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