upstream backend {
    least_conn;
    server node1:4000 max_fails=1 fail_timeout=5s;
    server node2:4000 max_fails=1 fail_timeout=5s;
    keepalive 32;
}

server {
    listen 80;

    location / {
        proxy_pass http://backend;

        proxy_http_version 1.1;

        # WebSocket support (required for LiveView)
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";

        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;

        # Fast failure detection and automatic retry on the other node
        proxy_connect_timeout 2s;
        proxy_next_upstream error timeout http_502 http_503 http_504;
        proxy_next_upstream_tries 2;
        proxy_next_upstream_timeout 4s;

        proxy_read_timeout 86400;
        proxy_send_timeout 86400;
    }
}