how Python gRPC stream server spawn two clients that connect other same gRPC server

Question

1、proto

service RouteGuide { 
  rpc RouteChat(stream RouteNote) returns (stream RouteNote) {}
}
message RouteNote {
  // The location from which the message is sent.
  Point location = 1;

  // The message to be sent.
  string message = 2;
}

2、local client

def generate_messages():
    messages = [
        make_route_note("First message", 0, 0),
        make_route_note("Second message", 0, 1),
        make_route_note("Third message", 1, 0),
        make_route_note("Fourth message", 0, 0),
        make_route_note("Fifth message", 1, 0),
    ]
    for msg in messages:
        print("Sending %s at %s" % (msg.message, msg.location))
        yield msg


def guide_route_chat(stub):
    responses = stub.RouteChat(generate_messages())
    for response in responses:
        print("Received message %s at %s" % (response.message, response.location))

def run():
    with grpc.insecure_channel('localhost:50051') as channel:
        stub = route_guide_pb2_grpc.RouteGuideStub(channel)
        print("-------------- RouteChat --------------")
        guide_route_chat(stub)

if __name__ == '__main__':
    run()

3、Server

class RouteGuideServicer(route_guide_pb2_grpc.RouteGuideServicer):
    def RouteChat(self, request_iterator, context):
        yield from request_iterator

def serve():
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
    route_guide_pb2_grpc.add_RouteGuideServicer_to_server(RouteGuideServicer(), server)
    server.add_insecure_port('[::]:50051')
    server.start()
    server.wait_for_termination()


if __name__ == '__main__':
    serve()

4、my question

I want to spwan two clients in RouteGuideServicer.RouteChat method. The two clients is stub.RouteChat same with the local client above. like this:

class RouteGuideServicer(route_guide_pb2_grpc.RouteGuideServicer):
    def RouteChat(self, request_iterator, context):
        with grpc.insecure_channel('node1:50051') as channel:
            stub = route_guide_pb2_grpc.RouteGuideStub(channel)
            yield from stub.RouteChat(request_iterator)
        with grpc.insecure_channel('node2:50051') as channel:
            stub = route_guide_pb2_grpc.RouteGuideStub(channel)
            yield from stub.RouteChat(request_iterator)

but i want node1 and node2 receive same data, response from node1 and node2 return to local client promptly.

enter image description here

help me! thanks a lot.

sorry for my poor English