Prerequisites

To perform an HDF upgrade using Ambari, your cluster must meet the following prerequisites. These prerequisites are required because they allow Ambari to know whether the cluster is in a healthy operating mode and can be successfully managed from Ambari.

Table 1. Ambari-managed HDF Upgrade Prerequisites
Prerequisite	Description
Disk Space	Be sure to have adequate space on `/usr/hdf` for the target HDF installation.
Ambari Agent Heartbeats	All Ambari Agents must be communicating and heartbeating to Ambari Server. Any hosts that are not heartbeating must be in Maintenance Mode.
Host Maintenance Mode	The following two scenarios are checked: Any hosts in Maintenance Mode must not be hosting any Service Master Components. Any host in Maintenance Mode that is not hosting Master Components is allowed but you will receive a warning. You can proceed with your upgrade but these hosts will not be upgraded and before you can finalize the upgrade, you must delete the hosts from the cluster.
Service Maintenance Mode	No Services can be in Maintenance Mode.
Services Started	All Services must be started.
Service Checks	All Service Checks must pass. Be sure to run Service Actions > Run Service Check on all services (and remediate if necessary) prior to attempting an HDF upgrade.