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RE: Some proposed definitions of "web service" based on the call toda y

From: Christopher B Ferris <chrisfer@us.ibm.com>
Date: Sat, 19 Apr 2003 20:59:02 -0400
To: "Newcomer, Eric" <Eric.Newcomer@iona.com>
Cc: www-ws-arch@w3.org
Message-ID: <OF00299B87.FD036826-ON85256D0E.0004D018-85256D0E.0005659D@us.ibm.com>
I agree that there's nothing in the WSDL or SOAP that necessarily says
what the agent has to be, but nonetheless, it is the agent that performs 
the 
service.

Cheers,

Christopher Ferris
Architect, Emerging e-business Industry Architecture
email: chrisfer@us.ibm.com
phone: +1 508 234 3624

"Newcomer, Eric" <Eric.Newcomer@iona.com> wrote on 04/19/2003 03:12:45 PM:

> I still have the problem with defining the agent as the service.  The 
service is mapped or 
> transformed onto the agent.  Saying that a Web service is an interface 
to an agent, a 
> representation of an agent, or a description of an agent are all ok with 
me, but I can't (for 
> example) see anything in SOAP, WSDL, etc. that defines what the agent is 
or has to be.
> -----Original Message-----
> From: Christopher B Ferris [mailto:chrisfer@us.ibm.com]
> Sent: Friday, April 18, 2003 8:00 AM
> To: www-ws-arch@w3.org
> Subject: Re: Some proposed definitions of "web service" based on the 
call toda y

> 
> I would prefer that we not include references to version numbers in the 
definition, as these will 
> change over time. I think that the acronyms should suffice. Secondly, I 
thinn that qualifying SOAP by 
> calling out the XML Infoset and processing model suggests that other 
aspects of SOAP are either 
> not used, or not allowed, or who knows what. I think that it is 
sufficient to say just SOAP. Finally, since 
> we have spent some time discussing the various types of ways in which 
people have been using the term, 
> I felt that it is probably worthwhile that we share some of these 
alternate uses with the readers of the 
> WSA and give them a little more background. 
> 
> How 'bout this: 
> 
------------------------------------------------------------------------- 
> The term "Web service" has been used to refer to a wide variety of 
things, 
> and it is clear that not all people share the same understanding and 
definition. 
> For some, it has meant simply the exchange of XML over the Web, 
typically using HTTP. 
> For others, it has meant simply the exchange of SOAP messages, typically 
using HTTP, 
> or some software component that has been described using WSDL. In a 
sense, all of these 
> things might be considered to be "Web services", and the Working Group 
does not 
> preclude the use of the term to describe these sorts of things. 
Nevertheless, for 
> the purposes of this document, we will define the term Web services as 
follows: 
> 
> [Definition: Web service - an executable software agent that is 
identified by 
> a URI and whose interface and binding(s) are described using WSDL. Other 
software agents 
> interact with a Web service in a manner prescribed by its WSDL 
description, using SOAP.] 
> 
> 
---------------------------------------------------------------------------------------------------------------------------------------------------
> 
> Now, this definition probably deserves some further explanation in order 
to say things like 
> "there's nothing 
> to preclude the use of other protocols (than SOAP) to interact with a 
Web service... for the 
> purposes of this document, we simply 
> aren't going to go there" and "while the definition requires the use of 
WSDL, it does not preclude
> the use of 
> other technologies or XML vocabularies for its description. however, for 
the purposes of this document, we 
> aren't going to go there..." 
> 
> Again, it might be nice to solve the equation for all possible solutions 
to WS = U + Xd + Xm (a 
> web service is identified 
> by a URI and described using XML and interacted with using XML messages) 
IMO this represents a daunting 
> task. We should be focused on defining an architecture that leverages 
the technologies being developed 
> in our sibling WGs in the Web Services Activity in its realization. 
> 
> Cheers, 
> 
> Christopher Ferris
> Architect, Emerging e-business Industry Architecture
> email: chrisfer@us.ibm.com
> phone: +1 508 234 3624 
> 
> www-ws-arch-request@w3.org wrote on 04/17/2003 05:36:27 PM:
> 
> > 
> > Whew, that was fun :-(  Although it got better when we stumbled on the
> > "instant straw poll in IRC" idea; we should do that more often.  I'd 
say
> > that in general, anyone who has the "floor" in the speaker queue may 
propose
> > one of those by typing the question into IRC; those not on IRC can ask 
to
> > have their vote recorded by someone who is.
> > 
> > Let me throw out some proposals that reflect the various opinions I 
heard
> > today; without my co-chair hat on, I could live with either of them:
> > 
> > 
===========================================================================
> > The term "web service" is used in a wide variety of ways by different
> > people, and we will not presume that the definition used here is 
consistent
> > with all of them.  Nevertheless, for the purposes of this document, we 
will
> > use the term to mean the following: A Web service is [an interface to 
?] an
> > executable software agent that is designed to be used by another 
software
> > agent.  A Web service is
> > identified by a URI, and MUST be [capable of being ?] formally defined 
in
> > WSDL 1.2.  A software agent interacts with an  Web service in the 
manner
> > prescribed by the formal definition, using the XML Infoset and 
processing
> > model defined by SOAP 1.2.
> > 
> > [Chris said some things about SOAP being general enough to describe 
any
> > reasonable "web service" interaction that I didn't capture very well 
...
> > maybe he can refresh my memory.]
> > 
> > 
==========================================================================
> > 
> > The term "web service" is used in a wide variety of ways by different
> > people, but there is a rough consensus along the following lines: A 
Web
> > service is an interface to an executable software agent that is 
designed to
> > be used by another software agent.  A Web service is identified by a 
URI,
> > and has a definition in a language sufficient to describe the 
interface to
> > developers of client agents. A software agent interacts with a Web 
service
> > in the manner that is consistent with the description, using standard
> > protocols. 
> > 
> > That definition of "web service" is not sufficiently precise or 
rigorous for
> > architectural purposes, however.  We will use a more restrictive term 
to
> > describe the scope of the architecture described here: "Extensible XML 
Web
> > Services", abbreviated XWS.   the purposes of this document, we will 
use the
> > term to mean the following: An XWS is an interface to an executable 
software
> > agent that is designed to be used by another software agent.  An XWS 
is
> > identified by a URI, and MUST be capable of being formally defined in 
WSDL
> > 1.2.  A software agent interacts with an  Web service in the manner
> > prescribed by the formal definition, using the XML Infoset and 
processing
> > model defined by SOAP 1.2."
> > 
> > ["XWS" is essentially a placeholder for some term ... I don't care 
what it
> > is, but it must specifically describe the "MUST" constraints specified 
by
> > the WSA.]
> > 
> > 
==========================================================================
> > Of course, improved definitions are solicited.
> > 
Received on Saturday, 19 April 2003 21:09:29 GMT

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