Modifying Configuration Properties Using Cloudera Manager

Minimum Required Role: Configurator (also provided by Cluster Administrator, Full Administrator)

When a service is added to Cloudera Manager, either through the installation or upgrade wizard or with the Add Services workflow, Cloudera Manager automatically sets the configuration properties, based on the needs of the service and characteristics of the cluster in which it will run. These configuration properties include both service-wide configuration properties, as well as specific properties for each role type associated with the service, managed through role groups. A role group is a set of configuration properties for a role type, as well as a list of role instances associated with that group. Cloudera Manager automatically creates a default role group named Role Type Default Group for each role type. See Role Groups.

Changing the Configuration of a Service or Role Instance

  1. Go to the service status page. (Cluster > service name)
  2. Click the Configuration tab.
  3. Locate the property you want to edit. You can type all or part of the property name in the search box, or use the filters on the left side of the screen:
    • The Status section limits the displayed properties by their status. Possible statuses include:
      • Error
      • Warning
      • Edited
      • Non-default
      • Has Overrides
    • The Scope section of the left hand panel organizes the configuration properties by role types; first those that are Service-Wide, followed by various role types within the service. When you select one of these roles, a set of properties whose values are managed by the default role group for the role display. Any additional role groups that apply to the property also appear in this panel and you can modify values for each role group just as you can the default role group.

    • The Category section of the left hand panel allows you to limit the displayed properties by category.

  4. Edit the property value.
    • To facilitate entering some types of values, you can specify not only the value, but also the units that apply to the value. for example, to enter a setting that specifies bytes per second, you can choose to enter the value in bytes (B), KiBs, MiBs, or GiBs—selected from a drop-down menu that appears when you edit the value.
    • If the property allows a list of values, click the icon to the right of the edit field to add an additional field. An example of this is the HDFS DataNode Data Directory property, which can have a comma-delimited list of directories as its value. To remove an item from such a list, click the icon to the right of the field you want to remove.

    Many configuration properties have different values that are configured by multiple role groups. (See Role Groups).

    To edit configuration values for multiple role groups:
    1. Go to the property, For example, the configuration panel for the Heap Dump Directory property displays the DataNode Default Group (a role group), and a link that says ... and 6 others.

    2. Click the ... and 6 others link to display all of the role groups:

    3. Click the Show fewer link to collapse the list of role groups.

      If you edit the single value for this property, Cloudera Manager applies the value to all role groups. To edit the values for one or more of these role groups individually, click Edit Individual Values. Individual fields display where you can edit the values for each role group. For example:

  5. Click Save Changes to commit the changes. You can add a note that is included with the change in the Configuration History. This changes the setting for the role group, and applies to all role instances associated with that role group. Depending on the change you made, you may need to restart the service or roles associated with the configuration you just changed. Or, you may need to redeploy your client configuration for the service. You should see a message to that effect at the top of the Configuration page, and services will display an outdated configuration (Restart Needed),(Refresh Needed), or outdated client configuration indicator. Click the indicator to display the Stale Configurations page.

Searching for Properties

You can use the Search box to search for properties by name or label. The search also returns properties whose description matches your search term.

Validation of Configuration Properties

Cloudera Manager validates the values you specify for configuration properties. If you specify a value that is outside the recommended range of values or is invalid, Cloudera Manager displays a warning at the top of the Configuration tab and in the text box after you click Save Changes. The warning is yellow if the value is outside the recommended range of values and red if the value is invalid.

Overriding Configuration Properties

For role types that allow multiple instances, each role instance inherits its configuration properties from its associated role group. While role groups provide a convenient way to provide alternate configuration properties for selected groups of role instances, there may be situations where you want to make a one-off configuration change—for example when a host has malfunctioned and you want to temporarily reconfigure it. In this case, you can override configuration properties for a specific role instance:
  1. Go to the Status page for the service whose role you want to change.
  2. Click the Instances tab.
  3. Click the role instance you want to change.
  4. Click the Configuration tab.
  5. Change the configuration values as appropriate.
  6. Save your changes.

You will most likely need to restart your service or role to have your configuration changes take effect. See Stale Configuration Actions.

Viewing and Editing Overridden Configuration Properties

To see a list of all role instances that have an override value for a particular configuration setting, go to the Status page for the service and select Status > Has overrides. A list of configuration properties where values have been overridden displays. The panel for each configuration property displays the values for each role group or instance. You can edit the value of this property for this instance, or, you can click the icon next to an instance name to remove the overridden value.

Resetting Configuration Properties to the Default Value

To reset a property back to its default value, click the icon. The default value is inserted and the icon turns into an Undo icon (). Explicitly setting a configuration to the same value as its default (inherited value) has the same effect as using the icon.

There is no mechanism for resetting to an autoconfigured value. However, you can use the configuration history and rollback feature to revert any configuration changes.

Viewing and Editing Host Overrides

You can override the properties of individual hosts in your cluster.

  1. Click the Hosts tab.
  2. Click the Configuration tab.
  3. Use the Filters or Search box to locate the property that you want to override.
  4. Click the Manage Host Overrides link.

    The Manage Overrides dialog box displays.

  5. Select one or more hosts to override this property.
  6. Click Update.

    A new entry area displays where you can enter the override values. In the example below, servers and were selected for overrides. Note that the first set of fields displays the value set for all hosts and the two sets of fields that follow allow you to edit the override values for each specified host.

    To remove the override, click the

    icon next to the hostname.

    To apply the same value to all hosts, click Edit Identical Values. Click Edit Individual Values to apply different values to selected hosts.

  7. If the property indicates Requires Agent Restart, restart the agent on the affected hosts.

Restarting Services and Instances after Configuration Changes

If you change the configuration properties after you start a service or instance, you may need to restart the service or instance to have the configuration properties become active. If you change configuration properties at the service level that affect a particular role only (such as all DataNodes but not the NameNodes), you can restart only that role; you do not need to restart the entire service. If you changed the configuration for a particular role instance (such as one of four DataNodes), you may need to restart only that instance.
  1. Follow the instructions in Restarting a Service or Starting, Stopping, and Restarting Role Instances.
  2. If you see a Finished status, the service or role instances have restarted.
  3. Go to the Home > Status tab. The service should show a Status of Started for all instances and a health status of Good.
For more information, see Stale Configurations.

Suppressing Configuration and Parameter Validation Warnings

You can suppress the warnings that Cloudera Manager issues when a configuration value is outside the recommended range or is invalid. If a warning does not apply to your deployment, you might want to suppress it. Suppressed validation warnings are still retained by Cloudera Manager, and you can unsuppress the warnings at any time. You can suppress each warning when you view it, or you can configure suppression for a specific validation before warnings occur.

Suppressing a Configuration Validation in Cloudera Manager

  1. Click the Suppress... link to suppress the warning.

    A dialog box opens where you can enter a comment about the suppression.

  2. Click Confirm.

You can also suppress warnings from the All Configuration Issues screen:

  1. Browse to the Home screen.
  2. Click Configurations > Configuration Issues.
  3. Locate the validation message in the list and click the Suppress... link.

    A dialog box opens where you can enter a comment about the suppression.

  4. Click Confirm.

The suppressed validation warning is now hidden.

Managing Suppressed Validations

On pages where you have suppressed validations, you see a link that says Show # Suppressed Warning(s). On this screen, you can:
  • Click the Show # Suppressed Warning(s) link to show the warnings.

    Each suppressed warning displays an icon: .

  • Click the Unsuppress... link to unsuppress the configuration validation.
  • Click the Hide Suppressed Warnings link to re-hide the suppressed warnings.

Suppressing Configuration Validations Before They Trigger Warnings

  1. Go to the service or host with the configuration validation warnings you want to suppress.
  2. Click Configuration.
  3. In the filters on the left, select Category > Suppressions.

    A list of suppression properties displays. The names of the properties begin with Suppress Parameter Validation or Suppress Configuration Validator. You can also use the Search function to limit the number of properties that display.

  4. Select a suppression property to suppress the validation warning.
  5. Enter a Reason for change, and then click Save Changes to commit the changes.

Viewing a List of All Suppressed Validations

Do one of the following:
  • From the Home page or the Status page of a cluster, select Configuration > Suppressed Health and Configuration Issues.
  • From the Status page of a service, select Configuration > Category > Suppressions and select Status > Non-default.
  • From the Host tab, select Configuration > Category > Suppressions and select Status > Non-default.