Re: Fw: Naming a Web service resource

+1

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

www-ws-arch-request@w3.org wrote on 07/07/2003 03:24:19 PM:

> 
> At 12:55 PM 2003-07-07, Francis McCabe wrote:
> 
> >Anne:
> >   This topic has been discussed a little in WSA.
> 
> See
> http://www.w3.org/2002/ws/arch/3/05/2003-05-15-ws-arch.htm
> 
> >I can give you my personal view on this; it is not one that is 
necessarily 
> >shared ;-)
> >
> >1. The targetResource concept is, IMO, a brain-dead idea. The principal 

> >reasons being:
> >
> >a. The resource that a service manipulates may not be identifiable in 
any 
> >obvious way
> >b. A service may be inherently `about' a dynamic set of resources, and 
> >therefore it becomes onerous to identify them in the service 
description
> >c. The action-oriented level of description implicit in a service 
> >description is not the appropriate level to discuss resources.
> 
> I respectfully disagree with Frank's view.
> 
> "Resources" are abstractions anyway, not necessarily a physical 
> resource.  I for one am not comfortable with the notion that a web 
service 
> is not associated with a resource ( a view that has been discussed a 
> little).  That would deviate too much from the TAG's web architecture, 
> where a Resource is a fundamental concept.
> 
> The dynamic set of resources can be viewed as just another abstract 
> resource, not necessarily a superset (or having sub-resources).
> The targetResource for a choreography (transparently-composed composite 
> service) is an abstraction (with perhaps some interesting relationships 
to 
> other more or less abstract resources).
> 
> What is the resource for the URI http://www.w3.org?  for 
> http://www.w3.org/TR?  They are abstractions.
> 
> I can see us having a discussion similar to
> http://www.w3.org/2001/tag/ilist#namespaceDocument-8
> 
> That is, given only a targetResource URI, I will try to dereference it 
> (like a namespace URI) to see if I can find out something more about 
> it.  TAG is leaning toward RDDL as "an" acceptable namespace document 
> (there may be others).  What is an acceptable "targetResource 
> document"?  RDDL probably is also a good candidate.
> 
> 
> >However, who am I to say what WSD gets up to?
> >
> >2. Web services *do* have identity; and hence can be expected to have a 

> >URI. However, that does not imply that a Web service has a meaningful 
> >representation:
> >a. For a simple, atomic, service, one might assert that the binding 
> >address of a service is a good candidate for the service identity. 
> >However, that seems too low-level and too transport specific.
> >b. The service description of a service is a potential candidate for 
the 
> >service representation, but different descriptions of the same service 
are 
> >likely.
> >c. A composite service, in the sense of a transparently composed 
service, 
> >is different to its component services and yet essentially unknown to 
the 
> >component parts. A simple example: a service composing a weather 
service 
> >with a language translation service to give weather reports in foreign 
> >languages. Ideally, one should be able to build such a service with no 
> >programming: simply by hooking together the weather service and the 
> >translation service. The service description amounts to a particular 
> >choreography over existing services. The foreign language weather 
service 
> >is still a service, and still had an identity (it may be composed 
further, 
> >by linking with an import-export service to predictively order 
umbrellas say).
> >
> >So, the upshot seems to be that a Web service has an identity, but that 

> >that identity is closer in spirit to the namespace uri than a web page 
uri.
> 
> The namespace URI does not hack it for me.  I liked the idea of the 
> targetResource.
> 
> For example, the public UDDI business Registry (UBR) could have a single 

> targetResource URI whether you access the "resource" through IBM, MS, 
SAP, 
> or NTT.  And it would differ from private UDDI registries, which would 
have 
> a different targetResource URI.  Both UBR and private UDDI registries 
would 
> use the same UDDI namespace and WSDL (interface, not implementation) 
> description, i.e., 
> 
http://www-3.ibm.com/services/uddi/uddiget?tModelKey=UUID:AC104DCC-D623-452F-88A7-F8ACD94D9B2B
> 
> I don't want to be forced to use OWL just to distinguish between UBR and 
a 
> private UDDI registry.
> 
> 
> 
> >>>>Frank
> >>>>
> >>>>On Friday, July 4, 2003, at 07:10  AM, Anne Thomas Manes wrote:
> <snip/>
> 
> Paul 
> 
>

Received on Monday, 7 July 2003 16:26:33 UTC