SAP-C02 Application Auto Scaling Practice Question
A company runs a web application on Amazon ECS with Fargate launch type. The application is behind an Application Load Balancer. During traffic spikes, the application becomes slow. The team suspects that the ECS service is not scaling fast enough. Which TWO actions should the team take to improve the scalability? (Choose two.)
⚠ Common exam trap
A common pitfall is assuming that increasing the target value for a scaling metric improves scalability. In fact, it makes scaling less aggressive, worsening the problem. The correct action is to decrease the target value.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Decrease the scale-in and scale-out cooldown periods.
Options B and D are correct. Decreasing cooldown periods (option B) allows scaling to happen more frequently, reducing lag during traffic spikes. Increasing the maximum number of tasks (option D) ensures the service can scale out to a higher capacity to handle increased load. Option A is incorrect because decreasing subnets does not improve scalability and reduces fault tolerance. Option C is incorrect because decreasing the ALB idle timeout does not directly affect scaling behavior; it only affects connection persistence. Option E is incorrect because increasing the target value for the scaling metric (e.g., CPU utilization) makes the scaling threshold harder to reach, reducing scaling aggressiveness. The correct action would be to decrease the target value.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Decrease the number of subnets in the VPC.
Why it's wrong here
Decreasing subnets does not affect scaling speed and reduces fault tolerance; incorrect.
- ✓
Decrease the scale-in and scale-out cooldown periods.
Why this is correct
Decreasing cooldown periods allows more frequent scaling actions, helping the service respond faster to traffic spikes; correct.
- ✗
Decrease the ALB idle timeout.
Why it's wrong here
Decreasing the ALB idle timeout does not directly impact scaling behavior; it only affects how long idle connections are kept; incorrect.
- ✓
Increase the maximum number of tasks in the ECS service.
Why this is correct
Increasing the maximum number of tasks ensures the service can scale to a higher capacity; correct.
- ✗
Increase the target value for the scaling metric (e.g., CPU utilization).
Why it's wrong here
Increasing the target value for the scaling metric (e.g., CPU utilization) makes the scaling threshold higher, reducing aggressiveness. This would make the scaling slower, not faster; incorrect.
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Same concept, more angles
1 more way this is tested on SAP-C02
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A startup runs its application on Amazon ECS with Fargate launch type. The application uses an Application Load Balancer to distribute traffic. During a recent marketing campaign, the application experienced high latency and some requests returned 503 errors. The team suspects that the tasks are hitting resource limits. The team wants to automatically scale the tasks based on CPU utilization. Which solution should the team implement?
easy- ✓ A.Configure Application Auto Scaling for the ECS service with a target tracking scaling policy based on average CPU utilization.
- B.Create a CloudWatch alarm that triggers a Lambda function to stop idle tasks.
- C.Create an Auto Scaling group for the ECS cluster and configure it to scale based on CPU utilization.
- D.Use AWS Lambda to periodically check CPU utilization and update the desired count of the ECS service.
Why A: Uses Application Auto Scaling with a target tracking scaling policy based on average CPU utilization, which automatically adjusts the desired count of ECS tasks to maintain CPU utilization. Option B stops idle tasks via Lambda, but does not scale based on CPU utilization. Option C creates an Auto Scaling group for the ECS cluster, which is designed for EC2 instances, not Fargate tasks. Option D uses Lambda to periodically check CPU and update desired count, which is inefficient compared to native Application Auto Scaling. Therefore, Option A is correct.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SAP-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SAP-C02 exam.