Consistency of Partitionable Object Groups in a CORBA Framework �

The Eternal system provides a novel methodology for the consistent replication of objects in an adaptive, faulttolerant, CORBA-compliant distributed system that is susceptible to partitioning. Passive and active replication schemes are supported in Eternal, and mechanisms are provided for the interaction of objects with different replication schemes. Nested operations for both passive and active objects are accommodated. Suppression of duplicate operations is ensured by unique message and operation identifiers. Continued operation is allowed in all components of a partitionedsystem. State transfer mechanisms and fulfillment operations restore the consistency of the states of replicas within the components of a partitioned system when communication is reestablished and the components remerge.