Load balancing

A load balancer spreads traffic and hides failed instances. The interesting choices are the algorithm and what happens to sessions.

What this lesson covers

• Compare round robin, least connections, and hashing
• Health check instances and drain them safely
• Handle session affinity without pinning users forever

This lesson sits in Core Building Blocks, part of System Design Foundations. It assumes what came before it and leads directly into the next lesson in the module.