I have discovered that if I set consumer-window-size to zero on a netty connection factory, then when calling consumer.receiveNoWait() many times in succession, no message is received every other time.

If I comment this out, then I receive one message every time I call consumer.receiveNoWait().

<consumer-window-size>0</consumer-window-size>

Steps to reproduce.

1. produce a bunch of messages.

2. create a consumer, and in a loop call Message message = consumer.receiveNoWait().

3. every other time, message is null even though there are messages on the queue.

Is this expected behavior?  I'm using HornetQ 2.1.1 Final.