Diego Fronza authored Nov 05, 2019 and Ondřej Surý committed Nov 06, 2019

This variable will report the maximum number of simultaneous tcp clients
that BIND has served while running.

It can be verified by running rndc status, then inspect "tcp high-water:
count", or by generating statistics file, rndc stats, then inspect the
line with "TCP connection high-water" text.

The tcp-highwater variable is atomically updated based on an existing
tcp-quota system handled in ns/client.c.