Gateway Timeout

5xx Server Error

ELI5

I'm a middleman server, and the server I was trying to talk to took too long to respond, so I gave up waiting.

Use 504 when acting as a gateway or proxy and the upstream server did not respond before your timeout expired.

•Return 504 when a backend or origin takes too long and the intermediary times out waiting
•Use it only when this server depends on an upstream response to finish the request
•Upstream server response timeout
•Load balancer timeout waiting for backend
•API gateway timeout
•Proxy timeout to origin server

•Set and monitor realistic upstream deadlines, then log which dependency timed out and after how long
•Return a clear timeout response instead of leaving the client hanging on an open connection

•No status-specific header is required; include request or trace metadata when it helps operators correlate the upstream timeout

•A body is optional but helpful; explain that an upstream dependency timed out and include safe retry guidance when appropriate

•Do not use 504 for client-to-server request timeouts; that is 408 Request Timeout
•Do not use 504 for malformed upstream responses; that is 502 Bad Gateway
•Client request timeout (use 408 Request Timeout)
•Bad upstream responses (use 502 Bad Gateway)
•Service unavailable (use 503 Service Unavailable)

Request:GET https://api.example.test/api/slow-operation

Response:

504 Gateway Timeout

# Headers
Content-Type: application/json

# Body
{
  "error": "gateway_timeout"
}

Backend API took longer than 30 seconds, proxy timed out

I'm a middleman server, and the server I was trying to talk to gave me a bad or broken response.

You took too long to send your request. The server got tired of waiting and gave up.

Our service is temporarily down for maintenance or overloaded. Please try again later.