Assessing Error Detection Coverage by Simulated Fault Injection

Abstract

Server dependability is of increasing importance as more critical applications rely on the client-server computing model. As a consequence, complex fault/error handling mechanisms are becoming common features of today servers. This paper presents a new simulated fault injection method, which allows the assessment of the effectiveness of error detection mechanisms without using expensive test circuits. Fault injection was performed in two stages. First, physical fault injection was performed on a prototype server. Transient faults were injected in randomly selected signals. Traces of the signals sensitive to transients were captured. A complex protocol checker was devised for increasing error detection. The new detection circuitry was simulated in the second stage of the experiment. Signal traces, injected with transient faults, were used as inputs of the simulation. The error detection coverage and latency were derived. Fault injection also showed that coverage probability was a function of fault duration.