The Mochi Github migration is complete

All Mochi source code repositories have been migrated to at as of March 22, 2021.

If you are already using spack to install Mochi components, please update your Mochi repository at your earliest convenience:

spack repo rm mochi
git clone
spack repo add mochi-spack-packages

The package names have not changed; this will just enable you to retrieve new versions as they are released by updating your cloned copy of the mochi-spack-packages repo.

Mochi BoF at the ECP Annual Meeting

The Mochi team will be hosting a BoF entitled “Using Mochi to build data services: Overview and Updates” at the (virtual) ECP Annual Meeting on Tue. Apr 13, 2021 at 2:30 PM.

If you are an ECP project member attending the meeting, you can find more information about the BoF in the meeting agenda.

We will be providing an overview of Mochi, highlighting new capabilities, and offering sign-ups for one-on-one sessions for anyone who would like more detailed information or help.

Quarterly newsletter, January 2021

Platform notes:


  • All of the ANL-hosted git repositories ( will be moving within the next few months. We will communicate when that happens.
    • There are no changes to policy or access (in fact, access will likely change for the better); it’s just that the xgitlab.cels instance that we are using is being decommissioned
  • We are working on landing a Spack PR ( that will introduce a “mochi-margo” package, maintained by us, to replace the out-of-date “margo” package
    • Once this is done, we will likely start upstreaming more packages that depend on margo-mochi

Mochi service development news:

  • Work continues on a new component called “Bedrock” that can be used to more easily bootstrap microservice compositions (
    • Bedrock is already available, and we are in the process of updating existing services to use it.
    • You can think of bedrock as a general-purpose Mochi daemon that takes a JSON configuration file describing how to spin up embedded microservices
  • We are actively working on performance tuning of “Benvolio”, which you can think of as a runtime I/O delegation service (i.e. that provides a more generic version of MPI-IO aggregation capabilities).

Upcoming training events:

  • We plan to host a BoF session at this year’s (virtual) ECP annual meeting
    in mid-April, with a mechanism for people to sign up for one on one
    sessions for more detailed interaction. (
  • Please let us know what other kinds of outreach/training you are interested in this year.

Mochi at SC 2020

Highlighted events for the Mochi project at this year’s SC conference included the following:

  • Pascal Grosset, Jesus Pulido, and James Ahrens. 2020. “Personalized In Situ Steering for Analysis and Visualization,” in ISAV’20 In Situ Infrastructures for Enabling Extreme-Scale Analysis and Visualization (ISAV’20). Association for Computing Machinery, New York, NY, USA, 1–6. DOI:
  • Christopher Kelly, Sungsoo Ha, Kevin Huck, Hubertus Van Dam, Line Pouchard, Gyorgy Matyasfalvi, Li Tang, Nicholas D’Imperio, Wei Xu, Shinjae Yoo, and Kerstin Kleese Van Dam. 2020. “Chimbuko: A Workflow-Level Scalable Performance Trace Analysis Tool,” in ISAV’20 In Situ Infrastructures for Enabling Extreme-Scale Analysis and Visualization (ISAV’20). Association for Computing Machinery, New York, NY, USA, 15–19. DOI:
  • P. Carns, K. Harms, B. Settlemyer, B. Atkinson and R. Ross, “Keeping It Real: Why HPC Data Services Don’t Achieve I/O Microbenchmark Performance,” in 2020 IEEE/ACM Fifth International Parallel Data Systems Workshop (PDSW), GA, USA, 2020 pp. 1-6. doi: 10.1109/PDSW51947.2020.00006

Mochi at SC 2019

Highlighted events for the Mochi project at this year’s Supercomputing included:

  • Srinivasan Ramesh, Philip Carns, Robert Ross, Shane Snyder, and Allen Malony. “Profiling Composable HPC Data Services”, Work-In-Progress report at the 4th International Parallel Data Systems Workshop (PDSW 2019). LINK (paper) LINK (slides)
  • Jerome Soumagne et al. “Data Services for High Performance Computing”, Birds of a Feather session. LINK