High cpu on 2100 after upgrade to RC from Beta

marcosm

Does this eventually stop, or does it get stuck?

Would you generate diagnostic data while it's happening, and upload it here?

applesalwaysred

@marcosm I can add those but you can try to replicate this now. Found it is from options in KEA dhcp.

I re-installed RC from 24.03 and issue continues.
Found that I am using dns resolver & chose options 'Enable DNS registration' and 'Enable early DNS registration' from DHCP server.
CPU usage greatly increases as described.
Disable options from 2. & restart dhcp and cpu usage drops to ~30%. Note that my cpu usage before RC was ~10% nominally and I was using KEA dhcp in 24.03.

marcosm

Yes, that's where it comes from and some CPU usage is normal. The screenshot shows it's been running for longer than expected however - hence the follow up questions.

cmcdonald

@marcosm said in High cpu on 2100 after upgrade to RC from Beta:

Does this eventually stop, or does it get stuck?

@applesalwaysred ^

The answer here is important thanks

applesalwaysred

@cmcdonald @marcosm It doesn't get stuck and it doesn't stop. It rotates between sed journal activity building up over 80% dropping off. Then Kea will push cpu to high level. It repeats this scenario as long as you let it. Not seeing failures anywhere. Can you replicate this?

stephenw10

We saw it in earlier beta snapshots but not since.

How many DHCP clients do you have?

Are you seeing that 30% CPU usage with the webgui open or at the CLI?

applesalwaysred

@stephenw10 I have under 30 dhcp clients all ipv4. Yes, on the UI screen it does jump so I looked at the long term average: I do not see long term load average of under 20% with the RC candidate. With 24.03 release, I do see under 20% long term load average fyi.

cmcdonald

@applesalwaysred how long is your lease duration?

applesalwaysred

@cmcdonald 86400s.

stephenw10

@applesalwaysred said in High cpu on 2100 after upgrade to RC from Beta:

I do not see long term load average of under 20% with the RC candidate.

In the Status > Monitoring graphs?

applesalwaysred

@stephenw10 sorry, I meant I have not seen under 20% cpu usage (long term) on the RC build compared to the 24.03 release where it is common.

stephenw10

Right I'm just wondering where you are checking that?

Since I don't see that on 2100s here:

Screenshot from 2024-11-21 21-28-53.png

applesalwaysred

@stephenw10 load averages on system diagnostics (at thread top) & dashboard with the 3 state state load averages. Not the current cpu usage. What happens when you add in kea with 'Enable DNS registration' and 'Enable early DNS registration' ?