The Study And Implementation Of The Dynamic Reconfiguration Platform Based On CORBA Component Model

With the development of distributed computing, distributed component technology comes into being to adapt to the increasing complexity of software system, to simplify the development process, and to improve the productivity and quality of software. CORBA Component Model (CCM), as one of the typical distributed component technologies, can be widely applied to many areas. Distributed systems with high availability requirements have to support some form of dynamic reconfiguration, such as those systems that must run continuously for a considerable long time for critical tasks. This means that they must provide the ability to be maintained or upgraded without being taken off-line. Dynamic reconfiguration technology can support the management and maintenance of complex systems, and it can accomplish the critical application's appeal to evolving on-line for adapting to the technology advancement, requirement or environment changes, and the QoS control.This thesis reports our attempts to design and implement a dynamic reconfiguration platform based on CCM component technology. The work of this thesis includes:1. We study the dynamic reconfiguration model and process. From the view of solving the major issues in dynamic reconfiguration, which includes the description of application systems and configuration changes, system consistency maintenance and performance overhead. We also analyze the state-of-the-art of dynamic reconfiguration technology, and revealedthe deficiencies of current dynamic reconfiguration approaches.2. Based on the study of common systems consistences and their corresponding solutions, we define behavior consistency, and propose an approach to maintian behavior consistency, as well as component state consistency, application state consistency, and reference consistency.3. We analyze the realization course of each primary dynamic reconfiguration intention, and then design the corresponding dynamic reconfiguration implement algorithm, which can assure the system consistencies.4. We study the CCM component technology and analyze its potential support for dynamic reconfiguration. Combining the reconfiguration mechanisms extracted from dynamic reconfiguration algorithms, we designed a dynamic reconfiguration platform based on CCM component technology.5. By extending the StarCCM platform, which is an implementation of CCM specification, we implement the dynamic reconfiguration platform, and have functional and performance tests. The result of tests indicates that the applications that run on this platform can be dynamically reconfigured correctly, and the platform shows little performance overhead, satisfying performance requirements of most of the applications.