Memcached is a distributed, high-performance, in-memory caching system that allows you to improve and speed up the performance of dynamic web applications by caching data and objects in memory. It is primarily used to speed up sites that make heavy use of databases.
Memcached is also used to cache entire database tables and queries to improve the performance of the database. Memcached is free and is used by many sites like Facebook, YouTube and Twitter.
This tutorial shows you how to install and configure Memcached on CentOS 7.
- A server running CentOS 7 with Apache and PHP installed
First make sure all packages are up to date:
sudo yum -y update
Now execute the following commands to install Memcached:
sudo yum -y install memcached
Start Memcached services and add it to automatically start on your system start-up with:
sudo systemctl enable memcached sudo systemctl start memcached
The default Memcached configuration file is located in the
To configure Memcached, edit the
sudo nano /etc/sysconfig/memcached
Set or update parameters as follows, customizing them to your needs:
PORT="11211" USER="memcached" MAXCONN="1024" CACHESIZE="64" OPTIONS=""
This is a brief description of the parameters:
**PORT**: The default port used by Memcached to run. **USER**: The user Memcached runs as. **MAXCONN**: The maximum number of allowed connections to Memcached. You can increase to any number based on your requirements. **CACHESIZE**: The cache size for memory. **OPTIONS**: Set IP address of server, so that Apache or Nginx web servers can connect to it.
Exit and save the configuration file, and then restart Memcached:
sudo systemctl restart memcached
Run the following command to verify that Memcached is running:
sudo netstat -tulpn | grep :11211
You will see the following output:
To check the stats of the server using
sudo memcached-tool 127.0.0.1 stats
Installing the Memcached PHP Extension
You can install PHP extension to work with Memcached daemon with the command:
sudo yum install php-pecl-memcache
Now, restart Apache so that the changes take place:
sudo systemctl restart memcached sudo systemctl restart httpd
To test Memcached PHP extension, create an
info.php file in apache web root directory.
sudo nano /var/www/html/info.php
Add the following content:
<?php phpinfo(); ?>
Save the file and access it at
http://your_server_ip/info.php in a web browser.
When the PHP info page is rendered in your browser look for this section:
Installing the Memcached Python Library
You can install Memcached Python library by running the following command:
sudo yum install python-memcached
Now, restart the Apache service so that the changes take place:
sudo systemctl restart httpd
Congratulations! You have successfully installed Memcached