- From: David Orchard <dorchard@bea.com>
- Date: Wed, 6 Jul 2005 13:07:00 -0700
- To: "Glen Daniels" <gdaniels@sonicsoftware.com>, <public-ws-async-tf@w3.org>
I'd like to add in my original propose as the simple "one-way", and I just did a proposal for simplifying meps/bindings so there is no "soap meps". Dave > -----Original Message----- > From: public-ws-async-tf-request@w3.org [mailto:public-ws-async-tf- > request@w3.org] On Behalf Of Glen Daniels > Sent: Wednesday, July 06, 2005 12:54 PM > To: public-ws-async-tf@w3.org > Subject: Draft decision tree / summary > > > Async-ers: > > Here is a draft of what I'd like us to send to the various WGs. Sorry I > > didn't get this out earlier, comments/edits appreciated. > > --Glen > > ---------------------------------------------------------- > > WS-Community: > > This message is an attempt to coalesce the current thinking of the Async > > task force into a (relatively) crisp matrix of questions/issues which > can be > discussed and acted upon by the larger community. > > BACKGROUND > ---------- > > The Async task force was spawned in order to investigate the cross-group > issues between WS-Addressing, WSDL, and XMLP regarding the enabling of > asynchronous scenarios using WS-Addressing (since these types of > scenarios are one of the "raisons d'etre" of addressing). > > Over the past few months we have come to consensus on some particular > scenarios [1] we'd like to support, and the *wire level* messages which > move between communicating parties in order to enact these scenarios. > The problem is now how to communicate in the various specs the rules and > guidelines by which someone unfamiliar with the deep context we (as WG > members) have with web services might implement software which in fact > reliably produces these wire messages. > > THE PROPOSALS > ------------- > > We have several concrete proposals on the table, which are referenced in > the endnotes below. They vary in a number of directions, which are > captured in the large in the questions below. > > THE QUESTIONS > ------------- > > (some are simply questions, others have commentary) > > Q: What about one-way scenarios? (the easy one first) > > We have already requested the Web Services Coordination Group to > shephard > a SOAP one-way MEP into existence. We do not yet know exactly how this > work > will be accomplished (in particular the question below regarding a new > HTTP > binding versus errata on the old one is relevant here). Note that it is > possible > that some of the proposals will affect or obviate this work. > > Q: What is the relationship between SOAP MEPs and WSDL MEPs? (right on > to > the tough one... this is a really central issue) > > The group has not come to a solid consensus on this as yet. > > - In the OSI proposal [OSI], we have a single SOAP MEP being "stretched" > across multiple transport connections. > > - In one of DO's proposals [DO1] we have a single SOAP MEP being > "stretched" > even across multiple protocols. > > - In DH's proposal [DH] a SOAP MEP is much more closely bound to an > underlying protocol MEP. > > The choices come down to three: > 1) SOAP MEPs can be abolished - WSDL MEPs are the only "spec'ed" MEPs > necessary, and SOAP bindings may simply offer (well-named) > mechanisms to send, receive, and potentially correlate messages. > > 2) SOAP MEPs are "closer" to underlying protocol MEPs. They still > exist, but they are simply used to abstract the features of the > underlying protocol. If you take this tack, then WSDL MEPs can > be composed of potentially several underlying SOAP MEPs. > > 3) SOAP MEPs are "closer" to WSDL (application) MEPs. In other words, > a single WSDL MEP should bind to a single SOAP MEP, and you let > the SOAP binding do the work of potentially composing together > multiple underlying protocol interactions to achieve asynchrony. > > Choice 1 is a somewhat different way to think about SOAP bindings, > leaving the "heavy lifting" to the layer above (WS-Addressing/WSDL). > > Choice 2 doesn't require changes to the SOAP binding framework, > but does require WS-Addressing to specify how WSDL MEPs can compose > SOAP MEPs. > > Choice 3 puts more work in the hands of the SOAP binding, which > would then require some ability to "understand" WS-Addressing > constructs (in order to have the binding "switch" from doing a > "simple" MEP as per today's HTTP req/resp to doing a more complex > one involving multiple connections based on the presence of a > WSA header). > > Q: Do we modify the existing HTTP binding in order to allow the new > behavior > (errata), or do we create a new binding with its own URI? > > Q: Does the WSDL <wsa:UsingAddressing/> markup mandate the new features > in > the HTTP binding itself, or should some other markup be created to do > the job? > > Q: What level of expressiveness do we need in the WSDL markup for > expressing > what's offered/allowed? > > This question really comes down to some sub-questions such as "do we > want > to support a concept like "ResponseBinding" as per [DH]/[MH]?" and "do > we > want to be able to indicate support for asynchrony on a per-operation > basis?". > > Q: Is the low-level "ack" which indicates the successful processing of > at > least the <ReplyTo>/<FaultTo> headers a SOAP message (abstractly at > least), or something else? > > Q: Finally, a big underlying question here is "how much of this work > must be complete in order for WS-Addressing to declare success?" > > Thanks, > --Glen > > Scenarios/wire level messages > [1] http://www.pacificspirit.com/Authoring/async/async-scenarios.html > > David Hull'S proposal > [DH] > http://lists.w3.org/Archives/Public/public-ws-async-tf/2005Jun/0031.html > > Oracle/SAP/IBM proposal (OSI) > [OSI] > http://lists.w3.org/Archives/Public/public-ws-async-tf/2005May/0033.html > > Dave Orchard's "recursive bindings" proposal > [DO1] > http://lists.w3.org/Archives/Public/public-ws-async-tf/2005Jun/0008.html > > Marc Hadley's proposal > [MH] > http://lists.w3.org/Archives/Public/public-ws-async-tf/2005Jun/0029.html > >
Received on Wednesday, 6 July 2005 20:08:02 UTC