HP manual Serviceguard at a Glance, What is Serviceguard?

1 Serviceguard at a Glance

This chapter introduces Serviceguard on HP-UX, and shows where to find information in this book. It covers the following:

•What is Serviceguard?

•Using Serviceguard Manager (page 24)

•A Roadmap for Configuring Clusters and Packages (page 25)

If you are ready to start setting up Serviceguard clusters, skip ahead to Chapter 4: “Planning and

Documenting an HA Cluster ” (page 92). Specific steps for setup are given in Chapter 5: “Building an HA Cluster Configuration” (page 158).

Figure 1 shows a typical Serviceguard cluster with two nodes.

Figure 1 Typical Cluster Configuration

What is Serviceguard?

Serviceguard allows you to create high availability clusters of HP 9000 or HP Integrity servers (or a mixture of both; see the release notes for your version for details and restrictions).

A high availability computer system allows application services to continue in spite of a hardware or software failure. Highly available systems protect users from software failures as well as from failure of a system processing unit (SPU), disk, or local area network (LAN) component. In the event that one component fails, the redundant component takes over. Serviceguard and other high availability subsystems coordinate the transfer between components.

A Serviceguard cluster is a networked grouping of HP 9000 or HP Integrity servers (or both), known as nodes, having sufficient redundancy of software and hardware that a single point of failure will not significantly disrupt service.

A package groups application services (individual HP-UX processes) together. There are failover packages, system multi-node packages, and multi-node packages:

•The typical high availability package is a failover package. It usually is configured to run on several nodes in the cluster, and runs on one at a time. If a service, node, network, or other package resource fails on the node where it is running, Serviceguard can automatically transfer

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