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SUMMARY This paper addresses the challenge of transparent data sharing within computing Grids built as cluster federations. On such platforms, the availability of storage resources may change in a dynamic way, often due to hardware failures. We focus on the problem of handling the consistency of replicated data in the presence of failures. We propose a(More)
DHT-based P2P systems provide a fault-tolerant and scalable mean to store data blocks in a fully distributed way. Unfortunately, recent studies have shown that if connection/disconnection frequency is too high, data blocks may be lost. This is true for most current DHT-based system's implementations. To avoid this problem, it is necessary to build really(More)
Summary form only given. Code coupling applications can be divided into communicating modules, that may be executed on different clusters in a cluster federation. As a cluster federation comprises of a large number of nodes, there is a high probability of a node failure. We propose a hierarchical checkpointing protocol that combines a synchronized(More)
Cluster federations are attractive for executing applications like large scale code coupling. However faults may appear frequently in such architectures. Thus, checkpointing long-running applications is desirable to avoid to restart them from the beginning in the event of a node failure. To take into account the constraints of a cluster federation(More)
Designing and implementing a quality matchmaking service for Multiplayer Online Games requires an extensive knowledge of the habits, behaviors and expectations of the players. Gathering and analyzing traces of real games offers insight on these matters, but game server providers are very protective of such data in order to deter possible reuse by the(More)
Massively Multiplayer Online Games (MMOGs) recently emerged as a popular class of applications with millions of users. To offer acceptable gaming experience, such applications need to render the virtual world surrounding the player with a very low latency. However, current state-of-the-art MMOGs based on peer-to-peer overlays fail to satisfy these(More)
Grid computing has recently emerged as a response to the growing demand for resources (processing power, storage, etc.) exhibited by scientific applications. We address the challenge of sharing large amounts of data on such infrastructures, typically consisting of a federation of node clusters. We claim that storing, accessing, updating and sharing such(More)
Delivering on-demand web content to end-users in order to carry out strict QoS metrics is not a trivial task for globally distributed network providers. This task becomes still harder when content popularity varies over the time and the SLA definitions have to include both transfer rate and latency metrics. Current worldwide content delivery approaches and(More)
More and more, users store their data in the cloud. While the content is then retrieved, the retrieval has to respect quality of service (QoS) constraints. In order to reduce transfer latency, data is repli-cated. The idea is make data close to users and to take advantage of providers home storage. However to minimize the cost of their platform, cloud(More)
Computing grids are large-scale, highly-distributed, often hierarchical , platforms. At such scales, failures are no longer exceptions, but part of the normal behavior. When designing software for grids, developers have to take failures into account. It is crucial to make experiments at a large scale, with various volatility conditions, in order to measure(More)