Architecting Web Services

Chapter 14

Architecting Web Services

IN THIS CHAPTER

          What Are Web Services?

          Business Motivations for Web Services

•        Technical Motivations for Web Services

          The Service-Oriented Architecture (SOA)

• Architecting Web Services

No topic in this book is getting more attention and pure hype than the area of Web Services. Dozens of vendors, led by Microsoft and IBM, are pouring enormous resources into developing Web Services frameworks as well as the tools to support them. Part of the hype is unquestionably due to technology vendors’ need to sell new products (as well as new versions of old products). However, the potential for Web Services goes far beyond a straightforward economic need to innovate.

In fact, Web Services signal a paradigm shift in distributed computing. Web Services have the potential to change the way distributed systems interact, which will fundamen-tally affect the operation of the Internet. As a result, Web Services might form the back-bone of a new global e-business infrastructure.

However, many economic and political battles remain to be fought before Web Services can realize their enormous potential. Today, Web Services are on the bleeding edge, in the hands of the technologists and a few early adopters. As with other paradigm shifts, most of the work going on in the Web Services area involve new ways of solving old problems. People still follow the old ways of thinking about distributed computing and e-business frameworks. In order to break out of the old way of thinking and apply Web Services to new problems, you must understand how the core technologies of Web Services enable a new way of thinking about distributed computing. That’s the goal of this chapter.

In this chapter, you’ll learn the following:

   The definition of Web Services and the Web Services model

   The business and technical motivations for the development of Web Services

   The definition and structure of the service-oriented architecture, which is analo-gous to the now-familiar object-oriented architectures

   How to define and implement the service-oriented architecture’s four key func-tional components: service implementation, publication, discovery, and invocation

   About current work in the areas of security and quality of service as well as the composition of Web Services and conversations among Web Services

   How to approach the service-oriented architecture from different viewpoints

   How the Just-In-Time capabilities of the Web Services model can create a new par-adigm for distributed computing