Re: [ws-tx] Use or abuse of [reply endpoint] property?

[Joseph Fialli <Joseph.Fialli@Sun.COM>]

Just wanted to add this reply on public-ws-addressing@w3.org to this thread:
http://www.w3.org/mid/CA0992B2-28CC-46F1-8C3A-A7EDA9070E7D@Sun.COM

-Joe

Alastair Green wrote:
> A question (cluster of questions) has arisen in the OASIS WS-TX TC re 
> use of WS-Addressing.
>
> App A sends message "a" to app B, who may send "b" to A at a later 
> time, in an exchange where "a" and "b" are logically related (form 
> part of an exchange or conversation) at an application level.
>
> A possesses, a priori, an EPR for B (B.E) and likewise B possesses an 
> A.E, and these can be used to target the messages "a" and "b".
>
> Message "a" contains a non-anon, non-none value for [reply endpoint] 
> [address], A.E'.
>
> B chooses to ignore that value and sends "b", not to the new potential 
> target A.E' but to A.E. The A-B application-level contract defines "b" 
> not to be a "reply" to "a", but merely a one-way message that is, if 
> you like, in apposition to "a".
>
> B can also choose (at its whim, in any given execution of this 
> exchange) to send "b" to A.E', and not the old target A.E.
>
> Q.0. Is this a legitimate use of the [reply endpoint] of "a"? 
> Spiritually? Legally?
>
> Related questions:
>
> Q.1. Must message "a", having a [reply endpoint] value, therefore set 
> a [message id] value, or can this latter property be omitted in the 
> representation?
>
> Q.2. Closely related to Q.1. Can B ignore this message id even if it 
> is present, and refuse to express (omit) the [relationship] of its 
> message "b" to the original "a" message, in the case where it chooses 
> to target "b" on new reply target A.E'?
>
> Q.3. If message "a" desires no reply, should message A set [reply 
> endpoint] [address] to the "none" URI? Is the "none" value for this 
> property the effective definition of a "one way message" (one that 
> gives no indication of expected future interchanges)? Is the "none" 
> value the only circumstance in which the [message id] can be omitted?
>
> Q.4. Closely related to Q.3. If the [reply endpoint] is instead 
> omitted in "a" and the property is therefore inferred on receipt by B 
> to be anonymous, what should B send in the underlying transport 
> response if it wishes to send no reply at an application level?
>
> Close reading of 2004-08, the CR and the latest editors working draft 
> leaves me unable to answer these questions unambiguously and unaided. 
> That may well mean I'm missing something obvious or fundamental, but 
> help would be greatly appreciated.
>
> Many thanks for any elucidation that the WG and other users of this 
> list can offer.
>
> Alastair
>
>