Avoiding conditional requests

[uri_shaked@xxxxxxxxxxxxxxxxx]

Hi All,

I've been trying to improve my webapp's
performance by telling Apache [2.2.4] to force clients to cache static
content using mod_expires.
I'm basically trying to avoid having
the client browser resend the 'if-modified' conditional request for the
static content upon a refresh or a revisit to the site, thus saving the
round-trip time and having the page presented straight from cache . For
this, I've added the following lines to my httpd.conf:

LoadModule expires_module modules/mod_expires.so
ExpiresActive on
ExpiresDefault "access plus 2 hours"
ExpiresByType image/gif "access plus
7 days"
ExpiresByType image/jpeg "access plus
7 days"
ExpiresByType text/css "access plus
7 days"
ExpiresByType application/x-_javascript_
"access plus 12 hours"

The problem is that for some reason
this doesn't seem to work, and the browser [ie6] still sends the conditional
requests, disregarding the expiration directive.
here is an example HTTP traffic caputre
(using Fiddler): 

First Request

GET /Eip/Static/Images/Logos/siteLogo.gif
HTTP/1.0
Accept: */*
Referer: http://qcxp2/Eip/bin/ibp.jsp?ibpPage=HomePage&
Accept-Language: he
Proxy-Connection: Keep-Alive
User-Agent: Mozilla/4.0 (compatible; MSIE
6.0; Windows NT 5.1; SV1; InfoPath.1; FDM; .NET CLR 2.0.50727; .NET CLR
3.0.04506.30)
Host: qcxp2
Cookie: JSESSIONID=4662B8AA7EC6B9AE09258672CBDCE54C



First Response

HTTP/1.1 200 OK
Date: Wed, 24 Oct 2007 08:37:29 GMT
Server: Apache/2.2.4 (Win32) mod_jk/1.2.25
Last-Modified: Mon, 17 Sep 2007 09:00:24
GMT
ETag: "8e5a-782-8f6da00"
Accept-Ranges: bytes
Content-Length: 1922
Cache-Control: max-age=604800
Expires: Wed, 31 Oct 2007 08:37:29 GMT
Connection: close
Content-Type: image/gif

GIF89a]




Second Request (the one that
souldn't actually occur at all)

GET /Eip/Static/Images/Logos/siteLogo.gif
HTTP/1.0
Accept: */*
Referer: http://qcxp2/Eip/bin/ibp.jsp?ibpPage=HomePage&
Accept-Language: he
Proxy-Connection: Keep-Alive
If-Modified-Since: Mon, 17 Sep 2007 09:00:24
GMT
If-None-Match: "8e5a-782-8f6da00"
User-Agent: Mozilla/4.0 (compatible; MSIE
6.0; Windows NT 5.1; SV1; InfoPath.1; FDM; .NET CLR 2.0.50727; .NET CLR
3.0.04506.30)
Host: qcxp2
Pragma: no-cache
Cookie: JSESSIONID=4662B8AA7EC6B9AE09258672CBDCE54C



Second Response

HTTP/1.1 304 Not Modified
Date: Wed, 24 Oct 2007 08:41:12 GMT
Server: Apache/2.2.4 (Win32) mod_jk/1.2.25
Connection: close
ETag: "8e5a-782-8f6da00"
Expires: Wed, 31 Oct 2007 08:41:12 GMT
Cache-Control: max-age=604800


Any ideas?


Uri