How to implement load balancing and reverse proxy on Nginx?

Implementing load balancing and reverse proxy on Nginx involves configuring Nginx to distribute incoming traffic across multiple backend servers and to act as an intermediary between clients and servers.

Load Balancing:
To set up load balancing, you can use the upstream directive in Nginx to define a group of backend servers. Nginx then distributes requests among these servers using various algorithms like round-robin, least connections, or IP hash.

Example configuration for load balancing:

http {
    upstream backend {
        server backend1.example.com;
        server backend2.example.com;
        server backend3.example.com;
    }

    server {
        listen 80;

        location / {
            proxy_pass http://backend;
        }
    }
}

In this example, Nginx will distribute incoming requests to backend1.example.com, backend2.example.com, and backend3.example.com using the round-robin algorithm.

Reverse Proxy:
To set up a reverse proxy, you use the proxy_pass directive in Nginx to forward requests to a backend server. This allows Nginx to handle client requests and then pass them to the appropriate backend server.

Example configuration for reverse proxy:

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://backend_server;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

In this example, Nginx listens on port 80 for requests to example.com and forwards them to backend_server.

Combining Load Balancing and Reverse Proxy:
You can combine both load balancing and reverse proxy by defining an upstream block and using proxy_pass to forward requests to that upstream.

Example configuration combining both:

http {
    upstream backend {
        server backend1.example.com;
        server backend2.example.com;
        server backend3.example.com;
    }

    server {
        listen 80;
        server_name example.com;

        location / {
            proxy_pass http://backend;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }
    }
}

In this combined example, Nginx acts as a reverse proxy and load balancer, distributing incoming requests to the backend servers defined in the upstream block.

Recommendation for Cloud Services:
For enhanced scalability and reliability, consider using Tencent Cloud's services such as Tencent Cloud Load Balancer (CLB) and Tencent Cloud Container Service (TKE). These services integrate well with Nginx configurations to provide robust load balancing and management of containerized applications.