To monitor a cluster node for availability we recommend to check the URI /login on the server's hostname / IP and and web port, e.g. http://<server_ip>:8080/login. The URI should return HTML code and status code 200.
In case the node doesn't respond or runs into a timeout, the node should be restarted.
The cluster node can also be monitored through the output of jstack. If the node resturns "deadlock", it should be restarted.