Expired documents in the client queues and forward queues; that is, the documents that have completed their Time to Live, are deleted only when the client tries to retrieve them. In cases where a client retrieves documents infrequently, this can lead to overloaded queues or memory overflow, which can further affect operations of other Brokers in the topology.

To reduce the memory usage considerably, you can proactively delete the expired volatile documents from the client queues and forward queues even before the client tries to retrieve them. Expired documents are deleted whenever the total memory used by the volatile documents exceeds the specified threshold limit.

You can proactively delete volatile documents from a queue by setting the queue-cleanup-enable and the queue-cleanup-threshold parameters in the awbroker.cfg file of each Broker Server instance.