In this paper, we present a novel approach to model user request patterns in the World Wide Web. Instead of focusing on the user traffic for web pages, we capture the user interaction at the object level of the web pa...In this paper, we present a novel approach to model user request patterns in the World Wide Web. Instead of focusing on the user traffic for web pages, we capture the user interaction at the object level of the web pages. Our framework model consists of three sub-models: one for user file access, one for web pages, and one for storage servers. Web pages are assumed to consist of different types and sizes of objects, which are characterized using several categories: articles, media, and mosaics. The model is implemented with a discrete event simulation and then used to investigate the performance of our system over a variety of parameters in our model. Our performance measure of choice is mean response time and by varying the composition of web pages through our categories, we find that our framework model is able to capture a wide range of conditions that serve as a basis for generating a variety of user request patterns. In addition, we are able to establish a set of parameters that can be used as base cases. One of the goals of this research is for the framework model to be general enough that the parameters can be varied such that it can serve as input for investigating other distributed applications that require the generation of user request access patterns.展开更多
高动态的计算环境使得QoS(qualicy of service)保障对于基于组件的分布式系统越来越重要,软件系统需要具备自我调整的能力以适应外部环境的变化.给出一种自适应的中间件配置框架,能够动态感知负载变化,并自动调整系统参数配置以保持用...高动态的计算环境使得QoS(qualicy of service)保障对于基于组件的分布式系统越来越重要,软件系统需要具备自我调整的能力以适应外部环境的变化.给出一种自适应的中间件配置框架,能够动态感知负载变化,并自动调整系统参数配置以保持用户所要求的服务质量.该框架的核心是一个基于分层排队网络的性能预测模型,用于指导搜索最优的资源配置,使性能需求得到最大的满足.在OnceAS应用服务器上进行原型实现,并以StockOnline应用做实验,比较了在使用和不使用该框架时的性能需求的满足情况.结果显示,在负载增加时,通过自配置框架的调控,应用性能需求的保障程度得到了较大的提升.展开更多
文摘In this paper, we present a novel approach to model user request patterns in the World Wide Web. Instead of focusing on the user traffic for web pages, we capture the user interaction at the object level of the web pages. Our framework model consists of three sub-models: one for user file access, one for web pages, and one for storage servers. Web pages are assumed to consist of different types and sizes of objects, which are characterized using several categories: articles, media, and mosaics. The model is implemented with a discrete event simulation and then used to investigate the performance of our system over a variety of parameters in our model. Our performance measure of choice is mean response time and by varying the composition of web pages through our categories, we find that our framework model is able to capture a wide range of conditions that serve as a basis for generating a variety of user request patterns. In addition, we are able to establish a set of parameters that can be used as base cases. One of the goals of this research is for the framework model to be general enough that the parameters can be varied such that it can serve as input for investigating other distributed applications that require the generation of user request access patterns.
基金Supported by the National Natural Science Foundation of China under Grant No.60573126(国家自然科学基金)the National Basic Research Program of China under Grant No.2002CB312005(国家重点基础研究发展计划(973))
文摘高动态的计算环境使得QoS(qualicy of service)保障对于基于组件的分布式系统越来越重要,软件系统需要具备自我调整的能力以适应外部环境的变化.给出一种自适应的中间件配置框架,能够动态感知负载变化,并自动调整系统参数配置以保持用户所要求的服务质量.该框架的核心是一个基于分层排队网络的性能预测模型,用于指导搜索最优的资源配置,使性能需求得到最大的满足.在OnceAS应用服务器上进行原型实现,并以StockOnline应用做实验,比较了在使用和不使用该框架时的性能需求的满足情况.结果显示,在负载增加时,通过自配置框架的调控,应用性能需求的保障程度得到了较大的提升.
