Perform Express Upgrade

Ambari checks that your cluster meets prerequisites. A dialog displays the results:

If any required prerequisites are not met, the result displays an error.
You cannot proceed with the upgrade until you make the appropriate corrections and return to Perform Upgrade again.
If any optional prerequisites are not met, the result displays a warning.
You may proceed with the upgrade.
Ambari displays a list of configuration changes that occur during the upgrade.

When the prerequisite checks complete, the upgrade starts. The time required to perform the upgrade depends on many factors. As part of the upgrade process, each component in the cluster restarts in a serial fashion. The stop/start times contribute to the total upgrade time.

The upgrade process includes the following stages. Some stages require that you complete an action during normal operation.

If any stage fails, the upgrade stops and prompts you for action.

Stage	Description	Action Required
Prepare Upgrade	You should stop all apps on YARN queues, and deactivate & kill all running Storm topologies. If you have any applications running on Slider, it is recommended to stop them, since Slider would be removed as part of the Upgrade process.	Perform the actions to prepare for the upgrade.
Stop Components for High-Level Services	This will stop all components for High-Level Services. This includes all master components except those of HDFS, HBase, ZooKeeper and Ranger.	None
Perform Backups	This step prompts you to confirm that you have taken proper backups before proceeding.	You must acknowledge the prompt for database backups.
Stop Components for Core Service	Stops all components with HDFS, HBase, ZooKeeper and Ranger.	None
Update Target Respository	Updates the stack version in Ambari to the target version.	None
Add New YARN Components	In HDP 3.0, there are two new YARN components: YARN Registry DNS, and Timeline Reader. Both of these components are automatically added to the cluster.	None
Update Service Configs	Updates (i.e. transfers or replaces) any configurations that are necessary for the upgrade.	None
Restart Components	Restarts all core components such as ZooKeeper, Ranger, HDFS, YARN, MapReduce2 and various Clients (Tez, Pig, Sqoop).	In an SSO-enabled cluster: If the cookie is lost/session is expired:client should use local login to access the Ambari and proceed further. For example: <ambari_host:ambari_port>/#/login/local
All Service Checks	All Service Checks are performed against the cluster.	Any service check that fails prompts you to Ignore and Continue, Downgrade or Retry. If you selected the Skip all Service Check failures option, you will only be prompted when all Service Checks complete.
Restart Components	Restarts the remaining components such as Oozie, Hive, Spark2 and others.	None
Set Version on All Hosts	Sets the HDP version on all hosts to the target HDP version.	None
Finalize Upgrade Pre-Check	Checks if any hosts were not upgraded, either because the host was in Maintenance Mode, or one or more components on the host failed to upgrade (and were skipped).	Click the list that displays # hosts for details on the hosts (and their components) that are not upgraded. You can Pause Upgrade, delete the hosts and return to finalize.
Finalize Upgrade	The component upgrades are complete. You are presented the option to Finalize, which when selected, completes the upgrade process + saves the cluster state.	When prompted to remove hbase snapshots, look for snapshots matching $TABLE-ru-$TIMESTAMP Prompted to Finalize or Finalize Later or Downgrade.

When the upgrade stages complete, you may choose to Finalize the upgrade, or to Finalize Later. Finalizing later gives you a chance to perform more validation on the cluster.

	Note
	If you choose to finalize later, both versions will be listed on the Stack and Versions tab with the starting version displaying as Current. It is not until you finalize that Ambari makes the target version the current version. Also, until you finalize, you will not be able to perform operational changes to the cluster (such as move components, change configurations, etc).

Click Finalize to complete the express upgrade process.

​Perform Express Upgrade