What is more, other middleware products, such as application servers and distributed objects, are laying claim to the EAI space and are promoting their products as being mutually exclusive to message brokers. To understand what to look for in a message broker, you have to comprehend the components and features that this new technology has to offer. By doing this you re able to establish your own set of criteria for your specific problem. Things to look at include messaging, adapters, user interface, platform support, transformation, routing, rules processing, scalability, security and management. Messaging Since message brokers use messaging systems to move information between systems, the message transport layer that the message broker supports or provides is of great interest.
Most message brokers support some sort of asynchronous transport layer, either proprietary or open.
Some message brokers offer the ability to select any number of messaging systems, even to mix and match messaging systems to meet the requirements of the problem domain. The key thing to look for is industry support for a particular messaging layer, such as market penetration, as well as the number of platforms that the messaging layer runs across. Don t forget to consider performance of the messaging layer and support by third party products. Message brokers typically ship with their own messaging systems built in, but they tend to be proprietary. Architects should not undervalue the importance of the messaging layer, since it can limit the extensibility and flexibility of the EAI solution.