AWS Elastic Load Balancer - how many concurrent users allowed

Question

AWS Setup We have built an application for which we have setup load balancer and auto scaling to add more EC2 instances when load goes up. We currently have only 1 EC2 instance (c4.2xlarge) behind load balancer.

Traffic & Load Testing During peek hours, we are expecting to receive heavy traffic (More than 1 million requests per second) and need to do the load testing of our AWS setup for this scenario. But before even start setting up load testing env, we have below questions.

1. Can AWS load balancer handle this much traffic per second? We are afraid that AWS would stop processing requests marking it as Denial of Service Attack.
2. Is there any better way to do this setup (ex - adding more than 1 load balancers)?
3. What is the best way to do the load testing for this kind of load?

We would really appreciate any help on this.

Answer 1

This is answered by the ELB FAQ. It will basically scale to any level you can reasonably throw at it. Remember it's not a single device, it's a managed service, that will scale as far as you like.

You'll probably want to load test this before you go to production. If you go from nothing to 1 million hits per second it might take some time to catch up, you could consider pre-warming if appropriate, but if your load increases at a reasonable pace it won't be a problem. There's a paper on ELB scale, but it stopped testing at 20,000 requests per second.