- From: John Kemp <john.kemp@nokia.com>
- Date: Tue, 06 Dec 2005 14:08:05 -0500
- To: ext David Hull <dmh@tibco.com>
- CC: public-ws-addressing@w3.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi David, ext David Hull wrote: > I think there may be some ambiguity as to the meaning of > "asynchronous". In the context of WSA, asynchronous has specifically > meant "response sent on different channel from request." So using the anonymous [reply] endpoint to essentially turn on or off whether a message is handled synchronously or not seems a little at odds with this view. As far as I understand it, an anonymous [reply] endpoint means that the requester cannot provide a "meaningful" IRI (see my earlier reference below) for the response message. But, I can certainly see how the connection is made to the underlying transport. Using the > anonymous endpoint means (more or less) "use the response channel of the > low-level request-response MEP in effect." (i.e., don't use separate > connections) We are trying to keep our terminology in line with this > view. In particular, the WSA Core specification does not use the term > "asynchronous", and our currently proposed WSDL markup for the > two-connection flavor of asynchrony refers to use of the anonymous > endpoint, without reference to the term "asynchronous". Understood. > > In line with this, I would call the pattern you describe "polling". WSA > itself neither specifically supports nor prohibits this pattern. It's > an interesting question how best to model this. There was some > discussion [1] of this case (or a similar one) on the async TF list, but > I don't believe there was a specific recommendation to WSA as to how to > handle it. I think that all I'm looking for is a URI for the [reply] endpoint that indicates more or less the polling case then. Thanks for the additional information. - - JohnK > > [1] http://lists.w3.org/Archives/Public/public-ws-async-tf/2005Feb/0055 > and following thread. > > > John Kemp wrote: > > >>Hello, >> >>I have a question regarding the use of the anonymous URI to determine >>whether a SOAP response should be sent asynchronously. >> >>As you know, in many cases, a SOAP requester cannot offer a meaningful >>IRI for a SOAP responder to send its response to. In a synchronous >>transaction, this is not a problem, and the requester can simply >>advertise http://www.w3.org/2005/08/addressing/anonymous as its [reply] >>endpoint. >> >>When submitting a message for potentially asynchronous processing, it >>would seem that the response message must come back on a different >>channel than that used to submit the request. >> >>I guess I see a couple of issues with the current async proposal: >> >>1) The current text does not seem to allow a requester who cannot *ever* >>provide a meaningful IRI (even if it wants asynchronous processing of a >>message) as a [reply] endpoint to submit a message for asynchronous >>processing. One could simply define another IRI to indicate that not >>only can the client not provide a meaningful IRI as its [reply] >>endpoint, but it is also expecting an asynchronous response (which in >>this case would be provided by the client making a later connection to >>the same server). This also seems to me to perhaps overload the meaning >>of the anonymous URI (as written in [1]). >> >>Is it necessary to preclude requesters who can never offer a meaningful >>[reply] endpoint from asynchronous SOAP message processing? I hope not. >> >>2) Is it possible that the same endpoint might offer both synchronous >>and asynchronous processing of a message, again regardless of the value >>of the [reply] endpoint specified in the request? Imagine a client that >>submits a message with no knowledge of whether the message will be >>processed within the scope of the current HTTP transaction or at some >>later time. If the client receives an HTTP 202 status code, without a >>(WS-A correlated) SOAP response to its request, then it can expect that >>at some later time it could receive a response (perhaps when making >>another - unrelated - HTTP request to the same endpoint?). >> >>Both of these issues could be resolved by finding a different way than >>using the anonymous URI to indicate that a (potentially anonymous) >>client desires, requires or supports asynchronous processing of its >>request message. >> >>Cheers, >> >>- JohnK >> >>[1] http://www.w3.org/TR/2005/CR-ws-addr-core-20050817/#eprinfomodel >> >>ext Yalcinalp, Umit wrote: >> >> >>>This completes my action item from last week [1]. >> >>>Please find the updated writeup for the option1 [2] named ProposalLast. >>>Purple is the changed/new text in comparison to the editor's draft [3]. >> >>>Let me remind everyone that this writeup reflects the consensus point of >>>the f2f and past 2 weeks discussion in the tc to rewrite the agreed >>>semantics up to this point. >> >>>- We have two elements, UsingAddressing and Anonymous (changed from >>>AnonymousUse as suggested last week) >>>- UsingAddressing may appear in binding/endpoint. (as it is) >>>- I removed the default attribute, however UsingAddressing indicates >>>support for both anon and non-anon URIs as addresses as it was in the >>>previous writeup [2]. >>>- Anonymous element uses required/prohibited/allowed as values. It can >>>only appear within a binding operation. The values are changed per the >>>decision last week [1]. >>>- SOAP1.1/HTTP binding is described. I cleaned it up from the last >>>writeup [2]. >>>- I deleted one of the examples. >> >>>David Hull, I did NOT include your suggestions to this as I have made >>>some changes to the current SOAP1.1/HTTP section (some >>>restructuring/simplification). Since you felt that your changes were >>>additive, my suggestion for you is to take the text and illustrate the >>>changes with this latest writeup. I really do not have the cycles to >>>include your text and find the conflicts/synergy, at least not this >>>week, or whatever is left of it :-( >> >>>Marc, editorial comments are appreciated esp. with the last paragraph of >>>3.1 prior to 3.1.1 if we decide to use this writeup in the spec. >> >>>Thanks, >> >>>--umit >> >> >> >>>[1] http://www.w3.org/2002/ws/addr/5/11/28-ws-addr-minutes.html >>>[2] >>>http://lists.w3.org/Archives/Public/public-ws-addressing/2005Nov/0084.ht >>>ml >>>[3] >>>http://dev.w3.org/cvsweb/~checkout~/2004/ws/addressing/ws-addr-wsdl.html >>>?content-type=text/html;%20charset=utf-8 >> >> >>>Ps. It feels like Jonathan is trying to take the wind from my sails with >>>the policy assertion debate :-D. >>><<ProposalLastWithoutDefaults.html>> >>>---------------------- >> >>>Dr. Umit Yalcinalp >>>Standards Architect >>>NetWeaver Industry Standards >>>SAP Labs, LLC >>>umit.yalcinalp@sap.com >>>Tel: (650) 320-3095 >> >> >> -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (Darwin) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDleGVmNJiOOM57NMRAtcqAKDEBHuCmpG6nKCKNIqOVFeraP6wwwCdF7sc O0ecgqDUKFjnixMslr7J5tA= =JXE2 -----END PGP SIGNATURE-----
Received on Tuesday, 6 December 2005 19:08:47 UTC