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RE: Are nested assertions part of the policy vocabulary?

From: Maryann Hondo <mhondo@us.ibm.com>
Date: Thu, 19 Apr 2007 08:55:16 -0400
To: "Ashok Malhotra" <ashok.malhotra@oracle.com>, Anthony Nadalin <drsecure@us.ibm.com>
Cc: "Ashok Malhotra" <ashok.malhotra@oracle.com>, "public-ws-addressing@w3.org" <public-ws-addressing@w3.org>, public-ws-addressing-request@w3.org, "public-ws-policy@w3.org" <public-ws-policy@w3.org>, public-ws-policy-request@w3.org
Message-ID: <OFFE41E0C2.47C95518-ON872572C2.004517D8-852572C2.0046A077@us.ibm.com>
Ashok,
I would like to clarify my comments.

I was trying to say, that the WS-Addressing group seemed to be trying to 
use nested assertions to indicate a "constraint".
My understanding of the semantics are the following:
<Policy>
<ws-addressing>
<Policy/>
</ws-addressing>
</Policy>
was intended to mean that ALL options ( anonymous, non-anonymous) are 
supported.

and
<Policy>
<ws-addressing>
<Policy>
<ws-addressing: Anonymous> 
</Policy>
</ws-addressing>
</Policy>
was intended to mean that  ONLY anonymous was supported.

This to me, ths meant that the "intent" of the base assertion was being 
"constrained" by the presence off a nested assertion
and that was ok if the working group understood the semantics they were 
expressing ( i.e. the "absence" of a nested assertion
means "no constraints" or "all options are supported")

 and I thought the language of the ws-policy spec allowed this 
interpretation since  a nested assertion could be seen to be
qualifying the base assertion with a constraint rather than a capability. 

Authors MAY define that an assertion contains a policy expression (as 
defined in 4. Policy Expression) as one of its [children]. Nested policy 
expression(s) are used by authors to further qualify one or more specific 
aspects of the original assertion. 


The spec already says the following so I don't think alternative 1 really 
adds anything, unless I'm missing something, like Tony, I need more of an 
explanation of what you are suggesting you want the intersection to do: 

Because the set of behaviors indicated by a policy alternative depends on 
the domain-specific semantics of the collected assertions, determining 
whether two policy alternatives are compatible generally involves 
domain-specific processing.

Maryann




Anthony Nadalin/Austin/IBM@IBMUS 
Sent by: public-ws-addressing-request@w3.org
04/19/2007 03:41 AM

To
"Ashok Malhotra" <ashok.malhotra@oracle.com>
cc
"public-ws-addressing@w3.org" <public-ws-addressing@w3.org>, 
"public-ws-policy@w3.org" <public-ws-policy@w3.org>, 
public-ws-policy-request@w3.org
Subject
RE: Are nested assertions part of the policy vocabulary?






#1 " dependent on the semantics of the parent assertion." not sure what 
this would mean can you give some guidance here ?
#2 is real dangerous as you have no idea what you are matching on, one day 
it could be XYZ and another day it could be ABC.

Anthony Nadalin | Work 512.838.0085 | Cell 512.289.4122
"Ashok Malhotra" <ashok.malhotra@oracle.com>


"Ashok Malhotra" <ashok.malhotra@oracle.com> 
Sent by: public-ws-policy-request@w3.org 
04/16/2007 04:23 PM



To

"public-ws-policy@w3.org" <public-ws-policy@w3.org>, 
"public-ws-addressing@w3.org" <public-ws-addressing@w3.org>

cc


Subject

RE: Are nested assertions part of the policy vocabulary?





I’m at the OASIS Symposium and have had extensive discussions with the 
WS-Addressing folks re. the problems they are having in using WS-Policy to 
express their requirements.

As I see it, the sticky usecase is where the provider wants to say this it 
supports WS-Addressing in all its manifestations and the requester 
specifies that it supports a particular variation of WS-Addressing. These 
two policies must match. Thus, the provider says:

<Policy>
<ws-addressing>
<Policy/>
</ws-addressing>
</Policy>

And the requester says:

<Policy>
<ws-addressing>
<Policy>
<ws-addressing-specific-assertions> 
</Policy>
</ws-addressing>
</Policy>

These two policies must match in the intersection algorithm. The text that 
prevents them from matching says:

“If either assertion contains a nested policy expression, the two 
assertions are compatible if they both have a nested policy expression and 
the alternative in the nested policy expression of one is compatible with 
the alternative in the nested policy expression of the other.”

In the note below (which Glen +1ed), Maryann suggests that a Policy with 
just the <ws-addressing> assertion is expressing a constraint which can be 
met in several ways – at least that’s how I read her note. She does not, 
however, suggest concrete wording. Here are a couple of suggestions:
1. Change the quoted text above to say that matching of nested policy 
assertions is dependent on the semantics of the parent assertion. This 
way, WS-Addressing could define its own semantics for matching and solving 
their usecase.
2. Bob Freund suggested a wildcard assertion that could be included within 
a nested Policy that would match any other nested policy.

All the best, Ashok 

From: Maryann Hondo [mailto:mhondo@us.ibm.com] 
Sent: Wednesday, April 04, 2007 7:37 AM
To: Glen Daniels
Cc: Ashok Malhotra; Monica J. Martin; public-ws-policy@w3.org; 
public-ws-policy-request@w3.org
Subject: RE: Are nested assertions part of the policy vocabulary?


Glen, 
I think the problem is that the assertions are really trying to express a 
constraint .....and should be something 
like "nonAnonymousONLY". so the absence, is not the absence of support but 
rather the absence of the constraint. 

And in this case I think the " no constraints" is sufficient for your use 
case 
The client has no constraints on what the provider will do. 
That should intersect with all the provider options. 

I hope we can talk this through on the call. 
Maryann 

"Glen Daniels" <gdaniels@progress.com> 
Sent by: public-ws-policy-request@w3.org 
04/04/2007 09:59 AM 


To
"Monica J. Martin" <Monica.Martin@Sun.COM>, "Ashok Malhotra" 
<ashok.malhotra@oracle.com> 
cc
<public-ws-policy@w3.org> 
Subject
RE: Are nested assertions part of the policy vocabulary?









Hi Monica:

I'm a little confused here. Are you and MaryAnn indeed saying that
selecting the first alternative in Ashok's (and indeed WS-Addressing's)
example means that neither anonymous nor non-anonymous responses are
allowed? That certainly isn't the goal of the policy, and indeed this
interpretation would seem to disallow ANY kind of response.

How would you write a consumer policy which was meant to successfully
intersect with endpoint policies which either a) express nothing about
anonymous responses, b) express a requirement for anonymous responses,
or c) express a requirement for non-anonymous responses?

--Glen

> -----Original Message-----
> From: public-ws-policy-request@w3.org 
> [mailto:public-ws-policy-request@w3.org] On Behalf Of Monica J. Martin
> Sent: Tuesday, April 03, 2007 5:30 PM
> To: Ashok Malhotra
> Cc: public-ws-policy@w3.org
> Subject: Re: Are nested assertions part of the policy vocabulary?
> 
> 
> 
> hondo: Ashok,
> My response is yes.
> Maryann
> 
> >>mm1: Ashok, agree with MaryAnn on question one answer - this point 
> has been made that the nested assertions are part of the policy 
> vocabulary. Yet, an important point associated with this surrounds 
> whether or not the guiding conformance [1] requires support for those 
> response types - that provides substance on your second 
> question and its 
> disposition.. [2]
> 
> We also state in Section 3.2 Framework before the statement you cite:
> 
> An alternative with zero assertions indicates no behaviors. An
> alternative with one or more assertions indicates 
> behaviors implied
> by those, and only those assertions.
> 
> Remember: (no position just stating the action-result), we augmented 
> this text in 
> http://www.w3.org/Bugs/Public/show_bug.cgi?id=3602 Issue 3602.
> 
> [1] WS-A specification(s) referenced
> [2] Related to empty and the base assumptions of WS-Addressing.
> 
> >Ashok Malhotra wrote: Section 3.2 of Framework says "When an 
> assertion whose type is part of the policy's vocabulary is 
> not included in a policy alternative, the policy alternative 
> without the assertion type indicates that the assertion will 
> not be applied in the context of the attached policy 
> subject." Are nested assertions included in the policy's 
> vocabulary?
> >
> >Consider the following example:
> >
> > <wsp:ExactlyOne>
> > <wsp:All>
> > <wsam:Addressing> <-- supports all response 
> types --> Alternative 1
> > <wsp:Policy> 
> > </wsp:Policy>
> > </wsam:Addressing>
> > </wsp:All>
> > <wsp:All>
> > <wsam:Addressing> <-- requires Anonymous 
> responses --> Alternative 2
> > <wsp:Policy>
> > <AnonymousResponses />
> > </wsp:Policy>
> > </wsam:Addressing>
> > </wsp:All>
> > <wsp:All>
> > <wsam:Addressing> <- requires nonAnonymous 
> responses --> Alternative 3
> > <wsp:Policy>
> > <NonAnonymousResponses />
> > </wsp:Policy>
> > </wsam:Addressing>
> > </wsp:All>
> > </wsp:ExactlyOne>
> ></wsp:Policy>
> >
> >If Alternative 1 is selected, does this mean that neither 
> Anonymous responses nor NonAnonymous responses are allowed as 
> both are part of the policy vocabulary but not included in 
> the alternative.
> >
> >All the best, Ashok
> >
> > 
> >
> 
> 
> 
> 



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Received on Thursday, 19 April 2007 12:53:25 GMT

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