- From: Jeffrey Mogul <mogul@pa.dec.com>
- Date: Wed, 30 Jul 97 11:35:55 MDT
- To: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
Dave Morris writes:
I support the behavior for handling HTTP/1.1 responses strictly
conforming to Roy's position but I believe somthing like Jeff's
proposed wording is necessary when the 1.1 cache is covering a 1.0
server.
I would go along with this, except that I see no way that a proxy
in a chain of several proxies can reliably determine whether the
origin server is HTTP/1.0. E.g., if you have this configuration:
Origin_server----Proxy_p1-----Proxy_p2------client
how does Proxy_p2 know for sure that the Origin_server is not
HTTP/1.0?
Given that, there certainly are many cases where a proxy
can reliably know that the origin server is definitely HTTP/1.1.
For example, Proxy_p1 knows that it's talking to the origin
server, and it knows what HTTP-version is sent in the response
status-line. Or, if the response includes a header that could
only have been added by an HTTP/1.1 server (e.g., Cache-Control).
So, one possible rewording of the proposed resolution would be
to change:
A cache MUST NOT assign a heuristic expiration time to a
response for a URL that includes the strings "htbin", "cgi-bin", or
"?" in its rel_path part. If such a response does not
carry an explicit expiration time, it must be treated as
if it expires immediately.
to this:
A cache MUST NOT assign a heuristic expiration time to a
response for a URL that includes the strings "htbin",
"cgi-bin", or "?" in its rel_path part, if the response might
have been generated by an HTTP/1.0 (or earlier) origin server.
If such a response does not carry an explicit expiration time,
it must be treated as if it expires immediately.
-Jeff
Received on Wednesday, 30 July 1997 11:45:03 UTC