Elastic Load Balancing (ELB) distribuira dolazni promet na više ciljnih mjesta (EC2 instance, kontejneri, itd.) — poboljšavajući dostupnost (nema jedne točke neuspjeha) i skalabilnost (dijeljenje opterećenja). To je ključna komponenta za pouzdane i skalabilne aplikacije.
Što load balancer radi
A LOAD BALANCER sits in front of multiple backend targets and distributes requests:
Client → LOAD BALANCER → ┬→ Instance 1
├→ Instance 2
└→ Instance 3
→ spreads traffic across targets (scalability + no single instance overloaded)
→ HEALTH CHECKS: routes only to HEALTHY targets (an unhealthy one is bypassed)
→ if a target fails, traffic goes to the others → HIGH AVAILABILITY
→ single entry point (clients hit the LB, not individual instances)
