Re: No-Cache: Squid vs RFC2616

On Fri, 3 Mar 2000, Sandra Dykes wrote:

>
> The Squid FAQ (12.23) states Squid-2 does not cache a document
> returned with the response header Cache-Control:No-Cache.
>
> However, RFC2616 (HTTP1.1), Section 14.9.1, specifies the no-cache directive
> to mean "a cache MUST NOT use the response to satisfy a subsequent
> request without successful revalidation with the origin server."
> I take this to mean the response is cachable, but on a subsequent
> request the cache need to send an IMS request to the origin server,
> not necessarily refetch the object.
>
> Can anyone clarify this apparent discrepancy?

There is no discrepancy. Since Squid does not cache the
response, it is not going to be used "to satisfy a subsequent
request ...."

If you look at section 14.9.1 in RFC 2068 it says:

no-cache
  Indicates that all or part of the response message MUST NOT be cached
  anywhere. This allows an origin server to prevent caching even by
  caches that have been configured to return stale responses to client
  requests.

I have no idea why the RFC authors chose to make such a significant
change between these two documents. I think it really sucks because
the first version is quite clear, but the latter version confuses
things. In RFC 2616 it seems that 'no-cache' becomes almost the same
as 'must-revalidate'.

Duane W.
Received on Sat Mar 04 2000 - 03:40:14 MST