Re: Issue i020, subissue iv

Jonathan Marsh wrote:
> See below...
> 
> 
>>-----Original Message-----
>>From: public-ws-addressing-request@w3.org [mailto:public-ws-
>>addressing-request@w3.org] On Behalf Of Anish Karmarkar
>>Sent: Sunday, February 06, 2005 11:13 PM
>>To: public-ws-addressing@w3.org
>>Subject: Issue i020, subissue iv
>>
>>
>>I took an action to start a discussion on issue 020, subissue iv [1] .
>>This email fulfills that action item. Subissue 020 states:
>>
>>"WS-Addressing talks about an Endpoint Reference, but does not say
>>what
>>an endpoint is. So what does an EPR refer to? WSDL also has the
>>concept
>>of an endpoint. What is the difference between the two, if any."
>>
>>WS-Addressing Core [2] states:
>>
>>"A Web service endpoint is a (referenceable) entity, processor, or
>>resource to which Web service messages can be addressed."
>>
>>WSDL 2.0 also defines a component called Endpoint [3] which is scoped
>>to
>>a specific service. It defines the details of a specific endpoint at
> 
> 
> "Describes", not "defines".
> 

Yes. That is an important distinction.

> 
>>which a particular service is available.
>>
>>Clearly (at least to me), there are instances where they mean the same
>>thing, but it is also possible that they mean quite different things.
>>For example, an EPR may contain the value of [address] which is a URN
>>and also contains a [service endpoint] (without a designated port).
>>Such
>>a [service endpoint] may in fact contain multiple ports (or WSDL 2.0
>>endpoints). Such an EPR would not be confined to a single WSDL 2.0
>>endpoint.
> 
> 
> Sorry, I'm missing something.  Are you suggesting that leaving off the
> optional @EndpointName implies that the EPR refers simultaneously to
> multiple endpoints?
> 

No. I'm providing an example where a WSDL endpoint component is quite 
different from an endpoint as referred to by an EPR.
It does not mean that leaving off the optional @EndpointName implies 
that EPR always refers simultaneously to multiple endpoints.

> 
>>Given that most folks who read WSDL 2.0 will also read WS-Addressing
>>(and vice versa), the use of the same term with different meaning is a
>>source of confusion. I would like to suggest that we add wordings that
>>point out that an endpoint component in WSDL 2.0 and an endpoint that
>>is
>>referenced by an EPR can be different beasts.
>>
>>Comments?
> 
> 
> It seems to me that an endpoint is what it is.  It can be described to a
> certain level of fidelity with a WSDL Endpoint component, and it can be
> referenced by an EPR which also carries certain level of additional
> information or metadata.  Are simply you suggesting stating that a Web
> service endpoint consists of a set of semantics and behaviors, some of
> which cannot currently be described by WSDL or by any metadata embedded
> in an EPR?
> 

That could be the gist of the text that we point in the spec. I'm 
suggesting that we point out the fact that the two notions of endpoints 
are quite different between the two specs.

> 
>>-Anish
>>--
>>
>>[1] http://www.w3.org/2002/ws/addr/wd-issues/#i020
>>[2] http://dev.w3.org/cvsweb/~checkout~/2004/ws/addressing/ws-addr-
>>core.html
>>[3] http://www.w3.org/TR/2004/WD-wsdl20-20040803/#Endpoint
> 
> 
>

Received on Monday, 7 February 2005 19:58:39 UTC