HP Serviceguard manual Automatic Rotating Standby, Package Configuration Data

NOTE: For design and configuration information about clusters which span subnets, including site-aware disaster-tolerant clusters, see the documents listed under “Cross-Subnet Configurations” (page 30).

Figure 15 After Package Switching

Failover Policy

The Package Manager selects a node for a failover package to run on based on the priority list included in the package configuration file together with the failover_policy parameter, also in the configuration file. The failover policy governs how the package manager selects which node to run a package on when a specific node has not been identified and the package needs to be started. This applies not only to failovers but also to startup for the package, including the initial startup. The failover policies are configured_node (the default), min_package_node, site_preferred and site_preferred_manual. The parameter is set in the package configuration file. See “failover_policy” (page 237) for more information.

Package placement is also affected by package dependencies and weights, if you choose to use them. See “About Package Dependencies” (page 137) and “About Package Weights” (page 144).

Automatic Rotating Standby

Using the min_package_node failover policy, it is possible to configure a cluster that lets you use one node as an automatic rotating standby node for the cluster. Consider the following package configuration for a four node cluster. Note that all packages can run on all nodes and have the same node_name lists. Although the example shows the node names in a different order for each package, this is not required.

Table 2 Package Configuration Data

Package Name	NODE_NAME List	FAILOVER_POLICY
pkgA	node1, node2, node3, node4	MIN_PACKAGE_NODE
pkgB	node2, node3, node4, node1	MIN_PACKAGE_NODE
pkgC	node3, node4, node1, node2	MIN_PACKAGE_NODE

How the Package Manager Works 53