- From: David Hull <dmh@tibco.com>
- Date: Tue, 22 Mar 2005 15:08:55 -0500
- To: "public-ws-addressing@w3.org" <public-ws-addressing@w3.org>
- Message-id: <42407B57.20601@tibco.com>
I just had a quick --and I'll emphasize quick -- look at WS-ReliableMessaging, WS-Transfer and WS-Enumeration. These all refer to WSA fault or reply endpoints, but I don't believe they need to or should do so. Note that these specs refer to other MAPs, particularly [action], in ways that appear to make sense. In section 4 (faults) WS-RM says "The fault definitions defined in this section reference certain abstract properties, such as [fault endpoint], that are defined in section 3 of the WS-Addressing specification. Endpoints compliant with this specification MUST include required message information headers /[sic] /on all fault messages." As far as I can tell, none of the text that follows actually references [fault endpoint]. It /does /talk about where to send faults, but that's the [destination] property of the fault message itself (see * below). The only required MAP I can see here is the wsa:Action MAP for faults. WS-Transfer and WS-Enumeration talk variously about To, Action, ReplyTo, FaultTo, and MessageID headers in what appear to be basic request/reply messages. In all these cases, I don't see the value of talking about MAPs explicitly, particularly as headers in example SOAP messages. Depending on how we ultimately resolve various issues, these headers may or may not need to be present. I particularly don't see any reason that Transfer or Enumeration would not work just as well over existing SOAP/HTTP stacks without these headers present. Obviously we would like to be able to leverage WSA for asynchronous request/reply where appropriate, but we shouldn't have to say anything to make this happen, beyond "this is a request/reply". Or will we need to have every spec that currently uses request/reply change to say "this uses (or MAY use) request/reply as defined in WSA" in order to leverage WSA? In any case, I don't see how any of these specs depends materially on WSA. By contrast, Notification and Eventing depend materially on WSA, though they don't depend materially on MAPs, only on EPRs. I think we need to distinguish what parts of WSA are referenced by various specs, and to what degree there is a direct dependence (as opposed to an indirect one such as "we use request/reply and request/reply may use WSA for correlation"). I don't yet know of any specs outside ours that depend /directly/ on MAPs. I do know at least two that depend materially and directly on EPRs, and I expect this list to grow. (*) WS-RM says (in section 4) that sequence faults should go to the same place as message acknowledgments. It phrases this as "Sequence faults SHOULD be sent to the same [destination] as <SequenceAcknowledgement> messages." That is, the [destination] MAP for sequence faults should be the same as that for acknowledgments.
Received on Tuesday, 22 March 2005 20:09:31 UTC