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Displaying 1-50 out of 55 total
Schedulability Analysis of an Event-Based Real-Time Protocol Framework
Found in: Object-Oriented Real-Time Dependable Systems, IEEE International Workshop on
By João Rodrigues, João Ventura, Luís Rodrigues
Issue Date:January 2002
pp. 0319
This paper presents a method to analyz the timing behavior of an event-based real-time protocol composition framework. The framework, called RT-Appia, allows the development and implementation of configurabl real-time protocol stacks. The method performs t...
 
The design of RT-Appia
Found in: Object-Oriented Real-Time Dependable Systems, IEEE International Workshop on
By João Rodrigues, Hugo Miranda, João Ventura, Luís Rodrigues
Issue Date:January 2001
pp. 261
This paper presents the design of RT-Appia,a framework for the development and implementation of configurable real-time protocol stacks.The goal of RT-Appia is to allow the construction of specialized protocols through the composition of pre-defined micro ...
 
Response Time Analysis of Composable Micro-Protocols
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By João Ventura, Lúýs Rodrigues, João Rodrigues
Issue Date:May 2001
pp. 0335
Abstract: The paper presents a generic framework to analyse the timing behavior of protocol graphs derived from the composition of micro-protocols. The model assumes that a protocol stack is composed of a set of protocol objects that interact through the e...
 
Policies for Efficient Data Replication in P2P Systems
Found in: 2013 International Conference on Parallel and Distributed Systems (ICPADS)
By Joao Paiva,Luis Rodrigues
Issue Date:December 2013
pp. 404-411
This paper addresses the problem of maintaining replicated data in large scale P2P systems. Although this topic has been extensively studied in the literature, to maintain replicated data in this setting, in an efficient manner, still remains a significant...
 
Rollerchain: A DHT for Efficient Replication
Found in: 2013 IEEE 12th International Symposium on Network Computing and Applications (NCA)
By Joao Paiva,Joao Leitao,Luis Rodrigues
Issue Date:August 2013
pp. 17-24
In this paper we present Roller chain, a novel Distributed Hash Table that offers efficient data storage through the combination of gossip-based and structured overlay networks. The unstructured component maintains clusters of fully connected nodes, where ...
 
Order-Preserving Renaming in Synchronous Systems with Byzantine Faults
Found in: 2013 IEEE 33rd International Conference on Distributed Computing Systems (ICDCS)
By Oksana Denysyuk,Luis Rodrigues
Issue Date:July 2013
pp. 276-285
Renaming is a fundamental problem in distributed computing. It consists in having a set of processes with unique ids from a large namespace pick distinct names from a smaller namespace. Order-preserving renaming is a stronger variant of the renaming proble...
 
Lightweight cooperative logging for fault replication in concurrent programs
Found in: 2012 42nd Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN)
By Nuno Machado,Paolo Romano,Luis Rodrigues
Issue Date:June 2012
pp. 1-12
This paper presents CoopREP, a system that provides support for fault replication of concurrent programs, based on cooperative recording and partial log combination. CoopREP employs partial recording to reduce the amount of information that a given program...
   
When Scalability Meets Consistency: Genuine Multiversion Update-Serializable Partial Data Replication
Found in: 2012 IEEE 32nd International Conference on Distributed Computing Systems (ICDCS)
By Sebastiano Peluso,Pedro Ruivo,Paolo Romano,Francesco Quaglia,Luis Rodrigues
Issue Date:June 2012
pp. 455-465
In this article we introduce GMU, a genuine partial replication protocol for transactional systems, which exploits an innovative, highly scalable, distributed multiversioning scheme. Unlike existing multiversion-based solutions, GMU does not rely on a glob...
 
Modelo de Síntese e Processo de Otimização para o Projeto Conceitual/Preliminar de uma Embarcação para o Transporte de Gás Natural Comprimido
Found in: 2012 International Conference on Offshore and Marine Technology: Science and Innovation (NAVTEC)
By Rafael M'ximo Carreira Ribeiro,Lucas Lopes de Cerqueira,Bernardo Luis Rodrigues de Andrade,Claudio Mueller Prado Sampaio
Issue Date:March 2012
pp. 5-8
Este trabalho descreve um procedimento de projeto e otimização desenvolvido para determinar as características principais e uma representação preliminar da superfície do casco de um navio de gás natural comprimido (CNG) armazenado em cilindros verti...
 
Exploiting Total Order Multicast in Weakly Consistent Transactional Caches
Found in: Pacific Rim International Symposium on Dependable Computing, IEEE
By Pedro Ruivo,Maria Couceiro,Paolo Romano,Luís Rodrigues
Issue Date:December 2011
pp. 99-108
Nowadays, distributed in-memory caches are increasingly used as a way to improve the performance of applications that require frequent access to large amounts of data. In order to maximize performance and scalability, these platforms typically rely on weak...
 
Goal-oriented Self-management of In-memory Distributed Data Grid Platforms
Found in: Cloud Computing Technology and Science, IEEE International Conference on
By Liliana Rosa,Luís Rodrigues,Antónia Lopes
Issue Date:December 2011
pp. 587-591
This paper addresses the self-management of in-memory distributed data grid platforms. A growing number of applications rely in these platforms to speed up access to large sets of data. However, they are complex to manage due to the diversity of configurat...
 
Topology Stability-Aware Multicast Protocol for MANETs
Found in: Local Computer Networks, Annual IEEE Conference on
By Jose Mocito,Oksana Denysyuk,Luis Rodrigues,Hugo Miranda
Issue Date:October 2011
pp. 287-290
Multicast is an important building block for many applications in MANETs, including data dissemination, service discovery, publish-subscribe, among others. Therefore, it has been widely studied and many solutions can be found in the literature. However, mo...
 
A Generic Framework for Replicated Software Transactional Memories
Found in: Network Computing and Applications, IEEE International Symposium on
By Nuno Carvalho,Paolo Romano,Luis Rodrigues
Issue Date:August 2011
pp. 271-274
Software Transactional Memory (STM) has emerged a powerful abstraction for managing access to shared data. Therefore, it is no surprise that a handful of different STM replication schemes have been proposed in the last recent years. In this context, we pro...
 
Thicket: A Protocol for Building and Maintaining Multiple Trees in a P2P Overlay
Found in: Reliable Distributed Systems, IEEE Symposium on
By Mário Ferreira, João Leitão, Luís Rodrigues
Issue Date:November 2010
pp. 293-302
One way to efficiently disseminate information in a P2P overlay is to rely on a spanning tree. However, in a tree, interior nodes support a much higher load than leaf nodes. Also, the failure of a single node can break the tree, impairing the reliability o...
 
An Optimal Speculative Transactional Replication Protocol
Found in: Parallel and Distributed Processing with Applications, International Symposium on
By Paolo Romano, Roberto Palmieri, Francesco Quaglia, Nuno Carvalho, Luis Rodrigues
Issue Date:September 2010
pp. 449-457
In this paper we investigate the problem of speculative processing in a replicated transactional system layered on top of an optimistic atomic broadcast service. We consider a realistic model in which transactions' read/write sets are not known a-priori, a...
 
A Machine Learning Approach to Performance Prediction of Total Order Broadcast Protocols
Found in: Self-Adaptive and Self-Organizing Systems, IEEE International Conference on
By Maria Couceiro, Paolo Romano, Luís Rodrigues
Issue Date:October 2010
pp. 184-193
Total Order Broadcast (TOB) is a fundamental building block at the core of a number of strongly consistent, fault-tolerant replication schemes. While it is widely known that the performance of existing TOB algorithms varies greatly depending on the workloa...
 
Observable non-Sybil quorums construction in one-hop wireless ad hoc networks
Found in: Dependable Systems and Networks, International Conference on
By Diogo Monica, Joao Leitao, Luis Rodrigues, Carlos Ribeiro
Issue Date:July 2010
pp. 31-40
The Sybil Attack is a serious threat to the secure and dependable operation of wireless ad hoc networks. This paper proposes an algorithm to provide each correct node in an one-hop wireless network with a quorum of non-Sybil identities from the neighbourho...
 
RASM: A Reliable Algorithm for Scalable Multicast
Found in: Parallel, Distributed, and Network-Based Processing, Euromicro Conference on
By Mouna Allani, João Leitão, Benoît Garbinato, Luís Rodrigues
Issue Date:February 2010
pp. 137-144
Recently there has been an effort to build scalable and reliable application-level multicast solutions that combine the resilience of pure gossip-based with the efficiency of tree-based schemes. However, such solutions assume that participants have unlimit...
 
D2STM: Dependable Distributed Software Transactional Memory
Found in: Pacific Rim International Symposium on Dependable Computing, IEEE
By Maria Couceiro,Paolo Romano,Nuno Carvalho,Luís Rodrigues
Issue Date:November 2009
pp. 307-313
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 cons...
 
An Efficient Weak Mutual Exclusion Algorithm
Found in: Parallel and Distributed Computing, International Symposium on
By Paolo Romano, Luis Rodrigues
Issue Date:July 2009
pp. 205-212
The Weak Mutual Exclusion (WME) is a recently proposed abstraction which, analogously to classical Distributed Mutual Exclusion (DME), permits to serialize concurrent accesses to a shared resource. Unlike DME, however, the WME abstraction regulates the acc...
 
The Weak Mutual Exclusion problem
Found in: Parallel and Distributed Processing Symposium, International
By Paolo Romano,Luis Rodrigues,Nuno Carvalho
Issue Date:May 2009
pp. 1-12
In this paper we define the Weak Mutual Exclusion (WME) problem. Analogously to classical Distributed Mutual Exclusion (DME), WME serializes the accesses to a shared resource. Differently from DME, however, the WME abstraction regulates the access to a rep...
 
GORDA: An Open Architecture for Database Replication
Found in: Network Computing and Applications, IEEE International Symposium on
By Alfrânio Correia Jr., José Pereira, Luís Rodrigues, Nuno Carvalho, Ricardo Vilaça, Rui Oliveira, Susana Guedes
Issue Date:July 2007
pp. 287-290
Database replication has been a common feature in database management systems (DBMSs) for a long time. In particular, asynchronous or lazy propagation of updates provides a simple yet efficient way of increasing performance and data availability [5] and is...
 
Emergent Structure in Unstructured Epidemic Multicast
Found in: Dependable Systems and Networks, International Conference on
By Nuno Carvalho, Jose Pereira, Rui Oliveira, Luis Rodrigues
Issue Date:June 2007
pp. 481-490
In epidemic or gossip-based multicast protocols, each node simply relays each message to some random neighbors, such that all destinations receive it at least once with high probability. In sharp contrast, structured multicast protocols explicitly build an...
 
Policy-Driven Adaptation of Protocol Stacks
Found in: Autonomic and Autonomous Systems, International Conference on
By Liliana Rosa, Antonia Lopes, Luis Rodrigues
Issue Date:July 2006
pp. 5
Today?s mobile applications need to execute in a wide range of heterogeneous devices, that operate in different conditions. In this context, dynamic adaptation of the underlying communication support is fundamental to achieve adequate performance. We addre...
 
Context Adaptation of the Communication Stack
Found in: Distributed Computing Systems Workshops, International Conference on
By José Mocito, Liliana Rosa, Nuno Almeida, Hugo Miranda, Luís Rodrigues, Antónia Lopes
Issue Date:June 2005
pp. 652-655
This position paper presents a middleware framework to support the development of context-aware adaptive communication protocols, that can be reconfigured according, not only to the local context, but also to the context of the remaining remote participant...
 
Atomic Broadcast in Asynchronous Crash-Recovery Distributed Systems and Its Use in Quorum-Based Replication
Found in: IEEE Transactions on Knowledge and Data Engineering
By Luís Rodrigues, Michel Raynal
Issue Date:September 2003
pp. 1206-1217
<p><b>Abstract</b>—<it>Atomic Broadcast</it> is a fundamental problem of distributed systems: It states that messages must be delivered in the same order to their destination processes. This paper describes a solution to this ...
 
Workshop on Reliable Peer-to-Peer Distributed Systems
Found in: Reliable Distributed Systems, IEEE Symposium on
By Ozalp Babaoglu, Anne-Marie Kermarrec, Robbert van Renesse, Luis Rodrigues, Maarten van Steen, Amin Vadhat
Issue Date:October 2002
pp. 316
No summary available.
   
On QoS-Aware Publish-Subscribe
Found in: Distributed Computing Systems Workshops, International Conference on
By Filipe Araújo, Luís Rodrigues
Issue Date:July 2002
pp. 511
<p>This position paper addresses the issue of supporting quality of service (QoS) parameters in distributed publish-subscribe systems. It advocates that QoS parameters should be handled using the same constructs as other information regarding events,...
 
Measuring Distributed Durations with Stable Errors
Found in: Real-Time Systems Symposium, IEEE International
By Antonio Casimir, Pedro Martins, Luis Rodrigues, Paulo Veríssimo
Issue Date:December 2001
pp. 310
The round-trip duration measurement technique is fundamental to solve many problems in asynchronous distributed systems. In essence, this technique provides the means for reading remote clocks with a known and bounded error. Therefore, it is used as a fund...
 
Probabilistic Semantically Reliable Multicast
Found in: Network Computing and Applications, IEEE International Symposium on
By José Pereira, Rui Oliveira, Luís Rodrigues, Anne-Marie Kermarrec
Issue Date:October 2001
pp. 0100
Traditional reliable broadcast protocols fail to scale to large settings [13, 1]. This paper proposes a reliable multicast protocol that integrates two recent approaches to deal with the large-scale dimension in group communication protocols: gossip-based ...
 
Separating Replication from Distributed Communication: Problems and Solutions
Found in: Distributed Computing Systems Workshops, International Conference on
By Miguel Antunes, Antonio Rito Silva, Jorge Martins, Hugo Miranda, Luis Rodrigues
Issue Date:April 2001
pp. 0103
Abstract: Replication and distributed communication are usually tightly coupled. This code tangling forbids their independent reuse and adaptation. In this position paper the problems resulting from coupling replication with distributed communication are d...
 
Semantically Reliable Multicast Protocols
Found in: Reliable Distributed Systems, IEEE Symposium on
By José Pereira, Rui Oliveira, Luís Rodrigues
Issue Date:October 2000
pp. 60
Reliable multicast protocols can strongly simplify the design of distributed applications. However, it is hard to sustain a high-multicast throughput when groups are large and heterogeneous. In an attempt to overcome this limitation, previous work has focu...
 
Chasing the Optimum in Replicated In-memory Transactional Platforms via Protocol Adaptation
Found in: IEEE Transactions on Parallel and Distributed Systems
By Maria Couceiro,Pedro Ruivo,Paolo Romano,Luis Rodrigues
Issue Date:February 2015
pp. 1
Replication plays an essential role for in-memory distributed transactional platforms, given that it represents the primary means to ensure data durability. Unfortunately, no single replication technique can ensure optimal performance across a wide range o...
 
Chasing the optimum in replicated in-memory transactional platforms via protocol adaptation
Found in: 2013 43rd Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN)
By Maria Couceiro,Pedro Ruivo,Paolo Romano,Luis Rodrigues
Issue Date:June 2013
pp. 1-12
Replication plays an essential role for in-memory distributed transactional platforms, such as NoSQL data grids, given that it represents the primary mean to ensure data durability. Unfortunately, no single replication technique can ensure optimal performa...
 
SPECULA: Speculative Replication of Software Transactional Memory
Found in: 2012 IEEE 31st International Symposium on Reliable Distributed Systems (SRDS)
By Sebastiano Peluso,Joao Fernandes,Paolo Romano,Francesco Quaglia,Luis Rodrigues
Issue Date:October 2012
pp. 91-100
This paper introduces SPECULA, a novel replication protocol for Software Transactional Memory (STM) systems that seeks maximum overlap between transaction execution and replica synchronization phases via speculative processing techniques. By removing the r...
   
Supporting Linearizable Semantics in Replicated Databases
Found in: Network Computing and Applications, IEEE International Symposium on
By Luis Rodrigues, Nuno Carvalho, Emili Miedes
Issue Date:July 2008
pp. 263-266
This paper proposes a novel database replication algorithm that??offers strong consistency (linearizable semantics) and allows reads??and non-conflicting writes to execute in parallel in multiple??replicas. The proposed algorithm supports the use of quorum...
 
Epidemic Broadcast Trees
Found in: Reliable Distributed Systems, IEEE Symposium on
By Joao Leitao, Jose Pereira, Luis Rodrigues
Issue Date:October 2007
pp. 301-310
<p>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...
 
HyParView: A Membership Protocol for Reliable Gossip-Based Broadcast
Found in: Dependable Systems and Networks, International Conference on
By Joao Leitao, Jose Pereira, Luis Rodrigues
Issue Date:June 2007
pp. 419-429
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 relia...
 
DSN 2007 Tutorials
Found in: Dependable Systems and Networks, International Conference on
By Luis Rodrigues
Issue Date:June 2007
pp. 801
Tutorials are an important part of the DSN program. They provide an opportunity for attendees to acquire a basic understanding of, and familiarity with, several state of the art topics related to the dependability, security and resilience of systems and ne...
   
Reducing Latency in Rendezvous-Based Publish-Subscribe Systems for Wireless Ad Hoc Networks
Found in: Distributed Computing Systems Workshops, International Conference on
By Nuno Carvalho, Filipe Araujo, Luis Rodrigues
Issue Date:July 2006
pp. 28
To ensure decoupling between publishers and subscribers, most publish-subscribe systems route notifications through intermediate message brokers. A byproduct of this practice is that notifications often follow suboptimal paths that are much longer than a d...
 
Scalable QoS-Based Event Routing in Publish-Subscribe Systems
Found in: Network Computing and Applications, IEEE International Symposium on
By Nuno Carvalho, Filipe Araujo, Luýs Rodrigues
Issue Date:July 2005
pp. 101-108
<p>This paper proposes a distributed and scalable publishsubscribe broker with support for QoS. The broker, called IndiQoS , leverages on existing mechanisms to reserve resources in the underlying network and on an overlay network of peer-to-peer ren...
 
Using a Fairness Monitoring Service to Improve Load-Balancing in DSR
Found in: Distributed Computing Systems Workshops, International Conference on
By Hugo Miranda, Luís Rodrigues
Issue Date:June 2005
pp. 314-320
Many routing protocols for MANETs do not promote a balanced use of resources among the participating nodes, since they are designed to optimize other criteria, such as the number of hops in the message path. This behavior is undesired in open MANETs, where...
 
GeoPeer: A Location-Aware Peer-to-Peer System
Found in: Network Computing and Applications, IEEE International Symposium on
By Filipe Araújo, Luís Rodrigues
Issue Date:September 2004
pp. 39-46
This paper 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 suitabil...
 
Friends and Foes: Preventing Sel.shness in Open Mobile Ad Hoc Networks
Found in: Distributed Computing Systems Workshops, International Conference on
By Hugo Miranda, Luís Rodrigues
Issue Date:May 2003
pp. 440
Technological advances are leveraging the widespread deployment of mobile ad hoc networks. An interesting characteristic of ad hoc networks is their self-organization and their dependence of the behavior of individual nodes. Until recently, most research o...
 
The Road to a More Configurable and Adaptive Communication and Coordination Support
Found in: Future Trends of Distributed Computing Systems, IEEE International Workshop
By Luís Rodrigues
Issue Date:May 2003
pp. 16
This paper discusses the problem of designing and implementing the communication and coordination support for distributed applications. One way to implement these services is to rely on application-specific solutions, in an attempt to obtain the best perfo...
 
A Genetic Algorithm for Multicast Mapping in Publish-Subscribe Systems
Found in: Network Computing and Applications, IEEE International Symposium on
By Mário Guimarães, Luís Rodrigues
Issue Date:April 2003
pp. 67
In publish-subscribe systems, multicast is an efficient way to propagate information from the publishers to a group of subscribers. This paper studies the problem of mapping a large set of subscriptions into a fixed, smaller, set of multicast groups in ord...
 
Semantically Reliable Multicast: Definition, Implementation, and Performance Evaluation
Found in: IEEE Transactions on Computers
By José Pereira, Luís Rodrigues, Rui Oliveira
Issue Date:February 2003
pp. 150-165
<p><b>Abstract</b>—Semantic Reliability is a novel correctness criterion for multicast protocols based on the concept of message obsolescence: A message becomes obsolete when its content or purpose is superseded by a subsequent message. B...
 
An Indulgent Uniform Total Order Algorithm with Optimistic Delivery
Found in: Reliable Distributed Systems, IEEE Symposium on
By Pedro Vicente, Luís Rodrigues
Issue Date:October 2002
pp. 92
A total order algorithm is a fundamental building block in the construction of distributed fault-tolerant applications. Unfortunately, the implementation of such a primitive can be expensive both in terms of communication steps and of number of messages ex...
 
Reducing the Cost of Group Communication with Semantic View Synchrony
Found in: Dependable Systems and Networks, International Conference on
By José Pereira, Luís Rodrigues, Rui Oliveira
Issue Date:June 2002
pp. 293
<p>View Synchrony (VS) is a powerful abstraction in the design and implementation of dependable distributed systems. By ensuring that processes deliver the same set of messages in each view, it allows them to maintain consistency across membership ch...
 
Appia: A Flexible Protocol Kernel Supporting Multiple Coordinated Channels
Found in: Distributed Computing Systems, International Conference on
By Hugo Miranda, Alexandre Pinto, Luis Rodrigues
Issue Date:April 2001
pp. 0707
Abstract: Distributed applications are becoming increasingly complex, often requiring the simultaneous use of several communication channels with different qualities-of-service. This paper presents the Appia system, a protocol kernel that supports applicat...
 
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