5.1 Introduction

In this chapter, we will talk about clustering from a systems architecture perspective using Microsoft's Cluster Service as our example. We will discuss the design that Microsoft used to implement clustering solutions for Windows NT/2000 that is known as Cluster Server. We intend to give the reader a basic understanding of how the system works and why the software developers chose particular architectures for their implementation of Windows NT/2000 Clustering. We will concentrate on the nature or characteristic of a Cluster implementation rather than discussing how to simply install or manage a cluster. Although our primary focus is Windows NT/2000 Clusters, we occasionally reference the clustering technology used on other operating systems during the past 10 to 20 years. We hope that by understanding some of these other successful cluster designs you will be better prepared to understand the different design tradeoffs that have been made in designing and implementing Windows NT/2000 Clustering.