Distributed SDN Controller Oriented To Data Center Networks And Data Dissemination Application

The development of mobile applications based on cloud services has let to the expansion of the data center,which poses a series of challenges for the management of the data center network.The east-west traffic gradually becomes the main body in the data center network.However,some problems have occured such as low network utilization.The three advantages of SDN technology and the problems faced by the data center network are just the same,and a single controller can no longer manage the data center network.Therefore,it is necessary to build a distributed controller cluster to manage the east-west traffic in the data center network,implement load balancing for data center networks.In addition,the problem of low network utilization and lack of effective management tools in the data dissemination network has become increasingly prominent,and the node selection strategy needs to be optimized.In view of the above problems,this paper proposes a distributed SDN controller system for data center networks and a dynamic node selection method for data dissemination based on SDN.The main work is summarized as follows:(1)The problem of unbalanced load and low network utilization in the east-west direction of large-scale data center network is studied,and analyze the advantages and disadvantages of the existing equalization scheme.In the east-west direction of the controller,a distributed SDN controller load balancing system applied to the data center network is designed;The problems of management difficulty and low distribution efficiency in data dissemination network are studied.A dynamic node selection system based on SDN controller for data dissemination network is constructed.(2)Aiming at the problem of unbalanced load in the east-west direction of the data center,a dynamic load balancing algorithm based on Pastry(PDLB)for data center network is designed,that is PDLB algorithm.In this algorithm,each common controller node periodically collects respective load information,and determines whether there is overload controller based on the set load threshold.According to the judgment result,the notification message is constructed and routed to the root controller node on the cluster via the Pastry,then the root controller determines where the load is going.The experimental results show that the algorithm can achieve load balancing of the data center network and reduce the load communication overhead between controllers.(3)An SDN-based dynamic node selection algorithm for the data dissemination is designed.The controller collects the link state parameters of the dissemination network,which are provided to the tracking server in the form of interfaces.According to the obtained link state parameters,the tracking server evaluates the service capabilities of the nodes,and select a optimal resource node list.Then,selecting one node from the list of optimal resource node to download.The controller can real-time monitor the overview network status,and display the parameters of the network status on the topology,which can impletment the visual management of the data dissemination network.