Rabbitmq Asynchronous Queue Consumption

I am working on this tutorial: http://www.rabbitmq.com/tutorials/tutorial-five-java.html

And if I follow these instructions:

1 > java java -cp $CP ReceiveLogsTopic 1
2 > java java -cp $CP ReceiveLogsTopic 2
3 > java -cp $CP EmitLogTopic 1 a

Message "a" is received by the consumer and displayed.

But if I do this:

1 > java java -cp $CP ReceiveLogsTopic 1
2 > java -cp $CP EmitLogTopic 1 a
3 > java java -cp $CP ReceiveLogsTopic 2
4 > java -cp $CP EmitLogTopic 2 b

Only message “b” is displayed because the consumer is being announced to the manufacturer.

So my question is: is there a way to declare the queue “asynchronous” and force it to store messages in the queue until the consumer reads it?

Yours faithfully