Prior to update (20.4.0), we observed the data_engine probe periodic hang ups. It would stop forwarding queue messages and become 'yellow' in the Hub status.
After installing the update, which went very smooth, the data_engine hang ups became much more frequent. The probe currently hangs like this multiple times per day, once every few hours.
I attached data_engine log taken during the hung state.
Release : 20.4
https://techdocs.broadcom.com/us/en/ca-enterprise-software/it-operations-management/unified-infrastructure-management/20-4/installing/pre-installation-planning/install-and-configure-your-database-software/oracle.html
update Oracle DB
processes = 1600
sessions = 2200
and make sure you are using the correct version of Oracle Instant Client.