A fix is available
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 number
IT00493
Reported component name
WMQ BASE MULTIP
Reported component ID
5724H7241
Reported release
750
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2014-03-20
Closed date
2014-04-30
Last modified date
2014-04-30
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
UP
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSFKSJ","label":"WebSphere MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.5"}]
Document Information
Modified date:
24 September 2021