Starting the Site Controller Package at a site implies starting the complex workload packages that are associated with it.

In normal circumstances, when the primary cluster is available, the Site Controller Package configured in the primary cluster is running and the Site Controller Package configured in the recovery cluster is halted. In the event of a catastrophic failure in the primary cluster, the complex workload can be recovered using the cmrecovercl command to start the complex workload configuration at the recovery cluster. This command starts the Site Controller Package at the recovery cluster which in turn starts the complex workload in the recovery cluster as shown in Figure 81.

Figure 81 Recovery of a complex workload after primary cluster failure

Figure 80 (page 448) illustrates a complex workload with 3DC replication in a Multi-Hop Bi-Link configuration. You can also have the 3DC replication in Multi-Target Bi-Link or Tri-Link configuration.

IMPORTANT: In this section, subsequent topics describe configuring complex workloads in 3DC with SADTA using Oracle RAC as an example. These topics also explain how to configure volume managers such as SLVM and LVM in this solution. Administrators or operators can configure any other application as a complex workload in this solution. While using different applications, the Oracle specific steps must be replaced or modified with the steps that are specific to the application.

Deploying Oracle RAC in a 3DC Solution using SADTA

An Oracle RAC database can be deployed in a 3DC solution for disaster recovery using SADTA. In this architecture, a RAC database is configured as three RAC databases that are replicas of one another; one at each site in the 3DC solution for disaster recovery. A Metrocluster must be configured between two of the three sites. This cluster acts as a primary cluster in the Continentalclusters environment. A Serviceguard cluster must be configured at the third site. This cluster acts as a recovery cluster in the Continentalclusters environment.

To configure Oracle RAC in the 3DC solution, two Oracle CRS sub-clusters are created in the primary cluster; one at each site in the primary cluster, and one CRS cluster is created in the recovery cluster. The Oracle Clusterware software is installed at each site in the 3DC solution. The CRS daemons at the sub-clusters are configured as a Serviceguard package using the HP Serviceguard Extension for Oracle RAC Toolkit (delivered as part of the HP Serviceguard Extension for Oracle RAC). The CRS Home is installed on a file system that is local to a site. The CRS voting and OCR disks must not be configured for replication.

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