Rule Engine works either in the master or in the dormant mode. In a multi-server deployment, there is only one master Rule Engine that executes all rules. Each Campaign Manager communicates with the master Rule Engine over a socket.

The following diagram illustrates a high-level overview of the communication between Campaign Manager and Rule Engine:

Rule Engine maintains a heartbeat connection with the other server to monitor its connection. When the heartbeat connection fails, the master and dormant servers update the database with their respective status to avoid multiple masters during a network failure. If the master Rule Engine process fails gracefully, the dormant becomes master immediately. However, for an ungraceful process shutdown, there is a failover time of 45 seconds. After the failover, Campaign Manager gets broken socket connection and polls the database to identify and connect to the new master server for communications.

Rule Engine heartbeat ports can be configured from the Global Configuration page. For more information, see Administering Avaya Proactive Outreach Manager.