Azure Ml LLM Trainer

Azure ML LLM Trainer

This skill provides direct training on Azure ML managed compute using TRL trainers—an alternative to Azure AI Foundry's serverless fine-tuning APIs.

Four fine-tuning options in Azure AI Foundry:

1. Serverless API (Foundry models) — Use create_finetuning_job() for Phi, Mistral; no compute setup needed
2. OpenAI API (OpenAI models) — Use OpenAI SDK with Azure endpoint for GPT-4o, GPT-4 Turbo
3. Managed Compute (Portal UI) — Web UI–driven fine-tuning with automatic compute provisioning; limited SDK
4. Direct Training (This Skill) — Run TRL trainers on your own Azure ML compute for full control and transparency

Use this skill when:

• You need full control over training loops and hyperparameters
• You want to use TRL (Transformer Reinforcement Learning) methods directly
• You prefer running on your own compute resources (no vendor lock-in)
• You want to experiment with advanced training techniques (LoRA, gradient checkpointing, etc.)

Template Files

These are templates in examples/ directory. Generate new files in your project based on these templates:

• examples/submit_sft_job.py — Template for submitting SFT training jobs
• examples/src/train_sft.py — Template for SFT trainer entry point (TRL SFTTrainer)
• examples/submit_dpo_job.py — Template for DPO training job submission
• examples/src/train_dpo.py — Template for DPO trainer entry point (TRL DPOTrainer)
• examples/submit_rl_job.py — Template for RL/PPO training job submission
• examples/src/train_rl.py — Template for RL trainer entry point (TRL PPOTrainer)
• examples/environment/conda.yml — Template for runtime dependencies (transformers, trl, datasets, torch)

Do NOT reference these files directly. Copy and adapt them for your project structure.

Quick start

1. az login then set AZURE_SUBSCRIPTION_ID, AZURE_RESOURCE_GROUP, AZUREML_WORKSPACE_NAME.
2. Create training files in your project:
   • Copy examples/submit_sft_job.py to your project as submit_training.py
   • Copy examples/src/train_sft.py to your project as src/train_sft.py
   • Copy examples/environment/conda.yml to your project as environment/conda.yml
3. Upload a JSONL dataset to a workspace datastore (workspaceblobstore or your own). SFT dataset format: Each line must be valid JSON with a "messages" field containing chat-completion format: {"messages": [{"role": "system", "content": "..."}, {"role": "user", "content": "..."}, {"role": "assistant", "content": "..."}]}. The trainer uses this field directly.
4. Ensure a compute target exists (GPU recommended, for example gpu-cluster).
5. Submit: python submit_training.py --compute <compute-name> --data-path <azureml://.../dataset.jsonl> --model-name azureml://registries/azureml/models/Phi-3-mini-4k-instruct/versions/1.
6. Monitor in Azure ML studio; trained weights land in the job output folder.

DPO quick start

• Dataset format (JSONL): Each line must contain "chosen" and "rejected" fields with chat-completion format messages: {"chosen": [{"role": "user", "content": "..."}, {"role": "assistant", "content": "..."}], "rejected": [{"role": "user", "content": "..."}, {"role": "assistant", "content": "..."}]}.
• Hyperparameters: beta (default 0.1) controls KL penalty, l2_multiplier (default 0.1) for regularization.
• Submit: python sample/submit_dpo_job.py --compute <compute-name> --data-path <azureml://.../dpo.jsonl> --model-name azureml://registries/azureml/models/Phi-3-mini-4k-instruct/versions/1 --beta 0.1 --l2_multiplier 0.1.

RL (PPO-style) quick start

• Dataset format (JSONL): Each line must contain a "prompt" field (string) and optional "reward" (float) for explicit reward signals. If reward is missing, length-based reward shaping is used as fallback: {"prompt": "user message", "reward": 0.5}.
• Submit: python sample/submit_rl_job.py --compute <compute-name> --data-path <azureml://.../rl.jsonl> --model-name azureml://registries/azureml/models/Phi-3-mini-4k-instruct/versions/1.

Notes

• Why direct training? Serverless APIs abstract away training details; direct training gives you full control over trainer config, callbacks, checkpointing, and custom loss functions.
• Model source: Use fine-tuning-enabled base models from Azure AI Foundry model catalog (e.g., azureml://registries/azureml/models/Phi-3-mini-4k-instruct/versions/1). Avoid Hugging Face downloads.
• Hyperparameters:
  • SFT: batch_size, learning_rate (default 2e-5), n_epochs (default 1), seed
  • DPO: Add beta (KL penalty, default 0.1), l2_multiplier (regularization, default 0.1)
  • RL/PPO: ppo_epochs, learning_rate, reward shaping via custom logic
• Data: Must be in Azure ML datastores as JSONL; referenced via azureml:// URIs. Keep datasets in Azure; do not rely on external sources.
• Artifacts: Trained models saved to job output folder; register as Azure AI Foundry model for deployment or further fine-tuning.

When to Use This vs Other Fine-Tuning Methods