Performance and Reliability Evaluation of Passive Replication Scheme in Application Level Fault Tolerance
15 June 1999
Replication of software systems has been provided as the central mechanism for application level software fault tolerance in NT-SwiFT, DOORS. These technologies, implemented as reusable software modules support passive replication schemes including cold and warm. The choice of a scheme for a particular application is based on its availability and performance requirements. In this paper, we analyze the reliability and performance of a sever software which may potentially use these technologies. We derive closed form formulae for availability, throughput and probability of loss of a job. Six scenarios of loss are modeled and for each, these expressions are derived. The formulae can be used either offline or online to determine the optimal replication scheme.