AutoScaling in EC2onDB

Hello.

In the case of EC2 on DB, data disappears when you scale in or scale out with AutoScaling.
An error will occur because consistency will no longer be maintained.
When managing databases with EC2, we do not recommend managing them with AutoScaling groups.

https://aws.amazon.com/ec2/autoscaling/faqs/?nc1=h_ls

Q: What does the term “stateful instances” refer to?
When we refer to a stateful instance, we mean an instance that has data on it, which exists only on that instance. In general, terminating a stateful instance means that the data (or state information) on the instance is lost. You may want to consider using lifecycle hooks to copy the data off of a stateful instance before it’s terminated, or enable instance protection to prevent Amazon EC2 Auto Scaling from terminating it.