TCP connections from swarm manager on docker nodes are accumulating. Connection on swarm manager seems closed properly but persistent on each node. My setup is, TLS enabled. Discover using token.
netstat -t
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp6 0 0 node1:9076 swarm-manager:43319 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:42818 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:42421 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:42817 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43506 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43503 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:42769 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:42768 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43335 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43318 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43410 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43505 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43334 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:42422 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:42328 ESTABLISHED
tcp6 0 0 node1:9076 swarm-manager:43409 ESTABLISHED