【作者】 刘炫；

【导师】 贾惠波；

【作者基本信息】 清华大学 ， 仪器科学与技术， 2007， 博士

【摘要】 数字化信息的爆炸性增长使得人们需要对海量数据进行可靠的存储与有效的利用。网络光盘库作为层次化海量存储中的一种准在线存储设备,在科研、生产等广泛领域中具有非常重要的应用价值,提高其应用性能是改善超大容量存储仪器实际应用的关键。本文在深入研究网络光盘库基本模型的基础上,对影响网络光盘库应用性能的因素进行深入的研究分析,探索提高传输性能的途径和方法,为网络光盘库的实际应用提供了坚实的理论和实验基础。论文主要内容包括:首先,研究了网络光盘库的用户访问请求到达的特点,建立了具有不同优先权的用户排队模型。在深入研究用户访问行为之间逻辑联系的基础上,构建了具有时效性和重复性的“主动限制多访问模型”,为提高网络光盘库的应用性能提供了新的模型基础。其次,论文分析了网络光盘库的Cache与磁盘中的Cache区别,为网络光盘库建立了在不同的访问负载条件下的Cache替换算法。研究表明,通过建立有效的负载处理机制,可以减少对光盘库的操作次数,提高网络光盘库存取速度,从而改善海量存储系统性能。第三,论文针对网络光盘库的实际应用环境,利用线性神经网络方法对网络光盘库的应用性能进行了分析;结合网络光盘库的应用特点,建立了网络光盘库的对等系统模型。分析表明,通过建立对等系统模型,网络光盘库不仅能够降低系统的响应时间,还可以提高系统的吞吐量,有效降低系统的访问负载。最后,论文在上述研究的基础上,利用附网存储的模块化方法,设计并实现了网络光盘库的软硬件模块结构,并在此基础上,结合本文的研究内容对网络光盘库的实际性能进行了实验评测。测试结果表明:在实际的应用中,采用新处理机制的网络光盘库有很高的应用性能。这种通过对用户访问行为进行有效处理的机制,为超大容量数据存储仪器的网络化应用提供了一种新的方案,使网络光盘库具有高性能、高可用性、可扩展、易管理等特点。更多还原

【Abstract】 The explosive increase of digital information demands a reliable storage and effective utilization for mass data. As a partial online storage facility in the hierarchical mass storage, Network Attached Optical Jukebox has a very important application value in scientific research, production and many other fields. The key of improving the application of super-big capacity storage instruments is to enhance its application performance.In this thesis, based on the advanced research on the basic model of Network Attached Optical Jukebox, the factors that influence the application performance of Network Attached Optical Jukebox were analyzed, and the approaches and methods for improving the transfer performance were probed. All of them provided a solid academic and experimental foundation for the application of Network Attached Optical Jukebox. The main contents of the thesis include:Firstly, the characteristics of the arrival of user’s accessing requests of the Network Attached Optical Jukebox were investigated. Based on it, a queuing model with different priorities was constructed, and the key factors including the priorities of each class were analyzed and calculated. Based on the research on the logical relationship between the user’s accessing behaviors, an“Active Restricted Multi-Accessing Model”with time-effectiveness and repetitiveness was built, so that a new model foundation for the improvement of the Network Attached Optical Jukebox application was provided.Secondly, the difference between the Caches in the Network Attached Optical Jukebox and in the magnetic disk was analyzed in the thesis. Based on the“Active Restricted Multi-Accessing Model”, the Cache substitution algorithm under the different accessing load conditions was derived for the Network Attached Optical Jukebox. The research work showed that, the operation times to the Network Attached Optical Jukebox can be reduced by the effective load processing mechanism, so that the access capability can be improved, and the performance of the mass storage system was enhanced. Thirdly, aiming at the real application environment of the Network Attached Optical Jukebox, its application capacity was evaluated by the linear neural network algorithm. Based on the research on the Peer-to-Peer System, combining the application characteristics of the Network Attached Optical Jukebox, the Peer-to-Peer System model of the Network Attached Optical Jukebox was created. It showed that, by the Peer-to-Peer model, the Network Attached Optical Jukebox could not only reduce the system responding time, but also enhance the system throughout. Thereby the system accessing load quantity was reduced.Finally, based on the above research work, the software and hardware module structure was designed and implemented by the Network Attached Storage, and the application performance of the Network Attached Optical Jukebox was evaluated via experiments. The testing results showed that, the Network Attached Optical Jukebox with the new processing mechanism had a high application performance in practical use. The mechanism which effectively dealt with the user’s accessing behaviors provided a new plan for the networking application of the super-big capacity storage instruments, and made the Network Attached Optical Jukebox with the characteristics of high capacity, high usability, extendibility, and easy to manage.更多还原