PI65522: LE/VSE DSA LOOP CAUSED BY DLI D106 ABENDS IN CICS ENVIRONMENT

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Experiencing an DL/1 type D106 abend (deadlock indication) may
  cause LE/VSE DSA loop and CICS becoming unresponsive in this
  situation. The event actually triggers CICS to call LE for
  processing however to-date LE/VSE behavior (in snyc with APAR
  PQ15103) ignores D106 abends so returning back to CICS.
  .
  CICS on it's own may issue APC2 abend but the LE/VSE DSA scan
  process is impacted in this situation so that it fails and ends
  up in a CPU loop never being able to exit the process.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All LE z/VSE CICS/DLI Users.                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: When a CICS transaction that uses       *
  *                      EXEC DLI or any of the call             *
  *                      interface routines other than CEETDLI,  *
  *                      should experience a D106 or D801 DL/1   *
  *                      abend, a CPU loop may result rendering  *
  *                      the CICS system unresponsive.           *
  *                                                              *
  *                      Extra Keywords: MSGDLZ106I MSGDLZ801I   *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF.                      *
  ****************************************************************
  Application programs attempting to handle D106 abends using
  the "LABEL" option on the EXEC CICS HANDLE ABEND command are
  not supported as LE z/VSE does not provide support for DL/1
  D106 abends (see APAR PQ15103). D801 abends are from a
  similar processing situation and can result in CICS issuing an
  APC2 abend as LE is unable to find the target label for
  continuation. Any outstanding CICS "HANDLE" commands that may
  attempt to process/handle the APC2 issued by CICS can then lead
  to a CPU loop as LE attempts to locate an unavailable "LABEL"
  using the available DSA chain.
  
  Extra Keywords: ABENDUD106 ABENDUD801
  

Problem conclusion

• This APAR will ensure LE z/VSE percolates any D106 DL/1
  issued abends immediately back to CICS.
  Any attempts to "handle" (with LABEL) a D106, D801 or APC2
  abend (either from an earlier DL/1 abend or another abend)
  will result in unpredictable behaviour.
  

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:

  UI39739

Modules/Macros

• CEECGOTO CEECREIN CEEHCHK6 CEELVL
  

Fix information

• Fixed component name

  LE BASE + JAP

• Fixed component ID

  5686CF932

Applicable component levels

• R52K PSY UI39739

     UP16/08/24 I 1000

Fix is available

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