# CPU spikes on Raspberry 4 every hour

**URL:** <https://discourse.nodered.org/t/cpu-spikes-on-raspberry-4-every-hour/57414>\
**Category:** General\
**Created:** [28 January 2022 16:43 UTC](https://discourse.nodered.org/t/cpu-spikes-on-raspberry-4-every-hour/57414 "2022-01-28T16:43:39Z")\
**Posts on this page:** 1\
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**Author:** ![WhiteLion](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/whitelion/32/12266_2.png) [@WhiteLion](https://discourse.nodered.org/u/WhiteLion)\
**Post date:** [29 January 2022 17:13 UTC](https://discourse.nodered.org/t/cpu-spikes-on-raspberry-4-every-hour/57414/11 "2022-01-29T17:13:42Z")

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I am still trying to find out. htop paints a different picture than "loadavg" node (node-red-contrib-os). There I could see only a spike for about 1 second. That is caused by an arp request -\> pinging every 10 seconds for present detection. The curve loadavg draws is not comprehensible. In my theory could this be the case:

- Every 10 seconds cpu spike by arp - request.
- Every 60 seconds cpu load measure by loadavg.  
At some point the time where these events meet (maybe by a delay of the trigger (both use an injection node) and then the curve of high load will be drawn.

But I could be totally wrong with that.

I dont use influxdb. I use MariaDB for only two values. all the rest of my config is a json object saved to SD card every 10 minutes.

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