AWS DevOps Engineer Professional Practice Test

To use a mixture of spot and on-demand instance types in an Auto Scaling Group, which configuration tool should you use?

1. Launch Configuration

2. Launch Templates

3. Auto Scaling Policies

4. Elastic Load Balancing

The correct answer is: Launch Templates

Using Launch Templates is the appropriate choice for configuring a mixture of spot and on-demand instance types in an Auto Scaling Group. Launch Templates offer enhanced functionality compared to Launch Configurations, allowing for greater flexibility and configurability. With Launch Templates, you can specify multiple instance types, including both spot and on-demand instances, which enables the Auto Scaling Group to make decisions based on availability and cost. This allows for more efficient resource usage and cost savings, as the Auto Scaling group can scale using the more economical spot instances when available while still maintaining the ability to use on-demand instances as needed for additional capacity or during spot instance interruptions. Other tools like Launch Configurations are more limited, as they only allow the specification of a single instance type. Auto Scaling Policies are focused on the rules and conditions for scaling and do not directly determine the types of instances to be launched. Elastic Load Balancing additionally does not play a role in determining instance types; it is primarily concerned with distributing incoming application traffic across multiple targets. Thus, the capabilities provided by Launch Templates make them the correct choice for this scenario, facilitating the effective management of cost and resources in an Auto Scaling environment.