The Ambari install wizard installs all available Hadoop services by default. You may choose to deploy only some services initially, then add other services at later times. For example, many customers deploy only core Hadoop services initially. Add Service supports deploying additional services without interrupting operations in your Hadoop cluster. When you have deployed all available services, Add Service displays disabled.
For example, if you are using HDP 2.1 Stack and did not install Falcon or Storm, you can use the Add Service capability to add those services to your cluster.
![[Note]](../common/images/admon/note.png) | Note |
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After installing Storm via Ambari, you should configure the Storm service to run as a supervised service. For more information, see Configuring Storm for Supervision. |
To add a service, select Actions -> Add Service, then complete the following procedure using the Add Service Wizard.
This example shows the Falcon service selected for addition.
Choose Services.
Choose an available service. Alternatively, choose all to add all available services to your cluster. Then, choose Next.
The Add Services wizard displays installed services highlighted green and marked unavailable for selection.
In Assign Masters, confirm the default host assignment. Alternatively, choose a different host machine to which master components for your selected service will be added. Then, choose Next.
The Add Services Wizard indicates hosts on which the master components for a chosen service will be installed. A service chosen for addition displays as:
A green label located on the host to which its master components will be added, or
An active drop-down list on which available host names appear.
Using the drop-down, choose an alternate host name, if necessary.
In Assign Slaves and Clients, accept the default assignment of slave and client components to hosts. Then, choose Next.
Alternatively, select hosts to which you want to assign slave and client components.
You must select at least one host for the slave of each service being added.
Table 2.5. Host Roles Required for Added Services Service Added Host Role Required MapReduce TaskTracker YARN NodeManager HBase RegionServer The Add Service Wizard skips and disables the Assign Slaves and Clients step for a service requiring no slave nor client assignment.
In Customize Services, accept the default configuration properties. Then, choose Next.
Alternatively, edit the default values for configuration properties, if necessary.
Choose Override to create a configuration group for this service.
In Review, make sure the configuration settings match your intentions. Then, choose Deploy.
Monitor the progress of installing, starting, and testing the service. When the service installs and starts successfully, choose Next.
Summary displays the results of installing the service. Choose Complete.
Restart the Nagios service and any other components having stale configurations.
![[Important]](../common/images/admon/important.png) | Important |
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If you do not restart Nagios service after completing the Add Service Wizard, alerts and notifications may not work properly. |
