# Addding monitorable components

Once you’ve installed the CMC, you may want to want to add Caplin components to monitor, in addition to the components that you configured using the `./dfw mon` command (Liberator and optionally Transformer).

## Requirements

Before you can use the CMC to monitor a component, you must activate the component’s JMX interface. For more information, see [Activating a component’s JMX interface](activating-component-jmx-interface.md).

## Adding a component

Follow the steps below:

1. Open the CMC overview screen:

   ![CMC-Detail-Screen-Liberator_2](../../images/CMC-Detail-Screen-Liberator_2.png)
2. Right-click in any free area of the main pane, and then select the **Add New DataSource...** option. The **DataSource Properties** dialog appears:

   ![datasourcePropertiesDialogbox](../../images/datasourcePropertiesDialogbox.png)
3. Complete the dialog’s fields:

   | Field name | Description |
   | --- | --- |
   | **Name** | Free text name for the component. |
   | **Host** | IP address or host name of the machine that the component is running on. |
   | **Port** | The port number of the DataSource’s Java RMI registry, as configured by the DataSource’s [rmi-registry-port](../datasource/datasource-datasource-monitoring-configuration-part-1.md#rmi-registry-port) configuration option. |
   | **Use Local Credentials** | Authenticate using local credentials. Specify the monitoring credentials in the **Username** and **Password** fields. |
   | **Use Global Credentials** | Authenticate using global credentials. Select the credentials from the dropdown. To manage global credentials, click **File > Credentials**. |
4. Click **OK**.

## Troubleshooting

If both the CMC and the relevant Caplin component have been configured correctly, then your new monitorable component should display as a blue rectangle.

If your new component is red rather than blue, then it could be for one of the following reasons:

* The component is not running.
* Your credentials are not correct. Check the component’s [add-monuser](../datasource/datasource-datasource-monitoring-configuration-part-1.md#add-monuser) configuration item for the correct credentials to use.
* The DataSource component’s Java RMI ports are blocked by a firewall between the component and the CMC.
* The DataSource component’s Java RMI hostname has defaulted to 'localhost' and the component is running on a different host to the CMC. For information on setting the Java RMI hostname, see [Activating a component’s JMX interface](activating-component-jmx-interface.md).

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**See also**:

* [DataSource > Monitoring configuration 1](../datasource/datasource-datasource-monitoring-configuration-part-1.md)
* [DataSource > Monitoring configuration 2](../datasource/datasource-datasource-monitoring-configuration-part-1.md)