Adding a Host to a Cluster

Disable TLS Encryption or Authentication

If you have enabled TLS encryption or authentication for the Cloudera Manager Agents, you must disable both of them before starting the Add Hosts wizard. Otherwise, skip to the next step.

1. From the Administration tab, select Settings.
2. Select the Security category.
3. Disable TLS by clearing the following options: Use TLS Encryption for Agents, and Use TLS Authentication of Agents to Server.
4. Click Save Changes to save the settings.
5. Log in to the Cloudera Manager Server host.
6. Restart the Cloudera Manager Server.

   sudo systemctl restart cloudera-scm-server

Alternate Method of Installing Cloudera Manager Agent without Disabling TLS

Add Hosts to an Existing Cluster

1. Click the Hosts tab.
2. Click the Add Hosts button.
3. Select Add hosts to cluster.
4. If the cluster uses Kerberos authentication, ensure that the Kerberos packages are installed on the new hosts. If necessary, use the package commands provided on the Add Hosts screen to install these packages.
5. Select the cluster where you want to add the host from the drop-down list.
6. Click Continue.

   The Specify Hosts page displays. You can either add a new host to the cluster, or add an existing managed host to the cluster.

   Do one of the following:

   • Add a new host:
     1. On the Specify Hosts page, enter a host name or pattern (click "using patterns" for more information) to search for new hosts to add to the cluster.

        A list of matching hosts displays.

     2. Select the hosts that you want to add.
     3. Click Continue.
     4. Select the Repository Location where Cloudera Manager can find the software to install on the new hosts. Select Public Cloudera Repository or Custom Repository and enter the URL of a custom repository available on your local network.
     5. Click Continue.
     6. Follow the instructions in the wizard to install the Oracle JDK.
     7. Enter Login Credentials:
        1. Select root for the root account, or select Another user and enter the username for an account that has password-less sudo privileges.
        2. Select an authentication method:
           • If you choose password authentication, enter and confirm the password.
           • If you choose public-key authentication, provide a passphrase and path to the required key files.

           You can modify the default SSH port if necessary.

        3. Specify the maximum number of host installations to run at once. The default and recommended value is 10. You can adjust this based on your network capacity.
        4. Click Continue.

           The Install Agents page displays and Cloudera Manager installs the Agent software on the new hosts.

        5. When the agent installation finishes, click Continue.
   • Add an existing managed host:
     1. Click the Currently Managed Hosts tab.

        A list of hosts previously added to Cloudera Manager displays.

     2. Select the hosts that you want to add to the cluster.
     3. Click Continue.
7. Cloudera Manager begins to install the Cloudera Runtime parcels.
8. When the parcel installation finishes, click Continue.
9. The Host Inspector runs and displays any problems with the hosts. Correct the problems before continuing.
10. After correcting any problems, click Continue.
11. To add role instances to the hosts now or select None to add them later.
12. To add roles now:
    1. Select an existing host template, or create a new one.
    2. To create a new host template, click the Create... button. The Create New Host Template screen opens.. See Host Templates for details on how you select the role groups that define the roles that should run on a host. After you have created the template, it will appear in the list of host templates from which you can choose.
    3. Select the host template you want to use.
    4. By default Cloudera Manager will automatically start the roles specified in the host template on your newly added hosts. To prevent this, uncheck the option to start the newly-created roles.
13. When the wizard is finished, you can verify the Agent is connecting properly with the Cloudera Manager Server by clicking the Hosts tab and checking the health status for the new host. If the Health Status is Good and the value for the Last Heartbeat is recent, then the Agent is connecting properly with the Cloudera Manager Server.

If you did not specify a host template during the Add Hosts wizard, then no roles will be present on your new hosts until you add them. You can do this by adding individual roles under the Instances tab for a specific service, or by using a host template. See Adding a Role Instance for information about adding roles for a specific service. See Host Templates to create a host template that specifies a set of roles (from different services) that should run on a host.

Add New Hosts To Cloudera Manager

This option allows you to add a host, but without adding them to a specific cluster. Later, you can use these hosts to create new clusters or expand existing clusters.

Enable TLS Encryption or Authentication

If you previously enabled TLS security on your cluster, you must re-enable the TLS options on the Administration page and also configure TLS on each new host after using the Add Hosts wizard. Otherwise, you can ignore this step. For instructions, see Configuring TLS Encryption for Cloudera Manager and CDH Using Auto-TLS.

Enable TLS/SSL for cluster Components

If you have previously enabled TLS/SSL on your cluster, and you plan to start these roles on this new host, make sure you install a new host certificate to be configured from the same path and naming convention as the rest of your hosts. Since the new host and the roles configured on it are inheriting their configuration from the previous host, ensure that the keystore or truststore passwords and locations are the same on the new host. For instructions on configuring TLS/SSL, see Configuring TLS Encryption for Cloudera Manager and CDH Using Auto-TLS.

Enable Kerberos