Pre-Upgrade Steps for Tez

Complete the following steps before you upgrade Tez with or without the Installer.

If you made any configuration changes that you want to carry over to the next version, you need to back up the configuration properties files:

Locate the files in the /opt/mapr/tez/tez-<version>/conf/ and /opt/mapr/tez/tez-<version>/tomcat/apache-tomcat-<version>/webapps/tez-ui/config/ directories.
Copy the files to a location outside the installation directory.
Delete the old /apps/tez directory on the filesystem layer.
```
hadoop fs -rm -r /apps/tez
```
After upgrading, you can reapply changes to the updated Tez installation using the backup.

Preserving the Tez Configuration

Starting from MEP 6.0.0, Tez assists you in preserving the user configuration.

For a minor version update (for example, Tez-0.8-1803 to Tez-0.8-1808), the user configuration from a previous version is copied to a folder with an old version timestamp and also copied to a new version conf folder.
For a major version update (for example, Tez-0.8-1803 to Tez-0.9-1808), the user configuration from a previous version is only copied to a folder with an old version timestamp.
CentOS and SUSE OS
- For upgrades from MEP 3.x to MEP 6.0.0, no additional steps are needed to preserve the user configuration.
- For upgrades from MEP 4.0.0/4.1.0 to MEP 6.0.0, preserving the user configuration works only for configuration files (such as tez-site.xml and configs.js), but the Tomcat service is still present from the previous Tez version. As a precondition for upgrade from MEP 4.0.0/4.1.0, manually stop the Tomcat service and remove the tez-0.8/ directory.
- For upgrades from MEP 4.1.1/5.0.0 to MEP 6.0.0, no additional steps are needed to preserve the user configuration.
Ubuntu
- For upgrades from MEP 3.x to MEP 6.0.0, no additional steps are needed to preserve the user configuration.
- For upgrades from MEP 4.0.0/4.1.0 to MEP 6.0.0, preserving the user configuration works only for configuration files (such as tez-site.xml and configs.js), but the Tomcat service is still present from the previous Tez version. As a precondition for upgrade from MEP 4.0.0/4.1.0, manually stop the Tomcat service and remove the tez-0.8/ directory.
- For upgrades from MEP 4.1.1/5.0.0 to MEP 6.0.0, you need to preserve the user configuration manually.