Chapter 13 Advanced Web Services

Team Fly 

Page 319

Chapter 13
Advanced Web Services

Nobody Yet Knows What the final ratio between web-based computing and local computing will eventually be. Will it end up 10% local, or even 0% local—with all databases and computations residing on the Internet with your home and portable devices merely dumb terminals? Or will the speed, and especially security, advantages of local computing cause a backlash against the current trend toward distributed computing?

No matter how it turns out, it's clear now that data storage and processing are currently migrating from local machines to Internet servers. What we used to call personal computing is mutating into something more like extended computing, with software subscriptions potentially replacing ownership, remoting replacing self-contained applications, and servers located whoknows-where replacing your resident hard drive.

And we programmers have to deal with this new .NET world, learning new techniques. For example, debugging might require that we step through a series of procedures located on various hard drives around the world. And how do you preserve state in a ''stateless" environment?

Obviously new communication and security issues arise when you call a procedure across the world, and wait for the response. If you substitute the words Web for "across the world," and service for "procedure," you come up with Web service—the idea that a query-response messaging relationship can be set up between widely distributed computers, and that this relationship can be both efficient and secure.

That's the hope for Web Services, a novel technology built upon familiar components (fundamentally, computing is always about data that gets processed, and always will be, no matter what new communications protocols are invented, or what new names are used for it).

What Are Web Services?

First, how big is a Web service? Some say that Web services can be as large as a full business solution—a set of applications working together to handle a complete distributed enterprise.

Others say that Web services are small, individual procedures—single functions that accept some data, process it, and send back a result. We shall see. Currently the term Web service is used to describe both large and small processing—the essence being that a message is sent over the Internet to trigger the Web service.

Team Fly 


Visual Basic  .NET Power Tools
Visual Basic .NET Power Tools
ISBN: 0782142427
EAN: 2147483647
Year: 2003
Pages: 178

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