class ActiveRecord::ConnectionAdapters::ConnectionPool

def disconnect!

disconnected without any regard for other connection owning threads.
spec.db_config.checkout_timeout * 2 seconds), then the pool is forcefully
do so within a timeout interval (default duration is
The pool first tries to gain ownership of all connections. If unable to

Disconnects all connections in the pool, and clears the pool. 
def disconnect!
  disconnect(false)
end