Bug 1984030

Summary:	Reduce CPU overhead for ignore-listed NICs
Product:	OpenShift Container Platform	Reporter:	Jan Fajerski <jfajersk>
Component:	Monitoring	Assignee:	Jan Fajerski <jfajersk>
Status:	CLOSED ERRATA	QA Contact:	Junqi Zhao <juzhao>
Severity:	medium	Docs Contact:
Priority:	high
Version:	4.9	CC:	amuller, anpicker, aos-bugs, erooth, spasquie
Target Milestone:	---
Target Release:	4.9.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	No Doc Update
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-18 17:40:26 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:	1984074

Description Jan Fajerski 2021-07-20 13:14:19 UTC

Description of problem:
Nodes with a high number of NICs cause high CPU load even if NICs are ignored by node_exporter. See also 
https://issues.redhat.com/browse/MON-1339


Version-Release number of selected component (if applicable):


How reproducible:

Start a single node cluster.

Steps to Reproduce:
1.
2.
3.

Actual results:

CPU utilization is high, no matter how many NICs are ignored.

Expected results:

CPU utilization should decrease as NICs are ignored.
Additional info:

Comment 4 Junqi Zhao 2021-07-22 03:57:01 UTC

tested with 4.9.0-0.nightly-2021-07-21-081948 single-node cluster
# oc get no
NAME                                         STATUS   ROLES           AGE   VERSION
ip-10-0-151-142.us-east-2.compute.internal   Ready    master,worker   52m   v1.21.1+8268f88

total cpu requests for node-exporter is 9Mi
node-exporter-pv4f8
Container Name: node-exporter
resources: map[requests:map[cpu:8m memory:32Mi]]
Container Name: kube-rbac-proxy
resources: map[requests:map[cpu:1m memory:15Mi]]

watched for a while, cpu usage is about 9Mi, no sudden increase
sum(kube_pod_resource_request{resource='cpu',pod='node-exporter-pv4f8',namespace='openshift-monitoring'}) BY (pod, namespace)
{namespace="openshift-monitoring", pod="node-exporter-pv4f8"} 0.009000000000000001

Comment 11 errata-xmlrpc 2021-10-18 17:40:26 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 4.9.0 bug fix and 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-2021:3759