IBM Support

PK59051: HA MANAGER ATTEMPTS TO ACTIVATE A MESSAGING EENGINE, WHICH FAILS IMMEDIATLY IF THE DATABASE IS UNAVAILABLE

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • When HA manager attempts to activate a messaging engine on an
    application server, and the database hosting the message store
    is unavailable, the activation fails immediately.
    

Local fix

  • Restart the application servers that can host
    the messaging engine, or use the coregroup runtime panels to
    remove the disabled status.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: Users of the default messaging provider in   *
    *                                                     WebSpher *
    *                 e Application Server V6.0 or V6.1            *
    ****************************************************************
    * PROBLEM DESCRIPTION: When a messaging engine in a            *
    *                      service integration bus is              *
    *                      requested to start on an application    *
    *                      server by the High Availability         *
    *                      manager, and the database hosting       *
    *                      a datastore is unavailable, the         *
    *                      start fails immediately.                *
    *                                                              *
    *                      Manual intervention may then be         *
    *                      required to restart the messaging       *
    *                      engine.                                 *
    *                                                              *
    *                      The messaging engine should have        *
    *                      instead delayed reporting the failure   *
    *                      to start for a period of time, to       *
    *                      give the database an opportunity to     *
    *                      recover.                                *
    ****************************************************************
    * RECOMMENDATION:                                              *
    *                                                              *
    ****************************************************************
    When a cluster is added as a member of a service integration
    bus, the High Availability Manager of WebSphere Application
    Server is responsible for starting and stopping the
    messaging engines on available application servers.
    
    When the application server where a messaging engine is
    running is stopped, the messaging engine will be
    automatically started on another eligible application
    server, or restarted by the High Availability Manager
    once the application server has been restarted.
    
    The problem was that if the database hosting the datastore
    for the messaging engine was unavailable at the time
    this activation happened, the messaging engine would
    immediately fail to activate.
    
    Instead, it should have waited for a period of time
    (default 15mins) for the database to become available
    before reporting a failure to activate to the high
    availability manager.
    
    This is because when activation of a messaging engine (by the
    High Availability Manager) fails, that application server
    becomes 'disabled' as a location for that messaging engine to
    run. The following message is produced when this occurs:
    CWSID0039E:  HAManager-initiated activation has failed,
                messaging engine <ME_NAME> will be disabled
    
    This 'disabled' status has to be removed manually, either by
    restarting the application server or by using the
    administrative console.
    
    The current status of a messaging engine and the available
    locations can be viewed/controlled in the administrative
    console using the following panel:
    Servers -> Core groups -> Core group settings ->
     <core_group_name> -> Runtime -> [Show Groups] ->
     <high_availability_group_name>
    
    A related issue can also occur for Server members of a
    Service Integration Bus. In this case, the messaging engine
    starts as part of application server startup - there is only
    one place the messaging engine is eligable to start so
    the High Availability Manager is not involved.
    If the database is unavailable at server startup the
    messaging engine enters may enter stopped state and need to
    be started manually - even if the database becomes available
    shortly after startup of the Application Server.
    

Problem conclusion

  • This APAR ensures that a messaging engine does not report
    an activation failure to the High Availability Manager
    immediately. Instead, it waits the configured amount of time
    (default 15mins) for the datastore to become available.
    This time period includes the time required to establish
    a connection to the database, and obtain the table locks
    required.
    
    The following messaging engine tuning parameters can be used
    to configure this behaviour:
    
    sib.msgstore.jdbcInitialDatasourceWaitTimeout
     The maximum duration to wait in milliseconds
    
    sib.msgstore.jdbcStaleConnectionRetryDelay
     The time in milliseconds to wait between attempts to connect
    

Temporary fix

Comments

APAR Information

  • APAR number

    PK59051

  • Reported component name

    PLAT MSG COM

  • Reported component ID

    620400101

  • Reported release

    100

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2008-01-09

  • Closed date

    2008-03-14

  • Last modified date

    2008-06-24

  • 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

    PLAT MSG COM

  • Fixed component ID

    620400101

Applicable component levels

  • R100 PSY

       UP



Document information

More support for: WebSphere Application Server
Service Integration Technology

Software version: 6.0

Reference #: PK59051

Modified date: 24 June 2008