Bug 2108679

Summary: OCP 4.11 AWS excessively high kube-apiserver resources with OVN-Kubernetes on large cluster-density tests
Product: OpenShift Container Platform Reporter: Andrew Collins <ancollin>
Component: NetworkingAssignee: Surya Seetharaman <surya>
Networking sub component: ovn-kubernetes QA Contact: Anurag saxena <anusaxen>
Status: CLOSED ERRATA Docs Contact:
Severity: unspecified    
Priority: unspecified CC: dcbw, jhopper, mfojtik, mifiedle, msheth, rravaiol, rsevilla, surya, wking, xxia
Version: 4.11   
Target Milestone: ---   
Target Release: 4.11.z   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: perfscale-ovn
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Clone Of: Environment:
Last Closed: 2022-09-12 10:14:28 UTC Type: Bug
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2115479    
Bug Blocks:    

Description Andrew Collins 2022-07-19 16:51:39 UTC
Description of problem: 
On an OpenShift 4.11.0-rc.1 configured with OVN-Kubernetes, we observed significant regression in the kube-apiserver CPU and Memory usage from 4.10 to 4.11.

When compared to Openshift SDN, the kube-apiserver resources grow at a significantly higher rate than an OpenShift SDN cluster installed with the same version.

Version-Release number of selected component (if applicable):
4.11.0-rc.1

How reproducible:
100%


Steps to Reproduce:
1. Install a 4.11.0-rc.1 cluster with r5.4xlarge masters
2. Scale cluster to 252 nodes
3. Apply cluster-density e2e-benchmarking workload with 4000 iterations 

Actual results:
kube-apiserver CPU usage maxes out at 14 (of 16) cores, and 53.7 GiB (of 124GiB)

Expected results:
kube-apiserver resource consumption scales closer to OpenShiftSDN at this scale, which is 4.52 out of 16 cores and 29.6GiB of 124GiB.

Comment 6 Dan Williams 2022-08-04 19:21:09 UTC
We think that https://bugzilla.redhat.com/show_bug.cgi?id=2115479 may help with this.

Comment 12 Raul Sevilla 2022-08-30 09:22:54 UTC
*** Bug 2108697 has been marked as a duplicate of this bug. ***

Comment 14 Dan Williams 2022-09-01 15:49:03 UTC
*** Bug 2108720 has been marked as a duplicate of this bug. ***

Comment 17 errata-xmlrpc 2022-09-12 10:14:28 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 (OpenShift Container Platform 4.11.4 bug fix 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/RHBA-2022:6376