How to Install Memcached on Ubuntu Linux

This post shows students and new users how to install and use Memcached on Ubuntu Linux. Memcached is a free, open-source, high-performance in-memory key-value data store. It allows repeated PHP object or database calls to be cached in system memory to help speed up dynamic web applications.

Memcached can be used with dynamic web applications like WordPress, Drupal, and others to speed up applications by caching various objects from the results of API and database calls.

There’s an alternative to Memcached called Redis, but Memcached is lightweight, mature, and suitable for most applications. If you’re running a web application or portal and need to improve its performance, installing Memcached might be something you’ll want to implement.

Also, for students and new users learning Linux, Ubuntu Linux is the easiest place to start learning. Ubuntu is the modern, open-source Linux operating system for desktops, servers, and other devices.

To start installing Memcached on Ubuntu Linux, follow the steps below.

How to install Memcached on Ubuntu Linux

The Memcached package is included with Ubuntu default repositories, and the installation process is straightforward. Simply run the commands below to install it along with its support tools.

sudo apt update
sudo apt install memcached libmemcached-tools

Memcached tools provide several command line tools for managing the Memcached server. You’ll mostly want to install it with the Memcached server.

After running the commands above, the Memcached server should be installed and ready to use. To check its status, run the commands below:

sudo systemctl status memcached

You should see similar lines below:

● memcached.service - memcached daemon
   Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
   Active: active (running) since Thu 2019-06-06 10:36:25 CDT; 27s ago
     Docs: man:memcached(1)
 Main PID: 19852 (memcached)
    Tasks: 10 (limit: 4682)
   CGroup: /system.slice/memcached.service
           └─19852 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached.pid

Jun 06 10:36:25 ubuntu1804 systemd[1]: Started memcached daemon.

The server should be running and should respond to requests. The commands below can be used to stop, start and enable Memcached.

sudo systemctl stop memcached.service
sudo systemctl start memcached.service
sudo systemctl enable memcached.service

How to configure Memcached on Ubuntu Linux

Now that the Memcached is installed, its configuration file can be found at /etc/memcached.conf

The default settings in the file should be enough for most environments and applications. However, for more advanced settings, open the file and make the changes you want to apply to your environment.

For example, Memcached listens on the server’s local IP address (127.0.0.1). If you want only to have it listen on a different IP, edit the lines in the file to look similar to the one below:

sudo nano /etc/memcached.conf

Then replace the local server IP with the one you want to use. You can also change its default port number as well.

# Default connection port is 11211
-p 11211

# Run the daemon as root. The start-memcached will default to running as root if no
# -u command is present in this config file
-u memcache
# Specify which IP address to listen on. The default is to listen on all IP addresses
# This parameter is one of the only security measures that memcached has, so make sure
# it's listening on a firewalled interface.
-l 192.168.2.1

Save the file and exit. Then restart Memcached services for the changes to apply.

How to block remote access to Memcached

When the Memcached server is improperly configured, it can be used to perform a distributed denial-of-service (DDoS) attack. If you’re allowing remote access, you must ensure that only trusted clients can access it remotely.

You can define the remote client IP in the configuration file above. IPs that are not in the file above are automatically denied access remotely.

You can also set up an Ubuntu firewall to block all remote clients except those explicitly allowed on port 11211.

sudo ufw allow from 192.168.2.1 to any port 11211

Th

To use Memcached as a caching database for your PHP application, such as WordPress, Drupal, Joomla, or Magento, you need to install the php-memcached extension.

Run the commands below to install the PHP Memcached PHP extension.

sudo apt install php-memcached

To use Memcached with Python, install the extension below.

pip install pymemcache

pip install python-memcached

That should do it!

Conclusion:

• Memcached is a powerful tool for improving the performance of web applications by caching data in memory.
• Installing and configuring Memcached on Ubuntu Linux is a straightforward process, suitable for both students and new users.
• Proper configuration and security measures are essential to prevent unauthorized access and potential misuse.
• Integrating Memcached with PHP applications enhances efficiency, making it an excellent choice for frameworks like WordPress and Drupal.
• Explore additional extensions for languages like Python to take full advantage of Memcached’s capabilities.
• Overall, implementing Memcached can significantly enhance your application’s speed and responsiveness.