Managing scientific data at large scale is challenging for scientists but also for the host data center. The storage and file systems deployed within a data center are expected to meet users' requirements for data integrity and high performance across heterogeneous and concurrently running applications.

With new storage technologies and layers in the memory hierarchy, the picture is becoming murkier. To effectively manage the data load within a data center, I/O experts must understand how users expect to use these new storage technologies and what services they should provide in order to enhance user productivity. We seek to ensure a systems-level perspective is included in these discussions.

In this workshop we bring together I/O experts from data centers and application workflows to share current practices for scientific workflows, issues and obstacles for both hardware and the software stack, and R&D to overcome these issues.

The workshop content is built on two tracks with calls for papers/talks:

• research paper track – requesting submissions regarding state-of-the-practice and research about I/O in the datacenter.
• talks from I/O experts – requesting submissions of talks.

Contributions to both tracks are peer reviewed and require submission of the respective research paper or idea for your presentation via Easychair (see the descriptions below).

The workshop is held in conjunction with the ISC-HPC during the ISC workshop day. Note that the attendance of ISC workshops requires a workshop pass. See also our last year's workshop web page.

The HPC-IODC workshop is embedded into a full-day program for I/O that we organize with the team of the Workshop on Performance and Scalability of Storage Systems (WOPSSS) URL: http://wopsss.org/ We will build a program with a joint morning session with keynote talks and best papers and then diverge into two independent workshops in the afternoon.

This workshop is powered by the Virtual Institute for I/O and ESiWACE ¹⁾.

The morning session is organized together with the WOPSSS.

• 09:00 Welcome – Jean-Thomas Acquaviva, Julian Kunkel, Jay Lofstead
  Slides
• 09:15 Keynote: Understanding and Tuning HPC I/O: How hard can it be? – Phil Carns (Argonne National Laboratory)
  Slides
• 10:00 Research paper session, chair Jean-Thomas Acquaviva
  • I/O Interference Alleviation on Parallel File Systems Using Server-Side QoS-Based Load-Balancing
    Yuichi Tsujita, Yoshitaka Furutani, Hajime Hida, Keiji Yamamoto, Atsuya Uno and Fumichika Sueyasu
    Slides
  • Understanding Metadata Latency with MDWorkbench
    Julian Kunkel, George Markomanolis
    Slides
• 11:00 Coffee break
• 11:30 Mixed session, chair Jean-Thomas Acquaviva
  • 11:30 Self-Optimized Strategy for IO Accelerator Parametrization
    Lionel Vincent
    Slides
  • 12:00 Community Development of Next Generation Semantic Interfaces
    Julian Kunkel
    Slides
• 12:30 Discussion moderated by Jean-Thomas Acquaviva
• 13:00 Lunch break

After lunch, the big room is separated for the two workshops.

• 14:00 Welcome, Julian Kunkel, Jay Lofstead
• 14:02 Expert talk session, chair Jay Lofstead
  • Addressing data center storage diversity for high-performance computing applications using Faodel
    Patrick Widener
    Slides
  • Planning for the Future of Storage for HPC: 2020, 2025, and Beyond
    Glenn K. Lockwood, Damian Hazen, Quincey Koziol, R. Shane Canon, Katie Antypas and Nicholas J. Wright
    Slides
• 15:00 Research paper session, chair Julian Kunkel
  • Analyzing the I/O scalability of a Particle-in-Cell parallel code
    Sandra Mendez, Nicolay Hammer and Anupam Karmakar
    Slides
  • Cost and Performance Modeling for Earth System Data Management and Beyond
    Jakob Luettgau and Julian Kunkel
    Slides
  • Lustre-On-ZFS
    Stephen Simms
    Slides
• 16:00 Coffee break
• 16:30 Expert talk session, chair Jay Lofstead
  • Development of a high-performance distributed object-store for Numerical Weather Prediction and Climate model data
    Simon Smart
    Slides
  • Exploiting Nonvolatile memory for HPC
    Juan Rodriguez Herrera (EPCC)
    Slides
• 17:30 Discussion: Data Intensive Workflows and Benchmarking, chair Jay Lofstead
• 18:00 End

The workshop is organized by

• Julian Kunkel (University of Reading, UK), j.m.kunkel@reading.ac.uk
• Jay Lofstead (Sandia National Lab, USA), gflofst@sandia.gov

• Adrian Jackson (The University of Edinburgh)
• Ann Gentile (Sandia National Laboratories)
• Bing Xie (Oak Ridge National Lab)
• Brad Settleyer (Los Alamos National Laboratory)
• Feiyi Wang (Oak Ridge National Lab)
• George Markomanolis (King Abdullah University of Science and Technology)
• Javier Garcia Blas (University Carlos III of Madrid)
• Jay Lofstead (Sandia National Lab)
• Jean-Thomas Acquaviva (DDN)
• Jim Brandt (Sandia National Laboratories)
• Julian Kunkel (DKRZ)
• Matt Bryson (University of California, Santa Cruz)
• Michael Kluge (TU Dresden)
• Rob Ross (Argonne National Laboratory)
• Sandro Fiore (CMCC)
• Suren Byna (Lawrence Berkeley National Laboratory)
• Sven Breuner (ThinkparQ)
• Thomas Boenisch (HLRS)
• Tiago Quintino (ECMWF)
• Wolfgang Frings (Jülich Supercomputing Center)

The workshop is integrated into ISC-HPC. We welcome everybody to join the workshop, including:

• I/O experts from data centers and industry.
• Researchers/Engineers working on high-performance I/O for data centers.
• Interested domain scientists and computer scientists interested in discussing I/O issues.
• Vendors are also welcome, but their presentations must align with data center topics (e.g. how do they manage their own clusters) and not focus on commercial aspects.

The call for papers and talks is already open. We accept early submissions, too, and typically proceed with them within 45 days. We particularly encourage early submission of abstracts such that you indicate your interest in submissions.

You may be interested to join our mailing lists at the Virtual Institute of I/O.

We especially welcome participants that are willing to give a presentation about the I/O of the representing institutions data center. Note that such presentations should cover the topics mentioned below.

The research track accepts papers covering state-of-the-practice and research dedicated to storage in the datacenter. We accept short papers with up to 12 pages (excl. references) in LNCS format. Please see the instructions and templates for authors provided by Springer.

Our targeted proceedings are ISC's post-conference workshop proceedings in Springers LNCS. We use Easychair for managing the proceedings and PC interaction.

For accepted papers, the length of the talk during the workshop depends on the controversiality and novelty of the approach (the length is decided based on the preference provided by the authors and feedback from the reviewers). We also allow virtual participation (without attending the workshop personally). All relevant work in the area of data center storage will be able to publish with our joint workshop proceedings, we just believe the available time should be used best to discuss ambivalent topics.

• Submission deadline: 2018-04-19 AoE
  • Note: The call for papers and talks is already open.
  • You can submit an abstract anytime.
  • We also appreciate early full submissions, too, and typically review with them within 45 days.
• Author notification: 2018-05-04
• Pre-final submission: 2018-06-10 (to be shared during the workshop)
• Workshop: 2018-06-28
• Camera-ready papers: 2018-07-28 – As they are needed for ISC's post-conference workshop proceedings. We embrace the chance for authors to improve their papers based on the feedback received during the workshop.

The main acceptance criteria is the relevance of the approach to be presented – i.e., is the core idea worthwhile in the community to be discussed or novel. Since the camera-ready version of the papers is due after the workshop, we pursue two rounds of reviews:

1. Acceptance for the workshop (as a talk)
2. Acceptance as a paper *after* the workshop, this incorporates feedback from the workshop.

After the first review, all papers undergo a shepherding process.

The topics of interest in this track include but are not limited to:

• A description of the operational aspects of your data center
• A particular solution for certain data center workloads in production

We also accept industry talks, given that they focus on operational issues on data centers and omit marketing.

We use Easychair for managing the acceptance and PC interaction. If you are interested to participate please submit a short (1/2 page) intended abstract of your talk together with a short Bio.

• Submission deadline: 2018-04-19 AoE
• Author notification: 2018-05-04

The following list of items should be tried to be integrated into a talk covering your data center, if possible. We hope your sites administrator will support you to gather the information with little effort.

1. Workload characterization
   1. Scientific Workflow (give a short introduction)
      1. A typical use-case (if multiple are known, feel free to present more)
      2. Involved number of files / amount of data
   2. Job mix
      1. Node utilization (rel. to peak-performance)
2. System view
   1. Architecture
      1. Schema of the client/server infrastructure
         1. Capacities (Tape, Disk, etc.)
      2. Potential peak-performance of the storage
         1. Theoretical
         2. Optional: performance results of acceptance tests.
      3. Software / Middleware used, e.g. NetCDF 4.X, HDF5, …
   2. Monitoring infrastructure
      1. Tools and systems used to gather and analyse utilization
   3. Actual observed performance in production
      1. Throughput graphs of the storage (e.g. from Ganglia)
      2. Metadata throughput (Ops/s)
   4. Files on the storage
      1. Number of files (if possible per file type)
      2. Distribution of file sizes
3. Issues / Obstacles
   1. Hardware
   2. Software
   3. Pain points (what is seen as the biggest problem(s) and suggested solutions, if known)
4. Conducted R&D (that aim to mitigate issues)
   1. Future perspective
   2. Known or projected future workload characterization
   3. Scheduled hardware upgrades and new capabilities we should focus on exploiting as a community
   4. Ideal system characteristics and how it addresses current problems or challenges
   5. what hardware should be added
   6. what software should be developed to make things work better (capabilities perspective)
   7. Items requiring discussion to work through how to address