hi, fpaoline 

following above steps in description. when one master node marked as 'NotReady',  However the ds sdn-controller is changing to 2 from 3.  and network operator did not report this? , is it expected?

$ oc get ds -n openshift-sdn
NAME             DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                     AGE
ovs              6         6         5       6            5           kubernetes.io/os=linux            71m
sdn              6         6         5       6            5           kubernetes.io/os=linux            71m
sdn-controller   2         2         2       2            2           node-role.kubernetes.io/master=   71m


$ oc get node
NAME                                         STATUS     ROLES    AGE   VERSION
ip-10-0-146-157.us-east-2.compute.internal   Ready      worker   57m   v1.20.0+5f82cdb
ip-10-0-147-64.us-east-2.compute.internal    NotReady   master   63m   v1.20.0+5f82cdb
ip-10-0-163-226.us-east-2.compute.internal   Ready      master   63m   v1.20.0+5f82cdb
ip-10-0-163-73.us-east-2.compute.internal    Ready      worker   57m   v1.20.0+5f82cdb
ip-10-0-201-132.us-east-2.compute.internal   Ready      worker   56m   v1.20.0+5f82cdb
ip-10-0-203-137.us-east-2.compute.internal   Ready      master   63m   v1.20.0+5f82cdb



$ oc get co network -o yaml
apiVersion: config.openshift.io/v1
kind: ClusterOperator
metadata:
  annotations:
    include.release.openshift.io/ibm-cloud-managed: "true"
    include.release.openshift.io/self-managed-high-availability: "true"
    include.release.openshift.io/single-node-developer: "true"
    network.operator.openshift.io/last-seen-state: '{"DaemonsetStates":[{"Namespace":"openshift-sdn","Name":"sdn","LastSeenStatus":{"currentNumberScheduled":6,"numberMisscheduled":0,"desiredNumberScheduled":6,"numberReady":5,"observedGeneration":1,"updatedNumberScheduled":6,"numberAvailable":5,"numberUnavailable":1},"LastChangeTime":"2021-04-14T08:05:11.242309949Z"},{"Namespace":"openshift-multus","Name":"multus","LastSeenStatus":{"currentNumberScheduled":6,"numberMisscheduled":0,"desiredNumberScheduled":6,"numberReady":5,"observedGeneration":1,"updatedNumberScheduled":6,"numberAvailable":5,"numberUnavailable":1},"LastChangeTime":"2021-04-14T08:05:11.241749394Z"},{"Namespace":"openshift-sdn","Name":"ovs","LastSeenStatus":{"currentNumberScheduled":6,"numberMisscheduled":0,"desiredNumberScheduled":6,"numberReady":5,"observedGeneration":1,"updatedNumberScheduled":6,"numberAvailable":5,"numberUnavailable":1},"LastChangeTime":"2021-04-14T08:05:11.242059449Z"}],"DeploymentStates":[]}'
  creationTimestamp: "2021-04-14T06:54:26Z"
  generation: 1
  managedFields:
  - apiVersion: config.openshift.io/v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          .: {}
          f:include.release.openshift.io/ibm-cloud-managed: {}
          f:include.release.openshift.io/self-managed-high-availability: {}
          f:include.release.openshift.io/single-node-developer: {}
      f:spec: {}
      f:status:
        .: {}
        f:extension: {}
    manager: cluster-version-operator
    operation: Update
    time: "2021-04-14T06:54:26Z"
  - apiVersion: config.openshift.io/v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          f:network.operator.openshift.io/last-seen-state: {}
      f:status:
        f:conditions: {}
        f:relatedObjects: {}
        f:versions: {}
    manager: cluster-network-operator
    operation: Update
    time: "2021-04-14T07:02:34Z"
  name: network
  resourceVersion: "52784"
  uid: 18598777-0af3-4ae0-ad6d-0ce2ff180acd
spec: {}
status:
  conditions:
  - lastTransitionTime: "2021-04-14T08:17:11Z"
    message: |-
      DaemonSet "openshift-multus/multus" rollout is not making progress - last change 2021-04-14T08:05:11Z
      DaemonSet "openshift-sdn/ovs" rollout is not making progress - last change 2021-04-14T08:05:11Z
      DaemonSet "openshift-sdn/sdn" rollout is not making progress - last change 2021-04-14T08:05:11Z
    reason: RolloutHung
    status: "True"
    type: Degraded
  - lastTransitionTime: "2021-04-14T07:01:53Z"
    status: "False"
    type: ManagementStateDegraded
  - lastTransitionTime: "2021-04-14T07:01:53Z"
    status: "True"
    type: Upgradeable
  - lastTransitionTime: "2021-04-14T08:05:11Z"
    message: |-
      DaemonSet "openshift-multus/multus" is not available (awaiting 1 nodes)
      DaemonSet "openshift-multus/network-metrics-daemon" is not available (awaiting 1 nodes)
      DaemonSet "openshift-sdn/ovs" is not available (awaiting 1 nodes)
      DaemonSet "openshift-sdn/sdn" is not available (awaiting 1 nodes)
      DaemonSet "openshift-network-diagnostics/network-check-target" is not available (awaiting 1 nodes)
    reason: Deploying

The sdn controller daemon changed it's number of replicas, I checked when I tested this and I think it's because of the node.kubernetes.io/unreachable taint.
The other ds have toleration: exist

However, the initial bug was CNO not reporting the degraded state, and that is working now.
I did not want to mess up with more logic than we needed to have the degraded state reported.

@zzhao does my comment above make sense?

ok, thanks the information.  Federico Paolinelli

Move this bug to verified.

Hey folks,

Is there a reason the leader election fix wasn't backported? We found the problem on openshift upgrade when we were looking into a similar locking issue in the openshift-marketplace operator: https://bugzilla.redhat.com/show_bug.cgi?id=1958888#c6

The main reason was the original scenario, which was not related to upgrades but to a very specific case where a master goes not reachable and the operator was not reporting the state in a proper manner.
It's not clear to me if this issue in CNO is preventing upgrades like the marketplace-operator did or not, I would say it does given the comments on the other bug but we weren't aware of such issue.

I'll create the backport right now, does it make sense to go back to 4.6?

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 4.8.2 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-2021:2438

The needinfo request[s] on this closed bug have been removed as they have been unresolved for 500 days