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

examples/features/keepalive/client/main.go

@@ -0,0 +1,64 @@
+/*
+ *
+ * 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 configure keepalive pings to maintain
+// connectivity and detect stale connections.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"time"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	pb "google.golang.org/grpc/examples/features/proto/echo"
+	"google.golang.org/grpc/keepalive"
+)
+
+var addr = flag.String("addr", "localhost:50052", "the address to connect to")
+
+var kacp = keepalive.ClientParameters{
+	Time:                10 * time.Second, // send pings every 10 seconds if there is no activity
+	Timeout:             time.Second,      // wait 1 second for ping ack before considering the connection dead
+	PermitWithoutStream: true,             // send pings even without active streams
+}
+
+func main() {
+	flag.Parse()
+
+	conn, err := grpc.NewClient(*addr, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithKeepaliveParams(kacp))
+	if err != nil {
+		log.Fatalf("did not connect: %v", err)
+	}
+	defer conn.Close()
+
+	c := pb.NewEchoClient(conn)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Minute)
+	defer cancel()
+	fmt.Println("Performing unary request")
+	res, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "keepalive demo"})
+	if err != nil {
+		log.Fatalf("unexpected error from UnaryEcho: %v", err)
+	}
+	fmt.Println("RPC response:", res)
+	select {} // Block forever; run with GODEBUG=http2debug=2 to observe ping frames and GOAWAYs due to idleness.
+}