How do resources scale automatically in AWS Auto Scaling?

Resources in AWS Auto Scaling scale automatically by automatically increasing or decreasing designated resources based on pre-defined policies. This means that Auto Scaling monitors the application’s performance and adjusts the number of running instances or resources according to the current demand.

When certain thresholds are met—such as CPU utilization or request rate—Auto Scaling can automatically spin up additional instances to handle increased loads. Conversely, when demand decreases, it can terminate unneeded instances to reduce costs. This ability to dynamically adjust resource capacity ensures that applications maintain performance during peak periods while optimizing resource use when demand is low.

This automated management helps in maintaining availability and cost-efficiency, which are crucial aspects of cloud computing. In contrast to making manual adjustments, using fixed amounts of resources, or employing reserved instances, this policy-driven approach provides flexibility and responsiveness to varying load conditions.