Interpreted Formalisms for Configurations

Abstract

Imprecise and incomplete specification of system configurations threatens safety, security, functionality, and other critical system properties and uselessly enlarges the configuration spaces to be searched by configuration engineers and auto-tuners. To address these problems, this paper introduces interpreted formalisms based on real-world types for configurations. Configuration values are lifted to values of real-world types, which we formalize as subset types in Coq. Values of these types are dependent pairs whose components are values of underlying Coq types and proofs of additional properties about them. Real-world types both extend and further constrain machine-level configurations, enabling richer, proof-based checking of their consistency with real-world constraints. Tactic-based proof scripts are written once to automate the construction of proofs, if proofs exist, for configuration fields and whole configurations. Failures to prove reveal real-world type errors. Evaluation is based on a case study of combinatorial optimization of Hadoop performance by meta-heuristic search over Hadoop configurations spaces.