Communicating between multiple pox controllers

Question

I am developing a load balancing between multiple controllers in sdn. Once a load is calculated on a controller-1 I need to migrate some part of that to controller-2. I have created the topology using mininet and running 2 remote pox controllers one on 127.0.0.1:6633 and other on 127.0.0.1:6634.How do I communicate between these controllers? How can I send load information of controller-1 to controller-2 and migrate some flows there?

Answer 1

In general you are after of a distributed SDN framework where controllers should communicate each other. In order for the controllers to be able to exchange information you should establish a communication channel between them. First decide over the type of communicatoin, inbound or outbound. Most distributed systems use outbound having the inbound communication channels as a failsafe solution. Choosing over the communication module is easy. You have several options but I will examine only 2 general ways of doing it. First one is the native messenger component of POX https://github.com/noxrepo/pox/blob/carp/pox/messenger/ init .py Secondly and most widely used is the RabbitMQ message exchange broker system https://www.rabbitmq.com/tutorials/tutorial-one-python.html You should try to follow a Agent programming approach. Here is a paper to help you out http://jeremie.leguay.free.fr/files/disco_noms_2014.pdf . In the end if you will decide to go with Agents there is nice python library called SPADE https://pypi.python.org/pypi/SPADE but it becomes glitchy sometimes.

Answer 2

POX is not a distributed controller. I would really recommend you to migrate immediately to ONOS or opendaylight. You would implement your solution on top of ONOS.