A simulated fault injection tool for dependable VoD application design

This work presents a simulation-based tool for dependability-oriented design of Video on Demand (VoD) applications. The tool is organized in a layered architecture, so that simulation models can be built and detailed according to a hierarchical and modular approach. The higher layer, namely the Application Level, provides a variety of objects to rapidly model fundamental components typically found in most VoD systems. The lower level, namely the Network Level, consists of the basic building blocks needed to represent the communication infrastructure of a distributed system. The paper illustrates how to combine the tool's built-in objects, in order to construct a simulated model of a generic multimedia application. Some of the potentialities of the tool are then demonstrated by performing dependability evaluation of a real VoD system prototype. Fault injection experiments are conducted on a simulated model of DiVA, a distributed architecture for VoD applications, currently under development at the University of Naples.