Reverse Proxy Load Balancer

Reverse proxy load balancers are components in a network architecture that serve two main purposes:

🔁 1. Reverse Proxy

A reverse proxy sits in front of backend servers and handles client requests on their behalf. It:

• Receives requests from clients (e.g., web browsers)
• Forwards those requests to one of the backend servers
• Returns the server's response to the client

📌 Think of it as a gatekeeper between clients and servers.

⚖️ 2. Load Balancer

A load balancer distributes incoming traffic across multiple backend servers to:

• Maximize speed and capacity utilization
• Prevent any one server from being overwhelmed
• Provide redundancy and high availability

🔧 Combined: Reverse Proxy Load Balancer

When combined, this system:

• Accepts all client requests
• Chooses a backend server based on a load balancing algorithm
• Forwards the request to that server
• Returns the response to the client

📊 Common Load Balancing Algorithms

• Round Robin – rotates through servers in order
• Least Connections – sends to the server with the fewest active connections
• IP Hash – hashes the client IP to choose a server
• Weighted Round Robin / Least Connections – gives preference to more powerful servers

🔐 Benefits

• Scalability – easily add/remove backend servers
• Security – hides internal servers, enabling TLS termination and DDoS protection
• Caching – can cache responses to reduce backend load
• SSL Offloading – handles encryption at the proxy instead of each backend

🛠️ Examples

• Nginx and HAProxy – widely used open-source reverse proxy/load balancers
• AWS ELB, Cloudflare, Traefik – managed or modern alternatives