Improving Resource Discovery in the Arigatoni Overlay Network

International audienceArigatoni is a structured multi-layer overlay network providing various services with variable guarantees, and promoting an intermittent participation to the virtual organization where peers can appear, disappear and organize themselves dynamically. Arigatoni mainly concerns with how resources are declared and discovered in the overlay, allowing global computers to make a secure, PKI-based, use of global aggregated computational power, storage, information resources, etc. Arigatoni provides fully decentralized, asynchronous and scalable resource discovery, and provides mechanisms for dealing with dynamic virtual organizations. This paper introduces a non trivial improvement of the original resource discovery protocol by allowing to register and to ask for multiple instances. Simulations show that it is efficient and scalable

04451 Abstracts Collection -- Future Generation Grids

The Dagstuhl Seminar 04451 "Future Generation Grid" was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl from 1st to 5th November 2004. The focus of the seminar was on open problems and future challenges in the design of next generation Grid systems. A total of 45 participants presented their current projects, research plans, and new ideas in the area of Grid technologies. Several evening sessions with vivid discussions on future trends complemented the talks. This report gives an overview of the background and the findings of the seminar

Légiférer sur la neutralité d'Internet pour en finir avec l'utopie numérique

National audienceThis paper presents the reason for which legislation is needed on network neutrality

Minimum number of wavelengths equals load in a DAG without internal cycle

International audienceLet P be a family of dipaths. The load of an arc is the number of dipaths containing this arc. Let (G,P) be the maximum of the load of all the arcs and let w(G,P) be the minimum number of wavelengths (colors) needed to color the family of dipathsP in such a way that two dipaths with the same wavelength are arc-disjoint. Let G be a DAG (Directed Acyclic Graph). An internal cycle is an oriented cycle such that all the vertices have at least one predecessor and one successor in G (said otherwise every cycle contain neither a source nor a sink of G). Here we prove that if G is a DAG without internal cycle, then for any family of dipaths P, w(G,P) = (G,P). On the opposite we give examples of DAGs with internal cycles such that the ratio between w(G,P) and (G,P) cannot be bounded. We also consider an apparently new class of DAGs, which is of interest in itself, those for which there is at most one dipath from a vertex to another. We call these digraphs UPP-DAGs. For these UPP-DAGs we show that the load is equal to the maximum size of a clique of the conflict graph. We show that if an UPP-DAG has only one internal cycle, then for any family of dipaths w(G,P) = 4 3(G,P) and we exhibit an UPP-DAG and a family of dipaths reaching the bound. We conjecture that the ratio between w(G,P) and (G,P) cannot be bounded

L' Inria a 40 ans par Pascal Griset. En quarante ans l'informatique a complètement modifié notre société, entretien avec Michel Cosnard, propos recueillis par Dominique Chouchan. Prospective avec Malik Ghallab "sept priorités pour 2008-2012"

National audienceAu cours des dernières années, l'INRIA a connu un développement sans précédent, confirmant son excellence au plan français et européen comme au plan international. En quatre décennies, l'Institut a non seulement su imposer une nouvelle discipline en France, l'informatique, mais aussi allier recherche fondamentale et réponses aux besoins de la société

Virtual Organizations in Arigatoni

International audienceArigatoni is a lightweight communication model that deploys the Global Computing Paradigm over the Internet. Communications over the behavioral units of the model are performed by a simple Global Internet Protocol (GIP) on top of TCP or UDP protocol. Basic Global Computers Units (GCU) can communicate by first registering to a brokering service and then by mutually asking and offering services. Colonies and Communities are the main entities in the model. A Colony is a simple virtual organization composed by exactly one leader and some set (possibly empty) of individuals. A Community is a raw set of colonies and global computers (think it as a soup of colonies and global computer without a leader). We present an operational semantics via a labeled transition system, that describes the main operations necessary in the Arigatoni model to perform leader negotiation, joining/leaving a colony, linking two colonies and moving one GCU from one colony to another. Our formalization results to be adequate w.r.t. the algorithm performing peer logging/delogging and colony aggregation

Powerful Resource Discovery for Arigatoni Overlay Network

International audienceArigatoni is a structured multi-layer overlay network providing various services with variable guarantees, and promoting an intermittent participation in the overlay since peers can appear, disappear, and organize themselves dynamically. Arigatoni provides fully decentralized, asynchronous and scalable resource discovery; it also provides mechanisms for dealing with an overlay with a dynamic topology. This paper introduces a non trivial improvement of the resource discovery protocol by allowing the registration and request of multiple instances of the same service, service conjunctions, and multiple services. Adding multiple instances is a non trivial task since the discovery protocol must keep track (when routing requests) of peers that accept to serve and peers that deny the service. Adding service conjunctions allows a single peer to offer different services at the same time. Simulations show that it is efficient and scalable

Resource Discovery in the Arigatoni Model.

Arigatoni is a lightweight communication model for dynamic Resource Discovery. Inspired by the Publish/Subscribe paradigm, the Arigatoni model implements a Resource-Discovery Oriented Overlay Network. Entities in Arigatoni are organized in Colonies. A Colony is a simple virtual organization composed by exactly one leader, offering some broker-like services, and some set of Individuals. Individuals are SubColonies of Individuals, or basic units called Global Computers. Global Computers communicate by first registering to the Colony and then by mutually asking and offering services. The leader, called Global Broker, has the job to analyze service requests/responses coming from its own Colony or arriving from a surrounding Colony, and to route requests/responses to other Individuals. After this discovery phase, Individuals get in touch with each others without any further intervention from the system, typically in a P2P fashion. Communications over the behavioral units of the model are performed by a simple Global Internet Protocol on top of the TCP or UDP protocol. Arigatoni provides fully decentralized, asynchronous and scalable Resource Discovery, that can be used for various purposes from P2P applications to more sophisticated Grid applications. The main focus of this paper is to present the Resource Discovery mechanism used in the Arigatoni model, along with some simulations that show that Resource Discovery in Arigatoni is efficient and scalable