SAA-C03 Question 450
Select 2A company runs a web application on a fleet of Amazon EC2 instances. The application experiences predictable spikes in traffic during the holiday season, and the company wants to minimize costs while ensuring sufficient compute capacity during these high-traffic periods. What is the MOST cost-effective purchasing strategy the company should use?
- A
Purchase Reserved Instances for the baseline traffic and use Spot Instances for the additional capacity during high-traffic periods.
- B
Use On-Demand Instances for the entire workload to handle both baseline and peak traffic.
- C
Purchase Reserved Instances for the baseline traffic and use On-Demand Instances for the additional capacity during high-traffic periods.
- D
Use Savings Plans for all EC2 instances to cover both baseline and peak traffic.
- E
Use Auto Scaling with Spot Instances to handle the entire workload.
Show answer and explanation
Correct answers: A, C
Explanation
To achieve cost optimization, a mix of purchasing options is often the best approach. Reserved Instances are well-suited for predictable baseline workloads because of their cost savings, while On-Demand or Spot Instances provide flexibility for handling spikes in traffic. Spot Instances are highly cost-effective but should only be used for workloads that can tolerate interruptions, making them suitable for additional capacity during spikes. On-Demand Instances, while more expensive, are a reliable option for unpredictable or temporary needs.
- A. Correct.
Correct. Reserved Instances are ideal for predictable, steady-state workloads like baseline traffic. Spot Instances can be used for additional capacity during spikes, as they are cost-effective but can be interrupted.
- B. Incorrect.
Incorrect. On-Demand Instances are the most expensive option and are not cost-effective for predictable workloads like baseline traffic or planned holiday spikes.
- C. Correct.
Correct. Reserved Instances are cost-effective for predictable workloads like baseline traffic, and On-Demand Instances provide the flexibility needed for handling additional capacity during high-traffic periods.
- D. Incorrect.
Incorrect. While Savings Plans are cost-effective for steady or predictable usage, they do not provide flexibility for the variable traffic spike, making this option less optimal.
- E. Incorrect.
Incorrect. Spot Instances are not suitable for the entire workload, as they can be interrupted. This would risk availability during high-traffic periods.