How load balancing works

A load balancer distributes incoming requests across backend servers. Routing decisions affect queue length, latency, and how well spare capacity is used. Health checks help avoid unavailable backends, but detection takes time.

When to use it

Load balancing helps spread traffic across replicas and tolerate individual backend failures. It does not remove a database bottleneck or make unlimited capacity available.

Explore the tradeoffs

Compare round robin, weighted round robin, least connections, and IP hash using the same traffic scenario. Equal request counts do not guarantee equal work: request duration, backend capacity, and uneven clients can change the result.

Use the lab

Choose a lesson and routing algorithm, adjust traffic and backend settings, then run or step the simulation. Read routing events and queue metrics; pause and inspect decisions at your own pace. The challenge and quiz help check your understanding.

Results describe a simplified, seeded simulation. They are not benchmarks or guarantees of production performance.