In fact when using the DataStax Java Driver, you have a hidden/magic capability embedded:
The driver is aware of the full network topology (nodes topology across datacenters and nodes availabilities).
Thus, the only thing you have to do is to initialise your cluster with a few nodes(1) and then you can be sure at every moment that if there is at least one available node your request will be performed correctly. Because the driver is topology aware, if one node (even initialisation nodes) goes out of availability, the driver will automagically route your request to another available node.
In summary, your code is good(1).
(1): You should provide a few nodes in order to be fault tolerant in the cluster initialisation phase. Indeed, if one initialisation node is down, the driver has then the possibility to contact another one to discover the full topology.