【作者】 金星；

【导师】 彭寿全；

【作者基本信息】 电子科技大学 ， 计算机应用技术， 2002， 硕士

【摘要】 自从电子邮件系统诞生以后，电子邮件就成为网络重要应用之一，随着中国互联网应用的日益普及和逐步深入，其重要性也越加体现出来。传统的电子邮件存在着种种的局限性，在负载不断增加时日益明显。在此情况下，大容量邮件系统应运而生，它有扩展性强、可移植性好、速度快和性能稳定等特点。特别是，系统的伸缩性和扩展性使服务商可以根据自己的具体要求和实际情况，进行不同容量的系统配置和扩充容量。 大容量邮件系统集成了应用服务器的概念，至少就有三个层次的体系结构。在实现可扩展性和负载均衡时，系统根据情况采用不同的算法，选择进程、线程的模式，实现多服务器对请求的分担。此外，大容量邮件系统有两个重要的组成部分，邮件列表服务器和日志系统。邮件列表服务器实现了邮件列表的管理和收发，是一个独立的服务器。日志系统对系统信息进行记录和读取，是了解系统运行情况的窗口。 本文阐述了大容量邮件系统的概念、发展、体系结构、软件模型，描述了应用服务器的功能和特点，重点讨论了大容量邮件系统中应用服务器层和邮件列表服务器，日志系统的分析、设计和实现。最后，对大容量系统的作用，系统实现的不足和发展方向做了一个小结。更多还原

【Abstract】 From the birth of email system, Email Application has become the most important Application of the Internet. With the developing of Internet, email system become more and more common and popular. The traditional email system has many flaw, it becomes more obvious when with a heavy load. Large-scale email system has features such as high Scanlability, good portability, high speed and high ability. Most important, the high scanlability makes Internet providers configure their own system and enlarge scale with situation.Large-scale email system has a concept of Application server. Large-scale email system has an architecture at least three tiers. In order to accomplish scanlability and load balance, system adopt different algorithm and choose process, thread model according different situation, than realize load balance among several servers. Additional, the system has another two important part: mail list server and log system. Mail list server accomplish administration and receive, send mail list, it is an alone server. The log system record information and provide read interface, it is a window to email system.This thesis talk about large-scale email system’s concept, developing situation, infrastructure and software model, describe application server’s function and feature, then discuss application server layer, mail list server, log system’s design and accomplishment. At last, talk over about the important, shortcomings and develop direction as a sub total.更多还原