Design And Implementation Of The Hot Backup Function For The Network Controller In A Survellence System

The topic of this thesis is originated from a project of escalating Panasonic (Beijing)'s Video Surveillance System to be more digitalized and suitable for network environment. The main works focus on the problem of replicated backup of the core control device-the Network Controller (NC) in the system.We first introduced some backgrounds of the project and the importance of the backup system in it. Then based on the widely used current mirror techniques, we described some basic functions of the dual-hot-standby system, and analyzed the functions and their requirements of it in NC. Next according to the requirements, we studied and analyzed the involved functions of the underlying operation system (Linux) and protocols used in the network. Finally on the basis of the works above, we proposed a practical scheme of backup system that could meet the requirement of the NC project. The scheme is implemented upon Linux, and can be divided into two layers. The function of the core layer is mainly used to coordinate the system of backup to capture data from the operation system, and perform management accordingly. Functions in the user layer include the monitoring of system status, switching between active and standby devices, transmiting log files and backup data, and etc. Basically each function will be carried out by a process, and the coordination of them can be achieved by inter-process communications and synchronizations. Elementary analyses show that the design is feasible.