Steps to reproduce:
If password for DB user in Oracle is almost expired then we get warning about that.

15743:20171203:182108.904 [Z3001] connection to database '//localhost:1521/zabbix.db.rbs' failed: [1] ORA-28002: ???? ???????? ?????? ??????? ? ??????? 5 ????

Looks like we don't have processing for ORA-28002 which leads to busy process.

In this case, Housekeeper that was disabled in frontend went 100% busy.

Only housekeeper was affected probably because of new connections to the database.
If connections from other processes would reset I think that would be a blocker.