When you configure the application services, you must select the mode as high availability. In a high-availability mode, you need to distribute the primary and backup instances on different nodes. Nodes can be distributed across same or multiple host machines. If one of the service instance becomes unavailable on one node, the grid manager ensures that the secondary service takes over as the primary, without any loss of events.

The primary service instance on a node takes care of all its activities, whereas the backup instance on another node waits passively. When the primary instance goes down, the backup instance becomes the primary and performs the activities of the primary. Meanwhile, the previous primary instance becomes the backup instance. The ultra messaging layer picks up events that occur between the failover from the primary to the backup instance, ensuring that none of the events are lost. In RulePoint, high availability switches over from the primary to the secondary instance seamlessly.

You can also create multiple instances for the grid manager. Each host can have only one grid manager. When you start RulePoint in a particular host, the grid manager in that host is designated as the leader, and the secondary instance is designated as the backup. Only the primary instance can be active at a time.

You can also create multiple instances for the UM store and UM lbmrd for scalability. Each host can have only one instance of UM lbmrd and UM store.

The grid manager controls the primary and the backup run-time components, and manages the change of state from primary to secondary. In a failover situation, the grid manager detects a problem with the primary component, and makes the backup the primary.