多媒体会议系统负载均衡机制的研究

发布时间：2018-05-15 07:35

本文选题：负载均衡 + 集群　；参考：《北京邮电大学》2014年硕士论文

【摘要】：随着网络技术的发展以及互联网应用的普及,Web服务器端的访问量也在急剧增长,而服务器的处理能力跟不上访问量的增加导致了系统的响应速度越来越慢。为了解决这些问题,学者们提出了一些新的技术。其中,负载均衡技术被认为是提高系统性能及响应速度的最有效的方法之一。基于Web技术开发的多媒体会议系统同样面临着高并发情况下服务器负载过重以及处理能力不足的问题。但是,传统的基于用户、会话等负载均衡技术无法完全适用于多媒体会议系统。因此,本论文提出了适用于多媒体会议系统的负载均衡机制,并在此基础上设计并实现了具有普适性的LBaaS (Load Balance as a Service)系统。本论文的研究工作主要包含两个部分。首先,为了提高多媒体会议系统在高并发、高负载情况下系统的承载能力,我们设计并实现了基于负载均衡的多媒体会议系统。区别于一般的负载均衡系统将单个访问请求进行负载均衡的方法,该系统以会议请求为粒度,将请求合理地分配至集群中的会议服务器,从而保证参与同一个会议的所有用户请求能被分配至相同的服务器环境中。该系统共分为五个层次：客户端层、负载均衡器层、会议服务器集群层、媒体服务器集群层和数据库层。客户端层接收用户请求,并根据请求类型的不同做相应的处理；负载均衡器层接收来自客户端层的会议请求,将其合理地分配至集群中的会议服务器；会议服务器集群层接收并处理来自客户端和负载均衡器的请求；媒体服务器集群层提供媒体流的上传下载服务；数据库层为客户端做决策时提供支撑。其次,为了提高基于负载均衡的多媒体会议系统的可维护性,同时提高创建负载均衡集群的效率,将“创建负载均衡集群”作为一项服务提供给用户,实现“一键建集群”,我们设计并实现了LBaaS系统。LBaaS系统主要包括三部分：Web客户端模块、服务支撑模块和laaS模块。Web客户端用于接收用户所要创建的负载均衡集群的相关信息,包括集群中节点服务器的IP、负载均衡策略、负载均衡器的名称等；服务支撑模块将集群相关信息转化为标准化参数,传送给IaaS模块进行处理；IaaS模块为系统提供基础架构平台。本论文中使用OpenStack作为IaaS平台。本论文的最后,对两个系统进行了实验和测试。结果表明,基于负载均衡的多媒体会议系统顺利实现了正常的会议流程,且具有一定的抗压性和容错性,同时LBaaS系统能够屏蔽底层实现细节,显著地提高了用户创建集群的效率,达到了预期的效果。
[Abstract]:With the development of network technology and the popularity of Internet application, the access to Web server is also increasing rapidly, and the processing ability of server can not keep up with the increase of traffic, which leads to the system's response speed becoming slower and slower. In order to solve these problems, scholars put forward some new technologies. Load balancing is considered to be one of the most effective methods to improve system performance and response speed. The multimedia conference system based on Web technology also faces the problem of overloaded server and insufficient processing power under high concurrency. However, traditional load balancing techniques, such as user-based and session-based, can not be fully applied to multimedia conference systems. Therefore, this paper proposes a load balancing mechanism suitable for multimedia conference system, and then designs and implements a universal LBaaS load Balance as a Service) system. The research work of this thesis mainly includes two parts. Firstly, in order to improve the load carrying capacity of multimedia conference system under high concurrency and high load, we design and implement the multimedia conference system based on load balance. Different from the general load balancing system, which balances the load of a single access request, the system allocates the request to the conference server in the cluster with the meeting request as the granularity. This ensures that all user requests that participate in the same meeting can be assigned to the same server environment. The system is divided into five layers: client layer, load balancer layer, conference server cluster layer, media server cluster layer and database layer. The client layer receives the user request and processes it according to the different request types, the load balancer layer receives the meeting request from the client layer and allocates it to the conference server in the cluster reasonably. The conference server cluster layer receives and processes requests from the client and load balancer; the media server cluster layer provides the upload and download service of the media flow; and the database layer provides support for the client to make decisions. Secondly, in order to improve the maintainability of the multimedia conference system based on load balancing, and to improve the efficiency of creating load balanced cluster, "creating load balanced cluster" is provided as a service to users to realize "building cluster with one click". We design and implement LBaaS system. LBaaS system mainly includes three parts: Web client module, service support module and laaS module. It includes IP of node server, load balancing strategy, name of load balancer and so on; Service support module converts cluster related information into standardized parameters, and sends it to IaaS module to process IaaS module to provide infrastructure platform for the system. In this paper, OpenStack is used as IaaS platform. At the end of this thesis, two systems are tested and tested. The results show that the multimedia conference system based on load balancing realizes the normal meeting flow smoothly, and has the ability of resistance to pressure and fault tolerance, and the LBaaS system can shield the implementation details of the bottom layer at the same time. The efficiency of creating cluster is improved significantly and the expected effect is achieved.
【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

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