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

Disaster Tolerance and Recovery in an MC/ServiceGuard Cluster

What is a Disaster Tolerant Architecture?

Chapter 120

What is a Disaster Tolerant Architecture?

In an MC/ServiceGuard cluster configuration, high availability is

achieved by using redundant hardware to eliminate single points of

failure. This protects the cluster against hardware faults, such as the

node failure in Figure 1-1.

Figure 1-1 High Availability Architecture.

This architecture, which is typically implemented on one site in a single

data center, is sometimes called a local cluster. For some installations,

the level of protection given by a local cluster is insufficient. Consider the

order processing center where power outages are common during harsh

weather. Or consider the systems running the stock market, where

multiple system failures, for any reason, have a significant financial

node 1 node 2

pkg A

pkg B

pkg A mirrors

pkg B mirrors

pkg B disks

pkg A disks

Client Connections

pkg A fails

over to node 2