Briefing Amazon Knowledge

Which of the below mentioned statements is true?

A user has created an Auto Scaling group with default configurations from CLI. The user wants to setup the
CloudWatch alarm on the EC2 instances, which are launched by the Auto Scaling group. The user has setup an
alarm to monitor the CPU utilization every minute. Which of the below mentioned statements is true?

A.
It will fetch the data at every minute but the four data points [corresponding to 4 minutes] will not have
value since the EC2 basic monitoring metrics are collected every five minutes

B.
It will fetch the data at every minute as detailed monitoring on EC2 will be enabled by the default
launch configuration of Auto Scaling

C.
The alarm creation will fail since the user has not enabled detailed monitoring on the EC2 instances

D.
The user has to first enable detailed monitoring on the EC2 instances to support alarm monitoring at
every minute

Explanation:
CloudWatch is used to monitor AWS as well as the custom services. To enable detailed instance monitoring for
a new Auto Scaling group, the user does not need to take any extra steps. When the user creates an Auto
Scaling launch config using CLI, each launch configuration contains a flag named InstanceMonitoring.Enabled.
The default value of this flag is true. Thus, by default detailed monitoring will be enabled for Auto Scaling as
well as for all the instances launched by that Auto Scaling group.