can not running

[hidexir]

(~/.go/src/github.com/jun06t/grpc-sample/bidirectional-streaming) ❯ go run server/main.go

(~/.go/src/github.com/jun06t/grpc-sample/bidirectional-streaming) ❯ go run client/main.go [master] U 2018/09/22 01:00:38 send message: tokyo 2018/09/22 01:00:38 send message: 001 2018/09/22 01:00:38 send message: Japan 2018/09/22 01:00:38 rpc error: code = Unavailable desc = transport is closing exit status 1

please tell me