Easier Said Than Done: Diagnosing Misconfiguration via Configuration Constraints Analysis: A Study of the Variance of Configuration Constraints in Source Code

Misconfigurations have drawn tremendous attention for their increasing prevalence and severity, and the main causes are the complexity of configurations as well as the lack of domain knowledge for software. To diagnose misconfigurations, one typical approach is to find out the conditions that configuration options should satisfy, which we refer to as configuration constraints. Current researches only handled part of the situations of configuration constraints in source code, which provide only limited help for misconfiguration diagnosis. To better extract configuration constraints, we conduct a comprehensive manual study on the existence and variance of the configuration constraints in source code from five pieces of popular open-source software. We summarized several findings from different aspects, including the general statistics about configuration constraints, the general features for specific configurations, and the obstacles in extraction of configuration constraints. Based on the findings, we propose several suggestions to maximize the automation of constraints extraction.