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POWhy does browser request file, even though Apache mod_expires is enabled?
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copied!<p>I'm really confused by all that caching stuff. I'm trying to setup <code>mod_expires</code> to reduce the number of <code>HTTP Requests</code> from my website to the server.</p> <p>I did well so far, I installed <code>mod_expires</code> and wrote a little .conf file from the instructions on <a href="http://httpd.apache.org/docs/2.0/mod/mod_expires.html" rel="nofollow noreferrer">http://httpd.apache.org/docs/2.0/mod/mod_expires.html</a>.</p> <p>Now, for instance, all my <code>.png, .gif, .jpeg</code> files have a <code>Cache-Control</code> header. My expected result was, that the browser won't do any <code>GET Request</code> within the time period (given from the <code>Cache-Control</code> value). But it does, every single file fires a request and receives <code>HTTP 304 not Modified</code>.</p> <p>That is the wrong behavior isn't it ? It should load that files from the internal cache. One thing I don't understand is, that the browser sends a <code>Response header</code>: <code>Cache-Control: max-age=0</code>. Should it be like that?</p> <p>Here is an complete example <code>Request + Response headers</code> for a single <code>.png file</code>:</p> <p><strong>Request</strong></p> <pre><code>Host dev-mgg.localdomain User-Agent Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 Accept image/png,image/*;q=0.8,*/*;q=0.5 Accept-Language de-de,de;q=0.8,en-us;q=0.5,en;q=0.3 Accept-Encoding gzip,deflate Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive 115 Connection keep-alive Referer http://dev-mgg.localdomain/css/global/icons.css?18224 Cookie IR_SQLPwdStore=; IR_SQLUser=sysadm If-Modified-Since Thu, 24 Jul 2008 06:24:11 GMT If-None-Match "4010127-3c4-452bf1aefd8c0" Cache-Control max-age=0 </code></pre> <p><strong>Response</strong></p> <pre><code>Date Mon, 02 Aug 2010 14:00:28 GMT Server Apache/2.2.9 (Debian) PHP/5.2.6-1+lenny8 with Suhosin-Patch mod_perl/2.0.4 Perl/v5.10.0 Connection Keep-Alive Keep-Alive timeout=15, max=59 Etag "4010127-3c4-452bf1aefd8c0" Expires Mon, 02 Aug 2010 14:04:28 GMT Cache-Control max-age=240 </code></pre>

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