XTLS/Xray-core · error · errors.Error

failed to write response

Error message

failed to write response

What it means

Error "failed to write response" thrown in XTLS/Xray-core.

Source

Thrown at proxy/http/server.go:302

			defer response.Body.Close()
		} else {
			errors.LogWarningInner(ctx, err, "failed to read response from ", request.Host)
			response = &http.Response{
				Status:        "Service Unavailable",
				StatusCode:    503,
				Proto:         "HTTP/1.1",
				ProtoMajor:    1,
				ProtoMinor:    1,
				Header:        http.Header(make(map[string][]string)),
				Body:          nil,
				ContentLength: 0,
				Close:         true,
			}
			response.Header.Set("Connection", "close")
			response.Header.Set("Proxy-Connection", "close")
		}
		if err := response.Write(writer); err != nil {
			return errors.New("failed to write response").Base(err).AtWarning()
		}
		return nil
	}

	if err := task.Run(ctx, requestDone, responseDone); err != nil {
		common.Interrupt(link.Reader)
		common.Interrupt(link.Writer)
		return errors.New("connection ends").Base(err)
	}

	return result
}

// Sometimes, server might send 1xx response to client
// it should not be processed by http proxy handler, just forward it to client
func readResponseAndHandle100Continue(r *bufio.Reader, req *http.Request, writer io.Writer) (*http.Response, error) {
	// have a little look of response
	peekBytes, err := r.Peek(56)

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at proxy/http/server.go:302 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/e94bff70b971f920. Report an issue: GitHub.