Runtime state change detector of computer system resources under non stationary conditions

Abstract

All runtime management decisions in computer and information systems require immediate detection of relevant changes in the state of their resources. This is accomplished by continuously monitoring the performance/utilization of key system resources and by using appropriate statistical tests to detect the occurance of significant state changes. Unfortunately, the complexity of today systems and applications and the unpredictability of user request patterns result in highly variable and non stationary time series which are difficult to analyze. As a consequence, present solutions for detecting state changes at runtime are affected by excessive time delays or false positives. We propose a novel “agile” runtime detector that solves the delay vs. false positive tradeoff: it is able to detect the relevant state changes as fast as the best reactive models with the lowest percentages of false positives. All evaluations carried out for a large set of scenarios confirm the efficacy and robustness of the proposed model.