Experience with distributed replicated objects: The Nile project

Abstract

The goal of the Nile project is to develop an inexpensive, scalable, fault-tolerant, widely distributed job processing environment. On the systems side, Nile must manage and provide transparent access to hundreds of commodity processors spread across the United States, and a distributed database that will exceed 100˜terabytes. These are scales not commonly encountered by projects concerned with fault tolerance. On the software engineering side, Nile must be easily maintained, outlive its development phase, and be able to incorporate, or even migrate to, new software components; these requirements led us to the CORBA standard. CORBA does not yet include a fault tolerance specification, and only a small number of experimental Object Request Brokers support object fault tolerance through replication. Our experiences over two years of building Nile have taught us a great deal that may be of use to designers of ORBs that will support object replication and fault tolerance. © 1998 John Wiley & Sons, Inc.