HowTo: load balancing with HAProxy on Debian

HAProxy spreads traffic across multiple servers, with health checks and centrally terminated TLS. Step-by-step, production-ready setup.

1. Install

sudo apt -y install haproxy
haproxy -v

2. Frontend + backend

# /etc/haproxy/haproxy.cfg — frontend + backend
frontend web
    bind *:80
    bind *:443 ssl crt /etc/haproxy/certs/site.pem
    redirect scheme https if !{ ssl_fc }
    default_backend app_servers

backend app_servers
    balance roundrobin
    option httpchk GET /health
    server app1 10.0.0.11:8080 check
    server app2 10.0.0.12:8080 check

3. Algorithms + sticky

# algoritmi uzuali:
#   balance roundrobin   -> pe rand
#   balance leastconn    -> cel mai putin incarcat (bun pt sesiuni lungi)
#   balance source       -> sticky pe IP client
# sticky pe cookie:
#   cookie SRV insert indirect nocache

4. Stats page

# pagina de statistici (protejata cu user/parola)
listen stats
    bind *:8404
    stats enable
    stats uri /
    stats auth admin:parolaAici

5. Verify

sudo haproxy -c -f /etc/haproxy/haproxy.cfg   # verifica sintaxa
sudo systemctl reload haproxy
curl -I http://LB_IP/                          # trebuie sa raspunda un backend

Conclusion

You now have load balancing with health checks and TLS, no single point of failure on the app. We design and configure it for you.