1 research outputs found
Understanding the Timed Distributed Trace of a Partially Synchronous System at Runtime
It has gained broad attention to understand the timed distributed trace of a
cyber-physical system at runtime, which is often achieved by verifying
properties over the observed trace of system execution. However, this
verification is facing severe challenges. First, in realistic settings, the
computing entities only have imperfectly synchronized clocks. A proper timing
model is essential to the interpretation of the trace of system execution.
Second, the specification should be able to express properties with real-time
constraints despite the asynchrony, and the semantics should be interpreted
over the currently-observed and continuously-growing trace. To address these
challenges, we propose PARO - the partially synchronous system observation
framework, which i) adopts the partially synchronous model of time, and
introduces the lattice and the timed automata theories to model the trace of
system execution; ii) adopts a tailored subset of TCTL to specify temporal
properties, and defines the 3-valued semantics to interpret the properties over
the currently-observed finite trace; iii) constructs the timed automaton
corresponding to the trace at runtime, and reduces the satisfaction of the
3-valued semantics over finite traces to that of the classical boolean
semantics over infinite traces. PARO is implemented over MIPA - the open-source
middleware we developed. Performance measurements show the cost-effectiveness
of PARO in different settings of key environmental factors