IT00493: MQXR SERVER RECEIVES PROBE ID XR071002 UNSUBSCRIBE FAILED WITH MQCC_FAILED RC=2429 MQRC_SUBSCRIPTION_IN_USE AMQXR0004E

Fix Pack 8.0.0.1 for WebSphere MQ V8.0

APAR status

• Closed as program error.

Error description

• Probe Id XR071002 is thrown when an attempt to unsubscribe
  fails with MQRC_SUBSCRIPTION_IN_USE. This is the type of error
  that would cause an unsubscribe FollowOnWorkRecord to be
  written to the persistent queue for later replay. Looking in
  the mqxr.log after the FDC is thrown for the failed
  unsubscribe the deferred unsubscribe from the work record
  fails since the subscription has gone away, but no new
  FDCs or messages to the persistent state queue are
  created - instead a single message is written to the log
  and processeing continues as normal.
  i.e.
  com.ibm.ws.objectManager.utils.FFDCImpl
  AMQCO2001E: An error (probe: XR071002) occurred and a Failure
  Data Capture (FDC) file has been written.
  ---------------------------------------------------------------
  com.ibm.mq.MQXRService.MQTTServerSessionV3
  AMQXR0002E: On channel B2E_SSL, a throwable
  com.ibm.mq.MQXRService.MQException: AMQXR0004E: MQSeries
  verb=SPIUnsubscribe(String) returned cc=2(int) MQCC_FAILED
  rc=2429(int) MQRC_SUBSCRIPTION_IN_USE. resulted when the MQXR
  service received a message from an MQTT client 1061442858.
  ---------------------------------------------------------------
  com.ibm.mq.MQXRService.MQTTServerSessionV3
  AMQXR2020E: Client 1061442858 attempted to unsubscribe from
  the topic ''<topic/name./#'' which it is not subscribed to.
  ------------------------------------------------------------
    XR071002
  
   -> the stack of this error from the FDC is:
   .
   | | Cause:1 :- com.ibm.mq.MQXRService.MQException:
   AMQXR0004E: MQSeries verb=SPIUnsubscribe(String) returned
   cc=2(int) MQCC_FAILED rc=2429(int) MQRC_SUBSCRIPTION_IN_USE.
   | | Message:1 :- AMQXR0004E: MQSeries
   verb=SPIUnsubscribe(String) returned cc=2(int) MQCC_FAILED
   rc=2429(int) MQRC_SUBSCRIPTION_IN_USE.
  | | StackTrace:1 :- com.ibm.mq.MQXRService.MQException:
  AMQXR0004E: MQSeries verb=SPIUnsubscribe(String) returned
  cc=2(int) MQCC_FAILED rc=2429(int) MQRC_SUBSCRIPTION_IN_USE.
  | | at
  com.ibm.mq.MQXRService.MQConnection.getMQException(MQConnection
  .java:708)
  | | at
  com.ibm.mq.MQXRService.MQConnection.spiUnsubscribe(MQConnection
  .java:333)
  | | at
  com.ibm.mq.MQXRService.MQTTServerSession.deleteSubscription(MQT
  TServerSession.java:1199)
  | | at
  com.ibm.mq.MQXRService.MQTTServerSessionV3.unregisterSubscripti
  ons(MQTTServerSessionV3.java:975)
  | | at
  com.ibm.mq.MQXRService.MQTTServerSessionV3.receiveUnsubscribe(M
  QTTServerSessionV3.java:941)
  | | at
  com.ibm.mq.MQXRService.MQTTServerSessionV3.handleReceive(MQTTSe
  rverSessionV3.java:177)
  | | at
  com.ibm.mq.MQXRService.MQTTServerContext.handleReceive(MQTTServ
  erContext.java:170)
  | | at
  com.ibm.mq.MQXRService.MQTTWireContext.receive(MQTTWireContext.
  java:319)
  | | at
  com.ibm.mq.communications.NonBlockingSslConnection.receive(NonB
  lockingSslConnection.java:472)
  | | at
  com.ibm.mq.communications.NonBlockingWorker.run(NonBlockingWork
  er.java:404)
  | | at java.lang.Thread.run(Thread.java:738)
  
  .
  There is another important piece of information in the FDC
  - the history of MQTT packet types sent and received for this
    instance of the client is also dumped out - for instance:
  .
  | isClean=false
  | sendAsynchronous.size()=2
  | UNSUBACK 6
  | UNSUBACK 7
  | History:SEND_MQTT PINGRESP
  | History:RECEIVED_MQTT PINGREQ
  | History:SEND_MQTT PINGRESP
  | History:RECEIVED_MQTT PINGREQ
  | History:SEND_MQTT PINGRESP
  | History:RECEIVED_MQTT UNSUBSCRIBE
  | History:SEND_MQTT UNSUBACK
  | History:RECEIVED_MQTT UNSUBSCRIBE
  | History:RECEIVED_MQTT UNSUBSCRIBE
  | History:RECEIVED_MQTT UNSUBSCRIBE
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of the MQXR Listener Service V7.5
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  This issue was caused when two UNSUBSCRIBE packets were received
  by the MQXR Listener without an UNSUBACK being sent between
  them. The first UNSUBSCRIBE request locked the subscription and
  the second UNSUBSCRIBE request resulted in an FDC being written
  with probe ID XR071002 and an underlying error of
  MQRC_SUBSCRIPTION_IN_USE.
  

Problem conclusion

• The MQXR Listener has been changed to handle the scenario where
  two UNSUBSCRIBE packets are received concurrently. As a result
  an FDC is no longer written.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.5       7.5.0.5
  
  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

  5724H7241

Applicable component levels

• R750 PSY

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