Q91 — AWS SAA-C03 Ch.15

Question 91 of 100 | ← Chapter 15

Q1191. A company has a website that handles dynamic traffic loads. The website architecture is based on Amazon EC2 instances in an Auto Scaling group that is configured to use scheduled scaling. Each EC2 instance runs code from an Amazon Elastic File System (Amazon EFS) volume and stores shared data back to the same volume.The company wants to optimize costs for the website.Which solution will meet this requirement?

Correct Answer: C. Reconfigure the Auto Scaling group to use a target tracking scaling policy.

Explanation

To optimize costs for the website that handles dynamic traffic loads and is currently using an Auto Scaling group with scheduled scaling, let's analyze each option:Analysis of Options:A. Reconfigure the Auto Scaling group to set a desired number of instances. Turn off scheduled scaling. Limitation: Setting a fixed desired number of instances and turning off scheduled scaling means the Auto Scaling group will not automatically adjust the number of instances based on traffic demands. This could lead to either underutilization (if the fixed number is too high for low traffic periods) or poor performance (if the fixed number is too low for high traffic periods). This approach does not optimize costs effectively as it fails to adapt to dynamic traffic loads.B. Create a new launch template version for the Auto Scaling group that uses larger EC2 instances. Limitation: Using larger EC2 instances will likely increase costs rather than optimize them. Larger instances have higher compute and memory capacities, which are not necessary if the traffic is dynamic and can be handled by a smaller number of appropriately sized instances. This option does not address the cost optimization requirement.C. Reconfigure the Auto Scaling group to use a target tracking scaling policy. Advantage: A target tracking scaling policy allows the Auto Scaling group to automatically adjust the number of instances based on a specified target value for a CloudWatch metric, such as CPU utilization or average network in/out. This means the Auto Scaling group can scale in and out in response to dynamic traffic loads, ensuring that the website has enough capacity during high traffic periods while reducing costs during low traffic periods by scaling down. This option directly addresses the cost optimization requirement by adapting to traffic demands.D. Replace the EFS volume with instance store volumes.Limitation: Instance store volumes provide temporary block-level storage for EC2 instances. They are not suitable for storing shared data that needs to persist beyond the lifecycle of an individual instance. Since the website architecture requires shared data to be stored back to the volume, replacing EFS with instance store volumes would not be feasible and could lead to data loss or inconsistency. This option does not meet the website's requirements and does not optimize costs.Conclusion:C. Reconfigure the Auto Scaling group to use a target tracking scaling policy. is the best solution to meet the company's requirement of optimizing costs for the website. It allows the Auto Scaling group to automatically adjust the number of instances based on dynamic traffic loads, ensuring efficient resource utilization and cost savings.