Set the queue or topic Maximum Messages In Memory property to constrain memory used to manage messages. The value is the number of messages that can be held in memory at once.
Persistent messages are always stored in the database, and some will be held in memory to improve performance. This property affects the size of the in-memory cache if the queue or topic is used only for persistent messaging.
EAServer manages non-persistent messages primarily in memory. You can configure the Store Transient Messages property how transient message overflow is handled. A value of false causes EAServer to discard overflow messages. A value of true enables storage of overflow messages in the database.
Keeping more messages in memory generally improves performance, unless the memory used leaves too little for other server tasks. Tune the message limit and overflow handling properties to balance performance requirements and 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 unless you enable the Store Transient Messages property.
You can also control the memory used by queues and topics by:
Configuring the idle timeout setting
Setting the time-to-live message property in your application code
Minimizing the message size
