HTTP Reference
HTTP 503 Service Unavailable
The server is temporarily unable to handle the request.
Common Causes
- Maintenance windows or rolling deploy downtime.
- Resource exhaustion (CPU, memory, DB connections).
- Autoscaling lag under sudden traffic spikes.
Debugging Notes
- Set Retry-After where possible for client backoff.
- Check saturation dashboards and load-shedding rules.
Example Response
{
"status": 503,
"error": "Service Unavailable",
"message": "Try again later"
}