> ## Documentation Index
> Fetch the complete documentation index at: https://docs.porter.run/llms.txt
> Use this file to discover all available pages before exploring further.

# Node groups

> Configure node groups with custom instance types, enable cost optimization with smart instance selection, and manage compute capacity

Node groups are collections of compute instances that run your workloads. Porter provides flexible options for managing compute resources, including custom node groups for specialized workloads and cost optimization features.

## Default Node Groups

Porter provisions three node groups by default:

| Node Group      | Purpose                             | Autoscaling              |
| --------------- | ----------------------------------- | ------------------------ |
| **System**      | Kubernetes system workloads         | Fixed                    |
| **Monitoring**  | Observability stack (metrics, logs) | Fixed                    |
| **Application** | Your application workloads          | Enabled (1 node minimum) |

The application node group autoscales based on demand. You can customize instance types, node counts, and scaling limits for all node groups.

***

## Changing Instance Types

You can modify the instance type for any node group from the Infrastructure settings.

<Steps>
  <Step title="Navigate to Infrastructure">
    From your Porter dashboard, click on the **Infrastructure** tab in the left sidebar.
  </Step>

  <Step title="Select your cluster">
    Click on **Overview** to view your cluster configuration and node groups.
  </Step>

  <Step title="Configure the node group">
    Expand the node group dropdown (e.g., **Default node group**) to see the following settings:

    | Setting           | Description                                                        |
    | ----------------- | ------------------------------------------------------------------ |
    | **Machine type**  | The underlying instance for nodes. Options vary by cloud provider. |
    | **Maximum nodes** | Upper limit for autoscaling under high load                        |
    | **Minimum nodes** | Lower limit for autoscaling under low load                         |
    | **Disk size**     | Storage capacity for each node (default: 50GB)                     |
  </Step>

  <Step title="Update">
    Select the appropriate **Machine type** from the dropdown, then scroll to the bottom and click **Update**.
  </Step>
</Steps>

### Instance Type Pricing

<CardGroup cols={3}>
  <Card title="AWS Instance Types" icon="aws" href="https://aws.amazon.com/ec2/pricing/on-demand" />

  <Card title="Azure Instance Types" icon="microsoft" href="https://azure.microsoft.com/en-us/pricing/details/virtual-machines/linux/#pricing" />

  <Card title="GCP Instance Types" icon="google" href="https://cloud.google.com/compute/all-pricing#general_purpose" />
</CardGroup>

### Why is my instance type not available?

Instance types may not be available if:

* The instance is not available in your cluster's region (cloud providers release new instances on a phased, region-by-region basis)
* The instance type hasn't been validated by Porter for compatibility

If you need a specific instance type that isn't listed, contact us through the dashboard chat bot.

***

## Creating a Custom Node Group

Create custom node groups for specialized workloads like GPU processing, high-memory applications, or isolated environments.

<Steps>
  <Step title="Navigate to Infrastructure">
    From your Porter dashboard, click on the **Infrastructure** tab in the left sidebar.
  </Step>

  <Step title="Select your cluster">
    Click on **Cluster** to view your cluster configuration and node groups.
  </Step>

  <Step title="Add a node group">
    Click **Add an additional node group** to open the configuration panel.
  </Step>

  <Step title="Configure the node group">
    Choose between two configuration approaches:

    <Tabs>
      <Tab title="Cost Optimization">
        Cost optimization automatically selects the most cost-effective instance types for your workloads. Any cluster provisioned in AWS will default to cost optimized node groups.

        Set your **maximum CPU cores limit** to prevent unexpected scaling. This caps infrastructure costs while allowing flexibility in instance selection.

        ### Limitations

        The following configurations should use fixed instance types instead:

        * GPU instances (e.g., instances with NVIDIA GPUs)
        * Spot instances
        * Instances in public subnets
        * Instances with specialized hardware requirements
      </Tab>

      <Tab title="Fixed Instance Type">
        Fixed node groups use a specific instance type. Applications scheduled on this group run only on the exact instance type you specify.

        This gives you precise control but may result in over-provisioning if configured incorrectly.

        Configure:

        | Setting           | Description                                          |
        | ----------------- | ---------------------------------------------------- |
        | **Instance type** | The machine type for nodes in this group             |
        | **Minimum nodes** | Minimum number of nodes (set to 0 for scale-to-zero) |
        | **Maximum nodes** | Upper limit for autoscaling                          |

        <Info>
          For GPU workloads, select instances with GPU support:

          * **AWS**: `g4dn.xlarge`, `p3.2xlarge`
          * **Azure**: `Standard_NC4as_T4_v3`
          * **GCP**: `g2-standard-4`
        </Info>
      </Tab>
    </Tabs>

    <Info>
      **Health Checks Required**: For production applications on cost-optimized node groups, configure proper [health checks](/applications/configure/zero-downtime-deployments#health-checks). This ensures applications can be safely rescheduled as nodes are reshuffled.
    </Info>
  </Step>

  <Step title="Save and apply">
    Click **Save** to create the node group. Porter provisions the new nodes, which may take a few minutes.
  </Step>
</Steps>

***

## Assigning Workloads to Node Groups

Once your custom node group is created, assign applications to run on it:

1. Navigate to your application in the Porter dashboard
2. Go to the **Services** tab
3. Click the service you want to assign
4. Under **General**, find the **Node group** selector
5. Select your custom node group from the dropdown
6. Save and redeploy your application

***

## Deleting a Node Group

<Warning>
  Ensure no workloads are scheduled on the node group before deleting. Workloads will be disrupted if their node group is removed.
</Warning>

To remove a custom node group:

1. Migrate any workloads running on the node group to another node group
2. Navigate to **Infrastructure** → **Cluster**
3. Find the node group you want to delete
4. Click the delete icon and confirm