Reply To: Editing ambari postgres database

Instead of modifying the Ambari database directly, do you want to set those configuration values via the Ambari REST API?

https://github.com/apache/ambari/blob/trunk/ambari-server/docs/api/v1/configuration.md

Alternatively, ambari ships with a script (/var/lib/ambari-server/resources/scripts/configs.sh) that uses this REST API and is useful to do simple config changes.

Note: you are correct that if you go onto machines directly and modify yarn-site or other config files that ambari is managing, those changes will be overwritten. You’ll want to make sure the configs you want are set in Ambari so it pushes out the changes to the files.