Account locking in an Active Data Guard environment

During the Data Guard round table of the excellent UKOUG Tech18 conference I got aware of this topic that I’d like to share with the Oracle community:

What is the locking behavior for user accounts in an environment where users may connect to the primary as well as to the standby database?

User gets locked on the primary

SQL> alter profile default limit failed_login_attempts 2;

Profile altered.

SQL> create user adam identified by adam;

User  (more...)