IBM Support

IT21548: Client connection fails and a FDC is cut with probe XR014005 reporting a null pointer exception

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APAR status

  • Closed as program error.

Error description

  • The NPE causes the channel to fail.  It takes manual
    intervention to get it going again.
    .
    The logs report:
    7/18/17 14:23:52.467  AMQXR0022I: Client 'client name'
    previously connected at network address 'ipaddress' now
    connected at
    'ipaddress'.
    7/18/17 14:23:53.276  AMQUT1003I: 30 instances of message
    'AMQXR0022I:'
    were suppressed.
    7/18/17 14:23:53.275  AMQCO2001E: An error (probe: XR014005)
    occurred
    and a Failure Data Capture (FDC) file has been written to file
    '/var/mqm/errors/MQXR0.FDC'.
    7/18/17 14:23:54.308  AMQCO1006I: Channel 'channelname' has
    stopped
    7/18/17 15:51:50.408  AMQXR0016I: Channel 'channelname' has
    started
    .
    The FDC reports a NPE.
    .
    java.lang.NullPointerException
        at
    com.ibm.mq.MQXRService.MQTTServerSession.purge
      (MQTTServerSession.java:462)
        at
    com.ibm.mq.MQXRService.MQTTServerContext.close
      (MQTTServerContext.java:225)
        at
    com.ibm.mq.communications.NonBlockingConnection.closeFinal
      (NonBlockingConnection.java:667)
        at
    com.ibm.mq.communications.NonBlockingConnection.sendRemainder
      (NonBlockingConnection.java:338)
        at
    com.ibm.mq.communications.NonBlockingWorker.run
      (NonBlockingWorker.java:402)
        at java.lang.Thread.run(Thread.java:809)
    

Local fix

  • NA
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    The issue affects the users of:
    
     - IBM MQ Telemetry (MQXR) service V8
     - IBM MQ Telemetry (MQXR) service V9
    
     who have a client connecting to the MQXR service.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    There was a small timing window where if a MQTT client request
    is being made to close the client connection that got just got
    closed by another thread on the MQXR service, a close request
    was made on the closed connection object, which resulted in a
    NullPointerException. This exception caused the MQXR channel to
    stop and cut probe XR014005.
    

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 CD    9.0.5
    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 number

    IT21548

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-07-21

  • Closed date

    2017-10-31

  • Last modified date

    2017-10-31

  • 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

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Document Information

Modified date:
31 October 2017