Semantic-Driven Model Composition for Accurate Anomaly Diagnosis

In this paper, we introduce a semantic-driven approach to system modeling for improving the accuracy of anomaly diagnosis. Our framework composes heterogeneous families of models, including generic statistical models, and resource-specific models into a belief network, i.e., Bayesian network. Given a set of models which sense the behavior of various system components, the key idea is to incorporate expert knowledge about the system structure and dependencies within this structure, as meta-correlations across components and models. Our approach is flexible, easily extensible and does not put undue burden on the system administrator. Expert beliefs about the system hierarchy, relationships and known problems can guide learning, but do not need to be fully specified. The system dynamically evolves its beliefs about anomalies over time. We evaluate our prototype implementation on a dynamic content site running the TPC-W industry-standard e- commerce benchmark. We sketch a system structure and train our belief network using automatic fault injection. We demonstrate that our technique provides accurate problem diagnosis in cases of single and multiple faults. We also show that our semantic-driven modeling approach effectively finds the component containing the root cause of injected anomalies, and avoids false alarms for normal changes in environment or workload.