Improvement And Implementation Of Load Balancing Based On LVS

With the popularization of Internet and the increasement of network bandwidth, most commercial websites are required to provide high-quality network services. They need to provide 24 hours 365 days one year without interruption of network service, and timely response to the request of massive users. Nowdays, the commercial competions of Internet are serious. Network service providers want more and more profits, and then they are required to provide better network service. They need to buy more excellent servers, so the level of server's performance impacts the network service and become be a major bottleneck. The simply upgrade of server's hardwares can't meet to solve the bottleneck problem, so the server cluster technology becomes true.The server cluster uses LAN or WAN to gather a lot of servers, these servers can provide service separately, and they are a whole to the clients. With the development of the server cluster technology in commercial fields, the open source operating system Linux can build good web server cluster system and it is transparent, high availability, high reliability, and good scalability.This thesis is based on Linux Virtual Server, and study about LVS system for research purposes. This thesis study about the load balancing's implementation mechanism and many methods, and anlysis the IPVS software algorithm of LVS system. The most important of this thesis is analysis and research about the IPVS software's weight least connection (WLC) algorithm, and give some good proposal of improvement based on WLC. This thesis recommends some methods to achieve these improvements, and program these methods in this thesis.This thesis's results include the following points:(l)This thesis proposes some system's new load parameters, and the original WLC need to consider them.(2)This thesis designs one mathematical model to calculate the dynamic weight of the WLC algorithm, and this calculation is based on the system's new load parameters.(3)This thesis solves the method of obtaining system's load parameters real-time, and optimizes the mathematicak model calcualtion's determine conditions, and realize communtication between the Windows server and Linux load balancer based on UDP mode, and transfer server's dynamic weight to the WLC algorithm's kernel scheduling strategy.(4)At the end of this thesis build one small-scale LVS cluster system, and choose the Web Application Stress (WSA) software to simulate Internet clients' access experiment, and get some simulation experiment data, analyze and contrast the before and after improvement of WLC experiment data. Finaly this thesis conclude the fact that LVS cluster system can perform better after the improvement of WLC algorithm.