// Module included in the following assemblies:
// * installing_tnf/operating-a-degraded-tnf.adoc

:_mod-docs-content-type: CONCEPT
[id="cluster-operator-stability-during-degraded-operation_{context}"]
= Cluster operator stability during degraded operation

[role="_abstract"]
{product-title} cluster Operators maintain control plane stability and API availability when a two-node OpenShift cluster with fencing (TNF) enters a degraded state.

During degraded operations, cluster Operator conditions exhibit the following behaviors:

* Most Operators maintain an `Available=True` condition, ensuring that core API functionality remains accessible.

* The following Operators transition to a `Degraded=True` condition because only one of the two expected control plane instances is operational:
    - `etcd`
    - `kube-apiserver`
    - `kube-controller-manager`
    - `kube-scheduler`
    - `machine-config`

* Specific Operators might exhibit a `Progressing=True` condition during reconciliation routines that require data from both infrastructure nodes. This condition resolves when the second node returns to an online state.

[NOTE]
====
Unexpected or cascading Operator failures must not occur during degraded operation. If they do, investigate the issue as a potential bug.
====
