How do you distribute load among servers during horizontal scaling of a system?

When horizontally scaling, the load is distributed among servers using load balancers. Main approaches:

• Round Robin: requests are evenly distributed to servers in turn.
• Least Connections: requests are directed to the server with the fewest active connections.
• IP Hash: requests from the same client are always directed to the same server.

Example of configuring a simple load balancer on Nginx:

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

server {
    listen 80;

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

This approach allows for even load distribution and ensures system fault tolerance.