SAP-C02 Question 523
Select 2A company runs a web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The application experiences predictable traffic spikes during specific hours of the day. The company wants to optimize its costs while ensuring availability during peak times. Which combination of solutions should the company implement?
- A
Use Spot Instances with a diversified Spot Fleet for the EC2 instances behind the ALB.
- B
Configure an Auto Scaling group with a scheduled scaling policy to add or remove instances based on peak and off-peak hours.
- C
Use Reserved Instances for the EC2 instances to always guarantee capacity and reduce costs.
- D
Enable instance rightsizing recommendations in AWS Cost Explorer and adjust instance types accordingly.
- E
Migrate the application to AWS Lambda to eliminate the need for EC2 instances.
Show answer and explanation
Correct answers: B, D
Explanation
To optimize costs in an EC2-based architecture with predictable traffic spikes, the company should use a scheduled scaling policy for the Auto Scaling group to adjust the number of instances based on traffic patterns. Additionally, enabling instance rightsizing recommendations ensures that the instances are appropriately sized for the workload, avoiding over-provisioning and reducing costs. Spot Instances and Reserved Instances are not suitable for this scenario due to the need for consistent availability and flexibility. Migrating to AWS Lambda is outside the scope of the current architecture.
- A. Incorrect.
Using Spot Instances can reduce costs but is not ideal for predictable traffic patterns where consistent availability is required. Spot Instances can be interrupted at any time, which might not meet the application's availability needs during peak traffic.
- B. Correct.
Scheduled scaling allows the Auto Scaling group to add or remove instances based on predictable traffic patterns, optimizing costs by running fewer instances during off-peak hours.
- C. Incorrect.
Reserved Instances are cost-effective for steady-state workloads but do not provide flexibility for varying or predictable traffic spikes. They are not the best choice for this scenario.
- D. Correct.
Instance rightsizing recommendations in AWS Cost Explorer help optimize costs by identifying over-provisioned or underutilized instances, ensuring that the application runs on appropriately sized resources.
- E. Incorrect.
Migrating to AWS Lambda could be a viable solution but would require significant application refactoring. The question focuses on optimizing the existing EC2-based architecture, so this option is not relevant.