+

Search Tips   |   Advanced Search

Configure the timer service

Use wsadmin scripting to configure the EJB timer service.

We must have a working knowledge of Jacl or Jython and wsadmin scripting.

The behavior for EJB timers is configured using the EJBTimer configuration object in the server.xml file. If we have EJB timers, you must 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.

  1. Launch the scripting tool using the Jython or scripting language.

  2. Determine the attributes on the EJBTimer configuration object that must be updated. We can update the following attributes on the EJBTimer configuration object:

    • datasourceJNDIName

    • datasourceAlias

    • tablePrefix

    • pollInterval

    • numAlarmThreads

    • schedulerJNDIName

    • numNPTimerThreads

    • nonPersistentTimerRetryCount

    • nonPersistentTimerRetryInterval

    • uniqueTimerManagerForNP

    For a complete description of each attribute, see information about EJB timer service settings.

    Four types of EJB timers exist:

    • Persistent timers, supported by a default internal scheduler instance.

    • Persistent timers, supported by a custom scheduler instance.

    • Non-persistent timers, sharing a thread pool with persistent timers.

    • Non-persistent timers, 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, you must understand which type of timer you are configured to use, and which configuration attributes apply to that type of timer.

    and configuration attributes. Indicates the EJBTimer attributes
    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 console. The numNPTimerThreads attribute maps to the Number of timer threads option in the Non-persistent EJB timer configuration section of the 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 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.

    attribute impacts. The uniqueTimerManagerForNP attribute
    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

  3. Obtain a reference to the correct EJBTimer configuration object and store it in a variable.

    Jacl:

      set timer [$AdminConfig list EJBTimer]

    Using 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, we can manually select the correct EJBTimer object and copy and paste it into the variable.

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

    (cells/myCell01/nodes/myCellManager01/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 the variable.

    Using Jacl:

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

    Using Jython:

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

  4. 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"]]')

  5. Save the configuration changes.

    Jython:

      AdminConfig.save()

    Jacl:

      $AdminConfig save

  6. In a network deployment environment only, synchronize the node.

    Jacl: 

    set sync1 [$AdminControl completeObjectName type=NodeSync,node=<your node>,*]
$AdminControl invoke $sync1 sync
    Using Jython: 

    sync1 = AdminControl.completeObjectName('type=NodeSync,node=<your node>,*')
AdminControl.invoke(sync1, 'sync')
    The node synchronization in these examples must be executed while connected to the server.


Results

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


Subtopics

  • Commands for the AdminConfig object