RE: attributes & WSDL (was: Re: attributes in CORBA IDL)

Krishna,

The technology or programming model that is used to implement a web
service is not of concern here. The discussion was about the web
services architectural model.

--
Savas Parastatidis
http://savas.parastatidis.name

> -----Original Message-----
> From: Krishna Sankar [mailto:ksankar@cisco.com]
> Sent: 18 July 2003 18:17
> To: 'Steve Graham'; 'Savas Parastatidis'
> Cc: public-ws-desc-state@w3.org; public-ws-desc-state-request@w3.org
> Subject: RE: attributes & WSDL (was: Re: attributes in CORBA IDL)
> 
> Methinks ;-) :
> 
> 	Objects and services are, in some sense, orthogonal.
> 
> 	Let us not confuse interfaces with implementations. Interfaces
> cross boundaries while implementations are always local. SOA, in a
way,
> is a mechanism to string the objects.
> 
> 	The WS stuff, in some sense, are interfaces to define, describe,
> distribute, discover and execute services. The services themselves
would
> be implemented in OO systems, COBOL or any other way the service
> provider chooses.
> 
> 	Double-clicking one more level, we have the object system and
> the interfaces. We also have the wire format - which is what many of
the
> WS specifications are trying to standardize. Remember the wire format
> not only includes the exchange of information and context (SOAP, SAML)
> but also the capability to express one's infrastructure (using
> WS-Policy, WS-federation et al). We also have the option to build
higher
> level abstractions by chaining services, using choreography,
> transactions and other similar mechanisms.
> 
> 	objects -> fronted by -> services -> chained by ->
> choreography/transactions
> 
> 	services -> use wire format (XML/SOAP/SAML) -> to exchange
> information and express capabilities, policies
> 
> 	services -> expressed by -> interfaces (WSDL)
> 
> -k.
> 
> 
> > -----Original Message-----
> > From: public-ws-desc-state-request@w3.org
> > [mailto:public-ws-desc-state-request@w3.org] On Behalf Of Steve
Graham
> > Sent: Thursday, July 17, 2003 9:25 AM
> > To: Savas Parastatidis
> > Cc: public-ws-desc-state@w3.org; public-ws-desc-state-request@w3.org
> > Subject: RE: attributes & WSDL (was: Re: attributes in CORBA IDL)
> >
> >
> >
> >
> >
> >
> >
> > I do not concur that Objects imply tight coupling.  They are
> > orthogonal
> > concepts.  I have built systems using Object TEchnology that are
very
> > loosely coupled.
> >
> > CORBA and DCOM did not fail.  They had certain successes, but
> > they are not
> > mainstream.  COBOL, for example, is not currently top of
> > mind, but I would
> > not say that COBOL failed.
> >
> > sgg
> >
> > ++++++++
> > Steve Graham
> > sggraham@us.ibm.com
> > (919)254-0615 (T/L 444)
> > STSM, On Demand Architecture
> > ++++++++
> >
> >
> >
> >
> >
> >
> >                       "Savas Parastatidis"
> >
> >
> >                       <Savas.Parastatidis@newca        To:
> >    Steve Graham/Raleigh/IBM@IBMUS
> >
> >                       stle.ac.uk>                      cc:
> >    <public-ws-desc-state@w3.org>
> >
> >                       Sent by:
> > Subject:  RE: attributes & WSDL (was: Re: attributes in CORBA
> > IDL)
> >                       public-ws-desc-state-requ
> >
> >
> >                       est@w3.org
> >
> >
> >
> >
> >
> >
> >
> >
> >                       07/17/2003 12:19 PM
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > >
> > > >I don't think object-based architectures are appropriate for a
> > loosely
> > > coupled,
> > > >inter-organisation environment.
> > >
> > > Why?
> >
> >
> > Objects imply a tightly coupled system. It's ok to build distributed
> > applications using objects when you own the infrastructure, when you
> > remain within the boundaries of your organisation. You have tighter
> > control of what is going on.
> >
> > Once you start talking about inter-organisation, loosely coupled
> > infrastructures, you have to live in an environment where you
> > don't have
> > control. My organisation will not allow you to create objects
> > representing the resources I maintain. I am providing a service, an
> > interface to what I want you to see. I am telling you the
> > messages that
> > you can exchange with me but not the resources that are
> > hidden behind my
> > service interface. I am not going to give you control of what can be
> > created and/or destroyed behind my interface.
> >
> > A service is coarse grained. It's the entry point to my
organisation.
> > That's the way I chose for my communications with others. Through
> > message exchanges of well-defined documents and not through
> > method calls
> > on a stateful entity, an object, that I allowed you to create on my
> > resources. If I wanted that, I would have chosen CORBA or DCOM.
> >
> > CORBA failed! DCOM is dead! Let's not try to do the same mistakes.
> >
> > .savas.
> >
> >
> >
> >
> >
> >

Received on Saturday, 19 July 2003 14:30:47 UTC