A user has configured an ELB to distribute the traffic among multiple instances. The user instances are facing some issues due to the back-end servers. Which of the below mentioned CloudWatch metrics helps the user understand the issue with the instances?

Answer options:

A.HTTPCode_Backend_3XX
B.HTTPCode_Backend_4XX
C.HTTPCode_Backend_2XX
D.HTTPCode_Backend_5XX

Answer – D
The Either HTTPCode_Backend_5XXfor the load balancer is caused by issues in the backend servers. The different sort of errors are given below
· HTTP 502: Bad Gateway
· HTTP 503: Service Unavailable
· HTTP 504: Gateway Timeout
For more information on ELB errors visit the link:
http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/ts-elb-http-errors.html