Managing node groups
You should rarely need to set the minimum and maximum values for a node group. If you find you need to adjust these values often, it could be an indication of another issue that needs to be addressed. Please reach out to our support team if you have any questions or concerns.
You cannot change the instance type of an existing node group, only the number of instances. To change the instance type, you'll need to create a new node group and delete the old one during a maintenance window. Our support team can assist you with any questions or concerns.
Once you have created a cluster, you can view the cluster info. You can also view the associated node groups below the cluster details.
The node groups for a cluster
Click the Edit button to show the edit dialog. Here you can adjust the minimum, maximum, and desired node size for this node group.
Adjusting the sizes for a node group
Click Save to scale the node group up or down according to your changes.
Keep in mind that the "Desired Nodes" value is only set initially and may change later, for example, as workloads are removed or deployed. The cluster will automatically adjust this number according to the workload present during a scheduler cycle. You may wish to increase the number in advance of a large new deployment, or when you know in advance more capacity is needed. In general, your desired value will be closer to the minimum number than the maximum number for most workloads.
To find out what value to use for "Desired Nodes", check the existing number of nodes you have running in your cluster and set it to the same value (or higher). To enforce the "Desired Nodes" value as the baseline, set "Minimum Size" to be the same as "Desired Nodes". To enforce that the "Desired Nodes" value is never exceeded, set "Maximum Size" to be the same as "Desired Nodes". Get in touch with our support team if you have any questions or concerns.
Setting "Desired Nodes" and/or "Maximum Size" to a value less than the number of nodes you are currently running could cause an outage. For example, if you are currently running five nodes in your node group and you set either "Desired Nodes" or "Maximum Size" to four, you could cause some downtime in your application by forcing one node to be terminated. You should always schedule a maintenance window for this operation if you have workloads that end users will rely on.
Setting the minimum and maximum sizes to 0 will scale your node group down and could cause an outage.
To create a new node group for a cluster, click the Add New Node Group button on the Cluster Info page.
Cluster info and actions
This will open the Add Node Group dialog.
New node group dialog
The node group you create here will be associated to the current cluster.
Although the minimum and maximum size values are useful to estimate how your workloads will be distributed, keep in mind that having two or more different node groups with different instance types will not guarantee your workloads will scale the correct resources without additional configuration. The ReleaseHub support team can provide more information about this.
In very rare cases (for example, Windows workloads, machine learning instances, and GPU-enabled instances), you can create a node group with a "Minimum Size" value of 0. In such a case, no new nodes will be created until the appropriate pods are scheduled and the workloads are running. This is called "scale up and down from zero" and typically requires extra configuration to enable.
We recommend having at least three nodes of any type available, even for an empty cluster, since there are service-level pods that need to run for even small workloads in the cluster. In rare cases where you are running very small workloads, you can set the minimum to two. We do not recommend having less than two nodes available in the cluster.
Setting "Maximum Size" to 0 will not allow any pods to run on the new node group, effectively disabling it.
Last modified 29d ago