基于动态备份虚拟机的高可靠网络系统

发布时间：2018-11-28 20:08

【摘要】：随着互联网技术的发展，网络服务已经覆盖到了各个领域。由于服务器发生故障会带来一定程度的损失，因此，网络服务器的高可靠性至关重要。虚拟机状态同步（将主虚拟机的状态以一定方式同步到后备虚拟机）是当前学术界普遍认为可以提高网络服务器高可靠性的技术。然而，现存的基于虚拟机状态同步的高可靠方案由于过分地进行状态同步使得性能不理想。本文基于虚拟机同步技术提出了一种通用且高效的网络高可靠解决方案——Shadow VM。Shadow VM将客户端的请求数据包同时发送给主虚拟机和后备虚拟机，并比较两个虚拟机产生的响应数据包。只要后备虚拟机产生的响应数据包能和主虚拟机的响应数据包保持一致，那么Shadow VM就认为后备虚拟机是主虚拟机的合法备份，且后备虚拟机能够在主虚拟机发生故障后替代主虚拟机继续向客户端提供服务。当两个虚拟机产生的响应数据包不一致时，Shadow VM将主虚拟机的状态同步到后备虚拟机，以保证后备虚拟机仍然是主虚拟机的合法备份。主虚拟机和后备虚拟机都处于活动状态，本文是首次实现了两个动态虚拟机之间的状态同步。通过消除一部分TCP/IP协议栈的不确定因素，Shadow VM延长了两个虚拟机产生相同的响应数据包的时间。此外，通过减少同步两个动态运行的虚拟机的开销，Shadow VM获得了良好的性能。实验结果显示，Shadow VM在保护Web服务器和FTP服务器时，，能够达到30%以上的性能。Shadow VM引入的网络延迟也非常小，并且，能够在主服务器发生故障之后，在几百毫秒之内切换到后备服务器。
[Abstract]:With the development of Internet technology, network services have been covered in various fields. Because the failure of the server will bring some losses, the high reliability of the network server is very important. Virtual machine state synchronization (which synchronizes the state of the primary virtual machine to the backup virtual machine in a certain way) is widely regarded as the technology that can improve the high reliability of the network server. However, the existing high reliability scheme based on virtual machine state synchronization has poor performance due to excessive state synchronization. In this paper, based on virtual machine synchronization technology, a general and efficient network high reliability solution is proposed, in which Shadow VM.Shadow VM sends the request packets from the client to both the primary virtual machine and the backup virtual machine at the same time. The response packets generated by the two virtual machines are compared. As long as the response packet generated by the backup virtual machine is consistent with the response packet of the primary virtual machine, Shadow VM considers the backup virtual machine to be a legitimate backup of the primary virtual machine. And the backup virtual machine can continue to provide service to the client after the main virtual machine fails. When the response packets generated by the two virtual machines are inconsistent, Shadow VM synchronizes the state of the primary virtual machine to the backup virtual machine to ensure that the backup virtual machine is still the legal backup of the primary virtual machine. The primary virtual machine and the backup virtual machine are both active. This paper realizes the state synchronization between the two dynamic virtual machines for the first time. By eliminating some uncertainties in the TCP/IP stack, Shadow VM extends the time between the two virtual machines to generate the same response packets. In addition, Shadow VM achieves good performance by reducing the overhead of synchronizing two dynamic virtual machines. The experimental results show that, Shadow VM can achieve more than 30% performance when protecting Web server and FTP server, and the network delay caused by. Shadow VM is very small. Switch to the backup server within a few hundred milliseconds.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP393.09;TP302

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