- From: David W. Morris <dwm@xpasc.com>
- Date: Mon, 27 Apr 1998 12:37:16 -0700 (PDT)
- To: Jeffrey Mogul <mogul@pa.dec.com>
- Cc: http-wg@cuckoo.hpl.hp.com, http-wg@hplb.hpl.hp.com
On Mon, 27 Apr 1998, Jeffrey Mogul wrote: > Clarification is needed on what error is to be returned if a Proxy > times out looking up a hostname. The spec is silent on what is a > very common failure. > > My current opinion is that returning 504 Gateway Timout is correct, > but that clarification to the spec is in order. But other options > include introducting other error codes, or less likely, some other > existing error code. > > Before we charge off on a detailed discussion of what to do when a > proxy times out on a DNS translation, we might want to consider whether > is error is part of a larger class. > > For example, > what if the proxy has no route to the server? (i.e., > it gets a "host unreachable" error). This may also > be a transient error (cf. the paper in USITS '97 on > the observed routing instability in the Internet). Is > this the same as a "504 Gateway Timeout"? > > I'm not sure whether there are any other errors in this class. > But if these are the only two that we can think of, perhaps > the proper name for the error is > > 504 Temporarily Unable to Forward Request > > with an entity body that explains the reason in more detail. > I.e., the relevant question is not "was this a timeout or not?" > but "is the error (probably) transient or is it permanent?" > > If people think that these cases are actually different enough > to warrant separate error codes, then I think we ought to add > a "No route to next-hop server" code if we add a "DNS timeout" code. As I tried to say, there are more errors than just a timeout between the proxy and the down stream server and they need to be differentiated. Dave
Received on Monday, 27 April 1998 12:47:04 UTC