PH17546: STORAGE LEAK WITH QSGDISP(GROUP)

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The above the line 31-bit private storage is exhausted by
  "MNLS" blocks that relate to Namelist objects.
  DEFINING and DELETING a Namelist does not properly clean up the
  control blocks associated with it.
  Over a long period of time and with a large number of
  Namelists, this results in a storage leak.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0 and Release 1       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Storage is leaked when QSGDISP(GROUP)   *
  *                      objects are deleted or altered.         *
  *                      Over time this can lead to performance  *
  *                      degradation and/or a short on storage   *
  *                      (SOS) condition in the queue manager    *
  *                      address space.                          *
  *                      When the QSGDISP(GROUP) object involved *
  *                      is a CLNTCONN channel, a storage        *
  *                      overlay can occur leading to            *
  *                      unpredictable results.                  *
  ****************************************************************
  When retrieving the object definition for a QSGDISP(GROUP)
  object from DB2, page aligned storage is obtained for the
  definition to be read into. However, this storage is not always
  freed when no longer required.
  Depending on the object type, this results in either 4128 bytes
  or 65568 bytes of storage being leaked.
  

Problem conclusion

• CSQIDGET and CSQIDDEL are changed to correctly free the page
  aligned storage when it is no longer required.
  

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:

  UI66156 UI66157

Modules/Macros

• CSQIDDEL CSQIDGET CSQILOC2 CSQSFBK
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI66156

     UP19/11/27 P F911 ¢

• R100 PSY UI66157

     UP19/11/27 P F911 ¢

Fix is available

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