- From: Jacek Kopecky <jacek@systinet.com>
- Date: Thu, 8 Nov 2001 10:51:22 +0100 (CET)
- To: Doug Davis <dug@us.ibm.com>
- cc: "Williams, Stuart" <skw@hplb.hpl.hp.com>, <xml-dist-app@w3.org>
Doug,
the spec must say to whom the body blocks are addressed. I says
now it's the default/[whatever] actor. If we make the change, the
addressing of body would not be the default (any) but the final -
therefore I feel the need for .../final.
Anyway, anyone can shoot themselves in the foot by designing an
application in the wrong way, I don't think that our omission of
.../final would force everyone to make sane applications. If a
piece of processing can possibly be made by a non-final node, the
actor URI should reflect it and not be .../final. I'd leave this
to the architects. 8-)
Jacek Kopecky
Senior Architect, Systinet (formerly Idoox)
http://www.systinet.com/
On Wed, 7 Nov 2001, Doug Davis wrote:
> Obviously, I like the idea of making no-actor semantically
> equal to what actor="any" would have meant - it makes a lot
> more sense to me. I need to think more about whether the
> idea of having a "final" (pick your favorite word) actor
> is a good idea - can't explain why, but for some reason it
> feels strange to allow the client to specify which HOP in
> the message path instead of which actor/role should process
> a header.
> <warning-ramblings>
> Should a sender be allowed to say "only process
> this header on the same Node that processes the Body" - this
> is in essence what actor="final" will do. Shouldn't we allow
> someone to configure it so that all headers are processed
> by intermediaries and the Body on the ultimate recipient
> (how they share the data is up to them)? Remember, the semantic
> meaning behind the Header(and actor?) will say how the header
> changes the processing of the Body, so as long as those rules
> are adhered to should we really care whether its on one Node
> or two? And of course, this configuration should be transparent
> to the sender - so by having a "final" actor we could be
> breaking their configuration. Aside from actor="next" (always
> have to have one exception to any rule), it seems like headers
> should be required to ask that they be processed by a Node
> who is agreeing to take on a "role" rather than they just happen
> to appear at the right place in the message path.
> </warning-ramblings>
> But I need to think more about it...
>
> -Dug
>
>
> Jacek Kopecky <jacek@systinet.com> on 11/07/2001 12:33:28 PM
>
> To: Doug Davis/Raleigh/IBM@IBMUS
> cc: "Williams, Stuart" <skw@hplb.hpl.hp.com>, <xml-dist-app@w3.org>
> Subject: RE: Issue 146 (default and anon actors, endpoints and ultimate re
> cipients - for danbri :-))
>
>
>
> Doug,
> I think your semantics were intended for the .../any actor URI.
> IIRC we've decided against it, but I don't recall the reasons,
> probably "against the rest of the actor semantics". 8-)
> I think the solution could be to redefine the default actor to
> be as you want it (equivalent to .../any) and add a .../default
> for the "final", "ultimate", whichever of the synonyms.
> The rationale: I think it's not assymetric if nothing (omitted
> actor) has different meaning from something (actor specified). I
> think that it is assymetric when nothing brings a default
> something (default meaning of the omitted actor), and all
> somethings have such and such semantics, with the one exception
> (.../any).
> But this change might be pushed against by those who value
> backwards compatibility between 1.2 and 1.1 more than I do. 8-)
> Best regards,
>
>
> Jacek Kopecky
>
> Senior Architect, Systinet (formerly Idoox)
> http://www.systinet.com/
>
>
>
> On Tue, 6 Nov 2001, Doug Davis wrote:
>
> > Agreed - "processing" is different than "just peeking". :-)
> > I also agree that the wording you quoted does seem to prevent
> > the scenario I'd like to see us support - so using the current
> > spec how does someone say "here's a header, and I don't care
> > who *processes* it just as long as someone does" ? I'm beginning
> > to think that we don't allow this (as of now).
> >
> > In the 1.1 spec it says:
> > The SOAP actor global attribute can be used to indicate
> > the recipient of a header element.
> > Its the "can" part that interests me. I read that to mean
> > that there may be other pieces of information that determine
> > who the recipient is. So, in my head (scary place) I extended
> > that to mean that any Node along the path may pick-off any header
> > and *process* it - as long as it adheres to the semantics defined
> > by the header. And if this were true then my scenario would
> > be supported. But we seem (based on ch2) to be headed away from
> > this.
> >
> > -Dug
> >
> >
> > "Williams, Stuart" <skw@hplb.hpl.hp.com> on 11/06/2001 10:14:45 AM
> >
> > To: Doug Davis/Raleigh/IBM@IBMUS
> > cc: xml-dist-app@w3.org
> > Subject: RE: Issue 146 (default and anon actors, endpoints and ultimate
> re
> > cipients - for danbri :-))
> >
> >
> >
> > Hi Dug,
> >
> > So now on the other tack of discussing the issue rather than framing
> it...
> >
> > The 'tricky' word in what you describe is 'processed'. I think that
> we've
> > long agreed that there is little we can do to prevent any SOAP Node
> along
> > the message path peeking inside any part of the message (other than
> > encrypting it out of sight). I don't think that just looking constitues
> > processing. According to the Section 2 rules processing a SOAP Message
> at a
> > SOAP Node involves the removal (and possible replacement) of header
> blocks
> > targetted at that node [1]
> >
> > Part 1 section 2.3 defines the targetting of SOAP headers and states
> > "...SOAP header blocks with no such attribute information item [actor]
> and
> > the SOAP body are implicitly targeted at the anonymous SOAP actor,
> implying
> > that they are to be *processed* by the *ultimate SOAP receiver*."
> >
> > I guess you would argue... yes, but it doesn't say that blocks targetted
> at
> > default/anon can't be 'processed' elsewhere. It seems to me that all the
> > indications in the spec. are that default/anon is intended to denote the
> > ultimate recipient. I think this make it pretty implicit that there is
> only
> > one default/anon actor per message (excepting multicast cases!) - which
> > SOAP
> > Node along a message path takes on the default/anon actor role may be
> > emergent, but I think it is always the last node on the message path for
> > that message.
> >
> > It may be that we want to separate the concepts of default actors,
> > anonymous
> > actors and ultimate recipients, but I think the terms have grown up as
> > synonyms and if they are distinct then we have not described the
> > differences.
> >
> > Regards
> >
> > Stuart
> > [1] http://www.w3.org/TR/soap12-part1/#procsoapmsgs
> > [2] http://www.w3.org/TR/soap12-part1/#N4002A2
> >
> > > -----Original Message-----
> > > From: Doug Davis [mailto:dug@us.ibm.com]
> > > Sent: 06 November 2001 13:03
> > > To: xml-dist-app@w3.org
> > > Subject: RE: Issue 146
> > >
> > >
> > > Stuart,
> > > Yep, sorry, I misunderstood your note. Related to the issue at hand,
> > > I'm wondering how people view the following example:
> > > <env>
> > > <headers>
> > > <h1 MU="1"/>
> > > <h2 MU="1"/>
> > > </headers>
> > > <body.../>
> > > </env>
> > >
> > > h1 and h2 don't have actor attributes.
> > > As you said in your note, people are using the terms default actor,
> > > anonymous actor and ultimate recipient interchangeably, so can h1
> > > and h2 be processed by anyone other than the ultimate recipient?
> > > I always thought so. I interpreted it this way:
> > > - any node along the message path may process untargeted headers
> > > as long as they fully understand the semantics of the header
> > > - the ultimate recipient, however, MUST assume the role of
> > > default/anonymous actor. Meaning that it MUST process h1 and h2
> > > if they are still in the message.
> > > The main reason I see behind allowing other nodes to assume the role
> > > of the anon actor is that a client knows nothing about the message
> > > path - all it really knows is the one/next node it is supposed to
> > > send it's message to. So, there will be times when it does not know
> > > what Nodes the message will pass through and as such can't control
> > > which Node along the message path will process which part - so by
> > > leaving the "actor" off (IMO) it is saying "I don't care which exact
> > > Node processes this header, just as long as it does get processed
> > > (hence the MU="1")."
> > > So, while I agree that the ultimate recipient is also the default/anon
> > > actor - I do not agree that a Node that acts as a default/anon
> > > actor is also the ultimate recipient.
> > > Am I alone in this interpretation?
> > > -Dug
> > >
> >
> >
>
>
>
>
>
Received on Thursday, 8 November 2001 04:51:32 UTC