PI70611: 2019 RC2019) MQRC_HOBJ_ERROR'MQRC_HOBJ_ERROR' AFTER SWITCHING TO A NEW USERID: V7 APAR PM03445.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The behavior at MQ V9 is the same as at MQ V7 - if the userid
  changes,  all handles are deemed invalid and are closed. This
  is working correctly, and is the expected/correct behaviour for
  MQ.
  
  Due to this unexpected change in behaviour at V7 APAR PM03445
  was raised to introduce a service parm to allow the the old V6
  behaviour,  where handles were not invalidated, to be reverted
  to for computability purposes while migrating to V7.
  However, it is not guaranteed that this service parm will
  remain available in subsequent releases, and so the old
  behaviour should not be relied upon - after switching userids
  it is expected that handles  will be invalidated and that the
  application will need to reopen any queues that it requires
  access to under the new userid.
  
   The service parm to revert to the old V6 behaviour IS still
  available in MQ v9, and so it should still be possible to use
  the workaround added at PM03445 by enabling this service parm
  at V9.
  
  It appears that an error exists that sometimes prevents this
  particular service parm taking effect correctly when SET SYSTEM
  is issued -  thus this  APAR.
  

Local fix

• issue any SET SYSTEM commands that set/reset this service parm
  twice, or by setting the service parm in the queue manager's
  ZPARM
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of IBM WebSphere MQ Version 9 Release 0            *
  * Modification 0.                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * When the service parm added by PM03445 is enabled,           *
  * MQRC_HOBJ_ERROR 2019 is still returned after switching to a  *
  * new userid                                                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * None                                                         *
  ****************************************************************
  A user's authority to access an MQ object is checked when the
  object is opened. If a task opens an object and then switches to
  another user any attempt to access an MQ object will detect the
  change in user and invalidate all open handles. Any attempt to
  use these handles will result in MQRC_HOBJ_ERROR.
  Applications wishing to switch user identities are required to
  open any objects they wish to access after the user switch has
  taken place.
  Prior to MQ V6 this was not enforced, and a service parameter
  exists to revert to the old V6 behaviour, however when this
  service parameter is set, it does not always take effect
  correctly.
  

Problem conclusion

• CSQJC00B has been changed to ensure changes to the service
  parameter take effect correctly.
  

Temporary fix

Comments

APAR Information

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

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

  UI41797

Modules/Macros

• CSQJC00B
  

Fix information

• Fixed component name

  MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI41797

     UP17/01/10 P F701

Fix is available

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