The Right Stuff on SOA: Book Review Pt1

I started reading "Service-Oriented Architecture: Concepts, Technology and Design" by Thomas Earl yesterday. This is the sort of book I've been looking for in this area. It describes the theory and practice of SOA and has practical bent. Earl is not afraid to subscribe to a particular approach and explore this to the fullest.

Earl avoids some of the vagueness of the SOA term by coming up with another term 'Contemporary SOA'. He starts the definition by saying "Contemporary SOA represents an architecture that promotes service-orientation through the use of Web services". This instantly puts a clear focus on the book. It frees Earl to describe the WS-* standards in detail and means that he does not have to speak in generalities or address competing approaches to SOA.

I had for some time decided that my organisation had to move towards Web Services, not because it was the only way to do SOA but that it was generally accepted path of least resistance for and organisation with not much history of enterprise integration technologies. So I found solace in an opening quote:

"You don't need Web services to build SOA!" These are words you'll hear many say prior to explaining service-oriented architecture. However, this statement is typically followed by something equivalent to "...but using Web services to build SOA is a darn good idea..."

It does not look the sort of book that will gloss over the technical details although I have read four chapters and Earl keeps promising to get to the detail later in the book. He has covered some important territory though.

He defines "Primitive SOA" which is the more general SOA that most authors describe. He describes 19 characteristics of contemporary SOA. He discusses the Services Oriented Platform and the Services Oriented Enterprise. He looks at 13 effects of SOA and 8 benefits of SOA but keeps things real by naming 7 pitfalls.

I like the fact that he talks about SOAP, WSDL, UDDI, XML and WS-* standards. Realistically an SOA book cannot be useful to me without doing this. Earl is strong on an enterprise XML data model. He talks about the standards bodies and describes the evolution of SOA through client server and N-Tier architecture.

I have got a fair bit out of this book so far and it has wet my appetite to continue.

"Service-Oriented Architecture: Concepts, Technology and Design" by Thomas Earl comes with a companion web-site at http://www.soasystems.com/