How to Install and Configure Redis on a Separate DigitalOcean Droplet for Magento

Install redis on separate droplet to offload Redis from the Magento monolith.

Create a Droplet for Redis

Let’s create a droplet for Redis in DigitalOcean (DO from now on).

I chose the following minimal parameters (you can scale later):

• Basic Droplet
• Premium AMD: 1GB RAM, 25GB NVMe SSD, 1000GB transfer.

IMPORTANT: Make sure the new droplet is within the same VPC and Region as your Magento server.

Redis installation

Once the droplet is successfully created, SSH into the droplet and install Redis:

# install Redis and enable it
sudo apt update
sudo apt install redis
sudo systemctl enable redis
sudo systemctl start redis

Networking

We do not need direct public access to Redis. For security, ensure only the Magento server can access Redis by setting up a private connection.

Binding to Private IP

Edit /etc/redis/redis.conf to bind Redis to the private IP of the server. You can find the private IP in the DigitalOcean dashboard.

# bind redis to the private IP
# edit /etc/redis/redis.conf
bind 127.0.0.1 <PRIVATE_IP>

# Example
bind 127.0.0.1 10.10.10.10

Setup password

In the same file, find and configure the requirepass directive to secure Redis with a password:

# setup password
# edit /etc/redis/redis.conf
requirepass <REDIS_PASSWORD>

# Example
requirepass m4wgCo60YWxMZvn

Tip: Generate a secure password using tools like LastPass Password Generator.

Restart Redis to apply the changes:

systemctl restart redis

Create Redis firewall

In the DigitalOcean Networking section, create a new firewall to restrict access. Add a custom rule to allow port 6379 only for your Magento server’s droplet (source) for both inbound and outbound traffic.

Testing connection

From the Magento server, test the connection to Redis:

redis-cli -h <REDIS_PRIVATE_IP> -a <REDIS_PASSWORD> ping

If successful, you will see the response PONG. This confirms that Redis is correctly set up and accessible.

Configuring Magento to Use Redis

Edit the app/etc/env.php file in your Magento installation to configure it to use Redis on the remote server:

# edit app/etc/env.php of your magento installation
'cache' => [
    'frontend' => [
        'default' => [
            'backend' => 'Cm_Cache_Backend_Redis',
            'backend_options' => [
                'server' => '<REDIS_PRIVATE_IP>',
                'port' => '6379',
                'persistent' => '',
                'database' => 0,
                'password' => '<REDIS_PASSWORD>',
                'compress_data' => 1
            ]
        ]
    ]
],

Final tests

To ensure everything is working, monitor Redis while browsing your Magento store:

# Run this command on the Redis server
redis-cli -a <REDIS_PASSWORD> monitor

While navigating your Magento store, you should see activity logged in the Redis monitor.

By following these steps, you have successfully offloaded Redis from your Magento monolith, improving scalability and performance while maintaining a secure setup.