RESTORING MESSAGES TO A MEMORY UTILIZED BY A TOPIC IN A PUBLISH-SUBSCRIBE ENVIRONMENT

An apparatus manages memory utilization by a topic in a publish-subscribe environment, wherein the topic is a logical container for the messages and one or more of the messages can be published to the topic by a publishing entity for delivery of the one or more messages to one or more subscribers of the topic. The apparatus includes a primary memory device that stores a first set of messages published to the topic and a secondary memory device that stores a second set of messages previously transferred to the secondary memory device. The apparatus further includes a processor configured to monitor utilization of a portion of the primary memory device assigned to the topic and detect that the utilization has dropped below a threshold. In response, the processor is configured to forward a portion of the second set of messages from the secondary memory device to the primary memory device.