- From: Josh Cohen <josh@netscape.com>
- Date: Wed, 2 Jul 1997 03:22:42 -0700 (PDT)
- To: Graham Klyne <GK@acm.org>
- Cc: Henrik Frystyk Nielsen <frystyk@w3.org>, http-wg@cuckoo.hpl.hp.com
> Nasty! > Yes.. it is. > This is probably 'closing the stable door after the horse has bolted' (HTTP > 1.1 now being a published spec), but it occurs to me that an trail of > proxies between client and origin server, similar to RECEIVED headers in > RFC822 mail messages, might allow the client to determine the reliability > of the HTTP 1.1 path. I posit that each entry in the trail would contain > host name, HTTP version number and server implementation and version > identification (e.g. "WWW.ACME.COM, HTTP/1.1 (MoonSoft HTTPD V3.28)") > > This assumes that legacy proxies in the path which don't add this > information can be detected, which I think should be possible. Unfortunately, its common that the current proxies dont insert any header. Ie: josh@birdcage>telnet w3proxy 8080 Trying 205.218.156.43... Connected to supernova.netscape.com. Escape character is '^]'. GET http://www.early.com/~josh/1k.txt HTTP/1.0 HTTP/1.0 200 OK Date: Wed, 02 Jul 1997 10:17:55 GMT Server: Apache/1.1.3 Content-type: text/plain Content-length: 2 Last-modified: Wed, 02 Jul 1997 00:22:49 GMT Connection closed by foreign host. josh@birdcage> If there was a cache hit, there usually is a 'proxy-agent' header (from our proxy), but in this case, an origin retreive, there was not. This foils your scheme because the client wouldnt know that this proxy exists if there is another proxy between the client and it. ie client -> 1.1proxy -> 1.0proxy -> webserver At least if the proxies propogated the OPTIONS request down the proxy chain, a 1.0 proxy would report an error and a 1.1 proxy not supporting the requested feature/spec would reply accordingly. ( the client can detect the ;unclean; pipe ) > > GK. ----------------------------------------------------------------------------- Josh Cohen Netscape Communications Corp. Netscape Fire Department #include<disclaimer.h> Server Engineering josh@netscape.com http://home.netscape.com/people/josh/ -----------------------------------------------------------------------------
Received on Wednesday, 2 July 1997 03:27:49 UTC