Flow entries installation based on distributed SDN controller

Software-Defined Networking (SDN), which is relatively a new concept, proposes a more intelligent way to manage network resources. The controller is a key component in SDN, which sends management and forwarding policies to switches by flow entries. With the increase of network scale, there are too many flows to install, especially in data center (DC). The number of flow entries is up to 757,000. This has exceeded the processing capability of centralized controller. Thus we put forward a distributed architecture to install flows. There are two ways to install flow entries, proactive and reactive. In proactive way, flows are stored in the distributed storage in a key-value way, and use the identifier of switch as the key of flows. As for reactive way, one controller instance sends flow entries to other controller instances other than the synchronize function of distributed storage. We build a prototype system on Floodlight to demonstrate our design and test the performance of our solution. According to the experiment, our design to install flows has a good scalability and better performance. In the reactive mode, it can save 10 times of time than the synchronize way.