IBM Support

PI70900: Events get lost when the logstashCollector config gets updated

Fixes are available

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

  • Collector manager uses internal buffers to store events.
    These buffers are discarded when the last handler goes away.
    This behavior does not doesn't work well for certain
    situations. Example below.
    
    1) We have one handler (logmet/logstash collector feature).
    2) User updates the config for this feature, example bad
    port to a valid port.
    3) Logmet/Logstash collector calls an unsubscribe &
    subscribe on the sources on config update.
    4) Unsubscribe will discard the existing buffers and a
    subscribe operation will result in new buffers getting
    allocated.
    5) End result is we lose events in the old buffer.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server Liberty - Perf Monitoring Tools      *
    ****************************************************************
    * PROBLEM DESCRIPTION: Some events get lost when the           *
    *                      logstashCollector configuration gets    *
    *                      updated                                 *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Collector manager uses internal buffers to store events. These
    buffers are discarded when the last handler goes away. This
    behavior is not doesn't work well for certain situations.
    Example below.
    
    1) We have one logmet/logstash collector feature.
    2) User updates the config for this feature, example bad port to
    a valid port.
    3) Logmet/Logstash collector calls a unsubscribe & subscribe on
    the sources on config update.
    4) Unsubscribe will discard the existing buffers and a subscribe
    operation will result in new buffers getting allocated.
    5) End result is that we lose events in the old buffer.
    

Problem conclusion

  • Program change: We now maintain the buffer contents across
    configuration changes as long as the source is present both
    before and after the change. If the source is removed, the
    configuration saved, and then the source is added again at a
    later time, the events in between will still be lost, as
    intended.
    
    The fix for this APAR is currently targeted for inclusion in fix
    pack 16.0.0.4.  Please refer to the Recommended Updates page for
    delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI70900

  • Reported component name

    LIBERTY PROFILE

  • Reported component ID

    5724J0814

  • Reported release

    CD0

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-10-18

  • Closed date

    2016-10-25

  • Last modified date

    2016-10-25

  • 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

  • RCD0 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":"CD0","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
18 October 2021