Re: HEAD and max-age=0

The comment is most likely drawn from the fact that there is no
mentioning of HEAD in 10.3.5 304 "Not modified", only GET, and the
restrictions set in section 10.

Seems to read the same in RFC2616.

But on the other hand I don't see anything that says that we MUST NOT
send 304 in response to a HEAD, so my interpretation is that clients
should not expect servers to support conditional HEAD requests, but
if the server wishes to it MAY. This conclusion is from the
extensibility of the protocol and from the fact that HEAD in all
other aspects is defined to be identical to GET except that no reply
entity body is returned in the response.

Should perhaps add that this is also the interpretation done by the
Apache group, and most other server vendors (MS IIS included, even if
they often get HEAD very wrong and returns a reply entity body..).

Regards
Henrik

On Sunday 08 September 2002 11.28, Robert Collins wrote:
> This comment:
>
> * RFC 2068 seems to indicate there is no "conditional HEAD"
> * request. We cannot validate a cached object for a HEAD
> * request, nor can we return 304.
>
> has me stumped. max-age=foo should apply to HEAD AFAICT. We may not
> be able to perform IMS processing, but we should be able to
> validate and return the upstream object if needed.
>
> Can anyone point me with a little more precision than 'rfc 2068' at
> the logic the comment was drawn from?
>
> Rob
Received on Sun Sep 08 2002 - 04:21:14 MDT