Q61 — AWS SAP-C02 Ch.3

Question 61 of 75 | ← Chapter 3

Q286. 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, master, and core nodes. The EMR tasks run each morning, starting at 1:00AM, 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?

Correct Answer: D. Launch the master 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

Explanation

To minimize compute costs for the EMR cluster while meeting the requirement to perform critical business tasks and processing data in a timely manner, the solution should be to launch the master and core nodes on On-Demand Instances and launch the task nodes on Spot Instances in an instance fleet. Terminate only the task node instances when the processing is completed. Additionally, Compute Savings Plans should be purchased to cover the On-Demand Instance usage. Option D is the correct solution: D. Launch the master 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. By using On-Demand Instances for the master and core nodes, the EMR cluster can ensure that it has reliable capacity and consistent performance for these critical components of the architecture. By launching the task nodes on Spot Instances, the cost of the processing can be minimized since Spot Instances are available at a lower cost than On-Demand Instances. With this approach, the instances can be terminated once the EMR tasks are completed, which will further reduce costs. Compute Savings Plans can be purchased to cover the On-Demand Instance usage, which will provide additional cost savings. Option A involves launching all nodes on Spot Instances in an instance fleet. This option may not be optimal for critical business tasks since Spot Instances are subject to interruptions and are not guaranteed. Option B involves launching the master and core nodes on On-Demand Instances and launching the task nodes on Spot Instances in an instance fleet. However, terminating all instances when the processing is completed may not be optimal if there are other workloads running on the EMR cluster. Option C involves continuing to launch all nodes on On-Demand Instances and purchasing Compute Savings Plans to cover the On-Demand Instance usage. While this option may provide some cost savings, it does not take advantage of the potential cost savings available with Spot Instances.