Perpetual: Byzantine Fault Tolerance for Federated Distributed Applications

Modern distributed applications rely upon the functionality of services from multiple providers. Mission-critical services, possibly shared by multiple applications, must be replicated to guarantee correct execution and availability in spite of arbitrary (Byzantine) faults. Furthermore, shared services must enforce strict fault isolation policies to prevent cascading failures across organizational and application boundaries. Most existing protocols for Byzantine fault-tolerant execution do not support interoperability between replicated services while others provide poor fault isolation. Moreover, existing protocols place impractical limitations on application development by disallowing long-running threads of computation, asynchronous operation invocation, and asynchronous request processing. We present Perpetual, a protocol that facilitates unrestricted interoperability between replicated services while enforcing strict fault isolation criteria. Perpetual supports both asynchronous operation invocation and asynchronous request processing. Perpetual also supports long-running threads of computation, enabling Byzantine fault-tolerant execution of services that carry out active computations. We present performance evaluations demonstrating a moderate overhead due to replication. Type of Report: Other Department of Computer Science & Engineering Washington University in St. Louis Campus Box 1045 St. Louis, MO 63130 ph: (314) 935-6160 Perpetual: Byzantine Fault Tolerance for Federated Distributed Applications Sajeeva L. Pallemulle Haraldur D. Thorvaldsson Kenneth J. Goldman Department of Computer Science and Engineering Washington University in St. Louis, St. Louis, MO 63130 USA {sajeeva, harri, kjg}@cse.wustl.edu