What problem does it solve?
This Skill solves the challenge of training large language models with RLHF efficiently by coordinating distributed PPO/GRPO/RLOO/DPO-style workflows without excessive GPU idle time.
Core Features & Use Cases
- Ray-based distributed RLHF training: Runs actor/critic/reward/reference roles with Ray job submission for multi-node or single-node clusters.
- vLLM-accelerated rollout generation: Uses vLLM engines to speed up generation during PPO-style rollouts and supports tensor parallelism.
- Hybrid Engine GPU sharing: Enables sleep/wake scheduling so actor/critic/reward/reference and vLLM reuse GPU capacity more efficiently.
- Common RL training paths: Covers full RLHF pipelines (SFT → reward model → PPO/GRPO) and preference optimization via DPO.
- Common troubleshooting playbooks: Provides targeted fixes for GPU OOM, Ray CUDA device issues, slow generation, and instability tuning.
Use it when you need PPO/GRPO/RLOO/DPO training for 7B–70B+ models with production-grade distributed resource management, such as running RLHF on a GPU cluster with vLLM rollout acceleration.
Quick Start
Submit an RLHF PPO job on a Ray cluster by running the OpenRLHF PPO Ray training command from your environment.