Graph various performance statistics over time using pnp4nagioshttps://www.monitoringexchange.org/inventory/Check-Plugins/Software/Nagios/check_nagiostats
check_nagiostats calls the "nagiostats" or "icingastats" executable (which
comes with Nagios or Icinga itself) to read various data about the running
Nagios/Icinga instance. See the output of "nagiostats -h" or "icingastats -h"
for a detailed list of what data you can get that way.