SAA-C03 Question 376
Select 3A company is running a fleet of Amazon EC2 instances in an Auto Scaling group to handle its e-commerce application during a seasonal sale. The application experiences highly variable traffic patterns, with significant spikes during flash sales. The company wants to optimize costs while ensuring high availability during peak traffic. Which combination of approaches should the Solutions Architect recommend?
- A
Use a combination of On-Demand Instances and Spot Instances in the Auto Scaling group.
- B
Increase the minimum and desired capacity of the Auto Scaling group to handle peak traffic.
- C
Use Reserved Instances for predictable traffic and Spot Instances for variable traffic.
- D
Enable Auto Scaling with a scaling policy based on CPU utilization or request count.
- E
Switch all instances to On-Demand Instances to handle unpredictable traffic.
Show answer and explanation
Correct answers: A, C, D
Explanation
The best cost-optimized strategy for handling highly variable traffic patterns involves using a mix of instance types and leveraging Auto Scaling policies. Reserved Instances are cost-effective for predictable workloads, while Spot Instances provide significant savings for variable workloads that can tolerate interruptions. Auto Scaling ensures the application scales out during peak traffic and scales in during idle times, further optimizing costs. This approach balances cost optimization with high availability.
- A. Correct.
Using a combination of On-Demand Instances and Spot Instances can reduce costs. Spot Instances are significantly cheaper than On-Demand Instances but are suitable only for workloads that can handle interruptions, which is ideal for variable traffic.
- B. Incorrect.
Increasing the minimum and desired capacity ensures handling peak traffic but does not optimize costs. This approach would lead to over-provisioning resources and higher costs during non-peak times.
- C. Correct.
Using Reserved Instances for predictable traffic and Spot Instances for variable traffic is a cost-effective strategy. Reserved Instances provide savings for steady-state workloads, while Spot Instances offer lower costs for variable workloads.
- D. Correct.
Enabling Auto Scaling with a scaling policy based on CPU utilization or request count ensures that the number of instances adjusts dynamically based on traffic, optimizing costs by scaling out only when needed.
- E. Incorrect.
Switching all instances to On-Demand Instances does not optimize costs. On-Demand Instances are the most expensive option and are not ideal for variable traffic patterns.