AWS Certified Advanced Networking Specialty Practice Exam

Which AWS feature allows the application servers to scale based on demand?

1. Elastic Load Balancing

2. Auto Scaling

3. EC2 Instance Scheduler

4. Amazon CloudWatch

The correct answer is: Auto Scaling

Auto Scaling is the feature that allows application servers to automatically adjust the number of instances in response to demand. This means that as the application's load increases, Auto Scaling can launch additional EC2 instances to handle the increased traffic or workload. Conversely, it can also terminate instances when demand decreases, ensuring that resources are not wasted and costs are optimized. Auto Scaling works in conjunction with CloudWatch, which monitors application performance and triggers scaling actions based on predefined metrics or thresholds. This integration ensures that the scaling process is responsive to real-time data about the application's needs, providing a robust and flexible way to maintain performance during varying levels of demand. While Elastic Load Balancing distributes incoming application traffic across multiple targets (like EC2 instances), it does not inherently provide scaling capabilities; it works in conjunction with Auto Scaling to ensure that the load is balanced across the available instances. The EC2 Instance Scheduler is designed for scheduling specific start and stop times for EC2 instances and is not focused on dynamic scaling based on demand. Amazon CloudWatch is primarily a monitoring and observability service, offering data and insights that can inform Auto Scaling decisions but does not perform the scaling action itself.