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

examples/features/retry/client/main.go

@@ -0,0 +1,77 @@
+/*
+ *
+ * Copyright 2019 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 enable and configure retry policies for
+// gRPC requests.
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	pb "google.golang.org/grpc/examples/features/proto/echo"
+)
+
+var (
+	addr = flag.String("addr", "localhost:50052", "the address to connect to")
+	// see https://github.com/grpc/grpc/blob/master/doc/service_config.md to know more about service config
+	retryPolicy = `{
+		"methodConfig": [{
+		  "name": [{"service": "grpc.examples.echo.Echo"}],
+		  "retryPolicy": {
+			  "MaxAttempts": 4,
+			  "InitialBackoff": ".01s",
+			  "MaxBackoff": ".01s",
+			  "BackoffMultiplier": 1.0,
+			  "RetryableStatusCodes": [ "UNAVAILABLE" ]
+		  }
+		}]}`
+)
+
+func main() {
+	flag.Parse()
+
+	// Set up a connection to the server with service config and create the channel.
+	// However, the recommended approach is to fetch the retry configuration
+	// (which is part of the service config) from the name resolver rather than
+	// defining it on the client side.
+	conn, err := grpc.NewClient(*addr, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithDefaultServiceConfig(retryPolicy))
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer func() {
+		if e := conn.Close(); e != nil {
+			log.Printf("failed to close connection: %s", e)
+		}
+	}()
+
+	c := pb.NewEchoClient(conn)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+	defer cancel()
+
+	reply, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Try and Success"})
+	if err != nil {
+		log.Fatalf("UnaryEcho error: %v", err)
+	}
+	log.Printf("UnaryEcho reply: %v", reply)
+}