Hi Frank, > Morning list;
This list might be the wrong place to discuss such matters. > While playing around with mod_cache & Drupal (Pressflow actually) I > think I may have found a problem in mod_cache's implementation of the > http/1.1 cache expiration mechanism. > > According to the spec (rfc 2616, 14.9.3), cache-control max-age > overrules expires: > "If a response includes both an Expires header and a max-age > directive, the max-age directive overrides the Expires header, even > if > the Expires header is more restrictive. This rule allows an origin > server to provide, for a given response, a longer expiration time to > an HTTP/1.1 (or later) cache than to an HTTP/1.0 cache. This might be > useful if certain HTTP/1.0 caches improperly calculate ages or > expiration times, perhaps due to desynchronized clocks." I believe we're talking about this PR here https://issues.apache.org/bugzilla/show_bug.cgi?id=35247 > Indeed, this part of the spec is used by Pressflow to tell http/1.0 > caches not to cache (with an expires in the past) because those don't > understand vary:cookie, while cache-control's max-age specifies a > value > 0, which should allow http/1.1 caches to store the object. > > Now while testing Pressflow with mod_cache (with Apache's loglevel > set > to debug), I got "not cached. Reason: Expires header already expired, > not cacheable" entries in my logfile, although there was a valid > cache-control:max-age present. Judging by the mod_cache.c sourcecode > (warning: i'm not a C-developer by any account) it indeed seems > Expires in the past are enough to not cache an object, disregarding a > potential cache-control's max-age; > > --- > else if (exp != APR_DATE_BAD && exp < r->request_time) > { > /* if a Expires header is in the past, don't cache it */ > reason = "Expires header already expired, not cacheable"; > } > --- > (cfr. > http://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x/modules/cache/mod_cache.c > line 503) > > So shouldn't the condition be expanded with checks on > cache-control:max-age to comply with the spec? Or am I missing > something here? > > Kind regards, > frank > ----- > http://blog.futtta.be/ So long, i -- Igor Galić Tel: +43 (0) 664 886 22 883 Mail: i.ga...@brainsware.org URL: http://brainsware.org/ --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org " from the digest: users-digest-unsubscr...@httpd.apache.org For additional commands, e-mail: users-h...@httpd.apache.org
