Sun Java System Application Server Enterprise Edition 8.1 2005Q2 High Availability Administration Guide

- Previous: Chapter 8 Configuring High Availability Session Persistence and Failover
- Next: Configuring the Java Message Service

# Overview of Java Message Service

The Java Message Service (JMS) API is a messaging standard that allows J2EE applications and components to create, send, receive, and read messages. It enables distributed communication that is loosely coupled, reliable, and asynchronous. The Sun Java System Message Queue 3 2005Q1 (MQ), which implements JMS, is tightly integrated with Application Server, enabling you to create components such as message-driven beans (MDBs).

MQ is integrated with Application Server using a connector module, also known as a resource adapter, defined by the J2EE Connector Architecture Specification 1.5. J2EE components deployed to the Application Server exchange JMS messages using the JMS provider integrated via the connector module. Creating a JMS resource in Application Server creates a connector resource in the background. So, each JMS operation invokes the connector runtime and uses the MQ resource adapter in the background.

You can manage the Java Message Service through the Admin Console or the `asadmin` command-line utility.

## Sample Application

The `mqfailover` sample application demonstrates MQ failover with a Message Driven Bean receiving incoming messages from a JMS Topic. The sample contains an MDB and a application client. The Application Server makes the MDB highly available. If one broker goes down, the conversational state (the messages received by MDB) is migrated transparently to another available broker instance in the cluster.

The sample is installed to

    install_dir/samples/ee-samples/failover/apps/mqfailover

## Further Information

For more information on JMS, see Chapter 14, Using the Java Message Service, in Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Developer’s Guide. For more information on connectors (resource adapters), see Chapter 9, Developing Connectors, in Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Developer’s Guide.

For more information about the Sun Java System Message Queue, see the Sun Java System Message Queue documentation. For general information about the JMS API, see the JMS web page

- Previous: Chapter 8 Configuring High Availability Session Persistence and Failover
- Next: Configuring the Java Message Service

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