RE: Intermediaries

Frank,
I doubt we are going to solve that problem in the little more than a month left ...

Ugo

> -----Original Message-----
> From: Francis McCabe [mailto:fgm@fla.fujitsu.com]
> Sent: Friday, December 05, 2003 12:30 PM
> To: Ugo Corda
> Cc: <www-ws-arch@w3.org>
> Subject: Re: Intermediaries
> 
> 
> I kind of take a mild exception to this Ugo. I don't think it is fair 
> to say that I am try to "satisfy my philosophical interests" with 
> computer technologies.
> 
> I am banging on quite a lot about intermediaries because I think that 
> it represents a way into a very difficult problem: how to actually 
> build large scale systems.
> 
> Frank
> 
> 
> On Dec 5, 2003, at 12:16 PM, Ugo Corda wrote:
> 
> >
> > Roger,
> >
> > I would not go for the deep philosophical meaning in all 
> this. We just 
> > have to acknowledge that specs have always some 
> underspecified areas. 
> > Maybe when WS-I decides to tackle intermediaries in a Basic Profile 
> > (right now they are just "extension points"), it will pick a 
> > particular interpretation of this subject and run with it.
> >
> > In my view, computer technologies are not the right place 
> to look when 
> > you want to satisfy your philosophical interests ;-).
> >
> > Ugo
> >
> >> -----Original Message-----
> >> From: www-ws-arch-request@w3.org 
> [mailto:www-ws-arch-request@w3.org]On
> >> Behalf Of Cutler, Roger (RogerCutler)
> >> Sent: Friday, December 05, 2003 11:59 AM
> >> To: Ricky Ho; www-ws-arch@w3.org
> >> Subject: RE: Intermediaries
> >>
> >>
> >>
> >> I might also comment that Frank seems to have a more 
> Olympian view of
> >> the matter and, as far as I can tell, is saying that the 
> messages are
> >> "the same" because we DEFINE them to be the same, not 
> because they are
> >> judgeed to be the same by any criteria.  Maybe I didn't 
> put this quite
> >> right because I don't understand what he is saying, so I
> >> didn't make an
> >> effort to capture it.
> >>
> >> -----Original Message-----
> >> From: www-ws-arch-request@w3.org
> >> [mailto:www-ws-arch-request@w3.org] On
> >> Behalf Of Cutler, Roger (RogerCutler)
> >> Sent: Friday, December 05, 2003 1:53 PM
> >> To: Ricky Ho; www-ws-arch@w3.org
> >> Subject: RE: Intermediaries
> >>
> >>
> >>
> >> Again, this is sort of third hand -- I have been trying to
> >> capture what
> >> other people said.  However, I believe that the sense I 
> got from David
> >> Booth and others is that the issue of whether the message 
> going from A
> >> to I is "the same" as that going from I to B is something
> >> that has to be
> >> considered in the context of "the application", broadly
> >> understood. That
> >> is, "the application" includes both what A is doing and what
> >> B is doing.
> >> So I guess that there is a God-like observer involved in 
> this scenario
> >> or something.  I don't see how you can think about
> >> choreography without
> >> postulating some observer that can see everything that
> >> happens and whose
> >> observations correspond absolute reality, as opposed to what
> >> is visible
> >> to any particular participant.
> >>
> >> -----Original Message-----
> >> From: Ricky Ho [mailto:riho@cisco.com]
> >> Sent: Friday, December 05, 2003 1:30 PM
> >> To: Cutler, Roger (RogerCutler); www-ws-arch@w3.org
> >> Subject: RE: Intermediaries
> >>
> >>
> >> 1) I can't see how B or C can determine whether the modified
> >> message is
> >> the
> >> same message given that they haven't seen the original one.
> >>
> >> 2) SOAP doesn't have the "SAME MESSAGE" concept and therefore
> >> it is NOT
> >> possible to make such differentiation at the SOAP level.  In
> >> some other
> >> spec (such as RM), the "SAME MESSAGE" concept is very 
> important, there
> >> they
> >> define the messageID explicitly.
> >>
> >> About your encryption scenario, if determining the "SAME 
> MESSAGE" is
> >> important to me, then I have to decrypt the messageID.  And
> >> if I cannot
> >> decrypt it, I shouldn't process the message.
> >>
> >> Rgds, Ricky
> >>
> >> At 12:45 PM 12/5/2003 -0600, Cutler, Roger (RogerCutler) wrote:
> >>> I'm not an expert here, and I was mostly trying to capture
> >> the sense of
> >>
> >>> a conversation.  However, I believe that several people
> >> agreed that it
> >>> is, indeed, up to B and C to participate in this decision,
> >> and that the
> >>
> >>> "application" envisaged includes both sender and 
> receiver.  This was
> >>> explicitly stated, I believe, by both David Booth and at least one
> >>> other person, I've forgotten whom.
> >>>
> >>> About the messageID -- does a SOAP message necessarily 
> have one?  If
> >>> the intermediary encrypts the message, including the ID, 
> do you have
> >>> the same messageID?  It seems to me, from listening and
> >> participating
> >>> in a certain amount of conversation trying to sharpen up the
> >> concept of
> >>
> >>> "same message" that this is a swamp.
> >>>
> >>> -----Original Message-----
> >>> From: Ricky Ho [mailto:riho@cisco.com]
> >>> Sent: Friday, December 05, 2003 10:49 AM
> >>> To: Cutler, Roger (RogerCutler); www-ws-arch@w3.org
> >>> Subject: Re: Intermediaries
> >>>
> >>>
> >>> Can we use messageID to determine whether this is the "SAME"
> >> message ?
> >>> In other words, all other modification is insignificant.
> >>>
> >>> 1) Intermediary isn't the endpoint so it doesn't generate
> >> new messages,
> >>
> >>> so the message it send MUST have same messageID as some previous
> >>> messages it
> >>> received.
> >>> 2) Orchestration is the endpoint which produce or consume
> >> messages, so
> >>> the
> >>> message it send MUST have different messageID from 
> previous received
> >>> messages
> >>>
> >>> Going back to your example, it is NOT up the B and C to
> >> interprete the
> >>> changes made by I differently.  The decision is completely
> >> finalized by
> >>
> >>> I.
> >>>
> >>> Best regards,
> >>> Ricky
> >>>
> >>> At 09:44 AM 12/5/2003 -0600, Cutler, Roger (RogerCutler) wrote:
> >>>
> >>>> Here is some text that expresses my understanding of the sense of
> >>>> some of the telcon conversation about intermediaries.  
> Please use,
> >>>> modify or
> >>>
> >>>> ignor as seems appropriate.
> >>>>
> >>>> It is useful to draw a distinction between situations
> >> where messages
> >>>> are passed through intermediaries and choreographies.  The
> >> essential
> >>>> issue is that an intermediary passes along a message that is
> >>>> essentially, or functionally, the same as it received.  
> If, on the
> >>>> other hand, the purpose or function of the message is
> >> substantially
> >>>> changed one should consider the situation to be a
> >> choreography.  This
> >>
> >>>> cannot be defined, however, in an entirely rigorous or black and
> >>>> white way -- one person's intermediary may legitimately be
> >> considered
> >>
> >>>> a choreography by others. Note that since an intermediary
> >> can change
> >>>> the message, for example by encrypting it or by adding ancillary
> >>>> information, it remains a judgment call whether those changes are
> >>>> significant and functional.  In addition, whether a service that
> >>>> passes
> >>>
> >>>> messages is considered an intermediary depends on
> >> participants in the
> >>
> >>>> entire chain of the message.  For example, if sender A
> >> sends messages
> >>
> >>>> through I, which modifies the messages, to receivers B and
> >> C, B might
> >>
> >>>> consider the modified message to be functionally unchanged
> >> whereas C
> >>>> might consider it to be different and take different
> >> action because
> >>>> of the modification.  In the first case I would be considered an
> >>>> intermediary, in the second it would not.
> >>
> >>
> >>
> >>
> >>
> >>
> >
> 
>

Received on Friday, 5 December 2003 15:34:31 UTC