Burt Logger

A lightweight, production-ready Python package for collecting LLM training data. Automatically pipe LLM request/response data to your backend for model fine-tuning and dataset creation.

Features

✨ Non-blocking & Asynchronous - Uses background threads and queues to ensure zero impact on your application performance

🔄 Intelligent Batching - Automatically batches logs by size or time interval for optimal network efficiency

🛡️ Production-Ready - Thread-safe, graceful error handling, and automatic retry with exponential backoff

🚀 Minimal Dependencies - Only requires requests library, everything else from Python stdlib

⚙️ Highly Configurable - Customize batch sizes, flush intervals, queue sizes, retry logic, and more

🔌 Provider Agnostic - Works with OpenAI, Anthropic, or any LLM provider

Installation

pip install burt-logger

Or install from source:

git clone https://github.com/trainburt/burt-logger-python.git
cd burt-logger-python
pip install -e .

Quick Start

from burt_logger import LLMLogger

# Initialize the logger
logger = LLMLogger(
    endpoint="https://your-api.com/logs",
    api_key="your-api-key"
)

# Log your LLM requests and responses
response = openai.ChatCompletion.create(...)  # Your existing LLM call

logger.log(
    request={
        "model": "gpt-3.5-turbo",
        "messages": [...],
    },
    response={
        "content": response.choices[0].message.content,
        "usage": {
            "prompt_tokens": usage.get("prompt_tokens", 0),
            "completion_tokens": usage.get("completion_tokens", 0),
            "total_tokens": usage.get("total_tokens", 0),
        },
    }
)

# Gracefully shutdown (flushes remaining logs)
logger.shutdown()

That's it! The logger handles everything asynchronously in the background.

Using Context Manager

The logger supports context managers for automatic cleanup:

with LLMLogger(endpoint="...", api_key="...") as logger:
    # Your code here
    logger.log(request=..., response=...)
    # Automatic shutdown and flush on exit

Configuration

The LLMLogger class accepts the following parameters:

Parameter	Type	Default	Description
endpoint	str	Required	Backend API endpoint to send logs to
api_key	str	Required	API key for authentication
batch_size	int	10	Number of logs to batch before sending
flush_interval	float	5.0	Seconds to wait before flushing incomplete batch
max_queue_size	int	10000	Maximum number of logs to queue
max_retries	int	3	Maximum number of retry attempts
initial_retry_delay	float	1.0	Initial delay for exponential backoff (seconds)
max_retry_delay	float	60.0	Maximum retry delay (seconds)
timeout	float	10.0	HTTP request timeout (seconds)
debug	bool	False	Enable debug logging

Example with Custom Configuration

logger = LLMLogger(
    endpoint="https://your-api.com/logs",
    api_key="your-api-key",
    batch_size=20,           # Send in batches of 20
    flush_interval=10.0,     # Or every 10 seconds
    max_queue_size=50000,    # Large queue for high-volume apps
    max_retries=5,           # More retries for flaky networks
    debug=True,              # See what's happening
)

API Reference

log(request, response, metadata=None)

Log an LLM request/response pair.

Parameters:

• request (dict): The LLM request data (prompt, model, parameters, etc.)
• response (dict): The LLM response data (completion, tokens, etc.)
• metadata (dict, optional): Additional metadata (user_id, session_id, etc.)

Returns:

• bool: True if log was queued successfully, False if queue is full

Example:

success = logger.log(
    request={"model": "gpt-4", "prompt": "..."},
    response={"completion": "...", "tokens": 150},
    metadata={"user_id": "123", "environment": "production"}
)

flush(timeout=None)

Flush all queued logs and wait for them to be sent.

Parameters:

• timeout (float, optional): Maximum time to wait in seconds. None means wait indefinitely.

Example:

logger.flush(timeout=5.0)  # Wait up to 5 seconds

shutdown(timeout=10.0)

Gracefully shutdown the logger, flushing all remaining logs.

Parameters:

• timeout (float): Maximum time to wait for shutdown in seconds

Example:

logger.shutdown(timeout=10.0)

get_stats()

Get statistics about logger performance.

Returns:

• dict: Dictionary containing statistics

Example:

stats = logger.get_stats()
print(stats)
# {
#     'logs_queued': 150,
#     'logs_sent': 145,
#     'logs_failed': 5,
#     'batches_sent': 15,
#     'batches_failed': 1
# }

How It Works

1. Queueing: When you call log(), the entry is immediately added to a thread-safe queue and the method returns instantly (non-blocking)

2. Batching: A background worker thread monitors the queue and batches logs based on:

   • Batch size (e.g., 10 logs)
   • Time interval (e.g., every 5 seconds)

3. Sending: Batches are sent to your backend API via HTTP POST with proper authentication headers

4. Retry Logic: If sending fails:

   • 5xx errors: Retries with exponential backoff
   • 429 (rate limit): Retries with exponential backoff
   • 4xx errors: No retry (client error)
   • Network errors: Retries with exponential backoff

5. Shutdown: On program exit or explicit shutdown, all remaining logs are flushed

Backend API Expected Format

Your backend should expect POST requests with the following format:

Headers:

Content-Type: application/json
Authorization: Bearer <api_key>

Payload:

{
  "logs": [
    {
      "request": { /* your request data */ },
      "response": { /* your response data */ },
      "metadata": { /* optional metadata */ },
      "timestamp": 1234567890.123
    },
    ...
  ],
  "timestamp": 1234567890.456
}

Expected Response:

• Success: HTTP 200, 201, or 202
• Server Error: HTTP 5xx (will retry)
• Client Error: HTTP 4xx (will not retry)
• Rate Limited: HTTP 429 (will retry)

Error Handling

The logger is designed to be resilient and never crash your application:

• Queue Full: If the queue is full, log() returns False and the log is dropped
• Network Errors: Automatic retry with exponential backoff
• Backend Down: Retries up to max_retries times, then drops the batch
• Thread Crashes: The worker thread is monitored and restarted if needed

All errors are logged to Python's logging system. Enable debug mode to see detailed logs:

logger = LLMLogger(..., debug=True)

Testing

Run the test suite:

# Install dev dependencies
pip install -e ".[dev]"

# Run tests
pytest tests/ -v

# With coverage
pytest tests/ --cov=burt_logger --cov-report=html

Development

# Clone the repository
git clone https://github.com/trainburt/burt-logger-python.git
cd burt-logger-python

# Install in development mode
pip install -e ".[dev]"

# Run tests
pytest

# Format code
black burt_logger/ tests/

# Lint
flake8 burt_logger/ tests/

Performance Considerations

• Non-blocking: log() calls take ~0.001ms (just queue insertion)
• Memory: Each log entry is ~1-5KB. Default max queue size is 10,000 logs = ~10-50MB
• Network: Batching reduces network overhead. 1000 logs/second = 100 batches (batch_size=10)
• Threads: Uses a single background worker thread

Production Recommendations

1. Set appropriate batch_size: Larger batches are more efficient but increase memory usage

   logger = LLMLogger(..., batch_size=50)  # For high-volume apps
   

2. Monitor queue size: If logs are being dropped, increase max_queue_size or reduce traffic

   stats = logger.get_stats()
   if stats['logs_failed'] > 0:
       # Handle appropriately
   

3. Use metadata: Add user_id, session_id, etc. for better data analysis

   logger.log(..., metadata={"user_id": user_id, "env": "prod"})
   

4. Graceful shutdown: Always call shutdown() or use context manager

   import atexit
   atexit.register(logger.shutdown)
   

License

MIT License - see LICENSE file for details

Support

• Issues: https://github.com/yourusername/burt-logger-python/issues
• Email: support@burt.ai

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Add tests for new functionality
4. Ensure all tests pass
5. Submit a pull request

Changelog

0.1.0 (Initial Release)

• ✅ Non-blocking asynchronous logging
• ✅ Intelligent batching (by size and time)
• ✅ Thread-safe operations
• ✅ Retry with exponential backoff
• ✅ Graceful shutdown and cleanup
• ✅ Comprehensive test suite
• ✅ Context manager support
• ✅ Statistics tracking

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