AWS Certified Solutions Architect – Professional — Question 841

A company CFO recently analyzed the company's AWS monthly bill and identified an opportunity to reduce the cost for AWS Elastic Beanstalk environments in use. The CFO has asked a Solutions Architect to design a highly available solution that will spin up an Elastic Beanstalk environment in the morning and terminate it at the end of the day.
The solution should be designed with minimal operational overhead and to minimize costs. It should also be able to handle the increased use of Elastic Beanstalk environments among different teams, and must provide a one-stop scheduler solution for all teams to keep the operational costs low.
What design will meet these requirements?

Answer options

• A. Set up a Linux EC2 Micro instance. Configure an IAM role to allow the start and stop of the Elastic Beanstalk environment and attach it to the instance. Create scripts on the instance to start and stop the Elastic Beanstalk environment. Configure cron jobs on the instance to execute the scripts.
• B. Develop AWS Lambda functions to start and stop the Elastic Beanstalk environment. Configure a Lambda execution role granting Elastic Beanstalk environment start/stop permissions, and assign the role to the Lambda functions. Configure cron expression Amazon CloudWatch Events rules to trigger the Lambda functions.
• C. Develop an AWS Step Functions state machine with ג€waitג€ as its type to control the start and stop time. Use the activity task to start and stop the Elastic Beanstalk environment. Create a role for Step Functions to allow it to start and stop the Elastic Beanstalk environment. Invoke Step Functions daily.
• D. Configure a time-based Auto Scaling group. In the morning, have the Auto Scaling group scale up an Amazon EC2 instance and put the Elastic Beanstalk environment start command in the EC2 instance user data. At the end of the day, scale down the instance number to 0 to terminate the EC2 instance.

Correct answer: B

Explanation

Option B is correct because using serverless AWS Lambda functions triggered by Amazon CloudWatch Events (EventBridge) cron rules represents a highly available, low-cost solution with minimal operational overhead. Options A and D are incorrect because they require provisioning and managing Amazon EC2 instances, which increases costs and operational maintenance. Option C is incorrect because utilizing AWS Step Functions with long 'Wait' states is overly complex and less cost-effective for a simple daily schedule compared to EventBridge.