SAA-C03 Question 201
Single answerA company is hosting a web application on an Amazon EC2 instance behind an Application Load Balancer (ALB). During peak traffic, users report slow response times and intermittent errors. You notice that the EC2 instance is operating at 100% CPU utilization. What is the most cost-effective solution to improve application availability and performance?
- A
Add more EC2 instances to the target group of the Application Load Balancer.
- B
Upgrade the EC2 instance to a larger instance type to handle more traffic.
- C
Enable sticky sessions on the Application Load Balancer to route users to the same instance.
- D
Configure an Auto Scaling group to dynamically add or remove EC2 instances based on traffic patterns.
Show answer and explanation
Correct answer: D
Explanation
The most cost-effective solution is to configure an Auto Scaling group with the Application Load Balancer. This ensures that additional EC2 instances are launched during peak traffic and terminated during low traffic, optimizing both performance and cost. While adding more EC2 instances or upgrading the instance type might temporarily resolve the issue, these approaches do not dynamically adjust to changes in traffic patterns, which can lead to inefficient resource utilization.
- A. Incorrect.
This solution would distribute the traffic across multiple instances, but it does not dynamically adjust the number of instances based on traffic patterns, which may lead to overprovisioning or underprovisioning.
- B. Incorrect.
Upgrading the instance may temporarily resolve the issue, but it is not cost-effective in the long term and does not account for variable traffic patterns.
- C. Incorrect.
Sticky sessions ensure that users are routed to the same instance, but this does not address the issue of high CPU utilization or scale the application to handle increased traffic.
- D. Correct.
Configuring an Auto Scaling group allows the application to automatically scale out during high traffic and scale in during low traffic, improving both cost efficiency and performance.