Exam AWS-SysOps topic 1 question 434 discussion

Cooldown prevents from launching or terminating before effects of previous activities are visible

Correct answer is B. The cool down period is the time difference between the end of one scaling activity (can be start or terminate) and the start of another one (can be start or terminate). Thus, after auto-scaling was triggered for the first time, it added one instance, giving us six instances in total. The second trigger appeared in 2 minutes, which is within the 5-minutes cool-down period, thus no action was taken. Still we have six instances running.

Since the cool down period is 5 minutes and only 2 minutes have passed since the first trigger, the Auto Scaling group is still within the cool down period. During this cool down period, the Auto Scaling group does not launch any new instances or terminate any existing instances. Therefore, at the end of 4 minutes, the count of instances will remain the same as the initial desired capacity of 5.