共查询到19条相似文献,搜索用时 187 毫秒
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五、应用平台 1、计算机 在一个网络中,设置的计算机分为客户机和服务器两类。对于客户端的计算机设备,一般没有特别的要求,只要能够支持客户端应用软件,通常选用微机。 服务器按照所要承担的功能分为许多种:承担常规应用处理的,有应用服务器、文件服务器和数据库服务器等;承担通信处理功能的,有通信服务器(又称前置机);对于Intranet应用,则有Web服务器、电子邮件服务器、FTP服务器、讨论组服务器、代理服务器等等。(注意,终端服务器是一种网络连接设备,用于连接多个远程设备,不是这里所说的服务器。)用作服务器的计算机的台数,要由应用要求来决定。有时,一台服务器可以承担多种服务器的功能;有时,一项功能需要多台服务器来承担,如数据库服务器。 相似文献
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高可用冗余TCP协议堆栈 总被引:1,自引:0,他引:1
提出了一个冗余TCP堆栈(RTS)方案以提高TCP网络连接的可靠性和计算机集群提供服务的可用性.RTS允许多个服务器同时在一个TCP连接里工作,极大的改善了TCP连接提供的服务的可信赖性.在RTS中还设计了两个算法(SWMU和SWFR)来解决在多个TCP协议堆栈中的同步问题.实验表明,使用SWFR和BRC算法可以将网络性能的损耗减到最少,并且配备两台服务器的集群所发挥的性能可充分满足在实际使用中所需的高效传送. 相似文献
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利用BT下载时并不只对外进行一个连接.而是同是连接到多个用户的IP.所以对ADSL Modem这样低性能的NAT功能来说是很大的负载。用交接机连接多台PC上网.理论上每台PC的带宽是一样的,但实际上由于没有流量控制,有时会导致一台PC占去很多的带宽.比如在线BT就会这样.因此我们最好是通过一台服务器做代理上网,在服务器上把端口封锁掉。 相似文献
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基于主动TCP连接复制的高性能高可用MySQL数据库集群 总被引:2,自引:0,他引:2
提出一种基于主动TCP连接复制的高性能高可用MySQL数据库集群解决方案.该方案采用集群技术对并发的多个TCP连接进行原子多播转换和复制以达到连接容错的效果,同时,对连接流中的只读操作进行分流以达到提高性能的目的.该方案将对TCP连接进行复制的技术应用于MySQL数据库集群中,从而实现了数据库集群整体的高可用性和高性能.经过原型系统的实现和测试,证明了该方案在复制过程中对数据库写操作造成了较小的性能损耗,同时极大地提高了数据库集群的只读查询性能. 相似文献
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分布式Web服务器中负载均衡的实现 总被引:3,自引:2,他引:3
实现和测试了一种可扩展的分布式Web服务器原型。原型由多台接收和处理TCP连接的服务器通过负载均衡集群而成,主机IP地址利用Round Robin DNS发布,任意主机都可以接收客户端的请求。一旦当客户试图建立连接,主机要决定接收连接提供服务还是重定向连接到其它主机。每台主机保持集群定期组播的系统负载信息,并利用低负荷的IP封装IP技术重构数据包来重定向请求。性能测试表明这种技术比RR—DNS具有更好的性能,而且利用系统负载状态的重定向连接比无状态的重定向效果更好。 相似文献
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关键词服务器开发框架 ACE当前,一般采用 Client/Server 架构来开发网络游戏,客户端和服务器一般通过 TCP 协议进行通信。在设计游戏服务器的过程中,如何保证服务器的安全和最大限度的支持更多的客户端连接是摆在开发者面前一个重要的问题。 相似文献
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陈钰龙 《A&S(安防工程商)》2006,(5):52-54
传统门禁控制系统不支持网络功能,本文通过引入网络通信平台,给出了一种实现TCP/IP的新方法,通信平台在操作软件客户端和控制器之间架起了TCP通道,通过对串口数据和客户端TCP/IP数据包进行转换可以使任意客户端访问网络节点上的硬件服务器,实现TCP/IP通信。 相似文献
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本文提出一种基于Active Replication的TCP连接容错技术(ARTCP),采用两层的Cluster结构,并通过前端的分发器和聚合网关机维持多个同步的TCP连接副本,达到了相互容错的效果。测试结果表明,该技术不仅保证网络服务连接级的高可用性,而且具有恢复时间短、开销小的优势。 相似文献
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对相关Web分配器技术进行分析,并提出一个新颖的构架来改进在服务器和缓存集群中Web请求路由,MPLS方案利用应用层信息到第二层标签以提高复杂的请求路由功能,而不会发生TCP连接终止瓶颈。需要客户端代理服务器参与为客户请求申请到合适的标签,可用off-the-shelf MPLS交换去执行分配。允许分配器执行一些关健功能实现可伸缩性。 相似文献
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Transmission Control Protocol (TCP) connection migration has been previously proposed to allow for the mobility of servers. In this paper we revisit TCP connection migration for purposes of server survivability against malicious denial-of-service attacks. We present a protocol that allows an on-going TCP connection to be migrated from one server to another. This migration is performed in a secure manner such that the protocol itself cannot be exploited for malicious attacks. Further the migration can be performed even in the case where the original server is compromised. The protocol has been designed so as to allow interoperability with legacy TCP protocols. It is intended to be the transport layer foundations over which survivable applications can be built. 相似文献
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Recently, the words “browser war” have filled the Internet headlines. Each browser comes up with new schemes to be faster and to support newer, more powerful standards. Sometimes we seem to forget that behind the browser is a server, and, just like any other client-server architecture, the server's quality, functionality, robustness and efficiency are important to the well-being of the entire system. There is a technology that promises to combine the benefits of both the Common Gateway Interface (CGI) and the application program interface (API): FastCGI, brought to the Web world by OpenMarket. Each FastCGI program runs in its own process and can be accessed by the server in one of two ways: through a direct pipe if the Web server and FastCGI processes are running on the same machine, or through a TCP/IP connection if the FastCGI is running on a different machine. The FastCGI model seems ideal in terms of server-side extensions. It combines the safety of a separate process with server software independence, yet without the overhead of starting that separate process on every request 相似文献
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A DoS attack can be regarded as an attempt of attackers to prevent legal users from gaining a normal network service. The TCP connection management protocol sets a position for a classic DoS attack, namely, the SYN flood attack. In this attack some sources send a large number of TCP SYN segments, without completing the third handshake step to quickly exhaust connection resources of the under attack system. This paper models the under attack server by using the queuing theory in which attack requests are recognized based on their long service time. Then it proposes a framework in which the defense issue is formulated as an optimization problem and employs the particle swarm optimization (PSO) algorithm to optimally solve this problem. PSO tries to direct the server to an optimum defense point by dynamically setting two TCP parameters, namely, maximum number of connections and maximum duration of a half-open connection. The simulation results show that the proposed defense strategy improves the performance of the under attack system in terms of rejection probability of connection requests and efficient consumption of buffer space. 相似文献
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在GPRS数据模式通信中,TCP服务器端意外断开时,GPRS模块仍然保持连接状态造成虚连接现象。提出了缩短未确认时间和定时判断的方法,较好地解决了虚连接现象,实现了GPRS模块自动联网功能。 相似文献
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随着Internet网络用户的迅速增加,IPv4地址出现了严重的短缺.网络地址转换(NAT)设备的出现解决了这个问题,但也给P2P通信带来了困难.目前,UDP穿透已经得到较好地解决,TCP穿透NAT虽然有一些解决方案,但都不完善.文章提出一种由应用程序来协助完成TCP穿透NAT的方案,减轻了对第三方服务器的依赖,提高了建立连接的安全性和效率. 相似文献
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This paper proposes a novel scheme, named ER-TCP, which transparently masks the failures happened on the server nodes of a cluster
from clients at TCP connection granularity. In this scheme, TCP connections at the server side are actively and fully replicated
to remain consistency so as to be transplanted over healthy parts during failure. A log mechanism is designed to cooperate
with the replication to achieve small sacrifice on the performance of communication and makes the scheme scales beyond a few
nodes, even when they have different processing capacities. We built a prototype system at a four-node cluster with ER-TCP,
and conducted a series of experiments on that. The experimental result told us that ER-TCP has relatively small penalty on
the communication performance, especially when it is used to synchronize multiple replicas. The results of real applications
show that ER-TCP will incur small sacrifice on performance of web server at light load, and it can be used to distribute files
very efficiently and reliably.
相似文献
Hai JinEmail: |