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PM94437: MINIMIZE THE NUMBER OF THREADS THAT WAIT ON THE LDAP CONTEXT POOL CREATION AFTER LDAP FAILURE.

Fixes are available

8.0.0.8: WebSphere Application Server V8.0 Fix Pack 8
7.0.0.31: WebSphere Application Server V7.0 Fix Pack 31
8.5.5.2: WebSphere Application Server V8.5.5 Fix Pack 2
7.0.0.33: WebSphere Application Server V7.0 Fix Pack 33
8.0.0.9: WebSphere Application Server V8.0 Fix Pack 9
8.5.5.3: WebSphere Application Server V8.5.5 Fix Pack 3
7.0.0.35: WebSphere Application Server V7.0 Fix Pack 35
8.5.5.4: WebSphere Application Server V8.5.5 Fix Pack 4
8.0.0.10: WebSphere Application Server V8.0 Fix Pack 10
7.0.0.37: WebSphere Application Server V7.0 Fix Pack 37
8.5.5.5: WebSphere Application Server V8.5.5 Fix Pack 5
8.5.5.6: WebSphere Application Server V8.5.5 Fix Pack 6
8.0.0.11: WebSphere Application Server V8.0 Fix Pack 11
8.5.5.7: WebSphere Application Server V8.5.5 Fix Pack 7
7.0.0.39: WebSphere Application Server V7.0 Fix Pack 39
8.5.5.8: WebSphere Application Server V8.5.5 Fix Pack 8
8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.31: Java SDK 1.6 SR15 Cumulative Fix for WebSphere Application Server
7.0.0.35: Java SDK 1.6 SR16 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.37: Java SDK 1.6 SR16 FP3 Cumulative Fix for WebSphere Application Server
7.0.0.39: Java SDK 1.6 SR16 FP7 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14

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APAR status

  • Closed as program error.

Error description

  • When Ldap connection fails, VMM discards all the old contexts
    from the context pool and recreates a new pool. While this new
    pool is being created, all threads requesting access to Ldap
    are put in a 'wait' state. This APAR, minimizes the number of
    threads that wait on the Ldap Context pool creation to a user
    configured number.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server                                      *
    ****************************************************************
    * PROBLEM DESCRIPTION: When an LDAP server goes down, all      *
    *                      threads trying to communicate with      *
    *                      the LDAP get blocked until the read     *
    *                      times out.                              *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When an LDAP Server goes down, any new thread that tries to
    read from the server gets an exception. Virtual Member manager
    (VMM) then tries to recreate the LDAP Context Pool and during
    this creation all incoming threads are blocked. If a
    connection cannot be made for 120 seconds an exception is
    thrown and the threads are able to complete their processing.
    All requesting threads are, however, blocked for the duration
    until the exception is thown.
    

Problem conclusion

  • The code was modified to ensure that all threads are not
    blocked during this context pool recreation. You can
    configure if you want to minimize the number of threads
    blocked and also configure the exact number of threads blocked
    with the help of custom properties
    "minimizeContextPoolThreadBlock" and "maxThreadsToBlock". By
    default these values are "true" and "5". You can also
    customize to trace the bind timeout with a custom property
    named "bindTimeout".
    
    In order to set these properties, use the following commands:
    
    $AdminTask setIdMgrCustomProperty {-id <LDAP_repos_ID> -name
    minimizeContextPoolThreadBlock -value true}
    
    $AdminTask setIdMgrCustomProperty {-id <LDAP_repos_ID> -name
    maxThreadsToBlock -value 5}
    
    $AdminTask setIdMgrCustomProperty {-id <LDAP_repos_ID> -name
    bindTimeout -value <millseconds>}
    
    Here "LDAP_repos_ID" is the repository id of the LDAP
    configured in VMM.
    "millseconds" is to track the count of "quick" binds.  Dump
    the updated statistic to the log.
    
    Also save the configuration after running the previous command
    using:
    
    $AdminConfig save
    
    The fix for this APAR is currently targeted for inclusion in
    fix packs 7.0.0.31, 8.0.0.8 and 8.5.5.2.  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

    PM94437

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-08-02

  • Closed date

    2013-10-31

  • Last modified date

    2013-10-31

  • 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

  • R700 PSY

       UP

  • R800 PSY

       UP

  • R850 PSY

       UP



Document information

More support for: WebSphere Application Server
General

Software version: 8.0

Reference #: PM94437

Modified date: 31 October 2013