24-01-2012, 05:26 PM
Rapid and accessible performance evaluation of complex software systems requires two critical features: being able to specify useful performance metrics easily and the capability to analyse massively distributed architectures, without recourse to large compute clusters. We present the unified stochastic probe, a performance specification mechanism for process algebra models that combines many existing ideas: state and action-based activation, location-based specification, many-probe specification and immediate signalling. These features, between them, allow the precise and compositional construction of complex performance measurements. The paper shows how a subset of the stochastic probe language can be used to specify common response time measures in massive process algebra models. The second contribution of the paper is to show how these response-time measures can be analysed using so-called fluid techniques to produce rapid results. In doing this, we extend the fluid approach to incorporate immediate activities and a new type of response-time measure. Finally, we calculate various response-time measurements on a complex distributed wireless network of O(10^129) states in size.