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Re: multipe protocols/bindings that implements serviceType [Re: slides from my presentation on issues with the core spec]

From: Sanjiva Weerawarana <sanjiva@watson.ibm.com>
Date: Thu, 25 Apr 2002 06:15:08 -0400
Message-ID: <018e01c1ec42$26b5cd50$b63c8640@lankabook2>
To: <www-ws-desc@w3.org>
Hi Alek!

> in the last issue "Services and Service Types"  the proposed solution is
> creation of serviceType element that i believe is an excellent idea
> especially if it would allow to aggregate not only portTypes but also
> serviceTypes recursively.

This is a possibility, but I'm not sure its needed. Can you provide
some use-cases for when it would be useful to recursively build
serviceTypes out of serviceTypes?

> however requiring for service that implements serviceType
> to have exactly one binding for each portType makes it impossible
> to provide multiple access mechanism to service (multiprotocol),
> for example SOAP/HTTP and EJB/RMI as equivalent protocols
> to interact with service.

No, I don't think so: it just means that different binding selections
is done at a serviceType granularily and not at a portType granularity.
That is, right now if you have 3 portTypes (pt1, pt2 and pt3) and 2
bindings (ejb-pt1, soap-pt1, ejb-pt2, soap-pt2, ejb-pt3, soap-pt3) for
each one, then its not clear whether you have to use the same binding
type for both portTypes or not. So can I choose ejb-pt1/pt1 and
soap-pt2/pt2? Not clear, but most probably not. If we group these via
serviceType/service, then its clear that binding choices offer different
services and that binding choices are offered as different services
for the same serviceType.

> i think it is important to keep ability of client to introspects WSDL
> and employ the best access mechanism to service if choices are available
> (for example it may be SOAP but it may be something more optimized ...)

I agree.

> finally: if service implements serviceType doe sit mean that service ports
> are accessing the same logical instance of service?

Yes, a given implementation of a serviceType should represent one logical
instance of a service. Is that what you're asking; I'm not clear on the
question?

Sanjiva.
Received on Thursday, 25 April 2002 06:41:45 GMT

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