SAP-C02 Question 526
Single answerAn e-commerce company has a steady workload that involves hosting its web application on Amazon EC2 instances and processing data in Amazon RDS. The usage patterns for both EC2 and RDS are predictable, with consistent utilization of resources throughout the year. The company wants to reduce costs while ensuring the required performance levels. Which pricing model is the most cost-effective for their needs?
- A
On-Demand Instances for both EC2 and RDS
- B
Reserved Instances for both EC2 and RDS with a 1-year commitment
- C
Savings Plans for EC2 and Reserved Instances for RDS
- D
Spot Instances for EC2 and On-Demand Instances for RDS
Show answer and explanation
Correct answer: B
Explanation
For predictable workloads with steady usage patterns, Reserved Instances are the most cost-effective option for both EC2 and RDS. They provide significant cost savings over On-Demand pricing and are designed for scenarios where the user can commit to a specific usage level for a fixed term (such as 1 or 3 years). This balances cost efficiency with performance reliability, making it the optimal choice for the given scenario.
- A. Incorrect.
On-Demand Instances are the most flexible but are not cost-effective for predictable workloads with steady usage, as they charge the highest rates.
- B. Correct.
Reserved Instances are ideal for predictable workloads with steady usage because they offer significant discounts (up to 72%) compared to On-Demand pricing. Choosing a 1-year commitment balances cost savings and flexibility.
- C. Incorrect.
Savings Plans provide cost savings for EC2 but are not as effective when paired with Reserved Instances for RDS compared to fully committing to Reserved Instances for both services.
- D. Incorrect.
Spot Instances are not suitable for workloads requiring consistent, predictable performance because they can be interrupted at any time. On-Demand Instances for RDS would also lead to higher costs compared to Reserved Instances for predictable workloads.