Bug 2004585

Summary: prometheus-k8s-0 cpu usage keeps increasing for the first 3 days
Product: OpenShift Container Platform Reporter: yliu1
Component: kube-apiserverAssignee: Luis Sanchez <sanchezl>
Status: CLOSED ERRATA QA Contact: Ke Wang <kewang>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.9CC: akashem, amuller, anpicker, aos-bugs, erooth, hongyli, imiller, mfojtik, pgough, xxia
Target Milestone: ---   
Target Release: 4.10.0   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: No Doc Update
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2022-03-10 16:10:42 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2012346    
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Description Flags
prometheus pod cpu usage for the first 5 days none

Description yliu1 2021-09-15 15:33:31 UTC
Created attachment 1823359 [details]
prometheus pod cpu usage for the first 5 days

Description of problem:

On a freshly deployed SNO cluster, cpu usage of prometheus pod will keep increase from ~0.15 to ~0.45 for the first 3 days. It takes too long to settle.


Version-Release number of selected component (if applicable):
4.9.0 rc.0


How reproducible:


Steps to Reproduce:
1. Deploy a sno cluster
2. Deploy some workload pods
3. Observe cpu usage of each platform pod via prometheus queries for a week

Actual results:
3. prometheus-k8s-0 cpu usage kept increasing steadily for the first 3 days from ~0.15 to ~0.45, and settled on the 4th day.


Expected results:
3. It should settle earlier with lower cpu usage (maybe).

Additional info:
Prom chart for prometheus-k8s-0 pod is attached

Comment 1 Philip Gough 2021-09-15 16:09:11 UTC
Looking at the attached screenshot, I don't see any major issues.

What alarms you about the situation and what results/threshold would you expect to see instead?

Comment 2 yliu1 2021-09-15 16:58:14 UTC
We are expecting < 300 mc based on previous measurements.

Comment 15 yliu1 2021-10-26 16:37:43 UTC
Verified on 4.9.1. 
prometheus-k8s-0 pod cpu usage has been relatively stable in the past 4 days since fresh deployment. It uses ~0.17 cpu in steady state.

Comment 16 Ke Wang 2021-10-28 07:33:34 UTC
Verified on 4.10 nightly payload, prometheus-k8s-0 pod cpu usage is around 0.1 with some workload pods created by clusterbuster tool(./clusterbuster -P server -b 5 -p 2 -D .01 -M 1 -N 4 -r 4 -d 2 -c 6 -m 1000 -v -s 5 -x) in the past 2 days.

Comment 21 errata-xmlrpc 2022-03-10 16:10:42 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: OpenShift Container Platform 4.10.3 security update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2022:0056