PM56051: A TARGET REGION DSRTPGM PROGRAM IS UNEXPECTEDLY CALLED FOR ROUTE SELECTION WHEN DYROPTER=N WAS SPECIFIED IN ROUTING REGION.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• You have a DSRTPGM program that is unexpectedly invoked for
  Route Selection in a target region.  Here are the circumstances
  that lead to this:
  .
  1) In a routing region (a front-end region), there is an EXEC
      CICS START of a non-terminal transaction.  There is no
      SYSID specified on the EXEC CICS START.  And the transaction
      definition of the transaction being STARTed specifies
      DYNAMIC (YES) and ROUTABLE (YES).  All this makes it
      possible for the routing region DSRTPGM program to
      dynamically route the START to any available target region.
  2) The DSRTPGM program in the routing region is invoked for
      Route Selection (DYRFUNC = 0).  It chooses the target region
      to which this START should be shipped.  It also sets
      DYROPTER = N telling CICS that when the STARTed transaction
      runs on the target region, the DSRTPGM program on
      that target region should not be invoked ( for DYRFUNC
      2, 4, or 5.)
  3) In the chosen target region, the CSMI mirror task mirrors
      the EXEC CICS START .  During the processing of the
      mirror's EXEC CICS START , the target region's DSRTPGM
      program is driven for Route Selection ( DYRFUNC = 0 ) .
      This is unexpected as it allows the target region's DSRTPGM
      program to behave as a routing region and dynamically route
      for a second time this same EXEC CICS START request.  This
      is Daisy Chaining and is not supposed to be possible.  It
      makes it possible for a single non-terminal START to be
      continually dynamicaly routed between target regions without
      the STARTed transaction ever running.
  

Local fix

• Set DYROPTER=Y in the routing region when the DSRTPGM is driven
  for Route Selection (DYRFUNC=0).
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: The dynamic routing program is called   *
  *                      with function 'route selection' for a   *
  *                      START request that has already been     *
  *                      dynamically routed.                     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A transaction TRAN is defined as dynamic(yes) and routable(yes).
  An EXEC CICS START TRANSACTION(TRAN) FROM(DATA) is issued.
  DFHEIIC calls the distributed routing program with function code
  0, 'route selection'. The distributed routing program returns a
  target region of SYSB and sets DYROPTER=N in the passed
  commarea. The START command is function shipped from the local
  region SYSA to SYSB. The commarea is not shipped as DYROPTER=N.
  In the target region the mirror task is started which calls
  DFHEIIC to re-issue the START request. However DFHEIIC does not
  process the request as a dynamically routed start, and
  incorrectly calls the distributed routing program on the target
  region for route selection. The daisy chaining of dynamic start
  requests is not permitted.
  The routing program on SYSB returns the original system as the
  target region and the START is shipped back to SYSA. On SYSA the
  START is re-issued and once again dynamically routed to SYSB.
  This shipping of the START between SYSA and SYSB continues until
  there are no more free sessions available between the two
  systems, without the started transaction ever running. After
  this point subsequent tasks requiring a session between the two
  systems are suspended in an ALLOCATE type wait.
  

Problem conclusion

• DFHEIIC has been changed for the reported problem so that it
  does not call the dynamic routing program for route selection
  when a transaction has already been dynamically routed.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

• ž**** PE12/10/24 FIX IN ERROR. SEE APAR PM75335  FOR DESCRIPTION
  ž**** PE12/10/24 FIX IN ERROR. SEE APAR PM75335  FOR DESCRIPTION
  

APAR Information

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

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

  UK78670 UK78671

Modules/Macros

•    DFHEIIC
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R600 PSY UK78670

     UP12/05/19 P F205

• R700 PSY UK78671

     UP12/05/19 P F205

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.