This behavior is incorrect, as timeout isn't reached. SimpleACK is received, and the *DefaultTransport *class calls
ResponseConsumer.success(null)

ServiceFutureImpl, which implements ResponseConsumer, handles the success, notifying the thread, and then finds the ack field to be null, resulting in the mentioned exception. This is not a correct behavior, because the write was successful.

Is there a way to go around this? I believe there should be an acknowledgement service to be passed from the *SimpleACK *to the ServiceFuture, instead of null.