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RE: operation safety as semantic annotation?

From: Arthur Ryman <ryman@ca.ibm.com>
Date: Thu, 1 Feb 2007 16:08:47 -0500
To: Jacek Kopecky <jacek.kopecky@deri.org>
Cc: Jonathan Marsh <jonathan@wso2.com>, "'WS-Description WG'" <www-ws-desc@w3.org>, www-ws-desc-request@w3.org
Message-ID: <OFB5147635.02F186A4-ON85257275.007241BE-85257275.00742936@ca.ibm.com>
Jack,

I disagree that safety is a semantic annotation. 

Theorem: Safety tells you nothing about the semantics of the operation.


Proof: Consider the same service deployed at two endpoints, say just 
giving you stock quotes:

Service 1 is safe but returns quotes over HTTP so someone could spy on you 
and see what quotes you are interested in.
Service 2 is unsafe since you need an account and you get charged $1 per 
request, but the quotes are returned over HTTPS.

Same "semantics" for both but not the same safety. QED


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



Jacek Kopecky <jacek.kopecky@deri.org> 
Sent by: www-ws-desc-request@w3.org
02/01/2007 10:10 AM

To
Arthur Ryman/Toronto/IBM@IBMCA
cc
Jonathan Marsh <jonathan@wso2.com>, "'WS-Description WG'" 
<www-ws-desc@w3.org>
Subject
RE: operation safety as semantic annotation?







Dear Arthur, 

previously, when the expressing of operation safety was discussed, we
didn't have SAWSDL so we couldn't consider using it. I'm asking that we
should.

I wonder if we might want to ask the TAG's opinion on this, as they
requested that we add this feature, and we still have an open issue
CR021 for the purpose of tracking the development of the safety
assertion feature for them. I could ask them if we feel it could help.

I just think that in the long term, putting the safety assertion into
WSDL using a SAWSDL model reference is the right thing - it would put
the assertion where it belongs and thus also help people understand the
role of SAWSDL.

But I won't object to closing CR147 with no action if the groups
considers and rejects it.

Jacek

On Thu, 2007-02-01 at 09:35 -0500, Arthur Ryman wrote:
> 
> Jonathan, 
> 
> The {safety} property was discussed at length by the working group and
> we implemented its decision. I see no reason to reopen it now. We
> should be focusing on getting to PR. 
> 
> 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 
> 
> 
> "Jonathan Marsh"
> <jonathan@wso2.com> 
> Sent by:
> www-ws-desc-request@w3.org 
> 
> 01/31/2007 04:06 PM 
> 
> 
>                To
> "'Jacek Kopecky'"
> <jacek.kopecky@deri.org>, "'WS-Description WG'" <www-ws-desc@w3.org> 
>                cc
> 
>           Subject
> RE: operation
> safety as
> semantic
> annotation?
> 
> 
> 
> 
> 
> 
> 
> 
> 
> AIUI, adding such an attribute would result in a {model reference}
> property
> being added to the WSDL, along with the {safety} attribute.  Are you
> OK with
> having duplicate information in the component model?
> 
> Currently, the HTTP binding requires the wsdlx:safe extension be
> supported
> for interoperability.  Will it be clear that
> sawsdl:modelReference="
http://www.w3.org/2006/01/wsdl-extensions#SafeInterac
> tion" is still required to be supported, but that the whole sawsdl
> extension, including any {model reference} properties, need not be?
> 
> Right now we declare in the interchange format which extensions are
> supported, by URI (usually the namespace URI).  We would be unable to
> use
> the SAWSDL namespace URI to indicate this "safe sawsdl profile"
> extension is
> engaged - I guess we would continue to use the wsdlx namespace for
> this
> purpose.
> 
> It all seems kind of messy.  My ideal would be to simply remove the
> wsdlx:safe and the {safety} attribute from WSDL and rely wholly on
> SAWSDL
> for this functionality.  The interaction between {safety} and the HTTP
> method selection is artificial IMO.  If one's intention is to use GET,
> then
> marking something as safe is no harder, and in fact one level more
> abstract
> and therefore tricky, than marking the whttp:method as GET. 
> 
> Anyway, this will be issue CR147.
> 
> Jonathan Marsh - http://www.wso2.com -
> http://auburnmarshes.spaces.live.com
> 
> 
> > -----Original Message-----
> > From: www-ws-desc-request@w3.org [mailto:www-ws-desc-request@w3.org]
> On
> > Behalf Of Jacek Kopecky
> > Sent: Monday, January 29, 2007 7:04 AM
> > To: WS-Description WG
> > Subject: RFC: operation safety as semantic annotation?
> > 
> > 
> > Dear all,
> > 
> > as you may know, the specification for Semantic Annotations for WSDL
> and
> > XML Schema [1] (SAWSDL) moving to CR. In our institute (my W3C hats
> are
> > off), we work on Semantic Web Services, and we plan to use SAWSDL as
> the
> > glue between our semantic description language and WSDL.
> > 
> > For my work, I will need to know the semantic description, i.e. what
> the
> > various service operations and data mean and do. One piece that I
> need
> > is operation safety. Currently, that is realized in WSDL as an
> extension
> > attribute, wsdlx:safe="boolean", with the default being false.
> > 
> > Operation safety is, at least to me, a clear semantic annotation. It
> > says nothing about the structure of the interface, instead it
> indicates
> > what the operation does (or rather, what it doesn't do - any side
> > effects or additional obligations in Web Architecture speak).
> > 
> > I would propose that we change the syntax from wsdlx:safe="true"  to
> > sawsdl:modelReference="http://www.w3.org/2006/01/wsdl-
> > extensions#SafeInteraction"
> > I know it's much longer, but please bear with me. 8-)
> > 
> > The WSDL Interface Operation {safety} property can stay as it is,
> only
> > its XML representation would change to "the IRI for SafeInteraction
> (as
> > above) will be included among the IRIs that are the value of
> > sawsdl:modelReference". The URI above is currently used in the RDF
> > mapping of WSDL to represent the safety property.
> > 
> > At worst, the people hand-writing and reading WSDL would have their
> > lives just a bit harder. At best, this would blend right in with the
> > plethora of other semantic annotations. Certainly, from my own point
> of
> > view, having safety as a semantic annotation as opposed to an
> extension
> > attribute would make my life just a bit easier.
> > 
> > Thanks for your consideration,
> > Jacek
> > 
> > [1] http://w3.org/tr/sawsdl
> 
> 
> 
> 
Received on Thursday, 1 February 2007 21:09:02 GMT

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