Abstract. We present the implementation of an experimental tool that automatically synthesises monitors from specifications written in mHML, a monitorable subset of the branching-time logic µHML. The synthesis algorithm is compositional wrt. the structure of the formula and follows closely a synthesis procedure that has been shown to be correct. We discuss how this compositionality facilitates a translation into concurrent Erlang monitors, where each individual (sub)monitor is an actor that autonomously analyses individual parts of the source specification formula while still guaranteeing the correctness of the overall monitoring process.

Runtime Verification is a lightweight technique that complements other verification methods in an effort to ensure software correctness. The technique poses novel questions to software engineers: it is not easy to identify which specifications are amenable to runtime monitoring, nor is it clear which monitors effect the required runtime analysis correctly. This exposition targets a foundational understanding of these questions. Particularly, it considers an expressive specification logic (a syntactic variant of the modal µ-calculus) that is agnostic of the verification method used, together with an elemental framework providing an operational semantics for the runtime analysis performed by monitors. The correspondence between the property satisfactions in the logic on the one hand, and the verdicts reached by the monitors performing the analysis on the other, is a central theme of the study. Such a correspondence underpins the concept of monitorability, used to identify the subsets of the logic that can be adequately monitored for by RV. Another theme of the study is that of understanding what should be expected of a monitor in order for the verification process to be correct. We show how the monitor framework considered can constitute a basis whereby various notions of monitor correctness may be defined and investigated.

Abstract. We propose an instrumentation technique for monitoring asynchronous component systems that departs from the traditional runtime verification set-up assuming a single execution trace. The technique generates partitioned traces that better reflect the interleaved execution of the asynchronous components under scrutiny, and lends itself well to local monitoring. We provide argumentation for the qualitative benefits of our approach, demonstrate its implementability for actor-based systems, and justify claims related to the applicability and efficiency gains via an empirical evaluation over a third party component-based system.

We present a synthetic benchmarking framework that targets the systematic evaluation of RV tools for message-based concurrent systems. Our tool can emulate various load profiles via configuration. It provides a multi-faceted view of measurements that is conducive to a comprehensive assessment of the overhead induced by runtime monitoring. The tool is able to generate significant loads to reveal edge case behaviour that may only emerge when the monitoring system is pushed to its limit. We evaluate our framework in two ways. First, we conduct sanity checks to assess the precision of the measurement mechanisms used, the repeatability of the results obtained, and the veracity of the behaviour emulated by our synthetic benchmark. We then showcase the utility of the features offered by our tool in a two-part RV case study.