Managing Robustness of Distributed Applications Under Uncertainties: An Information Assurance Perspective

The paper deals with how to manage the dependability of a distributed information system (DIS), in the presence of inaccuracies and partial knowledge of system models pertaining to failures of infrastructure components. The computational parts of a DIS are faced with two types of uncertainties: at ’information level’ due to the multi-dimensional nature of measurement data emanating from the external environment (i.e., the physical world), and at ’control level’ due to the incompleteness in knowledge about the application model for processing the measured data. These uncertainties have a compounded effect on the robustness of decisionmaking in the applications running on a DIS. Based on service-layer abstractions, the paper identifies applicationoriented metrics to quantify the quality of information flowing through a DIS. Suitable high-level quality metrics enable reasonably accurate decision-making by the application-layer control algorithms. Our approach is useful in the probabilistic management of: i) peer-to-peer communication assurance, and ii) fault-tolerance against component failures.