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

Disaster Tolerance and Recovery in an MC/ServiceGuard Cluster
Types of Disaster Tolerant Clusters
Chapter 126
Continental Cluster
A continental cluster provides an alternative disaster tolerant
solution in which distinct clusters are separated by large distances, with
wide area networking used between them. Continental cluster
architecture is implemented via the ContinentalClusters product,
described fully in Chapter 5. The design is implemented with two
distinct ServiceGuard clusters located in different geographic areas. In
this architecture, each cluster maintains its own quorum, so an
arbitrator data center is not used. A continental cluster can use any
WAN connection via a TCP/IP protocol; however, due to data replication
needs, high speed connections such as T1 or T3/E3 leased lines or
switched lines may be required. See Figure 1-5.
NOTE A continental cluster can also be built using two clusters that
communicate over shorter distances using a conventional LAN.
Figure 1-5 Continental Cluster
The key issues concerning a continental cluster over a WAN are:
• Inter-cluster connections are TCP/IP based.
node 1b node 2b
pkg A_R pkg B_R
node 1a
node 2a
pkg A
pkg B
Data Center A
Los Angeles Cluster:
Data Center B
New York Cluster:
WAN
Data Replication
and/or Mirroring
High Availability Network