This figure shows a multi-server domain containing two servers: server 1 is the primary and server 2 is the secondary. Both servers belong to the same deployment group and notification group. The same application is deployed to both servers. The application EPN consists of InputAdapter connected to HAInputAdapter connected to Processor connected to HAOutputAdapter connected to OutputAdapter. Input streams arrive at InputAdapter on both servers. Output streams leave OutputAdapter on server 1 only. The HAInputAdapter on server 1 is communicating Key, Timestamp messages to the HAInputAdapter on server 2. The HAOutputAdapter on server 1 is communicating optional Queue Trimming messages to the HAOutputAdapter on server 2.