RE: Bug 6463: Attaching Policy to WS-Mex GetMetadata - Marked up proposal

Hi Asir

Thanks for your comments.

> We are afraid that the proposed Example 8-1 does not provide sufficient 
protocol binding information to allow requesters to issue a GetMetadata 
request against a service endpoint. For instance, how can a requester 
infer what is the version of SOAP? What is the underlying protocol 
transport?

We can exploit the fact that the WS-Metadata Endpoint is the same as the 
application endpoint  (that the EPR represents) and therefore would share 
its protocol binding information.  Hence, in this case, I don't think we 
require this information (it may be defaulted to).

> We think that the WS-MetadataExchange specification should provide an 
example that provides sufficient binding information, including policies 
(to address issue 6463), to bootstrap.

> The description of the alternative sounds right. But, example 7.1 
describes how to embed service metadata within an EPR. These are two 
different use cases. It might help to show case an example that 
illustrates how to embed a bootstrap binding in an EPR and how to attach a 
policy expression (to address issue 6463) to the bootstrap binding.

How about the attached update?  I've taken your example (from a previous 
email) and included it as example 8.2.  I have made some minor changes 
(the Identifier and tns on line 10 - let me know if I got this wrong). 
I've also added so explanation below the example for your review/comments 
and made some very minor tweaks to the other explanations to ensure that 
the explanations were consistent and that the text flows ok.

Regards,
Katy





From:
Asir Vedamuthu <asirveda@microsoft.com>
To:
Katy Warr/UK/IBM@IBMGB, "public-ws-resource-access@w3.org" 
<public-ws-resource-access@w3.org>
Date:
14/12/2009 17:13
Subject:
RE: Bug 6463: Attaching Policy to WS-Mex GetMetadata - Marked up proposal



Thanks Katy. 
 
Here are some initial comments on the proposal.
 
>In Example 8-1, a [WS-Addressing] endpoint reference to a service 
endpoint contains the metadata to allow requesters to issue a GetMetadata 
request against it
 
We are afraid that the proposed Example 8-1 does not provide sufficient 
protocol binding information to allow requesters to issue a GetMetadata 
request against a service endpoint. For instance, how can a requester 
infer what is the version of SOAP? What is the underlying protocol 
transport?
 
We think that the WS-MetadataExchange specification should provide an 
example that provides sufficient binding information, including policies 
(to address issue 6463), to bootstrap.
 
>As an alternative to using MetadataLocation (lines 08-17), the 
WS-MetadataExchange WSDL containing the appropriately attached policy 
could have been embedded directly into the MetadataSection.  The embedded 
WSDL approach was used in example Example 7.1 to pass metadata in the EPR.
 
The description of the alternative sounds right. But, example 7.1 
describes how to embed service metadata within an EPR. These are two 
different use cases. It might help to show case an example that 
illustrates how to embed a bootstrap binding in an EPR and how to attach a 
policy expression (to address issue 6463) to the bootstrap binding.
 
We will be more than happy to work with Katy to prepare a revised 
proposal.
 
Regards,
 
Asir S Vedamuthu
Microsoft Corporation
 
From: public-ws-resource-access-request@w3.org [
mailto:public-ws-resource-access-request@w3.org] On Behalf Of Katy Warr
Sent: Monday, December 07, 2009 10:42 AM
To: public-ws-resource-access@w3.org; Asir Vedamuthu
Subject: Bug 6463: Attaching Policy to WS-Mex GetMetadata - Marked up 
proposal
 

Following my action to create a markup version of the proposal for bug 
http://www.w3.org/Bugs/Public/show_bug.cgi?id=6463, please find the marked 
up document attached.  The changes are all in Section 8 (and an example is 
moved from section 7). 



Asir, 

The difference between your example and my previous one is primarily that 
you have embedded the WSDL metadata within the EPR, rather than using 
Policy Attachments.   

Whilst both approaches work, I believe that we should have a wider 
variation of examples within the specification in order to illustrate 
different features and usage scenarios. From my experience, a wide range 
of examples is of great benefit to developers.  Embedded WSDL is already 
illustrated in example 7-1.   

In this particular example (8.1), policy attachments also work very well 
as it provides a mechanism to associate policy with a single operation 
without having the whole WSDL included within the EPR. 

As a suggested compromise, I've included the policy attachments example 
(8-1) in the proposal attached to this mail, but added a detailed 
explanation below it in order to aid understanding.  I have also added 
some text to say that the WSDL could be embedded, as an alternative 
approach. 

Regards 
Katy 



 
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Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 
741598. 
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU