Introduction › WebSphere MQ Concepts and Terminology › Supported Application Behaviors

Supported Application Behaviors

WebSphere MQ includes support for the following application behaviors:

• Simple Messaging

  Applications that use simple messaging do not expect a reply. The application sends a datagram message to a target queue. This type of application behavior is also known as fire and forget. Simple messaging is often used for event logging.

• Request/Response

  Applications using request/response behavior make use of both the request and reply message types. The requesting application adds control information to the request message to identify the name of the queue manager and the queue to which the corresponding response should be sent. The application processing the request uses the reply to control information to return the response to the requesting application.

• Event Driven

  WebSphere MQ can initiate applications in response to a message arriving on a particular queue. The event is represented by the contents of the message. WebSphere MQ drives the application associated with the queue, and the queue manager defines certain conditions as constituting trigger events. When a queue that is configured for triggering receives a trigger event, the queue manager sends a trigger message to a local queue, which is known as an initiation queue. The presence of a trigger message on the initiation queue indicates that a triggered event occurred.

• A trigger monitor is an application that monitors an initiation queue associated with a queue manager. When a trigger message arrives on the initiation queue, the trigger monitor retrieves it and, typically, the trigger monitor starts an application that is specified in the message on the initiation queue.
• Time Independent

  With message queuing, the exchange of messages between sending and receiving programs is time independent. That is, the sending and receiving applications are decoupled so that the sender can continue processing without having to wait for the receiver to acknowledge the receipt of the message. The target application does not need to be running when the message is sent, as it is able to retrieve the message after it starts.