Load Balancer
the traffic distributorA load balancer spreads incoming connections across a pool of servers. It accepts each request at one address, picks a healthy backend, and forwards the request there — so no single server carries the whole load.
A load balancer shares traffic across many servers and routes around any that fail.
How it works
backend
Clients connect to the balancer’s single virtual address. It health-checks the pool and sends each new request to an available server — spreading the load and routing around web-3, which is down.
What a load balancer does, step by step
Clients connect to one virtual IP, not to any server directly.
It continuously tests which backends are alive.
It chooses one by round-robin, least-connections or a similar rule.
It proxies the request there and passes the response back.
In cybersecurity
Sitting in front of every server, the balancer is a natural place to terminate TLS and absorb attacks — and a single point to harden.
Decrypt once, inspect, then re-encrypt to the backends.
Spread and rate-limit floods before they reach servers.
Pull a compromised or failing node out of rotation.
Layer-7 balancers can filter application attacks.
It must itself be made redundant.
Sanitise forwarded headers like X-Forwarded-For.