Which of the following metrics can help understand if your infrastructure in AWS (EC2+ELB) is under a DDos attack. Choose 2 answers from the options given below.

Answer options:

A.EC2 CPU utilization
B.ELB SurgeQueueLength
C.HealthyHostCount
D.UnHealthyHostCount

Answer – A and B
Definitely the CPU utilization of the backend instances can give an indication of whether the backend instances are under tremendous load.
Surge queue length is defined by the number of requests that are queued by Elastic Load Balancing (ELB). These requests are queued when back-end systems are unable to process incoming requests as fast as the requests are being received
For more information on ELB troubleshooting please refer to the below URL:
https://aws.amazon.com/premiumsupport/knowledge-center/elb-capacity-troubleshooting/