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RE: Generic proposal for enganging MTOM in WSDL 2.0

From: Jonathan Marsh <jonathan@wso2.com>
Date: Mon, 27 Nov 2006 10:58:00 -0800
To: "'Arthur Ryman'" <ryman@ca.ibm.com>, <paul.downey@bt.com>
Cc: <www-ws-desc@w3.org>
Message-ID: <013c01c71255$f71d9660$3901a8c0@DELLICIOUS>
My first reaction to this clever idea was that the profile unfortunately
goes against the style encouraged by WS-Policy specs, which is to use
PolicyReference elements pointing to top-level policies.  This is
illustrated in the primer [1].  I think this style is more readable and
maintainable than embedding policy expressions inside WSDL operations, and
seems to be the current practice on the ground.  The profile of policy that
the proposal below implies doesn't match this style, and therefore it's
unlikely to be as broadly interoperable as we'd like. 




Jonathan Marsh -  <http://www.wso2.com> http://www.wso2.com -
<http://auburnmarshes.spaces.live.com> http://auburnmarshes.spaces.live.com



From: www-ws-desc-request@w3.org [mailto:www-ws-desc-request@w3.org] On
Behalf Of Arthur Ryman
Sent: Friday, November 24, 2006 1:51 PM
To: paul.downey@bt.com
Cc: www-ws-desc@w3.org; www-ws-desc-request@w3.org
Subject: Re: Generic proposal for enganging MTOM in WSDL 2.0



I like the spirit of this proposal but it seems to me that you are proposing
to profile WS-Policy. Wouldn't it be better if the WS-Policy WG defined a
simple subset so that simple processors could implement it? This is like SVG
Tiny. Maybe we need a WS-Policy Tiny? 

Arthur Ryman,
IBM Software Group, Rational Division

blog: http://ryman.eclipsedevelopersjournal.com/
phone: +1-905-413-3077, TL 969-3077
assistant: +1-905-413-2411, TL 969-2411
fax: +1-905-413-4920, TL 969-4920
mobile: +1-416-939-5063, text: 4169395063@fido.ca 

Sent by: www-ws-desc-request@w3.org 

11/14/2006 04:39 AM 






Generic proposal for enganging MTOM in WSDL 2.0




One of the issues resulting from the removal of Features and Properties
from WSDL 2.0 is the loss of the ability to make simple assertions to
indicate a feature is engaged.  

Applying such assertions as first class WSDL extension elements,
whilst possible, is unlikely to achieve interoperability in a world
dominated by WS-Policy. 

But supporting the whole of WS-Policy is seen as too high a bar 
for simple processors whose only use-case is applying simple assertions
such as engaging MTOM or Addressing. 


WSDL 2.0 provides an extension attribute which MAY be used to indicate
a WS-Policy attachment is "vanilla", only contains a single set of 
assertions and does not contain any compositors, e.g.:

 <Policy wsdli:simpleAssertions="true">
   <wsoma:OptimizedMimeSerialization /> 
   <wsa:UsingAddressing />

A non-Policy aware processor may process the wrapped assertions
as just another hop in their XPaths, and yet continue to interoperate
with processors which support the whole of WS-Policy.

In the case of MTOM, there still needs to be a set of extension elements
defined, but there is work in this area, all be it currently 
outside of a recognised standards body [1].


Received on Monday, 27 November 2006 18:58:25 UTC

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