Network Deployment (Distributed operating systems), v8.0 > Administer applications and their environment > Administer EJB applications > Configure a timer service


Configure the timer service using scripting

The behavior for EJB timers is configured using the EJBTimer configuration object in the server.xml file. If we have EJB timers, update the EJBTimer configuration object to obtain the optimal settings for the environment.

The EJBTimer configuration object exists at the server level. This means that each server in a multi-server environment has its own EJBTimer configuration object and must be configured individually.


Procedure

  1. Launch wsadmin.sh

  2. We can update the following attributes:

    • datasourceJNDIName
    • datasourceAlias
    • tablePrefix
    • pollInterval
    • numAlarmThreads
    • schedulerJNDIName
    • numNPTimerThreads
    • nonPersistentTimerRetryCount
    • nonPersistentTimerRetryInterval
    • uniqueTimerManagerForNP

    Four types of EJB timers exist:

    • Persistent supported by a default internal scheduler instance.
    • Persistent supported by a custom scheduler instance.
    • Non-persistent sharing a thread pool with persistent timers.
    • Non-persistent not sharing a thread pool with persistent timers.

    The server is always configured to use one of the two types of persistent timers, and one of the two types of non-persistent timers.

    The EJBTimer configuration object contains the configuration data for all four types of EJB timers. Each of the four types of timer uses a subset of the configuration attributes on the EJBTimer configuration object. All the attributes on the EJBTimer configuration object are used to configure at least one of the timer types, and none of the attributes are used to configure all the timer types. Thus, understand which type of timer you are configured to use, and which configuration attributes apply to that type of timer.


    Timer types

    Attribute Persistent, default scheduler Persistent, custom scheduler Non-persistent, shared thread pool Non-persistent, unique thread pool
    datasourceJNDIName Yes No, specified on custom scheduler configuration instead No No
    datasourceAlias Yes No, specified on custom scheduler configuration instead No No
    tablePrefix Yes No, specified on custom scheduler configuration instead No No
    pollInterval Yes No, specified on custom scheduler configuration instead No No
    numAlarmThreads Yes No Yes No
    schedulerJNDIName No Yes No No
    numNPTimerThreads No No No Yes
    nonPersistentTimerRetryCount No No Yes Yes
    nonPersistentTimerRetryInterval No No Yes Yes
    uniqueTimerManagerForNP No No Yes Yes

    The presence of a value for the schedulerJNDIName attribute determines which type of persistent timer is used. If the schedulerJNDIName attribute has a value, then a custom scheduler instance is used. If the schedulerJNDIName does not have a value, then the default internal scheduler instance is used.

    The numAlarmThreads attribute maps to the Number of timer threads option in the Persistent EJB timer configuration section of the admin console. The numNPTimerThreads attribute maps to the Number of timer threads option in the Non-persistent EJB timer configuration section of the admin console.

    The uniqueTimerManagerForNP attribute maps to the Share thread pool configured for persistent timers and Create a separate thread pool for non-persistent timers options in the admin console.

    The uniqueTimerManagerForNP attribute determines if the thread pool is shared between persistent and non-persistent timers. It also determines if the numAlarmThreads or numNPTimerThreads configuration attribute is used.


    uniqueTimerManagerForNP attribute impacts

    The uniqueTimerManagerForNP attribute affects both thread pool sharing and thread configuration.

    uniqueTimerManagerForNP attribute Persistent and non-persistent timers share a thread pool Thread configuration attribute used Thread configuration attribute that is ignored
    true No numNPTimerThreads numAlarmThreads
    false Yes numAlarmThreads numNPTimerThreads


      ### Obtain a reference EJBTimer configuration object
      ### Store it in a variable.

      ### Jacl
      set timer [$AdminConfig list EJBTimer]

      ### Jython:
      timer = AdminConfig.list('EJBTimer')

    If we have a multi-server environment, then multiple EJBTimer configuration objects are returned. Programmatically loop over the list and select the EJBTimer configuration object that corresponds to the server you must update.

    In a multi-server environment, as an alternative to programmatically looping over the list of EJBTimer objects, you can manually select the correct EJBTimer object and copy and paste it into your variable.

    For example, if the output of your AdminConfig list command is:

    (cells/myCell01/nodes/cellMgr/servers/dmgr|server.xml#EJBTimer_1)(cells/myCell01/nodes/myNode02/servers/server1|server.xml#EJBTimer_1246050925244)

    Copy and paste the reference for the needed EJBTimer object into your variable.

      ### Jacl
      set timer "(cells/myCell01/nodes/myNode02/servers/server1|server.xml#EJBTimer_1246050925244)"

      ### Jython
      timer = "(cells/myCell01/nodes/myNode02/servers/server1|server.xml#EJBTimer_1246050925244)"

  3. Update attributes on the EJBTimer configuration object.

    Update attributes on the EJBTimer configuration object using the AdminConfig modify command. The first argument to the command is the EJBTimer reference that you obtained in the previous step. The second argument to the command is a list of name-value pairs.

    To set a retry count of 10 attempts, and a retry interval of 15 seconds between each attempt:

    ### Jacl

      set update "{nonPersistentTimerRetryCount 10} {nonPersistentTimerRetryInterval 15}"
      $AdminConfig modify $timer $update

    ### Jython

      AdminConfig.modify(timer, '[[nonPersistentTimerRetryCount "10"] [nonPersistentTimerRetryInterval "15"]]')

  4. Save the configuration changes.

  5. Synchronize the node.

      ### Jacl
      set sync1 [$AdminControl completeObjectName type=NodeSync,node=mynode,*]
      $AdminControl invoke $sync1 sync

      ### Jython
      sync1 = AdminControl.completeObjectName('type=NodeSync,node=mynode,*')
      AdminControl.invoke(sync1, 'sync')

    The node synchronization in these examples must be executed while connected to the server.


Results

As a result of your updates, the EJBTimer configuration object now reflects the attribute values you specified. Restart your server so that the changes are updated on the server.


Related


Configure a timer service for network deployment
Example: Using the Timer Service with the TimedObject interface
EJB timer service settings
Configure a timer service


Related


Commands for the AdminConfig object using wsadmin.sh

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