Custom Configuration

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

Cloudera Manager exposes properties that allow you to insert custom configuration text into XML configuration, property, and text files, or into an environment. The naming convention for these properties is: XXX Advanced Configuration Snippet (Safety Valve) for YYY or XXX YYY Advanced Configuration Snippet (Safety Valve), where XXX is a service or role and YYY is the target.

The values you enter into a configuration snippet must conform to the syntax of the target. For an XML configuration file, the configuration snippet must contain valid XML property definitions. For a properties file, the configuration snippet must contain valid property definitions. Some files simply require a list of host addresses.

The configuration snippet mechanism is intended for use in cases where there is configuration setting that is not exposed as a configuration property in Cloudera Manager. Configuration snippets generally override normal configuration. Contact Cloudera Support if you are required to use a configuration snippet that is not explicitly documented.

Service-wide configuration snippets apply to all roles in the service; a configuration snippet for a role group applies to all instances of the role associated with that role group.

There are configuration snippets for servers and client configurations. In general after changing a server configuration snippet you must restart the server, and after changing a client configuration snippet you must redeploy the client configuration. Sometimes you can refresh instead of restart. In some cases however, you must restart a dependent server after changing a client configuration. For example, changing a MapReduce client configuration marks the dependent Hive server as stale, which must be restarted. The Admin Console displays an indicator when a server must be restarted. In addition, the All Configuration Issues tab on the Home page lists the actions you must perform to propagate the changes.

Configuration Snippet Types and Syntax

Type Description Syntax
Configuration Set configuration properties in various configuration files; the property name indicates into which configuration file the configuration will be placed. Configuration files have the extension .xml or .conf.

For example, there are several configuration snippets for the Hive service. One Hive configuration snippet property is called the HiveServer2 Advanced Configuration Snippet for hive-site.xml; configuration you enter here is inserted verbatim into the hive-site.xml file associated with the HiveServer2 role group.

To see a list of configuration snippets that apply to a specific configuration file, enter the configuration file name in the Search field in the top navigation bar. For example, searching for mapred-site.xml shows the configuration snippets that have mapred-site.xml in their name.

For example, to specify a MySQL connector library, put this property definition in that configuration snippet:
Environment Specify key-value pairs for a service, role, or client that are inserted into the respective environment.

One example of using an environment configuration snippet is to add a JAR to a classpath. Place JARs in a custom location such as /opt/myjars and extend the classpath via the appropriate service environment configuration snippet. The value of a JAR property must conform to the syntax supported by its environment. See Setting the class path.

Do not place JARs inside locations such as /opt/cloudera or /usr/lib/{hadoop*,hbase*,hive*,etc.} that are managed by Cloudera because they are overwritten at upgrades.

For example, to add JDBC connectors to a Hive gateway classpath, add
to Gateway Client Advanced Configuration Snippet for
Logging Set log4j properties in a file.
For example:
log4j.rootCategory=INFO, console
Metrics Set properties to configure Hadoop metrics in a or file.
For example:
White and black lists Specify a list of host addresses that are allowed or disallowed from accessing a service.

Setting an Advanced Configuration Snippet

  1. Click a service.
  2. Click the Configuration tab.
  3. In the Search box, type Advanced Configuration Snippet.
  4. Choose a property that contains the string Advanced Configuration Snippet (Safety Valve).
  5. Specify the snippet properties.
  6. Click Save Changes to commit the changes.
  7. Restart the service or role or redeploy client configurations as indicated.

Setting Advanced Configuration Snippets for a Cluster or Clusters

  1. Do one of the following
    • specific cluster
      1. On the Home > Status tab, click a cluster name.
      2. Select Configuration > Advanced Configuration Snippets.
    • all clusters
      1. Select Configuration > Advanced Configuration Snippets.
  2. Specify the snippet properties.
  3. Click Save Changes to commit the changes.
  4. Restart the service or role or redeploy client configurations as indicated.