SAP-C02 Question 280
Select 3Your company runs a web application on Amazon EC2 instances behind an Elastic Load Balancer (ELB). The application experiences variable traffic patterns, with significant spikes during promotional events. You have configured an Auto Scaling group for the EC2 instances. The marketing team expects a spike in traffic tomorrow due to a scheduled campaign. Which of the following Auto Scaling policies and configurations would best ensure the application can handle the expected traffic spike while minimizing under-provisioning or over-provisioning of resources?
- A
Configure a scheduled scaling policy to increase the desired capacity of the Auto Scaling group before the campaign starts.
- B
Enable dynamic scaling with a target tracking policy based on average CPU utilization.
- C
Use step scaling policies to scale out incrementally as traffic increases during the campaign.
- D
Manually adjust the minimum and desired capacity of the Auto Scaling group to a high value before the campaign starts.
- E
Configure predictive scaling to forecast traffic patterns and automatically adjust the desired capacity accordingly.
Show answer and explanation
Correct answers: A, B, E
Explanation
To handle the expected traffic spike effectively, you should use a combination of proactive and dynamic scaling strategies. Scheduled scaling ensures that resources are provisioned ahead of time, while dynamic scaling with target tracking policies responds to real-time traffic changes. Predictive scaling can also be beneficial for forecasting and preparing for traffic spikes during predictable events. Step scaling and manual adjustments are less efficient and should be avoided in this scenario.
- A. Correct.
Correct. A scheduled scaling policy allows you to proactively adjust the desired capacity of the Auto Scaling group based on an anticipated event, such as a promotional campaign. This ensures that resources are available before the traffic spike begins.
- B. Correct.
Correct. Dynamic scaling with a target tracking policy helps maintain the desired performance metrics (e.g., average CPU utilization) during the campaign by automatically scaling resources in or out as needed.
- C. Incorrect.
Incorrect. While step scaling policies can help during unpredictable traffic patterns, they may not be ideal for a predictable spike because they react to metric changes rather than proactively preparing for known events.
- D. Incorrect.
Incorrect. Manually adjusting the capacity might work, but it is operationally inefficient and prone to errors. Automated solutions like scheduled or predictive scaling are more reliable.
- E. Correct.
Correct. Predictive scaling uses machine learning to forecast future traffic patterns and adjusts the desired capacity accordingly. This is especially effective for predictable events like a scheduled marketing campaign.