In case you are not able to connect using NX to ITER cluster, due to message "Server capacity reached..."
Connect to a login node that displays such error using SSH
Code Block > ssh <user>@hpc-loginX (X=4,5,6,7,8)
List your NX processes
Code Block > ps -eaf |grep $USER |grep nxagent
Kill NX process
Code Block kill -9 [ProcessID]
Now you should be able to connect using NX...