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>Although no single, authoritative definition exists for basic terms like "service" and "Web Service", here are some fundamental characteristics that some folks believe that anything described as a "Web Service" should possess:
>(1) Can interact with it through the WWW;
Yes, this seems to be one of the goals. I saw in many article
praising web services that they can pass thru standard proxies+firewalls
because they are based on HTTP (like SOAP is)
>(2) Platform- and programming language-agnostic;
>(3) Interface & invocation requirements are well-described;
I can some up with some well-described (in my opinion) protocol but
that doesn't mean that it is going to be a web service. Microsoft can
some up tomorrow with some new protocol called "M-SUPER-C" that will
meet the above constrains but that does not mean that this is a web service.
So point 3 is only valid toghether with point 9.
>(4) XML-encoded interaction mechanism;
This is true according to W3C, but is this valid in the general
sense ? Who says that a web service must be text-based and not binary ?
>(5) Payload most often is XML;
"Most often" cannot be part of a definition.
>(6) Loose coupling between invoker and Web Service;
You mean it must not have a state (like HTTP) ?
>(7) Performs a specific, well-defined function;
!!!? I am really tired of such high level super-generic definitions.
What entity in the computing world isn't supposed to be specific and
>(8) May invoke other Web Services;
Remote invocation is not big deal. How about a self-describing
feature (WSDL) ? Can a "service" be called a "web service" if it doesn't
have this feature ? How about automatic discovery (UDDI) ? Is such a
feature an integral part of a web service or is it just optional ?
Of course WSDL and UDDI are just implementations. You can replace
those with ASDF and YRRT or whatever.
>(10) Has the ability to perform its functionality synchronously or asynchronously, as needed; (i.e. does not use synchronous interaction when asynchronous is best, and vice-versa);
Can you please explain what you mean by this ?
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