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PH31540: DIAGNOSTIC APAR TO IMPROVE THE DIAGNOSTICS FOR DUPLICATE MQ QUEUE CONTROL BLOCKS.

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APAR status

  • Closed as program error.

Error description

  • Diagnostic APAR to improve the diagnostics for duplicate MQ
queue control blocks.
.
Additional symptoms/keywords:
Reason 2343 MQRC_OBJECT_NOT_UNIQUE occurs due to two shared
queue instances with the same name.
.
In a dump of the queue manager, there are two MQSH control
blocks with the same queue name.

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: When MQ detects duplicate queue control *
*                      blocks it returns                       *
*                      MQRC_OBJECT_NOT_UNIQUE. This is usually *
*                      the result of two queues being defined  *
*                      with the same name but a different      *
*                      QSGDISP. If the two queues have the     *
*                      same QSGDISP then this is indicative of *
*                      a more serious problem and requires     *
*                      documentation to be gathered.           *
****************************************************************
MQ endeavours to only create one in-storage copy of MQ queue
control blocks. There are multiple safeguards to prevent
duplication on creation, thus if MQ detects that duplication has
occurred it should take diagnostic action to determine the root
cause.

    



Problem conclusion


    

  • The code has been changed to issue a 5C6-00C94526 abend and dump
when detecting duplicate queues of the same name with
QSGDISP(SHARED).

The IBM MQ for z/OS Version 9.1.x and Version 9.2.x Knowledge
Center are updated:
IBM MQ 9.1.x/9.2.x
  IBM MQ
    Reference
      Messages
        IBM MQ for z/OS messages, completion, and reason codes
          IBM MQ for z/OS codes
            Data manager codes (X'C9')
(https://www.ibm.com/support/knowledgecenter/SSFKSJ_9.1.0/
                             com.ibm.mq.ref.doc/codes_c9.html )
(https://www.ibm.com/support/knowledgecenter/SSFKSJ_9.2.0/
                             com.ibm.mq.ref.doc/codes_c9.html )

Added new abend reason code 00C94526:
"
00C94526
    During MQOPEN processing, IBM MQ detected the presence of
    duplicate queue control blocks.

System action
    The MQOPEN call fails with reason code
    MQRC_OBJECT_NOT_UNIQUE and a dump is produced.

System programmer response
    Collect the items listed in Diagnostics and contact your IBM
    support center.
"

    



Temporary fix


    

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    PH31540
    • 

  • Reported component name
    IBM MQ Z/OS V9
    • 

  • Reported component ID
    5655MQ900
    • 

  • Reported release
    100
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2020-11-11
    • 

  • Closed date
    2021-01-29
    • 

  • Last modified date
    2021-04-01
    • 





    

  • APAR is sysrouted FROM one or more of the following:
    

    • 

  • APAR is sysrouted TO one or more of the following:
    

    
UI73685 UI73686
    

    • 



Modules/Macros


    

  • CSQEDMPS CSQILOC2 CSQWDSDM

    



Fix information


    

  • Fixed component name
    IBM MQ Z/OS V9
    • 

  • Fixed component ID
    5655MQ900
    • 



Applicable component levels


    

  • R100  PSY  UI73686
       UP21/03/03  P  F103
    • 

  • R200  PSY  UI73685
       UP21/03/03  P  F103
    • 



Fix is available


    

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              [{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"100"}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            02 April 2021
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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