PH49686: STREAMING QUEUE IMPROVEMENTS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Improvements/fixes for the streaming queue functionality
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 3 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Various problems when using the STREAMQ *
  *                      attribute for streaming queues.         *
  *                      Symptoms include:                       *
  *                      - Applications receive 2033 when posted *
  *                      for message arrival on a stream queue   *
  *                                                              *
  *                      In addition, streaming queue functions  *
  *                      are restricted so that:                 *
  *                      - STREAMQ cannot be set on shared       *
  *                      queues                                  *
  *                      - STREAMQ cannot be set to point to     *
  *                      shared queues                           *
  ****************************************************************
  When messages arrive on a stream queue, getwaiters are posted
  too early. In some timing conditions this can result in the
  getter attempting to get the message before all locks have been
  released.
  
  When configuring streaming queues, shared queues are restricted
  from either having or being a streaming queue.
  

Problem conclusion

• Applications waiting for messages on stream queues are only
  posted after locks have been released.
  
  Restrictions preventing shared queues being used as streaming
  queues, or streaming to other queues, are removed, allowing the
  streaming queue functionality to exploit shared queues.
  
  The IBM MQ Knowledge Center topics are updated as follows:
  Topic:
  https://www.ibm.com/docs/en/ibm-mq/9.3?topic=
       wnim9-whats-new-in-mq-931-zos-base-advanced-vue-entitlement
  
  The information about "Streaming queues supported with shared
  queues" is updated with the following additional information:
  "With APAR PH49686, the same functionality is also available on
  an IBM MQ 9.3.0 queue manager."
  
  
  Topic:
  https://www.ibm.com/docs/en/ibm-mq/9.3?topic=
                             queues-streaming-queue-restrictions
  
  The statement:
  "Defining STREAMQ on a shared queue if at IBM MQ 9.3.0.
  This restriction no longer applies from IBM MQ 9.3.1. "
  
  is changed to
  
  "Defining STREAMQ on a shared queue at IBM MQ 9.3.0 when APAR
  PH49686 is not applied. This restriction has been lifted at IBM
  MQ 9.3.0 when APAR PH49686 is applied, or from 9.3.1."
  
  The statement:
  "Setting STREAMQ to the name of a shared queue if at
  IBM MQ 9.3.0. This restriction no longer applies from
  IBM MQ 9.3.1. "
  
  is changed to
  
  "Setting STREAMQ to the name of a shared queue at IBM MQ 9.3.0
  when APAR PH49686 is not applied. This restriction has been
  lifted at IBM MQ 9.3.0 when APAR PH49686 is applied, or from
  9.3.1."
  
  
  Topics:
  https://www.ibm.com/docs/en/ibm-mq/9.3?topic=
                                          reference-define-queues
  and
  https://www.ibm.com/docs/en/ibm-mq/9.3?topic=
                      reference-alter-queues-alter-queue-settings
  
  The description of the STREAMQ attribute is changed to replace
  the following statement:
  
  "On z/OS at IBM MQ 9.3.0 this parameter is not valid on queues
  with QSGDISP(SHARED). At IBM MQ 9.3.0 it is also not valid to
  set this parameter to the name of a queue which has
  QSGDISP(SHARED). Neither of these restrictions apply from
  IBM MQ 9.3.1."
  
  with:
  
  "Restrictions for when STREAMQ can be set are documented at
  https://www.ibm.com/docs/en/ibm-mq/9.3?topic=queues-streaming-qu
  eue-restrictions."
  

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:

  UI83118

Modules/Macros

• CSQIERS3 CSQMCLOS CSQMCNA1 CSQMOPNI CSQMPUT  CSQMPUTW
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R300 PSY UI83118

     UP22/11/29 P F211

Fix is available

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