101101 Switching Protocols
The server is switching protocols as requested by the client via an Upgrade header.
504A gateway or proxy server did not receive a timely response from the upstream server.
The reverse proxy timed out waiting for the backend server to respond. The backend may be overloaded, running a slow query, or experiencing network issues between the proxy and backend.
Increase proxy timeout settings. Optimize slow backend operations (queries, external API calls). Add caching for expensive operations. Consider async processing for long-running tasks.
101The server is switching protocols as requested by the client via an Upgrade header.
201The request has been fulfilled and a new resource has been created as a result.
204The server successfully processed the request but is not returning any content in the response body.
203The response has been modified by a transforming proxy and differs from what the origin server sent.
405The HTTP method used is not supported for the requested resource.
407The client must first authenticate with the proxy before the request can be forwarded to the target server.