rebased main

Author: RawthiL

pkg/relayer/proxy/sync.go

@@ -324,28 +324,10 @@ func (server *relayMinerHTTPServer) serveSyncRequest(
 	// Capture the service call request duration metric.
 	relayer.CaptureServiceDuration(serviceId, serviceCallStartTime, httpResponse.StatusCode)
 
-	// Serialize the service response to be sent back to the client.
-	// This will include the status code, headers, and body.
-	wrappedHTTPResponse, responseBz, err := SerializeHTTPResponse(logger, httpResponse, server.serverConfig.MaxBodySize)
-	if err != nil {
-		logger.Error().Err(err).Msg("❌ Failed serializing the service response")
-		return relayRequest, err
-	}
-
-	// Pass through all backend responses including errors.
-	// Allows clients to see real HTTP status codes from backend service.
-	// Log non-2XX status codes for monitoring but don't block response.
-	if httpResponse.StatusCode >= http.StatusMultipleChoices {
-		logger.Error().
-			Int("status_code", httpResponse.StatusCode).
-			Str("request_url", httpRequest.URL.String()).
-			Str("request_payload_first_bytes", polylog.Preview(string(relayRequest.Payload))).
-			Str("response_payload_first_bytes", polylog.Preview(string(wrappedHTTPResponse.BodyBz))).
-			Msg("backend service returned a non-2XX status code. Passing it through to the client.")
-	}
-
 	// Check if the response is a stream
 	streamThis := IsStreamingResponse(httpResponse)
+	// Capture the time after response time for the relay.
+	responsePreparationEnd := time.Now()
 	// Create empty relay response
 	relayResponse := &types.RelayResponse{
 		Meta:    types.RelayResponseMetadata{SessionHeader: meta.SessionHeader},
@@ -366,16 +348,28 @@ func (server *relayMinerHTTPServer) serveSyncRequest(
 
 		// Serialize the service response to be sent back to the client.
 		// This will include the status code, headers, and body.
-		_, responseBz, err := SerializeHTTPResponse(logger, httpResponse, server.serverConfig.MaxBodySize)
+		wrappedHTTPResponse, responseBz, err := SerializeHTTPResponse(logger, httpResponse, server.serverConfig.MaxBodySize)
 		if err != nil {
 			logger.Error().Err(err).Msg("❌ Failed serializing the service response")
 			return relayRequest, err
 		}
 
+		// Pass through all backend responses including errors.
+		// Allows clients to see real HTTP status codes from backend service.
+		// Log non-2XX status codes for monitoring but don't block response.
+		if httpResponse.StatusCode >= http.StatusMultipleChoices {
+			logger.Error().
+				Int("status_code", httpResponse.StatusCode).
+				Str("request_url", httpRequest.URL.String()).
+				Str("request_payload_first_bytes", polylog.Preview(string(relayRequest.Payload))).
+				Str("response_payload_first_bytes", polylog.Preview(string(wrappedHTTPResponse.BodyBz))).
+				Msg("backend service returned a non-2XX status code. Passing it through to the client.")
+		}
+
 		logger.Debug().
 			Str("relay_request_session_header", meta.SessionHeader.String()).
 			Msg("building relay response protobuf from service response")
-		
+
 		// Check context cancellation before building relay response to prevent signature race conditions
 		if ctxErr := ctxWithDeadline.Err(); ctxErr != nil {
 			logger.Warn().Err(ctxErr).Msg("⚠️ Context canceled before building relay response - preventing signature race condition")
@@ -398,7 +392,7 @@ func (server *relayMinerHTTPServer) serveSyncRequest(
 		}
 
 		// Capture the time after response time for the relay.
-		responsePreparationEnd := time.Now()
+		responsePreparationEnd = time.Now()
 		// Add response preparation duration to the logger such that any log before errors will have
 		// as much request duration information as possible.
 		logger = logger.With(
@@ -408,11 +402,14 @@ func (server *relayMinerHTTPServer) serveSyncRequest(
 		relayer.CaptureResponsePreparationDuration(serviceId, backendServiceProcessingEnd)
 
 		// Send the relay response to the client.
-		if err = server.sendRelayResponse(relay.Res, writer); err != nil {
+		err = server.sendRelayResponse(relayResponse, writer)
+		logger = logger.With("send_response_duration", time.Since(responsePreparationEnd).String())
+		if err != nil {
 			// If the originHost cannot be parsed, reply with an internal error so that
 			// the original error is not exposed to the client.
 			clientError := ErrRelayerProxyInternalError.Wrap(err.Error())
-			logger.Warn().Err(err).Msg("❌ Failed sending relay response")
+			// Log current time to highlight writer i/o timeout errors.
+			logger.Warn().Err(err).Time("current_time", time.Now()).Msg("❌ Failed sending relay response")
 			return relayRequest, clientError
 		}
 
@@ -424,7 +421,6 @@ func (server *relayMinerHTTPServer) serveSyncRequest(
 	// Create the relay response
 	relay := &types.Relay{Req: relayRequest, Res: relayResponse}
 
-
 	logger.ProbabilisticDebugInfo(polylog.ProbabilisticDebugInfoProb).Msg("relay request served successfully")
 
 	relayer.RelaysSuccessTotal.With("service_id", serviceId).Add(1)