IT34358: Displaying channel status for MQ Telemetry channels using filteron CONNAME attribute may fail with NullPointerException

APAR status

• Closed as program error.

Error description

• When using IBM MQ Telemetry service, running the command:
  
  DISPLAY CHSTATUS (MQTT)
  
  specifying a filter condition that includes the CONNAME
  attribute, as shown in the example below:
  
  DISPLAY CHSTATUS(*) CHLTYPE(MQTT) CLIENTID(*) ALL WHERE( CONNAME
  EQ '1.2.3.4')
  
  results in a NullPointerException occurring. In addition to
  this, an FDC is generated containing the following information:
  
  Thread       :- name=Jmqi AsyncConsume Thread. tid: 5
                  priority=5 group=main
                  ccl=sun.misc.Launcher$AppClassLoader@3269d6b
  Source Class :- com.ibm.mq.MQXRService.MQTTCommandProcessor
  Source Method:- processEscapePCFCommand
  Probe Id     :- XR052012
  Loaded from  :- jar:file:/opt/mqm910/mqxr/lib/MQXRListener.jar
      !/com/ibm/mq/MQXRService/MQTTCommandProcessor.class
  |------------------------------------------------------------|
  
  java.lang.NullPointerException
   at com.ibm.mq.MQXRService.PCFUtils.matchClientFilter
      (PCFUtils.java:113)
   at com.ibm.mq.MQXRService.MQTTCommandProcessor.
      resolveClientID(MQTTCommandProcessor.java:3292)
   at com.ibm.mq.MQXRService.MQTTCommandProcessor.
       inquireChannelStatusInstance
       (MQTTCommandProcessor.java:2239)
   at com.ibm.mq.MQXRService.MQTTCommandProcessor.
       inquireChannelStatus(MQTTCommandProcessor.java:2053)
   at com.ibm.mq.MQXRService.MQTTCommandProcessor.
       processPCFCommand(MQTTCommandProcessor.java:851)
   at com.ibm.mq.admin.contributions.telemetry.status.
       InquireTelemetryChannelStatusCommandHandler.callSpi
       (InquireTelemetryChannelStatusCommandHandler.java:84)
  

Local fix

• Run the command without the filter option.
  
  e.g.
  runmqsc <QMgr>
     DISPLAY CHSTATUS(*) CHLTYPE(MQTT) CLIENTID(*) ALL
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of the IBM MQ Telemetry service, who
  use the MQSC command:
  
  DISPLAY CHSTATUS (MQTT)
  
  to display the status of one or more MQ Telemetry channels.
  
  
  Platforms affected:
  Windows, Linux on x86-64, Linux on zSeries, AIX
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When using the MQSC command:
  
  DISPLAY CHSTATUS (MQTT)
  
  to display the status of MQ Telemetry channels, it is possible
  to specify a filter condition so that the command only displays
  information about those channels that match the condition. More
  information about the:
  
  DISPLAY CHSTATUS(MQTT)
  
  command can be found in the DISPLAY CHSTATUS (MQTT) topic in the
  MQ sections of IBM Knowledge Center. The URI for this topic in
  the MQ 9.1.x section of IBM Knowledge Center is
  https://www.ibm.com/support/knowledgecenter/SSFKSJ_9.1.0/com.ibm
  .mq.ref.adm.doc/q086100_.htm
  
  If the filter condition contains the CONNAME attribute, the MQ
  Telemetry service reads the value of that attribute for each of
  the MQ Telemetry channels and then compare that value to the
  specified condition in order to determine which channels to
  display.
  
  The MQ Telemetry service incorrectly assumed that the CONNAME
  attribute would always have a value. However, it was possible
  for an MQ Telemetry channel to have a null value for that
  attribute. In this situation, the MQ Telemetry service would try
  to access the attribute and generate a NullPointerException. As
  a result, the command would fail and the MQ Telemetry service
  would generate an FDC containing the information shown below:
  
  ...
  Source Class :- com.ibm.mq.MQXRService.MQTTCommandProcessor
  Source Method:- processEscapePCFCommand
  Probe Id     :- XR052012
  ...
  :---------------------------------------------------------------
  -----------------------------------:
  : Exception cause: :
  :---------------------------------------------------------------
  -----------------------------------:
  java.lang.NullPointerException
   at com.ibm.mq.MQXRService.PCFUtils.matchClientFilter
  (PCFUtils.java:113)
   at
  com.ibm.mq.MQXRService.MQTTCommandProcessor.resolveClientID(MQTT
  CommandProcessor.java:3292)
   at
  com.ibm.mq.MQXRService.MQTTCommandProcessor.inquireChannelStatus
  Instance(MQTTCommandProcessor.java:2239)
   at
  com.ibm.mq.MQXRService.MQTTCommandProcessor.inquireChannelStatus
  (MQTTCommandProcessor.java:2053)
   at
  com.ibm.mq.MQXRService.MQTTCommandProcessor.processPCFCommand(MQ
  TTCommandProcessor.java:851)
   at
  com.ibm.mq.admin.contributions.telemetry.status.InquireTelemetry
  ChannelStatusCommandHandler.callSpi(InquireTelemetryChannelStatu
  sCommandHandler.java:84)
  	
  

Problem conclusion

• The MQ Telemetry service has been updated to correctly handle
  the situation when the MQSC command:
  
  DISPLAY CHSTATUS(MQTT)
  
  is run with a filter condition containing the CONNAME attribute,
  and one or more of the MQ Telemetry channels has a null value
  for that attribute. This prevents the NullPointerException from
  occurring, and allows the command to correctly filter the
  results based on the value of the attribute.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 LTS   9.1.0.8
  v9.2 LTS   9.2.0.2
  v9.x CD    9.2.2
  
  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