|Summary:||304 - Not Modified does not return Expires/Cache-Control headers|
|Product:||Apache httpd-2||Reporter:||Marc Jauvin <marc>|
|Component:||mod_expires||Assignee:||Apache HTTPD Bugs Mailing List <bugs>|
Description Marc Jauvin 2003-12-01 20:42:44 UTC
According to W3C spec of 304 response header (http://www.w3.org/Protocols/HTTP/HTRESP.html): "Response headers are as if the client had sent a HEAD request, but limited to only those headers which make sense in this context. This means only headers that are relevant to cache managers and which may have changed independently of the document's Last-Modified date. Examples include Date , Server and Expires . " The following example shows the results of a request done to an Apache2 server: # curl -s -I http://jauvin.com/images/email.gif HTTP/1.1 200 OK Date: Mon, 01 Dec 2003 20:34:15 GMT Server: Apache/2 Vary: Host Last-Modified: Fri, 20 Dec 2002 15:49:27 GMT ETag: "6cd17-51aa-dab1cfc0" Accept-Ranges: bytes Content-Length: 20906 Cache-Control: max-age=7200 Expires: Mon, 01 Dec 2003 22:34:15 GMT Content-Type: image/gif # curl -s -I http://jauvin.com/images/email.gif -H 'If-Modified-Since: Fri, 30 Nov 2003 08:43:27 GMT' HTTP/1.1 304 Not Modified Date: Mon, 01 Dec 2003 20:34:16 GMT Server: Apache/2 ETag: "6cd17-51aa-dab1cfc0" Vary: Host We can see from the first request, that the "Expires/Cache-Control" headers are missing from the second request (304). Here is an example on an Apache 1.3.X server: # curl -s -I http://redhat.com/img/homepg_rh_logo.gif HTTP/1.1 200 OK Date: Mon, 01 Dec 2003 20:41:00 GMT Server: Apache Set-Cookie: Apache=188.8.131.52.235271070311260394; path=/; expires=Sat, 29-Nov-08 20:41:00 GMT Cache-Control: max-age=86400 Expires: Tue, 02 Dec 2003 20:41:00 GMT Last-Modified: Thu, 07 Jun 2001 13:01:59 GMT ETag: "bd440-46c-3b1f7b47" Accept-Ranges: bytes Content-Length: 1132 Content-Type: image/gif # curl -s -I http://redhat.com/img/homepg_rh_logo.gif -H 'If-Modified-Since: Fri, 30 Nov 2003 08:43:27 GMT' HTTP/1.1 304 Not Modified Date: Mon, 01 Dec 2003 20:41:00 GMT Server: Apache ETag: "bd440-46c-3b1f7b47" Expires: Tue, 02 Dec 2003 20:41:00 GMT Cache-Control: max-age=86400 As we can see here, both queries contain the "Expires/Cache-Control" headers.
Comment 1 André Malo 2003-12-01 20:48:52 UTC
Both responses look correct to me. From RFC 2616: 10.3.5 304 Not Modified [...] The response MUST include the following header fields: [...] - Expires, Cache-Control, and/or Vary, if the field-value might differ from that sent in any previous response for the same variant So if the fields don't differ, they may or may not be sent, right?
Comment 2 Marc Jauvin 2003-12-01 21:05:24 UTC
I guess it depends on what "previous response for the same variant" means... but why is Apache 1.3.X returning those headers?
Comment 3 Joshua Slive 2003-12-01 23:07:22 UTC
*** This bug has been marked as a duplicate of 24884 ***
Comment 4 Paul J. Reder 2003-12-01 23:40:25 UTC
This is a valid bug. Try setting the ExpiresByType to "access plus 5 minutes". Every acccess should get a new Expires header but doesn't. Please see http://marc.theaimsgroup.com/?l=apache-httpd-dev&m=106947094322141&w=2 for a summary of the problem. I'm still looking for the solution.
Comment 5 Paul J. Reder 2003-12-12 17:34:24 UTC
This PR has been fixed in the 2.1-dev branch and has been suggested for backporting to the 2.0 stable branch. Thank you for using Apache and for submitting this report.