diff --git a/docs/tasks/run-application/upgrade-pet-set-to-stateful-set.md b/docs/tasks/run-application/upgrade-pet-set-to-stateful-set.md deleted file mode 100644 index 1909283b39fd7..0000000000000 --- a/docs/tasks/run-application/upgrade-pet-set-to-stateful-set.md +++ /dev/null @@ -1,166 +0,0 @@ ---- -approvers: -- bprashanth -- enisoc -- erictune -- foxish -- janetkuo -- kow3ns -- smarterclayton -title: Upgrade from PetSets to StatefulSets ---- - -{% capture overview %} -This page shows how to upgrade from PetSets (Kubernetes version 1.3 or 1.4) to *StatefulSets* (Kubernetes version 1.5 or later). -{% endcapture %} - -{% capture prerequisites %} - -* If you don't have PetSets in your current cluster, or you don't plan to upgrade - your master to Kubernetes 1.5 or later, you can skip this task. - -{% endcapture %} - -{% capture steps %} - -## Differences between alpha PetSets and beta StatefulSets - -PetSet was introduced as an alpha resource in Kubernetes release 1.3, and was renamed to StatefulSet as a beta resource in 1.5. -Here are some notable changes: - -* **StatefulSet is the new PetSet**: PetSet is no longer available in Kubernetes release 1.5 or later. It becomes beta StatefulSet. To understand why the name was changed, see this [discussion thread](https://github.com/kubernetes/kubernetes/issues/27430). -* **StatefulSet guards against split brain**: StatefulSets guarantee at most one Pod for a given ordinal index can be running anywhere in a cluster, to guard against split brain scenarios with distributed applications. *TODO: Link to doc about fencing.* -* **Flipped debug annotation behavior**: The default value of the debug annotation (`pod.alpha.kubernetes.io/initialized`) is now `true`. The absence of this annotation will pause PetSet operations, but will NOT pause StatefulSet operations. In most cases, you no longer need this annotation in your StatefulSet manifests. - - -## Upgrading from PetSets to StatefulSets - -Note that these steps need to be done in the specified order. You **should -NOT upgrade your Kubernetes master, nodes, or `kubectl` to Kubernetes version -1.5 or later**, until told to do so. - -### Find all PetSets and their manifests - -First, find all existing PetSets in your cluster: - -```shell -kubectl get petsets --all-namespaces -``` - -If you don't find any existing PetSets, you can safely upgrade your cluster to -Kubernetes version 1.5 or later. - -If you find existing PetSets and you have all their manifests at hand, you can continue to the next step to prepare StatefulSet manifests. - -Otherwise, you need to save their manifests so that you can recreate them as StatefulSets later. -Here's an example command for you to save all existing PetSets as one file. - -```shell -# Save all existing PetSets in all namespaces into a single file. Only needed when you don't have their manifests at hand. -kubectl get petsets --all-namespaces -o yaml > all-petsets.yaml -``` - -### Prepare StatefulSet manifests - -Now, for every PetSet manifest you have, prepare a corresponding StatefulSet manifest: - -1. Change `apiVersion` from `apps/v1alpha1` to `apps/v1beta1`. -2. Change `kind` from `PetSet` to `StatefulSet`. -3. If you have the debug hook annotation `pod.alpha.kubernetes.io/initialized` set to `true`, you can remove it because it's redundant. If you don't have this annotation, you should add one, with the value set to `false`, to pause StatefulSets operations. - -It's recommended that you keep both PetSet manifests and StatefulSet manifests, so that you can safely roll back and recreate your PetSets, -if you decide not to upgrade your cluster. - -### Delete all PetSets without cascading - -If you find existing PetSets in your cluster in the previous step, you need to delete all PetSets *without cascading*. You can do this from `kubectl` with `--cascade=false`. -Note that if the flag isn't set, **cascading deletion will be performed by default**, and all Pods managed by your PetSets will be gone. - -Delete those PetSets by specifying file names. This only works when -the files contain only PetSets, but not other resources such as Services: - -```shell -# Delete all existing PetSets without cascading -# Note that should only contain PetSets that you want to delete, but not any other resources -kubectl delete -f --cascade=false -``` - -Alternatively, delete them by specifying resource names: - -```shell -# Alternatively, delete them by name and namespace without cascading -kubectl delete petsets -n= --cascade=false -``` - -Make sure you've deleted all PetSets in the system: - -```shell -# Get all PetSets again to make sure you deleted them all -# This should return nothing -kubectl get petsets --all-namespaces -``` - -At this moment, you've deleted all PetSets in your cluster, but not their Pods, Persistent Volumes, or Persistent Volume Claims. -However, since the Pods are not managed by PetSets anymore, they will be vulnerable to node failures until you finish the master upgrade and recreate StatefulSets. - -### Upgrade your master to Kubernetes version 1.5 or later - -Now, you can [upgrade your Kubernetes master](/docs/admin/cluster-management/#upgrading-a-cluster) to Kubernetes version 1.5 or later. -Note that **you should NOT upgrade Nodes at this time**, because the Pods -(that were once managed by PetSets) are now vulnerable to node failures. - -### Upgrade kubectl to Kubernetes version 1.5 or later - -Upgrade `kubectl` to Kubernetes version 1.5 or later, following [the steps for installing and setting up -kubectl](/docs/tasks/kubectl/install/). - -### Create StatefulSets - -Make sure you have both master and `kubectl` upgraded to Kubernetes version 1.5 -or later before continuing: - -```shell -kubectl version -``` - -The output is similar to this: - -```shell -Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.0", GitCommit:"0776eab45fe28f02bbeac0f05ae1a203051a21eb", GitTreeState:"clean", BuildDate:"2016-11-24T22:35:03Z", GoVersion:"go1.7.3", Compiler:"gc", Platform:"linux/amd64"} -Server Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.0", GitCommit:"0776eab45fe28f02bbeac0f05ae1a203051a21eb", GitTreeState:"clean", BuildDate:"2016-11-24T22:30:23Z", GoVersion:"go1.7.3", Compiler:"gc", Platform:"linux/amd64"} -``` - -If both `Client Version` (`kubectl` version) and `Server Version` (master -version) are 1.5 or later, you are good to go. - -Create StatefulSets to adopt the Pods belonging to the deleted PetSets with the -StatefulSet manifests generated in the previous step: - -```shell -kubectl create -f -``` - -Make sure all StatefulSets are created and running as expected in the -newly-upgraded cluster: - -```shell -kubectl get statefulsets --all-namespaces -``` - -### Upgrade nodes to Kubernetes version 1.5 or later (optional) - -You can now [upgrade Kubernetes nodes](/docs/admin/cluster-management/#upgrading-a-cluster) -to Kubernetes version 1.5 or later. This step is optional, but needs to be done after all StatefulSets -are created to adopt PetSets' Pods. - -You should be running Node version >= 1.1.0 to run StatefulSets safely. Older versions do not support features which allow the StatefulSet to guarantee that at any time, there is **at most** one Pod with a given identity running in a cluster. - -{% endcapture %} - -{% capture whatsnext %} - -Learn more about [scaling a StatefulSet](/docs/tasks/manage-stateful-set/scale-stateful-set/). - -{% endcapture %} - -{% include templates/task.md %}