SOA-C02 Question 54
Select 2Your organization runs a web application on an Auto Scaling group of Amazon EC2 instances behind an Application Load Balancer (ALB). During peak traffic hours, the application experiences high latency due to increased demand. Which of the following steps should you take to implement scalability and elasticity for the application?
- A
Configure a target tracking scaling policy to automatically add or remove EC2 instances based on CPU utilization.
- B
Manually launch additional EC2 instances during peak traffic to handle the increased load.
- C
Configure the Auto Scaling group to use a scheduled scaling policy that adds instances during expected peak hours.
- D
Increase the instance size of the EC2 instances in the Auto Scaling group to handle more traffic per instance.
- E
Ensure that the ALB has cross-zone load balancing enabled to distribute traffic evenly across all instances.
Show answer and explanation
Correct answers: A, C
Explanation
To implement scalability and elasticity, you should use automatic scaling mechanisms that adjust resources dynamically based on demand or predictable traffic patterns. A target tracking scaling policy allows the system to scale automatically based on real-time metrics like CPU utilization, while a scheduled scaling policy ensures resources are provisioned in advance for expected demand. These approaches align with AWS best practices for scalability and elasticity.
- A. Correct.
This is correct. A target tracking scaling policy ensures that the Auto Scaling group can dynamically adjust the number of EC2 instances based on a specific metric, such as CPU utilization, enabling scalability and elasticity.
- B. Incorrect.
This is incorrect. Manually launching instances does not implement scalability or elasticity, as it requires manual intervention and does not allow the system to adjust dynamically.
- C. Correct.
This is correct. Scheduled scaling policies are useful for predictable traffic patterns, as they allow the Auto Scaling group to scale out or in at specific times, ensuring resources are available during peak hours.
- D. Incorrect.
This is incorrect. While increasing the instance size may temporarily address performance issues, this approach does not align with the principles of scalability and elasticity, as it does not allow for dynamic scaling based on demand.
- E. Incorrect.
This is incorrect. Enabling cross-zone load balancing on the ALB improves traffic distribution but does not directly address the need for automatically scaling the number of EC2 instances to handle traffic spikes.