IBM Support

PH45117: DFHLG0002 UNKNOWN_LOG_TOKEN DUE TO CORRUPTED DSNB

A fix is available

Subscribe

You can track all active APARs for this component.

 

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

APAR Information

  • APAR number

    PH45117

  • Reported component name

    CICS TS Z/OS V5

  • Reported component ID

    5655Y0400

  • Reported release

    100

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2022-03-23

  • Closed date

    2022-11-23

  • Last modified date

    2023-01-03

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

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

    PH50400 UI83426 UI83427 UI83428

Modules/Macros

  • DFHFCRO
    

Fix information

  • Fixed component name

    CICS TS Z/OS V5

  • Fixed component ID

    5655Y0400

Applicable component levels

  • R100 PSY UI83428

       UP22/12/21 P F212

  • R200 PSY UI83427

       UP22/11/24 P F211

  • R300 PSY UI83426

       UP22/11/24 P F211

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.

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.4","Line of Business":{"code":"LOB35","label":"Mainframe SW"}}]

Document Information

Modified date:
05 January 2023