RE: issue 7728: point 1 - proposal for indicating effective endpoint policy in an EPR

Then, we do not fully understand the underlying use case. Let’s step back a bit … How would a consumer use a policy expression within a wsa:Metadata element in an interoperable manner without any binding descriptions (that usually appear in a WSDL)?

Regards,

Asir S Vedamuthu
Microsoft Corporation

From: Gilbert Pilz [mailto:gilbert.pilz@oracle.com]
Sent: Thursday, October 29, 2009 4:14 PM
To: Asir Vedamuthu
Cc: public-ws-resource-access@w3.org; antoine.mensch@odonata.fr
Subject: Re: issue 7728: point 1 - proposal for indicating effective endpoint policy in an EPR

From what you described at one of the F2F's (I forget which), the policies in a MetadataSection with @Dialect="http://www.w3.org/ns/ws-policy"<http://www.w3.org/ns/ws-policy> have no specific attachment points or policy subjects. In the example you provided below, you can't know if the assertions in the wsp:Policy apply to the endpoint, an operation of that endpoint, or a particular message; they are just a collection of policies. If you need to know how/if the policies relate to messages, operations, or endpoints you need to consult at "other metadata" like WSDL or PolicyAttachments.

The purpose of Section 7.2 is to describe how to "communicate the effective policies of the endpoints referenced by those EPRs". When WS-Policy expressions appear as children of wsa:Metadata there is no uncertainty about how/where these policies apply. "The scope of a Policy in an EPR is the endpoint referenced by that EPR. The assertions within the alternatives contained by a Policy in an EPR MUST have endpoint policy subject." Whereas wsa:Metadata/mex:Metadata gives you a big blob of metadata that you (the EPR consumer) have to process (which may include further mex:GetMetadata operations) to determine the effective policies, wsa:Metadata/wsp:Policy says "this is the effective policy"; wsa:Metadata/mex:Metadata is general, wsa:Metadata/wsp:Policy is specific.

- gp

On 10/28/2009 7:12 PM, Asir Vedamuthu wrote:
The underlying use case is addressed by a general-purpose, existing feature [1][2] in the current WS-MetadataExchange draft. For example,

<wsa:EndpointReference>
  <wsa:Address>http://services.example.org/stockquote</wsa:Address>
  <wsa:Metadata>
   <mex:Metadata>
    <mex:MetadataSection>
      Dialect='http://www.w3.org/ns/ws-policy'>
     <wsp:Policy> ... </wsp:Policy>
    </mex:MetadataSection>
   </mex:Metadata>
  </wsa:Metadata>
</wsa:EndpointReference>

Adobe, IBM, Microsoft, Oracle, Sun and WSO2 interop tested [3][4] the feature in April 2007.

Has anyone analyzed why the existing feature does not address the underlying use case?

[1] http://www.w3.org/TR/2009/WD-ws-metadata-exchange-20090924/#Metadata-in-Endpoint-References

[2] http://www.w3.org/Submission/2007/03/Comment

[3] http://www.w3.org/2002/ws/ra/9/01/WS-MetadataExchange-Scenarios-01-19-2007.pdf

[4] http://www.w3.org/2002/ws/ra/9/01/ws-mex-workshop-minutes-April-2007.pdf


Regards,

Asir S Vedamuthu
Microsoft Corporation

From: public-ws-resource-access-request@w3.org<mailto:public-ws-resource-access-request@w3.org> [mailto:public-ws-resource-access-request@w3.org] On Behalf Of Gilbert Pilz
Sent: Wednesday, October 28, 2009 4:34 PM
To: public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>
Cc: antoine.mensch@odonata.fr<mailto:antoine.mensch@odonata.fr>
Subject: issue 7728: point 1 - proposal for indicating effective endpoint policy in an EPR

I've attached the first draft of our proposal for incorporating WS-PAEPR into WS-Mex [1] to the entry for issue 7728. This is accomplished by creating a new section, Section 7.2, that describes what it means to put a wsp:Policy or wsp:PolicyReference in a wsa:EndpointReference/wsa:Metadata element.

Note this addresses the WS-DD comments ([2], [3]) made on WS-MetadataExchange by Antoine Mensch.

[1] http://www.w3.org/Bugs/Public/attachment.cgi?id=775

[2] http://lists.w3.org/Archives/Public/public-ws-resource-access/2009Oct/0027.html

[3] http://lists.w3.org/Archives/Public/public-ws-resource-access/2009Oct/0033.html\<http://lists.w3.org/Archives/Public/public-ws-resource-access/2009Oct/0033.html>

- gp