- From: David Hull <dmh@tibco.com>
- Date: Wed, 08 Jun 2005 20:55:09 +0200
- To: tom@coastin.com
- Cc: Doug Davis <dug@us.ibm.com>, public-ws-addressing@w3.org
- Message-id: <42A73F0D.2080607@tibco.com>
Again, whether [reply endpoint] is anonymous and whether [message id] is needed are completely separate. The client needs [message id] for correlation when it cares about correlation and there is no other means of correlation (see here <http://lists.w3.org/Archives/Public/public-ws-addressing/2005Mar/0170.html> for a slightly dated case analysis, reading "some means of correlation" for "in-reply-to"). Because of the mechanics of [reference parameters], this turns out to be never, strictly speaking. I don't believe multiple-hop routing changes this, but if someone can demonstrate a solid counterexample I'd be very interested to see it. Tom Rutt wrote: > > Based on this discussion, is see wsa:MessageId as an element designed > soley for use with ws addressing. > > Since WS addressing does not need the concept of a sequence ID or a > sequence number for its purposes, I no longer am pushing > for having wsa:MessageId be a complex type. > > > wsa:MessageID is required for correlation purposes, only when a "ws > addressing reply" is expected > (and the wsa:reply to property is not anonymous, ). > We need to realize that a "reply" to another ws-xxx spec's header in > the form of > another soap header in a future message may not be considered a > ws-addressing reply. > For example, if a one way message (which by wsadd essing sematics > expects no "application level" reply), is sent with a > ws-Reliability (or ws reliable messageing) header, then the > reliability spec will include a soap header in a future message which > carries acknolowedgment of receipt or delivery of that message to > the sending reliable messaging processor. However this is not a ws > addresssing reply > > In fact, both ws-reliability and ws-reliabile messaging specs have > their own reliability:messageId (they both use a uid, integer pair) > and both specs have their own "reliability:AckTo" address, which is > distinct from any ws-addressing Reply To. > > I think this "orthogonality" is good for independence of ws-xxx > processing semantics. > > But, at the same time, we must not confuse this "reliability > acnowledgement" as a ws addressing reply. > > Tom Rutt > > > > Doug Davis wrote: > >> >> Robert, >> I get worried when some WS-* spec wants to set some other WS-* >> spec's data. What would do you if WS-AAA has one algorithm, WS-BBB >> has another and both specs are used at the same time? If some other >> WS-* spec wants some unique ID for its own purposes its safer if it >> just defines its own header and not try to overload or change WS-A's. >> thanks, >> -Doug >> >> >> >> *"Robert Freund" <bob.freund@hitachisoftware.com>* >> Sent by: public-ws-addressing-request@w3.org >> >> 06/08/2005 06:11 AM >> >> >> To >> <paul.downey@bt.com>, <tom@coastin.com>, <mark.little@arjuna.com> >> cc >> <rsalz@datapower.com>, <public-ws-addressing@w3.org> >> Subject >> RE: Another go at lc75 and lc88 language (correction) >> >> >> >> >> >> >> >> >> >> >> If we specify that the message id must be unique, but do not specify the >> algorithm, does that not permit other protocols to define a specific >> algorithm more to their liking as long as the result remains an IRI? >> Would that not supply adequate flexibility? >> -bob >> >> -----Original Message----- >> From: public-ws-addressing-request@w3.org >> [mailto:public-ws-addressing-request@w3.org] On Behalf Of >> paul.downey@bt.com >> Sent: Tuesday, June 07, 2005 9:12 AM >> To: tom@coastin.com; mark.little@arjuna.com >> Cc: rsalz@datapower.com; public-ws-addressing@w3.org >> Subject: RE: Another go at lc75 and lc88 language (correction) >> >> >> Tom >> >> > I guess what I am seeing in this discussion is that the >> requirements for >> > wsa:messageId are not clear. >> >> I don't see that at all. I see we have messageId for correlation, >> though I heard during the discussion in Berlin several potential >> use-cases enabled by having a mandatory messageId. These included, >> but were by no means limited to, transport independent message >> correlation, logging and auditing by a transparent proxy observing >> messages being exchanged, and elimination of duplicate messages. >> >> > If it is intended to be a general purpose message id for use in wsa >> > message correlation as well as for other uses, then >> > we might want to include the uid,integer pair. >> >> I don't see how that follows at all. The introduction of integers >> implies to me you are thinking about some kind of windowing protocol >> where messages may be collated, missing messages may be identified >> and requested to be retransmitted within a range of messages. Possibly >> even that the sequence number will roll-over and be reused. >> >> That goes way, way beyond addressing, and isn't something we should >> be following at all. From a procedural POV, i'm puzzled as to >> what LC issue introducing such complexity and restriction >> on the format of messageId would resolve. >> >> > However, if it is just for use in ws addressing correlation, then >> > a URI would suffice, with no semantics on its contents. >> >> I'm OK with a URI, but don't follow the reasoning. >> >> > With a clarification on such a restricted use, it should only be >> > required when the reply to is present with a non anonymous value. >> >> No. I disagree. That's making matters more complex and dependent >> upon the binding for a single hop, rendering messagId less useful in >> end to end message passing scenarios where the message passes over >> HTTP and then another transport such as Email/MQ. >> >> > Other ws specs which need further semantics would be required to >> define >> > their own identity elements. >> Possibly, possibly not. It seems to me that making messageId >> mandatory and unique will make it more attractive for other >> specs to layer upon it for identifying a unique message. >> >> > This has the advantage of allowing their >> > use when ws addressing is not being used. >> >> That's their business. >> >> Paul >> >> >> >> >> >> >
Received on Wednesday, 8 June 2005 18:55:12 UTC