AWS EC2 Auto Scaling now supports Launch Before Terminate at account-level to replace instances

AWS EC2 Auto Scaling now supports enabling Launch Before Terminate as the default replacement behavior across all Auto Scaling groups in an account. This feature ensures a replacement instance launches and passes health checks before the original instance terminates, maintaining application capacity during replacement events. The setting applies to instance refreshes, rebalancing, health checks, and maximum-instance-lifetime replacements. Users can configure this behavior once at the account level rather than individually for each Auto Scaling group.

The new functionality is managed through the `PutAccountSetting` and `DescribeAccountSettings` APIs, accessible via the AWS Management Console, AWS CLI, or AWS SDKs. These APIs allow administrators to enable or review the Launch Before Terminate setting centrally. The feature is designed to simplify configuration while improving operational consistency across Auto Scaling groups.

Launch Before Terminate is available in all AWS Regions and does not incur additional charges. This makes the feature accessible to all AWS customers without cost implications. The absence of extra fees aligns with AWS’s approach to providing core Auto Scaling capabilities as part of the standard service offering.

To implement this feature, users can refer to the AWS EC2 Auto Scaling User Guide and API Reference Guide for detailed instructions. The documentation provides step-by-step guidance on enabling and managing the setting. This resource ensures users can leverage the feature effectively while maintaining compliance with best practices for Auto Scaling configurations.