SOA: Principles of Service Design

Great book, I really expected something simplest but this is unbelievable and very well done.

What this book is not: it is not a handbook for architecting an SOA (try Erl's other book, Service-Oriented Architecture (SOA): Concepts, Technology, and Design (The Prentice Hall Service-Oriented Computing Series from Thomas Erl), for this). Nor is this a book for developers looking for code examples, WSDL pointers, or the like -- there's no code in this book, other than sparse snippets of XML schema. What this book *is*: a stellar handbook for designing the services that participate in an SOA. If you have designed a suite of services and are looking to improve them, or are about to design a suite of services . . . then you're irresponsible if this book isn't on your desk. In particular, this book helps you think, in a structured way, about what makes *good* services. The book starts (part I, about 100 pages) with a drive-by overview of service-orientation and design principles -- not much new here, but gets you in the mood. Part II, the meat of the book (about 300 pages) gives you what you're really looking for: crisp, interrelated, cohesive principles for designing quality services: - Contracts - Coupling - Abstraction - Reusability - Autonomy - Statelessness - Discoverability - Composability Rather than just ticking these off, Erl describes each principle in terms of the other principles, provides an analytic framework for assessing suitability and compliance, describes both positive and negative characteristics of the principle, and illustrates the principle in the context of an imaginary case study (surprisingly effective -- rather than the usual banal dialogues, the "case studies" include practical guidance and analytic insights). Throughout, as other reviewers have noted, the production quality is great (solid, consistent diagramming and easily-readable/flippable layout). Part III has a useful comparison between OOAD and service orientation, a useful processes/glossary/roles section, and some bookkeeping.

Thomas Erl is an SOA book machine...the next one is scheduled for 2008. The good news is that, as far as I am concerned, it's only getting better. Here are another 531 pages filled with expertise. And for all the ones who don't think quantity matters, just read the first 100 pages. Those alone are worth getting the book for. If you are a CIO who wants to understand what SOA is really all about, read those first 100 pages and the lightbulbs will go on! For serious integration architects, I couldn't imagine a better way Thomas Erl could have structured this book. It really has it all: (a) a case study that weaves itself through the entire book. I don't know about you, but when I had to study in college it were always the examples that helped me make sense of all the theory (b) great visuals - I am a visual person, and I know many others are. The graphics in this book are very helpful to make this an easy read! (c) as any Thomas Erl book, a clear and precise structure. Don't expect the latest standards or programming code. But if you want to discover the architectural beauty behind SOA, pick up this book.

This was a very timely book for me to read, since I am currently writing a new course on Testing Service-Oriented Architectures. This book has a very well-defined aspect of SOA, namely the design of services. Erl is very clear that this book does not cover topics he has previouly addressed in his other books on SOA, nor does it cover SOA standards since adoption of these proposed standards is not on the horizon. With that said, I really appreciated the organization and presentation of this book. I have been reading some other titles and found this book very understandable. There are many illustrations that help explain the concepts of service design. The scope of topic coverage is also good. After explaining basic design of SOA, Erl covers topics such as service contracts, service coupling, service abstration, service reusability, service autonomy, service statelessness, and service discovery. The book concludes with a discussion of Object-orientation and service-orientation, supporting practices, and mapping service orientation principles to strategic goals. There is also a case study that is referenced throughout the book to give a real-world application to the concepts explained in the book. I found this book to be very readable, so anyone with an IT background should be able to understand it. Design experience would give an added perspective in understanding this topic, but others in the organization such as testers, business analysts, etc. should be able to profit from this book. This is also a good reference book on service design. I could pick up the book, find a topic and immediately gain understanding of the topic. I like that! One final thing I appreciated about the book was the lack of reference to specific vendors and tools. Not that tools and vendors aren't an important part of the SOA picture, but this vendor-neutral approach makes the book applicable in any environment. I highly recommend this book to anyone who is involved in SOA design, people who may be investigating SOA as a new direction in building and reengineering systems, and people who just want to gain a better understanding of how services are designed. For testers and other software quality professionals, this book can form the basis of designing tests for services. Readability - 5 Applicability - 5 Coverage of topics - 5 Depth of coverage - 5 Credibility - 5 Accuracy - 5 Relevance to software quality - 5 Overall - 5

The author of this book raised reader's awareness of the major challenges in the fundamental element of the SOA practice: define and design services. He walked readers through the labyrinth of service-oriented computing layer by layer and lead the readers into the subjects with comprehensive background introduction and fascinating subjects. After being educated with the solid services design models presented in the book, I had a compelling desire to roll up sleeps and start to apply the methodology presented right away. It surely makes SOA practitionerslife easier in adopting part or all of the design principles and approaches by providing the systematic and workable approaches in creating service blueprints and contracts, as well as technical and methodical considerations around them. It is well organized. The fundamental part is well suited for IT professionals at all levels. Management can benefit from understanding the overall concept in the design paradigm while the technologists can benefit by shifting their design paradigm to this SOA centric approach. Thus it helps to align both IT management and professional in SOA adoption, practice goals and methodology. The design principles part further elaborate and drill-down in-depth those design concepts introduced in the previous part.