SQL Developer allows to open so-called "unshared connection". It's another connection with the same name to the same database but as independent session. Those connections are not polled by keepalive plugin. It's easy to see in logs, because if you have one standard connection and one unshared then only one info message "successfully kept alive!" is presented during keep alive cycle.
There should exists some method of getting a list of opened unshared connections, because SQL Developer has dialogue window asking about closing them when you're going to close a standard one. So it look like there is a way of tracking them in some way.
SQL Developer allows to open so-called "unshared connection". It's another connection with the same name to the same database but as independent session. Those connections are not polled by keepalive plugin. It's easy to see in logs, because if you have one standard connection and one unshared then only one info message "successfully kept alive!" is presented during keep alive cycle.
There should exists some method of getting a list of opened unshared connections, because SQL Developer has dialogue window asking about closing them when you're going to close a standard one. So it look like there is a way of tracking them in some way.