Managing scientific data at a large scale is challenging for both scientists and the host data centre.

The storage and file systems deployed within a data centre 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 even murkier. To effectively manage the data load within a data centre, I/O experts must understand how users expect to use the storage and what services they should provide to enhance user productivity.

In this workshop, we bring together I/O experts from data centres 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. We seek to ensure that a systems-level perspective is included in these discussions.

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

• Research paper track – Requesting submissions regarding state-of-the-practice and research about I/O in the data centre (see our topic list).
• Talks from I/O experts – Requesting submissions of talks.
• Student Mentoring Sessions

We are excited to announce that research papers will be published in Springer LNCS open access and extended manuscripts in the Journal of High-Performance Storage as well. Contributions to both tracks are peer-reviewed and require submission of the respective research paper or idea for your presentation via Easychair (see the complete description in Track: Research Papers).

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

This workshop is powered by the Virtual Institute for I/O and the Journal of High-Performance Storage.

Please find the summary of our workshop here.

The workshop is organised by

• Julian Kunkel (Georg-August-Universität Göttingen/GWDG), julian.kunkel@gwdg.de
• Jay Lofstead (Sandia National Lab, USA), gflofst@sandia.gov
• Jean-Thomas Acquaviva (DDN, France), jtacquaviva@ddn.com

Our collaborative notebook is here.

You must register to attend the workshop.

• 09:00 Welcome – Julian Kunkel (GWDG/Uni Göttingen), Jay Lofstead (Sandia National Laboratories), Jean-Thomas Acquaviva (DDN)
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• 09:15 Session about storage semantics
  • 09:15 Analyzing Parallel Applications for Unnecessary I/O Semantics That Inhibit File System Performance – Sebastian Oeste (ZIH/TUD), Michael Kluge and Ronny Tschueter
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    Almost all applications use POSIX I/O explicitly or implicitly through third party libraries like MPI-IO to perform I/O operations on the file system. POSIX I/O is known to be one of the lead causes of poor I/O performance due to its restrictive access semantics and consistency requirements. Some file systems therefore relax specific POSIX semantics to alleviate I/O performance penalties. To use the offered file systems features most effectively it is required to know what kind of POSIX semantics an application requires. Existing tools can analyze parallel I/O performance to report type and duration of executed I/O operations. There are even tools that analyse the consistency requirements of data operations, but none that also consider perfromance critical patterns of metadata operations. In this paper, we present a novel, systematic approach that groups parallel I/O operations and analyzes their I/O semantics with respect to POSIX I/O. We provide the tool rabbitxx that identifies concurrent overlapping accesses to the same file but also identifies metadata accesses such as concurrent create operations in the same directory. Our work indicates that POSIX defined I/O access semantics, in its current form, are often not necessary for parallel applications.

• 09:45 POSIX Consistency Limitations and Relaxations – Andreas Dilger (Whamcloud)
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• 10:00 Toward IOVerbs with the Memory-Centric Storage for Exascale (MCSE) Project – Julian Kunkel (GWDG)
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• 10:15 Leveraging NVME on GPUs with alternative interfaces – CJ Newburn
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  To date, the autonomy of accelerators has been constrained. GPUs rely on the CPU to prepare IO requests, and GPUs just provide or consume the data and trigger execution when dependencies are met. But recently, workloads are more comprehensively migrated to the GPU, including the logic that decides what to access (which file for storage, which node for network). Thus, fuller autonomy is granted to the GPU to prepare and not just trigger IO, creating the opportunity for greater concurrency from an order of magnitude more threads, and for greater efficiency by using HW mechanisms to coalesce accesses. New APIs, issued from a full set of GPU threads, can harvest an order of magnitude more parallelism than a CPU could. That increase in concurrency harvests enough performance to saturate a GPU's PCIe pins with IO. We'll show how this coalescing across threads can achieve 100x increases in network message rates, and how use of NVMe for storage instead of CPU DRAM can improve TCO by a multi-X factor. This shift toward accelerator autonomy has implications for the design of computing nodes and the overall data center.
• 10:40 Panel about semantics and interfaces
• 11:00 break
• 11:30 BeeGFS On Demand Experiences, Infrastructure, and Goals – Matthew Curry (Sandia National Laboratories), Michael Aguilar and Shyamali Mukherjee
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• 12:00 Transfer Learning Workflow for I/O Bandwidth Prediction – Dmytro Povaliaiev and Radita Liem (RWTH Aachen)
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• 12:30 Current progress in ad-hoc storage systems within ADMIRE project – Javier Garcia Blas (Universidat Carlos III de Madrid), Marc-Andre Vef (Uni Mainz)
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• 13:00 Lunch break
• 14:00 DAOS performance and I/O challenges – Adrian Jackson (EPCC)
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• 14:30 Governance-Centric Paradigm: Overcoming the Information Gap between Users and Systems by Enforcing Data Management Plans on HPC-Systems – Hendrik Nolte (GWDG)
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• 15:00 Innovative Data Foundation accelerate the HPC/AI/Bigdata application – Yong Zheng (Huawei)
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  With the rapid growth of data volume and the data distribution in multi-location, the future-proof storage should be more flexible in scalability, performance, and management. This topic will presents Huawei storage innovation on the acceleration for HPC,AI and Bigdata. you will also learn the global access and data mobility solution for data in edge, center or cloud.
• 15:30 Data Queries on the National Science Data Fabric – Jay Lofstead (Sandia National Laboratories)
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• 16:00 break
• 16:30 AI for Science and Exascale – Jean-Thomas Aquaviva
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• 17:00 Smarter Data Processing in the DECICE and KISSKI projects – Julian Kunkel (GWDG)
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• 17:15 Introducing the Scalable Storage Competition (SSC) – Julian Kunkel (GWDG)
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• 17:30 Discussion slot
• 18:00 End

• Thomas Bönisch (HLRS)
• Suren Byna (Lawrence Berkeley National Laboratory)
• Matthew Curry (Sandia National Laboratories)
• Sandro Fiore (University of Trento)
• Javier Garcia Blas (Carlos III University)
• Stefano Gorini (Swiss National Supercomputing Centre)
• Adrian Jackson (The University of Edinburgh)
• Ivo Jimenez (University of California, Santa Cruz)
• George S. Markomanolis (AMD)
• Sandra Mendez (Barcelona Supercomputing Center (BSC))
• Feiyi Wang (Oak Ridge National Laboratory)

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

• I/O experts from data centres and industry.
• Researchers/Engineers working on high-performance I/O for data centres.
• Domain scientists and computer scientists interested in discussing I/O issues.
• Vendors are also welcome, but their presentations must align with data centre 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 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 in joining our mailing list at the Virtual Institute for I/O.

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

Call for Papers/Contributions (CfP)

The research track accepts papers covering state-of-the-practice and research dedicated to storage in the data centre.

Proceedings will appear in ISC's post-conference workshop proceedings in Springers LNCS. Extended versions have a chance for acceptance in the first issue of the JHPS journal. We will apply the more restrictive review criteria from JHPS and use the open workflow of the JHPS journal for managing the proceedings. For interaction, we will rely on Easychair, so please submit the metadata to EasyChair before the deadline.

For the workshop, we accept papers with up to 12 pages (excluding references) in LNCS format. You may already submit an extended version suitable for the JHPS in JHPS format. Upon submission, please indicate potential sections for the extended version (setting a light red background colour). There are two JHPS templates, a LaTeX and a Word template. The JHPS template can be easily converted to the LNCS Word format such that the effort is minimal for the authors to obtain both publications. See the Manuscript Preparation, Layout & Templates, Springer.

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). All relevant work in the area of data centre storage will be published with our joint workshop proceedings. We just believe the available time should be used best to discuss controversial topics.

The relevant topics for papers cover all aspects of data centre I/O, including:

• Application workflows
• User productivity and costs
• Performance monitoring
• Dealing with heterogeneous storage
• Data management aspects
• Archiving and long term data management
• State-of-the-practice (e.g., using or optimising a storage system for data centre workloads)
• Research that tackles data centre I/O challenges
• Cloud/Edge storage aspects

This is the schedule of last year, we will adjust this year's schedule.

• 2023-03-06: Submission deadline: AoE ¹⁾
  • Note: The call for papers and talks is already open.
  • We appreciate early submissions of abstracts and full papers and review them within 24 days.
• 2023-04-24: Author notification
• 2023-05-22: Pre-final submission for ISC (Papers to be shared during the workshop. We will also use the JHPS papers, if available.)
• 2023-05-25: Workshop
• 2023-07-02: Camera-ready papers for ISC ²⁾ – As they are needed for ISC's post-conference workshop proceedings. We embrace the opportunity for authors to improve their papers based on the feedback received during the workshop.
• 2023-08-24: Camera-ready papers for the extended JHPS paper (It depends on the author's ability to incorporate feedback into their submission in the incubator.)

The main acceptance criterion is the relevance of the approach to be presented, i.e., the core idea is novel and worthwhile to be discussed in the community. Considering that 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, incorporating feedback from the workshop.

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

The criteria for The Journal of High-Performance Storage are described on its webpage.

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

• A description of the operational aspects of your data centre
• A particular solution for specific data centre workloads in production

We also accept industry talks, given that they are focused on operational issues on data centres and omit marketing.

We use Easychair for managing the interaction with the program committee. If you are interested in participating, please submit a short (1/2 page) intended abstract of your talk together with a brief Bio.

• Submission deadline: 2023-04-24 AoE
• Author notification: 2023-05-02

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

1. Workload characterisation
   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 utilisation (related 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 utilisation
   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 most significant 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 characterisation
   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 foster the next generation of data-related practitioners and researchers, students are encouraged to submit an abstract following the expert talk guidelines above as far as their research is aligned with these topics. At the workshop, the students will be given 10 minutes to talk about what they are working on followed by 10-15 minutes of conversation with the community present about how to further the work, what the impact could be, alternative research directions, and other topics to help the students progress in their studies. We encourage students to work with a shepherd towards a JHPS paper illustrating their research based on the feedback obtained during the workshop.