Go micro rpc request slow for simple service

Question

I wrote a simple rpc service using go-micro, and I found each call would cost 1+ second, same in micro web. So I run official examples package and choose helloworld to test, and this happens again.

type Greeter struct{}

func (g *Greeter) Hello(ctx context.Context, req *proto.HelloRequest, rsp *proto.HelloResponse) error {
    rsp.Greeting = "Hello " + req.Name
    return nil
}

func main() {
    service := micro.NewService(
        micro.Name("greeter"),
    )

service.Init()

proto.RegisterGreeterHandler(service.Server(), new(Greeter))

if err := service.Run(); err != nil {
    log.Fatal(err)
    }
}

Here are the results from executing a few sample requests:

started
Id:"1" UserName:"max"
1.099975019s
started
Id:"1" UserName:"max"
1.104435591s
started
Id:"1" UserName:"max"
1.103551837s
started
Id:"1" UserName:"max"
1.100724299s
started
Id:"1" UserName:"max"
1.098161724s

Can anyone tell me why each request takes so long?