My cluster is currently located in a single data center. I've been trying to change that by adding a single worker node from another data center, but so far it hasn't worked.
I'm able to make this node join the swarm and get listed by the managers, but it is always shown as "Down". Here is what "docker inspect" shows me about this node:
"Status": {
"State": "down",
"Message": "heartbeat failure",
"Addr": "xxx.xxx.xxx.xxx"
}
I've opened the following ports in both sides:
2377 tcp
7946 tcp+udp
4789 udp
How do I troubleshoot and fix this?