Installing and configuring Memcached

Whether you're running a VPS, Web Hosting or a Dedicated Server, installing Memcached is a powerful way to boost your application's speed by storing frequently used data directly in RAM. It’s an essential tool for everything from small personal blogs to high-traffic Linux-based enterprise projects.

Fast Track: You can deploy Memcached with a single click during the server checkout process. Learn more in our One-Click-Apps documentation.

Think of Memcached as a massive hash table living on your server. It stores data with a defined lifespan (TTL), allowing for near-instant retrieval via unique keys. It is primarily used to cache web pages, database query results, and API objects that require low-latency access.

Installing Memcached

On Ubuntu / Debian

sudo apt update
sudo apt install memcached php-memcached -y

On CentOS / Rocky Linux / AlmaLinux

sudo yum install memcached php-pecl-memcached -y
# Or for newer versions:
sudo dnf install memcached php-pecl-memcached -y

Configuration

To fine-tune your instance, open the configuration file:

sudo nano /etc/memcached.conf

Recommended Settings:

# Default listening port
-p 11211

# Run as a specific user
-u memcached

# Maximum simultaneous connections
-c 1024

# Allocated memory for the cache (in megabytes)
-m 128

# Listen to localhost only (highly recommended for security)
-l 127.0.0.1

Save the file and restart the service to apply changes:

sudo systemctl restart memcached
sudo systemctl enable memcached

Verifying the setup

Check the service status:

sudo systemctl status memcached

You can also verify the connection and pull statistics directly:

echo "stats" | nc localhost 11211

Enabling Memcached for PHP

Confirm that the PHP extension is active:

php -m | grep memcached

If it’s missing, install it using your package manager:

• Ubuntu/Debian: sudo apt install php-memcached
• CentOS/Rocky: sudo yum install php-pecl-memcached

After installation, restart your web server or PHP handler:

sudo systemctl restart php-fpm
# OR
sudo systemctl restart apache2

Best practices

• Memory allocation: for small sites, 64–128 MB is usually plenty. For high-traffic applications, consider bumping the -m value to 512 MB or 1 GB.
• Security first: never expose port 11211 to the public internet. Ensure Memcached is only accessible via localhost or a trusted private network.
• Go local: for maximum security and slightly better performance on a single-server setup, consider using a Unix socket instead of a TCP port.