The Horus and Ensemble Projects: Accomplishments and Limitations

unofficial copies [PDF], [PS]


by Kenneth Birman, Robert Constable, Mark Hayden, Jason Hickey, Christoph Kreitz, Robbert van Renesse, Ohad Rodeh, and Werner Vogels

Proceedings of DARPA Information Survivability Conference and Exhibition (DISCEX'00), 2000.

Abstract

The Horus and Ensemble efforts culminated a multi-year Cornell research program in process group communication used for fault-tolerance, security and adaptation. Our intent was to understand the degree to which a single system could offer flexibility and yet maintain high performance, to explore the integration of fault-tolerance with security and real-time mechanisms, and to increase trustworthiness of our solutions by applying formal methods. Here we summarize the accomplishments of the effort and evaluate the successes and failures of the approach.