If you are using Red Hat Fuse Service Works with the default HornetQ broker you should be aware that by default HornetQ is configured to have JMS writers block when a message queue fills (fill being defined by the maximum number of bytes allowed for the queue). This document is particularly useful in learning a bit more about the configuration of HornetQ particularly associated with the paging of JMS messages

http://docs.jboss.org/hornetq/2.3.0.Final/docs/user-manual/html_single/#paging

In particular note that the setting of ** is key to how the queue will be managed. This can be set to any of these values *BLOCK, PAGE, DROP*

DROP tells the broker to not enqueue any additional messages once the queue has reached the maximum allowed.

BLOCK will cause the sender to potentially block when trying to send to a full queue, potentially not the behavior that you are looking for.

PAGE will cause paging files to be created in a unique directory under jboss-eap-6.1/standalone/data/messagingpaging/ with the contents being files named simiar to 000000042.page.

The paging directory should also contain the file address.txt which will hold the actual name of the queue.

The behavior of paging will allow paged messsages to be dequeued as soon as a consumer is able to.

JMS in general is a highly configurable means of performing many functions but you should be aware of what configuration settings are in effect and how they may impact your application or system.