Configure work managers

A work manager acts as a managed executor (thread pool), thread factory, and thread context service for application components that use Concurrency Utilities for Java EE or asynchronous beans. Use the administrative console to configure work managers. The work manager service is always enabled. In previous versions of the product, the work manager service could be disabled using the administration console or configuration service. The work manager service configuration objects are still present in the configuration service, but the enabled attribute is ignored. We can define multiple work managers for each cell. Each work manager is bound to a unique place in the JNDI namespace.

Important: The work manager service is only supported from within the EJB container or web container. Looking up and using a configured work manager from a Java EE application client container is not supported.

Tasks

1. Start the administrative console.

2. Select...
   Resources > Concurrency > Work managers > Scope > New

3. Specify the required properties for work manager settings.

   Scope	The scope of the configured resource. This value indicates the location for the configuration file.
   Name	The display name for the work manager.
   JNDI Name	The JNDI name for the work manager. Resource environment references can be bound to this name and used by components that must look up the work manager. Each work manager must have a unique JNDI name within the cell.
   Number of Alarm Threads	The maximum number of threads to use for a separate thread pool dedicated to processing alarms and work scheduled to run at a specific point in time. The work manager monitors and dispatches pending alarms and scheduled work to this thread pool. The number of alarm threads specified for this property has no impact on the number of threads we specify for the Minimum Number Of Threads and Maximum Number Of Threads properties. The Number of Alarm Threads property only applies to the thread pool for alarm threads. The Minimum Number Of Threads and Maximum Number Of Threads properties only apply to the main thread pool that handles work requests.
   Minimum Number Of Threads	Applies to the main thread pool for work submitted to the work manager to run immediately (not scheduled for a specific point in time). The number of threads to be kept in the thread pool, created as needed.
   Maximum Number Of Threads	Applies to the main thread pool for work submitted to the work manager to run immediately (not scheduled for a specific point in time). The maximum number of threads to be created in the thread pool. The maximum number of threads can be exceeded temporarily when the Growable check box is selected. These additional threads are discarded when the work on the thread completes.
   Thread Priority	The priority to assign to all threads in the thread pool and all threads created by the managed thread factory. Every thread has a priority. Threads with higher priority are run before threads with lower priority. For more information about how thread priorities are used, see the Javadoc for the setPriority method of the java.lang.Thread class in the Java Standard Edition specification.

4. [Optional] Specify a Description and a Category for the work manager.

5. [Optional] Select the Service Names (types of thread context made available to Java EE components) that we want this work manager to capture from the submitting thread (or from the thread that looks up or injects the managed thread factory) and to make available on the thread of execution. The list of selected services also is known as the "sticky" context policy for the work manager.

   Select more services than are required might impede performance.

   Other optional fields include:

   Work timeout	Number of milliseconds to wait before a started unit of work is canceled or released. If a value is not specified, then the timeout is disabled.
   Work request queue size	Size of the work request queue. The work request queue is a buffer that holds scheduled work objects and can be a value of 1 or greater. The thread pool pulls work from this queue. If we do not specify a value or the value is 0, the queue size is managed automatically. When the queue size is managed automatically, it is computed as the larger of (maximum_number_of_threads) or 20. Large values can consume significant system resources.
   Work request queue full action	Action taken when the thread pool is exhausted, and the work request queue is full. This action starts when we submit non-daemon work to the work manager. If set to FAIL, the executor or work manager API methods raise an exception instead of blocking.

6. [Optional] Select Custom Properties > New. Other optional fields include:

   Name	lateWorkTime
   Value	Number of seconds
   Description	Specify a description
   Type	Select java.lang.String

   The lateWorkTime custom property is the number of seconds beyond which late-starting work must cause an informational message to be logged. The informational message is logged once per work manager. The default is 60 seconds and a value of 0 disables this property.

   Name	lateAlarmTime
   Value	Number of seconds
   Description	Specify a description
   Type	Select java.lang.String

   The lateAlarmTime custom property is the number of seconds beyond which a late-firing alarm must cause an informational message to be logged. The informational message is logged once per work manager. The default is 5 seconds and a value of 0 disables this property.

7. Save the configuration.

The work manager is now configured and ready for access by application components that must manage the start of asynchronous code.

Subtopics

• Work manager collection
  
• Work manager settings
  

Related:

Work managers

Configure work manager custom properties