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Re: Ignorable assertions and interoperability

From: Christopher B Ferris <chrisfer@us.ibm.com>
Date: Wed, 21 Feb 2007 08:20:11 -0500
To: "Sergey Beryozkin" <sergey.beryozkin@iona.com>
Cc: public-ws-policy@w3.org, public-ws-policy-request@w3.org
Message-ID: <OF2C206C1A.AEBB7FD6-ON85257289.0048DC03-85257289.004942AB@us.ibm.com>
I see now what you mean. However, IMO, this isn't an interoperability 
issue, as much as one of
understanding the reality that despite the fact that a policy provider 
might mark something as
ignorable, there will always be some policy consumers that will ignore 
that advice:-)

I guess it is a matter of expectation setting.

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

"Sergey Beryozkin" <sergey.beryozkin@iona.com> wrote on 02/21/2007 
08:01:13 AM:

> Hi Chris
> 
> "I guess I don't understand why strict mode presents interoperability 
> challenges. We have both strict and lax mode intersection for a reason. 
> Those policy consumers that don't want to ignore assertions that are 
> marked as ignorable can use strict to achieve that objective. Those that 

> are okay with ignoring what is marked ignorable can use lax mode. The 
> policy consumer has the choice to do whatever they feel is right for 
> their circumstances. "
> 
> I agree. From the consumer's perspective we have no issues at all.
> The things are slightly different from the provider's perspective 
though.
> Provider marks the assertion as wsp:ignorable=true so that it can be
> ignored for the intersection purposes. Otherwise why else would the 
> provider do it ? If the provider wants the assertion be understood 
> always then it would just expose that assertion as the normal 
> required assertion.
> But the provider does not aware of what mode consumers will be 
> using. By marking the assertion as ignorable the provider can get 
> some consumers fail to consume the service if they work in the 
> strict mode. Yes, that's what consumers chose to but I think it's 
> not something a provider will really want... So it's a possible 
> interop concern at the WS-Policy level
> 
> Do you see what I mean ? Would you agree ?
> 
> Cheers, Sergey
> 
> 
> ----- Original Message ----- 
> From: Christopher B Ferris 
> To: Sergey Beryozkin 
> Cc: public-ws-policy@w3.org ; public-ws-policy-request@w3.org 
> Sent: Wednesday, February 21, 2007 12:32 PM
> Subject: Re: Ignorable assertions and interoperability
> 
> 
> Sergey, 
> 
> Thanks for elaborating. 
> 
> Please see my inlined comments below. 
> 
> 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 
> 
> public-ws-policy-request@w3.org wrote on 02/21/2007 04:36:19 AM:
> 
> > Hi Chris 
> > 
> > Thanks for your comments. 
> > 
> > I agree, I should've created a bug with a specific proposal rather 
> > just suggesting (the editors :-)) to do some revisioning of the 
> primer's text. 
> > 
> > One goal of this email was to explain why I was concerned about the 
> > interoperability statement during the concall as I promised at the 
> > time to reply in email... 
> > As far as wsp:ignorable and WS-Policy interoperability were 
> > concerned, one possible take on it can be that using wsp:ignorable 
> > might cause at the moment at least WS-Policy-level interoperability 
> > problems due to third-party consumers using a strict mode. This is 
> > one interop concern. 
> 
> I guess I don't understand why strict mode presents interoperability 
> challenges. We have both strict and lax mode intersection for a reason. 
> Those policy consumers that don't want to ignore assertions that are 
> marked as ignorable can use strict to achieve that objective. Those that 

> are okay with ignoring what is marked ignorable can use lax mode. The 
> policy consumer has the choice to do whatever they feel is right for 
> their circumstances. 
> 
> > As far as a provider is concerned, I believe a provider's motivation
> > to mark the assertion as wsp:ignorable is to try to reach with the 
> > (assertion) message to as many requesters as possible and yet 
> > continue to interoperate at the ws-policy level with ideally every 
> 
> Agreed. 
> 
> > requester out there. Thats's another possible view on what wsp:
> > ignorable means to the provider as far as a ws-level interop is 
concerned. 
> > Then there's on the wire interoperability which is what was referred
> > to during the call. 
> 
> I still don't understand the interop concern. 
> 
> > 
> > Hopefully this explains the reason behind the message I've sent. 
> > 
> > I've reviewed the primer and the guidelines yesterday and I've seen 
> > just a few references to the interoperability term. As far as wsp:
> > ignorable and interop are concerned, section 2.7 adequately refers 
> > to both on the wire interop and the ws-policy level interop 
> > (implicitly by advising to be aware of the impact of this attribute 
> > on the compatibility of policies). 
> > I'll add a bug with a proposal to add a minor update to that section
> > (with respect to referring to interop). Specifically, I'll propose 
> > to add a text sent by yourself earlier on the ignorability being at 
> > the discretion of the requester. 
> > 
> > Cheers, Sergey 
> > 
> > 
> > ----- Original Message ----- 
> > From: Christopher B Ferris 
> > To: Sergey Beryozkin 
> > Cc: public-ws-policy@w3.org ; public-ws-policy-request@w3.org 
> > Sent: Tuesday, February 20, 2007 12:52 PM 
> > Subject: Re: Ignorable assertions and interoperability 
> > 
> > 
> > Sergey, 
> > 
> > Would you please log this as a bug against the primer and guidelines
> > so that it can be tracked? 
> > 
> > Also, it would help to have specific areas of the primer and 
> > guidelines that mention interoperability 
> > so that we can focus on what exactly needs to be changed. 
> > 
> > Finally, if you could provide a proposal to address your concerns, 
> > that would help greatly towards 
> > closing the issue. 
> > 
> > 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 
> > 
> > public-ws-policy-request@w3.org wrote on 02/20/2007 05:52:22 AM:
> > 
> > > Hi 
> > > 
> > > During the latest concall it was recommended to advise not to use 
> > > ignorable assertions if the interoperability would be affected...I 
> > > thought it was a strong statement at a time. 
> > > The reason for that was that I was assuming at a time a WS-Policy 
> > > level interoperability was referred to. 
> > > Most of the time it's obvious what interoperability the spec/primer 
> > > texts refer to, but I feel it would be useful to revisit (in the 
> > > primer and guidelines) all references to the 'interoperability' 
> > > terms and qualify them as appropriate... 
> > > 
> > > Cheers, Sergey Beryozkin
Received on Wednesday, 21 February 2007 13:20:42 GMT

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