+ # self.rref is now stale: all callRemote()s will get a
+ # DeadReferenceError. We leave the stale reference in place so that
+ # uploader/downloader code (which received this IServer through
+ # get_connected_servers() or get_servers_for_psi()) can continue to
+ # use s.get_rref().callRemote() and not worry about it being None.
+ self._is_connected = False