[mnutt]

Are you sure? My understanding was that nginx would fill up all free connections up to the max, but then would begin draining idle connections so it could create new ones for new visitors.

[Laforet]

I can only find a reference to what you said with regard to upstream connections. Are you sure this also happens with downstream clients?

https://www.nginx.com/blog/overcoming-ephemeral-port-exhaust...