Note: This article was originally published in 2013. Some steps, commands, or software versions may have changed. Check the current WordPress documentation for the latest information.

Prerequisites

Before you begin, make sure you have:

  • WordPress installation (self-hosted)
  • Administrator access to WordPress dashboard
  • FTP/SFTP or file manager access to server files

How to: Install (http://www.memcached.org/ “Memcached”) for php and (http://wordpress.org “WordPress”)

In what seems the eternal quest of having a good performing hosting server one of the tools that are generally referred to is Memcache. What Memcache offers you is a centralized server/cluster that holds in memory cached information. Some of the reasons why it is so popular is because:

  • It allows you to share a common cache store across servers. Think accessing db cached information obtained by Server01 on Server02 or sharing session information between servers.
  • Because it stores information in memory, it is supposed to be fast.

WordPress can leverage Memcache either through php or with plugins. Php can leverage shared session for instance while a plugin like (http://WordPress.org/extend/plugins/w3-total-cache/ “W3 Total Cache”) can use object caching through Memcache. This could provide a great performance improvement specially if your site is hosted on multiple servers. Now, this installation instructions are meant to be simple and provide a quick way to deploy Memcache. I am no expert so some important settings might be overlooked but this should be a good starting guide for someone new to Memcache that wants to deploy it on a (http://www.ubuntu.com “Ubuntu (operating system)”) box. Note: There are two flavors for the php libraries: (http://www.php.net/manual/en/intro.memcache.php) and (http://www.php.net/manual/en/intro.memcached.php). Fortunately for us W3 Total Cache has decided to go with memcache so we can avoid a lenghty discussion of which is better and why. First install memcache and the php library in order for it to work with php and WordPress:

apt-get install memcached php5-memcache

and that’s it! Well, that was rather short. So now let’s go into some settings worth taking a look at:

I. Increase Max Memory Memecached can use

I know it says that the default (64MB) is enough, but you may need more. I am already using 64 mb for what I consider a small site.

  1. Open /etc/memcached.conf
  2. Look for value -m 64
  3. Change it to -m 256
  4. Restart memcached: sudoservice memcached restart

II. Move PHP’s session storage to Memcache

Open /etc/php5/mods-available/memcache.ini Add following lines:

session.save_handler = memcache
session.save_path = "tcp://localhost:11211"

As mentioned this would effectively allow you to share session across multiple servers that use Memcache.

III. Web-Viewer for Memcache Stats

There are many options out there but I saw (https://code.google.com/p/phpmemcacheadmin/) and liked it, plus many sites referenced it. To install visit the site to obtain the latest version: http://blog.elijaa.org/index.php?pages/phpMemcachedAdmin-Download-Version-1.2.2 cd /var/www/memcache.CloudIngenium.com/wwwroot/ wget http://phpmemcacheadmin.googlecode.com/files/phpMemcachedAdmin-1.2.2-r262.tar.gz tar -xvzf phpMemcachedAdmin-1.2.2-r262.tar.gz chmod 0777 Config/Memcache.php So now we need to configure (http://https://httpd.apache.org/ “Apache HTTP Server”):

cd /etc/httpd/conf.d sudo nano memcached.conf include the following in memcached.conf

<VirtualHost *:80>

``ServerName memcached.CloudIngenium.com

``UseCanonicalName Off

``ServerAdmin ``"AdminUser@CloudIngenium.com"

``DocumentRoot ``"/var/www/memcache.CloudIngenium.com/wwwroot/"

<``/VirtualHost``>

Because we didn’t specify the Allow from directive only localhost would be able to access this site. Don´t forget to add this site to Apache and restart for it to publish it. If you wanted to use nginx you should use the following conf config as a template:

server {

``listen 80;

``server_name memcached.CloudIngenium.com;

``access_log /var/``log``/nginx/memcached.CloudIngenium.com-access.``log main;

``location / {

``allow 10.0.0.1``/32;

``deny all;

``proxy_set_header Host $host;

``proxy_set_header X-Real-IP $remote_addr;

``proxy_set_header X-Forwarded-Host $host;

``proxy_set_header X-Forwarded-Server $host;

``proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

``proxy_pass http:``//127.0.0.1:80;

``}

}

(http://img.zemanta.com/zemified_e.png?x-id=ac47e021-b9cc-4654-b960-36e7b023bd03)](http://www.zemanta.com/?px “Enhanced by Zemanta”)