pglookout: OperationalError (could not connect to server: Connection refused

Hi Team,

Need your suggestion on why pglookout is throwing the warning message OperationalError.

### pglookout logs:

Nov 18 09:14:49 vm-db1 pglookout: 2021-11-18 09:14:49,630#011ClusterMonitor#011Thread-1#011INFO#011Connecting to 'vm-db2.nokia.local' (dbname='postgres' host='vm-db2.nokia.local' user='pglookout'; hidden password)
Nov 18 09:14:49 vm-db1 pglookout: 2021-11-18 09:14:49,632#011ClusterMonitor#011Thread-1#011WARNING#011OperationalError (could not connect to server: Connection refused
Nov 18 09:14:49 vm-db1 pglookout: Is the server running on host "vm-db2.nokia.local" (192.9.0.12) and accepting
Nov 18 09:14:49 vm-db1 pglookout: TCP/IP connections on port 5432?) connecting to vm-db2.nokia.local ('vm-db2.nokia.local' (dbname='postgres' host='vm-db2.nokia.local' user='pglookout'; hidden password))
Nov 18 09:14:49 vm-db1 pglookout: 2021-11-18 09:14:49,634#011ClusterMonitor#011ThreadPoolExecutor-3_0#011WARNING#011OperationalError (server closed the connection unexpectedly