# DPO (Direct Preference Optimization) Notebook Template

This template provides the complete cell structure for a DPO finetuning notebook.

---

## Cell 1: Install Dependencies

```python
!pip install --upgrade 'sagemaker>=3.7.1,<4.0' boto3 -q
```

---

## Cell 2: Setup & Credentials

```python
import boto3
from botocore.exceptions import ClientError
from sagemaker.ai_registry.dataset import DataSet
from sagemaker.core.resources import ModelPackageGroup
from sagemaker.core.helper.session_helper import Session, get_execution_role
from sagemaker.core import Attribution, set_attribution

set_attribution(Attribution.SAGEMAKER_AGENT_PLUGIN)

# Setup
sm_client = boto3.Session().client("sagemaker")
sagemaker_session = Session(sagemaker_client=sm_client)
bucket = sagemaker_session.default_bucket()

# Configuration - USER please fill in these fields with your information:

BASE_MODEL = ""  # e.g., "meta-textgeneration-llama-3-8b"
TRAINING_DATA_S3 = ""  # S3 path
S3_OUTPUT_PATH = f"s3://{bucket}/finetuning-output/"
ROLE_ARN = get_execution_role() # You can change this to a specific role.
ACCEPT_EULA = False  # Set to True to accept the base model's End-User License Agreement
MODEL_PACKAGE_GROUP_NAME = ""  # Auto-generated based on use case
```

---

## Cell 3: Create Dataset and Model Package Group

```python
# Create Model Package Group
try:
    model_package_group = ModelPackageGroup.create(
        model_package_group_name=MODEL_PACKAGE_GROUP_NAME,
        model_package_group_description="",
    )
    print(f"Created new model package group named {MODEL_PACKAGE_GROUP_NAME}")
except ClientError as e:
    if e.response['Error']['Code'] in ('ResourceInUse', 'ValidationException'):
        model_package_group = ModelPackageGroup.get(model_package_group_name=MODEL_PACKAGE_GROUP_NAME)
        print(f"There is already a model package group with the name {MODEL_PACKAGE_GROUP_NAME}.\nIf you want to save your finetuned model under a different name, change the value of MODEL_PACKAGE_GROUP_NAME in the previous cell.")
    else:
        raise

# Create Dataset
# Register dataset in SageMaker AI Registry. This creates a versioned dataset that can be referenced by ARN
dataset = DataSet.create(
    name=MODEL_PACKAGE_GROUP_NAME,
    source=TRAINING_DATA_S3,
    wait=True
)

TRAINING_DATASET_ARN = dataset.arn
print(f"Here is your model package group ARN: {model_package_group.model_package_group_arn}\n")
print(f"Here is your training dataset ARN: {dataset.arn}")
```

---

## Cell 4: Configure Trainer

```python
from sagemaker.train.dpo_trainer import DPOTrainer
from sagemaker.train.common import TrainingType

trainer = DPOTrainer(
    model=BASE_MODEL,
    training_type=TrainingType.LORA,
    model_package_group=model_package_group,
    training_dataset=TRAINING_DATASET_ARN,
    s3_output_path=S3_OUTPUT_PATH,
    sagemaker_session=sagemaker_session,
    #accept_eula=ACCEPT_EULA, # Uncomment for Meta models
    role=ROLE_ARN
)
print ("Here are the recommended hyperparameters for the current training job:")
print(f"Batch size: {trainer.hyperparameters.global_batch_size}")
print(f"Number of epochs: {trainer.hyperparameters.max_epochs}")
print(f"Learning rate: {trainer.hyperparameters.learning_rate}")
print(f"Learning rate warmup ratio: {trainer.hyperparameters.lr_warmup_ratio}")
print(f"Adam Beta: {trainer.hyperparameters.adam_beta}")
```

---

## Cell 5: Hyperparameter Overrides

```python
# To change a hyperparameter, uncomment its corresponding line, and set the value you want.

# Note: If the value you choose is not supported for your model, you will get an error indicating the allowed range. 


# Uncomment the following line to change the learning rate
# trainer.hyperparameters.learning_rate = 0.0002

# Uncomment the following line to change the batch size
# trainer.hyperparameters.global_batch_size = 16

# Uncomment the following line to change the number of epochs
# trainer.hyperparameters.max_epochs = 5

# Uncomment the following line to change the learning rate warmup ratio - Not available for Nova models
# trainer.hyperparameters.lr_warmup_ratio = 0.05

# Uncomment the following line to change Adam Beta 
# trainer.hyperparameters.adam_beta = 0.01
```

---

## Cell 6: Start Training

```python
# Start training
training_job = trainer.train(wait=True)

print(f"Training Job Name: {training_job.training_job_name}")
print(f"Training Status: {training_job.training_job_status}")
```

---

## Cell 7: Plot and Display Metrics

```python
import matplotlib.pyplot as plt
import mlflow
from mlflow.tracking import MlflowClient

run_id = training_job.mlflow_details.mlflow_run_id
mlflow.set_tracking_uri(training_job.mlflow_config.mlflow_resource_arn)
client = MlflowClient()

metrics = ["loss_per_batch", "rewards/chosen", "rewards/rejected", "rewards/margins", "acc_per_batch"]
fig, axes = plt.subplots(1, len(metrics), figsize=(4 * len(metrics), 3))
for idx, metric in enumerate(metrics):
    history = client.get_metric_history(run_id, metric)
    axes[idx].plot([h.step for h in history], [h.value for h in history], linewidth=2, marker='o', markersize=4)
    axes[idx].set_xlabel('Step')
    axes[idx].set_ylabel(metric.split('/')[-1])
    axes[idx].set_title(metric, fontweight='bold')
    axes[idx].grid(True, alpha=0.3)

plt.suptitle(f'Training Metrics: {training_job.training_job_name}', fontweight='bold')
plt.tight_layout()
plt.show()
```