Posted On: Apr 8, 2021

Amazon EC2 Auto Scaling Warm Pools help applications scale out faster and save money by requiring fewer continuously running instances. With Warm Pools, customers can improve the elasticity of their applications by creating a pool of pre-initialized EC2 instances that are ready to quickly serve application traffic. Additionally, Warm Pools offer a way to save compute costs by placing pre-initialized instances in a stopped state.

Warms Pools are a good fit for applications that have time consuming initialization steps—like loading gigabytes of data, provisioning services, or running custom scripts—that can take several minutes or longer to serve traffic. Now, these applications can start pre-initialized, stopped instances to serve traffic in as low as 30 seconds. By default, when configured, a warm pool will maintain enough pre-initialized, stopped instances so that the Auto Scaling group can rapidly scale out to its maximum size at any time. Additionally, customers can run custom initialization steps on an EC2 instance that moves to and from a warm pool using lifecycle hooks.

This feature is available through the AWS Management Console, the AWS SDKs, and the AWS Command Line Interface (CLI). AWS CloudFormation support for Warm Pools will be coming soon. Amazon EC2 Auto Scaling is available in all public AWS Regions and AWS GovCloud (US) Regions. To learn more about this feature, visit this AWS documentation.