AWS PrivateLink Max Connections - Is there a Metric for this?

Question

Reference:

https://docs.aws.amazon.com/vpc/latest/userguide/endpoint-service.html

Under limitations is quoted:

For the endpoint service, the associated Network Load Balancer can support 55,000 simultaneous connections or about 55,000 connections per minute to each unique target (IP address and port). If you exceed these connections, there is an increased chance of port allocation errors. To fix the port allocation errors, add more targets to the target group.

Is there some place within CloudWatch where I can view our current connection count and thus know how close we are to hitting this limit? I can see New/Active Flow Counts within the dashboard - is this it?

Answer 1

I would suggest looking at theActiveFlowCount metric which tracks how many connections an NLB has.

https://docs.aws.amazon.com/elasticloadbalancing/latest/network/load-balancer-cloudwatch-metrics.html

Note that this metric I believe is only visible on the service provider side of the connection.