PK52623: AIDS ON THE AID CHAIN NOT GETTING IMMEDIATELY ACTIONED

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• This customer has a process that will do an
  EXEC CICS START TRANSID(NPRS) TERMID(C0C1) FROM(data). C0C1 is
  a 'dummy' console TCTTE that the transaction will never converse
  with. The purpose of the TERMID on the START is just to help do
  an EXEC CICS SIGNON. (This application does it the old way like
  when you needed a terminal to do a SIGNON.)
  .
  So every incoming piece of work will get started on this same
  console terminal. This causes the work to be single threaded.
  .
  The problem is that recently there came to be a queue of work
  backing up as AIDs waiting to run on this console TCTTE. We
  think that it was a flood of work that caused this problem to
  occur. But those AIDs weren't actioned in a timely manner.
  Each new START will trigger one of the old AIDs to be actioned.
  But when a task finishes on that TCTTE, the next AID is not
  immediately actioned. It takes another new START to trigger the
  oldest remaining AID to get actioned or if no new STARTs happen,
  the oldest AID will get actioned into a task every 5 seconds
  which is the value of ICV.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: EXEC CICS START commands at a Console   *
  *                      fail to attach the ATI task until after *
  *                      the ICV value has expired.              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Following the completion of an ATI task at a Console, DFHALP's
  RESET_AID_QUEUE is driven and finds another AID waiting to start
  at this Console.
  
  DFHZLOC is driven for a DFHTC CTYPE=ATI request to initiate the
  new task. It sets TCTCEATI (ATI request) in the CCE (Console
  Control Element) and tells DFHZCNA (TCTV_CCE_ATI) to scan the
  CCEs the next time TCP runs. However it fails to tell the
  Dispatcher to wake up the TCP task.
  
  This means that if there is no other VTAM Terminal activity in
  that region the ATI task will not be attached until after the
  ICV interval has expired.
  
  Additional keywords
  ZLOCCON3 CSATCPEV CSZTCPEV
  

Problem conclusion

• The DFHZLOC's ATI routine (ZLOCATIR) for Consoles has been
  amended to ensure that the Dispatcher wakes up TCP (CSATCPEV)
  to attach the outstanding ATI task.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

  PK49341

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

  UK31606 UK31612

Modules/Macros

•    DFHZLOC
  

Fix information

• Fixed component name

  CICSTS V3 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R400 PSY UK31606

     UP07/12/01 P F711

• R500 PSY UK31612

     UP07/12/01 P F711

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.