Re: Initial formulation of intermediary semantics for MTOM

I'm generally in favor of the direction of the suggested changes. I'd 
like to see these made in conjunction with clarifying the relationship 
of MTOM to the current HTTP binding[1]. I think its possible that some 
of the things explicitly stated here would naturally fall out from such 
an effort, in particular the hop-by-hop nature.

Regards,
Marc.

[1] http://lists.w3.org/Archives/Public/xml-dist-app/2003Jul/0032.html

On Friday, Aug 29, 2003, at 18:14 US/Eastern, 
noah_mendelsohn@us.ibm.com wrote:

>
>
>
>
>
> I took an action item af the France f2f to formulate a proposal for
> intermediary handling of MTOM.  This note is in fulfillment of that 
> action.
> What I've written here is the rough outline of a direction.  The 
> proposal
> is as follows.  All section numbers are with respect to the MTOM WD at 
> [1]:
>
> <current fromSection="Introduction">
> The usage of the Abstract Transmission Optimization Feature is a 
> hop-by-hop
> contract between a SOAP node and the next SOAP node in the SOAP message
> path, providing no normative convention for optimization of SOAP
> transmission through intermediaries.
> </current>
> <proposed forSection="Introduction">
> The usage of the Abstract Transmission Optimization Feature is a 
> hop-by-hop
> contract between a SOAP node and the next SOAP node in the SOAP message
> path, providing no mandatory convention for optimization of SOAP
> transmission through intermediaries.   The feature does provide 
> optional
> means by which binding implementations MAY choose to facilitate the
> efficient passthrough of optimized data contained within headers or 
> bodies
> relayed by an intermediary.
> </proposed>
>
> <current fromSection="2.4.3 Transmitting a Message">
> The usage of the Abstract Transmission Optimization Feature is a 
> hop-by-hop
> contract between a SOAP node and the next SOAP node in the SOAP message
> path. Therefore, no specific rules exist for a SOAP intermediary
> implementing the Abstract Transmission Optimization Feature.
> </current>
> <proposed  forSection="2.4.3 Transmitting a Message">
> The usage of the Abstract Transmission Optimization Feature is a 
> hop-by-hop
> contract between a SOAP node and the next SOAP node in the SOAP message
> path. Therefore, no changes or restrictions to the SOAP processing 
> model
> are introduced by this feature at an intermediary.  Section 2.4.4 
> details
> the means by which certain optimizations can be performed by bindings 
> at
> intermediaries.
> </proposed>
>
> <proposed newSection="2.4.4 Binding Optimizations at Intermediaries">
> As described in SOAP Part 1 Section 2.7 Relaying SOAP Messages, a SOAP
> intermediary may be called upon to to relay intact certain headers, or 
> to
> reinsert headers identical to those received and removed for 
> processing.
> Furthermore, many intermediaries will relay unmodified the contents of 
> the
> SOAP body.   In all these cases, portions of the relayed message have
> content identical to corresponding portions of the inbound message.
>
> The Abstract Transmission Optimization Feature does not require any
> particular correspondence between the optimization of the inbound 
> message
> and the outbound message, even when optimized portions of the inbound
> message are relayed intact, or reinserted in identical form in the 
> envelope
> Infoset.  Nonetheless, the implementations of the receiving binding 
> and the
> binding used to transmit the relayed message MAY cooperate to provide
> efficient relay.  For example, if the inbound and outbound binding use 
> the
> same representation for optimized binary, the implementations MAY 
> cooperate
> to pass the optimized form directly from the inbound to the outbound
> binding.  The choice of whether to implement such cooperation, and if 
> so
> the means used, is at the discretion of the binding specification(s) 
> and/or
> the implementation of the bindings.
>
> Note:  a consequence of these rules is that there are no invariant 
> rules
> for the degree to which optimizations are preserved as a message passes
> through intermediaries.  Certain outbound bindings may be incapable of 
> any
> optimization, and will therefore transmit unoptimized forms in all 
> cases.
> Other bindings may be capable of optimization, but may or may not 
> choose to
> or succeed in optimizing the same portions (if any) that were 
> optimized in
> the inbound message.  Other bindings, perhaps under the direction of 
> logic
> provided in SOAP modules or perhaps as consequence of conventions 
> embodied
> in the bindings, may optimize portions of the message that were not
> optimized inbound, or which were optimized using different techniques.
> </proposed>
>
> [1] http://www.w3.org/TR/soap12-mtom/
> ------------------------------------------------------------------
> Noah Mendelsohn                              Voice: 1-617-693-4036
> IBM Corporation                                Fax: 1-617-693-8676
> One Rogers Street
> Cambridge, MA 02142
> ------------------------------------------------------------------
>
>
>
>
--
Marc Hadley <marc.hadley@sun.com>
Web Technologies and Standards, Sun Microsystems.

Received on Tuesday, 2 September 2003 08:57:09 UTC