IT36047: The destination queue of the durable subscription might change when an MQTT application restarts

APAR status

• Closed as program error.

Error description

• An alias queue manager is defined with an MQTT client ID, here
  is
  an example:
  
  DEFINE QREMOTE(MQTT_MY_CLIENT_ID) +
         RQMNAME(MQTT_MY_CLIENT_ID) +
         XMITQ(SYSTEM.MQTT.TRANSMIT.QUEUE)
  
  When the MQTT application starts for the first time, a durable
  subscription is created and the destination queue is set to
  SYSTEM.MQTT.TRANSMIT.QUEUE as expected.
  
  When the application restarts, the durable
  subscription is altered with destination equal to
  SYSTEM.MQTT.PUBLICATION.QUEUE and the application can no
  longer consume messages, receiving MQRC_UNKNOWN_REMOTE_Q_MGR.
  

Local fix

• The destination queue in the subscription can be altered with
  the correct queue name:
  
  ALTER SUB('sub_name') DEST('expected_mqtt_xmitq')
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of MQXR on a version of IBM MQ containing APAR IT30843 and
  who do not use a DEFXMITQ of SYSTEM.MQTT.TRANSMIT.QUEUE may be
  affected by this problem.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A coding error in APAR IT30843 meant that an MQOPEN request
  failed to look locally for an object if called by the MQXR
  server.
  

Problem conclusion

• The code was corrected to ensure a local object lookup takes
  place during an MQOPEN if the calling application is the MQXR
  server.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.17
  v9.0 LTS   9.0.0.12
  v9.1 LTS   9.1.0.10
  v9.2 LTS   9.2.0.4
  v9.x CD    9.2.4
  
  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

  MQ BASE V9.2

• Fixed component ID

  5724H7281

Applicable component levels