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Sobre

Sobre

Eu sou investigador no HASLab e professor na U. Minho. A minha investigação centra-se em sistemas distribuidos confiáveis. Interesso-me principalmente pela gestão de dados, incluindo replicação de bases de dados e processamento de SQL sobre sistemas NoSQL, e por comunicação em grupo, incluindo protocolos de consenso e de difusão epidémica para sistemas em grande escala. Interesso-me também por técnicas e ferramentas para testar, avaliar e observar sistemas distribuídos confiáveis. Mais informação está disponível na minha página pessoal.

Tópicos
de interesse
Detalhes

Detalhes

  • Nome

    José Orlando Pereira
  • Cargo

    Investigador Coordenador
  • Desde

    01 novembro 2011
005
Publicações

2023

MRVs: Enforcing Numeric Invariants in Parallel Updates to Hotspots with Randomized Splitting

Autores
Faria, N; Pereira, J;

Publicação
Proc. ACM Manag. Data

Abstract
Performance of transactional systems is degraded by update hotspots as conflicts lead to waiting and wasted work. This is particularly challenging in emerging large-scale database systems, as latency increases the probability of conflicts, state-of-the-art lock-based mitigations are not available, and most alternatives provide only weak consistency and cannot enforce lower bound invariants. We address this challenge with Multi-Record Values (MRVs), a technique that can be layered on existing database systems and that uses randomization to split and access numeric values in multiple records such that the probability of conflict can be made arbitrarily small. The only coordination needed is the underlying transactional system, meaning it retains existing isolation guarantees. The proposal is tested on five different systems ranging from DBx1000 (scale-up) to MySQL GR and a cloud-native NewSQL system (scale-out). The experiments explore design and configuration trade-offs and, with the TPC-C and STAMP Vacation benchmarks, demonstrate improved throughput and reduced abort rates when compared to alternatives.

2023

TADA: A Toolkit for Approximate Distributed Agreement

Autores
da Conceição, EL; Alonso, AN; Oliveira, RC; Pereira, JO;

Publicação
Distributed Applications and Interoperable Systems - 23rd IFIP WG 6.1 International Conference, DAIS 2023, Held as Part of the 18th International Federated Conference on Distributed Computing Techniques, DisCoTec 2023, Lisbon, Portugal, June 19-23, 2023, Proceedings

Abstract

2023

An Experimental Evaluation of Tools for Grading Concurrent Programming Exercises

Autores
Barros, M; Ramos, M; Gomes, A; Cunha, A; Pereira, J; Almeida, PS;

Publicação
Formal Techniques for Distributed Objects, Components, and Systems - 43rd IFIP WG 6.1 International Conference, FORTE 2023, Held as Part of the 18th International Federated Conference on Distributed Computing Techniques, DisCoTec 2023, Lisbon, Portugal, June 19-23, 2023, Proceedings

Abstract

2023

TiQuE: Improving the Transactional Performance of Analytical Systems for True HybridWorkloads

Autores
Faria, N; Pereira, J; Alonso, AN; Vilaca, R; Koning, Y; Nes, N;

Publicação
PROCEEDINGS OF THE VLDB ENDOWMENT

Abstract
Transactions have been a key issue in database management for a long time and there are a plethora of architectures and algorithms to support and implement them. The current state-of-the-art is focused on storage management and is tightly coupled with its design, leading, for instance, to the need for completely new engines to support new features such as Hybrid Transactional Analytical Processing (HTAP). We address this challenge with a proposal to implement transactional logic in a query language such as SQL. This means that our approach can be layered on existing analytical systems but that the retrieval of a transactional snapshot and the validation of update transactions runs in the server and can take advantage of advanced query execution capabilities of an optimizing query engine. We demonstrate our proposal, TiQuE, on MonetDB and obtain an average 500x improvement in transactional throughput while retaining good performance on analytical queries, making it competitive with the state-of-the-art HTAP systems.

2023

PADLL: Taming Metadata-intensive HPC Jobs Through Dynamic, Application-agnostic QoS Control

Autores
Macedo, R; Miranda, M; Tanimura, Y; Haga, J; Ruhela, A; Harrell, SL; Evans, RT; Pereira, J; Paulo, J;

Publicação
CoRR

Abstract

Teses
supervisionadas

2022

Scientific data management

Autor
Rui Nuno Borges Cruz Oliveira

Instituição
UM

2022

Using Machine Learning to Automatically Infer an Approximation of a Physical System

Autor
Afonso João Borges Cabral Cerejeira da Silva

Instituição
UM

2022

Interpretação e execução de SQL sobre ficheiros

Autor
Bruno Filipe de Sousa Dias

Instituição
UM

2022

Machine Learning and Deep Learning Algorithms to Correct and Classify Product Reviews in a Marketplace

Autor
Licinio Daniel Gomes Carvalho

Instituição
UP-FEUP

2022

Integrated Business Planning: Development of a Framework For Technological Improvement

Autor
Maria Teresa Forte Fernandes Gonçalves Teixeira

Instituição
UP-FEUP