What is meant by Distributed Systems AND Pervasive Middleware and Services

What is meant by

1) Distributed Systems

2) Pervasive Middleware and Services.

What开发者_开发问答 technologies are involved, and what programming languages might be used for them ( as they are included in the program structure of a postgraduate course )?

1) Distributed systems are systems that: - There are several autonomous computational entities, each of which has its own local memory. - The entities communicate with each other by message passing

That is the system runs on many different computers but appears to clients as a single system.

See this link for more info.

2) Pervasive implies that various components exist everywhere. So you can have wildlife monitoring using mobile technologies for instance.

The technologies vary widely so its very difficult to create list. Any programming language can be used. The components of a distributed system rely on the services of the underlying OS and middleware etc. Obviously networking is involved.

Distributed System is a group of independent or autonomous computer hardware & software that're networked together & operate together to achieve a common goal. While Pervasive System is a distributed system type that components exists everywhere, its automatic self configuration and can discover services and react accordingly. eg Smart- homes sensor networks.