Reliability and fault-tolerance issues in distributed VoD systems

This work presents a simulation-based tool for designing fault-tolerat Video on Demand (VoD) applications. The architecture of the tool relies on a two layer structure, namely the application level and the network level. The former contains a variety of objects to rapidly model fundamental components typically found in most distributed multimedia systems for VoD applications. The latter provides the building blocks needed to represent the communication infrastructure of a distributed architecture. Some of the potentialities of the tool are demonstrated by applying it to the analysis of a real system prototype. The contribution of this work is twofold. First, it provides a flexible and versatile template for efficient and accurate simulation of distributed systems for VoD applications. Second, it shows that models and techniques developed for traditional fault tolerant system design can be re-targeted, in order to address specific dependability issues of VoD applications.