基于Windows DDE的客户/服务器应用开发

Windows应用程序进程间客户／服务器模式的通信实现，是软件工程设计中经常涉及的一个重要问题。阐述了Windows应用程序进程间DDE通信的基本原理，由此给出了设计开发DDE客户／服务器应用的两种方案，并论述了两种方案各自的优点及不足之处。结合工程实际，详细给出了应用Windows DDE API方案开发设计DDE服务器和客户端应用程序的方法。实践表明，应用Windows DDE技术设计客户／服务器应用具有开发周期短、实用性强的优点。     

基于API监控的服务程序防御技术

目前大多数因特网应用都采用服务器／客户机模式,服务器程序安全对网络安全至关重要。本文提出了一种新的针对服务进程的防御技术,通过对关键API的拦截和安全性检查,可以发现大多数针对服务器程序的攻击．这种方法具有鲜明的特色：效率高,通用性好,漏报率低,误报率为零。实验表明,该方法能够防范一大类针对服务器程序的已
知和未知攻击。本文给出了该技术在Microsof IIS上的实现。     

Peer-To-Peer Technology: A Technology Reborn

Peer-to-peer (P2P) networks are poised to be reborn in networking technology. the combination of proven P2P topology and recent advances in computer technology has led some analysts to predict that P2P will likely be the next major step on the Internet. P2P networking overcomes the existing client/server hierarchy to efficiently use the processing power, disk space, and data available in a network and promises a significant number of applications in information sharing and knowledge management. P2P is not expected to replace the client/server architecture employed in most contemporary networks, but rather merge to create a hybrid P2P-client/server network that is faster, cheaper, and more powerful.     

Provisioning Services与XenApp联合组建局域网应用环境的研究

Citrix公司推出的基于应用流技术的ProvisioningServices软件可以实现客户端通过PXE技术获取服务端采用VDisk磁盘存放的操作系统镜像文件,实现无盘启动;而同公司的基于应用虚拟化技术的XenApp软件则可以实现瘦客户端对服务器端所发布程序的访问。将两者相互结合来组建局域网应用环境,不但可以节省软硬件成本,而且对局域网络环境的管理也变得更加轻松和安全。此外还可以指定客户端可运行的应用程序,对服务器端的访问也不仅限于局域网内部。     

信息系统中的客户机/服务器计算策略

文章介绍了Ｃｌｉｅｎｔ／Ｓｅｒｖｅｒ计算的概念及其在信息系统中的应用，并针对现有Ｃ／Ｓ结构的不足，结合一个银行系统的实践，从应用风格，计算模型等方面探讨了新一代Ｃ／Ｓ计算的基本思想与策略。     

基于JavaBeans组件标准的中间件的开发方法与实现

实现3层Client／Server结构的关键技术是中间件技术，将基于JavaBeans组件的中间件组装到分布式应用程序中，不仅大大提高了应用程序的开发效率，同时也使系统的可靠性和适应性得到明显改善。给出了利用Java开发JavaBeans组件的方法和步骤。     

Visual C++6下实现基于多线程的网络通信

本文介绍了如何通过TCP／IP网络协议的客户／月艮务器(C／S)模式，实现指纹采集模块终端与服务器之间的网络通信，同时介绍了多线程技术在服务器与终端间的数据传输方面的应用。实践表明，在Visual C 环境下，多线程技术应用于网络通信可达到比较好的效果。     

Semantic acid properties in multidatabases using remote procedure calls and update propagations

Global ACID properties (Atomicity, Consistency, Isolation and Durability) may be implemented by using a DDBMS (Distributed Data Base Management System.) However, in this solution data availability is low. Further, data may be blocked, i.e. if some data are locked from a remote location, the data cannot always be unlocked when the connection to the data fails. This is not a problem when client/server technology is used because client/server technology only uses local locks, a reason why multidatabases and client/server technology are widely used in real-life distributed systems. However, the trouble with such systems is that they have no inherent global ACID properties. The objective of this paper is to illustrate how global semantic ACID properties, enforced by the transactions themselves, may be implemented on top of client/server technology. This is done to preserve high data availability. The global atomicity property is implemented by using retriable and compensatable subtransactions. The global consistency property must be implemented by the transactions themselves. The global isolation property is implemented by using countermeasures to isolation anomalies. The global durability property is implemented by using the durability property of the local DBMSs. The largest bank in Denmark, Den Danske Bank, has implemented all its applications using methods described in this paper. © 1998 John Wiley & Sons, Ltd.     

RIA在电子商务虚拟实验系统中的应用

RIA富互联网应用系统模式是以浏览器技术为基础,通过开放的用户接口,将C/S程序的丰富用户体验与B/S程序的部署灵活性结合起来的一种网络应用系统模式。该文将RIA的引入到电子商务虚拟实验系统中来。在系统开发中综合运用JSON-RPC、J2EE等技术不仅实现了客户端与服务器端的异步交互通讯,还实现了功能模块和显示模块的分离,提高了系统的可维护性、增强了用户体验性。     

基于透明计算模式的I/O Server的设计

设计并实现了一个基于透明计算模式的I/O Server系统，I/O Server和I/O Client是一个在透明计算环境下，支持多操作系统远程启动和运行的网络存储访问服务I/O Manager的2个软件模块，I/O Server工作在服务器端，I/O Client工作在客户端。在透明计算模式中，各客户机硬件与操作系统分离，用户需要的操作系统的应用程序存储在服务器端。在客户机启动时，I/O Server和启动协议将I/O Client下载到端系统上运行，然后I/O Client向I/O Server发出I/O请求，I/O Server对收到的I/O请求加以分析，进行优先级分类，在优先级分时轮转调度I/O请求、操作服务器上的虚拟硬盘文件，并通过预取和缓存策略减少磁盘I/O操作，将处理结果返回给客户端，支持操作系统的远程启动，并为系统运行时的各种请求提供服务。     

Design and implementation of MP3-music on demand system using streaming technology

The success of the Internet and the use of broadband in homes have caused a gradual shift in traffic on the Internet from data to multimedia communication. Multimedia applications typically include a large quantity of video/audio information. Streaming technology is normally adopted to handle the transmission of multimedia traffic and thus reduce the buffer requirement on the client side and the service request/response time. This work focuses on the transmission of MP3 music which has a constant bit rate characteristic. The design of both the server side and the client side of the MP3-music on demand (MoD) system with streaming technology, is considered to meet the quality of service (QoS) requirements of MP3 music. A stream buffering technique is used and an adaptive rate control mechanism is applied in combination with a client feedback packet to prevent stream buffer overflow or underflow on the client side, and thereby accommodate the network delay, jitter, and timing deviation between the server machine and the client host. A server self-timing revision scheme is used to reduce the network overhead of the feedback mechanism. The adaptive rate control mechanism is developed and verified using a computer simulation. Finally, for completeness a MoD system is constructed with a low-cost embedded network system to which an Altera FPGA is applied to provide cut-through data movement and an adaptive rate control mechanism is realized to evaluate QoS.     

银河分布计算环境

分布式客户／服务器计算环境是90年代分布处理的主流计算环境．应用需求的发展使分布式客户／服务器计算环境面临许多新的技术问题，包括应用级系统集成问题、智能服务问题和支持协同工作问题等等．本文以银河分布式客户／服务器计算机系统YHCS为背景，讨论YHCS分布计算环境的构成及主要设计技术．该环境以系统集成技术为重点，在解决上述3个技术问题方面取得了重要进展．     

一个基于MVC的通用Client/Server应用开发框架

在论述了应用开发框架的基本概念及优势的基础上,给出了一个基于MVC模式的Client/Server通用应用开发框架,详述了该框架客户端、代理和服务端的主要组成及其实现技术。该框架主要借鉴了目前流行的J2EE和Struts框架原理,利用代理在客户端和服务端转发XML格式的业务数据,在保持传统的Client/Server优势的同时,增强了系统的可扩展性并实现了用户界面和业务逻辑数据的分离,为大型Client/Server应用软件系统开发提供了一个高层次的通用开发平台,大大提高了软件复用度和缩短了软件开发生命周期。     

动态网页加速技术

综述了动态网页加速技术的最新发展，首先介绍了主动缓存，它通过在代理服务器上运行原始服务器提供的Applets以完成必要的处理，并返回结果给用户而不用连接服务器，接着介绍了服务器加速器，它放置于Web Server前端或内部以加速服务器访问速度，最后重点介绍了一种简单的标记语言ESI（Edge Side Includes)，用于定义网页片段，使得在因特网边缘可以动态地组装和分发Web应用。     

Distributed coordination models for client/server computing

A major limitation in the basic client/server model is its focus on clients requesting individual services. Clients often need to invoke multiple services, coordinated to reflect how those services interrelate and contribute to the overall application. Important examples include task allocation and event notification in collaborative workgroup systems, and task sequencing and routing in workflow applications. Failure to address control requirements for such interactions has impeded development of uniform methods and tools for building many types of distributed systems with client/server architectures. The article identifies and examines extensions to the basic client/server model that provide explicit support for coordinating multiserver interactions     

Optimal chaining scheme for video-on-demand applications on collaborative networks

By forwarding the server stream client by client, a chaining-based scheme is a good way to reduce the server streams for streaming applications in well-connected networks. In this paper, we prove that the minimum number of required server streams in such schemes is n-k+1, where n is the number of client requests and k is a value determined by client buffer sizes and the distribution of requests. In addition, we present an optimal chaining algorithm using a dynamic buffer allocation strategy. Compared to existing chaining schemes, our scheme not only utilizes the backward (basic chaining) and/or forward (adaptive chaining) buffer, but also exploits the buffers of other clients in order to extend the chain as much as possible. In this way, more clients can be chained together and served by the same server stream. Our simulation results show that the requirements of the server streams in the presented scheme are much lower those of existing chaining schemes. We also introduce mechanisms for handling VCR functions and fault exceptions in practical applications.     

一种支持客户端界面设计的人机对话模型

本文将客户端的应用程序划分为计算逻辑和对话逻辑,并在此基础上提出了一个人机对话的层次模型,以期实现对话的独立性,指导客户服务器系统中客户端人机对话过程的分析与设计,以提高应用系统最终界面的质量和开发效率。     

VB基于ADO访问ORACLE数据库的策略

网络环境下的数据库应用程序属于一种非常典型的客户/服务器应用程序,对远程数据库的访问是开发这类应用程序的关键。本文介绍了Oracle数据库的特点和ADO技术,并结合实例介绍在VB中用ADO访问远程O-racle数据库的策略。     

基于Flex和ArcGIS技术的面积相交问题研究与实现

基于ArcGIS Server相关服务的研究,实现基于流域、行政区划及其他专项相交面积的查询,前端采用富客户端Flex技术实现其查询结果的展示。结果表明,ArcGIS Server技术在水务普查数据面积相交应用方面有一定优势,Flex富客户端的界面设计方面有其强大的表现力。     

工程数据库管理系统OSCAR的页面服务器

为了适应工程应用的特点，工程数据库管理系统OSCAR采用了页面服务器体系结构．OSCAR的页面服务器集中实现了数据库管理系统核心的事务管理，即并发控制和恢复功能．它向客户端提供支持多用户共享的、可靠的数据页面服务，客户端模块在此基础上构建一个功能完备的工程数据库管理系统．介绍了设计与实现OSCAR页面服务器过程中碰到的问题及其解决方法，包括OSCAR页面服务器的功能在物理层、缓冲层和事务层的分配，客户／服务器环境中ARIES恢复策略的改进以及先写日志文件原则的实现方案。