HPC Monthly Call -- 2020-09-03
===

###### tags: `HPC`

:::info
- **Date:** September 3rd, 2020
- **Agenda**
- **Participants:**
- Valentin Churavy, JuliaLab, MIT
- Elliot Saba, Julia Computing
- Simon Byrne, CliMA project/Caltech
- Todd Gamblin, LLNL & Spack
- Ngoc Nguyen, MIT
- Chris de Graaf, JuliaLab
- Albert Reuther, Lincoln Labs, MIT
- Chris Hill, MIT
- Bart Janssens, Royal Military Academy Belgium
- Mose Giordano, UCL

- [Next notes](/@juliaparallel/2019-09-23)
:::

## Summary of last meeting
### Challenges
- Optimized binaries for clusters
- MPI ABI and incompatibilities between Vendors
- Transitive dependency, i.e. MPI used by C/C++ libraries

## Notes

- Add MPI as an ABI to BinaryBuilder?
- Polymorph MPI ABI from OpenMPI to Vendor X MPI
- Japanese MPIAdapter (K-Computer @ RIKEN)
- Convert Project.toml/Manifest.toml to Spack.yaml to generate and build an HPC optimized environment.
- How do we “subvert” Julia to then use those Spack generated binaries
- Overrrides.toml?
- Old prototype for Summit
- https://github.com/JuliaLabs/julia-on-summit/blob/master/gen_overrides.jl
- https://github.com/JuliaLabs/julia-on-summit/blob/master/collect_lmods.jl
- Endusers & cluster administrators/system engineers
- Offline tool for system administrators
- Spackify a global depot
- How do you limit the hit of loading precompiled files on 100’s of nodes / stop DDOS’ing your filesystem
https://github.com/hpc/spindle
- Blessed global depot + user specific environments
- How does Julia store information about what is being used
- Content hashing
- How do you decide which ABI to download
- Depends on Julia was built
- Julia & Python