TimeoutError
asyncio.exceptions.TimeoutError
Stack trace
Traceback (most recent call last):
File "app.py", line 45, in <module>
response = await fireworks_client.generate(prompt)
File "/usr/local/lib/python3.9/site-packages/fireworks_ai/client.py", line 102, in generate
await asyncio.wait_for(self._model_inference(prompt), timeout=30)
File "/usr/lib/python3.9/asyncio/tasks.py", line 481, in wait_for
raise exceptions.TimeoutError()
asyncio.exceptions.TimeoutError Why it happens
Fireworks AI model cold start timeout occurs because the model server or container takes too long to initialize and respond to the first inference request. This delay can be caused by resource constraints, network latency, or model loading overhead during cold start.
Detection
Monitor inference latency metrics and catch asyncio TimeoutError exceptions around model generate calls to detect cold start delays before they impact user experience.
Causes & fixes
Model container or server is cold starting and takes longer than the configured timeout to load the model.
Increase the timeout duration in the client code or pre-warm the model server before sending requests.
Insufficient compute resources causing slow model initialization.
Scale up CPU/GPU resources or optimize model loading to reduce cold start latency.
Network latency or connectivity issues delaying the response from the model endpoint.
Check network stability and reduce request payload size to improve response times.
Code: broken vs fixed
import asyncio
async def main():
response = await asyncio.wait_for(fireworks_client.generate(prompt), timeout=30) # This line causes TimeoutError on cold start
print(response)
asyncio.run(main())import os
import asyncio
os.environ['FIREWORKS_API_KEY'] = os.environ.get('FIREWORKS_API_KEY', '') # Use environment variable for API key
async def main():
# Increased timeout to 60 seconds to handle cold start delay
response = await asyncio.wait_for(fireworks_client.generate(prompt), timeout=60)
print(response)
asyncio.run(main())Workaround
Wrap the generate call in a try/except block catching asyncio.TimeoutError, then retry the request after a short delay to handle transient cold start delays.
Prevention
Pre-warm the Fireworks AI model server during deployment or scale with warm instances to avoid cold start delays, and monitor latency to adjust timeouts proactively.