IBM Support

PI57488: Null characters added to logs when truncated by user

Fixes are available

16.0.0.2: WebSphere Application Server Liberty 16.0.0.2
16.0.0.3: WebSphere Application Server Liberty 16.0.0.3
16.0.0.4: WebSphere Application Server Liberty 16.0.0.4
17.0.0.1: WebSphere Application Server Liberty 17.0.0.1
17.0.0.2: WebSphere Application Server Liberty 17.0.0.2
17.0.0.3: WebSphere Application Server Liberty 17.0.0.3
17.0.0.4: WebSphere Application Server Liberty 17.0.0.4
18.0.0.1: WebSphere Application Server Liberty 18.0.0.1
18.0.0.2: WebSphere Application Server Liberty 18.0.0.2
18.0.0.3: WebSphere Application Server Liberty 18.0.0.3
18.0.0.4: WebSphere Application Server Liberty 18.0.0.4
19.0.0.1: WebSphere Application Server Liberty 19.0.0.1
19.0.0.2: WebSphere Application Server Liberty 19.0.0.2
19.0.0.3: WebSphere Application Server Liberty 19.0.0.3
19.0.0.4: WebSphere Application Server Liberty 19.0.0.4
19.0.0.5: WebSphere Application Server Liberty 19.0.0.5
19.0.0.6: WebSphere Application Server Liberty 19.0.0.6
19.0.0.7: WebSphere Application Server Liberty 19.0.0.7
19.0.0.8: WebSphere Application Server Liberty 19.0.0.8
19.0.0.9: WebSphere Application Server Liberty 19.0.0.9
19.0.0.10: WebSphere Application Server Liberty 19.0.0.10
19.0.0.11: WebSphere Application Server Liberty 19.0.0.11
19.0.0.12: WebSphere Application Server Liberty 19.0.0.12
20.0.0.1: WebSphere Application Server Liberty 20.0.0.1
20.0.0.2: WebSphere Application Server Liberty 20.0.0.2
20.0.0.3: WebSphere Application Server Liberty 20.0.0.3
20.0.0.4: WebSphere Application Server Liberty 20.0.0.4
20.0.0.5: WebSphere Application Server Liberty 20.0.0.5
20.0.0.6: WebSphere Application Server Liberty 20.0.0.6
20.0.0.7: WebSphere Application Server Liberty 20.0.0.7
20.0.0.8: WebSphere Application Server Liberty 20.0.0.8
20.0.0.9: WebSphere Application Server Liberty 20.0.0.9
20.0.0.10: WebSphere Application Server Liberty 20.0.0.10
20.0.0.11: WebSphere Application Server Liberty 20.0.0.11
20.0.0.12: WebSphere Application Server Liberty 20.0.0.12

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APAR status

  • Closed as program error.

Error description

  • WebSphere Application Server adding null characters to the
    messages.log  when the server re-writes to the log after it
    has
    been truncated.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server Liberty Profile - Debug/Tracing      *
    ****************************************************************
    * PROBLEM DESCRIPTION: Null characters added to log files when *
    *                      truncated by user                       *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Null characters are added to the console.log and messages.log
    when users manually truncate the files - typically this is in a
    scenario where users have cron jobs that copy the logs to a
    backup location and then empty the active log file using methods
    such as 'cat /dev/null > messages.log' or '> messages.log'.
    
    The server continues writing log data at the offset it had last
    written into the log file rather than from the top of the file
    as the user might expect.
    

Problem conclusion

  • The console.log creation was modified from using the > operator
    to the >> operator, with deletion of the old console.log prior
    to creation of the new one.  For the messages.log the output
    stream is now created with the append argument set to true.  The
    logging will now continue from the start of the file after
    truncation.
    
    The fix for this APAR is currently targeted for inclusion in fix
    pack 16.0.0.2.  Please refer to the Recommended Updates page for
    delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

  • When trying to implement time based log rolling, consider using
    the binary logging facility which allows configuration of time
    based durations.
    

Comments

APAR Information

  • APAR number

    PI57488

  • Reported component name

    LIBERTY PROFILE

  • Reported component ID

    5724J0814

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-02-17

  • Closed date

    2016-02-25

  • Last modified date

    2016-06-13

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

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

Fix information

  • Fixed component name

    LIBERTY PROFILE

  • Fixed component ID

    5724J0814

Applicable component levels

  • R850 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"850","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
16 October 2021