Chapter 14. Distributed Objects and the Enterprise

In the past several years , the term enterprise computing has become a major part of the information technology lexicon. Today, much of the major development in the area of IT technology is that of enterprise computing. But what does enterprise computing actually mean?

Perhaps the most basic definition of enterprise computing is that it's essentially distributed computing. Distributed computing is just what the name implies, a distributed group of computers working together over a network. In this context, a network can be a proprietary network or the Internet.

The power of distributed computing is that computers can share the work. In a truly distributed environment, you do not even need to know what computer is actually servicing your request ”in fact, it might be better that you don't know. For example, when you shop online you connect to a company's Web site. All you know is that you are connecting using a URL. However, the company will connect you to whatever physical machine is available.

Why is this desirable? Suppose that a company has a single machine to service all the requests . Then consider what would happen if the machine crashes. Now let's suppose that the company can distribute the online activities over a dozen machines. If one of the machines goes down, the impact will not be as devastating.

Also consider the situation when you download files from a Web site. You probably have encountered the situation in which the download site provides you with links to a number of sites, and then asks you to choose the site closest to you. This is a means of distributing the load over the network. Computer networks can balance the load themselves . Figure 14.1 provides a diagram of how a distributed system might look.

Figure 14.1. Distributed computing.

This book is focused on objects and object-oriented concepts. So in many ways, the entities we are interested in are called distributed objects. The fact that objects are totally self-contained makes them perfect for distributed applications. The thrust of this chapter is this: If your application (client) requires the service of some object, that object can reside anywhere on the network. Let's explore some of the technologies that exist for distributed objects.