AWS Certified SysOps Administrator – Associate — Question 446

A company has a stateful, long-running workload on a single xlarge general purpose Amazon EC2 On-Demand Instance Metrics show that the service is always using 80% of its available memory and 40% of its available CPU. A SysOps administrator must reduce the cost of the service without negatively affecting performance.
Which change in instance type will meet these requirements?

Answer options

• A. Change to one large compute optimized On-Demand Instance.
• B. Change to one large memory optimized On-Demand Instance.
• C. Change to one xlarge general purpose Spot Instance.
• D. Change to two large general purpose On-Demand Instances.

Correct answer: B

Explanation

The current workload uses 80% of the memory but only 40% of the CPU of an xlarge instance. Moving to a large memory-optimized On-Demand Instance provides the necessary memory capacity at a lower CPU tier, reducing costs without degrading performance. Spot Instances are not suitable for stateful, long-running workloads due to the risk of interruption, and a compute-optimized or standard general-purpose large instance would lack sufficient memory.