APAR status
Closed as program error.
Error description
Queue manager fails to start due to amqzmuc0 ending abruptly because of memory exception(SIGSEGV) when generating a failure data capture (FDC) record with probe Id KN467078 in component kqiReconcileDurableSubscribers. The following FDC records were generated during the failure: amqzmuc0 44592 23 KN467078 kqiReconcileDurableSubscribers krcE_UNEXPECTED_ERROR amqzxma0 44581 1 ZX005020 zxcProcessChildren zrcX_PROCESS_MISSING amqzxma0 44581 1 ZX000040 zxcExecutionController STOP_ALL Probe Id :- KN467078 Component :- kqiReconcileDurableSubscribers Program Name :- amqzmuc0 Process :- 44592 Process(Thread) :- 44666 Thread :- 23 DurSubsMgr Major Errorcode :- krcE_UNEXPECTED_ERROR Probe Type :- INCORROUT Probe Description :- AMQ6125E: An internal IBM MQ error has occurred FDCSequenceNumber :- 0 MQM Function Stack zmuThreadMain zmuDurableSubscriptionManagerTask kpiDurableSubscriptionManagerTask kqiReconcileDurableSubscribers xcsFFST Probe Id :- ZX005020 Component :- zxcProcessChildren Program Name :- amqzxma0 Process :- 44581 Process(Thread) :- 44581 Thread :- 1 ECMain Probe Description :- AMQ5008S: An essential IBM MQ process 44592 (zllCRIT) cannot be found and is assumed to be terminated. FDCSequenceNumber :- 0 Arith1 :- 44592 (0xae30) Comment1 :- zllCRIT MQM Function Stack amqzxma0 zxcExecutionController zxcStartupLogic zxcProcessChildren xcsFFST Probe Id :- ZX000040 Component :- zxcExecutionController Program Name :- amqzxma0 Process :- 44581 Process(Thread) :- 44581 Thread :- 1 ECMain Major Errorcode :- STOP_ALL Minor Errorcode :- OK Probe Type :- HALT6110 Probe Severity :- 1 Probe Description :- AMQ6110S: An internal IBM MQ error has occurred. FDCSequenceNumber :- 1 MQM Function Stack amqzxma0 zxcExecutionController xcsFFST
Local fix
Workaround 1: Note: This procedure affects existing subscriptions, some subscriptions might be lost and some old subscriptions might be restored. * Backup the queue file 'SYSTEM!DURABLE!SUBSCRIBER!QUEUE' * Replace the queue file 'SYSTEM!DURABLE!SUBSCRIBER!QUEUE' from queue manager backup * Start the QM * Delete/Create/Modify the subscriptions as required Workaround 2: Note: This procedure deletes all existing subscriptions and the user needs to newly create the subscriptions * Replace the queue file 'SYSTEM!DURABLE!SUBSCRIBER!QUEUE' from a newly created temporary queue manager * Start the QM * Create subscriptions as required
Problem summary
**************************************************************** USERS AFFECTED: Users using MQ publish/subscribe messaging Platforms affected: MultiPlatform **************************************************************** PROBLEM DESCRIPTION: The system queue SYSTEM.DURABLE.SUBSCRIBER.QUEUE stores persistent copy of the durable subscriptions in the queue manager. When the QM starts, the QM reads and processes the messages and recreates the subscriptions. During this processing, the QM detected an invalid subscription type from the message read and the MQ generated a FDC. However when dumping the subscription details in the FDC the QM process amqzmuc0 encountered a memory exception due to a defect in code that dumps the subscription in question. This resulted in failure of critical MQ process amqmuc0 and QM startup.
Problem conclusion
MQ code has been modified to prevent the memory exception. The fix only prevents the memory exception and allows the QM to continue the startup. The publish/subscribe feature might be disabled due to the bad subscription message that triggers the issue. The user needs to recreate the subscriptions as suggested in the workaround section to resolve the publish/subscribe issue. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v9.0 LTS 9.0.0.13 v9.1 LTS 9.1.0.11 v9.2 LTS 9.2.0.6 v9.x CD 9.2.5 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
IT39632
Reported component name
IBM MQ BASE MP
Reported component ID
5724H7271
Reported release
910
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2022-01-12
Closed date
2022-02-25
Last modified date
2022-06-21
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
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"910"}]
Document Information
Modified date:
22 June 2022