A fault-tolerant system for Java/CORBA objects

Frameworks like CORBA facilitate the development of distributed applications through the use of off-the-shelf components. Though the use of distributed components allows faster building of applications, it also reduces the application availability as failure of any component can make the application unavailable. In this paper we present the design and implementation of a fault-tolerant system for CORBA objects implemented in Java. The proposed fault tolerant system employs object replication. We use a three tier architecture in which the middle tier manages replication and acts as a proxy for replicated objects. The proxy ensures consistency and transparency. In the current implementation, the proxy uses the primary-site approach to ensure strong consistency. Saving and restoring of objects´ state is done transparently and it does not require object implementation to have special functions implemented for this purpose.