Load Balancing

Distribute traffic across application servers.

nginx Load Balancer

upstream backend {
    least_conn;
    server backend1:8080 weight=3;
    server backend2:8080;
    server backend3:8080 backup;
}

server {
    listen 80;
    
    location / {
        proxy_pass http://backend;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

HAProxy

frontend http_front
    bind *:80
    default_backend http_back

backend http_back
    balance roundrobin
    option httpchk GET /health
    server web1 10.0.0.1:8080 check
    server web2 10.0.0.2:8080 check

AWS ALB

aws elbv2 create-load-balancer \
  --name my-alb \
  --subnets subnet-xxx subnet-yyy \
  --security-groups sg-xxx \
  --type application

Best Practices

• Implement health checks
• Use sticky sessions when needed
• Enable connection draining
• Monitor backend health