Re: [squid-users] URL with Invalid Expire Date

 On Thu, 17 Nov 2011 02:54:54 +0200, Ghassan Gharabli wrote:
> Hello,
>
> I was wondering what would we do with this URL
> http://www.youtube-nocookie.com/gen_204?attributionpartner=vevo if we
> want to cache it.
>
>
> I'e been looking and found that its expire header has an invalid date
> ! . I thought I can cache it since it has no-cache but as I can see
> the object can be cached & cant be served without validation.
>
>
> Isthere any other way that I can force it to cache ?

 RFC 2048 (HTTP/1.0) requires that invalid Expires: headers are treated
 as already expired regardless of their value. Under HTTP/1.1 this could
 be cached and served stale.

 However ... the status code is 204. Merely passing the URL to the web
 server changes some state there. Caching this could present clients with
 a lie, indicating that some server state has been changed when the
 server has not even been contacted. Also, the presence of no-cache and
 absence of max-stale means the server must be contacted on every re-use.
 Since there is no reply body content involved there is zero benefit from
 caching this. In fact a net loss in cache efficiency as one entry gets
 filled with an object which is guaranteed to be fully replaced on every
 usage.

 Amos
Received on Thu Nov 17 2011 - 02:41:46 MST