[ https://issues.jboss.org/browse/WFLY-10555?page=com.atlassian.jira.plugin... ] Miroslav Novak commented on WFLY-10555: --------------------------------------- [~jcacek] Hi Pepo, it's cool to see you here :-) There is message buffer on receiver side which is filled by messages from server once consumer is created. This is to prevent round-robin call everytime consumer.receiveBody(...) is called. This buffer is limited and by default it has size 1 MB. This can be configured by attribute consumer-windows-size on connectin factory which is used by client. If it set to 0 then no buffering on client side will occur. However in case when you need to load balance messages between more consumers on one queue it's not necessary to do it. Artemis will automatically load-balance messages to all consumers on queue. Setting consumer-windows-size=0 makes sense only in case when one consumer is very slow and it's necessary to avoid buffering messages in its buffer. Operation {{:list-messages()}} is not precise and shows just very near value. The reason is that to show precise number of messages would mean to stop all new "message deliveries" threads on queue and wait for all in-progress deliveries to be finished to get precise value. This would severely affect performance. -- This message was sent by Atlassian JIRA (v7.5.0#75005)