Chapter 9 - Application Integration

About This Chapter

The Internet’s ever-increasing popularity has changed the architecture of distributed computing and how we think of application design. In many organizations the client/server topology, which consists of two tiers, is being replaced by multitiered environments in which computing tasks are spread across multiple layers, each of which provides specific functionality. As a result, applications no longer simply sit on a client or server and respond to client requests. For many applications, particularly ones that are Web-related, application components are distributed across multiple layers that are each assigned a particular computing task. In this model, an application might respond to a client request that’s initiated through a thin client, such as Microsoft Internet Explorer. The application, which is hosted on an Internet Information Services (IIS) server or another Web server, might require access to resources such as Component Object Model (COM) objects or data stores in order to respond to the client request. These resources might be on separate layers, or tiers, depending on the network configuration. In this chapter you’ll learn how to design a content and application topology that supports a distributed environment. You’ll also learn how to design a database and a messaging integration strategy.

Before You Begin

To complete the lessons in this chapter, you must have

• A basic understanding of multitier Web application design and middle-tier (business logic layer) technologies
• An understanding of how Network Load Balancing (NLB) and Component Load Balancing (CLB) are implemented in a multitiered environment