ASG instance refresh does not honor ELB health-checks

Hello,

Please have a check on the health check type configured in the ASG configuration.

If the health check type is set to Amazon EC2, during the instance refresh the instance will be marked as successful based on the results of the Amazon EC2 instance status checks and system status checks. So in this case, the ASG will not wait for the ELB health check to be successful.

When using ELB health checks, the Auto Scaling group Instance Refresh process will respect the Minimum Healthy Percentage setting based on the ELB health checks. This means that if you set the Minimum Healthy Percentage to 100%, the Instance Refresh will only proceed to the next batch of instances when all existing instances are considered healthy by the ELB.