Accompanying Component Based Systems Dynamic Reconfiguration with Formal Modelling and Analysis

Nowadays systems should be able to perform evolutionary changes without degrading performances of online services. To achieve that, it is interesting to predict performances of a system reconfiguration, as introducing such properties in a system may lead to quality of service loss and performance degradation. In this case, the impact analysis of a reconfiguration before applying it effectively becomes a challenge, to help software engineers in analyzing their applications and deciding whether a reconfiguration should be done or discarded to avoid performance problems. We are interested in that concern, in the field of Component-Based Systems (CBS). In our previous work, we proposed, a new formalism for checking consistency of dynamic reconfigurations of component based systems. In this paper, we provide a new approach for formal Modelling of a dynamic reconfiguration on CBS to allow quantitative analysis. The modelling consists of generating stochastic Well-formed net (SWN) models, starting from reconfiguration description. Performance indices can be computed through the analysis of obtained models with an SWN tool such as the GreatSPN package used here. A case study of a Fractalbased system reconfiguration illustrates the effectiveness of our approach.