Re: [ws-caf] RE: [ogsi-wg] RE: [ws-caf] WS-Resource Framework

["Mark Little" <mark.little@arjuna.com>]

I believe this isn't really a technical discussion but a political one, as
seems to be the case so many times in the WS space. I also agree that trying
to merge these specifications where there is overlap makes a lot of sense,
particularly for end-users.

Mark.

----
Mark Little,
Chief Architect, Transactions,
Arjuna Technologies Ltd.

www.arjuna.com

----- Original Message -----
From: "Savas Parastatidis" <Savas.Parastatidis@newcastle.ac.uk>
To: <ogsi-wg@gridforum.org>; <ws-caf@lists.oasis-open.org>
Sent: Tuesday, January 27, 2004 4:05 AM
Subject: [ws-caf] RE: [ogsi-wg] RE: [ws-caf] WS-Resource Framework


> Hey all,
>
> Since Mark asked for my comment...
>
> [...]
>
> > I'm still waiting to see what the real differentiator is in the useage
> > pattern, the interaction pattern, or whatever that means that this
> > couldn't
> > have been achieved with WS-RF. If you look at the paper that Savas et
> al.
> > produced many months ago, doesn't that map to precisely the same
> goals,
> > but
> > using WS-Context at the core? Hopefully Savas can comment on this too.
> >
>
> [...] (lots of [...])
>
> Mark, I agree with your arguments (I know... that doesn't happen very
> often :-)
>
> In our paper all those months ago we wanted to present a way to do
> stateful interactions in a service-oriented fashion. WS-Context provided
> us with the means to do just that. We wanted to model stateful
> _interactions_ through message correlation.
>
> There are many ways for doing this:
>
> - BPEL uses properties from application messages to model stateful
> interactions.
>
> - One could use information in the messages to explicitly correlate
> messages (e.g., order numbers explicitly sent as "arguments" to
> operations) (similar to the above really).
>
> - One could overload the semantics of a service and introduce "service
> instances" (the OGSI approach and we know how that ended).
>
> - Or, contextualisation could be used. WS-Context was the only
> specification at the time explicitly talking about contextualisation
> (and still the only one as far as I know).
>
> Your choice of any of the above methods is application-specific. If you
> want to model stateful interactions with a particular resource, you
> could do it with any of the above ways. The WS-RF authors decided to use
> WS-Addressing, which is fine. It means that parts of a WS-Address
> structure will have to travel as headers in a message. It's a form of
> contextualisation. However, it's not different from WS-Context which
> scales better to multiple participant interactions. I can't see how this
> could be done with WS-Resources.
>
> Could WS-RF have used WS-Context? Sure! No doubt about that.
>
> I would welcome an effort by the two communities to bridge their
> differences. Until then... let's build some applications to test the
> ideas: http://www.neresc.ac.uk/ws-gaf/AboutWSGAFApplication.html.
>
> Best regards,
> .savas.
>
>