1
Verify the likely cause
Check upstream logs, align proxy timeouts and redesign long jobs to return an identifier that can be polled asynchronously.
FULL AI ANALYSIS
Nginx returns 502 only for long-running API requests
Generated Sep 22, 2026, 11:55:04 AM
Analysis summary
The reported behaviour is consistent with the upstream closes or exceeds proxy read timeout before returning the report. The safest next step is to verify that hypothesis with a reversible test before making permanent configuration changes.
Possible causes
The upstream closes or exceeds proxy read timeout before returning the report.
79%A recent software, firmware or configuration change is exposing an existing compatibility issue.
31%Suggested fixes
2
Validate and monitor
Reproduce the issue once after the change, review relevant logs or metrics, and keep a rollback path until the system has remained stable.