Technical Report Number
Web Services that provide mission-critical functionality must be replicated to guarantee correct execution and high availability in spite of arbitrary (Byzantine) faults. Existing approaches for Byzantine fault-tolerant execution of Web Services are inadequate to guarantee correct execution due to several major limitations. Some approaches do not support interoperability between replicated Web Services. Other approaches do not provide fault isolation guarantees that are strong enough to prevent cascading failures across organizational and application boundaries. Moreover, existing approaches place impractical limitations on application development by not supporting long-running active threads of computation, fully asynchronous communication, and access to host specific information. We present Perpetual-WS, middleware that supports interaction between replicated Web Services while providing strict fault isolation guarantees. Perpetual-WS supports both synchronous and asynchronous message passing and enables an application model that supports long-running active threads of computation. We present an implementation based on Axis2 and performance evaluations demonstrating only a moderate decrease in throughput due to replication.
Pallemulle, Sajeeva L. and Goldman, Kenneth J., "Byzantine Fault-Tolerant Web Services for n-Tier and Service Oriented Architectures" Report Number: WUCSE-2007-53 (2007). All Computer Science and Engineering Research.