snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

examples/features/orca/server/main.go

@@ -0,0 +1,97 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Binary server demonstrates how to use ORCA for reporting out-of-band
+// and per-RPC load metrics.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/orca"
+	"google.golang.org/grpc/status"
+
+	pb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var port = flag.Int("port", 50051, "the port to serve on")
+
+type server struct {
+	pb.UnimplementedEchoServer
+}
+
+func (s *server) UnaryEcho(ctx context.Context, in *pb.EchoRequest) (*pb.EchoResponse, error) {
+	// Report a sample cost for this query.
+	cmr := orca.CallMetricsRecorderFromContext(ctx)
+	if cmr == nil {
+		return nil, status.Errorf(codes.Internal, "unable to retrieve call metrics recorder (missing ORCA ServerOption?)")
+	}
+	cmr.SetRequestCost("db_queries", 10)
+
+	return &pb.EchoResponse{Message: in.Message}, nil
+}
+
+func main() {
+	flag.Parse()
+
+	lis, err := net.Listen("tcp", fmt.Sprintf("localhost:%d", *port))
+	if err != nil {
+		log.Fatalf("Failed to listen: %v", err)
+	}
+	fmt.Printf("Server listening at %v\n", lis.Addr())
+
+	// Create the gRPC server with the orca.CallMetricsServerOption() option,
+	// which will enable per-call metric recording.  No ServerMetricsProvider
+	// is given here because the out-of-band reporting is enabled separately.
+	s := grpc.NewServer(orca.CallMetricsServerOption(nil))
+	pb.RegisterEchoServer(s, &server{})
+
+	// Register the orca service for out-of-band metric reporting, and set the
+	// minimum reporting interval to 3 seconds.  Note that, by default, the
+	// minimum interval must be at least 30 seconds, but 3 seconds is set via
+	// an internal-only option for illustration purposes only.
+	smr := orca.NewServerMetricsRecorder()
+	opts := orca.ServiceOptions{
+		MinReportingInterval:  3 * time.Second,
+		ServerMetricsProvider: smr,
+	}
+	internal.ORCAAllowAnyMinReportingInterval.(func(so *orca.ServiceOptions))(&opts)
+	if err := orca.Register(s, opts); err != nil {
+		log.Fatalf("Failed to register ORCA service: %v", err)
+	}
+
+	// Simulate CPU utilization reporting.
+	go func() {
+		for {
+			smr.SetCPUUtilization(.5)
+			time.Sleep(2 * time.Second)
+			smr.SetCPUUtilization(.9)
+			time.Sleep(2 * time.Second)
+		}
+	}()
+
+	s.Serve(lis)
+}