Fault-tolerant Corba, Replication Management And Failure Of The Research And Implementation Of The Management Infrastructure

With the computer networks growing rapidly nowadays, we can see the computers connected with networks acting as a computing environments here and there. As a result of it, distributed computing technique is influencing every part of our social life strongly, i.e. politics, economics. With the ever increasing amount of distributed computing systems applied in wide range of critical domains, the requirement of high reliability and high availability of distributed computing systems tend to be more and more urgent. However, distributed fault-tolerant applications are hard to be developed, since the programmers must handle not only the complex business logic but also the confused fault tolerance logic.. Therefore, people concern more and more on how to form an unified platform supporting the development of distributed fault-tolerant applications.This thesis focuses on the research and implementation of the fault-tolerant supporting platform, Ftbus, conforming to the fault-tolerant CORBA specification 1.0 in a work group, which is built on the StarBus3.0 conforming to the CORBA specification 2.3. It aims at making four major contributions:Firstly, the thesis analyses the research efforts recently devoted to build up a fault-tolerant CORBA system, which can be categorized into three approaches: integration approach, service approach and interception approach. To address the flaw of these approaches, Ftbus, which is configurable and extensible, will implement the fault tolerance management efficiently, and provide well interoperability and well transparency for clients.Secondly, the thesis designs and implements the replication management subsystem of the Ftbus. To resolve the issues of object group's life cycle management and fault tolerance properties management, an object factory model is designed to load the objects dynamically, a set of fault tolerance properties are defined according to the common characteristics of the fault-tolerant system, and moreover a hierarchy model is proposed to enable the dynamic and flexible configuration.Thirdly, the thesis designs and implements the fault management subsystem of the Ftbus. The notification model is imported to deliver the fault events efficiently. Facing the entities on different level, like object, process and host, a fault detection model of hierarchy tree structure is adopted to enhance the extensibility. And finally a ring-check algorithm is proposed to resolve the single-failure problem.The final contribution of the thesis is the implementation of the Ftbus, which is the production of our Ftbus work group. Then the experiments on the functionality and the performance have also been carried out to demonstrate the efficiency of the Ftbus. Now, the CVIC Software Engineer Co. Ltd has applied the Ftbus to its enterprise application integrated platform .