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RE: Proposal for Resolution of 3564

From: Daniel Roth <Daniel.Roth@microsoft.com>
Date: Wed, 25 Oct 2006 10:04:44 -0700
To: "Yalcinalp, Umit" <umit.yalcinalp@sap.com>
CC: "public-ws-policy@w3.org" <public-ws-policy@w3.org>
Message-ID: <E2903CF1E4B5B144B559237FDFB291CE3EED2A8D@NA-EXMSG-C117.redmond.corp.microsoft.com>
We are looking at the same version.

The behavior described by WS-RMP is contingent on the assertion being added at the endpoint subject and marked as optional:

"If an RM policy assertion is attached to any of:
* wsdl:binding/wsdl:operation/wsdl:input
* wsdl:binding/wsdl:operation/wsdl:output
* wsdl:binding/wsdl:operation/wsdl:fault
then an RM policy assertion, specifying wsp:Optional=true MUST be attached to the corresponding
wsdl:binding or wsdl:port, indicating that the endpoint supports WS-RM."

Daniel Roth


________________________________
From: Yalcinalp, Umit [mailto:umit.yalcinalp@sap.com]
Sent: Wednesday, October 25, 2006 9:52 AM
To: Daniel Roth
Cc: public-ws-policy@w3.org
Subject: RE: Proposal for Resolution of 3564

Dan,

Perhaps you are looking at a different version of the RM Policy?

For your last point, please see the statement from WS-RMP for clear guidance on this point.


Any messages, regardless of whether they have an attached Message Policy Subject RM policy assertion, MAY be sent to that endpoint using WS-RM. Additionally, the receiving endpoint MUST NOT reject any message belonging to a Sequence, simply because there was no Message Policy Subject RM policy assertion attached to that message.

See Lines 163-165 in [1].

--umit

[1] http://docs.oasis-open.org/ws-rx/wsrmp/200608/wsrmp-1.1-spec-cd-04.pdf

________________________________
From: Daniel Roth [mailto:Daniel.Roth@microsoft.com]
Sent: Wednesday, Oct 25, 2006 9:16 AM
To: Yalcinalp, Umit
Cc: public-ws-policy@w3.org
Subject: RE: Proposal for Resolution of 3564
Hi Umit,

Here is the bullet point that I suggested cutting with comments inline:

+ When optional behaviors are attached with only one side of an
> interaction, such as an inbound message of a request-response, the
> engagement of the rest of the interaction will be undefined.

I think this is true regardless of whether the behaviors are optional.  The inbound message policy doesn't tell you anything about the outbound message policy

> For example, if a request-response interaction only specified MTOM
> optimization for an inbound message, it would not be clear whether the
> outbound message from the provider could also utilize the
> behavior.

I believe this would be made clear by attaching policy to the outbound message, or by using the operation subject instead of the message subject.

> Therefore, the assertion authors are encouraged to consider
> how the attachment on a message policy subject on a response message
> should be treated when optional behaviors are specified for message
> exchanges within a request response for response messages. Leaving the
> semantics undescribed may result in providers making assumptions
> (i.e. if the incoming message utilized the optimization, the response
> will be returned utilizing the MTOM serialization).

I think the assertion author would utilize the operation subject if they want to tie together the policy for the inbound and outbound messages.

> Similarly, if engagement of a behavior is only specified for an outbound message,
> it may be necessary to describe the semantics if the incoming messages
> also utilized the behavior. WS-RM Policy currently allows the
> incoming messages to utilize WS-RM protocol to be engaged although the
> assertion may only appear on an outbound message in a request
> response.
I don't see this behavior defined in WS-RM Policy.  I also don't see the justification for this guidance.

Daniel Roth

________________________________
From: Yalcinalp, Umit [mailto:umit.yalcinalp@sap.com]
Sent: Wednesday, October 25, 2006 8:52 AM
To: Daniel Roth
Cc: public-ws-policy@w3.org
Subject: RE: Proposal for Resolution of 3564

Dan,

Thanks for the reviewing this.

Could you elaborate why you want the specific points removed? They are included to caution users about the scope of their assertions and they certainly do not mandate but caution. So I want to understand what the concern is.

--umit


________________________________
From: Daniel Roth [mailto:Daniel.Roth@microsoft.com]
Sent: Wednesday, Oct 25, 2006 8:49 AM
To: Yalcinalp, Umit
Cc: public-ws-policy@w3.org
Subject: RE: Proposal for Resolution of 3564
Hi Umit,

I have reviewed this proposal and it looks good.

I have the following comments (see attached doc):
The first paragraph uses the phrase "optional assertions" while the rest of the doc uses the phrase "optional behaviors.  For consistency, I suggest we use "optional behaviors" throughout this section.
I pulled out the recommendation to not put policy on outbound messages into its own bullet point.
The second to last bullet point isn't specific to optional behaviors.  I propose that we cut this bullet point.
Other minor editorial cleanups

It looks like this material is already in the guidance doc.  I propose that we accept this material with the attached changes to resolve issue 3564.

Thanks for putting this material together!

Daniel Roth


________________________________
From: public-ws-policy-request@w3.org [mailto:public-ws-policy-request@w3.org] On Behalf Of Christopher B Ferris
Sent: Monday, October 23, 2006 12:08 PM
To: Yalcinalp, Umit
Cc: public-ws-policy@w3.org
Subject: Re: Proposal for Resolution of 3564


All,

On the telcon 2 weeks ago, it was suggested during the discussion that Umit's email may hold a key to
unraveling the "tarball" ( I like to refer to it as the hairball, since I have none).

All were encouraged to review Umit's note and continue discussion on the mailing list.

I would like to resume the discussion on this topic this week. So, please do review
Umit's proposal and be prepared to discuss. If you have a better suggestion, please
do make a proposal and send it to the list.

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 10/03/2006 07:00:09 PM:

> Folks,
> As we have decided to divide the understanding the framework
> concerns from the assertion development concerns, below find the
> proposal for Optional Assertions as we would like to propose for the
> Author's Guidelines Document.
> In this proposal, it is assumed that the Primer will introduce an
> example as it does today and the Assertion Guidelines document will
> refer to the example by further guidance and illustration of
> pitfalls. These pitfalls that are covered below were also noted in
> the creation of this issue [3564]
> In developing this proposal, I realized that we have a separate
> issue with the Primer document, namely the choice of MTOM capability
> as an example for optional assertions. I am creating a new issue for
> that so it can be tackled separately. The current writeup, as it
> refers to the Primer, assumes that such an assertion exists but the
> text can easily be changed to refer to WS-RMP, or any other
> assertion that is currently in practice to be used with
> optional="true" marker. Therefore, please keep that in mind while
> reading this proposal.
> Thanks,
> --umit
> [3564] http://www.w3.org/Bugs/Public/show_bug.cgi?id=3564
> -------------------------------------------------------------------------------------------------------------------------------
> Section 5.7 Optional Policy Assertion:
> Optional assertions represent behaviors which may be engaged by a
> consumer. When using the compact authoring form for assertions,
> behaviors are marked by using wsp:optional attribute that has a
> value, "true". During the process of normalization, the runtime
> behavior is indicated by two policy alternatives, one with and one
> without containing the assertion. In a consumer/provider scenario, the
> choice of engaging the runtime behavior is upon the consumer although
> the provider is capable of engaging the runtime behavior.
> The Primer document contains an example that proposes MTOM as an
> optional behavior that can be engaged by a consumer. The primer
> proposes that this assertion identifies the use of MIME
> Multipart/Related serialization for messages to enable a Policy-aware
> clients to recognize the policy assertion and if they select an
> alternative with this assertion, they engage Optimized MIME
> Serialization for messages.
> The semantics of this assertion declare that the behavior is reflected
> in messages: they use an optimized wire format (MIME Multipart/Related
> serialization). Note that in order for an optional behaviors to be
> engaged, the wire message that would utilize the specific assertion
> must be self describing. For example, an inbound message to a web
> service that asserts MTOM, must evaluate, the protocol format of the
> message to determine whether the incoming message adheres to the
> Optimized MIME Serialization. By examining the message, the provider
> can determine whether the policy alternate that contains the MTOM
> assertion is being selected.
> Assertion authors should be aware that optional behaviors, like
> utilizing optional support for Optimized MIME Serialization require
> some care.
> + Since optional behaviors indicate optionality for both the provider
> and the consumer, behaviors that must always be engaged by a consumer
> must not be marked as "optional" with a value "true" since presence of
> two alternatives due to normalization enables a consumer to choose the
> alternative that does not contain the assertion, and thus making the
> behavior not being engaged in an interaction.
> + As demonstrated in the MIME optimization behavior, behaviors must
> be engaged with respect to messages that are targeted to the provider
> so that the provider can determine that the optional behavior is
> engaged. In other words, the requirement of self describing nature of
> messages in order to engage behaviors must not be forgotton with
> regard to the client's ability to detect and select the alternative if
> it is to participate in the exchange. It is recommended that authors
> not utilize optional assertions for outbound messages unless there is
> explicit, out of band mechanism (currently such a mechanism is outside
> the scope of WS-Policy Framework) that a client can use to indicate
> that the optional capability must be engaged.
> + When optional behaviors are attached with only one side of an
> interaction, such as an inbound message of a request-response, the
> engagement of the rest of the interaction will be undefined. For
> example, if a request-response interaction only specified MTOM
> optimization for an inbound message, it would not be clear whether the
> outbound message from the provider could also utilize the
> behavior. Therefore, the assertion authors are encouraged to consider
> how the attachment on a message policy subject on a response message
> should be treated when optional behaviors are specified for message
> exchanges within a request response for response messages. Leaving the
> semantics undescribed may result in providers making assumptions
> (i.e. if the incoming message utilized the optimization, the response
> will be returned utilizing the MTOM serialization). Similarly, if
> engagement of a behavior is only specified for an outbound message,
> it may be necessary to describe the semantics if the incoming messages
> also utilized the behavior. WS-RM Policy currently allows the
> incoming messages to utilize WS-RM protocol to be engaged although the
> assertion may only appear on an outbound message in a request
> response.
> + Optional assertion authors should explicitly state how the
> capability that is enabled by the assertion would be engaged when they
> are designing their assertion, whether by specific headers or some
> other means.
> ----------------------
> Dr. Umit Yalcinalp
> Architect
> NetWeaver Industry Standards
> SAP Labs, LLC
> Email: umit.yalcinalp@sap.com Tel: (650) 320-3095
> SDN: https://www.sdn.sap.com/irj/sdn/weblogs?blog=/pub/u/36238
> --------
> "First they ignore you, then they ridicule you,
> then they fight you, then you win." Gandhi
Received on Wednesday, 25 October 2006 17:05:10 GMT

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