As Release Automation is DB intrinsic application it basically on startup do various write operation to DB around actions sync, last-access time, active-inactive node update etc. The RA application on startup expect the connection to the DB is stable and connected. As per errors observed in nolio_dm_all.log
2019-01-31 14:33:52,795 [localhost-startStop-1] WARN (org.hibernate.engine.jdbc.spi.SqlExceptionHelper:143) - SQL Error: 16000, SQLState: 72000
2019-01-31 14:33:52,796 [localhost-startStop-1] ERROR (org.hibernate.engine.jdbc.spi.SqlExceptionHelper:144) - ORA-16000: database or pluggable database open for read-only access
2019-01-31 14:33:52,796 [localhost-startStop-1] WARN (org.hibernate.engine.jdbc.spi.SqlExceptionHelper:143) - SQL Error: 16000, SQLState: 72000
2019-01-31 14:33:52,796 [localhost-startStop-1] ERROR (org.hibernate.engine.jdbc.spi.SqlExceptionHelper:144) - ORA-16000: database or pluggable database open for read-only access
2019-01-31 14:33:52,798 [localhost-startStop-1] ERROR (org.hibernate.engine.jdbc.batch.internal.BatchingBatch:119) - HHH000315: Exception executing batch [ORA-16000: database or pluggable database open for read-only access]
2019-01-31 14:33:52,799 [localhost-startStop-1] ERROR (com.nolio.platform.server.dataservices.services.hibernate.NolioHibernateTemplate:195) - Caught hibernate exception.
org.hibernate.QueryTimeoutException: ORA-16000: database or pluggable database open for read-only access
In aligned to ORA 16000 error, cause is "Most prominent cause is that database is physical standby which is READ ONLY mode. The only operation allowed is select in this mode. If you want to do any changes then you need to change mode to READ WRITE and recreate your standby database. Else do the changes on primary database which will reflect the changes on Standby database."
So, I think it is something related to your environment and the way DB is configured. Can you please check with your DBA on the database setup for the Release Automation in relation to DR environment setup. Also as you mentioned you want to connect to raprddb instance for testing, I leave it to your choice, but the issue is more around your DB setup and you need to consult your DB administrators.