Skip to content

Unhandled WebSocket disconnection during media streaming crashes call session #505

Description

During active inbound calls, if there is a transient network hiccup or an abrupt disconnection on the WebSocket media channel (used for streaming audio chunks to/from Azure Communication Services), the application encounters an unhandled exception. Instead of gracefully attempting a reconnection or tearing down the call cleanly, the entire container session/worker process crashes.

To Reproduce
Initiate an inbound call to the service.

Establish the audio stream and begin a conversation.

Simulate a sudden network drop or manually terminate the WebSocket connection from the client side while audio data is actively being written/read.

Observe the application logs and container state.

Expected Behavior
The application should catch the connection drop cleanly, stop trying to write to the closed socket, log a warning, and gracefully terminate the specific call session (or attempt a brief reconnection handshake) without crashing the entire service worker process.

Actual Behavior / Logs
The application throws an unhandled ConnectionClosedError or BrokenPipeError deep within the media streaming loop, causing the FastAPI/Python worker to panic and terminate.

Plaintext
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/uvicorn/protocols/websockets/websockets_impl.py", line 254, in run_asgi
result = await app(self.scope, self.receive, self.send)
...
File "./app/media/streamer.py", line 84, in stream_audio
await websocket.send_bytes(chunk)
File "/usr/local/lib/python3.11/site-packages/starlette/websockets.py", line 133, in send_bytes
await self.send({"type": "websocket.send", "bytes": data})
websockets.exceptions.ConnectionClosedError: code = 1006 (connection closed abnormally [internal]), no reason
CRITICAL:root:Worker process died due to unhandled WebSocket exception. Terminating container.
Environment Details
Language/Framework: Python 3.11 / FastAPI

Deployment: Azure Container Apps / Docker

Dependencies: websockets, azure-communication-callautomation

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions