When an Instance Is Removed from an AS Group and Deleted, Is the Application Data Saved?

No. You must ensure that instances in the AS group do not store application status information or other important data, such as sessions, databases, and logs, or the data will be lost when AS automatically releases them. If you want to store your application status, you can store it on an independent server (such as an ECS) or database (such as an RDS database).

If you want to back up data or download log files before an instance is removed from an AS group, you can add a lifecycle hook of the instance removal type to the AS group. When the lifecycle hook is added to the AS group, if the AS group scales in, the lifecycle hook suspends the instance that is being removed from the AS group and puts the instance in a wait state. During the waiting period, you can perform operations on the instance, like backing up data or downloading log files.