Software Concepts: Middleware

In a distributed computing system, middleware is defined as the software layer that lies between the operating system and the applications on each site of the system.

The goal of middleware is to combine the best of two worlds:

•    The scalability and openness of NOS.
•    The transparency and ease of use of DOS.

General structure of a distributed system as middleware.

In an open middleware-based distributed system, the protocols used by each middleware layer should be the same, as well as the interfaces they offer to applications.

Services common to many middleware systems are:

•    Communication.
•    Naming.
•    Persistence.
•    Distributed.
•    Transaction.
•    Security.