RE: Updated proposal for WS-Policy assertions

As an extensibility point for WSA makes sense. I agree that there wouldn't be a clean way to prevent abuse by other specifications. Therefore we should carefully evaluate whether or not this extensibility is needed at all.

-----Original Message-----
From: Bob Freund [mailto:bob@freunds.com]
Sent: Tuesday, November 14, 2006 10:34 AM
To: Marc Goodner; Marc Hadley; public-ws-addressing@w3.org
Subject: RE: Updated proposal for WS-Policy assertions

I think that Mr. Hadley, (now that we have two Marcs), suggested an
extensibility point for use by potential future uses of WS-A.
I cannot imagine how we can describe the semantics of uses made by other
specifications unless we start a meta-spec which may take us down a road
similar to Russell's paradox ( e.g. A set of anonURIs that is not a
member of the set of anonURIs)
I think we have been indirectly wrestling with this in a way.
-bob

-----Original Message-----
From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Marc Goodner
Sent: Tuesday, November 14, 2006 11:32 AM
To: Marc Hadley; public-ws-addressing@w3.org
Subject: RE: Updated proposal for WS-Policy assertions


It occurs to me we should not waste any more time worrying about
<wsfoo:AnonReplies/> as we struck the text asking others to define their
own anon URIs. We shouldn't close one invitation and then offer another.

-----Original Message-----
From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Marc Hadley
Sent: Monday, November 13, 2006 3:41 PM
To: public-ws-addressing@w3.org List
Subject: Updated proposal for WS-Policy assertions

The first part of the proposal is to remove the current
wsaw:Anonymous WSDL marker. I think we might need to tweak the
section describing the UsingAddressing marker to include the
following text (modified to remove mentions of policy and anonymous)
from the section describing the wsaw:Anonymous marker:

"A WSDL-based service description that includes the
wsaw:UsingAddressing makes no assertion regarding a requirement or a
constraint in the use of the anonymous URI in EPRs contained in
messages sent to the endpoint."

The current text for UsingAddressing could be taken to imply that
endpoints using it explicitly support anon and non-anon addresses but
I think the intent is that UsingAddressing makes no claim about the
types of address supported.

The second part of the proposal is to define three new elements for
use in WS-Policy.

(i) <wsaw:AddressingRequired/> - the endpoint requires WS-Addressing,
optionality can be conveyed using WS-Policy constructs.

(ii) <wsaw:AnonymousResponses/> (a child element of
<wsaw:AddressingRequired>) - the endpoint can send replies using WS-A
anonymous; the endpoint can't send to anon if not present.

(iii) <wsaw:NonAnonymousResponses/> (a child element of
<wsaw:AddressingRequired>) - the endpoint can send replies using
other addresses; the endpoint can't send to other addresses if not
present (unless some other assertion adds a class of supported
addresses).

Element (iii) is deliberately vague, its presence means that a non-
anon address might work but doesn't constrain what such an address
might look like - a receiver can still reject an address that it
doesn't grok or that requires a binding it doesn't support. The WG
decided against specifying things like available response bindings so
I think this is in line with that decision.

Here are some examples:

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:AnonymousReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and only anonymous replies are
supported.

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:NonAnonymousReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and only non-anonymous replies are
supported.

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:AnonymousReplies/>
     <wsaw:NonAnonymousReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and both anonymous and non-anonymous
replies are supported.

<wsp:Policy>
   <wsaw:AddressingRequired/>
</wsp:Policy>

Wouldn't be too useful for anything other than a one-way message
since neither anonymous nor non-anonymouse replies are supported.

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:AnonymousReplies/>
     <wsfoo:AnonReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and that anon replies as defined by
WS-Addr or WS-Foo are supported.

Marc.

---
Marc Hadley <marc.hadley at sun.com>
CTO Office, Sun Microsystems.

Received on Tuesday, 14 November 2006 20:59:20 UTC