Recover 'unreachable'

Using FoundationDB
1

fdbcli --exec status:

Using cluster file `/etc/foundationdb/fdb.cluster'.

Could not communicate with all of the coordination servers.
  The database will remain operational as long as we
  can connect to a quorum of servers, however the fault
  tolerance of the system is reduced as long as the
  servers remain disconnected.

  10.242.2.1:4501  (unreachable)
  10.242.2.2:4507  (reachable)
  10.242.2.3:4505  (reachable)

Configuration:
  Redundancy mode        - double
  Storage engine         - ssd-2
  Coordinators           - 3

Question: How to make the unreachable shard reachable again?
Everything looks fine - but the shard still remains unreachable.

2

Is the process 10.242.2.1:4501 up and running? Without more information (like logs etc) it is hard to know what is going wrong.

One thing you can try is to move the coordinators to a different set of processes (using the coordinator command in fdbcli).

3

Yes, 10.242.2.1:4501 up and running.
I saw tons of GB “moving data” from the other two machines.

But 4501 remains unreachable.
Is it necessary to shutdown/restart the cluster?

FDB: 6.0

4

Stop. A simple systemctl restart foundationdb fixed everything.
But thanks a lot lot your answer!