SOA-C02 Question 58
Select 4You are managing an application hosted on Amazon EC2 instances behind an Application Load Balancer (ALB). The application experiences unpredictable traffic spikes, and you need to ensure that it scales automatically to handle demand while optimizing cost. Which steps should you take to create and maintain an AWS Auto Scaling plan for this application?
- A
Create a target tracking scaling policy that adjusts the desired capacity based on the average CPU utilization of the instances.
- B
Configure step scaling policies to add or remove a fixed number of instances based on CloudWatch alarms.
- C
Enable Auto Scaling predictive scaling to forecast demand and automatically scale in advance.
- D
Manually adjust the desired capacity of the Auto Scaling group during traffic spikes.
- E
Set the minimum and maximum instance counts in the Auto Scaling group to ensure scaling stays within a defined range.
Show answer and explanation
Correct answers: A, B, C, E
Explanation
To create and maintain an AWS Auto Scaling plan for an application with unpredictable traffic spikes, you should use a combination of target tracking policies, step scaling policies, and predictive scaling to automate capacity adjustments. Defining minimum and maximum instance counts ensures cost control and prevents scaling issues. Manual adjustments are not recommended as they are not automated or scalable.
- A. Correct.
Correct: Target tracking scaling policies automatically adjust the desired capacity to maintain a specific metric, such as CPU utilization, making it suitable for dynamic scaling.
- B. Correct.
Correct: Step scaling policies allow more granular control by adding or removing instances based on specific CloudWatch alarm thresholds, which is useful for handling traffic spikes.
- C. Correct.
Correct: Predictive scaling can forecast traffic patterns and adjust capacity proactively, which is ideal for unpredictable traffic spikes.
- D. Incorrect.
Incorrect: While manually adjusting the desired capacity can work temporarily, it is not an automated or scalable solution and does not fit within the scope of creating and maintaining an Auto Scaling plan.
- E. Correct.
Correct: Setting minimum and maximum instance counts ensures that your Auto Scaling group operates within a predefined range, preventing over-scaling or under-scaling.