Overview of Deploying a Complex Workload in 3DC using SADTA

Site Aware Disaster Tolerant Architecture (SADTA) enables deploying complex workloads in a cluster. Complex workloads are applications configured using multi-node and failover packages with dependencies. This complex workload is a multi-instance application that uses active resources across multiple nodes in a cluster. These workloads are configured using multiple, interdependent multi-node packages or failover packages. These packages that comprise a complex workload need to be managed and moved collectively for disaster recovery. SADTA includes crucial components such as the Site Controller Package and the Site Safety Latch that manage the complex workload configuration. The Site Controller Package is a special failover package that is created using the dts/sc module. Each complex workload that is configured using SADTA must have a corresponding Site Controller Package. The Site Safety Latch is an internal mechanism that is created for each Site Controller Package. It is created automatically on all the cluster nodes when the corresponding Site Controller Package configuration is applied in the cluster. The Site Safety Latch prevents the inadvertent simultaneous startup of the workload configuration on both sites.

SADTA is extended to support 3DC configurations. This enables deploying complex workloads in a 3DC solution. This solution specifies a method to configure and move complex workloads across three data centers, while using P9000 or XP Continuous Access 3DC replication technology for replicating data.

Figure 80 shows the package view of a complex workload configuration in a 3DC solution using SADTA. It shows three sites - Site1, Site2 and Site3. A Metrocluster is configured with Site1 and Site2 and an independent Serviceguard cluster is configured at Site3. Continentalclusters is configured with the Metrocluster as the primary cluster and the independent Serviceguard cluster at Site3 is configured as the recovery cluster. A Serviceguard cluster at Site 3 is configured with only one site defined in the cluster configuration.

Figure 80 Package view for SADTA configuration in a 3DC solution

In the 3DC Solution, a complex workload is configured redundantly by configuring it at all sites. A separate set of packages is used to configure complex workloads at each site. A Site Controller Package is created in both, the primary cluster (Metrocluster between Site1 and Site2) and the recovery cluster (Serviceguard cluster at Site3) to manage the complex workload. A recovery group is configured in Continentalclusters with the Site Controller Package in the primary cluster as a primary package and the Site Controller Package in the recovery cluster as a recovery package.

448 Designing a Three Data Center Disaster Recovery Solution