APAR status
Closed as program error.
Error description
After migrating from MQ V7.5 to V8.0, user noticed many Temporary Dynamic Queues (TDQs) are generated by MQ Explorer users. In this case, user started MQ Explorer but had not yet connected to the V8 queue manager. However, because Autoreconnect was enabled, MQ Explorer was connecting and disconnecting to the new V8 qmgr due to the mismatch in Command Levels resulting in a large number of TDQs. The customer noticed these TDQs led to large number of GHOST queues that could not be cleaned up by either deleting, recreating the MQ Explorer TDQs or cycling the queue manager. . Additional symptoms: - ENDMQM may fail, for example with AMQ6153. - RCDMQIMG (or RCDMQMIMG for IBMi) may experience AMQ7047 and an FDC with: Probe Id :- OP130012 Component :- AS400ReportLogTail Probe Description :- AMQ6125: An internal WebSphere MQ error has occurred. FDCSequenceNumber :- 0 Arith1 :- 402 0x'192' Comment1 :- Checkpoint Process died ! - STRMQM may receive FDCs for: AD004020 adhOpen arcE_OBJECT_MISSING AQ168001 aqpReadData arcE_OBJECT_MISSING AQ143008 aqqAccessQHeader arcE_OBJECT_DAMAGED for Temporary Dynamic Queues (TDQs), e.g. Currently attached object: AMQ.5646B30D20046C02 RealName queues/!!GHOST!797F85C3!0!EF40C4FD!16
Local fix
A v8 queue manager can tolerate queue files associated with temporary dynamic queues being deleted while the queue manager is not active. As long as the affected queue files can be reliably identified, and the queue manager is stopped, these files can simply be deleted.
Problem summary
**************************************************************** USERS AFFECTED: Users of IBM MQ version 8 who delete a model queue and then abruptly terminate the queue manager before all of the temporary dynamic queues associated with that instance of that model queue have been cleaned up. Platforms affected: AIX, HP-UX Itanium, HP-UX PA-RISC, IBM iSeries, Linux on Power, Linux on S390, Linux on x86, Linux on x86-64, Linux on zSeries, Solaris SPARC, Solaris x86-64, Windows **************************************************************** PROBLEM DESCRIPTION: When an application releases a temporary dynamic queue, the resources associated with that queue may be kept around to be reused when a further TDQ is created based upon the same model queue. If a model queue is deleted then any unused resources (a.k.a ghost queues) associated with the current instance of that model are released. TDQs based off the deleted model that are still in use when the model is deleted will NOT be reused when they are eventually deleted. The problem arose when a TDQ created from a model still existed when the model was deleted, and then the queue manager was abruptly terminated without the TDQ first being cleaned up. In these circumstances the resources associated with that TDQ should have been deleted when the queue manager next restarts. This was not happening, leading to a potential accumulation of ghost queues.
Problem conclusion
The IBM MQ V8 queue manager routines have been corrected to identify this condition and release the unreferenced TDQs at the next queue manager restart. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v8.0 8.0.0.5 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
IT12007
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
2015-10-28
Closed date
2015-12-22
Last modified date
2016-01-28
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:
28 January 2016