IBM Support

PI80447: Disable MMAP for static files by default on z/OS

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APAR status

  • Closed as program error.

Error description

  • Change the default to disable the use of memory-mapping to
    avoid potential issues such as deadlocks and latch contentions.
    

Local fix

  • Remove the comment in the httpd.conf so it reads
    EnableMMAP off
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  IBM HTTP Server users on z/OS               *
    ****************************************************************
    * PROBLEM DESCRIPTION: Possible deadlock and contention        *
    *                      issues with memory-mapping enabled.     *
    ****************************************************************
    * RECOMMENDATION:  Apply this fix if using IBM HTTP Server on  *
    *                  z/OS                                        *
    ****************************************************************
    MMAP for static files is being disabled by default on z/OS.
    It can be re-enabled with "EnableMMAP ON"
    

Problem conclusion

  • The default for memory-mapping directive was changed to
    disabled.
    
    This fix is targeted for IBM HTTP Server fix packs:
    - 7.0.0.45
    - 8.0.0.14
    - 8.5.5.12
    - 9.0.0.4
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI80447

  • Reported component name

    WAS IHS ZOS

  • Reported component ID

    5655I3510

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-04-24

  • Closed date

    2017-05-16

  • Last modified date

    2017-05-16

  • 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

    WAS IHS ZOS

  • Fixed component ID

    5655I3510

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF054","label":"z\/OS"}],"Version":"9.0.0.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
09 January 2021