The Design And Implementation Of Fault-Tolerant Sub-System For Parlay Application Server

NGN(Next Generation Network) is a service-driven network, as a key component of the service layer in the architecture of NGN, Parlay application service should provide a steady and effective environment, which is in charge of holding and running the various service logic with high-level reliability. This paper aims for improving the reliability and dependability of the Parlay application server, design and implement a solution for the fault-tolerance.At the very beginning, the paper analyzes the requirements of the fault-tolerant in the system by launching on the structure of the application server. By integrating the worldwide study and research on software fault-torrent, the author summarized the feasibility to enable the system to provide the uninterrupted service.In the next place, on the assumption that only the single-point fault can happen in the system, the author designs the detailed solution and procedure for solving the node fault and the fault of the key process, and achieve the target of the fault-tolerant deployment of the service logic, that is, whenever a singe-point fault happens in the system, the service logic deployed can run normally and the system can still receive and handle the notification message triggered in the network. Additionally, the author also proposes a brief measure for resolving the problems such as the restoring of the call instance, the treatment of the thread-level fault-tolerant.In the second-half part of the paper, the design and the implementation of the modules which composed the fault-tolerant sub-system was depicted in detail. At last, the author illustrates the test case and the test result of the fault-tolerant, which initially validate the usability of the fault-tolerant subsystem.