Which solution meets these requirements?
Configure a target tracking scaling policy that is based on the Auto Scaling group’s average CPU utilization, and set a target of 75%. Create a scheduled action for the Auto Scaling group to adjust the desired capacity to six instances just before business hours begin.
Configure the Auto Scaling group with two scheduled actions for Amazon EC2 Auto Scaling. Configure one action to start nine EC2 instances at the start of business hours. Configure the other action to stop nine instances at the end of business hours.
Change to an AWS Application Auto Scaling group. Configure a target tracking scaling policy that is based on the Auto Scaling group’s average CPU utilization, and set a target of 75%. Create a scheduled action for the Auto Scaling group to adjust the minimum number of instances to three instances at the end of business hours and to reset the number to six instances before business hours begin.
Change to an AWS Application Auto Scaling group. Configure a target tracking scaling policy that is based on the Auto Scaling group’s average CPU utilization, and set a target of 75%. Create a scheduled action to terminate nine instances each evening at the end of business hours.
Explanations:
This option uses target tracking to adjust scaling based on CPU usage and schedules a capacity increase before business hours, optimizing costs and meeting demand.
This option lacks flexibility since it schedules fixed capacity changes without accounting for the actual workload or sudden increases in CPU utilization.
Application Auto Scaling is typically used for scaling other services, not EC2 instances directly. Also, setting the minimum to three instances could hurt reliability.
Like option C, Application Auto Scaling is not meant for EC2 Auto Scaling. Terminating nine instances each evening could result in insufficient capacity at peak times.
In my experience, the answer is:
Configure a target tracking scaling policy that is based on the Auto Scaling group’s average CPU utilization, and set a target of 75%. Create a scheduled action for the Auto Scaling group to adjust the desired capacity to six instances just before business hours begin.