root@hack3rs:/srv/www$ curl -i /503/
HTTP/1.1 503 Service Unavailable
The service cannot handle requests right now.
status-summary.log
HTTP 503 Service Unavailable
The server is overloaded, in a maintenance window, or a critical dependency has failed. This is a temporary condition — it differs from a 404 or 410 in that the resource does exist.
Distinguish planned maintenance from an unplanned overload before deciding on a response. The fix is different in each case.
likely-causes.lst
- $Planned maintenance or deployment lock preventing new requests.
- $Traffic spike exhausting available application workers or connections.
- $Autoscaling lag or failed capacity provisioning.
- $Downstream dependency failure causing fail-closed behavior upstream.
recovery-steps.md
- Check the status page, on-call channel, and maintenance announcements first.
- Review CPU, memory, and connection saturation metrics alongside autoscaling events.
- Shift traffic, add capacity, or enable graceful degradation if the cause is load.
- Surface a Retry-After header or clear user-facing messaging about expected recovery time.
quick-actions.sh
ops-note.txt
Use these pages for debugging and user guidance. In production, configure your host or reverse proxy to return the matching HTTP status code for the route (especially for 503 and 404/500 responses) rather than serving a 200 with error-themed content.