What is Load Balancing?

Load balancing distributes incoming network traffic across multiple servers. It's like having multiple checkout lanes at a store — instead of everyone waiting in one line, traffic is spread across all lanes to keep things moving fast.

Why It Matters:

• Performance: No single server gets overwhelmed
• Reliability: If one server fails, others handle traffic
• Scalability: Add more servers to handle more traffic
• Efficiency: Better resource utilization

Load Balancing Algorithms:

• Round robin: Distribute requests evenly in rotation
• Least connections: Send to server with fewest active connections
• IP hash: Route based on client IP (sticky sessions)
• Weighted: Give more traffic to more powerful servers

Types:

• Hardware load balancer: Physical device
• Software load balancer: Runs on servers (like NGINX, HAProxy)
• Cloud load balancer: Managed service (AWS ELB, Cloudflare)

FAQ

Do I need load balancing?

If you have one server handling all traffic, probably not. If you have multiple servers or expect high traffic, yes.

What's session affinity?

Also called sticky sessions — ensures a user's requests go to the same server, important for stateful applications.