Load Balancer


  • Types: Application, Network, Classic load balancer.
  • X-forward-For header is forwared from outside to the instance server
  • HTTP 504 if the backend app is having issues, not reacheable.
  • LBs costs money :)

Application load balancer

  • HTTP/HTTPS (based on methods, routes)
  • operates on layer 7

Network load balancer

  • TCP traffic based
  • layer 4
  • millions of requests per second, ultra low latencies

Classic load balancer

  • Elastic load balancer
  • Mix of layer 7 and 4.
  • Mix of HTTP/HTTPS and other TCP specifics