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Re: Initial formulation of intermediary semantics for MTOM

From: Jean-Jacques Moreau <jean-jacques.moreau@crf.canon.fr>
Date: Mon, 15 Sep 2003 17:33:22 +0200
Message-ID: <3F65DBC2.7080900@crf.canon.fr>
To: noah_mendelsohn@us.ibm.com
Cc: xml-dist-app@w3.org

This looks good to me. Maybe one additional point would be to cover 
active intermediaries, i.e. can it optimize someelse's header block?

Sorry for the late reply; just catching up with email.

Jean-Jacques.

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
> ------------------------------------------------------------------
> 
> 
> 
Received on Monday, 15 September 2003 11:33:46 GMT

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