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RE: Multiple endpoints with the same interface

From: Jeffrey Schlimmer <jeffsch@windows.microsoft.com>
Date: Thu, 17 Apr 2003 11:25:13 -0700
Message-ID: <2E33960095B58E40A4D3345AB9F65EC109D200E1@win-msg-01.wingroup.windeploy.ntdev.microsoft.com>
To: "David Orchard" <dorchard@bea.com>, "Kenneth Chiu" <chiuk@cs.indiana.edu>, <www-ws-desc@w3.org>

> From: David Orchard [mailto:dorchard@bea.com]
> 
> If I understand the CCA requirement, they would like to differentiate
> between ports that are semantically equivalent versus not equivalent
> whithin a single service.  This leads me to 2 questions:
> 
> 1. If two ports are semantically equivalent, is there any way of
talking
> about the single thing that they represent? It seems to me that there
is
> no way of saying what the thing is, nor expressing equivalence of the
> endpoints for the singe thing.  In WS-ReliableMessaging, this "thing"
is
> called the ultimate receiver or the initial sender.  Each may have
> multiple endpoints that are equivalent as they represent the ultimate
> receiver or initial sender.
> 
> 2. Is it possible to express that equivalence of porttypes also
depends
> upon which service they are part of?  The problem that I see is that
> sometimes it's not just the porttypes that determine equivalence, it
is
> service + porttype.  I could have 2 equivalent port types, but when
used
> in different services they aren't equivalent.

Are you suggesting that whether two wsdl:endpoints (nee wsdl:ports) are
semantically equivalent is orthogonal to whether they are defined within
the same wsdl:service?

> I think these are separate issues, maybe I'm mistaken.  Though it does
> seem, again maybe naively, that they could be satisfied with roughly
one
> construct.  Something like
> <service name="Purchasing">
>    <ultimateReceiver name="AcceptPO">
>      <endpoint binding="AcceptPOSoapbinding">
> 	 ...</endpoint>
> 	<endpoint binding="AcceptPOsomeotherbinding">
> 	....</endpoint>
>    <endpoint name="unrelatedendpoint' binding="...">
>     ....</endpoint>
> </service>

Did you mean to close the ultimateReceiver element to indicate which
endpoints were equivalent?

> Then CCA could put endpoints that represent the same ultimate receiver
in
> one construct, and put endpoints that don't represent the same
ultimate
> receiver yet have the same interface in one service.  I'm sure there's
> more that could be done about expressing the identity of the ultimate
> receiver and other things, but this gives a rough outline.
> 
> I don't know if this has been talked about.  If it has, I'd appreciate
any
> pointers.

The general issue was discussed at one of the face-to-face meetings last
year, perhaps as early as the Paris meeting. As I recall, given two
workarounds, the sentiment of the WG was that the status quo was
sufficient. 
Received on Thursday, 17 April 2003 14:25:24 GMT

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