A fix is available
APAR status
Closed as program error.
Error description
The Object Create requests count is incremented whenever a model queue is opened to create a dynamic queue (whether temporary or permanent). However, it was observed that for shared dynamic queues the Object Create requests count is zero while the Object Delete requests count has high number recorded. IBM MQ Development: z/OS service team has found a code path which can result in this scenario which applies to shared dynamic queues only. Consider this scenario with QM1 and QM2 being in a queue sharing group: 1. APP1 opens shared queue SQ1 on QM1 2. APP1 opens a DEFTYPE(SHAREDYN) model queue on QM1, resulting in shared dynamic queue DYNSQ1 being created 3. APP1 puts a request message to SQ1 on QM1 and waits for the reply on queue DYNSQ1 on QM1 4. APP2 gets the request message from SQ1 on QM2, and processes it 5. APP2 opens and puts the reply message to the reply queue DYNSQ1 on QM2 6. APP1 gets the reply message and closes and deletes DYNSQ1 This scenario will result in the objects deleted count being incremented on both QM1 and QM2, however, the objects created count will only be incremented on QM1. The reason that this happens is that when the shared dynamic queue is created and opened on QM1, an XCF notification is sent to the other QMGRs in the queue sharing group to notify them about the new queue. This results in a worker task on QM2 creating the queue IVSA, but the code path which it takes does not increment the objects created count. When the object is closed and deleted on QM1, this again results in an XCF notification being sent to the other QMGRs in the queue sharing group. This will again drive a worker task on QM2, however in this scenario, the code path taken will correctly increment the objects deleted count.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM MQ for z/OS Version 9 * * Release 1 Modification 0 and Release 2 * * Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: The object create requests and object * * delete requests values in SMF may be * * inconsistent. * **************************************************************** When a shared dynamic queue is opened, the object create requests count is only incremented on the current QMGR, while the object delete requests count is incremented on all QMGRs in the QSG.
Problem conclusion
The incrementing of object delete requests has been changed to ensure consistency between this and the object create requests count.
Temporary fix
Comments
APAR Information
APAR number
PH39940
Reported component name
IBM MQ Z/OS V9
Reported component ID
5655MQ900
Reported release
200
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2021-08-18
Closed date
2022-05-16
Last modified date
2022-09-08
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI80531
Modules/Macros
CSQICDSQ
Fix information
Fixed component name
IBM MQ Z/OS V9
Fixed component ID
5655MQ900
Applicable component levels
R200 PSY UI80531
UP22/06/29 P F206
Fix is available
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Document Information
Modified date:
08 September 2022