Backend metrics
- Backend|System <host> on <port> are produced by the socket tracers.
- Backend|<something> (Oracle or DB2 or <a database> are produced by the SQL tracers.
Theses tracers are independent.
You could disable socket and still have JDBC metrics.
And the list could go on with
- Backend| WebServices <something> which are produced by the HTTP tracers (Generic, SOAP, Spring)
- Backend| *Messaging* (JMS tracers, APM 10.5+)