chore(refactor): use interface

core/cli/worker.go

@@ -512,11 +512,9 @@ func (s *backendSupervisor) stopBackend(backend string) {
 
 	// Network I/O outside the lock
 	client := grpc.NewClientWithToken(bp.addr, false, nil, false, s.cmd.RegistrationToken)
-	if freeFunc, ok := client.(interface{ Free(context.Context) error }); ok {
-		xlog.Debug("Calling Free() before stopping backend", "backend", backend)
-		if err := freeFunc.Free(context.Background()); err != nil {
-			xlog.Warn("Free() failed (best-effort)", "backend", backend, "error", err)
-		}
+	xlog.Debug("Calling Free() before stopping backend", "backend", backend)
+	if err := client.Free(context.Background()); err != nil {
+		xlog.Warn("Free() failed (best-effort)", "backend", backend, "error", err)
 	}
 
 	xlog.Info("Stopping backend process", "backend", backend, "addr", bp.addr)
@@ -774,10 +772,8 @@ func (s *backendSupervisor) subscribeLifecycleEvents() {
 		if targetAddr != "" {
 			// Best-effort gRPC Free()
 			client := grpc.NewClientWithToken(targetAddr, false, nil, false, s.cmd.RegistrationToken)
-			if freeFunc, ok := client.(interface{ Free(context.Context) error }); ok {
-				if err := freeFunc.Free(context.Background()); err != nil {
-					xlog.Warn("Free() failed during model.unload", "error", err, "addr", targetAddr)
-				}
+			if err := client.Free(context.Background()); err != nil {
+				xlog.Warn("Free() failed during model.unload", "error", err, "addr", targetAddr)
 			}
 		}
 

core/services/nodes/health_mock_test.go

@@ -231,6 +231,9 @@ func (c *fakeBackendClient) QuantizationProgress(_ context.Context, _ *pb.Quanti
 func (c *fakeBackendClient) StopQuantization(_ context.Context, _ *pb.QuantizationStopRequest, _ ...ggrpc.CallOption) (*pb.Result, error) {
 	return nil, nil
 }
+func (c *fakeBackendClient) Free(_ context.Context) error {
+	return nil
+}
 
 // --- fakeBackendClientFactory ---
 

core/services/nodes/inflight_test.go

@@ -175,6 +175,10 @@ func (f *fakeGRPCBackend) StopQuantization(_ context.Context, _ *pb.Quantization
 	return &pb.Result{}, nil
 }
 
+func (f *fakeGRPCBackend) Free(_ context.Context) error {
+	return nil
+}
+
 // --- Tests ---
 
 var _ = Describe("InFlightTrackingClient", func() {

pkg/grpc/backend.go

@@ -85,4 +85,7 @@ type Backend interface {
 	StartQuantization(ctx context.Context, in *pb.QuantizationRequest, opts ...grpc.CallOption) (*pb.QuantizationJobResult, error)
 	QuantizationProgress(ctx context.Context, in *pb.QuantizationProgressRequest, f func(update *pb.QuantizationProgressUpdate), opts ...grpc.CallOption) error
 	StopQuantization(ctx context.Context, in *pb.QuantizationStopRequest, opts ...grpc.CallOption) (*pb.Result, error)
+
+	// Free releases GPU/model resources (e.g. VRAM) without stopping the process.
+	Free(ctx context.Context) error
 }

pkg/grpc/embed.go

@@ -163,6 +163,11 @@ func (e *embedBackend) StopQuantization(ctx context.Context, in *pb.Quantization
 	return e.s.StopQuantization(ctx, in)
 }
 
+func (e *embedBackend) Free(ctx context.Context) error {
+	_, err := e.s.Free(ctx, &pb.HealthMessage{})
+	return err
+}
+
 var _ pb.Backend_FineTuneProgressServer = new(embedBackendFineTuneProgressStream)
 
 type embedBackendFineTuneProgressStream struct {

pkg/model/process.go

@@ -1,6 +1,7 @@
 package model
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"os"
@@ -52,11 +53,9 @@ func (ml *ModelLoader) deleteProcess(s string) error {
 	}
 
 	// Free GPU resources before stopping the process to ensure VRAM is released
-	if freeFunc, ok := model.GRPC(false, ml.wd).(interface{ Free() error }); ok {
-		xlog.Debug("Calling Free() to release GPU resources", "model", s)
-		if err := freeFunc.Free(); err != nil {
-			xlog.Warn("Error freeing GPU resources", "error", err, "model", s)
-		}
+	xlog.Debug("Calling Free() to release GPU resources", "model", s)
+	if err := model.GRPC(false, ml.wd).Free(context.Background()); err != nil {
+		xlog.Warn("Error freeing GPU resources", "error", err, "model", s)
 	}
 
 	process := model.Process()