AWS DevOps Engineer Professional Practice Test

Which AWS service can automatically scale your applications based on conditions defined in CloudWatch?

1. AWS Auto Scaling

2. AWS Elastic Load Balancing

3. AWS Step Functions

4. AWS Lambda

The correct answer is: AWS Auto Scaling

AWS Auto Scaling is designed to automatically adjust the number of instances or resources available to applications based on the demand and predefined conditions set in Amazon CloudWatch. This service effectively monitors the application's performance and can scale the resources up or down, ensuring optimal performance and cost efficiency. When certain metrics, such as CPU utilization, request count, or custom metrics, breach specified thresholds in CloudWatch, AWS Auto Scaling responds by launching or terminating instances as necessary. This allows for flexible handling of varying workloads without manual intervention, ensuring that applications remain responsive during peak times and cost-effective during lower demand. The other services mentioned do not provide the same level of automation for scaling based on CloudWatch conditions. Elastic Load Balancing distributes incoming traffic across multiple targets such as EC2 instances but does not manage scaling itself. Step Functions is a serverless orchestration service designed for workflow automation, rather than resource scaling. Lambda, while capable of handling variable workloads by executing code in response to events, technically scales itself automatically but does not manage the scaling of traditional servers or instances based on CloudWatch metrics.