it seems NOT support concurrent write, but NOT break reading.
it seems NOT support concurrent write, but NOT break reading. after many times test, later write request will be ignored when under construct some write operation.
throw WritePendingException Unchecked exception thrown when an attempt is made to write to an asynchronous socket channel and a previous write has not completed.
send heat beat data.
send heat beat data. disconnect socket if not get response 1. send before set heart as false 2. after 1 mins (or other values) check does the value is true