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| 1 | +# GRPO Fine-Tuning with Training Hub |
| 2 | + |
| 3 | +This example provides an overview of Training Hub's [GRPO (Group Relative Policy Optimization)](https://github.com/Red-Hat-AI-Innovation-Team/training_hub?tab=readme-ov-file#grpo) capabilities and demonstrates how to use them with Red Hat OpenShift AI. |
| 4 | + |
| 5 | +## What is GRPO? |
| 6 | + |
| 7 | +GRPO is a reinforcement learning from verifiable rewards (RLVR) algorithm that improves a model's outputs by comparing groups of responses and reinforcing the better ones: |
| 8 | + |
| 9 | +- Generates multiple candidate responses per prompt |
| 10 | +- Scores them with a reward function (e.g. tool-call correctness) |
| 11 | +- Uses the group's relative ranking to compute advantage signals |
| 12 | +- Updates LoRA adapter weights via policy gradient with group normalization |
| 13 | + |
| 14 | +Each training iteration has two phases: |
| 15 | + |
| 16 | +1. **Rollout phase** — vLLM generates candidate responses and a reward function scores them |
| 17 | +2. **Train phase** — Unsloth updates the LoRA adapter weights using the advantage signals |
| 18 | + |
| 19 | +The ART backend time-shares a single GPU between vLLM (inference) and Unsloth (training) via `gpu_memory_utilization`. |
| 20 | + |
| 21 | +### Training Task: Tool-Call Verification |
| 22 | + |
| 23 | +The example uses the [Agent-Ark/Toucan-1.5M](https://huggingface.co/datasets/Agent-Ark/Toucan-1.5M) dataset, which contains tool-calling conversations. The reward function verifies that the model produces syntactically correct tool calls with the expected function name and arguments. |
| 24 | + |
| 25 | +## Execution mode |
| 26 | + |
| 27 | +GRPO runs as a **single-GPU TrainJob** submitted via the Kubeflow SDK. ART is single-GPU by design and manages its own vLLM subprocess internally. |
| 28 | + |
| 29 | +The notebook submits a `TrainJob` from a lightweight workbench, and the training runs on a dedicated GPU pod managed by Kubeflow Trainer. |
| 30 | + |
| 31 | +To learn more about execution modes for other algorithms, see the [fine-tuning execution modes overview](../README.md#execution-modes). |
| 32 | + |
| 33 | +## RHOAI compatibility |
| 34 | + |
| 35 | +This example is compatible with RHOAI version 3.5. |
| 36 | + |
| 37 | +## Requirements |
| 38 | + |
| 39 | +- An OpenShift cluster with OpenShift AI (RHOAI 3.5) installed: |
| 40 | + - The `dashboard` and `workbenches` components enabled |
| 41 | + - The `trainer` component enabled |
| 42 | +- A worker node with an NVIDIA GPU (Ampere-based or newer, 40GB+ VRAM). |
| 43 | +- A dynamic storage provisioner supporting RWX PVC provisioning. Talk to your cluster administrator about RWX storage options. |
| 44 | + |
| 45 | +## Hardware requirements |
| 46 | + |
| 47 | +For the workbench image, the example was run on `Training | Jupyter | PyTorch | CUDA | Python` and `Training | Jupyter | PyTorch | CPU Python`. |
| 48 | +This is a single image serving both as training runtime and jupyter notebook and comes with pre-installed dependencies required |
| 49 | +to seamlessly run fine-tuning jobs. |
| 50 | + |
| 51 | +### Workbench Requirements |
| 52 | + |
| 53 | +| Image Type | Use Case | GPU | CPU | Memory | |
| 54 | +|------------|----------|-----|-----|--------| |
| 55 | +| Training \| Jupyter \| PyTorch \| CPU Python | Job submission and monitoring | None | 2 cores | 8Gi | |
| 56 | +| Training \| Jupyter \| PyTorch \| CUDA \| Python | Job submission + model evaluation | 1× GPU | 2 cores | 8Gi | |
| 57 | + |
| 58 | +> [!NOTE] |
| 59 | +> |
| 60 | +> - The workbench does not run the training itself — it submits a TrainJob and monitors progress. |
| 61 | +> - A GPU on the workbench is only needed if you want to load and test the fine-tuned LoRA adapter after training completes. |
| 62 | +
|
| 63 | +### Training Pod Requirements |
| 64 | + |
| 65 | +| Component | GPU | GPU Type | CPU | Memory | |
| 66 | +|-----------|-----|----------|-----|--------| |
| 67 | +| Training Pod | 1× GPU | NVIDIA A100, H100, or L40S (40GB+ VRAM) | 8 cores | 64Gi | |
| 68 | + |
| 69 | +> [!NOTE] |
| 70 | +> |
| 71 | +> - GRPO requires a single GPU with at least 40GB VRAM. The `gpu_memory_utilization` parameter (default `0.45`) controls how much GPU memory is reserved for vLLM inference, with the remainder available for Unsloth training. |
| 72 | +> - CPU and memory requirements scale with model size and group size. The above values suit the example configuration (Qwen3-4B, group_size=4). |
| 73 | +> - The training pod is configured from the `client.train()` call within the notebook. |
| 74 | +
|
| 75 | +### Storage Requirements |
| 76 | + |
| 77 | +| Purpose | Size | Access Mode | Storage Class | Notes | |
| 78 | +|---------|------|-------------|---------------|-------| |
| 79 | +| Shared Storage (PVC) total | 50Gi (Example Default) | RWX | Dynamic provisioner required | Shared between workbench and training pod | |
| 80 | + |
| 81 | +> [!NOTE] |
| 82 | +> |
| 83 | +> - Storage can be created in `Create Workbench` view on RHOAI Platform, however, dynamic RWX provisioner is required to be configured prior to creating shared file storage in RHOAI. |
| 84 | +> - Shared storage is required — the training pod writes checkpoints and metrics to the PVC, and the workbench reads them for inspection and plotting. |
| 85 | +
|
| 86 | +## GRPO-specific considerations |
| 87 | + |
| 88 | +- **`/dev/shm` volume**: vLLM requires a memory-backed `/dev/shm` for inter-process communication. The notebook configures this automatically via a `PodSpecOverride` that mounts an `emptyDir` with `medium: Memory`. |
| 89 | +- **`gpu_memory_utilization`**: Controls the vLLM/Unsloth memory split on the single GPU. The default `0.45` reserves 45% for vLLM inference and leaves the rest for Unsloth training. Adjust based on your model size and available VRAM. |
| 90 | +- **HuggingFace token**: Not strictly required for public models (e.g. Qwen3-4B) but recommended to avoid rate limits. Set `HF_TOKEN` in the environment variables if needed. |
| 91 | + |
| 92 | +## Setup |
| 93 | + |
| 94 | +### Setup Workbench |
| 95 | + |
| 96 | +**Step 1.** Access the OpenShift AI dashboard, for example from the top navigation bar menu: |
| 97 | + |
| 98 | + |
| 99 | + |
| 100 | +**Step 2.** Log in, then go to **_Data Science Projects_** and create a project: |
| 101 | + |
| 102 | + |
| 103 | + |
| 104 | +**Step 3.** Once the project is created, click on **_Create a workbench_**: |
| 105 | + |
| 106 | + |
| 107 | + |
| 108 | +**Step 4.** Select the appropriate Workbench image. See options above: |
| 109 | + |
| 110 | + |
| 111 | + |
| 112 | +**Step 5.** You may want to create a **Hardware Profile** with GPU support, similar to the one below: |
| 113 | + |
| 114 | + |
| 115 | + |
| 116 | +**Step 6.** Select the Hardware profile you want to use: |
| 117 | + |
| 118 | + |
| 119 | + |
| 120 | +> [!NOTE] |
| 121 | +> A GPU on the workbench is only needed if you want to test the fine-tuned model after training. The workbench itself only submits and monitors the TrainJob. |
| 122 | +
|
| 123 | +**Step 7.** Create **shared storage** that will be shared between the workbench and the training pod. Make sure it uses a storage class with RWX capability: |
| 124 | + |
| 125 | + |
| 126 | + |
| 127 | +> [!NOTE] |
| 128 | +> You can attach an existing shared storage if you already have one instead. |
| 129 | +
|
| 130 | +**Step 8.** Review the storage configuration and click "Create workbench": |
| 131 | + |
| 132 | + |
| 133 | + |
| 134 | +**Step 9.** From "Workbenches" page, click on **_Open_** when the workbench you've just created becomes ready: |
| 135 | + |
| 136 | + |
| 137 | + |
| 138 | +### Running the example notebook |
| 139 | + |
| 140 | +- From the workbench, clone this repository: `https://github.com/red-hat-data-services/red-hat-ai-examples.git` |
| 141 | +- Navigate to the `examples/fine-tuning/grpo` directory and open the [`grpo_lora-kubeflow-trainjob.ipynb`](./grpo_lora-kubeflow-trainjob.ipynb) notebook. |
| 142 | + |
| 143 | +> [!NOTE] |
| 144 | +> |
| 145 | +> - You will need a Hugging Face token if using gated models (e.g., Llama models). |
| 146 | +> Set the `HF_TOKEN` environment variable in your job configuration. |
| 147 | +> You can skip the token if switching to non-gated models like Qwen3-4B. |
| 148 | +
|
| 149 | +You can now proceed with the instructions from the notebook. Enjoy! |
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