The purpose of this study is to analyze and then model, using neural network models, the performance of the Web server in order to improve them. In our experiments, the parameters taken into account are the number of ...The purpose of this study is to analyze and then model, using neural network models, the performance of the Web server in order to improve them. In our experiments, the parameters taken into account are the number of instances of clients simultaneously requesting the same Web page that contains the same SQL queries, the number of tables queried by the SQL, the number of records to be displayed on the requested Web pages, and the type of used database server. This work demonstrates the influences of these parameters on the results of Web server performance analyzes. For the MySQL database server, it has been observed that the mean response time of the Web server tends to become increasingly slow as the number of client connection occurrences as well as the number of records to display increases. For the PostgreSQL database server, the mean response time of the Web server does not change much, although there is an increase in the number of clients and/or size of information to be displayed on Web pages. Although it has been observed that the mean response time of the Web server is generally a little faster for the MySQL database server, it has been noted that this mean response time of the Web server is more stable for PostgreSQL database server.展开更多
Network Time Protocol(NTP)是用来使计算机及网络设备时间同步化的一种协议,其目的是为各种网络设备提供高精准度的时间校正。伴随着高校网络设备数量爆炸式增长,我们所依赖的文件服务器、邮件服务器、互联网网关等诸多网络设备之间都...Network Time Protocol(NTP)是用来使计算机及网络设备时间同步化的一种协议,其目的是为各种网络设备提供高精准度的时间校正。伴随着高校网络设备数量爆炸式增长,我们所依赖的文件服务器、邮件服务器、互联网网关等诸多网络设备之间都需要一个精准的时钟作为信息共享的基础,因为数据共享、设备日志和网络安全是互联网上最常用也是最易遭受攻击的信息。为确保网络设备安全,网络工程师需要精准的时间确保这些应用及其它关键网络应用的安全。本文基于NTP协议网络应用时间戳同步机制的研究,可有效应用于高校网络中,使所有网络设备的时间戳具有高度统一性。所以在互联网中设计专门的时间服务器为需要精准时间的网络设备同步成为当今日益复杂网络应用环境的现实需求。展开更多
针对仪器资源无法实现开放互联与资源共享,以及大量测试信息不能被有效传输和利用,基于"测量信息完整性"的观点及开放体系结构的原则,提出了以测控网为基础、具有开放互联与信息完整性支持能力的网络仪器(ION,Instrument On N...针对仪器资源无法实现开放互联与资源共享,以及大量测试信息不能被有效传输和利用,基于"测量信息完整性"的观点及开放体系结构的原则,提出了以测控网为基础、具有开放互联与信息完整性支持能力的网络仪器(ION,Instrument On Network),设计了一种以探头、测控HUB和测控服务器为基本设备单元,由接入层、传输层和构造层组成的网络仪器结构,深入阐述了网络仪器的基本概念与技术要素,并就统一时间支持体系、时间确定性传输关键技术问题进行了初步的分析。展开更多
文摘The purpose of this study is to analyze and then model, using neural network models, the performance of the Web server in order to improve them. In our experiments, the parameters taken into account are the number of instances of clients simultaneously requesting the same Web page that contains the same SQL queries, the number of tables queried by the SQL, the number of records to be displayed on the requested Web pages, and the type of used database server. This work demonstrates the influences of these parameters on the results of Web server performance analyzes. For the MySQL database server, it has been observed that the mean response time of the Web server tends to become increasingly slow as the number of client connection occurrences as well as the number of records to display increases. For the PostgreSQL database server, the mean response time of the Web server does not change much, although there is an increase in the number of clients and/or size of information to be displayed on Web pages. Although it has been observed that the mean response time of the Web server is generally a little faster for the MySQL database server, it has been noted that this mean response time of the Web server is more stable for PostgreSQL database server.
基金supported in part by the school scientific research project of Beijing University of Civil Engineering and Architecture,(101203308)
文摘Network Time Protocol(NTP)是用来使计算机及网络设备时间同步化的一种协议,其目的是为各种网络设备提供高精准度的时间校正。伴随着高校网络设备数量爆炸式增长,我们所依赖的文件服务器、邮件服务器、互联网网关等诸多网络设备之间都需要一个精准的时钟作为信息共享的基础,因为数据共享、设备日志和网络安全是互联网上最常用也是最易遭受攻击的信息。为确保网络设备安全,网络工程师需要精准的时间确保这些应用及其它关键网络应用的安全。本文基于NTP协议网络应用时间戳同步机制的研究,可有效应用于高校网络中,使所有网络设备的时间戳具有高度统一性。所以在互联网中设计专门的时间服务器为需要精准时间的网络设备同步成为当今日益复杂网络应用环境的现实需求。
文摘针对仪器资源无法实现开放互联与资源共享,以及大量测试信息不能被有效传输和利用,基于"测量信息完整性"的观点及开放体系结构的原则,提出了以测控网为基础、具有开放互联与信息完整性支持能力的网络仪器(ION,Instrument On Network),设计了一种以探头、测控HUB和测控服务器为基本设备单元,由接入层、传输层和构造层组成的网络仪器结构,深入阐述了网络仪器的基本概念与技术要素,并就统一时间支持体系、时间确定性传输关键技术问题进行了初步的分析。
