Memcached is a free and open-source high-performance in-memory key-value data store. It is generally used to speed up applications by caching various objects from the results of API and database calls.
This article shows how to install and configure Memcached on Ubuntu 20.04.
Installing Memcached
The memcached package is included in the default Ubuntu 20.04 repositories. To install it, enter the following command as root or user with sudo privileges :
sudo apt updatesudo apt install memcached libmemcached-tools
The libmemcached-tools package provides command-line utilities that you can use to manage the memcached server.
Once the installation is completed, the memcached service will start automatically. To check the status of the service, enter:
sudo systemctl status memcachedThe output will look something like this:
● memcached.service - memcached daemon
Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
Active: active (running) since Mon 2020-07-13 19:32:01 UTC; 23s ago
That’s it, you have installed memcached on your Ubuntu 20.04 server, and you can start using it.
Configuring Memcached
Memcached options can be configured in the /etc/memcached.conf file. By default, memcached is set to listen only on localhost.
The default configuration settings are sufficient for most users.
Remote Access
If the client connecting to memcached is running on the same host, you should not allow remote access.
When improperly configured, memcached can be used to perform a distributed denial-of-service (DDoS) attack. To allow remote access to the memcached server, you need to configure the firewall and open the memcached UDP port 11211 only from trusted clients.
The following example assumes that you want to connect to the memcached server over a private network. The memcached server IP is 192.168.100.20, and the client’s IP address is 192.168.100.30.
The first step is to edit the memcached configuration and set the service to listen on the server’s private networking interface:
To do so, open the memcached.conf configuration file:
sudo nano /etc/memcached.confLocate the line that begins with -l 127.0.0.1 and replace 127.0.0.1 with the server IP address 192.168.100.20./etc/memcached.conf
-l 192.168.100.20Copy
Restart the Memcached service for the changes to take effect:
sudo systemctl restart memcachedOnce the service is configured, the next step is to open the memcached port in the firewall .
sudo ufw allow from 192.168.100.30 to any port 11211Connecting to Memcached
There are many implementations of memcached clients written for different programming languages.
PHP
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:
sudo apt install php-memcachedPython
There are several Python libraries for interacting with memcache. You can install your preferred library using pip :
pip install pymemcachepip install python-memcached
