Goal
The original deployment had one Nginx process forwarding traffic to one Gunicorn-backed Django process on 127.0.0.1:8000.
The practice goal was to run two backend instances and let Nginx distribute requests:
Nginx
-> Gunicorn on 127.0.0.1:8000
-> Gunicorn on 127.0.0.1:8001
Nginx upstream
The key Nginx concept is upstream:
upstream django_backend {
server 127.0.0.1:8000;
server 127.0.0.1:8001;
}
location / {
proxy_pass http://django_backend;
}
This keeps the public server block simple while allowing multiple private backend targets.
What needs to match
The backend processes must be started separately and listen on different ports. Nginx must point to those ports, and both processes must serve the same application version.
Useful checks:
ss -lntp
curl http://127.0.0.1:8000
curl http://127.0.0.1:8001
sudo nginx -t
Takeaway
Load balancing is not only about scaling traffic. It also forces the deployment to define process boundaries, health checks, and how Nginx should behave if one backend is unavailable.
