PH50400: DFHLG0002 UNKNOWN_LOG_TOKEN DUE TO CORRUPTED DSNB

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• An overlay of several DSNBs at offset x'B8' causes DFHLG0002
  abends with reason UNKNOWN_LOG_TOKEN at shutdown when closing
  the files associated with them. The Forward Recovery Log token
  is overwritten which causes CICS to try cleaning this up, even
  though Forward Recovery is not active for these files.
  
  Additional Symptom(s) Search Keyword(s): KIXREVPAD
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: CICS will abend LG0002, issue message   *
  *                      DFHLG0002 and trace UNKNOWN_LOG_TOKEN   *
  *                      upon closing an RLS file whose forward  *
  *                      recovery token has been corrupted, even *
  *                      when forward recovery is not enabled.   *
  ****************************************************************
  When an RLS file is closed CICS checks whether it is necessary
  to close the forward recovery log, but it does not check whether
  forward recovery is actually enabled to determine this. In the
  situation where the forward recovery token has been corrupted
  this will cause abend LG0002.
  

Problem conclusion

• A code change has been introduced to DFHFCRO so that a check for
  whether forward recovery is enabled is made prior to any attempt
  to close the forward recovery log. If forward recovery is not
  enabled no attempt to close the forward recovery log is made and
  it does not matter if the forward recovery token was corrupted,
  or not.
  
  CICS will still validly abend LG0002 (and issue the message
  DFHLG0002 and trace UNKNOWN_LOG_TOKEN) if forward recovery is
  enabled and the forward recovery token has been corrupted.
  

Temporary fix

Comments

• ×**** PE25/06/18 FIX IN ERROR. SEE APAR PH67011  FOR DESCRIPTION
  

APAR Information

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

  PH45117

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

  UI83429

Modules/Macros

• DFHFCRO
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI83429

     UP22/11/24 P F211

Fix is available

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