AWS Certified SysOps Administrator – Associate (legacy) — Question 744

A developer created a new application that uses Spot Fleet for a variety of instance families across multiple Availability Zones.
What should the developer do to ensure that the Spot Fleet is configured for cost optimization?

Answer options

• A. Deploy a capacityOptimized allocation strategy for provisioning Spot Instances.
• B. Ensure instance capacity by specifying the desired target capacity and how much of that capacity must be On-Demand.
• C. Use the lowestPrice allocation strategy with InstancePoolsToUseCount in the Spot Fleet request.
• D. Launch instances up to the Spot Fleet target capacity or the maximum acceptable payment amount.

Correct answer: B

Explanation

Specifying the desired target capacity along with a designated portion of On-Demand instances allows the Spot Fleet to balance cost savings with application reliability by maintaining a baseline of guaranteed resources. While allocation strategies like lowestPrice or capacityOptimized help manage Spot instances, they do not provide the foundational cost-reliability balance achieved by blending On-Demand and Spot capacities. Defining maximum payment amounts or relying solely on Spot instances without an On-Demand baseline risks application interruption during periods of high Spot price volatility.