okaybase opened a new pull request, #13655: URL: https://github.com/apache/apisix/pull/13655
### Description When an AI provider's SSE stream stalls mid-response (e.g. the upstream sends a few chunks then hangs), the `body_reader()` call in `parse_streaming_response` times out. The error handler at `ai-providers/base.lua:551` unconditionally returns a transport-layer error code via `transport_http.handle_error(err)` (504 for timeout, 500 for other errors). However, before entering `parse_streaming_response`, the caller at `ai-proxy/base.lua:350` has already set the `Content-Type` response header. If at least one SSE chunk has been dispatched to the downstream client, the HTTP response headers — including status `200` — have already been flushed. Returning a 504/500 after this point causes nginx to emit: **attempt to set status 504 via ngx.exit after sending out the response status 200 attempt to set ngx.status after sending out response headers** ### Checklist - [x] I have explained the need for this PR and the problem it solves - [x] I have explained the changes or the new features added to this PR - [x] I have added tests corresponding to this change - [x] I have verified that this change is backward compatible (If not, please discuss on the [APISIX mailing list](https://github.com/apache/apisix/tree/master#community) first) <!-- Note 1. Mark the PR as draft until it's ready to be reviewed. 2. Always add/update tests for any changes unless you have a good reason. 3. Always update the documentation to reflect the changes made in the PR. 4. Make a new commit to resolve conversations instead of `push -f`. 5. To resolve merge conflicts, merge master instead of rebasing. 6. Use "request review" to notify the reviewer after making changes. 7. Only a reviewer can mark a conversation as resolved. --> -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
