- From: David Hull <dmh@tibco.com>
- Date: Tue, 15 Mar 2005 22:43:48 -0500
- To: Savas Parastatidis <Savas.Parastatidis@newcastle.ac.uk>
- Cc: Rich Salz <rsalz@datapower.com>, public-ws-addressing@w3.org
- Message-id: <4237AB74.2080901@tibco.com>
A few points, in no particular order: * I'll note that these comments were clearly marked "BlueSkySpeculation", so I'm not going to defend any of them with any great deal of energy. * I agree that faults, or something materially like them, /are/ one way of dealing with errors in the asynchronous world. My main point was that they're not universally applicable there. For example, if I broadcast a one-way message to a gazillion subscribers, I may well /not/ want to hear faults coming back. This would be a case where dropping errors on the floor might well be an acceptable strategy. * From the brief look I had, I liked SSDL, particularly its extensibility story. Actually demonstrating two or more clearly distinct extensions that might otherwise have been treated as part of the core makes a pretty convincing case. One may draw one's own conclusions as to how this relates to WSA. Savas Parastatidis wrote: >Hey David, > ><snip /> > > > >>In short, I don't think faults make much sense outside >>request/response. Even in request/response, they're more a >>well-established convenience for binding to languages that use >>exceptions than they are an inherent necessity. >> >> >> > > >Since faults are messages that carry 'something went bad' semantics, >they do have a place in other MEPs apart from request/response. I >personally don't see faults as a mechanism to deal with exceptions at >the implementation (e.g. procedure/method call exceptions), which if I >understood correctly is what your message suggested. > >Although difficult to support in WSDL, there may still be ways of >describing more complex MEPs than request/response. In such MEPs, fault >messages may have a place in conveying protocol or application fault >semantics. For example, imagine the following MEP that a service may >support: > >msg 1 in -> msg 2 out -> msg 3 in -> (fault msg 1 out) OR (msg 5 out -> >msg 6 out -> msg 7 in -> (msg 8 out OR fault msg 2 out)) > >These are the kind of protocol interactions for a service we can >describe with SSDL (http://ssdl.org). The messages are part of a single, >multi-message protocol exchange. > >Regards, >.savas. > > >
Received on Wednesday, 16 March 2005 03:44:52 UTC