topic Re: R80.40 - Performance Tuning Tip - CPU Spike Detective in General Topics

R80.40 - Performance Tuning Tip - CPU Spike Detective

HeikoAnkenbrand — Sat, 17 Oct 2020 19:18:48 GMT

The CPU Spike Detective is a tool running only on Gaia OS 3.10 that monitors the system CPU usage and checks for CPU utilization spikes. This tool is introduced starting from R80.40 JHF 69.

How does the spike detective work:

A spike in a CPU core utilization is considered when these conditions are met:

- CPU utilization is over 80% (this threshold is configurable)
- CPU utilization of the specific CPU core is at least 1.5 times higher than the entire system average usage (this threshold is configurable).

This ensures that a highly utilized system (for example, during a performance testing) will not detect all CPU cores as "spiked".

A thread/process is considered as "spiked" if it meets the below conditions:
- Running on a "spiked" CPU core
- Utilization is over 70% (this threshold is configurable)
- Utilization is at least 1.5 times higher than the system average (this threshold is configurable)

Tip 1

The Thread-Spikes information can be reviewed:
# cpview -> CPView > CPU > Spikes > Thread-Spikes

Tip 2

The CPU-Spikes information can be reviewed:
# cpview -> CPView > CPU > Spikes > CPU-Spikes

Re: R80.40 - Performance Tuning Tip - CPU Spike Detective

nils_alfer — Sun, 18 Oct 2020 16:21:51 GMT

With this you can easily find CPU spikes. Is it possible to analyse this over time and output the values in a table?

Re: R80.40 - Performance Tuning Tip - CPU Spike Detective

G_W_Albrecht — Sun, 18 Oct 2020 20:48:51 GMT

From SK166454 it seems the only source is /var/log/spike_detective/spike_detective.log as CPView only has the last minute. And how to find the culprit process without External Stats Collector if this CPU is nothing special?

Re: R80.40 - Performance Tuning Tip - CPU Spike Detective

nils_alfer — Mon, 19 Oct 2020 07:17:51 GMT

tnx

Re: R80.40 - Performance Tuning Tip - CPU Spike Detective

sapirna — Wed, 21 Oct 2020 15:47:00 GMT

CPU spike detective saves spikes’ history across time in the spike_detective.log file and in cpview _services (accessible using the command ‘cpview –t’).
The tool may also extract perf records during the spike which are saved in the /var/log/spike_detective/ directory (same location as the log), which greatly assist in locating the process and/or flow which ran during the spike.

Re: R80.40 - Performance Tuning Tip - CPU Spike Detective

T_Westwood — Sun, 01 Nov 2020 12:16:38 GMT

Nice tool!

Re: R80.40 - Performance Tuning Tip - CPU Spike Detective

charlie_h — Sun, 06 Dec 2020 07:04:17 GMT

Is also a network Spike Detective available?

Re: R80.40 - Performance Tuning Tip - CPU Spike Detective

G_W_Albrecht — Sun, 06 Dec 2020 09:22:11 GMT

Same Tool ! Look ony at the CPU/core(s) that work as SND(s) and - voilà ! - here is Network Spike Detective 8)