IBM Support

PH20311: PLUG-IN DOES NOT READ ENTIRE RESPONSE FROM THE SOCKET WHEN ESI IS ENABLED AND RESPONSE SHOWS DATA IS NOT MODIFIED

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APAR status

  • Closed as program error.

Error description

  • Plug-in does not read the entire response from the socket when
    ESI is enabled and the response indicates that the data is
    not modified.
    
    Problem reported on Plug-in v9.0.5 and 8.5.5.x
    

Local fix

  • Disable ESI cache in the plugin-cfg.xml file so that large
    responses can be cached.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  IBM WebSphere Application Server web        *
    *                  server plugin users                         *
    ****************************************************************
    * PROBLEM DESCRIPTION: If ESI caching is enabled on plugin,    *
    *                      servers could be incorrectly marked     *
    *                      down                                    *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When ESI is enabled, if a request includes an "If-Modified"
    header and the response indicates that the data has not been
    modified, then plugin may not read the entire response. Data
    left unread on the socket may then be read on the next request
    using the socket to the application server. This lingering
    data would not have the expected format so the server would be
    marked down due to invalid format.
    

Problem conclusion

  • Corrected the issue to close the socket under these conditions
    to prevent unread data from lingering on the socket.
    
    The fix for this APAR is targeted for inclusion in fix pack
    8.5.5.17 and 9.0.5.3.  For more information, see 'Recommended
    Updates for WebSphere Application Server':
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

Comments

APAR Information

  • APAR number

    PH20311

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-12-13

  • Closed date

    2019-12-17

  • Last modified date

    2019-12-17

  • 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

    WEBS APP SERV N

  • Fixed component ID

    5724H8800

Applicable component levels

  • R850 PSY

       UP

  • R900 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":"900","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
17 October 2021