Behavioral Log Analysis with Statistical Guarantees

Scalability is a major challenge for existing behavioral log analysis algorithms, which extract finite-state automaton models or temporal properties from logs generated by running systems. In this paper we present statistical log analysis, which addresses scalability using statistical tools. The key to our approach is to consider behavioral log analysis as a statistical experiment.Rather than analyzing the entire log, we suggest to analyze only a sample of traces from the log and, most importantly, provide means to compute statistical guarantees for the correctness of the analysis result.We present the theoretical foundations of our approach and describe two example applications, to the classic k-Tails algorithm and to the recently presented BEAR algorithm.Finally, based on experiments with logs generated from real-world models and with real-world logs provided to us by our industrial partners, we present extensive evidence for the need for scalable log analysis and for the effectiveness of statistical log analysis.