HTTP 504 — 7th Timeout
What does this error mean?
A gateway did not receive a response from the server upstream within the set time.
Probable causes
- request backend too slow
- blocked database
- timeout proxy too short
- network loss between the proxy and application
Verification and resolution
- Measure the backend’s direct response time
- Control slow and dependencies queries
- Compare timeouts and apps
- Check network errors between layers
Precaution: Adding timeout without treating the slow backend only moves the problem.