- From: Tom Rutt <tom@coastin.com>
- Date: Fri, 02 Mar 2007 16:38:17 -0500
- To: WS-Addressing <public-ws-addressing@w3.org>, ws policy <public-ws-policy@w3.org>
while changing the examples for both proposals A and C I noticed a
troublesome aspect
of the nested addressing assertions with respect to the default
intersection algorithm..
In either alternative C, where absence of a nested assertion means
nothing, it
seems troublesome that an addressing assertion with no nested policy
alternatives:
<wsp:Policy>
<wsam:Addressing>
<wsp:Policy/>
</wsam:Addressing>
</wsp:Policy>
has a null intersection with one that has no empty nested alternative (e.g
<wsp:Policy>
<wsam:Addressing>
<wsp:Policy>
<wsp:ExactlyOne>
<wsam:AnonymousResponses/>
<wsam:NonAnonymousResponses/>
</wsp:ExactlyOne>
</wsp:Policy>
</wsam:Addressing>
</wsp:Policy>
This intersection outcome makes a little more sense with Proposed
alternative A (where absence implies prohibition), but I am not sure why
anyone would every want to prohibit both kinds of response. Thus the
example with no nested assertions seems useless for if Proposed
alternative A is accepted. In fact, another problem with Proposed
option A is that there seems to be no difference in an alternative with
AnonymousResponses absent and one with NonAnonymousResponses present!
If a response sender is not behind a firewall, then it is of little
value to be able to signal
a requirement for either non anon or Anon Replies, since the cost of
supporting both is small.
such a response sender would most lkely always have both alternatives in
their nested Addressing assertion.
The more typical case is the response receiver is behind a firewall.
It can indicate the need for anonymous responses by only including
anonymous URI in its response EPRs. It does not need a policy for this.
However we have defined these nested assertions as being attached to the
response sender. I am having trouble coming up with realistic use cases
for a response sender needing to assert requirments on the types of
response EPRs the request sender must use.
After thinking how to resolve the difficulties cited above for either
Alternative A or C, I came up with a sudden realization for a new
alternative proposal D.
Alternative proposal D is to simply delete sections 3.2.1 thru 3.1.5.
That is, do not define any nested policy assertions for the Addressing
assertion.
--
----------------------------------------------------
Tom Rutt email: tom@coastin.com; trutt@us.fujitsu.com
Tel: +1 732 801 5744 Fax: +1 732 774 5133
Received on Friday, 2 March 2007 21:40:45 UTC