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RE: Issue 146 (default and anon actors, endpoints and ultimate re cipients - for danbri :-))

From: Williams, Stuart <skw@hplb.hpl.hp.com>
Date: Wed, 7 Nov 2001 18:50:11 -0000
Message-ID: <5E13A1874524D411A876006008CD059F19273B@0-mail-1.hpl.hp.com>
To: "'Doug Davis'" <dug@us.ibm.com>, Jacek Kopecky <jacek@systinet.com>
Cc: xml-dist-app@w3.org
Doug,

This is not to take a particular position here, but I believe that the terms
default actor, anonymous actor and ultimate recipient are used widely
throughout our documents. I believe in their current usage they were
intended to be synonymous. We will have to be very careful about the impact
of changeing the meaning of any one of these terms with respect to the
actual and intended meaning of our documentation... 

Personnally, I'd like a most one term for one concept :-) and if we're
introducing new concepts I'd appeal for new terms rather than reuse of old
ones.

Cheers,

Stuart
> -----Original Message-----
> From: Doug Davis [mailto:dug@us.ibm.com]
> Sent: 07 November 2001 18:31
> To: Jacek Kopecky
> Cc: Williams, Stuart; xml-dist-app@w3.org
> Subject: RE: Issue 146 (default and anon actors, endpoints 
> and ultimate
> re cipients - for danbri :-))
> 
> 
> 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 Wednesday, 7 November 2001 13:50:34 GMT

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