PH57508: IBM MQ Z/OS: IMPROVE STREAMQ VALIDATION LOGIC

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The client complains that CSQM591I CSQMAQLC Queue attributes
  are incompatible for use as a streaming queue.
  
   Customer has the following local queue on queue manager CSQ1:
  
   QUEUE(LOCALQ1)
   TYPE(QLOCAL)
   QSGDISP(QMGR)
   STREAMQ(OLDSTRMQ)
  
  He tried the command:
  
  ALTER QLOCAL(LOCALQ1) STRMQOS(BESTEF) STREAMQ(REMOTEQ)
  
  However received the message:
  
  CSQM591I ;CSQ1 CSQMAQLC Queue attributes are incompatible for
  use as a
  streaming queue
  
  It seems that the problem is caused because the remote queue
  REMOTEQ is mapped to the same queue name, however in another
  queue manager:
  
   QUEUE(REMOTEQ)
   TYPE(QREMOTE)
   QSGDISP(QMGR)
   CLUSTER()
   CLUSNL()
   DESCR(Test to CSQ2)
   PUT(ENABLED)
   DEFPRTY(0)
   DEFPSIST(NO)
   DEFPRESP(SYNC)
   RNAME(LOCALQ1) <===
   RQMNAME(CSQ2)    <===
   XMITQ(XQ1)
   DEFBIND(OPEN)
   CLWLRANK(0)
   CLWLPRTY(0)
   CUSTOM()
  
  But if customer executes:
  
  ALTER QLOCAL(LOCALQ1) STRMQOS(BESTEF) STREAMQ(' ')
  
  and then executes once more the command
  
  ALTER QLOCAL(LOCALQ1) STRMQOS(BESTEF) STREAMQ(REMOTEQ)
  
  the same command that was failing executes successfully.
  
  
  The STREAMQ validation logic tries to prevent circular
  streaming by checking the resolved base queue attributes for
  model, alias and remote queues. In this case, the chaining to
  the resolved base queue ends up at the same queue which the
  ALTER QLOCAL command is being issued against. There is a check
  that the resolved base queue doesn't also have the STREAMQ
  attribute set. The attribute won't be set the first time
  STREAMQ is set for a queue, but will be the second time. This
  explains why the command behaves inconsistently.
  
  
  
  It doesn't make sense to be checking the remote queue RNAME
  queue.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 3 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Trying to set a remote queue as a       *
  *                      streaming queue for a local queue that  *
  *                      has previously had its STREAMQ          *
  *                      attribute set may result in a CSQM591I  *
  *                      message "Queue attributes are           *
  *                      incompatible for use as a streaming     *
  *                      queue" being issued and the operation   *
  *                      being unsuccessful if the remote        *
  *                      queue's RNAME is the same as that of    *
  *                      the local queue from which the request  *
  *                      originated.                             *
  ****************************************************************
  The code handling the validation of stream queues tries to find
  the attributes of a candidate queue by it's RNAME if the queue
  is remote. If the originating queue's and remote queue's RNAMEs
  are the same the attributes of the former are found and
  inspected instead of the latter's. This leads to the check for
  the queue already streaming to another queue to fail if the
  STREAMQ attribute has previously been set and causes the
  validation to determine the target queue as incompatible for
  streaming.
  

Problem conclusion

• The call to find the remote queue's attributes by its RNAME has
  been removed, so the validation is no longer erroneously run
  against the originating queue's attributes.
  

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:

  UI94942

Modules/Macros

• CSQMCNA1
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R300 PSY UI94942

     UP24/01/18 P F401

Fix is available

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