Remove Existing Collections and Upgrade Binaries

Once the data has been backed up, the old collections need to be deleted, and the Ambari Infra Solr, and Log Search (if installed) components need to be upgraded.

To do all of that, run the following script:
/usr/lib/ambari-infra-solr-client/ \
--mode delete | tee delete_output.txt

During this process, the script generates Ambari tasks that are visible in the Background Operations dialog in the Ambari Server.

After the process has completed, retain the output of the script for your records. This output is helpful when debugging any issues that may occur during the migration process.