Dynamic content web applications: Crash, failover, and recovery analysis

This work assesses how crashes and recoveries affect the performance of a replicated dynamic content web ap- plication. RobustStore is the result of retrofitting TPC-W's on-line bookstore with Treplica, a middleware for build- ing dependable applications. Implementations of Paxos and Fast Paxos are at the core of Treplica's efficient and programmer-friendly support for replication and recovery. The TPC-W benchmark, augmented with faultloads and de- pendability measures, is used to evaluate the behaviour of RobustStore. Experiments apply faultloads that cause se- quential and concurrent replica crashes. RobustStore's per- formance drops by less than 13% during the recovery from two simultaneous replica crashes. When subject to an iden- tical faultload and a shopping workload, a five-replicas RobustStore maintains an accuracy of 99.999%. Our re- sults display not only good performance, total autonomy and uninterrupted availability, they also show that it is sim- ple to develop efficient recovery-oriented applications using Treplica.