Important
	If you installed and manage HDP 2.2 with Ambari, you must use the Ambari Upgrade Guide to perform the HDP 2.2 to HDP 2.3.4 upgrade.

	Note
	These instructions cover the upgrade between two minor releases, such as HDP-2.2 to HDP-2.3. Component information has been updated for HDP-2.3.4 where appropriate. If you need to upgrade between two maintenance releases such as HDP-2.3.0 to 2.3.2, follow the upgrade instructions in the HDP Release Notes.

Starting with HDP 2.2, HDP 2.3.4 supports side-by-side installation of HDP 2.2 and subsequent releases, which lets you perform rolling upgrades on your cluster and improve execution times for in-place upgrade. To support side-by-side installation, the HDP package version naming convention for both RPMs and Debs has changed to include the HDP product version. For example, hadoop-hdfs is now hadoop-2.3.4-hdfs. HDP 2.2 marked the first release where HDP rpms, debs, and directories contained versions in the names to permit side-by-side installations of later HDP releases. To select from the releases you have installed side-by-side, Hortonworks provided hdp-select, a command that lets you select the active version of HDP from the versions you have installed.

Now with HDP 2.3.4, you can take advantage of this versioned installation to perform Rolling Upgrade from 2.2 to 2.3.4. However, Rolling Upgrade involves complex orchestration as well as side-by-side installation. It is too complex for a manual procedure, and is therefore supported only as an Ambari feature. If you wish to perform a Rolling Upgrade, refer to the Ambari Install instructions to install Ambari, then follow the Ambari Rolling Upgrade instructions, see Ambari Upgrade Guide.

This chapter provides instructions on how to manually upgrade to HDP 2.3.4 from the HDP 2.2 release. It assumes the existing HDP 2.2 was also installed manually.

The HDP packages for a complete installation of HDP 2.3.4 will occupy about 2.5 GB of disk space.

	Warning
	Until the upgrade is finalized, no HDFS data is deleted from the cluster. Be sure to review your capacity and ensure that you have extra space available during the upgrade window.

The following provides an overview of steps for upgrading to the latest release of HDP 2.3.4 from HDP 2.2: