RE: Are nested assertions part of the policy vocabulary?

Hi Dan

 

"In some cases a single message may specify both an anonymous ReplyTo EPR
and a non-anonymous FaultsTo EPR.  To satisfy this scenario you need to have
some way of saying that addressing is fully supported without
qualifications".

 

This is the point I've missed. It's the fact that a *single* message may
specify both types which makes an empty <Policy> expression a useful
alternative.

IMHO, highlighting it in the wsa-addressing policy profile would help.
Otherwise it's very tempting to use an empty <Policy> expression alone to
meet different client's

requirements for a more qualified support.

 

Thanks for the explanation

Sergey 

 

 

 

  _____  

From: Daniel Roth [mailto:Daniel.Roth@microsoft.com] 
Sent: 08 May 2007 21:26
To: Sergey Beryozkin; Bob Freund; Ashok Malhotra; Maryann Hondo; Anthony
Nadalin
Cc: public-ws-addressing@w3.org; public-ws-policy@w3.org
Subject: RE: Are nested assertions part of the policy vocabulary?

 

Hi Sergey,

 

> According to [1] If the provider uses <Policy/> then it means this
provider will work with consumers using either anonymous or non-anonymous
WSA qualifications. 

> And yet, the requester saying, by using
<ws-addressing><Policy><AnonymousResponses/></Policy></ws-addressing>, that
it wishes a provider to support  

> <AnonymousResponses/> will fail to intersect with the provider using
<Policy/> which says that all types of responses are supported

 

A client that requires a service that supports anonymous responses will work
with a service that supports all of addressing or just anonymous responses.
This means, the client should reflect that by including both alternatives in
its policy.  The client policy with both alternatives intersects with the
service policy and is specifically recommended in section 3.6.1 of the
WS-Addressing Metadata spec.

 

> I'd even say that the empty nested ws-adressing <Policy> should be
prohibited

 

In some cases a single message may specify both an anonymous ReplyTo EPR and
a non-anonymous FaultsTo EPR.  To satisfy this scenario you need to have
some way of saying that addressing is fully supported without
qualifications.

 

I hope this helps.

 

Daniel Roth

 

 

From: Sergey Beryozkin [mailto:sergey.beryozkin@iona.com] 
Sent: Tuesday, May 08, 2007 2:25 AM
To: Bob Freund; Daniel Roth; Ashok Malhotra; Maryann Hondo; Anthony Nadalin
Cc: public-ws-addressing@w3.org; public-ws-addressing-request@w3.org;
public-ws-policy@w3.org; public-ws-policy-request@w3.org
Subject: Re: Are nested assertions part of the policy vocabulary?

 

Hi

 

What confuses me is that it appears to be some inconsistency in the
definition of what the empty nested Policy means in the scope of
ws-addressing (see [1]), <ws-addressing><Policy/></ws-addressing> and the
fact that this nested <Policy> does not intersect with a more qualified
nested Policy such as
<ws-addressing><Policy><AnonymousResponses/></Policy></ws-addressing>.

 

According to [1] If the provider uses <Policy/> then it means this provider
will work with consumers using either anonymous or non-anonymous WSA
qualifications. And yet, the requester saying, by using
<ws-addressing><Policy><AnonymousResponses/></Policy></ws-addressing>, that
it wishes a provider to support  <AnonymousResponses/> will fail to
intersect with the provider using <Policy/> which says that all types of
responses are supported...

 

I think what this means is using an all inclusive <Policy> alternative alone
on the server is just not safe as it will cause compliant clients (say those
wishing a provider to support <AnonymousResponses/>) to break...I'd even say
that the empty nested ws-adressing <Policy> should be prohibited...Just have
two nested policies, one allowing anonymous responses, another one allowing
non-anonymous ones...That way a provider supporting all types of responses
can list two alternatives and it will match all clients....

 

 

Thanks, Sergey

 

[1]
http://lists.w3.org/Archives/Public/public-ws-policy/2007Apr/att-0094/WSAddr
PolicyAlgerntiveGprime.htm

----- Original Message ----- 

From: Bob Freund <mailto:bob@freunds.com>  

To: Daniel <mailto:Daniel.Roth@microsoft.com>  Roth ; Ashok Malhotra
<mailto:ashok.malhotra@oracle.com>  ; Maryann Hondo
<mailto:mhondo@us.ibm.com>  ; Anthony Nadalin <mailto:drsecure@us.ibm.com>  

Cc: public-ws-addressing@w3.org ; public-ws-addressing-request@w3.org ;
public-ws-policy@w3.org ; public-ws-policy-request@w3.org 

Sent: Tuesday, May 08, 2007 12:22 AM

Subject: RE: Are nested assertions part of the policy vocabulary?

 

+1

>From a plain reading of the WS-Policy intersection algorithm, these policies
indeed are not compatible per the WS-Policy 1.5 framework CR spec.

-bob

 

From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Daniel Roth
Sent: Tuesday, May 01, 2007 4:52 PM
To: Ashok Malhotra; Maryann Hondo; Anthony Nadalin
Cc: public-ws-addressing@w3.org; public-ws-addressing-request@w3.org;
public-ws-policy@w3.org; public-ws-policy-request@w3.org
Subject: RE: Are nested assertions part of the policy vocabulary?

 

Hi Ashok, 

 

These two policies do not intersect and we believe this is verified in the
test cases.  If Policy 2 is the policy for a requester then this
intersection result may at first seem incorrect, so let me explain: 

 

It is incumbent on the Addressing authors to specify the semantics of the
assertions.  The Addressing assertion expresses a requirement that
WS-Addressing be used to exchange messages without qualifications.  The
nested addressing assertions (which indicate additional characteristics of
the base WS-Addressing assertion)  qualify this semantic to say that either
only non-anonymous responses are supported or that only anonymous responses
are supported.  In the WS-Addressing protocol it's the requester's message
that requests a specific kind of response - anonymous, non-anonymous, or
maybe even a mixture of the two.   

 

The thing to recognize is that if Policy 2 is a requester policy then it is
incomplete in that it is not acknowledging that the base assertion also
reflects support for anonymous responses.  The requester determines what
response type should be used.  So, a client that needs non-anonymous
responses will also work with a service that supports all of addressing.
The client's policy should reflect that  it is compatible with an endpoint
that supports all of addressing by adding a second alternative.  This can be
easily done using the Optional attribute as is shown in section 3.1.6 in the
WS-Addressing Metadata spec: 

              <Policy><Addressing ><Policy><AnonymousResponses
wsp:Optional="true" > </Policy></Addressing ></Policy> 

 

Note that if Policy 2 is a provider policy and Policy 1 is the requester
policy - where the requester wants unqualified support for addressing, but
the provider only supports a specific response type - then there is no
issue.  These policies should not intersect and they don't. 

 

We hope this helps. 

 

Daniel Roth

 

From: public-ws-policy-request@w3.org
[mailto:public-ws-policy-request@w3.org] On Behalf Of Ashok Malhotra
Sent: Thursday, April 19, 2007 12:33 PM
To: Maryann Hondo; Anthony Nadalin
Cc: public-ws-addressing@w3.org; public-ws-addressing-request@w3.org;
public-ws-policy@w3.org; public-ws-policy-request@w3.org
Subject: RE: Are nested assertions part of the policy vocabulary?

 

Hi Maryann:

Perhaps I misunderstood.  Let me rephrase my comments as questions.

 

Since Policy 1 

<Policy>
<ws-addressing>
<Policy/>
</ws-addressing>
</Policy> 
was intended to mean that ALL options ( anonymous, non-anonymous) are
supported. 

 

And Policy 2

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

Should Policy 1 match Policy 2 in the intersection algorithm?

All the best, Ashok 


  _____  


From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Maryann Hondo
Sent: Thursday, April 19, 2007 5:55 AM
To: Ashok Malhotra; Anthony Nadalin
Cc: Ashok Malhotra; public-ws-addressing@w3.org;
public-ws-addressing-request@w3.org; public-ws-policy@w3.org;
public-ws-policy-request@w3.org
Subject: RE: Are nested assertions part of the policy vocabulary?

 


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
<http://www.w3.org/TR/2007/CR-ws-policy-20070330/#policy_expression> policy
expression (as defined in
<http://www.w3.org/TR/2007/CR-ws-policy-20070330/#rPolicy_Expression> 4.
Policy Expression) as one of its [children].
<http://www.w3.org/TR/2007/CR-ws-policy-20070330/#nested_policy_expression>
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
<http://www.w3.org/TR/2007/CR-ws-policy-20070330/#policy_alternative> 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
Inactive hide details for "Ashok Malhotra" <ashok.malhotra@oracle.com>"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
<http://www.w3.org/TR/2007/CR-ws-policy-20070330/#policy_expression> 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> 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>
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>
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
> >
> > 
> >
> 
> 
> 
>