[🚀Launch Announcement] - AWS Network Load Balancer (NLB) introduces a new target health status while draining connections
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Content level: Advanced
This article provides overview of new target health status while draining connections on AWS Network Load Balancer (NLB)
Network Load Balancer (NLB) now supports a new target health status called “unhealthy.draining” that enables you to safely drain existing connections on targets that fail load balancer health checks. In the “unhealthy.draining” state, targets do not receive new connections but retain established connections for the configured interval. If targets recovers, the NLB will flip the target status back to “healthy” and resume routing new connections to the targets; otherwise, it will flip the target status to “unhealthy” and connections will be terminated. This feature provides protections to prevent or mitigate re-connect storms as existing connections can drain over time instead of being terminated together. You can view the target health status either in elbv2 describe-target-health API or visit EC2 console > Target Groups > Targets tab.