Disaster Tolerance and Recovery in a Serviceguard Cluster
What is a Disaster Tolerant Architecture?
What is a Disaster Tolerant Architecture?
In a 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
Figure | High Availability Architecture. |
| node 1 fails |
node 1 
Xpkg A
pkg A disks |
pkg A mirrors |
pkg B disks |
pkg B mirrors |
node 2
pkg B
Client Connections
pkg A fails over to node 2
node 1
X
pkg A disks |
pkg A mirrors |
pkg B disks |
pkg B mirrors |
node 2
pkg B
pkg A
Client Connections
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
16 | Chapter 1 |
