As the nodejs document said:
This method will cause a stream in flowing-mode to stop emitting data events. Any data that becomes available will remain in the internal buffer.
When I pause a response in client(We know this response is a http.IncomingMessage). Does the client just stop reading data from server or continue read data but store them in buffer?
It buffers data up to highWaterMark bytes and then stops reading from the socket when it hits that limit.