【作者】 胡子文；

【导师】 王芙蓉；

【作者基本信息】 华中科技大学 ， 通信与信息系统， 2007， 硕士

【摘要】 通信系统对于可用性有着很高要求,传统电信系统的四五类交换机已经达到了很高的稳定性及高可用性,作为下一代网络的核心控制设备的软交换也必须满足高可用性(High Availability)的要求。但是由于高可用性技术的复杂性,并且目前在技术实现上较少有公开的描述,其设计仍然是研究的重点。本文首先通过对高可用性的理论及技术加以研究,掌握可用性的基本概念、度量手段和分析方法,从系统结构、软硬件方面研究了目前通用的高可用性技术。在此基础上,对高可用性软交换设备进行研究设计,提出了一系列实现软交换设备高可用性解决方法。本文按照开放式高可用性系统架构的要求,对高可用性软交换设备给出了总体设计,并对于硬件平台、高可用性管理中间件、应用层同步等组件的设计与实现进行详细研究分析。在设计过程中,充分地分析了通用承载平台适用于高可用性控制的热插拔基础、通信基础、故障检测与控制基础,以硬件冗余和软件控制作为高可用性的实现基础,以有效地实现故障处理和提高应用的可靠性为系统高可用性地的实现途径。对高可用性管理中间件的设计实现加以重点研究分析,设计了相关的高可用性系统状态机,实现了系统的初始化和切换功能。本文对于系统的故障检测及冗余结构设计等方面的关键技术进行了深入的研究与探讨,其中论及的技术包括:看门狗、心跳检测、N+1冗余备份。最后,通过连续时间马尔可夫模型对本系统采用的N+1冗余结构的可靠性进行分析,对于系统的高可用性进行测试,取得了较为理想的结果。更多还原

【Abstract】 The telecom system always pays much attention on High availability. The Class 4 and 5 switch in traditional telecom system has already achieve High Availability.As the core equipment of NGN,the Softswitch must run with High Availability. However,because of the complication of HA technology and the lack of open description, the methods to implement a HA system in Softswitch equipment becomes our research focus.Through the study of HA technology,we can master the basic conception and implementation of HA system.So that we can design and research the implementation of a HA system and conclude a set of solutions.The overall system framework which is built on the open architecture HA solution provided by HA forum is discussed,and also the HA implementation of application layer,OS layer,hardware layer and most important,the HA manage middleware.In the course of design, characteristic of the universal hardware platform have been completely analyzed from the point of view of high availability, such as the ability in hot swapping, inter-communicating, fault detection and control. With the fact that high availability is composed by hardware and software reliability and maintainability, one way to realize high availability is to improve software reliability and combine hardware redundancy and software maintenance, so as to get the ability to deal with hardware fault and improve the availability of application layer. And the design of the HA manage middleware and Fault detect mechanism are discussed detailedly.And some critical technology,including heartbeat,watchdog,and redundancy of N+1module is deeply researched. Finally, the result of the analysis of high availability in logic and performance shows that the whole solution has been proven to be able to achieve the goal of high availability.更多还原