Question #1284
A research institution is conducting large-scale climate modeling simulations that require significant computational resources. The simulations can be interrupted and restarted without significant impact on the overall project timeline. What is the MOST cost-effective Amazon EC2 purchasing option for this scenario?
On-Demand Instances
Spot Instances
Reserved Instances
Savings Plans
Explanation
The correct answer is B. Spot Instances.
Why Spot Instances?
- Spot Instances provide the lowest cost (up to 90% cheaper than On-Demand) for workloads that can tolerate interruptions, such as batch jobs, simulations, or flexible compute tasks.
- The question specifies that the simulations can be interrupted and restarted without impacting the timeline, making Spot Instances ideal.
- AWS can reclaim Spot Instances with short notice (2 minutes), but the application's fault tolerance ensures no significant delays.
Why Not Other Options?
- A. On-Demand Instances: These are the most expensive and unnecessary for interruptible workloads.
- C. Reserved Instances: Require a long-term commitment (1-3 years) and are cost-effective only for steady-state, uninterrupted workloads.
- D. Savings Plans: Offer discounts for committed usage (like Reserved Instances) but are less optimal than Spot pricing for interruptible workloads.
Key Points to Remember:
- Use Spot Instances for fault-tolerant, flexible, or batch workloads.
- Prioritize cost savings when interruptions are acceptable.
- Avoid Reserved Instances/Savings Plans for non-steady or unpredictable workloads.
Answer
The correct answer is: B