This figure shows an Oracle Application Server Disaster Recovery topology with a symmetric production site and standby site. The production site and standby site are connected over a Wide Area Network. User requests are routed to the current production (active) site. The standby site is passive; it is started when the production site is not available.

The Web Tier at each site includes a host cluster that consists of hosts WEBHOST1 and WEBHOST2. This host cluster is labeled as the Web Cluster. The Application Server components for the Web Cluster are deployed on the Web volume set for the Web Cluster on the site's shared storage system (PRODSTOR for the production site and STBYSTOR for the standby site).

The Applications Tier at each site includes a host cluster that consists of hosts APPHOST1 and APPHOST2. This host cluster is labeled as the Application Cluster. The Application Server components for the Application Cluster are deployed on the Application volume set for the Application Cluster on the site's shared storage system (PRODSTOR for the production site and STBYSTOR for the standby site).

The Data Tier at each site includes a host cluster that consists of hosts OIDHOST1 and OIDHOST2. This host cluster is labeled as the Security Cluster. The Application Server components for the Security Cluster are deployed on the Security volume set for the Security Cluster on the site's shared storage system (PRODSTOR for the production site and STBYSTOR for the standby site).

Oracle Home directories, product binaries, middle tier file systems, Oracle Central Inventories, static HTML pages directories, and configuration data for Oracle Application Server components for each Application Server host cluster are stored on the volume set up for that cluster.

Disk replication technology is used to copy the Application Server middle tier file systems and other data from the production site's shared storage to the standby site's shared storage.

The Data Tier at each site also includes a database host cluster that consists of hosts DBHOST1 and DBHOST2 and the Real Applications Cluster database that serves as the metadata repository for the site. This host cluster is labeled as the Database Cluster. The database components for the Database Cluster are not deployed on the shared storage set up for each site (PRODSTOR and STBYSTOR).

Oracle Data Guard is used to replicate all Oracle database repositories, including Oracle Application Server repositories and custom application databases, from the production site to the standby site.