Perspectives on Web Services. Applying SOAP, WSDL, and UDDI to Real-World Projects.

Rating:
Summary: A must-have for successful webservice projects
Review: My primary reason for buying this book was the eye-catcher word "Real-World Projects" in the subtitle. I'm a professional developer/architect of enterprise size IT-projects and the fastest way for me to learn new things is by using examples. So in fact the "Development Perspective" chapter was the first chapter I've read and found it very useful if you are going to use WebSphere 5 in your project.
I was pleased to see that the next chapter "Operational Perspective" actually deals with questions regarding deployment and configuration. This is something most books are missing and many projects underestimate the importance of these aspects for a successful rollout.
Finally after reading two very useful chapters (written in an enjoyable style), I've decided to give the other chapters also a try and I wasn't disappointed. This book covers all important aspects for a successful webservice project and I strongly recomment it if you are going to start such a project.
During my time as a technical lead at Hewlett-Packard, I've got the opportunity to participate a pretty expensive software architect workshop. I was pleased to see lots of "Does and Dont's" I've learned in this workshop in the "Architecture Perspective" chapter of this book.
I finally ended up in reading all chapters of the book. I haven't read all pages of this book because of my previous knowledge and because of the excellent offered shortcuts within this book. But the time I've spent reading the rest was a rewarding investment. Whatever role you are going to play in a webservice project: you will find something useful within this book.
And finally don't forget: even Grady Booch thinks this book is a must-have. He wrote a nice forword for the book.

Rating:
Summary: A must-have for successful webservice projects
Review: My primary reason for buying this book was the eye-catcher word "Real-World Projects" in the subtitle. I'm a professional developer/architect of enterprise size IT-projects and the fastest way for me to learn new things is by using examples. So in fact the "Development Perspective" chapter was the first chapter I've read and found it very useful if you are going to use WebSphere 5 in your project.
I was pleased to see that the next chapter "Operational Perspective" actually deals with questions regarding deployment and configuration. This is something most books are missing and many projects underestimate the importance of these aspects for a successful rollout.
Finally after reading two very useful chapters (written in an enjoyable style), I've decided to give the other chapters also a try and I wasn't disappointed. This book covers all important aspects for a successful webservice project and I strongly recomment it if you are going to start such a project.
During my time as a technical lead at Hewlett-Packard, I've got the opportunity to participate a pretty expensive software architect workshop. I was pleased to see lots of "Does and Dont's" I've learned in this workshop in the "Architecture Perspective" chapter of this book.
I finally ended up in reading all chapters of the book. I haven't read all pages of this book because of my previous knowledge and because of the excellent offered shortcuts within this book. But the time I've spent reading the rest was a rewarding investment. Whatever role you are going to play in a webservice project: you will find something useful within this book.
And finally don't forget: even Grady Booch thinks this book is a must-have. He wrote a nice forword for the book.

Rating:
Summary: Textbook Review
Review: Review:

"Perspectives on Web services: Applying SOAP, WSDL, and UDDI to Real-World Projects" Zimmermann O., Tomlinson M., Peuser S.; Springer-Verlag New York, Inc., Secaucus, NJ, 2003.

This voluminous text is essentially about the classic man-machine relationship model.

The reviewer became interested in this topic and monitored the slowly evolving field until 1962 when he published a paper entitled "Shaping and Controlling Human Behaviour in Man-Machine Systems"; Proceedings of The Institution of Mechanical Engineers, Industrial Administration and Engineering Production Group, Vol. 177, Number 34, pp 935-950; 1963 (1 Birdcage Walk, Westminister, SW 1).

He presented the Performance System Spectrum with Man at one end and the Machine at the other. In between these two extremes he defined and illustrated a multitude of combinations including Simple Man-Machine, Complex Man-Machine, Men-Machine, Man-Machine-Man, Man-Machine-Men, and Men-Machine-Men.


By 1963, time-sharing and remote operator terminals had evolved and the computer systems were mainframe...the personal computer and the Internet, if they were envisioned at all, would have been considered purely science-fiction. In relation to the Men-Machine-Men system, he wrote: "...the total system has become so complex, with so many inputs from and outputs to human(s), that design engineers tend to move towards a fully automated system..." In the more than four decades which followed, the flood of computerized systems (and computer acronyms) increased as anyone reading this can testify. And that brings us to today...and Web Services.

We shall see that Web Services satisfies the definition and is a Men-Machine-Men system. To quickly understand what Web Services is the average reader shouldn't start with the text under review but with an excellent article, "The Web Within the Web," Enrique Castro-Leon, IEEE Spectrum, February 2004, pp 42-46. Examining this paper first and then delving leisurely into "Perspectives on Web Services: Applying SOAP, WSDL, and UDDI to Real-World Projects" will have a higher payoff even for those readers who are experienced software engineers, developers, analysts, and systems architects.

Castro-Leon presents a concise thumbnail view of this emerging concept. He argues that "...dusty, musty databases filled with useful data that would be far more useful if linked with other, equally dusty databases; enormous databases that are locked up inside ancient mainframes and quaintly archaic minicomputers; lonely databases residing on specialized file servers throughout an enterprise (pronounced business); even modern databases on Web servers...(are) stuck in long-obsolete proprietary formats or accessible only through hypermodern scripting languages..." Further, "... Web services are a way programmers can make their databases available across the Web , let other programmers access them, and tie these disparate databases together into services that are novel, perhaps even wonderful..." This, of course, is the basic reasoning for improving the Machine part of the Men-Machine-Men performance system.

"...Web browsers have liberated us from the tyranny of specific hardware and the near monopoly of the Windows operating system...(because of)...the Hypertext Transfer Protocol, which provides a standard for the way Web pages are downloaded from a Web site to a computer, and the generic nature of Web pages themselves..." The Hypertext Markup Language (HTML) ",...was designed to encode things that will be viewed by people, rather than processed by another machine. HTML mixes formatting commands...with data because it was designed as a display language..." Castro-Leon continues: "...if Web services are to build powerful networks of collaborating databases and services, the first step is replacing HTML with something more compatible with the world of databases, something that can be understood by another computer...such a new language has been developed...a subset of HTML, called XML, for Extensible Markup Language..."

This movement to improve the Machine subsystem did not end with the invention of XML. There had to be some mechanism to move XML data rather than HTML across the Internet. This was SOAP --- Simple Object Access Protocol --- a generic wrapper which is an envelope recognized and accepted by Web browsers and servers. Together, XML and SOAP give Web Services interoperability.

However, another specification was needed called UDDI ---Universal Discovery, Description and Integration --- which, as Castro-Leon states, "...lets Web Services look for databases (by Machine) in the same way that Google lets humans look for Webpages..." But the process didn't end with the development of UDDI. There had to be a standard which allowed the Machine to determine what is at a site once it has been identified. This standard was WSDL --- Web Services Description Language. All of these protocols took years to develop....and the improvements continue to this day.

Having presented an overview of Web Services from Castro-Leon, it is now time to review the 648 page text entitled, "Perspectives on Web Services: Applying SOAP, WSDL, and UDDI to Real-World Projects" This is in essence a "how-to" or a "cook" book, using an old world term, which goes into exquisite detail about how these software elements work inside the Machine and how to utilize them effectively and profitably. One might describe it as a "Web Services for Dummies" type of text but written at a much higher intellectual and professional level. The occasional humor is within acceptable limits and not extreme.

In the Men-Machine-Men model, the Machine is represented by all of the computer systems in the Internet world-wide and includes SOAP, WSDL, and UDDI as software and all of the hardware world-wide. The Men at one side are all the humans dealing with the Internet as users while the Men on the other side of the Machine are all the software people feeding the Machine world-wide with data and graphics which are then manipulated inside the Machine by SOAP, WSDL, and UDDI. You can visualize that the users might have a population of millions and possibly billions of individuals and the software people might represent a population of millions of individuals. That is why this volume on Web Services is an important reference today as the system is being implemented --- but there is a cautionary poem by the systems guy Kenneth Boulding regarding this Machine:

A system is a big black box
Of which we can't unlock the locks,
And all we can find out about
Is what goes in and what comes out.

Perceiving input-output pairs
Related by parameters
Permits us, sometimes, to relate
An input, output, and a state.

If this relation's good and stable,
Then to predict we may be able.
But if this fails us - heaven forbid
We'll be compelled to force the lid!

Having forced the lid --- you are now inside the Machine! The book is structured using the "goto" branching command. The authors encourage the reader to study a section and then decide to continue on or "goto" a different section. In fact, they suggest not reading from cover-to-cover at all but selecting those parts directly related to the reader's job role.

The text is neatly divided into Perspectives chapters which follow a typical project sequence: Business, Training, Architecture, Development, Operational, Engagement, and Future. The authors state that they and their anticipated readers are "technical people" and their approach in writing was shaped in that way

Chapter 1 is The Business Perspective. In 30 pages they discusses definitions, EAI (Enterprise Application Integration), B2C (Business-to- Consumer), B2B (Business-to-Business), A2A (Application-to-Application), H2A (Human-to-Application), and potential inhibitors to decision-making. The Case Study of a fictitious insurance company is introduced which will be threaded throughout the book. Some of the flowchart models are clearer than others.

Chapter 2 is The Training Perspective. A better term for this perspective would be the "technical information" found in a manual used by individuals for self-instruction to learn about the software. 123 pages are devoted to a tutorial of concepts and technologies but the reader is not expected at this point to be able to apply them.

There is an overview of WebServices concepts and detailed information on the XML markup language including namespaces and schema. Attention to given to SOAP message formats and encoding. This is followed by WSDL, the interface description, containment structure of WSDL documents, and binding-related document elements. There are descriptions of UDDI's registry structure, identifier bag, category bag, binding template, tModel structure, linking to a UDDI registry, an API (Application Programming Interface) overview, and brief mention of WSIL (Web Service Inspection Language). There many well-designed coding sheet examples which would make sense to experienced programmers but probably not to novices.

About 86 pages are assigned to Chapter 3: The Architecture Perspective. The authors provide an introduction to Web Services architecture oulining paradigm changes, J2EE (Java 2 Enterprise Edition) and defining Web Services as the software part of the Machine. WSA (Web Services Architecture) is explained with the use of stacks and a disclaimer is provided since not all of the terms are universally accepted. WSA building blocks and component walkthrough is covered. Explanations are given for WS principles, Generic vs. Generated API, design patterns, business patterns, architectural patterns (microflow, intermediary, and interceptor/pipeline) and process choreography including public-to-private process mapping. Architectural decisions are outlined along with service matchmaking. In addition, NFRs (Non-Functional Requirements), gaps and countermeasures and SOAP Section 5 encoding are discussed. Finally, XML-based, WS, and application layer security are explained. There is a useful FAQ (Frequently Asked Questions) section ending the chapter.

Chapter 4 is The Development Perspective. Consisting of 192 pages, this chapter has a considerable amount of meat and consequently may cause indigestion for the vegetarians among us. The authors state that a reader should have a "...solid reading comprehension of J2SE and J2EE APIs..." It is written at a fairly deep level of detail related to reader motivation and categorizes this interest as: casual, steady or junkie. There is an emphasis on "goto" branching. Most of the coding examples are also found on Springer websites.

The introduction to the development of WS in Java presents the WebSphere Studio Workbench and Eclipse.org. WebSphere SDK (WSDK), the Emerging Technologies Toolkit (ETTK), and Apache SOAP 2.3 are described with some caveats regarding known flaws. This is followed by JAX-RPC and Apache Axis, definitions, an introduction to WS for J2EE and JSR 109 and the WSDK Toolkit.

At this point, starting on page 259, the first example or case in The Case Study is considered --- all the prior pages having been dedicated to technical information to bring the reader up to speed. The authors refer to the example as a "sample" and it is, of course, a simulation where the case problem is run on the WS model being described so the reader can learn how to do it later in real-life. More precisely it is a training simulation testing (with some debugging) of the solution provided by the authors....the author's terminology will be used here.

The case scenario involves several fictitious insurance companies. In terms of the Performance System Spectrum, this scenario deals with the Men-Machine-Men model with Men being Internal Users and the Machine processing risk and fraud management matters. Business logic requirements are considered and "The Great Debate" over Apache Soap or JAX-RPC occurs, followed by configuring and building the sample. To build RPC/Encoded Services for Java the bottom-up and top-down approaches are reviewed. There is a discussion of building EJB (Enterprise Java Beans) WS with Apache SOAP, and using the WS Wizard. The process of exploring and modifying generated files is described. Building EJB WS with JAX-RPC and JSR 109 follows, In addition, exploring generated server side files, updating the project build paths, modifying generated files, and testing the deployed service are briefly delineated.

The reader is encouraged to build RPC/encoded services from WSDL first creating WS from WSDL using Apache SOAP and then testing the WS client. There is also the process of creating WS from WSDL using JAX-RPC/JSR 109 and updating the WSDL document and installing the SOAP Router, and finally testing the WS. A section is devoted to programmatic access to WSDL, using the WSDL4J toolkit, testing the JWSDL application and creating JWSDL clients with JAX-RPC and JSR 109. The reader learns to use WS-Inspection to build service indices from Java and also with Apache Soap and to configure WSIL4J.. There many excellent figures illustrating this part of the simulation. At this point, the text moves ahead to the use of UDDI.

There are discussions of UDDI access from Java and browsers, using UDDI with Apache SOAP and also with JAX-RPC and JSR 109, using other Web Services bindings, creating a document/literal Service from WSDL and a document/literal Service Client. A secton is dedicated to orchestrating Web Services and use of the Process Editor. The reader learns about using attachments with SOAP, using SOAP headers and finally exporting the completed sample. While space is assigned to finding more information, there isn't any for FAQ which could have been useful at this stage. Some System Administrators have argued that constructing the application in this chapter was the easy part. The next stage deals with implementing it in a production environment and might be viewed as more difficult.

Chapter 5 presents The Operational Perspective which the authors have truncated to 79 pages and rely on the experience of the reader to fill in some technical gaps. There are many specific references to coding samples in .zip format on Springer websites. This chapter deals with the system architecture hosting the software and we are now deep inside the Machine in the Men-Machine-Men system --- and continually aware of Boulding's admonition: "....If this relation's good and stable, Then to predict we may be able. But if this fails us - heaven forbid, We'll be compelled to force the lid!..."

There is a discussion of topology, standalone topology, additional components,and clustered and managed topology. Reference is made to the Access Management Subsystem, load balancing and high availability support. At this point, the Case Study simulation of a fictitious insurance company continues and for the remaining pages is interspersed with tutorial information .

There are explanations of Deploying Web Services, the WebSphere Application Server, deployment and configuring the application server. There is information on JDBC configuration, JAAS authentication and Cloudscape, and restarting and testing the installation. Next comes Deploying Services, wsadmin, ANT; working on the private UDDI Registry, including configuring and adding WSDL documents to the UDDI Registry. Descriptions are provided for testing, clustering, and node agents; working with the IBM HTTP Server, starting, testing clusters, and finally cold standby.

Attention is given to Securing the WS Implementation: security threats, countermeasures, WS-Security, and future WS-Security extensions, Securing WS with HTTPS and SSL --- as the simulation continues. The chapter closes with the WS Gateway and how to configure it, deploying a WS to the Gateway, updating and client testing. Frequent mention is made of specific websites to support the simulation so the reader is not completely alone with just the text.

Chapter 6 is The Engagement Perspective of 27 pages and a typical reader would sense that the end is in sight!! This chapter reviews many technical points emphasized in the Case Study simulation and adds the following: Planning a WS Development Project, Outlining Requirements and High Level Design, Planning and Staffing, Running the Project, including testing and going live, Success Factors, Elements of Risk,lessons learned and design advice. There is a final look at the Case Study simulation.

The Future Perspective appears in Chapter 7. The authors briefly identify SOAP Version 1.2, WSDL Version 1.2, UDDI Version 3.0, and grid computing for the immediate future. The Semantic Web including RDF and OWL are mentioned and they provide mid- and long-term visions.

The chapter concludes with "Now enjoy the first project in which you apply and exploit this hot technology!"

There are rather complete coding steps, flowcharts, and screen displays in the boilerplate content of the Appendix including: Building the Case Study Policy Systems, Java to XML Mapping, and C# --- and 87 References for those who desire additional background.

As Castro-Leon in summarizing his IEEE Spectrum article said: "...the semantic Web's benefits won't be seen for some time; Web Services are here today...it will connect almost every island of data, software, and device on the planet..." The reviewer believes that this volume which introduces Web Services is a valuable asset in the drive to improve the Men-Machine-Men system which we call the Internet.

Leonard C. Silvern
Systems Engineering Laboratories
Clarkdale, AZ