Three-Valued Asynchronous Distributed Runtime Verification

This paper studies runtime verification of distributed asynchronous systems and presents a monitor generation procedure for this purpose, which allows three-valued monitoring. The properties used in the monitors are specified in a logic that was newly created for this purpose and is called Distributed Temporal Logic (DTL). DTL combines the three-valued Linear Temporal Logic (LTL₃) with the past-time Distributed Temporal Logic (ptDTL), which allows to mark subformulas for remote evaluation. The monitor generation presented in this paper is based on an adopted version of the LTL₃ monitor generation, which integrates the ptDTL monitor construction. The aim of this new procedure is to increase the amount of monitorable properties compared to the properties monitorable with ptDTL. Runtime verification using this new monitoring has been implemented on LEGO Mindstorms NXT robots communicating via Bluetooth.