A DevOps Engineer is working with an application deployed to 12 Amazon EC2 instances across 3 Availability Zones. New instances can be started from an AMI image. On a typical day, each EC2 instance has 30% utilization during business hours and 10% utilization after business hours. The CPU utilization has an immediate spike in the first few minutes of business hours. Other increases in CPU utilization rise gradually.
The Engineer has been asked to reduce costs while retaining the same or higher reliability.
Which solution meets these requirements?
A. Create two Amazon CloudWatch Events rules with schedules before and after business hours begin and end. Create two AWS Lambda functions, one invoked by each rule. The first function should stop nine instances after business hours end, the second function should restart the nine instances before the business day begins.
B. Create an Amazon EC2 Auto Scaling group using the AMI image, with a scaling action based on the Auto Scaling group’s CPU Utilization average with a target of 75%. Create a scheduled action for the group to adjust the minimum number of instances to three after business hours end and reset to six before business hours begin.
C. Create two Amazon CloudWatch Events rules with schedules before and after business hours begin and end. Create an AWS CloudFormation stack, which creates an EC2 Auto Scaling group, with a parameter for the number of instances. Invoke the stack from each rule, passing a parameter value of three in the morning, and six in the evening.
D. Create an EC2 Auto Scaling group using the AMI image, with a scaling action based on the Auto Scaling group’s CPU Utilization average with a target of 75%. Create a scheduled action to terminate nine instances each evening after the close of business.
The Engineer has been asked to reduce costs while retaining the same or higher reliability.
Which solution meets these requirements?
A. Create two Amazon CloudWatch Events rules with schedules before and after business hours begin and end. Create two AWS Lambda functions, one invoked by each rule. The first function should stop nine instances after business hours end, the second function should restart the nine instances before the business day begins.
B. Create an Amazon EC2 Auto Scaling group using the AMI image, with a scaling action based on the Auto Scaling group’s CPU Utilization average with a target of 75%. Create a scheduled action for the group to adjust the minimum number of instances to three after business hours end and reset to six before business hours begin.
C. Create two Amazon CloudWatch Events rules with schedules before and after business hours begin and end. Create an AWS CloudFormation stack, which creates an EC2 Auto Scaling group, with a parameter for the number of instances. Invoke the stack from each rule, passing a parameter value of three in the morning, and six in the evening.
D. Create an EC2 Auto Scaling group using the AMI image, with a scaling action based on the Auto Scaling group’s CPU Utilization average with a target of 75%. Create a scheduled action to terminate nine instances each evening after the close of business.