What is happening to opened websocket connections when server healthcheck returns 4** error

Hi there! Can somebody explain what is happening to currently opened websocket connections when a server healtcheck starts returning 4** status codes?
Will traefik kill connections or just stop balancing new traffic to that server?

Thanks for any answer!

Hello @yurii,

Thanks for your interest in Traefik!

As long as open connections are not closed by the server, nor by the client, they are kept open by Traefik.
So if a server is considered unhealthy and is removed from the load balancer, the new traffic is balanced to one of the remaining healthy servers in the load balancer, and the existing connections to the unhealthy server are kept open (until the client or the server close it).

Hope it helps!