Re: Web service definition

On Monday, August 12, 2002, at 07:22  AM, Christopher B Ferris wrote:

>       Definition: A Web service is a software application 
> identified by a
>       URI, whose interfaces and bindings are defined and described
>       using XML artifacts. This definition can be discovered by 
> other software
>       applications which may then interact with the Web service, 
> through
>       the exchange of XML based messages via internet protocols, in a
>       manner prescribed by its definition.

In my last email I wondered if we ought to say *something* about the
nature of the interface to a Web Service. The original stipulated
that interaction (actually "direct interaction") took place "using XML
based messages via internet-based protocols". However the latest 
iterations
have specified only how service discovery takes places, If we plug
the interaction model back in, we get:

"A Web service is a software application identified by a URI, whose 
interfaces and
bindings are defined using XML artifacts. Its definition can be 
discovered by other
software applications by the exchange of XML-based messages 
transferred by internet
protocols. These applications may then interact with the Web 
service in a manner
prescribed by its definition, using XML-based messages transferred 
by internet
protocols."

This is wordy, and repetitive, but quite unambiguous. One can 
factor out the
common technology, thus:

"A Web service is a software application identified by a URI, whose 
interfaces and
bindings are defined using XML artifacts. Its definition can be 
discovered by other
software applications, which may then interact with the Web service 
in a manner
prescribed by its definition. All interactions, including service 
discovery, use
XML-based messages transferred by internet protocols."

This feels right. It avoid the "generic" trap, and makes a strong 
statement
about the relationship to web technologies. (Indeed the last 
sentence provides
a convenient hook to hang other conformance assertions.)

Geoff Arnold
Sun Microsystems Laboratories

Received on Monday, 12 August 2002 08:17:45 UTC