"timfox" wrote : By default messages will be prefetched into consumers. | | Since your consumer is so slow, you could try setting prefetch to a lower value (like 1). | | Prefetch is vital for high peformance consumers. This improves the situation a bit. with a prefetch size=10 I saw a burst of 10 high prio msg taking turns with approx. 100 low prio messages like: BOOOOOOOOBBB.........BBBBBBOOOOOOOOOBBBB..........BBBOOOOOOOO.... with prefetch size=1 I see one or two high prio messages separated by approx. 10 low prio messages. BOOOBBBBBBBOOBBBBBBBBOOBBBBBBBBOOBBBBBBBB Still, the rtt for high prio messages is in the order of seconds because of these low prio messages. With just high prio messages the rtt is less than 15msg on my linux box. The jboss.mq stack kept this below 100ms (if I remember correctly) when additional low prio messages where in the queue. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3981285#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...