Setting Up HAProxy as a Load Balancer

HAProxy distributes incoming traffic across multiple backend servers to improve availability and performance.

Install HAProxy

apt update
apt install haproxy -y

Basic Configuration

nano /etc/haproxy/haproxy.cfg

global
    log /dev/log local0
    maxconn 4096

defaults
    log global
    mode http
    timeout connect 5s
    timeout client 30s
    timeout server 30s

frontend http_in
    bind *:80
    default_backend webservers

backend webservers
    balance roundrobin
    option httpchk GET /health
    server web1 192.168.1.101:80 check
    server web2 192.168.1.102:80 check
    server web3 192.168.1.103:80 check

Balance Algorithms

• roundrobin — distribute requests evenly in rotation
• leastconn — send to the server with fewest active connections (best for long-lived connections)
• source — sticky sessions by client IP

Enable the Stats UI

listen stats
    bind *:8404
    stats enable
    stats uri /stats
    stats auth admin:password

Access at http://YOUR_SERVER_IP:8404/stats.

Start and Enable HAProxy

systemctl enable haproxy
systemctl start haproxy

SSL Termination at HAProxy

frontend https_in
    bind *:443 ssl crt /etc/ssl/certs/yourdomain.pem
    default_backend webservers

Combine your certificate and key into one PEM file: cat fullchain.pem privkey.pem > yourdomain.pem