Web服务中缓存机制的研究与实现

发布时间：2018-03-12 13:49

本文选题：缓存　切入点：替换策略　出处：《北京邮电大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着互联网的快速发展和浏览器技术的不断完善,Web已经成为用户信息获取和发布的主要平台。然而随着用户访问量的增加,Web服务器无法跟上用户需求导致服务响应速度越来越慢。为了解决这个问题,很多新的技术被提出,在不改变原有Web服务架构的情况下,缓存机制被认为是提高Web服务响应速度的最有效的方法之一,所以对缓存机制的研究具有重要的意义。本论文结合多媒体会议系统课题,从多个层面上研究Web服务中缓存机制。主要工作包括：首先,我们结合HTTP协议中与缓存相关的头字段,研究Web服务中静态缓存技术的原理,实现了服务中静态文件的缓存。然后,通过分析主流的缓存替换策略,结合多媒体会议此类应用数据的特征,我们设计实现了基于LRU缓存替换策略的缓存系统,该系统主要由四个功能模块组成：缓存控制器、缓存替换策略模块、缓存监听器和缓存数据存储模块。在缓存替换策略模块中,实现一种基于LRU的改进替换策略,与传统替换策略相比,它可有效提高了缓存系统的字节命中率。在缓存数据存储模块中,实现了基于标记法的缓存数据存储方式,它可以有效提高内存利用率,减少内存碎片,从而提高缓存系统响应速度。接着,本论文还针对分布式环境下服务器集群间无法实现session共享问题,提出了使用Memcached缓存技术的解决方案。此外,通过将Memcached技术应用于Hibernate框架中实现了数据库数据缓存,减少了数据库访问次数,从而提高访问吞吐量和服务响应速度。最后,我们将本论文所研究的缓存机制应用于多媒体会议系统中,并进行了功能测试。结果表明本论文设计实现的缓存系统具有较高的字节命中率、内存利用率以及较快的响应速度。从而有效的提高了多媒体会议系统的性能。
[Abstract]:With the rapid development of the Internet and the continuous improvement of browser technology, Web has become the main platform for users to obtain and publish information. However, with the increase of users' visits, Web servers are unable to keep up with the needs of users, resulting in service response. To solve this problem, Many new technologies have been proposed that, without changing the existing Web services architecture, caching is considered one of the most effective ways to increase the response speed of Web services. Therefore, it is of great significance to study the cache mechanism. This paper studies the cache mechanism in Web services from many aspects, combining with the multimedia conference system. The main work includes:. Firstly, we study the principle of static cache technology in Web service by combining the header fields related to cache in HTTP protocol, and realize the cache of static file in Web service. Then, by analyzing the mainstream cache replacement strategy and combining the characteristics of multimedia conference application data, we design and implement a cache system based on LRU cache replacement strategy. The system consists of four functional modules: cache controller, cache replacement policy module, cache listener and cache data storage module. In the cache replacement policy module, an improved replacement strategy based on LRU is implemented. Compared with the traditional replacement strategy, it can effectively improve the byte hit ratio of the cache system. In the cache data storage module, the cache data storage method based on the marking method is implemented, which can effectively improve the memory utilization and reduce the memory fragmentation. In order to improve the cache system response speed. Then, aiming at the problem that session sharing can not be realized among server clusters in distributed environment, this paper proposes a solution using Memcached caching technology. In addition, the database data cache is implemented by applying Memcached technology to Hibernate framework. Reduce the number of database visits, thereby improving access throughput and service response speed. Finally, we apply the cache mechanism studied in this paper to the multimedia conference system, and test the function of the system. The results show that the cache system designed in this paper has a high byte hit ratio. Memory utilization and fast response speed improve the performance of multimedia conference system.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.09;TP333

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