The Model and Adaptive Configuration Management Strategy for a Distributed Database Server System

Server redundancy technology solves the problem of availability and the performance bottleneck in the traditional distributed environment, and at the same time presents a new challenge to the system management. A kind of constituting principle and working model of a distributed database server system (DDSS) is presented in this paper. To overcome the weakness of dynamic scalability of redundancy resource in configuration management of the present redundancy server system, aiming at the server DDSS (every service in the system is abstracted to an object class in the model, and multi-instance of the same object class redundantly serving each other is proposed), the configuration management of redundancy resource is discussed, and adaptive configuration management policy based on mobile agent technology is proposed. With the precondition of ensuring the system availability, the system performance is improved and the resource waste is reduced. In ACM, by defining award-penalty function (as for static configuration) and user request arriving rate (as for dynamic configuration) which is the gist of configuration, redundancy instances is added or deleted dynamically. Finally, the algorithmic performance is analyzed and tested, and compared with traditional algorithm.