Question #881
A company is deploying a high-availability application on Amazon EC2 instances, which must run without interruption for a full year. Which EC2 purchasing option will be the most cost-effective for this scenario?
Spot Instances
On-Demand Instances
Reserved Instances
Dedicated Hosts
Explanation
Reserved Instances (C) are the correct choice because they provide up to 72% cost savings compared to On-Demand pricing for long-term commitments (1 or 3 years). The application requires uninterrupted operation for a full year, making Reserved Instances ideal. Spot Instances (A) are unsuitable due to potential interruptions. On-Demand (B) is more expensive for sustained usage. Dedicated Hosts (D) are costlier and used for compliance/licensing needs, not cost optimization. Key takeaway: Reserved Instances balance cost-effectiveness and stability for predictable, long-term workloads.
Answer
The correct answer is: C