A fix is available
APAR status
Closed as program error.
Error description
Attempts to open a shared queue are delayed due to system performance problems. By the time control is returned to the QMGR attempting to open the queue, the queue has been deleted and re-defined on a different QMGR in the QSG. The original QMGR accesses the list header in the CF structure for the queue and finds it reused due to the new instance of the queue however the create time does not match the DB2 record - indicating that this is a different queue instance. Retry logic then calls DB2 in order to re-read the queue definition (which obtains the definition for the new queue instance). After additional delays (before control is returned to the QMGR task) the queue is again deleted and re-defined by another QMGR. When the CF list header entry is checked this time, again it does not match. Given that this has now failed twice WebSphere MQ assumes something is wrong with the queue definition and thus abends with ABEND5C6 00C51053. This apar is taken in order to determine if these abends could be avoided given the underlying system performance issue that precipitated the abends. LEVEL 2 VERIFICATION STEPS : Abend was seen due to a failed match between the value for eRQE_OpenClose_SQ_Name and mqsh.csQName as executed at offset +1B56 where ERQE_OPENCLOSE_SQ_NAME contains the name of the queue that is deleted and re-instantiated.
Local fix
CORRECT UNDERLYING SYSTEM PERFORMANCE CONCERN
Problem summary
**************************************************************** * USERS AFFECTED: All users of WebSphere MQ Version 7 * * Release 1 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: Abend 5C6-00C51053 and message CSQE137E * * are generated when a shared queue is * * opened for the first time on this queue * * manager, after the queue is recreated. * **************************************************************** * RECOMMENDATION: * **************************************************************** This problem can occur, in a queue manager that is member of a QSG, when a shared queue has been recreated (deleted the defined again) several times. Depending on the timing of the open, this can happen when the shared queue is opened for first time after the recreation of the queue in another queue manager within the same QSG. This will cause an abend 5C6-00C51053 in CSQEOPEN (CSQE_Unexpected_ListHeader_ReUse) and the message CSQE137E to be issued.
Problem conclusion
In this situation, CSQEOPEN has been updated to re-read shared queue data from DB2 and CF structure rather than abend. 100Y CSQEOPEN
Temporary fix
Comments
APAR Information
APAR number
PM75468
Reported component name
WMQ Z/OS V7
Reported component ID
5655R3600
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2012-10-19
Closed date
2012-12-11
Last modified date
2013-02-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK90221
Modules/Macros
CSQEOPEN
Fix information
Fixed component name
WMQ Z/OS V7
Fixed component ID
5655R3600
Applicable component levels
R100 PSY UK90221
UP13/01/16 P F301
Fix is available
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Document Information
Modified date:
04 February 2013