# Configuring Existing Clusters

> Source: https://parallelworks.com/docs/compute/configuring-existing-clusters

# Configuring Existing Clusters

ACTIVATE allows users to access the capabilities of an existing HPC cluster remotely.

## Creating a Cluster Definition

Navigate to the **Clusters** page under the **Compute** tab.

![Screenshot of the user clicking the Clusters page.](/content-images/docs/compute/configuring-existing-clusters/click-clusters.png)

Click the **+ Add Resource** button

![Screenshot of the user clicking the Add Resource button.](/content-images/docs/compute/configuring-existing-clusters/click-add-resource.png)

Select **Existing Cluster**.

![step1](/content-images/docs/compute/configuring-existing-clusters/click-existing.png)

You must enter a **Resource Name**. The **Display Name**, **Short description**, and **Tags** are all optional.

Click the **Add Resource** button.

![step1](/content-images/docs/compute/configuring-existing-clusters/click-add-resource2.png)

On the next page, click the **Definition** tab.

![Screenshot of the user clicking the Definition tab.](/content-images/docs/compute/configuring-existing-clusters/click-definition.png)

If the existing cluster you wish to connect to utilizes a jump host, select **Yes** for the **Jump Node** option. Enter the proper **Jump Node User** and **Jump Node Host** information to continue.

![Screenshot of the Jump Node parameters.](/content-images/docs/compute/configuring-existing-clusters/jump-node-params.png)

In the **Cluster Configuration** section, enter the **Username** and **Cluster Login Node**. Typically, the **Cluster Login Node** refers to the IP address of the cluster you wish to access. Your organization should have provided this information to you.

Click **Save Changes**.

![Screenshot of the user clicking Save Changes.](/content-images/docs/compute/configuring-existing-clusters/click-save-changes.png)

## Connecting to the Cluster

After configuring the cluster, navigate to the **Sessions** tab and click the power button.

![Screenshot of the user clicking the power button.](/content-images/docs/compute/configuring-existing-clusters/click-power-button.png)

A dialog box will appear that will show HPC Connect authenticating your connection.

![Screenshot of a successful on-premises connection.](/content-images/docs/compute/configuring-existing-clusters/hpcconnect-modal.png)

If your organization uses multi-factor authentication, you will be prompted to enter a token. This may be an RSA token, YubiKey, or other type of token that’s specific to your organization.

This prompt will also appear if you use a passphrase protected key instead of the default workspace key.

If no token is required, you will be connected to the cluster immediately.

Once you're logged in to the cluster, you can run workflows as well as browse, edit, and upload files using the [**Editor**](/docs/your-workspace/editor).

## Disconnecting

After you've finished utilizing the cluster, click the power button in the **Sessions** tab. A dialog box will appear. Click **Turn Off**.

A notification will appear in the bottom right corner of your screen with the message _Stopping [cluster name]_.

## Configuring Settings

Typically when you create an existing cluster, you’ll be connecting to an on-premises cluster associated with your organization. However, the instructions here for existing clusters can be used with any pre-created Slurm cluster. The settings that are specific to this type of cluster are outlined below. If you’re unsure what to choose for these options, contact your organization’s ACTIVATE administrator.

### General Settings

#### Resource Account

Use this dropdown menu to select how ACTIVATE will connect to the existing cluster.

The `User Workspace (~/ssh/pw_id_rsa)` options means that ACTIVATE will try to SSH to the cluster by using only your account’s SSH key, which is stored at `~/.ssh/pw_id_rsa`. For more information about your SSH key, see [our documentation](/docs/compute/logging-in-controller#why-dont-i-have-to-use-an-ssh-key-from-within-the-platform).

#### Jump Node

Use this toggle button if you’re connecting to a cluster that has a jump node enabled. A jump node—also called a host node, bastion node, or login node—is a high-security server that allows a user to access a private machine or network.

If you enable this feature, two new fields will appear for **Jump Node User** and **Jump Node Host**. Your organization will have these credentials if you need them.

### Cluster Configuration Settings

#### Username

Use this field to enter the username assigned to you for this cluster.

:::info Username substitution
On existing clusters, you can enter `__USER__` into any box and ACTIVATE will automatically substitute your username for that field. For example, if your username is `jdoe`, ACTIVATE will automatically substitute `__USER__` for `jdoe` in the **Working Directory** field.
:::

#### Cluster Login Node

Use this field to enter the IP address or host name of the cluster.

#### Scheduler Type

Use this dropdown menu to select the type of job scheduler the cluster uses. Currently, the **Existing Cluster** resource type supports Slurm and PBS.