<strong>Load balancing</strong> is distributing incoming network traffic across multiple servers to ensure no single server gets overwhelmed. It improves reliability, performance, and scalability.
The Supermarket Checkout Analogy
A supermarket manager directs customers to the shortest checkout line. Load balancers do the same with web requests, sending each to the least busy server.
Customers (Requests)
Need to check out
Manager (Load Balancer)
Directs to shortest line
Cashiers (Servers)
Process checkouts
Send Requests
Distributes Traffic
Handle Requests
Request arrives
User visits your website
Load balancer receives
Acts as single entry point
Chooses a server
Uses algorithm (round-robin, least connections, etc.)
Forwards request
Sends request to selected server
Returns response
Server processes and returns through load balancer
Wrong
"Load balancing is only for huge websites"
Correct
Load balancing is valuable for <strong>any growing application</strong>. It provides redundancy (if one server fails, others continue), enables zero-downtime deployments, and allows horizontal scaling.
E-commerce site during Black Friday:
Traffic spikes from 1,000 to 100,000 users per second
Load balancer distributes across 50 servers instead of 5
If one server crashes, others handle its traffic automatically
Users experience no downtime or slowdowns