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

# Override data plane cluster configurations

Cluster overrides let you customize Deployment configuration for one data plane cluster. They don't change platform-level control plane settings.

Use [Configure Astro Private Cloud](/docs/astro-private-cloud/v-2-x/configure-astro-private-cloud) if you need to decide whether a setting belongs in platform config, a cluster override, a Workspace override, or a Deployment override.

Astro Private Cloud (APC) has two types of Deployment configurations that you can set at the data plane cluster level.

* **Default configuration**: The base, system-provided configuration. You can override default values, but you can't delete default keys.
* **Custom configuration**: Your own additional keys and values. You can add, modify, or delete these keys.

## Prerequisites

* An APC control plane is installed and reachable.
* You have System Admin permissions in the APC UI or access to the APC API.
* The data plane cluster is healthy and accessible from the control plane.

## Update your cluster

You can define cluster configurations when you first [register a cluster](/docs/astro-private-cloud/v-2-x/register-data-plane) or later by updating the cluster through the UI or APC API.

* **Registration**: The form includes an optional **Cluster Override** field. You can supply initial overrides when registering.
* **Edit**: The cluster page contains your overall cluster information and a **Deployment Configuration** section.
  * **Cluster Information**: View and edit the cluster name.
  * **Current Configuration**: Read-only view of the default configurations.
  * **Configuration Override**: Editable area where you provide override values for base keys and/or add custom keys.
  * After you add overrides, the **Current Configuration** shows a read-only, git-style diff of added/modified values.
* **APC API**: If you automate cluster management, use the APC API to update cluster metadata and connection secrets. Refer to your internal API client or see platform API docs.

## Update cluster information

Only the **Cluster name** is editable as a cluster property in the **Cluster Information** section. You must use **Configuration Override** to make changes to Deployment configurations by overriding the base Deployment configuration.

## Override base configuration

Add your own keys and values to tailor behavior per cluster. You can't delete default keys, but you can override their values to make custom configurations.

<Steps>
  <Step title="Select cluster">
    In the **Clusters** page, select the cluster where you want to override a configuration.
  </Step>

  <Step title="Find configuration to review">
    Search for the configuration that you want to edit in the **Current Configuration**.

    <Tip>Use `ctrl+F` or `cmd+F` on Mac to search for the config.</Tip>
  </Step>

  <Step title="Edit configuration override">
    Click **Edit** to unlock **Configuration Override**. You can now make override edits.
  </Step>

  <Step title="Add new key and value">
    Add your new key and value to the **Configuration Override**.

    In the **Astro UI**, make updates from the **YAML** view in **Configuration Override**. The UI sends the correct values to the APC API when you save, including when you clear an override for a key. Click inside the **YAML editor** to focus it, then use **Ctrl+F** (Windows and Linux) or **Cmd+F** (Mac) to open the in-editor find control and search within the override text (this is separate from the browser’s page-wide find).

    <Frame>
      <img src="https://mintcdn.com/astronomer/Ct4jHNJYwyny9aUD/images/astro-private-cloud/override_data_plane_cluster_configuration_yaml_search.png?fit=max&auto=format&n=Ct4jHNJYwyny9aUD&q=85&s=86dd984c942694edb41706384a682b96" alt="Configuration Override YAML editor focused, with the in-editor find control used to search the YAML." width="3456" height="1996" data-path="images/astro-private-cloud/override_data_plane_cluster_configuration_yaml_search.png" />
    </Frame>

    * **APC API `updateCluster` (GraphQL)**: To remove a key from the stored `deployments` override, pass a `deploymentsConfigOverride` object and set that key's value to the string `"DELETE_KEY"`. The merge rules are the same as for workspace- and deployment-level overrides; see [Config governance](/docs/astro-private-cloud/v-2-x/config-governance).
    * **Base configuration keys** can only have their *values* overridden, not removed from the underlying defaults, and you can't use `"DELETE_KEY"` on paths that are *required* in the platform's default `deployments` object.
    * **Schema validation**: When the APC API has `strictSchemaCheck.enabled` set to `true` (from `astronomer.houston.strictSchemaCheck` in the control plane's `values.yaml`, `true` by default in 2.0), unknown keys or bad types in `deployments` overrides are rejected. If you get validation errors for acceptable `helm` or other allow-listed subtrees, see [Disable the strict schema check](/docs/astro-private-cloud/v-2-x/config-governance#delete_key-and-strict-schema-validation) for the pattern to relax the check, or adjust overrides to match the [config governance](/docs/astro-private-cloud/v-2-x/config-governance) schema.

    <Warning>
      Carefully check your configuration updates before you update your cluster, as these configuration changes can impact all cluster users.
    </Warning>
  </Step>

  <Step title="Apply changes">
    Click **Update Cluster** to apply your changes.

    <Note>
      Deployment config updates aren't applied until each Deployment is individually updated.
    </Note>
  </Step>

  <Step title="Verify changes">
    * Confirm cluster status is **Healthy** on the **Clusters** page in the Astro UI.
    * For Airflow Deployments in your updated cluster, trigger a small change and confirm the deployment orchestrator applies it as expected.
    * In Prometheus on the control plane, verify the cluster appears in federated targets.
  </Step>
</Steps>

## Additional notes

* Cluster overrides apply to `deployments.*` values for the selected data plane cluster.
* In APC 2.x, Workspace and Deployment overrides can further override eligible `deployments.*` values after the cluster layer.
* Settings outside `deployments.*` stay in `values.yaml`, typically under `astronomer.houston.config`, and require a Helm upgrade.
* Use [Apply a config change](/docs/astro-private-cloud/v-2-x/apply-platform-config) for platform-level values and [Configure Astro Private Cloud](/docs/astro-private-cloud/v-2-x/configure-astro-private-cloud) for the full hierarchy.

## Best practices

* Keep overrides minimal. Prefer **Base Config** unless a cluster truly deviates.
* Use consistent naming and comments for custom keys.
* Review the diff in **Current Configuration** to validate the final effective settings before you **Update Cluster**.