Reverse Proxy & Load Balancing in Apache

From the Apache cheat sheet · Reverse Proxy · verified Jul 2026

Reverse Proxy & Load Balancing

Forward requests to Node.js, Python, or other backend servers

apacheconf

# Enable required modules
sudo a2enmod proxy proxy_http proxy_balancer lbmethod_byrequests

# Basic reverse proxy
<VirtualHost *:80>
    ServerName app.example.com
    ProxyPass / http://localhost:3000/
    ProxyPassReverse / http://localhost:3000/
</VirtualHost>

💡 ProxyPreserveHost On sends the original Host header to the backend — essential for virtual hosts

⚡ Use ProxyPass /path ! to exclude paths from proxying (serve static files directly)

📌 WebSocket proxying needs mod_proxy_wstunnel and RewriteRule for the Upgrade header

🟢 Load balancing with BalancerMember distributes traffic across multiple backend instances

proxyreverse-proxyload-balancing

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