Post-Doctoral Research Visit F/M Performance Modeling of HPC Applications [Inria/LNCC]



July 10, 2021


2021-03799 - Post-Doctoral Research Visit F/M Performance Modeling of HPC Applications Inria/LNCC

Contract type : Fixed-term contract

Level of qualifications required : PhD or equivalent

Fonction : Post-Doctoral Research Visit

About the research centre or Inria department

Team STORM combines strengths on high level DSLs, heterogeneous runtimes and performance analysis tools to help programmers get the highest efficiency from modern computer architectures in a portable manner.


This work will be developed within the framework of the HPCProSol joint team. This team was established in 2021 as a collaboration between Inria Bordeaux (TADaaM and STORM teams) and the National Laboratory for Scientific Computing (LNCC) in Petrópolis, Brazil.

The team's main goal is to study and characterize the new High-Performance Computing workload, represented by a set of scientific applications that are important to the LNCC because they are representative of its supercomputer's workload. Their machine, named Santos Dumont, was the largest in Latin America and used by a diverse scientific community, thus it runs applications from many fields. Therefore, its workload allows for drawing conclusions that can be generalized for many similar applications and systems. The generated knowledge will guide the proposal of monitoring and profiling techniques for applications, and the design of new coordination mechanisms to arbitrate resources in HPC environments.

Trips between Bordeaux and Petrópolis are planned during the contract. Travel expenses are covered by the joint team within limits set by Inria.

Scientific context

HPC architectures, the supercomputers, were conceived to efficiently run traditional HPC applications, namely numerical simulations. However, in the context of the convergence between HPC and Big Data 1, the notion of scientific application is evolving into a scientific workflow, composed of CPU-intensive and data-intensive tasks. This evolution characterizes the new HPC workload.

In this new scenario, efficient application execution becomes more challenging due to a mismatch between systems and applications. New applications include new methods, libraries, and runtime systems that may not have been properly optimized to the supercomputer, leading to problems such as load imbalance and poor communication performance. Meanwhile, supercomputers' resources are arbitrated between applications using little information as the number of CPUs and the estimated execution time, which potentially wastes resources that are unused at different moments during application execution 2. Additionally, although running on independent nodes, concurrent applications still share the network and I/O infrastructures, which means they can interfere with each other. The contention in the access to shared I/O resources has been shown to affect applications' performance non-uniformly, depending on their characteristics 3, 4. Hence these problems are expected to become worse as the new HPC workload includes more diverse codes, and should be tackled by better scheduling at application and system levels, and consider applications' characteristics to avoid issues such as interference 5.


1 M. Asch et al. Big data and extreme-scale computing: Pathways to convergence-toward a shaping strategy for a future software and data ecosystem for scientific inquiry. The International Journal of High Performance Computing Applications, 32(4):435–479, 2018.

2 J. L. Bez, A. Miranda, R. Nou, F. Zanon Boito, T. Cortes, and P. Navaux. Arbitration Policies for On-Demand User-Level I/O Forwarding on HPC Platforms. In IPDPS 2021 - 35th IEEE International Parallel and Distributed Processing Symposium, Portland, Oregon / Virtual, United States, May 2021.

3 X. Ji, B. Yang, T. Zhang, X. Ma, X. Zhu, X. Wang, N. El-Sayed, J. Zhai, W. Liu, and W. Xue. Automatic, application-aware i/o forwarding resource allocation. In 17th USENIX Conference on File and Storage Technologies (FAST 19), pages 265–279, Boston, MA, Feb. 2019. USENIX Association.

4 O. Yildiz, M. Dorier, S. Ibrahim, R. Ross, and G. Antoniu. On the root causes of cross-application I/O interference in HPC storage systems. In 2016 IEEE International Parallel and Distributed Processing Symposium (IPDPS), pages 750–759, 2016.

5 J. Yu, G. Liu, W. Dong, X. Li, J. Zhang, and F. Sun. On the load imbalance problem of I/O forwarding layer in HPC systems. In 2017 3rd IEEE International Conference on Computer and Communications (ICCC), volume 2018, pages 2424–2428. IEEE, Dec. 2017.


The goal of this post-doctoral research is to study and model the performance of applications that represent the new HPC workload, selected from the LNCC's workload:

  • A numerical simulation library, called MHM, developed by the LNCC 6. This library implements a number of finite element methods and offers support to hybrid parallelism (OpenMP + MPI) for classic and multiscale numerical simulations.
  • Data analysis tasks and workflows from the BioInfoPortal science gateway 7 developed by the LNCC to allow for easy execution of bioinformatics applications on the Santos Dumont machine.
  • The recruited person will work in collaboration with researchers from the joint team to profile these applications at different scales, and in concurrence with other codes and stress benchmarks. The recruited person will also be responsible for modeling the applications' performance, for finding ways to generalize these profiles to similar applications, and for identifying the information that should be obtained during application execution. This information should be useful for obtaining new profiles automatically, and to compute metrics that can help the runtime to predict deviations from the standard application behavior (for instance, if the input phase of an HPC simulation lasts longer than expected, it is possible the application is treating a larger problem and thus will run longer, with longer and more spaced output phases).


    6 A. T. A. Gomes, D. Paredes, W. D. S. Pereira, R. P. Souto, and F. Valentin. Per-formance analysis of the MHM simulator in a petascale machine. In Proceedings of the XXXVIII Iberian Latin American Congress on Computational Methods in Engineering., 2017

    7 K. A. Ocaña, M. Galheigo, C. Osthoff, L. M. Gadelha, F. Porto, A. T. A. Gomes, D. de Oliveira, and A. T. Vasconcelos. BioInfoPortal: A scientific gateway for integrating bioinformatics applications on the Brazilian national high-performance computing network. Future Gener. Comput. Syst., 107(C):192–214, June 2020.

    Main activities

    Main activities

  • Design and run experiments with applications on a supercomputer
  • Model application performance and the effects of interference
  • Identify useful information and performance metrics for modeling and predicting application behavior
  • Write reports and papers on the subject
  • Organize scripts and datasets for the reproduction of results and statistical analyses
  • Skills
  • Knowledge of parallel computing, HPC, and performance profiling and modeling are required.
  • Communication skills in English (reading, writing, presenting) are required.
  • Knowledge of the French and Portuguese languages are a plus.
  • Technical skills: command line usage of Linux-based HPC systems; script programming; ability to modify the source code of applications written in different programming languages; statistical analysis using R of Python.
  • This is a post-doctoral position for 12 to 24 months, offered in the context of the collaboration between Inria and the LNCC. The candidature must be submitted by email to before July 10th 2021 with all the documents listed below. If you want to apply, please contact us beforehand at,, and jean-

  • The summary sheet;
  • A research project detailing the research program, the work plan, the visits expected during the post-doc and when it should begin (November the 1st by default, January the 1st 2022 at the latest);
  • A detailed CV of the candidate including a description of the work conducted during the Ph.D., a complete list of the publications, and the 2 most important publications;
  • A motivation letter of the candidate;
  • Two recommendation letters (from people working in France or outside);
  • A support letter from the Inria team;
  • A support letter from the LNCC;
  • A copy of the passport.
  • Benefits package
  • Subsidized meals
  • Partial reimbursement of public transport costs
  • Possibility of teleworking and flexible organization of working hours
  • Professional equipment available (videoconferencing, loan of computer equipment, etc.)
  • Social, cultural and sports events and activities
  • Access to vocational training
  • Social security coverage
  • Remuneration

    2653€ / month (before taxs)

    General Information
  • Theme/Domain : Distributed and High Performance Computing Scientific computing (BAP E)

  • Town/city : Talence

  • Inria Center : CRI Bordeaux - Sud-Ouest
  • Starting date : 2021-11-01
  • Duration of contract : 12 months
  • Deadline to apply : 2021-07-10
  • Contacts
  • Inria Team : STORM
  • Recruiter : Lima Pilla Laercio /
  • The keys to success

    Important qualities to succeed in this work include the capacity for initiative and autonomy, integrity, a willingness to learn, and relational abilities to work in a diverse and geographically-distributed team. A thesis in computer science is required. A thesis in performance profiling or modeling is a real asset.

    About Inria

    Inria is the French national research institute dedicated to digital science and technology. It employs 2,600 people. Its 200 agile project teams, generally run jointly with academic partners, include more than 3,500 scientists and engineers working to meet the challenges of digital technology, often at the interface with other disciplines. The Institute also employs numerous talents in over forty different professions. 900 research support staff contribute to the preparation and development of scientific and entrepreneurial projects that have a worldwide impact.

    Instruction to apply

    Thank you to send: - CV - Cover letter - Support letters (mandatory) - List of publication

    Defence Security : This position is likely to be situated in a restricted area (ZRR), as defined in Decree No. 2011-1425 relating to the protection of national scientific and technical potential (PPST).Authorisation to enter an area is granted by the director of the unit, following a favourable Ministerial decision, as defined in the decree of 3 July 2012 relating to the PPST. An unfavourable Ministerial decision in respect of a position situated in a ZRR would result in the cancellation of the appointment.

    Recruitment Policy : As part of its diversity policy, all Inria positions are accessible to people with disabilities.

    Warning : you must enter your e-mail address in order to save your application to Inria. Applications must be submitted online on the Inria website. Processing of applications sent from other channels is not guaranteed.