About strategies to upgrade nodes

About rolling upgrades

To upgrade node group’s nodes, we typically do rolling upgrades. In a rolling upgrade, something new is added to replace something old before its removed.

When doing a rolling upgrade of node groups, we can do a rolling upgrade fast and forcefully or slow and patiently - either pods running on a node group’s nodes get forcefully stopped, or they get to stop on their own.

Managed node groups can do fast and forceful rolling upgrades, while unmanaged node groups need to be re-created to get upgraded k8s software (kubelet etc).

Core nodes’ workloads can be suitable to forcefully relocate, while user nodes’ workloads should be given time to stop on their own.

About re-creation upgrades

With unmanaged node groups like on EKS, if disruption isn’t a concern or if there isn’t anything running to disrupt, node groups can be deleted and re-created to save time.