Afterward we setted up another test, this time we setted the parameter to ten minutes, and we setted the FullSize parameter, PageSize parameter, DownCacheSize parameter of the queue to be tested to 3355444, 10000, and 10000, and the messages we sended in this test were all NON_PERSISTENT messages, so this time all the messages that sended to the queue were all stored in the memory. We also checked that the persistent database had never been writed or readed. In this test case we saw that messages send rate was very fast, almost equaled to it's target send rate, but the messages received by the consumer were so a little, almost equaled to 1/10 of the messages sended to the queue, so the mesages been buffered in the queue while receiving message were several hundred thousand or several million. And along with the send rate to be increased the buffered number was increased, so the time to complete the receving job increased too. And the most important point was that the receive rate was so poor, almost equaled to 1/10 of it's send rate per parallel test. Why the messages receive rate so poor? Does the queue must scan some of (or all) the message handles (or something like that) while a consumer receive a message because of the message selector mechanism ? Does the queue will copy all the message handles or synchronize all the message handles before it do this scan , so the message receiving time of one message receiving trip will increase along with the messages buffered in the queue increased ? Does message receive rate is computed like this : all messages received / message job spended time ? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4159505#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...