The features similar to Connection Manager's transparent connection support feature can be found in PostgreSQL's libpq and other client drivers.

Using libpq as an example, the connection parameter to use that feature is target_session_attrs parameter. If this parameter is used not through Connection Manager, libpq will attempt to find the required instance by connecting sequentially to all instances of the set of instance requested by the host parameter or hostaddr parameter. In the worst case, libpq may find the promoted primary at the connection to the last instance of instance set. This means that you cannot predict how long it will take to complete the switch.

However, when conmbined with the Connection Manager, the conmgr process obtains its attributes via the watchdog process from all servers in a set of servers in advance, so that the connections to that server can be initiated as soon as the application requests it.