HP serviceguard t2808-90006 pkg B, pkg B, pkg A, Figure, Chapter, local cluster, Client Connections, Client Connections, High Availability Architecture

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 1-1.
Figure 1-1	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

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