DevOps with Kubernetes - Second Edition

StatefulSet

The updating of StatefulSet and DaemonSet are pretty much the same; they don't create redundant pods during an update and their update strategies also behave in a similar way. There's a template file at 9-1_updates/ex-statefulset.yml that you can use for practice. The options of the update strategy are set at the .spec.updateStrategy.type path:

• OnDelete: Pods are only updated after they're manually deleted.
• RollingUpdate: Like rolling updates for other controllers, Kubernetes deletes and creates pods in a managed fashion. Kubernetes knows the order matters in StatefulSet, so it replaces pods in reverse order. Say we have three pods in StatefulSet: my-ss-0, my-ss-1, and my-ss-2. The update order will start at my-ss-2 and run to ...