top

To check cpu and memory usage of active jobs on a server use the command 'top':
    top

...

• D: Uninterruptible sleep
• R: Running
• S: Sleeping
• T: Traced (stopped)
• Z: Zombie

ps

You can check which processes you have open with:

   

If you cannot find where you opened a process to close it down properly you can kill it with 'kill'. You only need to kill the master process. For example, if you get something like the following:

                  parent
UID          PID    PPID  C STIME TTY          TIME CMD
username 1460822       1  0 May23 ?        00:01:48 tmux
username  945179 1460822  0 May25 pts/20   00:00:00 -bash
username  945272  945179  0 May25 pts/20   00:37:36 /sca/.../jupyter-notebook --no-browser
username  969070  945272  0 May25 ?        00:10:16 /sca/.../python -m ipykernel_launcher -f /.../kernel-...json
username  987828  945272  0 May25 ?        00:09:37 /sca/.../python -m ipykernel_launcher -f /.../kernel-...json

In the example above, the PID (process ID) '1460822', is the main master process. It does not have a "parent", the PPID (parent process ID) is 1. This is the one you need to kill, then all it's "children", "grandchildren" and "great-grandchildren" etc. will get killed as well.
Note that processes are not always sorted in order!

Sometimes, it happens that processes do not have a parent anymore, then you need to kill them with their own PID.

The command to kill a process is:
   

So, for the example above:
    kill -9 1460822