共查询到17条相似文献,搜索用时 62 毫秒
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介绍了大型网络游戏的服务器架构,基于架构提出了一个基于闭环排队网络的性能模型.给出了用平均值分析(MVA)求解该模型的算法,以及估计算法所需的性能参数的方法.模拟试验显示出,服务器系统的平均响应时间大致随着用户数量的增多成线性增长.通过模型计算出的结果与实验结果基本一致,从而验证了模型的有效性. 相似文献
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基于多类顾客排队网络的Exp-RAID系统性能评价模型 总被引:2,自引:1,他引:1
针对RAID在线扩展系统这一典型的存储系统混合负载访问问题,采用多类顾客闭合排队网络(multi-customer closed queueing network, MCQN)对系统建立性能评价模型.推广了平均值分析(MVA)方法使之适应多类型负载的需求,并采用这一方法对模型进行了理论计算.通过将计算结果与实际系统性能的测试结果进行对比可以表明,建立的模型基本上反映了真实系统的性能变化趋势,通过对模型的分析,可以发现系统的瓶颈资源,预测系统某个部件性能的变化对整个系统的影响程度. 相似文献
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异步电路设计方法是现在集成电路研究的热点,得到越来越多的研究人员的关注。在异步电路设计过程中对异步流水线进行性能分析对异步电路的设计过程有着重要的指导意义,但现阶段缺乏有效的方法对异步流水线(尤其是复杂的非线性流水线)进行性能分析。而排队网络是一种能直观地对异步流水线进行建模的数学工具,但排队网络(尤其是复杂的非线性排队网络)的分析求解十分困难。本文提出了一种采用带Fork和Join的阻塞排队网络对异步流水线进行建模,采用其排队网络模型的平均周期作为异步电路的性能评价指标,并通过将其转化为等价的随机标记图对其平均周期进行分析,并给出了其平均周期的上限和下限。 相似文献
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基于分层排队网络模型的MCU性能预测及优化研究 总被引:5,自引:0,他引:5
针对视频会议系统中的多点控制单元(MCU)提出了一个基于分层排队网络模型的性能预测方法.通过对分层排队网络模型进行扩展,建立了多点控制单元的分层排队模型.设计了一个仿真程序对模型进行评价,仿真程序的输入即模型配置文件.该方法可以较快地从多种设计方案或硬件平台中选择满足系统性能设计目标的软件或硬件配置.仿真结果显示,选择双处理器配置和采用多线程技术,多点控制单元的接入容量提高了50%.最后,多点控制单元终端接入实验证明了该方法的有效性。 相似文献
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无线移动网络中的QoS是最近的研究热点之一,其中资源预留协议(ResourceReserVationProtocol,RSVP)是一个关键技术.为了提供更多的服务,蜂窝在变小,这样切换更频繁了.因此为了保证切换时的QoS,需要进行资源预留.当有多个移动主机需要进行预留时,就需要对它们进行优先级排序.本文提出一种在全IP移动网络中基于信令预测优先级排队的动态排序算法,以有效地对多个移动主机进行资源预留.仿真结果表明本文提出的算法既保证了快速切换,又实现了资源的有效预留,有效地分配了有限的资源. 相似文献
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《计算机测量与控制》2014,(3):962-965
提出了一种利用软件的结构特性进行软件性能评估的方法;这种方法利用正式模型和非正式模型的优点,进行软件架构的描述,提供了一种软件架构设计级的软件性能评估方法;首先,将软件系统的静态结构描述为序列图,将结构性能描述为UML组件图;然后将所描述的模型自动转化为自动化接口(Interface Automata),从而能够提供性能评估的基础;最后,利用排队论(queuing theory)评估软件系统的性能;提出的方法与其它方法的主要区别在于提出的方法利用了信息描述方法,比如UML来描述软件系统的结构;这种方法具有正式的、简便的语言来提供验证和评估的基础;同时能够在软件开发的早期进行性能的评估,特别是在架构设计阶段,能够进一步降低软件开发的成本。 相似文献
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本文通过对系统性能评价方法的比较和分析,设计一种基于排队网络的可视化离散事件系统仿真与性能评价软件模型,介绍了该模型的体系结构和主要特点。 相似文献
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基于网络性能的VoIP语音质量评价模型 总被引:1,自引:1,他引:0
在VoIP应用中,为了实现服务质量的监测和路径切换,通常需要测量路径的网络性能,并将网络性能映射到语音质量评价.本文提出一种基于网络性能的VoIP语音质量评价模型,该模型在E-Model的基础上进行了改进,只考虑网络性能的动态变化对语音质量的影响.新的模型考虑更少的影响因素,比E-Model更容易计算,因此更适用于VoIP系统的语音质量评价.通过实验比较了新的模型和简单的网络参数评价模型,结果显示该模型具有更好的语音质量描述能力. 相似文献
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We develop new linear program performance bounds for closed reentrantqueueing networks based on an inequality relaxation of the averagecost equation. The approach exploits the fact that the transitionprobabilities under certain policies of closed queueing networksare invariant within certain regions of the state space. Thisinvariance suggests the use of a piecewise quadratic functionas a surrogate for the differential cost function. The linearprogramming throughput bounds obtained are provably tighter thanpreviously known bounds at the cost of increased computationalcomplexity. Functional throughput bounds parameterized by thefixed customer population N are obtained, alongwith a bound on the limiting throughput as N + .We show that one may obtain reduced complexity bounds while stillretaining superiority. 相似文献
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Queueing networks have been widely used to evaluation performance of mainframe computer systems. In contrast, few results have been reported for modern open systems, so it was not clear whether queueing networks are useful for modern systems or not. We think this situation has partly been due to lack of handy evaluation tools. This paper presents tow tools that we developed to evaluate open system performance. On is a measuring tool that is capable of accurately obtaining the service times of system resources requested by an application transaction. The other is an estimating tool which calculates various performance measures based on queueing network models. This paper also describes a case study in which the performance of a medium-sized UNIX client–server system (up to 24 clients) is estimated using the tools and these estimates are then compared with experimental results. The estimates closely agree with the measured results and are accurate enough for practical applications. Based on this, we conclude that queueing network models are also useful for modern systems. 相似文献
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T. Andrew Au 《Journal of Network and Systems Management》2001,9(4):389-408
Based on a clear separation between switching hardware and control software, the concept of open signaling creates an open programmable networking environment in which network entities can be realized as high level software objects with well-defined interfaces. This underlying architecture facilitates the creation of multiple mechanisms of network control, supporting applications for connection management. The feasibility of a connection management framework however depends mainly on the performance of CORBA because of binding overheads associated with remote invocations. It has been proposed that an implementation with reasonable performance may require certain criteria to be integrated into the design, including caching of network states, aggregation of access to the switch server object, and parallel processing of a single call request. This paper considers the effectiveness of these design criteria and the associated performance issues of a connection management system for ATM networks. 相似文献