Adaptive Load Balancing Mechanism Based On Flowlet Switching In Data Center Networks

Traditional load balancing schemes need to maintain global or local congestion information in asymmetric topologies,so it is generally more complex to implement such load balancing schemes.Flowlet switching based load balancing scheme is very simple to implement,and can achieve adaptive load balancing in asymmetric topologies,so it is an ideal load balancing scheme.However,if the timeout value used to distinguish different flowlets is not set correctly,this adaptive load balancing effect can not be achieved,but will aggravate the network congestion.Aiming at this problem,this paper studies how to set the timeout value to achieve the ideal load balancing effect in flowlet switching based load balancing scheme.Firstly,under the framework of software defined network,combined with OpenFlow group table technology,an adaptive load balancing system EasyLB based on flowlet switching is implemented.Then,aiming at the problem of setting timeout value in EasyLB system,the process of flowlet switching is modeled by Markov model.According to the stationary distribution,the theorem of how to set the timeout value to make EasyLB converge to the ideal load ratio is given.Combining the relationship between the convergence speed of Markov chain and the second largest absolute value of the eigenvalues of the transition probability matrix,the relationship between the timeout value and the convergence speed of load balancing is analyzed.In view of the complex network scenarios such as unequal probability path selection and multi-load balancing paths,this paper presents a theoretical reference on how to set the timeout value and the corresponding solving algorithm.In summary,this paper implements an adaptive load balancing system EasyLB based on flowlet switching under the more and more widely used software-defined network architecture,and focuses on the relationship between the value of timeout and the effect of load balancing in the flowlet switching based load balancing system.In different network scenarios,the corresponding theoretical reference for setting timeout value is given.