Load Balancer

Basics

• 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