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RE: Web Service Definition [Was "Some Thoughts ..."]

From: Vinoski, Stephen <steve.vinoski@iona.com>
Date: Fri, 1 Mar 2002 20:07:48 -0500
Message-ID: <4F4A31A61D72604FAF84C29C8EA284810939A2@amereast-ems1.IONAGLOBAL.COM>
To: "James M Snell" <jasnell@us.ibm.com>
Cc: <www-ws-arch@w3.org>
OK, James, if we take your inputs along with those of Heather, Mark, and
others, and apply them to my original strawman definition including
Mark's amendment, we get:

"A web service is a software application or component identified by a
URI that, through an application programming interface capable of being
described, supports direct interactions with other software applications
or components via internet-based protocols, where said interactions do
not require direct human involvement."

Are we there? :-)

--steve


> -----Original Message-----
> From: James M Snell [mailto:jasnell@us.ibm.com]
> Sent: Friday, March 01, 2002 6:21 PM
> To: Vinoski, Stephen
> Cc: www-ws-arch@w3.org
> Subject: RE: Web Service Definition [Was "Some Thoughts ..."]
> 
> 
> Stephen,
> 
> We actually are on the same page here.  We both seem to agree 
> that yes, 
> Web services can be described and discovered, but we disagree 
> whether or 
> not those properties need to be called out explicitly in the 
> definition. 
> You seem to be saying no, I'm saying yes they do.  The reason 
> is the same 
> as why we explicitly define Web resources as having unique URI 
> identifiers.  Of course Web resources have identifiers, 
> they're objects 
> and all objects have identifiers -- of what use is it to 
> explicitly call 
> out that point?  The answer is that by stating the fact, we lay the 
> groundwork for standardizing how those identifiers are created, 
> represented, communicated, etc.  We're basically stating that Web 
> resources need to have a standardized method of 
> identification.  For Web 
> Services, explicitly calling out description and discovery as 
> properties 
> of a Web service indicate that there needs to be standardized 
> mechanisms 
> for description and discovery -- regardless of whether or not 
> every Web 
> service actually implements those standards.  Because a Web 
> Service can be 
> described and discovered, the overall Web Services 
> Architecture needs to 
> take into account standardized mechanisms for description and 
> discovery. 
> I'm not saying we have to create such standards here, just 
> acknowledge 
> their existence and role.  Make sense?
> 
> - James M Snell/Fresno/IBM
>     Web services architecture and strategy
>     Internet Emerging Technologies, IBM
>     544.9035 TIE line
>     559.587.1233 Office
>     919.486.0077 Voice Mail
>     jasnell@us.ibm.com
>  Programming Web Services With SOAP, O'reilly & Associates, ISBN 
> 0596000952 
> 
> ==
> Have I not commanded you?  Be strong and courageous.  Do not 
> be terrified, 
> 
> do not be discouraged, for the Lord your God will be with you 
> wherever you 
> go.  
> - Joshua 1:9
> 
> To:     James M Snell/Fresno/IBM@IBMUS
> cc: 
> Subject:        RE: Web Service Definition [Was "Some Thoughts ..."]
> 
> 
> 
> Given that you won't be able to prove it, let's look at it in a
> practical manner. Everything in the universe is both describable and
> discoverable. Therefore, speaking about D&D generally does not add any
> clarity to the definition. On the other hand, if you're speaking
> specifically about discovery services like UDDI and 
> description services
> like WSDL, then that too is wrong, as I know of several web services
> already in production that use neither WSDL nor anything like UDDI.
> 
> --steve
> 
> > -----Original Message-----
> > From: James M Snell [mailto:jasnell@us.ibm.com]
> > Sent: Friday, March 01, 2002 3:57 PM
> > To: Vinoski, Stephen
> > Subject: RE: Web Service Definition [Was "Some Thoughts ..."]
> >
> >
> > 100% of all Web resources, including Web Services CAN be
> > described and
> > discovered.  The differentiating factor is HOW.  Every Web
> > service CAN be
> > discovered regardless of whether or not the Web service explicitly
> > supports a specific discovery mechanism.  Every Web service CAN be
> > decribed regardless of whether or not the Web service
> > explicity supports a
> > specific description mechanism.  You are right in that 
> decription and
> > discovery alone do not distinguish Web services from other
> > types of web
> > resources, but that does not mean that the properties of
> > discoverability
> > and description are not part of the formal definition of a
> > Web service.
> >
> > - James M Snell/Fresno/IBM
> >     Web services architecture and strategy
> >     Internet Emerging Technologies, IBM
> >     544.9035 TIE line
> >     559.587.1233 Office
> >     919.486.0077 Voice Mail
> >     jasnell@us.ibm.com
> >  Programming Web Services With SOAP, O'reilly & Associates, ISBN
> > 0596000952
> >
> > ==
> > Have I not commanded you?  Be strong and courageous.  Do not
> > be terrified,
> >
> > do not be discouraged, for the Lord your God will be with you
> > wherever you
> > go.
> > - Joshua 1:9
> >
> > To:     James M Snell/Fresno/IBM@IBMUS, "Joseph Hui"
> > <jhui@digisle.net>
> > cc:     <www-ws-arch@w3.org>
> > Subject:        RE: Web Service Definition [Was "Some Thoughts ..."]
> >
> >
> >
> > > -----Original Message-----
> > > From: James M Snell [mailto:jasnell@us.ibm.com]
> > > Sent: Friday, March 01, 2002 1:21 PM
> > > To: Joseph Hui
> > > Cc: www-ws-arch@w3.org
> > > Subject: RE: Web Service Definition [Was "Some Thoughts ..."]
> > >
> > >
> > > A Web Service must be defined as having the properties that
> > it can be
> > > decribed and discovered.  Both the Web service and it's
> > > description must
> > > be discoverable.
> >
> > No, and no. This thread of email already contain multiple 
> explanations
> > of why.
> >
> > > Definition ==> A Web service can be described and discovered.
> >
> > As I've already explained using real-world examples, neither
> > of these is
> > necessarily true (other than the discovery via URI that Mark
> > mentioned).
> >
> > Neither discovery (as in UDDI-like services) nor description
> > distinguish
> > Web Services from prior art, nor are they found in 100% of
> > existing Web
> > Services systems. They are therefore not needed to define Web
> > Services.
> >
> > --steve
> >
> > >
> > > - James M Snell/Fresno/IBM
> > >     Web services architecture and strategy
> > >     Internet Emerging Technologies, IBM
> > >     544.9035 TIE line
> > >     559.587.1233 Office
> > >     919.486.0077 Voice Mail
> > >     jasnell@us.ibm.com
> > >  Programming Web Services With SOAP, O'reilly & Associates, ISBN
> > > 0596000952
> > >
> > > ==
> > > Have I not commanded you?  Be strong and courageous.  Do not
> > > be terrified,
> > >
> > > do not be discouraged, for the Lord your God will be with you
> > > wherever you
> > > go.
> > > - Joshua 1:9
> > >
> > > Sent by:        www-ws-arch-request@w3.org
> > > To:     <www-ws-arch@w3.org>
> > > cc:
> > > Subject:        RE: Web Service Definition [Was "Some 
> Thoughts ..."]
> > >
> > >
> > >
> > > By now IMHO we the WG have made the progress that D&D ought to be
> > > in the def.  (Have we not?  I don't want to be presumptuous here.)
> > > So the issue to be settled is whether D&D is already accounted for
> > > in URI.
> > >
> > > In my view URI is for addressability.  A globally unique ID offers
> > > no intrinsic value to a resource's discovery.  E.g. there's no way
> > > johny, seeking to buy books, can discover a book seller by
> > > inferring from a URI like http://www.amazon.com.
> > > Mark's made some good points; yet I find the
> > > "D&D-accounted-for-in-URI"
> > > argument too tenuous.  Withi the web context, D&D is an integral
> > > (as Sandeep put it) part of WS.  It's not a property that can be
> > > assumed by default, thus calling it out is warranted.
> > >
> > > Cheers,
> > >
> > > Joe Hui
> > > Exodus, a Cable & Wireless service
> > > =========================================
> > >
> > > > -----Original Message-----
> > > > From: Mark Baker [mailto:distobj@acm.org]
> > > > Sent: Friday, March 01, 2002 6:53 AM
> > > > To: Sandeep Kumar
> > > > Cc: Vinoski Stephen; Joseph Hui; www-ws-arch@w3.org
> > > > Subject: Re: Web Service Definition [Was "Some Thoughts ..."]
> > > >
> > > >
> > > > Sandeep,
> > > >
> > > > > If D&D are not an integral part of a Web Service defintion,
> > > >
> > > > I was claiming that discoverability *is* an integral part of the
> > > > definition.  It's just already accounted for by defining
> > that a Web
> > > > service be URI identifiable.
> > > >
> > > > I know this is a bit different than some Web service work
> > > people have
> > > > already done, but this is (IMO) one of those times where our
> > > > mandate to
> > > > be integrated with Web architecture effects our work.
> > > >
> > > > > pl help me define
> > > > > how would you define a Web (or a Network) of Web Services,
> > > > the participants.
> > > > >
> > > > > At a high-level, they must at least have the same
> > > > characteristics. If not,
> > > > > it would be much harder to reason about them
> > > semantically, deal with
> > > > > managing & monitoring them.
> > > >
> > > > Sorry, I'm unclear what you're asking.
> > > >
> > > > MB
> > > > --
> > > > Mark Baker, Chief Science Officer, Planetfred, Inc.
> > > > Ottawa, Ontario, CANADA.      mbaker@planetfred.com
> > > > http://www.markbaker.ca   http://www.planetfred.com
> > > >
> > >
> > >
> > >
> > >
> >
> >
> > 
> 
> 
> 
Received on Friday, 1 March 2002 20:08:59 GMT

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