Handle limited open Connections due to keepalive connections (cool#9621)

[sgothel]

Is your feature request related to a problem?

Issue #9621 resolved by pull request #9777 keeps connections alive to enhance performance. This may result in a shortage of available connection on the server and should be addressed

Describe the solution you'd like

We should track inactivity of each socket and close the oldest-inactive sockets either (a) in general and/or (b) when available connection count is below a threshold.

Describe alternatives you've considered

Alternatively, we may need to close high-frequency short lived connections.