PH29405: CQM OR STAP CLEANUP OF THREAD RELATED STORAGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CQM or STAP cleanup of thread related storage
  

Local fix

• Set PARALLEL(N), or remove the PARALLEL parm, and recycle CQM
  and/or STAP whenever DB2 is recycled.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of IBM Db2 Query Monitor for z/OS      *
  *                 users of component:                          *
  *                 - CQM Data Collector                         *
  *                 - TCz                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: 1. CQM or STAP cleanup of thread        *
  *                      related storage.                        *
  *                      2. Update SMEM_SIZE default values.     *
  *                      3. Memory overlay of an internal QM     *
  *                      storage management control block as a   *
  *                      result of an over-reaching DISCARDDATA  *
  *                      function during the execution of QM's   *
  *                      memory management routines.             *
  *                      4. Wrong text for message CQM3284I in   *
  *                      collector log.                          *
  ****************************************************************
  * RECOMMENDATION: Apply the PTF.                               *
  ****************************************************************
  1. Memory leak when parallel threads are cancelled via the
  Db2 CANCEL THREAD command or when jobs running parallel threads
  are terminated abnormally.
  2. Update SMEM_SIZE default values.
  3. Memory overlay during execution of QM's internal memory
  management functions.
  4. The text for message CQM3284I was incorrect and misleading.
  

Problem conclusion

• 1. Logic is added to detect a cancelled CPU parallelism
  thread if PARALLEL(Y) is specified in the CQM start up
  parameters. Additionally, if a Db2 is stopped and restarted and
  CQM or STAP remain active there is logic now at Db2 Monitoring
  Agent installation to clean up any CQM/STAP thread related
  storage that may remain from the previous time Db2 was active.
  2. Update SMEM_SIZE default values.
  3. QM's internal memory management was issuing a z/OS
  DISCARDDATA function and releasing memory pages that were not
  supposed to be released.
  4. CQM3284I message is corrected.
  
  Search Keywords:
  MEMORY LEAK PARALLEL(Y) SMEM_SIZE CQM3284I
  

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:

  UI72672

Modules/Macros

• CQM#BCMX CQM#COMX CQM#PARM CQM$$PRM CQMMINIX CQMMSRCX CQMPARMS
  

Fix information

• Fixed component name

  DB2 QUERY MONIT

• Fixed component ID

  5655E6701

Applicable component levels

• R330 PSY UI72672

     UP20/11/26 P F011

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.