In this illustration, the single sign-on middle tier, Oracle Internet Directory, and database processes appear within two dotted-line boxes labeled OracleAS Active Failover Cluster Node 1 and OracleAS Active Failover Cluster Node 2. In front of these two boxes, to the left, sits a load balancer. In front of this load balancer sits the browser. To the extreme right of the cluster nodes sits the identity management infrastructure database. Flow arrows run from the browser to the load balancer to the cluster nodes and finally to the database.