Keep Your ASG Healthy: Put EC2 Instances in Standby Mode Before Stopping/Rebooting Them.

As an AWS user, you know that stopping an EC2 instance in an Auto Scaling group (ASG) can trigger the ASG to replace the instance with a new one. This is because the ASG considers the stopped instance unhealthy and replaces it as part of its scaling policy.

However, there may be times when you need to stop/reboot an EC2 instance in an ASG for AWS scheduled updates or for other reasons. In these cases, you should put the instance in standby mode first .

By setting an EC2 instance in standby mode, the ASG knows not to replace the instance and instead waits for you to manually return it to service. This helps ensure that your ASG remains healthy and stable during the update or maintenance process.

To learn more about putting EC2 instances in standby mode, check out the AWS documentation.

Do you have any additional tips or best practices for protecting EC2 instances in AWS? Share them in the comments below!