Message oriented middleware
Message Oriented Middleware
Because businesses, institutions, and technologies change continually, the software systems that serve them must be able to accommodate such changes. Following a merger, the addition of a service, or the expansion of available services, a business can ill afford to recreate its information systems. It is at this most critical point that it needs to integrate new components or to scale existing ones as efficiently as possible. The easiest way to integrate heterogeneous components is not to recreate them as homogeneous elements but to provide a layer that allows them to communicate despite their differences. This layer, called middleware, allows software components (applications, enterprise java beans, servlets, and other components) that have been developed independently and that run on different networked platforms to interact with one another. It is when this interaction is possible that the network can become the computer.
Applications distributed on different network nodes use the application interface to communicate without having to be concerned with the details of the operating environments that host other applications nor with the services that connect them to these applications. In addition, by providing an administrative interface, this new, virtual system of interconnected applications can be made reliable and secure. Its performance can be measured and tuned, and it can be scaled without losing function.
Middleware can be grouped into the following categories: • Remote Procedure Call or RPC-based middleware, which allows procedures in one application to call procedures in remote applications as if they were local calls. The middleware implements a linking mechanism that locates remote procedures and makes these transparently available to a caller. Traditionally, this type of middleware handled procedure-based programs; it now also includes object-based components. • Object Request Broker or ORB-based middleware, which enables an application’s objects to be distributed and shared across heterogeneous networks. • Message Oriented Middleware or MOM-based middleware, which allows distributed applications to communicate and exchange data by sending and receiving messages.