Towards QoS Prediction Based on Composition Structure Analysis and Probabilistic Models

The quality of service (QoS) of complex software systems, built by composing many components, is essential to determine their usability. Since the QoS of each component usually has some degree of uncertainty, the QoS of the composite system also exhibits stochastic behavior. We propose to compute probability distributions of the QoS of a service composition using its structure and the probability distributions of the QoS of the components. We experimentally evaluate our approach on services deployed in a real setting using a tool to predict probability distributions for the composition QoS and comparing them with those obtained from actual executions.