Amazon EC2 Auto Scaling Groups (ASG) introduces a new capability for customers to strictly balance their workloads across Availability Zones, enabling greater control over provisioning and management of their EC2 instances.
Previously, customers that wanted to strictly balance an ASGs EC2 instances across availability zones had to override default behaviors of EC2 Auto Scaling and invest in custom code to modify the ASG’s existing behaviors with life cycle hooks or through maintaining multiple ASGs. With this feature, customers can now to easily achieve strict availability zone balance and ensure higher levels of resiliency for their applications.
This capability is now available through the AWS Command Line Interface (CLI), AWS SDKs, or the AWS Console in all AWS Regions. To get started, please refer to the documentation.
Source:: Amazon AWS