Would it be possible to install plugin which to check how many resource / connections / bandwidth does moodle server used as shown as below? Thanks a lot.
I don't think that network resources monitoring is a job for a Moodle plugin to do. You should search for a proper solution on web server or even operating system level. If I recall correctly, tools like Munin can help a lot with such monitoring. If you choose this particular one, there was also integration with Moodle (not sure it still works) - https://docs.moodle.org/23/en/Munin_plugin_for_Moodle