Starting with Oracle Database 12c release 2 (12.2), Oracle Data Guard Broker has more features to assist rolling upgrades.
Oracle Data Guard Broker now supports Oracle Active Data Guard rolling upgrade. Oracle Active Data Guard rolling upgrade was introduced in Oracle Database 12c release 1 (12.1). It simplifies the execution of the transient logical database rolling upgrade process by automating many manual steps in a simple PL/SQL package (DBMS_ROLLING). In addition to making database rolling upgrades simpler, the automated process is much more reliable. Oracle Data Guard broker can now direct Oracle Active Data Guard rolling upgrades from the DGMGRL command-line interface. Broker support also adds substantial simplification to the rolling upgrade process by transparently handling redo transport destination settings and other tasks.
In Oracle Database 12c release 2 (12.2) and later releases, when you perform a rolling upgrade using the DBMS_ROLLING PL/SQL package, you no longer have to disable the broker. In addition, the broker now reports when a rolling upgrade is in place, and tracks its status. The status information is displayed in the output of the DGMGRL commands SHOW CONFIGURATION and SHOW DATABASE.
Using Oracle Data Guard Broker to manage database rolling upgrades can simplify the upgrade process by minimizing your downtime and risk when introducing change to production environments.