- From: Ugo Corda <UCorda@SeeBeyond.com>
- Date: Mon, 24 Feb 2003 12:49:30 -0800
- To: "Cutler, Roger (RogerCutler)" <RogerCutler@chevrontexaco.com>, "Walden Mathews" <waldenm@optonline.net>, <www-ws-arch@w3.org>
I just noticed that, interestingly enough, the request-acknowledgement sequence in a reliable messaging context can also lend itself to synchronous or asynchronous interactions, even within the same type of transport binding. Please take a look at WS-Reliability section 5, "HTTP binding", and the diagrams for the various synchronous and asynchronous sequences. Ugo > -----Original Message----- > From: Ugo Corda > Sent: Monday, February 24, 2003 12:34 PM > To: Cutler, Roger (RogerCutler); Walden Mathews; www-ws-arch@w3.org > Subject: RE: Snapshot of Web Services Glossary > > > > I think part of the difficulty here is trying to define > synchronous and asynchronous the same way across different > levels. As Assaf said in a previous note, synchronous and > asynchronous can have different specific meanings depending > on the scope/layer/context we are referring to. > In our case, we should give a definition that applies at the > level I would roughly call the SOAP level. Not at the > transport/transfer level. Not at the choreography level. > That's the level I had in mind when I sent out [1]. > > > Sooooo -- I am really wondering how one can make an > > asynchronous message > > out of synchronous components. > > The usual example is two HTTP requests making up a single > request-response interaction. I think everybody agrees that > HTTP is a synchronous protocol at the transport/transfer > level. Nevertheless, the whole interaction would be > asynchronous at the SOAP request-response level if you > follows a definition like the one I gave at [1].. > > Ugo > > [1] http://lists.w3.org/Archives/Public/www-ws-arch/2003Feb/0261.html > > > > -----Original Message----- > > From: Cutler, Roger (RogerCutler) > > [mailto:RogerCutler@chevrontexaco.com] > > Sent: Monday, February 24, 2003 12:25 PM > > To: Walden Mathews; Ugo Corda; www-ws-arch@w3.org > > Subject: RE: Snapshot of Web Services Glossary > > > > > > That's a really good idea. Using your suggestions from > > http://lists.w3.org/Archives/Public/www-ws-arch/2003Feb/0300.html: > > > > If synchronous means "blocking", then it you block you block -- you > > cannot create an unblocked interaction out of blocking > interactions -- > > so under that meaning you can't build an asynch out of synch's. > > > > If synchronous means solicited, then again I don't see how one can > > combine solicited messages to create an unsolicited one. > > > > If, however, synchronous means "relatively short time" (which most > > people on this thread seem to think is not a good idea), > then I guess > > you can put together a bunch of messages that take a short > time into a > > whole that takes a long time. This seems, however, > relatively trivial > > and maybe it illustrates why people don't seem to like the > > "short time" > > approach. > > > > Even if you go to Mr. Arkin's rather formal definition which, if I > > understand it, says that a message is synchronous if it is > > possible for > > people on the two ends to agree what time it is -- it still > > seems to me > > that if you compose a message out of a bunch of messages > > where you know > > what time it is, in the composite it still should be possible > > to figure > > out what time it is. > > > > Sooooo -- I am really wondering how one can make an > > asynchronous message > > out of synchronous components. > > > > -----Original Message----- > > From: Walden Mathews [mailto:waldenm@optonline.net] > > Sent: Monday, February 24, 2003 1:48 PM > > To: Ugo Corda; Cutler, Roger (RogerCutler); www-ws-arch@w3.org > > Subject: Re: Snapshot of Web Services Glossary > > > > > > Er, especially if no one agrees on what these terms actually > > mean. Ugo, > > would it be possible for you to restate what you said below without > > using either 'synch' term? Maybe if each of us tried that > > once or twice > > we might get to a better place? > > > > WM > > > > ----- Original Message ----- > > From: "Ugo Corda" <UCorda@SeeBeyond.com> > > To: "Cutler, Roger (RogerCutler)" <RogerCutler@chevrontexaco.com>; > > <www-ws-arch@w3.org> > > Sent: Monday, February 24, 2003 1:38 PM > > Subject: RE: Snapshot of Web Services Glossary > > > > > > > > > > >Incidentally, in one of the earlier go-arounds on this subject I > > > >believe that it was pointed out that one can build a synchronous > > > >interaction out of asynchronous components. > > > > > > And vice-versa, one could build an asynchronous interaction out of > > synchronous components. > > > > > > Ugo > > > > > > > > > > > > > > > > > > >
Received on Monday, 24 February 2003 15:50:01 UTC