IT32987: NullPointerException occurs when activation specification or WASlistener port is configured to use message retention

APAR status

• Closed as program error.

Error description

• When using WebSphere Application Server V9.0.5.1, the following
  resources have been defined using the WebSphere Administrative
  Console:
  
  - An IBM MQ messaging provider connection factory which contains
  details about how to connect to a queue manager using the CLIENT
  transport. The connection factory has the "Retain messages, even
  if no matching consumer is available" checkbox unselected.
  - An IBM MQ messaging provider queue destination that maps to a
  queue on the queue manager.
  - Two listener ports, both of which use the connection factory
  and queue destination definitions mentioned above.
  
  Two different enterprise applications had been deployed into the
  application server. Each application server is bound to a
  different listener port.
  
  When the application server starts, one of the listener ports
  fails to start and the following error message is written to the
  SystemOut.log file:
  
  WMSG0019E: Unable to start MDB Listener MDB, JMSDestination
  jms/testQueue : java.lang.NullPointerException
  	at java.util.Hashtable.put(Hashtable.java:505)
  	at
  com.ibm.msg.client.wmq.internal.WMQMessageRetentionProcessor$WMQ
  MessageRetentionAgent.addBrowser(WMQMessageRetentionProcessor.ja
  va:102)
  	at
  com.ibm.msg.client.wmq.internal.WMQMessageRetentionProcessor.reg
  isterConnectionBrowser(WMQMessageRetentionProcessor.java:355)
  	at
  com.ibm.msg.client.wmq.internal.WMQConnectionBrowser.<init>(WMQC
  onnectionBrowser.java:1480)
  	at
  com.ibm.msg.client.wmq.internal.WMQConnection.createConnectionBr
  owser(WMQConnection.java:849)
  	at
  com.ibm.msg.client.jms.internal.JmsConnectionImpl.createConnecti
  onBrowser(JmsConnectionImpl.java:1360)
  	at
  com.ibm.msg.client.jms.internal.JmsConnectionConsumerImpl.create
  ConnectionBrowser(JmsConnectionConsumerImpl.java:259)
  	at
  com.ibm.msg.client.jms.internal.JmsConnectionConsumerImpl.<init>
  (JmsConnectionConsumerImpl.java:180)
  	at
  com.ibm.msg.client.jms.internal.JmsConnectionConsumerImpl.<init>
  (JmsConnectionConsumerImpl.java:125)
  	at
  com.ibm.msg.client.jms.internal.JmsConnectionImpl.createConnecti
  onConsumer(JmsConnectionImpl.java:658)
  	at
  com.ibm.msg.client.jms.internal.JmsXAConnectionImpl.createConnec
  tionConsumer(JmsXAConnectionImpl.java:235)
  	at
  com.ibm.mq.jms.MQConnection.createConnectionConsumer(MQConnectio
  n.java:204)
  	at
  com.ibm.ejs.jms.JMSConnectionHandle.createConnectionConsumer(JMS
  ConnectionHandle.java:1309)
  	at
  com.ibm.ejs.jms.listener.MDBListenerImpl.createResources(MDBList
  enerImpl.java:550)
  	at
  com.ibm.ejs.jms.listener.MDBListenerImpl.internalStart(MDBListen
  erImpl.java:738)
  	at
  com.ibm.ejs.jms.listener.MDBListenerImpl.restart(MDBListenerImpl
  .java:711)
  	at
  com.ibm.ejs.jms.listener.MDBListenerImpl.alarm(MDBListenerImpl.j
  ava:1134)
  	at com.ibm.ejs.util.am._Alarm.runImpl(_Alarm.java:151)
  	at com.ibm.ejs.util.am._Alarm.run(_Alarm.java:136)
  	at
  com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1909)
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects three categories of user:
  
  Category 1:
  ---------------
  Users of the IBM MQ resource adapter who have:
  
  - Defined two or more activation specifications that monitor the
  same JMS destination, where at least one of the activation
  specifications have the "messageRetention" property set to the
  value "false".
  - And have at least one enterprise application deployed that use
  one of the activation specifications, and does not specify a
  message selector.
  
  Category 2:
  ---------------
  Users of the WebSphere Application Server IBM MQ messaging
  provider who have:
  
  - Defined two or more activation specifications that monitor the
  same JMS destination, where at least one of the activation
  specifications has the checkbox "Retain messages, even if no
  matching consumer is available" unselected.
  - And have at least one enterprise application deployed that
  uses one of the activation specifications, and does not specify
  a message selector.
  
  Category 3:
  ---------------
  Users of the WebSphere Application Server IBM MQ messaging
  provider who have:
  
  - Defined IBM MQ messaging provider connection factories that
  have the checkbox "Retain messages, even if no matching consumer
  is available" unselected.
  - And created an IBM MQ messaging provider destination.
  - And have two or more listener ports configured to use the one
  of the connection factories, and the destination.
  - And have deployed enterprise applications that are bound to
  one of the listener ports, where at least one of the
  applications does not specify a message selector.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The message retention functionality provided by the IBM MQ
  resource adapter (which is embedded into WebSphere Application
  Server, and handles all of the communication between the
  application server and a queue manager) allows users to specify
  what happens if:
  
  - An activation specification or WebSphere Application Server
  listener port is monitoring a JMS destination for messages that
  match a message selector.
  - And a message is found that doesn't match the selector.
  
  By default, messages that don't match the selector are left on
  the destination. However, if:
  
  - Either the IBM MQ activation specification property
  "messageRetention" is set to false.
  - Or the WebSphere Application Server IBM MQ messaging provider
  connection factory definition used by a listener port has the
  checkbox "Retain messages, even if no matching consumer is
  available" unselected.
  
  then the IBM MQ resource adapter will create an internal
  MessageRetentionAgent and use it to remove any messages that
  don't match the selector from the destination. This prevents the
  JMS destination from filling up with messages that will never be
  processed.
  
  In the situation that:
  
  - Either the IBM MQ activation specification property
  "messageRetention" is set to false.
  - Or the WebSphere Application Server IBM MQ messaging provider
  connection factory definition used by a listener port has the
  checkbox "Retain messages, even if no matching consumer is
  available" unselected.
  
  and the enterprise application using the activation
  specification or listener port does not specify a message
  selector, then the MessageRetentionAgent will not remove any
  messages from the destination.  This is because all of the
  messages on the destination are suitable for delivery to the
  application, as it is not using a selector.
  
  There is one internal MessageRetentionAgent per destination. If
  two or more activation specifications or listener ports are
  configured to monitor the same destination, they share the same
  MessageRetentionAgent. In this situation, the
  MessageRetentionAgent will only remove message that don't match
  either selector from the destination. If one or more of the
  applications has not specified a selector, then no messages will
  be removed from the queue.
  
  Now:
  
  - If two or more activation specifications or listener ports
  were configured to monitor the same destination.
  - And at least one of the enterprise applications using the
  activation specification or listener ports did not specify a
  message selector.
  
  then it was possible for the MessageRetentionAgent to try to
  register the activation specifications or listener ports with a
  null value for the message selector. If this happened, then the
  following exception would be thrown:
  
  NullPointerException
  	at java.util.Hashtable.put(Hashtable.java:505)
  	at
  com.ibm.msg.client.wmq.internal.WMQMessageRetentionProcessor$WMQ
  MessageRetentionAgent.addBrowser(WMQMessageRetentionProcessor.ja
  va)
  	at
  com.ibm.msg.client.wmq.internal.WMQMessageRetentionProcessor.reg
  isterConnectionBrowser(WMQMessageRetentionProcessor.java)
  	at
  com.ibm.msg.client.wmq.internal.WMQConnectionBrowser.<init>(WMQC
  onnectionBrowser.java)
  &#09;at
  com.ibm.msg.client.wmq.internal.WMQConnection.createConnectionBr
  owser(WMQConnection.java)
  &#09;at
  com.ibm.msg.client.jms.internal.JmsConnectionImpl.createConnecti
  onBrowser(JmsConnectionImpl.java)
  &#09;at
  com.ibm.msg.client.jms.internal.JmsConnectionConsumerImpl.create
  ConnectionBrowser(JmsConnectionConsumerImpl.java)
  &#09;at
  com.ibm.msg.client.jms.internal.JmsConnectionConsumerImpl.<init>
  (JmsConnectionConsumerImpl.java)
  &#09;at
  com.ibm.msg.client.jms.internal.JmsConnectionConsumerImpl.<init>
  (JmsConnectionConsumerImpl.java)
  &#09;at
  com.ibm.msg.client.jms.internal.JmsConnectionImpl.createConnecti
  onConsumer(JmsConnectionImpl.java)
      .....
  
  and the activation specification or listener port would fail to
  start.
  

Problem conclusion

• To resolve this issue, the IBM MQ resource adapter has been
  updated to ensure that:
  
  - If two or more activation specifications or listener ports are
  configured to monitor the same destination.
  - And at least one of the enterprise applications using the
  activation specification or listener ports does not specify a
  message selector.
  
  then the MessageRetentionAgent will always register the
  activation specification or listener port using the special
  selector string "<NULL>". This ensures that the activation
  specifications or listener ports are registered successfully,
  and prevents the NullPointerException from occurring.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 LTS   9.1.0.7
  v9.2 LTS   9.2.0.2
  v9.x CD    9.2.1
  
  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

  IBM MQ BASE MP

• Fixed component ID

  5724H7271

Applicable component levels