Dynamic Load Balancing in Distributed Heterogeneous Multi-Resource Servers

• Main Authors: Chih-Chiang Yang, 楊智強
• Other Authors: Chien Chen
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/34233244815813182349

碩士 === 國立交通大學 === 資訊科學與工程研究所 === 96 === Due to the progress of the Internet, there are more and more people using Internet services nowadays. In order to satisfy the huge service requirements, using multiple servers to provide different services at the same time is necessary. However, if we can’t effectively divide loads among servers, server utilization could decline and service quality could become uneven. Because of this reason, there are many researches have be presented to solve this problem. The load balancing methods can be roughly classified to four architectures: dispatcher-based, DNS-based, client-based and server-based, and different architectures have their own advantages and disadvantages. The conventional methods of load balancing always set a load buffer range to decrease the state change frequency of a service server in the geographic distributed load balancing architecture, and mostly assume that servers are homogeneous and just consider single resource consumption, such as CPU load. However, the load buffer range would result in load oscillation among servers. On the other hand, servers may not always have the same capacity, and jobs need many kinds of resource requirements. Only considering single resource consumption would cause the system bottleneck to derive from the lack of a small number of resources, and lead to low system utilization. For this reason, in the geographic distributed load balancing architecture, we use the concept of Random Early Detection (RED) to determine the server state probabilistically, and in the cluster load balancing architecture, we present a distributed market mechanism (MM) load balancing method which would consider the server heterogeneity and multiple-resource consumption simultaneously. In our simulation, we show that the oscillation of service server load can be reduced by using the concept of RED in the geographic distributed load balancing architecture. And distributed market mechanism load balancing method can improve the inter-server and intra-server load balancing at the same time, and keep the performance even if the server heterogeneity increasing, achieve high system utilization and low request response time.