Skip to content

GRPO: Scalable training with one LLM/node #3186

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 16 commits into
base: main
Choose a base branch
from

Conversation

jglaser
Copy link

@jglaser jglaser commented Mar 31, 2025

What does this PR do?

Truly scalable training with GRPO + 1 local vllm process per node. Also works with FSDP. Tested on 256 nodes of Frontier (2048 GPUs).

Before submitting

  • This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
  • Did you read the contributor guideline,
    Pull Request section?
  • Was this discussed/approved via a GitHub issue? Please add a link
    to it if that's the case. Scaling bottleneck in GRPO Training. #3258 Support FSDP #3259
  • Did you make sure to update the documentation with your changes? Here are the
    documentation guidelines.
  • Did you write any new necessary tests?
    • developing FSDP or multinode tests is challenging and might be addressed best via a separate PR. For now we would like to make sure that existing single node tests are not breaking. Suggestions welcome!

Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.
@qgallouedec @binary-husky

Caveat:

  • currently disables an optimization for multiple completions as that one does not seem to be robust w.r.t. duplicate user inputs

@jglaser jglaser marked this pull request as ready for review April 4, 2025 18:22
@qgallouedec
Copy link
Member

Thanks @jglaser

I'm not sure to understand why FSDP requires to have one vLLM instance per node?

@jglaser
Copy link
Author

jglaser commented Apr 8, 2025

Thanks @jglaser

I'm not sure to understand why FSDP requires to have one vLLM instance per node?

It does not... FSDP changes and vllm scaling in this PR are not strictly related - however they arose in the same stream of work, as I was trying to train a 14B model which also required sharding (in addition to data parallelism).

If the FSDP feature complicates review unnecessarily, this can be factored out into a separate PR. Suggestions?

@qgallouedec
Copy link
Member

Ok, it makes more sense. To make the review easier can you split into two separate PRs 🙏

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

2 participants