Re: [uddi-spec] FW: W3C WS-Policy 1.5 Last Call review by OASIS UDDI Specification TC

[Paul Denning <pauld@mitre.org>]

I had raised an issue with WS-Policy that was more or less dismissed 
by the WS-Policy WG, and I have not had the time to pursue it further.

My concern was how to specify and resolve indirect policy 
attachments.  Both WSDL and UDDI can include a policy reference.

I was thinking that organizations/businesses that use a UDDI registry 
for SOA governance may want to reference WS-Policy from UDDI tModels.
Rather than have a WSDL point to a WS-Policy document, I was thinking 
that WSDL could point to the UDDI tModel, which then points to the 
WS-Policy document.

If a policy change was needed, then the tModel would be updated to 
point to the new policy, but the WSDL would still point to the same tModel.

If you had both the WSDL and the tModel pointing to a WS-Policy 
document, and you wanted to update the policy, you may need to change 
both the WSDL and the tModel to point to the new WS-Policy 
document.  This assumes that the URL for the old and new WS-Policy 
documents are different; you could have a URL for "current policy" 
the way that W3C specs have a URL for the latest version, and 
separate URLs for a specific (dated) version.

Here are some links to the threads in WS-Policy where this was discussed:

http://del.icio.us/mitrepauld/wsp+uddi

Daniel Roth suggested that a WSDL could include

<wsp:PolicyReference URI="urn:currentPolicy" />


where the URI attribute "identifies" the policy, but how you resolve 
that URI is not specified.  Obviously, if the URI scheme is "http", 
you would do HTTP GET to resolve it, but if the URI points to a 
tModel, which then points to the policy, it is not clear from @URI 
how to actually resolve the policy.  I had suggested adding an 
optional RetrievalAlgorithm attribute that would be used to identify 
a process for resolving @URI.  In the case where @URI is a URN (as in 
Daniel's example), how do I resolve the URN (identifier) to a URL 
that I can use to retrieve the policy?  Assuming I had a way to 
resolve URNs to HTTP URLs, we are still in the same situation where 
we don't know if the URL points to the policy or to a tModel.

I suggested that RetrievalAlgorithm would be similar to DigestAlgorithm.
http://lists.w3.org/Archives/Public/public-ws-policy/2006Oct/att-0066/00-part

There is probably a UDDI TN needed to address this, especially since 
I did not submit an "issue" to get my RetrievalAlgorithm idea into 
the WS-Policy Attachment spec.

The TN could say something like

<wsp:PolicyReference URI="uddi:4345ff60-7fc4-11db-9fe1-0800200c9a66" />

when used in a WSDL, then the value of the URI attribute is a 
tModelKey whose overviewURL points to a WS-Policy document.
This tModel should have a categoryBag as specified in
http://www.w3.org/TR/2006/WD-ws-policy-attach-20061117/#RegisteringReusablePolicyExpressions 
and
http://www.w3.org/TR/2006/WD-ws-policy-attach-20061117/#RegisteringPoliciesUDDIVersion3 
(for v3)

We may need to get more involved in the TN, for example, if the @URI 
holds a serviceKey whose categoryBag points to the policy as in
http://www.w3.org/TR/2006/WD-ws-policy-attach-20061117/#ReferencingRemotePolicyExpressions.

There are several ways of doing the indirection, which is why I 
suggested that WS-Policy Attachment define an optional 
RetrievalAlgorithm attribute.

Note that WS-Policy allows
/wsp:PolicyReference/@{any}
http://www.w3.org/TR/2006/WD-ws-policy-20061117/#Policy_References

So, a UDDI TN could define a new namespace with a RetrievalAlgorithm 
attribute to be used in wsp:PolicyReference elements.  However, the 
RetrievalAlgorithm idea is generic and not tied to UDDI, so it seems 
like RetrievalAlgorithm should be defined using the WS-Policy namespace.


Paul


At 09:10 AM 2006-11-29, Luc Clement wrote:
>Posted on behalf of Paul Cotton, W3C WS-Policy WG co-chair
>
> > -----Original Message-----
> > From: Paul Cotton
> > Sent: November 29, 2006 8:22 AM
> > To: 'Tony.Rogers@ca.com'; 'luc.clement@systinet.com'
> > Cc: 'Christopher B Ferris'; 'uddi-spec@lists.oasis-open.org'
> > Subject: W3C WS-Policy 1.5 Last Call review by OASIS UDDI
> > Specification TC
> >
> > I am sending this note to you in my role as co-chair of the W3C
> > WS-Policy WG.
> >
> > The W3C WS-Policy WG has published Last Call Working Drafts of Web
> > Services Policy 1.5 - Framework [1] and Attachment [2] specifications.
> > The Last Call review period is from Nov 20 thru Jan 12 2007.
> >
> > The WS-Policy WG would like the OASIS UDDI Specification TC to review
> > these specifications since your TC is responsible for the UDDI
> > specification that might want to take advantage of the features of WS-
>
> > Policy.
> >
> > We look forward to receiving any comments your TC has on these Last
> > Call Working Drafts.  Instructions on filing comments can be found in
> > the Status sections of [1-2].
> >
> > /paulc
> > W3C WS-Policy WG co-chair
> >
> > [1] http://www.w3.org/TR/2006/WD-ws-policy-20061117/
> > [2] http://www.w3.org/TR/2006/WD-ws-policy-attach-20061117/
> >
> > Paul Cotton, Microsoft Canada
> > 17 Eleanor Drive, Ottawa, Ontario K2E 6A3
> > Tel: (613) 225-5445 Fax: (425) 936-7329
> > mailto:Paul.Cotton@microsoft.com