sudo apt-add-repository ppa:rwky/redis

sudo apt-get update && sudo apt-get upgrade
sudo apt-get install redis-server

sudo apt-get install python-software-properties

cd /to/site/root
git clone https://github.com/nrk/predis.git

<?php
 
/*
    Author: Jim Westergren, Jeedo Aquino & Flynsarmy
    File: index-with-redis.php
    Updated: 2012-10-25
 
    This is a redis caching system for wordpress.
    see more here: www.jimwestergren.com/wordpress-with-redis-as-a-frontend-cache/
 
    Originally written by Jim Westergren but improved by Jeedo Aquino.
 
    some caching mechanics are different from jim's script which is summarized below:
 
    - cached pages do not expire not unless explicitly deleted or reset
    - appending a ?c=y to a url deletes the entire cache of the domain, only works when you are logged in
    - appending a ?r=y to a url deletes the cache of that url
    - submitting a comment deletes the cache of that page
    - refreshing (f5) a page deletes the cache of that page
    - includes a debug mode, stats are displayed at the bottom most part after </html>
 
    for setup and configuration see more here:
 
    www.jeedo.net/lightning-fast-wordpress-with-nginx-redis/
 
    use this script at your own risk. i currently use this albeit a slightly modified version
    to display a redis badge whenever a cache is displayed.
 
*/
 
// change vars here
$debug = 0;			// set to 1 if you wish to see execution time and cache actions$display_powered_by_redis = 1;  // set to 1 if you want to display a powered by redis message with execution time, see below 
$start = microtime();   // start timing page exec
 
// if cloudflare is enabled
if ( isset($_SERVER['HTTP_CF_CONNECTING_IP']) )
    $_SERVER['REMOTE_ADDR'] = $_SERVER['HTTP_CF_CONNECTING_IP'];
 
// from wp
define('WP_USE_THEMES', true);
 
// init predis
require 'predis/lib/Predis/Autoloader.php';
Predis\Autoloader::register();
$redis = new Predis\Client();
 
// init vars
$cached = 0;
$domain = $_SERVER['HTTP_HOST'];
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
$url = str_replace('?r=y', '', $url);
$url = str_replace('?c=y', '', $url);
$dkey = md5($domain);
$ukey = md5($url);
 
// check if page isn't a comment submission
$submit = isset($_SERVER['HTTP_CACHE_CONTROL']) && $_SERVER['HTTP_CACHE_CONTROL'] == 'max-age=0';
 
// check if logged in to wp
$cookie = var_export($_COOKIE, true);
$loggedin = preg_match("/wordpress_logged_in/", $cookie);
 
// check if a cache of the page exists
if (!$loggedin && !$submit && $redis->hexists($dkey, $ukey) && !strpos($url, '/feed/')) {
 
    echo $redis->hget($dkey, $ukey);
    $cached = 1;
    $msg = 'this is a cache';
 
// if a comment was submitted or clear page cache request was made delete cache of page
} else if ($submit || substr($_SERVER['REQUEST_URI'], -4) == '?r=y') {
 
    require('./wp-blog-header.php');
    $redis->hdel($dkey, $ukey);
    $msg = 'cache of page deleted';
 
// delete entire cache, works only if logged in
} else if ($loggedin && substr($_SERVER['REQUEST_URI'], -4) == '?c=y') {
 
    require('./wp-blog-header.php');
    if ($redis->exists($dkey)) {
        $redis->del($dkey);
        $msg = 'domain cache flushed';
    } else {
        $msg = 'no cache to flush';
    }
 
// if logged in don't cache anything
} else if ($loggedin) {
 
    require('./wp-blog-header.php');
    $msg = 'not cached';
 
// cache the page
} else {
 
    // turn on output buffering
    ob_start();
 
    require('./wp-blog-header.php');
 
    // get contents of output buffer
    $html = ob_get_contents();
 
    // clean output buffer
    ob_end_clean();
    echo $html;
 
    // Store to cache only if the page exist and is not a search result.
    if (!is_404() && !is_search()) {
        // store html contents to redis cache
        $redis->hset($dkey, $ukey, $html);
        $msg = 'cache is set';
    }
}
 
$end = microtime(); // get end execution time
 
// show messages if debug is enabled
if ($debug) {
    echo "REDIS DEBUG ";
    echo $msg.': ';
    echo t_exec($start, $end);
}
 
if ($cached && $display_powered_by_redis) {
    // You should move this CSS to your CSS file and change the: float:right;margin:20px 0;    echo "<style>#redis_powered{float:right;margin:20px 0;background:url(http://images.staticjw.com/jim/3959/redis.png) 10px no-repeat #fff;border:1px solid #D7D8DF;padding:10px;width:190px;}#redis_powered div{width:190px;text-align:right;font:10px/11px arial,sans-serif;color:#000;}</style>";    echo "<a href='http://www.jimwestergren.com/wordpress-with-redis-as-a-frontend-cache/' style='text-decoration:none;'><div id='redis_powered'><div>Page generated in<br/> ".t_exec($start, $end)." sec</div></div></a>";}
 
// time diff
function t_exec($start, $end) {
    $t = (getmicrotime($end) - getmicrotime($start));
    return round($t,5);
}
 
// get time
function getmicrotime($t) {
    list($usec, $sec) = explode(" ",$t);
    return ((float)$usec + (float)$sec);
}
 
?>

DirectoryIndex index.html index-with-redis.php index.php

if (!$loggedin && !$submit && $redis->hexists($dkey, $ukey) && !strpos($url, '/feed/')) {

if (!$loggedin && !$submit && !strpos($url, '/feed/') && !strpos($url, '/page/') && !strpos($url, '/category/') && $redis->hexists($dkey, $ukey)) {

/**
 *  Redis Cache invalidation
 */
function get_redis()
{
	require_once ABSPATH . 'predis/lib/Predis/Autoloader.php';
	Predis\Autoloader::register();
	return new Predis\Client();
}
 
// Chances are you'll have a list of categories on every page.
// So delete all site cache if categories are messed with
add_action('add_category', 'redis_invalidate_all');
add_action('delete_category', 'redis_invalidate_all');
add_action('edit_category', 'redis_invalidate_all');
// Delete all site cache for the current domain
function redis_invalidate_all()
{
	$redis = get_redis();
 
	$domain = $_SERVER['HTTP_HOST'];
	$dkey = md5($domain);
	if ( $redis->exists($dkey) )
		$redis->del($dkey);
}
 
// When adding/editing/deleting a post, invalidate post and home pages
add_action('trashed_post', 'redis_invalidate_post');
add_action('save_post', 'redis_invalidate_post');
function redis_invalidate_post( $post_id )
{
	// Don't delete cache on auto-save
	if ( isset($_POST['action']) && $_POST['action'] == 'autosave' )
		return;
 
	// Don't delete cache if we're saving as draft or pending
	if ( isset($_POST['save']) && in_array($_POST['save'], array('Save Draft', 'Save as Pending')) )
		return;
 
	$redis = get_redis();
 
	$domain = $_SERVER['HTTP_HOST'];
	$dkey = md5($domain);
 
	// Invalidate homepage
	$ukey = md5("http://".$_SERVER['HTTP_HOST'].'/');
	if ( $redis->hexists($dkey, $ukey) )
		$redis->hdel($dkey, $ukey);
 
	// Invalidate post page
	$ukey = md5($permalink = get_permalink( $post_id ));
	if ( $redis->hexists($dkey, $ukey) )
		$redis->hdel($dkey, $ukey);
}
 
// When adding/editing/deleting a comment, invalidate post and home pages
add_action('comment_closed', 'redis_invalidate_comment');
add_action('comment_post', 'redis_invalidate_comment');
add_action('edit_comment', 'redis_invalidate_comment');
add_action('delete_comment', 'redis_invalidate_comment');
add_action('wp_set_comment_status', 'redis_invalidate_comment');
function redis_invalidate_comment( $comment_id )
{
	$comment = get_comment( $comment_id );
	redis_invalidate_post( $comment->comment_post_ID );
}