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I'm trying to reduce my server load by providing 304 Not Modified responses for content where appropriate. CloudFlare is my middle man, so they should be sending If-Modified-Since headers whenever a cached page has expired, right?

I'm receiving these responses, client-side:

• CF-Cache-Status: MISS on first page load
• CF-Cache-Status: Hit on page reloads for 20 seconds
• CF-Cache-Status: EXPIRED on page reload after 20 seconds

The expired request is forwarded to my server, but doesn't include an If-Modified-Since header. How can I get this to work?

<?php
$now = time();
header( "ETag: W/\"$now\"" );
header( 'Expires: '.gmdate('D, d M Y H:i:s \G\M\T', $now + 20) );

header( 'Last-Modified: '.time() );
header( 'Cache-Control: public, max-age=20' );

print('<pre>');
print_r($_SERVER);
print('</pre>');

UPDATE: Here's working code

<?php

if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
    // $date = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
    header("HTTP/1.1 304 Not Modified");
    exit();
}

$format = 'D, d M Y H:i:s \G\M\T';
$now = time();

$date = gmdate($format, $now);
header('Date: '.$date);
header('Last-Modified: '.$date);

$date = gmdate($format, $now+30);
header('Expires: '.$date);

header('Cache-Control: public, max-age=30');

print('<pre>'); 
print_r($_SERVER); 
print('</pre>');

I'm trying to reduce my server load by providing 304 Not Modified responses for content where appropriate. CloudFlare is my middle man, so they should be sending If-Modified-Since headers whenever a cached page has expired, right?

I'm receiving these responses, client-side:

• CF-Cache-Status: MISS on first page load
• CF-Cache-Status: Hit on page reloads for 20 seconds
• CF-Cache-Status: EXPIRED on page reload after 20 seconds

The expired request is forwarded to my server, but doesn't include an If-Modified-Since header. How can I get this to work?

<?php
$now = time();
header( "ETag: W/\"$now\"" );
header( 'Expires: '.gmdate('D, d M Y H:i:s \G\M\T', $now + 20) );

header( 'Last-Modified: '.time() );
header( 'Cache-Control: public, max-age=20' );

print('<pre>');
print_r($_SERVER);
print('</pre>');

I'm trying to reduce my server load by providing 304 Not Modified responses for content where appropriate. CloudFlare is my middle man, so they should be sending If-Modified-Since headers whenever a cached page has expired, right?

I'm receiving these responses, client-side:

• CF-Cache-Status: MISS on first page load
• CF-Cache-Status: Hit on page reloads for 20 seconds
• CF-Cache-Status: EXPIRED on page reload after 20 seconds

The expired request is forwarded to my server, but doesn't include an If-Modified-Since header. How can I get this to work?

<?php
$now = time();
header( "ETag: W/\"$now\"" );
header( 'Expires: '.gmdate('D, d M Y H:i:s \G\M\T', $now + 20) );

header( 'Last-Modified: '.time() );
header( 'Cache-Control: public, max-age=20' );

print('<pre>');
print_r($_SERVER);
print('</pre>');

I'm trying to reduce my server load by providing 304 Not Modified responses for content where appropriate. CloudFlare is my middle man, so they should be sending If-Modified-Since headers whenever a cached page has expired, right?

I'm receiving these responses, client-side:

• CF-Cache-Status: MISS on first page load
• CF-Cache-Status: Hit on page reloads for 20 seconds
• CF-Cache-Status: EXPIRED on page reload after 20 seconds

The expired request is forwarded to my server, but doesn't include an If-Modified-Since header. How can I get this to work?

<?php
$now = time();
header( "ETag: W/\"$now\"" );
header( 'Expires: '.gmdate('D, d M Y H:i:s \G\M\T', $now + 20) );

header( 'Last-Modified: '.time() );
header( 'Cache-Control: public, max-age=20' );

print('<pre>');
print_r($_SERVER);
print('</pre>');

UPDATE: Here's working code

<?php

if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
    // $date = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
    header("HTTP/1.1 304 Not Modified");
    exit();
}

$format = 'D, d M Y H:i:s \G\M\T';
$now = time();

$date = gmdate($format, $now);
header('Date: '.$date);
header('Last-Modified: '.$date);

$date = gmdate($format, $now+30);
header('Expires: '.$date);

header('Cache-Control: public, max-age=30');

print('<pre>'); 
print_r($_SERVER); 
print('</pre>');

I'm trying to reduce my server load by providing 304 Not Modified responses for content where appropriate. CloudFlare is my middle man, so they should be sending If-Modified-Since headers whenever a cached page has expired, right?

I'm receiving these responses:

• CF-Cache-Status: MISS on first page load
• CF-Cache-Status: Hit on page reloads for 20 seconds
• CF-Cache-Status: EXPIRED on page reload after 20 seconds

The expired request is forwarded to my server, but doesn't include an If-Modified-Since header. How can I get this to work?

<?php
$now = time();
header( "ETag: W/\"$now\"" );
header( 'Expires: '.gmdate('D, d M Y H:i:s \G\M\T', $now + 20) );

header( 'Last-Modified: '.time() );
header( 'Cache-Control: public, max-age=20' );

print('<pre>');
print_r($_SERVER);
print('</pre>');

I'm trying to reduce my server load by providing 304 Not Modified responses for content where appropriate. CloudFlare is my middle man, so they should be sending If-Modified-Since headers whenever a cached page has expired, right?

I'm receiving these responses, client-side:

• CF-Cache-Status: MISS on first page load
• CF-Cache-Status: Hit on page reloads for 20 seconds
• CF-Cache-Status: EXPIRED on page reload after 20 seconds

The expired request is forwarded to my server, but doesn't include an If-Modified-Since header. How can I get this to work?

<?php
$now = time();
header( "ETag: W/\"$now\"" );
header( 'Expires: '.gmdate('D, d M Y H:i:s \G\M\T', $now + 20) );

header( 'Last-Modified: '.time() );
header( 'Cache-Control: public, max-age=20' );

print('<pre>');
print_r($_SERVER);
print('</pre>');