Ambari-managed host participation

When you use Ambari to configure manage.include.file properities for HDFS and YARN, Ambari manages how hosts for each component participate in the cluster when you add, delete, or decommission a component.

You can configure Ambari to manage the hosts that participate in a cluster for both YARN and HDFS services. You can enable this feature only for HDFS or for YARN, or for both services. When enabled, Ambari manages files included and excluded and updates their contents based on the state of hosts as displayed in Ambari Web. When files changes occur, Ambari calls the necessary refreshNodes commands to update the DataNode, NameNode, and ResourceManager host states as necessary.

Table 1. User Actions, Ambari Operations, and Automated Tasks
User Action	Ambari Operation	Include File Action	Exclude File Action	Refresh Nodes Call	Triggers Master Restart Indicator
Add a NodeManager or DataNode	Add Component	Add hostname	Remove hostname	Yes	No
Remove a NodeManager or DataNode	Delete Component	Remove hostname	Remove hostname	No	No
Decommission a NodeManager or DataNode	Decommission Component	Remove hostname (YARN only)	Add hostname	Yes	No
Recommission a NodeManager or DataNode	Recommission Component	Add hostname (YARN only)	Remove hostname	Yes	No