Styles of messaging in applications
Applications can use the following styles of asynchronous messaging:
- Point-to-Point
- Point-to-point applications use queues to pass messages between
each other. The applications are called point-to-point, because a client sends
a message to a specific queue and the message is picked up and processed by
a server listening to that queue. It is common for a client to have all its
messages delivered to one queue. Like any generic mailbox, a queue can contain
a mixture of messages of different types.
- Publish/subscribe
- Publish/subscribe systems provide named collection points for messages,
called topics. To send messages, applications publish messages
to topics. To receive messages, applications subscribe to topics; when a message
is published to a topic, it is automatically sent to all the applications
that are subscribers of that topic. By using a topic as an intermediary, message
publishers are kept independent of subscribers.
Both styles of messaging can be used in the same application.
Applications can use asynchronous messaging in the following ways:
- One-way
- An application sends a message, and does not want a response. This pattern
of use is often referred to as a datagram.
- Request / response
- An application sends a request to another application and expects to receive
a response in return.
- One-way and forward
- An application sends a request to another application, which sends a message
to yet another application.
These messaging techniques can be combined to produce a variety of asynchronous
messaging scenarios.
For more information about how such messaging scenarios are used by WebSphere
enterprise applications, see the following topics:
For more information about these messaging techniques and the Java Messaging
Service (JMS), see
Sun's Java Message Service
(JMS) specification documentation
.

WebSphere Application Server cloning and WebSphere MQ clustering
Asynchronous messaging - security considerations
Asynchronous messaging with WebSphere - an overview
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cm_ovrv2
Last updated: Jun 21, 2007 4:55:42 PM CDT
WebSphere Application Server Network Deployment, Version 5.0.2
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