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  • New paper accepted at ATC 2017

    Unobtrusive Deferred Update Stabilization for Efficient Geo-Replication
    C. Gunawardhana, M. Bravo, L. Rodrigues

  • New paper accepted at EuroVis 2017

    Towards an Adaptive Framework for Real-Time Visualization of Streaming Big Data
    A. Khan, D. Gonçalves, D. C. Leão

  • AP2SI Prize of Merit for a Master thesis in Information Security

    Congratulations to André Joaquim and Diogo Raposo

    André Joaquim recent master student of the group (advised by Miguel Pardal and Miguel Correia)
    won the AP2SI Prize of Merit for a Master thesis in Information Security (Prémio de Mérito para
    Mestres na área da Segurança da Informação).

    Diogo Raposo also recent master student of the group (same advisors) received a Honorable
    Mention in the same context.

  • New paper accepted at ISMM 2017

    NG2C: Pretenuring N-Generational GC for HotSpot Big Data Applications
    R. Bruno, L. Oliveira, P. Ferreira

  • New paper accepted at MobiHoc 2017

    TrUbi: A System for Dynamically Constraining Mobile Devices within Restrictive Usage Scenarios
    M. Costa, N. O. Duarte, N. Santos, P. Ferreira

  • New paper accepted at IWANN 2017

    A Systematic Approach for the Application of Restricted Boltzmann Machines in Network Intrusion Detection
    A. Gouveia, M. Correia

  • New paper accepted at IFIP Networking 2017

    PRIVO: A PRIvacy-preserVing Opportunistic routing protocol for Delay Tolerant Networks
    N. Magaia, C. Borrego, P. Pereira, M. Correia

  • New paper accepted at DSN 2017

    Demonstrating a Tool for Injection Attack Prevention in MySQL
    I. Medeiros, M. Beatriz, N. Neves, M. Correia

  • New paper accepted at DAIS 2017, DISCOTEC

    Similarity Aware Shuffling for the Distributed Execution of SQL Window Functions
    F. Coelho, M. Matos, J. Pereira, R. Oliveira

  • New paper accepted at EuroSys 2017

    Saturn: a Distributed Metadata Service for Causal Consistency
    Manuel Bravo, Luís Rodrigues, Peter Van Roy

  • New paper accepted at PaPoC 2017

    Transparent cross-system consistency.
    João Loff, Daniel Porto, Carlos Baquero, João Garcia, Nuno Preguiça, Rodrigo Rodrigues

  • New paper accepted at MARS Workshop 2017

    Making data center computations fast, but not so furious.
    Daniel Porto, João Loff, Luis Ceze, Rui Duarte, Rodrigo Rodrigues

  • Two papers accepted at EuroDW 2017

    HomePad: Guardian of a Smart Home Galaxy
    Igor Zavalyshyn, Nuno Duarte, Nuno Santos

    Profiling for Asymmetric NUMA Systems
    David Gureya, João Barreto

  • CAT defense: Rodrigo Fraga Barcelos Paulus Bruno

    Rodrigo Fraga Barcelos Paulus Bruno CAT Defense
    February 21st, 2017 at 15:00, Sala E1, Torre de Eletricidade, IST, Alameda

    Title: Nova VM: enhanced Java Virtual Machine for Big Data Applications
    Advisor: Professor Paulo Jorge Pires Ferreira

  • Cristian Cadar about Symbolic Execution for Evolving Software

    February 24th, 2017 at 11 am in room 0.20 (INESC)

    Cristian Cadar, Imperial College London
    Symbolic Execution for Evolving Software

    One of the distinguishing characteristics of software systems is that they evolve: new patches are committed to software repositories and new versions are released to users on a continuous basis.  Unfortunately, many of these changes bring unexpected bugs that break the stability of the system or affect its security.  In this talk, I describe our work on devising novel symbolic execution techniques for increasing the confidence in evolving software: a technique for reasoning about the correctness of optimisations, in particular those that take advantage of SIMD and GPGPU capabilities; a technique for high-coverage patch testing, and a technique for revealing regression bugs and behavioural divergences across versions.

  • Thesis defense: João Matos

    João Matos PhD Defense
    February 24th, 2017 at 15:00, in Anfiteatro PA-3 (-1 floor, Mathematics Building)

    Ph.D. thesis “Privacy in Software Error Reporting”

  • CAT defense: David Matos

    David Matos CAT Defense
    February 7th, 2017 at 09:30 am, in Sala QA1.1, Torre Sul (Química), IST – Alameda

  • CAT defense: Amin Mohtasham

    Amin Mohtasham CAT Defense
    January 26th, 2017 at 10:00 am, in Sala V1.06, Pavilhão de Civil, IST – Alameda

  • Two papers accepted at CCGrid 2017

    Chrysaor: Fine-Grained, Fault-Tolerant Cloud-of-Clouds MapReduce
    Pedro A. R. S. Costa, Fernando Ramos and Miguel Correia

    Practical Service Placement Approach for Microservices Architecture
    Mennan Selimi, Llorenc Cerda, Marc Sanchez-Artigas, Felix Freitag, Luis Veiga

  • Please welcome Miguel Matos

    Miguel Matos just joined the GSD group. Please welcome him!
    http://www.gsd.inesc-id.pt/blog/miguel-matos/

  • INESC-ID 2016 Researcher Award

    Congratulations to Paolo Romano, awarded in the category of Researcher.

  • Thesis presented: André Filipe Pessoa Negrão

    Congratulations to André Filipe Pessoa Negrão for successfully defending his PhD thesis:

    Interest Aware Consistency Management and Cloud Aware Resource Provisioning for Distributed Interactive Applications

    Abstract
    Distributed Interactive Applications (DIAs) enable geographically distributed users to interact in real time over the Internet through a shared application state. Due to their interactive nature, DIAs require the continuous dissemination and processing of potentially large amounts of data that must reach users timely and consistently. This faces application designers with two main challenges. First, the geographically distributed users are connected through networks with limited bandwidth. For that reason, it is not feasible to propagate every update to every user. Intelligent mechanisms are, thus, required to make sure that users receive the information that actually matters to them. Second, in large scale DIAs such as MMOGs, the number of concurrent users is highly dynamic, making it difficult to predict the exact number of resources necessary to efficiently provision the application. As a result, application operators tend to adopt pessimistic measures by deploying static infrastructures in which the number of resources is based on worst case predictions of load. The result is an over-provisioned computing environment in which some resources are idle for long periods of the time, leading to unnecessary operational expenses.

    In this thesis, we address these issues by proposing a framework built upon two core elements: i) interest aware consistency management and ii) cloud aware resource provisioning. Our framework employs a network efficient and flexible consistency model that propagates information to users according to their interest in the different objects of the shared application state. Updates considered relevant to the user’s current task are propagated promptly; less relevant updates are postponed for a configurable time interval. Postponed updates are, then, subject to optimization strategies to improve the efficiency of update propagation. Additionally, our framework provides a dynamic resource management infrastructure for DIAs. The infrastructure makes use of a hybrid resource pool comprising privately owned resources as well as public resources acquired from a public cloud. Servers are acquired from the resource pool only when necessary and removed when they are no longer required. Within this infrastructure, we employ hybrid and task based load distribution mechanisms to improve the cost-effectiveness of the system.

  • Thesis presented: Leila Sharifi

    Congratulations to Leila Sharifi for successfully defending her PhD thesis:

    Energy-aware Service Provisioning in P2P-assisted Cloud Ecosystems

    Abstract
    Energy has emerged as a first-class computing resource in modern systems. The trend has primarily led to the strong focus on reducing the energy consumption of data centers, coupled with the growing awareness of the adverse impact on the environment due to data centers. This has led to a strong focus on energy management for server class systems.

    In this work, we intend to address the energy-aware service provisioning in P2P-assisted cloud ecosystems, leveraging economics-inspired mechanisms. Toward this goal, we addressed a number of challenges. To frame an energy aware service provisioning mechanism in the P2P-assisted cloud, first, we need to compare the energy consumption of each individual service in P2P-cloud and data centers. However, in the procedure of decreasing the energy consumption of cloud services, we may be trapped with the performance violation. Therefore, we need to formulate a performance aware energy analysis metric, conceptualized across the service provisioning stack. We leverage this metric to derive energy analysis framework.

    Then, we sketch a framework to analyze the energy effectiveness in P2P-cloud and data center platforms to choose the right service platform, according to the performance and energy characteristics. This framework maps energy from the hardware oblivious, top level to the particular hardware setting in the bottom layer of the stack.

    Afterward, we introduce an economics-inspired mechanism to increase the energy effectiveness in the P2P-assisted cloud platform as well as moving toward a greener ICT for ICT for a greener ecosystem.

     

  • Thesis presented: Xavier Araújo Morgado Vilaça

    Congratulations to Xavier Araújo Morgado Vilaça for successfully defending his PhD thesis:

    Sustaining Cooperation in Dependable Systems: a Game Theorectical Approach

    Abstract
    A dependable distributed system is composed of different processes that execute a distributed protocol to provide some reliable distributed service. Typically, one assumes that all processes cooperate by executing the specified protocol, unless faults occur; if the processes do not cooperate, then the service that the system is intended to provide may be compromised. Unfortunately, the assumption that processes do not deviate from the protocol may not hold in open systems, where each process is under the control of a different entity. In fact, if the entities are selfish and they benefit from deviations, then they may change the protocol run by the processes. To avoid this problem, protocols must sustain cooperation, i.e., they must provide incentives that deny any benefits to the entities responsible for deviations.
    One way of modelling selfish behaviour is to adopt the approach of Game Theory. In this approach, processes are seen as being under the control of rational agents that seek to maximize individual utility functions, interactions are modelled as games, and protocols correspond to strategies of the game that specify the actions taken at each point in time. The main goal is to devise equilibria protocols, i.e., protocols such that no agent increases its utility by causing a deviation. Equilibria protocols sustain cooperation, thus being extremely relevant to the development of dependable distributed systems.

    In this work, we apply Game Theory to identify and analyse protocols that sustain cooperation in three fundamental distributed problems: (i) the problem gossip dissemination, (ii) the problem of pairwise exchanges of messages over links of a dynamic network, and (i) the problem of consensus with crash failures. Our main results identify necessary and sufficient conditions for devising equilibria protocols that solve the aforementioned problems. These results unveil the necessary and sufficient requirements for the construction of dependable distributed systems robust to selfish behaviour.

  • New paper accepted at WWW 2017

    Blotter: Low Latency Transactions for Geo-Replicated Storage
    Henrique Moniz, João Leitão, Ricardo Dias, Johannes Gehrke, Nuno Preguiça and Rodrigo Rodrigues

  • Thesis defense: André Filipe Pessoa Negrão

    André Filipe Pessoa Negrão PhD Defense
    20 de dezembro de 2016, pelas 10:30 horas, na Sala de Reuniões do Departamento de Engenharia informática (0.19), Pavilhão de informática II do IST

  • Thesis defense: Xavier Vilaça

    Xavier Vilaça PhD Defense
    December 14th, 2016 at 10:30 am, in Anfiteatro PA-3 (-1 floor, Mathematics Building)

  • Two papers accepted at ICDCN 2017

    FastRank: Practical Lightweight Tolerance to Rational Behaviour in Edge Assisted Streaming
    Xavier Vilaça, Luís Rodrigues, João Silva, Hugo Miranda

    Accountability in Dynamic Networks
    Xavier Vilaça, Luís Rodrigues

  • New paper accepted at SAC 2017

    Automatic Generation of Policies to Support Elastic Scaling in Cloud Environments.
    Richard Martinez, Luís Rodrigues

  • New poster accepted at IM 2017

    Redundancy Can Save You, When You Control It Smart
    Pradeeban Kathiravelu, Luís Veiga

  • New paper accepted at Workshop on Smart Cities: People, Technology and Data

    Increasing Bicycle Usage in Smart Cities
    Miguel Costa, Rodrigo Lourenço, João Barreto, Paulo Ferreira, João Bernardino, Bossuyt Evelien, Christiaens Jan, Deham Nick, Franchois Elke, Vleugels Ilse

  • Seven papers accepted at NCA 2016

    Task Based Load Balancing for Cloud Aware Massively Multiplayer Online Games
    André Negro, Luis Veiga, Paulo Ferreira

    DARSHANA: Detecting Route Hijacking For Communication Confidentiality
    Karan Balu, Miguel Pardal and Miguel Correia.

    NoSQL Undo: Recovering NoSQL Databases by Undoing Operations
    David Matos and Miguel Correia

    Feature Set Tuning for Machine Learning based Network Intrusion Detection
    Arnaldo Gouveia and Miguel Correia

    MACHETE: Multi-path Communication for Cloud Security
    Diogo Raposo, Miguel Pardal, Luís Rodrigues and Miguel Correia

    Leveraging an Homomorphic Encryption Library to Implement a Coordination Service
    Eugénio Silva and Miguel Correia
    (short paper)

    vtTLS: A Vulnerability-Tolerant Communication Protocol
    André Joaquim, Miguel L. Pardal and Miguel Correia
    (short paper)

  • New paper accepted at Middleware 2016

    ALMA – GC-assisted JVM Live Migration for Java Server Application
    Rodrigo Bruno, Paulo Ferreira

  • The website has been redesigned!

    Dear members,

    We have drastically redesigned the Distributed Systems Group website!
    It has a cleaner look and new organization, and it is with pleasure that we present it to you.

    We hope it will help you keep up with events and make it easier to use the group resources.

    – GSD Team

    The new Distributed Systems Group website is launched!