Bug 1986418

Summary:	kube-storage-version-migrator-operator needs to handle API server downtime gracefully in SNO
Product:	OpenShift Container Platform	Reporter:	Naga Ravi Chaitanya Elluri <nelluri>
Component:	kube-storage-version-migrator	Assignee:	Luis Sanchez <sanchezl>
Status:	CLOSED ERRATA	QA Contact:	Rahul Gangwar <rgangwar>
Severity:	high	Docs Contact:
Priority:	high
Version:	4.9	CC:	aojeagar, aos-bugs, nelluri, rgangwar, sanchezl
Target Milestone:	---
Target Release:	4.9.0
Hardware:	Unspecified
OS:	Linux
Whiteboard:	chaos
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-18 17:42:03 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:	1984730

Description Naga Ravi Chaitanya Elluri 2021-07-27 13:44:45 UTC

Description of problem:
kube-storage-version-migrator-operator is crashing/restarting and is going though leader elections during the kube-apiserver rollout which takes around ~60 seconds with shutdown-delay-duration and gracefulTerminationDuration is now set to 0 and 15 seconds ( https://github.com/openshift/cluster-kube-apiserver-operator/pull/1168 and https://github.com/openshift/library-go/pull/1104 ). kube-storage-version-migrator-operator leader election timeout should be set to > 60 seconds to handle the downtime gracefully in SNO.

Recommended lease duration values to be considered for reference as noted in https://github.com/openshift/enhancements/pull/832/files#diff-2e28754e69aa417e5b6d89e99e42f05bfb6330800fa823753383db1d170fbc2fR183:

LeaseDuration=137s, RenewDealine=107s, RetryPeriod=26s.
These are the configurable values in k8s.io/client-go based leases and controller-runtime exposes them.
This gives us
1. clock skew tolerance == 30s
2. kube-apiserver downtime tolerance == 78s
3. worst non-graceful lease reacquisition == 163s
4. worst graceful lease reacquisition == 26s

Here is the trace of the events during the rollout:
http://dell-r510-01.perf.lab.eng.rdu2.redhat.com/chaos/sno/kube-storage-version-migrator-operator/cerberus_cluster_state.log. We can see that leader lease failures in the log: http://dell-r510-01.perf.lab.eng.rdu2.redhat.com/chaos/sno/kube-storage-version-migrator-operator/openshift-kube-storage-version-migrator-operator.log. The leader election can also be disabled given that there's no HA in SNO.

Version-Release number of selected component (if applicable):
4.9.0-0.nightly-2021-07-26-031621

How reproducible:
Always

Steps to Reproduce:
1. Install a SNO cluster using the latest nightly payload.
2. Trigger kube-apiserver rollout/outage
3. Observe the state of kube-storage-version-migrator-operator

Actual results:
kube-storage-version-migrator-operator is crashing/restarting and going through leader elections.

Expected results:
kube-storage-version-migrator-operator should handle the API rollout/outage gracefully.

Additional info:
Logs including must-gather: http://dell-r510-01.perf.lab.eng.rdu2.redhat.com/chaos/sno/kube-storage-version-migrator-operator/

Comment 1 Antonio Ojea 2021-07-28 10:04:01 UTC

I've done a similar one before, so I think that same solution applies, bumping openshift-api to bring the new leader election defaults timeouts
https://github.com/openshift/cluster-kube-storage-version-migrator-operator/pull/63

Please check if this is correct

Comment 6 errata-xmlrpc 2021-10-18 17:42:03 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