PH58635: DFHXM0004 MESSAGE LOOPING IN DFHXMAT WITH ONLY 50K TRANSACTIONS QUEUED

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DFHXM0004 message stating possible loop in DFHXMAT with only
  50K transactions queued.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: CICS is receiving 50000 remote          *
  *                      transaction STARTs into a region. The   *
  *                      remote started transaction is TCLASSed  *
  *                      to allow only 1 active at a time.       *
  *                      DFHXM0004 message and dump are issued   *
  *                      indicating a possible loop in DFHXMAT.  *
  ****************************************************************
  When message DFHXM0004 was issued, the CSNC task was running and
  showed DFHXMAT processing ALLOCATE_NEW_TRANNUM_RANGE. The CICS
  region had 49936 tasks queuing + 7 active, so there should have
  been about 50000 free task number slots to use.
  CICS miscalculated the slot value causing the region to loop
  looking for a new slot number. When the ICVR limit was hit CICS
  issued message DFHXM0004 and continued to do so despite there
  appearing to be  no more than 50000 tasks in the system out of
  the possible 99999.
  Analysis of the dump shows that trannums are incremented by 2.
  

Problem conclusion

• DFHXMAT has been changed to ensure that the trannums
  are incremented correctly when allocating
  a new number
  

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:

  UI96413

Modules/Macros

• DFHXMAT  DFHXMXE
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI96413

     UP24/04/10 P F404

Fix is available

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