Feature Request - Add CPU count to cpu input

[rossmcdonald]

Adding a CPU count (the number of CPU's on the system) to the cpu (or maybe system) input would be very helpful when alerting based on system load.

[sparrc]

will do 👍

[eduser25]

Guys, I think this implementation is wrong. NumCPU is, defined by go, NumCPU returns the number of logical CPUs usable by the current process.

This is NOT the number of CPUs a system may have.

[jdmaloney]

How hard would this be to add to the cpu input? I'm trying to figure out how many cores are being used in a given host so I'd like to be able to do usage_user * n_cpu to get that value. With them being in different measurements that isn't possible (without Flux).

[oserde]

Hi @eduser25 . This behavior was updated in #6214 .

[danielnelson]

@jdmaloney You may want to turn on totalcpu = true.

[jdmaloney]

@danielnelson I do have that enabled on the system, however if I look at top on a compute node I see the job process is using ~2600% CPU (almost 26 cores), but looking at what I see from the cpu plugin I only get percentages that add up to 100. I don't have a way to tell how many CPU's on a node are engaged from the information in either cpu or system individually. I can from info in both, but I can't multiply n_cpu from the system plugin with usage_user from the cpu plugin since they're in different measurements. Maybe a config parameter that shows aggregate cpu utilization % instead of the average across the cpus? Not sure if that's easier than adding the n_cpu value to the cpu input.

[danielnelson]

I might still not be fully understanding, sorry about that ahead of time. If you want something similar to what top is showing here enable report_active = true and then select sum(usage_active) from cpu group by time(10s).