OA43579: ISRSUPC HIGH CPU CONSUMPTION AND HIGH EXCP'S WITH SPECIFIC DPLINE'S SPECIFIED

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The DPLINE statement does not perform the same padding with
  trailing spaces as normal comparisons, so what is happening is
  that the DPLINE statements with trailing blanks are failing to
  match the shorter lines in one of the input files.  As this is
  a frequently occurring line, SuperC needs to scan a long way
  back and forwards during the matching process.  If it needs to
  scan too far back, it may need to reposition to an earlier
  record in the sequential file by record number.  As this
  is not a function directly provided in MVS (unlike in CMS), this
  is done by repositioning to the start and then skipping the
  required number of records, which is obviously very
  time-consuming.  It gets there eventually, but obviously with
  unacceptable performance (it took two hours here instead of two
  seconds in the case where the lines had been padded with
  spaces).
  

Local fix

• Problems with performance can be circumvented with either the
  DPBLKCL
  process option but the issue with the "LEGEND" data line can
  only be
  bypassed by converting to a RECFM=FB file.
  Which seems at odds with the statement
  
  "For files with input line lengths <= 256, a LINE comparison is
  performed after padding the lines to the longest line length.
  Consequently two lines, originally of unequal length, compare
  equally
  only if the spaces at the end of the longer line coincide with
  the
  shorter line's space padding."
  
  from the Superc publication.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All ISPF users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: If the search string on a DPLINE        *
  *                      statement contains trailing spaces,     *
  *                      these only matched the input line if it *
  *                      contained spaces in the corresponding   *
  *                      positions.                              *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF.                      *
  ****************************************************************
  When a DPLINE statement is used to exclude input lines
  containing certain strings, trailing spaces in the search value
  are matched against corresponding positions in the input record.
  If the input record was too short to include the trailing
  spaces (for example for variable length records where trailing
  spaces had been removed) then the DPLINE search value would not
  match.  This meant for example that when one of two similar
  input files had trailing spaces removed, the DPLINE statements
  would match on one but not the other, causing spurious
  differences to be indicated.  The documentation says that during
  comparison processing, the input line is assumed to be padded
  with spaces if necessary, but DPLINE processing was not
  consistent with this principle.
  

Problem conclusion

• SuperC processing of the DPLINE statement has been modified so
  that trailing spaces on a search string are handled as if the
  input record is padded with spaces if necessary.  If a search
  string is entirely blank, it will be treated as matching even
  when the start position is beyond the end of the input record.
  This ensures consistency with the documented principle that
  comparison processing is performed as if the input record were
  padded with trailing spaces if necessary.
  
  This corresponds to HLASM Toolkit Feature SuperC APAR PM98134.
  

Temporary fix

Comments

APAR Information

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

  PM98134

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

  UA71456 UA71457 UA71458

Modules/Macros

• ISRSPPRM ISRSRDLN ISRSRDWD
  

Fix information

• Fixed component name

  ISPF Z/OS PDF&S

• Fixed component ID

  565504202

Applicable component levels

• RJ02 PSY UA71456

     UP13/11/23 P F311

• RM02 PSY UA71457

     UP13/11/23 P F311

• RN02 PSY UA71458

     UP13/11/23 P F311

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.