What Happens to a DOKS Control Plane When an Upgrade Fails?

When a DigitalOcean Kubernetes (DOKS) control plane upgrade fails, the exact cluster state is not fully documented. Understanding whether the API server remains reachable and how node pools are affected is critical for planning a safe recovery.

Current documentation states that upgrades can be automatic or manual, but it does not specify whether a failed upgrade triggers an automatic rollback to the previous Kubernetes version or leaves the control plane in a partially upgraded state. This uncertainty makes it difficult to assess cluster availability during an outage.

Because node pool upgrades are independent, a failed control‑plane upgrade could leave the cluster in a version‑skewed state that may block subsequent node‑pool updates or even prevent new workloads from running.

What is the precise status of the API server after a failed control‑plane upgrade?

Does DigitalOcean automatically roll back to the previous Kubernetes version on failure, or must operators intervene manually?

What are the recommended manual steps to restore a cluster to a functional state after such a failure?