W3C home > Mailing lists > Public > public-ws-policy@w3.org > May 2007

Re: from the whiteboard f2f dicussion

From: Sergey Beryozkin <sergey.beryozkin@iona.com>
Date: Thu, 24 May 2007 15:33:35 +0100
Message-ID: <004101c79e10$83178310$c301020a@sberyoz>
To: "Christopher B Ferris" <chrisfer@us.ibm.com>
Cc: <public-ws-policy@w3.org>, <public-ws-policy-request@w3.org>
Hi Chris

Thanks for answering my questions  (showing that I haven't read the spec properly :-))

A couple of questions remain though :

> 2. why the provider's F is in the effective policy produced by the 
> lax intersection mode

Thanks for the answer to this question below... 
Still, after reading the policy intersection section, it does not seem right.
Here's an extract from that section :
"Because there is only one alternative (A2) in policy P1 with the same vocabulary - the assertions have the same type - as another alternative (A3) in policy P2, the intersection is a policy with a single alternative that contains all of the assertions in A2 and in A3."

Yes, but in that example all assertion types in A2 and A3 match completely....

I see that F is an ignorable assertion, but the lax-mode requester has not asked for F, so in the absense of the match for F the intersection engine should just drop 'F', what is the value of keeping 'F' in the intersected policy ? 


> 3.Why D is in the effective policy produced by the lax intersection 
> mode ? Provider does not know anything about D so the effect of 
> requester putting D in the effective policy can be undefined - 

>> See above, it is ignorable. 

Ignorable for whom ? wsp:ignorable is a marker for the entity initiating the intersection, right ?
In this case it's the requester initiating the intersection, and the provider has not said anything about D, it's not aware of it (at least it hasn't said so explicitly). 

So I believe putting 'D' in the intesected policy is not correct. Moreover the intersection should fail in this example, ortherwise the requester(client) will just engage 'D' which may or may not cause the communication to fail.

What do you think ?

Cheers, Sergey


  ----- Original Message ----- 
  From: Christopher B Ferris 
  To: Sergey Beryozkin 
  Cc: public-ws-policy@w3.org ; public-ws-policy-request@w3.org 
  Sent: Thursday, May 24, 2007 2:04 PM
  Subject: RE: from the whiteboard f2f dicussion



  Sergey, 

  Please see my comments below. 

  Christopher Ferris
  STSM, Software Group Standards Strategy
  email: chrisfer@us.ibm.com
  blog: http://www.ibm.com/developerworks/blogs/page/chrisferris
  phone: +1 508 377 9295 

  public-ws-policy-request@w3.org wrote on 05/23/2007 03:44:59 PM:

  > Hello 
  >   
  > I'd like to ask few questions (I'm assuming  the requestor initiates
  > the intersection) : 
  >   
  > 1. why Lax intersection mode produces duplicates for A & B ? 

  Take a look at the example in sect 4.5 
          http://www.w3.org/TR/2007/CR-ws-policy-20070330/#Policy_Intersection 


  > 2. why the provider's F is in the effective policy produced by the 
  > lax intersection mode ? My understanding of the lax mode is that it accepts 
  > an ignorable provider's assertion only if it understands it, and in 
  > this case it does not, so it tshould be dropped 

  The intersection does not change aside from the determination of compatibility of 
  assertions. The statement that follows makes it clear that if the two alternatives 
  are compatible, the result of intersection is still: 
          "an alternative containing all of the assertions in both alternatives." 

  > 3.Why D is in the effective policy produced by the lax intersection 
  > mode ? Provider does not know anything about D so the effect of 
  > requester putting D in the effective policy can be undefined - 

  See above, it is ignorable. 

  > 4. Given 3 should the intersection fail ? 

  Nope. 

  >   
  > Thanks, Sergey 
  >   
  >   
  > 
  > From: public-ws-policy-request@w3.org [mailto:public-ws-policy-
  > request@w3.org] On Behalf Of Christopher B Ferris
  > Sent: 23 May 2007 17:14
  > To: public-ws-policy@w3.org
  > Subject: from the whiteboard f2f dicussion 
  >   
  > 
  > Provider Policy: 
  > <Policy> 
  >   <A/> 
  >   <B/> 
  >   <C wsp:Optional="true"/> 
  >   <D wsp:Ignorable="true"/> 
  > </Policy> 
  > 
  > Requestor Policy: 
  > <Policy> 
  >   <A/> 
  >   <B/> 
  >   <E wsp:Optional="true"/> 
  >   <F wsp:Ignorable="true"/> 
  > </Policy> 
  > 
  > Lax intersection yields: 
  > <Policy> 
  >   <A/> 
  >   <B/> 
  >   <A/> 
  >   <B/> 
  >   <D wsp:Ignorable="true"/> 
  >   <F wsp:Ignorable="true"/> 
  > </Policy> 
  > 
  > There is a policy <Z/> that the Provider knows about, and a policy <Y/> 
  > that the Requester knows about.  It does not matter whether these are 
  > optional or ignorable. 
  > 
  > Style \             WILL       | MUST NOT       | MAY         | WILL NOT 
  > AIN Vocabulary      A, B, D, F   E                Y, Z          C 
  > AIN Closed          A, B, D, F   E, Y, Z                        C 
  > AIN Client Vocab    A, B, D, F   E, Y             Z             C 
  > Open World          A, B, D, F                    C, E, Y, Z     
  > 
  > 
  >                                                   Out of Scope 
  > Requestor as entity that engages an interaction 
  > AIN Client Vocab    A, B, F            E                Z, Y, C, D         
  >                                                   Provider as recipient 
  > 
  > 
  > Provider as entity that engages an interaction 
  > AIN Client Vocab    A, B, D      C                Z, Y, E, F 
  >                                                   Requestor as recipient 
  >           
  > 
  > Cheers, 
  > 
  > Christopher Ferris
  > STSM, Software Group Standards Strategy
  > email: chrisfer@us.ibm.com
  > blog: http://www.ibm.com/developerworks/blogs/page/chrisferris
  > phone: +1 508 377 9295
Received on Thursday, 24 May 2007 14:32:33 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:38:34 UTC