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Electrical and Computer Engineering

Selected Works

2014

Dependable Systems

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Design And Implementation Of A Byzantine Fault Tolerance Framework For Non-Deterministic Applications, H. Zhang, Wenbing Zhao, Louise E. Moser, P. Michael Melliar-Smith Aug 2014

Design And Implementation Of A Byzantine Fault Tolerance Framework For Non-Deterministic Applications, H. Zhang, Wenbing Zhao, Louise E. Moser, P. Michael Melliar-Smith

Wenbing Zhao

State-machine-based replication is an effective way to increase the availability and dependability of mission-critical applications. However, all practical applications contain some degree of non-determinism. Consequently, ensuring strong replica consistency in the presence of application non-determinism has been one of the biggest challenges in building dependable distributed systems. In this Study, the authors propose a classification of common types of application non-determinism with respect to the requirement of achieving Byzantine fault tolerance (BFT), and present the design and implementation of a BFT framework that controls these types of non-determinism in a systematic manner.


End-To-End Latency Of A Fault-Tolerant Corba Infrastructure, Wenbing Zhao, Louise E. Moser, P. Michale Melliar-Smith Aug 2014

End-To-End Latency Of A Fault-Tolerant Corba Infrastructure, Wenbing Zhao, Louise E. Moser, P. Michale Melliar-Smith

Wenbing Zhao

This paper presents an evaluation of the end-to-end latency of a fault-tolerant CORBA infrastructure that we have implemented. The fault-tolerant infrastructure replicates the server applications using active, passive and semi-active replication, and maintains strong replica consistency of the server replicas. By analyses and by measurements of the running fault-tolerant infrastructure, we characterize the end-to-end latency under fault-free conditions. The main determining factor of the run-time performance of the fault-tolerant infrastructure is the Totem group communication protocol, which contributes to the end-to-end latency primarily in two ways: the delay in sending messages and the processing cost of the rotating token. To …


A Reservation-Based Extended Transaction Protocol For Coordination Of Web Services, Wenbing Zhao, Firat Kart, Louise Moser, P. Melliar-Smith Aug 2014

A Reservation-Based Extended Transaction Protocol For Coordination Of Web Services, Wenbing Zhao, Firat Kart, Louise Moser, P. Melliar-Smith

Wenbing Zhao

Web services can be used to automate business activities that span multiple enterprises over the Internet. Such business activities require a coordination protocol to reach consistent results among the participants in the business activity. In the current state of the art, either classical distributed transactions or extended transactions with compensating transactions are used. However, classical distributed transactions lock data in the databases of different enterprises for unacceptable durations or involve repeated retries, and compensating transactions can lead to inconsistencies in the databases of the different enterprises. In this article, we describe a novel reservation protocol that can be used to …