基于Docker技术的GUI应用的在线迁移研究

GUI应用在桌面环境中占据主流，在线迁移GUI应用能够提升用户体验.然而，当今广泛使用的X窗口系统所定义的协议十分复杂，不利于GUI进程的在线迁移.另外，如果两台机器的运行时环境不一致，将会导致迁移失败.因此至今未有实现GUI应用的在线迁移.近年来，Wayland作为新的图形接口协议面世，其中规定软件图形渲染由GUI客户端负责，这为迁移工作带来极大的便利.而当今热门的Docker容器技术则能把Wayland GUI应用及其运行时库打包，确保运行时环境的一致性.当迁移发生时，整个容器都会被迁移至目标机器继续运行.本文开发了相应的处理Wayland协议模块，并在CRIU工具的基础上实现了重建Wayland状态.通过实验证明，本文方案是可行的，容易推广到其他的GUI应用.

Research on the Live Migration of GUI Applications Based on the Docker technology

As GUI applications are dominant in desktop environment, online migration GUI applications can improve user experience. However, the X Window System protocol which is in widespread use today, is very complex and not conducive to the live migration of GUI applications. In addition, if the runtime environments of the two machines are not consistent, it will lead to the migration failure. Therefore the live migration of GUI applications has not been realized so far. In recent years, Wayland emerges as a new graphical interface protocol, in which rendering is left to GUI clients. This brings great convenience for the migration. And today''s popular Docker container technology is able to package the Wayland GUI application and its runtime library, which ensures the consistency of the runtime environments. When migration happens, the whole container will be migrated to the target machine so that the GUI application can continue its running status. In this paper, the corresponding processing Wayland protocol module is developed. And on the basis of the CRIU tool, it realizes the reconstruction of Wayland state. The experiments show that our scheme is feasible, and can be extended to most GUI applications with minor modification.