I mainly use LibreNMS for server monitoring, and I have multiple Windows and Linux-servers (all VMs) running with multi-core setups. It works great. But I am having some issues with false positive CPU utilization alerts going off, when only one of the cores (not all) are at a certain percent.
From what I understand, LMNS does not support alerts for aggregate CPU utilization for multiple cores, instead they trigger if only one core is at x CPU %.
Assuming others are having issues with the same limitations; how do you work around it?
You need to go to the advanced tab in the rule, set override SQL to on and enter a query something similar to this:
SELECT *,AVG(processors.processor_usage) as cpu_avg FROM devices,processors WHERE (devices.device_id = ? AND devices.device_id = processors.device_id) AND (devices.status = 1 && (devices.disabled = 0 && devices.ignore = 0)) = 1 and devices.os = “linux” and HAVING AVG(processors.processor_usage) > 90
I am using this on devices of os type “linux” so you’d likely want to change that part for matching matching both windows / linux.