Luís E. T. Rodrigues

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Distributed applications are becoming increasingly complex, often requiring the simultaneous use of several communication channels with different qualitiesof-service. This paper presents the Appia system, a protocol kernel that supports applications requiring multiple coordinated channels. Appia offers a clean and elegant way for the application to express(More)
At current date the problem of how to build distributed and replicated Software Transactional Memory (STM) to enhance both dependability and performance is still largely unexplored. This paper fills this gap by presenting D2STM, a replicated STM whose consistency is ensured in a transparent manner, even in the presence of failures. Strong consistency is(More)
Fault-tolerant distributed systems based on eld-buses may take advantage from reliable and atomic broadcast. There is a current belief that CAN native mechanisms provide atomic broadcast. In this paper, we dismiss this misconception, explaining how network errors may lead to: inconsistent message delivery; generation of message duplicates. These errors may(More)
There is an inherent trade-off between epidemic and deterministic tree-based broadcast primitives. Tree-based approaches have a small message complexity in steady-state but are very fragile in the presence of faults. Gossip, or epidemic, protocols have a higher message complexity but also offer much higher resilience. This paper proposes an integrated(More)
Gossip, or epidemic, protocols have emerged as a powerful strategy to implement highly scalable and resilient reliable broadcast primitives. Due to scalability reasons, each participant in a gossip protocol maintains a partial view of the system. The reliability of the gossip protocol depends upon some critical properties of these views, such as degree(More)
This work presents a novel peer-to-peer system that is particularly well suited to support context-aware computing. The system, called GeoPeer, aims to combine the advantages of peer-to-peer systems that implement distributed hash tables with the suitability of geographical routing for supporting location-constrained queries and information dissemination.(More)
This paper proposes a Geo-distributed key-value datastore, named ChainReaction, that offers <i>causal</i>+ consistency, with high performance, fault-tolerance, and scalability. ChainReaction enforces causal+ consistency which is stronger than eventual consistency by leveraging on a new variant of chain replication. We have experimentally evaluated the(More)
Epidemic, or probabilistic, multicast protocols have emerged as a viable mechanism to circumvent the scalability problems of reliable multicast protocols. However, most existing epidemic approaches use connectionless transport protocols to exchange messages and rely on the intrinsic robustness of the epidemic dissemination to mask network omissions.(More)