I replaced the default checks with the Invoke-Checks some time ago and I noticed that the Invoke-IcingaCheckCPU is very demanding on the CPU. When the check is executed, the CPU load increases a lot and the Icinga then reports a Critical. When the check is run again, it is mostly OK.
However, I have already increased the check repetitions to 3, but this does not solve the problem. The CPUs are usually quad cores. Do you have any ideas?