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About

About

I am a researcher at HASLab and professor at the U. Minho. My research focuses on dependable distributed systems. I am interested mainly in data management, including database replication and SQL processing over NoSQL systems, and in group communication, including consensus and gossip-based protocols for large-scale systems. I am also interested in tools for testing, evaluating, and monitoring dependable distributed systems. More information is available at my personal home page.

Interest
Topics
Details

Details

  • Name

    José Orlando Pereira
  • Role

    Research Coordinator
  • Since

    01st November 2011
005
Publications

2023

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

Authors
Faria, N; Pereira, J;

Publication
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

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

Publication
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

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

Publication
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

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

Publication
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

TADA: A Toolkit for Approximate Distributed Agreement

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

Publication
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

Supervised
thesis

2022

Distributed and Dependable SDS Control Plane for HPC

Author
Mariana Martins de Sá Miranda

Institution
UM

2022

Interpretação e execução de SQL sobre ficheiros

Author
Bruno Filipe de Sousa Dias

Institution
UM

2022

Acordo distribuído em sistemas de computação de alto desempenho

Author
Diogo José Cruz Sobral

Institution
UM

2022

Towards Tunable Distributed Data Management for IoT

Author
Luís Manuel Meruje Ferreira

Institution
UM

2022

Intelligent Auto Scalling (Dev Ops)

Author
Tiago Manuel Gonçalves Lameira

Institution
UM