Instructions from the manual are not clear or easy to follow for DC, "
Upgrades to the Data Collector
The data collector upgrade process backs up the <DC_installation_directory>/<apache-karaf-version>
directory to the <DC_installation_directory>/backup/apache-karaf directory. It also backs up the
customizations that are located in the <DC_installation_directory>/<apache-karaf-version>/etc/
directory, such as default logging levels or other configurations, but it does not restore them to the installation directory
automatically. To avoid losing these customizations, restore these customizations manually.
If you are upgrading from a version with apache-karaf-2.4.3 to apache-karaf-4.2.6, to avoid to the data
aggregator and data collector from failing to start properly, reapply the customizations manually using log4j2
property file syntax.
For more information, see the log4j site.
Do not copy files with log4j.logger entries into the etc directory.
The installation directory for the data collecter.
The installation directory for Apache Karaf
Release : 20.2
This section refers solely to the org.ops4j.pax.logging.cfg file. The format of the file changed totally, so any debug enabled before will need to be reapplied using the new format. Do not copy from the pre-4.2.x org.ops4j.pax.logging.cfg to the new directory structure.