Set the queue maximum property to constrain the size of the in-memory queue. A positive number specifies how many messages can be stored in memory at once. When the number of messages exceeds the specified limit, EAServer discards messages in the order that they would have been retrieved.
A negative number or the default of 0 specifies that there is no size limit (other than that imposed by available memory) for the number of transient messages in the queue. In this case, the number of persistent messages in the queue is limited by the default.maximum setting in the MessageServiceConfig.props file—see “Other global settings”.
Tune the queue size to balance memory constraints against the possibility of lost messages. Persistent messages that are discarded from memory can be retrieved from the database. Transient messages are lost when discarded from the queue.
You can also control the memory used by queues and topics by:
Configuring timeout settings
Setting the time-to-live message property in your application code
Minimizing the message size
