服务组合中一种自适应的负载均衡算法

An Adaptive Load Balancing Algorithm for Service Composition

服务组合可以整合网络上现有的多种异构服务,形成新的服务.针对服务组合中服务路径的选择和负载均衡问题,提出了一种自适应的分布式负载均衡算法——LCB(loadcapacitybasedalgorithm)算法.LCB算法使用服务路由来查找服务和转发数据,使用负载容率(loadcapacity,简称LC)测度来进行服务副本的选择,从而建立一条适当的组合服务路径.LC测度是对服务器负载的估算,它根据服务器的负载波动信息不断地进行自适应的调整,从而实现多个服务副本之间的负载均衡.与现有的服务组合负载均衡算法相比,LCB算法不需要知道服务器的最大负载量和当前负载信息,而且具有更好的可扩展性,更适用于分布式环境下动态服务副本的组合.模拟实验表明,LCB算法具有良好的负载均衡效果.

Service Composition enables a new way to create new services by assembling independent service components. One of the important goals in service composition is load balancing across service replicas. In this paper, a novel adaptive distributed load capacity based （LCB） algorithm is presented to solve the load balancing problem in service composition. LCB algorithm uses service routing mechanism to search services and transfer the application data. By self-adaptively calculating the load capacity （LC） metric, LCB algorithm can choose a reasonable service path. LC metric reflects the workload of the service node, and is adaptively adjusted according to the variations of the server＇s load. Compared with the previous researches, LCB algorithm needn＇t the global topology information and load information. It is much suitable for dynamic service composition in distributed systems. Simulations show that LCB algorithm performs well in terms of load balancing across the service replicas.