去grpc服务器不知道客户端丢人死了

Question

I am using go-grpc to create a bidirectional stream. When I unplug the cable, the server doesn't known client is dead for a very very long time. How can I detect client is gone in this case ???

Answer 1

Your GRPC server-side handler will know about client context cancellation the next time it will try to Send/Recv message to/from stream: the error will be returned:

func (s *server) handler(stream your_service.Stream) error {
    if err := stream.Recv(); err != nil {
        // you will have context cancelation error here
    }
}

In some cases it may be useful to check context cancellation explicitly:

func (s *server) handler(stream your_service.Stream) error {
     // some logic
     select {
         case <-stream.Context().Done():
             return stream.Context().Err()
         default:
     }
}

By the way, do you unplug the cable literally? Because it may be treated in different ways by the operational system. Why don't you use any modern virtualization tools, like Docker, for your tests?