How to Install and Configure Memcached on Debian 10

Introduction

Before we begin talking about how to install and configure Memcached on Debian 10, let's briefly understand – What is Memcached ?

Memcached is a popular open-source, high-performance, distributed caching system used to improve website and application performance. It stores frequently accessed data in the server's memory, allowing quick retrieval and reducing database load.

Memcached is commonly employed in web applications to speed up dynamic content delivery by caching database queries, API responses, and HTML fragments.

In this tutorial, you will install and configure Memcached in Debian 10.

Advantages of Memcached

1. Enhanced Performance: Memcached improves website speed by caching frequently accessed data in memory, reducing database load.
2. Scalability: It can be easily scaled by adding more servers, accommodating increasing traffic and data demands.
3. Reduced Database Load: Memcached minimizes the number of database queries, freeing up server resources.
4. Language Compatibility: It supports various programming languages, making it accessible for developers across different platforms.
5. Simple Implementation: Memcached is easy to install and integrate into existing systems, requiring minimal configuration and maintenance.

1) Ensure that the server is up-to-date

It's always a good idea to check if the server packages have been updated before proceeding. Use this command to do so:

sudo apt update && sudo apt upgrade -y

Let's also install some common packages that we'll require for installation and configuration.

sudo apt install -y vim

2) Install Memcached

Memcached packages can be obtained in the default Ubuntu repositories. To install them, use the below command:

sudo apt install -y memcached

Verify the installation of Memcached

sudo apt-cache policy memcached

Output

memcached:
  Installed: 1.5.6-1.1
  Candidate: 1.5.6-1.1
  Version table:
 *** 1.5.6-1.1 500
        500 http://cdn-aws.deb.debian.org/debian buster/main amd64 Packages
        100 /var/lib/dpkg/status

3) Start and enable the Memcached service

Start the service by using the below command:

sudo systemctl start memcached

With this command, ensure that the service has been started:

sudo systemctl status memcached

Output

● memcached.service - memcached daemon
     Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
     Active: active (running) since Sat 2022-01-22 14:02:18 UTC; 25s ago
       Docs: man:memcached(1)
   Main PID: 52238 (memcached)
      Tasks: 10 (limit: 4626)
     Memory: 3.1M
        CPU: 19ms
     CGroup: /system.slice/memcached.service
             └─52238 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1 -P /var/run/memcached/memcached.pid

Jan 22 14:02:18 dev-debiansrv.inv.re systemd[1]: Started memcached daemon.

It is evident from the output above that Memcached is operational.

To make the service available upon boot:

sudo systemctl enable memcached

4) Enable Memcached on the firewall

Use this command to open port 11211 on the firewall to allow traffic from the client host if you have ufw installed and enabled.

sudo ufw allow 11211/tcp

Execute the command to verify that port 11211 is open on the firewall.

sudo ufw app list

5) Configure Memcached

The path to the Memcached configuration file is /etc/memcached.conf. To open a file for editing, use this command:

sudo vim /etc/memcached.conf

This is how Memcached is set up by default:

-d

logfile /var/log/memcached.log

-m 64

-p 11211

-u memcache

-l 127.0.0.1

-P /var/run/memcached/memcached.pid

As shown in the final line, Memcached is set up by default to only listen to the localhost system on port 11211. You must either modify the localhost address 127.0.0.1 to the IP of the remote host or configure Memcached to listen on all interfaces in order for applications from remote systems to connect to the server.

Replace the localhost address with the remote client's IP address, 10.70.5.214, to use the remote host.

-l 10.70.5.214

Use 0.0.0.0 instead of 127.0.0.1 to listen on all network interfaces. Modify the OPTIONS line to the one below.

-l 0.0.0.0,::1

After modifying the configuration file, restart the Memcached service:

sudo systemctl restart memcached 

Adjust the firewall to allow the client IP address or any address on port 11211:

sudo ufw allow from 192.168.100.30 to any port 11211
        OR
sudo ufw allow from 0.0.0.0 to any port 11211

Use this command to authenticate the modifications:

sudo ss -tulpn | grep 11211

Output

tcp   LISTEN 0      128      10.70.5.214:11211      0.0.0.0:*    users:(("memcached",pid=55522,fd=28))
tcp   LISTEN 0      128            [::1]:11211         [::]:*    users:(("memcached",pid=55522,fd=29))

FAQs to Install Memcached on Debian 10

Conclusion

You now know how to install and configure the Memcached server. You may now set up your applications to use the Memcached instance and connect to it.

If you have any queries, please leave a comment below and we’ll be happy to respond to them.