Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Building a Continental Cluster
Understanding Continental Cluster Concepts
Chapter 5 181
In the above figure, the salespkg is running on the New York cluster and
can be recovered by the Los Angeles cluster. Similarly, the custpkg
running on the Los Angeles cluster can be recovered by the New York
cluster. As stated previously, physical data replication is carried out
using ESCON (Enterprise Storage Connect) links between the disk
array hardware in New York and Los Angeles via an ESCON/WAN
converter at each end. Each cluster is running a monitor that checks
the status of the alternate cluster.
As shown in the above example, each cluster runs just like any
ServiceGuard cluster, with applications configured in packages that may
fail from node to node as necessary. Each cluster is configured with a
recovery version of the packages that are running on the alternate
cluster. These packages do not run under normal circumstances, but are
set to start up when they are needed. In addition, either cluster may run
other packages that are not involved in ContinentalClusters operation.