AWS Certified Solutions Architect – Professional (SAP-C02) — Question 232

A solutions architect needs to review the design of an Amazon EMR cluster that is using the EMR File System (EMRFS). The cluster performs tasks that are critical to business needs. The cluster is running Amazon EC2 On-Demand Instances at all times for all task, primary, and core nodes. The EMR tasks run each morning, starting at 1:00 AM. and take 6 hours to finish running. The amount of time to complete the processing is not a priority because the data is not referenced until late in the day.

The solutions architect must review the architecture and suggest a solution to minimize the compute costs.

Which solution should the solutions architect recommend to meet these requirements?

Answer options

• A. Launch all task, primary, and core nodes on Spot Instances in an instance fleet. Terminate the cluster, including all instances, when the processing is completed.
• B. Launch the primary and core nodes on On-Demand Instances. Launch the task nodes on Spot Instances in an instance fleet. Terminate the cluster, including all instances, when the processing is completed. Purchase Compute Savings Plans to cover the On-Demand Instance usage.
• C. Continue to launch all nodes on On-Demand Instances. Terminate the cluster, including all instances, when the processing is completed. Purchase Compute Savings Plans to cover the On-Demand Instance usage.
• D. Launch the primary and core nodes on On-Demand Instances. Launch the task nodes on Spot Instances in an instance fleet. Terminate only the task node instances when the processing is completed. Purchase Compute Savings Plans to cover the On-Demand Instance usage.

Correct answer: B

Explanation

The correct answer is B because it optimizes costs by using On-Demand Instances for the essential primary and core nodes while leveraging Spot Instances for the less critical task nodes, which can save money. Option A would be less efficient, as terminating all nodes could disrupt critical functions. Options C and D do not fully utilize the cost-saving potential of Spot Instances for the task nodes, leading to higher overall expenses.