Managing your node groups

Editing a node group

Setting the minimum and maximum values for a node group should be done rarely. If you find yourself adjusting them often, it could be an indication of some other issue. Please reach out to support with any questions or concerns.
You cannot change the instance type of an existing node group, only the count of number of instances. To change the instance type, create a new node group and delete the old one during a maintenance window. Reach out to support with any questions or concerns.
After 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
Clicking the "Edit" button will show the edit dialog where you can adjust the minimum, maximum, and desired node size for this node group.
Adjusting the sizes for a node group
Clicking "save" will scale the node group up or down depending on the changes. Keep in mind that the "desired" value is only set initially and may change later, for example, as new workloads are removed or deployed. The cluster will automatically adjust the correct "desired" number based on the workload that is 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", check the existing number of nodes you have running in your cluster and set it the same value (or higher). To enforce the "desired" value is the baseline, you can set minimum to be the same as "desired". To enforce that the "desired" value is never exceeded, set maximum to be the same as "desired". Reach out to support if you have any questions or concerns.
Setting desired and/or maximum to less than the number of nodes currently running could cause an outage. For example, if you are currently running 5 nodes in your node group and you set either desired or maximum to a smaller number, like 4, then 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

Adding a node group

Clicking on the "Add new node group" button on the cluster info page will show the dialog where you can create a new node group for a cluster.
Cluster info and actions
New node group dialog
This will create and associate a node group to the current cluster.
Although the minimum and maximum 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 (for example) will not guarantee your workloads will scale the correct resources without additional configuration. Reach out to support for more information.
In very rare cases (for example, Windows workloads, machine learning instances, and GPU-enabled instances), you can create a node group with minimum value of 0. In that 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 3 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 2. We do not recommend having less than 2 nodes available in the cluster.
Setting the maximum size to 0 will not allow any pods to run on the new node group, effectively disabling it.