environment/lib/python2.7/site-packages/IPython/parallel/engine/engine.py
def register(self):
        """send the registration_request"""

        self.log.info("Registering with controller at %s"%self.url)
        ctx = self.context
        connect,maybe_tunnel = self.init_connector()
        reg = ctx.socket(zmq.DEALER)
        reg.setsockopt(zmq.IDENTITY, self.bident)
        connect(reg, self.url)
        self.registrar = zmqstream.ZMQStream(reg, self.loop)


        content = dict(queue=self.ident, heartbeat=self.ident, control=self.ident)
        self.registrar.on_recv(lambda msg: self.complete_registration(msg, connect, maybe_tunnel))
        # print (self.session.key)
        self.session.send(self.registrar, "registration_request",content=content)
def register(self):
        """send the registration_request"""

        self.log.info("Registering with controller at %s"%self.url)
        ctx = self.context
        connect,maybe_tunnel = self.init_connector()
        reg = ctx.socket(zmq.DEALER)
        reg.setsockopt(zmq.IDENTITY, self.bident)
        connect(reg, self.url)
        self.registrar = zmqstream.ZMQStream(reg, self.loop)


        content = dict(queue=self.ident, heartbeat=self.ident, control=self.ident)
        self.registrar.on_recv(lambda msg: self.complete_registration(msg, connect, maybe_tunnel))
        # print (self.session.key)
        self.session.send(self.registrar, "registration_request",content=content)
send the registration_request