Enabling high availability

When you create a new Gardener cluster, you have the option to enable high availability (HA) features for its control plane. In case you have an existing Gardener cluster with a non-HA control plane, you may at any time enable the HA features for that control plane.

Keep in mind that once you enable HA for the control plane of a Gardener cluster, you cannot disable it for that particular cluster.

Additionally, you may add HA characteristics to one or more Worker Groups of an existing cluster.

Enabling HA for the control plane

Using your favorite web browser, navigate to https://cleura.cloud and log in. In the left-hand side panel, choose Containers → Gardener. Then, in the central pane of the Cleura Cloud Management Panel, you see all of your Gardener clusters, organized by Cleura Cloud region.

Locate the cluster you are interested in, and click the orange icon on the right of the corresponding row. From the drop-down menu that appears, select Modify Cluster.

A vertical pane titled Modify Gardener Shoot Cluster slides over from the right. In it, you see the disabled option Enable Highly Available Control Plane. Click on it to enable HA for the control plane of the shoot cluster.

Before the change is applied, a warning appears: enabling HA is an irreversible action. Once you take it, there is no way to disable HA at a later time.

If you are sure you want to enable HA, scroll down a bit until you see the green Update button and click on it.

Enabling HA for the control plane of any Gardener cluster takes a few minutes. You can see how the process is progressing by the animated icon on the left of the cluster row.

As soon as HA is enabled, the animated icon changes into a check mark ().

Enabling HA for Worker Groups

You may add HA characteristics to one or more Worker Groups by modifying the Autoscaler Min and Autoscaler Max parameters.

First off, select the Gardener cluster you are interested in. Click on the cluster row to expand its characteristics, then select the Worker Groups tab.

Click once more on the icon of the Worker Group you wish to modify. A vertical pane named Modify Worker Group slides over from the right.

Modify the Autoscaler Min and Autoscaler Max parameters. You may, for instance, set Autoscaler Min to 3 and Autoscaler Max to 5. When you are ready to apply the changes, click the green Update button.

After a few seconds, the new values for the autoscaler parameters will be visible in the Worker Groups tab.