PI53072: DFHIS0002 A SEVERE ERROR (CODE X'0000') HAS OCCURRED IN MODULE DFHISEM

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A CICS region was suffering severe IPIC connectivity problems
  which finally lead to a DFHIS0002 SEVERE ERROR (CODE X'0000')
  condition in module DFHISEM.
  
  The trace within the dump shows the following sequence of events
  that lead to the problem:
  
  - Before the trace started a connection error was detected on
    one of the ISSSs used by IPCONN xxxx. That ISSS was queued
    for error processing and appears to be on the error queue
    when the trace starts
  
  - A new request arrives on a different ISSS for IPCONN xxxx.
    The IPCONN is still in ACQuired state so an ISSB is allocated
    (/yyy). A new mirror task gets attach (zzzzz).
  
  - CISE starts processing the ISSS in error for IPCONN xxxx. It
    sets   the IPCONN state to FREEing.  It then tries to purge
    all the current tasks using the IPCONN.  This causes the
    attempt to purge task  zzzzz, which has not actually started
    running yet.
  
  - zzzzz starts running. It does IPIC initial receive processing
    and finds that this conversation has been purged. This
    triggers the task to start abend processing.
  
  - CISR receives a second message for the /yyy session. The
    session is re-allocated successfully because this process
    does not check the IPCONN state.
    However, an INVALID_CHAIN_SEQNO error is detected. This
    causes the ISSB to be added to the error queue.
  
  - zzzzz eventually completes and as part of task termination it
    frees the ISSB.  This action causes the ISSB_ERROR_CODE field
    to be cleared.
  
  - CISE completes processing of the ISSS in error and then moves
    on to process the /yyy ISSB.
    As part of the process an appropriate error message should be
    written out.
    This message is based on the value in ISSB_ERROR_CODE. This
    value has been cleared out so a catch-all section of code
    issues the DFHIS0002 including the unknown error code of 0.
  

Local fix

• not available
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHIS0002 a severe error (CODE X'0000') *
  *                      occurred in module DFHISEM.             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Two CICS regions SYSA and SYSB are connected via an IPIC
  connection.  In SYSB, a connection error is detected and CISE is
  resumed for error processing.  As the system is very busy, CISE
  which should set the IPIC status to FREEing doesn't get control
  to run for a while.  In this time slot, a request arrives in
  SYSB.  CISR which has no idea about the connection error is
  notified to handle the request.  An ISSB is allocated and a
  mirror task is attached.  Then when CISE starts to run, it tries
  to purge the mirror task which is attached but has not yet got
  control to run.
  
  The mirror task starts to run, but then goes into abend
  processing.  Accordingly the ISSB is queued to the error queue
  with a proper error code.  Eventually this ISSB is freed from
  the mirror task as part of task termination, but the ISSB is
  still queued in the error queue.  When CISE finally gets the
  chance to handle this ISSB, the error code is nulls because it
  has been cleared during ISSB free process.
  This causes a DFHIS0002 message with code x'0000'.
  

Problem conclusion

• IS domain has been changed so that the ISSB can not be allocated
  and the mirror task can not be attached if a connection error
  is detected.
  

Temporary fix

• 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:

  PI57933 UI36457

Modules/Macros

• DFHISRR
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R900 PSY UI36457

     UP16/04/01 P F603

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.