Question 38
Domain 4: Billing, Pricing, and SupportIn which scenario should Amazon EC2 Spot Instances be used?
Correct answer: D
Explanation
Spot Instances fit workloads that are “infrequent” and “interruptible” because AWS can reclaim them when capacity is needed, making them a low-cost choice for flexible jobs. They are better than On-Demand Instances when the task can tolerate interruption and does not need continuous availability.
Why each option is right or wrong
A. A company wants to move its main website to AWS from an on-premises web server.
B. A company has a number of application services whose Service Level Agreement (SLA) requires 99.999% uptime.
C. A company's heavily used legacy database is currently running on-premises.
D. A company has a number of infrequent, interruptible jobs that are currently using On-Demand Instances.
Amazon EC2 Spot Instances are governed by the EC2 pricing model in which AWS can interrupt and reclaim capacity when needed, so they are appropriate only for workloads that can tolerate being stopped and restarted. In this fact pattern, the jobs are both infrequent and interruptible, which aligns with using the lower-cost Spot capacity instead of paying On-Demand rates for always-available compute.