Nagios assumes that DataNode is deployed on all the host machine in your cluster.
The Nagios server displays DataNode alert on all the host machines even if a particular slave machine does not host a DataNode daemon.
Ambari user interface (UI) allows adding existing properties to custom
core-site.xmlandhdfs-site.xmlsettings. For more information, see AMBARI-2313
For more information on the specific issues for Ambari, see Troubleshooting - Specific Issues section.
