Re: Issue 168 (Which Operation?) / Requirement R114

Hugo Haas wrote:

>Hi David.
>
>* David Booth <dbooth@w3.org> [2004-06-30 14:18-0400]
>  
>
>>This message contains a fairly detailed analysis of issue 168 / requirement 
>>R114.
>>    
>>
>[..]
>  
>
>>R114
>>    The description language MUST allow unambiguously mapping any
>>on-the-wire Message to an Operation. (From WG discussion. Last revised 4
>>Apr 2002.)
>>    
>>
>[..]
>
>Thank you for this excellent analysis. I think that you framed the
>problem very well.
>
>  
>
>>OPTIONS FOR MOVING FORWARD
>>I believe the scenario above illustrates the heart of this dilemma.  Would 
>>this scenario represent an acceptable reality?  Or should this WG try to 
>>prevent it?  If so, how?
>>
>>We are now approaching Last Call, which is the time when we announce to the 
>>world that we believe we have met all of our requirements.  We cannot 
>>afford to delay LC, but we obviously have not yet met requirement 
>>R114.  What should we do?  I see a few options.
>>
>>Option 1a: Rescind requirement R114.
>>
>>Option 1b: Acknowledge in our LC draft that R114 has not been met, without 
>>formally rescinding it.  At this point I don't know if there is much 
>>difference between this option and option 1a.  Either one is likely to 
>>result in minority opinions being filed.
>>
>>Option 2: Come up with a new proposal and adopt it.  (But we are running 
>>out of time to do so.)
>>
>>Option 3: Reconsider an existing proposal.
>>    
>>
>
>I have been thinking about this over the past few days, and I reached
>the following conclusions.
>- this is an interoperability problem: as scenario X shows, it means
>  that a WSDL document could potentially not describe a service
>  precisely enough to allow the use of it.
>- there are ways to address the problem, that do not constrain
>  described services: while the unique GED proposal constrains
>  services, the WS-Addressing/WS-MD/operation name feature proposals
>  allow to disambiguate such cases.
>- because of its extensibility, WSDL 2.0 allows one to specify that
>  the use of such a mechanism is required in order to use the service
>  properly and unambiguously.
>
>Therefore, thinking out loud, I think that we could say in Part 1
>that, if the GED of operations is not unique, extra information must
>be used in order to unambiguously identify the operation relating to a
>message received by a service, by using a feature at the interface
>operation level. We could even define such a feature, say the
>Operation Name Specification Feature, which would be an abstract
>feature: we would not define how it is implemented (in SOAP, HTTP, or
>any other way), just noting that its use makes the receiver of the
>message aware of which operation the message is related to.
>
>WS-Addressing, WS-MD, Glen/Umit Operation Name, etc.  could then claim
>that they implement the Operation Name Specification Feature and
>therefore are valid solutions to this problem.
>
Hi Hugo,

I agree with your points. One thing to add however is that WSDL should 
also have a mechanism to indicate what is being engaged by the service 
to deliver the feature. By processing the WSDL, it is clear which 
mechanism is involved.

As a matter of fact, this is what I am intending to address with my 
proposal.

>
>And I believe that R114 would be met since WSDL 2.0 would allow such a
>description.
>
>Comments?
>
>Regards,
>
>
>Hugo
>  
>
Cheers,
--umit


-- 
Umit Yalcinalp                                  
Consulting Member of Technical Staff
ORACLE
Phone: +1 650 607 6154                          
Email: umit.yalcinalp@oracle.com