Posted On: Nov 17, 2022

Application Load Balancers now support the ability to route traffic only to targets in the same zone as load balancer nodes. This allows you to maintain zonal isolation of your software stacks, while using Application Load Balancers across multiple zones, providing increased availability during zonal failures.

You can turn off cross-zone load balancing on a per target group basis, per region. You can also use an AWS SDK to turn off cross-zone load balancing programmatically for multiple target groups associated with one or more load balancers. This feature works for auto-scaling scenarios in the background, and ensures that target applications are scaled on a per AZ basis. This feature also adds the required zonal dimensions for various existing load balancer metrics.

There is no additional charge for turning off cross-zone load balancing. This feature is available in all commercial AWS Regions and AWS GovCloud (US) Regions. Please visit the ALB documentation to learn more.