Container resets/crashes when HTTP request reaches receive_response_headers.started in httpcore.http11 logs despite using timeouts and connection pooling #1026
Description
Description:
I am experiencing an issue where my container crashes or resets immediately after an HTTP POST request logs this debug message:
2025-08-06 10:07:03,466 - httpcore.connection - DEBUG - close.started
2025-08-06 10:07:03,467 - httpcore.connection - DEBUG - close.complete
2025-08-06 10:07:03,468 - httpcore.connection - DEBUG - connect_tcp.started host='us-central1-aiplatform.googleapis.com' port=443 local_address=None timeout=60.0 socket_options=None
2025-08-06 10:07:03,653 - httpcore.connection - DEBUG - connect_tcp.complete return_value=<httpcore._backends.sync.SyncStream object at 0x7bd514187b10>
2025-08-06 10:07:03,654 - httpcore.connection - DEBUG - start_tls.started ssl_context=<ssl.SSLContext object at 0x7bd514731be0> server_hostname='us-central1-aiplatform.googleapis.com' timeout=60.0
2025-08-06 10:07:03,840 - httpcore.connection - DEBUG - start_tls.complete return_value=<httpcore._backends.sync.SyncStream object at 0x7bd62bd80250>
2025-08-06 10:07:03,840 - httpcore.http11 - DEBUG - send_request_headers.started request=<Request [b'POST']>
2025-08-06 10:07:03,841 - httpcore.http11 - DEBUG - send_request_headers.complete
2025-08-06 10:07:03,841 - httpcore.http11 - DEBUG - send_request_body.started request=<Request [b'POST']>
2025-08-06 10:07:04,201 - httpcore.http11 - DEBUG - send_request_body.complete
2025-08-06 10:07:04,202 - httpcore.http11 - DEBUG - receive_response_headers.started request=<Request [b'POST']>
The request headers and body are sent successfully, but right when the client starts receiving the response headers, the container unexpectedly resets.
Additional Info:
- I have implemented timeouts and configured a safe connection pool with a high number of connections to handle load smoothly.
Environment:
- Containerized app running on Docker
- HTTP client using
httpcore(likely viahttpx) - Timeouts and connection pool settings already applied
- LLM Async Streaming like this Rare edge case issue causing a thread deadlock with access to _optional_thread_lock in ConnectionPool #990
What I have tried:
- Configured client timeouts to avoid hanging connections.
- Increased connection pool size for high concurrency.
- Checked container logs, but no specific errors aside from the sudden reset.
Request for help:
- Has anyone experienced sudden container restarts at the point of
receive_response_headers.started? - Could networking or
httpcorebugs be the culprits despite proper timeout and connection management? - Recommendations for debugging this issue further or any known workarounds would be highly appreciated.
If you want, I can also help you phrase this for a particular platform or add more technical detail — just let me know!
Activity
Lujeni commentedon Jan 8, 2026
@Mahdi-Ba I’d like to follow up on your issue. The simplest approach would be to provide a small code example along with your Docker/Docker Compose configuration so that we can reproduce the problem and continue the investigation.
Additionally, the recommended way to report such problems is to start with a discussion. A maintainer can then decide whether or not it should be turned into an issue.
The starting point for reports should usually be a discussion:
https://github.com/encode/httpcore/discussions
Possible bugs may be raised as a “Potential Issue” discussion, and feature requests as an “Ideas” discussion. We can then determine whether the discussion needs to be escalated into an issue.
This helps ensure that the Issues list accurately reflects ongoing or required work on the project.