At JavaOne last month, I was fortunate to receive an invitation to Dave (Sonic) Chappell's launch party for his latest book, entitled Enterprise Service Bus. I spent last week at the beach, recovering from JavaOne, and took time out from digging in the sand to read ESB. This book should be required reading for anyone involved with EAI, especially integration architects.
For those of you who may not have heard about ESB, it is a rather new approach to structuring a SOA (service-oriented architecture), using a distributed MOM infrastructure, XML messages, intelligent message routing, automatic transformation of messages, and centralized administration. The SOA approach to EAI solutions is compelling, and the alignment with JBI is clear, but it is still too early in the game to tell if ESB will take the world by storm. It has a lot of promise, and many EAI vendors are jumping onto the bandwagon that Sonic, including Dave Chappell, helped to build.
The books offers the first comprehensive definition of an ESB that I have seen, almost entirely stripped bare of vendor-specific information and sales info. I say almost, for some issues (such as app-servers vs. ESB service containers) are presented in a less vendor neutral fashion than I would like. Overall, the book stays high on useful content, and low on vendor product positioning.
The books combines nicely described technical descriptions of ESB features with some high-level case studies culled from Dave's experiences in industry, or based on interviews of IT leaders that he conducted while researching the book.
The technical descriptions avoid becoming too detailed, but are sufficient to capture the essential issues encountered in integration. The diagrams, resembling Gregor-grams, are very useful, although I was a bit mystified to find a reference card for the glyphs used, tucked away in the back of the book. The diagrams are self-explanatory, IMHO.
The case studies are similarly abstract, avoiding introducing a level of detail that would cause the forest to be lost amongst the trees. At times I wished to a little more detail here, but I suspect I'm something of a glutton for punishment that way.
ESB is threatening to become something of a buzz word these days, what with IBM weighing into the ESB market. This book should help secure a rational, useful definition of Enterprise Service Bus before the marketing machines of the various integration vendors obliterate it in a storm of white papers and glossy brochures.
 Of course, I work for a major appserver vendor, so I may be exhibiting extra sensitivity in this arena.