Minimum Required Role:
Limited Cluster
Administrator (also provided by Full
Administrator and Cluster
Administrator)
After creating services, you can add role instances to the services. For example, after
initial installation in which you created the HDFS service, you can add a DataNode role
instance to a host where one was not previously running. Upon upgrading a cluster to a new
version of Cloudera Runtime you might want to create a role instance for a role added in the
new version.
- Go to the service for which you want to add a role instance.
For example, to add a DataNode role instance, go to the HDFS
service.
- Click the Instances tab.
- Click the Add Role Instances button.
- Customize the assignment of role
instances to hosts. The wizard evaluates the hardware configurations
of the hosts to determine the best hosts for each role. The wizard
assigns all worker roles to the same set of hosts to which the HDFS
DataNode role is assigned. You can reassign role instances.
Click a field below a role to display a dialog box containing a
list of hosts. If you click a field containing multiple hosts, you
can also select All Hosts to assign the role to all hosts, or
Custom to display the hosts dialog box.
The following shortcuts for specifying hostname
patterns are supported:
- Range of hostnames (without the domain portion)
Range Definition |
Matching Hosts |
10.1.1.[1-4] |
10.1.1.1, 10.1.1.2, 10.1.1.3, 10.1.1.4 |
host[1-3].company.com |
host1.company.com, host2.company.com,
host3.company.com |
host[07-10].company.com |
host07.company.com, host08.company.com,
host09.company.com, host10.company.com |
- IP addresses
- Rack name
Click the View By Host button for an overview of the role
assignment by hostname ranges.
- Click
Continue.
- In the Review Changes page, review the configuration changes to
be applied.
Confirm the settings entered for file system
paths. The file paths required vary based on the services to be
installed. For example, you might confirm the NameNode Data Directory
and the DataNode Data Directory for HDFS.
- Click Continue.
The wizard finishes by performing any actions necessary to prepare the cluster for
the new role instances. For example, new DataNodes are added to the NameNode
dfs_hosts_allow.txt
file. The new role instance is configured with the
default role group for its role type, even if there are multiple role groups for the role
type. If you want to use a different role group, follow the instructions in the topic
Managing Role Groups for moving role instances to a different role
group