Which one makes much big difference, block-on-acknowledge or send-p-messages-synchronously? I thought sending asynchronously means unblocking on ack. Why two attributes are needed? <!--Whether or not we use a blocking call when acknowledging a message--> | <block-on-acknowledge>false</block-on-acknowledge> | <!--Whether we send persistent messages synchronously--> | <send-p-messages-synchronously>true</send-p-messages-synchronously> Thank you very much for the prompt reply. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4165445#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...