AWS Certified Solutions Architect – Professional — Question 853

A company provides specialized analytics services to customers. The analytics run on Amazon EC2 instances that need to be launched and terminated in response to requests from customers. A solutions architect is creating automation to manage the EC2 instances that handle customer requests. However, when the automation scripts attempt to launch many EC2 instances at the same time, a RequestLimitExceeded error frequently occurs.
What should the solutions architect do to handle this error?

Answer options

• A. Implement an exponential backoff strategy so that the API token bucket can refill.
• B. Modify the EC2 instance launch configuration to install diagnostic tools on each instance to troubleshoot the issue.
• C. Request an increase for API throttling quotas from the AWS Support Center.
• D. Request an EC2 API quota increase through the Service Quotas console.

Correct answer: A

Explanation

The RequestLimitExceeded error is caused by AWS API rate limiting, which is managed using a token bucket algorithm. Implementing an exponential backoff strategy allows the script to retry failed calls after progressively longer delays, giving the token bucket time to refill and successfully complete the requests. Requesting quota increases or installing instance-level diagnostic tools will not address this API-level throttling behavior.