Pablo Fuentes

@unican.es

Profesor Ayudante Doctor, Departamento de Ingeniería Informática y Electrónica
Universidad de Cantabria

Pablo Fuentes


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https://researchid.co/pablofuentes

RESEARCH, TEACHING, or OTHER INTERESTS

Computer Networks and Communications, Hardware and Architecture, Computer Engineering
14

Scopus Publications

234

Scholar Citations

9

Scholar h-index

8

Scholar i10-index

Scopus Publications

  • The CAMINOS interconnection networks simulator
    Cristóbal Camarero, Daniel Postigo, Pablo Fuentes
    Journal of Parallel and Distributed Computing, 2025
    This work presents CAMINOS, a new interconnection network simulator focusing on router microarchitecture. It was developed in Rust, a novel programming language with a syntax similar to C/C++ and strong memory protection. The architecture of CAMINOS emphasizes the composition of components. This allows new designs to be defined in a configuration file without modifying source code, greatly reducing effort and time. In addition to simulation functionality, CAMINOS assists in managing a collection of simulations as an experiment. This includes integration with SLURM to support executing batches of simulations and generating PDFs with results and diagnostics. We show that CAMINOS makes good use of computing resources. Its memory usage is dominated by in-flight messages, showing low overhead in memory usage. We attest that CAMINOS can effectively use CPU time, as scenarios with little contention execute faster.
  • Defining the Boundaries for Endpoint Congestion Management in Networks for High-Performance Computing
    Daniel Postigo, David Herreros, Eloy Barón, Cristóbal Camarero, Pablo Fuentes
    Snta 2024 Proceedings of the 2024 7th International Workshop on Systems and Network Telemetry and Analytics Part of Hpdc 2024 33rd International Symposium on High Performance Parallel and Distributed Computing, 2024
    A hotspot traffic pattern of communications can be a common phenomenon in HPC topologies that causes significant and lasting network performance degradation. This performance deterioration remains persistent over time, intensifying its impact even after the cessation of the detrimental traffic injection into the network. To understand its causes and effects, we analyze the network behavior under different hotspot traffic scenarios and compare the performance on various topologies. We examine both the performance drop due to traffic flows with endpoint contention, and the recovery process of the network after this phenomenon has occurred, if swift action is taken to mitigate it.
  • Addressing Student Fatigue in Computer Architecture Courses
    Pablo Fuentes, Cristobal Camarero, David Herreros, Vladimir Mateev, Fernando Vallejo, Carmen Martinez
    IEEE Transactions on Learning Technologies, 2022
    Understanding the architecture of a processor can be uninteresting and deterring for computer science students, since low-level details of computer architecture are often perceived to lack real-world impact. These courses typically have a strong practical component where students learn the fundamentals of the computer architecture and the handling of input/output operations through the development of simple programs in a low-level assembly programming language. Since these practical sessions require a strong involvement, student attendance and withdrawal rates are poor, lowering academic results and introducing a negative feedback loop that preconditions students to dislike them. This article introduces a new methodology for the practical sessions of Computer Organization and Design courses. This methodology disavows the use of simulators and focuses on actual hardware to promote a feeling of proximity to the execution and outcome of the programs. The proposed setup uses Raspberry Pi devices to encourage students to work autonomously, due to their low cost, capability of running an OS, and rich ecosystem of simple hardware devices. The setup is completed with RISC OS, which combines a simple window-based graphical interface with a low-level management of the hardware without requiring software abstraction layers. The article presents the methodology and the UCDebug tool, developed to help students debug their codes in RISC OS. After the introduction of the new setup at the University of Cantabria, academic results and student satisfaction have improved. The setup has also allowed to sustain a similar organization of the courses throughout the COVID-19 pandemic.
  • ACOR: Adaptive congestion-oblivious routing in dragonfly networks
    M. Benito, P. Fuentes, E. Vallejo, R. Beivide
    Journal of Parallel and Distributed Computing, 2019
  • Analysis and improvement of valiant routing in low-diameter networks
    Mariano Benito, Pablo Fuentes, Enrique Vallejo, Ramon Beivide
    Proceedings 2018 IEEE 4th International Workshop on High Performance Interconnection Networks in the Exascale and Big Data Era Hipineb 2018, 2018
    Valiant routing randomizes network traffic to avoid pathological congestion issues by diverting traffic to a random intermediate switch. It has received significant attention in recently proposed high-radix, low-diameter topologies, which are prone to congestion issues. It has been implemented obliviously, or as the basis of some non-minimal adaptive routing algorithms. An analysis of the original mechanism identifies two potential improvements regarding the selection of the intermediate switch. First, when traffic is local the randomization introduced by Valiant results in unnecessarily long paths. Instead, the introduced Restricted Valiant routing randomizes traffic within a local partition, avoiding congestion and generating shorter paths. Second, in certain cases the path to the selected random intermediate node can be blocked; a version with recomputation selects a new random intermediate node as long as the associated path remains stalled. The proposals are evaluated by simulation in a state-of-the-art Dragonfly network with different traffic patterns. Results show that Restricted Valiant is highly effective in cases of local traffic, with a small improvement under global patterns. Valiant with recomputation increases injection, further reducing average latency and increasing throughput. However, the higher injection increases congestion effects in some cases. Such problem is emphasized when more injection buffers are added, because of the increased pressure on the interconnect. Overall, the results are very relevant for routing in high-radix networks and might constitute the basis for other adaptive routing algorithms.
  • A scalable synthetic traffic model of Graph500 for computer networks analysis
    Pablo Fuentes, Mariano Benito, Enrique Vallejo, José Luis Bosque, Ramón Beivide, Andreea Anghel, Germán Rodríguez, Mitch Gusat, Cyriel Minkenberg, Mateo Valero
    Concurrency and Computation Practice and Experience, 2017
    SummaryThe Graph500 benchmark attempts to steer the design of High‐Performance Computing systems to maximize the performance under memory‐constricted application workloads. A realistic simulation of such benchmarks for architectural research is challenging due to size and detail limitations. By contrast, synthetic traffic workloads constitute one of the least resource‐consuming methods to evaluate the performance. In this work, we provide a simulation tool for network architects that need to evaluate the suitability of their interconnect for BigData applications. Our development is a low computation‐ and memory‐demanding synthetic traffic model that emulates the behavior of the Graph500 communications and is publicly available in an open‐source network simulator. The characterization of network traffic is inferred from a profile of several executions of the benchmark with different input parameters. We verify the validity of the equations in our model against an execution of the benchmark with a different set of parameters. Furthermore, we identify the impact of the node computation capabilities and network characteristics in the execution time of the model in a Dragonfly network.
  • FlexVC: Flexible Virtual Channel Management in Low-Diameter Networks
    Pablo Fuentes, Enrique Vallejo, Ramon Beivide, Cyriel Minkenberg, Mateo Valero
    Proceedings 2017 IEEE 31st International Parallel and Distributed Processing Symposium IPDPS 2017, 2017
    Deadlock avoidance mechanisms for lossless lowdistance networks typically increase the order of virtual channel (VC) index with each hop. This restricts the number of buffer resources depending on the routing mechanism and limits performance due to an inefficient use. Dynamic buffer organizations increase implementation complexity and only provide small gains in this context because a significant amount of buffering needs to be allocated statically to avoid congestion. We introduce FlexVC, a simple buffer management mechanism which permits a more flexible use of VCs. It combines statically partitioned buffers, opportunistic routing and a relaxed distancebased deadlock avoidance policy. FlexVC mitigates Head-of-Line blocking and reduces up to 50% the memory requirements. Simulation results in a Dragonfly network show congestion reduction and up to 37.8% throughput improvement, outperforming more complex dynamic approaches. FlexVC merges different flows of traffic in the same buffers, which in some cases makes more difficult to identify the traffic pattern in order to support nonminimal adaptive routing. An alternative denoted FlexVCminCred improves congestion sensing for adaptive routing by tracking separately packets routed minimally and nonminimally, rising throughput up to 20.4% with 25% savings in buffer area.
  • Network unfairness in dragonfly topologies
    Pablo Fuentes, Enrique Vallejo, Cristóbal Camarero, Ramón Beivide, Mateo Valero
    Journal of Supercomputing, 2016
  • Synthetic traffic model of the Graph500 communications
    Pablo Fuentes, Enrique Vallejo, José Luis Bosque, Ramón Beivide, Andreea Anghel, Germán Rodríguez, Mitch Gusat, Cyriel Minkenberg
    Lecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics, 2016
  • Characterizing the Communication Demands of the Graph500 Benchmark on a Commodity Cluster
    Pablo Fuentes, Jose Luis Bosque, Ramon Beivide, Mateo Valero, Cyriel Minkenberg
    Proceedings 2014 International Symposium on Big Data Computing Bdc 2014, 2015
    Big Data applications have become more and more important over the last few years. Such applications are focused on the analysis of huge amounts of unstructured information and present a series of differences with traditional High Performance Computing (HPC) applications. For illustrating such dissimilarities, this paper analyzes the behavior of the most scalable version of the Graph500 benchmark when run on a state-of-the-art commodity cluster facility. Our work shows that this new computation paradigm stresses the interconnection subsystem. In this work, we provide both analytical and empirical characterizations of the Graph500 benchmark, showing that its communication needs bound the achieved performance on a cluster facility. Up to our knowledge, our evaluation is the first to consider the impact of message aggregation on the communication overhead and explore the selection of a trade off that diminishes benchmark execution time, increasing system performance.
  • Throughput unfairness in dragonfly networks under realistic traffic patterns
    Pablo Fuentes, Enrique Vallejo, Cristobal Camarero, Ramon Beivide, Mateo Valero
    Proceedings IEEE International Conference on Cluster Computing Iccc, 2015
  • Contention-Based Nonminimal Adaptive Routing in High-Radix Networks
    Pablo Fuentes, Enrique Vallejo, Marina Garcia, Ramon Beivide, German Rodriguez, Cyriel Minkenberg, Mateo Valero
    Proceedings 2015 IEEE 29th International Parallel and Distributed Processing Symposium IPDPS 2015, 2015
  • A throughput-optimized optical network for data-intensive computing
    Laurent Schares, Benjamin G. Lee, Fabio Checconi, Russell Budd, Alexander Rylyakov, Nicolas Dupuis, Fabrizio Petrini, Clint L. Schow, Pablo Fuentes, Oliver Mattes, Cyriel Minkenberg
    IEEE Micro, 2014
  • Comparison study of scalable and cost-effective interconnection networks for HPC
    Pablo Fuentes, Enrique Vallejo, Carmen Martinez, Marina Garcia, Ramon Beivide
    Proceedings of the International Conference on Parallel Processing Workshops, 2012

RECENT SCHOLAR PUBLICATIONS

  • The CAMINOS Interconnection Networks Simulator
    C Camarero, D Postigo, P Fuentes
    Journal of Parallel and Distributed Computing, 105136 , 2025
    2025
    Citations: 2
  • Defining the Boundaries for Endpoint Congestion Management in Networks for High-Performance Computing
    D Postigo, D Herreros, E Barón, C Camarero, P Fuentes
    Proceedings of the Seventh International Workshop on Systems and Network … , 2024
    2024
  • Addressing Student Fatigue in Computer Architecture Courses
    P Fuentes, C Camarero, D Herreros, V Mateev, F Vallejo, C Martinez
    IEEE Transactions on Learning Technologies , 2022
    2022
    Citations: 9
  • Un sistema para la docencia a distancia en asignaturas con hardware real
    V Mateev, E Stafford, P Fuentes
    Proc. Jornadas Sarteco, 255-262 , 2021
    2021
  • ACOR: Adaptive congestion-oblivious routing in dragonfly networks
    M Benito, P Fuentes, E Vallejo, R Beivide
    Journal of Parallel and Distributed Computing 131, 173-188 , 2019
    2019
    Citations: 15
  • Tecnología low-cost para motivar al alumno
    P Fuentes, C Camarero, C Martínez, F Vallejo
    Actas de las Jornadas sobre Enseñanza Universitaria de la Informática 4, 319–326 , 2019
    2019
    Citations: 2
  • Analysis and improvement of valiant routing in low-diameter networks
    M Benito, P Fuentes, E Vallejo, R Beivide
    2018 IEEE 4th International Workshop on High-Performance Interconnection … , 2018
    2018
    Citations: 8
  • A scalable synthetic traffic model of Graph500 for computer networks analysis
    P Fuentes, M Benito, E Vallejo, JL Bosque, R Beivide, A Anghel, ...
    Concurrency and Computation: Practice and Experience 29 (24), e4231 , 2017
    2017
    Citations: 15
  • Balanced and efficient interconnects for Exascale supercomputers
    P Fuentes Sáez
    Universidad de Cantabria , 2017
    2017
  • Aprendizaje autónomo del estudiante apoyado en recursos audiovisuales en el contexto de un Grado de Ingeniería Informática: experiencias con metodologías de enseñanza activas
    E Vallejo, P Fuentes, M Benito
    In-Red 2017. III Congreso Nacional de innovación educativa y de docencia en … , 2017
    2017
  • Flexvc: Flexible virtual channel management in low-diameter networks
    P Fuentes, E Vallejo, R Beivide, C Minkenberg, M Valero
    2017 IEEE International Parallel and Distributed Processing Symposium (IPDPS … , 2017
    2017
    Citations: 5
  • Synthetic traffic model of the Graph500 communications
    P Fuentes, E Vallejo, JL Bosque, R Beivide, A Anghel, G Rodríguez, ...
    International Conference on Algorithms and Architectures for Parallel … , 2016
    2016
    Citations: 5
  • Network unfairness in dragonfly topologies
    P Fuentes, E Vallejo, C Camarero, R Beivide, M Valero
    The Journal of Supercomputing 72 (12), 4468-4496 , 2016
    2016
    Citations: 11
  • Throughput Unfairness in Dragonfly Networks under Realistic Traffic Patterns
    P Fuentes, E Vallejo, C Camarero, R Beivide, M Valero
    1st IEEE International Workshop on High-Performance Interconnection Networks … , 2015
    2015
    Citations: 12
  • Contention-based Nonminimal Adaptive Routing in High-radix Networks
    P Fuentes, E Vallejo, M Garcıa, R Beivide, G Rodrıguez, C Minkenberg, ...
    2015
    Citations: 40
  • Characterizing the Communication Demands of the Graph500 Benchmark on a Commodity Cluster
    P Fuentes, JL Bosque, R Beivide, M Valero, C Minkenberg
    Proceedings of the 2014 IEEE/ACM International Symposium on Big Data … , 2014
    2014
    Citations: 12
  • A throughput-optimized optical network for data-intensive computing
    L Schares, BG Lee, F Checconi, R Budd, A Rylyakov, N Dupuis, F Petrini, ...
    IEEE Micro 34 (5), 52-63 , 2014
    2014
    Citations: 73
  • FOGSim interconnection network simulator
    M Garcıa, P Fuentes, M Odriozola, E Vallejo, R Beivide
    University of Cantabria , 2014
    2014
    Citations: 19
  • Comparison study of scalable and cost-effective interconnection networks for HPC
    P Fuentes, E Vallejo, C Martinez, M Garcia, R Beivide
    2012 41st International Conference on Parallel Processing Workshops, 594-595 , 2012
    2012
    Citations: 6
  • Plataforma web para retroalimentación automática en la docencia de ensamblador
    P Fuentes, C Martınez, E Vallejo, E Stafford, JL Bosque
    2012

MOST CITED SCHOLAR PUBLICATIONS

  • A throughput-optimized optical network for data-intensive computing
    L Schares, BG Lee, F Checconi, R Budd, A Rylyakov, N Dupuis, F Petrini, ...
    IEEE Micro 34 (5), 52-63 , 2014
    2014
    Citations: 73
  • Contention-based Nonminimal Adaptive Routing in High-radix Networks
    P Fuentes, E Vallejo, M Garcıa, R Beivide, G Rodrıguez, C Minkenberg, ...
    2015
    Citations: 40
  • FOGSim interconnection network simulator
    M Garcıa, P Fuentes, M Odriozola, E Vallejo, R Beivide
    University of Cantabria , 2014
    2014
    Citations: 19
  • ACOR: Adaptive congestion-oblivious routing in dragonfly networks
    M Benito, P Fuentes, E Vallejo, R Beivide
    Journal of Parallel and Distributed Computing 131, 173-188 , 2019
    2019
    Citations: 15
  • A scalable synthetic traffic model of Graph500 for computer networks analysis
    P Fuentes, M Benito, E Vallejo, JL Bosque, R Beivide, A Anghel, ...
    Concurrency and Computation: Practice and Experience 29 (24), e4231 , 2017
    2017
    Citations: 15
  • Throughput Unfairness in Dragonfly Networks under Realistic Traffic Patterns
    P Fuentes, E Vallejo, C Camarero, R Beivide, M Valero
    1st IEEE International Workshop on High-Performance Interconnection Networks … , 2015
    2015
    Citations: 12
  • Characterizing the Communication Demands of the Graph500 Benchmark on a Commodity Cluster
    P Fuentes, JL Bosque, R Beivide, M Valero, C Minkenberg
    Proceedings of the 2014 IEEE/ACM International Symposium on Big Data … , 2014
    2014
    Citations: 12
  • Network unfairness in dragonfly topologies
    P Fuentes, E Vallejo, C Camarero, R Beivide, M Valero
    The Journal of Supercomputing 72 (12), 4468-4496 , 2016
    2016
    Citations: 11
  • Addressing Student Fatigue in Computer Architecture Courses
    P Fuentes, C Camarero, D Herreros, V Mateev, F Vallejo, C Martinez
    IEEE Transactions on Learning Technologies , 2022
    2022
    Citations: 9
  • Analysis and improvement of valiant routing in low-diameter networks
    M Benito, P Fuentes, E Vallejo, R Beivide
    2018 IEEE 4th International Workshop on High-Performance Interconnection … , 2018
    2018
    Citations: 8
  • Comparison study of scalable and cost-effective interconnection networks for HPC
    P Fuentes, E Vallejo, C Martinez, M Garcia, R Beivide
    2012 41st International Conference on Parallel Processing Workshops, 594-595 , 2012
    2012
    Citations: 6
  • Flexvc: Flexible virtual channel management in low-diameter networks
    P Fuentes, E Vallejo, R Beivide, C Minkenberg, M Valero
    2017 IEEE International Parallel and Distributed Processing Symposium (IPDPS … , 2017
    2017
    Citations: 5
  • Synthetic traffic model of the Graph500 communications
    P Fuentes, E Vallejo, JL Bosque, R Beivide, A Anghel, G Rodríguez, ...
    International Conference on Algorithms and Architectures for Parallel … , 2016
    2016
    Citations: 5
  • The CAMINOS Interconnection Networks Simulator
    C Camarero, D Postigo, P Fuentes
    Journal of Parallel and Distributed Computing, 105136 , 2025
    2025
    Citations: 2
  • Tecnología low-cost para motivar al alumno
    P Fuentes, C Camarero, C Martínez, F Vallejo
    Actas de las Jornadas sobre Enseñanza Universitaria de la Informática 4, 319–326 , 2019
    2019
    Citations: 2
  • Defining the Boundaries for Endpoint Congestion Management in Networks for High-Performance Computing
    D Postigo, D Herreros, E Barón, C Camarero, P Fuentes
    Proceedings of the Seventh International Workshop on Systems and Network … , 2024
    2024
  • Un sistema para la docencia a distancia en asignaturas con hardware real
    V Mateev, E Stafford, P Fuentes
    Proc. Jornadas Sarteco, 255-262 , 2021
    2021
  • Balanced and efficient interconnects for Exascale supercomputers
    P Fuentes Sáez
    Universidad de Cantabria , 2017
    2017
  • Aprendizaje autónomo del estudiante apoyado en recursos audiovisuales en el contexto de un Grado de Ingeniería Informática: experiencias con metodologías de enseñanza activas
    E Vallejo, P Fuentes, M Benito
    In-Red 2017. III Congreso Nacional de innovación educativa y de docencia en … , 2017
    2017
  • Plataforma web para retroalimentación automática en la docencia de ensamblador
    P Fuentes, C Martınez, E Vallejo, E Stafford, JL Bosque
    2012