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Re: New issue: Default value of To property

From: Anish Karmarkar <Anish.Karmarkar@oracle.com>
Date: Mon, 30 Jan 2006 12:39:40 -0800
Message-ID: <43DE798C.10501@oracle.com>
To: Marc Hadley <Marc.Hadley@Sun.COM>
CC: Francisco Curbera <curbera@us.ibm.com>, Mark Nottingham <mnot@mnot.net>, WS-Addressing <public-ws-addressing@w3.org>

Marc Hadley wrote:
> I think it complicates things to have a default in some circumstances  
> and not others. Provided the default value is always the same  
> (anonymous in our case), it is easy to formulate the value of MAPs  and 
> check the validity of an inbound message regardless of whether  the 
> message is a request, response, notification, fault or some other  
> classification that we haven't yet come up with. If we start adding  
> provisos to the defaulting rules then things just get more complex  and 
> we'll end up introducing edge cases etc.
> 

I agree that making a special case default makes things complex 
(specifically because [destination] is required and wsa:To is optional) 
when checking for validity. I would rather:
1) keep things as is (resolution of CR18 will tell us what, if any, anon 
wsa:To means in a request message) OR
2) make wsa:To required and remove default
3) make [destination] optional and remove default

-Anish
--

> To be honest I'm not clear what problem you are trying to solve, why  is 
> it better to have an explicit <wsa:To>http://.../../anonymous</ wsa:To> 
> in the message than an implicit default one ?
> 
> FWIW, I can see that having an anonymous wsa:To in a request message  
> might cause some implementations difficulties, but changing the  
> defaulting rules won't fix this problem (you could still get an  
> explicit anonymous to) and as I outlined in my previous mail its  
> unlikely to occur in the first place. If an anonymous wsa:To in  request 
> messages is the problem you are trying to attack then I think  it would 
> be much more effective to work on that directly rather than  
> complicating the defaulting rules.
> 
> Marc.
> 
> On Jan 24, 2006, at 10:24 AM, Francisco Curbera wrote:
> 
>> Hi Marc,
>>
>> You are taking the sender's view only; there is also the receiver's  
>> view,
>> who may or may not have access to the EPR the sender used. In any  
>> case, it
>> is clear that any default works as long as it is not ambiguous.  What 
>> I am
>> arguing is that a default only makes sense when it cover (and maybe  
>> helps
>> optimize) a common case. It can certainly be argued that for  synchronous
>> request response interactions it makes sense to default the To of  the 
>> reply
>> message to anonymous. Arguing that that is also the case for all  
>> other uses
>> of WSA is to take a very narrow perspective IMO - particularly  since 
>> one of
>> WSA's major contributions is  to enable interoperable asynchronous
>> messaging over different interaction patterns.
>>
>> We essentially went through a similar argument when we recognized that
>> defaulting the [reply endpoint] to an EPR with an anonymous address  
>> makes
>> sense only in the context of Section 3.4 - Formulating a Reply  
>> Message. I
>> think we just need to finish the job and scope the defaulting of the
>> [destination] property to anonymous to the case of reply messages  as 
>> well.
>>
>> Paco
>>
>>
>>
>>
>>
>>                       Marc Hadley
>>                       <Marc.Hadley@Sun.COM>           To:        
>> Francisco Curbera/Watson/IBM@IBMUS
>>                       Sent by:                        cc:        Mark 
>> Nottingham <mnot@mnot.net>, WS-Addressing
>>                       public-ws-addressing-req         <public-ws- 
>> addressing@w3.org>
>>                       uest@w3.org                     Subject:  Re:  
>> New issue: Default value of To property
>>
>>
>>                       01/23/2006 10:50 AM
>>
>>
>>
>>
>>
>> I don't think we need to special-case things as you suggest since the
>> rules for sending a message[1] already require the wsa:To to have the
>> same address as that contained in the EPR to which the message is
>> sent. Therefore the only time the wsa:To value can be defaulted is
>> when the EPR to which the message is sent has an 'anonymous' address
>> and I don't see that happening regularly with request messages
>> because, if it did, you wouldn't know where to send then.
>>
>> Marc.
>>
>> [1] http://dev.w3.org/cvsweb/~checkout~/2004/ws/addressing/ws-addr-
>> core.html?content-type=text/html;%20charset=utf-8#sendmsgepr
>>
>>
>> On Jan 20, 2006, at 1:23 PM, Francisco Curbera wrote:
>>
>>>
>>> Can I please add this new CR issue against the WS-Addressing core
>>> spec.
>>>
>>> The spec currently defaults the value of the To property to anonymous
>>> (Core, 3.2); the goal of this decision was to optimize the request
>>> reply
>>> synchronous interaction. However, as written in Section 3.2 this
>>> applies to
>>> arbitrary messages. Just as in the case of ReplyTo, addressed in
>>> CR13, I
>>> propose the defaulting of To to anonymous be moved to Section 3.4 and
>>> limited to request reply interactions.
>>>
>>> Paco
>>>
>>>
>>
>> ---
>> Marc Hadley <marc.hadley at sun.com>
>> Business Alliances, CTO Office, Sun Microsystems.
>>
>>
>>
>>
>>
>> #### smime.p7s has been removed from this note on January 24, 2006 by
>> Francisco Curbera
>> <smime.p7s>
> 
> 
> ---
> Marc Hadley <marc.hadley at sun.com>
> Business Alliances, CTO Office, Sun Microsystems.
> 
> 
Received on Monday, 30 January 2006 20:43:04 GMT

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