Move GetHealth from a pipe RPC to a controller component method.

controller.go

@@ -45,6 +45,11 @@ func (*noopController) UpdateRoutingInfo(context.Context, *protos.UpdateRoutingI
 	return nil, fmt.Errorf("controller.UpdateRoutingInfo not implemented")
 }
 
+// GetHealth implements controller nterface.
+func (*noopController) GetHealth(context.Context, *protos.GetHealthRequest) (*protos.GetHealthReply, error) {
+	return nil, fmt.Errorf("controller.GetHealth not implemented")
+}
+
 // GetProfile implements controller nterface.
 func (*noopController) GetProfile(context.Context, *protos.GetProfileRequest) (*protos.GetProfileReply, error) {
 	return nil, fmt.Errorf("controller.GetProfile not implemented")

internal/control/controller.go

@@ -33,6 +33,9 @@ type Controller interface {
 	// UpdateRoutingInfo updates the weavelet with a component's most recent routing info.
 	UpdateRoutingInfo(context.Context, *protos.UpdateRoutingInfoRequest) (*protos.UpdateRoutingInfoReply, error)
 
+	// GetHealth fetches weavelet health information.
+	GetHealth(context.Context, *protos.GetHealthRequest) (*protos.GetHealthReply, error)
+
 	// GetProfile gets a profile from the weavelet.
 	GetProfile(context.Context, *protos.GetProfileRequest) (*protos.GetProfileReply, error)
 }

internal/envelope/conn/envelope_conn.go

@@ -114,8 +114,8 @@ func NewEnvelopeConn(ctx context.Context, r io.ReadCloser, w io.WriteCloser, inf
 	//     }
 	//
 	// If an EnvelopeHandler, invoked by handleMessage, calls an RPC on the
-	// weavelet (e.g., GetHealth), then it will block forever, as the RPC
-	// response will never be read by conn.recv.
+	// weavelet, then it will block forever, as the RPC response will never
+	// be read by conn.recv.
 	e.running.Go(func() error {
 		for {
 			msg := &protos.WeaveletMsg{}
@@ -265,19 +265,6 @@ func (e *EnvelopeConn) GetMetricsRPC() ([]*metrics.MetricSnapshot, error) {
 	return e.metrics.Import(reply.GetMetricsReply.Update)
 }
 
-// GetHealthRPC gets a weavelet's health.
-func (e *EnvelopeConn) GetHealthRPC() (protos.HealthStatus, error) {
-	req := &protos.EnvelopeMsg{GetHealthRequest: &protos.GetHealthRequest{}}
-	reply, err := e.rpc(req)
-	if err != nil {
-		return protos.HealthStatus_UNHEALTHY, err
-	}
-	if reply.GetHealthReply == nil {
-		return protos.HealthStatus_UNHEALTHY, fmt.Errorf("nil HealthStatusReply received from weavelet")
-	}
-	return reply.GetHealthReply.Status, nil
-}
-
 // GetLoadRPC gets a load report from the weavelet.
 func (e *EnvelopeConn) GetLoadRPC() (*protos.LoadReport, error) {
 	req := &protos.EnvelopeMsg{GetLoadRequest: &protos.GetLoadRequest{}}

internal/envelope/conn/weavelet_conn.go

@@ -160,11 +160,6 @@ func (w *WeaveletConn) handleMessage(handler WeaveletHandler, msg *protos.Envelo
 			Id:              -msg.Id,
 			GetMetricsReply: &protos.GetMetricsReply{Update: update},
 		})
-	case msg.GetHealthRequest != nil:
-		return w.conn.send(&protos.WeaveletMsg{
-			Id:             -msg.Id,
-			GetHealthReply: &protos.GetHealthReply{Status: protos.HealthStatus_HEALTHY},
-		})
 	case msg.GetLoadRequest != nil:
 		reply, err := handler.GetLoad(msg.GetLoadRequest)
 		return w.conn.send(&protos.WeaveletMsg{

internal/weaver/remoteweavelet.go

@@ -571,6 +571,11 @@ func (w *RemoteWeavelet) UpdateRoutingInfo(ctx context.Context, req *protos.Upda
 	return &protos.UpdateRoutingInfoReply{}, nil
 }
 
+// GetHealth implements controller.GetHealth.
+func (w *RemoteWeavelet) GetHealth(ctx context.Context, req *protos.GetHealthRequest) (*protos.GetHealthReply, error) {
+	return &protos.GetHealthReply{Status: protos.HealthStatus_HEALTHY}, nil
+}
+
 // GetProfile implements controller.GetProfile.
 func (w *RemoteWeavelet) GetProfile(ctx context.Context, req *protos.GetProfileRequest) (*protos.GetProfileReply, error) {
 	data, err := getProfile(ctx, req)

runtime/envelope/envelope.go

@@ -311,11 +311,11 @@ func (e *Envelope) WeaveletInfo() *protos.WeaveletInfo {
 
 // GetHealth returns the health status of the weavelet.
 func (e *Envelope) GetHealth() protos.HealthStatus {
-	status, err := e.conn.GetHealthRPC()
+	reply, err := e.controller.GetHealth(context.TODO(), &protos.GetHealthRequest{})
 	if err != nil {
-		return protos.HealthStatus_UNHEALTHY
+		return protos.HealthStatus_UNKNOWN
 	}
-	return status
+	return reply.Status
 }
 
 // GetProfile gets a profile from the weavelet.

runtime/envelope/envelope_test.go

@@ -432,9 +432,8 @@ func TestRPCBeforeServe(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	health := e.GetHealth()
-	if health != protos.HealthStatus_HEALTHY {
-		t.Fatalf("expected healthy, got %v", health)
+	if _, err := e.GetMetrics(); err != nil {
+		t.Fatalf("expected metrics, got %v", err)
 	}
 	h := &handlerForTest{logSaver: testSaver(t)}
 

runtime/protos/runtime.proto

@@ -97,7 +97,6 @@ message EnvelopeMsg {
   EnvelopeInfo envelope_info = 2;
 
   // Envelope initiated RPC requests.
-  GetHealthRequest get_health_request = 3;
   GetMetricsRequest get_metrics_request = 4;
   GetLoadRequest get_load_request = 5;
 
@@ -110,7 +109,7 @@ message EnvelopeMsg {
   VerifyClientCertificateReply verify_client_certificate_reply = 13;
   VerifyServerCertificateReply verify_server_certificate_reply = 14;
 
-  reserved 6, 7, 8;
+  reserved 3, 6, 7, 8;
 }
 
 // WeaveletMsg is a message sent by a weavelet to an envelope.
@@ -130,7 +129,6 @@ message WeaveletMsg {
 
   // Envelope initiated RPC replies.
   string error = 5;  // non-nil on error
-  GetHealthReply get_health_reply = 6;
   GetMetricsReply get_metrics_reply = 7;
   GetLoadReply get_load_reply = 8;
 
@@ -142,7 +140,7 @@ message WeaveletMsg {
   VerifyClientCertificateRequest verify_client_certificate_request = 15;
   VerifyServerCertificateRequest verify_server_certificate_request = 16;
 
-  reserved 9, 10, 11;
+  reserved 6, 9, 10, 11;
 }
 
 // EnvelopeInfo is the information provided by an envelope to a weavelet during

runtime/protos/version_test.go

@@ -45,7 +45,7 @@ func TestDeployerVersion(t *testing.T) {
 	got := fmt.Sprintf("%x", h.Sum(nil))
 
 	// If runtime.proto has changed, the deployer API version may need updating.
-	const want = "ebf594eced1e857f5cd24af3d95988e82260a61baf2e86100ee85ac6ac8d6ea3"
+	const want = "a4c589df11159cafac26f242d5be7a55116c399b2e2a3e75db347a42b5b9e991"
 	if got != want {
 		t.Fatalf(`Unexpected SHA-256 hash of runtime.proto: got %s, want %s. If this change is meaningful, REMEMBER TO UPDATE THE DEPLOYER API VERSION in runtime/version/version.go.`, got, want)
 	}