Configuring a JMS activation specification for MDBs used by the default messaging provider

A JMS activation specification is a configurable resource that enables a message-driven bean (MDB) to communicate with the default messaging provider.

About this task

The JMS activation specification is based on the J2EE Connector Architecture (JCA) 1.5 standard, and provides Java™ connectivity between application servers such as WebSphere® Application Server, and enterprise information systems. It provides a standardized way of integrating JMS providers with J2EE application servers, and provides a framework for exchanging data with enterprise systems, where data is transferred in the form of messages.

For earlier versions of WebSphere Application Server, the interface between an MDB and its destination is the listener port. A listener port is a messaging component that can be manually started and stopped by the administrator. When a listener port stopped, the MDB associated with it can no longer process messages. If an MDB fails to process a message several times, the listener port is automatically stopped by the application server. Listener ports are used with the MQ Client Link (the WebSphere Application Server Version 5 provider), and with WebSphere MQ when used as an external JMS provider.

With WebSphere Application Server Version 6, the interface between an MDB and its destination is the JMS activation specification. Because a JMS activation specification is a group of messaging configuration properties not a component, it cannot be manually started and stopped. For this reason, to prevent an MDB from processing messages, you must complete the following tasks:
  • Stop the application that contains the MDB.
  • Stop the messaging engine.

It is possible to share a single JMS activation specification with multiple MDBs. This simplifies administration because it is only necessary to provide a single set of messaging configuration properties.

Note: Although it is not possible to use the listener port configuration settings with the WebSphere Application Server Version 6 default messaging provider, listener ports can still be configured for earlier messaging providers, for example the WebSphere MQ messaging provider. If you want to use an activation specification with WebSphere MQ, you must use the default messaging provider to configure activation specifications and then use WebSphere MQ Link. For information about the setup of a WebSphere MQ link to exchange messages between queues of the default messaging provider and WebSphere MQ see related tasks.
The following guidelines show which scenarios use activation specifications or listener ports:
  • If you are using J2EE 1.2 and EJB 1.1 with WebSphere Application Server v4, MDBs are not used so you do not need listener ports or activation specifications. WebSphere Application Server v4 uses message beans, but these are not MDBs or EJBs.
  • If you are using J2EE 1.3 and EJB 2.0 with WebSphere Application Server Version 5, you must use listener ports. The MDBs are JMS MDBs that implement MessageListener, and there is no JCA support. WebSphere Application Server Version 5 uses listener ports to associate MDB classes with their JMS destinations.
  • If you are using J2EE 1.4 and EJB 2.1 with WebSphere Application Server Version 6 and not using JMS, you must use activation specifications. A connector MDB uses JCA to access its resources, so the connector must therefore be configured with an activation specification. This is for new bean development, and does not affect the conversion of MDBs from EJB 2.0 to EJB 2.1.
  • If you are using J2EE 1.4 and EJB 2.1 with WebSphere Application Server Version 6, the decision depends on whether your JMS provider API is implemented with JCA. In J2EE 1.4, the JMS 1.1 API can now be implemented with the JCA 1.5 API. If so, your MDB is a JMS MDB that is implemented as a connector MDB, and must therefore be configured with an activation specification. If not, this is the same JMS situation as for J2EE 1.3, and you must configure this EJB 2.1 MDB in the same way as you would configure an EJB 2.0 MDB, which in WebSphere Application Server is to use a listener port.

To configure a JMS activation specification for the default messaging provider, you use the administrative console to complete the following steps. This task contains an optional step for creating a new JMS activation specification:

Procedure

  1. Display the default messaging provider. In the navigation pane, expand Resources > JMS > JMS Providers .
  2. Select the default provider for which you want to configure an activation specification.
  3. Optional: Change the Scope check box to the scope level at which the activation specification is to be visible to applications, according to your needs.
  4. In the content pane, under the Additional properties heading, click Activation specifications. This lists any existing JMS activation specifications for the default messaging provider in the content pane.
  5. Display the properties of the JMS activation specification. If you want to display an existing JMS Activation Specifications, click one of the names listed.
    Alternatively, if you want to create a new JMS activation specification, click New, then specify the following required properties:
    Name
    Type the name by which the activation specification is known for administrative purposes.
    JNDI name
    Type the JNDI name that is used to bind the activation specification into the JNDI namespace.
    Destination type
    Whether the message-driven bean uses a queue or topic destination.
    Destination JNDI name
    Type the JNDI name that the message-driven bean uses to look up the JMS destination in the JNDI namespace.

    Select the type of destination on the Destination type property.

    Bus name
    The name of the bus to connect to.

    Specify the name of the service integration bus to which connections are made. This must be the name of the bus on which the bus destination identified by the Destination JNDI name property is defined.

    You can either select an existing bus or type the name of another bus. If you type the name of a bus that does not exist, you must create and configure that bus before the activation specification can be used.

  6. Specify properties for the JMS activation specification, according to your needs.
  7. Optional: Specify custom properties of the JMS activation specification, as J2C activation specification custom properties.
  8. Click OK.
  9. Save your changes to the master configuration.



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Last updated: Aug 29, 2010 6:22:59 PM CDT
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