Research On The Key Technologies For Load Balancing Of Data Center Network Based On SDN

With the rapid development of Internet and the arrival of the era of cloud computing and big data,data centers' needs and values continue to increase,which the scale of the data center network,availability,scalability become a huge challenge.The increasing scale of data center network deployment,the complexity of flow patterns and the requirement of fine-grained performance management lead to more and more network performance problems become prominent,mainly concentrated in the data center network architecture,load balancing and so on.Through using the network load balancing technology to improve data center link utilization,increase throughput and reduce the network delay becomes the key to improve network performance in the data center.Software defined network architecture presents new challenges and opportunities for the development of data center networks,which provides a new solution for network load balancing.The characteristics of SDN centralized control enable the SDN controller to dynamically obtain the network topology,link information,node information and flow information in time,which can realize flexible and fine-grained centralized scheduling of network flow.So the use of SDN network architecture for dynamic global network load balancing has a great advantage.The main research work is as follows:1.SDN Load Balanced architecture(S_LBA)for data center network is proposed based on SDN,which adopts loosely coupled hierarchical structure,including application layer,control layer and infrastructure layer.Through the detection of elephant flow,congestion discovery and advertisement,and flow scheduling control mechanism.As a whole,the performance and efficiency of load balancing management is improved,and it has good expansibility.2.In view of the shortcomings of the current flow scheduling algorithm,such as locality,bandwidth fragmentation,and large overhead,a Maximum Probability Path Scheduling Algorithm(MPP_SA)is proposed,which computes the path that satisfies the flow bandwidth requirement,and the available bandwidth of the path,and then use the probability mechanism to determine the final path,so as to realize the tradeoff between load balancing and bandwidth fragmentation.At the same time,the cost of the controller is reduced by adopting different path calculation method for the size flow.MPP_SA algorithm not only achieves global load balancing but also reduces the fragmentation of network bandwidth,and improves the overall network performance and service quality.3.A congestion control method(S_ETCP)is proposed based on SDN.The method can make the SDN controller detect the congestion in time,which adds the thresholdearly warning mechanism and the congestion notification mechanism of the OpenFlow switch.Then scheduling long live flows and modifying the receiving window of ACK packet,and to realize the rapid response and processing of congestion.S_ETCP congestion control method that congestion control and flow scheduling are combined,not only ease the network congestion and balance the network load,greatly improving network performance.