Architecting Web Services

The chapters devoted to XML (technical primer and using XML) were clear explanations of this important facet of web architecture. If you are coming from a legacy background or are attempting to web-enable systems in support of enterprise application integration, these two chapters will get you quickly up-to-speed. Chapter 5, Web Services Models, is the heart of this book and should be carefully read by architects and the design team; chapter 7, Building a Web Services Workflow, is essential reading for functional analysts, the creative and technical members of the design team, and QA. A nice touch is how the author used a hotel reservation system as an example to marry theory with a realistic web-based application.

As a non-developer I thought the way the author kept the level of abstraction above actual code (although example code is provided) and made examples independent of any particular development environment was a masterful way of describing the process of architecture without getting bogged down into details that have more to do with coding than design or seeing the grand scheme. Too many authors are developers at heart and cannot resist details that lose the attention of the intended audience - architects in the case of this book. He wisely left out the gory details associated with the build phase of a web project, and also showed wisdom by not attempting to get lost in scalability, performance or other issues that would merit another book to cover. As such this book is focused, and provides a structured and coherent framework for component-based software engineering approach to web architecture. If you or your team is not committed to doing up-front design and architecture you may not find this book very useful. However, if you want to see how employing sound architectural principles to web systems design can be done, or are working in a mature development environment, you will find this book well written and the approach consistent with best practices in software engineering and architecture.

I like the way Mr. Oellermann compares Web services to CORBA in such a way that those familiar with object request brokers in general will see that web services at the architectural level should be treated as objects that are the building blocks of a total system, with services managed and arbitrated in a controlled fashion that not only promotes Mr. Oellermanns premise for reusability and efficient development, but in finer detail in matters such as configuration management, effective build analysis and streamlined regression testing. These alone show the authors high level of real world experience and his deep knowledge of software engineering. Another strong point is the wide array of architectural models that are given. This, and the fact that all of the examples are independent of a single platform, show that a good architecture is not based on an single magic solution, but does involve trade-offs and an intelligent review of constraints even at the level of abstraction that architects work at. This is reinforced by the way business models and other realities are treated at a high level because no single book could hope to cover all possible architecture/business model or system goals combinations.

This book hands you the process and a lot of examples, but it does not promise to do your thinking for you. Like any profession, tools alone will not produce a masterpiece--you have to have a blueprint, understand how to use those tools and apply logic and deep thought. Architects with more than one project in their portfolio will see the beauty in this books message and should appreciate the blueprint and tools that Mr. Oellermann is sharing in the form of this book. If you have no exposure to process, architectural principles or have no interest in proven blueprints and tools that require your effort to intelligently adapt them to a given situation you are not going to be happy with this book. On the other hand, if professionalism, process and methods are important and you are a web architect this book will save you a lot of time and transfer to you a lot of the authors knowledge and experience.