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

examples/features/debugging/client/main.go

@@ -0,0 +1,93 @@
+/*
+ *
+ * Copyright 2018 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 client demonstrates how to use logging and Channelz for debugging
+// gRPC operations.
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"net"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/channelz/service"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/resolver/manual"
+
+	pb "google.golang.org/grpc/examples/helloworld/helloworld"
+)
+
+const (
+	defaultName = "world"
+)
+
+var (
+	addr = flag.String("addr", "localhost:50051", "the address to connect to")
+	name = flag.String("name", defaultName, "Name to greet")
+)
+
+func main() {
+	flag.Parse()
+	/***** Set up the server serving channelz service. *****/
+	lis, err := net.Listen("tcp", *addr)
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+	defer lis.Close()
+	s := grpc.NewServer()
+	service.RegisterChannelzServiceToServer(s)
+	go s.Serve(lis)
+	defer s.Stop()
+
+	/***** Initialize manual resolver and Dial *****/
+	r := manual.NewBuilderWithScheme("whatever")
+	r.InitialState(resolver.State{Addresses: []resolver.Address{{Addr: ":10001"}, {Addr: ":10002"}, {Addr: ":10003"}}})
+	// Set up a connection to the server.
+	conn, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r), grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy":"round_robin"}`))
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer conn.Close()
+	// Manually provide resolved addresses for the target.
+
+	c := pb.NewGreeterClient(conn)
+
+	// Contact the server and print out its response.
+
+	/***** Make 100 SayHello RPCs *****/
+	for i := 0; i < 100; i++ {
+		// Setting a 150ms timeout on the RPC.
+		ctx, cancel := context.WithTimeout(context.Background(), 150*time.Millisecond)
+		defer cancel()
+		r, err := c.SayHello(ctx, &pb.HelloRequest{Name: *name})
+		if err != nil {
+			log.Printf("could not greet: %v", err)
+		} else {
+			log.Printf("Greeting: %s", r.Message)
+		}
+	}
+
+	/***** Wait for user exiting the program *****/
+	// Unless you exit the program (e.g. CTRL+C), channelz data will be available for querying.
+	// Users can take time to examine and learn about the info provided by channelz.
+	select {}
+}