Posted On: Oct 12, 2023

AWS Network Load Balancer (NLB) now supports Availability Zone DNS affinity, disable connection termination for unhealthy targets, and UDP connection termination by default.

Availability Zonal DNS affinity: This capability resolves DNS such that clients resolving the NLB DNS receive the load balancer IP addresses in the same Availability Zone (AZ) they are in. It enables customers to build zonally independent application stacks and improve application performance by reducing latency. You will still have the ability to build your application across multiple AZs for redundancy. See details of Availability Zone DNS affinity here and here.

Disable connection termination for unhealthy targets: NLB terminates established connections to targets that fail health checks by default. With this feature, you can choose to maintain or terminate active connections to targets that fail health checks. By disabling the default NLB behavior you can prevent client reconnect storms in the event of an outage. Learn more about Disable connection termination for unhealthy targets here.

UDP connection termination by default: NLB now terminates UDP connections at the end of the deregistration timeout by default for newly created UDP target groups from today. Prior to this change UDP connections remained open resulting in the overhead of having to maintain large connection pools for you application. With this new feature, you can gracefully terminate long lived UDP connections improving the performance of your application. Configuration details for connection termination is described here.

These features are available in all commercial and China Regions.