The monitor doesn't update the nodes' states when replication connection is corrupted.

[gfphoenix78]

Version: 1.4.0

If we inject a network corruption between the primary and secondary, the monitor doesn't update the nodes' state. So, the primary still tries to synchronize its WAL records to the secondary, which causes almost all queries blocked.

The monitor should be able to detect this scenario, update the nodes' states, and tell the primary to update its synchronized standbys.