That's one of the ones I use...Observium
Check the PT_LOAD_AVG minute Load Average (can be set to 1 5 or 15 and
defaults to 5 if set otherwise) on the server every PT_LOAD seconds. If the
load average is greater than or equal to PT_LOAD_LEVEL then an email alert is
sent. lfd then does not report subsequent high load until PT_LOAD_SKIP
seconds has passed to prevent email floods.
Set PT_LOAD to "0" to disable this feature
PT_LOAD = Default: 30 [0-3600]
PT_LOAD_AVG = Default: 5 [1 or 5 or 15]
PT_LOAD_LEVEL = Default: 6 [2-20]
PT_LOAD_SKIP = Default: 3600 [1800-86400]
That's actually very neat idea! I didn't know CSF does that as well! Omg they are great.That's one of the ones I use...
If the OP is installing CSF and doesn't want to install an external monitoring script like Observium, he could also use the build-in light load monitoring CSF/LFD provides