- From: Henrik Frystyk Nielsen <henrikn@microsoft.com>
- Date: Sat, 23 Feb 2002 14:51:15 -0800
- To: <noah_mendelsohn@us.ibm.com>, "Williams, Stuart" <skw@hplb.hpl.hp.com>
- Cc: "Christopher Ferris" <chris.ferris@sun.com>, "Williams, Stuart" <skw@hplb.hpl.hp.com>, <xml-dist-app@w3.org>
+1 Henrik >This is in response to several comments earlier in the thread. I read >these to be generally along the lines of "why mandate exactly >one fault if >in certain MEPs it will be dropped on the floor anyway" and/or >the closely >related "it would be unwise to relay on it". With respect, I >disagree, >and see this as reasoning inappropriately from the converse. > >There do indeed exist cases in which the fault is not reliably >delivered >to anyone, and in that sense of questionable value. However, the >important point is that there are important cases in which the >existence >of exactly one fault or successful response is important, and may be >relied upon. Consider the HTTP binding for request response. In >practice, we open a TCP connection for the request, and the >receiver keeps >that connection open. Until when? Until the node generates either a >successful response or a fault! If there's any question that >one or the >other of these will surely be generated, then we get into the >business of >timeouts, which is a big mess IMO. Note that this >requirement is indeed >at the message level, not per header or body. > >So, I think on balance it's a useful model to say that every message >sooner or later reaches an endpoint in its processing. That >endpoint is >formally demarcated by the availability of some sort of >result, which is >either success or failure. Modeling this as a fault seems a >good idea to >me.
Received on Saturday, 23 February 2002 17:52:48 UTC