem Max/Free/Tot:- xxxxxxxx / xxxxxxx / xxxxxxxx
  Loaded from     :-
                    jar:file:/C:/ibm/mq/mqxr/lib/MQXRListener.jar!
                /com/ibm/mq/communications/NonBlockingWorker.class
  ----------------------------------------------------------------
  java.lang.NullPointerException
  at com.ibm.mq.MQXRService.MQSubscriptionWrapper.subWithOptions
    (MQSubscriptionWrapper.java:340)
  at
  com.ibm.mq.MQXRService.MQSubscriptionWrapper.doNextRemainingWork
    (MQSubscriptionWrapper.java:658)
  at com.ibm.mq.MQXRService.MQTTServerSession.doFollowOnWork
    (MQTTServerSession.java:1515)
  at com.ibm.mq.MQXRService.WorkerContext.doFollowOnWork
    (WorkerContext.java:669)
  at com.ibm.mq.MQXRService.WorkerContext.synchronousWorkCompleted
    (WorkerContext.java:326)
  at
  com.ibm.mq.communications.NonBlockingWorker.synchronousWorkCompl
    eted(NonBlockingWorker.java:620)
  at com.ibm.mq.communications.NonBlockingWorker.run
    (NonBlockingWorker.java:422)
  at java.lang.Thread.run(Thread.java:809)
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users connecting to the queue manager's MQTT
  channel and making subscriptions.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  There was a small timing window where if a subscription request
  being made for a MQTT client coincided with the connection
  closing, a subscription request was made on the closed
  connection object, intermittently resulting in a
  NullPointerException. This exception caused the MQTT service to
  end.
  

Problem conclusion

• The timing window where the NullPointerException could occur has
  been removed, and the exception no longer occurs.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.9
  v9.0 LTS   9.0.0.3
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

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

  WMQ BASE MULTIP

• Fixed component ID

  5724H7251

Applicable component levels

• R800 PSY

     UP