Question

A Solutions Architect has a multi-layer application running in Amazon VPC. The application has an ELB Classic Load Balancer as the front end in a public subnet, and an Amazon EC2-based reverse proxy that performs content-based routing to two backend Amazon EC2 instances hosted in a private subnet. The Architect sees tremendous traffic growth and is concerned that the reverse proxy and current backend set up will be insufficient.

Answer 1

To deal with the traffic growth in a cost-effective manner, the architect should Add Auto Scaling to the Amazon EC2 backend fleet and Replace both the frontend and reverse proxy layers with an ELB Application Load Balancer.

Classic load balancer isn't compatible with path/host-based routing. So it can not replace reverse proxy.