This document provides information on the difference between queues, temporary queues and subscribers
Message queues transfer messages to and from the hubs. Queues fall into two categories:
Permanent queues are stored in the local hub database and survive a hub restart. This type of queue ensures that messages are delivered even if the receiver is down when a message is generated.
Example: Nimsoft Alarm Server probe (nas). If the hub running this service goes down and then comes back up, it fetches all alarms generated while it was down. This ensures no alarms are lost.
Temporary queues are used for less-critical communication paths.
Example: UMP alarm console portlet. When a user starts UMP, the portlet subscribes to alarm messages and a temporary queue is created. Messages are forwarded to this queue as long as the alarm viewer is active. When the viewer is closed, the queue is removed.