How to Set Up Nginx as a Reverse Proxy for Memcached

Setting up Nginx as a reverse proxy for Memcached can be helpful when you want to distribute the load across multiple Memcached servers or when you want to access Memcached from a location where direct connection is not possible. Here’s a step-by-step guide:

1. Install Nginx:

If Nginx is not already installed on your server, you can install it using your package manager. On Ubuntu, you can use:

sudo apt update
sudo apt install nginx

2. Install Memcached:

Install Memcached on your server using your package manager:

sudo apt install memcached

3. Configure Memcached:

You may need to adjust Memcached settings depending on your specific use case. The configuration file for Memcached is usually located at /etc/memcached.conf.

4. Configure Nginx for Memcached:

Create a new Nginx configuration file for Memcached. You can create this file in the /etc/nginx/conf.d/ directory:

sudo nano /etc/nginx/conf.d/memcached.conf

Add the following configuration:

upstream memcached_backend {
    server 127.0.0.1:11211; # Address and port of your Memcached server
}

server {
    listen 80;
    server_name memcached.example.com; # Replace with your domain or server IP

    location / {
        set $memcached_key $uri;
        memcached_pass memcached_backend;
        default_type text/html;
        error_page 404 = @fallback;
    }

    location @fallback {
        proxy_pass http://backend_server;
    }
}

• upstream memcached_backend: Defines a group of Memcached servers.
• server 127.0.0.1:11211: Specifies the address and port of your Memcached server.
• location /: Handles requests to the Memcached proxy.
• set $memcached_key $uri;: Sets the key used for the Memcached request to the URI.
• memcached_pass memcached_backend;: Passes the request to the Memcached servers defined in the upstream block.
• error_page 404 = @fallback;: Redirects to the fallback location in case of a cache miss.

5. Test Nginx Configuration:

Before applying the changes, test your Nginx configuration:

sudo nginx -t

If the test is successful, you should see a message indicating that the configuration is okay.

6. Reload Nginx:

Reload Nginx to apply the new configuration:

sudo systemctl reload nginx

7. Access Memcached via Nginx:

Now, you can access Memcached via Nginx using the server name or IP address you configured in the Nginx reverse proxy.

For example, if you set up Nginx with the server name memcached.example.com, you can access Memcached by visiting:

http://memcached.example.com/

Nginx will proxy requests to the Memcached server.

By following these steps, you have set up Nginx as a reverse proxy for Memcached, allowing you to control access and potentially distribute the load across multiple Memcached servers.