SAP-C02 Question 138
Select 2A financial services company is running a critical analytics application on Amazon EC2 instances in a single AWS Region. The application has predictable usage patterns during business hours, but occasionally requires additional compute during month-end financial reporting. The company wants to minimize costs while ensuring that the application always has sufficient capacity to handle the workload. Which combination of AWS purchasing options should the company use to optimize costs and ensure availability?
- A
Purchase Reserved Instances for the predictable baseline capacity and use On-Demand Instances for month-end spikes.
- B
Use Savings Plans for the predictable baseline capacity and Spot Instances for month-end spikes.
- C
Purchase Reserved Instances for the predictable baseline capacity and Spot Instances for month-end spikes.
- D
Use Savings Plans for the predictable baseline capacity and On-Demand Instances for month-end spikes.
- E
Use Spot Instances exclusively for both baseline capacity and month-end spikes.
Show answer and explanation
Correct answers: A, D
Explanation
For workloads with predictable usage patterns, Savings Plans or Reserved Instances are cost-effective options for the baseline capacity, as they provide significant discounts compared to On-Demand pricing. For additional, unpredictable spikes in usage, On-Demand Instances are recommended as they ensure capacity availability without the risk of interruption. Spot Instances, while cost-effective, are not suitable for critical workloads due to their potential for interruption.
- A. Correct.
This is a valid option because Reserved Instances are a cost-effective way to handle predictable, long-term usage, and On-Demand Instances can handle short-term, unpredictable spikes. However, Savings Plans are often more flexible than Reserved Instances.
- B. Incorrect.
This is incorrect because Spot Instances are not suitable for critical workloads that require guaranteed availability, as they can be interrupted.
- C. Incorrect.
This is incorrect because Spot Instances are not reliable for critical workloads, even for burst capacity, as they can be reclaimed by AWS with little notice.
- D. Correct.
This is a valid option because Savings Plans provide flexible and cost-effective pricing for predictable workloads, while On-Demand Instances ensure availability for short-term, unpredictable spikes.
- E. Incorrect.
This is incorrect because Spot Instances are not appropriate for critical workloads that require consistent availability, as they can be interrupted without notice.