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/*
*
* 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 is an example client.
package main
import (
"context"
"log"
"net"
"os"
"time"
"google.golang.org/grpc"
"google.golang.org/grpc/channelz/service"
"google.golang.org/grpc/resolver"
"google.golang.org/grpc/resolver/manual"
pb "google.golang.org/grpc/examples/helloworld/helloworld"
)
const (
defaultName = "world"
)
func main() {
/***** Set up the server serving channelz service. *****/
lis, err := net.Listen("tcp", ":50052")
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")
// Set up a connection to the server.
conn, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), 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.
r.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: ":10001"}, {Addr: ":10002"}, {Addr: ":10003"}}})
c := pb.NewGreeterClient(conn)
// Contact the server and print out its response.
name := defaultName
if len(os.Args) > 1 {
name = os.Args[1]
}
/***** 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 {}
}
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