Re: HTTP 1.1, proxy servers, and failed connections

> > If a proxy server, when initiating a connection to the real server,
> > gets ECONNREFUSED, EHOSTDOWN, or EHOSTUNREACH, what error should
> > it return to the client? Some existing proxy servers return 500,
> 
> It should return 502 (Bad Gateway).

Are you sure? I'm surprised at that. The RFC says 502 means:
   The server, while acting as a gateway or proxy, received an invalid
   response from the upstream server it accessed in attempting to
   fulfill the request.
I would have thought "invalid response" means a response that is
contrary to (non-conforming with) the specification. I would take
it to mean the upstream server actually responded, but incorrectly.
How do you define "invalid response"?

- Bob