Customer Reviews

Business Process Execution Language for Web Services : BPEL and BPEL4WS

5 star:		(2)
4 star:		(3)
3 star:		(0)
2 star:		(2)
1 star:		(0)

 

 

This is the first book I have seen on BPEL - the business process execution language. A number of Web services orchestration / process tools are based on BPEL but hide the language behind a drag-and-drop GUI. I found that to effectively use these tools, though, you have to understand the concepts that make up BPEL - scopes, partner links, correlation sets etc. This book likely provides the best introduction to these concepts. Examples are given in "raw" BPEL as well as using Oracle BPEL Manager and Microsoft BizTalk.

I wished for a little more in-depth coverage of advanced topics, such as correlation and convoys, but I think more people have to gain experience using these before we can expect a book to present "best practices".

In summary, if you are interested specifically in BPEL, this is likely the book you want to get.

"Business Process Execution Language for Web Services" is a good tutorial and reference for BPEL. The authors state that the book is targeted towards current web services developers and architects. Appropriately, the book assumes knowledge of XML, UML, and of course, web services.

The book was written by three authors and the chapters are separated by author. One author wrote chapter one, which includes an overview of BPEL, concrete examples of workflow and how BPEL fits into the big picture. The main author wrote chapters two through four, which flow well and teach BPEL through a running example, along with describing Oracle's BPEL tools. The third author wrote chapter five, which describes Microsoft's BPEL tools. The book ends with a clear, concise syntax reference. While all the chapters provide valuable information, the first and last chapters seem disjointed from the remainder of the book.

There are plenty of diagrams to show architecture and flow, something very important in BPEL. The meat of the book teaches BPEL, something it does very well. The examples in chapters two and three gradually grow in complexity and build on each other. When describing Oracle and Microsoft's tools, appropriate screenshots are provided. I recommend this book for anyone starting out with BPEL or just looking to learn it.

The book really did a good job about introducing the BPEL Spec..saves much of your time from Google. Beyond that, the examples using Oracle BPEL Engine are poorly written and too confusing. After the first 3 chapters, the book chapters stretches in different directions and I doubt the editors/authors did a final review together. The code examples are not working ! This means ..I regret to say 60% of book is not worth reading.

Why this language? That is, why another language? Just a few years ago, XML reached a fairly stable state. Then WSDL came along, to describe Web Services. But it turned out that WSDL is really best suited for describing a single Web Service, or a simple interaction between 2 such services. As the authors relate, business logic is far more complex. Especially for the main envisioned scenario of interactions between services scattered across a panoply of companies.

You might want an orchestration of services, built around a central co-ordinating service. Or in other cases, you might have a flow of business messages, without a central service. This is termed choreography. These are 2 extremes. You might have some combination of the two. And more complex cases can be imagined.

The book points out that WSDL basically ran out of steam. It lacks the expressive power to easily handle the above cases; if it can even do so. Hence, BPEL arose to describe such logic in a programmatic fashion. The authors then go on to flesh out BPEL as it currently exists. While some of the examples, written in XML, are fairly verbose, if you keep in mind the basic ideas, they should be understandable.

You might also note that the book only touches on the possible complexity and nuances of business logic. It's fair to predict that in a few years, BPEL will be heavily expanded.

This is a response from the Publisher, Packt, in reply to the two reviews below...

The code examples in the book have been written for the Oracle BPEL Process Manager version 2.x, which has been one of the few working BPEL engines at that time (2004, former Collaxa engine). In the mean time, Oracle BPEL Process Manager has been upgraded to version 10.1.2 and code examples required some minor modifications. New code examples have been available from the publisher's web site (www.packtpub.com). If Oracle BPEL Process manager is installed appropriately, code examples definitely work.

Please notice that the 2nd Edition of the book is about to be published in January 2006. The 2nd Edition has been improved, particularly with the introduction of SOA and BPEL, and coverage of advanced features of Oracle BPEL Process Manager and Microsoft BizTalk.

This answers the complaints in the last two customer reviews, thank you.

Packt Publishing

This book introduces bpel using oracle bpel engine beyond that this book fall short of introducing the bigger picture in terms of soa. the book also needs a revision. this book also suffers too much repetition and poor editing.

An excellent book for beginners and for those who want to get familiar with advanced BPEL features. First chapter is a little weak but chapters two and three are great. This book is also a must for everybody working with Oracle BPEL Process Manager (chapter four). The examples are great. Highly recommended.