Closer is the common interface for things that can be closed.

A Connector represents a driver in a fixed configuration and can create any number of equivalent Conns for use by multiple goroutines.

If a Driver implements DriverContext, then sql.DB will call OpenConnector to obtain a Connector and then invoke that Connector's Connect method to obtain each needed connection, instead of invoking the Driver's Open method for each connection.

Publisher should realize the retry by themselves.

Subscriber is a blocking method should be cancel() with ctx or call Driver.Close() to close all the subscribers.