PK69397: DFHXMAT LOOPS TRYING TO FIND A TRANNUM FOR A NEW TASK ATTACH WHEN ALL TASK NUMBERS ARE IN USE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CICS region goes into a hard loop when it tries to find a new
  TRANNUM for a new task ATTACH, but the current number of task
  numbers in use is now 99,999. The running task is a CSSY task
  that doesn't get abended with an AICA, and there is no
  DFHXM0004 to break CICS out of this loop. The loop occurs in
  the ALLOCATE_TRANNUM proc in DFHXMAT.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: CICS region loops because there are no  *
  *                      free transaction numbers available.     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  CICS region loops when it tries to find a free transaction
  number for a new task after the current number of
  transaction numbers in use has reached the maximum of 99999.
  The test, in DFHXMAT, that determines if all transaction
  numbers have been allocated is defective.
  Additional keywords: DFHXM0004 msgDFHXM0004 DFHXM0002
  msgDFHXM0002 ICVR RUNAWAY
  

Problem conclusion

• DFHXMAT has been changed so that message DFHXM0002 will be
  issued with severe error code X'1112' when an attempt is made
  to attach a new task after all available transaction numbers
  have been allocated.
  Message DFHXM0002 in the CICS Transaction Server for z/OS V3.1
  and V3.2 Messages and Codes manuals, GC34-6442-04 and
  GC34-6827-01 respectively, will be changed.
  The following paragraph will be added to the user's response
  just before the last paragraph beginning: 'You need further
  assistance from IBM to resolve this problem.'
  If severe error code is X'1112', there are no free transaction
  numbers to allocate to new transactions as all available
  transaction numbers are in use. If you are using transaction
  classes to limit the number of CICS tasks within your system,
  you should specify a transaction class purge threshold
  (PURGETHRESH) for any transaction class bearing a heavy
  transaction load. See the CICS Resource Definition Guide and
  the CICS Performance Guide for more information.
  

Temporary fix

•             *********
              * HIPER *
              *********
  FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UK42512 UK42513

Modules/Macros

•    DESXMAT  DFHMEXME DFHXMAB  DFHXMAT  DFHXMER
  DFHXMTA  DFHXMXE  DFH69397 MFHMEXME
  

Fix information

• Fixed component name

  CICSTS V3 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R400 PSY UK42512

     UP08/12/18 P F812

• R500 PSY UK42513

     UP08/12/18 P F812

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.