Operating System Concepts, Seventh Edition

Chapter 16. Distributed System Structures

A distributed system is a collection of processors that do not share memory or a clock. Instead, each processor has its own local memory The processors communicate with one another through various communication networks, such as high-speed buses or telephone lines. In this chapter, we discuss the general structure of distributed systems and the networks that interconnect them. We contrast the main differences in operating-system design between these systems and centralized systems. In Chapter 17, we go on to discuss distributed file systems. Then, in Chapter 18, we describe the methods necessary for distributed operating systems to coordinate their actions.

CHAPTER OBJECTIVES

• To provide a high-level overview of distributed systems and the networks that interconnect them.

• To discuss the general structure of distributed operating systems.

Motivation

A distributed system is a collection of loosely coupled processors interconnected by a communication network. From the point of view of a specific processor in a distributed system, the rest of the processors and their respective resources are remote, whereas its own resources are local.

The processors in a distributed system may vary in size and function. They may include small microprocessors, workstations, minicomputers, and large general-purpose computer systems. These processors are referred to by a number of names, such as sites, nodes, computers, machines, and hosts, depending on the context in ...