We are running an oracle database 19c for an healthcare customer, as a part of regular backup checks, clients logs to a customized web based (local host)application equals to OEM(oracle enterprise manager). as soon as customer logs to this application and verify the status of the database backup, the database gets hung. the healthcare app hosted on database will not respond and all the analysis running will be halted. the only way to bring back the app to work is restart the database.
tested the listener and connection is ok and listening. unable to connect to database.
ORA-12514 tns listener doesn't know the service requested in connect identifier