Question #1410
For which use case are Amazon EC2 On-Demand Instances MOST cost-effective?
A batch data analysis job that can be paused and resumed if interrupted
An application hosting environment required for a 3-month software development project
A high-traffic e-commerce website expected to run continuously for 2 years
A machine learning training workload that can utilize spare capacity
Explanation
Amazon EC2 On-Demand Instances are ideal for short-term, non-interruptible workloads without long-term commitments. Here's why:
- Option A: Batch jobs that tolerate interruptions are better suited for Spot Instances, which are significantly cheaper but can be reclaimed by AWS.
- Option B: A 3-month project is too short for Reserved Instances (1/3-year commitments) but long enough to avoid Spot interruptions. On-Demand balances cost and stability here.
- Option C: A 2-year workload benefits from Reserved Instances or Savings Plans, which offer steep discounts (up to 72%) compared to On-Demand.
- Option D: Machine learning workloads using spare capacity align with Spot Instances, which are cheaper and designed for fault-tolerant tasks.
Key Takeaway: On-Demand is cost-effective for short-term, predictable use cases where Reserved/Spot options are impractical. For long-term or interruptible workloads, other pricing models are more economical.
Answer
The correct answer is: B