PH03982: CICS REGION FLOODED WITH CESC TRANSACTIONS.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CICS region is flooded with CESC transactions. The internal
  trace a dump shows a sequence of events where IC starts a CESC
  transaction to process terminal signoff, and another ICE is
  created for CESC a minute out (safety net).  After processing
  terminals the safety net is canceled but another ICE is
  created for another run several minutes out. This would be a
  totally normal operation, if it weren't for that fact that
  there are 109-110 ICE for CESC currently, such that every 6
  minutes, CESC runs 100+ times.
  .
  Investigation of how multiple ICEs for CESC were added to the
  queue, when there should be only one with REQID=DFHCESC,
  revealed an issue with a timing window.
  If an ICE was created in a previous run of CICS and
  preserved over the START=AUTO there is a timing window, when the
  TCTV_CESC_SCHEDULED flag is OFF during restart, that allows an
  additional ICE to be created.
  .
  Additional Symptom(s) Search Keyword(s): KIXREVSVR
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users                               *
  ****************************************************************
  * PROBLEM DESCRIPTION: The ICE chain contains many ICEs with   *
  *                      REQID=DFHCESC and the CICS region       *
  *                      is periodically flooded with CESC       *
  *                      transactions being attached.            *
  ****************************************************************
  A CICS region was periodically being flooded with CESC
  transactions. A dump showed there were over a hundred ICEs
  on the ICE chain with REQID=DFHCESC whereas there should be no
  more than one.
  ICEs are restored over a warm restart of CICS but the
  TCTV_CESC_SCHEDULED flag is initialized to OFF. If an event
  occurs to cause the rescheduling of CESC before a recovered
  REQID=DFHCESC ICE has expired, the setting of the
  TCTV_CESC_SCHEDULED flag causes the cancelling of the
  recovered ICE to be bypassed in module DFHSNSC.
  

Problem conclusion

• CICS is changed so that ICEs for transaction CESC are not
  restored over a warm restart. When scheduling CESC in
  DFHSNSC a DFHIC TYPE=CANCEL is now always attempted for
  a REQID=DFHCESC ICE, regardless of the setting of
  TCTV_CESC_SCHEDULED. A response that the ICE was not found is
  treated as acceptable.
  

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:

  UI60693 UI60694 PH33375

Modules/Macros

• DFHICRC  DFHSNSC
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R100 PSY UI60693

     UP19/01/16 P F901

• R200 PSY UI60694

     UP19/01/25 P F901

Fix is available

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