PI95126: TRANSACTION IN A LOOP CONSUMING EXCESSIVE CPU

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Using CICS/TS 5.3 on z/OS 2.2, observed pipeline resolution
  transaction, CPIR, consuming a lot more CPU than other CICS
  regions.
  .
  It appears to be in a loop.  Cold started the region, Auto
  started the region, and still CPIR consumes excessive CPU.
  .
  Found the following Trace Entries in CICS Internal Trace
  repeated over and over confirming a Loop.
  .
  0E00 DHFS  ENTRY - FUNCTION(GET_NEXT_IN_DIRECTORY)
                     FILENAME(41876000 , 00000000 , 000000FF)
                     BROWSE_TOKEN(3DC401B0 , 00000080)
  .
        TASK-00049 KE_NUM-0079 TCB-C/QR   /008E5848 RET-BE080414
        TIME-07:14:23.5262667714 INTERVAL-00.0000002592 =001302=
  .
  .
  0E0C DHFS  *EXC* - READ_ERROR - FUNCTION(GET_NEXT_IN_DIRECTORY)
                     FILENAME(41876000 , 00000000 , 000000FF)
                     BROWSE_TOKEN(3DC401B0 , 00000080)
  .
        TASK-00049 KE_NUM-0079 TCB-C/L8004/008B1188 RET-BE080414
        TIME-07:14:23.5270311035 INTERVAL-00.0000443354 =002479=
  .
  .
  0E01 DHFS  EXIT  - FUNCTION(GET_NEXT_IN_DIRECTORY)
                     RESPONSE(EXCEPTION) REASON()
                     FILENAME(41876000 , 00000000 , 000000FF)
  .
        TASK-00049 KE_NUM-0079 TCB-C/QR   /008E5848 RET-BE080414
        TIME-07:14:23.5274725029 INTERVAL-00.0004413994 =002480=
  .
  .
  Going to the Filename address we see:
  .
  .
  LIST 41876000. ASID(X'02CD') LENGTH(X'FF') AREA
  ASID(X'02CD') ADDRESS(41876000.) KEY(80) ABSOLUTE(0E_710CF000.)
  41876000 LENGTH(X'E0')==>All bytes contain X'40', EBCDIC C' '
  418760E0. 40404040 40404040 40404040 40404040
            40404040 40404040 40404040 404040
  .
  .
  The BPX1RDD call made by DFHDHFS to read the next directory
  entry is returning an error, that is not EBADF.  This causes
  DFHDHFS to return an exception with reason set to
  DHFS_READ_ERROR.  DFHPIPL does not have any code to handle this
  exception response so it simply loops and makes the call again.
  .
  The BPX1RDD call has failed due to the following found in the
  Parmlist.
  .
  Return_value,  is -1
  Return_code,   is x'00000079'  121 EINVAL
  Reason_code)   is EF116126
  .
  Need to correct the CICS Code to not Loop when this error
  occurs.
  .
  Additional Symptom(s) Search Keyword(s): KIXREVDAM
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: CPIR consumes excessive CPU.            *
  ****************************************************************
  CICS is installing a PIPELINE definition and transaction CPIR
  is attached to do this.  At the end of the installation an
  implicit PIPELINE SCAN is performed.  DFHPIPL calls DFHDHFS to
  process every file found within the directory specified by the
  WSDIR parameter of the PIPELINE definition.
  
  DFHDHFS makes a BPX1RDD call to read the next file in the
  specified directory.  This call is failing with EINVAL and a
  reason code of EF116126.  DFHDHFS returns DHFS_EXCEPTON and
  DHFS_READ_ERROR to DFHPIPL.  DFHPIPL does not handle this error
  and simply calls DFHDHFS again.  The same zFS error occurs and
  DFHDHFS returns the same exception.  DFHPIPL now loops forever
  calling DFHDHFS GET_NEXT_IN_DIRECTORY until the runaway time
  is hit and the CPIR task is abended.
  

Problem conclusion

• DFHPIPL has been changed to handle the DHFS_EXCEPTION response
  with reason DHFS_READ_ERROR returned by DFHDHFS and to consider
  the WSDIR to be inaccessible.
  

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:

  UI55316 UI55317

Modules/Macros

• DFHDHFST DFHPIPL
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R000 PSY UI55317

     UP18/04/21 P F804

• R100 PSY UI55316

     UP18/04/21 P F804

Fix is available

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