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Summary of decision tree for Addr/Desc groups

From: Glen Daniels <gdaniels@sonicsoftware.com>
Date: Fri, 25 Feb 2005 16:03:46 -0500
Message-ID: <80A43FC052CE3949A327527DCD5D6B27DC390D@MAIL01.bedford.progress.com>
To: <public-ws-async-tf@w3.org>


The following is a series of questions which should be considered a tool
for the WS-Description and WS-Addressing groups to use in considering
the plans/actions necessary in order to support various "asynchronous"
use cases as discussed by the async task force.  The use-cases we've
been discussing can be found on the archives of the task force list [1].
These questions are divided into SOAP-related, WSDL-related, and
Addressing-related "buckets".

* The SOAP layer

Q. It seems a new SOAP MEP (one-way) is very likely needed.  Alternately
it *might* be possible to simply alter the request-response MEP in order
to support the possibility of a "null" response envelope.  Does this
work need to happen?
 Q. Who should do this work?
  a. XMLP group
  b. WSDL group
  c. Addr group

Q. Regardless of its technical feasibility, it's pretty clear that no
one yet implements a "polling" style callback using HTTP as described by
Marc in [2].  Do we want to try to encourage this pattern?  If so:
  Q. Where should the work be done to describe it?
   a. Errata to SOAP spec
   b. Separate note
  Q. how do we indicate in the WSDL that this is available/used?
  Q. Does this change the SOAP MEP, or is it still a SOAP req/resp?

Q. Assuming both of the above affect the SOAP 1.2 spec(s), can the
changes be published as "errata" so as not to cause a full release cycle
of the spec(s)?

* The WSDL layer

The essential question at the WSDL layer is "what, if anything, do we
need to change in WSDL (both 2.0 and 1.1) to enable the important
use-cases that fall under the general heading of 'async'".  This breaks
down into two categories - actual changes to WSDL core, and extensions.
Clearly WSDL core changes (for 2.0 at least) need to happen under the
auspices of the WSDL group.  Extensions could be built either by the
WSDL group or the Addressing group (and "who does the work" is therefore
an implicit secondary question to each of the ones in this section).

So here are some questions (these do not necessarily presuppose
solutions):

Q. Do we want to enable/support the case where a single WSDL
operation/MEP (request/response, say) can bind to multiple SOAP MEPs?
(i.e. the seemingly-common use case where the request comes in on one
HTTP interaction with a <replyTo>, and the response goes out in another
transport interaction (either HTTP or otherwise))

 Q. Do we want to enable/support the above with multiple transports?
(req is HTTP, resp is SMTP)

 Q. Do we feel the pattern/transports for the above need to be locked
down in the WSDL (i.e. all binding details except the actual address(es)
are specified), or do we want to enable/support "floating" bindings (for
which runtime EPRs may change the transport/binding details)?

Q. Whether or not we choose to move forward with asynchronously binding
single WSDL operations/MEPs, should we consider some form of
standardized extension in order to indicate a correlation between
multiple WSDL operations?  This would enable, for instance, a WSDL
in-only operation to be treated as a request, and a separate out-only
operation to be treated (somehow) as a correlated response.

Q. Assuming we do NOT want to move forward with any of the above work,
does anything in WSDL as it stands prevent/hinder others (or our future
selves) from using extensions to WSDL 1.1 / 2.0 to achieve these cases?

* The WS-Addressing layer

Nothing obvious came up which involved changes to the WS-Addressing core
beyond the work that the WS-Addressing group might take on as a result
of the stuff above.  So this layer simply contains the question:

Q. Does anything need to be done to the WSAddr spec(s) to enable this
stuff?

---------

[1] http://lists.w3.org/Archives/Public/public-ws-async-tf/
[2]
http://lists.w3.org/Archives/Public/public-ws-async-tf/2005Feb/0005.html

---------

Please take a look at the above (a work in progress, to be sure) and
send thoughts/comments/additions.  My plan is to send this to both
groups Sun eve, with further discussion to take place on Mon before our
presentation to the Addr group on Tuesday and the WSDL group later in
the week.

Thanks,
--Glen
Received on Friday, 25 February 2005 21:03:51 GMT

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