Decommission NodeManagers

Edit the configuration files on the ResourceManager host machine and add the details of the new set of NodeManagers.

Use the following instructions to decommission NodeManagers in your cluster:

On the ResourceManager host machine, edit the <HADOOP_CONF_DIR>/yarn.exclude file and add the list of NodeManager hostnames (separated by a newline character).
where <HADOOP_CONF_DIR> is the directory for storing the Hadoop configuration files. For example, /etc/hadoop/conf.

If your cluster utilizes a yarn.include file, remove the decommissioned nodes from the <HADOOP_CONF_DIR>/yarn.include file on the ResourceManager host machine.

	Note
	If no `yarn.include` file is specified, all NodeManagers are considered to be included in the cluster (unless excluded in the `yarn.exclude` file). `The yarn.resourcemanager.nodes.include-path` and `yarn.resourcemanager.nodes.exclude-path` properties in `yarn-site.xml` are used to specify the `yarn.include` and `yarn.exclude` files.

Update the ResourceManager with the new set of NodeManagers. On the ResourceManager host machine, execute the following command:
```
su <YARN_USER>
yarn rmadmin -refreshNodes
```
where <YARN_USER> is the user who owns the YARN services, for example, yarn.