HTTP 5xx
501 Not Implemented
The server does not support the functionality required to fulfill the request.
What causes it
- A request method or feature the server does not implement.
How to fix it
Confirm the server supports the requested method or feature.
Example response
A typical raw HTTP response a client receives for a 501, with the headers this code is defined around.
HTTP/1.1 501 Not Implemented
Content-Type: text/html; charset=utf-8Related codes
500Common
Internal Server ErrorA generic server-side error. Something failed on the server and it could not complete the request.502Common
Bad GatewayA server acting as a gateway or proxy got an invalid response from the upstream server it was trying to reach.503Common
Service UnavailableThe server is temporarily unable to handle the request, usually because it is overloaded or down for maintenance.504Common
Gateway TimeoutA gateway or proxy did not get a timely response from the upstream server.505
HTTP Version Not SupportedThe server does not support the HTTP protocol version used in the request.507Common
Insufficient StorageThe server cannot store what is needed to complete the request, often a full disk.Know before your visitors do.
Sentinel checks your site around the clock from multiple regions and alerts you the moment it starts returning a 5xx error, so you can fix it before it costs you.