D.4.1 – Application scenarii and Design of infrastructure

This report has been written by all members of the consortiumSocioPlug is a research project, funded by French National Agency for Research, which aims to investigate on Social Cloud over Plug Networks, Enabling Symmetric Access to Data and Preserving Privacy. In this project, we will perform both theoretical and practical evaluation of the solutions proposed in the all work packages. Task 4 (Infrastructure and Experimentation) will be structured around use-cases where partners developed previous expertise such as distributed collaborative systems, social web and Smart Building. These well known distributed systems will be revisited to fit federation of plug constraints using results of other tasks. In this deliverable, we present some details of the infrastructure of the federation of plug computers, that will be developed in this project. We plan to provide a demonstrator and deploy on it some application according to the use-cases presented in this deliverable

Nothing can compare with a population, besides agents

15 pagesLeveraging the resemblances between two areas explored so far independently enables to provide a theoretical framework for dis- tributed systems where global behaviors emerge from a set of local in- teractions. The contribution of this paper arise from the observation that population protocols and multi-agent systems (MAS) bear many resemblances. Particularly, some subclasses of MAS seem to fit the same computational power than population protocols. Population protocols provide theoretical foundations for mobile tiny device networks. On the other hand, from long-standing research study in distributed artificial in- telligence, MAS forms an interesting model for society and owns a broad spectrum of application field, from simple reactive system to social sci- ences. Linking the both model should offers several extremely interesting outcomes

New results on a generalized coupon collector problem using Markov chains

We study in this paper a generalized coupon collector problem, which consists in determining the distribution and the moments of the time needed to collect a given number of distinct coupons that are drawn from a set of coupons with an arbitrary probability distribution. We suppose that a special coupon called the null coupon can be drawn but never belongs to any collection. In this context, we obtain expressions of the distribution and the moments of this time. We also prove that the almost-uniform distribution, for which all the non-null coupons have the same drawing probability, is the distribution which minimizes the expected time to get a fixed subset of distinct coupons. This optimization result is extended to the complementary distribution of that time when the full collection is considered, proving by the way this well-known conjecture. Finally, we propose a new conjecture which expresses the fact that the almost-uniform distribution should minimize the complementary distribution of the time needed to get any fixed number of distinct coupons.Comment: 14 page

Sketch *-metric: Comparing Data Streams via Sketching

12 pages, double colonnesIn this paper, we consider the problem of estimating the distance between any two large data streams in small- space constraint. This problem is of utmost importance in data intensive monitoring applications where input streams are generated rapidly. These streams need to be processed on the fly and accurately to quickly determine any deviance from nominal behavior. We present a new metric, the Sketch ⋆-metric, which allows to define a distance between updatable summaries (or sketches) of large data streams. An important feature of the Sketch ⋆-metric is that, given a measure on the entire initial data streams, the Sketch ⋆-metric preserves the axioms of the latter measure on the sketch (such as the non-negativity, the identity, the symmetry, the triangle inequality but also specific properties of the f-divergence). Extensive experiments conducted on both synthetic traces and real data allow us to validate the robustness and accuracy of the Sketch ⋆-metric

GCP: Gossip-based Code Propagation for Large-scale Mobile Wireless Sensor Networks

Wireless sensor networks (WSN) have recently received an increasing interest. They are now expected to be deployed for long periods of time, thus requiring software updates. Updating the software code automatically on a huge number of sensors is a tremendous task, as ''by hand'' updates can obviously not be considered, especially when all participating sensors are embedded on mobile entities. In this paper, we investigate an approach to automatically update software in mobile sensor-based application when no localization mechanism is available. We leverage the peer-to-peer cooperation paradigm to achieve a good trade-off between reliability and scalability of code propagation. More specifically, we present the design and evaluation of GCP ({\emph Gossip-based Code Propagation}), a distributed software update algorithm for mobile wireless sensor networks. GCP relies on two different mechanisms (piggy-backing and forwarding control) to improve significantly the load balance without sacrificing on the propagation speed. We compare GCP against traditional dissemination approaches. Simulation results based on both synthetic and realistic workloads show that GCP achieves a good convergence speed while balancing the load evenly between sensors

Optimization results for a generalized coupon collector problem

We study in this paper a generalized coupon collector problem, which consists in analyzing the time needed to collect a given number of distinct coupons that are drawn from a set of coupons with an arbitrary probability distribution. We suppose that a special coupon called the null coupon can be drawn but never belongs to any collection. In this context, we prove that the almost uniform distribution, for which all the non-null coupons have the same drawing probability, is the distribution which stochastically minimizes the time needed to collect a fixed number of distinct coupons. Moreover, we show that in a given closed subset of probability distributions, the distribution with all its entries, but one, equal to the smallest possible value is the one, which stochastically maximizes the time needed to collect a fixed number of distinct coupons. An computer science application shows the utility of these results.Comment: arXiv admin note: text overlap with arXiv:1402.524

Système d'information pair-à-pair pour les réseaux de capteurs larges échelles

L'évolution de l'informatique a été marquée par des étapes dans la miniaturisation. Dernièrement, sont apparus d'infimes systèmes micro-électro-mécaniques notamment les réseaux de capteurs sans fil (WSN). La spontanéité, l'adaptabilité du réseau et la dynamicité de la topologie dans le déploiement des WSN soulèvent de nombreuses questions ouvertes. De plus, compte tenu du nombre potentiellement important de capteurs participants et de leurs ressources réduites, il apparaît indispensable de développer des solutions entièrement décentralisées, répartissant la charge entre les participants et permettant de passer à l'échelle. De nombreux procédés des systèmes distribués, et plus particulièrement ceux issus du paradigme pair-à-pair (P2P), nous apparaissent comme adaptables aux réseaux de capteurs sans fil

AnKLe: Detecting Attacks in Large Scale Systems via Information Divergence

In this paper, we consider the setting of large scale distributed systems, in which each node needs to quickly process a huge amount of data received in the form of a stream that may have been tampered with by an adversary. In this situation, a fundamental problem is how to detect and quantify the amount of work performed by the adversary. To address this issue, we propose AnKLe (for Attack-tolerant eNhanced Kullback-Leibler divergence Estimator), a novel algorithm for estimating the KL divergence of an observed stream compared to the expected one. AnKLe combines sampling techniques and information-theoretic methods. It is very efficient, both in terms of space and time complexities, and requires only a single pass over the data stream. Experimental results show that the estimation provided by AnKLe remains accurate even for different adversarial settings for which the quality of other methods dramatically decreases

Prise en compte d'aspects sémantiques dans la contruction d'un réseau pair-à-pair

Les systèmes pair-à-pair permettent de développer des systèmes distribués de grande taille. Ces systèmes construisent un réseau logique recouvrant le réseau physique existant. Par opposition au modèle classique dit de client-serveur, chaque noeud joue à la fois le rôle de client et de serveur et est connecté logiquement à un sous-ensemble du système. La plupart des systèmes existants optimisent le réseau recouvrant en minimisant la distance géographique (ou physique) entre chaque noeud. L'exploitation des intérêts communs entre pairs représente un axe de recherche récent dans l'optimisation de ces systèmes. Ceci consiste à ajouter des liens reflétant cette similarité d'intérêt en sus du réseau recouvrant. L'objectif de nos recherches dans ce domaine est de prendre en compte cette localité d'intérêt dans la construction même du réseau recouvrant. Cet article présente d'abord le paradigme de la communication épidémique, permettant de construire des réseaux pair-à-pair. Ensuite nous exposons des techniques permettant de prendre en compte une localité d'intérêt