This figure shows an Oracle Event Processing high availability multiserver domain with one active and two primaries. The input streams are connected to all servers. Only the primary server outputs events to the output streams. Each secondary server buffers output events using an in-memory queue. All of the servers belong to the same deployment group and notification group. Server 2 is the primary, and servers 1 and 3 are secondaries. The primary server outputs events to a JMS provider. The secondary servers listen to the JMS provider to receive notification of the events that the primary server publishes. The secondary servers delete these published events from their in-memory queue.