1. Preparing to Upgrade

Be sure to review the Release Notes for this Ambari release for Known Issues and Behavioral Changes.
You must have root, administrative, or root-equivalent authorization on the Ambari server host and all servers in the cluster.
You must backup the Ambari Server database.
You must make a safe copy of the Ambari Server configuration file found at /etc/ambari-server/conf/ambari.properties.
Plan to upgrade the Ambari Metrics service:
- Record the location of the Metrics Collector component before you begin the upgrade process.
- You must stop the Ambari Metrics service from Ambari Web.
- After upgrading Ambari, you must also Upgrade Ambari Metrics service and add the Grafana component.
Proceed to Upgrade to Ambari 2.4.
After upgrading Ambari, you must also Upgrade Hortonworks SmartSense.

	Important
	If your current Ambari version is 1.7 or below, you must upgrade the Ambari Server version to 2.2 before upgrading to version 2.4.

	Note
	During Ambari upgrade, the existing `/var/lib/ambari-server/ambari-env.sh` file is overwritten and a backup copy of `ambari-env.sh` (with extension `.rpmsave`) is created. If you have manually modified `ambari-env.sh` (for example, to change Ambari Server heap), you will need to re-apply your changes to the new file.

​1. Preparing to Upgrade