W3C home > Mailing lists > Public > public-ws-addressing@w3.org > October 2006

RE: What Problem are we trying to solve Rev 1 note new A7

From: Rogers, Tony <Tony.Rogers@ca.com>
Date: Thu, 19 Oct 2006 12:15:42 +1000
Message-ID: <BEE2BD647C052D4FA59B42F5E2D946B337574F@AUSYMS12.ca.com>
To: "Bob Freund" <bob@freunds.com>, "[WS-A]" <public-ws-addressing@w3.org>
I am increasingly of the belief that we can solve the problem by
specifying that the WSA anonymous URI is a prefix, and allowing other
specs to append to it while retaining the "anonymity" of the URI.
This solves the problem of "how does a WS-A processor know this address
means to send something to the back-channel" - it can know by a simple
check of the string prefix (which is neglibly more complex than the
existing string comparison) - there will be no need to add extra
infrastructure to handle an ever-expanding list of "anonymous URIs",
which was one of my concerns. We can change the
wsaw:anonymous="required" language to accept all URIs starting with the
WSA anon URI (a related concern).
It also allows distinguishing between the WSA anon and the RM anon - the
latter would be longer :-)  We can specify the full meaning of the URI
without suffix (restricting the language of "backchannel of THIS
message" to the unadorned URI, perhaps), and provide a somewhat looser
definition for all URIs that begin with this string - perhaps even using
the language that Glen suggested a long time ago: the processor "knows
what to do", or some other words that do NOT specify use of the
backchannel, thus returning to the original idea that the entity
addressed by this URI is not addressable via a non-anonymous URI, or
something along those lines.
It doesn't solve the whole RM problem, but I believe it solves the WSA
parts, and we can (and should) leave the rest up to the RM group.
Tony Rogers
tony.rogers@ca.com <blocked::mailto:tony.rogers@ca.com> 


From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Bob Freund
Sent: Wednesday, 18 October 2006 23:48
To: [WS-A]
Subject: What Problem are we trying to solve Rev 1 note new A7

This is a list of the results, as I heard them, of our discussion on
2006-10-02 related to our response to CR33 and amended based on the
discussions of the 2006-10-09 distributed meeting



It seems that the desire inferred by the issue is that an endpoint would
like to transmit identifying information (or perhaps some other
parametric information) in a one way message, and that one way message
is intended to be used to "open the backchannel" upon which may be
transmitted information that is determined in part by the identifying or
parametric information transmitted in the originating message.  In the
specific use case presented, the issue originator proposes that this
identifying or parametric information be passed in the replyTo uri as a
special form of "anonymous".  CR33 states that the WS-Addressing WSDL
binding CR document would create interoperability issues with their
implementation since it does not permit a form of anonymous other than
the literal "anonymous" to be represented in WSDL.


In the WS-Addressing Teleconference of 2006-10-02, there was a
brainstorming session intended to clarify exactly what problem the
WS-Addressing working group was trying to solve related to its
resolution of CR33 since several proposals related to a direct response
to CR33 have failed as yet to gain consensus.


Alternatives mentioned: (please feel free to come up with more if you
have a better idea)


A1) During the progress of the WS-Addressing working group, a feature
known as Reference Properties was removed from the original submission.
If this were to be added back, then this could be used to convey such
identifying or parametric information.  This would imply changes to both
rec level specifications as well as the WSDL binding.  It is not clear
if these might be "breaking changes".


A2) The WS-Addressing specifications include a feature known as
Reference Parameters which are created by the epr minter which are
considered to be "opaque" to all but the minter.  Outside of the
WS-Addressing "layer" there may be no such constraint.  Reference
Parameters might be used to convey this identifying or parametric
information.  Note that there is not general agreement that
WS-Addressing is a "layer" or if it is a set of kit parts which may be
used at any layer. This might imply a clarifying change to WS-Addressing


A3) WS-Addressing includes a feature known as "From" which contains a
uri.  There are no behavioral constraints imposed by "From" and
potentially anything that might be represented as a uri might be
conveyed. This might imply a clarifying change to WS-Addressing


A4) WS-Addressing defined a limited set of special URLs which mean
specific things to WS-Addressing when used in replyTo.  These are
"anonymous" and "none".  If the behavior specified by WS-Addressing is
not desired, then the authors of other specifications might specify
their own forms of replyTo semantics appropriate to their application
without WS-Addressing implications.  This would imply that CR33 be
closed with no action.


A5) It was suggested that there is wide latitude in what might be
contained in a SOAP header and the authors might be able to use such a
means to convey the desired identifying or parametric information. This
would imply that CR33 be closed with no action.


A6) WS-Addressing Core and SOAP binding are fine as-is, but we just need
to fix the WSDL binding or perhaps come up with a WSDL cum policy
related change.  For proposals related to this alternative, please refer
to the issue list.  


A7) The usage scenario can be accomplished through the use of
wsa:RelatesTo in conjunction with the wsa:RelationshipType extensibility
point provided in the WS-Addressing core specification to define a
domain specific relationship type.  This option requires no change to
the rec level documents. 


For the purposes of this thread please identify in the subject line the
alternative A[1-n] referenced or "exposition" if you feel the problem
statement needs improvement.


Miscellaneous comments:

It seems that there is at least two areas of the WS-Addressing specs
that might be clarified once we see our way through this maze.

1)       Usage of the words reply and response seem to be variously
interpreted to mean the specific application response to THIS message
rather than a returned soap body that was stimulated by THIS message but
that might relate to some other message.

2)       If the WG settles on a rejection of section 5.2.1 advice
concerning the potential of other forms of anonymous then that section
ought to be amended accordingly.  Conversely if the WG re-affirms that
section, then it ought to embrace that decision appropriately in the
WSDL binding such that full use of the core and SOAP bindings are









Received on Thursday, 19 October 2006 02:17:02 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:04:14 UTC